Fast de novo antibody structure prediction with atomic accuracy

Background: In the field of antibody engineering, an essential task is to design a novel antibody whose paratopes bind to a specific antigen with correct epitopes. Understanding antibody structure and its paratope can facilitate a mechanistic understanding of its function. Therefore, antibody structure prediction from its sequence alone has always been a highly valuable problem for de novo antibody design. AlphaFold2 (AF2), a breakthrough in the field of structural biology, provides a solution to this protein structure prediction problem by learning a deep learning model. However, the computational efficiency and undesirable prediction accuracy on antibody, especially on the complementarity-determining regions limit its applications in de novo antibody design. Method(s): To learn informative representation of antibodies, we trained a deep antibody language model (ALM) on curated sequences from observed antibody space database via a well-designed transformer model. We also developed a novel model named xTrimoABFold++ to predict antibody structure from antibody sequence only based on the pretrained ALM as well as efficient evoformers and structural modules. The model was trained end-to-end on the antibody structures in PDB by minimizing the ensemble loss of domain-specific focal loss on CDR and the frame aligned point loss. Result(s): xTrimoABFold++ outperforms AF2 and OmegaFold, HelixFold-Single with 30+% improvement on RMSD. Also, it is 151 times faster than AF2 and predicts antibody structure in atomic accuracy within 20 seconds. In recently released antibodies, for example, cemiplimab of PD1 (PDB: 7WVM) and cross-neutralizing antibody 6D6 of SARS-CoV-2 (PDB: 7EAN), the RMSD of xTrimoABFold++ are 0.344 and 0.389 respectively. Conclusion(s): To the best of our knowledge, xTrimoABFold++ achieved the state-of-the-art in antibody structure prediction. Its improvement on both accuracy and efficiency makes it a valuable tool for de novo antibody design, and could make further improvement in immuno-theory.

The Analysis of Oral and Fecal Virome Detects Multiple Novel Emerging Viruses in Snakes

Wild animals are considered reservoirs for emerging and reemerging viruses, such as the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Previous studies have reported that bats and ticks harbored variable important pathogenic viruses, some of which could cause potential diseases in humans and livestock, while viruses carried by reptiles were rarely reported. Our study first conducted snakes' virome analysis to establish effective surveillance of potential transboundary emerging diseases. Consequently, Adenoviridae, Circoviridae, Retroviridae, and Parvoviridae were identified in oral samples from Protobothrops mucrosquamatus, Elaphe dione, and Gloydius angusticeps based on sequence similarity to existing viruses. Picornaviridae and Adenoviridae were also identified in fecal samples of Protobothrops mucrosquamatus. Notably, the iflavirus and foamy virus were first reported in Protobothrops mucrosquamatus, enriching the transboundary viral diversity in snakes. Furthermore, phylogenetic analysis revealed that both the novel-identified viruses showed low genetic similarity with previously reported viruses. This study provided a basis for our understanding of microbiome diversity and the surveillance and prevention of emerging and unknown viruses in snakes.

Updated Real-World Safety of the Pfizer-BioNTech COVID-19 Vaccine in Pregnancy: Data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry

Purpose: Preliminary data indicate that pregnant women infected with COVID-19 are at increased risk of pregnancy complications (US Centers for Disease Control and Prevention, October 2022). Information on the real-world safety of COVID-19 vaccination in pregnancy is essential. We sought to describe preliminary results for pregnancy status among pregnancy registry participants enrolled in an ongoing safety study of the Pfizer-BioNTech COVID-19 vaccine to date. Method(s): This study uses data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry as part of the Vaccines and Medications in Pregnancy Surveillance System (VAMPSS) which enrolls pregnant women residing in the US or Canada. Data are captured through maternal interviews and the ion of medical records. The study population for this descriptive analysis includes Registry participants who met eligibility criteria on or after December 11, 2020, the date the US Food and Drug Administration granted emergency-use authorization for the Pfizer-BioNTech vaccine. The target sample size is 1,100 pregnant women who received any dose of the Pfizer-BioNTech vaccine from 30 days prior to the last menstrual period through the end of pregnancy, and 900 comparison women who received no COVID-19 vaccine in pregnancy. Result(s): Among pregnant women participating in the Registry between 11 December 2020 and 22 July 2022, 1,100/1,100 participants (100.0% of the target sample) were enrolled as part of the Pfizer-BioNTech COVID-19 vaccine exposure cohort, and 635/900 participants (70.6% of the target sample) were enrolled in the comparator cohort. As of 22 July 2022, 858 (78.0%) in the vaccine exposure cohort and 313 (34.8%) in the comparator cohort had completed pregnancies. Descriptive data indicated numerically similar percentages of pregnancies ending in at least one liveborn infant, spontaneous abortions, stillbirths, and elective terminations across the exposed cohort stratified by trimester of the earliest dose of the Pfizer-BioNTech COVID-19 vaccine received in pregnancy, and overall in the unexposed comparator cohort. Conclusion(s): Preliminary data have not identified any new safety concerns thus far for pregnant women who receive the Pfizer-BioNTech COVID-19 vaccine during pregnancy. Funding(s): This study was conducted as a collaboration between the University of California San Diego and Pfizer. Pfizer is the study sponsor.

Paxlovid Prophylaxis or Treatment in Pregnancy: Data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry

Background: The US Food and Drug Administration under an Emergency Use Authorization approved use of Paxlovid (nirmatrelavir and ritonavir) for the treatment of mild-to-moderate COVID-19 in adults and children with a positive test for SARS-Co-2 and who are at high risk for progression to severe COVID-19. Pregnant women are at increased risk of severe complications resulting from COVID-19 infection;however, minimal data on the safety of Paxlovid in human pregnancy are available. Objective(s): The objectives of this study are to assess risks of major congenital malformations, spontaneous abortion, elective termination, stillbirth, preterm delivery, small for gestational age infants at birth, or infants who were small for age at one year in pregnancies/infants prenatally exposed to Paxlovid in pregnancy compared to individuals who did not receive this treatment. Design(s): This study involves prospective data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry which enrolls pregnant women residing in the US or Canada and captures data through maternal interviews and ion of medical records. Result(s): Among pregnant women participating in the OTIS Pregnancy Registry as of February 1, 2023, 59 reported exposure to Paxlovid in pregnancy;25.4% exposed within 30 days prior to the last menstrual period and through the first trimester, 42.4% exposed in second trimester, and 32.2% exposed in the third trimester. As of January 2023, 17 of those enrolled have completed pregnancy outcomes. One was lost to follow-up. Of the remainder, there were no adverse pregnancy outcomes reported. Conclusion(s): Very limited data are available on this potentially beneficial treatment in pregnancy. To date, no serious signals for this exposure have been detected.

Comparison of the Effectiveness of Different Covid-19 Vaccines among Plwh

Background: Previous studies have demonstrated promising serologic responses in PLWH receiving a third dose of vaccine against SARS-CoV-2. However, real-world clinical effectiveness, especially during the pandemic caused by B.1.1.529 variant, remains less investigated. Method(s): PLWH seeking HIV care at our hospital from 2021/6 to 2022/6 were included and advised to receive the third dose of COVID-19 vaccine. Individuals were excluded from this study if they had been previously diagnosed with COVID-19. Different types of COVID-19 vaccines were available in the vaccination program, including BNT162b2, mRNA-1273 (either 50 or 100 mug), MVC-COV1901 and NVX-CoV2373 vaccines. PLWH were screening for the occurrence of COVID-19 through the reporting system of notifiable diseases of Taiwan CDC, and were tested for anti-nucleocapsid (anti-N) IgG every 1 to 3 months. Participants were followed for 180 days until the fourth dose of COVID-19 vaccination, occurrence of SARS-CoV-2 infection, seroconversion of anti-N IgG, death, or loss to follow-up, whichever occurred first. Result(s): 1,496 PLWH were included: 631 (42.2%) receiving 100 mug mRNA-1273 vaccine, 468 (31.3%) 50 mug mRNA-1273 vaccine, and 328 (21.9%) BNT162b2 vaccine, 65 (4.3%) MVC-COV1901 vaccine, and 4 (0.3%) NVX-CoV2373 vaccine for the third dose of SARS-CoV-2 vaccination. 297 (19.9%) PLWH were diagnosed with COVID-19 during the follow-up period, including 92 (14.6%) who received 100 mug mRNA-1273, 111 (23.7%) 50 mug mRNA-1273, 79 (24.1%) BNT162b2 and 15 (21.7%) either MVC-COV1901 or NVX-CoV2373;in addition, 98 PLWH had seroconversion of anti-N IgG during follow-up, including 23, 50, 19 and 6 PLWH who received 100 mug mRNA-1273, 50 mug mRNA-1273, BNT162b2, and either MVC-COV1901 or NVX-CoV2373, respectively. Similar rates of new infection with SARS-CoV-2 or seroconversion of anti-N IgG were demonstrated regardless the vaccine type of the third dose (log-rank test, p=0.46). Factors associated with a diagnosis of SARS-CoV-2 infection and seroconversion of anti-N IgG included an age >50 years (aOR, 0.67;95% CI, 0.49-0.91) and newly infected with hepatitis C virus (HCV) (aOR, 1.41;95% CI, 1.09-1.83). Conclusion(s): Our study demonstrated that clinical effectiveness of the third dose of different vaccines available to PLWH was similar in preventing SARSCoV- 2 infection or seroconversion of anti-N IgG Taiwan. PLWH aged less than 50 years and those with newly diagnosed HCV infection were at higher risk of acquiring COVID-19. Kaplan-Meier survival curve for acquiring COVID-19 or seroconversion of anti-N IgG in PLWH receiving different COVID-19 vaccination of the third dose (log-rank test, 4 groups, p = 0.46).

Effects of Targeted Poverty Alleviation on the Sustainable Livelihood of Poor Farmers

It is crucial to conduct a comprehensive evaluation of the effectiveness of targeted poverty alleviation (TPA) policies in promoting sustainable livelihoods among impoverished populations, particularly in light of the COVID-19 pandemic. The existing literature, however, predominantly focuses on assessing the policies' effectiveness in terms of income, while neglecting other critical dimensions of sustainable livelihoods. In line with sustainable livelihood theory, we utilized data from the Chinese Household Financial Survey Database from 2017 and 2019 and employed a fuzzy regression discontinuity (FRD) method to systematically examine the implementation outcomes of TPA policies through the lens of "capability-strategy-results”. Our analysis revealed that the implementation of TPA policies had a positive impact on the ability of poor households to cope with unexpected shocks, as evidenced by an increase in the accumulation rates of material, social, and financial capital. Furthermore, we observed an optimization of livelihood strategies among poor households, with a significant increase in the proportion of wage income. These policies also had a positive impact on their livelihood outcomes, such as a reduced likelihood of falling back into poverty and an increased possibility of escaping from marginal poverty without relying on government subsidies;however, some limitations require attention. Notably, our analysis revealed that the policies did not effectively improve the human capital of poor households. To further explore the heterogeneity of policy effects, we categorized poor households into three groups based on their farmer's market participation ability and willingness. Our findings indicate that TPA policies effectively reduced poverty among households lacking labor force through government subsidies and saw an increase in the proportion of medical insurance reimbursement;however, households lacking motivation or capability did not experience positive outcomes in the short term. Therefore, future support policies should prioritize these vulnerable groups and monitor their progress closely. Moreover, our analysis revealed that migrant work is the primary livelihood strategy among the poor, and stabilizing their employment faces significant challenges amid the COVID-19 pandemic. Consequently, additional policies and interventions are needed to address the adverse impact of the pandemic on the employment and livelihoods of low-income households. © 2023 by the authors.

Analysis of The Impact of SARS-CoV-2 Variants on Global Epidemic Prevention and Control

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed a serious threat to international public health. The SARS-COV-2 gene continues to mutate in COVID-19 outbreaks. Mutation mainly manifests in 3 forms: point mutation, gene recombination and epigenetic modification. Viral mutations are driven by multiple factors, with mutation rates modulated at 3 levels, the nature of virus, host-virus interactions and natural selection. Therefore, it is particularly important to strengthen the monitoring of the global novel coronavirus genome and the protection of immunosuppressed populations. In the early stage of virus evolution, the mutant strains exhibit greater transmissibility and less virulence than the wild-type strain, although 5 variants of concern (VOCs) showed different stability, transmission capacity, adaptability and pathogenicity. So physical interventions need to be further strengthened. As herd immunity is established, novel mutant strains tend to mutate against vaccines and antibodies. In that case, VOCs, especially the prevailing Omicron variant, bring challenges to the prevention and control of COVID-19 worldwide. The existing and potential prevention, diagnosis and treatment approaches for COVID-19 were summarized. In the vaccination part, the protective efficacy of COVID-19 vaccine against VOCs and the factors influencing the efficacy of COVID-19 vaccine were analyzed. In the detection part, the detection methods based on nucleic acid, antigen and antibody were summarized in order to satisfy the requirements for point-of-care testing and timely recognition of novel variants. And in the treatment part, the potential therapeutic drugs and targets of SARS-CoV-2 were summarized. Drug targets are generally divided into extracellular targets and intracellular targets. In general, this review proposes possible countermeasures by analyzing the impact of mutations on global epidemic prevention and control, hoping to provide theoretical basis for possible large-scale epidemic prevention and control in the future. © 2022 Institute of Biophysics,Chinese Academy of Sciences. All rights reserved.

Preparation of two kinds of membranes with reverse wettability from waste masks for continuous oil/water separation

Resourceful use of waste masks (WMs) has become an important challenge for humanity with the spread of the coronavirus disease (COVID-19). In this work, WMs were treated by disinfection treatment and then modified via the in situ chemical deposition of SiO2 followed by the grafting of dopamine (DA) and octadecyltrichlorosilane (OTS). By controlling the amount of DA or OTS added, WM-SiO2/DA (superhydrophilic) and WM-SiO2/OTS (hydrophobic) membranes were fabricated with reverse wettability with water contact angles of 0° and 147.5°, respectively. The WM-SiO2/DA and WM-SiO2/OTS membranes possessed attractive permeability toward water (6793 L m-2 h-1) and CCl4 (13 867 L m-2 h-1), together with separation efficiencies over 98.0% under gravity. Besides, the WM-SiO2/DA and WM-SiO2/OTS membranes were used in a T-shaped device for the analysis of continuous oil/water separation processes. The results showed that oil/water mixtures could be separated continuously regardless of the density of oil/water by virtue of the attractive permeability and separation efficiency. Furthermore, the membranes also demonstrated favorable stability and reusability under harsh operating conditions. Consequently, this work provides an effective and promising way to upcycle waste masks, especially in the field of oil/water separation. © 2023 The Royal Society of Chemistry.

Studying the Effect of Glycosylation towards SARS-CoV-2 Spike RBD and ACE2 Interaction by Native Mass Spectrometry

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has serious consequences on global public health and social development. The binding of receptor binding domain (RBD) of spike protein to angiotensin converting enzyme 2 (ACE2) on the surface of SARS-CoV-2 host cell initiates the infection progress. Spike and ACE2 are both glycoproteins, the impact of glycosylation on protein structures and protein-protein interactions remains largely elusive. Characterizing the structural and dynamics of protein-protein binding progress will improve mechanism understanding of viral infection and facilitate targeted drug design. Structural mass spectrometry (MS) method is widely used in protein structural studies, providing complementary information to conventional biophysical methods, such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy and cryo-electron microscopy (cryo-EM). Native mass spectrometry (native MS) is an emerging technology that enables the study of intact protein, non-covalent protein-protein, and protein-ligand complexes in their biological state, which can provide structural stability, binding stoichiometry, and spatial arrangement information. Here, native MS was used to examine the interaction between RBD and ACE2 as well as the impact of deglycosylation on the interaction stability of the RBD-ACE2 complex. The results revealed that both RBD and ACE2 are highly glycosylated, ACE2 presents as a dimer while RBD as a monomer, and they form a (RBD-ACE2)2 complex. The conditions of using PNGasc F to remove the N-glycan were optimized. At least two Oglycans including NcuAc(2) and GalNAcC 1) Gal( 1) NcuAc(2) or GlcNAcd ) Gal(l) NeuAc(2) were observed for the N-glycan removed RBD. Furthermore, the stability of the complexes formed by glycosylated and deglycosylated RBD with ACE2 was compared, and the results showed that the removal of N-glycan significantly drops the interaction stability of the RBD-ACE2 complex. Therefore, we recommend that glycosyla-tion should not be removed for structural and functional studies. Additional glycosyla-tion, structural and dynamics studies on Spike (including separated RBD) and ACE2 complexes would help us to understand the process of viral infection, advance drug design and vaccine developments. Nowadays, a comprehensive MS-based toolbox has been developed for the analysis of protein structure, function, and dynamics, including hydrogen-deuterium exchange MS (HDX-MS), native top-down (nTD) MS, cross-linking MS (XL-MS), and covalent labelling MS (CL-MS), etc. Through integrating structural MS methods, more detailed and comprehensive structural information about glycoproteins and their complexes will be uncovered. © 2022 Chinese Society for Mass Spectrometry. All rights reserved.

Studying the Effect of Glycosylation towards SARS-CoV-2 Spike RBD and ACE2 Interaction by Native Mass Spectrometry

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has serious consequences on global public health and social development. The binding of receptor binding domain (RBD) of spike protein to angiotensin converting enzyme 2 (ACE2) on the surface of SARS-CoV-2 host cell initiates the infection progress. Spike and ACE2 are both glycoproteins, the impact of glycosylation on protein structures and protein-protein interactions remains largely elusive. Characterizing the structural and dynamics of protein-protein binding progress will improve mechanism understanding of viral infection and facilitate targeted drug design. Structural mass spectrometry (MS) method is widely used in protein structural studies, providing complementary information to conventional biophysical methods, such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy and cryo-electron microscopy (cryo-EM). Native mass spectrometry (native MS) is an emerging technology that enables the study of intact protein, non-covalent protein-protein, and protein-ligand complexes in their biological state, which can provide structural stability, binding stoichiometry, and spatial arrangement information. Here, native MS was used to examine the interaction between RBD and ACE2 as well as the impact of deglycosylation on the interaction stability of the RBD-ACE2 complex. The results revealed that both RBD and ACE2 are highly glycosylated, ACE2 presents as a dimer while RBD as a monomer, and they form a (RBD-ACE2)2 complex. The conditions of using PNGasc F to remove the N-glycan were optimized. At least two Oglycans including NcuAc(2) and GalNAcC 1) Gal( 1) NcuAc(2) or GlcNAcd ) Gal(l) NeuAc(2) were observed for the N-glycan removed RBD. Furthermore, the stability of the complexes formed by glycosylated and deglycosylated RBD with ACE2 was compared, and the results showed that the removal of N-glycan significantly drops the interaction stability of the RBD-ACE2 complex. Therefore, we recommend that glycosyla-tion should not be removed for structural and functional studies. Additional glycosyla-tion, structural and dynamics studies on Spike (including separated RBD) and ACE2 complexes would help us to understand the process of viral infection, advance drug design and vaccine developments. Nowadays, a comprehensive MS-based toolbox has been developed for the analysis of protein structure, function, and dynamics, including hydrogen-deuterium exchange MS (HDX-MS), native top-down (nTD) MS, cross-linking MS (XL-MS), and covalent labelling MS (CL-MS), etc. Through integrating structural MS methods, more detailed and comprehensive structural information about glycoproteins and their complexes will be uncovered. © 2022 Chinese Society for Mass Spectrometry. All rights reserved.

International student mobility: A systematic review and research agenda

This study aimed to synthesize fragmented knowledge about international student mobility (ISM) in higher education to provide an understanding of existing studies and directions for future research. To this end, the authors conducted a systematic literature review using a hybrid approach that integrated bibliometric analysis with the theory, context, and method (TCM) framework (Paul et al., Journal of World Business, 2017;52(3):327–342). Applying bibliometric analysis, this study found publication trends, prolific journals, influential articles, and major themes in the field, whereas the TCM framework helped identify widely used theories (motivation theory, immigration theory, acculturation theory, learning theory, and capital theory), research contexts (destination country or region, population, and others), and methods in research and provided future study directions. The identified gaps in the existing literature suggest that future research should develop theoretical foundations and research designs to analyse new processes, patterns, and issues in ISM in higher education within the context of today's changing international environment. In addition to identifying the key research themes and research foundations of ISM in higher education, this review can help add value to the ISM literature from a marketing perspective. This is the first comprehensive literature review of this topic using a hybrid approach. © 2023 John Wiley & Sons Ltd.

Travel route planning method to avoid epidemic hot-spots in the post-epidemic era

The Chinese government adhered to the "dynamic clearance” epidemic prevention strategy from August 2021 to December 7, 2022, during the post-epidemic era (this study started in March 2022 and ended in September 2022). People are gradually resuming their daily routines, and demand for travel is rising again. Nonetheless, the epidemic occasionally breaks out on a smaller scale, causing social concern. As a social reaction, the essential issue is how to avoid COVID-19 hot-spots effectively by offering secure travel options for local residents who tend to travel privately. Two travel route planning models are proposed to avoid COVID-19 hot-spots based on the invalid road sections which are affected by epidemic. Specifically, the static model aims at generating the shortest travel distance after detours, with the constraint of avoiding COVID-19 hot-spots;the dynamic model takes real-time data into account, which includes epidemic risk levels, road grades, and real-time traffic information on road selection. Shenzhen, China, is illustrated as an example of the research area in this paper. To assess the effectiveness and efficiency of the suggested approaches, data regarding the road network, the prevalence of epidemics, and traffic congestion are collected. The experimental results demonstrate that 1) the proposed two route planning models can effectively bypass areas with high levels of epidemic risk. 2) The static route planning model increases the travel distance by 12.24% and 13.03%, while the dynamic route planning model increases the travel distance by 24.33% and 27.69% compared with the conventional shortest route, given the same origin and destination and the same impact radii of the COVID-19 hot-spots (300 and 500 m respectively). When taking detour routes to avoid COVID-19 hot-spots, the average increase in trip distance does not surpass 50%, which is acceptable psychologically for travelers. 3) The static travel route planning model is suitable for the severe epidemic situation for it can strictly avoid the epidemic hot-spots;The dynamic travel route planning model is applicable to the situation where the epidemic situation is relatively mild. Ultimately, the route planning models can be utilized to develop a framework to provide travelers with detour options, which would make a practical difference to ensure travelers' safety during traveling and contribute to preventing the spread of the epidemic. © 2023 The Author(s)

Gaseous and Particulate Pollution in the Wu-Chang-Shi Urban Agglomeration on the Northern Slope of Tianshan Mountains from 2017 to 2021

Rapid social development has led to serious air pollution problems in cities, and air pollutants, including gaseous pollutants and particulate matter, have an important impact on climate, the environment, and human health. This study analyzed the characteristics, potential sources, and causes of air pollution in the Wu-Chang-Shi urban cluster. The results showed that NO2, CO, SO2, PM10, and PM2.5 had a tendency to decrease, while O-3 showed an increasing trend. The concentrations of SO2, NO2, CO, PM2.5, and PM10 showed the highest values in winter and the lowest values in summer, with similar seasonal variations. However, the concentration of O-3 was highest in the summer and lowest in the winter. Compared with the pollutant concentrations in other Chinese cities, PM2.5, PM10, and NO2 are more polluted in the Wu-Chang-Shi urban. Meteorological factors have a greater impact on pollutant concentrations, with higher concentrations of major pollutants observed when wind speeds are low and specific wind directions are observed, and higher secondary pollutant O-3 concentrations observed when wind speeds are low and specific wind directions are observed. The backward trajectory and concentration weighting analysis show that the particulate pollutants in the Wu-Chang-Shi urban in winter mainly come from Central Asia and surrounding cities. O-3 showed an increasing trend before and after the novel coronavirus outbreak, which may be related to changes in NOX, volatile organic compounds, and solar radiation intensity, and the concentrations of SO2, NO2, CO, PM10, and PM2.5 showed an overall decreasing trend after the outbreak and was smaller than before the outbreak, which is related to the reduction of industrial and anthropogenic source emissions during the outbreak.

Unwanted Indoor Air Quality Effects from Using Ultraviolet C Lamps for Disinfection

Ultraviolet germicidal irradiation (UVGI) is known to inactivate various viruses and bacteria, including SARS-CoV-2, and is widely applied especially in medical facilities. This inactivation results from the high photon energies causing molecular bonds to break, but when nonpathogen molecules are affected, unwanted effects may occur. Here, we explored the effect of a commercial high intensity (similar to 2 kW) UVC disinfection device on the composition and concentration of gases and particles in indoor air. We find that the UVC (254 nm) caused dramatic increases in particle number concentrations, and nearly all (similar to 1000) monitored gas phase species also increased. These responses were unsurprising when considering the typical impacts of UVC on atmospheric chemistry. High particle concentrations are associated with adverse health effects, suggesting that the impact of UVGI devices on indoor air quality (IAQ) should be studied in much more detail. The high-intensity device in this study was intended for short durations in unoccupied rooms, but lower-intensity devices for continuous use in occupied rooms are also widely applied. This makes further studies even more urgent, as the potential IAQ effects of these approaches remain largely unexplored.

Unwanted Indoor Air Quality Effects from Using Ultraviolet C Lamps for Disinfection

Ultraviolet germicidal irradiation (UVGI) is known to inactivate various viruses and bacteria, including SARS-CoV-2, and is widely applied especially in medical facilities. This inactivation results from the high photon energies causing molecular bonds to break, but when nonpathogen molecules are affected, unwanted effects may occur. Here, we explored the effect of a commercial high-intensity (∼2 kW) UVC disinfection device on the composition and concentration of gases and particles in indoor air. We find that the UVC (254 nm) caused dramatic increases in particle number concentrations, and nearly all (∼1000) monitored gas phase species also increased. These responses were unsurprising when considering the typical impacts of UVC on atmospheric chemistry. High particle concentrations are associated with adverse health effects, suggesting that the impact of UVGI devices on indoor air quality (IAQ) should be studied in much more detail. The high-intensity device in this study was intended for short durations in unoccupied rooms, but lower-intensity devices for continuous use in occupied rooms are also widely applied. This makes further studies even more urgent, as the potential IAQ effects of these approaches remain largely unexplored. © 2023 The Authors. Published by American Chemical Society.

Analysis of The Impact of SARS-CoV-2 Variants on Global Epidemic Prevention and Control

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed a serious threat to international public health. The SARS-COV-2 gene continues to mutate in COVID-19 outbreaks. Mutation mainly manifests in 3 forms: point mutation, gene recombination and epigenetic modification. Viral mutations are driven by multiple factors, with mutation rates modulated at 3 levels, the nature of virus, host-virus interactions and natural selection. Therefore, it is particularly important to strengthen the monitoring of the global novel coronavirus genome and the protection of immunosuppressed populations. In the early stage of virus evolution, the mutant strains exhibit greater transmissibility and less virulence than the wild-type strain, although 5 variants of concern (VOCs) showed different stability, transmission capacity, adaptability and pathogenicity. So physical interventions need to be further strengthened. As herd immunity is established, novel mutant strains tend to mutate against vaccines and antibodies. In that case, VOCs, especially the prevailing Omicron variant, bring challenges to the prevention and control of COVID-19 worldwide. The existing and potential prevention, diagnosis and treatment approaches for COVID-19 were summarized. In the vaccination part, the protective efficacy of COVID-19 vaccine against VOCs and the factors influencing the efficacy of COVID-19 vaccine were analyzed. In the detection part, the detection methods based on nucleic acid, antigen and antibody were summarized in order to satisfy the requirements for point-of-care testing and timely recognition of novel variants. And in the treatment part, the potential therapeutic drugs and targets of SARS-CoV-2 were summarized. Drug targets are generally divided into extracellular targets and intracellular targets. In general, this review proposes possible countermeasures by analyzing the impact of mutations on global epidemic prevention and control, hoping to provide theoretical basis for possible large-scale epidemic prevention and control in the future.

Risk assessment and prevention and control effective assessment for COVID-19 in Hainan based on population migration

Objective To assess imported risk of COVID-19 in Hainan province from January 10 to March 7 in 2020, and to assess the effect of "The Normalization Prevention and Control" (measures during the Spring Festival Travel Rush (SFTR) in Hainan in 2021. Methods The daily reported imported cases in Hainan province, the daily reported cases in other 30 province of China, and the Baidu Migration Index were collected to calculated into the Imported Risk Index (IRI) to quantitatively assess the imported risk of Hainan province. Based on the analysis of the relationship between the imported risk index and imported cases, an imported case prediction model was constructed to fit the number of imported cases in "emergency containment" stage in Hainan. And number of imported cases during the Spring Festival Travel rush in 2021 was predicted by this model to compared with the actual number, which was to evaluate the "Normalization Prevention and Control" measures in this model was also used to assess the effect of "Normalization Prevention and Control" measures during the SFTR in 2021. Results Totally 112 imported cases were reported in Hainan. The average IRI was 0.98. Haikou, Sanya and Danzhou have the highest imported risk. Except Haikou, the imported risk index of all cities and counties reached the maximum value around January 24th. The generalized additive model based on the lag 4 days and lag 5 days was best fitted with the actual imported cases number (R2adjust1=83.50%, R2adjust2=82.00%, MRE=17.61%). If "Emergency Containment" strategy was still adopted, there were 10 COVID-19 cases imported into Hainan during the SFTR in 2021. Under the "Normalization Prevention and Control" strategy, virtually no imported cases were found in Hainan. Conclusions Tourism cities such as Haikou and Sanya have high imported risks. Hubei and Guangdong provinces are the main imported provinces. The Generalized Additive Model based on the Imported Risk Index can better fit with the imported cases number of COVID-19 in Hainan Province in "emergency containment". Compared with the "Emergency Containment" strategy, the "Normalization Prevention and Control" strategy adopted during the SFTR in 2021 reduced imported cases in Hainan by about 10. © 2022. China Tropical Medicine. All rights reserved.

Research Progress and Implication of Wastewater Surveillance of SARS-CoV-2

Since the outbreak of the coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been found in wastewater frequently worldwide. Based on the wastewater-based epidemiology (WBE), wastewater surveillance of SARS-CoV-2 can complement population surveillance for COVID-19. Quantification of viral load and genome sequencing of SARS-CoV-2 can help early warning of COVID-19 outbreaks, early identification of asymptomatic cases, assessment of infection scale, prediction of pandemic trend status, and identification of virus sources to provide scientific basis for polices for the prevention and control. Accordingly, here, the sources of SARS-CoV-2 in wastewater at home and abroad and the major factors affecting the survival of virus were reviewed. Common methods to concentrate, detect and quantify SARS-CoV-2 were reviewed, with an overview of global surveillance projects, progresses, and remaining scientific issues. Some shortcomings of the current procedures, including the lack of sufficient information on distribution characteristics and infectivity of SARS-CoV-2 in wastewater and limited development and application of prediction models were also discussed. WBE can provide insight into the scientific prevention and control of COVID-19 in the face of current or future pandemics in China, and enhance China′s ability to deal with the surveillance and early warning, epidemic scale assessment, and accurate policy-making for the infectious and non-infectious diseases. © 2022 Editorial Board, Research of Environmental Sciences. All rights reserved.

Study on the optimization of emergency medical staff regional dispatch considering the ratio of doctors and nurses

Public health emergencies will pose an enormous challenge to healthcare service systems. As COVID-19 rage across the globe, we realize that COVID-19 exposes the problem of inadequate research on the dispatch of emergency medical personnel in response to a major epidemic outbreak. In the face of major public health emergencies, failure in timely satisfaction of healthcare demands by local healthcare professionals necessitates human resource support from other regions. To address this issue, further research is needed to gain better insights into interregional emergency human resource allocation. This paper aims to offer attention to patients' medical needs and suppose that there are support hubs outside the outbreak region offering an external supply of medical personnel. The hospitals in these support hubs are categorized based on variables such as capacity, medical capability, and the number of dispatched personnel per day. An interregional emergency allocation model was established to consider the proper doctor-patient ratio and nurse-patient ratio in emergency response using methods such as mathematical programming. And relevant management suggestions were then offered via analysis. Research in this paper provides allocation models and proposals that healthcare professionals can refer to when making resource allocation decisions in emergency response. © 2022 ACM.

Analysis On the Challenges for Smart Elderly Care to Face in the Post-pandemic Era of Covid-19

Based on the investigation of the current situation of smart elderly care services in Wuhan, Hubei Province, combined with the results of field visits, this paper combs and analyzes the common problems faced by smart elderly care and the new problems and opportunities brought by the epidemic. Put forward countermeasures and suggestions to solve the problems faced by smart elderly care, so as to enhance the suitability and availability of smart elderly care services, and finally achieve the purpose of improving the well-being of the elderly and sharing the fruits of social development with the elderly. © 2022 ACM.