Comparison between emerging adults and adults in terms of contamination fear, post-COVID-19 PTSD and psychiatric comorbidity.

The present study compared Chinese emerging adults and adults regarding the association between contamination fear, posttraumatic stress disorder post-COVID-19 and psychiatric comorbidity after controlling for demographic and trauma exposure variables. 1089 Chinese civilians (M = 382; F = 707) with a mean age of 26 years (M = 26.36, SD = 8.58) were recruited from different provinces in China via an online survey posted on mainstream Chinese social networking platforms. They completed a demographic page with questions on trauma exposure, the Vancouver Obsessional Compulsive Inventory, the Posttraumatic Stress Disorder Checklist for DSM-5 and the General Health Questionnaire-28. Results showed that 12.7%, 68.7% and 18.6% met criteria for full, partial and no PTSD, respectively. Emerging adults reported significantly lower levels of symptoms of re-experiencing, avoidance, somatic problems, anxiety and fear of contamination than adults. In both emerging adults and adults, contamination fear was correlated with PTSD and psychiatric comorbidity. High educational attainment was significantly correlated with psychiatric comorbidity in emerging adults, but with PTSD in adults. Length of quarantine was correlated with psychiatric comorbidity only in adults. In conclusion, both emerging adults and adults developed varying levels of contamination fear, posttraumatic stress and general psychological symptoms following the outbreak of COVID-19. Emerging adults were more resilient than adults in coping with distress.

Circulating mid-regional proadrenomedullin is a predictor of mortality in patients with COVID-19: a systematic review and meta-analysis.

BACKGROUND: Although there is increasing understanding of the changes in the laboratory parameters of Coronavirus disease 2019 (COVID-19), the correlation between circulating Mid-regional Proadrenomedullin (MR-proADM) and mortality of patients with COVID-19 is not fully understood. In this study, we conducted a systematic review and meta-analysis to evaluate the prognostic value of MR-proADM in patients with COVID-19. METHODS: The PubMed, Embase, Web of Science, Cochrane Library, Wanfang, SinoMed and Chinese National Knowledge Infrastructure (CNKI) databases were searched from 1 January 2020 to 20 March 2022 for relevant literature. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to assess quality bias, STATA was employed to pool the effect size by a random effects model, and potential publication bias and sensitivity analyses were performed. RESULTS: 14 studies comprising 1822 patients with COVID-19 met the inclusion criteria, there were 1145 (62.8%) males and 677 (31.2%) females, and the mean age was 63.8 ± 16.1 years. The concentration of MR-proADM was compared between the survivors and non-survivors in 9 studies and the difference was significant (P < 0.01), I2 = 46%. The combined sensitivity was 0.86 [0.73-0.92], and the combined specificity was 0.78 [0.68-0.86]. We drew the summary receiver operating characteristic (SROC) curve and calculated the area under curve (AUC) = 0.90 [0.87-0.92]. An increase of 1 nmol/L of MR-proADM was independently associated with a more than threefold increase in mortality (odds ratio (OR) 3.03, 95% confidence interval (CI) 2.26-4.06, I2 = 0.0%, P = 0.633). The predictive value of MR-proADM for mortality was better than many other biomarkers. CONCLUSION: MR-proADM had a very good predictive value for the poor prognosis of COVID-19 patients. Increased levels of MR-proADM were independently associated with mortality in COVID-19 patients and may allow a better risk stratification.

Intraduodenal Delivery of Exosome-Loaded SARS-CoV-2 RBD mRNA Induces a Neutralizing Antibody Response in Mice.

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has presented numerous challenges to global health. Vaccines, including lipid-based nanoparticle mRNA, inactivated virus, and recombined protein, have been used to prevent SARS-CoV-2 infections in clinics and have been immensely helpful in controlling the pandemic. Here, we present and assess an oral mRNA vaccine based on bovine-milk-derived exosomes (milk-exos), which encodes the SARS-CoV-2 receptor-binding domain (RBD) as an immunogen. The results indicate that RBD mRNA delivered by milk-derived exosomes can produce secreted RBD peptides in 293 cells in vitro and stimulates neutralizing antibodies against RBD in mice. These results indicate that SARS-CoV-2 RBD mRNA vaccine loading with bovine-milk-derived exosomes is an easy, cheap, and novel way to introduce immunity against SARS-CoV-2 in vivo. Additionally, it also can work as a new oral delivery system for mRNA.

A Review and Perspective of Environmental Disinfection Technology Based on Microwave Irradiation.

Purpose of Review: In the context of COVID-19 sweeping the world, the development of microbial disinfection methods in gas, liquid, and solid media has received widespread attention from researchers. As a disinfection technology that can adapt to different environmental media, microwave-assisted disinfection has the advantages of strong permeability, no secondary pollution, etc. The purpose of this review is to put forward new development requirements for future microwave disinfection strategies by summarizing current microwave disinfection methods and effects. From the perspective of the interaction mechanism of microwave and microorganisms, this review provides a development direction for more accurate and microscopic disinfection mechanism research. Recent Findings: Compared to other traditional environmental disinfection techniques, microwave-assisted disinfection means have the advantages of being more destructive, free of secondary contamination, and thorough. Currently, researchers generally agree that the efficiency of microwave disinfection is the result of a combination of thermal and non-thermal effects. However, the performance of microwave disinfection shows the differences in the face of different environmental media as well as different types of microorganisms. Summary: This review highlights the inactivation mechanism of microwave-assisted disinfection techniques used in different scenarios. Suggestions for promoting the efficiency and overcoming the limitations of low energy utilization, complex reactor design, and inaccurate monitoring methods are proposed.

Enhance antibiotic resistance and human health risks in aerosols during the COVID-19 pandemic.

Aerosols are an important route for the transmission of antibiotic resistance genes (ARGs). Since the 2019 (COVID-19) pandemic, the large-scale use of disinfectants has effectively prevented the spread of environmental microorganisms, but studies regarding the antibiotic resistance of airborne bacteria remain limited. This study focused on four functional urban areas (commercial areas, educational areas, residential areas and wastewater treatment plant) to study the variations in ARG abundances, bacterial community structures and risks to human health during the COVID-19 pandemic in aerosol. The results indicated the abundance of ARGs during the COVID-19 period were up to approximately 13-fold greater than before the COVID-19 period. Large-scale disinfection resulted in a decrease in total bacterial abundance. However, chlorine-resistant bacteria tended to be survived. Among the four functional areas, the diversity and abundance of aerosol bacteria were highest in commercial aera. Antibiotic susceptibility assays suggested elevated resistance of isolated bacteria to several tested antibiotics due to disinfection exposure. The potential exposure risks of ARGs to human health were 2 times higher than before the COVID-19 pandemic, and respiratory intake was the main exposure route. The results highlighted the elevated antibiotic resistance of bacteria in aerosols that were exposed to disinfectants after the COVID-19 pandemic. This study provides theoretical guidance for the rational use of disinfectants and control of antimicrobial resistance.

A Review and Perspective of Environmental Disinfection Technology Based on Microwave Irradiation

Purpose of Review In the context of COVID-19 sweeping the world, the development of microbial disinfection methods in gas, liquid, and solid media has received widespread attention from researchers. As a disinfection technology that can adapt to different environmental media, microwave-assisted disinfection has the advantages of strong permeability, no secondary pollution, etc. The purpose of this review is to put forward new development requirements for future microwave disinfection strategies by summarizing current microwave disinfection methods and effects. From the perspective of the interaction mechanism of microwave and microorganisms, this review provides a development direction for more accurate and microscopic disinfection mechanism research. Recent Findings Compared to other traditional environmental disinfection techniques, microwave-assisted disinfection means have the advantages of being more destructive, free of secondary contamination, and thorough. Currently, researchers generally agree that the efficiency of microwave disinfection is the result of a combination of thermal and non-thermal effects. However, the performance of microwave disinfection shows the differences in the face of different environmental media as well as different types of microorganisms. Summary This review highlights the inactivation mechanism of microwave-assisted disinfection techniques used in different scenarios. Suggestions for promoting the efficiency and overcoming the limitations of low energy utilization, complex reactor design, and inaccurate monitoring methods are proposed.

Synergistic Immunity and Protection in Mice by Co-Immunization with DNA Vaccines Encoding the Spike Protein and Other Structural Proteins of SARS-CoV-2.

The emergence of new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has generated recurring worldwide infection outbreaks. These highly mutated variants reduce the effectiveness of current coronavirus disease 2019 (COVID-19) vaccines, which are designed to target only the spike (S) protein of the original virus. Except for the S of SARS-CoV-2, the immunoprotective potential of other structural proteins (nucleocapsid, N; envelope, E; membrane, M) as vaccine target antigens is still unclear and worthy of investigation. In this study, synthetic DNA vaccines encoding four SARS-CoV-2 structural proteins (pS, pN, pE, and pM) were developed, and mice were immunized with three doses via intramuscular injection and electroporation. Notably, co-immunization with two DNA vaccines that expressed the S and N proteins induced higher neutralizing antibodies and was more effective in reducing the SARS-CoV-2 viral load than the S protein alone in mice. In addition, pS co-immunization with either pN or pE + pM induced a higher S protein-specific cellular immunity after three immunizations and caused milder histopathological changes than pS alone post-challenge. The role of the conserved structural proteins of SARS-CoV-2, including the N/E/M proteins, should be investigated further for their applications in vaccine design, such as mRNA vaccines.

Risk of COVID-19 infection, hospitalization and mortality in psoriasis patients treated with interleukin-17 inhibitors: A systematic review and meta-analysis.

Background: Coronavirus disease 2019 (COVID-19) have brought great disaster to mankind, and there is currently no globally recognized specific drug or treatment. Severe COVID-19 may trigger a cytokine storm, manifested by increased levels of cytokines including interleukin-17 (IL-17), so a new strategy to treat COVID-19 may be to use existing IL-17 inhibitors, which have demonstrated efficacy, safety and tolerability in the treatment of psoriasis. However, the use of IL-17 inhibitors in patients with psoriasis during the COVID-19 pandemic remains controversial due to reports that IL-17 inhibitors may increase the risk of respiratory tract infections. Objectives: The systematic review and meta-analysis aimed to evaluate the effect of IL-17 inhibitors on the risk of COVID-19 infection, hospitalization, and mortality in patients with psoriasis. Methods: Databases (including Embase, PubMed, SCI-Web of Science, Scopus, CNKI, and the Cochrane Library) were searched up to August 23, 2022, for studies exploring differences in COVID-19 outcomes between psoriasis patients using IL-17 inhibitors and those using non-biologics. Two authors independently extracted data and assessed the risk of bias in a double-blind manner. The risk ratios (RRs) and 95% confidence intervals (CIs) were calculated and heterogeneities were determined by the Q test and I 2 statistic. And the numbers needed to treat (NNTs) were calculated to assess the clinical value of IL-17 inhibitors in preventing SARS-CoV-2 infection and treating COVID-19. Results: Nine observational studies involving 7,106 participants were included. The pooled effect showed no significant differences in the rates of SARS-CoV-2 infection (P = 0.94; I 2 = 19.5%), COVID-19 hospitalization (P = 0.64; I 2 = 0.0%), and COVID-19 mortality (P = 0.32; I 2 = 0.0%) in psoriasis patients using IL-17 inhibitors compared with using non-biologics. Subgroup analyses grouped by age and COVID-19 cases, respectively, revealed consistent results as above. Meanwhile, the pooled NNTs showed no significant differences between the two groups in the clinical value of preventing SARS-CoV-2 infection and treating COVID-19. Conclusion: The use of IL-17 inhibitors in patients with psoriasis does not increase the risk of SARS-CoV-2 infection or worsen the course of COVID-19. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022335195.

Impact of the COVID-19 Outbreak on the Antibiotic Use Patterns among a Rural Community Population in Eastern China.

There are growing concerns that the coronavirus disease of 2019 (COVID-19) pandemic may change antibiotic use patterns and accelerate antibiotic resistance, but evidence from the community level is lacking. This study aims to estimate the impact of the COVID-19 outbreak on the antibiotic use patterns among a community population in Eastern China. A self-administered medicine diary was used to collect information on antibiotic use from July 2019 to June 2021 among a rural community in Eastern China. We analyzed the changes in antibiotic use patterns over five months from August to December 2019 and the corresponding months in 2020. The risk of antibiotic use and its changes were measured with the incidence rate (IR) and relative risk (RR). In total, 1111 participants were eligible for the final analysis (440 in 2019 and 671 in 2020). After the COVID-19 outbreak, antibiotic use increased by 137% (5.43 per 100 person months in the 2019 vs. 12.89 per 100 person months in the 2020), and after the adjustment of covariates, the adjusted RR was 1.72 (95% CI: 1.10~2.34). It was higher among those who were women (RR = 2.62), aged 35-59 years old (RR = 2.72), non-farmers (RR = 2.75), had less than six years of education (RR = 2.61), had an annual household income over CNY 100,000 (USD 14,940) (RR = 2.60), and had no history of chronic diseases (RR = 2.61) (all p < 0.05). The proportion of cephalosporins consumed increased from 54.29% in 2019 to 64.92% in 2020 (p = 0.011). Among those aged 35 years and older, the proportion of antibiotics obtained from medical facilities increased, while the proportion obtained from retail pharmacies, homes, and other sources decreased (all p < 0.05). The COVID-19 outbreak changed antibiotic use patterns in this study population (Eastern China) significantly. More efforts to monitor and enhance antibiotic stewardship activities at the community level are needed in future.

Release of microplastics and nanoplastics in water from disposable surgical masks after disinfection.

During the COVID-19 pandemic, disposable surgical masks were generally disinfected and reused due to mask shortages. Herein, the role of disinfected masks as a source of microplastics (MPs) and nanoplastics (NPs) was investigated. The amount of MPs and NPs released from masks disinfected by UV ranged from 1054 ± 106 to 2472 ± 70 and from 2.55 ± 0.22 × 109 to 6.72 ± 0.27 × 109 particles/piece, respectively, comparable to that of the undisinfected masks, and the MPs were changed to small-sized particles. The amount of MPs and NPs released after alcohol and steam treatment were respectively lower and higher than those from undisinfected masks, and MPs were shifted to small-sized particles. The amount of MPs and NPs released in water after autoclaving was lower than for undisinfected masks. In all, the amount of fibers released after disinfection decreased greatly, and certain disinfection processes were found to increase the amount of small-sized NPs released from masks into aqueous environments.

Comparison between emerging adults and adults in terms of contamination fear, post-COVID-19 PTSD and psychiatric comorbidity

The present study compared Chinese emerging adults and adults regarding the association between contamination fear, posttraumatic stress disorder post-COVID-19 and psychiatric comorbidity after controlling for demographic and trauma exposure variables. 1089 Chinese civilians (M = 382;F = 707) with a mean age of 26 years (M = 26.36, SD = 8.58) were recruited from different provinces in China via an online survey posted on mainstream Chinese social networking platforms. They completed a demographic page with questions on trauma exposure, the Vancouver Obsessional Compulsive Inventory, the Posttraumatic Stress Disorder Checklist for DSM-5 and the General Health Questionnaire-28. Results showed that 12.7%, 68.7% and 18.6% met criteria for full, partial and no PTSD, respectively. Emerging adults reported significantly lower levels of symptoms of re-experiencing, avoidance, somatic problems, anxiety and fear of contamination than adults. In both emerging adults and adults, contamination fear was correlated with PTSD and psychiatric comorbidity. High educational attainment was significantly correlated with psychiatric comorbidity in emerging adults, but with PTSD in adults. Length of quarantine was correlated with psychiatric comorbidity only in adults. In conclusion, both emerging adults and adults developed varying levels of contamination fear, posttraumatic stress and general psychological symptoms following the outbreak of COVID-19. Emerging adults were more resilient than adults in coping with distress.

A Novel, Reverse Transcription, Droplet Digital PCR Assay for the Combined, Sensitive Detection of Severe Acute Respiratory Syndrome Coronavirus 2 with Swine Acute Diarrhea Syndrome Coronavirus.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread over the world since its emergence. Although the dominant route of SARS-CoV-2 infection is respiratory, a number of studies revealed infection risk from contaminated surfaces and products, including porcine-derived food and other products. The SARS-CoV-2 outbreak has been severely threatening public health, and disrupting porcine products trade and the pig industry. Swine acute diarrhea syndrome coronavirus (SADS-CoV), which was responsible for large-scale, fatal disease in piglets, emerged in 2017 and has caused enormous economic losses in the pig industry. Currently, reverse transcription real-time PCR (RT-rPCR) is the gold standard method for SARS-CoV-2 diagnosis and is most commonly used for SADS-CoV detection. However, inaccurate detection of the SARS-CoV-2 infection obtained by RT-rPCR is increasingly reported, especially in specimens with low viral load. OBJECTIVE: This study aimed to develop an accurate reverse transcription droplet digital PCR (RT-ddPCR) assay for the detection of SARS-CoV-2 and SADS-CoV simultaneously. METHODS: Two pairs of primers and one double-quenched probe targeting the RNA-dependent RNA polymerase (RDRP) region of the open reading frame 1ab (ORF1ab) gene of SARS-CoV-2 and the corresponding ORF1ab region of SADS-CoV were designed to develop the RT-ddPCR assay. The sensitivity, specificity, repeatability, and reproducibility were tested using complementary RNAs (cRNAs) and clinical specimens. RESULTS: The detection limits of RT-ddPCR were 1.48 ± 0.18 and 1.38 ± 0.17 copies in a 20 µL reaction for SARS-CoV-2 and SADS-CoV cRNAs, respectively (n = 8), showing approximately 4- and 10-fold greater sensitivity than the RT-rPCR assay. This assay also exhibited good specificity, repeatability, and reproducibility. CONCLUSION: The established RT-ddPCR assay was shown to be a highly effective, accurate, and reliable method for the sensitive detection of SARS-CoV-2 and SADS-CoV. HIGHLIGHTS: This RT-ddPCR assay could be used to detect both SARS-CoV-2 and SADS-CoV in a sample with one double-quenched probe, and is also the first reported RT-ddPCR assay for SADS-CoV detection.

Progress of research on COVID-19 animal models

OBJECTIVE: COVID-19 continues to spread globally, which poses a significant threat to global public health security. Recently, the emergence of new variant strains of SARS-CoV-2 complicates the containment of COVID-19 due to its rapid transmission, high infectivity, high viral load, atypical symptoms and high number of severe cases. In order to further understand the transmission route, pathogenesis and pathological changes of COVID-19, and accelerate the research and development of antiviral drugs and vaccines, animal models of COVID-19 have played an important role in this process. The status of research on different animal models of COVID-19 was reviewed, the characteristics were compared among the models so as to provide theoretical basis for selecting appropriate animal models of COVID-19.

Hydro electroactive Cu/Zn coated cotton fiber nonwovens for antibacterial and antiviral applications.

In this study, Cu/Zn galvanic electrodes were sputtered on the two surfaces of hydrophilic cotton fiber nonwovens (Cotton) to prepare hydro electroactive Cu/Cotton/Zn composites. When the Cu/Cotton/Zn was used as a functional layer in the face mask, the Cu/Zn galvanic electrodes can be spontaneously activated by water vapor molecules exhaled by the human body and generate galvanic current. Based on this, the hydro electroactive Cu/Cotton/Zn demonstrated excellent antibacterial activity against Escherichia coli and Staphylococcus aureus and could deactivate Enterovirus 71 (EV71) virions transmitted through the respiratory tract by 97.72% after 15 min of contact. Moreover, the Cu/Cotton/Zn did not affect the particle filtration efficiency and breathability of the face mask's polypropylene (PP) melt-blown layer. Furthermore, the cytotoxicity assessment of Cu/Cotton/Zn showed no cytotoxicity, indicating good biological security. Overall, the Cu/Cotton/Zn may provide a new approach to increase the antibacterial and antiviral performance of current personnel protective equipment on the market.

Analysis of Epidemic Characteristics and Related Pathogenic Factors of 2726 Cases of Pityriasis Alba.

PURPOSE: To understand the distribution characteristics of onset time, onset age and gender of pityriasis alba (PA) patients in the dermatology clinic of our hospital and to further explore the pathogenesis of the disease to provide a scientific basis for the prevention and treatment of this disease. PATIENTS AND METHODS: The clinical data of 2726 outpatients with PA diagnosed for the first time from January 2016 to December 2020 were collected and descriptively analyzed. RESULTS: The number of patients with PA was less from January to March. The peak was reached in July and August. The number of cases affected by the COVID-19 epidemic in 2020 was significantly lower than that in previous years. Furthermore, the onset age of the patients ranged from 0 to 64 years old, and the median age of the total population was 7 (3, 13) years old, including 1566 males (57.45%) and 1160 females (42.55%). The ratio of male to female was 1.35:1. The number of male patients before 18 years old was higher than that of female patients, especially in the high paroxysmal age group. CONCLUSION: PA can be seen all the year round, and the onset peak of the disease is from July to August every year. It occurs frequently at the age of 1 to 14 before puberty. In the season of high incidence of PA, the protection from sun and moisture retention should be strengthened for infants and adolescents.

Transcriptome profiling of PBMCs and formalin-fixed autopsy tissues from COVID-19 patients.

Here we present an optimized protocol for transcriptome profiling of COVID-19 patient samples, including peripheral blood mononuclear cells (PBMCs) and formalin-fixed paraffin-embedded tissue samples obtained from the lung, liver, heart, kidney, and spleen, with the matched controls. We describe RNA extraction and subsequent transcriptome analysis using NanoString technology of the patient samples. The protocol provides information about sample preparation, RNA extraction, and NanoString profiling and analysis. It can be also applied to differentiated Th17 and Treg subsets or formalin-fixed colon tissue samples. For complete details on the use and execution of this protocol, please refer to Wang et al. (2021).

Extraction optimization, physicochemical characterization, and antioxidant activity of polysaccharides from Rhodosorus sp. SCSIO-45730.

Microalgal polysaccharides have been reported in many studies due to their uniqueness, biocompatibility, and high value, and Rhodosorus sp. SCSIO-45730 was an excellent source of polysaccharides and ß-glucans. However, the polysaccharides from the red unicellular alga Rhodosorus sp. SCSIO-45730 have barely been studied. In this work, hot water extraction of Rhodosorus sp. SCSIO-45730 polysaccharides (RSP) was optimized using response surface methodology (RSM) based on Box-Behnken design (BBD). The maximum RSP yield (9.29%) was achieved under the optimum extraction conditions: liquid-solid ratio of 50.00 mL g-1; extraction temperature of 84 °C; extraction time of 2 h; and extraction times of 5 times. The results of physicochemical characterization showed that RSP had high sulfate and uronic acid with content of 19.58% and 11.57%, respectively, rough layered structure, and mainly contained glucose, galactose, xylose, and galacturonic acid with mass percentages of 34.08%, 28.70%, 12.46%, and 12.10%. Furthermore, four kinds of antioxidant assays were carried out, and the results indicated that RSP had strong scavenging activities on ABTS and hydroxyl radical and moderate scavenging activities on DPPH and ferrous chelating ability. These results indicated that RSP showed potential as a promising source of antioxidants applied in food, pharmaceutical, and cosmetics industry. Supplementary Information: The online version contains supplementary material available at 10.1007/s10811-021-02646-2.

Development and implementation of an “Internet+” management plan for cancer patients with wounds/stomas during the coronavirus disease 2019 pandemic

To explore the practical application and effect of the management plan for cancer patients with wounds/stomas based on the ?Internet+? model during the coronavirus disease 2019 (COVID-19) pandemic. Based on the specific situation during the COVID-19 pandemic, we established the ?Internet+? management team for cancer patients with wounds/stomas. After systematical literature search and brainstorming analysis, we developed a management plan for cancer patients with wounds/stomas based on the ?Internet+? model. Then, we included cancer patients with wounds/stomas who needed follow-up visits or consultations at Jiangsu Cancer Hospital from January 25 to April 30, 2020. A total of 304 patients were participated in the study. The effects of the plan were evaluated including patient satisfaction, the proportion of patients who did not need to go to the hospital for treatment, the proportion of patients with improved symptoms and the rate of the patients or nurses contracted COVID-19. After the implementation of the plan, 56.3% of the patients mastered the relevant self-care methods under the guidance of specialist nurses and did not need to go to the hospital for treatment. A total of 89.5% of the patients showed improvement in symptoms, and 99.4% of the patients were satisfied with the online treatment. None of the patients or nurses contracted COVID-19. The ?Internet+? management plan for cancer patients with wounds/stomas during the COVID-19 pandemic had supported epidemic prevention and control in medical institutions and reduced the risk of cross infection. In addition, this type of plan effectively improved disease symptoms in the patients, and their level of satisfaction was high.

Experimental evaluation of respiratory droplet spread to rooms connected by a central ventilation system.

This article presents results from an experimental study to ascertain the transmissibility of the SARS-CoV-2 virus between rooms in a building that are connected by a central ventilation system. Respiratory droplet surrogates made of mucus and virus mimics were released in one room in a test building, and measurements of concentration levels were made in other rooms connected via the ventilation system. The paper presents experimental results for different ventilation system configurations, including ventilation rate, filtration level (up to MERV-13), and fractional outdoor air intake. The most important finding is that respiratory droplets can and do transit through central ventilation systems, suggesting a mechanism for viral transmission (and COVID-19 specifically) within the built environment in reasonable agreement with well-mixed models. We also find the deposition of small droplets (0.5-4 µm) on room walls to be negligibly small.