Aptamer-modified magnetic nanoprobe for molecular MR imaging of VEGFR2 on angiogenic vasculature

Nucleic acid-based aptamers have been developed for the specific delivery of diagnostic nanoprobes. Here, we introduce a new class of smart imaging nanoprobe, which is based on hybridization of a magnetic nanocrystal with a specific aptamer for specific detection of the angiogenic vasculature of glioblastoma via magnetic resonance (MR) imaging. The magnetic nanocrystal imaging core was synthesized using the thermal decomposition method and enveloped by carboxyl polysorbate 80 for water solubilization and conjugation of the targeting moiety. Subsequently, the surface of the carboxylated magnetic nanocrystal was modified with amine-functionalized aptamers that specifically bind to the vascular growth factor receptor 2 (VEGFR2) that is overexpressed on angiogenic vessels. To assess the targeted imaging potential of the aptamer-conjugated magnetic nanocrystal for VEGFR2 markers, the magnetic properties and MR imaging sensitivity were investigated using the orthotopic glioblastoma mouse model. In in vivo tests, the aptamer-conjugated magnetic nanocrystal effectively targeted VEGFR2 and demonstrated excellent MR imaging sensitivity with no cytotoxicity.     

细胞Zn2+荧光探针研究进展

主要对近年来测定细胞内游离Zn^2＋的荧光探针进行较详细地评述，并对其化学规律、性质和其优缺点进行了讨论。     

细胞Zn2+荧光探针研究进展

本文主要对近年来测定细胞内游离Zn2 的荧光探针进行较详细地评述,并对其化学规律、性质和其优缺点进行了讨论.     

H2O2基燃料电池阴极催化剂的研究进展

本文综述了燃料电池中H2O2电还原催化剂的研究,其主要集中在贵金属、过渡金属的大环化合物、酶以及非贵金属氧化物,其中研究非贵金属氧化物作为H2O2电还原的催化剂将是未来发展的方向.     

适用于N_2／CO_2气源MgO－C供气元件的研究

对采用镁砂晶粒平均粒径在４００～６００ｕｒｎ，石墨纯度达到Ｃ≥９８％，石墨的细度在０．１４７～０．１７８ｍｍ，金属加入物以铝粉与硅粉复合形式加入，生产出的ＭｇＯ－Ｃ供气元件性能较好。同时研究了碳化硼和固体结合剂对该材质的抗氧化性和高温强度等的影响。     

小鼠血清乙型肝炎病毒前S2抗体间接ELISA检测方法的建立

目的建立小鼠血清乙型肝炎病毒(Hepatitis B virus,HBV)前S2抗体间接ELISA检测方法。方法以HBV前S2(1～26)多肽包被酶标板,利用方阵滴定法确定间接ELISA法的最适工作条件,验证该方法的精密度、灵敏度和特异性,并与商品化试剂盒进行比较。结果确定最佳抗原包被浓度为2μg/ml;血清稀释度为1︰10,37℃反应30 min;HRP标记的羊抗小鼠IgG最佳稀释度为1︰10 000,37℃反应30 min;TMB底物37℃显色15 min,以2.1×阴性对照血清A450均值(阴性对照血清小于0.05时按0.05计算)为Cut-off值。该方法具有良好的试验内和试验间精密度;与商品化试剂盒比较,灵敏度为100%,特异性为97.3%,二者符合率为98.5%。结论已成功建立HBV前S2抗体间接ELISA方法,可用于小鼠血清中前S2抗体的检测。     

油田用纳米荧光类示踪剂发展现状及前景

随着油田开发进入中后期,油田对示踪剂技术的需求越来越大.示踪剂技术已由之前的单井单层注入,逐步向多井、多层位、多轮次、区块整体注入转变,而目前常用的示踪剂种类已无法满足现场需求.近几年,纳米技术作为一项前沿技术,在油气行业中已经得到应用,同时纳米荧光示踪技术在医学、生物学和水处理等领域已得到广泛应用.对油田用纳米荧光类...     

鸡BF1和BF2基因实时荧光定量PCR检测方法的建立

目的建立鸡主要组织相容性复合体(Major histocompatibility complex,MHC)BF1和BF2基因实时荧光定量PCR[Real-time fluorescent quantitative(FQ)-PCR]检测方法。方法从鸡外周血淋巴白细胞(Peripheral blood leuk-ocytes,PBLs)中提取细胞总RNA,以其为模板,根据BF1、BF2和GAPDH基因相对保守序列各设计一对引物,应用RT-PCR法扩增目的基因,分别克隆至pGM-T载体上,制备重组质粒标准品,经PCR、EcoRⅠ酶切及测序鉴定;优化反应体系及反应条件,绘制标准曲线,建立Real-time FQ-PCR检测方法,并验证其敏感性、特异性及重复性。结果重组质粒标准品经PCR、酶切及测序鉴定构建正确;建立的定量标准曲线临界循环数(Threshold cycle,Ct)与BF1、BF2和GAPDH起始质粒DNA拷贝数的对数之间线性关系良好,相关系数分别为1.00、0.98、0.99,扩增效率分别为0.8、1.1、1.1;该方法的敏感性可达101copies/μl;融解曲线分析表明扩增效率一致,特异性较好;质粒DNA标准品3次检测的CV值误差不超过0.5,均小于5%。结论已成功建立了鸡BF1和BF2基因实时荧光定量PCR检测方法,为下一步应用该法检测BF1和BF2基因的转录水平奠定了基础。     

D2蛋白酶间接ELISA检测方法的建立

目的建立D2蛋白酶间接ELISA检测方法,为D2蛋白酶的进一步研究及应用奠定基础。方法以纯化的D2蛋白酶为抗原,免疫新西兰白兔,制备D2蛋白酶多克隆抗体,建立D2蛋白酶间接ELISA检测方法,并进行验证及初步应用。结果D2蛋白酶间接ELISA检测方法的最佳反应条件为:一抗稀释度为1∶64000,二抗稀释度为1∶80000,抗原稀释度为1∶100,饱和包被浓度为1160ng/ml,封闭剂为10%胎牛血清。标准曲线的线性检测范围为18～1160ng/ml。该方法准确性、重复性良好,特异性强、敏感性高,与琼脂扩散试验检测结果的符合率为95.5%。结论已建立了D2蛋白酶间接ELISA检测方法,可用于D2蛋白酶含量的检测。     

猪2型圆环病毒疫苗的研究进展

猪2型圆环病毒是引起猪圆环病毒病,如断奶仔猪多系统衰竭综合征、猪呼吸疾病综合征、猪皮肤和肾病综合征等的重要病原体。该病毒可诱发多种病毒和/或细菌的混合感染和继发感染,给养猪业造成巨大的经济损失。近年来,国内外研究者都在致力于猪2型圆环病毒疫苗的研究开发。到目前为止,部分疫苗已在临床试验中取得成功,有的已投入应用,其他候选疫苗也正在积极研究过程中。本文就近年来国内外各类猪2型圆环病毒疫苗的研究进展及存在的问题和可能的解决办法作一综述。     

Development of an improved falling ball viscometer for high-pressure measurements with supercritical CO2

This study presents the development of an improved technique for viscosity measurements under high pressure. The apparatus is based on the principle of the falling ball viscometer, implemented in a high-pressure autoclave fitted with visualisation windows. The originality here is that the balls fall through a tube open at both ends with a diameter slightly greater than that of the balls, allowing a simplified modelling and numerical simulation. A numerical approach has been used for viscosity determination. Calculations have been made with COMSOL Multiphysics^® with the laminar Navier-Stokes model for Newtonian mixtures. It includes the specific hydrodynamic effects without the need for a calibration fluid. However, validation experiments were carried out at atmospheric pressure with dimethylsulfoxide (DMSO) at 298, 308 and 318 K and with cocoa butter at 313 and 353 K, with values of viscosity in the range from 1.4 to 45.4 mPa s. Comparative measurements with literature data have been conducted with cocoa butter saturated with carbon dioxide at 313 and 353 K and for pressures ranging from 0.1 to 25 MPa. At 313 K, viscosity varies from 45.4 mPa s to 3.1 mPa s while at 353 K it varies from 12.4 to 1.9 mPa s. For both isotherms tested, within the range 0-15 MPa, the higher the CO₂ dissolution in the cocoa butter, the lower the viscosity. However, this decrease in viscosity is more pronounced at the lowest temperature. Above 15 MPa the CO₂ dissolution effect on viscosity becomes insignificant, i.e. within the experimental error, due to a counter effect linked with the high hydrostatic pressure. Furthermore, the limits of use of this method have been determined. This technique is revealed as reliable and can therefore be used with other binary systems.     

纳米TiO2光触媒的进展

本文对纳米TiO2光触媒的作用机理、功能开发现状及发展方向作了综述。     

生物催化法合成2-氨基吩恶嗪酮的研究进展

介绍了生物催化的概念和常用的催化酶,以及生物催化酶的结构活性和催化特点。并综述了合成2-氨基吩恶嗪-3-酮的几种生物催化方法。     

A three-dimensional, magnetic and electroactive nanoprobe for amperometric determination of tumor biomarkers

A novel electrochemical immunosensor for tumor biomarker detection based on three-dimensional, magnetic and electroactive nanoprobes was developed in this study. To fabricate the nanoprobes, negatively charged Fe(3)O(4) nanoparticles (Fe(3)O(4) NPs) and gold nanoparticles (Au NPs) were first loaded on the surface of multiple wall carbon nanotubes (MCNTs) which were functioned with redox-active hemin and cationic polyelectrolyte poly(dimethyldiallylammonium chloride) (PDDA). Using alpha fetoprotein (AFP) as a model analyte, AFP antibody (anti-AFP) was absorbed on the surface of Au NPs, bovine serum albumin (BSA) was then used to block sites against non-specific binding, and finally formed anti-AFP/Au NPs/Fe(3)O(4)/hemin/MCNTs named anti-AFP nanoprobes. When the target antigen AFP was present, it interacted with anti-AFP and formed an antigen-antibody complex on the nanoprobe interface. This resulted in a decreased electrochemical signal of hemin for quantitative determination of AFP when immobilized onto the screen-printed working electrode (SPCE). The results showed that the nanoprobe-based electrochemical immunosensor was sensitive to AFP detection at a concentration of 0.1 to 200 ng·mL(-1) with a detection limit of 0.04 ng·mL(-1), it also demonstrated good selectivity against other interferential substances. The electroactive nanoprobes can be massively prepared, easily immobilized on the SPCE for target detection and rapidly renewed with a magnet. The proposed immunosensor is fast, simple, sensitive, stable, magnet-controlled, nontoxic, label-free and reproducible.     

溶胶-凝胶制备Li2O-Al2O3-SiO2微晶玻璃的研究进展

Li2OAl2O3SiO2系统微晶玻璃由于其膨胀系数低,耐高温及抗热冲击性等优异性能而受到广泛重视。本文主要介绍了溶胶凝胶工艺原理、制备过程,及在Li2OAl2O3SiO2系微晶玻璃上的应用,最后简述了Li2OAl2O3SiO2系微晶玻璃的应用现状。     

基于J2EE框架的企业库存管理软件研发与应用

针对流程工业企业的仓库管理需求及特点，对其仓库库存管理软件的需求分析、系统设计、软件设计及工程应用等多方面进行详细的研究与分析，并且适宜地应用J2EE技术开发出一套实用的企业仓库库存管理软件。     

国内外钛白粉生产概况和发展建议

介绍了国内外钛白粉的生产概况,并提出了发展建议。     

负载型TiO2光催化剂的研究进展

TiO2光催化技术是一种节能、高效的绿色环保新技术。TiO2光催化剂在废水处理、空气净化和材料自洁等领域具有诱人的应用前景。将其负载于一定的载体上,并设计出高效的光反应器是其实用化的关键之一。本文综合评述了负载型TiO2光催化剂发展状况,着重介绍了负载型TiO2光催化剂载体类型与作用、固定化方法以及负载对光催化活性的影响,指出目前研究中存在的问题,并展望未来的研究方向。     

耐H_2S、CO_2腐蚀新型涂料的研制与应用

H_2S、CO_2酸性腐蚀是目前我国化学工业、石油石化工业以及其他部门面临的一个普遍存在的问题,除了常规的酸性腐蚀之外还存在严重的氢致应力开裂(HIC)和硫化氢致应力开裂(SSCC)。采用环氧树脂和多异氰酸酯为涂料的成膜基料,加上高效抑制氢渗透、高效防止HIC和SSCC的填料所研制的涂料可以较好地解决这一问题。