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Ganguly A, McGlynn RJ, Boies A, Maguire P, Mariotti D, Chakrabarti S. Flexible Bifunctional Electrode for Alkaline Water Splitting with Long-Term Stability. ACS Appl Mater Interfaces 2024; 16:12339-12352. [PMID: 38425008 PMCID: PMC10941191 DOI: 10.1021/acsami.3c12944] [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: 08/31/2023] [Revised: 01/25/2024] [Accepted: 02/13/2024] [Indexed: 03/02/2024]
Abstract
Progress in electrochemical water-splitting devices as future renewable and clean energy systems requires the development of electrodes composed of efficient and earth-abundant bifunctional electrocatalysts. This study reveals a novel flexible and bifunctional electrode (NiO@CNTR) by hybridizing macroscopically assembled carbon nanotube ribbons (CNTRs) and atmospheric plasma-synthesized NiO quantum dots (QDs) with varied loadings to demonstrate bifunctional electrocatalytic activity for stable and efficient overall water-splitting (OWS) applications. Comparative studies on the effect of different electrolytes, e.g., acid and alkaline, reveal a strong preference for alkaline electrolytes for the developed NiO@CNTR electrode, suggesting its bifunctionality for both HER and OER activities. Our proposed NiO@CNTR electrode demonstrates significantly enhanced overall catalytic performance in a two-electrode alkaline electrolyzer cell configuration by assembling the same electrode materials as both the anode and the cathode, with a remarkable long-standing stability retaining ∼100% of the initial current after a 100 h long OWS run, which is attributed to the "synergistic coupling" between NiO QD catalysts and the CNTR matrix. Interestingly, the developed electrode exhibits a cell potential (E10) of only 1.81 V with significantly low NiO QD loading (83 μg/cm2) compared to other catalyst loading values reported in the literature. This study demonstrates a potential class of carbon-based electrodes with single-metal-based bifunctional catalysts that opens up a cost-effective and large-scale pathway for further development of catalysts and their loading engineering suitable for alkaline-based OWS applications and green hydrogen generation.
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Affiliation(s)
- Abhijit Ganguly
- School
of Engineering, Ulster University, Belfast BT15 1AP, Northern Ireland, U.K.
| | - Ruairi J. McGlynn
- School
of Engineering, Ulster University, Belfast BT15 1AP, Northern Ireland, U.K.
| | - Adam Boies
- Department
of Engineering, University of Cambridge, Cambridge CB2 1PZ, U.K.
| | - Paul Maguire
- School
of Engineering, Ulster University, Belfast BT15 1AP, Northern Ireland, U.K.
| | - Davide Mariotti
- School
of Engineering, Ulster University, Belfast BT15 1AP, Northern Ireland, U.K.
| | - Supriya Chakrabarti
- School
of Engineering, Ulster University, Belfast BT15 1AP, Northern Ireland, U.K.
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2
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Woon LSC, Allison S, Bastiampillai T, Kisely S, Maguire P, Pring W, Reay R, Looi JC. Comparison of the out-of-pocket costs of Medicare-funded telepsychiatry and face-to-face consultations: A descriptive study. Australas Psychiatry 2024:10398562241237128. [PMID: 38438122 DOI: 10.1177/10398562241237128] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
OBJECTIVE Telepsychiatry items in the Australian Medicare Benefits Schedule (MBS) were expanded following the COVID-19 pandemic. However, their out-of-pocket costs have not been examined. We describe and compare patient out-of-pocket payments for face-to-face and telepsychiatry (videoconferencing and telephone) MBS items for outpatient psychiatric services to understand the differential out-of-pocket cost burden for patients across these modalities. METHODS out-of-pocket cost information was obtained from the Medical Costs Finder website, which extracted data from Services Australia's Medicare claims data in 2021-2022. Cost information for corresponding face-to-face, video, and telephone MBS items for outpatient psychiatric services was compared, including (1) Median specialist fees; (2) Median out-of-pocket payments; (3) Medicare reimbursement amounts; and (4) Proportions of patients subject to out-of-pocket fees. RESULTS Medicare reimbursements are identical for all comparable face-to-face and telepsychiatry items. Specialist fees for comparable items varied across face-to-face to telehealth options, with resulting differences in out-of-pocket costs. For video items, higher proportions of patients were not bulk-billed, with greater out-of-pocket costs than face-to-face items. However, the opposite was true for telephone items compared with face-to-face items. CONCLUSIONS Initial cost analyses of MBS telepsychiatry items indicate that telephone consultations incur the lowest out-of-pocket costs, followed by face-to-face and video consultations.
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Affiliation(s)
- Luke S-C Woon
- Academic Unit of Psychiatry and Addiction Medicine, School of Medicine and Psychology, Canberra Hospital, The Australian National University Medical, Canberra, ACT, Australia; and
- Department of Psychiatry, Faculty of Medicine, The National University of Malaysia, Kuala Lumpur, Malaysia
| | - Stephen Allison
- Consortium of Australian-Academic Psychiatrists for Independent Policy and Research Analysis (CAPIPRA), Canberra, ACT, Australia; and
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Tarun Bastiampillai
- Consortium of Australian-Academic Psychiatrists for Independent Policy and Research Analysis (CAPIPRA), Canberra, ACT, Australia
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia; and
- Department of Psychiatry, Monash University, Clayton, VIC, Australia
| | - Steve Kisely
- Consortium of Australian-Academic Psychiatrists for Independent Policy and Research Analysis (CAPIPRA), Canberra, ACT, Australia
- School of Medicine, Princess Alexandra Hospital, University of Queensland, Brisbane, QLD, Australia; and
- Departments of Psychiatry, Community Health and Epidemiology, Dalhouise University, Halifax, NS, Canada
| | - Paul Maguire
- Academic Unit of Psychiatry and Addiction Medicine, School of Medicine and Psychology, Canberra Hospital, The Australian National University Medical, Canberra, ACT, Australia; and
- Consortium of Australian-Academic Psychiatrists for Independent Policy and Research Analysis (CAPIPRA), Canberra, ACT, Australia
| | - William Pring
- Consortium of Australian-Academic Psychiatrists for Independent Policy and Research Analysis (CAPIPRA), Canberra, ACT, Australia
- Department of Psychiatry, Monash University, Melbourne, VIC, Australia
- Centre for Mental Health Education and Research at Delmont Private Hospital, Melbourne, VIC, Australia; and
- Egmont Terrace Specialist Rooms, Private Psychiatrist, Melbourne, VIC, Australia
| | - Rebecca Reay
- Academic Unit of Psychiatry and Addiction Medicine, School of Medicine and Psychology, Canberra Hospital, The Australian National University Medical, Canberra, ACT, Australia
| | - Jeffrey Cl Looi
- Academic Unit of Psychiatry and Addiction Medicine, School of Medicine and Psychology, Canberra Hospital, The Australian National University Medical, Canberra, ACT, Australia; and
- Consortium of Australian-Academic Psychiatrists for Independent Policy and Research Analysis (CAPIPRA), Canberra, ACT, Australia
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3
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Huang JD, Wang H, Power U, McLaughlin JA, Nugent C, Rahman E, Barabas J, Maguire P. Detecting Respiratory Viruses Using a Portable NIR Spectrometer-A Preliminary Exploration with a Data Driven Approach. Sensors (Basel) 2024; 24:308. [PMID: 38203170 PMCID: PMC10781395 DOI: 10.3390/s24010308] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/13/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024]
Abstract
Respiratory viruses' detection is vitally important in coping with pandemics such as COVID-19. Conventional methods typically require laboratory-based, high-cost equipment. An emerging alternative method is Near-Infrared (NIR) spectroscopy, especially a portable one of the type that has the benefits of low cost, portability, rapidity, ease of use, and mass deployability in both clinical and field settings. One obstacle to its effective application lies in its common limitations, which include relatively low specificity and general quality. Characteristically, the spectra curves show an interweaving feature for the virus-present and virus-absent samples. This then provokes the idea of using machine learning methods to overcome the difficulty. While a subsequent obstacle coincides with the fact that a direct deployment of the machine learning approaches leads to inadequate accuracy of the modelling results. This paper presents a data-driven study on the detection of two common respiratory viruses, the respiratory syncytial virus (RSV) and the Sendai virus (SEV), using a portable NIR spectrometer supported by a machine learning solution enhanced by an algorithm of variable selection via the Variable Importance in Projection (VIP) scores and its Quantile value, along with variable truncation processing, to overcome the obstacles to a certain extent. We conducted extensive experiments with the aid of the specifically developed algorithm of variable selection, using a total of four datasets, achieving classification accuracy of: (1) 0.88, 0.94, and 0.93 for RSV, SEV, and RSV + SEV, respectively, averaged over multiple runs, for the neural network modelling of taking in turn 3 sessions of data for training and the remaining one session of an 'unknown' dataset for testing. (2) the average accuracy of 0.94 (RSV), 0.97 (SEV), and 0.97 (RSV + SEV) for model validation and 0.90 (RSV), 0.93 (SEV), and 0.91 (RSV + SEV) for model testing, using two of the datasets for model training, one for model validation and the other for model testing. These results demonstrate the feasibility of using portable NIR spectroscopy coupled with machine learning to detect respiratory viruses with good accuracy, and the approach could be a viable solution for population screening.
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Affiliation(s)
- Jian-Dong Huang
- School of Computing, Ulster University, Belfast BT15 1AP, UK
| | - Hui Wang
- School of Computing, Ulster University, Belfast BT15 1AP, UK
| | - Ultan Power
- Wellcome Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - James A. McLaughlin
- NIBEC Nanotechnology & Integrated Bio-Engineering Centre, School of Engineering, Ulster University, Belfast BT15 1AP, UK
| | - Chris Nugent
- School of Computing, Ulster University, Belfast BT15 1AP, UK
| | - Enayetur Rahman
- NIBEC Nanotechnology & Integrated Bio-Engineering Centre, School of Engineering, Ulster University, Belfast BT15 1AP, UK
| | - Judit Barabas
- Wellcome Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Paul Maguire
- NIBEC Nanotechnology & Integrated Bio-Engineering Centre, School of Engineering, Ulster University, Belfast BT15 1AP, UK
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McGlynn R, Brunet P, Chakrabarti S, Ganguly A, Moghaieb H, Bo Z, Maguire P, Mariotti D. A Single-Step Process to Produce Carbon Nanotube-Zinc Compound Hybrid Materials. Small Methods 2023:e2300710. [PMID: 37997223 DOI: 10.1002/smtd.202300710] [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: 06/06/2023] [Revised: 10/16/2023] [Indexed: 11/25/2023]
Abstract
An atmospheric-pressure plasma system is developed and is used to treat carbon nanotube assemblies, producing a hybrid carbon-zinc structure. This system is integrated into a floating-catalyst chemical vapor deposition furnace used for the synthesis of macroscopic assemblies of carbon nanotubes to allow for the in-line, continuous, and single-step production of nano-composite materials. Material is deposited from a sacrificial zinc wire in the form of nanoparticles and can coat the surface of the individual carbon nanotubes as they form. Additionally, it is found that the deposited materials penetrate further into the carbon nanotube matrix than a comparable post-synthesis deposition, improving the uniformity of the material through the thickness. Thus, a single-step metal-based coating and carbon nanotube synthesis process which can form the basis of production scale manufacturing of metal-carbon nanotube composite materials with an atmospheric-pressure plasma system are demonstrated.
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Affiliation(s)
- Ruairi McGlynn
- School of Engineering, Ulster University, Belfast, BT15 1AP, UK
| | - Paul Brunet
- School of Engineering, Ulster University, Belfast, BT15 1AP, UK
| | | | - Abhijit Ganguly
- School of Engineering, Ulster University, Belfast, BT15 1AP, UK
| | | | - Zheng Bo
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Paul Maguire
- School of Engineering, Ulster University, Belfast, BT15 1AP, UK
| | - Davide Mariotti
- School of Engineering, Ulster University, Belfast, BT15 1AP, UK
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Dsouza SD, Buerkle M, Alessi B, Brunet P, Morelli A, Payam AF, Maguire P, Mariotti D, Svrcek V. Synthesis of water-stable and highly luminescent graphite quantum dots. Nanotechnology 2023; 34. [PMID: 37683622 DOI: 10.1088/1361-6528/acf7cc] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/08/2023] [Indexed: 09/10/2023]
Abstract
Highly stable and environmentally friendly nitrogen-doped graphite quantum dots consisting of ∼12 layers of graphene, average diameter of ∼7.3 nm, prepared by atmospheric pressure microplasma are reported to have blue emission due to surface states created by nitrogen doping (9 atomic%) and reaction with oxygen. The low-temperature synthesis method requires simple precursors in water, with no annealing or filtration, producing crystalline disc-shaped quantum dots with ∼68% photoluminescence emission quantum yield at 420 nm excitation and that have shown stability for more than one month after the synthesis. The nitrogen doping in the quantum dots mainly occurs in graphitic core as substituted type of doping (63-67 atomic%) and the amount of doping is sufficient to create emissive states without impacting the core structure. The optical and chemical properties do not undergo serious retardation even with re-dispersion suggesting easy applicability for cellular imaging or optoelectronics.
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Affiliation(s)
- Slavia Deeksha Dsouza
- National Institute of Advanced Industrial Science and Technology (AIST) Central 2, Umezono 1-1-1, Tsukuba, Ibaraki, 305-8568, Japan
- School of Engineering, Ulster University, Belfast, BT15 1AP, United Kingdom
| | - Marius Buerkle
- National Institute of Advanced Industrial Science and Technology (AIST) Central 2, Umezono 1-1-1, Tsukuba, Ibaraki, 305-8568, Japan
| | - Bruno Alessi
- School of Engineering, Ulster University, Belfast, BT15 1AP, United Kingdom
| | - Paul Brunet
- School of Engineering, Ulster University, Belfast, BT15 1AP, United Kingdom
| | - Alessio Morelli
- School of Engineering, Ulster University, Belfast, BT15 1AP, United Kingdom
| | - Amir Farokh Payam
- School of Engineering, Ulster University, Belfast, BT15 1AP, United Kingdom
| | - Paul Maguire
- School of Engineering, Ulster University, Belfast, BT15 1AP, United Kingdom
| | - Davide Mariotti
- School of Engineering, Ulster University, Belfast, BT15 1AP, United Kingdom
| | - Vladimir Svrcek
- National Institute of Advanced Industrial Science and Technology (AIST) Central 2, Umezono 1-1-1, Tsukuba, Ibaraki, 305-8568, Japan
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6
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Mahmud M, Wade C, Jawad S, Hadi Z, Otoul C, Kaminski RM, Muglia P, Kadiu I, Rabiner E, Maguire P, Owen DR, Johnson MR. Translocator protein PET imaging in temporal lobe epilepsy: A reliable test-retest study using asymmetry index. Front Neuroimaging 2023; 2:1142463. [PMID: 37554649 PMCID: PMC10406252 DOI: 10.3389/fnimg.2023.1142463] [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] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 02/24/2023] [Indexed: 08/10/2023]
Abstract
Objective Translocator protein (TSPO) targeting positron emission tomography (PET) imaging radioligands have potential utility in epilepsy to assess the efficacy of novel therapeutics for targeting neuroinflammation. However, previous studies in healthy volunteers have indicated limited test-retest reliability of TSPO ligands. Here, we examine test-retest measures using TSPO PET imaging in subjects with epilepsy and healthy controls, to explore whether this biomarker can be used as an endpoint in clinical trials for epilepsy. Methods Five subjects with epilepsy and confirmed mesial temporal lobe sclerosis (mean age 36 years, 3 men) were scanned twice-on average 8 weeks apart-using a second generation TSPO targeting radioligand, [11C]PBR28. We evaluated the test-retest reliability of the volume of distribution and derived hemispheric asymmetry index of [11C]PBR28 binding in these subjects and compared the results with 8 (mean age 45, 6 men) previously studied healthy volunteers. Results The mean (± SD) of the volume of distribution (VT), of all subjects, in patients living with epilepsy for both test and retest scans on all regions of interest (ROI) is 4.49 ± 1.54 vs. 5.89 ± 1.23 in healthy volunteers. The bias between test and retest in an asymmetry index as a percentage was small (-1.5%), and reliability is demonstrated here with Bland-Altman Plots (test mean 1.062, retest mean 2.56). In subjects with epilepsy, VT of [11C]PBR28 is higher in the (ipsilateral) hippocampal region where sclerosis is present than in the contralateral region. Conclusion When using TSPO PET in patients with epilepsy with hippocampal sclerosis (HS), an inter-hemispheric asymmetry index in the hippocampus is a measure with good test-retest reliability. We provide estimates of test-retest variability that may be useful for estimating power where group change in VT represents the clinical outcome.
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Affiliation(s)
- Mohammad Mahmud
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Charles Wade
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Sarah Jawad
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Zaeem Hadi
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Christian Otoul
- Clinical Imaging Translational, UCB Pharma SA, Brussels, Belgium
| | - Rafal M. Kaminski
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | | | - Irena Kadiu
- Clinical Imaging Translational, UCB Pharma SA, Brussels, Belgium
| | - Eugenii Rabiner
- Translational Applications, Invicro LLC, London, United Kingdom
| | - Paul Maguire
- Clinical Imaging Translational, UCB Pharma SA, Brussels, Belgium
| | - David R. Owen
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Michael R. Johnson
- Department of Brain Sciences, Imperial College London, London, United Kingdom
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Moghaieb HS, Amendola V, Khalil S, Chakrabarti S, Maguire P, Mariotti D. Nanofluids for Direct-Absorption Solar Collectors-DASCs: A Review on Recent Progress and Future Perspectives. Nanomaterials (Basel) 2023; 13:1232. [PMID: 37049324 PMCID: PMC10096558 DOI: 10.3390/nano13071232] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/22/2023] [Accepted: 03/27/2023] [Indexed: 06/19/2023]
Abstract
Owing to their superior optical and thermal properties over conventional fluids, nanofluids represent an innovative approach for use as working fluids in direct-absorption solar collectors for efficient solar-to-thermal energy conversion. The application of nanofluids in direct-absorption solar collectors demands high-performance solar thermal nanofluids that exhibit exceptional physical and chemical stability over long periods and under a variety of operating, fluid dynamics, and temperature conditions. In this review, we discuss recent developments in the field of nanofluids utilized in direct-absorption solar collectors in terms of their preparation techniques, optical behaviours, solar thermal energy conversion performance, as well as their physical and thermal stability, along with the experimental setups and calculation approaches used. We also highlight the challenges associated with the practical implementation of nanofluid-based direct-absorption solar collectors and offer suggestions and an outlook for the future.
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Affiliation(s)
| | - Vincenzo Amendola
- Dipartimento di Scienze Chimiche, Universita’ degli Studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Sameh Khalil
- School of Engineering, Ulster University, 2-24 York Street, Belfast BT15 1AP, UK
| | - Supriya Chakrabarti
- School of Engineering, Ulster University, 2-24 York Street, Belfast BT15 1AP, UK
| | - Paul Maguire
- School of Engineering, Ulster University, 2-24 York Street, Belfast BT15 1AP, UK
| | - Davide Mariotti
- School of Engineering, Ulster University, 2-24 York Street, Belfast BT15 1AP, UK
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8
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Looi JC, Bonner D, Maguire P, ACT C. Medical education in psychiatry and addiction medicine: pandemic education as usual or the new normal? Australas Psychiatry 2022; 30:669. [PMID: 35655336 PMCID: PMC9168410 DOI: 10.1177/10398562221106062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Henderson B, Maguire P, Keartland S, Barr M, Crulhas B, Keating G, Fitzmaurice G, Gray S, Nicholson S, Finn S, Gately K. EP02.01-002 Development of Circulating and Tissue Biomarkers Predicting Immune Phenotype and Response to Immunotherapy in NSCLC. J Thorac Oncol 2022. [DOI: 10.1016/j.jtho.2022.07.329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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10
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McGlynn RJ, Moghaieb HS, Brunet P, Chakrabarti S, Maguire P, Mariotti D. Hybrid Plasma-Liquid Functionalisation for the Enhanced Stability of CNT Nanofluids for Application in Solar Energy Conversion. Nanomaterials (Basel) 2022; 12:2705. [PMID: 35957139 PMCID: PMC9370158 DOI: 10.3390/nano12152705] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/27/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Macroscopic ribbon-like assemblies of carbon nanotubes (CNTs) are functionalised using a simple direct-current-based plasma-liquid system, with oxygen and nitrogen functional groups being added. These modifications have been shown to reduce the contact angle of the ribbons, with the greatest reduction being from 84° to 35°. The ability to improve the wettability of the CNTs is of paramount importance for producing nanofluids, with relevance for a number of applications. Here, in particular, we investigate the efficacy of these samples as nanofluid additives for solar-thermal harvesting. Surface treatments by plasma-induced non-equilibrium electrochemistry are shown to enhance the stability of the nanofluids, allowing for full redispersion under simulated operating conditions. Furthermore, the enhanced dispersibility results in both a larger absorption coefficient and an improved thermal profile under solar simulation.
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Affiliation(s)
- Ruairi J. McGlynn
- Correspondence: (R.J.M.); (D.M.); Tel.: +44-7548493594 (R.J.M.); +44-28-9536-5266 (D.M.)
| | | | | | | | | | - Davide Mariotti
- Correspondence: (R.J.M.); (D.M.); Tel.: +44-7548493594 (R.J.M.); +44-28-9536-5266 (D.M.)
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Miura S, Abady Z, Pollok F, Ma M, Kinoshita K, Fogarty S, Maguire P, Daugherty B, Lederman S, Pierson R. TNX-1500, an Fc-Modified Anti-CD154 Antibody, Prolongs Nonhuman Primate Cardiac Allograft Survival. J Heart Lung Transplant 2022. [DOI: 10.1016/j.healun.2022.01.348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Abstract
OBJECTIVE To discuss narrow pragmatism, manifest as digital and technical solutionism, in mental healthcare and psychiatric practice. Pragmatism is a view of the field of psychiatry as an instrument or tool for the purpose of providing psychiatric care for people with a mental illness. Solutionism, as proposed by Morozov, can be considered a special case of pragmatism that valorises an approach to solving real-world problems based on computation, algorithms and digital technology,1 which we extend to discuss other technical solutions such as medication, non-invasive brain stimulation and psychotherapy. CONCLUSIONS Digital or technical solutionism may unnecessarily constrain approaches to mental healthcare and psychiatric practice. Psychiatrists can consider, and should advocate for, appropriate adaptation of technology and technical solutions toward collaborative and effective mental healthcare.
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Affiliation(s)
- Jeffrey C L Looi
- Academic Unit of Psychiatry and Addiction Medicine, the Australian National University Medical School, Canberra Hospital, ACT, Australia
| | - Daniel Bonner
- Academic Unit of Psychiatry and Addiction Medicine, the Australian National University Medical School, Canberra Hospital, ACT, Australia
| | - Paul Maguire
- Academic Unit of Psychiatry and Addiction Medicine, the Australian National University Medical School, Canberra Hospital, ACT, Australia
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13
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Looi JCL, Maguire P, Bonner D, Reay RE, Finlay AJF, Keightley P, Tedeschi M, Wardle C, Kramer D. Conduct and evaluation of final-year medical student summative assessments in Psychiatry and Addiction Medicine during COVID-19: an Australian University Medical School experience. Australas Psychiatry 2021; 29:695-698. [PMID: 34039055 DOI: 10.1177/10398562211014229] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To describe and share with the medical education community, the conduct and evaluation of summative graduate medical student assessments in Psychiatry and Addiction Medicine during COVID-19 at an Australian university. METHODS Summative assessments were redesigned as follows: written assessments were administered via an online platform (WATTLE), while the Objective Structured Clinical Examinations (OSCE) were conducted via a secure video-conferencing software (Zoom). RESULTS Our preliminary analysis of the summative assessments indicated that both examiners and students adapted to the format, with overall performance of the students showing no variation due to timing of the assessment (earlier versus later in the day) and performances similar to face-to-face assessments in previous years. Examiners also expressed positive feedback on the assessment process. CONCLUSIONS Our graduate fourth-year medical student summative assessments were effectively conducted using online and video-conferencing software in accordance with existing COVID-19 pandemic public health measures for physical distancing and hygiene.
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Affiliation(s)
- Jeffrey C L Looi
- Academic Unit of Psychiatry and Addiction Medicine, The Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Paul Maguire
- Academic Unit of Psychiatry and Addiction Medicine, The Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Daniel Bonner
- Academic Unit of Psychiatry and Addiction Medicine, The Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Rebecca E Reay
- Academic Unit of Psychiatry and Addiction Medicine, The Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Angus J F Finlay
- Academic Unit of Psychiatry and Addiction Medicine, The Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Philip Keightley
- Academic Unit of Psychiatry and Addiction Medicine, The Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Michael Tedeschi
- Academic Unit of Psychiatry and Addiction Medicine, The Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Claire Wardle
- Medical Education Unit, The Australian National University Medical School, Acton, ACT, Australia
| | - David Kramer
- Medical Education Unit, The Australian National University Medical School, Acton, ACT, Australia
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14
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Flanagan P, Costello L, Alsaleh E, Byrne L, Maguire P, Adams A, Flannery S. Best practice in male urinary catheterization – A systematic review. EUR UROL SUPPL 2021. [DOI: 10.1016/s2666-1683(21)00243-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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15
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McDonald C, Ni C, Švrček V, Macias-Montero M, Velusamy T, Connor PA, Maguire P, Irvine JTS, Mariotti D. Carrier extraction from metallic perovskite oxide nanoparticles. Nanoscale 2021; 13:12271-12278. [PMID: 34241608 DOI: 10.1039/d1nr02890a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We observe the extraction of carriers excited between two types of bands in the perovskite oxide, Sr-deficient strontium niobate (Sr0.9NbO3). Sr0.9NbO3 exhibits metallic behaviour and high conductivity, whilst also displaying broad absorption across the ultraviolet, visible, and near-infrared spectral regions, making it an attractive material for solar energy conversion. Furthermore, the optoelectronic properties of strontium niobate can easily be tuned by varying the Sr fraction or through doping. Sr-deficient strontium niobate exhibits a split conduction band, which enables two types of optical transitions: intraband and interband. However, whether such carriers can be extracted from an unusual material as such remains unproven. In this report, we have overcome the immense challenge of photocarrier extraction by fabricating an extremely thin absorber layer of Sr0.9NbO3 nanoparticles. These findings open up great opportunities to harvest a very broad solar spectral absorption range with reduced recombination losses.
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Affiliation(s)
- Calum McDonald
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University, BT37 0QB, UK.
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16
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Su Z, Sun D, Zhang L, He M, Jiang Y, Millar B, Douglas P, Mariotti D, Maguire P, Sun D. Chitosan/Silver Nanoparticle/Graphene Oxide Nanocomposites with Multi-Drug Release, Antimicrobial, and Photothermal Conversion Functions. Materials (Basel) 2021; 14:2351. [PMID: 33946613 PMCID: PMC8124926 DOI: 10.3390/ma14092351] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/25/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023]
Abstract
In this work, we designed and fabricated a multifunctional nanocomposite system that consists of chitosan, raspberry-like silver nanoparticles, and graphene oxide. The room temperature atmospheric pressure microplasma (RT-APM) process provides a rapid, facile, and environmentally-friendly method for introducing silver nanoparticles into the composite system. Our composite can achieve a pH controlled single and/or dual drug release. Under pH 7.4 for methyl blue loaded on chitosan, the drug release profile features a burst release during the first 10 h, followed by a more stabilized release of 70-80% after 40-50 h. For fluorescein sodium loaded on graphene oxide, the drug release only reached 45% towards the end of 240 h. When the composite acted as a dual drug release system, the interaction of fluorescein sodium and methyl blue slowed down the methyl blue release rate. Under pH 4, both single and dual drug systems showed a much higher release rate. In addition, our composite system demonstrated strong antibacterial abilities against E. coli and S. aureus, as well as an excellent photothermal conversion effect under irradiation of near infrared lasers. The photothermal conversion efficiency can be controlled by the laser power. These unique functionalities of our nanocomposite point to its potential application in multiple areas, such as multimodal therapeutics in healthcare, water treatment, and anti-microbials, among others.
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Affiliation(s)
- Zheng Su
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, China;
- School of Mechanical & Aerospace Engineering, Queens University Belfast, Belfast BT9 5AH, UK; (D.S.); (B.M.); (P.D.)
| | - Daye Sun
- School of Mechanical & Aerospace Engineering, Queens University Belfast, Belfast BT9 5AH, UK; (D.S.); (B.M.); (P.D.)
| | - Li Zhang
- Research Center for Nano-Biomaterials, Analytical & Testing Center, Sichuan University, Chengdu 610065, China; (L.Z.); (M.H.); (Y.J.)
| | - Miaomiao He
- Research Center for Nano-Biomaterials, Analytical & Testing Center, Sichuan University, Chengdu 610065, China; (L.Z.); (M.H.); (Y.J.)
| | - Yulin Jiang
- Research Center for Nano-Biomaterials, Analytical & Testing Center, Sichuan University, Chengdu 610065, China; (L.Z.); (M.H.); (Y.J.)
| | - Bronagh Millar
- School of Mechanical & Aerospace Engineering, Queens University Belfast, Belfast BT9 5AH, UK; (D.S.); (B.M.); (P.D.)
| | - Paula Douglas
- School of Mechanical & Aerospace Engineering, Queens University Belfast, Belfast BT9 5AH, UK; (D.S.); (B.M.); (P.D.)
| | - Davide Mariotti
- Nanotechnology and Integrated Bioengineering Center (NIBEC), Ulster University, Co Antrim BT37 OQB, UK; (D.M.); (P.M.)
| | - Paul Maguire
- Nanotechnology and Integrated Bioengineering Center (NIBEC), Ulster University, Co Antrim BT37 OQB, UK; (D.M.); (P.M.)
| | - Dan Sun
- School of Mechanical & Aerospace Engineering, Queens University Belfast, Belfast BT9 5AH, UK; (D.S.); (B.M.); (P.D.)
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17
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Cawthorne C, Maguire P, Mercier J, Sciberras D, Serdons K, Bormans G, de Hoon J, Van Laere K, Koole M. Human biodistribution and dosimetry of [ 11C]-UCB-J, a PET radiotracer for imaging synaptic density. EJNMMI Phys 2021; 8:37. [PMID: 33891195 PMCID: PMC8065069 DOI: 10.1186/s40658-021-00384-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/13/2021] [Indexed: 11/10/2022] Open
Abstract
RATIONALE [11C]-UCB-J is an emerging tool for the noninvasive measurement of synaptic vesicle density in vivo. Here, we report human biodistribution and dosimetry estimates derived from sequential whole-body PET using two versions of the OLINDA dosimetry program. METHODS Sequential whole-body PET scans were performed in 3 healthy subjects for 2 h after injection of 254 ± 77 MBq [11C]-UCB-J. Volumes of interest were drawn over relevant source organs to generate time-activity curves and calculate time-integrated activity coefficients, with effective dose coefficients calculated using OLINDA 2.1 and compared to values derived from OLINDA 1.1 and those recently reported in the literature. RESULTS [11C]-UCB-J administration was safe and showed mixed renal and hepatobiliary clearance, with largest organ absorbed dose coefficients for the urinary bladder wall and small intestine (21.7 and 23.5 μGy/MBq, respectively). The average (±SD) effective dose coefficient was 5.4 ± 0.7 and 5.1 ± 0.8 μSv/MBq for OLINDA versions 1.1 and 2.1 respectively. Doses were lower than previously reported in the literature using either software version. CONCLUSIONS A single IV administration of 370 MBq [11C]-UCB-J corresponds to an effective dose of less than 2.0 mSv, enabling multiple PET examinations to be carried out in the same subject. TRIAL REGISTRATION EudraCT number: 2016-001190-32. Registered 16 March 2016, no URL available for phase 1 trials.
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Affiliation(s)
- Christopher Cawthorne
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | | | | | | | - Kim Serdons
- Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
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18
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Looi JC, Allison S, Kisely SR, Maguire P. Portents from Orwell's 1984: Bureaucracies, Ministries of Truth and Plenty - challenges facing the administration of mental healthcare in Australia. Australas Psychiatry 2021; 29:149-152. [PMID: 32615780 DOI: 10.1177/1039856220937646] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE We reflect upon the processes of mental health administration in Australia with reference to George Orwell's novel, 1984. CONCLUSIONS Mental healthcare in Australia is distorted by politicisation, spin and a refusal to acknowledge the reality of the current situation. These challenges for mental healthcare demonstrate some similarities with the Ministries of Truth and Plenty, which conversely performed as their opposites in Orwell's novel. Psychiatrists and their professional bodies should play a greater role in advocacy for clinician-led, evidence-based services in partnership with our communities.
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Affiliation(s)
- Jeffrey Cl Looi
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Stephen Allison
- Discipline of Psychiatry, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Stephen R Kisely
- School of Medicine, Princess Alexandra Hospital, The University of Queensland, Brisbane, QLD, Australia
- Departments of Psychiatry, Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Paul Maguire
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
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19
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Brunet P, McGlynn RJ, Alessi B, Smail F, Boies A, Maguire P, Mariotti D. Surfactant-free synthesis of copper nanoparticles and gas phase integration in CNT-composite materials. Nanoscale Adv 2021; 3:781-788. [PMID: 36133850 PMCID: PMC9419625 DOI: 10.1039/d0na00922a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 11/27/2020] [Indexed: 06/16/2023]
Abstract
Copper nanoparticles (Cu-NPs) represent a viable low-cost alternative to replace bulk copper or other more expensive NPs (e.g. gold or silver) in various applications such as electronics for electrical contact materials or high conductivity materials. This study deals with the synthesis of well dispersed Cu-NPs by using an Ar + H2 microplasma using a solid copper precursor. The morphological analysis is carried out by electron microscopy showing particles with a mean diameter of 8 nm. Crystallinity and chemical analyses were also carried out by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. In the second step, the Cu-NPs were successfully deposited onto porous carbon nanotube ribbons; surface coverage and the penetration depth of the Cu-NPs inside the CNT ribbon structure were investigated as these can be beneficial for a number of applications. The oxidation state of the Cu-NPs was also studied in detail under different conditions.
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Affiliation(s)
- Paul Brunet
- Nanotechnology and Integrated Bio Engineering Centre (NIBEC), Ulster University Newtownabbey BT370QB UK
| | - Ruairi J McGlynn
- Nanotechnology and Integrated Bio Engineering Centre (NIBEC), Ulster University Newtownabbey BT370QB UK
| | - Bruno Alessi
- Nanotechnology and Integrated Bio Engineering Centre (NIBEC), Ulster University Newtownabbey BT370QB UK
| | - Fiona Smail
- Department of Engineering, Cambridge University Cambridge UK
| | - Adam Boies
- Department of Engineering, Cambridge University Cambridge UK
| | - Paul Maguire
- Nanotechnology and Integrated Bio Engineering Centre (NIBEC), Ulster University Newtownabbey BT370QB UK
| | - Davide Mariotti
- Nanotechnology and Integrated Bio Engineering Centre (NIBEC), Ulster University Newtownabbey BT370QB UK
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20
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Looi JC, Bonner D, Maguire P, Finlay A, Keightley P, Parige R, Tedeschi M, Reay R, Davis SL. Flattening the curve of COVID-19 for medical education in psychiatry and addiction medicine. Australas Psychiatry 2021; 29:31-34. [PMID: 32772702 PMCID: PMC7424613 DOI: 10.1177/1039856220946647] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To describe the context, challenges and responses to COVID-19 public health measures for medical education in psychiatry, with an emphasis on sharing strategies for ongoing COVID-19 challenges. CONCLUSION The rapidity of COVID-19 public health measures instituted in Australia required swift action for medical education to address lockdowns of student clinical placements. The responses included a transition to interim online learning followed by a return to truncated clinical placements renegotiated to conform to public health measures. Adjustment of formative and summative assessment has been necessary. However, further contingencies may emerge depending upon the overall progress of the COVID-19 pandemic.
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Affiliation(s)
- Jeffrey Cl Looi
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Australia
| | - Daniel Bonner
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Australia
| | - Paul Maguire
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Australia
| | - Angus Finlay
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Australia
| | - Philip Keightley
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Australia
| | - Raj Parige
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Australia
| | - Michael Tedeschi
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Australia
| | - Rebecca Reay
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Australia
| | - Soo-Leng Davis
- Australian National University Medical School, Canberra Hospital Campus, Australia
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21
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Looi JC, Allison S, Bastiampillai T, Maguire P. Fire, disease and fear: Effects of the media coverage of 2019-2020 Australian bushfires and novel coronavirus 2019 on population mental health. Aust N Z J Psychiatry 2020; 54:938-939. [PMID: 32529837 DOI: 10.1177/0004867420931163] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Jeffrey Cl Looi
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Garran, ACT, Australia
| | - Stephen Allison
- Discipline of Psychiatry, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Tarun Bastiampillai
- Discipline of Psychiatry, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.,South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Paul Maguire
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Garran, ACT, Australia
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22
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Looi JCL, Anderson K, Bonner D, Maguire P, Reay R. Student evaluations of teaching (SET): implications for medical education in psychiatry and an approach to evaluating SET and student performance. Australas Psychiatry 2020; 28:463-465. [PMID: 32438873 DOI: 10.1177/1039856220924327] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE We present reflections on student evaluation of teaching (SET) in the context of recent higher educational research that assesses SET, as well as concurrent and/or subsequent student performance. CONCLUSIONS In a sense, there is in-built cynicism in SET, with more favourable SET for easier assessment. There is emerging evidence that SET is inversely proportional to the performance of students in subsequent courses, i.e. the higher the ratings, the poorer the students perform in subsequent studies. It is proposed that SET should be combined with contemporaneous formative and summative assessments of student performance in medical school settings, especially in psychiatry education.
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Affiliation(s)
- Jeffrey C L Looi
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Katrina Anderson
- Academic Unit of General Practice, ANU Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Daniel Bonner
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Paul Maguire
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
| | - Rebecca Reay
- Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra Hospital, Canberra, ACT, Australia
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23
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Alessi B, Macias-Montero M, Maddi C, Maguire P, Svrcek V, Mariotti D. Bridging energy bands to the crystalline and amorphous states of Si QDs. Faraday Discuss 2020; 222:390-404. [PMID: 32133465 DOI: 10.1039/c9fd00103d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The relationship between the crystallization process and opto-electronic properties of silicon quantum dots (Si QDs) synthesized by atmospheric pressure plasmas (APPs) is studied in this work. The synthesis of Si QDs is carried out by flowing silane as a gas precursor in a plasma confined to a submillimeter space. Experimental conditions are adjusted to propitiate the crystallization of the Si QDs and produce QDs with both amorphous and crystalline character. In all cases, the Si QDs present a well-defined mean particle size in the range of 1.5-5.5 nm. Si QDs present optical bandgaps between 2.3 eV and 2.5 eV, which are affected by quantum confinement. Plasma parameters evaluated using optical emission spectroscopy are then used as inputs for a collisional plasma model, whose calculations yield the surface temperature of the Si QDs within the plasma, justifying the crystallization behavior under certain experimental conditions. We measure the ultraviolet-visible optical properties and electronic properties through various techniques, build an energy level diagram for the valence electrons region as a function of the crystallinity of the QDs, and finally discuss the integration of these as active layers of all-inorganic solar cells.
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Affiliation(s)
- Bruno Alessi
- Nanotechnology and Integrated Bio-Engineering Centre (NIBEC), Ulster University, Newtownabbey, BT37 0QB, UK.
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24
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McQuaid SL, Loughran ST, Power PA, Maguire P, Szczygiel A, Johnson PA. Low-dose IL-2 induces CD56 bright NK regulation of T cells via NKp44 and NKp46. Clin Exp Immunol 2020; 200:228-241. [PMID: 31989589 PMCID: PMC7232012 DOI: 10.1111/cei.13422] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2020] [Indexed: 12/16/2022] Open
Abstract
Low-dose interleukin (IL)-2 has shown clinical benefits in patients with autoimmune and inflammatory diseases. Both regulatory T cells (Tregs ) and natural killer (NK) cells are increased in response to low-dose IL-2 immunotherapy. The role of regulatory T cells in autoimmune diseases has been extensively studied; however, NK cells have not been as thoroughly explored. It has not been well reported whether the increase in NK cells is purely an epiphenomenon or carries actual benefits for patients with autoimmune diseases. We demonstrate that low-dose IL-2 expands the primary human CD56bright NK cells resulting in a contact-dependent cell cycle arrest of effector T cells (Teffs ) via retention of the cycle inhibitor p21. We further show that NK cells respond via IL-2R-β, which has been shown to be significant for immunity by regulating T cell expansion. Moreover, we demonstrate that blocking NK receptors NKp44 and NKp46 but not NKp30 could abrogate the regulation of proliferation associated with low-dose IL-2. The increase in NK cells was also accompanied by an increase in Treg cells, which is dependent on the presence of CD56bright NK cells. These results not only heighten the importance of NK cells in low-dose IL-2 therapy but also identify key human NK targets, which may provide further insights into the therapeutic mechanisms of low-dose IL-2 in autoimmunity.
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Affiliation(s)
- S. L. McQuaid
- Viral Immunology LaboratorySchool of Nursing, Psychotherapy and Community HealthDublin City UniversityDublinIreland
- Mason Technology LtdDublinIreland
| | - S. T. Loughran
- Viral Immunology LaboratorySchool of Nursing, Psychotherapy and Community HealthDublin City UniversityDublinIreland
- Department of Applied ScienceDundalk Institute of TechnologyDundalkIreland
| | - P. A. Power
- Viral Immunology LaboratorySchool of Nursing, Psychotherapy and Community HealthDublin City UniversityDublinIreland
- Technological University DublinDublinIreland
| | - P. Maguire
- Viral Immunology LaboratorySchool of Nursing, Psychotherapy and Community HealthDublin City UniversityDublinIreland
- School of BiotechnologyDublin City UniversityDublinIreland
| | - A. Szczygiel
- Viral Immunology LaboratorySchool of Nursing, Psychotherapy and Community HealthDublin City UniversityDublinIreland
| | - P. A. Johnson
- Viral Immunology LaboratorySchool of Nursing, Psychotherapy and Community HealthDublin City UniversityDublinIreland
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25
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Jain G, Rocks C, Maguire P, Mariotti D. One-step synthesis of strongly confined, defect-free and hydroxy-terminated ZnO quantum dots. Nanotechnology 2020; 31:215707. [PMID: 32155133 DOI: 10.1088/1361-6528/ab72b5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This paper reports the production of strongly confined ligand-free, defect-free, hydroxy-terminated ZnO quantum dots with a mean diameter of 1.9 nm, by radio frequency atmospheric pressure microplasma. Systematic characterization is performed to understand the surface chemistry of ZnO quantum dots. Photoluminescence studies show strong confinement effect on emission with only ultraviolet (UV) emission without any defect-related visible emission. Emission is again tested after eighteen months and confirms the QDs long-term emission stability. The mechanism responsible for this UV emission is also discussed and originates from OH-related surface terminations.
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Affiliation(s)
- Gunisha Jain
- Nanotechnology and Integrated Bioengineering centre, Ulster University, Newtownabbey, United Kingdom
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26
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Haq AU, Buerkle M, Askari S, Rocks C, Ni C, Švrček V, Maguire P, Irvine JTS, Mariotti D. Controlling the Energy-Level Alignment of Silicon Carbide Nanocrystals by Combining Surface Chemistry with Quantum Confinement. J Phys Chem Lett 2020; 11:1721-1728. [PMID: 32040322 PMCID: PMC7145349 DOI: 10.1021/acs.jpclett.9b03828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 02/10/2020] [Indexed: 06/10/2023]
Abstract
The knowledge of band edges in nanocrystals (NCs) and quantum-confined systems is important for band alignment in technologically significant applications such as water purification, decomposition of organic compounds, water splitting, and solar cells. While the band energy diagram of bulk silicon carbides (SiCs) has been studied extensively for decades, very little is known about its evolution in SiC NCs. Moreover, the interplay between quantum confinement and surface chemistry gives rise to unusual electronic properties and remains barely understood. Here, we report for the first time the complete band energy diagram of SiC NCs synthesized such that they span the regime from strong to intermediate to weak quantum confinement. The absolute positions of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals show clear size dependence. While the HOMO level follows the expected behavior for quantum-confined electronic states, the LUMO energy shifts below the bulk conduction band minimum, which cannot be explained by a simple quantum confinement caused by the size effect. We show that this effect is a result of the interplay between quantum confinement and the formation of surface states due to partial and site-selective oxygen passivation.
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Affiliation(s)
- Atta Ul Haq
- Nanotechnology
& Integrated Bioengineering Centre (NIBEC), Ulster University, Shore Road, Newtownabbey BT37 0QB, United Kingdom
| | - Marius Buerkle
- National
Institute of Advanced Industrial Science and Technology (AIST), Central 2, Tsukuba 305-8568, Japan
| | - Sadegh Askari
- Institute
for Experimental and Applied Physics, Christian-Albrechts-Universität
zu Kiel, Leibnizstraße
17, 24118 Kiel, Germany
| | - Conor Rocks
- Nanotechnology
& Integrated Bioengineering Centre (NIBEC), Ulster University, Shore Road, Newtownabbey BT37 0QB, United Kingdom
| | - Chengsheng Ni
- School
of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, United Kingdom
- College
of Resources and Environment, Southwest
University, 400715, Chongqing, China
| | - Vladimir Švrček
- National
Institute of Advanced Industrial Science and Technology (AIST), Central 2, Tsukuba 305-8568, Japan
| | - Paul Maguire
- Nanotechnology
& Integrated Bioengineering Centre (NIBEC), Ulster University, Shore Road, Newtownabbey BT37 0QB, United Kingdom
| | - John T. S. Irvine
- School
of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, United Kingdom
| | - Davide Mariotti
- Nanotechnology
& Integrated Bioengineering Centre (NIBEC), Ulster University, Shore Road, Newtownabbey BT37 0QB, United Kingdom
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27
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McDonald C, Ni C, Maguire P, Mariotti D, Svrcek V. Performance and stability gain in zero-dimensional perovskite solar cells after >2 years when hybridized with silicon nanocrystals. Nanoscale Adv 2019; 1:4683-4687. [PMID: 36133124 PMCID: PMC9417058 DOI: 10.1039/c9na00516a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 11/06/2019] [Indexed: 06/16/2023]
Abstract
We report highly stable zero-dimensional (CH3NH3)3Bi2I9 photovoltaic cells which demonstrate a 33% increase in performance after 2 years when hybridized with silicon nanocrystals (SiNCs). The natural oxidation of SiNCs is expected to consume radical species and improve the SiNC/(CH3NH3)3Bi2I9 interface and electronic coupling whilst also inhibiting defect-induced degradation.
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Affiliation(s)
- Calum McDonald
- Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST) Central 2, Umezono 1-1-1 Tsukuba 305-8568 Japan
| | - Chengsheng Ni
- College of Resources and Environment, Southwest University Beibei Chongqing China
| | - Paul Maguire
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University Shore Road Newtownabbey BT37 0QB UK
| | - Davide Mariotti
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University Shore Road Newtownabbey BT37 0QB UK
| | - Vladimir Svrcek
- Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST) Central 2, Umezono 1-1-1 Tsukuba 305-8568 Japan
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Chakrabarti S, Carolan D, Alessi B, Maguire P, Svrcek V, Mariotti D. Microplasma-synthesized ultra-small NiO nanocrystals, a ubiquitous hole transport material. Nanoscale Adv 2019; 1:4915-4925. [PMID: 36133136 PMCID: PMC9417055 DOI: 10.1039/c9na00299e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/21/2019] [Indexed: 05/27/2023]
Abstract
We report on a one-step hybrid atmospheric pressure plasma-liquid synthesis of ultra-small NiO nanocrystals (2 nm mean diameter), which exhibit strong quantum confinement. We show the versatility of the synthesis process and present the superior material characteristics of the nanocrystals (NCs). The band diagram of the NiO NCs, obtained experimentally, highlights ideal features for their implementation as a hole transport layer in a wide range of photovoltaic (PV) device architectures. As a proof of concept, we demonstrate the NiO NCs as a hole transport layer for three different PV device test architectures, which incorporate silicon quantum dots (Si-QDs), nitrogen-doped carbon quantum dots (N-CQDs) and perovskite as absorber layers. Our results clearly show ideal band alignment which could lead to improved carrier extraction into the metal contacts for all three solar cells. In addition, in the case of perovskite solar cells, the NiO NC hole transport layer acted as a protective layer preventing the degradation of halide perovskites from ambient moisture with a stable performance for >70 days. Our results also show unique characteristics that are highly suitable for future developments in all-inorganic 3rd generation solar cells (e.g. based on quantum dots) where quantum confinement can be used effectively to tune the band diagram to fit the energy level alignment requirements of different solar cell architectures.
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Affiliation(s)
- Supriya Chakrabarti
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University Jordanstown, Newtownabbey Co. Antrim BT37 0QB UK
- Centre for Carbon Materials, International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI) Balapur P.O. Hyderabad 500005 India
| | - Darragh Carolan
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University Jordanstown, Newtownabbey Co. Antrim BT37 0QB UK
| | - Bruno Alessi
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University Jordanstown, Newtownabbey Co. Antrim BT37 0QB UK
| | - Paul Maguire
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University Jordanstown, Newtownabbey Co. Antrim BT37 0QB UK
| | - Vladimir Svrcek
- National Institute of Advanced Industrial Science and Technology (AIST), Department of Energy and Environment, Research Center of Photovoltaics, Advanced Processing Team Central 2, Umezono 1-1-1 Tsukuba Ibaraki 305-8568 Japan
| | - Davide Mariotti
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University Jordanstown, Newtownabbey Co. Antrim BT37 0QB UK
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Looi JC, Maguire P. Surviving the Heart of Darkness: reflections on the experience of psychiatrists working in public mental health services in Australia. Australas Psychiatry 2019; 27:634-636. [PMID: 31433204 DOI: 10.1177/1039856219866365] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE We reflect upon the bleak experiential landscape of psychiatrists working in underfunded, under-resourced and demoralised public mental health services through the metaphorical narrative of Joseph Conrad's Heart of Darkness. CONCLUSION It remains difficult to navigate through the Heart of Darkness. We suggest some navigable markers that may stave off metaphorical running aground.
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Affiliation(s)
- Jeffrey Cl Looi
- Associate Professor and Acting Head, Academic Unit of Psychiatry and Addiction Medicine, ANU Medical School, Canberra, ACT, Australia.,Clinical Associate Professor, Neuropsychiatry Unit, Royal Melbourne Hospital, Department of Psychiatry, Melbourne Medical School, Melbourne, VIC, Australia
| | - Paul Maguire
- Lecturer and Acting Co-Deputy Head, Academic Unit of Psychiatry and Addiction Medicine, ANU Medical School, Canberra, ACT, Australia
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30
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Sun D, Tang M, Zhang L, Falzon BG, Padmanaban DB, Mariotti D, Maguire P, Xu H, Chen M, Sun D. Microplasma assisted synthesis of gold nanoparticle/graphene oxide nanocomposites and their potential application in SERS sensing. Nanotechnology 2019; 30:455603. [PMID: 31207585 DOI: 10.1088/1361-6528/ab2a23] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This is the first study on the deployment of direct current atmospheric pressure microplasma technique for the single step synthesis of gold nanoparticle/graphene oxide (AuNP/GO) nanocomposites. The nanocomposites were characterized using ultraviolet-visible spectroscopy (UV-vis), x-ray diffraction and x-ray photoelectron spectroscopy and their formation mechanisms have been discussed in detail. Our AuNP/GO nanocomposites are highly biocompatible and have demonstrated surface enhanced Raman scattering (SERS) properties as compared to pure AuNPs and pure GO. Their potential as SERS substrate has been further demonstrated using probe molecules (methylene blue) at different concentrations.
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Affiliation(s)
- Daye Sun
- Advanced Composites Research Group (ACRG), School of Mechanical and Aerospace Engineering, Queen's University, Belfast BT9 5AH, United Kingdom
| | - Miao Tang
- The Wellcome-Wolfson Institute of Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast BT9 7BL, United Kingdom
| | - Li Zhang
- Research Center for Nano-Biomaterials, Analytical & Testing Center, Sichuan University, Chengdu 610065, People's Republic of China
| | - Brian G Falzon
- Advanced Composites Research Group (ACRG), School of Mechanical and Aerospace Engineering, Queen's University, Belfast BT9 5AH, United Kingdom
| | - Dilli Babu Padmanaban
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, Co Antrim BT37 OQB, United Kingdom
| | - Davide Mariotti
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, Co Antrim BT37 OQB, United Kingdom
| | - Paul Maguire
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, Co Antrim BT37 OQB, United Kingdom
| | - Heping Xu
- The Wellcome-Wolfson Institute of Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast BT9 7BL, United Kingdom
| | - Mei Chen
- The Wellcome-Wolfson Institute of Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast BT9 7BL, United Kingdom
| | - Dan Sun
- Advanced Composites Research Group (ACRG), School of Mechanical and Aerospace Engineering, Queen's University, Belfast BT9 5AH, United Kingdom
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McDonald C, Ni C, Maguire P, Connor P, Irvine JTS, Mariotti D, Svrcek V. Nanostructured Perovskite Solar Cells. Nanomaterials (Basel) 2019; 9:nano9101481. [PMID: 31635204 PMCID: PMC6835749 DOI: 10.3390/nano9101481] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/11/2019] [Accepted: 10/12/2019] [Indexed: 12/27/2022]
Abstract
Over the past decade, lead halide perovskites have emerged as one of the leading photovoltaic materials due to their long carrier lifetimes, high absorption coefficients, high tolerance to defects, and facile processing methods. With a bandgap of ~1.6 eV, lead halide perovskite solar cells have achieved power conversion efficiencies in excess of 25%. Despite this, poor material stability along with lead contamination remains a significant barrier to commercialization. Recently, low-dimensional perovskites, where at least one of the structural dimensions is measured on the nanoscale, have demonstrated significantly higher stabilities, and although their power conversion efficiencies are slightly lower, these materials also open up the possibility of quantum-confinement effects such as carrier multiplication. Furthermore, both bulk perovskites and low-dimensional perovskites have been demonstrated to form hybrids with silicon nanocrystals, where numerous device architectures can be exploited to improve efficiency. In this review, we provide an overview of perovskite solar cells, and report the current progress in nanoscale perovskites, such as low-dimensional perovskites, perovskite quantum dots, and perovskite-nanocrystal hybrid solar cells.
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Affiliation(s)
- Calum McDonald
- Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.
| | - Chengsheng Ni
- College of Resources and Environment, Southwest University, Beibei, Chongqing 400715, China.
| | - Paul Maguire
- School of Engineering, Ulster University, Newtownabbey BT14 8RT, UK.
| | - Paul Connor
- School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9AJ, UK.
| | - John T S Irvine
- School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9AJ, UK.
| | - Davide Mariotti
- School of Engineering, Ulster University, Newtownabbey BT14 8RT, UK.
| | - Vladimir Svrcek
- Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.
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Stephenson D, Hill D, Cedarbaum JM, Tome M, Vamvakas S, Romero K, Conrado DJ, Dexter DT, Seibyl J, Jennings D, Nicholas T, Matthews D, Xie Z, Imam S, Maguire P, Russell D, Gordon MF, Stebbins GT, Somer E, Gallagher J, Roach A, Basseches P, Grosset D, Marek K. The Qualification of an Enrichment Biomarker for Clinical Trials Targeting Early Stages of Parkinson's Disease. J Parkinsons Dis 2019; 9:825. [PMID: 31524182 DOI: 10.3233/jpd-199003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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33
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Sun D, McLaughlan J, Zhang L, Falzon BG, Mariotti D, Maguire P, Sun D. Atmospheric Pressure Plasma-Synthesized Gold Nanoparticle/Carbon Nanotube Hybrids for Photothermal Conversion. Langmuir 2019; 35:4577-4588. [PMID: 30840476 DOI: 10.1021/acs.langmuir.8b03945] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this work, a room-temperature atmospheric pressure direct-current plasma has been deployed for the one-step synthesis of gold nanoparticle/carboxyl group-functionalized carbon nanotube (AuNP/CNT-COOH) nanohybrids in aqueous solution for the first time. Uniformly distributed AuNPs are formed on the surface of CNT-COOH, without the use of reducing agents or surfactants. The size of the AuNP can be tuned by changing the gold salt precursor concentration. UV-vis, ζ-potential, and X-ray photoelectron spectroscopy suggest that carboxyl surface functional groups on CNTs served as nucleation and growth sites for AuNPs and the multiple potential reaction pathways induced by the plasma chemistry have been elucidated in detail. The nanohybrids exhibit significantly enhanced Raman scattering and photothermal conversion efficiency that are essential for potential multimodal cancer treatment applications.
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Affiliation(s)
- Daye Sun
- Advanced Composites Research Group (ACRG), School of Mechanical and Aerospace Engineering , Queen's University , Belfast BT9 5AH , U.K
| | | | - Li Zhang
- Research Center for Nano-Biomaterials, Analytical & Testing Center , Sichuan University , Chengdu 610065 , China
| | - Brian G Falzon
- Advanced Composites Research Group (ACRG), School of Mechanical and Aerospace Engineering , Queen's University , Belfast BT9 5AH , U.K
| | - Davide Mariotti
- Nanotechnology and Integrated Bioengineering Centre (NIBEC) , Ulster University , Newtownabbey BT37 0QB , U.K
| | - Paul Maguire
- Nanotechnology and Integrated Bioengineering Centre (NIBEC) , Ulster University , Newtownabbey BT37 0QB , U.K
| | - Dan Sun
- Advanced Composites Research Group (ACRG), School of Mechanical and Aerospace Engineering , Queen's University , Belfast BT9 5AH , U.K
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34
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Stephenson D, Hill D, Cedarbaum JM, Tome M, Vamvakas S, Romero K, Conrado DJ, Dexter DT, Seibyl J, Jennings D, Nicholas T, Matthews D, Xie Z, Imam S, Maguire P, Russell D, Gordon MF, Stebbins GT, Somer E, Gallagher J, Roach A, Basseches P, Grosset D, Marek K. The Qualification of an Enrichment Biomarker for Clinical Trials Targeting Early Stages of Parkinson's Disease. J Parkinsons Dis 2019; 9:553-563. [PMID: 31306141 PMCID: PMC6700608 DOI: 10.3233/jpd-191648] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 05/31/2019] [Indexed: 12/12/2022]
Abstract
As therapeutic trials target early stages of Parkinson's disease (PD), appropriate patient selection based purely on clinical criteria poses significant challenges. Members of the Critical Path for Parkinson's Consortium formally submitted documentation to the European Medicines Agency (EMA) supporting the use of Dopamine Transporter (DAT) neuroimaging in early PD. Regulatory documents included a comprehensive literature review, a proposed analysis plan of both observational and clinical trial data, and an assessment of biomarker reproducibility and reliability. The research plan included longitudinal analysis of the Parkinson Research Examination of CEP-1347 Trial (PRECEPT) and the Parkinson's Progression Markers Initiative (PPMI) study to estimate the degree of enrichment achieved and impact on future trials in subjects with early motor PD. The presence of reduced striatal DAT binding based on visual reads of single photon emission tomography (SPECT) scans in early motor PD subjects was an independent predictor of faster decline in UPDRS Parts II and III as compared to subjects with scans without evidence of dopaminergic deficit (SWEDD) over 24 months. The EMA issued in 2018 a full Qualification Opinion for the use of DAT as an enrichment biomarker in PD trials targeting subjects with early motor symptoms. Exclusion of SWEDD subjects in future clinical trials targeting early motor PD subjects aims to enrich clinical trial populations with idiopathic PD patients, improve statistical power, and exclude subjects who are unlikely to progress clinically from being exposed to novel test therapeutics.
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Affiliation(s)
| | | | | | - Maria Tome
- European Medicines Agency, Amsterdam, Netherlands
| | | | | | | | | | - John Seibyl
- Institute for Neurodegenerative Disorders, New Haven, CT, USA
| | | | | | | | | | - Syed Imam
- U.S. Food and Drug Administration, National Center for Toxicological Research, Jefferson, AR, USA
| | | | - David Russell
- Institute for Neurodegenerative Disorders, New Haven, CT, USA
| | | | | | | | | | | | | | | | - Kenneth Marek
- Institute for Neurodegenerative Disorders, New Haven, CT, USA
| | - on behalf of the Critical Path for Parkinson’s Consortium
- Critical Path Institute, Tucson, AZ, USA
- University College London, UK
- Biogen, Cambridge, MA, USA
- European Medicines Agency, Amsterdam, Netherlands
- Parkinson’s UK, London, UK
- Institute for Neurodegenerative Disorders, New Haven, CT, USA
- Denali Therapeutics, San Francisco, CA, USA
- Pfizer, Groton, CT, USA
- ADM Diagnostics, Northbrook, IL, USA
- UCB, Brussels, Belgium
- CPP Scientific Advisor, PA, USA
- GE Healthcare, London, UK
- Merck & Co., Philadelphia, PA, USA
- University of Glasgow, Scotland
- Rush University, Chicago, IL, USA
- U.S. Food and Drug Administration, National Center for Toxicological Research, Jefferson, AR, USA
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35
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Bonner D, Maguire P, Cartledge B, Keightley P, Reay R, Parige R, Cubis J, Tedeschi M, Craigie P, Looi JC. A new graduate medical school curriculum in Psychiatry and Addiction Medicine: reflections on a decade of development. Australas Psychiatry 2018; 26:422-428. [PMID: 29480014 DOI: 10.1177/1039856218758561] [Citation(s) in RCA: 2] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The aim of this study is to reflect upon the rationale, design and development of the Psychiatry and Addiction Medicine curriculum at the Australian National University Medical School, Canberra, Australian Capital Territory, Australia. CONCLUSIONS We conclude that the development of the fourth-year curriculum of a four-year graduate medical degree was a complex evolutionary process.
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Affiliation(s)
- Daniel Bonner
- Lecturer in Psychiatry, Academic Coordinator and Acting Co-Deputy Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; Staff Specialist, Mental Health ACT, Canberra, ACT, Australia
| | - Paul Maguire
- Lecturer in Adult Psychiatry and Acting Co-Deputy Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Björn Cartledge
- Associate Lecturer in Adult Psychiatry, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Philip Keightley
- Lecturer in Adult Psychiatry, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Rebecca Reay
- Lecturer and Research Officer, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; ACT Health, Canberra, ACT, Australia
| | - Raj Parige
- Clinical Lecturer in Addiction Medicine, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Jeff Cubis
- Senior Lecturer in Child and Adolescent Psychiatry, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Michael Tedeschi
- Clinical Senior Lecturer in Addiction Medicine, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Peggy Craigie
- Student Coordinator and Departmental Administrator, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; ACT Health, Canberra, ACT, Australia
| | - Jeffrey Cl Looi
- Associate Professor, Psychiatry, Neuropsychiatry and Psychiatry of Old Age, Acting Discipline Lead and Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Garran, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
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36
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Song W, Wang H, Maguire P, Nibouche O. Nearest clusters based partial least squares discriminant analysis for the classification of spectral data. Anal Chim Acta 2018; 1009:27-38. [DOI: 10.1016/j.aca.2018.01.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 12/18/2017] [Accepted: 01/15/2018] [Indexed: 11/29/2022]
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37
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Vincent J, Wang H, Nibouche O, Maguire P. Differentiation of Apple Varieties and Investigation of Organic Status Using Portable Visible Range Reflectance Spectroscopy. Sensors (Basel) 2018; 18:s18061708. [PMID: 29799461 PMCID: PMC6022119 DOI: 10.3390/s18061708] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/18/2018] [Accepted: 05/24/2018] [Indexed: 12/21/2022]
Abstract
Food fraud, the sale of goods that have in some way been mislabelled or tampered with, is an increasing concern, with a number of high profile documented incidents in recent years. These recent incidents and their scope show that there are gaps in the food chain where food authentication methods are not applied or otherwise not sufficient and more accessible detection methods would be beneficial. This paper investigates the utility of affordable and portable visible range spectroscopy hardware with partial least squares discriminant analysis (PLS-DA) when applied to the differentiation of apple types and organic status. This method has the advantage that it is accessible throughout the supply chain, including at the consumer level. Scans were acquired of 132 apples of three types, half of which are organic and the remaining non-organic. The scans were preprocessed with zero correction, normalisation and smoothing. Two tests were used to determine accuracy, the first using 10-fold cross-validation and the second using a test set collected in different ambient conditions. Overall, the system achieved an accuracy of 94% when predicting the type of apple and 66% when predicting the organic status. Additionally, the resulting models were analysed to find the regions of the spectrum that had the most significance. Then, the accuracy when using three-channel information (RGB) is presented and shows the improvement provided by spectroscopic data.
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Affiliation(s)
- Jordan Vincent
- School of Computing and Mathematics, University of Ulster, Shore Rd, Newtownabbey BT37 0QB, UK.
| | - Hui Wang
- School of Computing and Mathematics, University of Ulster, Shore Rd, Newtownabbey BT37 0QB, UK.
| | - Omar Nibouche
- School of Computing and Mathematics, University of Ulster, Shore Rd, Newtownabbey BT37 0QB, UK.
| | - Paul Maguire
- School of Engineering, University of Ulster, Shore Rd, Newtownabbey BT37 0QB, UK.
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38
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McDonald C, Ni C, Švrček V, Lozac'h M, Connor PA, Maguire P, Irvine JTS, Mariotti D. Zero-dimensional methylammonium iodo bismuthate solar cells and synergistic interactions with silicon nanocrystals. Nanoscale 2017; 9:18759-18771. [PMID: 29168534 DOI: 10.1039/c7nr05764d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Organometal trihalide perovskite solar cells have attracted monumental attention in recent years. Today's best devices, based on a three-dimensional perovskite structure of corner-sharing PbI6 octahedra, are unstable, toxic, and display hysteresis in current-voltage measurements. We present zero-dimensional organic-inorganic hybrid solar cells based on methylammonium iodo bismuthate (CH3NH3)3(Bi2I9) (MABI) comprising a Bi2I9 bioctahedra and observe very low hysteresis for scan rates in the broad range of 150 mV s-1 to 1500 mV s-1 without any interfacial layer engineering. We confirm good stability for devices produced and stored in open air without humidity control. The MABI structure can also accommodate silicon nanocrystals, leading to an enhancement in the short-circuit current. Through the material MABI, we demonstrate a promising alternative to the organometal trihalide perovskite class and present a model material for future composite third-generation photovoltaics.
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Affiliation(s)
- Calum McDonald
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, BT37 0QB, UK.
| | - Chengsheng Ni
- School of Chemistry, University of St Andrews, KY16 9ST, UK
| | - Vladimir Švrček
- Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan
| | - Mickaël Lozac'h
- Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan
| | - Paul A Connor
- School of Chemistry, University of St Andrews, KY16 9ST, UK
| | - Paul Maguire
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, BT37 0QB, UK.
| | | | - Davide Mariotti
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, BT37 0QB, UK.
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Keightley P, Maguire P, Reay RE, Cubis JC, Craigie P, Looi JC. Clinical research in an academic psychiatry department: some general principles and case studies. Australas Psychiatry 2017; 25:596-599. [PMID: 28990407 DOI: 10.1177/1039856217734675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE This paper gives guidance for developing collaborative clinical research within an academic psychiatry department. METHODS We describe the experience at the Australian National University Medical School, and present three case studies. RESULTS The results reveal that general principles include, but are not limited to, intellectual curiosity, mentorship, collaboration and protected time. CONCLUSIONS We conclude that a particular strength of a new research department at a medical school may be close collaborative research within clinical settings.
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Affiliation(s)
- Philip Keightley
- Clinical Lecturer in Adult Psychiatry, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Staff Specialist, ACT Health, Canberra, ACT, Australia.,Associate Professor Psychiatry, Psychiatry of Old Age & Neuropsychiatry, & Acting Discipline Lead & Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Paul Maguire
- Lecturer in Adult Psychiatry and Acting Co-Deputy Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Staff Specialist, ACT Health, Canberra, ACT, Australia.,Associate Professor Psychiatry, Psychiatry of Old Age & Neuropsychiatry, & Acting Discipline Lead & Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Rebecca E Reay
- Lecturer and Senior Research Coordinator, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; ACT Health, Canberra, ACT, Australia.,Associate Professor Psychiatry, Psychiatry of Old Age & Neuropsychiatry, & Acting Discipline Lead & Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Jeffrey C Cubis
- Senior Lecturer in Child and Adolescent Psychiatry, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia.,Associate Professor Psychiatry, Psychiatry of Old Age & Neuropsychiatry, & Acting Discipline Lead & Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Peggy Craigie
- Student Coordinator and Departmental Administrator, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; ACT Health, Canberra, ACT, Australia.,Associate Professor Psychiatry, Psychiatry of Old Age & Neuropsychiatry, & Acting Discipline Lead & Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Jeffrey Cl Looi
- Associate Professor Psychiatry, Psychiatry of Old Age & Neuropsychiatry, & Acting Discipline Lead & Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, Canberra, ACT, and; Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
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40
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Looi JC, Bonner D, Maguire P, Parige R, Tedeschi M, Cubis JC, Cartledge B, Keightley P, Reay RE, Craigie P. Salt in the soul, steel in the eye and caution towards the winds: a mariner's guide for navigating a new academic psychiatry department. Australas Psychiatry 2017; 25:588-595. [PMID: 28967276 DOI: 10.1177/1039856217732480] [Citation(s) in RCA: 2] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES This paper describes principles and advice regarding the development of a new academic psychiatry department within a medical school for aspiring academic psychiatrists. We describe general principles based on the experience of the foundation of the Academic Unit of Psychiatry and Addiction Medicine at the Australian National University Medical School. CONCLUSIONS Perspicacious leadership and organisation are the foundation for an academic psychiatry department which delivers teaching, research and broader intellectual engagement with the medical and broader community.
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Affiliation(s)
- Jeffrey Cl Looi
- Associate Professor, Psychiatry, Psychiatry of Old Age & Neuropsychiatry, & Acting Discipline Lead & Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School, & Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Daniel Bonner
- Lecturer in Psychiatry, Acting Co-Deputy Head & Academic Coordinator, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Paul Maguire
- Lecturer in Adult Psychiatry & Acting Co-Deputy Head, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Raj Parige
- Clinical Lecturer in Addiction Medicine, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Michael Tedeschi
- Clinical Senior Lecturer in Addiction Medicine, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Jeffrey C Cubis
- Senior Lecturer in Child and Adolescent Psychiatry, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & Senior Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Bjorn Cartledge
- Associate Lecturer in Adult Psychiatry, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & Academic Psychiatry Registrar, ACT Health, Canberra, ACT, Australia
| | - Philip Keightley
- Clinical Lecturer in Adult Psychiatry, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & Staff Specialist, ACT Health, Canberra, ACT, Australia
| | - Rebecca E Reay
- Lecturer and Senior Research Coordinator, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & ACT Health, Canberra, ACT, Australia
| | - Peggy Craigie
- Student Coordinator and Departmental Administrator, Academic Unit of Psychiatry and Addiction Medicine, Australian National University Medical School & ACT Health, Canberra, ACT, Australia
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41
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O'Connell R, Chen Y, Zhang H, Zhou Y, Fox D, Maguire P, Wang JJ, Rodenburg C. Comparative study of image contrast in scanning electron microscope and helium ion microscope. J Microsc 2017; 268:313-320. [PMID: 29154504 DOI: 10.1111/jmi.12660] [Citation(s) in RCA: 12] [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: 06/09/2017] [Revised: 09/27/2017] [Accepted: 10/02/2017] [Indexed: 11/29/2022]
Abstract
Images of Ga+ -implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga+ density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast.
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Affiliation(s)
- R O'Connell
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - Y Chen
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland.,Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing, China
| | - H Zhang
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - Y Zhou
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland.,School of Material Science and Engineering, Nanchang University, Nanchang, Jiangxi, China
| | - D Fox
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - P Maguire
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - J J Wang
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - C Rodenburg
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, U.K
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42
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Ni C, Hedley G, Payne J, Svrcek V, McDonald C, Jagadamma LK, Edwards P, Martin R, Jain G, Carolan D, Mariotti D, Maguire P, Samuel I, Irvine J. Charge carrier localised in zero-dimensional (CH 3NH 3) 3Bi 2I 9 clusters. Nat Commun 2017; 8:170. [PMID: 28761100 PMCID: PMC5537240 DOI: 10.1038/s41467-017-00261-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 06/13/2017] [Indexed: 11/24/2022] Open
Abstract
A metal-organic hybrid perovskite (CH3NH3PbI3) with three-dimensional framework of metal-halide octahedra has been reported as a low-cost, solution-processable absorber for a thin-film solar cell with a power-conversion efficiency over 20%. Low-dimensional layered perovskites with metal halide slabs separated by the insulating organic layers are reported to show higher stability, but the efficiencies of the solar cells are limited by the confinement of excitons. In order to explore the confinement and transport of excitons in zero-dimensional metal–organic hybrid materials, a highly orientated film of (CH3NH3)3Bi2I9 with nanometre-sized core clusters of Bi2I93− surrounded by insulating CH3NH3+ was prepared via solution processing. The (CH3NH3)3Bi2I9 film shows highly anisotropic photoluminescence emission and excitation due to the large proportion of localised excitons coupled with delocalised excitons from intercluster energy transfer. The abrupt increase in photoluminescence quantum yield at excitation energy above twice band gap could indicate a quantum cutting due to the low dimensionality. Understanding the confinement and transport of excitons in low dimensional systems will aid the development of next generation photovoltaics. Via photophysical studies Ni et al. observe 'quantum cutting' in 0D metal-organic hybrid materials based on methylammonium bismuth halide (CH3NH3)3Bi2I9.
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Affiliation(s)
- Chengsheng Ni
- School of Chemistry, University of St Andrews, Scotland, KY16 9ST, UK.,College of Resources and Environment, Southwest University, Beibei, Chongqing, 400716, China
| | - Gordon Hedley
- School of Physics and Astronomy, University of St Andrews, Scotland, KY16 9ST, UK
| | - Julia Payne
- School of Chemistry, University of St Andrews, Scotland, KY16 9ST, UK
| | - Vladimir Svrcek
- Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8568, Japan
| | - Calum McDonald
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, Northern Ireland, BT37 0QB, UK
| | | | - Paul Edwards
- Department of Physics, SUPA, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow, Scotland, G4 0NG, UK
| | - Robert Martin
- Department of Physics, SUPA, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow, Scotland, G4 0NG, UK
| | - Gunisha Jain
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, Northern Ireland, BT37 0QB, UK
| | - Darragh Carolan
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, Northern Ireland, BT37 0QB, UK
| | - Davide Mariotti
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, Northern Ireland, BT37 0QB, UK
| | - Paul Maguire
- Nanotechnology and Integrated Bioengineering Centre, Ulster University, Northern Ireland, BT37 0QB, UK
| | - Ifor Samuel
- School of Physics and Astronomy, University of St Andrews, Scotland, KY16 9ST, UK
| | - John Irvine
- School of Chemistry, University of St Andrews, Scotland, KY16 9ST, UK. .,Key Lab of Design and Assembly of Functional Nanostructure, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
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43
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Zei P, Gardner E, Fogarty T, Maguire P. P1809Noninvasive cardiac radiosurgery: current clinical experience for treatment of refractory arrhythmias. Europace 2017. [DOI: 10.1093/ehjci/eux161.118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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44
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Maguire P, Rutherford D, Macias-Montero M, Mahony C, Kelsey C, Tweedie M, Pérez-Martin F, McQuaid H, Diver D, Mariotti D. Continuous In-Flight Synthesis for On-Demand Delivery of Ligand-Free Colloidal Gold Nanoparticles. Nano Lett 2017; 17:1336-1343. [PMID: 28139927 DOI: 10.1021/acs.nanolett.6b03440] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate an entirely new method of nanoparticle chemical synthesis based on liquid droplet irradiation with ultralow (<0.1 eV) energy electrons. While nanoparticle formation via high energy radiolysis or transmission electron microscopy-based electron bombardment is well-understood, we have developed a source of electrons with energies close to thermal which leads to a number of important and unique benefits. The charged species, including the growing nanoparticles, are held in an ultrathin surface reaction zone which enables extremely rapid precursor reduction. In a proof-of-principle demonstration, we obtain small-diameter Au nanoparticles (∼4 nm) with tight control of polydispersity, in under 150 μs. The precursor was almost completely reduced in this period, and the resultant nanoparticles were water-soluble and free of surfactant or additional ligand chemistry. Nanoparticle synthesis rates within the droplets were many orders of magnitude greater than equivalent rates reported for radiolysis, electron beam irradiation, or colloidal chemical synthesis where reaction times vary from seconds to hours. In our device, a stream of precursor loaded microdroplets, ∼15 μm in diameter, were transported rapidly through a cold atmospheric pressure plasma with a high charge concentration. A high electron flux, electron and nanoparticle confinement at the surface of the droplet, and the picoliter reactor volume are thought to be responsible for the remarkable enhancement in nanoparticle synthesis rates. While this approach exhibits considerable potential for scale-up of synthesis rates, it also offers the more immediate prospect of continuous on-demand delivery of high-quality nanomaterials directly to their point of use by avoiding the necessity of collection, recovery, and purification. A range of new applications can be envisaged, from theranostics and biomedical imaging in tissue to inline catalyst production for pollution remediation in automobiles.
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Affiliation(s)
- Paul Maguire
- NIBEC, University of Ulster , Belfast, BT37 0QB, Northern Ireland
| | - David Rutherford
- NIBEC, University of Ulster , Belfast, BT37 0QB, Northern Ireland
| | | | - Charles Mahony
- NIBEC, University of Ulster , Belfast, BT37 0QB, Northern Ireland
| | - Colin Kelsey
- NIBEC, University of Ulster , Belfast, BT37 0QB, Northern Ireland
| | - Mark Tweedie
- NIBEC, University of Ulster , Belfast, BT37 0QB, Northern Ireland
| | | | - Harold McQuaid
- NIBEC, University of Ulster , Belfast, BT37 0QB, Northern Ireland
| | - Declan Diver
- SUPA, School of Physics and Astronomy, University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Davide Mariotti
- NIBEC, University of Ulster , Belfast, BT37 0QB, Northern Ireland
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45
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Askari S, Ul Haq A, Macias-Montero M, Levchenko I, Yu F, Zhou W, Ostrikov KK, Maguire P, Svrcek V, Mariotti D. Ultra-small photoluminescent silicon-carbide nanocrystals by atmospheric-pressure plasmas. Nanoscale 2016; 8:17141-17149. [PMID: 27722686 DOI: 10.1039/c6nr03702j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Highly size-controllable synthesis of free-standing perfectly crystalline silicon carbide nanocrystals has been achieved for the first time through a plasma-based bottom-up process. This low-cost, scalable, ligand-free atmospheric pressure technique allows fabrication of ultra-small (down to 1.5 nm) nanocrystals with very low level of surface contamination, leading to fundamental insights into optical properties of the nanocrystals. This is also confirmed by their exceptional photoluminescence emission yield enhanced by more than 5 times by reducing the nanocrystals sizes in the range of 1-5 nm, which is attributed to quantum confinement in ultra-small nanocrystals. This method is potentially scalable and readily extendable to a wide range of other classes of materials. Moreover, this ligand-free process can produce colloidal nanocrystals by direct deposition into liquid, onto biological materials or onto the substrate of choice to form nanocrystal films. Our simple but efficient approach based on non-equilibrium plasma environment is a response to the need of most efficient bottom-up processes in nanosynthesis and nanotechnology.
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Affiliation(s)
- Sadegh Askari
- Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK. and Department of Physics, Chemistry and biology (IFM), Linköping University, SE-581 83 Linköping, Sweden
| | - Atta Ul Haq
- Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK.
| | - Manuel Macias-Montero
- Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK.
| | - Igor Levchenko
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4000, Australia
| | - Fengjiao Yu
- EaStChem, School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Wuzong Zhou
- EaStChem, School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Kostya Ken Ostrikov
- Institute for Future Environments and School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4000, Australia and CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, Commonwealth Scientific and Industrial Research Organization, P.O. Box 218, Lindfield, NSW 2070, Australia
| | - Paul Maguire
- Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK.
| | - Vladimir Svrcek
- Research Center of Photovoltaics, National Institute of Advanced Industrial Science and Technology-AIST, Central 2, Tsukuba, Japan
| | - Davide Mariotti
- Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK.
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46
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Rocks C, Mitra S, Macias-Montero M, Maguire P, Svrcek V, Levchenko I, Ostrikov K, Mariotti D. Impact of Silicon Nanocrystal Oxidation on the Nonmetallic Growth of Carbon Nanotubes. ACS Appl Mater Interfaces 2016; 8:19012-19023. [PMID: 27362537 DOI: 10.1021/acsami.6b02599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Carbon nanotube (CNT) growth has been demonstrated recently using a number of nonmetallic semiconducting and metal oxide nanoparticles, opening up pathways for direct CNT synthesis from a number of more desirable templates without the need for metallic catalysts. However, CNT growth mechanisms using these nonconventional catalysts has been shown to largely differ and reamins a challenging synthesis route. In this contribution we show CNT growth from partially oxidized silicon nanocrystals (Si NCs) that exhibit quantum confinement effects using a microwave plasma enhanced chemical vapor deposition (PECVD) method. On the basis of solvent and a postsynthesis frgamentation process, we show that oxidation of our Si NCs can be easily controlled. We determine experimentally and explain with theoretical simulations that the Si NCs morphology together with a necessary shell oxide of ∼1 nm is vital to allow for the nonmetallic growth of CNTs. On the basis of chemical analysis post-CNT-growth, we give insight into possible mechanisms for CNT nucleation and growth from our partially oxidized Si NCs. This contribution is of significant importance to the improvement of nonmetallic catalysts for CNT growth and the development of Si NC/CNT interfaces.
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Affiliation(s)
- Conor Rocks
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University , Coleraine, Londonderry BT52 1SA, United Kingdom
| | - Somak Mitra
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University , Coleraine, Londonderry BT52 1SA, United Kingdom
| | - Manuel Macias-Montero
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University , Coleraine, Londonderry BT52 1SA, United Kingdom
| | - Paul Maguire
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University , Coleraine, Londonderry BT52 1SA, United Kingdom
| | - Vladimir Svrcek
- Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST) , Central 2, Umezono 1-1-1, Tsukuba 305-8568, Japan
| | - Igor Levchenko
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane, Queensland 4000, Australia
| | - Kostya Ostrikov
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane, Queensland 4000, Australia
- Joint CSIRO-QUT Sustainable Materials and Devices Laboratory, CSIRO , P.O. Box 218, Lindfield, New South Wales 2070, Australia
| | - Davide Mariotti
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University , Coleraine, Londonderry BT52 1SA, United Kingdom
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47
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Dörner T, Posch M, Wagner F, Hüser A, Fischer T, Mooney L, Petricoul O, Maguire P, Pal P, Doucet J, Cabanski M, Kamphausen E, Oliver S. THU0313 Double-Blind, Randomized Study of VAY736 Single Dose Treatment in Patients with Primary Sjögren's Syndrome (PSS). Ann Rheum Dis 2016. [DOI: 10.1136/annrheumdis-2016-eular.5840] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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48
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Zhang RC, Sun D, Lu A, Askari S, Macias-Montero M, Joseph P, Dixon D, Ostrikov K, Maguire P, Mariotti D. Microplasma Processed Ultrathin Boron Nitride Nanosheets for Polymer Nanocomposites with Enhanced Thermal Transport Performance. ACS Appl Mater Interfaces 2016; 8:13567-13572. [PMID: 27153343 DOI: 10.1021/acsami.6b01531] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This Research Article reports on the enhancement of the thermal transport properties of nanocomposite materials containing hexagonal boron nitride in poly(vinyl alcohol) through room-temperature atmospheric pressure direct-current microplasma processing. Results show that the microplasma treatment leads to exfoliation of the hexagonal boron nitride in isopropyl alcohol, reducing the number of stacks from >30 to a few or single layers. The thermal diffusivity of the resulting nanocomposites reaches 8.5 mm(2) s(-1), 50 times greater than blank poly(vinyl alcohol) and twice that of nanocomposites containing nonplasma treated boron nitride nanosheets. From TEM analysis, we observe much less aggregation of the nanosheets after plasma processing along with indications of an amorphous carbon interfacial layer, which may contribute to stable dispersion of boron nitride nanosheets in the resulting plasma treated colloids.
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Affiliation(s)
- Ri-Chao Zhang
- Department of Chemical and Biological Engineering, Zhejiang University , Hangzhou, 310002, PR China
- School of Mechanical and Aerospace Engineering, Queen's University Belfast, BT9 5AH, U.K
- Nanotechnology and Integrated Bioengineering Centre (NIBEC), University of Ulster , Newtownabbey, BT37 0QB, Northern Ireland, U.K
| | - Dan Sun
- School of Mechanical and Aerospace Engineering, Queen's University Belfast, BT9 5AH, U.K
| | - Ai Lu
- Institute of Chemical Materials, China Academy of Engineering Physics , Mianyang 621900, Sichuan People's Republic of China
| | - Sadegh Askari
- Department of Physics, Chemistry and Biology (IFM)/Plasma and Coatings Physics (PLASM), Linköping University , 581 83 Linköping, Sweden
| | - Manuel Macias-Montero
- Nanotechnology and Integrated Bioengineering Centre (NIBEC), University of Ulster , Newtownabbey, BT37 0QB, Northern Ireland, U.K
| | - Paul Joseph
- Centre for Environmental Safety and Risk Engineering (CESARE), College of Engineering and Science, Victoria University , Room 4206, Level 2, Building 4 Hoppers Lane, Werribee Campus Victoria 3030, Melbourne, Australia
| | - Dorian Dixon
- Nanotechnology and Integrated Bioengineering Centre (NIBEC), University of Ulster , Newtownabbey, BT37 0QB, Northern Ireland, U.K
| | - Kostya Ostrikov
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane, Queensland 4000, Australia
- Joint CSIRO-QUT Sustainable Materials and Devices Laboratory, CSIRO , P.O. Box 218, Lindfield, New South Wales 2070, Australia
| | - Paul Maguire
- Nanotechnology and Integrated Bioengineering Centre (NIBEC), University of Ulster , Newtownabbey, BT37 0QB, Northern Ireland, U.K
| | - Davide Mariotti
- Nanotechnology and Integrated Bioengineering Centre (NIBEC), University of Ulster , Newtownabbey, BT37 0QB, Northern Ireland, U.K
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49
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Macias-Montero M, Askari S, Mitra S, Rocks C, Ni C, Svrcek V, Connor PA, Maguire P, Irvine JTS, Mariotti D. Energy band diagram of device-grade silicon nanocrystals. Nanoscale 2016; 8:6623-6628. [PMID: 26939617 DOI: 10.1039/c5nr07705b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Device grade silicon nanocrystals (NCs) are synthesized using an atmospheric-pressure plasma technique. The Si NCs have a small and well defined size of about 2.3 nm. The synthesis system allows for the direct creation of thin films, enabling a range of measurements to be performed and easy implementation of this material in different devices. The chemical stability of the Si NCs is evaluated, showing relatively long-term durability thanks to hydrogen surface terminations. Optical and electrical characterization techniques, including Kelvin probe, ultraviolet photoemission spectroscopy and Mott-Schottky analysis, are employed to determine the energy band diagram of the Si NCs.
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Affiliation(s)
- M Macias-Montero
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), University of Ulster, BT37 0QB, UK.
| | - S Askari
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), University of Ulster, BT37 0QB, UK.
| | - S Mitra
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), University of Ulster, BT37 0QB, UK.
| | - C Rocks
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), University of Ulster, BT37 0QB, UK.
| | - C Ni
- School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - V Svrcek
- Research Center for Photovoltaic Technologies, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8568, Japan
| | - P A Connor
- School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - P Maguire
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), University of Ulster, BT37 0QB, UK.
| | - J T S Irvine
- School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - D Mariotti
- Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), University of Ulster, BT37 0QB, UK.
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50
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Askari S, Svrcek V, Maguire P, Mariotti D. The Interplay of Quantum Confinement and Hydrogenation in Amorphous Silicon Quantum Dots. Adv Mater 2015; 27:8011-8016. [PMID: 26523743 PMCID: PMC4738462 DOI: 10.1002/adma.201503013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 08/19/2015] [Indexed: 05/30/2023]
Abstract
Hydrogenation in amorphous silicon quantum dots (QDs) has a dramatic impact on the corresponding optical properties and band energy structure, leading to a quantum-confined composite material with unique characteristics. The synthesis of a-Si:H QDs is demonstrated with an atmospheric-pressure plasma process, which allows for accurate control of a highly chemically reactive non-equilibrium environment with temperatures well below the crystallization temperature of Si QDs.
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Affiliation(s)
- Sadegh Askari
- Nanotechnology & Integrated Bio-Engineering Centre-NIBEC, Ulster University, Newtownabbey, BT37 0QB, UK
| | - Vladmir Svrcek
- Research Center for Photovoltaic Technologies, National Institute of Advanced Industrial Science and Technology-AIST, Central 2, Umezono 1-1-1, Tsukuba, 305-8568, Japan
| | - Paul Maguire
- Nanotechnology & Integrated Bio-Engineering Centre-NIBEC, Ulster University, Newtownabbey, BT37 0QB, UK
| | - Davide Mariotti
- Nanotechnology & Integrated Bio-Engineering Centre-NIBEC, Ulster University, Newtownabbey, BT37 0QB, UK
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