毛细管电泳检测神经细胞凋亡

建立了毛细管电泳检测凋亡细胞DNA片段的方法.以DNA相对分子质量标准品为溶质,考察了分离条件(电压、进样时间、温度、聚合物浓度)对分离的影响.在优化条件下,利用毛细管无胶筛分电泳对缺氧缺血过程中不同时间点神经PC12细胞DNA片段进行了分析,并与流式细胞仪结果比较,研究缺氧缺血时胶质细胞凋亡过程.     

高效毛细管电泳安培法测定肉苁蓉中松果菊苷的含量

采用毛细管电泳安培法建立了肉苁蓉中松果菊苷含量的检测方法,探讨了缓冲溶液种类、工作电位、分离电压、进样时间等对分离和检测的影响.在15 mmol/L硼砂缓冲溶液(pH 9.5),25 kV电压,0.6 V工作电位的条件下,松果菊苷的质量浓度在0.5～50.0 mg/L范围内与峰面积呈良好线性,相关系数为0.9994,检...     

毛细管电泳法测定银杏叶片中的橙皮素、芦丁和槲皮素

建立了一种利用毛细管电泳法测定银杏叶片中橙皮素、芦丁和槲皮素的方法.研究了缓冲溶液pH和浓度、分离电压和进样时间对分离的影响,在优化的条件下,10 min内实现了三种物质的良好分离.橙皮素、芦丁和槲皮素分别在0.03～0.80、0.06～1.00,0.04～0.90 mg/mL浓度范围内和峰电流成线性关系,线性相关系数分别为0.9992、0.9976和0.999l,检出限分别为0.005、0.009和0.006 mg/mL.     

微芯片毛细管电泳快速测定加替沙星注射液中加替沙星的含量

研究了用微芯片毛细管电泳非接触电导检测系统快速测定加替沙星注射液中加替沙星的方法。对缓冲液的类型、浓度、分离电压以及进样时间等因素进行了优化。最佳条件为:缓冲液5.0 mmol/L HAc,分离电压2.0 kV,进样时间15.0 s。在该条件下,可在1.0 min内实现加替沙星的快速含量测定。线性范围为4.0～150μg/mL,检出限为1.0μg/mL,加标回收率为95.7%～101%,可成功测定注射液中加替沙星的含量。     

非水介质毛细管电泳高频电导法测定姜黄中姜黄素

建立了药材姜黄中姜黄素含量的非水介质毛细管电泳高频电导测定方法.对非水介质体系和支持电解质的种类,浓度以及操作电压和进样时间等影响因素进行了优化.以无水甲醇作为分离介质,NH4OAc-HOAc为电解质,25.0 kV为分离电压,可在12 min内实现对姜黄素的分离检测.在最佳试验条件下,姜黄素的线性范围为3.0～140.0 mg·L-1,检出限为0.5 mg·L-1,回收率为95.3%～100.9%.     

盐酸二甲双胍的毛细管电泳法快速测定

建立了毛细管电泳高频电导法快速测定片剂中盐酸二甲双胍的方法。考察了缓冲溶液、有机溶剂添加剂、毛细管长度以及分离电压和进样条件等因素对分离检测的影响。在最佳条件下5.0 min内即可实现盐酸二甲双胍分离检测,盐酸二甲双胍的线性范围为1.50μg/mL~130μg/mL,检出限为1.0μg/mL。该方法成功地测定了盐酸二甲双胍片剂中的盐酸二甲双胍。     

司帕沙星的毛细管电泳高频电导法测定

采用毛细管电泳高频电导法检测了司帕沙星。探讨了缓冲液的种类、浓度、添加剂以及操作电压和进样时间等因素对分离的影响。选择3.0mmol LHAc-5.0?H5OH(V V)为电泳介质,分离电压20.0kV,在4min内可实现司帕沙星的分离检测。在优化条件下,司帕沙星的线性范围为6 0～280 0μg mL,检出限为1 9μg mL。在该条件下,片剂中的敷料不干扰测定,可成功测定片剂中的司帕沙星,样品回收率为98.7%～101%。     

硫酸阿米卡星的毛细管电泳法快速测定

建立了毛细管电泳高频电导法快速测定注射液中硫酸阿米卡星的新方法.考察了缓冲溶液、有机溶剂添加剂以及分离电压和进样条件等因素对分离检测的影响.采用5.0 mmol/L乳酸-30%(体积分数)乙醇缓冲液体系为运行电泳介质,分离电压20.0 kV,在最佳实验条件下,5.5 min内即可实现硫酸阿米卡星的分离检测,硫酸阿米卡星的线性范围为5.00 ～150 mg/L,检出限为1.5 mg/L.     

在线富集-毛细管区带电泳法测定牛奶中三聚氰胺

提出了在线富集毛细管区带电泳法测定牛奶中三聚氰胺的含量。系统地考察了毛细管区带电泳工作条件,选定的试验条件为:①磷酸盐缓冲溶液浓度为20 mmol.L-1;②pH值为3.0;③运行电压为30 kV;④检测波长为208 nm。在优化的试验条件下,三聚氰胺在8 min内达到基线分离,其线性范围为0.83～106.70 mg.L-1,检出限(3S/N)为0.2 mg.L-1。在制备供试液后不同时间进样测定,三聚氰胺迁移时间的相对标准偏差为0.72%,峰面积的相对标准偏差为1.02%,结果表明样品在8 h内稳定。     

迁移时间归一化法改善毛细管电泳表征中药大黄的重现性

探讨了迁移时间归一化法改善中药毛细管电泳分析迁移时间重现性的原理,并将其应用于实际样品的分析。迁移时间归一化法认为,在相同的操作电压、缓冲液组成和温度条件下,多次电泳实验中迁移时间产生差别的主要原因是多次电泳实验中电渗流产生了差异。迁移时间归一化法就是通过选择电泳谱图中的一个或两个峰作为标记峰,将各次电泳实验的迁移时间都归一到第一次电泳实验中的迁移时间。比较多次电泳实验中迁移时间(t)的相对标准偏差(RSD)、经单峰归一化处理的迁移时间(t′)的RSD、经双峰归一化处理的迁移时间(t″)的RSD、迁移时间比(t/tistd,istd代表所选择的标记物)的RSD,发现RSD(t″)相似文献   

UV-光固化光纤涂料的研制

本文采用环氧丙烯酸酯与聚氨酯丙烯酸酯共混聚合的方法制备出新型的UV-光固化光纤涂料,其主要性能较好.研究了基体组成、引发剂、稀释剂以及固化工艺对UV-固化光纤涂料的光固化速度的影响.通过实验发现,环氧丙烯酸酯与聚氨酯丙烯酸酯的配比为 4:6～6:4、稀释剂的含量不大于20%时固化速度较快、性能较好,同时固化时灯距与固化膜厚度对固化速度的影响较大.     

Growth feature of PTFE coatings on rubber substrate by low‐energy electron beam dispersion

Polytetrafluoroethylene (PTFE) coatings were prepared on Si and acrylonitrile‐butadiene rubber substrates by low‐energy electron beam dispersion. The effects of substrate nature, distance of target to substrate (d_ts) and coatings thickness on the surface morphology, structure, and tribological properties of the coatings were investigated. The results showed that substrate nature affects the shape and size distribution of surface conglomerations of PTFE coatings due to the interaction process of active dispersion particles with underlying polymer layer. Surface energy of PTFE coatings decreases first with the coatings thickness increases to 1.25 µm and then slowly increases with the thickness. Structure defects (pore, interstice, and so on) in the coatings increase with the thickness increases but reduce significantly with the d_ts increases. PTFE coating prepared at the d_ts of 20 cm had a higher intensity of the amorphous absorption bands. Friction experiment indicated that the destroyed area of the coatings in the friction region decreases with increases the coatings thickness but increases with the d_ts. The rubber modified by PTFE coatings with spherical structure possesses a higher stability in the friction process and a lower coefficient of friction. Copyright © 2015 John Wiley & Sons, Ltd.     

Numerical Modeling of Thin Film Deposition in Expanding Thermal Plasma

Expanding thermal plasma (ETP) is a widely used technique for deposition of a thin layer of ceramic materials and metal oxide on a substrate for a wide range of applications including abrasion resistance, UV absorption, as well as conductive and optical coatings. The coating quality is found to be dependent on operating parameters as well as reactor designs. In this article, we have presented a CFD based model of the ETP process to simulate the deposition of silica-like coatings on a polycarbonate substrate. Along with the flow-thermal model of plasma jet expansion process, the study also reports the development of a simplified gas phase and surface reaction model to simulate the coating phenomena. The model has been used further to study the effect of various operating conditions on the coating thickness, viz. reactor pressure, reagent flow rate, distance of the substrate from the arc and substrate alignment.     

Diffusion of polyphosphates into (poly(allylamine)-montmorillonite) multilayer films: flame retardant-intumescent films with improved oxygen barrier

The present paper relies on the original idea to design multifunctional coatings, and in particular highly efficient intumescent flame retardant coatings, based on the diffusion of polyphosphates (PSPs) in exponentially growing "layer-by-layer" films made from montmorillonite (MMT) and poly(allylamine) (PAH). Here, we used polyphosphates as an acid source, polyallylamine as both a carbon source and a swelling agent, and finally clays to reinforce the intumescent char strength and also for their oxygen barrier property. The coatings made from the alternated deposition of n = 60 layer pairs of PAH and MMT reach a considerable thickness of ～18 μm with well-defined ordering of the MMT in the direction parallel to the substrate. Structural, morphological, mechanical, gas barrier, and fire resistance properties of these films have been studied. Excellent oxygen barrier properties and extraordinary fire resistance properties are demonstrated based on the basis of a strong increase of the time to ignition and on a decrease of the heat release rate of polylactide substrates during mass loss calorimeter tests. This new and innovative intumescent flame retardant system based on (PAH-MMT)(n)-PSP coatings is a promising universal treatment for current polymeric materials.     

A quartz crystal microbalance study of the removal of solid organic soils from a hard surface in aqueous surfactant solution

A quartz crystal microbalance (QCM) has been employed to monitor the removal of two model solid organic soils, dotriacontane and tripalmitin, from the hard surface of the QCM crystal in aqueous surfactant solutions of octa-ethyleneglycol mono n-dodecyl ether (C₁₂E₈). We have investigated the effect of varying the thickness of the soil coating on soil removal and the effect of soaking the soil in high-purity water for an extended period of time before adding surfactant. The QCM results support the view that net soil removal is preceded by a stage of water and surfactant penetration into the soil. The rate of penetration and rate of removal depends on the soil type. Water and surfactant take longer to penetrate dotriacontane compared to tripalmitin coatings. The removal process also occurs over a longer period of time in the case of dotriacontane coatings. The percentage of material removed is less for dotriacontane, compared to tripalmitin coatings. The initial coating thickness on the hard surface does not appear to govern the final percentage of soil removed, at least in the thickness range accessible to the QCM (approximately ≤800 nm). Immersing the soil coated surfaces in water for a relatively long time, hastens the onset of the removal stage after surfactant is added but does not significantly influence the rate and extent of removal from the hard surface.     

Examination of Zinc coatings on Copper substrates by thermal analysis

Copper has excellent thermal conductivity and is mainly applied in electrical and machinery applications. Its main disadvantage is its poor resistance in aggressive environments which can be significantly enforced by the deposition of Zinc coatings. In this study the effect of the deposition time and temperature on the thickness and microstructure of Zinc coatings on Copper substrates by pack cementation process using a DSC apparatus, is investigated. Moreover, the oxidation performance of the coated samples has been evaluated in a high-temperature environment. Oxidation tests were accomplished by thermogravimetric measurements while the coated and oxidized samples were examined with SEM microscopy and XRD diffraction analysis. DSC results revealed that the chemical reactions, which lead to the coating formation, take place up to 300 °C while the coating thickness increases with the duration of the deposition process. The as formed coatings consist of two layers corresponding to different Cu–Zn phases. Finally the coated samples were found to be more resistant when exposed in the aggressive environment, as they begin to oxidize at significant higher temperatures than the uncoated samples. This can mainly attributed to the formation of ZnO on the surface of the coating.     

不同厚度三倍频SiO2增透膜的设计、制备与改性

本文通过光学计算设计了具有不同厚度的三倍频增透膜。以氨水为催化剂、正硅酸乙酯(TEOS)为前驱体,通过溶胶-凝胶(Sol-Gel)技术制得SiO2溶胶;采用浸渍提拉法镀膜得到符合设计要求的三倍频增透膜。研究结果表明,增透膜的耐磨擦性能随着膜层厚度的增大而增大,本文制得的厚度达到200 nm以上的三倍频增透膜耐磨擦性能显著优于传统的1/4波长三倍频增透膜。此外,本文以甲基含氢硅油为膜表面修饰剂,提出一种全新的超快的表面疏水性改性的方法。经该方法处理后,增透膜由亲水膜转变为疏水膜,对水的接触角从23.4°增大至95°,增透膜的耐环境性显著提高。     

Depth profile analysis of various titanium based coatings on steel and tungsten carbide using laser ablation inductively coupled plasma--"time of flight" mass spectrometry

A homogenized 193 nm ArF* laser ablation system coupled to an inductively coupled plasma-"Time of Flight"-mass spectrometer (LA-ICP-TOFMS) was tested for depth profiling analysis on different single-layer Ti based coatings on steel and W carbides. Laser parameters, such as repetition rate, pulse energy and spatial resolution were tested to allow optimum depth related calibration curves. The ablation process using a laser repetition rate of 3 Hz, 120 microm crater diameter, and 100 mJ output energy, leads to linear calibration curves independent of the drill time or peak area used for calibrating the thickness of the layer. The best depth resolution obtained (without beam splitter) was 0.20 microm per laser shot. The time resolution of the ICP-TOFMS of 102 ms integration time per isotope was sufficient for the determination of the drill time of the laser through the coatings into the matrix with better than 2.6% RSD (about 7 microm coating thickness, n = 7). Variation of the volume of the ablation cell was not influencing the depth resolution, which suggests that the depth resolution is governed by the ablation process. However, the application on the Ti(N,C) based single layer shows the potential of LA-ICP-TOFMS as a complementary technique for fast depth determinations on various coatings in the low to medium microm region.     

Combinatorial materials research applied to the development of new surface coatings I: a multiwell plate screening method for the high-throughput assessment of bacterial biofilm retention on surfaces

Combinatorial, high-throughput capabilities have been established to aid in the rapid development of new and effective antifouling marine coatings for naval applications. A biological screening process involving marine bacteria was developed that allows for rapid and effective quantification of bacterial biofilm growth and retention on large numbers of coating surfaces in parallel. The screening process involves (1) multiwell plate modifications for coating deposition, (2) deposition of combinatorial coating libraries via an automated liquid dispensing robot, (3) coating thickness measurements of cured coatings, (4) preconditioning of coatings via immersion in deionized water, (5) bacterial incubation, (6) plate processing, and (7) data analysis for identification of promising candidates. The details of the method developed are described in this document.     

The Application of Nano-SiOx Coatings as Migration Resistance Layer by Plasma Enhanced Chemical Vapor Deposition

Accumulative intake of plasticizers that are generally used to produce flexibility of webs in plastics has been proven to cause reproductive system problems and women??s infertility, and long-term consumption may even cause cancer. Hence a nano-scale layer, named as functional barrier layer, was deposited on the plastic surface to prevent plasticizer diethylhexyl phthalate (DEHP) migration from food-contact materials to foods. The feasibility of a functional barrier layer, i.e. SiO_x coating through plasma enhanced chemical vapor deposition process was then described in this paper. In this research we used Fourier transform infrared spectroscope to analyze the chemical composition of the coatings, scanning electron microscope to explore the topography of the coating surfaces, surface profilemeter to measure coating thickness in plastics, and high-performance liquid chromatography to evaluate the barrier properties of coatings. The results have clearly shown that the coatings can perfectly block the migration of the DEHP from plastics to their containers. It is to be noted that process parameters had a critical influence on the block properties of coatings. When the deposition conditions of SiO_x coatings were optimized, i.e. the discharge power of 50?W, 4:1 of O₂: HMDSO ratio and the thickness of 100?nm, the 71.2?% DEHP was effectively blocked in the plastic film.