Cryo-EM structure of SARS-CoV-2 postfusion spike in membrane.

The entry of SARS-CoV-2 into host cells depends on the refolding of the virus-encoded spike protein from a prefusion conformation, which is metastable after cleavage, to a lower-energy stable postfusion conformation1,2. This transition overcomes kinetic barriers for fusion of viral and target cell membranes3,4. Here we report a cryogenic electron microscopy (cryo-EM) structure of the intact postfusion spike in a lipid bilayer that represents the single-membrane product of the fusion reaction. The structure provides structural definition of the functionally critical membrane-interacting segments, including the fusion peptide and transmembrane anchor. The internal fusion peptide forms a hairpin-like wedge that spans almost the entire lipid bilayer and the transmembrane segment wraps around the fusion peptide at the last stage of membrane fusion. These results advance our understanding of the spike protein in a membrane environment and may guide development of intervention strategies.

The Relationship Between Personality Traits and Clinical Decision-Making, Anxiety and Stress Among Intern Nursing Students During COVID-19: A Cross-Sectional Study.

Purpose: The aim of this study was to investigate whether the personality traits of intern nursing students could serve as valid predictors of their psychological status and clinical decision making. Additionally, we aimed to understand the psychological state of intern nursing students during the regular epidemic prevention and control stage of COVID-19. Participants and Methods: This study was designed as a cross-sectional survey. A total of 181 intern nursing students involved in clinical placements participated in this study. Participants provided relevant data by completing the Big Five Inventory-44, the Self-Rating Anxiety Scale, the Perceived Stress Scale 14, and the Clinical Decision-Making in Nursing Scale. Results: The results showed that neuroticism (ß = -0.282, p < 0.01) and openness (ß = 0.302, p < 0.001) played significant roles in predicting clinical decision-making skills among intern nursing students. Regression analysis also showed extraversion (ß = -0.249, p < 0.01), openness (ß = 0.2, p < 0.01), and neuroticism (ß = 0.391, p < 0.001) could significantly predict stress in intern nursing students. The agreeableness (ß = -0.354, p < 0.001) and neuroticism (ß = 0.237, p < 0.01) could also predict the anxiety of intern nursing students. Additionally, some intern nursing students still suffered from anxiety and stress in the context of the ongoing pandemic. Conclusion: Personality traits are good predictors of clinical decision-making, anxiety and stress among intern nursing students. In conclusion, the openness in personality traits of intern nursing students should be valued and cultivated in clinical work, which will benefit the development of nursing talents.

Reducing the Effectiveness of Ward Particulate Matter, Bacteria and Influenza Virus by Combining Two Complementary Air Purifiers.

Air purifiers should pay much attention to hospital-associated infections, but the role of a single air purifier is limited. The goal of this study was to evaluate the effectiveness of the combined application of the nonequilibrium positive and negative oxygen ion purifier (PNOI) and the high-efficiency particulate air filter (HEPA) on a complex, polluted environment. Two of the better performing purifiers were selected before the study. The efficacy of their use alone and in combination for purification of cigarette particulate matter (PM), Staphylococcus albicans, and influenza virus were then evaluated under a simulated contaminated ward. PNAI and HEPA alone are deficient. However, when they were combined, they achieved 98.44%, 99.75%, and 100% 30 min purification rates for cigarette PM, S. albus, and influenza virus, respectively. The purification of pollution of various particle sizes and positions was optimized and reduced differentials, and a subset of airborne influenza viruses is inactivated. Furthermore, they were superior to ultraviolet disinfection for microbial purification in air. This work demonstrates the strong purification capability of the combined application of these two air purifiers for complex air pollution, which provides a new idea for infection control in medical institutions.

Role of Neuroimmune Interactions in COVID-19-related Cardiovascular Damage.

Coronavirus disease 2019 (COVID-19) has caused a global pandemic impacting over 200 countries/regions and more than 200 million patients worldwide. Among the infected patients, there is a high prevalence of COVID-19-related cardiovascular injuries. However, the specific mechanisms linking cardiovascular damage and COVID-19 remain unclear. The COVID-19 pandemic also has exacerbated the mental health burden of humans. Considering the close association between neuroimmune interactions and cardiovascular disease, this review assessed the complex pathophysiological mechanisms connecting neuroimmune interactions and cardiovascular disease. It was revealed that the mental health burden might be a pivotal accomplice causing COVID-19-associated cardiovascular damage. Specifically, the proinflammatory status of patients with a terrible mood state is closely related to overdrive of the hypothalamus-pituitary-adrenal (HPA) axis, sympathovagal imbalance, and endothelial dysfunction, which lead to an increased risk of developing cardiovascular injury during COVID-19. Therefore, during the prevention and treatment of cardiovascular complications in COVID-19 patients, particular attention should be given to relieve the mental health burden of these patients.

Roles of the gut microbiota in severe SARS-CoV-2 infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. The pathophysiological mechanisms linking gut dysbiosis and severe SARS-CoV-2 infection are poorly understood, although gut microbiota disorders are related to severe SARS-CoV-2 infections. The roles of the gut microbiota in severe SARS-CoV-2 infection were compared with those in respiratory viral infection, which is an easily understood and enlightening analogy. Secondary bacterial infections caused by immune disorders and antibiotic abuse can lead to dysregulation of the gut microbiota in patients with respiratory viral infections. The gut microbiota can influence the progression of respiratory viral infections through metabolites and the immune response, which is known as the gut-lung axis. Angiotensin-converting enzyme 2 is expressed in both the lungs and the small intestine, which may be a bridge between the lung and the gut. Similarly, SARS-CoV-2 infection has been shown to disturb the gut microbiota, which may be the cause of cytokine storms. Bacteria in the gut, lung, and other tissues and respiratory viruses can be considered microecosystems and may exert overall effects on the host. By referencing respiratory viral infections, this review focused on the mechanisms involved in the interaction between SARS-CoV-2 infections and the gut microbiota and provides new strategies for the treatment or prevention of severe SARS-CoV-2 infections by improving gut microbial homeostasis.

[Effect of noninvasive positive pressure ventilation and high-flow nasal cannula oxygen therapy on the clinical efficacy of coronavirus disease 2019 patients with acute respiratory distress syndrome].

OBJECTIVE: To observe the effect of noninvasive positive pressure ventilation (NIPPV) and high-flow nasal cannula oxygen therapy (HFNC) on the prognosis of patients with coronavirus disease 2019 (COVID-19) accompanied with acute respiratory distress syndrome (ARDS). METHODS: A retrospective study was conducted in Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology when authors worked as medical team members for treating COVID-19. COVID-19 patients with pulse oxygen saturation/fraction of inspiration oxygen (SpO2/FiO2, S/F) ratio < 235, managed by medical teams [using S/F ratio instead of oxygenation index (PaO2/FiO2) to diagnose ARDS] from February to April 2020 were included. The patients were divided into NIPPV group and HFNC group according to their oxygen therapy modes. Clinical data of patients were collected, including general characteristics, respiratory rate (RR), fraction of FiO2, SpO2, heart rate (HR), mean arterial pressure (MAP), S/F ratio in the first 72 hours, lymphocyte count (LYM), percentage of lymphocyte (LYM%) and white blood cell count (WBC) at admission and discharge or death, the duration of dyspnea before NIPPV and HFNC, and the length from onset to admission. The differences of intubation rate, all-cause mortality, S/F ratio and RR were analyzed, and single factor analysis and generalized estimation equation (GEE) were used to analyze the risk factors affecting S/F ratio. RESULTS: Among the 41 patients, the proportion of males was high (68.3%, 28 cases), the median age was 68 (58-74) years old, 28 cases had complications (68.3%), and 34 cases had multiple organ dysfunction syndrome (MODS, 82.9%). Compared with HFNC group, the proportion of complications in NIPPV group was higher [87.5% (21/24) vs. 41.2% (7/17), P < 0.05], and the value of LYM% was lower [5.3% (3.4%-7.8%) vs. 10.0% (3.9%-19.7%), P < 0.05], the need of blood purification was also significantly lower [0% (0/24) vs. 29.4% (5/17), P < 0.05]. The S/F ratio of NIPPV group gradually increased after 2 hours treatment and RR gradually decreased with over time, S/F ratio decreased and RR increased in HFNC group compared with baseline, but there was no significant difference in S/F ratio between the two groups at each time point. RR in NIPPV group was significantly higher than that in HFNC group after 2 hours treatment [time/min: 30 (27-33) vs. 24 (21-27), P < 0.05]. There was no significant difference in rate need intubation and hospital mortality between NIPPV group and HFNC group [66.7% (16/24) vs. 70.6% (12/17), 58.3% (14/24) vs. 52.9% (9/17), both P > 0.05]. Analysis of the factors affecting the S/Fratio in the course of oxygen therapy showed that the oxygen therapy mode and the course of illness at admission were the factors affecting the S/F ratio of patients [ßvalues were -15.827, 1.202, 95% confidence interval (95%CI) were -29.102 to -2.552 and 0.247-2.156, P values were 0.019 and 0.014, respectively]. CONCLUSIONS: Compared with HFNC, NIPPV doesn't significantly reduce the intubation rate and mortality of patients with COVID-19 accompanied with ARDS, but it significantly increases the S/F ratio of those patients.

Liver diseases in COVID-19: Etiology, treatment and prognosis.

In December 2019, a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China causing coronavirus disease-2019 (COVID-19). Numerous studies have shown varying degrees of liver damage in patients infected with SARS-CoV-2. However, in previous case studies of COVID-19, the exact cause of liver injury has not been clearly elucidated, nor is there clear evidence of the interaction between liver injury and COVID-19. This study will analyze the causes of liver injury in COVID-19 and the influence of liver-related complications on the treatment and prognosis of COVID-19.

A cross-sectional comparison of epidemiological and clinical features of patients with coronavirus disease (COVID-19) in Wuhan and outside Wuhan, China.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has spread outside the initial epicenter of Wuhan. We compared cases in Guangzhou and Wuhan to illustrate potential changes in pathogenicity and epidemiological characteristics as the epidemic has progressed. METHODS: We studied 20 patients admitted to the Third Affiliated Hospital of Sun Yat-Sen University in Guangzhou, China from January 22 to February 12, 2020. Data were extracted from medical records. These cases were compared with the 99 cases, previously published in Lancet, from Wuhan Jinyintan Hospital from January 1 to January 20, 2020. RESULTS: Guangzhou patients were younger and had better prognosis than Wuhan patients. The Wuhan patients were more likely to be admitted to the ICU (23% vs 5%) and had a higher mortality rate (11% vs 0%). Cases in Guangzhou tended to be more community clustered. Diarrhea and vomiting were more common among Guangzhou patients and SARS-CoV-2 RNA was found in feces. Fecal SARA-CoV-2 RNA remained positive when nasopharyngeal swabs turned negative in some patients. CONCLUSIONS: This study indicates possible diminishing virulence of the virus in the process of transmission. Yet persistent positive RNA in feces after negative nasopharyngeal swabs suggests a possible prolonged transmission period that challenges current quarantine practices.

The clinical characteristic of eight patients of COVID-19 with positive RT-PCR test after discharge

Corona virus disease 2019 (COVID-19) was caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The phenomenon of positive real time reverse transcription polymerase chain reaction (RT-PCR) result of SARS-CoV-2 in recovered patients had occurred and the research about these patients was rare. In our study, we did a retrospective review of medical records from COVID-19 patients admitted to one ward of Tongji Hospital of Hua Zhong University of Science and Technology from 10 February to 13 April 2020. From 10 February to 13 April 2020, there were 108 patients of COVID-19 admitted in the one ward of Tongji Hospital. Among them, eight cases were readmission patients because the RT-PCR result of SARS-CoV-2 was positive again after discharge. On the second admission, they had no symptoms and their chest CT was almost normal. Data from laboratory tests of the re-admission patients showed that all eight patients had normal white blood cell count, lymphocyte count. The inflammatory factors like procalcitonin and interleukin 6 were normal. After treatment, two patients met the standard and were discharged. The other six patients were still in the hospital because their RT-PCR of SARS-CoV-2 did not get three consecutive negative results and the course of two patients had persisted more than 90 days. We still needed to be alert that these patients could infect other people as a source of infection, and we also needed to be alert that these patients become chronic virus carriers. It also aroused our concern about the discharge standard of COVID-19. This article is protected by copyright. All rights reserved.