部分还原氧化石墨烯的制备、 表征及对人宫颈癌HeLa细胞的体外杀伤作用

以氧化石墨烯(GO)为原料, 利用温和方法制备了3种不同还原程度的部分还原氧化石墨烯pRGO₁, pRGO₂和pRGO₃(pRGO_1—3)； 利用傅里叶变换红外光谱(FTIR)、 拉曼光谱(Raman)、 X 射线光电子能谱(XPS)、 紫外-可见光谱(UV-Vis)、 透射电子显微镜(TEM)和 EDS能谱对其结构和形貌进行了表征. 细胞实验结果表明, 无激光照射下pRGO_1—3本身的细胞毒性较低; 近红外(NIR)激光照射下pRGO_1—3通过光热和光毒性双重作用杀伤肿瘤细胞. 实验结果显示了pRGO 在肿瘤光热疗法和光动力疗法领域的应用潜力.     

Unconventional Secondary Structure Mimics: Ladder-Rungs

Secondary structures tend to be recognizable because they have repeating structural motifs, but mimicry of these does not have to follow such well-defined patterns. Bioinformatics studies to match side-chain orientations of a novel hydantoin triazole chemotype ( 1 ) to protein-protein interfaces revealed it tends to align well across parallel and antiparallel sheets, like rungs on a ladder. One set of these overlays was observed for the protein-protein interaction uPA⋅uPAR. Consequently, chemotype 1 was made with appropriate side-chains to mimic uPA at this interface. Biophysical assays indicate these compounds did in fact bind uPAR, and elicit cellular responses that affected invasion, migration, and wound healing.     

Modular Synthetic Approach to Carboranyl‒Biomolecules Conjugates

The development of novel, tumor-selective and boron-rich compounds as potential agents for use in boron neutron capture therapy (BNCT) represents a very important field in cancer treatment by radiation therapy. Here, we report the design and synthesis of two promising compounds that combine meta-carborane, a water-soluble monosaccharide and a linking unit, namely glycine or ethylenediamine, for facile coupling with various tumor-selective biomolecules bearing a free amino or carboxylic acid group. In this work, coupling experiments with two selected biomolecules, a coumarin derivative and folic acid, were included. The task of every component in this approach was carefully chosen: the carborane moiety supplies ten boron atoms, which is a tenfold increase in boron content compared to the l-boronophenylalanine (l-BPA) presently used in BNCT; the sugar moiety compensates for the hydrophobic character of the carborane; the linking unit, depending on the chosen biomolecule, acts as the connection between the tumor-selective component and the boron-rich moiety; and the respective tumor-selective biomolecule provides the necessary selectivity. This approach makes it possible to develop a modular and feasible strategy for the synthesis of readily obtainable boron-rich agents with optimized properties for potential applications in BNCT.     

Cancer Initiation,Progression and Resistance: Are Phytocannabinoids from Cannabis sativa L. Promising Compounds?

Cannabis sativa L. is a source of over 150 active compounds known as phytocannabinoids that are receiving renewed interest due to their diverse pharmacologic activities. Indeed, phytocannabinoids mimic the endogenous bioactive endocannabinoids effects through activation of CB1 and CB2 receptors widely described in the central nervous system and peripheral tissues. All phytocannabinoids have been studied for their protective actions towards different biological mechanisms, including inflammation, immune response, oxidative stress that, altogether, result in an inhibitory activity against the carcinogenesis. The role of the endocannabinoid system is not yet completely clear in cancer, but several studies indicate that cannabinoid receptors and endogenous ligands are overexpressed in different tumor tissues. Recently, in vitro and in vivo evidence support the effectiveness of phytocannabinoids against various cancer types, in terms of proliferation, metastasis, and angiogenesis, actions partially due to their ability to regulate signaling pathways critical for cell growth and survival. The aim of this review was to report the current knowledge about the action of phytocannabinoids from Cannabis sativa L. against cancer initiation and progression with a specific regard to brain, breast, colorectal, and lung cancer as well as their possible use in the therapies. We will also report the known molecular mechanisms responsible for such positive effects. Finally, we will describe the actual therapeutic options for Cannabis sativa L. and the ongoing clinical trials.     

Laser diagnostics of nanoscale dielectric films on absorbing substrate by differential reflectivity and ellipsometry

The differential reflection characteristics for ultrathin inhomogeneous dielectric film on absorbing substrate are investigated in the long-wavelength approximation. The obtained first-order expressions for differential reflectivity and changes in the ellipsometric angles caused by ultrathin layer are of immediate interest to the solution of the inverse problem. The method to determine the averaged values (not the realistic profile) of refractive index for inhomogeneous nanometric films are shown. The novel possibilities for determining the dielectric constant and thickness of nanoscale homogeneous films by the differential ellipsometric and reflectivity measurements are developed, and a simple method to estimate whether the nanometric film is homogeneous or not is also discussed.     

Au-Au2S复合纳米球壳微粒的空腔谐振及参量讨论

Au-Au2S复合纳米球壳微粒（金纳米球壳），是一种新型复合结构的纳米微粒，其结构为纳米级的Au2S介质球外包裹了一层几个纳米厚的黄金球壳。这种复合纳米球壳微粒可以被抽象为球型谐振腔。报道了它的空腔谐振吸收的实验结果，并且运用经典理论结合介观结构特征，讨论了有关Au-Au2S复合纳米球壳微粒空腔谐振吸收的一些重要参量，其中包括谐振吸收波长、品质因数、谐振能量等。另外，还讨论了金球壳的厚度对这些重要参量的影响。     

Some heteroclinic solutions of a model of skin pattern formation

In this paper we study travelling wave solutions to a system of four non‐linear partial differential equations, which arise in a tissue interaction model for skin morphogenesis. Under the ‘small‐stress’ assumption we prove the existence and uniqueness (up to a translation) of solutions with the dermis and epidermis cell densities being positive, which are a perturbation of a uniform epidermal cell density. We discuss the problem of the minimal wave‐speed. Copyright © 2004 John Wiley & Sons, Ltd.     

广义线性模型(六)

本讲座是广义线性模型这个题目的一个比较系统的介绍。主要分 3部分 :建模、统计分析与模型选择和诊断。写作时依据的主要参考资料是L .Fahrmeir等人的 :《MultivariateStatisticalModel ingBasedonGeneralizedLinearModles》。     

衍射辐射及其在电子束诊断中的应用

衍射辐射是由于运动的带电粒子遇到随空间变化的电介质而由感应电流产生的一种辐射. 衍射辐射由于其非阻拦性, 多参数性, 可在线性, 非常适合下一代对撞机和第四代光源的电子束诊断. 简要介绍了其物理机制, 系统的讨论了其在电子束诊断中的应用.     

我国低温等离子体研究进展(Ⅰ)

低温等离子体物理与技术的研究在国内受到了越来越多的重视．在等离子体中发现的一些有趣的物理现象，如磁场重联、尘埃等离子体等，使人们对等离子体物理的研究掀起了新的热潮．在应用方面，几乎所有理工类实验室都有涉及低温等离子体技术的实验装置，这使得在我国低温等离子体应用方面的研究非常普及，包括微电子工业中的等离子体工艺，各种坚硬、耐腐蚀、耐摩擦材料的制备，纳米材料的制备，聚合物以及生物材料的表面改性，等等．随着低温等离子体技术的发展，低温等离子体的诊断技术也随之发展起来．文章简要地介绍了近几年来低温等离子体研究在我国的发展，介绍了一些有关低温等离子体的热点研究课题．