ORCID Profile
0000-0003-0699-3464
Current Organisations
Mie University
,
ANSTO - Australian Synchrotron
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Publisher: Elsevier BV
Date: 11-2016
Publisher: American Chemical Society (ACS)
Date: 25-08-2023
Publisher: Journal Sovremennye Tehnologii v Medicine
Date: 02-2020
Publisher: Springer Science and Business Media LLC
Date: 30-05-2018
DOI: 10.1038/S41598-018-26563-6
Abstract: Insects represent the majority of known animal species and exploit a variety of fascinating nanotechnological concepts. We investigated the wings of the damselfly Calopteryx haemorrhoidalis , whose males have dark pigmented wings and females have slightly pigmented wings. We used scanning electron microscopy (SEM) and nanoscale synchrotron X-ray fluorescence (XRF) microscopy analysis for characterizing the nanostructure and the elemental distribution of the wings, respectively. The spatially resolved distribution of the organic constituents was examined by synchrotron Fourier transform infrared (s-FTIR) microspectroscopy and subsequently analyzed using hierarchical cluster analysis. The chemical distribution across the wing was rather uniform with no evidence of melanin in female wings, but with a high content of melanin in male wings. Our data revealed a fiber-like structure of the hairs and confirmed the presence of voids close to its base connecting the hairs to the damselfly wings. Within these voids, all detected elements were found to be locally depleted. Structure and elemental contents varied between wing membranes, hairs and veins. The elemental distribution across the membrane was rather uniform, with higher Ca, Cu and Zn levels in the male damselfly wing membranes.
Publisher: Elsevier BV
Date: 06-2020
Publisher: IOP Publishing
Date: 2020
DOI: 10.1088/1757-899X/744/1/012023
Abstract: Based on the technology of molecular multidimensional IR- synchrotron visualization, the paper explores integration of a new generation of biomimetic composites that regenerates a mineral organic dental enamel complex with native human hard dental tissues and dental cement. The data of spectral molecular visualization was obtained from the area of the healthy hard tissue (enamel/dentine) – biomimetic transition layer – dental material/adhesive interface. The resulting data is indicative of chemical differentiation of functional groups of all the materials at the biomimetic system/natural hard tissue and prove the chosen method to be effective in analyzing integration of dental concrete and new generation biomimetic composites.
Publisher: MDPI AG
Date: 25-07-2022
DOI: 10.3390/MI13081170
Abstract: THz band-pass filters were fabricated by femtosecond-laser ablation of 25-μm-thick micro-foils of stainless steel and Kapton film, which were subsequently metal coated with a ∼70 nm film, closely matching the skin depth at the used THz spectral window. Their spectral performance was tested in transmission and reflection modes at the Australian Synchrotron’s THz beamline. A 25-μm-thick Kapton film performed as a Fabry–Pérot etalon with a free spectral range (FSR) of 119 cm−1, high finesse Fc≈17, and was tuneable over ∼10μm (at ∼5 THz band) with β=30∘ tilt. The structure of the THz beam focal region as extracted by the first mirror (slit) showed a complex dependence of polarisation, wavelength and position across the beam. This is important for polarisation-sensitive measurements (in both transmission and reflection) and requires normalisation at each orientation of linear polarisation.
Publisher: Springer Science and Business Media LLC
Date: 18-11-2016
DOI: 10.1038/SREP37333
Abstract: Triple-negative breast cancer is the most aggressive breast cancer subtype with limited treatment options and a poor prognosis. Approximately 70% of triple-negative breast cancer patients fail to achieve a pathologic complete response (pCR) after chemotherapy due to the lack of targeted therapies for this subtype. We report here the development of a focal-plane-array Fourier transform infrared (FPA-FTIR) microspectroscopic technique combined with principal component analysis (PCA) for monitoring chemotherapy effects in triple-negative breast cancer patients. The PCA results obtained using the FPA-FTIR spectral data collected from the same patients before and after the chemotherapy revealed discriminatory features that were consistent with the pathologic and clinical responses to chemotherapy, indicating the potential of the technique as a monitoring tool for observing chemotherapy efficacy.
Publisher: American Chemical Society (ACS)
Date: 12-10-2023
DOI: 10.1021/JACS.3C05545
Publisher: Public Library of Science (PLoS)
Date: 09-03-2022
DOI: 10.1371/JOURNAL.PONE.0264347
Abstract: Triple negative breast cancer (TNBC) is regarded as the most aggressive breast cancer subtype with poor overall survival and lack of targeted therapies, resulting in many patients with recurrent. The insight into the detailed biochemical composition of TNBC would help develop dedicated treatments. Thus, in this study Fourier Transform Infrared microspectroscopy combined with chemometrics and absorbance ratios investigation was employed to compare healthy controls with TNBC tissue before and after chemotherapy within the same patient. The primary spectral differences between control and cancer tissues were found in proteins, polysaccharides, and nucleic acids. Amide I/Amide II ratio decrease before and increase after chemotherapy, whereas DNA, RNA, and glycogen contents increase before and decrease after the treatment. The chemometric results revealed discriminatory features reflecting a clinical response scheme and proved the chemotherapy efficacy assessment with infrared spectroscopy is possible.
Publisher: Elsevier BV
Date: 02-2015
DOI: 10.1016/J.PROTIS.2014.12.002
Abstract: The superior characteristics of high photon flux and diffraction-limited spatial resolution achieved by synchrotron-FTIR microspectroscopy allowed molecular characterization of in idual live thraustochytrids. Principal component analysis revealed distinct separation of the single live cell spectra into their corresponding strains, comprised of new Australasian thraustochytrids (AMCQS5-5 and S7) and standard cultures (AH-2 and S31). Unsupervised hierarchical cluster analysis (UHCA) indicated close similarities between S7 and AH-7 strains, with AMCQS5-5 being distinctly different. UHCA correlation conformed well to the fatty acid profiles, indicating the type of fatty acids as a critical factor in chemotaxonomic discrimination of these thraustochytrids and also revealing the distinctively high polyunsaturated fatty acid content as key identity of AMCQS5-5. Partial least squares discriminant analysis using cross-validation approach between two replicate datasets was demonstrated to be a powerful classification method leading to models of high robustness and 100% predictive accuracy for strain identification. The results emphasized the exceptional S-FTIR capability to perform real-time in vivo measurement of single live cells directly within their original medium, providing unique information on cell variability among the population of each isolate and evidence of spontaneous lipid peroxidation that could lead to deeper understanding of lipid production and oxidation in thraustochytrids for single-cell oil development.
Publisher: MDPI AG
Date: 28-07-2023
DOI: 10.3390/PHOTONICS10080881
Abstract: In our work, the effect of a dental Er:YAG pulsed laser and a diamond cylindrical drill with a turbine handpiece on dentin tissue was studied using spectral imaging. The combination of spectral imaging of FTIR microspectroscopy data and subsequent multivariate analysis (hierarchical cluster analysis (HCA) and principal component analysis (PCA)) was shown to unambiguously detect visually indistinguishable structural changes occurring in the hard dental tissue (dentin) depending on the method used for their pre-processing, and to classify and differentiate the identified features at the submicron level with high spatial resolution. The detectable spectral transformations indicate that the preparation of dental tissue with a dental laser leads to significant changes in the organic components of dentin, which may affect adhesion. The use of a diamond cylindrical drill with a turbine handpiece is characterized by a larger area (depth) of the altered hard tissue than in the case of a dental laser for dental cavity preparation. The observed redistribution of the phase composition of the inorganic component in the tissue is associated with the emergence of additional phases of weak calcium phosphates, and changes in the organic component with transformations in the secondary structure of proteins. Active use of the proposed integrated approach in the future will clarify the areas of its applicability to the analysis of biological tissues and pathologies in them, which will help in the clinical setting to choose the optimal personalized approach for patients.
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2551712
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/CH08204
Abstract: We report here, for the first time, the surface-enhanced Raman scattering (SERS) spectra of resveratrol using KNO3-aggregated citrate-reduced silver (Ag) colloids. The technique provided a substantial spectral enhancement and therefore good quality spectra of resveratrol at parts per million (ppm) concentrations. The detection limit was found to be μM, equivalent to .2 ppm. The SERS profile additionally closely resembled its normal solid-state Raman spectrum with some changes in relative intensity. These intensity changes, together with a precise band assignment aided by density functional theory calculations at the B3LYP/6–31G(d) level, allowed the determination of the structural orientation of the adsorbed resveratrol on the surface of the metal nanoparticles. In particular, the SERS spectra obtained at different resveratrol concentrations exhibited concentration-dependent features, suggesting an influence of surface coverage on the orientation of the adsorbed molecules. At a high concentration, an adoption of close-to-upright orientation of resveratrol adsorbed on the metal surface through the p-OH phenyl ring is favoured. The binding structure is, however, altered at lower surface coverage when the concentration decreases to a tilted orientation with the trans-olefin C=C bond aligning closer to parallel to the surface of the Ag nanoparticles.
Publisher: Springer Science and Business Media LLC
Date: 06-09-2019
DOI: 10.1038/S41598-019-49326-3
Abstract: Mantle cell lymphoma (MCL) is regarded as an incurable neoplasm, even to the novel drug strategies. It is known MCL has two morphological variants- classic and aggressive. Aggressive MCL is characterized by a higher mitotic index and proliferation rate, and poor overall survival in comparison to classic subtype. The insight into the detailed biochemical composition of MCL is crucial in the further development of diagnostic and treatment guidelines for MCL patients therefore Synchrotron radiation Fourier Transform Infrared (S-FTIR) microspectroscopy combined with Principal Component Analysis (PCA) was used. The major spectral differences were observed in proteins and nucleic acids content, revealing a classification scheme of classic and aggressive MCLs. The results obtained suggest that FTIR microspectroscopy has reflected the histopathological discrimination of both MCL subtypes.
Publisher: Wiley
Date: 16-12-2022
Abstract: Zinc metal battery (ZMB) is promising as the next generation of energy storage system, but challenges relating to dendrites and corrosion of the zinc anode are restricting its practical application. Here, to stabilize Zn anode, we report a controlled electrolytic method for a monolithic solid‐electrolyte interphase (SEI) via a high dipole moment solvent dimethyl methylphosphonate (DMMP). The DMMP‐based electrolytes can generate a homogeneous and robust phosphate SEI (Zn 3 (PO 4 ) 2 and ZnP 2 O 6 ). Benefiting from the protecting impact of this in situ monolithic SEI, the zinc electrode exhibits long‐term cycling of 4700 h and a high Coulombic efficiency 99.89 % in Zn|Zn and Zn|Cu cell, respectively. The full V 2 O 5 |Zn battery with DMMP‐H 2 O hybrid electrolyte exhibits a high capacity retention of 82.2 % following 4000 cycles under 5 A g −1 . The first success in constructing the monolithic phosphate SEI will open a new avenue in electrolyte design for highly reversible and stable Zn metal anodes.
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.TALANTA.2018.04.083
Abstract: Lung cancer has the highest mortality rate of all malignant tumours. The current effects of cancer treatment, as well as its diagnostics, are unsatisfactory. Therefore it is very important to introduce modern diagnostic tools, which will allow for rapid classification of lung cancers and their degree of malignancy. For this purpose, the authors propose the use of Fourier Transform InfraRed (FTIR) spectroscopy combined with Principal Component Analysis-Linear Discriminant Analysis (PCA-LDA) and a physics-based computational model. The results obtained for lung cancer tissues, adenocarcinoma and squamous cell carcinoma FTIR spectra, show a shift in wavenumbers compared to control tissue FTIR spectra. Furthermore, in the FTIR spectra of adenocarcinoma there are no peaks corresponding to glutamate or phospholipid functional groups. Moreover, in the case of G2 and G3 malignancy of adenocarcinoma lung cancer, the absence of an OH groups peak was noticed. Thus, it seems that FTIR spectroscopy is a valuable tool to classify lung cancer and to determine the degree of its malignancy.
Publisher: Wiley
Date: 29-06-2021
Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has resulted in an unprecedented need for diagnostic testing that is critical in controlling the spread of COVID‐19. We propose a portable infrared spectrometer with purpose‐built transflection accessory for rapid point‐of‐care detection of COVID‐19 markers in saliva. Initially, purified virion particles were characterized with Raman spectroscopy, synchrotron infrared (IR) and AFM‐IR. A data set comprising 171 transflection infrared spectra from 29 subjects testing positive for SARS‐CoV‐2 by RT‐qPCR and 28 testing negative, was modeled using Monte Carlo Double Cross Validation with 50 randomized test and model sets. The testing sensitivity was 93 % (27/29) with a specificity of 82 % (23/28) that included positive s les on the limit of detection for RT‐qPCR. Herein, we demonstrate a proof‐of‐concept high throughput infrared COVID‐19 test that is rapid, inexpensive, portable and utilizes s le self‐collection thus minimizing the risk to healthcare workers and ideally suited to mass screening.
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 11-2023
Publisher: Springer Science and Business Media LLC
Date: 25-01-2014
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.FOODCHEM.2018.09.043
Abstract: In this study, chia seed oil (CSO) microcapsules were produced using three types of shell materials, including chia seed protein (CPI), chia seed gum (CSG) and CPI-CSG complex coacervates. Synchrotron-Fourier transform infrared (S-FTIR) microspectroscopy was used to investigate the effect of shell materials on the distribution of CSO both on the surface and in the interior of the solid microcapsules. S-FTIR measurements were carried out in macroscopic attenuated total reflection (macro ATR) and transmission modes, to determine the surface lipid and the encapsulated lipid fractions, respectively. The amounts of lipid and protein distributed on the surface and in the interior of the microcapsules were compared based on the average spectra extracted from S-FTIR chemical images obtained from each type of the microcapsules. The unsaturated fatty acids (UFAs) to total oil ratios in all the three types of the microcapsules were closely similar to the original non-processed CSO, suggesting an effective encapsulation and thereby shielding protection of UFAs from oxidative damage during microencapsulation process. The type of the shell materials was found to affect the distribution of CSO on the surface and within the microcapsules. The complex coacervation based microcapsules had a significantly lower oil content (∼2% w/w) on the surface compared to those observed for the other two types of microcapsules (>5%, w/w).
Publisher: MDPI AG
Date: 16-08-2023
DOI: 10.20944/PREPRINTS202308.1179.V1
Abstract: Four-polarisation camera was used to map absorbance of olivine micro-grains before and after high temperature annealing (HTA). It is shown that HTA of olivine xenolith at above 1200∘C in O2 flow makes it magnetised. Different mode of operation of polariscope with polarisation control before and after the s le in transmission and reflection modes was used. The reflection type was assembled for non-transparent s les of olivine after HTA. S le for optical observation in transmission was placed on an achromatic plastic quarter-wavelength waveplate as a s le holder. Inspection for s le’s birefringence (retardance) as well as absorbance can be made. A best fit of transmitted intensity or transmittance T (hence absorbance A=−log10T) becomes accessible by simple best-fit using only three orientations (from measured four orientations by the camera). When intensity of transmitted light at one of the orientations was very low due to cross-polarised condition (polariser-analyser arrangement), the three-points fit can be used. Three-point fit in transmission and reflection modes was validated for T(θ)=Amp×cos(2θ−2θshift)+offset, where litude Amp, offset offset and orientation azimuth θshift are extracted for each pixel via the best fit.
Publisher: Wiley
Date: 03-07-2021
Abstract: The cycle life of aqueous zinc‐ion batteries (ZIBs) is limited by the notable challenges of cathode dissolution, water reactivity, and zinc dendrites. Here, it is demonstrated that by tuning the electrolyte solvation structure, the issues for both the electrodes and the electrolyte can be addressed simultaneously. Specifically, a fire‐retardant triethyl phosphate (TEP) is demonstrated as a cosolvent with strong solvating ability in a nonaqueous/aqueous hybrid electrolyte. The TEP features a higher donor number (26 kcal mol −1 ) than H 2 O (18 kcal mol −1 ), preferring to form a TEP occupied inner solvation sheath around Zn 2+ and strong hydrogen bonding with H 2 O. The TEP coordinated electrolyte structure can inhibit the reactivity of H 2 O with V 2 O 5 and leads to a robust polymeric‐inorganic interphase (poly‐ZnP 2 O 6 and ZnF 2 ) on zinc anode effectively preventing the dendrite growth and parasitic water reaction. With such an optimized electrolyte, the Zn/Cu cells perform high average Coulombic efficiency of 99.5%, and the full cell with a low capacity ratio of Zn:V 2 O 5 (2:1) and lean electrolyte (11.5 g Ah −1 ) delivers a reversible capacity of 250 mAh g −1 for over 1000 cycles at 5 A g −1 . This study highlights the promise of a successful electrolyte regulation strategy for the development of high‐performance and practical ZIBs.
Publisher: Elsevier BV
Date: 11-2012
DOI: 10.1016/J.FOODCHEM.2012.05.012
Abstract: The research describes a rapid method for the determination of fatty acid (FA) contents in a micro-encapsulated fish-oil (μEFO) supplement by using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic technique and partial least square regression (PLSR) analysis. Using the ATR-FTIR technique, the μEFO powder s les can be directly analysed without any pre-treatment required, and our developed PLSR strategic approach based on the acquired spectral data led to production of a good linear calibration with R(2)=0.99. In addition, the subsequent predictions acquired from an independent validation set for the target FA compositions (i.e., total oil, total omega-3 fatty acids, EPA and DHA) were highly accurate when compared to the actual values obtained from standard GC-based technique, with plots between predicted versus actual values resulting in excellent linear fitting (R(2)≥0.96) in all cases. The study therefore demonstrated not only the substantial advantage of the ATR-FTIR technique in terms of rapidness and cost effectiveness, but also its potential application as a rapid, potentially automated, online monitoring technique for the routine analysis of FA composition in industrial processes when used together with the multivariate data analysis modelling.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7TA01022B
Abstract: This study quantitatively defines the temperature induced chemical transformations and evolution of radial heterogeneity during the stabilisation of carbon fibre precursors.
Publisher: Springer Science and Business Media LLC
Date: 19-10-2020
DOI: 10.1038/S41598-020-74469-Z
Abstract: Our understanding of the extraordinary mechanical and physico-chemical properties of spider silk is largely confined to the fibers produced by orb-weaving spiders, despite the ersity of foraging webs that occur across numerous spider families. Crab spiders (Thomisidae) are described as ambush predators that do not build webs, but nevertheless use silk for draglines, egg cases and assembling leaf-nests. A little-known exception is the Australian thomisid Saccodomus formivorus , which constructs a basket-like silk web of extraordinary dimensional stability and structural integrity that facilitates the capture of its ant prey. We examined the physical and chemical properties of this unusual web and revealed that the web threads comprise microfibers that are embedded within a biopolymeric matrix containing additionally longitudinally-oriented submicron fibers. We showed that the micro- and submicron fibers differ in their chemical composition and that the web threads show a remarkable lateral resilience compared with that of the major ullate silk of a well-investigated orb weaver. Our novel analyses of these unusual web and silk characteristics highlight how investigations of non-model species can broaden our understanding of silks and the evolution of foraging webs.
Publisher: MDPI AG
Date: 19-07-2021
DOI: 10.3390/DIAGNOSTICS11071294
Abstract: In this short communication, we provide information on the use of the hierarchical cluster analysis of synchrotron ATR-FTIR 2D chemical imaging spectral data as a useful and powerful approach to the microspectroscopic diagnostics of molecular composition in the hybrid sound dentin/dental composite interfaces and materials, including ones developed with the use of biomimetic strategies. The described diagnostic approach can be successfully transferred to the analysis and visualisation of 2D spectral data, collected using laboratory Raman and FTIR microspectroscopy techniques.
Publisher: American Chemical Society (ACS)
Date: 19-07-2019
DOI: 10.1021/ACS.ANALCHEM.9B01843
Abstract: Fingermarks are an important form of crime-scene trace evidence however, their usefulness may be h ered by a variation in response or a lack of robustness in detection methods. Understanding the chemical composition and distribution within fingermarks may help explain variation in latent fingermark detection with existing methods and identify new strategies to increase detection capabilities. The majority of research in the literature describes investigation of organic components of fingermark residue, leaving the elemental distribution less well understood. The relative scarcity of information regarding the elemental distribution within fingermarks is in part due to previous unavailability of direct, micron resolution elemental mapping techniques. This capability is now provided at third generation synchrotron light sources, where X-ray fluorescence microscopy (XFM) provides micron or submicron spatial resolution and direct detection with sub-μM detection limits. XFM has been applied in this study to reveal the distribution of inorganic components within fingermark residue, including endogenous trace metals (Fe, Cu, Zn), diffusible ions (Cl
Publisher: Voronezh State University
Date: 14-06-2019
DOI: 10.17308/KCMF.2019.21/764
Abstract: В данной работе продемонстрирована возможность применения ИК-микроспектроскопии для многомерной визуализации и анализа интеграции с нативными твердыми тканями зуба человека нового поколения биомиметических материалов, воспроизводящих минералорганический комплекс эмали и дентина.На основе ИК-картирования интенсивности конкретной функциональной молекулярной группы с использованием синхротронного излучения найдены и визуализированы характеристические особенности биомиметического переходного слоя в межфазной области эмаль/стоматологический материал и определено расположение функциональных групп, отвечающих процессам интеграции биомиметического композита REFERENCES Rohr N., Fischer J. Tooth surface treatment strategies for adhesive cementation // The Journal of Advanced Prosthodontics, 2017, v. 9(2), pp. 85–92. 0.4047/jap.2017.9.2.85 Pereira C. N. de B., Daleprane B., Miranda G. L. P. de, Magalhães C. S. de, Moreira A. N. 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Biocompatibility evaluation of dicalcium phosphate/calcium sulfate oly (amino acid) composite for orthopedic tissue engineering in vitro and in vivo // Journal of Biomaterials Science. Polymer Edition, 2016, v. 27(11), pp. 1170–1186. 0.1080/09205063.2016.1184123 Lübke A., Enax J., Wey K., Fabritius H.-O., Raabe D., Epple M. Composites of fl uoroapatite and methylmethacrylate-based polymers (PMMA) for biomimetic tooth replacement // Bioinspiration & Biomimetics, 2016, v. 11(3), pp. 035001. 0.1088/1748-3190/11/3/035001 Sa Y., Gao Y., Wang M., Wang T., Feng X., Wang Z., Wang Y., Jiang T. Bioactive calcium phosphate cement with excellent injectability, mineralization capacity and drug-delivery properties for dental bio- mimetic reconstruction and minimum intervention therapy. RSC Advances, 2016, v. 6(33), pp. 27349–27359. 0.1039/C6RA02488B Adachi T., Pezzotti G., Yamamoto T., Ichioka H., Boffelli M., Zhu W., Kanamura N. Vibrational algorithms for quantitative crystallographic analyses of hydroxyapatite-based biomaterials: II, application to decayed human teeth // Analytical and Bioanalytical Chemistry, 2015, v. 407(12), pp. 3343–3356. 0.1007/s00216-015-8539-z Mitić Ž., Stolić A., Stojanović S., Najman S., Ignjatović N., Nikolić G., Trajanović M. Instrumental methods and techniques for structural and physicochemical characterization of biomaterials and bone tissue: A review // Materials Science and Engineering: C, 2017, v. 79, pp. 930–949. 0.1016/j.msec.2017.05.127 Optical spectroscopy and computational methods in biology and medicine / Ed. by Barańska M., Dordrecht: Springer, 2014, 540 p. URL: 0.1007/978-94-007-7832-0 Hędzelek W., Marcinkowska A., Domka L., Wachowiak R. Infrared Spectroscopic Identifi cation of Chosen Dental Materials and Natural Teeth // Acta Physica Polonica A, 2008, v. 114(2), pp. 471–484. 0.12693/APhysPolA.114.471 Vongsvivut J., Perez-Guaita D., Wood B. R., Heraud P., Khambatta K., Hartnell D., Hackett M. J., Tobin M. J. Synchrotron macro ATR-FTIR microspectroscopy for high-resolution chemical mapping of single cells // The Analyst, 2019, v. 144(10), pp. 3226–3238. 0.1039/c8an01543k Seredin P., Goloshchapov D., Ippolitov Y., Vongsvivut P. Pathology-specifi c molecular profi les of saliva in patients with multiple dental caries—potential application for predictive, preventive and personalised medical services // EPMA Journal, 2018, v. 9(2), pp. 195–203. 0.1007/s13167-018-0135-9 Dusevich V., Xu C., Wang Y., Walker M. P., Gorski J. P. Identifi cation of a protein-containing enamel matrix layer which bridges with the dentine–enamel junction of adult human teeth // Archives of Oral Biology, 2012, v. 57(12), pp. 1585–1594. 0.1016/j.archoralbio.2012.04.014 Seredin P. V., Kashkarov V. M., Lukin A. N., Goloshchapov D. L., Ippolitov Y. A. Research Hydroxyapatite Crystals and Organic Components of Hard Tooth Tissues Affected by Dental Caries Using Ftir-Microspectroscopy and Xrd-Microdiffraction // Condensed Matter and Interphases, 2013, v. 15(3), с. 224–231. URL: www.kcmf.vsu.ru/resources/t_15_3_2013_002.pdf Fattibene P., Carosi A., Coste V. D., Sacchetti A., Nucara A., Postorino P., Dore P. A comparative EPR, infrared and Raman study of natural and deproteinated tooth enamel and dentin // Physics in Medicine and Biology, 2005, v. 50(6), pp. 1095. 0.1088/0031-9155/50/6/004 Seredin P., Goloshchapov D., Kashkarov V., Ippolitov Y., Bambery K. The investigations of changes in mineral–organic and carbon–phosphate ratios in the mixed saliva by synchrotron infrared spectroscopy // Results in Physics, 2016, v. 6, pp. 315–321. 0.1016/j.rinp.2016.06.005 Goloshchapov D. L., Kashkarov V. M., Rumyantseva N. A., Seredin P. V., Lenshin A. S., Agapov B. L., Domashevskaya E. P. Synthesis of nanocrystalline hydroxyapatite by precipitation using hen’s eggshell // Ceramics International, 2013, v. 39(4), pp. 4539–4549. 0.1016/j.ceramint.2012.11.050 Goloshchapov D. L., Lenshin A. S., Savchenko D. V., Seredin P.V. Importance of defect nanocrystalline calcium hydroxyapatite characteristics for developing the dental biomimetic composites // Results in Physics, 2019, v. 13, pp. 102158. 0.1016/j.rinp.2019.102158 Nanci A. Ten Cate’s Oral Histology: Development, Structure, and Function. 8th ed., Elsevier Health Sciences, 2013, 400 p. Ippolitov Ju. A. Vozmozhnost’ povyshenija biologicheskoj tropnosti svetootverzhdaemoj bondingovoj sistemy dlja adgezii tverdyh tkanej zuba k plombirovochnomu material [The possibility of increasing the biological tropism of the lightcuring bonding system for adhesion of hard tooth tissues to the filling material]. Volgogradskij nauchno-medicinskij zhurnal, 2010, v. 4 (28), pp. 31–34. URL: www.volgmed.ru/uploads/journals/articles/1293119124-bulletin-2010-4-815.pdf Seredin P., Goloshchapov D., Prutskij T., Ippolitov Y. Phase Transformations in a Human Tooth Tissue at the Initial Stage of Caries. PLoS ONE, 2015, v. 10(4), pp. 1–11. 0.1371/journal.pone.0124008 Seredin P. V., Goloshchapov D. L., Prutskij T., Ippolitov Yu. A. A Simultaneous Analysis of Microregions of Carious Dentin by the Methods of Laser- Induced Fluorescence and Raman Spectromicroscopy. Optics and Spectroscopy, 2018, v. 125(5), pp. 803–809. 0.1134/S0030400X18110267 Seredin P. V., Goloshchapov D. L., Prutskij T., Ippolitov Yu. A. Fabrication and characterisation of composites materials similar optically and in composition to native dental tissues. Results in Physics, 2017, v. 7, pp. 1086–1094. 0.1016/j.rinp.2017.02.025
Publisher: MDPI AG
Date: 19-10-2021
DOI: 10.20944/PREPRINTS202110.0280.V1
Abstract: Polarisation analysis in the mid-infrared fingerprint region was carried out on thin (& sim & mu m) Si and SiO2 films evaporated via glancing angle deposition (GLAD) method at 70∘ to the normal. Synchrotron-based infrared microspectroscopic measurements were carried out on the Infrared Microspectroscopy (IRM) beamline at Australian Synchrotron. Specific absorption bands, particularly Si-O-Si stretching vibration, was found to follow the angular dependence of & sim cos2& theta , consistent with the absorption anisotropy. This unexpected anisotropy stems from the enhanced absorption in nano-crevices, which have orientation following the cos2& theta angular dependence as revealed by Fourier transforming the image of the surface of 3D columnar films and numerical modeling of light field enhancement by sub-wavelength nano-crevices.
Publisher: Walter de Gruyter GmbH
Date: 07-2019
Abstract: Metasurfaces are engineered thin surfaces comprising two-dimensional (2D) arrays of sub-wavelength-spaced and sub-wavelength-sized resonators. Metasurfaces can locally manipulate the litude, phase, and polarization of light with high spatial resolution. In this paper, we report numerical and experimental results of a vortex-beam-generating metasurface fabricated specifically for infrared (IR) and terahertz (THz) wavelengths. The designed metasurface consists of a 2D array of dielectric cross-shaped resonators with spatially varying length, thereby providing the desired spatially varying phase shift to the incident light. The metasurface was found to be insensitive to the polarization of the incident light. The dimensions of the cross-resonators were calculated using rigorous finite-difference time-domain analysis. The spectral scalability via physical scaling of the meta-resonators is demonstrated using two vortex-generating optical elements operating at 8.8 μm (IR) and 0.78 THz. The vortex beam generated in the mid-IR spectral range was imaged using a Fourier transform IR (FTIR) imaging miscroscope equipped with a focal plane array detector. This design could be used for efficient wavefront shaping and various optical imaging applications in the mid-IR spectral range, where polarization insensitivity is desired.
Publisher: IOP Publishing
Date: 12-2020
DOI: 10.1088/1742-6596/1697/1/012039
Abstract: We have investigated the molecular composition of the tooth enamel microregions in the normal and initial stages of the development of fluorosis by means of the IR and Raman spectroscopy. It has been shown that in the pathology of fluorosis, tooth mineralization takes place with the formation of calcium fluoroapaptite. It was found that an increased fluorine content causes a change in the characteristic profile of the bands and a redistribution of the intensity of the components of the υ 1 PO 4 and υ 3 CO 3 groups of the infrared and υ 4 PO 4 Raman spectra. The resulting IR and Raman spectra can be utilized as standards in the development of a new diagnostic approach of the early forms of the disease.
Publisher: MDPI AG
Date: 18-10-2022
DOI: 10.20944/PREPRINTS202210.0257.V1
Abstract: Phase imaging of biochemical s les has been demonstrated for the first time at the Infrared Microspectroscopy (IRM) beamline of the Australian Synchrotron using the usually discarded Near-IR (NIR) region of the synchrotron-IR beam. The synchrotron-IR beam at the Australian Synchrotron IRM beamline has a unique fork shaped intensity distribution as a result of the gold coated extraction mirror shape, which includes a central slit for rejection of the intense X-ray beam. The resulting beam configuration makes any imaging task challenging. For intensity imaging, the fork shaped beam is usually tightly focused to a point on the s le plane followed by a pixel-by-pixel scanning approach to record the image. In this study, a pinhole was aligned with one of the lobes of the fork shaped beam and the Airy diffraction pattern was used to illuminate biochemical s les. The diffracted light from the s les was captured using a NIR sensitive lensless camera. A rapid phase-retrieval algorithm was applied to the recorded intensity distributions to reconstruct the phase information corresponding to different planes. The preliminary results are promising to develop multimodal imaging capabilities at the IRM beamline of the Australian Synchrotron.
Publisher: Elsevier BV
Date: 2024
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2VA00313A
Abstract: Reflectance-FTIR spectroscopy provides opportunities for faster, more automated, and cheaper detection of microplastics in the environment.
Publisher: American Chemical Society (ACS)
Date: 23-05-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1TB02575A
Abstract: Black phosphorus (BP) nanoflakes have shown high antimicrobial activity. The interaction of microbial cells and black phosphorus nanoflakes was investigated using microscopic techniques and synchrotron source ATR-FTIR spectroscopy.
Publisher: Elsevier BV
Date: 11-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8AN01543K
Abstract: Coupling synchrotron IR beam to an ATR element enhances spatial resolution suited for high-resolution single cell analysis in biology, medicine and environmental science.
Publisher: IOP Publishing
Date: 12-2021
DOI: 10.1088/1742-6596/2086/1/012118
Abstract: The aim of the study is the problem of formation of the biomimetic interface between the dental product and dentin of the human tooth as well as the investigations of molecular-chemical features in biointerface with the use of molecular multivariate IR-visualization. The data on synchrotron IR-mapping made enabled to differentiate the regions of sound dentin tissue and biomimetic transition layer and also to determine molecular groups responsible for the process of integration.
Publisher: MDPI AG
Date: 02-10-2022
Abstract: Using a biomimetic strategy and bioinspired materials, our work proposed a new technological approach to create a hybrid transitional layer between enamel and dental biocomposite. For this purpose, an amino acid booster conditioner based on a set of polar amino acids (lysine, arginine, hyaluronic acid), calcium alkali, and a modified adhesive based on BisGMA and nanocrystalline carbonate-substituted hydroxyapatite are used during dental enamel restoration. The molecular properties of the hybrid interface formed using the proposed strategy were understood using methods of multivariate statistical analysis of spectral information collected using the technique of synchrotron infrared microspectroscopy. The results obtained indicate the possibility of forming a bonding that mimics the properties of natural tissue with controlled molecular properties in the hybrid layer. The diffusion of the amino acid booster conditioner component, the calcium alkali, and the modified adhesive with nanocrystalline carbonate-substituted hydroxyapatite in the hybrid interface region creates a structure that should stabilize the reconstituted crystalline enamel layer. The developed technology can form the basis for an in idualized, personalized approach to dental enamel restorations.
Publisher: Wiley
Date: 13-07-2010
Abstract: Glucose oxidase (GOx) is an important enzyme with great potential application for enzymatic sensing of glucose, in implantable biofuel cells for powering of medical devices in vivo and for large-scale biofuel cells for distributed energy generation. For these applications, immobilisation of GOx and direct transfer of electrons from the enzyme to an electrode material is required. This paper describes synthesis of conducting polymer (CP) structures in which GOx has been entrained such that direct electron transfer is possible between GOx and the CP. CP/enzyme composites prepared by other means show no evidence of such "wiring". These materials therefore show promise for mediator-less electronic connection of GOx into easily produced electrodes for biosensing or biofuel cell applications.
Publisher: Elsevier BV
Date: 12-2020
Publisher: American Chemical Society (ACS)
Date: 21-12-2021
DOI: 10.26434/CHEMRXIV-2021-QSBTD
Abstract: Degradation of fingermark residue has a major impact on the successful forensic detection of latent fingermarks. The time course of degradation has been previously explored with bulk chemical analyses, but little is known about chemical alterations at the micron-scale. Here we report the use of synchrotron-sourced attenuated total reflection-Fourier transform infrared (ATR-FTIR) microscopy to provide spatio-temporal resolution of chemical changes within fingermark droplets, as a function of time since deposition. Eccrine and sebaceous material within natural fingermark droplets were imaged on the micron scales at hourly intervals for the first 6 – 12 hours after deposition, revealing that substantial dehydration occurred within the first 8 hours. Changes to lipid material was more varied, with s les exhibiting an increase or decrease in lipid concentration due to the degradation and redistribution of this material. Across 12 donors, it was noticeable that the initial chemical composition and morphology of the droplet varied greatly, which appeared to influence on the rate of change of the droplet over time. Further, this study attempted to quantify the total water content within fingermark s les. The wide-spread nature and strength of the absorption of Terahertz/Far-infrared (THz/Far-IR) radiation by water vapour molecules were exploited for this purpose, using THz/Far-IR spectroscopy. Upon heating, water confined in natural fingermarks was evaporated and expanded in a vacuum chamber equipped with multipass optics. The amount of water vapour was then quantified by high-spectral resolution analysis, and fingermarks were observed to lose approximately 14 – 20 µg of water. The combination of both ATR-FTIR and Far-IR highlight important implications for experimental design in fingermark research, and operational practices used by law enforcement agencies.
Publisher: IOP Publishing
Date: 22-11-2017
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4345318
Publisher: Springer Science and Business Media LLC
Date: 24-01-2018
DOI: 10.1038/S41598-018-19721-3
Abstract: A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1SM01731D
Abstract: Improving the electrical performance of macroradical epoxy thermosets to surpass the semiconductor threshold requires a comprehensive understanding of the electrical charge transport mechanisms and characteristics.
Publisher: Elsevier BV
Date: 04-2015
Publisher: MDPI AG
Date: 04-05-2023
DOI: 10.3390/BIOPHYSICA3020021
Abstract: Deep eutectic solvents (DESs) and ionic liquids (ILs) are highly tailorable solvents that have shown a lot of promise for a variety of applications including cryopreservation, drug delivery, and protein stabilisation. However, to date, there is very limited information on the detailed interactions of these solvents with mammalian cells. In this work, we studied six DESs and one IL that show promise as cryoprotective agents, applying synchrotron macro–ATR–FTIR to examine their effects on key biochemical components of HaCat mammalian cells. These data were paired with resazurin metabolic assays and neutron reflectivity experiments to correlate cellular interactions with cellular toxicity. Stark differences were observed even between solvents that shared similar components. In particular, it was found that solvents that are effective cryoprotective agents consistently showed interactions with cellular membranes, while high toxicity correlated with strong interactions of the DES/IL with nucleic acids and proteins. This work sheds new light on the interactions between novel solvents and cells that may underpin future biomedical applications.
Publisher: Elsevier BV
Date: 09-2019
Publisher: MDPI AG
Date: 26-06-2022
DOI: 10.3390/PHARMACEUTICS14071355
Abstract: (1) Objectives: This study is the first one to investigate the molecular composition of the dental biofilm during the exogenous and endogenous prophylaxis stages (use of dentifrice/drug) of in iduals with different cariogenic conditions using molecular spectroscopy methods. (2) Materials and Methods: The study involved 100 participants (50 males and 50 females), aged 18–25 years with different caries conditions. Biofilm s les were collected from the teeth surface of all participants. The molecular composition of biofilms was investigated using synchrotron infrared microspectroscopy. Changes in the molecular composition were studied through calculation and analysis of ratios between organic and mineral components of biofilm s les. (3) Results: Based on the data obtained by synchrotron FTIR, calculations of organic and mineral component ratios, and statistical analysis of the data, we were able to assess changes occurring in the molecular composition of the dental biofilm. Variations in the phosphate rotein/lipid, phosphate/mineral, and phospholipid/lipid ratios and the presence of statistically significant intra- and inter-group differences in these ratios indicate that the mechanisms of ion adsorption, compounds and complexes arriving from oral fluid into dental biofilm during exo/endogenous prophylaxis, differ for patients in norm and caries development. (4) Conclusions: The conformational environment and charge interaction in the microbiota and the electrostatic state of the biofilm protein network in patients with different cariogenic conditions play an important role. (5) Clinical Significance: Understanding the changes that occur in the molecular composition of the dental biofilm in different oral homeostasis conditions will enable successful transition to a personalised approach in dentistry and high-tech healthcare.
Publisher: The Optical Society
Date: 17-07-2019
Publisher: Springer Science and Business Media LLC
Date: 24-08-2020
DOI: 10.1038/S41598-020-71092-W
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Publisher: Elsevier BV
Date: 03-2023
DOI: 10.1016/J.FOODCHEM.2022.134933
Abstract: Mozzarella cheese was industrially frozen (-18 °C), stored for up to six months, tempered at 4 °C for one or three weeks and the structure and functionality compared to cheese stored at 4 °C and cheese aged at 4 °C for four weeks prior to freezing. When combined with ageing or tempering, the slow industrial freezing minimised changes to the protein network as detected by confocal microscopy and arrested proteolysis. Cheese functionality improved with three weeks of tempering, with properties similar to cheese refrigerated for one month, potentially due to increased proteolysis and protein rehydration. Frozen storage induced β-sheet and β-turn structures, as detected by S-FTIR microspectroscopy, with longer tempering leading to structural recovery in the cheese. This study indicates the proteolysis and functionality of frozen cheese can be optimised with tempering time. It also provides new insights into heat transfer during the industrial freezing and tempering of cheese.
Publisher: MyJove Corporation
Date: 11-10-2016
DOI: 10.3791/54309
Publisher: Wiley
Date: 06-04-2023
Abstract: The use of the coordinated silver (I) complex based on solvate ionic liquid in epoxy resins is reported to enable unprecedented electrical and thermomechanical properties. The novel hybrid material is aligned at the molecular level using an electric field, demonstrating high electrical conductivity, excellent energy storage properties, and rapid curing behavior. The electric‐field treated epoxy resin system shows a maximum electric conductivity of 2.05 × 10 5 S m −1 , 20 folds of the same untreated system, and 3 folds of the same treated system but with 5.0% silver nanoparticles. Furthermore, this system shows an ultrafast curing rate of around 500 s at a temperature of 42.0 °C and reveals excellent energy storage achieving an average capacitance of 27.5 F g −1 at a scan rate of 1.0 mV s −1 . Quantum mechanics is applied and the synchrotron beamline is utilized to optimize and investigate the properties of the system, opening the door to the next generation of thermoset polymers with multifunctional properties.
Publisher: Springer Science and Business Media LLC
Date: 07-2007
Abstract: A simple, yet very powerful technique for the spectral acquisition of an extremely thin film with enhanced absorption was explored. An infrared absorption of an extremely thin film confined between media of high refractive indices was greater than that of its bulk when the spectrum was acquired under the attenuated total reflection (ATR) condition with parallel (p) polarized radiation. The absorption enhancement was not observed under perpendicular (s) polarized radiation. Theoretical investigations indicated that the absorption enhancement was proportional to the integration of the mean square evanescent field within the film. The field integration under p-polarized radiation increased, while that under s-polarized radiation decreased as the thickness of the confined film became thinner. The maximum enhancement was observed when the film was sufficiently thinner than the penetration depth. The phenomena were experimentally investigated, and the results agreed very well with theoretical predictions.
Publisher: Pirogov Russian National Research Medical University
Date: 08-2019
Abstract: The low affinity of composite materials for the hard tissue of human teeth poses a challenge to restorative dentists. This study was undertaken to explore molecular and chemical characteristics of the interface between the dental cement, the buffer layer formed from a next generation biomimetic material that mimics the organic mineral composition of human enamel and dentin, and the intact native hard dental tissue. Seven plane-parallel dental slices were analyzed using synchrotron IR microspectroscopy. The obtained absorption spectra of functional molecular groups were organized into cluster maps. This allowed us to identify the intact tissue, the adhesive agent and the biomimetic layer at their interface and to localize and measure concentrations of functional groups involved in the integration of the biomimetic composite into the hard tissue of the human tooth. The proposed biomimetic material is based on nanocrystal carbonate-substituted calcium hydroxyapatite synthesized from a biogenic calcium source and a complex of basic polar amino acids copying the composition of the human tooth and can form a functional bond with hard dental tissue.
Publisher: MDPI AG
Date: 13-05-2019
DOI: 10.3390/NANO9050732
Abstract: Polariscopy is demonstrated using hyperspectral imaging with a focal plane array (FPA) detector in the infrared (IR) spectral region under illumination by thermal and synchrotron light sources. FPA Fourier-transform IR (FTIR) imaging microspectroscopy is useful for monitoring real time changes at specific absorption bands when combined with a high brightness synchrotron source. In this study, several types of s les with unique structural motifs were selected and used for assessing the capability of polariscopy under this FPA-FTIR imaging technique. It was shown that the time required for polariscopy at IR wavelengths can be substantially reduced by the FPA-FTIR imaging approach. By using natural and laser fabricated polymers with sub-wavelength features, alignment of absorbing molecular dipoles and higher order patterns (laser fabricated structures) were revealed. Spectral polariscopy at the absorption peaks can reveal the orientation of sub-wavelength patterns (even when they are not spatially resolved) or the orientation of the absorbing dipoles.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 03-2015
Publisher: Elsevier BV
Date: 04-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1AN02293H
Abstract: Using synchrotron sourced ATR-FTIR microspectroscopy and THz/Far-IR gas phase spectroscopy to monitor the chemical changes in fingermark residues in the immediate hours following deposition.
Publisher: Elsevier BV
Date: 2020
Publisher: Science Society of Thailand
Date: 2008
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.FOODCHEM.2019.04.016
Abstract: Synchrotron Fourier transform infrared (S-FTIR) microspectroscopy allows the label-free examination of material microstructure but has not been widely applied to dairy products. Here, S-FTIR microspectroscopy was applied to observe the microstructure of Mozzarella cheese and assess the protein and lipid distribution within in idual cheese blocks. High lipid and high protein areas were identified in transmission and attenuated total reflectance (ATR) analysis modes and the secondary structures of cheese proteins determined. Hierarchical cluster analysis and principal component analysis identified variation in random coil, water content, lipid carbonyl and methylene stretching across the s led area. Similar spectral features were obtained in both analysis modes spatial resolution was higher with ATR and small differences were noted, potentially as a result of differences in s le preparation. S-FTIR is a useful microscopy tool that can detect structural alterations that may affect product properties and may assist reverse engineering of a range of dairy products.
Publisher: Optica Publishing Group
Date: 03-2022
DOI: 10.1364/OME.451669
Abstract: This study has demonstrated that 3D columnar micro-films/coatings can be deposited over pre-patterned surfaces with sub-micrometer periodic patterns. Four-angle polarisation analysis of thin (0.4 − 1~ μ m) Si and SiO 2 films, evaporated via glancing angle deposition (GLAD) at 70° to the normal, was carried out in reflection mode using synchrotron infrared microspectroscopy at the Australian Synchrotron. The angular dependence of absorbance followed A ( θ ) ∝ cos 2 θ , confirmed for Si substrates patterned by electron beam lithography and plasma etching, which were used to make checkerboard patterns of Λ = 0.4~ μ m period on Si. Retardance control by birefringence of a patterned SiO 2 substrate coated by columnar SiO 2 is promising for UV-visible applications due to the use of the same material to endow polarisation control.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1AN90049H
Abstract: Correction for ‘Synchrotron macro ATR-FTIR microspectroscopy for high-resolution chemical mapping of single cells’ by Jitraporn Vongsvivut et al. , Analyst , 2019, 144 , 3226–3238, DOI: 10.1039/C8AN01543K.
Publisher: Wiley
Date: 29-06-2021
Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has resulted in an unprecedented need for diagnostic testing that is critical in controlling the spread of COVID‐19. We propose a portable infrared spectrometer with purpose‐built transflection accessory for rapid point‐of‐care detection of COVID‐19 markers in saliva. Initially, purified virion particles were characterized with Raman spectroscopy, synchrotron infrared (IR) and AFM‐IR. A data set comprising 171 transflection infrared spectra from 29 subjects testing positive for SARS‐CoV‐2 by RT‐qPCR and 28 testing negative, was modeled using Monte Carlo Double Cross Validation with 50 randomized test and model sets. The testing sensitivity was 93 % (27/29) with a specificity of 82 % (23/28) that included positive s les on the limit of detection for RT‐qPCR. Herein, we demonstrate a proof‐of‐concept high throughput infrared COVID‐19 test that is rapid, inexpensive, portable and utilizes s le self‐collection thus minimizing the risk to healthcare workers and ideally suited to mass screening.
Publisher: MDPI AG
Date: 04-07-2022
DOI: 10.20944/PREPRINTS202207.0043.V1
Abstract: THz band-pass filters were fabricated by laser ablation of micro-foils of stainless steel and Kapton. Their spectral performance was tested in transmission and re- flection at the THz beamline at the Australian Synchrotron (AuSy). A 25 & mu m Kapton film performed as a Fabry-P& eacute rot etalon with a free spectral range of FSR = 119 cm& minus , high finesse Fc & asymp 17, and was tuneable over ~10 & mu m (at ~5 THz band) with & beta = 30& deg tilt. The structure of the THz beam focal region as extracted by the first mirror (slit) shows a complex polarisation-wavelength- position dependence across the beam. This is important for polarisation sensitive measurements (in transmission and reflection) and requires normalisation at each orientation of linear polarisation.
Publisher: Springer Science and Business Media LLC
Date: 07-08-2017
DOI: 10.1038/S41598-017-07502-3
Abstract: Molecular alignment underpins optical, mechanical, and thermal properties of materials, however, its direct measurement from volumes with micrometer dimensions is not accessible, especially, for structurally complex bio-materials. How the molecular alignment is linked to extraordinary properties of silk and its amorphous-crystalline composition has to be accessed by a direct measurement from a single silk fiber. Here, we show orientation mapping of the internal silk fiber structure via polarisation-dependent IR absorbance at high spatial resolution of 4.2 μ m and 1.9 μ m in a hyper-spectral IR imaging by attenuated total reflection using synchrotron radiation in the spectral fingerprint region around 6 μ m wavelength. Free-standing longitudinal micro-slices of silk fibers, thinner than the fiber cross section, were prepared by microtome for the four polarization method to directly measure the orientational sensitivity of absorbance in the molecular fingerprint spectral window of the amide bands of β -sheet polypeptides of silk. Microtomed lateral slices of silk fibers, which may avoid possible artefacts that affect spectroscopic measurements with fibers of an elliptical cross sections were used in the study. Amorphisation of silk by ultra-short laser single-pulse exposure is demonstrated.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7AN01615H
Abstract: Latent fingermark chemistry revealed by Raman microscopy and Synchrotron ATR-FTIR.
Publisher: MDPI AG
Date: 18-09-2023
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 10-2023
Publisher: Springer Science and Business Media LLC
Date: 02-09-2022
DOI: 10.1038/S41467-022-32819-7
Abstract: The soil carbon (C) saturation concept suggests an upper limit to the storage of soil organic carbon (SOC). It is set by the mechanisms that protect soil organic matter from mineralization. Biochar has the capacity to protect new C, including rhizodeposits and microbial necromass. However, the decadal-scale mechanisms by which biochar influences the molecular ersity, spatial heterogeneity, and temporal changes in SOC persistence, remain unresolved. Here we show that the soil C storage ceiling of a Ferralsol under subtropical pasture was raised by a second application of Eucalyptus saligna biochar 8.2 years after the first application—the first application raised the soil C storage ceiling by 9.3 Mg new C ha −1 and the second application raised this by another 2.3 Mg new C ha −1 . Linking direct visual evidence from one-, two-, and three-dimensional analyses with SOC quantification, we found high spatial heterogeneity of C functional groups that resulted in the retention of rhizodeposits and microbial necromass in microaggregates (53–250 µm) and the mineral fraction ( µm). Microbial C-use efficiency was concomitantly increased by lowering specific enzyme activities, contributing to the decreased mineralization of native SOC by 18%. We suggest that the SOC ceiling can be lifted using biochar in (sub)tropical grasslands globally.
Publisher: Elsevier BV
Date: 05-2020
Publisher: Springer Science and Business Media LLC
Date: 17-02-2021
DOI: 10.1038/S41598-021-83264-3
Abstract: Kingdom of Tonga in Polynesia is one of the most obese nations where metabolic conditions, sedentary lifestyles, and poor quality diet are widespread. These factors can lead to poor musculoskeletal health. However, whether metabolic abnormalities such as osteoporosis occurred in archaeological populations of Tonga is unknown. We employed a microscopic investigation of femur s les to establish whether bone loss afflicted humans in this Pacific region approximately 3000 years ago. Histology, laser confocal microscopy, and synchrotron Fourier-transform infrared microspectroscopy were used to measure bone vascular canal densities, bone porosity, and carbonate and phosphate content of bone composition in eight s les extracted from adult Talasiu males and females dated to 2650 BP. Compared to males, s les from females had fewer vascular canals, lower carbonate and phosphate content, and higher bone porosity. Although both sexes showed evidence of trabecularised cortical bone, it was more widespread in females (35.5%) than males (15.8%). Our data suggest experiences of advanced bone resorption, possibly as a result of osteoporosis. This provides first evidence for microscopic bone loss in a s le of archaeological humans from a Pacific population widely afflicted by metabolic conditions today.
Publisher: OSA
Date: 2016
Publisher: SPIE
Date: 05-03-2021
DOI: 10.1117/12.2577511
Publisher: Wiley
Date: 06-2023
Abstract: The radical‐bearing epoxy monomer could be the ideal embodiment of multifunctionality in epoxy‐based materials. This study demonstrates the potential of macroradical epoxies as surface coating materials. A diepoxide monomer derivatized with a stable nitroxide radical is polymerized with a diamine hardener under the influence of a magnetic field. The magnetically oriented and stable radicals in the polymer backbone render the coatings antimicrobial. The unconventional use of magnets during polymerization proved crucial in correlating the structure‐property relationships with antimicrobial performance inferred from oscillatory rheological technique, polarized macro‐attenuated total reflectance – infrared (macro‐ATR‐IR) spectroscopy and X‐ray photoelectron spectroscopy (XPS). The magnetic thermal curing influenced the surface morphology, resulting in a synergy of the coating's radical nature with microbiostatic performance assessed using the Kirby‐Bauer test and liquid chromatography – mass spectroscopy (LC–MS). Further, the magnetic curing of blends with a traditional epoxy monomer demonstrates that radical alignment is more critical than radical density in imparting biocidal behavior. This study shows how the systematic use of magnets during polymerization could pave for probing more significant insights into the mechanism of antimicrobial action in radical‐bearing polymers.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0NR05617K
Abstract: The heterogeneity of fungal biofilms are spatially characterized using a combination of AFM, nanoindentation, and ATR-FTIR.
Publisher: Public Library of Science (PLoS)
Date: 18-12-2017
Publisher: MDPI AG
Date: 31-01-2019
Abstract: High frequency (HF) electromagnetic fields (EMFs) have been widely used in many wireless communication devices, yet within the terahertz (THz) range, their effects on biological systems are poorly understood. In this study, electromagnetic radiation in the range of 0.3–19.5 × 1012 Hz, generated using a synchrotron light source, was used to investigate the response of PC 12 neuron-like pheochromocytoma cells to THz irradiation. The PC 12 cells remained viable and physiologically healthy, as confirmed by a panel of biological assays however, exposure to THz radiation for 10 min at 25.2 ± 0.4 °C was sufficient to induce a temporary increase in their cell membrane permeability. High-resolution transmission electron microscopy (TEM) confirmed cell membrane permeabilization via visualisation of the translocation of silica nanospheres (d = 23.5 ± 0.2 nm) and their clusters (d = 63 nm) into the PC 12 cells. Analysis of scanning electron microscopy (SEM) micrographs revealed the formation of atypically large (up to 1 µm) blebs on the surface of PC 12 cells when exposed to THz radiation. Long-term analysis showed no substantial differences in metabolic activity between the PC 12 cells exposed to THz radiation and untreated cells however, a higher population of the THz-treated PC 12 cells responded to the nerve growth factor (NGF) by extending longer neurites (up to 0–20 µm) compared to the untreated PC12 cells (up to 20 µm). These findings present implications for the development of nanoparticle-mediated drug delivery and gene therapy strategies since THz irradiation can promote nanoparticle uptake by cells without causing apoptosis, necrosis or physiological damage, as well as provide a deeper fundamental insight into the biological effects of environmental exposure of cells to electromagnetic radiation of super high frequencies.
Publisher: Springer Science and Business Media LLC
Date: 11-2022
DOI: 10.1007/S00018-022-04609-3
Abstract: Sulforaphane has been investigated in human pathologies and preclinical models of airway diseases. To provide further mechanistic insights, we explored L-sulforaphane (LSF) in the ovalbumin (OVA)-induced chronic allergic airways murine model, with key hallmarks of asthma. Histological analysis indicated that LSF prevented or reversed OVA-induced epithelial thickening, collagen deposition, goblet cell metaplasia, and inflammation. Well-known antioxidant and anti-inflammatory mechanisms contribute to the beneficial effects of LSF. Fourier transform infrared microspectroscopy revealed altered composition of macromolecules, following OVA sensitization, which were restored by LSF. RNA sequencing in human peripheral blood mononuclear cells highlighted the anti-inflammatory signature of LSF. Findings indicated that LSF may alter gene expression via an epigenetic mechanism which involves regulation of protein acetylation status. LSF resulted in histone and α-tubulin hyperacetylation in vivo, and cellular and enzymatic assays indicated decreased expression and modest histone deacetylase (HDAC) inhibition activity, in comparison with the well-known pan-HDAC inhibitor suberoylanilide hydroxamic acid (SAHA). Molecular modeling confirmed interaction of LSF and LSF metabolites with the catalytic domain of metal-dependent HDAC enzymes. More generally, this study confirmed known mechanisms and identified potential epigenetic pathways accounting for the protective effects and provide support for the potential clinical utility of LSF in allergic airways disease.
Publisher: Springer Science and Business Media LLC
Date: 16-07-2020
DOI: 10.1038/S41598-020-68671-2
Abstract: The ovalbumin-induced (OVA) chronic allergic airways murine model is a well-established model for investigating pre-clinical therapies for chronic allergic airways diseases, such as asthma. Here, we examined the effects of several experimental compounds with potential anti-asthmatic effects including resveratrol (RV), relaxin (RLN), l -sulforaphane (LSF), valproic acid (VPA), and trichostatin A (TSA) using both a prevention and reversal model of chronic allergic airways disease. We undertook a novel analytical approach using focal plane array (FPA) and synchrotron Fourier-transform infrared (S-FTIR) microspectroscopic techniques to provide new insights into the mechanisms of action of these experimental compounds. Apart from the typical biological effects, S-FTIR microspectroscopy was able to detect changes in nucleic acids and protein acetylation. Further, we validated the reduction in collagen deposition induced by each experimental compound evaluated. Although this has previously been observed with conventional histological methods, the S-FTIR technique has the advantage of allowing identification of the type of collagen present. More generally, our findings highlight the potential utility of S-FTIR and FPA-FTIR imaging techniques in enabling a better mechanistic understanding of novel asthma therapeutics.
Publisher: SPIE
Date: 08-03-2023
DOI: 10.1117/12.2654911
Publisher: Walter de Gruyter GmbH
Date: 31-10-2019
Publisher: Springer Science and Business Media LLC
Date: 25-04-2018
Publisher: MDPI AG
Date: 18-10-2023
Publisher: SAGE Publications
Date: 19-07-2023
DOI: 10.1177/00037028231180233
Abstract: The analysis of biological s les with polarized infrared spectroscopy (p-IR) has long been a widely practiced method for the determination of s le orientation and structural properties. In contrast to earlier works, which employed this method to investigate the fundamental chemistry of biological systems, recent interests are moving toward “real-world” applications for the evaluation and diagnosis of pathological states. This focal point review provides an up-to-date synopsis of the knowledge of biological materials garnered through linearly p-IR on biomolecules, cells, and tissues. An overview of the theory with special consideration to biological s les is provided. Different modalities which can be employed along with their capabilities and limitations are outlined. Furthermore, an in-depth discussion of factors regarding s le preparation, s le properties, and instrumentation, which can affect p-IR analysis is provided. Additionally, attention is drawn to the potential impacts of analysis of biological s les with inherently polarized light sources, such as synchrotron light and quantum cascade lasers. The vast applications of p-IR for the determination of the structure and orientation of biological s les are given. In conclusion, with considerations to emerging instrumentation, findings by other techniques, and the shift of focus toward clinical applications, we speculate on the future directions of this methodology.
Publisher: International Union of Crystallography (IUCr)
Date: 20-06-2023
DOI: 10.1107/S1600577523004228
Abstract: The routes by which foreign objects enter cells is well studied however, their fate following uptake has not been explored extensively. Following exposure to synchrotron-sourced (SS) terahertz (THz) radiation, reversible membrane permeability has been demonstrated in eukaryotic cells by the uptake of nanospheres nonetheless, cellular localization of the nanospheres remained unclear. This study utilized silica core-shell gold nanospheres (AuSi NS) of diameter 50 ± 5 nm to investigate the fate of nanospheres inside pheochromocytoma (PC 12) cells following SS THz exposure. Fluorescence microscopy was used to confirm nanosphere internalization following 10 min of SS THz exposure in the range 0.5–20 THz. Transmission electron microscopy followed by scanning transmission electron microscopy energy-dispersive spectroscopic (STEM-EDS) analysis was used to confirm the presence of AuSi NS in the cytoplasm or membrane, as single NS or in clusters (22% and 52%, respectively), with the remainder (26%) sequestered in vacuoles. Cellular uptake of NS in response to SS THz radiation could have suitable applications in a vast number of biomedical applications, regenerative medicine, vaccines, cancer therapy, gene and drug delivery.
Publisher: Elsevier BV
Date: 12-2015
Publisher: Springer Science and Business Media LLC
Date: 12-2020
DOI: 10.1038/S41598-020-78078-8
Abstract: This study is aimed at investigating the features of mineralization of the enamel apatite at initial stages of fluorosis development. S les of teeth with intact and fluorotic enamel in an early stage of the disease development (Thylstrup–Fejerskov Index = 1–3) were studied by Raman scattering and FTIR using Infrared Microspectroscopy beamline at Australian Synchrotron equipment. Based on the data obtained by optical microspectroscopy and calculation of the coefficient R [A-type/B-type], which represents the ratio of carbonation fraction of CO 3 2− , replacing phosphate or hydroxyl radicals in the enamel apatite lattice, the features of mineralization of enamel apatite in the initial stages of development of the pathology caused by an increased content of fluorine in the oral cavity were established. Statistical analysis of the data showed significant differences in the mean values of R [A-type/B-type] ratio between the control and experimental groups for surface layers ( p 0.01). The data obtained are potentially significant as benchmarks in the development of a new approach to preventive diagnostics of the development of initial and clinically unregistered stages of human teeth fluorosis, as well as personalized control of the use of fluoride-containing caries-preventive agents.
Publisher: Science Society of Thailand
Date: 2002
Publisher: Wiley
Date: 22-12-2010
Publisher: SPIE
Date: 08-03-2023
DOI: 10.1117/12.2655172
Publisher: MDPI AG
Date: 30-03-2022
DOI: 10.3390/BIOMIMETICS7020035
Abstract: The application of biomimetic strategies and nanotechnologies (nanodentology) has led to numerous innovations and provided a considerable impetus by creating a new class of modern adhesion restoration materials, including different nanofillers. An analysis of the molecular properties of biomimetic adhesives was performed in this work to find the optimal composition that provides high polymerisation and mechanical hardness. Nanocrystalline carbonate-substituted calcium hydroxyapatite (nano-cHAp) was used as the filler of the light-cured adhesive Bis-GMA (bisphenol A-glycidyl methacrylate). The characteristics of this substance correspond to the apatite of human enamel and dentin, as well as to the biogenic source of calcium: avian eggshells. The introduction and distribution of nano-cHAp fillers in the adhesive matrix resulted in changes in chemical bonding, which were observed using Fourier transform infrared (FTIR) spectroscopy. As a result of the chemical bonding, the Vickers hardness (VH) and the degree of conversion under photopolymerisation of the nano-cHAp/Bis-GMA adhesive increased for the specified concentration of nanofiller. This result could contribute to the application of the developed biomimetic adhesives and the clinical success of restorations.
Publisher: MDPI AG
Date: 11-03-2019
DOI: 10.20944/PREPRINTS201903.0127.V1
Abstract: A focal plane array (FPA) detector was used for hyperspectral imaging in the infrared (IR) spectral region using thermal and synchrotron light sources. FPA Fourier-transform IR (FTIR) imaging microspectroscopy will be able to monitor real time changes at specific absorption bands when combined with high brightness synchrotron source. In this study, several types of s les with unique structural motifs were selected and used for assessing the capability of the FPA-FTIR imaging technique. It was shown that the time required for polariscopy at IR wavelengths can be substantially reduced by the FPA-FTIR imaging approach. By using natural and laser fabricated polymers with sub-wavelength features, alignment of absorbing molecular dipoles was revealed as well as higher order patterns (laser fabricated structures). Micro-spectroscopy of absorber orientation reveals alignment patterns even when they are not spatially resolved.
Publisher: Voronezh State University
Date: 2022
Publisher: Springer Science and Business Media LLC
Date: 14-08-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7TA08653A
Abstract: Microstructural features significantly affecting lithium ion dynamics and conduction within the crystalline structure of pyrrolidinium based organic ionic plastic crystals.
Publisher: Royal Society of Chemistry (RSC)
Date: 05-09-2014
DOI: 10.1039/C4CP03613A
Abstract: The melt crystallization of poly(vinyl alcohol) (PVA) and PVA composites has been a controversial subject due to inconclusive evidence and different opinions for its decomposition during crystallization. Using graphene as a model, the melt crystallization of PVA and PVA-graphene composites occurring during single-cycle and multiple-cycle non-isothermal annealing processes was systematically analyzed using different characterization techniques. The results obtained using single-cycle non-isothermal annealing indicated that the entire crystallization process took place through two main stages. The graphene in the PVA matrix regulates the nucleation and crystal growth manner of the PVA, yet resulting in retardation of the entire crystallization. The FTIR and Raman spectroscopic results particularly demonstrated that the annealing process not only improved the crystallinity but also led to clear decomposition in PVA and PVA-graphene composites, such as the elimination of hydroxyl groups and the production of C=C double bonds. The newly produced C=C double bonds were found to be responsible for the retardation of PVA macromolecule crystallization and the breaking of hydrogen bonds among the hydroxyl groups in the PVA chains. In addition, the morphological observation and multi-cycle non-isothermal crystallization further confirmed the existence of decomposition based on the surface damage as well as decreased crystallization enthalpy and crystallization peak temperature. Therefore, the non-isothermal crystallizations of the pure PVA and the PVA-graphene composites were in fact the combination of non-isothermal crystallization and non-isothermal degradation processes.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3AN00485F
Abstract: The increase in polyunsaturated fatty acid (PUFA) consumption has prompted research into alternative resources other than fish oil. In this study, a new approach based on focal-plane-array Fourier transform infrared (FPA-FTIR) microspectroscopy and multivariate data analysis was developed for the characterisation of some marine microorganisms. Cell and lipid compositions in lipid-rich marine yeasts collected from the Australian coast were characterised in comparison to a commercially available PUFA-producing marine fungoid protist, thraustochytrid. Multivariate classification methods provided good discriminative accuracy evidenced from (i) separation of the yeasts from thraustochytrids and distinct spectral clusters among the yeasts that conformed well to their biological identities, and (ii) correct classification of yeasts from a totally independent set using cross-validation testing. The findings further indicated additional capability of the developed FPA-FTIR methodology, when combined with partial least squares regression (PLSR) analysis, for rapid monitoring of lipid production in one of the yeasts during the growth period, which was achieved at a high accuracy compared to the results obtained from the traditional lipid analysis based on gas chromatography. The developed FTIR-based approach when coupled to programmable withdrawal devices and a cytocentrifugation module would have strong potential as a novel online monitoring technology suited for bioprocessing applications and large-scale production.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4TA07155G
Abstract: Composite plastic crystal electrolytes are shown to exhibit enhanced ion transport due to release of Li + from a second phase into a solid solution.
Publisher: Pleiades Publishing Ltd
Date: 12-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2NH00187J
Abstract: Polarisation analysis of light-matter interactions established for propagating optical far-fields is now extended into an evanescent field as demonstrated in this study using an attenuated total reflection (ATR) setup and a synchrotron source at THz frequencies. Scalar intensity
Publisher: SAGE Publications
Date: 12-2002
DOI: 10.1366/000370202321116011
Abstract: Symmetrically tapered planar IR waveguides have been fabricated by starting with a ZnS coated concave piece of single-crystal Ge, embedding it in an epoxide resin as a supporting substrate, and then grinding and polishing a planar surface until the thickness at the taper minimum is μm. Such tapering is expected to enhance a waveguide's sensitivity as an evanescent wave sensor by maximizing the amount of evanescent wave energy present at the thinnest part of the waveguide. As predicted by theory, the surface sensitivity, i.e., the absorbance signal per molecule in contact with the sensing region, increases with decreasing thickness of the tapered region even while the total energy throughput decreases. The signal-to-noise ratio obtained depends very strongly on the quality of the polished surfaces of the waveguides. The surface sensitivity is superior to that obtained with a commercial Ge attenuated total reflection (ATR) accessory for several types of s le, including thin films ( ng) and small volumes ( μL) of volatile solvents. By using the waveguides, light-induced structural changes in the protein bacteriorhodopsin were observable using s les as small as ∼50 pmol (∼1 μg). In addition, the waveguide sensors can reveal the surface compositions on a single human hair, pointing to their promise as a tool for forensic fiber analysis.
Publisher: Informa UK Limited
Date: 26-09-2021
Publisher: Wiley
Date: 02-08-2021
Abstract: Analysis of the epicuticular wax layer on the surface of plant leaves can provide a unique window into plant physiology and responses to environmental stimuli. Well‐established analytical methodologies can quantify epicuticular wax composition, yet few methods are capable of imaging wax distribution in situ or in vivo. Here, the first report of Fourier transform infrared (FTIR) reflectance spectroscopic imaging as a non‐destructive, in situ, method to investigate variation in epicuticular wax distribution at 25 µm spatial resolution is presented. The authors demonstrate in vivo imaging of alterations in epicuticular waxes during leaf development and in situ imaging during plant disease or exposure to environmental stressors. It is envisaged that this new analytical capability will enable in vivo studies of plants to provide insights into how the physiology of plants and crops respond to environmental stresses such as disease, soil contamination, drought, soil acidity, and climate change.
Publisher: Springer Science and Business Media LLC
Date: 16-10-2023
Publisher: MDPI AG
Date: 15-11-2022
DOI: 10.3390/MA15228063
Abstract: The controlled deposition of CoCrFeNiMo0.2 high-entropy alloy (HEA) microparticles was achieved by using laser-induced forward transfer (LIFT). Ultra-short laser pulses of 230 fs of 515 nm wavelength were tightly focused into ∼2.4 μm focal spots on the ∼50-nm thick plasma-sputtered films of CoCrFeNiMo0.2. The morphology of HEA microparticles can be controlled at different fluences. The HEA films were transferred onto glass substrates by magnetron sputtering in a vacuum (10−8 atm) from the thermal spray-coated substrates. The absorption coefficient of CoCrFeNiMo0.2α≈6×105 cm−1 was determined at 600-nm wavelength. The real and imaginary parts of the refractive index (n+iκ) of HEA were determined from reflectance and transmittance by using nanofilms.
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.ACA.2013.09.036
Abstract: Molecule-coated nanoparticles are hybrid materials which can be engineered with novel properties. The molecular coating of metal nanoparticles can provide chemical functionality, enabling assembly of the nanoparticles that are important for applications, such as biosensing devices. Herein, we report a new self-assembly of core-satellite gold nanoparticles linked by a simple amino acid l-Cysteine for biosensing of Cu(2+). The plasmonic properties of core-satellite nano-assemblies were investigated, a new red shifted absorbance peak from about 600 to 800 nm was found, with specific wavelength depending on ratios with assembly of large and small gold nanoparticles. The spectral features obtained using surface-enhanced Raman spectroscopy (SERS) provided strong evidence for the assembly of the Cu(2+) ions to the L-Cysteine molecules leading to the successful formation of the core-satellite Cu(l-Cysteine) complex on the gold surfaces. In addition, a linear relationship between the concentration of mediating Cu(2+) and absorbance of self-assembled gold nanoparticles (GNPs) at 680 nm was obtained. These results strongly address the potential strategy for applying the functionalized GNPs as novel biosensing tools in trace detections of certain metal ions.
Publisher: MDPI AG
Date: 23-05-2014
DOI: 10.3390/NU6052104
Publisher: Elsevier BV
Date: 12-1991
Publisher: American Chemical Society (ACS)
Date: 05-06-2018
Publisher: Elsevier BV
Date: 04-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1AN00136A
Abstract: SR-ATR-FTIR has been used to improve the diffraction limited spatial resolution of infrared micro-spectroscopy, enabling this study to reveal the sub-cellular location of protein aggregates and lipophilic inclusions in brain cells, and bacteria.
Publisher: Beilstein Institut
Date: 23-04-2019
DOI: 10.3762/BJNANO.10.93
Abstract: The nanoscale composition of silk defining its unique properties via a hierarchial structural anisotropy needs to be analysed at the highest spatial resolution of tens of nanometers corresponding to the size of fibrils made of β-sheets, which are the crystalline building blocks of silk. Nanoscale optical and structural properties of silk have been measured from 100 nm thick longitudinal slices of silk fibers with ca. 10 nm resolution, the highest so far. Optical sub-wavelength resolution in hyperspectral mapping of absorbance and molecular orientation were carried out for comparison at IR wavelengths of 2–10 μm using synchrotron radiation. A reliable distinction of transmission changes by only 1–2% as the anisotropy of amide bands was obtained from nanometer-thin slices of silk.
Publisher: Elsevier BV
Date: 07-2022
Publisher: American Chemical Society (ACS)
Date: 12-04-2019
DOI: 10.26434/CHEMRXIV.7987247.V1
Abstract: Fingermarks are an important form of crime-scene trace evidence however, their usefulness may be h ered by a variation in response or a lack of robustness in detection methods. Understanding the chemical composition and distribution within fingermarks may help explain variation in latent fingermark detection with existing methods and identify new strategies to increase detection capabilities. The majority of research in the literature describes investigation of organic components of fingermark residue, leaving the elemental distribution less well understood. The relative scarcity of information regarding the elemental distribution within fingermarks is in part due to previous unavailability of direct, micron resolution elemental mapping techniques. This capability is now provided at third generation synchrotron light sources, where X-ray Fluorescence Microscopy (XFM) provides micron or sub-micron spatial resolution and direct detection with sub-μM detection limits. XFM has been applied in this study to reveal the distribution of inorganic components within fingermark residue, including endogenous trace metals (Fe, Cu, Zn), diffusible ions (Cl-, K+, Ca2+), and exogeneous metals (Ni, Ti, Bi). This study incorporated a multi-modal approach using XFM and Infrared Microspectroscopy (IRM) analyses to demonstrate co-localisation of endogenous metals within the hydrophilic organic components of fingermark residue. Additional experiments were then undertaken to investigate how sources of exogenous metals (e.g. coins and cosmetics) may be transferred to, and distributed within latent fingermarks. Lastly, this study reports a preliminary assessment of how environmental factors such as exposure to aqueous environments may effect elemental distribution within fingermarks. Taken together, the results of this study advance our current understanding of fingermark composition and its spatial distribution of chemical components, and may help explain detection variation observed during detection of fingermarks using standard forensic protocols.
Publisher: SAGE Publications
Date: 02-2004
DOI: 10.1366/000370204322842869
Abstract: Cylinder–planar Ge waveguides are being developed as evanescent-wave sensors for chemical microanalysis. The only non-planar surface is a cylinder section having a 300-mm radius of curvature. This confers a symmetric taper, allowing for direct coupling into and out of the waveguide's 1-mm 2 end faces while obtaining multiple reflections at the central -μm-thick sensing region. Ray-optic calculations indicate that the propagation angle at the central minimum has a strong nonlinear dependence on both angle and vertical position of the input ray. This results in rather inefficient coupling of input light into the off-axis modes that are most useful for evanescent-wave absorption spectroscopy. Mode-specific performance of the cylinder–planar waveguides has also been investigated experimentally. As compared to a blackbody source, the much greater brightness of synchrotron-generated infrared (IR) radiation allows a similar total energy throughput, but restricted to a smaller fraction of the allowed waveguide modes. However, such angle-selective excitation results in a strong oscillatory interference pattern in the transmission spectra. These spectral oscillations are the principal technical limitation on using synchrotron radiation to measure evanescent-wave absorption spectra with the thin waveguides.
Publisher: American Chemical Society (ACS)
Date: 07-11-2011
DOI: 10.1021/JP207730G
Abstract: A series of 5-hydroxy-isoflavones-genistein, biochanin A, prunetin, and 4',7-dimethoxygenistein-have been studied by surface-enhanced Raman spectroscopy (SERS). Citrate reduced silver colloids were employed as a standard technique to measure SER spectra over a range of pH and concentrations. Density functional theory calculations were used to assist in determining the mode of interaction of isoflavones with the silver nanoparticles. It is revealed that biochanin A and prunetin interact with the silver nanoparticles upon deprotonation of the 7- and the 4'-OH groups, respectively, to show SERS activity. Correlations of their spectra with SERS of genistein strongly support the presence of multiple interaction modes involving both of the OH groups in genistein, in a similar manner to daidzein. Surprisingly, however, under these conditions, the 5-OH group was found to be noninteractive as revealed by attempts to measure SERS of 4',7-dimethoxygenistein. This was attributed partly to the low solubility and, more importantly, to the influence of steric hindrance, caused by the position of the pendant phenyl ring, which prevented interaction with the Ag colloid surface. These results complement recent work on daidzein and formononetin and provide further insight into understanding the SER spectra of isoflavones.
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3482885
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.WASMAN.2019.10.029
Abstract: Catalytic pyrolysis is a useful technique for the conversion of scrap tyres into liquid fuels. Zeolite catalysts were employed in the pyrolysis of scrap tyres for the production of aromatic rich fuel. Deactivation of zeolite catalysts during pyrolysis reaction was investigated which played an important role in the product quality and composition. Herein, the performance of microporous zeolite catalysts and mesoporous MCM-41 catalyst was evaluated in a two-stage fixed bed reactor for the pyrolysis of scrap tyres. Comparative studies showed the increase in the production of aromatic compounds up to 23.7% over zeolite catalyst as compared to 18.7% over MCM-41 catalyst. However, Zeolite Y catalyst exhibited higher coke formation led to the rapid deactivation. The stability of zeolite catalysts is addressed by the incorporation of Cerium metal within the framework of two zeolite catalysts namely Zeolite Y and ZSM-5 through the ion-exchange technique. Parent and spent catalysts were characterised using synchrotron FT-IR spectroscopy, temperature-programmed desorption of ammonia (NH
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NH00340A
Abstract: Hyperspectral imaging is now augmented by separation of the birefringence, dichroism and orientation function at the same wavelength and pixel by combining Malus and Beer–Lambert laws.
Publisher: Elsevier BV
Date: 07-2021
Publisher: American Chemical Society (ACS)
Date: 10-01-2019
DOI: 10.1021/ACS.LANGMUIR.8B03470
Abstract: The waxy epicuticle of dragonfly wings contains a unique nanostructured pattern that exhibits bactericidal properties. In light of emerging concerns of antibiotic resistance, these mechano-bactericidal surfaces represent a particularly novel solution by which bacterial colonization and the formation of biofilms on biomedical devices can be prevented. Pathogenic bacterial biofilms on medical implant surfaces cause a significant number of human deaths every year. The proposed mechanism of bactericidal activity is through mechanical cell rupture however, this is not yet well understood and has not been well characterized. In this study, we used giant unilamellar vesicles (GUVs) as a simplified cell membrane model to investigate the nature of their interaction with the surface of the wings of two dragonfly species, Austrothemis nigrescens and Trithemis annulata, sourced from Victoria, Australia, and the Baix Ebre and Terra Alta regions of Catalonia, Spain. Confocal laser scanning microscopy and cryo-scanning electron microscopy techniques were used to visualize the interactions between the GUVs and the wing surfaces. When exposed to both natural and gold-coated wing surfaces, the GUVs were adsorbed on the surface, exhibiting significant deformation, in the process of membrane rupture. Differences between the tensile rupture limit of GUVs composed of 1,2-dioleoyl- sn-glycero-3-phosphocholine and the isotropic tension generated from the internal osmotic pressure were used to indirectly determine the membrane tensions, generated by the nanostructures present on the wing surfaces. These were estimated as being in excess of 6.8 mN m
Publisher: International Union of Crystallography (IUCr)
Date: 25-04-2018
DOI: 10.1107/S1600577518004460
Abstract: Damselflies Calopteryx haemorrhoidalis exhibiting black wings are found in the western Mediterranean, Algeria, France, Italy, Spain and Monaco. Wing pigmentation is caused by the presence of melanin, which is involved in physiological processes including defence reactions, wound healing and sclerotization of the insect. Despite the important physiological roles of melanin, the presence and colour variation among males and females of the C. haemorrhoidalis species and the localization of the pigment within the wing membrane remain poorly understood. In this study, infrared (IR) microspectroscopy, coupled with the highly collimated synchrotron IR beam, was employed in order to identify the distribution of the pigments in the wings at a high spatial resolution. It was found that the melanin is localized in the procuticle of the C. haemorrhoidalis damselfly wings, distributed homogeneously within this layer, and not associated with the lipids of the epicuticle.
Publisher: Springer Science and Business Media LLC
Date: 03-2017
DOI: 10.1007/S00253-017-8205-9
Abstract: Nanostructured insect wing surfaces have been reported to possess the ability to resist bacterial colonization through the mechanical rupture of bacterial cells coming into contact with the surface. In this work, the susceptibility of physiologically young, mature and old Staphylococcus aureus CIP 65.8 and Pseudomonas aeruginosa ATCC 9721 bacterial cells, to the action of the bactericidal nano-pattern of damselfly Calopteryx haemorrhoidalis wing surfaces, was investigated. The results were obtained using several surface characterization techniques including optical profilometry, scanning electron microscopy, synchrotron-sourced Fourier transform infrared microspectroscopy, water contact angle measurements and antibacterial assays. The data indicated that the attachment propensity of physiologically young S. aureus CIP 65.8
Publisher: MDPI AG
Date: 25-06-2021
DOI: 10.3390/MOLECULES26133890
Abstract: Biofilms are assemblages of microbial cells, extracellular polymeric substances (EPS), and other components extracted from the environment in which they develop. Within biofilms, the spatial distribution of these components can vary. Here we present a fundamental characterization study to show differences between biofilms formed by Gram-positive methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative Pseudomonas aeruginosa, and the yeast-type Candida albicans using synchrotron macro attenuated total reflectance-Fourier transform infrared (ATR-FTIR) microspectroscopy. We were able to characterise the pathogenic biofilms’ heterogeneous distribution, which is challenging to do using traditional techniques. Multivariate analyses revealed that the polysaccharides area (1200–950 cm−1) accounted for the most significant variance between biofilm s les, and other spectral regions corresponding to amides, lipids, and polysaccharides all contributed to s le variation. In general, this study will advance our understanding of microbial biofilms and serve as a model for future research on how to use synchrotron source ATR-FTIR microspectroscopy to analyse their variations and spatial arrangements.
Publisher: International Union of Crystallography (IUCr)
Date: 09-08-2021
DOI: 10.1107/S1600577521007104
Abstract: The Infrared Microspectroscopy Beamline at the Australian Synchrotron is equipped with a Fourier transform infrared (FTIR) spectrometer, which is coupled with an infrared (IR) microscope and a choice of two detectors: a single-point narrow-band mercury cadmium telluride (MCT) detector and a 64 × 64 multi-pixel focal plane array (FPA) imaging detector. A scanning-based point-by-point mapping method is commonly used with a tightly focused synchrotron IR beam at the s le plane, using an MCT detector and a matching 36× IR reflecting objective and condenser (NA = 0.5), which is time consuming. In this study, the beam size at the s le plane was increased using a 15× objective and the spatio-spectral aberrations were investigated. A correlation-based semi-synthetic computational optical approach was applied to assess the possibilities of exploiting the aberrations to perform rapid imaging rather than a mapping approach.
Publisher: Wiley
Date: 15-09-2023
Publisher: MDPI AG
Date: 24-11-2022
DOI: 10.3390/BIOS12121073
Abstract: Phase imaging of biochemical s les has been demonstrated for the first time at the Infrared Microspectroscopy (IRM) beamline of the Australian Synchrotron using the usually discarded near-IR (NIR) region of the synchrotron-IR beam. The synchrotron-IR beam at the Australian Synchrotron IRM beamline has a unique fork shaped intensity distribution as a result of the gold coated extraction mirror shape, which includes a central slit for rejection of the intense X-ray beam. The resulting beam configuration makes any imaging task challenging. For intensity imaging, the fork shaped beam is usually tightly focused to a point on the s le plane followed by a pixel-by-pixel scanning approach to record the image. In this study, a pinhole was aligned with one of the lobes of the fork shaped beam and the Airy diffraction pattern was used to illuminate biochemical s les. The diffracted light from the s les was captured using a NIR sensitive lensless camera. A rapid phase-retrieval algorithm was applied to the recorded intensity distributions to reconstruct the phase information. The preliminary results are promising to develop multimodal imaging capabilities at the IRM beamline of the Australian Synchrotron.
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.JINORGBIO.2011.08.005
Abstract: To investigate the nature of binding of quinoline antimalarial drugs to heme and to extract experimental evidence for this binding, the interaction of ferriprotoporphyrin IX (FP) with chloroquine and quinacrine (both of which have a similar side chain) and quinoline methanol antimalarials quinine and mefloquine has been studied using IR and NIR-Raman spectroscopy in the solid state. Attenuated total reflectance infrared spectroscopic data clearly show that heme in chloroquine-FP complex is not μ-oxo dimeric indicating that the hypothesis that chloroquine binds to FP μ-oxo dimer with a stoichiometry of 1 chloroquine:2 μ-oxo dimers is not valid in the solid state. Moreover, the first vibrational spectroscopy evidence is presented for the formation of hydrogen bonding between a propionate group of heme and the tertiary amino nitrogen of chloroquine and quinacrine. Raman spectroscopy data does not provide any evidence to support the formation of a similar salt bridge in the complexes of FP with quinine and mefloquine however, it suggests that the interaction of these drugs with FP happens through coordination of the Fe(III) center of the porphyrin to the 9-hydroxy group of the drug.
Publisher: American Chemical Society (ACS)
Date: 03-07-2017
Abstract: Nature has produced many intriguing and spectacular surfaces at the micro- and nanoscales. These small surface decorations act for a singular or, in most cases, a range of functions. The minute landscape found on the lotus leaf is one such ex le, displaying antiwetting behavior and low adhesion with foreign particulate matter. Indeed the lotus leaf has often been considered the "benchmark" for such properties. One could expect that there are animal counterparts of this self-drying and self-cleaning surface system. In this study, we show that the planthopper insect wing (Desudaba danae) exhibits a remarkable architectural similarity to the lotus leaf surface. Not only does the wing demonstrate a topographical likeness, but some surface properties are also expressed, such as nonwetting behavior and low adhering forces with contaminants. In addition, the insect-wing cuticle exhibits an antibacterial property in which Gram-negative bacteria (Porphyromonas gingivalis) are killed over many consecutive waves of attacks over 7 days. In contrast, eukaryote cell associations, upon contact with the insect membrane, lead to a formation of integrated cell sheets (e.g., among human stem cells (SHED-MSC) and human dermal fibroblasts (HDF)). The multifunctional features of the insect membrane provide a potential natural template for man-made applications in which specific control of liquid, solid, and biological contacts is desired and required. Moreover, the planthopper wing cuticle provides a "new" natural surface with which numerous interfacial properties can be explored for a range of comparative studies with both natural and man-made materials.
Publisher: Elsevier BV
Date: 10-2015
Publisher: Science Society of Thailand
Date: 2006
Publisher: American Chemical Society (ACS)
Date: 14-02-2023
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.FOODCHEM.2017.02.021
Abstract: Physicochemical and thermal characteristics of Australian chia seed oil (CSO) were studied. The specific gravity, viscosity and refractive index of CSO at ambient temperature were 0.93, 43.2mPa.s and 1.48, respectively. The acid, peroxide, saponification and iodine values and unsaponifiable matter content of CSO were 2.54gKOH/kg oil, 4.33meqO
Publisher: Elsevier BV
Date: 09-2019
Publisher: American Chemical Society (ACS)
Date: 05-05-2010
DOI: 10.1021/JP101389T
Abstract: Phytoestrogens daidzein (4',7-dihydroxy-isoflavone) and formononetin (4'-methoxy-7-hydroxy-isoflavone) have been studied by surface-enhanced Raman (SER) spectroscopy. Spectra were acquired in the presence of citrate-reduced silver colloids, over a range of pH and concentrations. Density functional theory calculations were used to assist assignment of the normal Raman spectra and help determine the mode of interaction of isoflavones with the silver nanoparticles. Formononetin does not show SER activity unless the 7-OH group is deprotonated, and accordingly, the interaction with the silver surface occurs via the deprotonated site. Daidzein, on the other hand, appears to contain multiple species at the surface, interacting via both the hydroxyl groups at 7-OH and 4'-OH, after deprotonation. This is an important result that points to potential future SERS applications in phytoestrogen analysis and provides a foundation for understanding the SER spectra of isoflavones.
Publisher: Wiley
Date: 26-01-2010
DOI: 10.1002/JRS.2579
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2AN02001G
Abstract: Oxidative treatment of human red blood cells (RBCs) prior to freeze-drying appears to stabilize the RBCs to withstand dried storage at room temperature.
Publisher: Wiley
Date: 18-12-2022
Abstract: The birefringence analysis of thin m SiO 2 films deposited via evaporation at a glancing angle of to the normal on resist pillar arrays on Si and nanopatterned SiO 2 substrates is carried out by spectral and color (red–green–blue [RGB]) imaging modes. Retardance and birefringence of the films deposited over flat and structured regions can be distinguished with only ≈1% difference between neighboring regions for the visible spectral range using RGB numerical analysis of images. The Michel‐Lévy color map is used for color rendering of birefringence to make quantitative measurements by numerical RGB color filtering. It is shown that by using at 530 nm waveplate inserted at angle to the cross polarizer‐analyzer setup, the range of changes in chromaticity xy ‐coordinates expands approximately twice upon angular rotation of a birefringent s le. This facilitates a better signal‐to‐noise determination of birefringence. The proposed method with ‐plate color shifting can be directly used to determine birefringence from step‐like spectral features in reflection and transmission polariscopy. Direct measurement of birefringence () and retardance of SiO 2 chevron film is carried out using Berek compensator as a benchmark.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.JBIOSC.2012.05.013
Abstract: Marine microbes are competent organisms, some of which can accumulate large amounts of lipids. A yeast strain, Rhodotorula mucilaginosa AMCQ8A was isolated from the marine water of the Queenscliff region, Victoria, Australia. The yeast isolate was identified by sequencing 18s rDNA genes. Scanning electron microscopy images revealed scars on the surface of the yeast cells. The Fourier transform infrared spectroscopy microspectroscopy studies demonstrated the presence of unsaturated fatty acids by differential microscopic analysis. The sharp band at 1745 cm⁻¹ was represented by ν(C=O) stretches of ester functional groups from lipids and fats, and therefore indicated the presence of total lipids produced by the cells. Over 65% of the fatty acids from the yeast strain were analyzed as C₁₆ and C₁₈:₁ with omega-3 content from about 6% to 7%. Thus, this marine-derived yeast could be a potential source of lipids, including omega-3 fatty acids.
Publisher: Portland Press Ltd.
Date: 19-03-2021
DOI: 10.1042/BCJ20200653
Abstract: Hepatocytes are essential for maintaining the homeostasis of iron and lipid metabolism in mammals. Dysregulation of either iron or lipids has been linked with serious health consequences, including non-alcoholic fatty liver disease (NAFLD). Considered the hepatic manifestation of metabolic syndrome, NAFLD is characterised by dysregulated lipid metabolism leading to a lipid storage phenotype. Mild to moderate increases in hepatic iron have been observed in ∼30% of in iduals with NAFLD however, direct observation of the mechanism behind this increase has remained elusive. To address this issue, we sought to determine the metabolic consequences of iron loading on cellular metabolism using live cell, time-lapse Fourier transform infrared (FTIR) microscopy utilising a synchrotron radiation source to track biochemical changes. The use of synchrotron FTIR is non-destructive and label-free, and allowed observation of spatially resolved, sub-cellular biochemical changes over a period of 8 h. Using this approach, we have demonstrated that iron loading in AML12 cells induced perturbation of lipid metabolism congruent with steatosis development. Iron-loaded cells had approximately three times higher relative ester carbonyl concentration compared with controls, indicating an accumulation of triglycerides. The methylene/methyl ratio qualitatively suggests the acyl chain length of fatty acids in iron-loaded cells increased over the 8 h period of monitoring compared with a reduction observed in the control cells. Our findings provide direct evidence that mild to moderate iron loading in hepatocytes drives de novo lipid synthesis, consistent with a role for iron in the initial hepatic lipid accumulation that leads to the development of hepatic steatosis.
Publisher: IM Publications Open LLP
Date: 11-04-2022
DOI: 10.1255/SEW.2022.A8
Publisher: MDPI AG
Date: 17-06-2021
DOI: 10.3390/IJMS22126510
Abstract: The aim of this work is to develop a biomimetic interface between the natural tooth tissue and the restorative composite and to study it on the basis of synchrotron micro-FTIR mapping and multidimensional processing of the spectral data array. Using hierarchical cluster analysis of 3D FTIR data revealed marked improvements in the formation of the dentine/adhesive/dental hybrid interface using a biomimetic approach. The use of a biomimetic strategy (application of an amino acid–modified primer, alkaline calcium and a nano-c-HAp–modified adhesive) allowed the formation of a matrix that can be structurally integrated with natural dentine and dental composite. The biomimetic hybrid layer was characterised by homogeneous chemical composition and a higher degree of conversion of the adhesive during polymerisation, which should provide optimal integration of the dental composite with the dentine.
Publisher: IOP Publishing
Date: 12-2018
Publisher: OSA
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 06-03-2022
DOI: 10.1007/S40735-022-00648-2
Abstract: Almost every abiotic surface of a material is readily colonised by bacteria, algae, and fungi, contributing to the degradation processes of materials. Both biocorrosion and microbially influenced corrosion (MIC) refer to the interaction of microbial cells and their metabolic products, such as exopolymeric substances (EPS), with an abiotic surface. Therefore, biofouling and biodeterioration of manufactured goods have economic and environmental ramifications for the user to tackle or remove the issue. While MIC is typically applied to metallic materials, newly developed and evolving materials frequently succumb to the effects of corrosion, resulting in a range of chemical reactions and transport mechanisms occurring in the material. Recent research on biocorrosion and biofouling of conventional and novel materials is discussed in this paper, showcasing the current knowledge regarding microbial and material interactions that contribute to biocorrosion and biofouling, including biofilms, anaerobic and aerobic environments, microbial assault, and the various roles microorganisms’ play. Additionally, we show the latest analytical techniques used to characterise and identify MIC on materials using a borescope, thermal imaging, Fourier transform infrared (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron microscopy (XPS), X-ray diffraction (XRD), optical and epifluorescence microscopy, electrochemical impedance spectroscopy, and mass spectrometry, and chemometrics.
Publisher: IOP Publishing
Date: 11-2019
DOI: 10.1088/1742-6596/1400/3/033006
Abstract: IR-spectra of the s les of the dentine and gingival fluids obtained with the use of synchrotron radiation can be applied for the diagnostics of the pathological processes of the caries character in a dentine. Vibrations within the range of 2100-2050 cm −1 observed in the spectra of dentine and gingival fluids characteristic of thiocyanates mean the development of the carious pathology. At the same time vibration modes of the carboxyl group of a complex ether detected within the range of 1765 – 1725 cm −1 in the spectra of dentine and gingival fluids certainly confirm the development of caries in dentine. These spectrometric signatures can be certainly and reliably detected also in the gingival fluid, indicating at the fact that the changes proceeding in its molecular composition are referred just to the development of pathological processes in the deep dental tissues.
Publisher: Springer Science and Business Media LLC
Date: 20-04-2021
Publisher: MDPI AG
Date: 29-11-2021
DOI: 10.3390/NANO11123247
Abstract: Polarisation analysis in the mid-infrared fingerprint region was carried out on thin (∼1 μm) Si and SiO2 films evaporated via glancing angle deposition (GLAD) method at 70∘ to the normal. Synchrotron-based infrared microspectroscopic measurements were carried out on the Infrared Microspectroscopy (IRM) beamline at Australian Synchrotron. Specific absorption bands, particularly Si-O-Si stretching vibration, was found to follow the angular dependence of ∼cos2θ, consistent with the absorption anisotropy. This unexpected anisotropy stems from the enhanced absorption in nano-crevices, which have orientation following the cos2θ angular dependence as revealed by Fourier transforming the image of the surface of 3D columnar films and numerical modeling of light field enhancement by sub-wavelength nano-crevices.
Publisher: MDPI AG
Date: 26-09-2022
DOI: 10.20944/PREPRINTS202209.0392.V1
Abstract: Controlled deposition of CoCrFeNiMo0.2 high entropy alloy (HEA) micro-particles was achieved using laser induced forward transfer (LIFT). Ultra-short laser pulses, 230 fs of 515 nm wavelength, were tightly focused into & sim 2.4 & mu m focal spots on the & sim nm thick plasma-sputtered films of CoCrFeNiMo0.2. The HTA films were transferred onto glass substrates by magnetron sputtering in vacuum (10& minus atm) from the thermal spray coated substrates. The absorption coefficient of CoCrFeNiMo0.2 & alpha & asymp 6 & times 105 cm& minus was determined at 600 nm wavelength. The real and imaginary parts of refractive index (n + i& kappa ) of HEA were determined from reflectance and transmittance using nano-films.
Publisher: Springer Science and Business Media LLC
Date: 16-05-2014
Publisher: Elsevier BV
Date: 10-2015
Location: Japan
No related grants have been discovered for Jitraporn Vongsvivut.