检索结果-南通市图书馆

Comparative analysis of astaxanthin and its esters in the mutant E1 of Haematococcus pluvialis and other green algae by HPLC with a C30 column

引用

science china(Life sciences) 2008年第12期51卷 1108-1115页

作者： PENG Juan1, XIANG WenZhou2,1, TANG QuanMing1, sun Ni1, CHEN Feng1,3 & YUAN JianPing 4 1 South china Sea Institute of Oceanology, Chinese Academy of sciences, guangzhou 510301, china 2 Institute of Oceanology, Chinese Academy of sciences, Qingdao 266071, china 3 school of Biological sciences, The university of Hong Kong, Hong Kong, china 4 Institute of Oceanology & College of Life sciences, sun yat-sen university, guangzhou 510301, china South china Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou China Institute of Oceanology Chinese Academy of Sciences Qingdao China school of Biological sciences The University of Hong Kong Hong Kong China Institute of Oceanology & College of Life sciences Sun Yat-Sen University Guangzhou China

A gradient reversed-phase high-performance liquid chromatography (HPLC) method using a C30 col-umn was developed for the simultaneous determination of astaxanthin, astaxanthin monoesters and astaxanthin diesters in the green algae Chlorococcum sp., Chlorella zofingiensis, Haematococcus plu-vialis and the mutant E1, which was obtained from the mutagenesis of H. pluvialis by exposure to UV-irradiation and ethyl methanesulphonate (EMS) with subsequent screening using nicotine. The re-sults showed that the contents of total astaxanthins including free astaxanthin and astaxanthin esters ranged from 1.4 to 30.9 mg/g dry biomass in these green algae. The lower total astaxanthin levels (16 mg/g dry biomass) were found in the green alga H. pluvialis and its mutant E1. It is notable that the mutant E1 is found to have considerably higher amounts of total astaxanthin (30.9 mg/g) as compared to the wild strain of H. pluvialis (16.1 mg/g). This indicates that UV-irradiation and EMS compound mutagenesis with subsequent screening using nicotine is an effective method for breeding of a high-producing astaxanthin strain of H. pluvialis. In addition, the green alga C. zofingien-sis had a remarkably higher percentage of astaxanthin diesters (76.3% of total astaxanthins) and a re-markably lower percentage of astaxanthin monoesters (18.0% of total astaxanthins) in comparison with H. pluvialis (35.5% for diesters and 60.9% for monoesters), the mutant E1 (49.1% and 48.1%) and Chlorococcum sp. (18.0% and 58.6%).

关键词： green algae Haematococcus pluvialis mutant astaxanthin HPLC C30 column

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

Polycyclic Aromatic Hydrocarbons in Agricultural Soils of the Southern Subtropics,china

引用

Pedosphere 2007年第5期17卷 673-680页

作者： HAO Rong WAN Hong-Fu SONG Yan-Tun JIANG Hong PENG Shao-Lin South china Botanical Garden Chinese Academy of Sciences Guangzhou 510650 （China） Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control Guangdong Institute of Eco- Environment and Soil Sciences Guangzhou 510650 （China） school of Life science Sun Yat-Sen University Guangzhou 510275 （China） Conservation Biology Institute 260 SW Madison Ave. Suite 106 Corvallis OR 97333 （USA）

The contributions of persistent organic pollutants （POPs） from the subtropical regions of china to pollution of the global environment have been paid great attention; however, little is known about the state of POPs in agricultural ecosystems within these regions of china. This study primarily revealed the state of the contamination and distribution of polycyclic aromatic hydrocarbons （PAH） in agricultural soils in the subtropical regions. 115 surface soils （0-20 cm） were sampled in the breadbaskets of these regions. The concentrations and types of PAH were determined using gas chromatography linked to mass spectrometry （GC-MS）. The total PAH concentrations ranged from 22.1 to 1 256.9 ng g^-1 with a mean of 318.2 ± 148.2 ng g^-1. In general terms, the current PAH concentrations were lower than most PAH levels reported in a number of investigations from different countries and regions. PAH isomer ratios indicated that pyrolytic origins, such as fossil fuel combustion related to vehicle tail gas and industrial emissions, were the dominant sources of PAH in the southern subtropical areas of china. Although PAH concentrations decreased with decreasing pollution, population, and traffic density, to a great extent PAH compositions were similar throughout subtropical soils, with naphthalene, phenanthrene, fluoranthene, and benzo（b）fluoranthene being dominant.

关键词： agricultural soils polycyclic aromatic hydrocarbons subtropical region

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

Unification and Comparison on Bi-Criteria Velocity,Acceleration and Torque Minimization Illustrated via Three-Link Planar Robot Arm

Unification and Comparison on Bi-Criteria Velocity,Accelerat...

引用

2011 Chinese Control and Decision Conference（CCDC）

作者： Yunong Zhang,Dongsheng Guo,Jun Li,and Kene Li The authors are with school of information science and technology,sun yat-sen university,guangzhou 510006,china

In this paper,the latest result that the bi-criteria redundancy-resolution schemes at different levels （i.e.,the joint-velocity,-acceleration and-torque levels） can be unified into a quadratic-programming （QP） problem formulation,is presented and summarized for redundant robot arms with joint physical *** addition,comparison on the three schemes is presented for further *** presented QP-based formulation,subject to equality,inequality and bound constraints simultaneously,is then solved online via a primaldual neural network based on linear variation inequalities （LVI）.Computer-simulation results based on PUMA560,PA10 and multi-link planar robot arms （specially,a three-link planar robot arm in this paper） have demonstrated the efficacy of the bi-criteria neural-weighting schemes,as well as the resultant QP-based unification of robots’ redundancy resolution.

关键词： Velocity level Acceleration level Torque level Bi-criteria Quadratic program Redundancy resolution

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Functional distinction of rat liver natural killer cells from spleen natural killer cells under normal and acidic conditions in vitro

引用

Hepatobiliary & Pancreatic Diseases International 2012年第3期11卷 285-293页

作者： Li-Hong Lv, Jian-Dong Yu, Guo-Lin Li, Tian-Zhu Long, Wei Zhang, Ya-Jin Chen, Jun Min and Yun-Le Wan Department of Hepatobiliary Surgery, sun yat-sen Memorial Hospital, sun yat-sen university Department of Breast Surgery, guangzhou Women and Children’s Medical Center guangzhou 510120, china Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, Zhejiang university school of Medicine, Hangzhou 310003, china Department of Hepatobiliary Surgery Sun Yat-Sen Memorial Hospital Sun Yat-Sen University (Lv LH Yu JD Li GL Chen YJ Min J and Wan YL) guangzhou 510120 China Department of Breast Surgery Guangzhou Women and Children's Medical Center (Long TZ) Department of Hepatobiliary and Pancreatic Surgery First Affiliated Hospital Zhejiang University School of Medicine Hangzhou 310003 China

BACKGROUND: The microenvironment within solid tumors has often been shown to exhibit an acidic extracellular pH. Although the morphologic and functional differences in natural killer (NK) cells of the liver and spleen have been reported previously under physiological conditions, the difference under acidic conditions is still unclear. This study was to investigate the differences in the morphological and functional characteristics between rat liver and spleen NK cells under normal and acidic conditions in vitro. METHODS: Liver and spleen NK cells were isolated and purified from Sprague-Dawley rats by density gradient centrifugation and the Dynabeads FlowComp TM Flexi system, and stimulated for 4 days with or without IL-2 or treated with low pH or control for different times. Morphology was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), cell death and proliferation assays were performed by flow cytometry, IFN-γ production was tested by ELISA, and cytotoxic activity was evaluated by lactate dehydrogenase (LDH) release assay. RESULTS: Liver NK cells had significantly higher levels of cytotoxic activity than spleen NK cells under normal and acidic conditions, and the maximum difference was observed at pH 5.6. Further analysis revealed that the cytotoxic activity of NK cells was correlated with morphology, cell death, proliferative activity and IFN-γ production. By TEM, liver NK cells contained a greater number of electron-dense granules per cell at pH ***, a modest elevation of cell death and reduction of proliferation of liver NK cells occurred within a range of 5.6-7.2. Interestingly, an acidic extracellular pH only marginally, and not significantly, suppressed IFN-γ production by liver NK cells. CONCLUSION: The sharp morphological and functional differences shown by the two types of NK cells in vitro indicate that liver NK cells are unexpectedly resistant to pH shock.

关键词： natural killer cells liver spleen tumor microenvironment extracellular pH

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

制造业服务化与经营绩效的实证检验——基于中美上市公司的比较

引用

商业经济与管理 2010年第4期222卷 33-41页

作者：陈洁雄中山大学管理学院广东广州510275

文章以中美两国的装备制造、汽车、家电以及电子信息等制造行业为研究对象,围绕服务化对制造企业经营绩效的影响展开探讨。研究结果表明:中美制造企业主要存在8种服务化形式;中国企业的服务化程度以及服务的资本、知识和技术强度低于美... 详细信息

文章以中美两国的装备制造、汽车、家电以及电子信息等制造行业为研究对象,围绕服务化对制造企业经营绩效的影响展开探讨。研究结果表明:中美制造企业主要存在8种服务化形式;中国企业的服务化程度以及服务的资本、知识和技术强度低于美国;中国企业的服务化对其经营绩效存有显著的倒U型关系,而美国企业只有显著的正向线性关系。在此基础上,文章认为促进企业从"制造文化"向"服务文化"转型;增强企业的服务运营能力;合理开展服务业务;提升服务能效是加强我国制造业竞争力,实现产业健康可持续发展的重要任务。

关键词：制造业服务化经营绩效

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

Advances in RFID-ILA: The Past, Present and Future of RFID-based Indoor Location Algorithms

Advances in RFID-ILA: The Past, Present and Future of RFID-b...

引用

第24届中国控制与决策会议

作者： Zhonghua Li*, Zijing Zhou, Chunhui He and Xiao Huang school of information science and technology, sun yat-sen university, guangzhou 510006, Guangdong china

Indoor location technologies refer to those positioning algorithms and methods that can offer the position of a target object under the indoor environment. With the advantages of non-contact, low-cost and high-accuracy, radio frequency identification （RFID） has become a class of preferred indoor location technology. Therefore, RFID-based indoor location algorithms （RFID-ILA） are an essential component in indoor location systems. In order to achieve accurate indoor location, many RFID-based indoor location algorithms have been proposed and studied. This paper attempts to globally review the advances in RFID-based indoor location algorithms and to further discuss the future prospects of research and development in the indoor location field for many industrial and domestic applications.

关键词： RFID indoor location algorithm signal time of arrival signal time difference of arrival signal angle of arrival received signal strength prospect

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

1994—2003年信息资源管理研究进程及发展趋势

引用

图书情报工作 2004年第11期48卷 115-118页

作者：周群中山大学信息管理系广州510275

依据对1994-2003年发表于图书馆学、情报学核心期刊上有关信息资源管理研究论文的分析,将信息资源管理研究进程分为3个阶段,即萌芽阶段、发展阶段和繁荣阶段;对各个阶段的研究内容及其特点进行详细论述;并对信息资源管理研究的发展趋势... 详细信息

依据对1994-2003年发表于图书馆学、情报学核心期刊上有关信息资源管理研究论文的分析,将信息资源管理研究进程分为3个阶段,即萌芽阶段、发展阶段和繁荣阶段;对各个阶段的研究内容及其特点进行详细论述;并对信息资源管理研究的发展趋势作出预测。

关键词：信息资源管理情报学核心期刊图书馆学研究论文研究内容发展阶段发展趋势预测依据

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

Minimizing Risk Models in Denumerable Semi-Markov Decision Processes with a Target Set

Minimizing Risk Models in Denumerable Semi-Markov Decision P...

引用

第二十九届中国控制会议

作者： HUANG Yonghui,GUO Xianping school of Mathematics and Computational science,sun yat-sen university,guangzhou 510275,P.R.china

This paper deals with the risk minimization problem in semi-Markov decision processes with denumerable *** criterion to be minimized is the risk probability that a total reward over a first passage time to some target set doesn’t exceed a *** first characterize the optimal value function,and then establish the optimality equation and the existence of optimal policies under mild ***,we give some sufficient conditions for the existence of an optimal policy,and these conditions are imposed on the primitive data of the model and are thus easy to ***,a numerical example is given to illustrate our results.

关键词： Semi-Markov Decision Processes Target Set Risk Probability Optimality Equation Optimal Policy

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

我国图书馆学专业论坛的现状及展望

引用

图书情报工作 2004年第12期48卷 110-114页

作者：庞蓓中山大学信息管理系广州510275

首先对我国目前较为知名的5个图书馆学专业论坛的现状进行简要介绍和分析比较,在此基础上提出建设图书馆学专业论坛必须注意的几个问题,包括论坛的稳定性和技术支持、论坛的信息质量、用户的忠诚度、知识产权和用户隐私的保护以及论坛... 详细信息

首先对我国目前较为知名的5个图书馆学专业论坛的现状进行简要介绍和分析比较,在此基础上提出建设图书馆学专业论坛必须注意的几个问题,包括论坛的稳定性和技术支持、论坛的信息质量、用户的忠诚度、知识产权和用户隐私的保护以及论坛的推广。最后,对图书馆学专业论坛的发展趋势进行展望,认为其规模将不断扩大,服务方式将多样化,网民素质和论坛整体水平将有所提高,讨论区也将进一步多元化、细分化。

关键词：图书馆学专业论坛 BBS 现状趋势

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

林则徐和魏源对西方图书馆的译介

引用

图书馆论坛 2004年第1期24卷 7-10页

作者：程焕文中山大学信息管理系广东广州510275

作为近代中国睁眼看世界第一人和近代中国维新运动的重要先驱,林则徐是晚清时期中国翻译介绍西方图书馆的第一人。本文全面分析了林则徐在1840年左右组织编译的《四洲志》,以及魏源于1842年重编的《海国图志》翻译介绍西方图书馆,尤其... 详细信息

作为近代中国睁眼看世界第一人和近代中国维新运动的重要先驱,林则徐是晚清时期中国翻译介绍西方图书馆的第一人。本文全面分析了林则徐在1840年左右组织编译的《四洲志》,以及魏源于1842年重编的《海国图志》翻译介绍西方图书馆,尤其是美国公共图书馆的历史史实,从而说明了西方图书馆观念最初流入中国的情形。

关键词：林则徐魏源西方图书馆史文献翻译《四洲志》《海国图志》

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：