[Experience in emergency response to 2019-nCoV positive cases in an international test competition].

Objective: To analyze the performance of emergency response to 2019 novel coronavirus (2019-nCoV) positive cases in an international test competition in an Winter Olympic Game venue and provide evidences for the COVID-19 prevention and control in similar competitions. Methods: A retrospective analysis on the epidemiological investigation and nucleic acid test results of the cases, the implementation of prevention and control measures, including the communication with sport teams and others, was conducted. Results: The positive cases of 2019-nCoV among entering people were detected before entry, at airport, hotel and venue. Two positive cases were reported before entry, 2 positive cases infected previously and 3 asymptomatic cases were reported after the entry. The venue public health team and local CDC conducted epidemiological investigation and contact assessment jointly in a timely and efficient manner. No local secondary transmission occurred, but the nucleic acid test results of positive persons fluctuated, posing serious challenges to the implementation of prevention and control measures. Conclusion: In large scale international competition, there is high risk of imported COVID-19. It is necessary to fully consider the fluctuation of nucleic acid test results, the criteria for determination and cancellation of positive results and give warm care to positive cases in the emergency response.

COVID-19 Literature Knowledge Graph Construction and Drug Repurposing Report Generation

To combat COVID-19, both clinicians and scientists need to digest vast amounts of relevant biomedical knowledge in scientific literature to understand the disease mechanism and related biological functions. We have developed a novel and comprehensive knowledge discovery framework, COVID-KG to extract fine-grained multimedia knowledge elements (entities and their visual chemical structures, relations and events) from scientific literature. We then exploit the constructed multimedia knowledge graphs (KGs) for question answering and report generation, using drug repurposing as a case study. Our framework also provides detailed contextual sentences, subfigures, and knowledge subgraphs as evidence. All of the data, KGs, reports(1), resources, and shared services are publicly available(2).

[Epidemiological characteristics of imported COVID-19 cases in Beijing].

Objective: To analyze the epidemiological characteristics of imported COVID-19 cases and the effect of vaccination on virus load and disease severity of the cases in Beijing. Methods: The data of the imported COVID-19 cases in Beijing were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and Epidemiology investigation. The data were processed and analyzed by Excel 2010 and SPSS 22.0. Results: From June 1 to September 30, 2021, a total of 171 imported COVID-19 cases were reported in Beijing, of which 66.67% (114/171) were asymptomatic. The cases were mainly from the Philippines, the United Arab Emirates, the United Kingdom and the Russian Federation, accounting for 67.84% (116/171). The male to female ratio of the cases was 2∶1 (114∶57). The median age M (Q1, Q3) of the cases was 28 (23, 36) years. The cases of Chinese accounted for 80.12% (137/171). The sequencing of the whole genome of the virus in 47 imported COVID-19 cases showed that the proportion of Delta variant was 76.60% (36/47). The COVID-19 vaccination coverage rate in the cases was 60.82% (104/171), but the full vaccination coverage rate was 53.80% (92/171). In the imported COVID-19 cases, 13.53% (23/170) were screened to be SARS-CoV-2 nucleic acid positive on the day when they arrived in Beijing, and all the cases were positive for 2019-nCoV nucleic acid within 28 days. The severity of the disease was higher in the unvaccinated group than in the partially vaccinated group and fully vaccinated group (P<0.001). In the unvaccinated group, there were 1 severe case and 1 critical case. The median Ct values M (Q1, Q3) of N gene and ORFlab gene in unvaccinated group were 32.51 (23.23, 36.06) and 32.78 (24.00, 36.38), respectively. There was no significant difference in the median of double-gene Ct value between the partially vaccinated group and the fully vaccinated group. Conclusions: During the study period, most of the imported COVID-19 cases in Beijing were asymptomatic. No matter vaccinated or not, the viral loads in the COVID-19 cases were similar, but the vaccination could reduce the severity of the disease.

[Epidemiological characteristics of close contacts of COVID-19 cases and infection-related risk factors in Beijing].

Objective: To analyze the epidemiological characteristics of close contacts of COVID-19 cases and infection-related risk factors in Beijing and provide evidences for COVID-19 prevention and control. Methods: A total of 20 681 close contacts of COVID-19 cases, who had exposures during January 6, 2020 to February 15, 2021, were traced in Beijing. The information about their demographic characteristics, exposure history, and quarantine outcomes were collected and analyzed with descriptive statistics. The logistic regression analysis was used to identify the risk factors for COVID-19. Results: The infection rate SARS-CoV-2 in close contacts was 2.16% (447/20 681). The age M(P25, P75) was 35 (27, 49) years. The majority of the close contacts were aged 20-59 years, accounting for 81.77% (16 912/20 681). Centralized isolation was the major type of medical observation, accounting for 82.15% (16 989/20 681). Among the exposure types, working and studying in the same room (16.06%, 3 322/20 681), sharing same transport vehicle (12.88%, 2 664/20 681), performing diagnosis and treatment nursing (7.80%,1 612/20 681), and living together (7.23%,1 495/20 681), accounting for 43.96% (9 093/20 681). The index cases included staff (19.34%, 3 999/20 681), the unemployed (17.34%, 3 586/20 681), people engaged in business service (13.85%, 2 864/20 681), people engaged in food service (10.77%, 2 228/20 681), their close contacts accounted for 61.30% (12 677/20 681). Multivariate logistic regression analysis showed that compared with other types of exposure, the risk factors for infection were having meal together (OR=3.96, 95%CI: 2.30-6.83) and living together (OR=6.41, 95%CI:4.48-9.17); Compared with the other occupations, the index case being engaged in food service (OR=3.06, 95%CI:1.29-7.25) and teacher (OR=4.94, 95%CI:1.43-17.08) were risk factors for the infection. Conclusions: The main environmental exposure types of SARS-CoV-2 infection in close contacts were having meal together and living together. Contact with the index case being engaged in food service and teacher increased the risk for COVID-19. Comprehensive prevention and control measures such as centralized isolation and vaccination should be continued.

E-commerce live broadcast influencing factors on impulsive clothing purchases

The COVID-19 pandemic in 2020 has expedited the rapid development of the online economy. E-commerce live streaming has become a new way of online shopping. This paper studies consumer impulse buy factors of e-commerce live broadcasts. Based on SOR theory, the theoretical model and research hypothesis are put forward, and the conclusions are drawn through the empirical analysis of consumer impulse characteristics, preferential price, time pressure and live broadcast anchors. These features all have a positive impact on consumers' impulse buying intentions and heightens the perceived value of products. This paper proposes that we should attach importance to the training and operation of live anchors to enrich product information and promotional activities, improve the perceived value of consumers for effective marketing to enhance consumer's purchasing impulse. © 2019 Textile Bioengineering and Informatics Symposium Proceedings 2021 - 14th Textile Bioengineering and Informatics Symposium, TBIS 2021. All rights reserved.

[Survey on source of infection of the first local outbreak caused by SARS-CoV-2 Alpha variant in China].

Objective: To investigate the epidemiological characteristics and the chain of infection of a local outbreak, which was the first outbreak caused by severe acute respiratory syndrome corona virus 2 Alpha variant in China and occurred in Daxing district, Beijing. Methods: Epidemiological investigation and big data technology were used to verify the exposure points of the cases. Close contacts were traced from the exposure points, and their human and environmental samples were collected for nucleic acid tests. Serum samples were collected from key persons for antibody detection. Results: A total of 33 corona virus disease 2019(COVID-19) cases were reported in the local outbreak, from January 17, 2021 to January 29, 2021 in Daxing district, Beijing, and there was epidemiological association in 32 cases. Except for one case who was infected in the workplace, other cases were all infected in the community and family. All cases involved 14 families, of which 6 families were all infected. The attack rate of all family members was 69%(33/48), and the secondary attack rate was 56%(19/34). There was no obvious source of infection found after the investigation of entry-exit personnel and goods. Conclusion: The first outbreak caused by severe acute respiratory syndrome corona virus 2 Alpha variant in China is found and handled in time, and thus the scope of influence is limited, but the family clustering characteristics are more obvious than previous outbreaks.

Changes in Source-Specific Black Carbon Aerosol and the Induced Radiative Effects Due to the COVID-19 Lockdown

The impacts of anthropogenic emissions on the reduction of source-specific equivalent black carbon (eBC) aerosols and their direct radiative effects (DREs) were investigated during the lockdown of the coronavirus outbreak in a megacity of China in 2020. Five eBC sources were identified using a hybrid environmental receptor model. Results showed that biomass burning, traffic-related emissions, and coal combustion were the dominant contributors to eBC. The generalized additive model indicated that the reduction of traffic-related eBC during the lockdown was entirely attributed to the decrease of emissions. Decreased biomass-burning activities and favorable meteorological factors are both important drivers for the biomass-burning eBC reduction during the lockdown. A radiative transfer model showed that the DRE efficiency of eBC from biomass burning was the strongest, followed by coal combustion and traffic-related emissions. This study highlights that aggressive reduction in the consumption of residential solid fuels would be effective in achieving climate change mitigation.

[Relationship between respiratory viral load of cases of COVID-19 and secondary attack risk in close contacts].

Objective: To analyze the relationship between the cycle threshold (Ct) values of N gene of COVID-19 cases and the secondary attack risk in close contacts, and identify the relationship between respiratory viral load and infectivity in COVID-19 cases. Methods: The COVID-19 cases with records of Ct values of N gene within 0-7 days of onset were selected, and their close contacts were recruited as the subjects of study. We collected the information of close contacts, including name, gender, age, isolation mode, exposure mode and outcome (whether they were infected with SARS-CoV-2 or not) and other variables. Multivariate logistic regression models were used to identify the relationship between Ct values of N gene of COVID-19 cases and secondary attack risk in close contacts. Results: A total of 1 618 close contacts were recruited, in whom 77 were confirmed as symptomatic or asymptomatic COVID-19 patients with overall secondary attack rate of 4.8%. The multivariate logistic regression analysis indicated that eating together (OR=2.741, P=0.054), living together (OR=9.721, P<0.001), non-centralized isolation (OR=18.437, P<0.001) and COVID-19 case's values of N gene within 0-7 days of onset being <20 (OR=8.998, P=0.004) or 20-25 (OR=3.547, P=0.032) were significantly associated with higher likelihood of being infected with SARS-CoV-2 in close contacts. Conclusion: The results indicated that positive relationship exists between respiratory viral load and infectivity in COVID-19 cases, suggesting that Ct values of N gene can be used as an early warning indicator for the management of close contacts of COVID-19 cases.

Severe Coronavirus disease 2019 successfully treated with glucocorticoid and high-dose intravenous immunoglobulin: A case report and analysis of clinical experience

Objective To report a case of severe Coronavirus disease 2019 (COVID-19) that had been successfully treated with glucocorticoid and intravenous immunoglobulin therapy. Methods and results The patient was a healthcare provider in Wuhan City who was taking care of COVID-19 patients before the onset of the disease. He started to cough with a little white sticky sputum on January 16, 2020 and had a fever on January 22 (up to 38.5 ℃) before admission. CT results showed mild exudation in both lungs. Oral oseltamivir and intravenous moxifloxacin, cefoperazone and sulbactam sodium were given in addition to nutritional support. On January 26, the patient had chest tightness and shortness of breath. A swab test was positive for severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) nucleic acid, and chest CT results showed moderate exudation in both lungs. On January 28, shortness of breath worsened and intravenous methylprednisolone (40 mg, qd) and immunoglobulin (10 g, qd) were given. On January 30, shortness of breath further worsened;he had a body temperature of 40.7 ℃, pulse oxygen saturation (SpO2) of 83% with oxygen inhalation at 10 L/min, and lymphocyte count of 0.5×109/L. The dose of methylprednisolone and immunoglobulin were adjusted to 40 mg, q12h and 20 g, qd, respectively. Subcutaneous injection of thymalfasin (1.6 mg, qd) was added. Then the body temperature returned to normal, and symptoms such as chest tightness and shortness of breath were gradually improved. On January 31, SpO2 was 88% with oxygen inhalation at 10 L/min and a chest CT results revealed large amount of exudation in both lungs. On February 2, SpO2 was 95% with oxygen inhalation at 5 L/min and the dose of methylprednisolone was then gradually reduced. A chest CT results on February 3 revealed improved lung inflammation, and a throat swab on February 4 and 9 was negative for SARS-CoV-2 nucleic acid. Conclusion Glucocorticoid should be used with caution in patients with early and mild COVID-19. However, appropriate dosage of glucocorticoid can be used to modulate lung inflammation in patients with decompensated respiratory failure. Additionally, large dose of immunoglobulin can be given if necessary.

[Exploration on contamination and transmission of SARS-CoV-2 in imported cold chain aquatic products].

Contaminations of SARS-CoV-2 have been found for many times in imported cold chain aquatic products and their packaging materials in China. The purpose of this paper is to analyze the contamination status, sources and transmission risks of SARS-CoV-2 in imported cold chain aquatic products, and try to put forward relevant suggestions and strategies in order to provide evidence for the prevention and control of SARS-CoV-2 infection.

[Epidemiological characteristics of COVID-19 cases in outbreak in Xinfadi market in Beijing].

Objective: To understand the epidemiological characteristics of COVID-19 cases, including asymptomatic cases and symptomatic cases, in the outbreak in Xinfadi market in Beijing. Methods: Data and epidemiological survey reports of COVID-19 cases in Xinfadi market in Beijing were extracted from China's Infectious Disease Information System. Epidemiological characteristics of symptomatic cases and asymptomatic cases were analyzed and compared by using software SPSS 19.0. Results: From June 11 to July 10, 2020, a total of 368 laboratory-confirmed COVID-19 cases reported in Xinfadi market, in which, 335 (91.03%) were symptomatic and 33 (8.97%) were asymptomatic. The cases were distributed in 11 districts, and most cases (252/368, 68.48%) were reported in Fengtai district. The incidence curve of the cases showed a typical outbreak pattern, the case number peaked on 13 June. The median age of the cases were 43 years (QR: 31-51). The asymptomatic cases (M=32, QR: 29-46) were younger than the symptomatic cases (M=43, QR: 31-52), the difference was significant (Z=2.416, P=0.016). The ratio of male to female was 1.26∶1. Most cases (236/368, 64.13%) were engaged in catering service and public place service. 73.91% (272/368) of the cases had historg of direct exposures in the Xinfadi market. 54.08%(199/368) of cases were detected through nucleic acid testing and screening. Mild and moderate cases accounted for 99.10% (332/335) and no death occurred. Conclusion: The COVID-19 cases in the outbreak in Xinfadi market were mainly engaged in catering service and public place service. The asymptomatic cases were younger than the symptomatic cases.

Nephrology's history is alive and well and helps predict the future

If there can be "love in the time of cholera", then there can be history of kidney medicine in the time of COVID-19. In our article, we celebrate the history of nephrology, which unites curious young minds with the legacy built by senior figures of the discipline. Notably, technological advances such as the Internet have made nephrology history more accessible to a wide range of audiences, including young students and physicians in training. The interest that continues to prevail for the field ensures that the future of kidney medicine is bright and bound to expand in new directions. We can treat the past and the future with equal precision and rigor under the umbrella of history. One can describe a symmetrical timeline with 193 years back to Richard Bright's book in 1827, and 193 years forward to 2213 the point when some expect that human consciousness will be routinely uploaded to inorganic substrates. But for now, we shall seek to excavate the past to have a better idea of where we're going and how to achieve desired outcomes, which is especially important in a time of global health emergency, where we are all fighting a single enemy, COVID-19.