32 results on '"Szanyi, J."'
Search Results
2. Structural Complexity and Loss of Long-range Order in θ-Al2O3 as Revealed by HAADF and Differential Phase Contrast Imaging
- Author
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Kovarik, L, primary, Khivantsev, K, additional, Bowden, M, additional, and Szanyi, J, additional
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- 2023
- Full Text
- View/download PDF
3. Individual variation in vaccine immune response can produce bimodal distributions of protection
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Zachreson, C, Tobin, R, Szanyi, J, Walker, C, Cromer, D, Shearer, FM, Conway, E, Ryan, G, Cheng, A, McCaw, JM, Geard, N, Zachreson, C, Tobin, R, Szanyi, J, Walker, C, Cromer, D, Shearer, FM, Conway, E, Ryan, G, Cheng, A, McCaw, JM, and Geard, N
- Abstract
The ability for vaccines to protect against infectious diseases varies among individuals, but computational models employed to inform policy typically do not account for this variation. Here we examine this issue: we implement a model of vaccine efficacy developed in the context of SARS-CoV-2 in order to evaluate the general implications of modelling correlates of protection on the individual level. Due to high levels of variation in immune response, the distributions of individual-level protection emerging from this model tend to be highly dispersed, and are often bimodal. We describe the specification of the model, provide an intuitive parameterisation, and comment on its general robustness. We show that the model can be viewed as an intermediate between the typical approaches that consider the mode of vaccine action to be either "all-or-nothing" or "leaky". Our view based on this analysis is that individual variation in correlates of protection is an important consideration that may be crucial to designing and implementing models for estimating population-level impacts of vaccination programs.
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- 2023
4. Hydrogeology of the Pannonian Basin
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Istv�n, Alm�si, primary and Szanyi, J�nos, additional
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- 2023
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5. Zrakové evokované potenciály lze vyšetřit novým mobilním přístrojem kdekoliv.
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Kuba, M., Kremláček, J., Vít, F., Kubová, Z., Szanyi, J., Chutná, M., Ramešová, L., and Langrová, J.
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VISUAL evoked potentials ,ANALOG-to-digital converters ,EVOKED potentials (Electrophysiology) ,ELECTROPHYSIOLOGY ,NEUROPHYSIOLOGY - Abstract
Copyright of Česká a Slovenská Neurologie a Neurochirurgie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2023
6. Application of 4D STEM and DPC Techniques to Study Surface Reconstruction of Transition Aluminas
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Kovarik, L, primary, Khivantsev, K, additional, and Szanyi, J, additional
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- 2022
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7. Ground motions induced by pore pressure changes at the Szentes geothermal area, SE Hungary
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Békési, E., Fokker, P.A., Candela, T., Szanyi, J., van Wees, J.-D., Tectonics, Experimental rock deformation, Tectonics, and Experimental rock deformation
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InSAR ,Pore water pressure ,Sustainability and the Environment ,Renewable Energy, Sustainability and the Environment ,Data assimilation ,Geomechanical modeling ,Szentes geothermal field (Hungary) ,Economic Geology ,Renewable Energy ,Petrology ,Geotechnical Engineering and Engineering Geology ,Geothermal gradient ,Geology - Abstract
The long-term sustainable exploitation of geothermal resources requires cautious planning and regulation. Exploitation in excess of natural recharge can result in reservoir pressure decline, causing a decrease in production rates. Furthermore, such “overexploitation” of geothermal reservoirs may lead to compaction and land subsidence. Understanding of such phenomena is critical for the assessment of societal-environmental risks, but can also be used for optimization by constraining reservoir processes and properties.Excessive thermal water volumes have been extracted from porous sedimentary rocks in the Hungarian part of the Pannonian Basin. Thermal water production in Hungary increased significantly from the early 70’s. Regional-scale overexploitation of geothermal reservoirs resulted in basin-scale pressure drop in the Upper Pannonian sediments, leading to compaction and ground subsidence.We investigated surface deformation at the Szentes geothermal filed, SE Hungary, where the largest pressure decline occurred. We obtained data from the European Space Agency’s ERS and Envisat satellites to estimate the ground motions for the periods of 1992-2000 and 2002-2010. We applied inverse geomechanical modelling to understand the compaction behaviour of the reservoir system and to estimate the subsurface properties. We constrained the model parameters using the Ensemble Smoother with Multiple Data Assimilation, which allowed us to incorporate large amounts of surface movement observations in a computationally efficient way. The model requires pressure time series as input parameters, therefore, the lack of regular pressure measurements in geothermal wells of Szentes resulted in significant uncertainties. Still, we managed to identify a potential delay in pressure drop and subsidence, implying a time-decay compaction behaviour of the reservoir system, and we arrived at realistic estimates for the compaction coefficient of the reservoir. The improved parametrization enables better forecasting of the reservoir behaviour and facilitates the assessment of future subsidence scenarios. This study thus demonstrates the effectiveness of InSAR-based ground motion data and inverse geomechanical modelling for the monitoring of geothermal reservoirs and the establishment of a sustainable production scheme.
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- 2022
8. Ground motions induced by pore pressure changes at the Szentes geothermal area, SE Hungary
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Tectonics, Experimental rock deformation, Békési, E., Fokker, P.A., Candela, T., Szanyi, J., van Wees, J.-D., Tectonics, Experimental rock deformation, Békési, E., Fokker, P.A., Candela, T., Szanyi, J., and van Wees, J.-D.
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- 2022
9. Laboratory R&D related to the development of technology for water re-injection in poorly consolidated Upper Miocene rocks
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Koroncz, P., Fedor, F., Vizhányó, Z., Kuncz, M., Ács, P., Fedor-Szász, A., Farkas, M., Sendula, E., Pernyeszi, T., Magyar, G., Szanyi, J., Kovács, L., Csicsák, J., Hofmann, H., and Kovács , J.
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- 2022
10. Structural Complexity and Loss of Long-range Order in θ-Al2O3 as Revealed by HAADF and Differential Phase Contrast Imaging.
- Author
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Kovarik, L, Khivantsev, K, Bowden, M, and Szanyi, J
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- 2023
- Full Text
- View/download PDF
11. The role of economic evaluation in modelling public health and social measures for pandemic policy: a systematic review.
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Rossiter S, Howe S, Szanyi J, Trauer JM, Wilson T, and Blakely T
- Abstract
Background: Dynamic transmission models are often used to provide epidemiological guidance for pandemic policy decisions. However, how economic evaluation is typically incorporated into this technique to generate cost-effectiveness estimates of pandemic policy responses has not previously been reviewed., Methods: We systematically searched the Embase, PubMed and Scopus databases for dynamic epidemiological modelling studies that incorporated economic evaluation of public health and social measures (PHSMs), with no date restrictions, on 7 July 2024., Results: Of the 2,719 screened studies, 51 met the inclusion criteria. Most studies (n = 42, 82%) modelled SARS-CoV-2. A range of PHSMs were examined, including school closures, testing/screening, social distancing and mask use. Half of the studies utilised an extension of a Susceptible-Exposed-Infectious-Recovered (SEIR) compartmental model. The most common type of economic evaluation was cost-effectiveness analysis (n = 24, 47%), followed by cost-utility analysis (n = 17, 33%) and cost-benefit analysis (n = 17, 33%)., Conclusions: Economic evaluation is infrequently incorporated into dynamic epidemiological modelling studies of PHSMs. The scope of this research should be expanded, given the substantial cost implications of pandemic PHSM policy responses., (© 2024. The Author(s).)
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- 2024
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12. Differential COVID-19 case ascertainment by age and vaccination status in Victoria, Australia: a serosurveillance and record linkage study.
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Szanyi J, Price DJ, Carville KS, Batty M, Yallop S, Nicholson S, Karapanagiotidis T, Rowe S, Sullivan S, Menon V, West D, Manoharan L, Copsey E, Majumdar SS, Sutton B, Williamson DA, and McVernon J
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- Humans, Male, Female, Victoria epidemiology, Middle Aged, Adult, Aged, Adolescent, Young Adult, Cross-Sectional Studies, Seroepidemiologic Studies, Aged, 80 and over, Child, Child, Preschool, Age Factors, Infant, Antibodies, Neutralizing blood, COVID-19 epidemiology, COVID-19 prevention & control, COVID-19 immunology, SARS-CoV-2 immunology, Antibodies, Viral blood, COVID-19 Vaccines immunology, COVID-19 Vaccines administration & dosage, Vaccination
- Abstract
Objectives: To compare serological evidence of prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with linked coronavirus disease 2019 (COVID-19) case notification data in Victoria, Australia, and to determine in vitro SARS-CoV-2 neutralisation activity based on prior infection and vaccination history., Design, Setting, Participants: Four cross-sectional serological surveys were conducted between 30 June and 31 October 2022 (a period of Omicron BA.4/BA.5 dominance) using 1,974 residual serum samples obtained from the Victorian Infectious Diseases Reference Laboratory. Serological results were linked to COVID-19 case notification and vaccination data. Surrogate virus neutralisation testing was performed to obtain in vitro inhibition estimates by anti-nucleocapsid serostatus and COVID-19 vaccination history., Main Outcome Measures: Adjusted anti-SARS-CoV-2 spike and nucleocapsid seropositivity by sex, age and region of residence; adjusted proportion of cases notified by anti-nucleocapsid serostatus, age and number of COVID-19 vaccination doses received; adjusted percentage in vitro inhibition against wildtype and Omicron BA.4/BA.5 SARS-CoV-2 variants by anti-nucleocapsid serostatus and COVID-19 vaccination history., Results: The prevalence of anti-SARS-CoV-2 nucleocapsid antibodies was inversely proportional to age. In October 2022, prevalence was 84% (95% confidence interval [95% CI]: 75-93%) among 18-29-year-olds, compared to 39% (95% CI: 27-52%) among ≥ 80-year-olds. In most age groups, approximately 40% of COVID-19 cases appear to have been notified via existing surveillance mechanisms. Case notification was highest among individuals older than 80 years and people who had received COVID-19 vaccine booster doses. In vitro neutralisation of Omicron BA.4/BA.5 sub-variants was highest for individuals with evidence of both prior infection and booster vaccination., Conclusions: Under-notification of SARS-CoV-2 infections in the Victorian population is not uniform across age and vaccination strata. Seroprevalence data that give insights into case notification behaviour provide additional context for the interpretation of existing COVID-19 surveillance information., (© Commonwealth of Australia CC BY-NC-ND.)
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- 2024
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13. Heat health alerts and emergency department presentations by people aged 65 years or older, Victoria, 2010-22: a case-crossover analysis.
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Thomson TN, Szanyi J, and Mulvenna V
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- Humans, Aged, Victoria epidemiology, Male, Female, Cross-Over Studies, Aged, 80 and over, Hot Temperature adverse effects, Heat Stress Disorders epidemiology, Emergency Service, Hospital statistics & numerical data
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- 2024
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14. Optic nerve involvement in patients with Lyme neuroborreliosis: an electrophysiological study.
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Szanyi J, Kremlacek J, Kubova Z, Kuba M, Vit F, Langrova J, Gebousky P, and Szanyi J
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- Humans, Middle Aged, Adult, Retrospective Studies, Male, Female, Aged, Young Adult, Adolescent, Facial Paralysis physiopathology, Facial Paralysis diagnosis, Child, Aged, 80 and over, Visual Acuity physiology, Optic Nerve physiopathology, Lyme Neuroborreliosis physiopathology, Lyme Neuroborreliosis diagnosis, Lyme Neuroborreliosis complications, Evoked Potentials, Visual physiology, Optic Nerve Diseases physiopathology, Optic Nerve Diseases diagnosis
- Abstract
Purpose: The aim of this neurophysiological study was to retrospectively analyze visual evoked potentials (VEPs) acquired during an examination for diagnosing optic nerve involvement in patients with Lyme neuroborreliosis (LNB). Attention was focused on LNB patients with peripheral facial palsy (PFP) and optic nerve involvement., Methods: A total of 241 Czech patients were classified as having probable/definite LNB (193/48); of these, 57 were younger than 40 years, with a median age of 26.3 years, and 184 were older than 40 years, with a median age of 58.8 years. All patients underwent pattern-reversal (PVEP) and motion-onset (MVEP) VEP examinations., Results: Abnormal VEP results were observed in 150/241 patients and were noted more often in patients over 40 years (p = 0.008). Muscle/joint problems and paresthesia were observed to be significantly more common in patients older than 40 years (p = 0.002, p = 0.030), in contrast to headache and decreased visual acuity, which were seen more often in patients younger than 40 years (p = 0.001, p = 0.033). Peripheral facial palsy was diagnosed in 26/241 LNB patients. Among patients with PFP, VEP peak times above the laboratory limit was observed in 22 (84.6%) individuals. Monitoring of patients with PFP and pathological VEP showed that the adjustment of visual system function occurred in half of the patients in one to more years, in contrast to faster recovery from peripheral facial palsy within months in most patients., Conclusion: In LNB patients, VEP helps to increase sensitivity of an early diagnostic process., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2024
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15. The importance of reporting accurate estimates of long COVID prevalence.
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Szanyi J, Howe S, and Blakely T
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- Humans, Prevalence, Post-Acute COVID-19 Syndrome, COVID-19 epidemiology
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- 2024
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16. New portable device for an examination of visual cognitive evoked potentials might extend their diagnostic applications in psychiatry.
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Kuba M, Kremláček J, Vít F, Masopust J, Hubeňák J, Kubová Z, Szanyi J, Ramešová L, Chutná M, and Langrová J
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- Humans, Pilot Projects, Reproducibility of Results, Evoked Potentials physiology, Cognition physiology, Event-Related Potentials, P300, Psychiatry
- Abstract
Despite positive prior results obtained by using event-related potentials (ERPs) in psychiatric patients, they are not routinely used in the clinical setting. This may in part be due to problems regarding a lack of transportable equipment availability. It can be difficult for these patients to repeatedly visit electrophysiological laboratories. To address this issue, we propose using a new, fully portable device for visually evoked potentials (VEP) and cognitive function assessment, that can be used for quick examinations (https://www.veppeak.com). Our device, called "VEPpeak", is built into a headset with a color LED visual stimulator. It weighs 390 g and is connected to a notebook (PC) with evaluation software via USB. In this pilot study, we verified the device's usability in 31 patients with schizophrenia. We used the oddball paradigm with the recognition of colors for the P300 wave and choice reaction time evaluation. The examination lasted only about ten minutes. The results indicated good reproducibility of large cognitive potentials (P300) with prolonged P300 latencies and reduced amplitudes in patients compared to 15 control subjects. The P300 latency and reaction time prolongation in patients correlated with their age and the sedative effect of the pharmacotherapy., Competing Interests: Declaration of Competing Interest All authors declare that their potential conflict of interest could be related only to the eventual routine use of the device in healthcare, which may be connected with a financial benefit. This will only be applicable after the device has been certified as a “medical device”., (Copyright © 2023 Elsevier B.V. All rights reserved.)
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- 2024
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17. Ultrasmall Pd Clusters in FER Zeolite Alleviate CO Poisoning for Effective Low-Temperature Carbon Monoxide Oxidation.
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Song I, Koleva IZ, Aleksandrov HA, Chen L, Heo J, Li D, Wang Y, Szanyi J, and Khivantsev K
- Abstract
Ultrasmall Pd
4 clusters form in the micropores of FER zeolite during low-temperature treatment (100 °C) in the presence of humid CO gas. They effectively catalyze CO oxidation below 100 °C, whereas Pd nanoparticles are not active as they are poisoned by CO. Using catalytic measurements, infrared (IR) spectroscopy, X-ray absorption spectroscopy (EXAFS), microscopy, and density functional theory calculations, we provide the molecular-level insight into this previously unreported phenomenon. Pd nanoparticles get covered with CO at low temperatures, which effectively blocks O2 activation until CO desorption occurs. Small Pd clusters in zeolites, in contrast, demonstrate fluxional behavior in the presence of CO, which significantly increases the affinity for binding O2 . Our study provides a pathway to achieve low-temperature CO oxidation activity on the basis of a well-defined Pd/zeolite system.- Published
- 2023
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18. Individual variation in vaccine immune response can produce bimodal distributions of protection.
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Zachreson C, Tobin R, Szanyi J, Walker C, Cromer D, Shearer FM, Conway E, Ryan G, Cheng A, McCaw JM, and Geard N
- Subjects
- Humans, SARS-CoV-2, Immunity, COVID-19 prevention & control, Vaccines, Communicable Diseases
- Abstract
The ability for vaccines to protect against infectious diseases varies among individuals, but computational models employed to inform policy typically do not account for this variation. Here we examine this issue: we implement a model of vaccine efficacy developed in the context of SARS-CoV-2 in order to evaluate the general implications of modelling correlates of protection on the individual level. Due to high levels of variation in immune response, the distributions of individual-level protection emerging from this model tend to be highly dispersed, and are often bimodal. We describe the specification of the model, provide an intuitive parameterisation, and comment on its general robustness. We show that the model can be viewed as an intermediate between the typical approaches that consider the mode of vaccine action to be either "all-or-nothing" or "leaky". Our view based on this analysis is that individual variation in correlates of protection is an important consideration that may be crucial to designing and implementing models for estimating population-level impacts of vaccination programs., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Cameron Zachreson reports financial support was provided by Australian Government Department of Health and Aged Care. Nicholas Geard reports financial support was provided by Australian Government Department of Health and Aged Care. Allen Cheng reports financial support was provided by Australian Government Department of Health and Aged Care. Joshua Szanyi reports a relationship with Moderna Inc that includes: funding grants. Co-author Allen Cheng is a member of Australian government advisory committees; the views in this paper may not necessarily reflect those of the Australian government., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2023
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19. Consistent mask use and SARS-CoV-2 epidemiology: a simulation modelling study.
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Szanyi J, Howe S, Wilson T, and Blakely T
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- Humans, Public Health, Masks, SARS-CoV-2, COVID-19 epidemiology
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- 2023
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20. The health impact of long COVID during the 2021-2022 Omicron wave in Australia: a quantitative burden of disease study.
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Howe S, Szanyi J, and Blakely T
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- Humans, Quality-Adjusted Life Years, Post-Acute COVID-19 Syndrome, Cross-Sectional Studies, SARS-CoV-2, Global Health, Australia epidemiology, Cost of Illness, Life Expectancy, COVID-19 epidemiology
- Abstract
Background: Long COVID symptoms occur for a proportion of acute COVID-19 survivors, with reduced risk among the vaccinated and for Omicron compared with Delta variant infections. The health loss attributed to pre-Omicron long COVID has previously been estimated using only a few major symptoms., Methods: The years lived with disability (YLDs) due to long COVID in Australia during the 2021-22 Omicron BA.1/BA.2 wave were calculated using inputs from previously published case-control, cross-sectional or cohort studies examining the prevalence and duration of individual long COVID symptoms. This estimated health loss was compared with acute SARS-CoV-2 infection YLDs and years of life lost (YLLs) from SARS-CoV-2. The sum of these three components equals COVID-19 disability-adjusted life years (DALYs); this was compared with DALYs from other diseases., Results: A total of 5200 [95% uncertainty interval (UI) 2200-8300] YLDs were attributable to long COVID and 1800 (95% UI 1100-2600) to acute SARS-CoV-2 infection, suggesting long COVID caused 74% of the overall YLDs from SARS-CoV-2 infections in the BA.1/BA.2 wave. Total DALYs attributable to SARS-CoV-2 were 50 900 (95% UI 21 000-80 900), 2.4% of expected DALYs for all diseases in the same period., Conclusion: This study provides a comprehensive approach to estimating the morbidity due to long COVID. Improved data on long COVID symptoms will improve the accuracy of these estimates. As data accumulate on SARS-CoV-2 infection sequelae (e.g. increased cardiovascular disease rates), total health loss is likely to be higher than estimated in this study. Nevertheless, this study demonstrates that long COVID requires consideration in pandemic policy planning, given it is responsible for the majority of direct SARS-CoV-2 morbidity, including during an Omicron wave in a highly vaccinated population., (© The Author(s) 2023. Published by Oxford University Press on behalf of the International Epidemiological Association.)
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- 2023
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21. Dynamic Evolution of Palladium Single Atoms on Anatase Titania Support Determines the Reverse Water-Gas Shift Activity.
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Chen L, Allec SI, Nguyen MT, Kovarik L, Hoffman AS, Hong J, Meira D, Shi H, Bare SR, Glezakou VA, Rousseau R, and Szanyi J
- Abstract
Research interest in single-atom catalysts (SACs) has been continuously increasing. However, the lack of understanding of the dynamic behaviors of SACs during applications hinders catalyst development and mechanistic understanding. Herein, we report on the evolution of active sites over Pd/TiO
2 -anatase SAC (Pd1 /TiO2 ) in the reverse water-gas shift (rWGS) reaction. Combining kinetics, in situ characterization, and theory, we show that at T ≥ 350 °C, the reduction of TiO2 by H2 alters the coordination environment of Pd, creating Pd sites with partially cleaved Pd-O interfacial bonds and a unique electronic structure that exhibit high intrinsic rWGS activity through the carboxyl pathway. The activation by H2 is accompanied by the partial sintering of single Pd atoms (Pd1 ) into disordered, flat, ∼1 nm diameter clusters (Pdn ). The highly active Pd sites in the new coordination environment under H2 are eliminated by oxidation, which, when performed at a high temperature, also redisperses Pdn and facilitates the reduction of TiO2 . In contrast, Pd1 sinters into crystalline, ∼5 nm particles (PdNP ) during CO treatment, deactivating Pd1 /TiO2 . During the rWGS reaction, the two Pd evolution pathways coexist. The activation by H2 dominates, leading to the increasing rate with time-on-stream, and steady-state Pd active sites similar to the ones formed under H2 . This work demonstrates how the coordination environment and nuclearity of metal sites on a SAC evolve during catalysis and pretreatments and how their activity is modulated by these behaviors. These insights on SAC dynamics and the structure-function relationship are valuable to mechanistic understanding and catalyst design.- Published
- 2023
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22. Single Ru(II) Ions on Ceria as a Highly Active Catalyst for Abatement of NO.
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Khivantsev K, Jaegers NR, Aleksandrov HA, Song I, Pereira-Hernandez XI, Engelhard MH, Tian J, Chen L, Motta Meira D, Kovarik L, Vayssilov GN, Wang Y, and Szanyi J
- Abstract
Atom trapping leads to catalysts with atomically dispersed Ru
1 O5 sites on (100) facets of ceria, as identified by spectroscopy and DFT calculations. This is a new class of ceria-based materials with Ru properties drastically different from the known M/ceria materials. They show excellent activity in catalytic NO oxidation, a critical step that requires use of large loadings of expensive noble metals in diesel aftertreatment systems. Ru1 /CeO2 is stable during continuous cycling, ramping, and cooling as well as the presence of moisture. Furthermore, Ru1 /CeO2 shows very high NOx storage properties due to formation of stable Ru-NO complexes as well as a high spill-over rate of NOx onto CeO2 . Only ∼0.05 wt % of Ru is required for excellent NOx storage. Ru1 O5 sites exhibit much higher stability during calcination in air/steam up to 750 °C in contrast to RuO2 nanoparticles. We clarify the location of Ru(II) ions on the ceria surface and experimentally identify the mechanism of NO storage and oxidation using DFT calculations and in situ DRIFTS/mass spectroscopy. Moreover, we show excellent reactivity of Ru1 /CeO2 for NO reduction by CO at low temperatures: only 0.1-0.5 wt % of Ru is sufficient to achieve high activity. Modulation-excitation in situ infrared and XPS measurements reveal the individual elementary steps of NO reduction by CO on an atomically dispersed Ru ceria catalyst, highlighting unique properties of Ru1 /CeO2 and its propensity to form oxygen vacancies/Ce+3 sites that are critical for NO reduction, even at low Ru loadings. Our study highlights the applicability of novel ceria-based single-atom catalysts to NO and CO abatement.- Published
- 2023
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23. Epidemiologic and economic modelling of optimal COVID-19 policy: public health and social measures, masks and vaccines in Victoria, Australia.
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Szanyi J, Wilson T, Howe S, Zeng J, Andrabi H, Rossiter S, and Blakely T
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Background: Identifying optimal COVID-19 policies is challenging. For Victoria, Australia (6.6 million people), we evaluated 104 policy packages (two levels of stringency of public health and social measures [PHSMs], by two levels each of mask-wearing and respirator provision during large outbreaks, by 13 vaccination schedules) for nine future SARS-CoV-2 variant scenarios., Methods: We used an agent-based model to estimate morbidity, mortality, and costs over 12 months from October 2022 for each scenario. The 104 policies (each averaged over the nine future variant scenarios) were ranked based on four evenly weighted criteria: cost-effectiveness from (a) health system only and (b) health system plus GDP perspectives, (c) deaths and (d) days exceeding hospital occupancy thresholds., Findings: More compared to less stringent PHSMs reduced cumulative infections, hospitalisations and deaths but also increased time in stage ≥3 PHSMs. Any further vaccination from October 2022 decreased hospitalisations and deaths by 12% and 27% respectively compared to no further vaccination and was usually a cost-saving intervention from a health expenditure plus GDP perspective. High versus low vaccine coverage decreased deaths by 15% and reduced time in stage ≥3 PHSMs by 20%. The modelled mask policies had modest impacts on morbidity, mortality, and health system pressure. The highest-ranking policy combination was more stringent PHSMs, two further vaccine doses (an Omicron-targeted vaccine followed by a multivalent vaccine) for ≥30-year-olds with high uptake, and promotion of increased mask wearing (but not Government provision of respirators)., Interpretation: Ongoing vaccination and PHSMs continue to be key components of the COVID-19 pandemic response. Integrated epidemiologic and economic modelling, as exemplified in this paper, can be rapidly updated and used in pandemic decision making., Funding: Anonymous donation, University of Melbourne funding., Competing Interests: Separate to the current study, the research group will likely soon receive funding from Moderna to conduct vaccine effectiveness studies in Australia. Moderna had no role in the current study., (© 2022 The Author(s).)
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- 2023
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24. Effectiveness of fourth dose of COVID-19 vaccine against the Omicron variant compared with no vaccination.
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Zeng J, Szanyi J, and Blakely T
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- Humans, SARS-CoV-2, Vaccination, COVID-19 Vaccines, COVID-19 prevention & control
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- 2023
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25. VEP examination with new portable device.
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Kuba M, Kremláček J, Vít F, Kubová Z, Langrová J, Szanyi J, and Chutná M
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- Humans, Electroretinography, Electrodes, Photic Stimulation, Evoked Potentials, Visual, Visual Cortex physiology
- Abstract
Introduction: We developed a new portable device called "VEPpeak" for the examination of visual evoked potentials (VEPs) to extend VEP examination beyond specialized electrophysiological laboratories and to simplify the use of this objective, noninvasive, and low-cost method for diagnostics of visual and central nervous system dysfunctions., Methods: VEPpeak consists of a plastic headset with a total weight of 390 g containing four EEG amplifiers, an A/D converter, a control unit, and a visual LED stimulator built in the front, vertically adjustable peak. The device is powered and controlled via USB connection from a standard PC/notebook using custom software for visual stimuli generation and for VEP recording and processing. Up to four electrodes can be placed at any scalp location or in combination with two dry electrodes incorporated into the headset. External visual stimulators, such as a tablet, can be used with synchronization. Feasibility and validation studies were conducted with 86 healthy subjects and 76 neuro-ophthalmological patients including 67 who were during the same session also tested with a conventional VEP system., Results: VEPpeak recordings to standard (pattern-reversal) and non-standard (motion-onset, red-green alternation) were robust and repeatable and obtained also in immobilized patients. Good comparability of results was achieved between VEPpeak and standard examination. Some systematic differences in peak latencies and amplitudes are consistent with differences in stimulus characteristics of the two compared systems., Discussion: VEPpeak provides an inexpensive system for clinical use requiring portability. In addition to ISCEV standard VEP protocols, free choice of stimuli and bio-signal recordings make the device universal for many electrophysiological purposes., (© 2022. The Author(s).)
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- 2023
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26. Protection against Omicron from Vaccination and Previous Infection.
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Zeng J, Szanyi J, and Blakely T
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- Humans, Prisons, Vaccination
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- 2023
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27. The intraocular implant and visual rehabilitation improve the quality of life of elderly patients with geographic atrophy secondary to age-related macular degeneration.
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Nekolova J, Kremlacek J, Lukavsky J, Sikl R, Sin M, Langrova J, Szanyi J, and Jiraskova N
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- Male, Female, Humans, Aged, Aged, 80 and over, Quality of Life, Prospective Studies, Surveys and Questionnaires, Geographic Atrophy diagnosis, Geographic Atrophy etiology, Macular Degeneration complications, Macular Degeneration diagnosis, Lenses, Intraocular
- Abstract
Introduction: The objective of this prospective study was to evaluate the effects of intraocular macular lens implantation and visual rehabilitation on the quality of life of patients with geographic atrophy (GA) secondary to age-related macular degeneration (AMD)., Methods: Patients with bilaterally decreased near vision (not better than 0.3 logMAR with the best correction), pseudophakia, were included in the project. The Scharioth macula lens (SML) was implanted into the patients' better-seeing eye. Intensive visual rehabilitation of the ability to perform nearby activities was performed for 20 consecutive postoperative days. All subjects were examined before and after SML implantation ophthalmologically. The National Eye Institute 25-Item Visual Function Questionnaire (NEI VFQ-25) was administered before and 6 months after surgery., Results: Twenty eligible patients with mean age 81 years (63 to 92 years) were included in the project: 7 males and 13 females. Nineteen of them completed the 6-month follow-up. Near uncorrected visual acuity was 1.321 ± 0.208 logMAR before SML implantation and improved to 0.547 ± 0.210 logMAR after 6 months (dz = - 2.846, p < 0.001, BF
10 = 3.29E + 07). In the composite score of the NEI VFQ-25, there was an improvement in the general score and the specific domains related to the implantation. Participants reported fewer difficulties in performing near activities (dz = 0.91, p = 0.001, BF10 = 39.718) and upturns in mental health symptoms related to vision (dz = 0.62, p = .014, BF10 = 3.937)., Conclusion: SML implantation, followed by appropriate rehabilitation, improved near vision and increased the quality of life of visually handicapped patients with AMD in our project., (© 2022. The Author(s).)- Published
- 2023
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28. Intrauterine HIV exposure is associated with linear growth restriction among Ethiopian children in the first 18 months of life.
- Author
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Szanyi J, Walles JK, Tesfaye F, Gudeta AN, and Björkman P
- Subjects
- Child, Child, Preschool, Ethiopia epidemiology, Female, Growth Disorders complications, Growth Disorders etiology, Humans, Infant, Pregnancy, Prospective Studies, HIV Infections complications, Pregnancy Complications, Infectious epidemiology
- Abstract
Objective: The role of HIV exposure in determining growth among HIV-uninfected children is debated. We determined whether intrauterine HIV exposure influences linear growth in a cohort of Ethiopian children followed up to 18 months of age in public health facilities in Adama city, Ethiopia., Methods: Participants were offspring of pregnant women enrolled in a prospective cohort study that included screening for HIV infection during antenatal care. Growth patterns of HIV-exposed and uninfected (HEU) and HIV-unexposed (HU) children were compared up to 18 months of age, with length-for-age z-score (LAZ) and proportion with stunting as primary outcomes. Multivariable linear and logistic regression models were constructed to investigate the associations between HIV exposure and linear growth, controlling for socio-demographic factors and breastfeeding status., Results: Of 1705 included infants (164 HEU), 1276 remained in follow-up at 18 months. Among HIV-positive mothers, 132 (80.5%) were receiving antiretroviral therapy at enrolment. At the 18-month visit, mean LAZ was -1.08 among HEU children and -0.74 among HU children (p = 0.052). Proportions of HEU and HU children with stunting at the 18-month visit were 27.8% and 18.7%, respectively (p = 0.010). In multivariable models, HIV exposure was associated with lower LAZ at all follow-up visits, and with stunting at the 18-month visit (adjusted odds ratio 2.29, 95% confidence interval 1.40-3.71). HIV exposure was not associated with weight-related growth outcomes., Conclusions: HEU children in Ethiopia had inferior linear growth compared with HU children, implying that intrauterine HIV exposure impacts early childhood growth in this setting., (© 2022 John Wiley & Sons Ltd.)
- Published
- 2022
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29. Identification of the mechanism of NO reduction with ammonia (SCR) on zeolite catalysts.
- Author
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Khivantsev K, Kwak JH, Jaegers NR, Koleva IZ, Vayssilov GN, Derewinski MA, Wang Y, Aleksandrov HA, and Szanyi J
- Abstract
Cu/zeolites efficiently catalyze selective reduction of environmentally harmful nitric oxide with ammonia. Despite over a decade of research, the exact NO reduction steps remain unknown. Herein, using a combined spectroscopic, catalytic and DFT approach, we show that nitrosyl ions (NO
+ ) in zeolitic micropores are the key intermediates for NO reduction. Remarkably, they react with ammonia even below room temperature producing molecular nitrogen (the reaction central to turning the NO pollutant to benign nitrogen) through the intermediacy of the diazo N2 H+ cation. Experiments with isotopically labeled N-compounds confirm our proposed reaction path. No copper is required for N2 formation to occur during this step. However, at temperatures below 100 °C, when NO+ reacts with NH3 , the bare Brønsted acid site becomes occupied by NH3 to form strongly bound NH4 + , and consequently, this stops the catalytic cycle, because NO+ cannot form on NH4 -zeolites when their H+ sites are already occupied by NH4 + . On the other hand, we show that the reaction becomes catalytic on H-zeolites at temperatures when some ammonia desorption can occur (>120 °C). We suggest that the role of Cu(ii) ions in Cu/zeolite catalysts for low-temperature NO reduction is to produce abundant NO+ by the reaction: Cu(ii) + NO → Cu(i)⋯NO+ . NO+ then reacts with ammonia to produce nitrogen and water. Furthermore, when Cu(i) gets re-oxidized, the catalytic cycle can then continue. Our findings provide novel understanding of the hitherto unknown steps of the SCR mechanism pertinent to N-N coupling. The observed chemistry of Cu ions in zeolites bears striking resemblance to the copper-containing denitrification and annamox enzymes, which catalyze transformation of NOx species to N2 , via di-azo compounds., Competing Interests: The authors have no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2022
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30. A log-odds system for waning and boosting of COVID-19 vaccine effectiveness.
- Author
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Szanyi J, Wilson T, Scott N, and Blakely T
- Subjects
- Humans, SARS-CoV-2, Vaccination, Vaccine Efficacy, COVID-19 epidemiology, COVID-19 prevention & control, COVID-19 Vaccines
- Abstract
Immunity to SARS-CoV-2 following vaccination wanes over time in a non-linear fashion, making modelling of likely population impacts of COVID-19 policy options challenging. We observed that it was possible to mathematize non-linear waning of vaccine effectiveness (VE) on the percentage scale as linear waning on the log-odds scale, and developed a random effects logistic regression equation based on UK Health Security Agency data to model VE against Omicron following two and three doses of a COVID-19 vaccine. VE on the odds scale reduced by 47% per month for symptomatic infection after two vaccine doses, lessening to 35% per month for hospitalisation. Waning on the odds scale after triple dose vaccines was 35% per month for symptomatic disease and 19% for hospitalisation. This log-odds system for estimating waning and boosting of COVID-19 VE provides a simple solution that may be used to parametrize SARS-CoV-2 immunity over time parsimoniously in epidemiological models., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
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31. On the Nature of Extra-Framework Aluminum Species and Improved Catalytic Properties in Steamed Zeolites.
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Khivantsev K, Jaegers NR, Kovarik L, Derewinski MA, Kwak JH, and Szanyi J
- Abstract
Steamed zeolites exhibit improved catalytic properties for hydrocarbon activation (alkane cracking and dehydrogenation). The nature of this practically important phenomenon has remained a mystery for the last six decades and was suggested to be related to the increased strength of zeolitic Bronsted acid sites after dealumination. We now utilize state-of-the-art infrared spectroscopy measurements and prove that during steaming, aluminum oxide clusters evolve (due to hydrolysis of Al out of framework positions with the following clustering) in the zeolitic micropores with properties very similar to (nano) facets of hydroxylated transition alumina surfaces. The Bronsted acidity of the zeolite does not increase and the total number of Bronsted acid sites decreases during steaming. O
5 Al(VI)-OH surface sites of alumina clusters dehydroxylate at elevated temperatures to form penta-coordinate Al1 O5 sites that are capable of initiating alkane cracking by breaking the first C-H bond very effectively with much lower barriers (at lower temperatures) than for protolytic C-H bond activation, with the following reaction steps catalyzed by nearby zeolitic Bronsted acid sites. This explains the underlying mechanism behind the improved alkane cracking and alkane dehydrogenation activity of steamed zeolites: heterolytic C-H bond breaking occurs on Al-O sites of aluminum oxide clusters confined in zeolitic pores. Our findings explain the origin of enhanced activity of steamed zeolites at the molecular level and provide the missing understanding of the nature of extra-framework Al species formed in steamed/dealuminated zeolites.- Published
- 2022
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32. Palladium/Ferrierite versus Palladium/SSZ-13 Passive NOx Adsorbers: Adsorbate-Controlled Location of Atomically Dispersed Palladium(II) in Ferrierite Determines High Activity and Stability.
- Author
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Khivantsev K, Wei X, Kovarik L, Jaegers NR, Walter ED, Tran P, Wang Y, and Szanyi J
- Abstract
Pd-loaded FER and SSZ-13 zeolites as low-temperature passive NOx adsorbers (PNA) are compared under practical conditions. Vehicle cold start exposes the material to CO under a range of concentrations, necessitating a systematic exploration of the effect of CO on the performance of isolated Pd ions in PNA. The NO release temperature of both adsorbers decreases gradually with an increase in CO concentration from a few hundred to a few thousand ppm. This beneficial effect results from local nano-"hot spot" formation during CO oxidation. Dissimilar to Pd/SSZ-13, increasing the CO concentration above ≈1000 ppm improves the NOx storage significantly for Pd/FER, which was attributed to the presence of Pd ions in FER sites that are shielded from NOx. CO mobilizes this Pd atom to the NOx accessible position where it becomes active for PNA. This behavior explains the very high resistance of Pd/FER to hydrothermal aging: Pd/FER materials survive hydrothermal aging at 800 °C in 10 % H
2 O vapor for 16 hours with no deterioration in NOx uptake/release behavior. Thus, by allocating Pd ions to the specific microporous pockets in FER, we have produced (hydro)thermally stable and active PNA materials., (© 2021 Wiley-VCH GmbH.)- Published
- 2022
- Full Text
- View/download PDF
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