Background:Coronavirus disease 2019 , formerly known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and 2019 novel coronavirus (2019-nCoV), was first identified in December 2019 in Wuhan City, China. Structural equation modeling (SEM) is a multivariate analysis method to determine the structural relationship between measured variables. This observational study aimed to use SEM to determine the effects of social support on sleep quality and function of medical staff who treated patients with COVID-19 in January and February 2020 in Wuhan, China. Material/Methods:A one-month cross-sectional observational study included 180 medical staff who treated patients with COVID-19 infection. Levels of anxiety, self-efficacy, stress, sleep quality, and social support were measured using the and the Self-Rating Anxiety Scale (SAS), the General Self-Efficacy Scale (GSES), the Stanford Acute Stress Reaction (SASR) questionnaire, the Pittsburgh Sleep Quality Index (PSQI), and the Social Support Rate Scale (SSRS), respectively. Pearson's correlation analysis and SEM identified the interactions between these factors. Results:Levels of social support for medical staff were significantly associated with self-efficacy and sleep quality and negatively associated with the degree of anxiety and stress. Levels of anxiety were significantly associated with the levels of stress, which negatively impacted self-efficacy and sleep quality. Anxiety, stress, and self-efficacy were mediating variables associated with social support and sleep quality. Conclusions:SEM showed that medical staff in China who were treating patients with COVID-19 infection during January and February 2020 had levels of anxiety, stress, and self-efficacy that were dependent on sleep quality and social support.

The presence of COVID-19 has had psychological consequences among health personnel; these include fear, anxiety, and depression. In the current study, we used the Fear of COVID-19 Scale (FCV-19S) to assess the response to fear within health staff in Mexico. This was a cross-sectional survey study in which we administered the FCV-19S to hospital staff. A total of 2,860 participants-1,641 female and 1,218 male personnel from three hospitals-were included in the study. We found a global FCV-19S mean score of 19.3 ± 6.9, with a signi cant difference in scores for women and men. There was a high correlation between items 3, 5, 6, and 7, suggesting that these items could indicate the physiological responses to fear, and a high correlation between items 1, 2, and 4, suggesting these items could represent the emotional responses to fear. Our survey shows a signi cantly higher level of fear in nursing and administrative personnel, which may be explained by the nursing staff being in close contact with infected patients and the administrative staff lacking understanding of the possible implications of the infection, compared with nonclinical hospital personnel. The FCV-19S showed validity and reliability in our population to assess fear in response to COVID-19. Our results are consistent with those of other researchers.

Intrauterine adhesion (IUA) caused by endometrial injury is one of the important causes of infertility in women of reproductive age and requires advanced treatment strategies. Increasing evidence suggests that the therapeutic effects of mesenchymal stem cells (MSC) mainly depend on their capacity to secrete paracrine factors and are mediated by MSC-derived exosomes. This study aimed to identify exosomes derived from adipose-derived mesenchymal stem cells (ADSC-exo) and explore the therapeutic potential in IUA rat models. ADSC-exo exhibited classic cup-shaped morphology with a positive expression of Alix and CD63 and were mainly concentrated at 109.5 nm. In IUA model, treatment with ADSC-exo maintained normal uterine structure, promoted endometrial regeneration and collagen remodeling, and enhanced the expression of integrin-β3, LIF, and VEGF. An improved receptivity of the regenerated endometrium was confirmed. Our findings demonstrated that ADSC-exo promoted endometrial regeneration and fertility restoration. It suggested that topical administration of ADSC-exo in uterus could be a promising strategy for patients suffering severe intrauterine adhesions and infertility.

Receptor recognition and subsequent membrane fusion are essential for the establishment of successful infection by SARS-CoV-2. Halting these steps can cure COVID-19. Here we have identified and characterized a potent human monoclonal antibody, HB27, that blocks SARS-CoV-2 attachment to its cellular receptor at sub-nM concentrations. Remarkably, HB27 can also prevent SARS-CoV-2 membrane fusion. Consequently, a single dose of HB27 conferred effective protection against SARS-CoV-2 in two established mouse models. Rhesus macaques showed no obvious adverse events when administrated with 10-fold of effective dose of HB27. Cryo-EM studies on complex of SARS-CoV-2 trimeric S with HB27 Fab reveal that three Fab fragments work synergistically to occlude SARS-CoV-2 from binding to ACE2 receptor. Binding of the antibody also restrains any further conformational changes of the RBD, possibly interfering with progression from the prefusion to the postfusion stage. These results suggest that HB27 is a promising candidate for immuno-therapies against COVID-19.

With the emergence and rapid spread of new pandemic variants, especially variants of concern (VOCs), the development of next-generation vaccines with broad-spectrum neutralizing activities is of great importance. In this study, SCTV01C, a clinical stage bivalent vaccine based on trimeric spike extracellular domain (S-ECD) of SARS-CoV-2 variants Alpha (B.1.1.7) and Beta (B.1.351) with a squalene-based oil-in-water adjuvant was evaluated in comparison to its two corresponding (Alpha and Beta) monovalent vaccines in mouse immunogenicity studies. The two monovalent vaccines induced potent neutralizing antibody responses against the antigen-matched variants, but drastic reductions in neutralizing antibody titers against antigen-mismatched variants were observed. In comparison, the bivalent vaccine SCTV01C induced relatively higher and broad-spectrum cross-neutralizing activities against various SARS-CoV-2 variants, including the D614G variant, VOCs (B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.1.529), variants of interest (VOIs) (C.37, B.1.621), variants under monitoring (VUMs) (B.1.526, B.1.617.1, B.1.429, C.36.3) and other variants (B.1.618, 20I/484Q). All three vaccines elicited potent Th1-biased T-cell immune responses. These results provide direct evidence that variant-based multivalent vaccines could play important roles in addressing the critical issue of reduced protective efficacy against the existing and emerging SARS-CoV-2 variants.