自噬在急性肾损伤中的作用研究进展

一、自噬的概述1.自噬现象的发现1955年,科学家De Duve发现了溶酶体和过氧化物酶体[1]。1963年,De Duve在电子显微镜下研究溶酶体的结构时在细胞内无意中发现了一种包含有降解的细胞器及溶酶体酶的双层膜结构,后将这种现象命名为"自噬",顾名思义"自食"[2]。在进一步的研究中,他发现了溶酶体参与了自噬体降解胞内物质的过程。2.自噬的分类及功能在过去几十年的研究中,自噬现象被证明广泛存在于真核细胞的生理及病理过程中。自噬可以分为巨自噬、微自噬以及

线粒体Surtuin3在急性肾损伤中的作用研究进展

Sirtuin3(SIRT3)是一种位于线粒体中依赖NAD~+的组蛋白去乙酰化酶,是sirtuin家族中的一员,其主要功能是对线粒体的结构及功能进行调节。在各种原因导致的急性肾损伤(AKI)的发生发展过程中,肾小管上皮细胞线粒体的结构及功能变化起到非常关键的作用。近年研究发现,SIRT3是通过维持线粒体功能和结构的稳定性在肾小管上皮细胞损伤中发挥保护作用,从而缓解AKI。充分了解SIRT3

控制沙尘暴的植被快速建设技术途径研究——以库布齐沙漠东缘为例

本文根据恢复生态学和景观生态学的基本原理,遵循自然规律和经济规律,依据当地生态条件和地表流沙分布状况,从水土资源优化配置角度出发,结合沙地植物自然分布的趋水性特征,采取以封育措施为主,因地制宜适度造林种草育藻,构建了一种创新的乔灌草藻四为一体的综合快速复合治沙模式,初步实现了脆弱生态系统趋于稳定,生物多样性明显增加,沙尘暴危害被有效遏制的目标

补体活化异常在IgA肾病致病机制中的研究进展

IgA肾病是世界上最常见的原发性肾小球疾病,近几十年来IgA肾病的发病率迅速增加,其起病隐匿,临床表现多样,但确切发病机制尚不清楚,目前认为IgA肾病的可能机制为糖基化缺陷的IgA1增多,与抗聚糖抗体结合为免疫复合物沉积于肾小球系膜区,进而激活补体途径,导致免疫炎症反应。补体激活的替代途径、凝集素途径、补体成分以及补体调节蛋白在IgA肾病的发病及进展过程中发挥重要作用。近年来,国内外关于补体系统与IgA肾

Dynamically reinforced heterogeneous grain structure prolongs ductility in a medium-entropy alloy with gigapascal yield strength

Ductility, i. e., uniform strain achievable in uniaxial tension, diminishes for materials with very high yield strength. Even for the CrCoNi medium-entropy alloy (MEA), which has a simple facecentered cubic (FCC) structure that would bode well for high ductility, the fine grains processed to achieve gigapascal strength exhaust the strain hardening ability such that, after yielding, the uniform tensile strain is as low as similar to 2%. Here we purposely deploy, in this MEA, a three-level heterogeneous grain structure (HGS) with grain sizes spanning the nanometer to micrometer range, imparting a high yield strength well in excess of 1 GPa. This heterogeneity results from this alloy's low stacking fault energy, which facilitates corner twins in recrystallization and stores deformation twins and stacking faults during tensile straining. After yielding, the elastoplastic transition through load transfer and strain partitioning among grains of different sizes leads to an upturn of the strain hardening rate, and, upon further tensile straining at room temperature, corner twins evolve into nanograins. This dynamically reinforced HGS leads to a sustainable strain hardening rate, a record-wide hysteresis loop in load-unload-reload stress-strain curve and hence high back stresses, and, consequently, a uniform tensile strain of 22%. As such, this HGS achieves, in a singlephase FCC alloy, a strength-ductility combination that would normally require heterogeneous microstructures such as in dual-phase steels