Reproductive disruption in fish downstream from an estrogenic wastewater effluent

To assess the impact of an estrogenic wastewater treatment plant (WWTP) effluent on fish reproduction, white suckers (Catostomus commersoni) were collected from immediately upstream and downstream (effluent site) of the city of Boulder, CO, WWTP outfall. Gonadal intersex, altered sex ratios, reduced gonad size, disrupted ovarian and testicular histopathology, and vitellogenin induction consistent with exposure to estrogenic wastewater contaminants were identified in white suckers downstream from the WWTP outfall and not at the upstream site. The sex ratio was female-biased at the effluent site in both the fall of 2003 and the spring of 2004; the frequency of males at the effluent site (17-21%) was half that of the upstream site (36-46%). Intersex white suckers comprised 18-22% of the population at the effluent site. Intersex fish were not found at the upstream site. Chemical analyses determined that the WWTP effluent contained a complex mixture of endocrine-active chemicals, including 17beta-estradiol (E2) 17alpha-ethynylestradiol, alkylphenols, and bisphenol A resulting in an estimated total estrogen equivalence of up to 31 ng E2 L(-1). These results indicate that the reproductive potential of native fishes may be compromised in wastewater-dominated streams.     

Zire 71音乐播放大串烧

Zire71是Palm推出的一款极具叛逆性的产品，它一改Palm传统的成熟稳重但又略显刻板的形象，它将时尚的外观与强大的多媒体性能集于一身，再加上价格相对低廉（相对索尼同样具备摄像头的Palm OS5.0机型而言）且可以买到简体中文版行货，因而一经推出即获得了广大胖友的青睐，成为了目前极具人气的一款常上电脑。然而Zire71也并非完美，笔者就听到不少用户抱怨其MP3播放效果较差，且没有CLIE机型的Hold按键，不能在听音乐的同时关闭屏幕。如果你也有同样的抱怨，那么一定不能错过本文。它将给你带来全套的Zire71音乐播放解决方案。     

Microspectrofluorometry and fluorescence imaging in the study of human cytopathology

The study of energy pools and dynamics of specific pathways in living cells by microspectrofluorometry and fluorescence imaging produces spectral and topographic images characterizing structural and functional changes associated with cytopathology. Microspectro-fluorometry and fluorescence imaging have been applied, together with organelle morphometry to a number of cells mimicking certain cytopathologies, including melanoma cells, long-term malignant cells, and gene-defective cells. These investigations of cellular pathology indicate that there is a convergence of various physiopathological processes. Cellular states that have similarities include senescence, detoxification, and transformation. While the NAD(P)H metabolic transients have been studied before, our emphasis in this article is on very rapidly scanned fluorescence images related to organelle integration and photoinduced cellular senescence.     

胶团寿命与各种技术过程的相关性

美国佛罗里达大学化学工程系教授、表面科学与工程中心主任Shah博士从事表面化学领域的研究已逾二十五年,最近成功地举办了一次“胶团、微乳及单分子层二十五年的进展”国际会议。本文介绍Shah博士的研究小组用了近十二年的时间在胶团动态学及应用方面取得的主要成果。原文刊载在“分散科学和技术杂志”(1994年)上,现经作者同意,译成中文。     

一种用于提高原油采收率且预防和减少硫化物的微生物新技术

本文在地层水预成型挥发性脂肪酸组分及其微生物利用的基础上提出了一种新技术，即通过地层水中挥发性脂肪酸的可竞争性分离产生的硫酸盐还原菌预防硫酸盐还原作用的技术。在硝酸盐存在的条件下繁殖了微生物群，它能就地生成气体和聚合物等提高采收率的产物。试验室研究通过地层水的细微变化证明了蚀变微生物群系统具有易变性和潜力。岩芯浸渍资料表明了采油量的增长。这种用于预防和减少硫化物县提高原油采收率的方法被称为“生物竞争淘汰法”。微生物用于油田，为石湖工业提供了一种控制和模拟油藏的经济的方法。     

Formation of nitrogen-containing oligomers by methylglyoxal and amines in simulated evaporating cloud droplets

Reactions of methylglyoxal with amino acids, methylamine, and ammonium sulfate can take place in aqueous aerosol and evaporating cloud droplets. These processes are simulated by drying droplets and bulk solutions of these compounds (at low millimolar and 1 M concentrations, respectively) and analyzing the residuals by scanning mobility particle sizing, nuclear magnetic resonance, aerosol mass spectrometry (AMS), and electrospray ionization MS. The results are consistent with imine (but not diimine) formation on a time scale of seconds, followed by the formation of nitrogen-containing oligomers, methylimidazole, and dimethylimidazole products on a time scale of minutes to hours. Measured elemental ratios are consistent with imidazoles and oligomers being major reaction products, while effective aerosol densities suggest extensive reactions take place within minutes. These reactions may be a source of the light-absorbing, nitrogen-containing oligomers observed in urban and biomass-burning aerosol particles.     

Mussel-inspired block copolymer lithography for low surface energy materials of teflon, graphene, and gold

Mussel-inspired interfacial engineering is synergistically integrated with block copolymer (BCP) lithography for the surface nanopatterning of low surface energy substrate materials, including, Teflon, graphene, and gold. The image shows the Teflon nanowires and their excellent superhydrophobicity.     

Optical properties of ZnO/ZnS and ZnO/ZnTe heterostructures for photovoltaic applications

Although ZnO and ZnS are abundant, stable, and environmentally benign, their band gap energies (3.44, 3.72 eV, respectively) are too large for optimal photovoltaic efficiency. By using band-corrected pseudopotential density functional theory calculations, we study how the band gap, optical absorption, and carrier localization can be controlled by forming quantum-well-like and nanowire-based heterostructures of ZnO/ZnS and ZnO/ZnTe. In the case of ZnO/ZnS core/shell nanowires, which can be synthesized using existing methods, we obtain a band gap of 2.07 eV, which corresponds to a Shockley-Quiesser efficiency limit of 23%. On the basis of these nanowire results, we propose that ZnO/ZnS core/shell nanowires can be used as photovoltaic devices with organic polymer semiconductors as p-channel contacts.