Recovery preparedness of global air transport influenced by COVID-19 pandemic: Policy intervention analysis.

The outbreak of COVID-19 constitutes an unprecedented disruption globally, in which risk management framework is on top priority in many countries. Travel restriction and home/office quarantine are some frequently utilized non-pharmaceutical interventions, which bring the worst crisis of airline industry compared with other transport modes. Therefore, the post-recovery of global air transport is extremely important, which is full of uncertainty but rare to be studied. The explicit/implicit interacted factors generate difficulties in drawing insights into the complicated relationship and policy intervention assessment. In this paper, a Causal Bayesian Network (CBN) is utilized for the modelling of the post-recovery behaviour, in which parameters are synthesized from expert knowledge, open-source information and interviews from travellers. The tendency of public policy in reaction to COVID-19 is analyzed, whilst sensitivity analysis and forward/backward belief propagation analysis are conducted. Results show the feasibility and scalability of this model. On condition that no effective health intervention method (vaccine, medicine) will be available soon, it is predicted that nearly 120 days from May 22, 2020, would be spent for the number of commercial flights to recover back to 58.52%-60.39% on different interventions. This intervention analysis framework is of high potential in the decision making of recovery preparedness and risk management for building the new normal of global air transport.

[The expression of nicotinamide phosphoribosyl transferase and vascular endothelial growth factor-A in gastric carcinoma and their clinical significance].

OBJECTIVES: To study the expression of nicotinamide phosphoribosyl transferase (Nampt) and vascular endothelial growth factor-A (VEGF-A) in gastric carcinoma and investigate their correlations to clinicopathologic features and prognostic significance. METHODS: The proteins of Nampt and VEGF-A in 68 specimens of gastric carcinoma and 59 specimens normal gastric tissue were detected by immunohistochemistry during January 2000 to December 2004, and the 68 patients were followed up. RESULTS: Nampt protein was detected in the cytoplasm of both tissues, and Nampt in gastric carcinoma (13 ± 5) were significantly higher than that in normal gastric tissue (6 ± 3) (t = 7.46, P < 0.01). The expression of Nampt was correlated to invasive depth (F = 4.693, P = 0.034), lymph node metastasis (F = 4.027, P = 0.049), clinical TNM stage (F = 9.979, P = 0.002), but not to gender, age, tumor location, tumor size, differentiation (P > 0.05). The expression of Nampt is correlated with survival of patients that underwent surgical resection for gastric cancer. The survival rate of patients in negative of Nampt was very higher than that of the positive patients, and its co-expression with VEGF-A showed a trend towards poorer survival. The positive correlation was found between the expression of Nampt and VEGF-A in gastric carcinoma (r = 0.293, P = 0.015). CONCLUSIONS: The expression of Nampt is positively correlated to that of VEGF-A in gastric carcinoma. The correlation between the expression of Nampt and VEGF-A in gastric carcinoma plays an important role cooperatively in carcinogenesis, development and metastasis of gastric carcinoma.

[Tissue culture of Vinca minor and determination of vincamine].

OBJECTIVE: To study tissue culture of Vinca minor and determine the content of vincamine. METHOD: Leaf blades, stalks, root segment of V. minor were used as explants to study the effect of 2, 4-D,6-BA,NAA on its callus induction and vincamine contents in the orthogonal design experiment. In the peak period of callus formation, vincamine content in callus of V. minor and sterile plants was determined by HPLC. The experimental data was statistically analyzed. RESULT: The content of 6-BA and NAA had no significant effect on its callus induction. But the content of 2, 4-D had significant effect on its callus induction. Within 20,40,60 d, the content of vincamine in sterile plant was (0.015 +/- 0.003)%, (0.097 +/- 0.001)% , (0.113 +/- 0.06)%, respectively. In the peak period of callus formation, vincamine content in callus of leaf blades, stalks, root segment was (0.024 +/- 0.0025)%, (0.016 +/- 0.0015)%, (0.010 +/- 0.0015)%, respectively. To 30 days of subculture, vincamine content in callus of leaf blades, stalks, root segment was (0.041 +/- 0.002)%, (0.019 +/- 0001)%, (0.016 +/- 0.002)%, respectively. CONCLUSION: The optimal hormone combination for callus initiation was MS +2, 4-D 1.0 mg x L(-1) +6-BA 0.5 mg x L(-1) + NAA 0.5 mg x L(-1). In different growth periods, vincamine content in sterile plants is significantly different. From different explants in callus vincamine content is different, in which leaves callus is significantly higher than that of stems, roots produced callus organization.