Cellular Internalization of Rod‐Like Nanoparticles with Various Surface Patterns: Novel Entry Pathway and Controllable Uptake Capacity

The cellular internalization of rod‐like nanoparticles (NPs) is investigated in a combined experimental and simulation study. These rod‐like nanoparticles with smooth, abacus‐like (i.e., beads‐on‐wires), and helical surface patterns are prepared by the cooperative self‐assembly of poly(γ‐benzyl‐l ‐glutamate)‐block‐poly(ethylene glycol) (PBLG‐b‐PEG) block copolymers and PBLG homopolymers. All three types of NPs can be internalized via endocytosis. Helical NPs exhibit the best endocytic efficacy, followed by smooth NPs and abacus‐like NPs. Coarse‐grained molecular dynamics simulations are used to examine the endocytic efficiency of these NPs. The NPs with helical and abacus‐like surfaces can be endocytosed via novel “standing up” (tip entry) and “gyroscope‐like” (precession) pathways, respectively, which are distinct from the pathway of traditional NPs with smooth surfaces. This finding indicates that the cellular internalization capacity and pathways can be regulated by introducing stripe patterns (helical and abacus‐like) onto the surface of rod‐like NPs. The results of this study may lead to novel applications of biomaterials, such as advanced drug delivery systems.     

3D map distribution of metallic nanoparticles in whole cells using MeV ion microscopy

In this work, a new tool was developed, the MORIA program that readily translates Rutherford backscattering spectrometry (RBS) output data into visual information, creating a display of the distribution of elements in a true three‐dimensional (3D) environment. The program methodology is illustrated with the analysis of yeast Saccharomyces cerevisiae cells, exposed to copper oxide nanoparticles (CuO‐NP) and HeLa cells in the presence of gold nanoparticles (Au‐NP), using different beam species, energies and nuclear microscopy systems. Results demonstrate that for both cell types, the NP internalization can be clearly perceived. The 3D models of the distribution of CuO‐NP in S. cerevisiae cells indicate the nonuniform distribution of NP in the cellular environment and a relevant confinement of CuO‐NP to the cell wall. This suggests the impenetrability of certain cellular organelles or compartments for NP. By contrast, using a high‐resolution ion beam system, discretized agglomerates of Au‐NP were visualized inside the HeLa cell. This is consistent with the mechanism of entry of these NPs in the cellular space by endocytosis enclosed in endosomal vesicles. This approach shows RBS to be a powerful imaging technique assigning to nuclear microscopy unparalleled potential to assess nanoparticle distribution inside the cellular volume.     

激光诱导荧光衰减探测光化学反应

激光诱导荧光衰减探测光化学反应＊王文科魏杰黄毓礼＊＊（北京化工大学材料科学与工程学院，北京１０００２９）关键词激光诱导荧光光谱，光化学反应激光荧光光谱为重要光谱分析手段之一，广泛用于物理、化学、生物学等研究领域．但对于一些含有发色基团的大有机分子，由...     

Photochemical formation of palladium patterns on surface-modified polyimide resin

A simplified method for forming a palladium circuit pattern on polyimide resin substrate was proposed. The carboxyl group, as a cation exchange group, was formed on the polyimide resin surface by a potassium hydroxide treatment. Palladium(II) ion was then adsorbed onto the surface modified polyimide resin by ion exchange. Ultraviolet irradiation of this palladium(II) ion absorbed resin with sodium formate coated on its surface resulted in the formation of a palladium thin film. Irradiation through a metal-on-quartz mask onto the modified polyimide resin surface photoreduced the palladium ion into metallic palladium circuit patterns easily without using a plating resist.     

利用太阳能进行化学反应

太阳能是人类最大的能源。利用太阳最关键的问题是如何有效地收集、贮存和转化。详细介绍为实现将太阳能转有的化学合成而答的天然叶绿素的模拟研究，并简要说明太阳能在处理废水中稠环芳烃与多氯联苯方面的直接利用。     

用UV/H2O2,UV/O3,UV/H2O2/O3催化处理城市固体垃圾填埋渗出物

The performance of UV/H2O2, UV/O3, and UV/H2O2/O3 oxidation systems for the treatment of municipal solid-waste landfill leachate was investigated. Main objective of the experiment was to remove total organic carbon (TOC), non-biodegradable organic compounds (NBDOC) and color. In UV/H2O2 oxidation experiment, with the increase of H2O2 dosage, removal efficiencies of TOC and color along with the ratio of biochemical oxygen demand (BOD) to chemical oxygen demand (COD) of the effluent were increased and a better performance was obtained than the system H2O2 alone. In UV/H2O2 oxidation, under the optimum condition H2O2 (0.2 time), removal efficiencies of TOC and color were 78.9% and 95.5%, respectively, and BOD/COD ratio was significantly increased from 0.112 to 0.366. In UV/O3 oxidation, with the increase of O3 dosage, removal efficiencies of TOC and color along with BOD/COD ratio of the effluent were increased and a better performance was obtained than the system O3 alone. Under the optimum condition UV/O3     

加氢尾油光氯化法合成氯化石蜡的新工艺

叙述了氯化石蜡国内外合成技术状况及各合成路线的对比,介绍了以加氢尾油、氯气为原料,浓硫酸为酸洗剂,白土为吸附剂,通过光氯化法合成氯化石蜡-52。取物料配比为m(硫酸)∶m(白土)∶m(加氢尾油)=8∶6∶100,酸洗处理的温度取100℃,酸洗时间为2h,静置时间为1h。白土吸附的温度为120℃,吸附时间为2h,静置时间为2h。氯化反应温度控制在70～80℃,氯化石蜡产品含量≥52%。     

多晶n-CdSe电极在K_4Fe(CN)_6-EDTA溶液中稳定性的研究

旋转环盘电极(RRDE)研究表明,多晶n-CdSe电极表面经金属离子溶液处理,提高溶液的pH及增加溶液中还原剂K_4Fe(CN)_6的浓度均使该电极在K_4Fe(CN)_6-FDTA体系中的稳定因子S提高。用Au、Ru、Pt及Pb等离子溶液处理电极表面时,S值增大。Ru离子处理使S增大几乎可达1。从X射线荧光光谱和Mott-Schottky关系图分析证明,处理后的CdSe多晶电极表面沉积了一层金属薄层。本文对电极表面沉积的金属薄层、溶液pH等的影响、稳定因子S提高的原因也作了初步讨论。     

测定空气中氢气的光化学传感器的研究进展

氢气是工业生产中常用的易燃易爆气体,因此研究用于空气中氢气浓度的快速监测的传感器有着重要的现实意义.本文综述了近年来用于测定空气中氢气的光化学传感器的研究现状和工业应用前景.     

聚烯烃的光化学与辐射化学改性

本文介绍了光化学及幅射化学交联的机理及其对聚合物结构与性能的影响,举例说明了它们在聚烯烃薄膜与电缆改性上的应用。