Nature-inspired catalytic asymmetric rearrangement of cyclopropylcarbinyl cation.

In nature, cyclopropylcarbinyl cation is often involved in cationic cascade reactions catalyzed by natural enzymes to produce a great number of structurally diverse natural substances. However, mimicking this natural process with artificial organic catalysts remains a daunting challenge in synthetic chemistry. We report a small molecule-catalyzed asymmetric rearrangement of cyclopropylcarbinyl cations, leading to a series of chiral homoallylic sulfide products with good to excellent yields and enantioselectivities (up to 99% enantiomeric excess). In the presence of a chiral SPINOL-derived N-triflyl phosphoramide catalyst, the dehydration of prochiral cyclopropylcarbinols occurs rapidly to generate symmetrical cyclopropylcarbinyl cations, which are subsequently trapped by thione-containing nucleophiles. A subgram-scale experiment and multiple downstream transformations of the sulfide products are further pursued to demonstrate the synthetic utility. Notably, a few heteroaromatic sulfone derivatives could serve as "covalent warhead" in the enzymatic inhibition of severe acute respiratory syndrome coronavirus 2 main protease.

Discovery of Potent Pyrazoline-Based Covalent SARS-CoV-2 Main Protease Inhibitors.

While vaccines and antivirals are now being deployed for the current SARS-CoV-2 pandemic, we require additional antiviral therapeutics to not only effectively combat SARS-CoV-2 and its variants, but also future coronaviruses. All coronaviruses have relatively similar genomes that provide a potential exploitable opening to develop antiviral therapies that will be effective against all coronaviruses. Among the various genes and proteins encoded by all coronaviruses, one particularly "druggable" or relatively easy-to-drug target is the coronavirus Main Protease (3CLpro or Mpro), an enzyme that is involved in cleaving a long peptide translated by the viral genome into its individual protein components that are then assembled into the virus to enable viral replication in the cell. Inhibiting Mpro with a small-molecule antiviral would effectively stop the ability of the virus to replicate, providing therapeutic benefit. In this study, we have utilized activity-based protein profiling (ABPP)-based chemoproteomic approaches to discover and further optimize cysteine-reactive pyrazoline-based covalent inhibitors for the SARS-CoV-2 Mpro. Structure-guided medicinal chemistry and modular synthesis of di- and tri-substituted pyrazolines bearing either chloroacetamide or vinyl sulfonamide cysteine-reactive warheads enabled the expedient exploration of structure-activity relationships (SAR), yielding nanomolar potency inhibitors against Mpro from not only SARS-CoV-2, but across many other coronaviruses. Our studies highlight promising chemical scaffolds that may contribute to future pan-coronavirus inhibitors.

Determinants of e-waste workers' intention to wear respiratory protective equipment at work in Hong Kong

IntroductionE-waste workers in Hong Kong are exposed to more chemicals because more e-waste needs to be handled locally. However, studies suggested that many e-waste workers are unwilling to wear respiratory protective equipment (RPE) for different reasons. This study aimed to identify the determinants of e-waste workers' intention to wear RPE in Hong Kong.Material and MethodsWe recruited 109 e-waste workers from June 2021 to September 2022. A workplace RPE intention scale (WRPIEs) was developed based on validated Robertsen's RPE behavior intention model and Hong Kong Occupational Safety Culture Index. The WRPIEs was consolidated by exploratory factor analysis and further enhanced by confirmatory factor analysis. Multivariate linear regression was used to test the association between the identified domain factors and the intention to use RPE at work.ResultsMost of the participants were aged over 40 years (76%), had middle school or below educational degrees (83%), wore RPE (94%) at work, and had increased time of wearing RPE after the Covid-19 pandemic (69%). Four domain factors (containing 17 manifest variables) were confirmed, including ‘subjective norms (SN)', ‘supportive working conditions (SWC)', ‘autonomy', and ‘occupational safety and health'. The enhanced WRPIEs had good indices in internal consistency reliability (Cronbach's α ranged: 0.78–0.94), good composite reliability (range: 0.79–0.95), and model fit (SRMR=0.05, RMSEA=0.03, CFI=0.99). Among the identified domain factors, SN (β=0.36) and SWC (β=0.30) significantly increased e-waste workers' intention to wear RPE at the workplace.ConclusionsThis newly validated WRPIEs scale can help capture Chinese e-waste workers' intention to wear RPE. Results from this study also suggested that various stakeholders could enhance SN and SWC to facilitate workers' willingness to wear PPE. (Acknowledgements: GRF/RGC-165056653 & VCDFIII-136366853. Ethics approval: CREC 2020.039;*shelly@cuhk.edu.hk)

A randomized controlled trial of an educational intervention in willingness of the COVID-19 vaccine booster shots among non-healthcare workers

IntroductionDespite a high proportion of workers infected with SARS-CoV-2 experienced no or mild symptoms, the business ought to shut down when there is an outbreak. Observational studies showed that willingness of COVID-19 vaccine increased vaccination rate. Although receiving booster shots may reduce infection and release symptoms, the public has concerns on booster vaccines and whether educational intervention improves the willingness remains unclear. This study aimed to evaluate the effectiveness of a theory-based educational programme on improving willingness intention/actual uptake of booster doses and reducing infection in non-healthcare workers.Materials and MethodsThis is an ongoing 9-month randomized controlled trial (RCT) with two arms and single blinding. From April to June 2022, 299 workers enrolled from a variety of work settings were randomly allocated to intervention and control group. Intervention was an online educational programme based on the theory of planned behavior (TPB), which was implemented at the beginning and repeated at 3-month. The outcomes were changes of willingness intention/actual uptake of booster vaccine and infection, measured at pre- and post- intervention of baseline, at 3-month, 6-month and 9-month follow-up. The ethics approval number is CREC-2021.531-T.ResultsAt the baseline, about 61% workers received 3 doses and 38% had ever been infected with SARS-CoV-2. Compared with the pre-intervention, both the post-intervention and control group had improved attitude (26.5±9.4 vs 26.7±9.4) and perceived behavioral control (30.7±8.1 vs 29.5±8.5), with a slightly better for the intervention group. These scores decreased slightly at 3-month intervention (28.7±8.7 vs 28.7±8.9), but they were still higher than the pre-intervention measurements. A similar pattern was observed for willingness intention to uptake booster doses but not for the infection rate.ConclusionsThis RCT shows that education intervention increased willingness of getting booster shots via improving attitude and perceived behavior control, but the effect was not significant. [HMRF#COVID1903008, shelly@cuhk.edu.hk]

Evaluation of infection probability of Covid-19 in different types of airliner cabins

According to the World Health Organization (https://covid19.who.int/), more than 651 million people have been infected by COVID-19, and more than 6.6 million of them have died. COVID-19 has spread to almost every country in the world because of air travel. Cases of COVID-19 transmission from an index patient to fellow passengers in commercial airplanes have been widely reported. This investigation used computational fluid dynamics (CFD) to simulate airflow and COVID-19 virus (SARS-CoV-2) transport in a variety of airliner cabins. The cabins studied were economy-class with 2-2, 3-3, 2-3-2, and 3-3-3 seat configurations, respectively. The CFD results were validated by using experimental data from a seven-row cabin mockup with a 3-3 seat configuration. This study used the Wells-Riley model to estimate the probability of infection with SARS-CoV-2. The results show that CFD can predict airflow and virus transmission with acceptable accuracy. With an assumed a flight time of 4 h, the infection probability was almost the same among the different cabins, except that the 3-3-3 configuration had a lower risk because of its airflow pattern. Flying time was the most important parameter for causing the infection, while cabin type also played a role. Without mask wearing by the passengers and the index patient, the infection probability could be 8% for a 10-h, long-haul flight, such as a twin-aisle air cabin with 3-3-3 seat configuration.

Breakthrough infection among workers in different non-healthcare working settings

IntroductionWorkplace is supposed to be an important transmission node of coronavirus disease-2019 (COVID-19) in the epic initiation. Assessing the contagious risk in the different workplaces is important to target effective measures workplace. However, there was limited data to explore transmission patterns in work settings after COVID-19 spread into the community and population vaccination.Materials and MethodsFrom April to June 2022, 328 workers were enrolled in a variety of work settings. An online questionnaire was used to collect their current work industry, geographic information, vaccination of SARS-CoV-2, infection, etc. To categorize their exposure risk to COVID-19 cases from the workplace, workers were grouped into 3 different work settings according to their job nature and working environment. Non-office workers were those who normally carried out their jobs in a range of environments in an indoor or outdoor working space where close contact with the general public is frequent;Mobile workers were those who frequently move for conducting business that involves closer and more frequent contact with the general public;Office workers were those normally carry out professional duties and administrative work in an indoor working space. Breakthrough infection is defined as an infection after 14 days of full vaccination. The ethics approval number is CREC-2021.531-T.ResultsThere were 97, 151, and 80 workers in mobile, non-office, and office work groups and the infection rate were 40.2%, 40.4%, and 37.5%, respectively. 96.3% of them were full-vaccinated or get a booster shot. There was no significant difference in the breakthrough infection rate of workers in these three work settings no matter getting two or three shots of vaccine.ConclusionsWorkplace infection especially after full vaccination is not an important SARS-CoV-2 transmission pathway. [HMRF#COVID1903008, shelly@cuhk.edu.hk]

Characterizing the cellular and molecular variabilities of peripheral immune cells in healthy recipients of BBIBP-CorV inactivated SARS-CoV-2 vaccine by single-cell RNA sequencing.

Over 3 billion doses of inactivated vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been administered globally. However, our understanding of the immune cell functional transcription and T cell receptor (TCR)/B cell receptor (BCR) repertoire dynamics following inactivated SARS-CoV-2 vaccination remains poorly understood. Here, we performed single-cell RNA and TCR/BCR sequencing on peripheral blood mononuclear cells at four time points after immunization with the inactivated SARS-CoV-2 vaccine BBIBP-CorV. Our analysis revealed an enrichment of monocytes, central memory CD4+ T cells, type 2 helper T cells and memory B cells following vaccination. Single-cell TCR-seq and RNA-seq comminating analysis identified a clonal expansion of CD4+ T cells (but not CD8+ T cells) following a booster vaccination that corresponded to a decrease in the TCR diversity of central memory CD4+ T cells and type 2 helper T cells. Importantly, these TCR repertoire changes and CD4+ T cell differentiation were correlated with the biased VJ gene usage of BCR and the antibody-producing function of B cells post-vaccination. Finally, we compared the functional transcription and repertoire dynamics in immune cells elicited by vaccination and SARS-CoV-2 infection to explore the immune responses under different stimuli. Our data provide novel molecular and cellular evidence for the CD4+ T cell-dependent antibody response induced by inactivated vaccine BBIBP-CorV. This information is urgently needed to develop new prevention and control strategies for SARS-CoV-2 infection. (ClinicalTrials.gov Identifier: NCT04871932).

Evaluation of infection probability of Covid-19 in different types of airliner cabins.

According to the World Health Organization (https://covid19.who.int/), more than 651 million people have been infected by COVID-19, and more than 6.6 million of them have died. COVID-19 has spread to almost every country in the world because of air travel. Cases of COVID-19 transmission from an index patient to fellow passengers in commercial airplanes have been widely reported. This investigation used computational fluid dynamics (CFD) to simulate airflow and COVID-19 virus (SARS-CoV-2) transport in a variety of airliner cabins. The cabins studied were economy-class with 2-2, 3-3, 2-3-2, and 3-3-3 seat configurations, respectively. The CFD results were validated by using experimental data from a seven-row cabin mockup with a 3-3 seat configuration. This study used the Wells-Riley model to estimate the probability of infection with SARS-CoV-2. The results show that CFD can predict airflow and virus transmission with acceptable accuracy. With an assumed flight time of 4 h, the infection probability was almost the same among the different cabins, except that the 3-3-3 configuration had a lower risk because of its airflow pattern. Flying time was the most important parameter for causing the infection, while cabin type also played a role. Without mask wearing by the passengers and the index patient, the infection probability could be 8% for a 10-h, long-haul flight, such as a twin-aisle air cabin with 3-3-3 seat configuration.

Surveillance of SARS-CoV-2 at the Huanan Seafood Market.

SARS-CoV-2, the causative agent of COVID-19, emerged in December 2019. Its origins remain uncertain. It has been reported that a number of the early human cases had a history of contact with the Huanan Seafood Market. Here we present the results of surveillance for SARS-CoV-2 within the market. From January 1st 2020, after closure of the market, 923 samples were collected from the environment. From 18th January, 457 samples were collected from 18 species of animals, comprising of unsold contents of refrigerators and freezers, swabs from stray animals, and the contents of a fish tank. Using RT-qPCR, SARS-CoV-2 was detected in 73 environmental samples, but none of the animal samples. Three live viruses were successfully isolated. The viruses from the market shared nucleotide identity of 99.99% to 100% with the human isolate HCoV-19/Wuhan/IVDC-HB-01/2019. SARS-CoV-2 lineage A (8782T and 28144C) was found in an environmental sample. RNA-seq analysis of SARS-CoV-2 positive and negative environmental samples showed an abundance of different vertebrate genera at the market. In summary, this study provides information about the distribution and prevalence of SARS-CoV-2 in the Huanan Seafood Market during the early stages of the COVID-19 outbreak.

Systematic pan-cancer analysis identifies cGAS as an immunological and prognostic biomarker.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus causes novel coronavirus disease 2019 (COVID-19), which is characterized by pneumonia, cytokine storms, and lymphopenia. Due to immunosuppression, cancer patients may be more susceptible to SARS-CoV-2 and have more serious complications. According to recent research, cyclic GMP-AMP synthase (cGAS) could be a potential SARS-CoV-2 sensor. However, at present, no studies have been conducted on cGAS gene alterations in pan-cancer. This study aimed to discover therapeutic implications for COVID-19-infected tumor patients by performing a comprehensive analysis of cGAS in malignant tumors. Methods: cGAS expression matrices were obtained from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), and Cancer Cell Line Encyclopedia (CCLE) databases, which were used to evaluate cGAS expression in various tumors, its prognostic value, and its relationship to the immune microenvironment, microsatellite instability (MSI), immune neoantigens, gene mutations, immune checkpoints, MSI, tumor mutational burden (TMB), mismatch repair (MMR) genes, and DNA methyltransferases (DNMT). We also used the cBioPortal, Human Protein Atlas (HPA), and GeneMANIA databases to explore the types of changes, gene networks and immunofluorescence localization, and protein expression of these genes. Results: Compared to normal tissues, cGAS was highly expressed in 13 types of cancer (e.g., lung cancer) and lowly expressed in other cancers (e.g., pancreatic cancer). cGAS expression was associated with prognosis in nine cancers, such as renal clear cell carcinoma (P<0.05). Furthermore, deep deletion was the most common type of cGAS genomic mutation. DNMT, immune infiltration levels, TMB, MSI, MMR genes, neoantigens, and immune checkpoints were all correlated with cGAS expression. Moreover, we used the GSE30589 dataset to investigate the post-SARS-CoV infection changes in cGAS expression in vitro. Finally, mithramycin, MI219, AFP464, aminoflavone, kahalide F, AT13387, doxorubicin, and other drugs increased the sensitivity of cGAS expression. According to the evidence presented above, cGAS may become an important target for cancer therapy. Conclusions: This study discovered that SARS-CoV-2-infected cancer patients might experience changes in their tumor environment as a result of cGAS, making patients with tumors expressing high cGAS more susceptible to COVID-19 and possibly a worsening prognosis. Furthermore, cGAS may be a novel biomarker for diagnosing and treating COVID-19-infected tumor patients.

SARS-CoV-2 evolves to reduce but not abolish neutralizing action.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) have prolonged coronavirus disease 2019 (COVID-19) pandemic by escaping pre-existing immunity acquired by natural infection or vaccination. Elucidation of VOCs' mutation trends and evasion of neutralization is required to update current control measures. Mutations and the prevalence of VOCs were analyzed in the global immunization coverage rate context. Lentivirus-based pseudovirus neutralization analysis platforms for SARS-CoV-2 prototype strain (PS) and VOCs, containing Alpha, Beta, Gamma, Delta, and Omicron, were constructed based on the spike protein of each variant and HEK 293T cell line expressing the human angiotensin-converting enzyme 2 (hACE2) receptor on the surface, and an enhanced green fluorescent protein reporter. Serum samples from 65 convalescent individuals and 20 WIBP-CorV vaccine recipients and four therapeutic monoclonal antibodies (mAbs) namely imdevimab, casirivimab, bamlanivimab, and etesevimab were used to evaluate the neutralization potency against the variants. Pseudovirus-based neutralization assay platforms for PS and VOCs were established, and multiplicity of infection (MOI) was the key factor influencing the assay result. Compared to PS, VOCs may enhance the infectivity of hACE2-293T cells. Except for Alpha, other VOCs escaped neutralization to varying degrees. Attributed to favorable and emerging mutations, the current pandemic Omicron variant of all VOCs demonstrated the most significant neutralization-escaping ability to the sera and mAbs. Compared with the PS pseudovirus, Omicron had 15.7- and 3.71-fold decreases in the NT50 value (the highest serum dilution corresponding to a neutralization rate of 50%); and correspondingly, 90% and 43% of immunization or convalescent serum samples lost their neutralizing activity against the Omicron variant, respectively. Therefore, SARS-CoV-2 has evolved persistently with a strong ability to escape neutralization and prevailing against the established immune barrier. Our findings provide important clues to controlling the COVID-19 pandemic caused by new variants.

Multiplexed detection of SARS-CoV-2 based on upconversion luminescence nanoprobe/MXene biosensing platform for COVID-19 point-of-care diagnostics.

Multiplexed detection is essential in biomedical sciences since it is more efficient and accurate than single-analyte detection. For an accurate early diagnosis of COVID-19, a multiplexed detection strategy is required to avoid false negatives with the existing gold standard assay. Nb2CTx nanosheets were found to efficiently quench the fluorescence emission of lanthanide-doped upconversion luminescence nanoparticles at wavelengths ranging from visible to near-infrared spectrum. Using this broad-spectrum quencher, we developed a label-free FRET-based biosensor for rapid and accurate detection of SARS-CoV-2 RNA. To target ORF and N genes, two types of oligo-modified lanthanide-doped upconversion nanoparticles can be used simultaneously to identify-two sites in one assay via upconversion fluorescence enhancement intensity measurement with detection limits of 15 pM and 914 pM, respectively. Moreover, with multisite cross-validation, this multiplexed and sensitive biosensor is capable of simultaneous and multicolor analysis of two gene fragments of SARS-CoV-2 Omicron variant within minutes in a single homogeneous solution, which significantly improves the detection efficiency. The diagnosis result via our assay is consistent with the PCR result, demonstrating its application in the rapid and accurate screening of multiple genes of SARS-CoV-2 and other infectious diseases.

Characterization of SARS-CoV-2 recombinants and emerging Omicron sublineages.

The SARS-CoV-2 Omicron is currently the predominant circulating variant in the COVID-19 pandemic. The dominating Omicron sublineages respond to host immune pressure and develop advantageous mutations or genetic recombination, which result in variants that are more contagious or better at escaping immune responses in response to previous infection or vaccination. Meanwhile, multiple genetic recombination events have been reported in coinfection cases, the majority of which have resulted from the recombination between co-circulating Omicron BA.1 (or BA.1.1) and Delta variant or BA.2. Here, we review the knowledge and characterization of recombination for SARS-CoV-2 at the population level, provide an update on the occurrence of newly circulating Omicron sublineages, and discuss the effectiveness of novel vaccines/therapeutic drugs against the Omicron variant.

Virofree, an Herbal Medicine-Based Formula, Interrupts the Viral Infection of Delta and Omicron Variants of SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) remains a threat with the emergence of new variants, especially Delta and Omicron, without specific effective therapeutic drugs. The infection causes dysregulation of the immune system with a cytokine storm that eventually leads to fatal acute respiratory distress syndrome (ARDS) and further irreversible pulmonary fibrosis. Therefore, the promising way to inhibit infection is to disrupt the binding and fusion between the viral spike and the host ACE2 receptor. A transcriptome-based drug screening platform has been developed for COVID-19 to explore the possibility and potential of the long-established drugs or herbal medicines to reverse the unique genetic signature of COVID-19. In silico analysis showed that Virofree, an herbal medicine, reversed the genetic signature of COVID-19 and ARDS. Biochemical validations showed that Virofree could disrupt the binding of wild-type and Delta-variant spike proteins to ACE2 and its syncytial formation via cell-based pseudo-typed viral assays, as well as suppress binding between several variant recombinant spikes to ACE2, especially Delta and Omicron. Additionally, Virofree elevated miR-148b-5p levels, inhibited the main protease of SARS-CoV-2 (Mpro), and reduced LPS-induced TNF-α release. Virofree also prevented cellular iron accumulation leading to ferroptosis which occurs in SARS-CoV-2 patients. Furthermore, Virofree was able to reduce pulmonary fibrosis-related protein expression levels in vitro. In conclusion, Virofree was repurposed as a potential herbal medicine to combat COVID-19. This study highlights the inhibitory effect of Virofree on the entry of Delta and Omicron variants of SARS-CoV-2, which have not had any effective treatments during the emergence of the new variants spreading.

Comparison of the Performance of 24 Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Assays in the Diagnosis of Coronavirus Disease 2019 Patients.

Background: The accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the key to control Coronavirus Disease-2019 (COVID-19). The performance of different antibody detection methods for diagnosis of COVID-19 is inconclusive. Methods: Between 16 February and 28 February 2020, 384 confirmed COVID-19 patients and 142 healthy controls were recruited. 24 different serological tests, including 4 enzyme-linked immunosorbent assays (EIAs), 10 chemiluminescent immunoassays (CLIAs), and 10 lateral flow immunoassays (LFIAs), were simultaneously performed. Results: The sensitivities of anti-SARS-CoV-2 IgG and IgM antibodies with different reagents ranged from 75 to 95.83% and 46.09 to 92.45%, respectively. The specificities of both anti-SARS-CoV-2 IgG and IgM were relatively high and comparable among different reagents, ranged from 88.03 to 100%. The area under the curves (AUCs) of different tests ranged from 0.733 to 0.984, and the AUCs of EIAs or CLIAs were significantly higher than those of LFIAs. The sensitivities of both IgG and IgM gradually increased with increase of onset time. After 3-4 weeks, the sensitivities of anti-SARS-CoV-2 IgG were maintained at a certain level but the sensitivities of IgM were gradually decreased. Six COVID-19 patients who displayed negative anti-SARS-CoV-2 results were associated with the factors such as older age, having underlying diseases, and using immunosuppressant. Conclusion: Besides the purpose of assessing the impact of the SARS-CoV-2 pandemic in the population, SARS-CoV-2 antibody assays may have an adjunct role in the diagnosis and exclusion of COVID-19, especially by using high-throughput technologies (EIAs or CLIAs).

Emergence of SARS-CoV-2 Omicron variant and strategies for tackling the infection.

INTRODUCTION: Nowadays, emerging SARS-CoV-2 Omicron, the novel highly mutated VOC, has quickly spread as the dominant variant in over 190 countries worldwide through the first part of 2022, which is influencing the infectivity, transmissibility, pathogenicity, and severity of COVID-19 pandemic. Additionally, clinical cases and experimental studies have reported that Omicron variant likely leads to weakened immune protection elicited by infection, antibody therapies, and vaccines. The new wave, from late February, 2022, was escalated abruptly by higher levels of transmission of Omicron BA.2 sublineage in China. METHODS AND RESULTS: Following a systematic database search, this review summarizes the salient features of Omicron sublineages, and their impact on transmissibility, disease severity as well as the efficacy of the available vaccines and treatment against the Omicron. CONCLUSION: We hope this study will provide a scientific reference for alleviating the burden of COVID-19.

Antiviral drug design based on structural insights into the N-terminal domain and C-terminal domain of the SARS-CoV-2 nucleocapsid protein.

Nucleocapsid (N) protein plays crucial roles in the life cycle of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including the formation of ribonucleoprotein (RNP) complex with the viral RNA. Here we reported the crystal structures of the N-terminal domain (NTD) and C-terminal domain (CTD) of the N protein and an NTD-RNA complex. Our structures reveal a unique tetramer organization of NTD and identify a distinct RNA binding mode in the NTD-RNA complex, which could contribute to the formation of the RNP complex. We also screened small molecule inhibitors of N-NTD and N-CTD and discovered that ceftriaxone sodium, an antibiotic, can block the binding of RNA to NTD and inhibit the formation of the RNP complex. These results together could facilitate the further research of antiviral drug design targeting N protein.

Age- and Severity-Associated Humoral Immunity Response in COVID-19 Patients: A Cohort Study from Wuhan, China.

Age has been found to be the single most significant factor in COVID-19 severity and outcome. However, the age-related severity factors of COVID-19 have not been definitively established. In this study, we detected SARS-CoV-2-specific antibody responses and infectious disease-related blood indicators in 2360 sera from 783 COVID-19 patients, with an age range of 1-92 years. In addition, we recorded the individual information and clinical symptoms of the patients. We found that the IgG responses for S1, N, and ORF3a and the IgM for NSP7 were associated with severe COVID-19 at different ages. The IgM responses for the S-protein peptides S1-113 (aa 673-684) and S2-97 (aa 1262-1273) were associated with severe COVID-19 in patients aged <60. Furthermore, we found that the IgM for S1-113 and NSP7 may play a protective role in patients aged <60 and >80, respectively. Regarding clinical parameters, we analyzed the diagnostic ability of five clinical parameters for severe COVID-19 in six age groups and identified three-target panel, glucose, IL-6, myoglobin, IL-6, and NT proBNP as the appropriate diagnostic markers for severe COVID-19 in patients aged <41, 41-50, 51-60, 61-70, 71-80, and >80, respectively. The age-associated severity factors revealed here will facilitate our understanding of COVID-19 immunity and diagnosis, and eventually provide meaningful information for combating the pandemic.

Impact of improved stroke green channel process on the delay of intravenous thrombolysis in patients with acute cerebral infarction during the COVID-19 pandemic: An observational study

Objective This study analyzed the impact of the improved stroke green channel process on the delay of intravenous thrombolysis in patients with acute cerebral infarction under coronavirus disease 2019 (COVID-19) prevention and control measures. Methods We included 57 patients from the stroke center of the Seventh People's Hospital of Shanghai University of Traditional Chinese Medicine before the improvement of the stroke green channel process (March–July 2019), as well as 94 patients during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak (March–July 2020) and 68 patients during the Omicron variant outbreak (March–July 2022) after the improvement of stroke green channel process. The door-to-needle time (DNT), door-to-imaging time (DIT), and door-to-test completion time were compared among the three groups. We analyzed the impact of this process improvement in the emergency green channel during the pandemic on the delay of intravenous thrombolysis. Results This study included a total of 229 patients with acute cerebral infarction who went through the green channel for intravenous thrombolysis (57 in the pre-pandemic group, 94 in the SARS-CoV-2 outbreak group, and 68 in the Omicron outbreak group). The percentages of patients undergoing intravenous thrombolysis in the pre-pandemic, SARS-CoV-2 outbreak, and Omicron outbreak groups differed significantly (19.32%, 22.27%, and 28.94%, respectively, P = 0.029). Compared to the pre-pandemic group, the National Institutes of Health Stroke Scale (NIHSS) score at admission was significantly higher in the Omicron outbreak group (7.71 ± 7.36 in the Omicron outbreak group vs. 5.00 ± 4.52 in the pre-pandemic group) (P = 0.026) but not in the SARS-CoV-2 outbreak group (4.79 ± 5.94 in the SARS-CoV-2 outbreak group vs. 5.00 ± 4.52 in the pre-pandemic group, P = 0.970). Significantly higher proportions of patients undergoing emergency intravenous thrombolysis came to the hospital by ambulance in the SARS-CoV-2 and Omicron outbreak groups compared to the pre-pandemic group (38.6% in the pre-pandemic group, 51.1% in the SARS-CoV-2 outbreak group, and 82.4% in the Omicron outbreak group, P < 0.001). Compared to the pre-pandemic group, the DIT was significantly higher in the SARS-CoV-2 outbreak group (22.42 ± 7.62 min in the SARS-CoV-2 outbreak group vs. 18.91 ± 8.23 min in the pre-pandemic group, P =0.031) but not the Omicron outbreak group (20.35 ± 10.38 min in the Omicron outbreak group vs. 18.91 ± 8.23 min in the pre-pandemic group, P = 0.543). The door-to-test completion time was significantly longer in the SARS-CoV-2 and Omicron outbreak groups compared to that in the pre-pandemic group (78.37 ± 25.17 min in the SARS-CoV-2 outbreak group, 92.60 ± 25.82 min in the Omicron outbreak group vs. 65.11 ± 22.35 min in the pre-pandemic group, P < 0.001);however, the DNT in the SARS-CoV-2 and Omicron outbreak groups did not differ significantly from those in the pre-pandemic group (both P > 0.05). Conclusion During the two periods of the COVID-19 outbreak (SARS-CoV-2 and Omicron), after the improvement of the green channel for intravenous thrombolysis, there might be some delay in in-hospital DIT during the SARS-CoV-2 outbreak, however, the in-hospital delay indicator DNT for intravenous thrombolysis were not affected.