环境内分泌干扰物对雌激素受体表达与转录激活的调控效应及分析技术

环境内分泌干扰物(Endocrine disrupting chemicals, EDCs)种类繁多,来源复杂,环境污染普遍,对野生动物与人类造成了不同程度的暴露。EDCs可通过调控机体内分泌系统,干扰心血管、生殖、神经等多个系统的正常功能,从而引起机体代谢综合征、肥胖症、神经毒性、生殖发育毒性和癌症等的发生发展。污染物调控雌激素受体(Estrogen receptors, ERs)产生内分泌干扰效应是当前EDCs研究的主要方向。本文围绕ERs的基本生理特征、ERs表达与转录激活的分析检测技术,及EDCs调控不同组织来源ERs的生物学意义进行系统综述,以期从ERs激动/拮抗效应的角度,为新型化学品的内分泌干扰效应筛选及分子机制解析提供科学思路。     

Annealing induced microstructure and fracture resistance changes in isotactic polypropylene/ethylene‐octene copolymer blends with and without β‐phase nucleating agent

Previous work showed that annealing induced the great improvement of fracture resistance of β‐iPP, relating to the decreased number of chain segments in the amorphous region. To further prove the rationality of this observation, in this work, the ethylene‐octene copolymer (POE) toughened isotactic polypropylene (iPP) blends with or without β‐phase nucleating agent (β‐NA) were adopted and the changes of microstructure and fracture resistance during the annealing process were further investigated comparatively. The results showed that, whether for the α‐phase crystalline structure (non‐nucleated) or for the β‐phase crystalline structure (β‐NA nucleated) in iPP matrix, annealing can induce the dramatic improvement of fracture resistance at a certain annealing temperature (120–140 °C for β‐NA nucleated blends whereas 120–150 °C for non‐nucleated blends). Especially, non‐nucleated blends exhibit more apparent variations in fracture resistance compared with β‐NA nucleated blends during the annealing process. The phase morphology of elastomer, supermolecular structure of matrix, the crystalline structure including the degree of crystallinity and the relative content of β‐phase, and the relaxation of chain segments were investigated to explore the toughening mechanism of the samples after being annealed. It was proposed that, even if the content of elastomer is very few, the excellent fracture resistance can be easily achieved through adjusting the numbers of chain segments in the amorphous phase by annealing. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010     

β/α Transformation of β-polypropylene during tensile deformation: effect of crystalline morphology

In this work, the β/α transformation of β-nucleated iPP at different tensile strains has been analyzed. The crystalline morphology of iPP is controlled by the content of β-phase nucleating agent (β-NA), namely, well-developed β-spherulites induced by critical content of β-NA and bundle-like morphology without distinctly developed spherulites by supercritical content of β-NA. It is interesting to observe that the crystalline morphology of β-iPP exhibits great influence on the β/α transformation process during deformation. For well-developed β-spherulites, the content of β-iPP increases at relatively low tensile strain and then decreases gradually with the further increase of tensile strain. However, for bundle-like morphology, the content of β-iPP decreases monotonically with the increase of tensile strain. More important, well-developed β-spherulites, which have integrated crystalline structures, exhibit much smaller degree of β/α transformation as compared with bundle-like morphology at the same tensile strain, leading to more β-iPP maintaining and participating in the deformation process at high strain and consequently, resulting in better ductility. The results of this study further show the importance of crystalline morphology in determining the ductility of β-nucleated iPP on the one hand. On the other hand, this work provides the illuminating explanation for the reason why the well-developed β-spherulites exhibits more excellent ductility compared with the bundle-like morphology.     

Integrated separation of blood plasma from whole blood for microfluidic paper-based analytical devices

Many diagnostic tests in a conventional clinical laboratory are performed on blood plasma because changes in its composition often reflect the current status of pathological processes throughout the body. Recently, a significant research effort has been invested into the development of microfluidic paper-based analytical devices (μPADs) implementing these conventional laboratory tests for point-of-care diagnostics in resource-limited settings. This paper describes the use of red blood cell (RBC) agglutination for separating plasma from finger-prick volumes of whole blood directly in paper, and demonstrates the utility of this approach by integrating plasma separation and a colorimetric assay in a single μPAD. The μPAD was fabricated by printing its pattern onto chromatography paper with a solid ink (wax) printer and melting the ink to create hydrophobic barriers spanning through the entire thickness of the paper substrate. The μPAD was functionalized by spotting agglutinating antibodies onto the plasma separation zone in the center and the reagents of the colorimetric assay onto the test readout zones on the periphery of the device. To operate the μPAD, a drop of whole blood was placed directly onto the plasma separation zone of the device. RBCs in the whole blood sample agglutinated and remained in the central zone, while separated plasma wicked through the paper substrate into the test readout zones where analyte in plasma reacted with the reagents of the colorimetric assay to produce a visible color change. The color change was digitized with a portable scanner and converted to concentration values using a calibration curve. The purity and yield of separated plasma was sufficient for successful operation of the μPAD. This approach to plasma separation based on RBC agglutination will be particularly useful for designing fully integrated μPADs operating directly on small samples of whole blood.     

液氢贮箱零蒸发数值模拟与分析

采用CFD技术,对处于微重力下的零蒸发(ZBO)液氢贮箱内采用喷嘴棒强迫混合的流场进行稳态数值模拟,建立了二维轴对称模型,预测了在不同几何参数下贮箱内温度场及速度场分布情况。研究表明,喷嘴棒伸入贮箱长度、入口直径等因素均会对系统内温度场产生影响。贮箱内平均温度和最大温度随喷嘴棒长度和入口直径的增大而减小,而喷口直径对贮箱内温度场影响不明显。由上述可以看出,通过增大入口直径、选择合适的喷嘴棒伸入长度,可以改善系统性能。     

超声空化泡运动特性的研究进展

超声空化是一个极其复杂的物理现象,超声空化泡运动是影响超声空化效应的重要因素,研究超声空化泡的运动特性已受到学术界的极大重视。本文研究了近几年国内外学者基于超声作用下的空化泡运动特性的工作,从空化泡运动方程、数值模拟、实验研究等方面介绍了超声空化泡运动特性的研究进展。最后指出了研究中需解决的关键问题,同时对超声空化泡的研究趋势进行了展望。     

锂离子电池液体电解质与电极相容性的研究进展

随着锂离子电池商业化的不断发展,提高电池在室温及高温下的循环性和安全性已经引起了人们的高度重视.改善电解质与电极的相容性,提高电极表面钝化膜的稳定性是提高电池综合性能的有效途径.本文介绍了在优化电解质组成以及改善电解质与电极的相容性方面的研究进展,讨论了电解质各组分在电极上的作用机理.     

有机太阳能电池中基于苝二酰亚胺结构小分子受体进展

最近几年,有机太阳能电池中的非富勒烯小分子受体研究引起了人们的兴趣。其中,苝二酰亚胺(PDI)类分子因具有良好的电子传输能力,较强的电子亲和力,稳定的光、热、化学性能以及化学结构的可设计性带来的性能可调控性而得到广泛的关注。本文总结了近三年来在体异质结有机太阳能电池应用方面PDI小分子受体的研究进展,重点关注了PDI分子结构对其性能的影响,希望为以后PDI类受体分子的设计思路起到一定的启发作用。     

超声速弹丸立靶弹着点定位模型研究

针对常规武器火炮直瞄射击时的弹着点测试问题,提出了一种双圆环形传声器阵列方法。该阵列将若干传感器布设在两个圆环上,并根据超声速弹丸产生的激波传播速度随传播距离增加逐渐递减的规律,对每个传声器阵分别引入一个视速度,建立了双视速度模型。计算机仿真分析表明,采用双圆环形传声器阵列及双视速度模型确定弹丸弹着点坐标,带来的模型误差优于3 mm,对于工程应用而言可以忽略。试验结果表明,双视速度模型明显优于将激波传播速度视为恒定的基本模型和交会模型。     

Cu_xZn_（1-x）O纳米复合物的制备及其抗菌性能

用柠檬酸溶胶-凝胶法制备了Cu2＋掺杂纳米ZnO复合粉末（CuxZn1-xO,x=0.02,0.05,0.08,0.10）,用X射线衍射、扫描电子显微镜、透射电子显微镜等表征了样品的物相、结构和形貌.结果表明纳米CuxZn1-xO粒子为六角纤锌矿结构,平均晶粒尺寸为25~35 nm.该纳米复合粉末对大肠杆菌、金黄色葡萄球菌和白色念珠菌具有强效抗菌性能,且随Cu2＋掺杂浓度的增加抗菌性能增强.其中,Cu0.1Zn0.9O对大肠杆菌、金黄色葡萄球菌和白色念珠菌的最小抑菌浓度分别为50,50,25 mg/L.该纳米复合粉末的抗菌性能明显优于普通无机抗菌剂.