Analysis of pathogenic factors of retinopathy of prematurity in Heilongjiang Province (preprint)

Background and purpose Retinopathy of prematurity is a vascular development disorder in immature retinas of premature infants, which is the leading cause of blindness in children worldwide. Because the screening delay may lead to the occurrence of blindness in children, it is particularly important to conduct timely screening for children with high risk factors. Currently, the pathogenesis of ROP may be related to multiple factors such as gestational age and birth weight of premature infants. In this study, the prevalence and risk factors of ROP in Heilongjiang Province were determined through screening for premature infants in the region, aiming to proceed early prevention of the disease. Methods Retrospectively analyzed 714 premature infants admitted to the Ophthalmology Clinic of the Second Affiliated Hospital of Harbin Medical University from January 2016 to February 2022. 12 related factors was recorded including patients’ gender, gestational age, birth weight, oxygen duration, blood transfusions, anemia, neonatal infections, respiratory distress syndrome, maternal feeding way, childbirth way, pregnancy age and parity. The prevalence of ROP and the differences in related factors between ROP patientsand non-ROP patients were found. Results Among 714 premature infants, 188 had ROP of which the incidence is 26.3%，and 61 patients received treatment. There were statistically significance(P<0.05) in gestational age, birth weight, oxygen duration, blood transfusion, anemia, neonatal infection, respiratory distress syndrome and childbirth way between the 188 ROP patients and non-ROP patients in univariate regression analysis. Variables with statistical significance for single factor were selected and conducted by multivariate regression analysis, which showed that gestational age, birth weight, and oxygen duration had remarkable statistical significance(P<0.05) with the occurrence of ROP. Gestational age and birth weight were the protective factors of disease (OR=0.43 and OR=0.8), while oxygen duration was the risk factor of disease (OR=1.02), and the diagnostic value of the model was high (AUC=0.776). five of the 61 patients who received treatment for ROP accepted two treatments, with gestational age < 32 weeks, birth weight < 1500g, and oxygen inhalation time > 20 days. The Kendall grade relative analysis of 188 patients with ROP showed that disease severity was significantly correlated with gestational age, birth weight, oxygen duration, anemia, blood transfusion and respiratory distress syndrome(P<0.05), in which the gestational age, birth weight, anemia, blood transfusion and respiratory distress syndrome were negatively correlated with the severity of the disease, while oxygen duration was positively correlated with severity of the disease. 507 children were screened from 2016 to December 31th in 2019, 138 of which were ROP patients, 36 children were treated (7.1%). Due to the spread of the COVID-19, 207 children were screened after January 1th in 2020, 50 children were ROP patients, and 25 of whom got treatment (12%), 21were treated after 8 weeks of birth or more than 37 weeks of corrected gestational age. Four out of five children who received the second treatment happened after the epidemic, and three of them missed treatment due to the epidemic. Conclusions The gestational age, birth weight and oxygen duration are significantly correlated with the incidence and severity of the disease in premature infants screening of Heilongjiang Province. Premature infants screening and subsequent visit were affected due to the spread of the COVID-19 in the past two years, the proportion of children needed to be cured augmented apparently, therefore, it matters a lot for premature infants to be screened standardly and timely.

Individual Surveillance Around Parked Aircraft at Nighttime: Thermal Infrared Vision-Based Human Action Recognition

The COVID-19 crisis has led to an unusually large number of commercial aircraft being currently parked or stored. For airlines, airports, and civil aviation authorities around the world, monitoring, and protecting these parked aircraft to prevent them from causing human-made damage are becoming urgent problems that are receiving increasing attention. In this study, we use thermal infrared monitoring videos to establish a framework for individual surveillance around parked aircraft by proposing a human action recognition (HAR) algorithm. As the focus of this article, the proposed HAR algorithm seamlessly integrates a preprocessing module in which a novel data structure is constructed to introduce spatiotemporal information of the action;a convolutional neural network-based module for spatial feature extraction;a triple-layer convolutional long short-term memory network for temporal feature extraction;and two fully connected layers for classification. Moreover, because no infrared dataset is available for the HAR task on airport grounds at nighttime, we present a dataset called IIAR-30, which consists of eight action categories that frequently occur on airport grounds and 2000 video clips. The experimental results on the IIAR-30 dataset demonstrated that the recognition accuracy of the proposed method was higher than 96%. We also further evaluated the effectiveness of the proposed method by comparing it with five baselines and four other methods.

七例2019冠状病毒病(COVID-19)普通型患者出院后病毒核酸随访结果 Follow-up testing of viral nucleic acid in discharged patients with moderate type of COVID-19

目的 随访研究2019冠状病毒病（COVID-19）患者在达到出院标准后病毒核酸检测结果，为医疗机构对出院患者随访管理提供决策依据。 方法 对浙江大学医学院附属第四医院经治疗后已符合出院标准的COVID-19患者采取院内继续隔离观察7 d，再居家隔离4周，期间记录患者每日临床体征，定期送检痰液行病毒核酸检测，评估患者病情变化。 结果 已符合现有出院标准的7例患者中有3例在5~7 d后再次出现痰液病毒核酸检测阳性，持续阳性2~6 d后再次转阴；复查患者血常规、C反应蛋白、血生化以及胸部CT结果均无明显异常，也无明显临床症状。其余4例患者随访4周，痰液病毒核酸检测均为阴性，未出现COVID-19相关临床症状，实验室和影像学检查结果无异常。 结论 COVID-19患者按现有标准出院后复阳的比例较高，建议有条件的医疗机构对满足现行出院标准的患者继续院内隔离观察7 d并进行连续的病毒核酸监测。

Research on the Differences in the Value Correlation of Accounting Data Under the Background of COVID-19: Comparative Evidence From China and Thailand

In today's highly developed world of financial globalization, international capital flows in my country and the entire Asia-Pacific region are gradually increasing. The stock market is an important part of the capital market. The stock market has gradually improved its capital liquidity. With the improvement of the investment environment in the international capital market and the gradual relaxation of capital controls, with the development of the "Belt and Road" development concept, Thailand has gradually chosen to buy and sell shares of Chinese investors. What investors need to consider is how to achieve capital appreciation. Investors need to consider how to achieve capital appreciation. However, a sudden new crown pneumonia epidemic broke the peace and excitement that the New Year should have, and also brought a great impact on the stock market. Of course, the stock market is affected by many factors. There are some problems here, such as the experience of the Chinese stock market.

Accelerating manufacturing to start large-scale supply of a new adenovirus-vectored vaccine within 100 days (preprint)

The Coalition for Epidemic Preparedness Innovations &rsquo &lsquo 100-day moonshot &rsquo aspires to launch a new vaccine within 100 days of pathogen identification. Here, we describe work to optimize adenovirus vector manufacturing for rapid response, by minimizing time to clinical trial and first large-scale supply, and maximizing the output from the available manufacturing footprint. We describe a rapid viral seed expansion workflow that allows vaccine release to clinical trials within 60 days of antigen sequence identification, followed by vaccine release from globally distributed sites within a further 40 days. We also describe a new perfusion-based upstream production process, designed to maximize output while retaining simplicity and suitability for existing manufacturing facilities. This improves upstream volumetric productivity of ChAdOx1 nCoV-19 by around four-fold and remains compatible with the existing downstream process, yielding drug substance sufficient for 10000 doses from each liter of bioreactor capacity. Transition to a new production process across a large manufacturing network is a major task. In the short term, the rapid seed generation workflow could be used with the existing production process. We also use techno-economic modelling to show that, if linear scale-up were achieved, a single cleanroom containing two 2000 L bioreactors running our new perfusion-based process could supply bulk drug substance for around 120 million doses each month, costing <0.20 EUR/dose. We estimate that a manufacturing network with 32000 L of bioreactor capacity could release around 1 billion doses of a new vaccine within 130 days of genomic sequencing of a new pathogen, in a hypothetical surge campaign with suitable prior preparation and resources, including adequate fill-and-finish capacity. This accelerated manufacturing process, along with other advantages such as thermal stability, supports the ongoing value of adenovirus-vectored vaccines as a rapidly adaptable and deployable platform for emergency response.

Human Mesenchymal Stem Cells Treatment for Severe COVID-19: 1-Year Follow-Up Results of a Randomized, Double-Blind, Placebo-Controlled Trial (preprint)

Background The long-term consequences of human umbilical cord-derived mesenchymal stem cell (UC-MSC) treatment for COVID-19 patients are yet to be reported. This study assessed the 1-year outcomes in patients with severe COVID-19, who were recruited in our previous UC-MSC clinical trial.Methods: In this prospective, longitudinal, cohort study, 100 patients enrolled in our phase 2 trial were prospectively followed up at 3-month intervals for 1 year to evaluate the long-term safety and effectiveness of UC-MSC treatment. The primary endpoint was an altered proportion of whole-lung lesion volumes measured by high-resolution CT. Other imaging outcomes, 6-minute walking distance (6-MWD), lung function, plasma biomarkers, and adverse events were also recorded and analyzed. This trial was registered with ClinicalTrials.gov (NCT04288102).Findings: Within 3 months, MSC administration exerted numerical improvement in whole-lung lesion volume compared with the placebo, leading to a significant difference of −10.82% (95% CI: −20.69%, −1.46%, P=0.030) on day 10. MSC also reduced the proportion of solid component lesion volume compared with the placebo at each follow-up point, with a significant difference of − 9.02% (95%CI: − 17.44%, − 0.10%, P=0.045) at month 9. More interestingly, 17.86% (10/56) of patients in the MSC group had normal CT images at month 12 ( P= 0.013), but none in the placebo group. The incidence of symptoms was lower in the MSC group than in the placebo group at each follow-up time, particularly sleep difficulties at month 3 (OR 0.19, 95% CI 0.07,0.50; P=0.001), and usual activity at month 12 (OR 0.15, 95% CI 0.03,0.79; P=0.018). Neutralizing antibodies were all positive, with a similar median inhibition rate (61.6% vs. 67.55%) in both groups at month 12. No difference in adverse events at the 1-year follow-up and tumor markers at month 12 were observed between the two groups.Interpretation: UC-MSC administration achieves a long-term benefit in the recovery of lung lesions and symptoms in COVID-19 patients.Trial Registration: This trial was registered with ClinicalTrials.gov (NCT04288102).Funding The National Key R&D Program of China, the Innovation Groups of the National Natural Science Foundation of China, and the National Science and Technology Major Project.Declaration of Interest: None to declare. Ethical Approval: This study was approved by the Ethics Committee of the Fifth Medical Center, Chinese PLA General Hospital (2020-013-D).

NLR combined with SaO2 predict severe illness among COVID-19 patients: a currently updated model (preprint)

Objectives: The pandemic of the coronavirus disease 2019 (COVID-19) continuously poses a serious threat to public health, highlighting an urgent need for simple and efficient early detection and prediction. Methods: We comprehensively investigated and reanalyzed the published indexes and models for predicting severe illness among COVID‑19 patients in our dataset, and validated them on an independent dataset. Results: 696 COVID-19 cases in the discovery stage and 337 patients in the validation stage were involved. The AuROC of neutrophil to lymphocyte ratio (NLR) (0.782) was significantly higher than that of the other 11 independent risk indexes in severe outcome prediction. The combination of NLR and oxygen saturation (SaO2) (NLR+SaO2) showed the biggest AuROC calculations with a value of 0.901; with a cut-off value of 0.532, it exhibited 84.2% sensitivity, 88.4% specificity and 86.8% correct classification ratio. Moreover, we first identified that principal component analysis (PCA) is an effective tool to predict the severity of COVID-19. We obtained 86.5% prediction accuracy with 86% sensitivity when PCA was applied to predict severe illness. In addition, to evaluate the performance of NLR+SaO2 and PCA, we compared them with currently published predictive models in the same dataset. Conclusions: It showed that NLR+SaO2 is an appropriate and promising method for predicting severe illness, followed by PCA. We then validated the results on an independent dataset and revealed that they remained robust accuracy in outcome prediction. This study is significant for early treatment, intervention, triage and saving limited resources.

Prevalence of delirium, depression, anxiety, and post-traumatic stress disorder among COVID-19 patients: protocol for a living systematic review (preprint)

Background: Previous studies on the impact of corona virus disease 2019 (COVID-19) on the mental health of the patients has been limited by the lack of relevant data. With the rapid and sustained growth of the publications on COVID-19 research, we will perform a living systematic review (LSR) to provide comprehensive and continuously updated data to explore the prevalence of delirium, depression, anxiety, and post-traumatic stress disorder (PTSD) among COVID-19 patients. Methods: We will perform a comprehensive search of the following databases: Cochrane Library, PubMed, Web of Science, Embase, and Chinese Biomedicine Literature to identify relevant studies. We will include peer-reviewed cross-sectional studies published in English and Chinese. Two reviewers will independently assess the methodological quality of included studies using the Joanna Briggs Institute Prevalence Critical Appraisal tool and perform data extraction. In the absence of clinical heterogeneity, the prevalence estimates with a 95% confidence interval (CI) of delirium, depression, anxiety, and post-traumatic stress disorder (PTSD) will be calculated by using random-effects model to minimize the effect of between-study heterogeneity separately. The literature searches will be updated every three months. We will perform meta-analysis if any new eligible studies or data are obtained. We will resubmit an updated review when there were relevant changes in the results, i.e. when outcomes became statistically significant (or not statistically significant anymore) or when heterogeneity became substantial (or not substantial anymore). Discussion: This LSR will provide an in-depth and up-to-date summary of whether the common neuropsychiatric conditions observed in patients hospitalized for severe acute respiratory syndrome (SARS-CoV) and Middle East respiratory syndrome (MERS) are also prevalent in a different stage of COVID-19 patients. Systematic review registration PROSPERO CRD42020196610

Treatment with human umbilical cord-derived mesenchymal stem cells for COVID-19 patients with lung damage: a randomised, double-blind, placebo controlled phase 2 trial (preprint)

Objective To assess the safety and efficacy of human umbilical cord-derived MSCs (UC-MSCs) for severe COVID-19 patients with lung damage. Design, Multicentre , randomised, double-blind, placebo-controlled trial. Setting Two hospitals in Wuhan, China, 5 March 2020 to 28 March 2020. Participants 101 severe COVID-19 patients with lung damage aged between 18-74 years. Intervention Patients were randomly assigned at a 2:1 ratio to receive either UC-MSCs (40 million cells per infusion) or placebo on days 0, 3, and 6. Main outcome measures The primary endpoints were safety and an altered proportion of whole lung lesion size from baseline to day 28, measured by chest computed tomography. Secondary outcomes were reduction of consolidation lesion sizeand lung function improvement (6-minute walk test, maximum vital capacity, diffusing capacity). Primary analysis was done in the modified intention-to-treat (mITT) population and safety analysis was done in all patients who started their assigned treatment. Results 100 patients were finally recruited to receive either UC-MSCs (n = 65) or placebo (n = 35). The patients receiving UC-MSCs exhibited a trend of numerical improvement in whole lung lesion size from baseline to day 28 compared with the placebo cases (the median difference was -13.31%, 95%CI -29.14%, 2.13%, P=0.080). UC-MSCs administration significantly reduced the proportions of consolidation lesion size from baseline to day 28 compared with the placebo (median difference: -15.45%, 95% CI -30.82%, -0.39%, P=0.043). The 6-minute walk test showed an increased distance in patients treated with UC-MSCs (difference: 27.00 m, 95% CI 0.00, 57.00, P=0.057). The incidence of adverse events was similar, and no serious adverse events were observed in the two groups. Conclusions UC-MSCs treatment is a safe and potentially effective therapeutic approach for COVID-19 patients with lung damage. A phase 3 trial is required to evaluate effects on reducing mortality and preventing long-term pulmonary disability.

Treatment with Human Umbilical Cord-Derived Mesenchymal Stem Cells for Severe COVID-19 Patients with Lung Damage: A Randomised, Double-Blind, Placebo‑Controlled Phase 2 Trial (preprint)

Background: Treatment of severe Corona Virus Disease 2019 (COVID-19) is challenging. We performed a phase 2 trial to assess the efficacy and safety of human umbilical cord-mesenchymal stem cells (UC‑MSCs) to treat patients with severe COVID-19 with lung damage, based on our phase 1 data.Methods: In this randomised, double-blind, and placebo-controlled trial, we recruited 101 eligible patients with severe COVID-19 with lung damage aged between 18–74 years from two hospitals. Enrolled patients were randomly assigned at a 2:1 ratio to receive either UC-MSCs (4 × 107 cells per infusion) or placebo on day 0, 3, and 6. We excluded patients with malignant tumours, shock, or other organ failure. The primary endpoint was an altered proportion of whole lung lesion areas from baseline to day 28, measured by chest computed tomography. Other imaging outcomes, 6-minute walk test, maximum vital capacity, diffusing capacity, plasma biomarkers, and adverse events were recorded and analysed. Primary analysis was done in the modified intention-to-treat (mITT) population and safety analysis was done in all patients who started their assigned treatment. Findings: From March 5, 2020, to March 28, 2020, 100 patients were finally enrolled and received either UC-MSCs (n = 65) or placebo (n = 35). During follow-up, the patients receiving UC-MSCs exhibited a trend of numerical improvement in whole lung lesions from baseline to day 28 compared with the placebo cases. UC-MSCs administration significantly reduced the proportions of consolidation lesions from baseline to day 28 in the treated patients compared with the placebo subjects. The 6-minute walk test showed an increased distance in patients treated with UC-MSCs. Notably, UC-MSCs delivery was well tolerated, with no serious adverse events.Interpretation: UC-MSCs treatment is a safe and potentially effective therapeutic approach for patients with severe COVID‑19. The trial suggests that UC-MSCs administration might benefit patients with COVID-19 with lung damage at the convalescent stage as well as the progression stage.Trial Registration: This trial is registered with ClinicalTrials.gov, number NCT04288102.Funding Statement: This trial was supported by The National Key R&D Program of China (2020YFC0841900, 2020YFC0844000, 2020YFC08860900); The Innovation Groups of the National Natural Science Foundation of China (81721002); The National Science and Technology Major Project (2017YFA0105703).Declaration of Interests: All authors declare no competing interests.Ethics Approval Statement: Ethical approval was obtained from the institutional review boards of each participating hospital. Written informed consent was obtained from all the enrolled patients or their legal representatives if they were unable to provide consent.

The Proteomic Characteristics of Airway Mucus from Critical Ill COVID-19 Patients (preprint)

Background: The pandemic of the coronavirus disease 2019 (COVID-19) has brought a global public health crisis. However, the pathogenesis underlying COVID-19 are barely understood.Methods: In this study, we performed proteomic analyses of airway mucus obtained by bronchoscopy from severe COVID-19 patients. In total, 2351 and 2073 proteins were identified and quantified in COVID-19 patients and healthy controls, respectively.Results: Among them, 92 differentiated expressed proteins (DEPs) (46 up-regulated and 46 down-regulated) were found with a fold change > 1.5 or < 0.67 and a p-value < 0.05, and 375 proteins were uniquely present in airway mucus from COVID-19 patients. Pathway and network enrichment analyses revealed that the 92 DEPs were mostly associated with metabolic, complement and coagulation cascades, lysosome, and cholesterol metabolism pathways, and the 375 COVID-19 only proteins were mainly enriched in amino acid degradation (Valine, Leucine and Isoleucine degradation), amino acid metabolism (beta-Alanine, Tryptophan, Cysteine and Methionine metabolism), oxidative phosphorylation, phagosome, and cholesterol metabolism pathways.Conclusions: This study aims to provide fundamental data for elucidating proteomic changes of COVID-19, which may implicate further investigation of molecular targets directing at specific therapy.Funding Statement: This work was supported by grants from the National Key R&D Program of China (2016YFC0903700), the National Natural Science Foundation of China (81520108001 and 81770043), and grant specific for COVID-19 study from Guangzhou Institute of Respiratory Health.Declaration of Interests: The authors have no conflict of interest to declare.Ethics Approval Statement: All the procedures were approved by the Ethics Committee of the First Affiliated Hospital of Guangzhou Medical University (No. 2020-65). Verbal informed consent were obtained from all participants because the family members were in quarantine.

NLR combined with SaO2 predict severe illness among COVID-19 patients: a currently updated model (preprint)

Objectives: The pandemic of the coronavirus disease 2019 (COVID-19) continuously poses a serious threat to public health, highlighting an urgent need for simple and efficient early detection and prediction. Methods: We comprehensively investigated and reanalyzed the published indexes and models for predicting severe illness among COVID‑19 patients in our dataset, and validated them on an independent dataset. Results: 696 COVID-19 cases in the discovery stage and 337 patients in the validation stage were involved. The AuROC of neutrophil to lymphocyte ratio (NLR) (0.782) was significantly higher than that of the other 11 independent risk indexes in severe outcome prediction. The combination of NLR and oxygen saturation (SaO2) (NLR+SaO2) showed the biggest AuROC calculations with a value of 0.901; with a cut-off value of 0.532, it exhibited 84.2% sensitivity, 88.4% specificity and 86.8% correct classification ratio. Moreover, we first identified that principal component analysis (PCA) is an effective tool to predict the severity of COVID-19. We obtained 86.5% prediction accuracy with 86% sensitivity when PCA was applied to predict severe illness. In addition, to evaluate the performance of NLR+SaO2 and PCA, we compared them with currently published predictive models in the same dataset. Conclusions: It showed that NLR+SaO2 is an appropriate and promising method for predicting severe illness, followed by PCA. We then validated the results on an independent dataset and revealed that they remained robust accuracy in outcome prediction. This study is significant for early treatment, intervention, triage and saving limited resources.

Research on coVID-19 Public Opinion Guidance Strategies based on Social Media

Objective: To study effective public Opinion guidance Strategies for COVID-19 To help create a good public opinion atmosphere To combat the epidemic. Methods: Between January 2020 and May comments under the ＂People's Daily,＂ the Official blog of data as the Basis, Combining with the status quo at home and abroad, The status quo analysis was carried out on the outbreak of the New Champions League Public Opinion, and text Mining, LDA Subject to review data Modeling analysis, On the basis of emotion classification to further explore the influence factors of positive and negative emotions. The public paid more attention to The information of epidemic prevention and control, Resumption of work and prevention and control measures. The factors influencing people's positive emotions include The advanced typical, of fighting against The epidemic and The firm faith in Defeating the epidemic. The negative emotions of the public are affected by the severe situation of the epidemic, the delay in returning to work and school, And the impact of entry and exit on an epidemic prevention and control. Conclusion: Suggestions and puts forward from three aspects:＂Authoritative information report is timely and effective＂, ＂temperature ＂publicity stimulates positive energy＂ and ＂innovative publicity strengthens the public opinion guidance＂.

Prevalence of depression, anxiety, delirium, and post-traumatic stress disorder among COVID-19 patients: protocol for a living systematic review (preprint)

Background Previous studies on the impact of COVID-19 on the mental health of the patients has been limited by the lack of relevant data. With the rapid and sustained growth of the publications on COVID-19 research, we will perform a living systematic review (LSR) to provide comprehensive and continuously updated data to explore the prevalence of depression, anxiety, delirium, and post-traumatic stress disorder (PTSD) among COVID-19 patients.Methods We will perform a comprehensive search of the following databases: Cochrane Library, PubMed, Web of Science, Embase, and Chinese Biomedicine Literature to identify relevant studies. We will utilize different tools to examine the bias risks (quality) regarding studies of varying design types, such as the revised Cochrane risk-of-bias tool (RoB 2) for randomized controlled trials (RCT), the Newcastle-Ottawa Scale (NOS) for cohort and case-control studies, etc. The literature searches would be updated every month. We will perform meta-analysis if any new eligible studies or data are obtained and resubmit an updated systematic review if any change in outcomes and heterogeneity is determined after the addition of the new studies. There will be no restrictions on language or year of publication.Discussion This LSR would provide an in-depth and up-to-date summary of the psychological impact of COVID-19 diagnosis and treatment on the patients. Systematic review registration PROSPERO CRD42020196610 

The values of coagulation function in COVID-19 patients (preprint)

ObjectiveTo investigate the blood coagulation function in COVID-19 patients, and the correlation between coagulopathy and disease severity. MethodsWe retrospectively collected 147 clinically diagnosed COVID-19 patients at Wuhan Leishenshan Hospital of Hubei, China. We analyzed the coagulation function in COVID-19 patients through the data including thrombin-antithrombin complex (TAT), 2-plasmininhibitor-plasmin Complex (PIC), thrombomodulin (TM), t-PA/PAI-1 Complex (t-PAIC), prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (FIB), thrombin time (TT), D-Dimer (DD), and platelet (PLT). ResultThe levels of TAT, PIC, TM, t-PAIC, PT, INR, FIB, and DD in COVID-19 patients were higher than health controls (p<0.05), and also higher in the patients with thrombotic disease than without thrombotic disease (p<0.05). Whats more, the patients with thrombotic disease had a higher case-fatality (p<0.05). TAT, PIC, TM, t-PAIC, PT, INR, APTT, FIB, DD, and PLT were also found correlated with disease severity. Meanwhile, we found that there were significant difference in TAT, TM, t-PAIC, PT, INR, APTT, DD, and PLT in the death and survival group. Further using univariate and multivariate logistic regression analysis also found that t-PAIC and DD were independent risk factors for death in patients and are excellent predicting the mortality risk of COVID-19. ConclusionThe coagulation systems in COVID-19 patients are inordinate, and dynamic monitoring of them, might be a key in the control of COVID-19 death.

Transmission of corona virus disease 2019 during the incubation period may lead to a quarantine loophole (preprint)

Background: The ongoing outbreak of novel corona virus disease 2019 (COVID-19) in Wuhan, China, is arousing international concern. This study evaluated whether and when the infected but asymptomatic cases during the incubation period could infect others. Methods: We collected data on demographic characteristics, exposure history, and symptom onset day of the confirmed cases, which had been announced by the Chinese local authorities. We evaluated the potential of transmission during the incubation period in 50 infection clusters, including 124 cases. All the secondary cases had a history of contact with their first-generation cases prior to symptom onset. Results: The estimated mean incubation period for COVID-19 was 4.9 days (95% confidence interval [CI], 4.4 to 5.4) days, ranging from 0.8 to 11.1 days (2.5th to 97.5th percentile). The observed mean and standard deviation (SD) of serial interval was 4.1{+/-}3.3 days, with the 2.5th and 97.5th percentiles at -1 and 13 days. The infectious curve showed that in 73.0% of the secondary cases, their date of getting infected was before symptom onset of the first-generation cases, particularly in the last three days of the incubation period. Conclusions: The results indicated the transmission of COVID-9 occurs among close contacts during the incubation period, which may lead to a quarantine loophole. Strong and effective countermeasures should be implemented to prevent or mitigate asymptomatic transmission during the incubation period in populations at high risk.