Research on Financial Systemic Risk Assessment Algorithm Based on Risk Data Fuzzy Cluster Analysis

The financial industry is a high-risk industry. Once the financial industry risk happen, it will affect the economic development. Ensuring the safe, efficient and steady operation of finance and preventing systemic financial risks are the urgent needs of China's opening up to the outside world and building a well-off society in an all-round way. Stable and efficient economic development is the basis of financial risk prevention and control, which is the inherent requirement of high-quality economic development. Strengthening macro-prudential management has become the core content of financial regulatory reform in major international organizations and economies after the international coronavirus outbreak and preventing systemic financial risks is the fundamental goal of macro-prudential management. This paper takes the assessment and monitoring of China's systemic financial risks as the research object, and proposes an assessment algorithm of systemic financial risks based on risk data fuzzy clustering analysis. The established financial systemic risk measurement method can identify risks to a certain extent, deeply understand the nature, root and key areas of systemic financial risks, and build a long-term mechanism to prevent and resolve systemic financial risks. © 2022 IEEE.

Various pathogen-laden aerosol deposition in the realistic human airway during inhalation

Studying the deposition of different pathogens with various sizes and shapes is vital for understanding various respiratory infectious diseases. Few studies focus on the deposition of pathogen-laden aerosol during inhalation, especially for different respiratory infectious pathogens. This paper studied the depositions of H3N2, SAR-CoV-2, Ebola virus, Escherichia coli, and different sizes of droplets in the realistic human respiratory airway during inhalation. And results show that large droplets are mainly deposited in the upper respiratory tract, while most of the small particles, especially viruses, will transmit to somewhere further than bronchi-G7 and be deposited into the deep lobes of the lungs. Over 90% of single virus particles will inhale into lobes. The deposition efficiency of pathogens in the right lobes is significantly higher than that in the left, and this phenomenon is more obvious in the superior lobes, which may also explain why lung carcinomas are more likely to develop in the right lung. Compared with other viruses, SARS-CoV-2 is more inhaled into the right superior lobe, which should be paid attention to. This paper may help learn about various respiratory infectious diseases and provide references for treatment methods and drug delivery locations. © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/)

Species-specific molecular barriers to SARS-CoV-2 replication in bat cells

Bats are natural reservoirs for numerous coronaviruses, including the potential ancestor of SARS-CoV-2. Knowledge concerning the interaction of coronaviruses and bat cells is, however, sparse. There is thus a need to develop bat cellular models to understand cell tropism, viral replication and virus-induced cell responses. Here, we report the first molecular study of SARS-CoV-2 infection in chiropteran cells. We investigated the ability of primary cells from Rhinolophus and Myotis species, as well as of established and novel cell lines from Myotis myotis, Eptesicus serotinus, Tadarida brasiliensis and Nyctalus noctula, to support SARS-CoV-2 replication. None of these cells were permissive to infection, not even the ones expressing detectable levels of angiotensin-converting enzyme 2 (ACE2), which serves as the viral receptor in many mammalian species including humans. The resistance to infection was overcome by expression of human ACE2 (hACE2) in three cell lines, suggesting that the restriction to viral replication was due to a low expression of bat ACE2 (bACE2) or absence of bACE2 binding in these cells. By contrast, multiple restriction factors to viral replication exist in the three N. noctula cells since hACE2 expression was not sufficient to permit infection. Infectious virions were produced but not released from hACE2-transduced M. myotis brain cells. E. serotinus brain cells and M. myotis nasal epithelial cells expressing hACE2 efficiently controlled viral replication, which correlated with a potent interferon response. Together, our data highlight the existence of species-specific molecular barriers to viral replication in bat cells. Our newly developed chiropteran cellular models are useful tools to investigate the interplay between viruses belonging to the SARS-CoV- 2 lineage and their natural reservoir, including the identification of factors responsible for viral restriction.

Estimation of epidemiological parameters of COVID-19 epidemic caused by Delta variant strain in Guangzhou

Objective An epidemic of COVID-19 caused by an imported Delta variant strain in Guangzhou was investigated, and the transmission chain, transmission characteristics and infection of each case were analyzed, so as to provide a theoretical basis for predicting disease development and epidemic prevention and control. Methods By collecting the information released by Guangzhou government, the confirmed cases with a clear transmission chain were selected, and the infectious disease indicators such as serial interval (SI), basic reproduction number (Rq) and time-dependent reproduction number (Rt) were calculated to analyze the epidemiological characteristics. Results From May 21 to June 20, 2021, a total of 144 cases of indigenous COVID-19 were confirmed in Guangzhou, among which 67 pairs of cases with a clear transmission chain were selected. SI was calculated to follow the Gamma distribution, with a mean of 4. 27 d and a standard deviation of 2.65 d. Rq = 3. 18 (95% CI: 2. 1974.428), and Rt showed an obvious decreasing trend over time. On June 10, Rt = 0.97 (95% CI: 0. 751 -1. 214), which was lower than 1. Since then Rt had been less than 1, and it got smaller and smaller over time. Conclusion In this COVID-19 epidemic, the SI was shorter and the Rq was larger, which indicated that the Delta variant strain had a faster transmission rate and stronger transmissibility than the COVID-19 infected in Wuhan in 2020.

A computational approach for designing novel SARS-CoV-2 Mproinhibitors: combined QSAR, molecular docking, and molecular dynamics simulation techniques

The normal expression of the main protease (Mpro) plays a vital role in the life cycle of coronavirus. Highly active inhibitors could inhibit the normal circulation of the main protease to achieve therapeutic effects as anti-coronavirus agents. In the present research, 48 peptide compounds with SARS-CoV Mproinhibition selected from the literature were used to establish robust Topomer CoMFA (q2= 0.743,r2= 0.938, andrpred2= 0.700) and HQSAR (q2= 0.774,r2= 0.955, andrpred2= 0.723) models. Structural modification information was used for designing new Mproinhibitors. The high contribution-value descriptor generated by Topomer CoMFA was used to screen for the fragments that possess significant inhibitory activities from the ZINC drug database, and 24 new compounds with predicted high inhibitory activity at nanomolar concentration were designed by combining the high contribution value fragments. The molecular docking results further justified that these potential inhibitors could form hydrogen bonds with the residues of CYS145, GLN189, GLU166, HIS163, and GLY143 of target Mpro, which well explains their strong inhibitory effects. The molecular dynamics simulation results indicated that four highly active compounds could stably bond with SARS-CoV-2 Mproand might be promising anti-SARS-CoV-2 Mprocandidates. Finally, all the newly designed compounds showed premium ADMET properties as per the predictions by the server in the public domain. This research work not only provides robust QSAR models as valuable screening tools for future anti-coronavirus drug development but also renders the newly designed SARS-CoV-2 Mproinhibitors with activity at nanomolar concentration, which can be used for further characterization to obtain novel anti-coronavirus drugs for both SARS-CoV and SARS-CoV-2.

Evaluation of COVID-19 control strategies in different countries and periods based on an adaptive PSO-SEIR model

The COVID-19 pandemic has battered the world in more than 100 countries and regions due to its deadly and high transmission. How to control or limit the first and possible second wave of the infection has become an essential problem based on the control strategies implemented globally. This study presented a model to evaluate the efficiency of strategies based on an improved multi-stage SEIR (susceptible-exposed-infectious-recovered) model considering quarantine factor, treatment delay, transmission risk by the exposed, and time. The particle swarm optimization (PSO) algorithm with an adaptive weight strategy is adopted to find the SEIR model's critical parameters associated with the control strategies based on the confirmed cases, the cured cases, and the death cases in the Chinese mainland, Italy, Spain, and Germany. The model was verified by the coefficients of correlation (R-2) between the predicted results using parameters found by PSO and the actual data on the confirmed, the death, and the cured cases. The R(2)s are all greater than 0.93 in the Chinese mainland, Italy, Spain, and Germany, showing a good accuracy of the proposed model. Base on the data of analyzed countries, PSO finds the incubation period of COVID-19 is approximately 5.1 d, which is consistent with other literatures. Besides, the period from exposure to medical care delivery is the most significant for controlling the transmission, followed by the quarantined rate according to our model. The effective reproduction number reduces from 3.9 to 1.4 while the delivery period shortens from 13 to 1 d, even without considering the effect of quarantined rate and crowd protection awareness, indicating the importance of acid testing. Moreover, the effective reproduction number is smaller than 1 when the delivery period is 1 d and the quarantined rate is higher than 0.1, which shows the transmission of COVID-19 can be contained in these conditions. Furthermore, the establishment of Fangcang shelter hospitals and the implication of aided diagnosis guideline of COVID-19 gradually reduce the period to the hospital for patients in Hubei Province from 16 to 1-2 d. In addition, the efficiency of strategies among Italy, Spain, and Germany shows that Germany reached a better condition in comparison with others, and the number of confirmed cases in each country can drop by nearly 1/3 as the protection awareness of the population rises from 0.25 to 0.69, through reducing social activities, keeping social distance, and wearing masks, indicating the importance of government advertisement, education, etc. This study might help the governments to make strategies to limit the spreading of COVID-19 or potential outbreak of emerging infectious diseases in the future.

Evaluation of COVID-19 control strategies in differentcountries and periods based on an adaptive PSO-SEIR model

The COVID-19 pandemic has battered the world in more than 100 countries and regions due to its deadly and high transmission. How to control or limit the first and possible second wave of the infection has become an essential problem based on the control strategies implemented globally. This study presented a model to evaluate the efficiency of strategies based on an improved multi-stage SEIR (susceptible-exposed-infectious-recovered) model considering quarantine factor, treatment delay, transmission risk by the exposed, and time. The particle swarm optimization (PSO) algorithm with an adaptive weight strategy is adopted to find the SEIR model's critical parameters associated with the control strategies based on the confirmed cases, the cured cases, and the death cases in the Chinese mainland, Italy, Spain, and Germany. The model was verified by the coefficients of correlation (R2) between the predicted results using parameters found by PSO and the actual data on the confirmed, the death, and the cured cases. The R2s are all greater than 0.93 in the Chinese mainland, Italy, Spain, and Germany, showing a good accuracy of the proposed model. Base on the data of analyzed countries, PSO finds the incubation period of COVID-19 is approximately 5.1 d, which is consistent with other literatures. Besides, the period from exposure to medical care delivery is the most significant for controlling the transmission, followed by the quarantined rate according to our model. The effective reproduction number reduces from 3.9 to 1.4 while the delivery period shortens from 13 to 1 d, even without considering the effect of quarantined rate and crowd protection awareness, indicating the importance of acid testing. Moreover, the effective reproduction number is smaller than 1 when the delivery period is 1 d and the quarantined rate is higher than 0.1, which shows the transmission of COVID-19 can be contained in these conditions. Furthermore, the establishment of Fangcang shelter hospitals and the implication of aided diagnosis guideline of COVID-19 gradually reduce the period to the hospital for patients in Hubei Province from 16 to 1-2 d. In addition, the efficiency of strategies among Italy, Spain, and Germany shows that Germany reached a better condition in comparison with others, and the number of confirmed cases in each country can drop by nearly 1/3 as the protection awareness of the population rises from 0.25 to 0.69, through reducing social activities, keeping social distance, and wearing masks, indicating the importance of government advertisement, education, etc. This study might help the governments to make strategies to limit the spreading of COVID-19 or potential outbreak of emerging infectious diseases in the future. © 2021, Science Press. All right reserved.

[Pregnancy with new coronavirus infection: clinical characteristics and placental pathological analysis of three cases].

Objective: To investigate the clinical characteristics and placental pathology of 2019-nCoV infection in pregnancy,and to evaluate intrauterine vertical transmission potential of 2019-nCoV infection. Methods: The placentas delivered from pregnant women with confirmed 2019-nCoV infection which were received in the Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology by February 4, 2020 were retrospectively studied. Their clinical material including placental tissue and lung CT, and laboratory results were collected, meanwhile, nucleic acid detection of 2019-nCoV of the placentas were performed by RT-PCR. Results: Three placentas delivered from pregnant women with confirmed 2019-nCoV infection, who were all in their third trimester with emergency caesarean section. All of the three patients presented with fever (one before caesarean and two in postpartum), and had no significant leukopenia and lymphopenia. Neonatal throat swabs from three newborns were tested for 2019-nCoV, and all samples were negative for the nucleic acid of 2019-nCoV. One premature infant was transferred to Department of Neonatology due to low birth weight. By the end of February 25, 2020, none of the three patients developed severe 2019-nCoV pneumonia or died(two patients had been cured and discharged, while another one had been transferred to a square cabin hospital for isolation treatment). There were various degrees of fibrin deposition inside and around the villi with local syncytial nodule increases in all three placentas. One case of placenta showed the concomitant morphology of chorionic hemangioma and another one with massive placental infarction. No pathological change of villitis and chorioamnionitis was observed in our observation of three cases. All samples from three placentas were negative for the nucleic acid of 2019-nCoV. Conclusions: The clinical characteristics of pregnant women with 2019-nCoV infection in late pregnancy are similar to those of non-pregnant patients, and no severe adverse pregnancy outcome is found in the 3 cases of our observation. Pathological study suggests that there are no morphological changes related to infection in the three placentas. Currently no evidence for intrauterine vertical transmission of 2019-nCoV is found in the three women infected by 2019-nCoV in their late pregnancy.

[Pathological changes of the spleen in ten patients with coronavirus disease 2019(COVID-19) by postmortem needle autopsy].

Objective: To study the pathological changes of the spleen in patients with COVID-19 and to analyze the relationship between the weakened immune system and splenic lesions. Methods: Postmortem needle autopsies from the spleen were carried out on 10 patients who died from COVID-19 in Wuhan. Routine hematoxylin and eosin (HE) staining was used to observe the pathological changes. The changes of lymphocytes were studied further with immunohistochemistry.RT-PCR was used to detect 2019-nCoV RNA in the spleen. In addition,the Epstein-Barr virus (EBV) was detected by in situ hybridization, and coronavirus particles were detected by transmission electron microscopy in 2 cases. Results: There were 7 males and 3 females, with an average age of 68.3 years.Of the 10 cases, 4 had cancer history and another 4 had other underlying diseases respectively.Cough, fever, malaise and dyspnea were the main clinical symptoms.The time from onset to death was 15-45 days.Ten cases patients had normal or slight increase in peripheral blood leukocyte count in the early stage of the disease, 6 cases had significant increase before death. Five patients' peripheral blood lymphocyte count decreased in the early stage of the disease, and 10 patients' peripheral blood lymphocyte count decreased significantly before the disease progressed or died. Seven cases were treated with corticosteroid (methylprednisolone ≤40 mg/d, not more than 5 days). Histopathological examination showed that the cell composition of the spleen decreased, white pulp atrophied at different levels, meanwhile lymphoid follicles decreased or absent;in addition, the ratio of red pulp to white pulp increased with varying degrees. In 7 cases, more neutrophil infiltration was found, and in 5 cases, scattered plasma cell infiltration was found. Macrophage proliferation and hemophagocytic phenomena in a few cells were found in a case. Meanwhile, necrosis and lymphocyte apoptosis were detected in 2 cases, small artery thrombosis and spleen infarction in 1 case, and fungal infection in 1 case. The results of immunohistochemistry showed that the T and B lymphocyte components of the spleen in all cases decreased in varying degrees. CD20(+) B cells were found to accumulate in the lymphoid sheath around the splenic artery in 8 cases. However, CD20 and CD21 immunostaining in 2 cases showed that the number of white pulp was almost normal, and splenic nodules were atrophic. CD3(+), CD4(+) and CD8(+)T cells were decreased. In 9 cases,CD68(+) macrophages were no significant changes in the distribution and quantity. While more CD68(+) cells were found in the medullary sinuses of 1 case (related to fungal infection). Few CD56(+) cells were found. EBV was negative by in situ hybridization. RT-PCR was used to detect the nucleic acid of 2019-nCoV. One of 10 cases was positive, 39 years old,who was the youngest patient in this group, and the other 9 cases were negative. Coronavirus particles were found in the cytoplasm of macrophage under electron microscope in 2 cases. Conclusions: The death of COVID-19 occurs mainly in the elderly, and some cases have no underlying diseases. Spleen may be one of the organs directly attacked by the virus in some patients who died from COVID-19. T and B lymphocyte in the spleen decrease in varying degrees, lymphoid follicles are atrophied, decreased or absent, and the number of NK cells do not change significantly. And the pathological changes of the spleen are not related to the use of low dose corticosteroid, which may be related to the direct attack of virus and the attack of immune system on its own tissues.

[Pathological changes of fatal coronavirus disease 2019 (COVID-19) in the lungs: report of 10 cases by postmortem needle autopsy].

Objectives: To observe the pulmonary changes with coronavirus disease 2019 (COVID-19) in postmortem needle specimens, to detect the presence of 2019 novel coronavirus(2019-nCoV) in the lung tissues, and to analyze the clinicopathological characteristics. Methods: For 10 decedents with 2019-nCoV infection in Wuhan, bilateral lungs underwent ultrasound-guided percutaneous multi-point puncture autopsy, and pulmonary pathological changes were described in routine hematoxylin-eosin staining (HE) slides. Electron microscopy was also performed. The reverse transcription polymerase chain reaction (RT-PCR) was employed to detect 2019-nCoV nucleic acid in lung tissue, and the pathological characteristics were demonstrated in combination with clinical data analysis. Results: Of the 10 deaths associated with COVID-19, 7 were male and 3 were female. The average age was 70 (39-87) years. Medical record showed that 7 patients had underlying diseases. The average course of disease was 30 (16-36) days. Nine cases showed fibrinous and suppurative exudation in the alveolar cavity accompanied by the formation of hyaline membrane, and fibroblastic proliferation of alveolar septum. Type Ⅱ alveolar epithelial cells showed reactive hyperplasia and desquamation. Many macrophages accumulated in the alveolar cavity. Capillary hyaline thrombus and intravascular mixed thrombus were noted. In some cases, acute bronchiolitis with mucous membrane exfoliation, accumulation of bronchiolar secretions, and bronchiolar epithelial metaplasia occurred. In the cohort, a large number of bacteria (cocci) were detected in 1 case and a large number of fungi (yeast type) were detected in 1 case. Nine cases were positive for the nucleic acids of 2019-nCoV while one case remained negative by RT-PCR. Coronavirus particles were detected in the cytoplasm of type Ⅱ alveolar epithelium. Conclusions: The pulmonary pathological changes of fatal COVID-19 are diffuse alveolar damage (DAD), mainly in the acute exudative stage and the organic proliferative stage. There are fibrinous exudate aggregation in alveolar cavity with hyaline membrane formation, fibroblastic proliferation in alveolar septum, and alveolar epithelial cell injuries with reactive hyperplasia and desquamation of type Ⅱ alveolar epithelial cells. A large amount of neutrophils and monocytes infiltration is present in most cases and bacteria and fungi are detected in some cases, suggesting a serious bacterial or fungal infection secondary to the DAD.