Risk diffusion of international oil trade cuts: A network-based dynamics model

International trade relations between countries have enabled the integration of global oil trade while also creating a platform for the risk diffusion of oil supply cuts. The global energy supply shortages sparked by the Covid-19 pandemic has made the problem even more pronounced. This study develops a network-based dynamics model based on the modified bootstrap percolation theory to simulate the cascading diffusion of oil supply shortages. We assess the destructive effects of exporting countries’ cuts in oil exports on global oil trade relations and the vulnerability of importing countries when they encounter oil supply shortages. The cascading diffusion of oil supply breakdown occurs less frequently from 2015 to 2019, proving that the entire network’s antirisk capacity strengthens over time. The coronavirus pandemic has impaired the robustness of the oil trade network in 2020. OPEC’s export influence has continued to decline in recent years. The diversified evolution of the oil supply is conducive to the stability of the oil trade economy. This paper analyzes the risk propagation mechanism in the global oil trade and conducts a case study. The results have a specific early warning effect on regional oil supply risks.

Assessing word-of-mouth reputation of influencers on B2C live streaming platforms: the role of the characteristics of information source

Purpose>The purpose of this paper is to assess the influence mechanism of the word-of-mouth reputation of influencers.Design/methodology/approach>This study explored word-of-mouth reputation from four characteristics of information source of influencers: credibility, professionalism, interactivity and attractiveness. The grounded theory was used to extract the characteristic indicators of influencers and used questionnaire surveys to obtain 218 valid samples. The fuzzy-set qualitative comparative analysis (fsQCA) was used for the configuration analysis.Findings>The results revealed the following: (1) a causal asymmetric correlation exists between the driving mechanism of high word-of-mouth reputation and non-high word-of-mouth reputation;(2) influencers matching high word-of-mouth reputation comprises potential, developmental and almighty types, whereas live streaming influencer matching non-high word-of-mouth reputation comprises elementary and groping types;and (3) all factors must be combined to play a role, and neutral permutations of two solutions were found among the three overall solutions to attain high word-of-mouth reputation;(4) the combination of high user activity and high exposure is the core configuration that results in high word-of-mouth reputation.Practical implications>This study provides recommendation for consumers, live streamers, brand and e-commerce platform on how to promote the sustainable and healthy development of influencer marketing.Originality/value>This study focused on elucidating how the characteristics of information source affect the word-of-mouth reputation of influencers and have a reference value for the research on word-of-mouth reputation in the context of live commerce.

Ligand/Receptor-mediated Cell Communication Alteration Causes the Lung Inflammation Microenvironment and the Redistribution of Inter-tissue Immune Cells in COVID-19 Patients (preprint)

How SARS-CoV-2 causes disturbances of the lung microenvironment and systemic immune response remains a mystery. Here, we first analyze detailedly paired single-cell transcriptome data of the lungs, blood and bone marrow of two patients who died of COVID-19. Second, our results demonstrate that SARS-CoV-2 infection significantly increases the cellular communication frequency between AT1/AT2 cells and highly inflammatory myeloid cells, and induces the pulmonary inflammation microenvironment, and drives the disorder of fibroblasts, club and ciliated cells, thereby causing the increase of pulmonary fibrosis and mucus accumulation. Third, our works reveal that the increase of the lung T cell infiltration is mainly recruited by myeloid cells through certain ligands/receptors (ANXA1/FPR1, C5AR1/RPS19 and CCL5/CCR1), rather than AT1/AT2. Fourth, we find that some ligands and receptors such as ANXA1/FPR1, CD74/COPA, CXCLs/CXCRs, ALOX5/ALOX5AP, CCL5/CCR1, are significantly activated and shared among patients’ lungs, blood and bone marrow, implying that dysregulated ligands and receptors may cause the migration, redistribution and the inflammatory storm of immune cells in different tissues. Overall, our study reveals a latent mechanism by which the disorders of ligands and receptors caused by SARS-CoV-2 infection drive cell communication alteration, the pulmonary inflammatory microenvironment and systemic immune responses across tissues in COVID-19 patients.

Sex-based clinical and immunological differences in COVID-19 (preprint)

Background Males and females differ in their immunological responses to foreign pathogens. However, most of the current COVID-19 clinical practices and trials do not take sex as consideration.Methods We performed an unbiased sex-based comparative analysis for the clinical outcomes, peripheral immune cells, and SARS-CoV-2 specific antibody levels of 1,558 males and 1,499 females COVID-19 patients from a single center. The lymphocyte subgroups were measured by Flow cytometry. Total antibody, Spike protein (S)-, receptor binding domain (RBD)-, and nucleoprotein (N)- specific IgM and IgG levels were measured by chemiluminescence.Results We found that the mortality and ICU admission rates were approximately 2-fold higher in males than that in females (P < 0.005). Survival analysis revealed that sex is an independent prognostic factor for COVID-19 (Hazard ratio = 2.2, P = 0.003). The concentration of inflammatory factors in peripheral blood was significantly higher in males. Besides, the renal and hepatic abnormality induced by COVID-19 was more common in males during the hospitalization. The analysis of lymphocyte subsets revealed that the percentage of CD19 + B cell and CD4 + T cell was significantly higher in females (P < 0.001) during hospitalization, indicating the stronger humoral immunity in females than males. Notably, the protective RBD-specific IgG against SARS-CoV-2 sharply increased and reached a peak in the fourth week after symptom onset in females, while gradually increased and reached a peak in the seventh week in males.Conclusions The unfavorable prognosis of male COVID-19 patients may result from the weak humoral immunity and indolent antibody responses during SARS-CoV-2 infection and recovery. Early medical intervention and close monitoring are important, especially for male COVID-19 patients. Convalescent plasma therapy may help improve the immunity of males to fight against SARS-CoV-2 infection.

Sex-based clinical and immunological differences in COVID-19 (preprint)

Abstract Background: Males and females differ in their immunological responses to foreign pathogens. However, most of the current COVID-19 clinical practices and trials do not take sex as consideration. Methods: We performed an unbiased sex-based comparative analysis for the clinical outcomes, peripheral immune cells, and SARS-CoV-2 specific antibody levels of 1,558 males and 1,499 females COVID-19 patients from a single center. The lymphocyte subgroups were measured by Flow cytometry. Total antibody, Spike protein (S)-, receptor binding domain (RBD)-, and nucleoprotein (N)- specific IgM and IgG levels were measured by chemiluminescence. Results: We found that the mortality and ICU admission rates were approximately 2-fold higher in males than that in females (P<0.005). Survival analysis revealed that sex is an independent prognostic factor for COVID-19 (Hazard ratio=2.2, P=0.003). The concentration of inflammatory factors in peripheral blood was significantly higher in males. Besides, the renal and hepatic abnormality induced by COVID-19 was more common in males during the hospitalization. The analysis of lymphocyte subsets revealed that the percentage of CD19+ B cell and CD4+ T cell was significantly higher in females (P<0.001) during hospitalization, indicating the stronger humoral immunity in females than males. Notably, the protective IgG sharply increased and reached a peak in the fourth week after symptom onset in females, while gradually increased and reached a peak in the seventh week in males. Conclusions: The unfavorable prognosis of male COVID-19 patients may result from the weak humoral immunity and indolent antibody responses during SARS-CoV-2 infection and recovery. Early medical intervention and close monitoring are important, especially for male COVID-19 patients. Hormonal or convalescent plasma therapy may help improve the immunity of males to fight against SARS-CoV-2 infection.

Clinical Characteristics and Risk Factors of Fatal Patients with COVID-19: a Retrospective Cohort Study in Wuhan, China (preprint)

Background The coronavirus disease 2019 (COVID-19) has caused global pandemic, resulting in considerable mortality. The risk factors, clinical treatments and especially comprehensive risk models for COVID-19 death are urgently warranted.Methods In this retrospective study, 281 non-survivors and 712 survivors with propensity score matching by age, sex and comorbidities were enrolled from January 13, 2020 to March 31, 2020.Results Higher SOFA, qSOFA, APACHE II and SIRS scores, hypoxia, elevated inflammatory cytokines, multi-organ dysfunction, decreased immune cells subsets and complications were significantly associated with the higher COVID-19 death risk. In addition to traditional predictors for death risk, including APACHE II (AUC = 0.83), SIRS (AUC = 0.75), SOFA (AUC = 0.70) and qSOFA scores (AUC = 0.61), another four prediction models that included immune cells subsets (AUC = 0.90), multiple organ damage biomarkers (AUC = 0.89), complications (AUC = 0.88) and inflammatory-related indexes (AUC = 0.75) were established. Additionally, the predictive accuracy of combining these risk factors (AUC = 0.950) was also significantly higher than that of each risk group alone, outperforming previous risk models, which was significant for early clinical management for COVID-19.Conclusions The potential risk factors could help to predict the clinical prognosis of COVID-19 patients at an early stage. The combined model might be more suitable for the death risk evaluation of COVID-19.

Risk factors related to acute respiratory distress syndrome and death in patients with COVID-19: a retrospective cohort study in Wuhan, China (preprint)

Background:The COVID-19 pandemic has been considered a great threat to global public health. We aimed to clarify the risk factors associated with the development of acute respiratory distress syndrome (ARDS) and progression from ARDS to death and construct a risk prediction model.Methods:In this single-centered, retrospective, and observational study, 796 COVID-19 patients developed ARDS and 735 COVID-19 patients without ARDS were matched by propensity score at an approximate ratio of 1:1 based on age, sex and comorbidities. Demographic data, symptoms, radiological findings, laboratory examinations, and clinical outcomes were compared between those with or without ARDS. Univariable and multivariable logistic regression models were applied to explore the risk factors for development of ARDS and progression from ARDS to death and establish a comprehensive risk model. Results:Higher SOFA, qSOFA, APACHE II and SIRS scores, elevated inflammatory cytokines, dysregulated multi-organ damage biomarkers, decreased immune cell subsets were associated with higher proportion of death (34.17% vs 1.22%; P<0.001) and increased risk odds of death (OR=57.216, 95%CI=28.373-115.378; P<0.001) in COVID-19 patients with ARDS. In addition to previous reported risk factors related to ARDS development and death, such as neutrophils, IL-6, D-Dimer, leukocytes and platelet, we identified elevated TNF-α (OR=1.146, 95%CI=1.100-1.194; P<0.001), CK-MB (OR=1.350, 95%CI=1.180-1.545; P<0.001), declined ALB (OR=0.834, 95%CI=0.799-0.872; P<0.001), CD8+ T cells (OR=0.983, 95%CI=0.976-0.990; P<0.001) and CD3-CD19+ B cells (OR=0.992, 95%CI=0.988-0.997; P=0.003) as novel risk factors. Most importantly, the predictive accuracy of the combined model integrating four score systems and these risk factors demonstrated highest among all models for the development of ARDS (AUC= 0.904) and the progression from ARDS to death (AUC= 0.959).Conclusion:COVID-19 patients with ARDS were more likely to develop into death. The potential risk factors and the comprehensive prediction model could be helpful to identify patients that are at risk of developing ARDS with poor prognosis at an early stage, which might help physicians to formulate a timely therapeutic strategy.

The Dynamic Changes of Antibodies against SARS-CoV-2 during the Infection and Recovery of COVID-19 (preprint)

Deciphering the dynamic changes of antibodies against SARS-CoV-2 is essential for understanding the immune response in COVID-19 patients. By comprehensively analyzing the laboratory findings of 1,850 patients, we describe the dynamic changes of the total antibody, spike protein (S)-, receptor-binding domain (RBD)-, and nucleoprotein (N)- specific IgM and IgG levels during SARS-CoV-2 infection and recovery. Our results indicate that the S-, RBD-, and N- specific IgG generation of severe/critical COVID-19 patients is one week later than mild/moderate cases, while the levels of these antibodies are 1.5-fold higher in severe/critical patients during hospitalization (P<0.01). The decrease of these IgG levels indicates the poor outcome of severe/critical patients. The RBD- and S-specific IgG levels are 2-fold higher in virus-free patients (P<0.05). Notably, we found that the patients who got re-infected had a low level of protective antibody on discharge. Therefore, our evidence proves that the dynamic changes of antibodies could provide an important reference for diagnosis, monitoring, and treatment, and shed new light on the precise management of COVID-19.

Lymphopenia acted as an adverse factor for severity in patients with COVID-19: a single-centered, retrospective study (preprint)

Purpose: The outbreak of SARS-CoV-2 began in December and rapidly caused a pandemic. To investigate the significance of lymphopenia for the severity of the disease, this study was performed.Methods: 115 patients confirmed COVID-19 from a tertiary hospital in Changsha, China were enrolled. The clinical, laboratory, treatment and outcome data were collected and compared between patients with lymphopenia or not.Results: The median age was 42 years (1-75). 54 patients (47.0%) of the patients had lymphopenia on admission. In the group of lymphopenia, more patients had hypertension (30.8% vs 10.0%, P=0.006) and coronary heart disease (3.6% vs 0%, P=0.029) and more patients with leucopenia (48.1% vs 14.8%, P<0.001) and eosinophilia (92.6% vs 54.1%, P<0.001) were observed. Lymphopenia was also correlated with severity grades of pneumonia (P<0.001) and C-reactive protein (CRP) level (P=0.0014). Lymphopenia was associated with a prolonged duration of hospitalization (17.0 days vs 14.0 days, P=0.002). Moreover, the recovery of lymphocyte appeared the earliest before CRP and chest radiographs in severe cases, suggesting its predictive value for disease improvement. Conclusion: Our results showed the clinical significance of lymphopenia for predicting the severity of COVID-19 and the recovery of the disease, emphasizing the need to monitor the lymphocyte count dynamically.

Elevated serum IgM levels indicate poor outcome in patients with coronavirus disease 2019 pneumonia: A retrospective case-control study (preprint)

Background: The coronavirus disease 2019 (COVID-19) pneumonia outbreak began in Wuhan and pandemics tend to occur. Although SARS-CoV-2-specific immunoglobulins have been detected in serum of COVID-19 patients, their dynamics and association with outcomes have not been characterized. Methods: A total of 116 hospitalized patients with confirmed COVID-19 pneumonia and SARS-CoV-2-specific immunoglobulins tested in Tongji hospital were retrospectively investigated. Clinical, laboratory, radiological characteristics and outcomes data were compared between mild-moderate group and died group. Further, a paired case-control study was conducted where each deceased case was matched to three mild-moderate patients of similar age. Findings: Among 116 subjects included, 101 mild-moderate patients survived and 15 cases died. SARS-CoV-2-specific IgM levels peaked in forth week after onset of COVID-19 pneumonia, while serum IgG levels increased over 8 weeks. Serum IgM levels were higher in deceased patients than mild-moderate patients (P = 0.024), but not IgG. Serum IgM levels were negatively correlated with clinical outcome, eosinophil count and albumin levels (r = -0.269, P = 0.003; r = -0.188, P = 0.043; and r = -0.198, P = 0.033, resp.). The area under the ROC curve (AUC) for IgM antibody was 0.681 (95% CI: 0.517-0.845, P = 0.024). In case-control study paired by age, serum IgM was higher in deceased patients than mild-moderate patients (P = 0.019), positively correlated with leucocyte count (r = 0.260, P = 0.045), while negatively correlated with clinical outcome and albumin levels (r = -0.337, P = 0.008; r = -0.265, P = 0.041). AUC for IgM levels was 0.704 (95% CI: 0.534-0.873, P = 0.019). Interpretation: These results indicate that dynamics of SARS-CoV-2 specific IgM and IgG antibodies was similar with that of SARS-CoV, while elevated serum IgM levels indicate poor outcome in patients with COVID-19 pneumonia.