• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Bacterial exposure to metal-oxide nanoparticles: Methods, physical interactions, and biological effects.
【24h】

Bacterial exposure to metal-oxide nanoparticles: Methods, physical interactions, and biological effects.

机译：细菌与金属氧化物纳米颗粒的接触：方法，物理相互作用和生物效应。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Nanotechnology is a major endeavor of this century, with proposed applications in fields ranging from agriculture to energy to medicine. Nanoscale titanium dioxide (nano-TiO2) is among the most widely produced nanoparticles worldwide, and already exists in consumer products including impermanent personal care products and surface coatings. Inevitably, nano-TiO2 will be transported into the environment via consumer or industrial waste, where its effects on organisms are largely unknown.;Out of concern for the possible ill-effects of nanoparticles in the environment, there is now a field of study in nanotoxicology. Bacteria are ideal organisms for nanotoxicology research because they are environmentally important, respond rapidly to intoxication, and provide evidence for effects in higher organisms. My doctoral research focuses on the effects and interactions of nano-TiO2 in aqueous systems with planktonic bacteria. This dissertation describes four projects and the outcomes of the research:;(1) A discovery, using a combination of environmental- and cryogenic-scanning electron microscopy and dynamic light scattering (DLS), that initially agglomerated nano-TiO2 is dispersed upon bacterial contact, as nanoparticles preferentially sorbed to cell surfaces.;(2) Establishment of a method to disperse nanoparticles in an aqueous culture medium for nanotoxicology studies. A combination of electrostatic repulsion, steric hindrance and sonication yielded a high initial level of nano-TiO2 dispersion (i.e. 300 nm average agglomerate size) and reduced nanoparticle sedimentation. The approach is described in the context of general considerations for dispersion that are transferable to other nanoparticle and media chemistries.;(3) Assessment and optimization of optically-based assays to simultaneously study effects of nanoparticles on bacterial membranes (membrane potential, membrane permeability, and electron transport chain function) and generation of reactive oxygen species. A systematic, widely-transferable approach was developed to test and account for nanoparticle interferences with available assays.;(4) Using the assay system above, discovery of the influences of nano-TiO 2 primary particle size and iron doping on the effects that nano-TiO 2 has on E. coli growth and membrane processes.;Together, this research is towards: better understanding outcomes of interactions between nanoparticles and bacteria, advancing methods in the relatively new field of nanotoxicology that are transferable to other nanoparticle and media chemistries, and improving our understanding of structure-activity relationships (e.g. size and doping effects) leading to intoxication in environmental organisms.
机译：纳米技术是本世纪的一项重大工作，其拟议的应用领域从农业到能源再到医学。纳米级二氧化钛（nano-TiO2）是全球生产最广泛的纳米颗粒之一，并且已经存在于消费产品中，包括无常的个人护理产品和表面涂层。不可避免的是，纳米二氧化钛将通过消费者或工业废物进入环境，在很大程度上其对生物体的影响尚不清楚。出于对纳米粒子在环境中可能产生的不良影响的关注，现在有一个研究领域纳米毒理学。细菌是纳米毒理学研究的理想生物，因为它们在环境方面很重要，对中毒反应迅速，并为高等生物的作用提供了证据。我的博士研究专注于纳米二氧化钛在水系统中与浮游细菌的相互作用。本文描述了四个项目和研究结果：；（1）利用环境扫描和低温扫描电子显微镜以及动态光散射（DLS）的发现，最初团聚的纳米TiO2通过细菌接触而分散。 （2）建立一种将纳米颗粒分散在水性培养基中进行纳米毒理学研究的方法。静电排斥，空间位阻和超声处理的结合产生了较高的初始纳米TiO2分散度（即平均团聚体尺寸小于300 nm）和减少的纳米粒子沉降。该方法是在可考虑转移到其他纳米颗粒和介质化学物质的一般性考虑因素的背景下进行描述的;（3）评估和优化基于光学的分析方法，以同时研究纳米颗粒对细菌膜的影响（膜电位，膜通透性，和电子传输链功能）和活性氧的生成。开发了一种系统的，可广泛转移的方法来测试和说明可用的测定方法对纳米粒子的干扰。（4）使用上述测定系统，发现了纳米TiO 2初级粒径和铁掺杂对纳米粒子的影响的影响。 -TiO 2对大肠杆菌的生长和膜过程具有影响。这项研究的目的是：更好地了解纳米颗粒与细菌之间相互作用的结果，在相对较新的纳米毒理学领域中推广可转移至其他纳米颗粒和介质化学的方法，并增进我们对导致环境生物中毒的结构-活性关系（例如尺寸和掺杂效应）的理解。

著录项

  • 作者

    Horst, Allison Marie.;

  • 作者单位

    University of California, Santa Barbara.;

  • 授予单位 University of California, Santa Barbara.;
  • 学科 Health Sciences Toxicology.;Biology Microbiology.;Nanoscience.;Environmental Sciences.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 267 p.
  • 总页数 267
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号