Neutralization effect of plasma from vaccinated COVID-19 convalescents on SARS-CoV-2 Omicron variants.

Background: COVID-19 has caused a global pandemic and the death toll is increasing. With the coronavirus continuously mutating, Omicron has replaced Delta as the most widely reported variant in the world. Studies have shown that the plasma of some vaccinated people does not neutralize the Omicron variant. However, further studies are needed to determine whether plasma neutralizes Omicron after one- or two-dose vaccine in patients who have recovered from infection with the original strain. Methods: The pseudovirus neutralization assays were performed on 64 plasma samples of convalescent COVID-19 patients, which were divided into pre-vaccination group, one-dose vaccinated group and two-dose vaccinated group. Results: In the three groups, there were significant reductions of sera neutralizing activity from WT to Delta variant (B.1.617.2), and from WT to Omicron variant (B.1.1.529) (ps<0.001), but the difference between Delta and Omicron variants were not significant (p>0.05). The average neutralization of the Omicron variant showed a significant difference between pre-vaccination and two-dose vaccinated convalescent individuals (p<0.01). Conclusions: Among the 64 plasma samples of COVID-19 convalescents, whether vaccinated or not, Omicron (B.1.1.529) escaped the neutralizing antibodies, with a significantly decreased neutralization activity compared to WT. And two-dose of vaccine could significantly raise the average neutralization of Omicron in convalescent individuals.

Visualizing the Landscape of Home IoT Research: A Bibliometric Analysis Using VOSviewer.

Currently, the internet of things (IoT) is being widely deployed in home automation systems. An analysis of bibliometrics is presented in this work that covers articles that were obtained from the Web of Science (WoS) databases and published between 1 January 2018, and 31 December 2022. With VOSviewer software, 3880 relevant research papers were analyzed for the study. Through VOSviewer, we analyzed how many articles were published about the home IoT in several databases and their relation to the topic area. In particular, it was pointed out that the chronological order of the research topics changed, and COVID-19 also attracted the attention of scholars in the IoT field, and it was emphasized in this topic that the impact of the epidemic was described. As a result of the clustering, this study was able to conclude the research statuses. In addition, this study examined and compared maps of yearly themes over 5 years. Taking into account the bibliometric nature of this review, the findings are valuable in terms of mapping processes and providing a reference point.

Omicron subvariant BA.5 is highly contagious but containable: Successful experience from Macau.

Introduction: Due to its high transmissibility and immune escape, Omicron subvariant BA.5 has become the dominant strain of the SARS-CoV-2 virus and led to escalating COVID-19 cases, how to cope with it becomes an urgent issue. A BA.5 infection surge burst out on 18 June 2022 and brought an unprecedented challenge to Macau, the most densely populated region worldwide. This study aimed to analyze the characteristics of this outbreak and summarize the useful anti-epidemic measures and experiences during this outbreak. Methods: All data were obtained from the Government Portal of Macao SAR (https://www.gov.mo), and the Special Webpage Against Epidemics, the Macao Health Bureau (www.ssm.gov.mo). An epidemiologic study was performed to analyze epidemic outcomes, including the infection rate, the proportion of symptomatic cases, the case fatality ratio (CFR), etc. Data were analyzed using SPSS Version 20. A p-value <0.05 was considered statistically significant. The anti-epidemic measures and experience were reviewed and summarized. Results: The BA.5 outbreak resulted in 1,821 new cases, which was significantly more than the cumulative cases of the previous variants of COVID-19 in Macau. The symptomatic cases accounted for 38.71% of the total cases, which was higher than that of the previous variants. After 6-week concerted efforts, Macau effectively controlled the outbreak, with an infection rate of 0.27%, which was much lower than many BA.5-attacked regions. The CFR was approximately 0.86%, which was not statistically different from that of previous variants. Six victims were chronically ill senior elders and their vaccination rate was much lower than the average level. Macau took a comprehensive anti-epidemic strategy to win a quick victory against BA.5, especially the "relatively static" strategy that was first formulated and applied by Macau for the management of the COVID-19 pandemic. Successful experience showed that although BA.5 was highly contagious, it could be contained by comprehensive anti-epidemic measures, including adequate anti-epidemic preparation, herd immunity through vaccination, repeated mass nucleic acid tests and rapid antigen tests, KN-95 mask mandate, the "relatively static" strategy, precise prevention and control, epidemiological investigation and tracing, and traditional Chinese medicine treatment, etc. Discussion: In Macau, compared with the previous subvariants, BA.5 is associated with increased transmissibility and a higher proportion of symptomatic cases, however, the risk of death remains similar, and the infection rate is much lower than that in many other BA.5-attacked regions. BA.5 is highly contagious but still containable, Macau's experience may offer hints for the regions experiencing the BA.5 waves to choose or adjust a more rational anti-epidemic strategy.

Omicron subvariant BA.5 is highly contagious but containable: Successful experience from Macau

Introduction Due to its high transmissibility and immune escape, Omicron subvariant BA.5 has become the dominant strain of the SARS-CoV-2 virus and led to escalating COVID-19 cases, how to cope with it becomes an urgent issue. A BA.5 infection surge burst out on 18 June 2022 and brought an unprecedented challenge to Macau, the most densely populated region worldwide. This study aimed to analyze the characteristics of this outbreak and summarize the useful anti-epidemic measures and experiences during this outbreak. Methods All data were obtained from the Government Portal of Macao SAR (https://www.gov.mo), and the Special Webpage Against Epidemics, the Macao Health Bureau (www.ssm.gov.mo). An epidemiologic study was performed to analyze epidemic outcomes, including the infection rate, the proportion of symptomatic cases, the case fatality ratio (CFR), etc. Data were analyzed using SPSS Version 20. A p-value <0.05 was considered statistically significant. The anti-epidemic measures and experience were reviewed and summarized. Results The BA.5 outbreak resulted in 1,821 new cases, which was significantly more than the cumulative cases of the previous variants of COVID-19 in Macau. The symptomatic cases accounted for 38.71% of the total cases, which was higher than that of the previous variants. After 6-week concerted efforts, Macau effectively controlled the outbreak, with an infection rate of 0.27%, which was much lower than many BA.5-attacked regions. The CFR was approximately 0.86%, which was not statistically different from that of previous variants. Six victims were chronically ill senior elders and their vaccination rate was much lower than the average level. Macau took a comprehensive anti-epidemic strategy to win a quick victory against BA.5, especially the "relatively static” strategy that was first formulated and applied by Macau for the management of the COVID-19 pandemic. Successful experience showed that although BA.5 was highly contagious, it could be contained by comprehensive anti-epidemic measures, including adequate anti-epidemic preparation, herd immunity through vaccination, repeated mass nucleic acid tests and rapid antigen tests, KN-95 mask mandate, the "relatively static” strategy, precise prevention and control, epidemiological investigation and tracing, and traditional Chinese medicine treatment, etc. Discussion In Macau, compared with the previous subvariants, BA.5 is associated with increased transmissibility and a higher proportion of symptomatic cases, however, the risk of death remains similar, and the infection rate is much lower than that in many other BA.5-attacked regions. BA.5 is highly contagious but still containable, Macau's experience may offer hints for the regions experiencing the BA.5 waves to choose or adjust a more rational anti-epidemic strategy.

Employment Intention of Chinese Medical Students During the COVID-19 Epidemic: A Cross-Sectional Survey.

Context: In the process of combating the coronavirus disease 2019 (COVID-19) epidemic, medical personnel were at the forefront of the fight. As the future medical workforce, medical students often experienced firsthand how their seniors and teachers had to commit to working hard in combating the epidemic. Many were directly involved in the front line of the fight and that experience could easily have affected their intention to seek employment in a medically related career. Objective: The study intended to evaluate the impact of the COVID-19 pandemic on Chinese medical students' employment intentions and the factors associated with them to put forward relevant suggestions to provide a basis for medical education in the future. Design: The research team conducted a cross-sectional study, using an anonymous online questionnaire. Setting: The study took place in many provinces and cities in China and was conducted in an online questionnaire. Participants: Participants were 1114 college students studying clinical medicine, college students studying nursing, and students interning during standardized resident training, medical interns. Outcome Measures: The participants completed a self-administered questionnaire, which investigated their psychological statuses related to anxiety and depression as well as COVID-19's impact on their intentions related to job searches, regarding their willingness to engage in clinical or basic research in epidemic-related specialties and epidemic-related work. Results: Compared to college students studying clinical medicine, the employment intentions of nursing students and medical interns were more vulnerable to the epidemic. Females and nursing students were more reluctant to choose clinical work, and the choice was associated with depression. Nursing college students and medical interns were significantly less willing to engage in infection medicine, respiratory medicine, and intensive care medicine (all P < .001). Medical students with a bachelor's degree and postgraduate degrees were significantly less willing to engage in infection medicine and respiratory medicine (all P < .001), but medical students from regions with stable epidemics were more willing to engage in intensive care medicine. Medical students with a bachelor's degree were significantly less likely to be involved in epidemiology-related work than undergraduate students, and students from severe epidemic regions were significantly less willing to work in isolation wards or to go to Wuhan as volunteers. Conclusions: Participants' psychological statuses related to anxiety and depression, genders, degrees, current educational statuses, and regions affected employment intentions during the epidemic.

Charge-Dependent Signal Changes for Label-Free Electrochemiluminescence Immunoassays.

Label-free electrochemiluminescence (ECL) immunoassays (lf-ECLIA), based on biomarker-induced ECL signal changes, have attracted increasing attention due to the simple, rapid, and low-cost detection of biomarkers without secondary antibodies and complicated labeling procedures. However, the interaction rule and mechanism between analytical interfaces and biomarkers have rarely been explored. Herein, the interactions between biomarkers and analytical interfaces constructed by assembly of a nanoluminophore and antibody-functionalized gold nanoparticles on an indium tin oxide electrode were studied. The nanoluminophore was synthesized by mixing Cu2+/l-cysteine chelate and N-(4-Aminobutyl)-N-ethylisoluminol-bifunctionalized gold nanoparticles with chitosan. It was found that positively charged biomarkers increased the ECL intensity, whereas negatively charged biomarkers decreased the ECL intensity. The assembly pH influenced the biomarker charges, which determined the ECL enhancement or inhibition. The detection pH only affected the ECL intensity but not the ECL changing trends. Based on the ECL signal changes, a charge-dependent lf-ECLIA was established, which exhibited inhibition responses to negatively charged human immunoglobulin G and copeptin and enhancement responses to positively charged cardiac troponin I, heart-type fatty acid binding protein, brain natriuretic peptide, and SARS-CoV-2 N protein. The linear range was 0.1-1000 pg/mL, and the detection limits were distributed in 0.024-0.091 pg/mL. Besides, a mechanism of the charge-dependent ECL enhancement and inhibition effects is proposed, which is very important for the development of new lf-ECLIA methodologies.

Neutralization effect of plasma from vaccinated COVID-19 convalescents on SARS-CoV-2 Omicron variants

Background COVID-19 has caused a global pandemic and the death toll is increasing. With the coronavirus continuously mutating, Omicron has replaced Delta as the most widely reported variant in the world. Studies have shown that the plasma of some vaccinated people does not neutralize the Omicron variant. However, further studies are needed to determine whether plasma neutralizes Omicron after one- or two-dose vaccine in patients who have recovered from infection with the original strain. Methods The pseudovirus neutralization assays were performed on 64 plasma samples of convalescent COVID-19 patients, which were divided into pre-vaccination group, one-dose vaccinated group and two-dose vaccinated group. Results In the three groups, there were significant reductions of sera neutralizing activity from WT to Delta variant (B.1.617.2), and from WT to Omicron variant (B.1.1.529) (ps<0.001), but the difference between Delta and Omicron variants were not significant (p>0.05). The average neutralization of the Omicron variant showed a significant difference between pre-vaccination and two-dose vaccinated convalescent individuals (p<0.01). Conclusions Among the 64 plasma samples of COVID-19 convalescents, whether vaccinated or not, Omicron (B.1.1.529) escaped the neutralizing antibodies, with a significantly decreased neutralization activity compared to WT. And two-dose of vaccine could significantly raise the average neutralization of Omicron in convalescent individuals.

Big Data and Sustainability in the Tourism Industry

A vital goal of this SI is to improve our understanding of how big data analyses can create social and environmental values, as well as economic and financial sustainability in line with the principles of the Sustainable Development Goals (SDGs). [...]this SI features original and relevant conceptual and empirical papers on how big data analysis provides tourism actors, organizations, territories, and ecosystems with new opportunities for creating economic, social, and environmental values. [...]their results indicate that consumers’ perceived risk plays a moderating role (1) between desire and use intentions, and (2) between desire and willingness to pay. [...]the authors extended the existing literature by finding the moderating role of perceived risk in the context of a robotic restaurant for the first time. After the COVID-19 pandemic started, “taste”, “corona”, and “weekend” were the new words that frequently appeared. [...]consistent with the previous study, in which some scholars pointed out that new eating habits centered on food delivery or digital consumers emerged, this study suggested that changing the perception of dining-out may be due to negative emotions. According to this effect, five types of smart work effectiveness have come to light: (1) self-development and energy saving, (2) quality of life, (3) job satisfaction, (4) work engagement, and (5) work–life balance.

Thermal Perception and Physiological Responses under Different Protection States in Indoor Crowded Spaces during the COVID-19 Pandemic in Summer

Currently, people in crowded indoor spaces are required to wear a variety of personal protective equipment to curb the spread of COVID-19. This study aimed to investigate the effects of wearing four types of personal protective equipment (unprotected, wearing masks, wearing face shield and wearing medical protective clothing) on human thermal perception and physiological responses in indoor crowded spaces in summer. The experiment was conducted in a climate chamber designed to simulate the indoor crowded spaces. Environmental parameters of climate chamber (air temperature, relative humidity and wind speed), physiological parameters of subjects (wrist skin temperature and pulse rate), and subjective perceptions (thermal sensation and thermal comfort) were collected during the experiment. The experimental results showed that medical protective clothing has the most obvious blocking effect on heat exchange between human and environment. Thermal sensation in state 4 (wearing medical protective clothing) was significantly (p < 0.05) higher than that in other states. The study of physiological parameters showed that the wrist skin temperature and pulse rate under different protection states increased with the increase of room temperature. Through regression analysis, the thermal sensation estimation model of protective personnel in indoor crowded spaces based on wrist skin temperature and pulse rate was established. The adjusted R2 and RMSE of all models were above 82% and less than 1, indicating that the established thermal sensation model had a good prediction effect.

Navigations for Hospitality Human Resource Management Research: Observing the Keywords, Factors, Topics under the COVID-19 Pandemic

The hospitality industry is one of the most affected by the pandemic, and because of its human close interaction and labor-intensive characteristics, it has left Human Resource Management (HRM) puzzles with organizations' stabilization and recovery. This study aimed to summarize current research on hospitality HRM research outcomes and trends during the COVID-19 pandemic. Utilizing the PRISMA technique and NVivo software, 102 research articles were extracted and analyzed to highlight to overall achievement and movement of hospitality HRM research under the shadow of the COVID-19 crisis. Considering the main purpose of this study, which was to show the status and prospects, the findings indicated 309 free nodes and 26 secondary nodes based on grounded theory. 7 key themes clustered from the analysis and include 'environmental factors';, 'industrial factors';, 'HRM practice';, 'organization';, 'employee';, 'external outcomes';, and 'methodology';. The results demonstrated the COVID-19 pandemic driven HRM transformation. In addition, it sheds light on how research responds to the shifting navigation of HRM within the hospitality context under the COVID-19 conditions.

COVID-19 school and kindergarten closure relates to children's social relationships: a longitudinal study in Japan.

The COVID-19 pandemic has led children to experience school closures. Although increasing evidence suggests that such intense social quarantine influences children's social relationships with others, longitudinal studies are limited. Using longitudinal data collected during (T1) and after (T2) intensive school closure and home confinement, this study investigated the impacts of social quarantine on children's social relationships. Japanese parents of children aged 0-9 years (n = 425) completed an online questionnaire that examined children's socio-emotional behavior and perceived proximity to parents or others. The results demonstrated that social quarantine was not significantly related to children's socio-emotional behavior across all age groups. However, changes in children's perceived proximity varied depending on certain age-related factors: elementary schoolers' perceived closeness to parents significantly decreased after the reopening of schools, whereas that to others, such as peers, increased. Such effects were not observed in infants and preschoolers. The follow-up survey 9-month after the reopening of schools (T3; n = 130) did not detect significant differences in both children's socio-emotional behavior and perceived proximity from that after the intense quarantine. These findings suggest that school closure and home confinement may have influenced children's social development differently across their age, and its effects were larger in perceived closeness rather than social behavior.

Chemical Pattern Recognition for Quality Analysis of Lonicerae Japonicae Flos and Lonicerae Flos Based on Ultra-High Performance Liquid Chromatography and Anti-SARS-CoV2 Main Protease Activity.

Lonicerae japonicae flos (L. japonicae flos, Lonicera japonica Thunb.) is one of the most commonly prescribed botanical drugs in the treatment or prevention of corona virus disease 2019. However, L. japonicae flos is often confused or adulterated with Lonicerae flos (L. flos, Lonicera macrantha (D.Don) Spreng., Shanyinhua in Chinese). The anti-SARS-CoV2 activity and related differentiation method of L. japonicae flos and L. flos have not been documented. In this study, we established a chemical pattern recognition model for quality analysis of L. japonicae flos and L. flos based on ultra-high performance liquid chromatography (UHPLC) and anti-SARS-CoV2 activity. Firstly, chemical data of 59 batches of L. japonicae flos and L. flos were obtained by UHPLC, and partial least squares-discriminant analysis was applied to extract the components that lead to classification. Next, anti-SARS-CoV2 activity was measured and bioactive components were acquired by spectrum-effect relationship analysis. Finally, characteristic components were explored by overlapping feature extracted components and bioactive components. Accordingly, eleven characteristic components were successfully selected, identified, quantified and could be recommended as quality control marker. In addition, chemical pattern recognition model based on these eleven components was established to effectively discriminate L. japonicae flos and L. flos. In sum, the demonstrated strategy provided effective and highly feasible tool for quality assessment of natural products, and offer reference for the quality standard setting.

Intermittent theta burst stimulation over the parietal cortex has a significant neural effect on working memory.

The crucial role of the parietal cortex in working memory (WM) storage has been identified by fMRI studies. However, it remains unknown whether repeated parietal intermittent theta-burst stimulation (iTBS) can improve WM. In this within-subject randomized controlled study, under the guidance of fMRI-identified parietal activation in the left hemisphere, 22 healthy adults received real and sham iTBS sessions (five consecutive days, 600 pulses per day for each session) with an interval of 9 months between the two sessions. Electroencephalography signals of each subject before and after both iTBS sessions were collected during a change detection task. Changes in contralateral delay activity (CDA) and K-score were then calculated to reflect neural and behavioral WM improvement. Repeated-measures ANOVA suggested that real iTBS increased CDA more than the sham one (p = .011 for iTBS effect). Further analysis showed that this effect was more significant in the left hemisphere than in the right hemisphere (p = .029 for the hemisphere-by-iTBS interaction effect). Pearson correlation analyses showed significant correlations for two conditions between CDA changes in the left hemisphere and K score changes (ps <.05). In terms of the behavioral results, significant K score changes after real iTBS were observed for two conditions, but a repeated-measures ANOVA showed a nonsignificant main effect of iTBS (p = .826). These results indicate that the current iTBS protocol is a promising way to improve WM capability based on the neural indicator (CDA) but further optimization is needed to produce a behavioral effect.

Antiviral drugs suppress infection of 2019-nCoV spike pseudotyped virus by interacting with ACE2 protein.

The outbreak of coronavirus disease 2019 (COVID-19) has induced a large number of deaths worldwide. Angiotensin-converting enzyme 2 (ACE2) is the entry receptor for the 2019 novel coronavirus (2019-nCoV) to infect the host cells. Therefore, ACE2 may be an important target for the prevention and treatment of COVID-19. The aim of this study was to investigate the inhibition effect of valaciclovir hydrochloride (VACV), zidovudine (ZDV), saquinavir (SQV), and efavirenz (EFV) on 2019-nCoV infection. The results of molecule docking and surface plasmon resonance showed that VACV, ZDV, SQV, and EFV could bind to ACE2 protein, with the KD value of (4.33 ± 0.09) e-8 , (6.29 ± 1.12) e-6 , (2.37 ± 0.59) e-5 , and (4.85 ± 1.57) e-5 M, respectively. But only ZDV and EFV prevent the 2019-nCoV spike pseudotyped virus to enter ACE2-HEK293T cells with an EC50 value of 4.30 ± 1.46 and 3.92 ± 1.36 µM, respectively. ZDV and EFV also have a synergistic effect on preventing entry of virus into cells. In conclusion, ZDV and EFV suppress 2019-nCoV infection of ACE2-HEK293T cells by interacting with ACE2.

Changes in accessibility to emergency and community food services during COVID-19 and implications for low income populations in Hamilton, Ontario.

In this paper we analyze the changes in accessibility to emergency and community food services before and during the COVID-19 pandemic in the City of Hamilton, Ontario. Many of these food services are the last line of support for households facing food insecurity; as such, their relevance cannot be ignored in the midst of the economic upheaval caused by the pandemic. Our analysis is based on the application of balanced floating catchment areas and concentrates on households with lower incomes (

SARS-CoV-2 infection induces the activation of tissue factor-mediated coagulation via activation of acid sphingomyelinase.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with the hypercoagulable state. Tissue factor (TF) is the primary cellular initiator of coagulation. Most of the TF expressed on cell surfaces remains cryptic. Sphingomyelin (SM) is responsible for maintaining TF in the encrypted state, and hydrolysis of SM by acid sphingomyelinase (ASMase) increases TF activity. ASMase was shown to play a role in virus infection biology. In the present study, we investigated the role of ASMase in SARS-CoV-2 infection-induced TF procoagulant activity. Infection of human monocyte-derived macrophages (MDMs) with SARS-CoV-2 spike protein pseudovirus (SARS-CoV-2-SP-PV) markedly increased TF procoagulant activity at the cell surface and released TF+ extracellular vesicles. The pseudovirus infection did not increase either TF protein expression or phosphatidylserine externalization. SARS-CoV-2-SP-PV infection induced the translocation of ASMase to the outer leaflet of the plasma membrane, which led to the hydrolysis of SM in the membrane. Pharmacologic inhibitors or genetic silencing of ASMase attenuated SARS-CoV-2-SP-PV-induced increased TF activity. Inhibition of the SARS-CoV-2 receptor, angiotensin-converting enzyme-2, attenuated SARS-CoV-2-SP-PV-induced increased TF activity. Overall, our data suggest that SARS-CoV-2 infection activates the coagulation by decrypting TF through activation of ASMase. Our data suggest that the US Food and Drug Administration-approved functional inhibitors of ASMase may help treat hypercoagulability in patients with COVID-19.

Potential antiviral activity of isorhamnetin against SARS-CoV-2 spike pseudotyped virus in vitro.

Coronavirus Disease 2019 (COVID-19) cases and deaths are still rising worldwide, there is currently no effective treatment for severe inflammation and acute lung injury caused by new coronavirus (SARS-COV-2) infection. Therapies to prevent or treat COVID-19, including antiviral drug and several vaccines, are still being development. Human angiotensin-converting enzyme 2 (ACE2), expressing in lung, has been confirmed to be a receptor for SARS-COV-2 infection, interventions for attachment of spike protein of SARS-CoV-2 to ACE2 may be a potential approach to prevent viral infections and it is considered as a potential target for drug development. In this study, we observed that seabuckthorn and its flavonoid compounds quercetin and isorhamnetin were shown strong retention to ACE2 overexpression HEK293 (ACE2h ) cells by CMC analysis. Based on drug receptor interaction analysis and viral entry studies in vitro, we evaluated the interaction of two flavonoid compounds and ACE2 as well as the inhibitory effect of the two compounds on viral entry. Surface plasmon resonance assay proved the effect that isorhamnetin bound to the ACE2, and its affinity (KD value) was at the micromolar level, that was, 2.51 ± 0.68 µM. Viral entry studies in vitro indicated that isorhamnetin inhibited SARS-CoV-2 spike pseudotyped virus entering ACE2h cells. Based on promising in vitro results, we proposed isorhamnetin to be a potential therapeutic candidate compound against COVID-19.

Three salvianolic acids inhibit 2019-nCoV spike pseudovirus viropexis by binding to both its RBD and receptor ACE2.

Since December 2019, the new coronavirus (also known as severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2, 2019-nCoV])-induced disease, COVID-19, has spread rapidly worldwide. Studies have reported that the traditional Chinese medicine Salvia miltiorrhiza possesses remarkable antiviral properties; however, the anti-coronaviral activity of its main components, salvianolic acid A (SAA), salvianolic acid B (SAB), and salvianolic acid C (SAC) is still debated. In this study, we used Cell Counting Kit-8 staining and flow cytometry to evaluate the toxicity of SAA, SAB, and SAC on ACE2 (angiotensin-converting enzyme 2) high-expressing HEK293T cells (ACE2h cells). We found that SAA, SAB, and SAC had a minor effect on the viability of ACE2h cells at concentrations below 100 µM. We further evaluated the binding capacity of SAA, SAB, and SAC to ACE2 and the spike protein of 2019-nCoV using molecular docking and surface plasmon resonance. They could bind to the receptor-binding domain (RBD) of the 2019-nCoV with a binding constant (KD ) of (3.82 ± 0.43) e-6 M, (5.15 ± 0.64)e-7 M, and (2.19 ± 0.14)e-6 M; and bind to ACE2 with KD (4.08 ± 0.61)e-7 M, (2.95 ± 0.78)e-7 M, and (7.32 ± 0.42)e-7 M, respectively. As a result, SAA, SAB, and SAC were determined to inhibit the entry of 2019-nCoV Spike pseudovirus with an EC50 of 11.31, 6.22, and 10.14 µM on ACE2h cells, respectively. In conclusion, our study revealed that three Salvianolic acids can inhibit the entry of 2019-nCoV spike pseudovirus into ACE2h cells by binding to the RBD of the 2019-nCoV spike protein and ACE2 protein.

Donor tolerability of convalescent plasma donation.

BACKGROUND: Since early 2020, convalescent plasma has been widely used for treating coronavirus disease 2019 (COVID-19). There is limited information regarding donor tolerability of convalescent plasma donation. In this study, we evaluated the short-term donor tolerability of convalescent plasma donation. METHODS: A prospective study of 309 convalescent plasma donation related adverse events were conducted at Wuhan Blood Center of China, from February 12 to April 1, 2020. Additionally, up to 28-day post-donation follow-ups were performed on the donors. RESULTS: Sixteen (5.2%) adverse events were reported in 309 donations. All of these were mild vasovagal without loss of consciousness. The frequency of adverse reactions was higher in donors with a per donation volume of >8 mL/kg body weight or ≥ 600 mL, <100 mm Hg in pre-donation systolic blood pressure, or less than 28 days from the onset of COVID-19 symptoms. There was no correlation to donation history, weight, sex, ABO blood type, pre-donation diastolic blood pressure, pulse, or hemoglobin. CONCLUSION: The donation of convalescent plasma is generally safe. Mitigation of risk factors associated with adverse events can further enhance donor tolerability of convalescent plasma donation.