检索结果-南通市图书馆

Ion-pairing HPLC methods to determine EDTA and DTPA in small molecule and biological pharmaceutical formulations

Journal of Pharmaceutical Analysis 2016年第3期6卷 150-156页

作者： george wang Frank P. Tomasella Analytical and Bioanalytical Development Pharmaceutical Development Bristol-Myers Squibb Company New Brunswick NJ 08903 USA

Ion-pairing high-performance liquid chromatography-ultraviolet （HPLC-UV） methods were developed to determine two commonly used chelating agents, ethylenediaminetetraacetic acid （EDTA） in Abilify （a small molecule drug with aripiprazole as the active pharmaceutical ingredient） oral solution and die- thylenetriaminepentaacetic acid （DTPA） in Yervoy （a monoclonal antibody drug with ipilimumab as the active pharmaceutical ingredient） intravenous formulation. Since the analytes, EDTA and DTPA, do not contain chromophores, transition metal ions （Cu2＋, Fe3＋） which generate highly stable metallocom- plexes with the chelating agents were added into the sample preparation to enhance UV detection. The use of metallocomplexes with ion-pairing chromatography provides the ability to achieve the desired sensitivity and selectivity in the development of the method. Specifically, the sample preparation in- volving metallocomplex formation allowed sensitive UV detection. Copper was utilized for the de- termination of EDTA and iron was utilized for the determination of DTPA. In the case of EDTA, a gradient mobile phase separated the components of the formulation from the analyte. In the method for DTPA, the active drug substance, ipilimumab, was eluted in the void. In addition, the optimization of the concentration of the ion-pairing reagent was discussed as a means of enhancing the retention of the aminopolycarboxylic acids （APCAs） including EDTA and DTPA and the specificity of the method. The analytical method development was designed based on the chromatographic properties of the analytes, the nature of the sample matrix and the intended purpose of the method. Validation data were presented for the two methods. Finally, both methods were successfully utilized in determining the fate of the chelates.

关键词： EDTA DTPA Ion-pairing HPLC Aripiprazole Ipilimumab

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Kinetic Studies on Aniline-catalyzed Carbohydrate Oxime Formation via Real-time NMR

引用

Chemical Research in Chinese Universities 2011年第5期27卷 886-890页

作者： wang Wen-jun CAO Chen-ming JIN Chen wang Xin wang george-peng College of Pharmacy Nankai University Tianjin 300071 P. R. China State Key Laboratory of Element-Organic Chemistry Nankai University Tianjin 300071 P. R. China Departments of Chemistry and Biochemistry The Ohio State University Columbus OH 43210 USA

The authors investigated an aniline-catalyzed method to accelerate the reaction between equimolar reducing glycans and hydroxylamines. The rate-constants determined by real-time NMR were associated with the equivalence ratio of aniline rather than the concentration. Conjugates of oligosaccharide with hydroxylamine can be obtained in high efficiency at pH=5.4.

关键词： Glycoconjugate Aniline Catalysis Kinetics Real-time NMR

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling and identification of a PEM fuel cell humidification system

引用

控制理论与应用（英文版） 2009年第4期7卷 373-378页

作者： Xianrui DENG Guoping LIU george wang Min TAN Departrnent of Computer Tangshan Teacher＇s College Tangshan Hebei 063000 China Lab of Complex Systems and Intelligence Science Chinese Academy of Sciences Beijing 100080 China School of Electronics University of Glamorgan Pontypridd CF37 1DL UK National Research council Vancouver Canada

A theoretical model of a humidifier of proton exchange membrane （PEM） fuel cell systems is developed and analyzed first in this paper. The model shows that there exists a strong nonlinearity in the system. Then, the system is identified using a wavelet networks method. To avoid the curse-of-dimensionality problem, a class of wavelet networks proposed by Billings is employed. The experimental data acquired from the test bench are used for identification. The one-step-ahead predictions and the five-step-ahead predictions are compared with the real measurements, respectively. It shows that the identified model can effectively describe the real system.

关键词： Modelling Identification Neural networks PEM fuel cell Humidification system

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Political Connections,Government Regulations and Risk-Taking--Evidence From China

引用

Frontiers of Economics in China-Selected Publications from Chinese Universities 2018年第4期13卷 655-684页

作者： Shangzhou Ji george Yungchih wang School of Finance Shanghai University of International Business and EconomicsShanghai 201620China Faculty of International Liberal Arts Soka UniversityTokyo-toHachioji-shi Tangi-cho 1-236 Japan

Sufficient evidence suggests that enterprises under strong government regulations suffer the economic effects of political connections, which not only leads to competitive disadvantages and loss of innovation, but also less willingness to take risks. This paper explores the relationship between political connections and corporate risk-taking behavior in corporate governance. Specifically, in 2008, the Chinese government announced new policies to regulate government officials concurrently holding the positions of independent directors in firms. We sample publicly listed firms in the Chinese A-share market over the period of 2005–2010 and investigate changes in risk-taking behavior due to the new policies. Our findings indicate that a reduction in politically connected independent directors may encourage risk-taking behavior subject to the factors of state ownership, industry regulations, local government control, and corporate characteristics.

关键词： political connections government regulations risk-taking independent directors

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Influence of Substrate Conformation on the Deglycosylation of Ribonuclease B by Recombinant Yeast Peptide:N-glycanase

引用

Acta Biochimica et Biophysica Sinica 2007年第1期39卷 8-14页

作者： Shengjun wang Peng george wang and Qingsheng QI State Key Laboratory of Microbial Technology,Life Science Schooll,Shandong University,Jinan 250100,China State Key Laboratory of Microbial Technology Life Science School Shandong UniversityJinan 250100 China

Peptide:N-glycanase has been thought to be responsible for proteasome-dependent degradationof misfolded glycoproteins translocated from the endoplasmic reticulum (ER) to the ***,theenzyme was supposed to be able to distinguish between native and non-native *** the presentstudy,a recombinant,yeast peptide:N-glycanase,Png lp, was expressed in Escherichia coli as inclusionbodies and was purified,refolded and *** results showed that the recombinant enzymehas a broad pH range adaptation,from pH 4.0 to pH 10.0,and has an optimum temperature of 30 ℃.This enzyme is a zinc *** activity was abolished with the addition of EDTA and notrestored by adding metal ***,the deglycosylation efficiency of recombinant Pnglpfrom *** was investigated with respect to the substrate conformation in *** ribonuclease B(RNase B) was denatured at 60-65 ℃ or by 40-60 mM dithiothreitol, indicated by its obvious structuralchange and sharpest activity change,its deglycosylation by Pnglp was most *** deglycosylationefficiency of RNase B by Pnglp was found to be related to its structural conformation and enzymaticactivity.

关键词： glycanase ribonuclease B glycoprotein deglycosylation circular dichroism

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Anticancer potential of metabolic compounds from marine actinomycetes isolated from Lagos Lagoon sediment

引用

Journal of Pharmaceutical Analysis 2019年第3期9卷 201-208页

作者： Olabisi Flora Davies-Bolorunduro Isaac Adeyemi Adeleye Moshood Olushola Akinleye Peng george wang Department of Microbiology University of Lagos Akoka Lagos Nigeria Department of Pharmaceutical Chemistry University of Lagos Idi-Araba Lagos Nigeria Department of Chemistry Georgia State University Atlanta GA United States

Thirty-two actinomycetes strains were isolated from sediment samples from 12 different sites at Lagos Lagoon and identified using standard physiological and biochemical procedures as well as 16S rDNA gene sequence analysis. Secondary metabolites were extracted from the strains and their anticancer activity on the K562 (Human acute myelocytic leukemia), HeLa (cervical carcinoma), AGS (Human gastric), MCF- 7 (breast adenocarcinoma) and HL-60 (Human acute promyelocytic leukemia) cell lines was determined. The metabolic extracts exhibited cytotoxicity with IC50 values ranging from 0.030 mg/mL to 4.4 mg/mL. The Streptomyces bingchenggensis ULS14 extract was cytotoxic against all the cell lines tested. The bioactivity-guided extraction and purification of the metabolic extracts from this strain yielded two purified anticancer compounds: ULDF4 and ULDF5. The structures of the extracted compounds were determined using spectroscopic analyses, including electrospray ionization mass spectrophotometer and nuclear magnetic resonance (1 Dimensional and 2 Dimensional), and were shown to be structurally similar to staurosporine and kigamicin. The IC50 of ULDF4 and ULDF5 against the HeLa cell line was 0.034 mg/mL and 0.075 mg/mL, respectively. This study is the first to reveal the anticancer potential of actinomycetes from Lagos Lagoon, which could be exploited for therapeutic purposes.

关键词： Streptomyces bingchenggensis ULS14 Metabolic extracts Cytotoxicity Spectroscopy Kigamicin Staurosporine

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Predicting the synthesizability of crystalline inorganic materials from the data of known material compositions

引用

npj Computational Materials 2023年第1期9卷 733-743页

作者： Evan R.Antoniuk Gowoon Cheon george wang Daniel Bernstein William Cai Evan J.Reed Materials Science Division Physical and Life Sciences DirectorateLawrence Livermore National LaboratoryLivermoreCAUSA Department of Chemistry Stanford UniversityStanfordCAUSA Department of Applied Physics Stanford UniversityStanfordCAUSA Google Research Mountain ViewCAUSA Department of Physics Stanford UniversityStanfordCAUSA Department of Mathematics Stanford UniversityStanfordCAUSA Department of Computer Science Stanford UniversityStanfordCAUSA Department of Materials Science and Engineering Stanford UniversityStanfordCAUSA

Reliably identifying synthesizable inorganic crystalline materials is an unsolved challenge required for realizing autonomous materials *** this work,we develop a deep learning synthesizability model(SynthNN)that leverages the entire space of synthesized inorganic chemical *** reformulating material discovery as a synthesizability classification task,SynthNN identifies synthesizable materials with 7×higher precision than with DFT-calculated formation *** a head-to-head material discovery comparison against 20 expert material scientists,SynthNN outperforms all experts,achieves 1.5×higher precision and completes the task five orders of magnitude faster than the best human ***,without any prior chemical knowledge,our experiments indicate that SynthNN learns the chemical principles of charge-balancing,chemical family relationships and ionicity,and utilizes these principles to generate synthesizability *** development of SynthNN will allow for synthesizability constraints to be seamlessly integrated into computational material screening workflows to increase their reliability for identifying synthetically accessible materials.

关键词： inorganic crystalline utilize

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

船舶-自升式海洋平台碰撞相似率研究

引用

振动与冲击 2016年第7期35卷 15-22页

作者：刘昆包杰王自力 wang george 江苏科技大学船舶与海洋工程学院江苏镇江212003 上海船舶设计研究院上海200120 美国船级社

海洋平台作为海洋能源勘探开发的主要组成部分,是海洋油气探井、钻井、开采的主要作业基地,船舶碰撞致使平台结构损伤破坏一直是威胁海洋平台安全的主要因素之一,开展海洋平台碰撞性能研究,揭示平台结构在碰撞过程中的损伤变形机理,对... 详细信息

海洋平台作为海洋能源勘探开发的主要组成部分,是海洋油气探井、钻井、开采的主要作业基地,船舶碰撞致使平台结构损伤破坏一直是威胁海洋平台安全的主要因素之一,开展海洋平台碰撞性能研究,揭示平台结构在碰撞过程中的损伤变形机理,对提升平台安全性具有重要意义。评估平台结构耐撞性能最可靠的方法是实船碰撞试验,然而因其耗资巨大而不易开展。按一定相似关系进行比例模型试验成为现实条件下的首选。基于相似第二定理,运用量纲分析法推导船舶-自升式海洋平台碰撞过程中各物理量的相似关系,为平台碰撞模型试验的开展及试验参数的确定提供重要依据;结合有限元仿真技术,以平台典型的T型和K型管节点为研究对象,建立不同缩尺比下的简化碰撞模型,比较验证相似理论的可靠性;研究结果表明,缩尺模型在碰撞冲击载荷下的结构损伤变形、碰撞力和能量吸收等动态响应与实尺度模型结果一致性较好。研究成果可以为大型平台结构碰撞模型试验设计提供技术支撑。

关键词：船舶碰撞相似关系量纲分析数值仿真模型试验设计

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Relationship between Corporate Social Responsibility and Firm Performance： An Application of Quantile Regression

引用

Frontiers of Business Research in China 2012年第2期6卷 218-244页

作者： Yungchih george wang Wen-Hsi Lydia Hsu Kuang-Wen Chang Department of International Business National Kaohsiung University of Applied Sciences Department of Business Administration National Ping-Tung University of Science and Technology Ping-Tung Taiwan China Department of Business Administration Soochow University Taiwan China

This study empirically examines the relationship between a firm＇s fulfilling of corporate social responsibility （CSR） and performance. We developed a CSR index （CSRI） to quantitatively evaluate CSR, which consists of four dimensions measuring a firm＇s contributions to the economy, society, environment, and corporate governance, respectively. With data from publicly-listed firms in Taiwan during the period of 2004--2009, results of quantile regression show that fulfilling CSR has a significantly positive impact on firm performance, and that the impact in a more profitable firm tends to be significantly greater than that in a less profitable firm. Specifically, when a firm is more profitable, its management would be more willing to implement CSR. The implication is that a firm could pursue better performance while serving as a good corporate citizen.

关键词： corporate social responsibility (CSR) corporate social responsibility index (CSRI) stakeholders firm performance socially responsible investment

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Recent progress in lantha-nide-catalyzed organic reactions in protic media

引用

Chinese Science Bulletin 2001年第20期46卷 1673-1681页

作者： LUO Sanzhong ZHANG Baolian XIAN Ming Adam Janczuk XIE Wenhua CHENG Jinpei Peng george wang Department of Chemistry Nankai UniversityTianjin 300071China Department of Chemistry Wayne State UniversityDetroit MI 48202-3489USA

Lanthanide triflates are stable in water. It is possible for lanthanides to undergo many organic reactions in environmentally friendly solvents. This makes lanthanides very promising in the field of green chemistry. This review describes the recent development of the lanthanide-catalyzed organic reactions in protic solvents. Those reac-tions include Diels-Alder, Aldol, Allylation, acetalization, pericyclization, radical reactions as well as some newly-developed lanthnides-based catalysts.

关键词： green chemistry lanthanide triflate aqueous media organic syntheses.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：