Search

Noroviruses are leading cause of acute gastroenteritis worldwide. In our previous study, we established an in vitro histo-blood group antigens (HBGAs) binding blockade assay against GII.3 Norovirus virus like particles (VLPs) with trypsin digestion. In this study, we characterized the blocking antibody binding site and epitope type (linear or conformational) by using hyperimmune sera produced against different antigens. VP1 from Jingzhou402 (GII.3, JZ402) strain was expressed by using pGEX-6p-1 expression vector and the insoluble proteins were purified for immunization in rabbit. Previously characterized chimeric VP1-assembled VLPs (GII.4-VP1/GII.3-P2) were used to immunize guinea pig. Peptides reactive with hyperimmune serum against VLPs derived from the VP1 of JZ402 strain were conjugated with BSA and used to immunize rabbits. Hyperimmune sera against above antigens and JZ402 and JZ403 strain-derived VLPs were used to compare their HBGAs blocking effects. Rabbit anti-GST-VP1 and BSA-peptide conjugated hyperimmune sera demonstrated no blocking effects against the binding of GII.3 and GII.4 NoV VLPs to salivary HBGAs. Guinea pig anti-GII.4-VP1/GII.3-P2 hyperimmune serum blocked the binding of trypsin cleaved GII.3 VLPs to salivary HBGAs with no or very weak blocking effects against the binding of GII.4 VLPs to salivary HBGAs. Our data indicated that HBGAs blocking antibodies primarily bound the P2 domain of GII.3 NoV VP1 and their binding epitopes were most probably conformation-dependent.

Aims Endothelial barrier dysfunction is associated with multiple diseases, and barrier repair may be a possible therapeutic target. Yes-associated protein and its pathway have been implicated in organ repair after injury. However, the mechanisms underlying barrier repair and any role YAP plays in the process are unclear. This study aimed to explore the role and mechanism of YAP in the repair of endothelial cell permeability after TNF-α-induced injury. Main methods A trans-endothelial electrical resistance assay was performed to investigate changes in endothelial cell permeability. Lentivirus packaging by calcium phosphate transfection was used to construct endothelial cell lines with knocked down or overexpressed YAP. Western blotting, immunofluorescence, CO-IP, and real-time PCR were used to detect related protein and gene expression. Key findings YAP is involved in the repair process of TNF-α-induced endothelial cell permeability injury; its overexpression promotes repair of endothelial cell permeability, and knockdown weakens repair ability. Moreover, YAP may promote repair by down-regulating STAT3 activity, thereby inhibiting VEGF expression. Significance Elucidating the role of YAP in endothelial cell permeability repair process after injury might reveal mechanisms of endothelial barrier repair and provide therapeutic targets for treatment of vascular hyper-permeability disease.

The splitter, a steady component in the downstream of fan blades in the turbo-fan engine, will be exposed to an icing environment when the engine is working in icing conditions. An anti-icing system should be used on the splitter in order to make the engine work well and not be affected by icing. In this study, both of experiments and CFD simulations were applied to acquire icing characteristics and the electronic anti-icing system’ energy requirement for this component. Factors of icing conditions varied from attacking angle, ambient temperature and pressure, air velocity and droplet factors. Experiments were performed in the AVIC Aerodynamics Research Institute Icing Wind Tunnel (FL-61). The test component was a combination of an arc segment of splitter and seven pieces of inlet guide vanes, covered by electrical heating film. The experiment was carried out under different icing conditions in the icing wind tunnel. Ice profiles, the results of icing experiment, were collected by 3D scanner. Anti-icing surface temperature profiles were collected by thermocouples. The CFD results of icing process were compared with the experimental data for validation, and showed that the droplet collection of on the lower surface of splitter was significant. The CFD simulation was established on the two-phase flow analysis conducted by ANSYS-CFX and Fensap-ice for the prediction on ice accretion, and a coupled simulation method was introduced to replace the conjugate simulation method for thermal analysis with a higher working efficiency in engineering design. Through the icing simulation, an estimated external boundary condition was applied on the thermal model of the test piece and the temperature field on the test piece was calculated.

The present paper proposes two weighted goal-programming models for optimizing crude oil production in the middle and later periods of oilfield development. These models divide the oil yield optimization problem into two stages according to the characteristics of Chinese oil companies’ yield compositions. In the first stage, the total planned crude oil yield will be optimized by four sub-yields, while each sub-yield will be allocated optimally among different oil extract plants in the later stage. A case study is conducted to validate the proposed models. The results show that the model can address the annual crude oil yield planning subjectively. Moreover, the proposed model can rationally allocate resources among various extract oil plants and effectively reduce production costs in the context of ensuring planned oil yields.

This paper addresses the peak shaving of West-East Gas Pipeline. For a gas pipeline system, the decision-making on the peak shaving scenarios usually involves a delicate balance between low operation cost and high gas supply reliability. In order to select an acceptable peak shaving scenario from these two angles for West-East Gas Pipeline, the idea of multi-objective decision-making has been introduced. Based on design flow-rate, eight typical peak shaving scenarios have been evaluated, analyzed and optimized with the help of TGNET. During the simulation, in order to make the peak shaving process more approach to the actual operation of the pipeline system, 51 days of forecasted data are used to establish the system starting state for the study period. On the other hand, in order to reduce the effect of different peak shaving process to the subsequent operation, the study period is extended by 7 days to fully account for operating costs and conditions subsequent to the study period, which make different peak shaving scenarios comparable. According to multi-objective optimization criteria including operation cost, gas supply reliability and operation stability, different pareto peak shaving scenarios have been obtained. These scenarios show that from the object of minimizing operation cost, inlet pressure of Shanghai terminal should approach to contractual pressure, from the object of gas supply reliability and operation stability, inlet pressure of Shanghai terminal should maintain a higher value. Operators can adopt different peak shaving scenarios according to different optimization object. Furthermore, with mathematical statistics knowledge, control value of inlet pressure of Shanghai terminal is recommended. When the change of withdrawal flow-rate from underground gas storage is more frequent, the fluctuation of inlet flow-rate is smaller. When withdrawal flow-rate from underground natural gas storage increases, it will not only increase the inventory of whole pipeline and end segment, but also decrease the inlet flow-rate.Copyright © 2008 by ASME