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Pham ST, Tieu AK, Sun C, Wan S, Collins SM. Direct Visualization of Chemical Transport in Solid-State Chemical Reactions by Time-of-Flight Secondary Ion Mass Spectrometry. Nano Lett 2024; 24:3702-3709. [PMID: 38477517 PMCID: PMC10979428 DOI: 10.1021/acs.nanolett.4c00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024]
Abstract
Systematic control and design of solid-state chemical reactions are required for modifying materials properties and in novel synthesis. Understanding chemical dynamics at the nanoscale is therefore essential to revealing the key reactive pathways. Herein, we combine focused ion beam-scanning electron microscopy (FIB-SEM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) to track the migration of sodium from a borate coating to the oxide scale during in situ hot corrosion testing. We map the changing distribution of chemical elements and compounds from 50 to 850 °C to reveal how sodium diffusion induces corrosion. The results are validated by in situ X-ray diffraction and post-mortem TOF-SIMS. We additionally retrieve the through-solid sodium diffusion rate by fitting measurements to a Fickian diffusion model. This study presents a step change in analyzing microscopic diffusion mechanics with high chemical sensitivity and selectivity, a widespread analytical challenge that underpins the defining rates and mechanisms of solid-state reactions.
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Affiliation(s)
- Sang T. Pham
- Bragg
Centre for Materials Research & School of Chemical and Process
Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Anh Kiet Tieu
- School
of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Chao Sun
- Bragg
Centre for Materials Research & School of Chemical and Process
Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Shanhong Wan
- State
Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical
Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
| | - Sean M. Collins
- Bragg
Centre for Materials Research & School of Chemical and Process
Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
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2
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Ghasemi M, Li X, Tang C, Li Q, Lu J, Du A, Lee J, Appadoo D, Tizei LHG, Pham ST, Wang L, Collins SM, Hou J, Jia B, Wen X. Effective Suppressing Phase Segregation of Mixed-Halide Perovskite by Glassy Metal-Organic Frameworks. Small 2023:e2304236. [PMID: 37616513 DOI: 10.1002/smll.202304236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/13/2023] [Indexed: 08/26/2023]
Abstract
Lead mixed-halide perovskites offer tunable bandgaps for optoelectronic applications, but illumination-induced phase segregation can quickly lead to changes in their crystal structure, bandgaps, and optoelectronic properties, especially for the Br-I mixed system because CsPbI3 tends to form a non-perovskite phase under ambient conditions. These behaviors can impact their performance in practical applications. By embedding such mixed-halide perovskites in a glassy metal-organic framework, a family of stable nanocomposites with tunable emission is created. Combining cathodoluminescence with elemental mapping under a transmission electron microscope, this research identifies a direct relationship between the halide composition and emission energy at the nanoscale. The composite effectively inhibits halide ion migration, and consequently, phase segregation even under high-energy illumination. The detailed mechanism, studied using a combination of spectroscopic characterizations and theoretical modeling, shows that the interfacial binding, instead of the nanoconfinement effect, is the main contributor to the inhibition of phase segregation. These findings pave the way to suppress the phase segregation in mixed-halide perovskites toward stable and high-performance optoelectronics.
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Affiliation(s)
- Mehri Ghasemi
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
| | - Xuemei Li
- School of Chemical Engineering, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Cheng Tang
- School of Chemistry and Physics, Centre for Materials Science, Queensland University of Technology, 2 George St, Brisbane City, QLD, 4001, Australia
| | - Qi Li
- Centre for Translational Atomaterials, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
| | - Junlin Lu
- Centre for Translational Atomaterials, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
| | - Aijun Du
- School of Chemistry and Physics, Centre for Materials Science, Queensland University of Technology, 2 George St, Brisbane City, QLD, 4001, Australia
| | - Jaeho Lee
- School of Chemical Engineering, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Dominique Appadoo
- Australian Synchrotron, 800 Blackburn Rd, Clayton, VIC, 3168, Australia
| | - Luiz H G Tizei
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Sang T Pham
- Bragg Centre for Materials Research, School of Chemical and Process Engineering and School of Chemistry, University of Leeds, LS2 9JT, Leeds, UK
| | - Lianzhou Wang
- School of Chemical Engineering, The University of Queensland, St. Lucia, QLD, 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Sean M Collins
- Bragg Centre for Materials Research, School of Chemical and Process Engineering and School of Chemistry, University of Leeds, LS2 9JT, Leeds, UK
| | - Jingwei Hou
- School of Chemical Engineering, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Baohua Jia
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
| | - Xiaoming Wen
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
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Pham ST, Tieu AK, Sencadas V, Joseph P, Arun M, Cortie D. Thermoresponsive Hybrid Colloidal Capsules as an Inorganic Additive for Fire-Resistant Silicone-Based Coatings. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c01967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sang T. Pham
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
- School of Chemical and Process Engineering, Faculty of Engineering and Physical Science, University of Leeds, Leeds LS2 9JT, U.K
| | - Anh Kiet Tieu
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Vitor Sencadas
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
- Department of Materials and Ceramic Engineering, CICECO─Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Paul Joseph
- Institute of Sustainable Industries and Liveable Cities, Victoria University, Melbourne, VIC 3030, Australia
| | - Malavika Arun
- Institute of Sustainable Industries and Liveable Cities, Victoria University, Melbourne, VIC 3030, Australia
| | - David Cortie
- Institute of Superconducting and Electronic Materials (ISEM), University of Wollongong, Wollongong, NSW 2522, Australia
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Pham ST, Tieu AK, Sencadas V, Lei W, Liu D, Wan S, Hao J. Smart-Responsive Colloidal Capsules as an Emerging Tool to Design a Multifunctional Lubricant Additive. ACS Appl Mater Interfaces 2021; 13:7714-7724. [PMID: 33533613 DOI: 10.1021/acsami.0c20759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The microencapsulation technique has been proven as a powerful and flexible tool to design and develop a multifunctional additive for various applications. The significant characteristics of this technique center around the ability to control the release of the core active ingredients by tuning the porosity and the permeability of the shell. However, this original concept has faced a major roadblock in lubricant research since it causes a major breakage of the microcapsules (∼70%) under severe stressed-shearing conditions. The shell fragments generated from such unwanted events significantly influence the friction and wear performances of the counterpart, thus limiting the ongoing research of the microencapsulation technique in tribology. To solve such technical bottlenecks, we develop a new strategy of utilizing the microencapsulation technique which focuses on the smart responsiveness of the shell with the base lubricant and the synergy between the incorporated materials. In this study, the smart-responsive colloidal capsule has been developed based on our proposed concept that demonstrates outstanding performances in improving the lubricity of the conventional melt lubricant (by ∼70%) under hot metal working conditions. An unprecedented oxidation-reduction (by ∼93%) and the first instance of ultralow friction (0.07) at elevated temperatures (880 °C) have been initially achieved. This work opens a new avenue of customizing a multifunctional additive package by utilizing the smart colloidal capsules in lubrication science.
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Affiliation(s)
- Sang T Pham
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - A Kiet Tieu
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Vitor Sencadas
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Weiwei Lei
- Institute for Frontier Materials, Deakin University, Waurn Ponds Campus, Geelong, Victoria 3220, Australia
| | - Dan Liu
- Institute for Frontier Materials, Deakin University, Waurn Ponds Campus, Geelong, Victoria 3220, Australia
| | - Shanhong Wan
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P.R. China
| | - Jingcheng Hao
- Key Laboratory of Colloid and Interface Chemistry & Key Laboratory of Special Aggregated Materials, Shandong University, Ministry of Education, Jinan 250100, PR China
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Nguyen HH, Tieu AK, Tran BH, Wan S, Zhu H, Pham ST. Porosity-induced mechanically robust superhydrophobicity by the sintering and silanization of hydrophilic porous diatomaceous earth. J Colloid Interface Sci 2021; 589:242-251. [PMID: 33460855 DOI: 10.1016/j.jcis.2020.12.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/24/2020] [Accepted: 12/24/2020] [Indexed: 01/09/2023]
Abstract
HYPOTHESIS Because they have self-similar low-surface-energy microstructures throughout the whole material block, fabricating superhydrophobic monoliths has been currently a promising remedy for the mechanical robustness of non-wetting properties. Noticeably, porous materials have microstructured interfaces throughout the complete volume, and silanization can make surfaces low-surface-energy. Therefore, the porous structure and surface silane-treatment can be combined to render hydrophilic inorganics into mechanically durable superhydrophobic monoliths. EXPERIMENTS Superhydrophobic diatomaceous earth pellets were produced by thermal-sintering, followed by a silanization process with octyltriethoxysilane. The durability of superhydrophobicity was evaluated by changes in wetting properties, surface morphology, and chemistry after a systematic abrasion sliding test. FINDINGS The intrinsic porosity of diatomite facilitated surface silanization throughout the whole sintered pellet, thus producing the water-repelling monolith. The abrasion sliding converted multimodal porosity of the volume to hierarchical roughness of the surface comprised of silanized particles, thereby attaining superhydrophobic properties of high contact angles over 150° and sliding angles below 20°. The tribological properties revealed useful information about the superhydrophobicity duration of the non-wetting monolith against friction. The result enables the application of porous structures in the fabrication of the anti-abrasion superhydrophobic materials even though they are originally hydrophilic.
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Affiliation(s)
- Huynh H Nguyen
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia
| | - A Kiet Tieu
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Bach H Tran
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia
| | - Shanhong Wan
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia
| | - Hongtao Zhu
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia
| | - Sang T Pham
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia
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Pham ST, Tieu AK, Wan S, Hao J, Zhu H, Tran NV, Do PT. Intrinsic Effect of Alkali Concentration on Oxidation Reactivity and High-Temperature Lubricity of Silicate Melts between Rubbed Steel/Steel Contacts. Langmuir 2020; 36:7850-7860. [PMID: 32551658 DOI: 10.1021/acs.langmuir.0c00895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The present study investigated oxidation reactivity and hot lubricity of a sodium silicate melt at different Na2O/SiO2 ratios under elevated temperature stimulation. Static oxidation prevention was achieved at 920 °C when the Na2O/SiO2 ratio reached 1:3 (trisilicate) and 1:2 (disilicate), but it started to deteriorate in the case of 1:1 (metasilicate). At a high concentration of sodium (metasilicate), a severe corrosion reaction between the melt and oxide took place that resulted in a composite coating on the steel substrate. This high-temperature reaction accelerated the formation of ionic charges from the steel base and promoted oxidation. However, friction and wear reduction is proportional to an increase in the sodium oxide fraction. Metasilicate (1:1) exhibited excellent lubricity under the hot frictional test at 920 °C compared to other lubricants. It was due to the formation of the sodium-saturated surfaces and an amorphous silica layer, which was associated with the high-temperature reactivity of sodium toward the oxide surface. In addition, the NaFeO2-Fe2O3 composite film, as the reaction product of individual sodium charge and oxide, plays a significant role in maintaining the tribofilm stability for metasilicate, which was not present for disilicate. This study advances the understanding of how sodium-containing compounds perform oxidation prevention and generate lubricity at hot rubbed surfaces.
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Affiliation(s)
- Sang T Pham
- Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Anh Kiet Tieu
- Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Shanhong Wan
- Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Jingcheng Hao
- Key Laboratory of Colloid and Interface Chemistry & Key Laboratory of Special Aggregated Materials, Shandong University, Jinan 250100, P. R. China
| | - Hongtao Zhu
- Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Nam V Tran
- Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Phuong T Do
- Faculty of Chemistry, Hanoi University of Science, Vietnam National University, Hanoi 100000, Vietnam
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7
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Pham VH, Gargiulo Isacco C, Nguyen KCD, Le SH, Tran DK, Nguyen QV, Pham HT, Aityan S, Pham ST, Cantore S, Inchingolo AM, Inchingolo AD, Dipalma G, Ballini A, Inchingolo F. Rapid and sensitive diagnostic procedure for multiple detection of pandemic Coronaviridae family members SARS-CoV-2, SARS-CoV, MERS-CoV and HCoV: a translational research and cooperation between the Phan Chau Trinh University in Vietnam and University of Bari "Aldo Moro" in Italy. Eur Rev Med Pharmacol Sci 2020; 24:7173-7191. [PMID: 32633414 DOI: 10.26355/eurrev_202006_21713] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE A new pandemic coronavirus causing coronavirus disease-2019 (COVID-19), initially called 2019-nCoV and successively named Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The COVID-19 refers to the disease while the SARS-CoV-2 refers to the virus and is characterized by a rapid contagious capacity able to spread worldwide in a very short time. The rise in the number of infected patients and deaths is of great concern especially because symptoms are vague and similar to other forms of flu infection and corona syndrome infections characterized by fever, fatigue, dry cough, and dyspnea. According to the latest guidelines published by the World Health Organization (WHO), the diagnosis of COVID-19 must be confirmed by quantitative reverse transcription polymerase chain reaction (rRT-PCR) or gene sequencing of specimen obtained from throat, sputum and blood samples. However, the limitations due to logistics, as well as low sensitivity and specificity diagnostic tools currently available have been reported as the main cause of high incidence of either false-negative or positive results. PATIENTS AND METHODS The purpose of the present translational research protocol is to discuss and present the original findings from our research team on new diagnostic technique to detect four Coronaviridae family members (SARS-CoV-2, SARS-CoV, HCoV and MERS-CoV), highlighting the methodology, the procedure and the possible advantages. Moreover, the authors review the current epidemiology, precautions and safety measures for health personnel to manage patients with known or suspected COVID-19 infection. RESULTS Implementation of an effective and rapid plan of diagnosing, screening and checking is a key factor to reduce and prevent further transmission. This procedure based on rRT-PCR could be of great help to decisively validate the results obtained from more conventional diagnostic procedures such as chest computed tomography (CT) imaging and chest ultrasound. CONCLUSIONS This translational diagnostic tool will assist emergency and primary care clinicians, as well as out-of-hospital providers, in effectively managing people with suspected or confirmed SARS-CoV-2.
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Affiliation(s)
- V H Pham
- Phan Chau Trinh University of Medicine, Danang City, Vietnam.
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Pham ST, Tieu KA, Wan S, Hao J, Nguyen HH, Mitchell DRG, Sencadas V. Intrinsic Effect of Nanoparticles on the Mechanical Rupture of Doubled-Shell Colloidal Capsule via In Situ TEM Mechanical Testing and STEM Interfacial Analysis. Small 2020; 16:e2001978. [PMID: 32548963 DOI: 10.1002/smll.202001978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/06/2020] [Indexed: 06/11/2023]
Abstract
The discovery of Pickering emulsion templated assembly enables the design of a hybrid colloidal capsule with engineered properties. However, the underlying mechanisms by which nanoparticles affect the mechanical properties of the shell are poorly understood. Herein, in situ mechanical compression on the transmission electron microscope and aberration-corrected scanning transmission microscope are unprecedentedly implemented to study the intrinsic effect of nanoparticles on the mechanical properties of the calcium carbonate (CaCO3 )-decorated silica (SiO2 ) colloidal capsule. The stiff and brittle nature of the colloidal capsule is due to the interfacial chemical bonding between the CaCO3 nanoparticles and SiO2 inner shell. Such bonding strengthens the mechanical strength of the SiO2 shell (166 ± 14 nm) from the colloidal capsule compared to the thicker single SiO2 shell (310 ± 70 nm) from the silica hollow sphere. At elevated temperature, this interfacial bonding accelerates the formation of the single calcium silicate shell, causing shell morphology transformation and yielding significantly enhanced mechanical strength by 30.9% and ductility by 94.7%. The superior thermal durability of the heat-treated colloidal capsule holds great potential for the fabrication of the functional additives that can be applied in the wide range of applications at elevated temperatures.
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Affiliation(s)
- Sang T Pham
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Kiet A Tieu
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Shanhong Wan
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Jingcheng Hao
- Key Laboratory of Colloid and Interface Chemistry and Key Laboratory of Special Aggregated Materials, Shandong University, Ministry of Education, Jinan, 250100, P. R. China
| | - Huynh H Nguyen
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - David R G Mitchell
- Electron Microscopy Centre, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Vitor Sencadas
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW, 2522, Australia
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW, 2522, Australia
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9
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Pham ST, Tieu AK, Wan S, Hao J, Zhu H, Nguyen HH, Mitchell DRG. Oxidative and Frictional Behavior of a Binary Sodium Borate–Silicate Composite in High-Temperature Lubricant Applications. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b05767] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Sang T. Pham
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, New South Wales 2522, Australia
| | - Anh Kiet Tieu
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, New South Wales 2522, Australia
| | - Shanhong Wan
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, New South Wales 2522, Australia
| | - Jingcheng Hao
- Key Laboratory of Colloid and Interface Chemistry & Key Laboratory of Special Aggregated Materials, Ministry of Education, Shandong University, Jinan 250100, PR China
| | - Hongtao Zhu
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, New South Wales 2522, Australia
| | - Huynh H. Nguyen
- Faculty of Engineering and Information Sciences, University of Wollongong, Northfields Avenue, Wollongong, New South Wales 2522, Australia
| | - David R. G. Mitchell
- Electron Microscopy Centre, University of Wollongong, Wollongong, New South Wales 2522, Australia
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Matthews GV, Pham ST, Hellard M, Grebely J, Zhang L, Oon A, Marks P, van Beek I, Rawlinson W, Kaldor JM, Lloyd A, Dore GJ, White PA. Patterns and characteristics of hepatitis C transmission clusters among HIV-positive and HIV-negative individuals in the Australian trial in acute hepatitis C. Clin Infect Dis 2011; 52:803-11. [PMID: 21282185 DOI: 10.1093/cid/ciq200] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Injecting drug users remain the population at greatest risk of acquiring hepatitis C virus (HCV) infection, although a recent increase in cases of sexually transmitted HCV infection has been observed among human immunodeficiency virus (HIV)-infected individuals. The extent to which these separate epidemics overlap is unknown. METHODS The Australian Trial in Acute Hepatitis C (ATAHC) enrolled 163 individuals (29% of whom were HIV infected) with recent HCV infection. E1/HVR1 sequences were used to construct phylogenetic trees demonstrating monophyletic clusters or pairs, and viral epidemic history and phylogeography were assessed using molecular clock analysis. Individual clusters were characterized by clinical and demographic characteristics. RESULTS Transmission through injection drug use occurred for 73% of subjects, with sexual transmission occurring for 18% (92% of whom were HIV infected). Among 112 individuals with available E1/HVR1 sequences, 23 (20%) were infected with a strain of HCV identical to that of another subject, comprising 4 homologous clusters and 3 monophyletic pairs, the majority of which (78%) were HIV infected. Clusters contained individuals with both injection drug use-related and sex-related acquisition, and in all clusters (except for 1 female HIV-uninfected pair), individuals identified as men who have sex with men, irrespective of HIV status. CONCLUSIONS This large unique study of HIV-infected and HIV-uninfected individuals with recently acquired HCV infection demonstrates that clustering is common in the HIV-infected population and that it occurred almost invariably among men who have sex with men, irrespective of the actual mode of acquisition. These findings suggest the coexistence of both injection drug use and sexual risk behaviors for individuals in the same social networks and have implications for the development of public health messages. Clinical trial registration. NCT00192569.
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Affiliation(s)
- G V Matthews
- National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Australia.
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Abstract
Congenital giant hairy nevi represent a special group of melanocytic lesions which generally cover large areas of the body surface. Giant hairy nevi assume special significance because of their predisposition to malignant transformation. Adequate treatment of this lesion involves complete surgical excision as early in the child's life as possible.
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Affiliation(s)
- M R Llaneras
- Emergency Medical Services, University of Virginia School of Medicine, Charlottesville 22908
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