ORCID Profile
0000-0002-6016-6438
Current Organisation
Flinders University
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Publisher: MDPI AG
Date: 20-01-2020
DOI: 10.3390/JFB11010006
Abstract: The editorial team greatly appreciates the reviewers who have dedicated their considerable time and expertise to the journal’s rigorous editorial process over the past 12 months, regardless of whether the papers are finally published or not [...]
Publisher: American Chemical Society (ACS)
Date: 25-08-2023
Publisher: American Chemical Society (ACS)
Date: 12-04-2021
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.BIOS.2012.03.019
Abstract: Untreated recycled water, such as sewage and graywater, will almost always contain a wide range of agents that are likely to present risks to human health, including chemicals and pathogenic microorganisms. The microbial hazards, such as large numbers of enteric pathogens that can cause gastroenteric illness if ingested, are the main cause of concern for human health. The presence of the enteropathogenic Escherichia coli (EPEC) serotype is of particular concern, as this group of bacteria is responsible for causing severe infant and travelers' diarrhea, gastroenteritis and hemolytic uremic syndrome. A biosensing system based on an optical Fabry-Pérot (FP) cavity, capable of directly detecting the presence of EPEC within 5 min, has been developed using a simple micro-thin double-sided adhesive tape and two semi-transparent FP mirror plates. The system utilizes a poly(methyl methacrylate) (PMMA) or glass substrates sputtered by 40-nm-thick gold thin films serving as FP mirrors. Mirrors have been activated using 0.1M mercaptopropionic acid, influencing an immobilization density of the translocated intimin receptor (TIR) of 100 ng/cm(2). The specificity of recognition was confirmed by exposing TIR functionalized surfaces to four taxonomically related and/or distantly related bacterial strains. It was found that the TIR-functionalized surfaces did not show any bacterial capture for these other bacterial strains within a 15 min incubation period.
Publisher: Elsevier BV
Date: 12-2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2014
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TB01880C
Abstract: Alignment of microbial colonies along with polymeric cell wall.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1EN00025J
Abstract: The use of various aspects of food processing, including the direct inclusion of nano-additives, are rapidly increasing in the field of nanotechnology to enhance the desired qualities in food production, use and storage.
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: Springer Science and Business Media LLC
Date: 26-11-2013
DOI: 10.1038/NCOMMS3838
Publisher: Elsevier
Date: 2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2014
Publisher: Wiley
Date: 18-12-2023
Abstract: The use of antibacterial and antifouling materials is widely being investigated to combat the increasing risk associated with bacterial infections and the evolution of drug‐resistant bacteria. Efficient antibacterial materials can be fabricated by mimicking the topography found on the surface of natural antibacterial materials. Natural materials such as the wings of cicadas and dragonflies have evolved to use the structural features on their surface to attain bactericidal properties. The nanopillars/nanospikes present on these natural materials physically damage the bacterial cells that settle on the nanostructures resulting in cell lysis and death. This article reviews the role of nanostructures found on the surface of some of these natural antibacterial and antifouling materials such as lotus leaf, cicadas and dragonflies wings, shark skin, and rose petals. These natural structures provide guidelines for the design of synthetic bio‐inspired materials. This review article also presents some novel fabrication techniques used to produce biomimetic micro‐ and nano‐structures on synthetic material surfaces. The role of size, shape, aspect ratio, and spacing between the micro/nano‐structures on the bactericidal properties is also discussed. Finally, the review is finished with the author's view on the future of the field.
Publisher: American Chemical Society (ACS)
Date: 13-04-2022
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 10-2016
Publisher: Springer Berlin Heidelberg
Date: 2008
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4TB00239C
Abstract: A mechano-responsive topology provides a highly active yet autogenous surface for erythrocyte lysis towards microfluidic haematology platforms.
Publisher: MDPI AG
Date: 25-05-2012
DOI: 10.3390/RS4061519
Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.JCIS.2022.08.052
Abstract: Titanium and its alloys are commonly used implant materials. Once inserted into the body, the interface of the biomaterials is the most likely site for the development of implant-associated infections. Imparting the titanium substrate with high-aspect-ratio nanostructures, which can be uniformly achieved using hydrothermal etching, enables a mechanical contact-killing (mechanoresponsive) mechanism of bacterial and fungal cells. Interaction between cells and the surface shows cellular inactivation via a physical mechanism meaning that careful engineering of the interface is needed to optimse the technology. This mechanism of action is only effective towards surface adsorbed microbes, thus any cells not directly in contact with the substrate will survive and limit the antimicrobial efficacy of the titanium nanostructures. Therefore, we propose that a dual-action mechanoresponsive and chemical-surface approach must be utilised to improve antimicrobial activity. The addition of antimicrobial silver nanoparticles will provide a secondary, chemical mechanism to escalate the microbial response in tandem with the physical puncture of the cells. Hydrothermal etching is used as a facile method to impart variant nanostrucutres on the titanium substrate to increase the antimicrobial response. Increasing concentrations (0.25 M, 0.50 M, 1.0 M, 2.0 M) of sodium hydroxide etching solution were used to provide differing degrees of nanostructured morphology on the surface after 3 h of heating at 150 °C. This produced titanium nanospikes, nanoblades, and nanowires, respectively, as a function of etchant concentration. These substrates then provided an interface for the deposition of silver nanoparticles via a reduction pathway. Methicillin-resistant Staphylococcous aureus (MRSA) and Candida auris (C. auris) were used as model bacteria and fungi, respectively, to test the effectiveness of the nanostructured titanium with and without silver nanoparticles, and the bio-interactions at the interface. The presence of nanostructure increased the bactericidal response of titanium against MRSA from ∼ 10 % on commercially pure titanium to a maximum of ∼ 60 % and increased the fungicidal response from ∼ 10 % to ∼ 70 % in C. auris. Introducing silver nanoparticles increased the microbiocidal response to ∼ 99 % towards both bacteria and fungi. Importantly, this study highlights that nanostructure alone is not sufficient to develop a highly antimicrobial titanium substrate. A dual-action, physical and chemical antimicrobial approach is better suited to produce highly effective antibacterial and antifungal surface technologies.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2013
Publisher: Springer Science and Business Media LLC
Date: 05-2022
DOI: 10.1007/S00339-022-05599-6
Abstract: With the development of soft gripper systems, food processing, packaging, and processing technology has seen a significant advancement. The soft gripper must be protected from surface contamination and liquid lubrication hence, a hydrophobic and contamination-resistant surface is used. There is an urgent need for a soft gripper that meets the functions of hydrophobic performance and contamination resistance, but there has been little study. In this study, the two functions are well achieved by introducing a flexible superhydrophobic surface. A novel design of a flexible superhydrophobic surface-based gripper (SSBG) is proposed by the template method. After a series of testing, it was discovered that the friction coefficient between the SSBG surface and the glass plate, cardboard, and steel plate is larger than that of a standard surface gripper (SSG). At the same time, the contamination resistance of SSBG is particularly important. Because of the existence of the plastron layer, the surface was discovered to be able to repel bacterial colonization. Finally, when the usual gripping force of the SSBG is measured on a 250 ml beaker with contamination and liquid lubrication, it can be shown that the gripping ability is improved by at least 100% and 170% compared to the SSG, respectively. As a result, the SSBG has a high potential for utilization in industrial and therapeutic contexts.
Publisher: Wiley
Date: 17-06-2015
DOI: 10.1111/NPH.13524
Abstract: The health of several East Antarctic moss‐beds is declining as liquid water availability is reduced due to recent environmental changes. Consequently, a noninvasive and spatially explicit method is needed to assess the vigour of mosses spread throughout rocky Antarctic landscapes. Here, we explore the possibility of using near‐distance imaging spectroscopy for spatial assessment of moss‐bed health. Turf chlorophyll a and b , water content and leaf density were selected as quantitative stress indicators. Reflectance of three dominant Antarctic mosses Bryum pseudotriquetrum , Ceratodon purpureus and Schistidium antarctici was measured during a drought‐stress and recovery laboratory experiment and also with an imaging spectrometer outdoors on water‐deficient (stressed) and well‐watered (unstressed) moss test sites. The stress‐indicating moss traits were derived from visible and near infrared turf reflectance using a nonlinear support vector regression. Laboratory estimates of chlorophyll content and leaf density were achieved with the lowest systematic/unsystematic root mean square errors of 38.0/235.2 nmol g −1 DW and 0.8/1.6 leaves mm −1 , respectively. Subsequent combination of these indicators retrieved from field hyperspectral images produced small‐scale maps indicating relative moss vigour. Once applied and validated on remotely sensed airborne spectral images, this methodology could provide quantitative maps suitable for long‐term monitoring of Antarctic moss‐bed health.
Publisher: MDPI AG
Date: 13-04-2021
DOI: 10.3390/SU13084299
Abstract: Background: Increasing population and food consumption are placing unprecedented demands on crop production. Maize is one of the most important food crops in the world, the improvement of its yield primarily depends on the application of chemical fertilizer. Methods: Earthworm activity is an essential factor in promoting soil fertility and stimulating plant growth. Inspired by amino acids composition of earthworm (Eisenia fetida) epidermal mucus, the liquid fertilizer was developed and prepared by utilizing a bionic approach. The influence of earthworm epidermal mucus (mucus), the mucus-mimicked mixture of amino acids (bionic fertilizer) and urea fertilizer (urea) on maize emergence and growth were studied and compared with the control group (distilled water). Experimental cultivation tests were conducted. The aforementioned three types of liquid fertilizer effects on maize seed vigor index, seedling emergence rate and plant quality were quantitatively evaluated. Results: Based on the conducted research, it was found that the beneficial effects of different fertilizers for maize emergence rate were ranked as follows: mucus bionic fertilizer urea. The low concentration treatments were beneficial to the maize emergence, while the high concentration treatments were helpful to the maize growth and root development. Besides, the lower concentration of mucus was the most effective fertilizer treatment for improving seedling quality. In addition, the test results of three types of liquid fertilizer effects on maize growth indicated that the higher concentration treatments provided more nitrogen nutrition than lower concentration treatments. Furthermore, the maize stem height and diameter were significantly promoted (p 0.05) by the three types of liquid fertilizer. The beneficial influences of liquid fertilizer treatments for plant height, stem diameter, relative chlorophyll content and photosynthetic characteristic of leaves were ranked as follows: bionic fertilizer urea mucus. Conclusions: Bionic fertilizer demonstrated significant beneficial fertilizing effects (p 0.05), which increased soil nutrients, improved maize physiological parameters, promote its growth and improved dry matter accumulation. The tested results verified the effectiveness of bionic fertilizer on stimulating maize growth.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 22-02-2017
DOI: 10.1212/NXI.0000000000000334
Abstract: To trace microstructural changes in patients with aquaporin-4 antibody (AQP4-ab)-seropositive neuromyelitis optica spectrum disorders (NMOSDs) by investigating the afferent visual system in patients without clinically overt visual symptoms or visual pathway lesions. Of 51 screened patients with NMOSD from a longitudinal observational cohort study, we compared 6 AQP4-ab–seropositive NMOSD patients with longitudinally extensive transverse myelitis (LETM) but no history of optic neuritis (ON) or other bout (NMOSD-LETM) to 19 AQP4-ab–seropositive NMOSD patients with previous ON (NMOSD-ON) and 26 healthy controls (HCs). Foveal thickness (FT), peripapillary retinal nerve fiber layer (pRNFL) thickness, and ganglion cell and inner plexiform layer (GCIPL) thickness were measured with optical coherence tomography (OCT). Microstructural changes in the optic radiation (OR) were investigated using diffusion tensor imaging (DTI). Visual function was determined by high-contrast visual acuity (VA). OCT results were confirmed in a second independent cohort. FT was reduced in both patients with NMOSD-LETM ( p = 3.52e −14 ) and NMOSD-ON ( p = 1.24e −16 ) in comparison with HC. Probabilistic tractography showed fractional anisotropy reduction in the OR in patients with NMOSD-LETM ( p = 0.046) and NMOSD-ON ( p = 1.50e −5 ) compared with HC. Only patients with NMOSD-ON but not NMOSD-LETM showed neuroaxonal damage in the form of pRNFL and GCIPL thinning. VA was normal in patients with NMOSD-LETM and was not associated with OCT or DTI parameters. Patients with AQP4-ab–seropositive NMOSD without a history of ON have microstructural changes in the afferent visual system. The localization of retinal changes around the Müller-cell rich fovea supports a retinal astrocytopathy.
Publisher: American Chemical Society (ACS)
Date: 11-01-2023
Publisher: Elsevier BV
Date: 06-2019
Publisher: Wiley
Date: 31-01-2022
Abstract: Liquid metals (LMs) have emerged as novel materials for biomedical applications. Here, the interactions taking place between cells and LMs are reported, presenting a unique opportunity to explore and understand the LM‐biological interface. Several high‐resolution imaging techniques are used to characterize the interaction between droplets of gallium LM and bacterial, fungal, and mammalian cells. Adhesive interactions between cells and LM droplets are observed, causing deformation of the LM droplet surface, resulting in surface wrinkling and in some cases, breakage of the native oxide layer present on the LM droplet surface. In many instances, the cell wall deforms to intimately contact the LM droplets. Single‐cell force spectroscopy is performed to quantify the adhesion forces between cells and LM and characterize the nature of the adhesion. It is proposed that the flexible nature of the cell enables multiple adhesion sites with the LM droplets, imparting tensile forces on the LM droplet surface, which results in surface wrinkling on the LM droplets due to their liquid nature. Molecular dynamics simulations also suggest that flexible biomolecules on the cell surface can disrupt the Ga 2 O 3 layer formed at the LM droplet surface. This study reveals a unique biointerfacial interaction and provides insights into the mechanisms involved.
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.JCIS.2015.08.029
Abstract: The impact of non- and poorly wetting soils has become increasingly important, due to its direct influence on the water-limited potential yield of rain-fed grain crops at a time of enhanced global competition for fresh water. This study investigates the physical and compositional mechanisms underlying the influence of soil organic matter (SOM) on the wetting processes of model systems. These model systems are directly related to two sandy wheat-producing soils that have contrasting hydrophobicities. Atomic force microscopy (AFM), contact angle and Raman micro-spectroscopy measurements on model planar and particulate SOM-containing surfaces demonstrated the role of the hierarchical surface structure on the wetting dynamics of packed particulate beds. It was found that a nanoscale surface topology is superimposed over the microscale roughness of the packed particles, and this controls the extent of water ingress into particulate packed beds of these particles. Using two of the dominant component organic species found in the SOM of the two soils used in this study, it was found that the specific interactions taking place between the SOM components, rather than their absolute quantities, dictated the formation of highly hydrophobic surface nanotopologies. This hydrophobicity was demonstrated, using micro-Raman imaging, to arise from the surface being in a composite Cassie-Baxter wetting state. Raman imaging demonstrated that the particle surface nanotopography influenced the degree of air entrapment in the interstices within the particle bed. The influence of a conventional surfactant on the wetting kinetics of both the model planar surfaces and packed particulate beds was quantified in terms of their respective advancing contact angles and the capillary wetting force vector. The information obtained for all of the planar and particulate surfaces, together with that obtained for the two soils, allowed linear relationships to be obtained in plots of the contact angle data as a function of the wetting liquid surface tensions. These linear relationships were found to reflect the mechanisms underlying the surface energy parameter requirements for wetting.
Publisher: Springer Science and Business Media LLC
Date: 23-06-2021
DOI: 10.1038/S41467-021-23278-7
Abstract: A major health concern of the 21 st century is the rise of multi-drug resistant pathogenic microbial species. Recent technological advancements have led to considerable opportunities for low-dimensional materials (LDMs) as potential next-generation antimicrobials. LDMs have demonstrated antimicrobial behaviour towards a variety of pathogenic bacterial and fungal cells, due to their unique physicochemical properties. This review provides a critical assessment of current LDMs that have exhibited antimicrobial behaviour and their mechanism of action. Future design considerations and constraints in deploying LDMs for antimicrobial applications are discussed. It is envisioned that this review will guide future design parameters for LDM-based antimicrobial applications.
Publisher: Springer Science and Business Media LLC
Date: 19-02-2021
Publisher: MDPI AG
Date: 14-05-2012
DOI: 10.3390/RS4051392
Publisher: ACM
Date: 11-11-2014
Publisher: Elsevier BV
Date: 08-2020
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: Wiley
Date: 06-04-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TB01655A
Abstract: Broad-spectrum treatment of monoculture and mixed species biofilms using magnetically actuated, liquid metal particles.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TB00102F
Abstract: The colonisation of biomaterial surfaces by pathogenic bacteria is a significant issue of concern, particularly in light of the rapid rise of antibiotic resistance.
Publisher: MDPI AG
Date: 25-05-2021
DOI: 10.3390/NANO11061391
Abstract: Antimicrobial resistance (AMR) is predicted to soon become one of the most serious threats to human and animal health [...]
Publisher: MDPI AG
Date: 2020
Abstract: Microbial contamination remains a significant issue for many industrial, commercial, and medical applications. For instance, microbial surface contamination is detrimental to numerous aspects of food production, infection transfer, and even marine applications. As such, intense scientific interest has focused on improving the antimicrobial properties of surface coatings via both chemical and physical routes. However, there is a lack of synthetic coatings that possess long-term microbiocidal performance. In this study, silver nanoparticle cluster coatings were developed on copper surfaces via an ion-exchange and reduction reaction, followed by a silanization step. The durability of the microbiocidal activity for these develped surfaces was tested against pathogenic bacterial and fungal species, specifically Escherichia coli O157:H7 and Candida auris, over periods of 1- and 7-days. It was observed that more than 90% of E. coli and C. auris were found to be non-viable following the extended exposure times. This facile material fabrication presents as a new surface design for the production of durable microbicidal coatings which can be applied to numerous applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0AY01389G
Abstract: Chemometrics is used to analyse complex, multivariate data for environmental monitoring.
Publisher: Springer International Publishing
Date: 2015
Publisher: American Chemical Society (ACS)
Date: 21-07-2015
Abstract: Pristine graphene, its derivatives, and composites have been widely reported to possess antibacterial properties. Most of the studies simulating the interaction between bacterial cell membranes and the surface of graphene have proposed that the graphene-induced bacterial cell death is caused either by (1) the insertion of blade-like graphene-based nanosheets or (2) the destructive extraction of lipid molecules by the presence of the lipophilic graphene. These simulation studies have, however, only take into account graphene-cell membrane interactions where the graphene is in a dispersed form. In this paper, we report the antimicrobial behavior of graphene sheet surfaces in an attempt to further advance the current knowledge pertaining to graphene cytotoxicity using both experimental and computer simulation approaches. Graphene nanofilms were fabricated to exhibit different edge lengths and different angles of orientation in the graphene sheets. These substrates were placed in contact with Pseudomonas aeruginosa and Staphylococcus aureus bacteria, where it was seen that these substrates exhibited variable bactericidal efficiency toward these two pathogenic bacteria. It was demonstrated that the density of the edges of the graphene was one of the principal parameters that contributed to the antibacterial behavior of the graphene nanosheet films. The study provides both experimental and theoretical evidence that the antibacterial behavior of graphene nanosheets arises from the formation of pores in the bacterial cell wall, causing a subsequent osmotic imbalance and cell death.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.SAA.2019.117548
Abstract: Extensive research has been carried out to study and characterise different properties of alcoholic beverages using spectroscopy methods. Although UV-VIS spectroscopy is being used for the routine analysis of several beverages and foods, it has not been extensively used as a high throughput method. The objective of this study was to evaluate the application of derivatives to interrogate the UV-VIS spectra of gin s les to monitor changes related with storage conditions. S les were analysed using an UV-VIS (200-800 nm) spectrophotometer with 1 cm path length. The raw spectra, second, third and fourth derivatives were used to analyse and interpret the UV-VIS spectra related to storage conditions. The results of this study indicated that the use of derivatives (third and fourth) as pre-process method to the UV-VIS spectra of gin s les allowed for a better identification of wavelengths as well as interpretation of the spectra associated with the different storage conditions.
Publisher: MDPI AG
Date: 17-02-2021
DOI: 10.3390/IJMS22041965
Abstract: Gastrointestinal (GIT) diseases have risen globally in recent years, and early detection of the host’s gut microbiota, typically through fecal material, has become a crucial component for rapid diagnosis of such diseases. Human fecal material is a complex substance composed of undigested macromolecules and particles, and the processing of such matter is a challenge due to the unstable nature of its products and the complexity of the matrix. The identification of these products can be used as an indication for present and future diseases however, many researchers focus on one variable or marker looking for specific biomarkers of disease. Therefore, the combination of genomics, transcriptomics, proteomics and metabonomics can give a detailed and complete insight into the gut environment. The proper s le collection, s le preparation and accurate analytical methods play a crucial role in generating precise microbial data and hypotheses in gut microbiome research, as well as multivariate data analysis in determining the gut microbiome functionality in regard to diseases. This review summarizes fecal s le protocols involved in profiling coeliac disease.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2VA00059H
Abstract: GO, CuO-rGO and ZnO-rGO were tested for their ability to remove textile dyes (R-6G, MG) and antibiotics (AMOX, TC) as wastewater depollution materials. Although GO was most effective for the cationic dyes, CuO-rGO efficiently removed anionic antibiotics.
Publisher: MyJove Corporation
Date: 11-10-2016
DOI: 10.3791/54309
Publisher: MDPI AG
Date: 14-05-2019
DOI: 10.3390/MA12101575
Abstract: Biomaterials that have been newly implanted inside the body are the substratum targets for a “race for the surface”, in which bacterial cells compete against eukaryotic cells for the opportunity to colonize the surface. A victory by the former often results in biomaterial-associated infections, which can be a serious threat to patient health and can undermine the function and performance of the implant. Moreover, bacteria can often have a ‘head start’ if implant contamination has taken place either prior to or during the surgery. Current prevention and treatment strategies often rely on systemic antibiotic therapies, which are becoming increasingly ineffective due to a growing prevalence of antibiotic-resistant bacteria. Nanostructured surfaces that kill bacteria by physically rupturing bacterial cells upon contact have recently emerged as a promising solution for the mitigation of bacterial colonization of implants. Furthermore, these nanoscale features have been shown to enhance the adhesion and proliferation of eukaryotic cells, which is a key to, for ex le, the successful osseointegration of load-bearing titanium implants. The bactericidal activity and biocompatibility of such nanostructured surfaces are often, however, examined separately, and it is not clear to what extent bacterial cell-surface interactions would affect the subsequent outcomes of host-cell attachment and osseointegration processes. In this study, we investigated the ability of bactericidal nanostructured titanium surfaces to support the attachment and growth of osteoblast-like MG-63 human osteosarcoma cells, despite them having been pre-infected with pathogenic bacteria. MG-63 is a commonly used osteoblastic model to study bone cell viability, adhesion, and proliferation on the surfaces of load-bearing biomaterials, such as titanium. The nanostructured titanium surfaces used here were observed to kill the pathogenic bacteria, whilst simultaneously enhancing the growth of MG-63 cells in vitro when compared to that occurring on sterile, flat titanium surfaces. These results provide further evidence in support of nanostructured bactericidal surfaces being used as a strategy to help eukaryotic cells win the “race for the surface” against bacterial cells on implant materials.
Publisher: American Chemical Society (ACS)
Date: 04-04-2020
Publisher: Wiley
Date: 17-11-2021
Abstract: Soft devices that sense touch are important for prosthetics, soft robotics, and electronic skins. One way to sense touch is to use a capacitor consisting of a soft dielectric layer sandwiched between two electrodes. Compressing the capacitor brings the electrodes closer together and thereby increases capacitance. Ideally, sensors of touch should have both large sensitivity and the ability to measure a wide range of stress (dynamic range). Although skin has such capabilities, it remains difficult to achieve both sensitivity and dynamic range in a single manmade sensor. Inspired by skin, this work reports a soft capacitive pressure sensor based on a bilayer of liquid metal elastomer foam (B‐LMEF). The B‐LMEF consists of an elastomer slab (elastic modulus: ≈655 kPa) laminated with a soft liquid metal elastomer foam (LMEF, elastic modulus: ≈7 kPa). The LMEF deforms at small stresses ( kPa), and both layers deform at large stresses ( kPa). The B‐LMEF has high sensitivity (0.073 kPa –1 ) at small stress and can operate over a large range of stress (200 kPa), which leads to a large dynamic range (≈4.1 × 10 5 ). Additionally, the elastomer slab has a large energy dissipation coefficient the skin uses this property to cushion the human body from external stress and strain.
Publisher: SPIE
Date: 25-10-2016
DOI: 10.1117/12.2241289
Publisher: MDPI AG
Date: 17-09-2015
DOI: 10.3390/RS70911933
Publisher: Wiley
Date: 25-11-2022
Abstract: The need for novel antimicrobial agents in response to a growing antibiotic and antimicrobial resistance crisis is now at a breaking point. In this work, the use of 5 nm zinc oxide quantum dots (ZnO QDs), demonstrating rapid and high antimicrobial activity against Gram‐positive methicillin‐resistant Staphylococcus aureus and highly pathogenic yeast Candida auris cells under both non‐photocatalytic and photocatalytic conditions, is showcased. Results show ZnO QDs adhere and cluster around the microbial cell surfaces, and exhibit antimicrobial response toward attached cells, resulting in the cell membrane damage. With the introduction of ultraviolet‐A light, autogenous reactive oxygen species (ROS) are produced and caused further increase in cell membrane/wall disruption, in particular Gram‐negative Escherichia coli . Nanoscale Fourier transform infrared is used to further confirm the intrinsic biochemical changes that occur with the Gram‐negative cell membrane within 30 min and spectra demonstrate that biochemical alterations are achieved for the protein and carbohydrate component of the membrane, which is a common mechanism of ROS damage. Investigation of the cell membrane–material interaction and mechanism is crucial in developing and optimizing effective antimicrobial materials in combating the rise of antimicrobial resistance.
Publisher: American Chemical Society (ACS)
Date: 27-02-2020
Publisher: MDPI AG
Date: 14-09-2021
DOI: 10.3390/APP11188547
Abstract: Octopus cyanea has a wide range of natural distribution and is interesting for scientific research. However, unlike Octopus vulgaris, the species is poorly studied, and few data exist on best practices for keeping them. One of the most common reasons for losing octopuses in human care is their ability to escape from holding tanks. Adult Octopus cyanea (n = 33) were locally collected in Okinawa throughout the year. All animals were housed at the laboratory facilities at the Marine Station of the Okinawa institute of Science and Technology. Animals were kept in a flow-through saltwater system in three different types of holding tanks ranging from 550 L to 600 L tanks or in 2000 L tanks, all with an environment enriched with clay pots or natural rocks as dens. They were fed a daily diet of dead fish or live or dead crustaceans ad libitum. To characterize the effectiveness of different keeping conditions, we compared escape attempts and non-natural deaths during the animals’ time under human care. We found that two types of tanks, the 600 L transparent acrylic glass tanks with weighted lids and the 2000 L tanks with synthetic grass lined walls, had significantly fewer escapes than the 550 L tanks.
Publisher: American Chemical Society (ACS)
Date: 04-05-2020
Publisher: Portland Press Ltd.
Date: 10-09-2020
DOI: 10.1042/BCJ20200454
Abstract: Immunotherapy has been successful in treating many tumour types. The development of additional tumour-antigen binding monoclonal antibodies (mAbs) will help expand the range of immunotherapeutic targets. Lewis histo-blood group and related glycans are overexpressed on many carcinomas, including those of the colon, lung, breast, prostate and ovary, and can therefore be selectively targeted by mAbs. Here we examine the molecular and structural basis for recognition of extended Lea and Lex containing glycans by a chimeric mAb. Both the murine (FG88.2) IgG3 and a chimeric (ch88.2) IgG1 mAb variants showed reactivity to colorectal cancer cells leading to significantly reduced cell viability. We determined the X-ray structure of the unliganded ch88.2 fragment antigen-binding (Fab) containing two Fabs in the unit cell. A combination of molecular docking, glycan grafting and molecular dynamics simulations predicts two distinct subsites for recognition of Lea and Lex trisaccharides. While light chain residues were exclusively used for Lea binding, recognition of Lex involved both light and heavy chain residues. An extended groove is predicted to accommodate the Lea–Lex hexasaccharide with adjoining subsites for each trisaccharide. The molecular and structural details of the ch88.2 mAb presented here provide insight into its cross-reactivity for various Lea and Lex containing glycans. Furthermore, the predicted interactions with extended epitopes likely explains the selectivity of this antibody for targeting Lewis-positive tumours.
Publisher: Elsevier BV
Date: 11-2012
DOI: 10.1016/J.CIS.2012.06.015
Abstract: Substratum surface roughness is known to be one of the key factors in determining the extent of bacterial colonization. Understanding the way by which the substratum topography, especially at the nanoscale, mediates bacterial attachment remains ambiguous at best, despite the volume of work available on the topic. This is because the vast majority of bacterial attachment studies do not perform comprehensive topographical characterization analyses, and typically consider roughness parameters that describe only one aspect of the surface topography. The most commonly reported surface roughness parameters are average and root mean square (RMS) roughness (R(a) and R(q) respectively), which are both measures of the typical height variation of the surface. They offer no insights into the spatial distribution or shape of the surface features. Here, a brief overview of the current state of research on topography-mediated bacterial adhesion is presented, as well as an outline of the suite of roughness characterization parameters that are available for the comprehensive description of the surface architecture of a substratum. Finally, a set of topographical parameters is proposed as a new standard for surface roughness characterization in bacterial adhesion studies to improve the likelihood of identifying direct relationships between substratum topography and the extent of bacterial adhesion.
Publisher: Elsevier BV
Date: 03-2022
Publisher: ACM
Date: 02-12-2014
Publisher: Elsevier BV
Date: 10-2012
Publisher: Informa UK Limited
Date: 20-08-2009
Publisher: Elsevier BV
Date: 2023
Publisher: Public Library of Science (PLoS)
Date: 09-07-2013
Publisher: Elsevier BV
Date: 04-2019
Publisher: Copernicus GmbH
Date: 08-2012
DOI: 10.5194/ISPRSARCHIVES-XXXIX-B7-499-2012
Abstract: Abstract. Airborne LiDAR data has become an important tool for both the scientific and industry based investigation of forest structure. The uses of discrete return observations have now reached a maturity level such that the operational use of this data is becoming increasingly common. However, due to the cost of data collection, temporal studies into forest change are often not feasible or completed at infrequent and at uneven intervals. To achieve high resolution temporal LiDAR surveys, this study has developed a micro-Unmanned Aerial Vehicle (UAV) equipped with a discrete return 4-layer LiDAR device and miniaturised positioning sensors. This UAV has been designed to be low-cost and to achieve maximum flying time. In order to achieve these objectives and overcome the accuracy restrictions presented by miniaturised sensors a novel processing strategy based on a Kalman smoother algorithm has been developed. This strategy includes the use of the structure from motion algorithm in estimating camera orientation, which is then used to restrain IMU drift. The feasibility of such a platform for monitoring forest change is shown by demonstrating that the pointing accuracy of this UAV LiDAR device is within the accuracy requirements set out by the Australian Intergovernmental Committee on Surveying and Mapping (ICSM) standards.
Publisher: Wiley
Date: 13-02-2012
DOI: 10.1002/SCA.21002
Abstract: The nanoarchitecture and surface roughness of metallic thin films prepared by magnetron sputtering were analyzed to determine the topographical statistics that give the optimum description of their nanoarchitechture. Nanoscale topographical profiles were generated by performing atomic force microscopy (AFM) scans of 1 μm × 1 μm areas of titanium and silver films of three different thicknesses (3 nm, 12 nm, and 150 nm). Of the titanium films, the 150-nm film had the highest average roughness (R(a) = 2.63 nm), more than four times that of the 3-nm and 12-nm titanium films. When silver films were coated on top of 150-nm titanium films, the average roughness increased further the 3-nm (R(a) = 4.96 nm) and 150-nm (R(a) = 4.65 nm) silver films average roughnesses were approximately twice that of the 150-nm titanium film. For topographical analysis, seven statistical parameters were calculated. These parameters included commonly used roughness measurements, as well as some less commonly used measurements, in order to determine which combination of parameters gave the best overall description of the nanoarchitecture of the films presented. Skewness (R(skw)), surface area increase (R(sa)), and peak counts (R(pc)) provided the best description of horizontal surface dimensions, and in conjunction with vertical descriptors R(a) and R(q) gave the best characterization of surface architecture. The five roughness parameters R(a), R(q), R(skw), R(sa), and R(pc) are proposed as a new standard for describing surface nanoarchitecture.
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3MA00222E
Abstract: Polyurethane acrylate film with hierarchical surface structures produced using UV-imprinting followed by a hydrothermal method for antibacterial applications.
Publisher: American Chemical Society (ACS)
Date: 10-01-2020
Abstract: Antibiotic resistance has made the treatment of biofilm-related infections challenging. As such, the quest for next-generation antimicrobial technologies must focus on targeted therapies to which pathogenic bacteria cannot develop resistance. Stimuli-responsive therapies represent an alternative technological focus due to their capability of delivering targeted treatment. This study provides a proof-of-concept investigation into the use of magneto-responsive gallium-based liquid metal (LM) droplets as antibacterial materials, which can physically damage, disintegrate, and kill pathogens within a mature biofilm. Once exposed to a low-intensity rotating magnetic field, the LM droplets become physically actuated and transform their shape, developing sharp edges. When placed in contact with a bacterial biofilm, the movement of the particles resulting from the magnetic field, coupled with the presence of nanosharp edges, physically ruptures the bacterial cells and the dense biofilm matrix is broken down. The antibacterial efficacy of the magnetically activated LM particles was assessed against both Gram-positive and Gram-negative bacterial biofilms. After 90 min over 99% of both bacterial species became nonviable, and the destruction of the biofilms was observed. These results will impact the design of next-generation, LM-based biofilm treatments.
Publisher: Wiley
Date: 25-02-2023
Abstract: Thin film transistors (TFTs) are key components for the fabrication of electronic and optoelectronic devices, resulting in a push for the wider exploration of semiconducting materials and cost‐effective synthesis processes. In this report, a simple approach is proposed to achieve 2‐nm‐thick indium oxide nanosheets from liquid metal surfaces by employing a squeeze printing technique and thermal annealing at 250 °C in air. The resulting materials exhibit a high degree of transparency ( %) and an excellent electron mobility of ≈96 cm 2 V −1 s −1 , surpassing that of pristine printed 2D In 2 O 3 and many other reported 2D semiconductors. UV‐detectors based on annealed 2D In 2 O 3 also benefit from this process step, with the photoresponsivity reaching 5.2 × 10 4 and 9.4 × 10 3 A W −1 at the wavelengths of 285 and 365 nm, respectively. These values are an order of magnitude higher than for as‐synthesized 2D In 2 O 3 . Utilizing transmission electron microscopy with in situ annealing, it is demonstrated that the improvement in device performances is due to nanostructural changes within the oxide layers during annealing process. This work highlights a facile and ambient air compatible method for fabricating high‐quality semiconducting oxides, which will find application in emerging transparent electronics and optoelectronics.
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.JCIS.2018.10.059
Abstract: The interface between water and a textured hydrophobic surface can exist in two regimes either the Wenzel (surface-engulfed) or Cassie-Baxter (water-suspended) state. Better understanding of the influence of pattern geometry and spacing is crucial for the design of functional (super)hydrophobic surfaces, as inspired by numerous ex les in nature. In this work, we have employed litude modulated - atomic force microscopy to visualize the air-water interface with an unprecedented degree of clarity on a superhydrophobic and a highly hydrophobic nanostructured surface. The images obtained provide the first real-time experimental visualization of the Cassie-Baxter wetting on the surface of biomimetic silicon nanopillars and a naturally superhydrophobic cicada wing. For both surfaces, the air-water interface was found to be remarkably well-defined, revealing a distinctly nanostructured air-water interface in the interstitial spacing. The degree of interfacial texture differed as a function of surface geometry. These results reveal that the air-water interface is heterogeneous in its structure and confirmed the presence of short-range interfacial ordering. Additionally, the overpressure values for each point on the interface were calculated, quantifying the difference in wetting behavior for the biomimetic and natural surface. Results suggest that highly-ordered, closely spaced nanofeatures facilitate robust Cassie-Baxter wetting states and therefore, can enhance the stability of (super)hydrophobic surfaces.
Publisher: ACM
Date: 28-11-2011
Publisher: Wiley
Date: 27-03-2014
DOI: 10.1002/ROB.21508
Publisher: Wiley
Date: 06-05-2015
Publisher: Public Library of Science (PLoS)
Date: 18-12-2017
Publisher: American Chemical Society (ACS)
Date: 11-08-2023
Publisher: Elsevier BV
Date: 06-2022
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: Elsevier BV
Date: 03-2020
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: American Chemical Society (ACS)
Date: 11-2022
Publisher: American Chemical Society (ACS)
Date: 18-11-2019
Abstract: The resistance of pathogenic bacteria toward traditional biocidal treatment methods is a growing concern in various settings, including that of water treatment and in the medical industry. As such, advanced antibacterial technologies are needed to prevent infections, against which current antibiotics are failing. This study introduces copper oxide nanoparticles (CuONPs) doped in graphene oxide (GO) as a potential pathogenic bacterial treatment. The aim of the study was to evaluate the antibacterial properties of the GO-CuONP hybridized material against pathogenic
Publisher: Springer Science and Business Media LLC
Date: 05-12-2020
Publisher: MDPI AG
Date: 18-05-2012
DOI: 10.3390/RS4051462
Publisher: Elsevier BV
Date: 06-2010
Publisher: MDPI AG
Date: 02-05-2014
DOI: 10.3390/RS6054003
Publisher: MDPI AG
Date: 02-02-2021
Abstract: Electrically conductive hydrogels (ECHs), an emerging class of biomaterials, have garnered tremendous attention due to their potential for a wide variety of biomedical applications, from tissue-engineered scaffolds to smart bioelectronics. Along with the development of new hydrogel systems, 3D printing of such ECHs is one of the most advanced approaches towards rapid fabrication of future biomedical implants and devices with versatile designs and tuneable functionalities. In this review, an overview of the state-of-the-art 3D printed ECHs comprising conductive polymers (polythiophene, polyaniline and polypyrrole) and/or conductive fillers (graphene, MXenes and liquid metals) is provided, with an insight into mechanisms of electrical conductivity and design considerations for tuneable physiochemical properties and biocompatibility. Recent advances in the formulation of 3D printable bioinks and their practical applications are discussed current challenges and limitations of 3D printing of ECHs are identified new 3D printing-based hybrid methods for selective deposition and fabrication of controlled nanostructures are highlighted and finally, future directions are proposed.
Publisher: Copernicus GmbH
Date: 08-2012
DOI: 10.5194/ISPRSARCHIVES-XXXIX-B7-475-2012
Abstract: Abstract. Low-cost Unmanned Aerial Vehicles (UAVs) are becoming viable environmental remote sensing tools. Sensor and battery technology is expanding the data capture opportunities. The UAV, as a close range remote sensing platform, can capture high resolution photography on-demand. This imagery can be used to produce dense point clouds using multi-view stereopsis techniques (MVS) combining computer vision and photogrammetry. This study examines point clouds produced using MVS techniques applied to UAV and terrestrial photography. A multi-rotor micro UAV acquired aerial imagery from a altitude of approximately 30–40 m. The point clouds produced are extremely dense ( –3 cm point spacing) and provide a detailed record of the surface in the study area, a 70 m section of sheltered coastline in southeast Tasmania. Areas with little surface texture were not well captured, similarly, areas with complex geometry such as grass tussocks and woody scrub were not well mapped. The process fails to penetrate vegetation, but extracts very detailed terrain in unvegetated areas. Initially the point clouds are in an arbitrary coordinate system and need to be georeferenced. A Helmert transformation is applied based on matching ground control points (GCPs) identified in the point clouds to GCPs surveying with differential GPS. These point clouds can be used, alongside laser scanning and more traditional techniques, to provide very detailed and precise representations of a range of landscapes at key moments. There are many potential applications for the UAV-MVS technique, including coastal erosion and accretion monitoring, mine surveying and other environmental monitoring applications. For the generated point clouds to be used in spatial applications they need to be converted to surface models that reduce dataset size without loosing too much detail. Triangulated meshes are one option, another is Poisson Surface Reconstruction. This latter option makes use of point normal data and produces a surface representation at greater detail than previously obtainable. This study will visualise and compare the two surface representations by comparing clouds created from terrestrial MVS (T-MVS) and UAV-MVS.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier
Date: 2020
Publisher: Elsevier
Date: 2019
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JCIS.2019.10.067
Abstract: Titanium and titanium alloys are often the most popular choice of material for the manufacture of medical implants however, they remain susceptible to the risk of device-related infection caused by the presence of pathogenic bacteria. Hydrothermal etching of titanium surfaces, to produce random nanosheet topologies, has shown remarkable ability to inactivate pathogenic bacteria via a physical mechanism. We expect that systematic tuning of the nanosheet morphology by controlling fabrication parameters, such as etching time, will allow for optimisation of the surface pattern for superior antibacterial efficacy. Using time-dependent hydrothermal processing of bulk titanium, we fabricated bactericidal nanosheets with variable nanoedge morphologies according to a function of etching time. A systematic study was performed to compare the bactericidal efficiency of nanostructured titanium surfaces produced at 0.5, 1, 2, 3, 4, 5, 6, 24 and 60 h of hydrothermal etching. Titanium surfaces hydrothermally treated for a period of 6 h were found to achieve maximal antibacterial efficiency of 99 ± 3% against Gram-negative Pseudomonas aeruginosa and 90 ± 9% against Gram-positive Staphylococcus aureus bacteria, two common human pathogens. These surfaces exhibited nanosheets with sharp edges of approximately 10 nm. The nanotopographies presented in this work exhibit the most efficient mechano-bactericidal activity against both Gram-negative and Gram-positive bacteria of any nanostructured titanium topography reported thus far.
Publisher: Wiley
Date: 15-12-2021
DOI: 10.1002/JBM.B.34987
Abstract: Gallium and its alloys, such as eutectic gallium indium alloy (EGaIn), a form of liquid metal, have recently attracted the attention of researchers due to their low toxicity and electrical and thermal conductivity for biomedical application. However, further research is required to harness EGaIn‐composites advantages and address their application as a biomedical scaffold. In this research, EGaIn‐polylactic acid olycaprolactone composites with and without a second conductive filler, MXene, were prepared and characterized. The addition of MXene, into the EGaIn‐composite, can improve the composite's electrochemical properties by connecting the liquid metal droplets resulting in electrically conductive continuous pathways within the polymeric matrix. The results showed that the composite with 50% EGaIn and 4% MXene, displayed optimal electrochemical properties and enhanced mechanical and radiopacity properties. Furthermore, the composite showed good biocompatibility, examined through interactions with fibroblast cells, and antibacterial properties against methicillin‐resistant Staphylococcus aureus . Therefore, the liquid metal (EGaIn) polymer composite with MXene provides a first proof‐of‐concept engineering scaffold strategy with low toxicity, functional electrochemical properties, and promising antimicrobial properties.
Publisher: MDPI AG
Date: 28-01-2011
DOI: 10.3390/POLYM3010388
Publisher: Proceedings of the National Academy of Sciences
Date: 26-05-2020
Abstract: The bactericidal action delivered by rigid nanopillar arrays stems from the mechanical rupture of the bacterial cell membrane however, the precise mechanism may be unique to the in idual nanopillar geometries. In this study, we demonstrate that the bactericidal action of highly ordered, high-aspect-ratio nanopillar arrays may be associated with the relative flexibility of the in idual nanopillars and the mechanical energy stored within the nanopillars. We propose that the lateral stretching of the cell membrane and interactions at the cell edge are induced by elastic pillar deformations that occur during bacterial adhesion. The results obtained in this study provide insight into a previously unknown category of mechano-bactericidal mechanism, highlighting another facet to the mechano-bactericidal action of nanostructured surfaces.
Publisher: Elsevier BV
Date: 04-2014
Publisher: MDPI AG
Date: 09-12-2022
Abstract: In this study, a eutectic gallium–indium (EGaIn) alloy and graphene nanoplatelets (GnPs) were employed as reinforcements for a comonomer vinyl ester (cVE) resin at different weight fractions up to 2% via a direct polymerization process. First, the effect of EGaIn on the curing kinetics of cVE was evaluated. The thermal and mechanical properties, and the fracture toughness of two types of cVE composites consisting of EGaIn and GnPs were then studied. The results showed that sub-micron sized EGaIn (≤1 wt.%) could promote the curing reaction of cVE without changing the curing mechanism. However, with further increases in EGaIn loading between 1 and 2 wt.%, the curing reaction rate tends to decrease. Both EGaIn and GnPs showed a significant enhancement in strengthening and toughening the cVE matrix with the presence of filler loading up to 1 wt.%. EGaIn was more effective than GnPs in promoting the flexural and impact strength. An increase of up to 50% and 32% were recorded for these mechanical properties, when EGaln was used, as compared to 46%, and 18% for GnPs, respectively. In contrast, the GnPs/cVE composites exhibited a greater improvement in the fracture toughness and fracture energy by up to 50% and 56% in comparison with those of the EGaIn/cVE ones by up to 32% and 39%, respectively. Furthermore, the stiffness of both the EgaIn/cVE and GnPs/cVE composites showed a significant improvement with an increase of up to 1.76 and 1.83 times in the normalized storage modulus, respectively, while the glass transition temperature (Tg) values remained relatively constant. This work highlights the potential of EGaIn being employed as a filler in creating high-performance thermoset composites, which facilitates its widening applications in many structural and engineering fields, where both higher toughness and stiffness are required.
Publisher: Elsevier BV
Date: 08-2019
Publisher: Wiley
Date: 06-07-2020
Abstract: Soft, capacitive tactile (pressure) sensors are important for applications including human–machine interfaces, soft robots, and electronic skins. Such capacitors consist of two electrodes separated by a soft dielectric. Pressing the capacitor brings the electrodes closer together and thereby increases capacitance. Thus, sensitivity to a given force is maximized by using dielectric materials that are soft and have a high dielectric constant, yet such properties are often in conflict with each other. Here, a liquid metal elastomer foam (LMEF) is introduced that is extremely soft (elastic modulus 7.8 kPa), highly compressible (70% strain), and has a high permittivity. Compressing the LMEF displaces the air in the foam structure, increasing the permittivity over a large range (5.6–11.7). This is called “positive piezopermittivity.” Interestingly, it is discovered that the permittivity of such materials decreases (“negative piezopermittivity”) when compressed to large strain due to the geometric deformation of the liquid metal droplets. This mechanism is theoretically confirmed via electromagnetic theory, and finite element simulation. Using these materials, a soft tactile sensor with high sensitivity, high initial capacitance, and large capacitance change is demonstrated. In addition, a tactile sensor powered wirelessly (from 3 m away) with high power conversion efficiency (84%) is demonstrated.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 2023
Publisher: Copernicus GmbH
Date: 24-07-2012
DOI: 10.5194/ISPRSARCHIVES-XXXIX-B1-393-2012
Abstract: Abstract. The increased availability of unmanned aerial vehicles (UAVs) has resulted in their frequent adoption for a growing range of remote sensing tasks which include precision agriculture, vegetation surveying and fine-scale topographic mapping. The development and utilisation of UAV platforms requires broad technical skills covering the three major facets of remote sensing: data acquisition, data post-processing, and image analysis. In this study, UAV image data acquired by a miniature 6-band multispectral imaging sensor was corrected and calibrated using practical image-based data post-processing techniques. Data correction techniques included dark offset subtraction to reduce sensor noise, flat-field derived per-pixel look-up-tables to correct vignetting, and implementation of the Brown- Conrady model to correct lens distortion. Radiometric calibration was conducted with an image-based empirical line model using pseudo-invariant features (PIFs). Sensor corrections and radiometric calibration improve the quality of the data, aiding quantitative analysis and generating consistency with other calibrated datasets.
Publisher: Elsevier
Date: 2022
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.ACTBIO.2010.09.033
Abstract: Commercial purity titanium with an average grain size in the low sub-micron range was produced by equal channel angular pressing (ECAP). Attachment of human bone marrow-derived mesenchymal stem cells (hMSCs) to the surface of conventional coarse grained and ECAP-modified titanium was studied. It was demonstrated that the attachment and spreading of hMSCs in the initial stages (up to 24h) of culture was enhanced by grain refinement. Surface characterization by a range of techniques showed that the main factor responsible for the observed acceleration of hMSC attachment and spreading on titanium due to grain refinement in the bulk is the attendant changes in surface topography on the nanoscale. These results indicate that, in addition to its superior mechanical properties, ECAP-modified titanium possesses improved biocompatibility, which makes it to a potent candidate for applications in medical implants.
Publisher: American Chemical Society (ACS)
Date: 28-07-2023
Publisher: American Chemical Society (ACS)
Date: 18-07-2022
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 08-2009
Publisher: SAGE Publications
Date: 2022
DOI: 10.1177/17455057221142698
Abstract: Research into how medical schools support students who are pregnant or with current parental responsibilities has been mostly limited to the US context. To review pregnancy and parental leave policies for students at Australian/New Zealand medical schools. A cross-sectional survey. Data were collected between June and September 2021. Websites of Australian/New Zealand medical schools (n = 23) were searched for freely available information on pregnancy and parental leave policies. Each school was contacted to provide supplementary information on the processes to support students who apply for pregnancy and/or parental leave. Outcome harvesting techniques were used to analyse the key attributes and processes used by medical schools. None of the 23 accredited Australian/New Zealand medical schools had specific pregnancy and/or parental leave policies. Fourteen of the 23 Australian/New Zealand medical schools responded to the request for more information. All confirmed, beyond their University’s general student leave policies, they had no additional pregnancy and parental leave policy. Analysis of each school’s processes identified the following themes: lack of school specific pregnancy and/or parental leave policies lack of public statements of support for medical students who are pregnant and/or with current parental responsibilities and lack of attention to the specific needs of medical students who are pregnant and/or with current parental responsibilities, including those with pregnant partners or are a birth support person. There was a lack of documentation and formalized processes related to the support of this group of students. By creating easily accessible information on pregnancy and parental leave which is nuanced to the challenges of medical school and clinical placements, medical schools and medical education accreditation bodies in Australia/New Zealand can address the needs of medical students who are pregnant and/or with current parental responsibilities and normalize pregnancy and parental status within entry-to-practice medical courses.
Publisher: Elsevier BV
Date: 06-2021
Publisher: American Chemical Society (ACS)
Date: 14-12-2022
DOI: 10.1021/ACS.BIOMAC.1C01386
Abstract: We report on the formation of counterpropagating density gradients in poly([2-dimethylaminoethyl] methacrylate) (PDMAEMA) brushes featuring spatially varying quaternized and betainized units. Starting with PDMAEMA brushes with constant grafting density and degree of polymerization, we first generate a density gradient of quaternized units by directional vapor reaction involving methyl iodide. The unreacted DMAEMA units are then betainized through gaseous-phase betainization with 1,3-propanesultone. The gas reaction of PDMAEMA with 1,3-propanesultone eliminates the formation of byproducts present during the liquid-phase modification. We use the counterpropagating density gradients of quaternized and betainized PDMAEMA brushes in antibacterial and antifouling studies. Completely quaternized and betainized brushes exhibit antibacterial and antifouling behaviors. S les containing 12% of quaternized and 85% of betainized units act simultaneously as antibacterial and antifouling surfaces.
Publisher: Elsevier BV
Date: 06-2010
Publisher: Oxford University Press (OUP)
Date: 09-09-2016
DOI: 10.1093/JPE/RTV056
Publisher: MDPI AG
Date: 09-08-2019
DOI: 10.3390/APP9163254
Abstract: The definition of the optimal temperature and its effects (either increasing or variations) during analysis of alcoholic beverages are of importance to develop protocols based in spectroscopy. Although several reports have been published on the use of spectroscopy combined with chemometrics to classify and authenticate alcoholic beverages (e.g., wine, tequila, whisky), few reports deal with issues related with the spectra collection (e.g., temperature, path length) and its effect on the classification performances. The objective of this study was to evaluate the effect of increasing temperature on both the UV-VIS spectra of whisky and on the classification results of the s les according to country of origin. Whisky s les from different commercial labels were analysed at different temperatures (25, 35, 45, 55 °C) using a UV-VIS instrument (Agilent, Cary 3500). Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) models based in cross validation were used to classify whisky s les according to scanning temperature and origin. The results of this study indicated that temperature did not affect the classification of whisky s les according to country of origin. Overall, well defined protocols need to be defined for routine use of these methods in research and by the industry.
Publisher: Informa UK Limited
Date: 06-01-2021
DOI: 10.1080/10408398.2020.1863328
Abstract: By 2050, the global population is projected to be in excess of nine billion people. This will result in an increased burden and stress on the food production systems, particularly in adjustments to several stages of the value chain that will require improvements and/or modifications in their effectiveness such as reducing waste, adapting to climate change, food security, and health. Disruptions such as digital agriculture, digital food, food agility, big data, have been utilized to characterize the changes in the way agro-food systems evolve and function, as well as in the approach they have been analyzed, measured, and monitored. It has been long recognized that the food industry is considered as a data driven enterprise. These characteristics are very important as the food industry becomes global and sustainable. The food industry is currently undergoing significant changes, and with this, challenges are occurring. These challenges are brought about from the food chains, climate changes, and the ability to be resilient in the production of food. Furthermore, health and cultural changes to food are occurring, where the diseases of obesity, diabetes, and aging in the population will continue to change the consumer's patterns and choices whereby the consumer will be persuaded to choose and eat healthy and more nutritious foods. Indeed, the cultural awareness and social innovation to prevent food waste and therefore improve food security and sustainability will also prove to further complexities. This short review will briefly discuss some of the forefront issues in food value chains with a focus on using technology.
Publisher: Informa UK Limited
Date: 20-08-2009
Publisher: MDPI AG
Date: 07-03-2016
DOI: 10.3390/F7030062
Publisher: American Geophysical Union (AGU)
Date: 19-01-2016
DOI: 10.1029/2016EO043673
Abstract: As climate change reshapes the Earth's polar regions, scientists turn to drone-mounted cameras to measure sea ice. One expedition found out that flying drones near Antarctica isn't easy.
Publisher: MDPI AG
Date: 14-05-2019
DOI: 10.3390/FOODS8050164
Abstract: There is no doubt that the current knowledge in chemistry, biochemistry, biology, and mathematics have led to advances in our understanding about food and food systems. However, the so-called reductionist approach has dominated food research, hindering new developments and innovation in the field. In the last three decades, food science has moved into the digital and technological era, inducing several challenges resulting from the use of modern instrumental techniques, computing and algorithms incorporated to the exploration, mining, and description of data derived from this complexity. In this environment, food scientists need to be mindful of the issues (advantages and disadvantages) involved in the routine applications of chemometrics. The objective of this opinion paper is to give an overview of the key issues associated with the implementation of chemometrics in food research and development. Please note that specifics about the different methodologies and techniques are beyond the scope of this review.
Publisher: American Chemical Society (ACS)
Date: 05-06-2018
Publisher: American Chemical Society (ACS)
Date: 11-01-2023
Publisher: American Chemical Society (ACS)
Date: 07-09-2021
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 08-2014
Publisher: MDPI AG
Date: 05-02-2015
DOI: 10.3390/RS70201736
Publisher: Wiley
Date: 13-08-2015
Abstract: Fibrillar forms of the Amyloid-β (Aβ) protein have been implicated in the early stages of Alzheimer's disease (AD), however there are no standardised assays for soluble Aβ oligomer biomarkers that provide the best indication of the disease progression [1,2]. As a step towards a fast and label-free method for testing different AD biomarkers, we have combined laser nano-textured substrates with a SERS mapping technique and validated it using soluble Aβ-40 oligomers [3-5]. The nano-textured SERS substrates provide fast ( min), label-free spectra associated with soluble Aβ-40 oligomers down to a concentration of 10 nM. Statistical analysis of the spectral intensities mapped over the substrate surface shows a quantitative correlation with the oligomer concentration. Schematics of experiments: SERS mapping of Aβ-40 (left figure: measured SERS intensity overlayed with an SEM image of ripples) was carried out on the laser nano-textured (ripple) surface of sapphire and statistical analysis of the SERS intensity was carried out for qualitative (a high SERS intensity at low probability) and quantitative (a moderate SERS intenisty at the highest probability) measures. Quantitative statistical analysis of SERS mapping data can be performed off line for cross correlations with other known SERS signatures.
Publisher: Public Library of Science (PLoS)
Date: 05-08-2013
Publisher: Wiley
Date: 14-07-2022
Abstract: Wide bandgap semiconducting oxides are emerging as potential 2D materials for transparent electronics and optoelectronics. This fuels the quest for discovering new 2D metal oxides with ultrahigh transparency and high mobility. While the former can be achieved by reducing the thickness of oxide films to only a few nanometers, the latter is more commonly realized by intentional doping. This article reports a one‐step synthesis of few‐unit‐cell‐thick and laterally large antimony‐doped indium oxide (IAO). The doping process occurs spontaneously when the oxide is grown on the surface of a molten Sb–In alloy and 2D IAO nanosheets can be easily printed onto desired substrates. With thicknesses at the atomic scale, these materials exhibit excellent transparency exceeding 98% across the visible and near‐infrared range. Field‐effect transistors based on low‐doped IAO nanosheets reveal a high electron mobility of ≈40 cm 2 V −1 s −1 . Additionally, a notable photoresponse is observed in 2D IAO‐based photodetectors under ultraviolet (UV) radiation. Photoresponsivities of low‐doped and highly doped IAO at a wavelength of 285 nm are found to be 1.2 × 10 3 and 0.7 × 10 3 A W −1 , respectively, identifying these materials as promising candidates for the fabrication of high‐performance optoelectronics in the UV region.
Publisher: American Chemical Society (ACS)
Date: 20-06-2023
Publisher: Public Library of Science (PLoS)
Date: 17-10-2019
Publisher: IEEE
Date: 07-2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TC01937F
Abstract: Liquid metal chemistry offers a new pathway towards the creation of functional 2D metal oxysulfides.
Publisher: Springer Science and Business Media LLC
Date: 21-02-2022
DOI: 10.1038/S41563-022-01195-4
Abstract: Ionogels are compelling materials for technological devices due to their excellent ionic conductivity, thermal and electrochemical stability, and non-volatility. However, most existing ionogels suffer from low strength and toughness. Here, we report a simple one-step method to achieve ultra-tough and stretchable ionogels by randomly copolymerizing two common monomers with distinct solubility of the corresponding polymers in an ionic liquid. Copolymerization of acrylamide and acrylic acid in 1-ethyl-3-methylimidazolium ethyl sulfate results in a macroscopically homogeneous covalent network with in situ phase separation: a polymer-rich phase with hydrogen bonds that dissipate energy and toughen the ionogel and an elastic solvent-rich phase that enables for large strain. These ionogels have high fracture strength (12.6 MPa), fracture energy (~24 kJ m
Publisher: Wiley
Date: 21-01-2021
DOI: 10.1002/BIT.27664
Abstract: UV‐visible spectroscopy (UV‐Vis) is routinely used in microbiology as a tool to check the optical density (OD) pertaining to the growth stages of microbial cultures at the single wavelength of 600 nm, better known as the OD 600 . Typically, modern UV‐Vis spectrophotometers can scan in the region of approximately 200–1000 nm in the electromagnetic spectrum, where users do not extend the use of the instrument's full capability in a laboratory. In this study, the full potential of UV‐Vis spectrophotometry (multiwavelength collection) was used to examine bacterial growth phases when treated with antibiotics showcasing the ability to understand the point of resistance when an antibiotic is introduced into the media and therefore understand the biochemical changes of the infectious pathogens. A multiplate reader demonstrated a high throughput experiment (96 s les) to understand the growth of Escherichia coli when varied concentrations of the antibiotic tetracycline was added into the well plates. Principal component analysis (PCA) and partial least squares discriminant analysis were then used as the data mining techniques to interpret the UV‐Vis spectral data and generate machine learning “proof of principle” for the UV‐Vis spectrophotometer plate reader. Results from this study showed that the PCA analysis provides an accurate yet simple visual classification and the recognition of E. coli s les belonging to each treatment. These data show significant advantages when compared to the traditional OD 600 method where we can now understand biochemical changes in the system rather than a mere optical density measurement. Due to the unique experimental setup and procedure that involves indirect use of antibiotics, the same test could be used for obtaining practical information on the type, resistance, and dose of antibiotic necessary to establish the optimum diagnosis, treatment, and decontamination strategies for pathogenic and antibiotic resistant species.
Publisher: American Chemical Society (ACS)
Date: 20-11-2017
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.ACTBIO.2017.07.004
Abstract: The wings of insects such as cicadas and dragonflies have been found to possess nanostructure arrays that are assembled from fatty acids. These arrays can physically interact with the bacterial cell membranes, leading to the death of the cell. Such mechanobactericidal surfaces are of significant interest, as they can kill bacteria without the need for antibacterial chemicals. Here, we report on the bactericidal effect of two of the main lipid components of the insect wing epicuticle, palmitic (C16) and stearic (C18) fatty acids. Films of these fatty acids were re-crystallised on the surface of highly ordered pyrolytic graphite. It appeared that the presence of two additional CH Nanostructured cicada and dragonfly wing surfaces have been discovered to be able physically kill bacterial cells. Here, we report on the successful fabrication of bactericidal three-dimensional structures of two main lipid components of the epicuticle of insect wings, palmitic (C16) and stearic (C18) acids. After crystallisation onto highly ordered pyrolytic graphite, both the palmitic and stearic acid films displayed bactericidal activity against both Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus cells. The simplicity of the production of these microcrystallite interfaces suggests that a fabrication technique, based on solution deposition, could be an effective technique for the application of bactericidal nanocoatings.
Publisher: Springer Science and Business Media LLC
Date: 18-11-2015
DOI: 10.1038/SREP16817
Abstract: Titanium and its alloys remain the most popular choice as a medical implant material because of its desirable properties. The successful osseointegration of titanium implants is, however, adversely affected by the presence of bacterial biofilms that can form on the surface and hence methods for preventing the formation of surface biofilms have been the subject of intensive research over the past few years. In this study, we report the response of bacteria and primary human fibroblasts to the antibacterial nanoarrays fabricated on titanium surfaces using a simple hydrothermal etching process. These fabricated titanium surfaces were shown to possess selective bactericidal activity, eliminating almost 50% of Pseudomonas aeruginosa cells and about 20% of the Staphylococcus aureus cells coming into contact with the surface. These nano-patterned surfaces were also shown to enhance the aligned attachment behavior and proliferation of primary human fibroblasts over 10 days of growth. These antibacterial surfaces, which are capable of exhibiting differential responses to bacterial and eukaryotic cells, represent surfaces that have excellent prospects for biomedical applications.
Publisher: American Chemical Society (ACS)
Date: 16-08-2016
Abstract: With an aging population and the consequent increasing use of medical implants, managing the possible infections arising from implant surgery remains a global challenge. Here, we demonstrate for the first time that a precise nanotopology provides an effective intervention in bacterial cocolonization enabling the proliferation of eukaryotic cells on a substratum surface, preinfected by both live Gram-negative, Pseudomonas aeruginosa, and Gram-positive, Staphylococcus aureus, pathogenic bacteria. The topology of the model black silicon (bSi) substratum not only favors the proliferation of eukaryotic cells but is biocompatible, not triggering an inflammatory response in the host. The attachment behavior and development of filopodia when COS-7 fibroblast cells are placed in contact with the bSi surface are demonstrated in the dynamic study, which is based on the use of real-time sequential confocal imaging. Bactericidal nanotopology may enhance the prospect for further development of inherently responsive antibacterial nanomaterials for bionic applications such as prosthetics and implants.
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: American Chemical Society (ACS)
Date: 30-07-2021
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: Bentham Science Publishers Ltd.
Date: 08-2011
DOI: 10.2174/092986711796504673
Abstract: Nature has created an array of superhydrophobic surfaces that possess water-repellent, self-cleaning and anti-icing properties. These surfaces have a number of potential applications in the biomedical industry, as they have the potential to control protein adsorption and cell adhesion. Natural superhydrophobic surfaces are typically composed of materials with a low intrinsic surface free-energy (e.g the cuticular waxes of lotus leaves and insect wings) with a hierarchical structural configuration. This hierarchical surface topography acts to decrease the contact area of water droplets in contact with the surface, thereby increasing the extent of the air/water interface, resulting in water contact angles greater than 150º. In order to employ these surfaces in biotechnological applications, fabrication techniques must be developed so that these multi-scale surface roughness characteristics can be reproduced. Additionally, these fabrication techniques must also be able to be applied to the material required for the intended application. An overview of some of the superhydrophobic surfaces that exist in nature is presented, together with an explanation of the theories of their wettability. Also included is a description of some of the biomedical applications of superhydrophobic surfaces and fabrication techniques that can be used to mimic superhydrophobic surfaces found in nature.
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: Springer Science and Business Media LLC
Date: 21-11-2017
DOI: 10.1038/S41598-017-16253-0
Abstract: Managing the impact of anthropogenic and climate induced stress on plant growth remains a challenge. Here we show that polymeric hydrogels, which maintain their hydrous state, can be designed to exploit functional interactions with soil microorganisms. This microbial enhancement may mitigate biotic and abiotic stresses limiting productivity. The presence of mannan chains within synthetic polyacrylic acid (PAA) enhanced the dynamics and selectivity of bacterial ingress in model microbial systems and soil microcosms. Pseudomonas fluorescens exhibiting high mannan binding adhesins showed higher ingress and localised microcolonies throughout the polymeric network. In contrast, ingress of Bacillus subtilis , lacking adhesins, was unaltered by mannan showing motility comparable to bulk liquids. Incubation within microcosms of an agricultural soil yielded hydrogel populations significantly increased from the corresponding soil. Bacterial ersity was markedly higher in mannan containing hydrogels compared to both control polymer and soil, indicating enhanced selectivity towards microbial families that contain plant beneficial species. Here we propose functional polymers applied to the potential root zone which can positively influence rhizobacteria colonization and potentially plant growth as a new approach to stress tolerance.
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: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.MIMET.2011.05.021
Abstract: Atomic force microscopy (AFM) is a technique that has long been employed in materials science, but is now increasingly being used in the biological sciences. AFM provides excellent topographical information on prokaryotic and eukaryotic cell surfaces, and the extracellular material produced by the cells. It helps to generate important data on the mechanical properties of cells, such as hardness and elasticity. AFM can also be used to measure the strength of adhesion, attraction, and repulsion forces between cells and surfaces or even between in idual molecules. Additionally, by combining AFM with other complementary techniques such as fluorescence microscopy or Raman spectroscopy, the chemistry of given surface structures can be identified. This review aims to provide an update on the AFM techniques currently used in cell biology studies, along with a description of the range of recently developed research methodologies in which AFM plays a key role.
Publisher: Wiley
Date: 15-09-2023
Publisher: Wiley
Date: 10-2009
Publisher: MDPI AG
Date: 30-05-2012
DOI: 10.3390/RS4061573
Publisher: Wiley
Date: 27-01-2022
Abstract: Ultrasmall nanoparticles are often grouped under the broad umbrella term of “nanoparticles” when reported in the literature. However, for biomedical applications, their small sizes give them intimate interactions with biological species and endow them with unique functional physiochemical properties. Carbon quantum dots (CQDs) are an emerging class of ultrasmall nanoparticles which have demonstrated considerable biocompatibility and have been employed as potent theragnostic platforms. These particles find application for increasing drug solubility and targeting, along with facilitating the passage of drugs across impermeable membranes (i.e., blood brain barrier). Further functionality can be triggered by various environmental conditions or external stimuli (i.e., pH, temperature, near Infrared (NIR) light, ultrasound), and their intrinsic fluorescence is valuable for diagnostic applications. The focus of this review is to shed light on the therapeutic potential of CQDs and identify how they travel through the body, reach their site of action, administer therapeutic effect, and are excreted. Investigation into their toxicity and compatibility with larger nanoparticle carriers is also examined. The future of CQDs for theragnostic applications is promising due to their multifunctional attributes and documented biocompatibility. As nanomaterial platforms become more commonplace in clinical treatments, the commercialization of CQD therapeutics is anticipated.
Publisher: SAGE Publications
Date: 26-02-2020
Abstract: The variations in temperature during the analysis of alcoholic beverages are of importance to develop protocols based on near infrared spectroscopy. The objective of this study was to evaluate the effect of increasing temperature on the near infrared spectra of whisky s les using two-dimensional correlation spectroscopy. Whisky s les from different commercial labels were analyzed at four different temperatures (25°C, 35°C, 45°C, and 55°C) using a UV–VIS–NIR instrument. Asynchronous and synchronous two-dimensional correlation spectroscopy was used to reveal the effect of temperature on the near infrared spectra of the s les. The results of this study indicated that temperatures between 40°C and 55°C alter absorption at specific wavelengths in the near infrared region of the whisky s les analyzed. The combination of near infrared spectroscopy with two-dimensional correlation spectroscopy has the potential to dramatically improve the efficiency of analytical laboratories, considering the range of data that can be collected.
Publisher: MDPI AG
Date: 14-04-2018
DOI: 10.3390/MA11040605
Publisher: Elsevier BV
Date: 02-2013
Publisher: MDPI AG
Date: 30-11-2019
DOI: 10.3390/HT8040021
Abstract: Compared to traditional laboratory methods, spectroscopic techniques (e.g., near infrared, hyperspectral imaging) provide analysts with an innovative and improved understanding of complex issues by determining several chemical compounds and metabolites at once, allowing for the collection of the s le “fingerprint”. These techniques have the potential to deliver high-throughput options for the analysis of the chemical composition of grapes in the laboratory, the vineyard and before or during harvest, to provide better insights of the chemistry, nutrition and physiology of grapes. Faster computers, the development of software and portable easy to use spectrophotometers and data analytical methods allow for the development of innovative applications of these techniques for the analyses of grape composition.
Publisher: Informa UK Limited
Date: 11-2012
Publisher: Elsevier BV
Date: 11-2021
Publisher: MDPI AG
Date: 10-07-2015
Publisher: American Chemical Society (ACS)
Date: 09-06-2021
Publisher: Elsevier
Date: 2021
Publisher: MDPI AG
Date: 13-11-2019
DOI: 10.3390/NANO9111610
Abstract: In this work, we report on the incorporation of a siloxane copolymer additive, poly((2-phenylethyl) methylsiloxane)-co(1-phenylethyl) methylsiloxane)-co-dimethylsiloxane), which is fully soluble at room temperature, in a rapid-cure thermoset polyester coating formulation. The additive undergoes polymerization-induced phase segregation (PIPS) to self-assemble on the coating surface as discrete discoid nanofeatures during the resin cure process. Moreover, the copolymer facilitates surface co-segregation of titanium dioxide pigment microparticulate present in the coating. Depending on the composition, the coatings can display persistent superhydrophobicity and self-cleaning properties and, surprisingly, the titanium dioxide pigmented coatings that include the siloxane copolymer additive display high levels of antibacterial performance against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria. This antibacterial performance is believed to be associated with the unique surface topology of these coatings, which comprise stimuli-responsive discoid nanofeatures. This paper provides details of the surface morphology of the coatings and how these relates to the antimicrobial properties of the coating.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8NA00124C
Abstract: Bactericidal interactions of Pseudomonas aeruginosa cells with multi-directional gold nanospikes.
Publisher: MDPI AG
Date: 11-06-2023
DOI: 10.3390/MD21060358
Abstract: Shell wastes pose environmental and financial burdens to the shellfish industry. Utilizing these undervalued shells for commercial chitin production could minimize their adverse impacts while maximizing economic value. Shell chitin conventionally produced through harsh chemical processes is environmentally unfriendly and infeasible for recovering compatible proteins and minerals for value-added products. However, we recently developed a microwave-intensified biorefinery that efficiently produced chitin, proteins eptides, and minerals from lobster shells. Lobster minerals have a calcium-rich composition and biologically originated calcium is more biofunctional for use as a functional, dietary, or nutraceutical ingredient in many commercial products. This has suggested a further investigation of lobster minerals for commercial applications. In this study, the nutritional attributes, functional properties, nutraceutical effects, and cytotoxicity of lobster minerals were analyzed using in vitro simulated gastrointestinal digestion combined with growing bone (MG-63), skin (HaCaT), and macrophage (THP-1) cells. The calcium from the lobster minerals was found to be comparable to that of a commercial calcium supplement (CCS, 139 vs. 148 mg/g). In addition, beef incorporated with lobster minerals (2%, w/w) retained water better than that of casein and commercial calcium lactate (CCL, 21.1 vs. 15.1 and 13.3%), and the lobster mineral had a considerably higher oil binding capacity than its rivals (casein and CCL, 2.5 vs. 1.5 and 1.0 mL/g). Notably, the lobster mineral and its calcium were far more soluble than the CCS (98.4 vs. 18.6% for the products and 64.0 vs. 8.5% for their calcium) while the in vitro bioavailability of lobster calcium was 5.9-fold higher compared to that of the commercial product (11.95 vs. 1.99%). Furthermore, supplementing lobster minerals in media at ratios of 15%, 25%, and 35% (v/v) when growing cells did not induce any detectable changes in cell morphology and apoptosis. However, it had significant effects on cell growth and proliferation. The responses of cells after three days of culture supplemented with the lobster minerals, compared to the CCS supplementation, were significantly better with the bone cells (MG-63) and competitively quick with the skin cells (HaCaT). The cell growth reached 49.9–61.6% for the MG-63 and 42.9–53.4% for the HaCaT. Furthermore, the MG-63 and HaCaT cells proliferated considerably after seven days of incubation, reaching 100.3% for MG-63 and 115.9% for HaCaT with a lobster mineral supplementation of 15%. Macrophages (THP-1 cells) treated for 24 h with lobster minerals at concentrations of 1.24–2.89 mg/mL had no detectable changes in cell morphology while their viability was over 82.2%, far above the cytotoxicity threshold ( %). All these results indicate that lobster minerals could be used as a source of functional or nutraceutical calcium for commercial products.
Publisher: Wiley
Date: 17-09-2020
DOI: 10.1111/IJFS.14367
Publisher: Informa UK Limited
Date: 26-03-2010
Publisher: Informa UK Limited
Date: 17-01-2013
DOI: 10.1080/08927014.2012.757697
Abstract: Despite the volume of work that has been conducted on the topic, the role of surface topography in mediating bacterial cell adhesion is not well understood. The primary reason for this lack of understanding is the relatively limited extent of topographical characterisation employed in many studies. In the present study, the topographies of three sub-nanometrically smooth titanium (Ti) surfaces were comprehensively characterised, using nine in idual parameters that together describe the height, shape and distribution of their surface features. This topographical analysis was then correlated with the adhesion behaviour of the pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa, in an effort to understand the role played by each aspect of surface architecture in influencing bacterial attachment. While P. aeruginosa was largely unable to adhere to any of the three sub-nanometrically smooth Ti surfaces, the extent of S. aureus cell attachment was found to be greater on surfaces with higher average, RMS and maximum roughness and higher surface areas. The cells also attached in greater numbers to surfaces that had shorter autocorrelation lengths and skewness values that approached zero, indicating a preference for less ordered surfaces with peak heights and valley depths evenly distributed around the mean plane. Across the sub-nanometrically smooth range of surfaces tested, it was shown that S. aureus more easily attached to surfaces with larger features that were evenly distributed between peaks and valleys, with higher levels of randomness. This study demonstrated that the traditionally employed litudinal roughness parameters are not the only determinants of bacterial adhesion, and that spatial parameters can also be used to predict the extent of attachment.
Publisher: Wiley
Date: 02-04-2023
Abstract: Conductive textiles are promising for human–machine interfaces and wearable electronics. A simple way to create conductive textiles by coating fabric with liquid metal (LM) particles is reported. The coating process involves dip‐coating the fabric into a suspension of LM particles at room temperature. Despite being coated uniformly after drying, the textiles remain electrically insulating due to the native oxide that forms on the LM particles. Yet, they can be rendered conductive by compressing the textile to rupture the oxide and thereby percolate the particles. Thus, compressing the textile with a patterned mold can pattern conductive circuits on the textile. The electrical conductivity of these circuits increases by coating more particles on the textile. Notably, the conductive patterns autonomously heal when cut by forming new conductive paths along the edge of the cut. The textiles prove to be useful as circuit interconnects, Joule heaters, and flexible electrodes to measure ECG signals. Further, the LM‐coated textiles provide antimicrobial protection against Pseudomonas aeruginosa and Staphylococcus aureus . Such simple coatings provide a route to convert otherwise insulating textiles into electrical circuits with the ability to autonomously heal and provide antimicrobial properties.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0RA07352K
Abstract: Free Energy Pertubation (FEP) can be used to accurately predict the binding affinity of a ligand to the main protease (Mpro) of the novel coronavirus SARS-CoV-2.
Publisher: Informa UK Limited
Date: 31-03-2010
DOI: 10.1080/08927011003753399
Abstract: Optical fibres have received considerable attention as high-density sensor arrays suitable for both in vitro and in vivo measurements of biomolecules and biological processes in living organisms and/or nano-environments. The fibre surface was chemically modified by exposure to a selective etchant that preferentially erodes the fibre cores relative to the surrounding cladding material, thus producing a regular pattern of cylindrical wells of approximately 2.5 mum in diameter and 2.5 mum deep. The surface hydrophobicity of the etched and non-etched optical fibres was analysed using the sessile pico-drop method. The surface topography was characterised by atomic force microscopy (AFM), while the surface chemistry was probed by time-of-flight secondary ion mass spectrometry (ToF-SIMS). Six taxonomically different bacterial strains showed a consistent preference for attachment to the nano-scale smoother (R(q) = 273 nm), non-etched fibre surfaces (water contact angle, theta = 106 degrees +/- 4 degrees). In comparison, the surfaces of the etched optical fibres (water contact angle, theta = 96 degrees +/- 10 degrees) were not found to be amenable to bacterial attachment. Bacterial attachment on the non-etched optical fibre substrata varied among different strains.
Publisher: Wiley
Date: 22-09-2021
Abstract: Fabrics are widely used in hospitals and many other settings for bedding, clothing, and face masks however, microbial pathogens can survive on surfaces for a long time, leading to microbial transmission. Coatings of metallic particles on fabrics have been widely used to eradicate pathogens. However, current metal particle coating technologies encounter numerous issues such as nonuniformity, processing complexity, and poor adhesion. To overcome these issues, an easy‐to‐control and straightforward method is reported to coat a wide range of fabrics by using gallium liquid metal (LM) particles to facilitate the deposition of liquid metal copper alloy (LMCu) particles. Gallium particles coated on the fabric provide nucleation sites for forming LMCu particles at room temperature via galvanic replacement of Cu 2+ ions. The LM helps promote strong adhesion of the particles to the fabric. The presence of the LMCu particles can eradicate over 99% of pathogens (including bacteria, fungi, and viruses) within 5 min, which is significantly more effective than control s les coated with only Cu. The coating remains effective over multiple usages and against contaminated droplets and aerosols, such as those encountered in facemasks. This facile coating method is promising for generating robust antibacterial, antifungal, and antiviral fabrics and surfaces.
Publisher: Springer International Publishing
Date: 2019
Publisher: Elsevier BV
Date: 11-2019
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: CRC Press
Date: 17-10-2007
Publisher: Copernicus GmbH
Date: 27-07-2012
DOI: 10.5194/ISPRSARCHIVES-XXXIX-B1-429-2012
Abstract: Abstract. This study is the first to use an Unmanned Aerial Vehicle (UAV) for mapping moss beds in Antarctica. Mosses can be used as indicators for the regional effects of climate change. Mapping and monitoring their extent and health is therefore important. UAV aerial photography provides ultra-high resolution spatial data for this purpose. We developed a technique to extract an extremely dense 3D point cloud from overlapping UAV aerial photography based on structure from motion (SfM) algorithms. The combination of SfM and patch-based multi-view stereo image vision algorithms resulted in a 2 cm resolution digital terrain model (DTM). This detailed topographic information combined with vegetation indices derived from a 6-band multispectral sensor enabled the assessment of moss bed health. This novel UAV system has allowed us to map different environmental characteristics of the moss beds at ultra-high resolution providing us with a better understanding of these fragile Antarctic ecosystems. The paper provides details on the different UAV instruments and the image processing framework resulting in DEMs, vegetation indices, and terrain derivatives.
Publisher: Springer Science and Business Media LLC
Date: 17-04-2015
DOI: 10.1007/S00253-015-6572-7
Abstract: The surface nanotopography and architecture of medical implant devices are important factors that can control the extent of bacterial attachment. The ability to prevent bacterial attachment substantially reduces the possibility of a patient receiving an implant contracting an implant-borne infection. We now demonstrated that two bacterial strains, Staphylococcus aureus and Pseudomonas aeruginosa, exhibited different attachment affinities towards two types of molecularly smooth titanium surfaces each possessing a different nanoarchitecture. It was found that the attachment of S. aureus cells was not restricted on surfaces that had an average roughness (S a) less than 0.5 nm. In contrast, P. aeruginosa cells were found to be unable to colonise surfaces possessing an average roughness below 1 nm, unless sharp nanoprotrusions of approximately 20 nm in size and spaced 35.0 nm apart were present. It is postulated that the enhanced attachment of P. aeruginosa onto the surfaces possessing these nanoprotrusions was facilitated by the ability of the cell membrane to stretch over the tips of the nanoprotrusions as confirmed through computer simulation, together with a concomitant increase in the level of extracellular polymeric substance (EPS) being produced by the bacterial cells.
Publisher: Elsevier BV
Date: 04-2023
Location: Australia
No related grants have been discovered for Vi Khanh Truong.