Impact of human capital and social capital on employability of Chinese college students under COVID-19 epidemic-Joint moderating effects of perception reduction of employment opportunities and future career clarity.

This research constructed a relationship model between human capital, social capital, and the employability of college students. With two moderating variables introduced, the perception reduction of employment opportunities under the COVID-19 epidemic and future career clarity, this research studied the direct impact of human capital and social capital on the employability of college students and boundary conditions. Research data from 810 employed Chinese college graduates shows that both human capital and social capital have a positive and significant impact on the employability; the perception reduction of employment opportunities under the COVID-19 epidemic negatively regulates the relationship between human capital and the employability of college students; the future career clarity positively regulates the relationship between human capital and the employability of college students; the perception reduction of employment opportunities under COVID-19 epidemic and the future career clarity jointly regulate the relationship between human capital, social capital and the employability of college students. These conclusions enrich the relevant theoretical and practical research on the employability of college students under the COVID-19 epidemic.

Impact of COVID-19 prevention and control on tuberculosis and scarlet fever in China’s Guizhou (preprint)

China has implemented a series of long-term measures for the public in order to control spread of COVID-19,whether these measures will affect other chronic and acute respiratory infectious diseases and what kind of impact are unclear. Tuberculosis (TB) and scarlet fever (SF) as the representative of chronic and acute respiratory infectious diseases respectively,and China’s Guizhou was an area with high prevalence of TB and SF ,with about 40,000 TB and hundreds of SF cases were reported every year.To assess impact of COVID-19 prevention and control on TB and SF in China’s Guizhou, exponential smoothing method was used to establish a prediction model to analyze the impact of COVID-19 on the number of TB and SF cases in Guizhou,and spatial aggregation analysis was used to describe the spatial changes of TB and SF before and after the outbreak of COVID-19.The parameters of TB and SF prediction models are R²=0.856, BIC=10.972;R²=0.714,BIC=5.325, respectively.TB and SF cases declined rapidly at the beginning of COVID-19 prevention and control,but SF cases number in decline for about 3-6 months,TB cases number remained in decline for 7 months after implementation for 11 months. Spatial aggregation of TB and SF did not change much before and after the COVID-19 outbreak but decreased significantly.Our fndings indicated that China's COVID-19 prevention and control measures also reduced TB and SF prevalence in Guizhou, these measures may lead to a long-term beneficial impact on TB, but a short-term on SF. Area with high TB incidence may benefit from COVID-19 experiences in the future.

Exploring the Impact of COVID-19 on the Air Quality in China (preprint)

At the end of 2019, the COVID-19 emerged in Wuhan, China. It has since put global public health institutions on high alert. People in China reduced their traveling, and production has stopped nationwide during the height of the epidemic. This study explores the effects of these COVID-19-derived changes on air quality in China. Air quality data of 367 cities around China were analyzed. The daily air quality index and air pollutant concentrations (CO, O3, NO2, SO2, PM10, and PM2.5) were collected and compared the epidemic period (23.1.2020-23.3.2020) with the preceding two months (22.11.2019-22.1.2020) and the parallel period the year before (23.1.2019-23.3.2019).To compare, we calculated the daily average number of cities with pollution, and the trend in air quality index change. The air quality in the 50 cities with the highest number of confirmed COVID-19 cases and Wuhan was also analyzed. During the period between 23.1.2020 and 23.3.2020, the number of cities with excellent air quality was significantly higher than that in the other two periods. The concentrations of PM2.5, PM10, NO2, SO2, CO, and O3 decreased significantly during this period. The most significant decreases were in PM10 and NO2. The number of cities with good air quality in the later period was significantly higher than a year before. The air quality has improved significantly during the COVID-19 outbreak. The reason for this change might be changes in human activities such as reduced transportation and production stoppage.

Clinical features and prognosis of COVID-19 patients with metabolic syndrome: A multicenter, retrospective study Características clínicas y pronóstico de los pacientes con COVID-19 y síndrome metabólico: un estudio multicéntrico y retrospectivo

Background Few studies have investigated the impacts of metabolic syndrome (MS) on coronavirus disease 2019 (COVID-19). We described the clinical features and prognosis of confirmed COVID-19 patients with MS during hospitalization and after discharge. Methods Two hundred and thirty-three COVID-19 patients from the hospitals in 8 cities of Jiangsu, China were retrospectively included. Clinical characteristics of COVID-19 patients were described and risk factors of severe illness were analyzed by logistic regression analysis. Results Forty-five (19.3%) of 233 COVID-19 patients had MS. The median age of COVID-19 patients with MS was significantly higher than non-MS patients (53.0 years vs. 46.0 years, P = 0.004). There were no significant differences of clinical symptoms, abnormal chest CT images, and treatment drugs between two groups. More patients with MS had severe illness (33.3% vs. 6.4%, P < 0.001) and critical illness (4.4% vs. 0.5%, P = 0.037) than non-MS patients. The proportions of respiratory failure and acute respiratory distress syndrome in MS patients were also higher than non-MS patients during hospitalization. Multivariate analysis showed that concurrent MS (odds ratio [OR] 7.668, 95% confidence interval [CI] 3.062–19.201, P < 0.001) and lymphopenia (OR 3.315, 95% CI 1.306–8.411, P = 0.012) were independent risk factors of severe illness of COVID-19. At a median follow-up of 28 days after discharge, bilateral pneumonia was found in 95.2% of MS patients, while only 54.7% of non-MS patients presented bilateral pneumonia. Conclusions 19.3% of COVID-19 patients had MS in our study. COVID-19 patients with MS are more likely to develop severe complications and have worse prognosis. More attention should be paid to COVID-19 patients with MS.

Association of COVID-19 Lockdown With Gestational Diabetes Mellitus

Importance The ongoing pandemic of COVID-19 is still affecting our life, but the effects of lockdown measures on gestational diabetes mellitus (GDM) in pregnant women remain unclear. Aim To investigate the association between COVID-19 lockdown and GDM. Subjects and Methods Medical records of 140844 pregnant women during 2015-2020 were extracted from 5 hospitals in Guangdong Province, China. Pregnant women who underwent the COVID-19 Level I lockdown (1/23 - 2/24/2020) during pregnancy were defined as the exposed group (N=20472) and pregnant women who underwent the same calendar months during 2015-2019 (1/23 - 2/24) were defined as the unexposed group (N=120372). Subgroup analyses were used to explore the potential susceptible exposure window of COVID-19 lockdown on GDM. Cumulative exposure is quantitatively estimated by assigning different weights to response periods with different exposure intensities. A logistic regression model was used to estimate the association between COVID-19 lockdown exposure and GDM. Results The rates of GDM in the exposed and unexposed groups were 15.2% and 12.4%, respectively. The overall analyses showed positive associations (odds ratio, OR=1.22, 95%CI: 1.17, 1.27) between lockdown exposure and GDM risk in all pregnant women. More pronounced associations were found in women who underwent the COVID-19 lockdown in their first four months of pregnancy, and the adjusted OR values ranged from 1.24 (95%CI: 1.10, 1.39) in women with 5-8 gestational weeks (GWs) to 1.35 (95%CI: 1.20, 1.52) with < 5 GWs. In addition, we found a positive exposure-response association of cumulative lockdown exposure with the risk of GDM. Conclusions The COVID-19 lockdown was associated with an increased risk of GDM, and the first four months of pregnancy may be the window for sensitive exposure.

Reduced infectivity but increased immune escape of the new SARS-CoV-2 variant of concern Omicron (preprint)

A new detected SARS-CoV-2 variant Omicron (B.1.1.529) had reported from more than 80 countries. In the past few weeks, a new wave of infection driven by Omicron is in progress. Omicron Spike (S) protein pseudotyped virus was used to determine the effect of S mutations on its capacity of infectivity and immune evasion. Our results showed the lower entry efficiency and less cleavage ability of Omicron than D614G variant. Pseudotype-based neutralizing assay was performed to analyze neutralizing antibodies elicited by previously infection or the RBD-based protein subunit vaccine ZF2001 against the Omicron variant. Sera sampled at around one month after symptom onset from 12 convalescents who were previously infected by SARS-CoV-2 original strain shows a more than 20-fold decrease of neutralizing activity against Omicron variant, when compared to D614G variant. Among 12 individuals vaccinated by RBD subunit vaccine, 58.3% (7/12) sera sampled at 15-60 days after 3rd-dose vaccination did not neutralize Omicron. Geometric mean titers (GMTs, 50% inhibitory dose [ID50]) of these sera against Omicron were 9.4-fold lower than against D614G. These results suggested a higher risk of Omicron breakthrough infections and reduced efficiency of the protective immunity elicited by existing vaccines. There are important implications about the modification and optimization of the current epidemic prevention and control including vaccine strategies and therapeutic antibodies against Omicron variant.

Machine Learning-based CT Radiomics Model Distinguishes COVID-19 From Non-COVID-19 Pneumonia (preprint)

Background: To develop a machine learning-based CT radiomics model is critical for the accurate diagnosis of the rapid spread Coronavirus disease 2019 (COVID-19).Methods: In this retrospective study, a total of 326 chest CT exams from 134 patients (63 confirmed COVID-19 patients and 71 non-COVID-19 patients) were collected from January 20 to February 8, 2020. A semi-automatic segmentation procedure was used to delineate the region of interest (ROI), and the radiomic features were extracted. The Support Vector Machine(SVM) model was built on the combination of the 4 groups of features, including radiomic features, traditional radiological features, quantifying features and clinical features, by repeated cross-validation procedure and the performance on the time-independent testing cohort was evaluated by the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity and specificity. Results: For the SVM model that built on the combination of 4 groups of features(integrated model), the per-exam AUC of 0.925(95% CI: 0.856 to 0.994) was reached for differentiating COVID-19 on the testing cohort, and the sensitivity and specificity were 0.816(95% CI: 0.651 to 0.917) and 0.923(95% CI: 0.621 to 0.996), respectively. For the SVM models that built on radiomic features, radiological features, quantifying features and clinical features individually, the AUC on the testing cohort reached 0.765, 0.818, 0.607 and 0.739 respectively, significantly lower than the integrated model, except for the radiomic model.Conclusion: The machine learning-based CT radiomics models may accurately detect COVID-19, helping clinicians and radiologists to identify COVID-19 positive cases.

A survey of grief counseling of clinicians from coronavirus disease 2019 designated hospitals

Objective: To investigate the current status of grief counseling of clinicians from five coronavirus disease 2019 (COVID-19) designated hospitals in Wuhan and to provide reference for hospital management.

The status of grief counseling among front-line nurses during the coronavirus disease 2019 epidemic

Objective: To investigate the status of grief counseling among front-line nurses in Wuhan during the coronavirus disease 2019 (COVID-19) epidemic, so as to provide reference for formulating reasonable nursing management strategies.

The architecture of the SARS-CoV-2 RNA genome inside virion (preprint)

SARS-CoV-2 carries the largest single-stranded RNA genome and is the causal pathogen of the ongoing COVID-19 pandemic. How the SARS-CoV-2 RNA genome is folded in the virion remains unknown. To fill the knowledge gap and facilitate structure-based drug development, we developed a virion RNA in situ conformation sequencing technology, named vRIC-seq, for probing viral RNA genome structure unbiasedly. Using vRIC-seq data, we reconstructed the tertiary structure of the SARS-CoV-2 genome and revealed a surprisingly "unentangled globule" conformation. We uncovered many long-range duplexes and higher-order junctions, both of which were under purifying selections and contributed to the sequential package of the SARS-CoV-2 genome. Unexpectedly, the D614G and the other two accompanying mutations might remodel duplexes into more stable forms. Lastly, the structure-guided design of potent small interfering RNAs could obliterate the SARS-CoV-2 in Vero cells. Overall, our work provides a framework for studying the genome structure, function, and dynamics of emerging deadly RNA viruses.

The differences of clinical characteristics and outcomes between imported and local patients of COVID-19 in Hunan: A two-center retrospective study (preprint)

Background: The clinical characteristics and outcomes of the 2019 novel coronavirus (COVID-19) pneumonia are different in Hubei compared to other regions in China. But there are few comparative studies on the differences between imported and local patients which may provide information of the different courses of the virus after transmission. Methods: : We investigated 169 cases of COVID-19 pneumonia in two centers in Hunan Province, and divided them into two groups according to epidemiological history, "imported patients" refers to patient with a clear history of travel in Wuhan within 14 days before onset, and " local patients” refers to local resident without a recent history of travel in Wuhan, aiming to analyze the difference in clinical characteristics and outcomes between the two groups. All the epidemiological, clinical, imaging, and laboratory data were analyzed and contrasted. Results: : The incidence of fever on admission in imported patients was significantly higher than local patients. There was a significantly higher proportion of abnormal pulmonary signs, hypokalemia, hyponatremia, prolonged PT, elevated D-dimer and elevated blood glucose in imported patients. Compared with local patients, the proportion using antibiotics, glucocorticoids and gamma globulin were significantly higher in imported patients. The moderate type was more common in local patients, and the severe type were more frequent in imported patients. In addition, the median duration of viral clearance was longer in imported patients. Conclusions: : In summary, we found that imported cases were more likely to develop into severe cases, compared with local patients and required more powerful treatments. Trial registration: Registered 21 st March 2020, and this study has been approved by the Medical Ethics Committee (Approved Number. 2020017).

Efficacy and safety of tocilizumab in COVID-19 patients: A Meta-Analysis (preprint)

The therapeutic effect of tocilizumab remains controversial. We aimed to evaluate whether tocilizumab might be beneficial in COVID-19 patients. We searched PubMed, Embase and Cochrane library from inception to June 23, 2020. Summary estimates of overall response rate (ORR) and all-cause death rate in all patients were analyzed. This study was registered with PROSPERO (CRD42020191313). We included data from 28 articles including 991 COVID-19 patients who underwent tocilizumab administration. The pooled ORR was 72% (95% CI, 66-79%) and pooled all-cause death rate was 16% (95% CI, 11-22%). The optimal timing of administration was the 7.15 day from the symptom onset and with the lowest death rate of 13.11%. 562 patients were defined as with severe infection, and the pooled ORR was 78% (95% CI, 70-85%). The pooled ORR of 56 organ transplantation recipients was 53% (95% CI, 26-78%), which was lower than non-transplant patients [75% (95% CI, 69-81%)]. Nearly all studies confirmed the safety of tocilizumab administration. Tocilizumab improves the clinical outcome of COVID-19 patients, especially in severe cases, and the optimal timing of administration may provide the guidance for management. However, tocilizumab may be used with caution in solid transplant recipients for the suboptimal efficacy.

Longitudinal dynamics of the neutralizing antibody response to SARS-CoV-2 infection (preprint)

Background Coronavirus disease 2019 (COVID-19) is a global pandemic with no licensed vaccine or specific antiviral agents for therapy. Little is known about the longitudinal dynamics of SARS-CoV-2-specific neutralizing antibodies (NAbs) in COVID-19 patients. Methods Blood samples (n=173) were collected from 30 COVID-19 patients over a 3-month period after symptom onset and analyzed for SARS-CoV-2-specific NAbs, using the lentiviral pseudotype assay, coincident with the levels of IgG and proinflammatory cytokines. Results SARS-CoV-2-specific NAb titers were low for the first 7-10 d after symtom onset and increased after 2-3 weeks. The median peak time for NAbs was 33 d (IQR 24-59 d) after symptom onset. NAb titers in 93.3% (28/30) of the patients declined gradually over the 3-month study period, with a median decrease of 34.8% (IQR 19.6-42.4%). NAb titers increased over time in parallel with the rise in IgG antibody levels, correlating well at week 3 (r = 0.41, p < 0.05). The NAb titers also demonstrated a significant positive correlation with levels of plasma proinflammatory cytokines, including SCF, TRAIL, and M-CSF. Conclusions These data provide useful information regarding dynamic changes in NAbs in COVID-19 patients during the acute and convalescent phases.

Epidemic Dynamics and Clinical Features of COVID-19 and Government Measures to Control Disease Transmission in Southern Hainan Island, China (preprint)

Objective: The objective of this study is to determine the epidemic dynamics and clinical features of COVID-19 in southern Hainan Island, China, and provide experience for other tropical areas of the world. Methods: This retrospective study included confirmed cases of COVID-19 in southern Hainan. All enrolled patients were treated in Sanya, and data on epidemiological and clinical features of the disease and infection prevention and control measures adopted by the local government during the epidemic were collected. Results: Of the 74 cases, 71 (95.95%) were imported from Wuhan, Hubei Province (47, 63.51%), other cities in Hubei Province (11, 14.86%), or provinces other than Hubei and Hainan (13, 17.57%). Three (4.06%) patients were infected in southern Hainan, including one autochthonous case in Sanya. Fifty-four cases (72.97%) were detected in Sanya, and 27 cases (27.03%) were diagnosed in other cities. The rate of severe or critical cases was 28.38% (21/74), and mortality was 2.7% (2/74). The serum lactate levels and base excess of severe-critical patients were higher than those of patients with mild-moderate disease. Multivariate logistic regression analysis showed that chronic conditions were risk factors for severe and critical COVID-19. Seventy-four patients were diagnosed with COVID-19 over a 22-day period in Sanya, and the epidemic period in the city was 48 days. The outbreak was controlled rapidly because the local government adopted strict infection prevention and control measures. Conclusions: The clinical characteristics of COVID-19 in Hainan Island were similar to those reported in other regions. In Sanya, the rate of severe and very severe cases was higher than in other regions; however, most cases were imported, and there was only one autochthonous case. The rapid control of the outbreak in Sanya may be related to the tropical climate, adoption of strict infection prevention and control measures, daily reporting of new cases, increased public awareness about the epidemic, and other emergency actions implemented by the local government.

The D614G mutation of SARS-CoV-2 spike protein enhances viral infectivity and decreases neutralization sensitivity to individual convalescent sera (preprint)

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The spike (S) protein that mediates SARS-CoV-2 entry into host cells is a major target for vaccines and therapeutics. Thus, insights into its sequence variations are key to understanding the infection and antigenicity of SARS-CoV-2. A dominant mutational variant at position 614 of the S protein (aspartate to glycine, D614G mutation) was observed in the SARS-CoV-2 genome sequence obtained from the Nextstrain database. Using a pseudovirus-based assay, we identified that S-D614 and S-G614 protein pseudotyped viruses share a common receptor, human angiotensin-converting enzyme 2 (ACE2), which could be blocked by recombinant ACE2 with the fused Fc region of human IgG1. However, S-D614 and S-G614 protein demonstrated functional differences. First, S-G614 protein could be cleaved by serine protease elastase-2 more efficiently. Second, S-G614 pseudovirus infected 293T-ACE2 cells significantly more efficiently than did the S-D614 pseudovirus, especially in the presence of elastase-2. Third, an elastase inhibitor approved for clinical use blocked elastase-enhanced S-G614 pseudovirus infection. Moreover, 93% (65/70) convalescent sera from patients with COVID-19 could neutralize both S-D614 and S-G614 pseudoviruses with comparable efficiencies, but about 7% (5/70) convalescent sera showed reduced neutralizing activity against the S-G614 pseudovirus. These findings have important implications for SARS-CoV-2 transmission and immune interventions.Competing Interest StatementThe authors have declared no competing interest.View Full Text

Clinical and Radiological Features of Patients with Coronavirus Disease 2019 (preprint)

Background: Confirmed cases of coronavirus disease 2019 (COVID-19) is still increasing, detailed analysis of confirmed cases may be beneficial for disease control.Methods: To describe the clinical and radiological findings of patients confirmed with COVID-19 infection in Haikou, China.Results: A total of 67 patients confirmed with COVID-19 infection were included in this study. 50 were imported cases. Most infected patients presented with fever and cough. The typical CT findings of lung lesions were bilateral, multifocal lung lesions (52[78%]), with subpleural distribution, and more than two lobes involved (51[78%]). 54 (81%) patients of COVID-19 pneumonia had ground glass opacities. Consolidation was in 30 (45%) patients, crazy paving pattern or interlobular thickening in 17 (25%), adjacent pleura thickening in 23 (34%) patients. Additionally, baseline chest CT did not reveal positive CT findings in 7 patients (23%), but 3 patients presented unilateral ground glass opacities at follow-up. Importantly, the follow-up CT findings were fitted well with the clinical outcomes.Conclusions: Chest CT could be used as an important tool for early diagnosis of COVID-19, monitoring the disease evolution, judging the treatment effectiveness and predicting the clinical outcomes.