ORCID Profile
0000-0002-4663-5111
Current Organisations
University of Queensland
,
Department of Education
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Publisher: Elsevier BV
Date: 04-2006
Publisher: American Institute of Physics
Date: 2009
DOI: 10.1063/1.3203244
Publisher: American Chemical Society (ACS)
Date: 30-10-2012
DOI: 10.1021/LA304141M
Abstract: The interactions of block copolymers with surfaces can be controlled by coating those surfaces with appropriate statistical copolymers. Usually, a statistical copolymer comprised of monomer units identical to those of the block copolymer is used that is, typically a poly(styrene)-stat-poly(methyl methacrylate) (PS-stat-PMMA) is used to direct the alignment of poly(styrene)-block-poly(methyl methacrylate) (PS-block-PMMA), and poly(styrene)-stat-poly(2-vinylpyridine) (PS-stat-P2VP) has been used for poly(styrene)-block-poly(2-vinylpyridine) (PS-block-P2VP). Reports of controlling the orientation of block copolymers with statistical copolymers with a dissimilar composition are limited. Here, we demonstrate that this method can be further extended to show that PS-stat-PMMA can be used to control the wetting properties of poly(styrene)-block-poly(D,L-lactide) (PS-block-PDLA). Surfaces were modified with a series of cross-linked PS-stat-PMMA-stat-glycidyl methacrylate terpolymers, and the surface chemistries and energies were assessed using angle-dependent X-ray photoelectron spectroscopy and the two-liquid harmonic method, respectively. From these experiments, an expected neutral compositional window was identified for symmetrical PS-block-PDLA. Moreover, high-resolution SEM, AD-XPS, and grazing-incidence SAXS measurements were used to evaluate the morphology of PS-block-PDLA as a function of the surface composition of the underlying cross-linked copolymer films, and the neutral composition was found to range from 32 to 38 mol % of PS, in the bulk polymer. Ultimately, we demonstrated the determination of nonpreferential surface compositions that allow the self-assembly of lamellae with sizes in the sub-10 nm regime that are oriented perpendicular to the substrate. These findings have important implications for the use of PS-block-PDLA block copolymers in directed self-assembly, most specifically in advanced lithographic processes.
Publisher: Beilstein Institut
Date: 19-10-2015
DOI: 10.3762/BJNANO.6.208
Abstract: In this paper we image the highly confined long range plasmons of a nanoscale metal stripe waveguide using quantum emitters. Plasmons were excited using a highly focused 633 nm laser beam and a specially designed grating structure to provide stronger incoupling to the desired mode. A homogeneous thin layer of quantum dots was used to image the near field intensity of the propagating plasmons on the waveguide. We observed that the photoluminescence is quenched when the QD to metal surface distance is less than 10 nm. The optimised spacer layer thickness for the stripe waveguides was found to be around 20 nm. Authors believe that the findings of this paper prove beneficial for the development of plasmonic devices utilising stripe waveguides.
Publisher: Media Sphere Publishing Group
Date: 2022
Publisher: eLife Sciences Publications, Ltd
Date: 27-04-2021
DOI: 10.7554/ELIFE.64630
Abstract: Genetic tags allow rapid localization of tagged proteins in cells and tissues. APEX, an ascorbate peroxidase, has proven to be one of the most versatile and robust genetic tags for ultrastructural localization by electron microscopy (EM). Here, we describe a simple method, APEX-Gold, which converts the diffuse oxidized diaminobenzidine reaction product of APEX into a silver/gold particle akin to that used for immunogold labelling. The method increases the signal-to-noise ratio for EM detection, providing unambiguous detection of the tagged protein, and creates a readily quantifiable particulate signal. We demonstrate the wide applicability of this method for detection of membrane proteins, cytoplasmic proteins, and cytoskeletal proteins. The method can be combined with different EM techniques including fast freezing and freeze substitution, focussed ion beam scanning EM, and electron tomography. Quantitation of expressed APEX-fusion proteins is achievable using membrane vesicles generated by a cell-free expression system. These membrane vesicles possess a defined quantum of signal, which can act as an internal standard for determination of the absolute density of expressed APEX-fusion proteins. Detection of fusion proteins expressed at low levels in cells from CRISPR-edited mice demonstrates the high sensitivity of the APEX-Gold method.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8ME00007G
Abstract: Herein we demonstrate the design and use of sub-10 nm etch-durable polymeric particles for healing roughness in lithographic patterns.
Publisher: Elsevier BV
Date: 12-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2012
Publisher: MDPI AG
Date: 29-06-2022
DOI: 10.3390/NCRNA8040047
Abstract: Non-coding RNAs reflect many biological processes in the human body, including athero-sclerosis. In a cardiology outpatient department cohort (N = 83), we aimed to compare the levels of circulating microRNAs in groups with vulnerable plaques (N = 22), stable plaques (N = 23) and plaque-free (N = 17) depending on coronary computed tomography angiography and to evaluate associations of microRNA levels with calculated cardiovascular risks (CVR), based on the SCORE2 (+OP), ACC/AHA, ATP-III and MESA scales. Coronary computed tomography was performed on a 640-slice computed tomography scanner. Relative plasma levels of microRNA were assessed via a real-time polymerase chain reaction. We found significant differences in miR-143-3p levels (p = 0.0046 in plaque-free vs. vulnerable plaque groups) and miR-181b-5p (p = 0.0179 in stable vs. vulnerable plaques groups). Analysis of microRNA associations with CVR did not show significant differences for SCORE2 (+OP) and ATPIII scales. MiR-126-5p and miR-150-5p levels were significantly higher (p 0.05) in patients with ACC/AHA risk % and miR-145-5p had linear relationships with ACC/AHA score (adjusted p = 0.0164). The relative plasma level of miR-195 was higher (p 0.05) in patients with MESA risk 7.5% and higher (p 0.05) in patients with zero coronary calcium index (p = 0.036). A linear relationship with coronary calcium was observed for miR-126-3p (adjusted p = 0.0484). A positive correlation with high coronary calcium levels ( 100 Agatson units) was found for miR-181-5p (p = 0.036). Analyzing the biological pathways of these microRNAs, we suggest that miR-143-3p and miR-181-5p can be potential markers of the atherosclerosis process. Other miRNAs (miR-126-3p, 126-5p, 145-5p, 150-5p, 195-5p) can be considered as potential cardiovascular risk modifiers, but it is necessary to validate our results in a large prospective trial.
Publisher: SPIE
Date: 17-03-2011
DOI: 10.1117/12.881491
Publisher: Silicea - Poligraf, LLC
Date: 13-04-2019
DOI: 10.15829/1560-4071-2019-3-60-68
Abstract: Aim. To evaluate the diagnostic accuracy of a noninvasive method of fractional flow reserve (FFR) assessment based on a one-dimensional hemodynamic model build on data obtained from the coronary computed tomography angiography (CCTA). Material and methods. The study enrolled 57 patients: 16 of them underwent 64-slice computed tomography — included retrospectively, 34 — prospectively, with a 640-slice CT scan. Specialists from the Laboratory of Mathematical Modeling processed CT images and evaluated noninvasive FFR. Ischemia was confirmed if FFR ,80 and disproved if FFR ≥0,80. After that the prospective group of patients was hospitalized for invasive FFR assessment as a reference standard if ischemia was proved, patients underwent stent implantation. In the retrospective group, patients already had invasive FFR values estimated. Statistical analysis was performed using R programming language packages (cran-r.project.com). Continuous variables are presented as mean values ± standard deviations, order variables are presented as medians with interquartile ranges in parentheses. We used the D’Agostino-Pearson omnibus test for the assessment of normality of distribution a Q-Q Plot was also constructed. We performed the Bland-Altman analysis and ROC-analysis for comparison of these two methods, and the Pearson’s chi-squared to assess the degree of correlation. Results. During data processing, 3 patients of the retrospective and 34 patients of the prospective group were excluded from the study. The sensitivity of our method was 90,91% (95% CI 58,72-99,77), specificity — 86,67% (95% CI 59,54-98,34), P ,05, accuracy — 88,46 (95% CI 69,85-97,55) — in per-vessel analysis. In perpatient analysis, the sensitivity was 91,67% (95% CI 61,52-99,79), specificity — 80% (95% CI 28,36-99,49), (P ,05) accuracy 88,24 (95% CI 63,56-98,54). Conclusion. Our method has quite a high accuracy and can be successfully used in clinical practice in order to enhance the diagnostic efficiency of the CCTA.
Publisher: Wiley
Date: 22-08-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NA00095J
Abstract: Photolysis of the homopolymer poly(4-acetoxystyrene) allows spatial control of surface interactions and block copolymer orientation over different length scales.
Publisher: American Chemical Society (ACS)
Date: 15-08-2017
Abstract: Single-crystal cubic silicon carbide has attracted great attention for MEMS and electronic devices. However, current leakage at the SiC/Si junction at high temperatures and visible-light absorption of the Si substrate are main obstacles hindering the use of the platform in a broad range of applications. To solve these bottlenecks, we present a new platform of single crystal SiC on an electrically insulating and transparent substrate using an anodic bonding process. The SiC thin film was prepared on a 150 mm Si with a surface roughness of 7 nm using LPCVD. The SiC/Si wafer was bonded to a glass substrate and then the Si layer was completely removed through wafer polishing and wet etching. The bonded SiC/glass s les show a sharp bonding interface of less than 15 nm characterized using deep profile X-ray photoelectron spectroscopy, a strong bonding strength of approximately 20 MPa measured from the pulling test, and relatively high optical transparency in the visible range. The transferred SiC film also exhibited good conductivity and a relatively high temperature coefficient of resistance varying from -12 000 to -20 000 ppm/K, which is desirable for thermal sensors. The biocompatibility of SiC/glass was also confirmed through mouse 3T3 fibroblasts cell-culturing experiments. Taking advantage of the superior electrical properties and biocompatibility of SiC, the developed SiC-on-glass platform offers unprecedented potentials for high-temperature electronics as well as bioapplications.
Publisher: Silicea - Poligraf, LLC
Date: 21-05-2019
Publisher: Springer Science and Business Media LLC
Date: 17-02-2021
DOI: 10.1038/S41467-021-21431-W
Abstract: The introduction of immune checkpoint inhibitors has demonstrated significant improvements in survival for subsets of cancer patients. However, they carry significant and sometimes life-threatening toxicities. Prompt prediction and monitoring of immune toxicities have the potential to maximise the benefits of immune checkpoint therapy. Herein, we develop a digital nanopillar SERS platform that achieves real-time single cytokine counting and enables dynamic tracking of immune toxicities in cancer patients receiving immune checkpoint inhibitor treatment - broader applications are anticipated in other disease indications. By analysing four prospective cytokine biomarkers that initiate inflammatory responses, the digital nanopillar SERS assay achieves both highly specific and highly sensitive cytokine detection down to attomolar level. Significantly, we report the capability of the assay to longitudinally monitor 10 melanoma patients during immune inhibitor blockade treatment. Here, we show that elevated cytokine concentrations predict for higher risk of developing severe immune toxicities in our pilot cohort of patients.
Publisher: SPIE
Date: 03-2012
DOI: 10.1117/12.916744
Publisher: IEEE
Date: 2004
Publisher: American Chemical Society (ACS)
Date: 26-12-2013
DOI: 10.1021/MA4019735
Publisher: AIP Publishing
Date: 02-05-2023
DOI: 10.1063/5.0147376
Abstract: Epitaxial graphene (EG) on cubic silicon carbide (3C-SiC) on silicon holds the promise of tunable nanoelectronic and nanophotonic devices, some uniquely unlocked by the graphene/cubic silicon carbide combination, directly integrated with the current well-established silicon technologies. Yet, the development of graphene field-effect devices based on the 3C-SiC/Si substrate system has been historically hindered by poor graphene quality and coverage, as well as substantial leakage issues of the heteroepitaxial system. We address these issues by growing EG on 3C-SiC on highly resistive silicon substrates using an alloy-mediated approach. In this work, we demonstrate a field-effect transistor based on EG/3C-SiC/Si with gate leakage current 6 orders of magnitude lower than the drain current at room temperature, which is a vast improvement on the current literature, opening the possibility for dynamically tunable nanoelectronic and nanophotonic devices on silicon at the wafer level.
Publisher: Wiley
Date: 22-07-2018
Publisher: IOP Publishing
Date: 19-11-2020
Abstract: The interaction of bacteria on nanopatterned surfaces has caught attention since the discovery of the bactericidal property of cicada wing surfaces. While many studies focused on the inspiration of such surfaces, nanolithography-based techniques are seldom used due to the difficulties in fabricating highly dense (number of pillars per unit area), geometrical nanostructured surfaces. Here we present a systematic modelling approach for optimising the electron beam lithography parameters in order to fabricate biomimicked nanopillars of varying patterned geometries. Monte Carlo simulation was applied to optimize the beam energy and pattern design prior to the experimental study. We optimized the processing parameters such as exposure factor, write field size, pitch, the different types and thicknesses of the PMMA resist used, and the shape of the feature (circle or a dot) for the fabrication of nanopillars to achieve the best lift-off with repeatable result. Our simulation and experimental results showed that a circle design with a voltage of 30 kV and 602 nm thickness of PMMA 495 A4 as base layers and 65 nm of PMMA 950 A2 as top layer achieves the best results. The antibacterial activity was also validated on the representative fabricated titanium nanopillar surface. The surface with a base diameter of 94.4 nm, spike diameter of 12.6 nm, height of 115.6 nm, density of 43/ μ m 2 , aspect ratio of 2.16 and centre to centre distance of 165.8 nm was the optimum surface for antibacterial activity. Such a systematic design approach for fabrication of insect wing-mimicked closely packed nanopillars have not been investigated before which provides an excellent platform for biomedical Ti implants.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2018
Publisher: SPIE-Intl Soc Optical Eng
Date: 21-07-2014
Publisher: Elsevier BV
Date: 05-2015
Publisher: SPIE
Date: 26-03-2013
DOI: 10.1117/12.2012488
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0JM03288C
Publisher: Wiley
Date: 16-07-2012
DOI: 10.1002/POLA.26232
Publisher: Elsevier BV
Date: 2021
Publisher: The Optical Society
Date: 13-04-2015
DOI: 10.1364/OE.23.010188
Publisher: SPIE
Date: 27-03-2014
DOI: 10.1117/12.2046296
Publisher: Bentham Science Publishers Ltd.
Date: 26-08-2016
No related grants have been discovered for Han Hao Cheng.