摘要：抗体(antibody)又称免疫球蛋白(immunoglobulin,Ig),是人体免疫反应的重要参与者.了解抗体的结构和结构动态特征,是理解人体免疫作用机理、修复或提高免疫能力、定向设计抗体以治疗各种疾病的基础.本文以人体IgG1抗体为对象,综述了使用透射电子显微学方法研究IgG1抗体结构方向的最新进展.详细介绍了使用逐个分子的电子断层三维重构技术(individual-particle electron tomography,IPET)对抗体进行结构研究的方法,包括样品制备、图像处理和数据分析等.并描述了利用该技术,在研究抗体结合肽分子后的结构形变和通过收集不同构象来研究抗体动态结构特征方面所取得的阶段性成果.最后,对尚待解决的关键问题与该技术未来的发展方向进行了讨论与展望.

摘要：A catalyst of ferroelectric-BaTiO_(3)@photoelectric-TiO_(2) nanohybrids(BaTiO_(3)@TiO_(2))with enhanced photocatalytic activity was synthesized via a hydrolysis precipitation combined with a hydrothermal *** to pure TiO_(2),pure BaTiO_(3) and BaTiO_(3)/TiO_(2) physical mixture,the heterostructured BaTiO_(3)@TiO_(2) exhibits significantly improved photocatalytic activity and cycling stability in decomposing Rhodamine B(RhB)and the degradation efficiency is 1.7 times higher than pure TiO_(2) and 7.2 times higher than pure BaTiO_(3).These results are mainly attributed to the synergy effect of photoelectric TiO_(2),ferroelectric-BaTiO_(3) and the rationally designed interfacial *** mesoporous microstructure of TiO_(2) is of a high specific area and enables excellent photocatalytic *** ferroelectric polarization induced built-in electric field in BaTiO_(3) nanoparticles,and the intimate interfacial interactions at the interface of BaTiO_(3) and TiO_(2) are effective in driving the separation and transport of photogenerated charge *** strategy will stimulate the design of heterostructured photocatalysts with outstanding photocatalytic performance via interface engineering.

摘要：人类心血管等疾病与胆固醇含量的高低有着十分密切的关系.人体内胆固醇主要通过血液中的脂蛋白来调节和运载.因此,新一代调节胆固醇的药物设计迫切地需要揭示脂蛋白分子结构与功能之间的关系.由于脂蛋白分子的成分高度复杂、结构特征灵活、尺寸微小,传统的蛋白质结构标定技术,如X射线衍射、核磁共振谱、质谱和冷冻电子显微镜等手段都面临着巨大的困难.针对这一问题,任罡小组最近提出一种优化的电镜负染制备方法,可以观测到单个脂蛋白分子的空间结构.此方法应用的成功,使得对单个脂蛋白分子的结构研究成为可能.同时也证明该负染色技术作为一种普遍的实验手段,可以用于对蛋白质小分子的结构研究,从而将促进新一代蛋白质分子药物的研发.