UBA1-CDK16: A Sex-Specific Chimeric RNA and Its Role in Immune Sexual Dimorphism (preprint)

RNA processing mechanisms, such as alternative splicing and RNA editing, have been recognized as critical means to expand the transcriptome. Chimeric RNAs formed by intergenic splicing provide another potential layer of RNA diversification. By analyzing a large set of RNA-Seq data and validating results in over 1,200 blood samples, we identified UBA1-CDK16, a female-specific chimeric transcript. Intriguingly, both parental genes, are expressed in males and females. Mechanistically, UBA1-CDK16 is produced by cis-splicing between the two adjacent X-linked genes, originating from the inactive X chromosome. A female-specific chromatin loop, formed between the junction sites, facilitates the alternative splicing of its readthrough precursor. This unique chimeric transcript exhibits evolutionary conservation, evolving to be female-specific from non-human primates to humans. Furthermore, our investigation reveals that UBA1-CDK16 is enriched in the myeloid lineage and plays a regulatory role in myeloid differentiation. Notably, female COVID-19 patients who tested negative for this chimeric transcript displayed higher counts of neutrophils, highlighting its potential role in disease pathogenesis. These findings support the notion that chimeric RNAs represent a new repertoire of transcripts that can be regulated independently from the parental genes, and a new class of RNA variance with potential implications in sexual dimorphism and immune responses.

FABP4 as a Therapeutic Host Target Controlling SARS-CoV2 Infection (preprint)

Host metabolic fitness is a critical determinant of infectious disease outcomes. In COVID-19, obesity and aging are major high-risk disease modifiers, although the underlying mechanism remains unknown. Here, we demonstrate that fatty acid binding protein 4 (FABP4), a critical regulator of metabolic dysfunction in these conditions, regulates SARS-CoV2 pathogenesis. Our study revealed that elevated FABP4 levels in COVID-19 patients strongly correlate with disease severity. In adipocytes and airway epithelial cells we found that loss of FABP4 function by genetic or pharmacological means impaired SARS-CoV2 replication and disrupted the formation of viral replication organelles. Furthermore, treatment of infected hamsters with FABP4 inhibitors alleviated lung damage and fibrosis and reduced lung viral titers. These results highlight a novel host factor critical for SARS-CoV2 infection and the therapeutic potential of FABP4-targeting agents in treating COVID-19 patients.

Analysis of Pathogenic Bacteria and Drug Resistance Among Girls with Bacterial Vaginitis.

Objective: The aim of this study was to analyze the prevalence of vaginal flora and drug resistance in bacterial vaginitis among girls. Methods: A total of 3099 girls (0-10 years old) with vaginitis who visited the Beijing Children's Hospital from January 2020 to December 2021 were included in the present study. The clinical data, results of bacterial culture of vaginal secretions, and drug sensitivity reports of the subjects were collected and analyzed. Results: Of the 3099 girls with vaginitis, 399 girls had a positive bacterial culture of vaginal secretions. Nineteen types of bacteria were cultured from the vaginal secretions of these 399 girls, with a total of 419 strains. The top three infective bacteria were Haemophilus influenzae (127 strains, 30.31%), Staphylococcus aureus (66 strains, 15.75%), and Streptococcus agalactiae (32 strains, 7.64%). Additionally, 20 girls were simultaneously infected with two types of bacteria. Staphylococcus aureus, Group G Streptococcus, Haemophilus parainfluenzae, and Pseudomonas aeruginosa more frequently occurred in mixed infections. The number and bacterial detection rate among school-age girls were higher than those of preschool-age girls. We found seasonal variation in infection rates, and vaginitis among girls was higher in summer. Recurrence of vaginitis in girls was not related to the type of pathogenic bacteria in the infection. Drug sensitivity analyses showed that the resistance rates of clindamycin and erythromycin were generally high, 70-100%. After the coronavirus disease 2019 outbreak, the resistance rates of some antibiotics had decreased to varying degrees. Conclusion: Improving the understanding of vaginal flora and drug resistance in girls with vaginitis will facilitate the selection of highly effective and sensitive antibacterial drugs and reduce the production of drug-resistant strains.

A Probiotic Intervention With Bifidobacterium longum NCC3001 on Perinatal Mood Outcomes (PROMOTE Study): Protocol for a Decentralized Randomized Controlled Trial.

BACKGROUND: Perinatal mood disorders such as depression and anxiety are common, with subclinical symptomology manifesting as perinatal mood disturbances being even more prevalent. These could potentially affect breastfeeding practices and infant development. Pregnant and lactating women usually limit their exposure to medications, including those for psychological symptoms. Interestingly, the naturally occurring probiotic Bifidobacterium longum (BL) NCC3001 has been shown to reduce anxious behavior in preclinical models and feelings of low mood in nonpregnant human adults. During the COVID-19 pandemic, mental health issues increased, and conventionally conducted clinical trials were restricted by social distancing regulations. OBJECTIVE: This study, Probiotics on Mothers' Mood and Stress (PROMOTE), aimed to use a decentralized clinical trial design to test whether BL NCC3001 can reduce symptoms of depression, anxiety, and stress over the perinatal period. METHODS: This double-blind, placebo-controlled, randomized, and 3-parallel-arm study aimed to recruit 180 women to evaluate the efficacy of the probiotic taken either during pregnancy and post partum (from 28-32 weeks' gestation until 12 weeks after delivery; n=60, 33.3%) or post partum only (from birth until 12 weeks after delivery; n=60, 33.3%) in comparison with a placebo control group (n=60, 33.3%). Participants consumed the probiotic or matched placebo in a drink once daily. Mood outcomes were measured using the State-Trait Anxiety Inventory and Edinburgh Postnatal Depression Scale questionnaires, captured electronically at baseline (28-32 weeks' gestation) and during e-study sessions over 5 further time points (36 weeks' gestation; 9 days post partum; and 4, 8, and 12 weeks post partum). Saliva and stool samples were collected longitudinally at home to provide mechanistic insights. RESULTS: In total, 520 women registered their interest on our website, of whom 184 (35.4%) were eligible and randomized. Of these 184 participants, 5 (2.7%) withdrew after randomization, leaving 179 (97.3%) who completed the study. Recruitment occurred between November 7, 2020, and August 20, 2021. Advertising on social media brought in 46.9% (244/520) of the prospective participants, followed by parenting-specific websites (116/520, 22.3%). Nationwide recruitment was achieved. Data processing is ongoing, and there are no outcomes to report yet. CONCLUSIONS: Multiple converging factors contributed to speedy recruitment and retention of participants despite COVID-19-related restrictions. This decentralized trial design sets a precedent for similar studies, in addition to potentially providing novel evidence on the impact of BL NCC3001 on symptoms of perinatal mood disturbances. This study was ideal for remote conduct: because of the high digital literacy and public trust in digital security in Singapore, the intervention could be self-administered without regular clinical monitoring, and the eligibility criteria and outcomes were measured using electronic questionnaires and self-collected biological samples. This design was particularly suited for a group considered vulnerable-pregnant women-during the challenging times of COVID-19-related social restrictions. TRIAL REGISTRATION: ClinicalTrials.gov NCT04685252; https://clinicaltrials.gov/ct2/show/NCT04685252. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/41751.

Expectations of nursing home residents and their family members during the COVID-19 epidemic: A qualitative study (preprint)

Background COVID-19 has spread worldwide. Older people are at the greatest risk of contracting and dying from the virus. Nursing homes are densely populated places for older adults who are generally vulnerable and at high-risk. Although Chinese nursing homes have been trying to protect their residents, the needs and expectations of the residents and their families have been ignored. The aim of this study was to explore and better understand the expectations of nursing home residents and their family members during the COVID-19 epidemic in China.Methods Data was collected via face-to-face semi-structured interviews with nursing home residents and focus group online interviews with family members between June 2021 and February 2022. Data analysis followed inductive content analysis.Results 16 residents and 24 family members were interviewed. Four themes with 11 sub-themes were identified from the descriptions of participants. Their expectations were mainly focus on prevention and control measures for COVID-19, medical capacity of nursing homes, health education and expectations for some aged care policies.Conclusions In the face of concerns about the impact of COVID-19 on nursing homes, we sought to bring firsthand perspectives to the forefront by interviewing residents and their family members about their expectations to address this issue. Our findings provide important areas on which should be focused and may improve the sense of gain, happiness, and security of nursing home residents during the COVID-19 epidemic.

Protocol for characterizing the inhibition of SARS-CoV-2 infection by a protein of interest in cultured cells

Here, we present a protocol to characterize the antiviral ability of a protein of interest to SARS-CoV-2 infection in cultured cells, using MUC1 as an example. We use SARS-CoV-2 ΔN trVLP system, which utilizes transcription and replication-competent SARS-CoV-2 virus-like particles lacking nucleocapsid gene. We describe the optimized procedure to analyze protein interference of viral attachment and entry into cells, and RT-qPCR-based quantification of viral infection. The protocol can be applied to characterize more antiviral candidates and clarify their functioning stage. Graphical Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

Cytokine nanosponges suppressing overactive macrophages and dampening systematic cytokine storm for the treatment of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a highly fatal condition with the positive feedback loop between continued immune cell activation and cytokine storm as the core mechanism to mediate multiple organ dysfunction. Inspired by macrophage membranes harbor the receptors with special high affinity for proinflammation cytokines, lipopolysaccharide (LPS)-stimulated macrophage membrane-coated nanoparticles (LMNP) were developed to show strong sponge ability to both IFN-γ and IL-6 and suppressed overactivation of macrophages by inhibiting JAK/STAT signaling pathway both in vitro and in vivo. Besides, LMNP also efficiently alleviated HLH-related symptoms including cytopenia, hepatosplenomegaly and hepatorenal dysfunction and save the life of mouse models. Furthermore, its sponge effect also worked well for five human HLH samples in vitro. Altogether, it's firstly demonstrated that biocompatible LMNP could dampen HLH with high potential for clinical transformation, which also provided alternative insights for the treatment of other cytokine storm-mediated pathologic conditions such as COVID-19 infection and cytokine releasing syndrome during CAR-T therapy.

Clinical characteristics of COVID-19 and analysis of the outcomes in 31 cases

Objective: To describe the clinical characteristics of COVID-I9, and analyze the factors affecting prognosis as well as outcomes of patients for summarizing the clinical experience in diagnosis and treatment of this infection.

Development of a thermostable SARS-CoV-2 variant-based bivalent protein vaccine with cross-neutralizing potency against Omicron subvariants

SARS-CoV-2 variants have posed significant challenges to the hopes of using ancestral strain-based vaccines to address the risk of breakthrough infection by variants. We designed and developed a bivalent vaccine based on SARS-CoV-2 Alpha and Beta variants (named SCTV01C). SCTV01C antigens were stable at 25 oC for at least 6 months. In the presence of a squalene-based oil-in-water adjuvant SCT-VA02B, SCTV01C showed significant protection efficacy against antigen-matched Beta variant, with favorable safety profiles in rodents. Notably, SCTV01C exhibited cross-neutralization capacity against Omicron subvariants (BA.1, BA.1.1, BA.2, BA.3, and BA.4/5) in mice, superior to a WT (D614G)-based vaccine, which reinforced our previously published findings that SCTV01C exhibited broad-spectrum neutralizing potencies against over a dozen pre-Omicron variants and the Omicron BA.1 variant. In summary, variant-based multivalent protein vaccine could be a platform approach to address the challenging issues of emerging variants, vaccine hesitancy and the needs of affordable and thermal stable vaccines.

Characteristics of SARS - CoV - 2 nucleic acids and serum antibodies in different clinical specimens and their correlation with the course of COVID -19

To investigate the characteristics of the nucleic acids of severe acute respiratory syndrome coronavirus (SARS-CoV) -2 and antibodies in different specimens obtained from coronavirus disease 2019 (COVID-19) patients;if a correlation between these parameters and the disease course was present. The throat swabs and stool samples of 39 COVID-19 patients admitted to our hospital were collected in this study. Real-time reverse transcription-quantitative polymerase chain reaction (RT-PCR) was undertaken on throat swabs and stool samples. Peripheral blood was taken and serum levels of immunoglobulin IgM and IgG measured. Results showed That, Throat swabs and stool samples tested positive for the nucleic acid of SARS-CoV-Z, but nucleic acid levels were reduced significantly 15 days after disease onset compared with that upon diagnosis. The Ct value of the nucleic acid test was increased significantly. Serum levels of IgM and IgG were significantly higher than those of healthy people. nucleic acid loads in throat swabs and stool samples as well as serum levels of IgM and IgG were highly correlated with the disease course (r = 0.7387,0.5696, -0.546 and 0.6117,respectively, P < 0.05). In this study nucleic acid loads in throat swabs and stool samples as well as serum levels of IgM and IgG are highly correlated with the course of COVID-19.

The effect of i-deals on employees’ unethical behavior during the COVID-19 pandemic: The roles of hubristic pride and grandiose narcissism

The COVID-19 pandemic has created enormous challenges for organizations and employees. Due to the effectiveness of idiosyncratic deals (i-deals for short) in management practices, more and more organizations use this human resource management tool to address the challenges posed by the COVID-19 pandemic. However, whether there are potential risks or negative effects of i-deals in the COVID-19 pandemic environment is not very clear. Drawing upon social cognitive theory, we proposed that i-deals may foment focal employees’ unethical behavior by triggering their hubristic pride, and such process may be moderated by their trait of grandiose narcissism. We conducted a survey during the COVID-19 outbreak and tested our hypotheses with 492 samples from Shandong Province, China. Consistent with predictions, we found a positive relationship between i-deals and hubristic pride, which, in turn, increased their unethical behavior. And the relationship between i-deals and unethical behavior was mediated by hubristic pride. Furthermore, grandiose narcissism strengthened the positive relationship between i-deals and hubristic pride, as well as the indirect effect of i-deals on unethical behavior via hubristic pride. Our findings contributed to the literature on i-deals and provided guidance for organizations to address the challenges posed by the COVID-19 pandemic.

Analysis of the effects of predictive nursing in hospitalization of patients with COVID-19

This study aimed to explore the clinical application effects of predictive nursing in nursing management of patients with new type of coronavirus pneumonia during hospitalization. A retrospective study was used to collect the demographic and clinical characteristics of the patients. The medical team of our hospital supporting the First Hospital of Wuhan City implemented predictive mursing interventions on 83 confirmed patients with new type of coronavirus pneumonia, 2 of whom were mild, 73 were severe, and 8 were critical ill, admitted from 14 February to 17 March, 2020. As of 17 March, 74 patients have been discharged, 12 cases converted from severe to mild, 2 cases were transferred to other department, 3 cases were transferred to other hospital, 3 cases died. One patient died of stroke at admission. The medical staffs in the clinical treatment data of 83 patients(using logistic ordered regression analysis) found that: age may be the factor that promotes the development of the new type of coronavirus pneumonia (B=-0.09, P<0.05), for a total of 8 critically ill patients with an average age of>73 vears;patients with a history of coronary heart disease may be at a greater risk during treatment(B=-2.39, P<0.05): smoking history may adverse the recovery progression (B=1.52,P<0.05);the abnormal albumin (ALB) and hemoglobin (HGB) indicators may speed up the disease process (B=-0.40, -0.05;P<0.00,0.00). Following the guidelines for clinical nursing of new type of coronavirus pneumonia, foreseeably formulate timely treatment and nursing intervention protocols, propose and strictly implement medical care measures for the new type of coronavirus pneumonia have obvious effects in the clinical treatment of severe and critically ill patients.

Evaluation of Patients with Vaccine Allergies Prior to mRNA-Based COVID-19 Vaccination.

During the initial rollout of coronavirus disease 2019 (COVID-19) vaccination in Singapore, the Ministry of Health (MOH) issued a recommendation that patients with a history of any previous vaccine allergy be referred to an allergist for further review of their suitability to proceed with mRNA-based COVID-19 vaccines. Patients fulfilling the above criterion were divided into three groups: immediate reaction (Group A), delayed reaction (Group B) and no/irrelevant reaction (Group C). They were subjected to either a skin prick test (SPT) and intradermal test (IDT) with polyethylene glycol (PEG) or polysorbate-containing products; direct injection with the Pfizer BNT162b2 vaccine in the allergy clinic; or injection at community vaccination centres, respectively. Groups A and B were also invited to complete a questionnaire survey on post-vaccination reactions, and blood sampling pre-vaccination and 1 h after the first dose of the BNT162b2 vaccine to measure immunoglobulin (Ig) G, IgM and IgE antibodies to the Pfizer BNT162b2 vaccine via ELISA assays immobilised with the BNT162b2 vaccine, as well as levels of allergic cytokines interleukin (IL)-4 and IL-33, complement C5a and the endothelial activation marker intercellular adhesion molecule-1 (ICAM-1). Groups A and B comprised 62 (20.5%) patients each. In Group A, two subjects (3.2%) with equivocal IDT results tolerated both doses of the BNT162b2 vaccine without major allergic reactions. The remaining 60 (96.8%) in Group A and 62 (100%) in Group B completed both doses of BNT162b2 vaccination without major adverse reactions. Among the 99 who completed the questionnaire survey, 13 (13%) patients reported mild allergic reactions after the first dose of the vaccine. Immunoglobulin (Ig) G and M antibodies, but not IgE antibodies to the Pfizer BNT162b2 vaccine were detected in 67 subjects prior to vaccination. The presence of anti-Pfizer BNT162b2 IgG and IgM prior to vaccination did not result in major allergic reactions nor increases in Th2-related cytokines (IL-4, IL-33), complement activation products (C5a) or endothelial activation (ICAM-1). The majority of those with suspected reactions to non-COVID-19 polysorbate-containing vaccines tolerated the BNT162b2 vaccine. Excipient skin tests for PEG and polysorbate prior to vaccination are unnecessary.

Adverse environmental effects of disposable face masks due to the excess usage.

The widespread use of disposable face masks as a preventative strategy to address transmission of the SARS-CoV-2 virus has been a key environmental concern since the pandemic began. This has led to an unprecedented new form of contamination from improperly disposed masks, which liberates significant amounts of heavy metals and toxic chemicals in addition to volatile organic compounds (VOCs). Therefore, this study monitored the liberation of heavy metals, VOCs, and microfibers from submerged disposable face masks at different pH (4, 7 and 12), to simulate distinct environmental conditions. Lead (3.238% ppb), cadmium (0.672 ppb) and chromium (0.786 ppb) were found in the analyzed leachates. By pyrolysis, 2,4-dimethylhept-1-ene and 4-methylheptane were identified as the VOCs produced by the samples. The chemically degraded morphology in the FESEM images provided further evidence that toxic heavy metals and volatile organic compounds had been leached from the submerged face masks, with greater degradation observed in samples submerged at pH 7 and higher. The results are seen to communicate the comparable danger of passively degrading disposable face masks and the release of micro- or nanofibers into the marine environment. The toxicity of certain heavy metals and chemicals released from discarded face masks warrants better, more robust manufacturing protocols and increased public awareness for responsible disposal to reduce the adverse impact on ecology and human health.

Insights into potential mechanisms of asthma patients with COVID-19: A study based on the gene expression profiling of bronchoalveolar lavage fluid.

BACKGROUND: The 2019 novel coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently a major challenge threatening the global healthcare system. Respiratory virus infection is the most common cause of asthma attacks, and thus COVID-19 may contribute to an increase in asthma exacerbations. However, the mechanisms of COVID-19/asthma comorbidity remain unclear. METHODS: The "Limma" package or "DESeq2" package was used to screen differentially expressed genes (DEGs). Alveolar lavage fluid datasets of COVID-19 and asthma were obtained from the GEO and GSV database. A series of analyses of common host factors for COVID-19 and asthma were conducted, including PPI network construction, module analysis, enrichment analysis, inference of the upstream pathway activity of host factors, tissue-specific analysis and drug candidate prediction. Finally, the key host factors were verified in the GSE152418 and GSE164805 datasets. RESULTS: 192 overlapping host factors were obtained by analyzing the intersection of asthma and COVID-19. FN1, UBA52, EEF1A1, ITGB1, XPO1, NPM1, EGR1, EIF4E, SRSF1, CCR5, PXN, IRF8 and DDX5 as host factors were tightly connected in the PPI network. Module analysis identified five modules with different biological functions and pathways. According to the degree values ranking in the PPI network, EEF1A1, EGR1, UBA52, DDX5 and IRF8 were considered as the key cohost factors for COVID-19 and asthma. The H2O2, VEGF, IL-1 and Wnt signaling pathways had the strongest activities in the upstream pathways. Tissue-specific enrichment analysis revealed the different expression levels of the five critical host factors. LY294002, wortmannin, PD98059 and heparin might have great potential to evolve into therapeutic drugs for COVID-19 and asthma comorbidity. Finally, the validation dataset confirmed that the expression of five key host factors were statistically significant among COVID-19 groups with different severity and healthy control subjects. CONCLUSIONS: This study constructed a network of common host factors between asthma and COVID-19 and predicted several drugs with therapeutic potential. Therefore, this study is likely to provide a reference for the management and treatment for COVID-19/asthma comorbidity.

Long Duration and Increase in Pediatric Complicated Appendicitis During the Period of Lockdown in April 2022 in Shanghai (preprint)

Objective: The Corona Virus Disease 2019 (COVID-19) has tremendously transformed medical care worldwide, and elective surgery has been affected. The aim of the current study was to determine whether complicated appendicitis rates in children were influenced by the lockdown in April 2022 in Puxi region of Shanghai due to COVID-19.Background: The progression of acute appendicitis from simple to complicated is affected by the presentation timeliness. In the context of city-mandated control, the influences of lockdown in Puxi April on children suffering from acute appendicitis will be investigated in this study. Methods: The medical records of all children presenting in 2 hospitals with acute appendicitis between April 1 and April 30, 2022 (The first lockdown month in Puxi region) were reviewed and analyzed as the lockdown group. Moreover, the medical records of the latest 2 years of acute appendicitis in the same period were reviewed and analyzed as the control group. In addition, the clinical and laboratory parameters, treatment ways, intraoperative and pathological findings, and postoperative outcomes were analyzed.Results: A total of 22 children were diagnosed with acute appendicitis in the first month of the lockdown period in 2 hospitals. Compared with a 2-year control cohort of acute appendicitis, we observed a longer mean duration of symptoms (67.2±77.6 vs 31.9±34.7 h, P=0.01) and higher rate (72.73% vs 43.75%, P=0.038) in children with complicated appendicitis and a long operation time (92.5±35.46 vs 71.25±34.44 min, P=0.03), as well as a higher CRP (61.82±49.75 vs 23.43±28.19 mg/dL, P<0.001) and serum bilirubin (19.07±11.07 vs 10.74±4.37 umol/L, P<0.0001). The mean length of stay was longer in the lockdown group than that in the control group (10.77±5.37 vs 7.70±3.74 d, P=0.0072). The admission WBC and neutrophil percentage had no significant differences, the mean number of hospital or clinic visits had no differences, and the interval between diagnosis and operation has no statistical differences (5.28±2.94 vs 3.73±3.11 h, P=0.076). However, the overall conservative treatment cases, postoperative morbidity and mortality did not change.Conclusions: The lockdown affected the symptoms’ duration time of pediatric acute appendicitis. The children in the lockdown period demonstrated higher complicated appendicitis compared with the historical controls, as well as longer mean length of hospital stay. 

The Moderating Effect of Compassionate Mindfulness on the Psychological Needs and Emotions of Generation Y in the 21st Century in Taiwan.

During the 2020 COVID-19 pandemic in Taiwan, 6.5% of Generation Y required medical treatment for emotional and stress-related mental disorders. This study explores the moderating effect of mindfulness training on psychological needs and emotions to propose effective measures to promote the mental health of Generation Y. This study was carried out by questionnaire, using the data of respondents born in 1980-1999, collected in three different periods for quantitative analysis with compassionate mindfulness as the main variable. The results show that the compassionate mindfulness effect on emotion regulation varies greatly among different educational levels. However, it still plays a positive role in the psychological needs of Generation Y. Most members of Generation Y who receive compassionate mindfulness training have fewer basic needs and more interpersonal trust. They pay more attention to individual-oriented self-realization. Compassionate mindfulness has a greater positive moderating effect on the mental health of women aged 30-39 and those who are highly educated. Compassionate mindfulness has a more positive moderating effect on the psychological needs of members of Generation Y who were born more recently. During the COVID-19 pandemic, providing compassionate mindfulness has a significant positive effect on the prevention of mental disorders of Generation Y in Taiwan.

Aerodynamics performance of a ventilation system for droplets controlling by coughing in a hospital isolation ward (preprint)

Over 270 million people have been infected by the coronavirus disease 2019 (COVID-19) in the past two years, resulting in 5 million deaths. The virus primarily transmitted through droplets or aerosols produced by coughing, sneezing, and talking. A full-scale isolation ward in Wuhan Pulmonary Hospital is modeled in this work, and water droplet diffusion is simulated using the Computational Fluid Dynamics (CFD) approach. In an isolation ward, a local exhaust ventilation system is intended to avoid cross-infection. The existence of a local exhaust system increases turbulent movement, leading to a complete breakup of the droplet cluster and improved droplet dispersion inside the ward. When outlet negative pressure is 4.5 Pa, the number of moving droplets in the ward decreases by approximately 30% compared to the original ward. The local exhaust system could minimize the number of droplets evaporated in the ward; however, the formation of aerosols cannot be avoided. Furthermore, in six different scenarios there are 60.83%, 62.04%, 61.03%, 60.22%, 62.97% and 61.52% droplets produced by cough deposited on the surface of the patient. However, the local exhaust ventilation system has no apparent influence on the control of surface contamination. This study provides several suggestions for the optimization of ventilation in the wards, and scientific evidence to ensure the air quality of hospital isolation wards.

How Risky if China Moves Away from Its Zero-COVID Policy? (preprint)

There are two contrary opinions regarding the risk if mainland China (MC) moves away from its zero-COVID policy. Some experts think the risk shall be much lower than influenza as per MC’s own COVID-19 case fatality rate (CFR), while some other experts think the risk shall be much higher than influenza as per the COVID-19 CFRs of other regions. We elucidate here that this and multiple other striking differences in the CFR between various scenarios all support and substantially resulted from the view that good IDM is highly powerful to mitigate COVID-19, where IDM (isolation-disinfection-maintenance) means isolation of COVID-19 cases from other people, disinfection of their living environments, and health maintenance (e.g., rest, nutrition, breathing). The high effect of good IDM is also supported by the theoretic functions of IDM in minimizing co-infections and maintaining body functions, and the fact that all the 505 COVID-19 deaths reported in MC in 2022 before May 5 died directly of severe underlying diseases with COVID-19. Although it is tough for people in poverty to obtain good IDM, good IDM can be feasible at home for the most mild cases and in hospitals for the most severe cases. Therefore, good IDM can be crucial to mitigating COVID-19 worldwide. It also suggests that the risk for China to end its zero-COVID policy depends on China’s control policies or measures. Based on the effect of IDM, the cautious co-existence policy was proposed for COVID-19 control. This policy could reduce the whole death toll in MC because good IDM is non-specific and can reduce deaths of various other diseases. The cautious co-existence policy (non-specific) and the vaccination policy (specific) aid each other to mitigate COVID-19, and they cannot replace each other. Those who are qualified in health for vaccination should be vaccinated against COVID-19 timely.