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Search Results: 1 - 10 of 251296 matches for " 李盈辰 "
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Determination of Brilliant Blue and Amaranth in drinks by modification of polyamide adsorption-high performance capillary electrophoresis with internal standard method
改良聚酰胺吸附-高效毛细管电泳内标法测定饮料中的亮蓝和苋菜红

YAN Zheng,LI Yingchen,ZHANG Yu,
闫正
,,张玉

色谱 , 2010,
Abstract: A high performance capillary electrophoresis (HPCE) method has been established for the separation of Brilliant Blue and Amaranth in carbonated beverages. Sunset Yellow was added into the sample as the internal standard. The separation was carried out on a fused-silica uncoated capillary column (40 cm×75 μm). The sample was injected by air pressure injection (14 kPa×3 s) at room temperature. The analysis was completed in 10 mmol/L Na2HPO4 buffer (pH 8.56) at 20 kV of separation voltage and 390 nm of detection wavelength. The relative correction factors of Brilliant Blue and Amaranth were 0.8329 and 1.2253, and the relative standard deviations (RSDs) were 3.3% and 2.6%, respectively. The respective quantification limits (S/N=10) were 1.629 mg/L and 4.160 mg/L, the recoveries were in the ranges of 97.87%~102.1% (RSD=1.8%) and 94.07%~103.8% (RSD=4.1%), and the method precisions were 3.2% and 2.0%. The optimization of the pretreatment made the method more suitable for the determination of Brilliant Blue and Amaranth in carbonated beverages by capillary electrophoresis. The systematic error brought by the background was eliminated basically by using the blank sample as the base solution. The relative factors of Brilliant Blue and Amaranth were reproducible in the ranges of 1.629~228.8 mg/L and 4.16~401.6 mg/L, respectively. So this method can be used to quantify the two synthetic pigments in carbonated beverages accurately.
二羟基二过碘酸合镍(Ⅳ)氧化还原引发丙烯酰胺聚合反应动力学的研究
,商亚娟,卫平,,邓奎林
高分子学报 , 2000,
Abstract: 近年来,人们对过渡金属的超常价态有着浓厚的兴趣.对超常氧化态如Cu(Ⅲ)、Ni(Ⅳ)、Ag(Ⅲ)等的研究无疑会给人们提供新的知识.我们曾报道过超常价态过渡金属Cu(Ⅲ),Ag(Ⅲ)用于引发自由基聚合反应的研究[1~3].对于超常价态Ni(Ⅳ)用于引发自由基聚合反应的研究,国内外报道较少.一般文献认为,Ni(Ⅳ)与小分子间的氧化还原反应属双电子转移反应,没有中间自由基产生,故不能引发烯类单体聚合[4,5].虽?...
抗体异质性对抗体药物功能和代谢影响的研究进展
,张哲文,,张喜全,赵伟
- , 2017,
Abstract: 抗体药物常呈现微观不均一性,即“异质性”,包括糖基化、电荷、相对分子质量大小等相关的异构体。这些异构体绝大部分来自于“细胞工厂”对重组蛋白的翻译后修饰作用,如聚体、降解、糖基化修饰、氧化、脱酰基化、二硫键错配等。这些修饰不仅对抗体的质量、安全性和有效性均可能造成影响,而且也是整个抗体生产工艺的重要指征。本文对抗体糖基化、电荷及相对分子质量大小等异质性与药物有效性、安全性、药代动力学及免疫原性等的联系进行综述,有助于进一步认识抗体结构与功能关系,并希望为抗体药物尤其是生物类似药物的开发提供一定的依据和指导。
Antibody drugs often show “heterogeneity”, including the related isomers differing from one another in glycosylation, charge or molecular size. Most of these isomers come from post-translational modifications, such as aggregation, degradation, glycosylation, oxidation, deamidation or disulfide misfolding, of the recombinant protein in the “cell factories”. These modifications not only influence the quality, safety and efficacy of the antibodies, but also serve as an important indication of product quality throughout the whole process of antibody production. This paper reviews the relationship between glycoslation, charge and size heterogeneities of monoclonal antibodies and drug efficacy, safety, pharmacokinetics as well as immunogenicity, contributing to a better understanding of the relationship between antibody structure and function. It will provide some support and guidance for the research and development of antibody drugs, especially biosimilars
半乳糖修饰的海藻酸纳米载体构建及其抗肿瘤功效
Fabrication of Galactosylated Alginate Nanoparticles as Drug Delivery System for Hepatocellular Carcinoma
 [PDF]

政雄, 吴晓
Hans Journal of Nanotechnology (NAT) , 2016, DOI: 10.12677/NAT.2016.62004
Abstract:
本文设计制备肝靶向聚合物纳米粒–半乳糖(Gal)修饰海藻酸酯(HA-Gal)纳米粒,以阿霉素(DOX)为抗肿瘤模型药物制备载药纳米粒(DOX/HA-Gal),研究DOX/HA-Gal的理化性质、载药与释药、体外细胞增殖抑制,考察不同Gal接枝比对体外抗肿瘤功效的影响。结果表明DOX/HA-Gal为大小均一的球形粒子,水合动力学粒径为180-250nm,荷负电(<?30 mV);随Gal接枝比的增大,DOX/HA-Gal的粒径增大,Zeta电势升高,包封率增加,肿瘤细胞杀伤率提高。
The alginate derivative naonoparticles modified by galactose (HA-Gal) with various galactose (Gal) substitution degrees were synthesized to evaluate their potential for hepatocellular carcinoma (HCC) targeting. Their physicochemical characteristics were investigated. Doxorubicin hydrochloride (DOX) as a model antitumor drug was incorporated into the HA-Gal. The in vitro drug release and antitumor capability of DOX loaded HA-Gal (DOX/HA-Gal) with different Gal substitution degrees were evaluated. Negatively charged DOX/HA-Gal appeared monodisperse and spherical in shape with a size range of 180 - 250 nm, and their Zeta potentials were above 30 mV (absolute value). The size, Zeta potentials, encapsulation efficiency and in vitro cytotoxicity of HA-Gal were increased with the increment in Gal substitution degree.
我国人口与劳动就业的发展趋势

期刊检索-中国人口科学 , 1987,
Abstract: <正>在我国的经济社会发展中,人口与劳动就业问题始终占有极为重要的位置。这是由我国的特殊国情所决定的。我国人口目前已超过10亿,社会劳动者已近5亿。将人口与劳动就业联系起来研究,对解决我国人口问题,对四个现代化建设,对实现2000年的宏伟战略目标,都是很有意义的。
利用功率谱分解与系统辨识法对离散系统模型进行降阶处理

自动化学报 , 1989,
Abstract: ?本文介绍一种离散系统模型降阶的混合方法.从能量影响的观点到系统的输出,系统中处于主导地位的特征值会在系统输出产生优势的动态模态,从而确定降阶模型传函中分母的参数估值,再用辨识技术求出分子参数.降阶模型与原系统相比,暂态响应与稳态响应中均有很好的逼近.
我国中药产业链问题与成因分析
,
中国中药杂志 , 2010,
Abstract: 作者从产业链角度对中药产业进行剖析,认为我国中药产业链中存在产业环节发展失衡、整体创新能力弱、信息化程度低、中药材资源枯竭等问题,并从产业链构建和整合的角度对其成因进行了深入分析,以期为提出科学的中药产业发展对策奠定基础。
基于非线性混合模型的油松天然林树高曲线研究
Height-diameter Models of Pinus tabuliformis Based on Nonlinear Mixed Models

,许昊
- , 2016, DOI: 10.3969/j.issn.1001-7461.2016.03.07
Abstract: 树高和胸径作为重要的林分因子,二者的异速生长关系是林分生长与收获预估的基础。以北京市古石峪61块油松(Pinus tabuliformis)天然林样地为研究对象,样地按郁闭度CD≥0.6(类型Ⅰ)、0.5≤CD<0.6(类型Ⅱ)、0.4≤CD<0.5(类型Ⅲ)、0.3≤CD<0.4(类型Ⅳ)和CD<0.3(类型Ⅴ)划分5个等级类型,采用非线性混合模型方法,从26种常用树高曲线中选择拟合精度最高的作为基础模型,以类型和样地作为随机效应,分别基于单水平和嵌套二水平,考虑异方差构建最优的油松天然林树高曲线。采用AIC、BIC和负2倍的对数似然值对不同模型的精度进行比较,并用平均绝对误差、剩余均方根误差和调整后的决定系数对模型进行检验。结果表明,混合参数个数不同,模型预测精度不同;考虑异方差结构的嵌套2水平非线性混合模型预测精度高,调整后的决定系数达0.924 4,剩余均方根误差为0.842 1,可以准确地反映油松树高与胸径的关系,但与以样地作为随机效应的单水平样模型的差异不显著。
Tree height and diameter at breast height are two important forest factors.The allometric growth between two factors is the basis for the forecast of stand growth and harvest.In this study,61 plots of Pinus tabuliformis stands in Gushiyu Village,Beijing were used as research objects,each plot was divided into five classes by stand canopy density(CD):CD≥0.6 (Type Ⅰ),0.5≤CD<0.6 (Type Ⅱ),0.4≤CD<0.5 (Type Ⅲ),0.3≤CD<0.4 (Type Ⅳ),and CD<0.3 (Type Ⅴ).The best model from 26 height curve functions was selected to model the height-diameter relationships of P.tabuliformis with one level (type or plot effect) and nested two-level (nested effects of type and plot) nonlinear mixed effects (NLME) models.Then the best model which had the lowest AIC,BIC and -2Log likelihood was chosen.Evaluation statistics,such as absolute mean residual (AMR),root mean square error (RMSE),and adjusted coefficient of determination (adj-R2) were used for precision analysis and comparison of different models.The results showed that there were different prediction accuracies of NLME models with different mixed parameters.The nested two-level NLME model considering heteroscedasticity structure possessed with predictable accuracy,with the high adjusted determination coefficient of 0.924 4 and root mean square error of 0.842 1.The nested two-level NLME model would be allowed for estimating accuracy the height-diameter relationships of P.tabuliformis,but there were no significant differences between the nested two-level NLME model and the one level (plots) NLME model
microRNA在固有免疫受体调控中的作用及相关研究进展
张悦,
中国科学 生命科学 , 2012,
Abstract: 固有免疫系统主要通过相应的模式识别受体(patternrecognitionreceptors,PRRs)识别各种病原体,包括病毒、细菌、真菌等的保守分子基序,因此是构成机体抵御病原生物入侵的第一道防线.模式识别受体信号转导中存在复杂精细的调控机制,能够针对病原体适时调控免疫反应的强度,保持机体的稳态.小分子RNA(miRNA)是一类非编码具有调控功能的小RNA,能够在转录后水平上抑制翻译或诱导mRNA降解,从而在免疫反应调控中发挥重要作用.已有研究发现,miRNA在固有免疫细胞内有独特的表达谱,并能有效调控固有免疫受体,如Toll样受体(toll-likereceptors,TLRs)、维甲酸诱导基因Ⅰ样受体(retinoic-acid-induciblegeneⅠ(RIG-Ⅰ)-likereceptors,RLRs)和核苷酸结合寡聚化结构域样受体(nucleotide-bindingoligomerizationdomain(NOD)-likereceptors,NLRs)的信号传导通路.本文将就miRNA对固有免疫受体信号通路调控的最新研究进展进行综述.
基于卓越绩效模式的企业持续创新机制研究
单汨源,
科技进步与对策 , 2010,
Abstract: 创新是企业核心竞争力的重要来源,持续创新对企业的持续发展至关重要。在"卓越绩效模式"的理论研究基础上构建了企业持续创新机制框架模型,该模型包括创新动力、创新过程、学习能力、创新管理、创新环境五大部分。创新动力是来源,创新过程是核心,学习能力是基础,创新管理是手段,创新环境是平台,通过五大部分的耦合和相互作用确保和促进企业的持续创新,实现企业的持续发展。卓越绩效模式创新持续创新机制
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