大鼠服用朱砂后脑内氨基酸类递质含量的变化

研究了朱砂对大鼠脑组织中氨基酸类神经递质含量的影响.将32只Wistar大鼠随机分为低、中、高剂量组和对照组,朱砂灌胃给药14天后,采用高效液相色谱法测定大鼠脑组织中谷氨酸(Glu)、天门冬氨酸(Asp)、甘氨酸(Gly)、γ-氨基丁酸(GABA)和牛磺酸(Tau)的含量,并计算兴奋毒性指数(EI)的变化.与对照组相比较,脑组织中氨基酸类神经递质含量均呈下降趋势,其中Asp和Gly的中、高剂量组差异有统计学意义(P0.05),Tau和GABA的高剂量组有统计学差异(P0.05),Glu和EI所有剂量组均有统计学差异(P0.05).朱砂对氨基酸类神经递质具有一定的抑制作用.     

柱前衍生化高效液相色谱法测定朱砂中可溶性汞的含量

采用二乙基二硫代氨基甲酸钠柱前衍生化高效液相色谱法测定了朱砂在人工胃液中的可溶性汞含量;本法简便,灵敏,精确,可用于朱砂及含朱砂的中成药中可溶性汞的含量测定及质量检验.     

Magnetic bead-based approach to monitoring of cigarette smoke-induced DNA oxidation damage and screening of natural protective compounds

Cigarette smoking can damage DNA and induce spontaneous mutagenesis or carcinogenesis. Here, we describe a novel strategy for in situ monitoring of cigarette smoke-induced DNA oxidation damage and offer a method for screening natural compounds that protect DNA against tobacco smoke. The present protocol takes advantage of a fast and simple magnetic separation/mixing method and a highly sensitive chemiluminescence (CL) ELISA. The DNA immobilized on the magnetic beads was oxidized by the smoke in the absence or presence of natural compounds, and then oxidative DNA was conveniently held by magnetic force, whereas the complex tobacco smoke matrix and any remaining compounds were completely eliminated by extensive washing, and possible interferences were thus removed and oxidative damage was then sensitively monitored by CL ELISA. A library of 32 natural products was then screened and three were found to protect DNA from oxidative damage and thus may be promising compounds for the development of new drugs. Moreover, the protection effect of these three natural compounds against DNA oxidation damage was successfully classified by directly spiking them in the reference cigarettes. In addition, the potential to screen a mixture in a complex sample matrix, such as crude extracts, was also demonstrated, and hence the proposed technique can screen compounds within a complex matrix and enhance the screening throughput.     

Preparation of anionic phosphine ligands in situ for the palladium-catalyzed Buchwald/Hartwig amination reactions of aryl halides

2-Phenylindenyl phosphine ligand can be changed into anionic phosphine ligand in situ and utilized in the palladium-catalyzed Buchwald/Hartwig amination reactions in DME, providing good to excellent yields of amination products from aryl chlorides, bromides and iodides. ³¹P NMR studies show that the resonance for the anionic phosphine appeared between those of the (2-phenylindenyl)-dicyclohexyl phosphonium salt and (2-phenylindenyl)dicyclohexylphosphine. The calculated results were consistent with the experimental results.     

Determination of Six Resorcylic Acid Lactones in Feed by GC–MS

A method was developed to simultaneously detect six resorcylic acid lactones in feed by GC–MS. Samples were extracted with methanol followed by a two step liquid–liquid extraction and an HLB SPE clean-up. The samples were derivatized with BSTFA + TMCS (99/1; v/v) and determined by GC–MS. For all analytes, the ranges of recoveries were 81.2–98.2%, with RSDs of 3.2–15.2%, and the LODs were 0.2–0.6 μg kg⁻¹.

     

不同产地珠子参中微量元素含量分析

分析不同产地珠子参中微量元素的含量变化情况。应用电感耦合等离子体-原子发射光谱法（ICP-AES）测定不同产地珠子参中Ca、Cr、Cu、Fe、Ga、Li、Mg、Mn、Ni、Sn、Sr、Ti、Tl、V、Zn、Pb 16种微量元素的含量。结果表明,不同产地珠子参中各微量元素含量有所差异,陕西宁强产珠子参中Ca、Mg、Mn、Zn、Cu等含量高于其他产地。珠子参中微量元素的含量与产地的土壤、水质等有关。     

地方高校省级物理示范实验室建设的探索与实践

提出了示范实验室建设的思路与目标,阐述分层次模块化的实验教学体系,介绍了多样化的实验教学手段。经过3年的探索与实践,示范实验室建设成效显著、特色明显,取得了较为显著的成绩,有一定示范性和辐射作用。     

Examining surface and bulk structures using combined nonlinear vibrational spectroscopies

We combined sum-frequency generation (SFG) vibrational spectroscopy with coherent anti-Stokes Raman scattering (CARS) spectroscopy in one system to examine both surface and bulk structures of materials with the same geometry and without the need to move the sample. Poly(methyl methacrylate) (PMMA) and polystyrene (PS) thin films were tested before and after plasma treatment. The sensitivities of SFG and CARS were tested by varying polymer film thickness and using a lipid monolayer.     

Dilations for systems of imprimitivity acting on Banach spaces

Motivated by a general dilation theory for operator-valued measures, framings and bounded linear maps on operator algebras, we consider the dilation theory of the above objects with special structures. We show that every operator-valued system of imprimitivity has a dilation to a probability spectral system of imprimitivity acting on a Banach space. This completely generalizes a well-known result which states that every frame representation of a countable group on a Hilbert space is unitarily equivalent to a subrepresentation of the left regular representation of the group. We also prove that isometric group representation induced framings on a Banach space can be dilated to unconditional bases with the same structure for a larger Banach space. This extends several known results on the dilations of frames induced by unitary group representations on Hilbert spaces.     

Cellular articular cartilage replacement tissues: Modeling and analysis

Long-term studies reveal that mechanical stimulation causes growth and remodeling phenomena within biological tissues. The main aim of this research is to fully understand and control these phenomena. For accomplishing that, two steps are considered: first, we determine a suitable numerical model based on different approaches by a comparative study using experimental validations, and second, investigate the mechanical properties of the tissue specimens after a remodeling process. We start with the first step by choosing a convenient model that mimics the biotissue for running the numerical simulations in the second step. There are different models available that determine the mechanical properties of soft replacement tissues seeded with human chondrocytes in modern medical applications. It is our objective to achieve a common methodology of theory and experiments that allows the determination of the mechanical properties of the native material. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)