天然生物质材料的制备、性质与应用(Ⅷ)——高黏多用的天然半乳甘露聚糖胶:瓜尔胶

瓜尔胶是从瓜尔豆种子胚乳中提取的一种天然半乳甘露聚糖胶。因瓜尔胶具有良好的水溶性、增稠性、胶凝性、成膜性等性质以及天然无毒、生物相容性良好、可生物降解的天然属性,且利用其分子结构中的羟基、糖苷键等活性官能团进行分子修饰、化学交联、接枝共聚、氧化等改性手段处理后能显著改善其理化性质、增强其功效性能,使得瓜尔胶及其改性产物被广泛应用于日用化工、造纸、食品加工、石油开采、生物医药、水处理等多个行业领域。本文浅述了瓜尔胶的名称、来源和结构及其性质、提取工艺和改性方法,同时介绍了瓜尔胶及其改性产物的应用情况,并提及了瓜尔胶及其改性产物当前面临的问题和今后的研发方向。

天然生物质材料的制备、性质与应用(Ⅶ)——支链异构阴离子多糖胶:黄芪胶

黄芪胶是从天然草本植物黄芪中提取的一种多糖类物质,因具有化学稳定性、非致畸性、非免疫原性、生物可降解性、生物相容性和天然无毒等特性,且利用其分子结构中的羟基、羧基、糖苷键等活性官能基团进行分子修饰、化学交联、接枝共聚等改性处理能明显改善其理化性质、增强其功能效用,使得黄芪胶及其改性产物在医药领域、食品加工、水处理、医用材料、日用化学品领域得到广泛应用。本文浅述了黄芪胶的来源、组成和结构,主要理化性质和功能作用,以及提取纯化技术和应用进展情况,并提及了黄芪胶及其改产物当前研究开发所面临的问题和发展趋势。

Moisture‑Electric–Moisture‑Sensitive Heterostructure Triggered Proton Hopping for Quality‑Enhancing Moist‑Electric Generator

Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal expression.However,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information representation.Here,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any attenuation.Our research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design.

Spatial correlation-based characterization of acoustic emission signal-cloud in a granite sample by a cube clustering approach

To extract more in-depth information of acoustic emission(AE)signal-cloud in rock failure under triaxial compression,the spatial correlation of scattering AE events in a granite sample is effectively described by the cube-cluster model.First,the complete connection of the fracture network is regarded as a critical state.Then,according to the Hoshen-Kopelman(HK)algorithm,the real-time estimation of fracture con-nection is effectively made and a dichotomy between cube size and pore fraction is suggested to solve such a challenge of the one-to-one match between complete connection and cluster size.After,the 3D cube clusters are decomposed into orthogonal layer clusters,which are then transformed into the ellip-soid models.Correspondingly,the anisotropy evolution of fracture network could be visualized by three orthogonal ellipsoids and quantitatively described by aspect ratio.Besides,the other three quantities of centroid axis length,porosity,and fracture angle are analyzed to evaluate the evolution of cube cluster.The result shows the sample dilatancy is strongly correlated to four quantities of aspect ratio,centroid axis length,and porosity as well as fracture angle.Besides,the cube cluster model shows a potential pos-sibility to predict the evolution of fracture angle.So,the cube cluster model provides an in-depth view of spatial correlation to describe the AE signal-cloud.

间充质干细胞源性外泌体对子痫前期滋养层细胞生物学行为影响的研究进展

子痫前期(PE)是一种严重影响孕产妇围产结局的妊娠中晚期特有并发症,其具体发病机制至今仍不明确,且目前尚无有效的治疗手段。外泌体作为间充质干细胞(MSCs)旁分泌作用的主要方式,在细胞间的信息交流中扮演重要角色,同时发现外泌体内携带的如微小RNA (miRNA)等小分子物质参与靶向细胞的多种生理病理过程。近年来相关研究发现不同来源MSCs的外泌体能够通过改善滋养层细胞功能为治疗PE患者提供潜在的治疗手段。随着研究的不断深入,不同来源MSCs及其外泌体将在PE患者的靶向药物治疗方面发挥巨大的潜力,可降低PE患者不良围产结局发生率及保障围产期母婴安全。本文将通过阐述不同来源MSCs的基本特点,分析其外泌体在PE滋养层细胞中的治疗作用,为临床治疗PE患者提供新的视角和思路。

青岛某医院穿透性角膜移植手术原因

目的:分析过去10余年穿透性角膜移植术(PKP)的手术原因及变化情况。方法:回顾性系列病例研究。收集2013年1月至2017年12月在青岛眼科医院接受PKP的所有患者的病历资料,并与2005-2010年在青岛眼科医院接受PKP患者的资料进行比较,分析其年龄、性别和接受PKP相关的临床诊断等资料。采用卡方检验对2个时间段的PKP的手术原因进行统计分析。结果:2013-2017年间,共行PKP855例,前4位的手术原因依次为化脓性角膜炎303例(35.4%)、再次角膜移植132例(15.4%)、圆锥角膜130例(15.2%)和病毒性角膜炎115例(13.5%)。2005-2010年间,共行PKP875例,前4位手术原因依次为化脓性角膜炎、病毒性角膜炎、圆锥角膜和大泡性角膜病变。2个时间段内,PKP的主要手术原因均为化脓性角膜炎,其所占比例无明显变化(χ^2=0.543,P=0.461)。再次角膜移植的比例增加,成为青岛眼科医院2013-2017年间PKP第2位的手术原因(χ^2=33.294,P<0.001)。圆锥角膜始终居于PKP手术原因的第3位,但2013-2017年间PKP手术原因中所占比例较2005-2010年增加(χ^2=6.061,P=0.014)。病毒性角膜炎的比例下降,从2005-2010年的第2位下降到2013-2017年第4位的手术原因(χ^2=6.397,P=0.011)。结论:化脓性角膜炎是2013-2017年青岛眼科医院PKP的首位手术原因,然后依次为再次角膜移植、圆锥角膜和病毒性角膜炎。与2005-2010年相比,2013-2017年青岛眼科医院因再次角膜移植与圆锥角膜行PKP的比例上升,而病毒性角膜炎的比例下降。