T cell regulation in microgravity – The current knowledge from in vitro experiments conducted in space,parabolic flights and ground-based facilities

Dating back to the Apollo and Skylab missions, it has been reported that astronauts suffered from bacterial and viral infections during space flight or after returning to Earth. Blood analyses revealed strongly reduced capability of human lymphocytes to become active upon mitogenic stimulation. Since then, a large number of in vitro studies on human immune cells have been conducted in space, in parabolic flights, and in ground-based facilities. It became obvious that microgravity affects cell morphology and important cellular functions. Observed changes include cell proliferation, the cytoskeleton, signal transduction and gene expression. This review gives an overview of the current knowledge of T cell regulation under altered gravity conditions obtained by in vitro studies with special emphasis on the cell culture conditions used. We propose that future in vitro experiments should follow rigorous standardized cell culture conditions, which allows better comparison of the results obtained in different flight- and ground-based experiment platforms.     

盐酸清洗缓蚀剂的研究进展

本文介绍了我国九十年代盐酸酸洗缓蚀剂的研究现状。盐酸酸洗缓蚀剂研究的重点是开发新型的高效、低毒、低成本缓蚀剂，并充分利用工业生产的副产品进行深加工，或利用天然植物进行加工、改性制备缓蚀剂，扩展原材料的来源。     

Thermal Polymerization of Cyanate Ester-Benzoxazine：Study of a Functional Model Compound

A novel benzoxazine (BOZ) monomer is synthesized by a pot method with solvent-free to blend with cyanate ester (CE). A soluble intermediate is obtained after being cured for 20 h at 80 ℃. The two model compound and the blends are analyzed with the infrared radiation (IR)， nuclear magnetic resonance (NMR) spectroscopy， and differential scanning calorimetry (DSC). The results show that an intermediate of the iminocarbonate and BOZ structures is formed by the ring-open BOZ reacting with the cyanate groups and ring-unopened BOZ. Moreover， rearrangement and ring-opening occur in the postcure of the intermediate to form the alkyl isocyanurate structure with polybenzoxazine.     

原子氧对碳纤维增强氰酸酯复合材料的侵蚀及机理研究

针对碳纤维增强氰酸酯复合材料(CFCE)开展原子氧暴露试验及反应产物原位测量的散射试验,并进行暴露前后的质量损失、SEM及XPS试验。结果表明,该材料的受原子氧腐蚀率为(2.20±0.36)×10~(-24)cm~3/atoms。受原子氧腐蚀后,样品表面C元素相对原子浓度增加,O元素基本不变;表面的树脂脱落,碳纤维暴露在原子氧环境中,表面出现蚀坑,且数量及形状逐渐变大,蚀坑相连,最终沿纤维方向形成一条沟壑。高能氧原子与复合材料发生反应,生成产物CO、CO_2、H_2O、OH和CH_3。