LISNET: A COVID-19 LUNG INFECTION SEGMENTATION NETWORK BASED ON EDGE SUPERVISION AND MULTI-SCALE CONTEXT AGGREGATION

Corona Virus Disease 2019 (COVID-19) spread globally in early 2020, leading to a new health crisis. Automatic segmentation of lung infections from computed tomography (CT) images provides an important basis for early diagnosis of COVID-19 quickly. In this paper, we propose an effective COVID-19 Lung Infection Segmentation Network (LISNet) based on edge supervision and multi-scale context aggregation. More specifically, an Edge Supervision module is introduced to the feature extraction part to enhance the low contrast between lesions and normal tissues. In addition, the Multi-scale Feature Fusion module is added to enhance the segmentation ability of different scales Lesions. Finally, the Context Aggregation module is used to aggregate high- and low-level features and generate global information. Experiments demonstrate that our method outperforms other state-of-the-art methods on the public COVID-19 CT segmentation dataset. © 2022 IEEE.

[Kinetics of SARS-CoV-2-specific antibodies among inactivated COVID-19 vaccine recipients, SARS-CoV-2 natural infection cases, and breakthrough cases].

Between August and September, 2021, this study included 605 SARS-CoV-2 natural infection cases and 589 SARS-CoV-2 breakthrough cases from Nanjing and Yangzhou, as well as 690 inactivated COVID-19 vaccine recipients from Changzhou, China. In SARS-CoV-2 natural infection cases, the age range was 19-91 years (median age: 66 year), and the medians(Q1,Q3) of IgG titers were 0.19 (0.06-1.31), 3.70 (0.76-69.48), 15.31 (2.59-82.16), 4.41 (0.99-31.74), 2.31 (0.75-13.83), 2.28 (0.68-9.94) and 2.80 (1.00-9.53) at one to seven weeks after SARS-CoV-2 infection, respectively. In SARS-CoV-2 breakthrough cases, the age range was 18-76 years (median age: 45 year), and the medians(Q1,Q3)of IgG titers were 1.93 (0.34-26.67), 38.87 (7.90-121.0), 75.09 (11.85-123.70), 21.97 (5.20-95.58), 13.97 (3.47-46.82), 9.56 (2.48-33.38) and 4.38 (1.87-11.00) at one to seven weeks after SARS-CoV-2 infection, respectively. In inactivated COVID-19 vaccine recipients, the age range was 18-87 years (median age: 47 years), and the medians(Q1,Q3)of IgG titers were 16.22 (15.84-33.42), 5.35 (2.96-13.23), 3.30 (2.18-6.18), 3.14 (1.16-5.70), 2.77 (1.50-4.52), 2.72 (1.76-4.36), 2.01 (1.27-3.51) and 1.94 (1.35-3.09) at one to eight months after SARS-CoV-2 infection, respectively. The results suggested that IgG antibodies increased gradually within two weeks after SARS-CoV-2 infection, then declined gradually at three to seven weeks in SARS-CoV-2 natural infection cases. In SARS-CoV-2 breakthrough cases, IgG antibodies increased rapidly within two weeks, then declined gradually at three to seven weeks after SARS-CoV-2 infection. Additionally, IgG antibodies decreased rapidly within three months, then decreased gradually and remained at a low level within three months after immunization.

Intercity Travel Resilience, Recovery Patterns and Influencing Factors of Resilience in Chinese Cities in the Context of COVID-19

"Since the outbreak of the COVID-19 epidemic in 2020, the intercity travel in China has been significantly affected. With the popularity of big data, spatiotemporal modeling and analysis are widely used in epidemic and transportation research. In the post epidemic era, residents' intercity travel shows a certain recovery mode under the influence of local epidemic. The recovery mode and resilience of intercity travel reflects the resilience of cities and can provide information for cities' epidemic prevention and control. Exploring different urban modes and factors affecting the resilience of intercity travel under the influence of epidemic situation has practical significance for normalized epidemic prevention and control management. Based on the migration big data, this paper describes the differentiation pattern of intercity travel resilience under the COVID-19 epidemic from different perspectives, summarizes the time series model, and explores the factors affecting intercity travel resilience. Four indicators, namely fluctuation ratio, recovery ratio, resilience, and recovery index, are constructed to measure the resilience of intercity travel. The results show that: (1) During the epidemic period, residents' resilience to travel shows certain spatial variation. On the whole, the eastern region is the best, followed by the western region and the central region, and the northeast region is the worst;(2) The temporal patterns of intercity travel in epidemic cities are consistent with ""resilience triangle"" of the typical model. According to the propagation mode and correlation of the epidemic, the specific temporal patterns can be classified into five types: Relative independence mode, intermediate fluctuation mode, starting-point correlation mode, end-point correlation mode, and bidirectional restraint mode, showing different curve forms and characteristics;(3) The resilience of intercity travel is affected by complex factors. When the epidemic wave and regional variables are controlled, economic and transportation factors have a significant impact on the recovery of intercity travel. There may be a U-shaped relationship between per capita GDP and industrial structure and the resilience of intercity travel. When the economic development reaches a certain level, the supporting effect of economy on the resilience of intercity travel becomes increasingly prominent. There is a positive correlation between high-speed rail and airport and the resilience of intercity travel, which plays an important role in increasing the resilience of intercity travel. The results of this study indicate that the application of spatiotemporal big data to analyze the mode and mechanism of urban recovery in the post epidemic era is a novel research method. Subsequent research can further explore the spatiotemporal pattern and mode mechanism of epidemic recovery, in order to provide scientific basis and guidance for epidemic prevention and control of cities. © 2022, Science Press. All right reserved."

The theory of multinational enterprises in the digital era: state-of-the-art and research priorities

Purpose Deglobalization and the coronavirus disease 2019 (COVID-19) pandemic have severely hindered multinational enterprise (MNE) investment. At the same time, digital technology is seriously challenging it with traditional production factor flows. Few studies have realized that the impact of digitalization is not limited to either transaction costs or the location-boundness of firm-specific advantages (FSAs), but extends to profound changes in the fundamental essence of MNEs. There is still limited understanding of this body of knowledge as a whole, including how its subtopics are interrelated. This study took the production factor change perspective to review MNE theory in the digital era. Therefore, this study aims to identify any upcoming and undeveloped themes in order to provide a platform suited to direct future research. Design/methodology/approach This paper presents a summary and a review of 151 articles published between 2007 and 2020. Such review was conducted to systematically explain the connotations and influential mechanisms of digital empowerment on MNE theory. This was achieved by using the CiteSpace citation visualization tool to build a keyword co-occurrence network. Findings The research findings pertain to how digitalization expands, breaks through, and even reshapes traditional MNE theory from four distinctive angles: the influential factors of internationalization, the process of internationalization, competitive advantage, and location choice. The findings are followed by the presentation of future research directions. Originality/value This paper presents an examination of MNE theory in the digital era from the perspective of production factor change. In doing so, it identifies significant theoretical innovation opportunities for future scholarly research priorities.

Effects of the COVID-19 lockdown in Hubei, China: cessation of incense burning reduces regional landscape fire

Both anthropogenic and climatic factors are important determinants of landscape fire. Because the two groups of factors are intertwined and often act simultaneously, dissecting their effects on landscape fire is challenging. We used the COVID-19 lockdown event in Hubei, in which all immediate influences of anthropogenic factors were effectively removed, to quantify the effects of anthropogenic factors on landscape fire occurrence. We hypothesized that outdoor incense burning is the main causal factor of landscape fire. To test the hypothesis, we used random forest algorithm to model fire occurrence, including fire frequency, total area burned, and area of forest burned, for the lockdown period. We then estimated the differences between historical, simulated, and observed values of landscape fire and used the differences to represent the effects of anthropogenic activities on landscape fire. Our results showed that during the lockdown, landscape fire frequency was reduced by 77%, total area burned by 80%, and area of forest burned by 63%. By month, fire frequency decreased the most in April (85%), followed by February (80%), coinciding with the Qingming and Spring Festivals of 2020. The cessation of outdoor incense burning during the festival season was likely to be the most important factor that decreased fire occurrence, confirming our hypothesis about the causal relationship between outdoor incense-burning and landscape fire. Thus, educational programs encouraging people to stop outdoor incense burning during the festival season could reduce the occurrence of landscape fire.

Preparation and effect evaluation of positive quality control reference for nucleic acid detection of 2019 Novel Corona Virus

Objective To prepare the indoor positive quality control reference for nucleic acid detection of 2019 Novel Corona Virus (2019-nCoV), investigate the feasibility of self-made quality control reference and evaluate the effect. Methods The positive control samples in the test kit from a third party were collected, diluted doubly with the virus preservation solution in which healthy human nasopharyngeal swabs were preserved, test samples to make a dilution, and determined for the Ct value of ORFlab gene by real-time fluorescent quantitative PCR. The dilutions with Ct values of about 31 and 34 were served as high-(nCov-H) and low-value quality control references (nCov-L) respectively and prepared in large quantities, then filled into small aliquots and stored at-80 °C to evaluate the uniformity and stability. Results The self-made indoor positive quality control reference for nucleic acid detection of 2019-nCoV showed good uniformity and good stability at various temperatures for storage, which could be kept stably at-80 °C for at least 6 months and could be controlled after repeated freezing and thawing for 3 times. Conclusion The self-made indoor positive quality control reference for nucleic acid detection of 2019-nCoV is simple to prepare, which has good uniformity and stability, and may be used as a substitute for commercial quality control for clinical test.

The systemic inflammatory response and clinicopathological characteristics in patients admitted to hospital with COVID-19 infection: Comparison of 2 consecutive cohorts.

BACKGROUND: In order to manage the COVID-19 systemic inflammatory response, it is important to identify clinicopathological characteristics across multiple cohorts. METHODS: The aim of the present study was to compare the 4C mortality score, other measures of the systemic inflammatory response and clinicopathological characteristics in two consecutive cohorts of patients on admission with COVID-19. Electronic patient records for 2 consecutive cohorts of patients admitted to two urban teaching hospitals with COVID-19 during two 7-week periods of the COVID-19 pandemic in Glasgow, U.K. (cohort 1: 17/3/2020-1/5/2020) and (cohort 2: 18/5/2020-6/7/2020) were examined for routine clinical, laboratory and clinical outcome data. RESULTS: Compared with cohort 1, cohort 2 were older (p<0.001), more likely to be female (p<0.05) and have less independent living circumstances (p<0.001). More patients in cohort 2 were PCR positive, CXR negative (both p<0.001) and had low serum albumin concentrations (p<0.001). 30-day mortality was similar between both cohorts (23% and 22%). In cohort 2, age >70 (p<0.05), male gender (p<0.05), COPD (p<0.05), cognitive impairment (p<0.05), frailty (p<0.001), delirium (p = 0.001), CRP>150mg/L (p<0.05), albumin <30 g/L (p<0.01), elevated perioperative Glasgow Prognostic Score (p<0.05), elevated neutrophil-lymphocyte ratio (p<0.001), low haematocrit (p<0.01), elevated PT (p<0.05), sodium <133 mmol/L (p<0.01) elevated urea (p<0.001), creatinine (p<0.001), glucose (p<0.05) and lactate (p<0.001) and the 4C score (p<0.001) were associated with 30-day mortality. In multivariate analysis, greater frailty (CFS>3) (OR 11.3, 95% C.I. 2.3-96.7, p<0.05), low albumin (<30g/L) (OR 2.5, 95% C.I. 1.0-6.2, p<0.05), high NLR (≥3) (OR 2.2, 95% C.I. 1.5-4.5, p<0.05) and the 4C score (OR 2.4, 95% C.I. 1.0-5.6, p<0.05) remained independently associated with 30-day mortality. CONCLUSION: In addition to the 4C mortality score, frailty score and a low albumin were strongly independently associated with 30-day mortality in two consecutive cohorts of patients admitted to hospital with COVID-19. TRIAL REGISTRATION: clinicaltrials.gov: NCT04484545.

Coronavirus disease 2019 with comorbid pulmonary tuberculosis: A case report

Introduction: In December 2019, a new type of pneumonia named coronavirus disease 2019 (COVID-19) was reported in Wuhan, Hubei province, China. The present study aimed to report the case of a patient with COVID-19 and comorbid pulmonary tuberculosis, on which there have been no relevant reports hitherto. Case Presentation: The case was a 47-year-old female patient with COVID-19 positive pharyngeal swabs. She did not suffer from fever, coughs, or difficulties in breathing. The patient was diagnosed with COVID-19 and pulmonary tuberculosis based on her epidemiological history, routine blood test, imaging findings, and COVID-19 nucleic acid test results. It should be noted that contact and droplet precautions were implemented for this patient. The administrated treatments for her included antiviral, anti-tuberculosis, and liver protection treatments. The patient did not complain about discomfort and her condition was stable. Conclusion: The COVID-19 and comorbid tuberculosis were suspected;however, epidemiological history, clinical presentation, laboratory tests, and imaging examinations must be combined to make a comprehensive diagnosis. Moreover, prompt quarantine and treatment measures should be implemented as well.

Epidemiology of Coronavirus Disease 2019 (COVID-19) Caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

In December, 2019, an infectious outbreak of unknown cause occurred in Wuhan, which attracted intense attention. Shortly after the virus was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the epidemic of coronavirus disease 2019 (COVID-19) broke out, and an information storm occurred. At that time, 2 important aspects, that is, the stages of spread and the components of the epidemic, were unclear. Answers to the questions (1) what are the sources, (2) how do infections occur, and (3) who will be affected should be clarified as the outbreak continues to evolve. Furthermore, components of the epidemic and the stages of spread should be explored and discussed. Based on information of SARS, Middle East respiratory syndrome (MERS), and COVID-19, the components of the epidemic (the sources, the routes of infection, and the susceptible population) will be discussed, as well as the role of natural and social factors involved. Epidemiologic characteristics of patients will be traced based on current information.

Prognostic factors in patients admitted to an urban teaching hospital with COVID-19 infection.

BACKGROUND: Severe COVID-19 infection results in a systemic inflammatory response (SIRS). This SIRS response shares similarities to the changes observed during the peri-operative period that are recognised to be associated with the development of multiple organ failure. METHODS: Electronic patient records for patients who were admitted to an urban teaching hospital during the initial 7-week period of the COVID-19 pandemic in Glasgow, U.K. (17th March 2020-1st May 2020) were examined for routine clinical, laboratory and clinical outcome data. Age, sex, BMI and documented evidence of COVID-19 infection at time of discharge or death certification were considered minimal criteria for inclusion. RESULTS: Of the 224 patients who fulfilled the criteria for inclusion, 52 (23%) had died at 30-days following admission. COVID-19 related respiratory failure (75%) and multiorgan failure (12%) were the commonest causes of death recorded. Age ≥ 70 years (p < 0.001), past medical history of cognitive impairment (p ≤ 0.001), previous delirium (p < 0.001), clinical frailty score > 3 (p < 0.001), hypertension (p < 0.05), heart failure (p < 0.01), national early warning score (NEWS) > 4 (p < 0.01), positive CXR (p < 0.01), and subsequent positive COVID-19 swab (p ≤ 0.001) were associated with 30-day mortality. CRP > 80 mg/L (p < 0.05), albumin < 35 g/L (p < 0.05), peri-operative Glasgow Prognostic Score (poGPS) (p < 0.05), lymphocytes < 1.5 109/l (p < 0.05), neutrophil lymphocyte ratio (p ≤ 0.001), haematocrit (< 0.40 L/L (male)/ < 0.37 L/L (female)) (p ≤ 0.01), urea > 7.5 mmol/L (p < 0.001), creatinine > 130 mmol/L (p < 0.05) and elevated urea: albumin ratio (< 0.001) were also associated with 30-day mortality. On multivariate analysis, age ≥ 70 years (O.R. 3.9, 95% C.I. 1.4-8.2, p < 0.001), past medical history of heart failure (O.R. 3.3, 95% C.I. 1.2-19.3, p < 0.05), NEWS > 4 (O.R. 2.4, 95% C.I. 1.1-4.4, p < 0.05), positive initial CXR (O.R. 0.4, 95% C.I. 0.2-0.9, p < 0.05) and poGPS (O.R. 2.3, 95% C.I. 1.1-4.4, p < 0.05) remained independently associated with 30-day mortality. Among those patients who tested PCR COVID-19 positive (n = 122), age ≥ 70 years (O.R. 4.7, 95% C.I. 2.0-11.3, p < 0.001), past medical history of heart failure (O.R. 4.4, 95% C.I. 1.2-20.5, p < 0.05) and poGPS (O.R. 2.4, 95% C.I. 1.1-5.1, p < 0.05) remained independently associated with 30-days mortality. CONCLUSION: Age ≥ 70 years and severe systemic inflammation as measured by the peri-operative Glasgow Prognostic Score are independently associated with 30-day mortality among patients admitted to hospital with COVID-19 infection.

An overview of coronavirus and progress in its detection and treatment

2019-nCoV has spread rapidly around the world, posing a major threat to global public health systems. This is the third time that a highly pathogenic coronavirus has emerged in the human population during the past 20 years. Researchers have conducted a number of studies since the coronavirus epidemic broke out, but there are no specific drugs or vaccines for coronavirus. Therefore, further systematic research on coronavirus is still needed. This review focused on the structure, life cycle and pathogenesis of coronavirus and summarized the current progress in detection approaches, treatment strategies and vaccines for COVID-19 with a view to provide references for further research.

[Analysis of the pregnancy outcomes in pregnant women with COVID-19 in Hubei Province].

Objective: To study the effect of COVID-19 on pregnancy outcomes and neonatal prognosis in Hubei Province. Method: s A retrospective comparison of the pregnancy outcomes was done between 16 women with COVID-19 and 45 women without COVID-19. Also, the results of laboratory tests, imaging examinations, and the 2019 novel coronavirus (2019-nCoV) nucleic acid test were performed in 10 cases of neonatal delivered from women with COVID-19. Result: s (1) Of the 16 pregnant women with COVID-19, 15 cases were ordinary type and 1 case was severe type. No one has progressed to critical pneumonia.The delivery method of the two groups was cesarean section, and the gestational age were (38.7±1.4) and (37.9±1.6) weeks,there was no significant difference between the two groups (P>0.05). Also, there wee no significant differences in the intraoperative blood loss and birth weight of the newborn between the two groups (all P>0.05). (2) Ten cases of neonates delivered from pregnant women with COVID-19 were collected. The 2019-nCoV nucleic acid test were all negative.There were no significant differences in fetal distress, meconium-stained amniotic fluid, preterm birth, and neonatal asphyxia between the two groups (all P>0.05).(3) In the treatment of uterine contraction fatigue, carbetocin or carboprost tromethamine was used more in cesarean section for pregnant women with COVID-19 (1.3±0.6), compared with Non-COVID-19 group (0.5±0.7),the difference was statistically significant (P=0.001). Conclusions: If there is an indication for obstetric surgery or critical illness of COVID-19 in pregnant women, timely termination of pregnancy will not increase the risk of premature birth and asphyxia of the newborn, but it is beneficial to the treatment and rehabilitation of maternal pneumonia. Preventive use of long-acting uterotonic agents could reduce the incidence of postpartum hemorrhage during surgery. 2019-nCoV infection has not been found in neonates delivered from pregnant women with COVID-19.