天然橡胶环保改性剂ORA-100的应用

在橡胶产品的生产过程中,特别是轮胎生产过程中,须大量使用天然橡胶。这个过程中遇到的一个棘手问题就是在天然橡胶的停放过程中,生胶的门尼黏度会显著地升高,从而影响天然橡胶的加工性能,增加生产能耗。同时天然橡胶在塑炼,混炼、硫化等生产过程中会产生浓重的气味,这种气味不利于生产企业的环保要求,也不利于这些企业与周边居民的和睦关系。天然橡胶环保改性剂ORA-100以其特殊的性能,能够很好地解决这些问题,起到稳定天然橡胶的门尼黏度,改善生产操作环境(降低天然橡胶的臭味)、实现节能环保的作用。通过对这个材料的性能研究,介绍了它的一些独特的功能、作用机理和应用。     

白炭黑的制备技术研究进展

白炭黑作为一种重要的无机非金属材料,主要成分为无定形水合二氧化硅,在涂料、塑料、医学、生物、造纸、橡胶、农业、化工、国防及机械等领域有广泛应用。作者根据采用的原料不同,特别是以工、农业废弃物(副产物)为原料,综述了白炭黑产品的制备方法。     

复合TiO_2光催化剂的制备及光催化性能研究进展

本文综述了近几年来复合TiO2光催化剂的发展现状。分别从分类、制备方法及光催化性能三方面进行系统论述。根据复合的物质不同,将复合TiO2光催化剂分为金属掺杂型、非金属掺杂型和半导体复合型。概述了溶胶-凝胶法、水热法、浸渍法等常用于复合TiO2光催化剂的制备方法以及复合TiO2光催化剂在降解水体有机污染物、分解水制氢、空气净化等方面的应用。     

北宋名园天王院花园子园址考 #

天王院花园子是北宋洛阳著名的牡丹花市,是《洛阳名园记》中唯一一处、也是北宋时期唯一一处有详实记录的公共园林,具有较高的史学和文化价值。以《洛阳名园记》的记载为基础,挖掘追溯文献典籍,从园林背景、园名解析、园址考辨依次展开,在时代背景下分析天王院花园子的发展历程,对四个可能园址一一辨别,推测天王院花园子可能位于宣教坊,原属安国寺的一部分,专门供奉毗沙门天王,后逐渐发展成培育、生产、展览、销售、游憩、配套居住等多种功能为一体的牡丹生产基地。     

聚氯乙烯有机稀土热稳定剂的制备与性能研究

分别制备了硬脂酸镧和甘油锌两种聚氯乙烯(PVC)热稳定剂,通过络合滴定法对稳定剂样品进行产率分析,并用熔点仪测试其熔点,讨论了制备两种稳定剂较适宜的工艺,然后将两种稳定剂以不同比例与PVC粉末进行复合,并对复合后的PVC混合粉进行了刚果红测试和热稳定白度测试。结果表明:当硬脂酸镧与甘油锌的质量比为3:1时,刚果红测试的稳定时间为48'58';165℃下老化10min后的白度为85.53%,其稳定性能较佳。     

Compound K, a Metabolite of Ginseng Saponin, Induces Mitochondria-Dependent and Caspase-Dependent Apoptosis via the Generation of Reactive Oxygen Species in Human Colon Cancer Cells

The objective of this study was to elucidate the cytotoxic mechanism of Compound K, with respect to the involvement of reactive oxygen species (ROS) and the mitochondrial involved apoptosis, in HT-29 human colon cancer cells. Compound K exhibited a concentration of 50% growth inhibition (IC(50)) at 20 μg/mL and cytotoxicity in a time dependent manner. Compound K produced intracellular ROS in a time dependent fashion; however, N-acetylcysteine (NAC) pretreatment resulted in the inhibition of this effect and the recovery of cell viability. Compound K induced a mitochondria-dependent apoptotic pathway via the modulation of Bax and Bcl-2 expressions, resulting in the disruption of the mitochondrial membrane potential (Δψ(m)). Loss of the Δψ(m) was followed by cytochrome c release from the mitochondria, resulting in the activation of caspase-9, -3, and concomitant poly ADP-ribosyl polymerase (PARP) cleavage, which are the indicators of caspase-dependent apoptosis. The apoptotic effect of Compound K, exerted via the activation of c-Jun NH(2)-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), was abrogated by specific MAPK inhibitors. This study demonstrated that Compound K-mediated generation of ROS led to apoptosis through the modulation of a mitochondria-dependent apoptotic pathway and MAPK pathway.     

SPR谱仪的研制及在磁光复合薄膜测试中的应用

针对SPR增强磁光效应研究中复合金属薄膜结构的SPR激发测试,研制了一套角度扫描型SPR谱仪。通过巧妙的结构设计和运动控制,使得角度扫描过程中样品测试点始终处于棱镜底面样品基片的中心,保证了测试过程的一致性。对50nm金膜的重复性测验表明SPR谱仪具有较高的重复性和稳定度。利用搭建的SPR谱仪对磁光复合薄膜的测试结果表明,在制备的样品中,Au(15nm)/Co(5/10nm)/Au(5nm)复合结构是磁光等离子体系研究的最佳平台。     

复方胆通片质量标准的研究

目的建立复方胆通片的质量标准。方法采用薄层色谱法鉴别方中的大黄、溪黄草与胆通;用高效液相色谱法测定羟甲香豆素和齐墩果酸的含量。结果薄层色谱法能明显检测出大黄、溪黄草、胆通,薄层图谱斑点清晰,阴性对照无干扰;羟甲香豆素进样量在4.92～49.2μg范围内呈良好线性关系(r=0.999 7),平均加样回收率为98.79%;齐墩果酸进样量在0.3～3.0μg范围内呈良好线性关系(r=0.999 3),平均加样回收率为99.90%。结论所建标准可用于复方胆通片的质量控制。     

白酒中白色粉末状沉淀物分析研究

实验定性分析了产生沉淀的酒样及沉淀物。结果表明:沉淀物主体成分是碳酸镁、碳酸钙,还含有少量的硫酸盐及有机物,并探讨了产生沉淀的机理,结合该酒厂的生产工艺,提出相应的解决和预防措施。     

Enhanced oral bioavailability and intestinal lymphatic transport of a hydrophilic drug using liposomes

A liposome system was evaluated for oral delivery of a poorly bioavailable hydrophilic drug. The system was prepared from proliposome, which consisted of negatively charged phosphatidylcholine, whereas cefotaxime was chosen as the model drug. An in vivo study was carried out on nine rats according to a three-way crossover design to compare the oral bioavailability of cefotaxime from the liposomal formulation with that of an aqueous drug solution and a physical mixture of cefotaxime with blank liposomes. The results indicated that the extent of bioavailability of cefotaxime was increased approximately 2.7 and 2.3 times compared with that of the aqueous solution and the physical mixture, respectively. In a separate study, simultaneous determination of cefotaxime in intestinal lymph (collected from the mesenteric lymph duct) and in plasma (collected from the tail vein) revealed that its concentration was consistently higher in the lymph than in the plasma when administered via the liposomal formulation, whereas the reverse was observed with the aqueous solution. Thus, the results indicated that the liposomes system has the potential of increasing the oral bioavailability of poorly bioavailable hydrophilic drugs and also promote their lymphatic transport in the intestinal lymph.