检索结果-南通市图书馆

Camouflage Patterning in Maize Leaves Results from a Defect in Porphobilinogen Deaminase

Molecular Plant 2009年第4期2卷 773-789页

作者： mingshu huanga Thomas L. Slewinski R. Frank Baker , Diane Janick-Buckner Brent Buckner Gurmukh S. Johal David M. Braun Department of Biology Pennsylvania State University University Park PA 16802 Division of Science Truman State University Kirksville MO 63501 Department of Botany and Plant Pathology Purdue University West Lafayette IN 47907

Maize leaves are produced from polarized cell divisions that result in clonal cell lineages arrayed along the long axis of the leaf. We utilized this stereotypical division pattern to identify a collection of mutants that form chloroplast pigmentation sectors that violate the clonal cell lineages. Here, we describe the camouflage1 （cfl） mutant, which develops nonclonal, yellow-green sectors in its leaves. We cloned the cfl gene by transposon tagging and determined that it encodes porphobilinogen deaminase （PBGD）, an enzyme that functions early in chlorophyll and heme biosynthesis. While PBGD has been characterized biochemically, no viable mutations in this gene have been reported in plants. To investigate the in vivo function of PBGD, we characterized the cfl mutant. Histological analyses revealed that cfl yellow sectors display the novel phenotype of bundle sheath cell-specific death. Light-shift experiments determined that constant light suppressed cfl sector formation, a dark/light transition is required to induce yellow sectors, and that sectors form only during a limited time of leaf development. Biochemical experiments determined that of 1 mutant leaves have decreased PBGD activity and increased levels of the enzyme substrate in both green and yellow regions. Furthermore, the cfl yellow regions displayed a reduction in catalase activity. A threshold model is hypothesized to explain the cfl variegation and incorporates photosynthetic cell differentiation, reactive oxygen species scavenging, and PBGD function.

关键词： camouflage1 maize porphobilinogen deaminase tetrapyrrole biosynthesis variegated leaf.

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

Growth hormone receptor expression in human primary gastric adenocarcinoma

引用

The Journal of Biomedical Research 2012年第5期26卷 307-314页

作者： Xiaodong Yang Ping huanga Feng Wang Zekuan Xu Xiaonin Wang Department of General Surgery the First Affiliated Hospital the Nanjing Medical University Nanjing Jiangsu 210029 China Department of General Surgery Jiangsu Hospital of Integrated Traditional Chinese and Western Medicine Nanjing Jiangsu 210028 China

The aim of this study was to determine the expression of growth hormone receptor（GHR） in patients with pri-mary gastric *** investigated 48 specimens of primary gastric adenocarcinoma and their cor-responding normal gastric *** and reverse transcription-polymerase chain reaction（RT-PCR） were used to detect the expression of *** analyses revealed that GHR was expressed in human primary gastric adenocarcinoma（36/48,75.0%） and appeared to be upregulated,compared to the normal mucosa（28/48,58.3%,P 〈 0.001）.A significant correlation was found between GHR expression and tumor stage（P 〈 0.001） and tumor differentiation（P 〈 0.001）.The average positive rate of ki-67 in GHR-positive tumors was 16.06%,while the positive rate in GHR-negative tumors was 6.17%（P 〈 0.01）.The average apoptosis index（AI） of GHR-positive tumors was 3.36%,which was significantly lower than that（7.33%） of GHR-negative *** addition,27 of 48 cases of tumors had GHR mRNA expression,while only 17 of all 48 cases of normal mucosa did *** results indicate that the frequency of GHR was significantly higher in primary gastric adeno-carcinoma than that in normal gastric *** expression was significantly correlated with tumor differen-tiation and tumor *** finding supported a possible role of growth hormone in primary gastric adenocarci-noma pathophysiology.

关键词： growth hormone receptor primary gastric cancer proliferative index apoptosis index

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

Covalent triazine-based frameworks confining cobalt single atoms for photocatalytic CO_(2) reduction and hydrogen production

引用

Journal of Materials Science & Technology 2022年第21期116卷 41-49页

作者： Guocheng Huang Guiyun Lin Qing Niu Jinhong Bi Ling Wu Department of Environmental Science and Engineering Fuzhou UniversityMinhouFujian 350108China State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou UniversityMinhouFujian 350108China

Single-atom catalysts(SACs)have emerged as an advanced frontier in heterogeneous catalysis due to their potential to maximize the atomic ***,covalent triazine-based frameworks(CTFs)confining cobalt single atoms(Co-SA/CTF)photocatalysts have been synthesized and used for efficient CO_(2) reduction and hydrogen production under visible light *** resulted Co-SA/CTF demonstrate excellent photocatalytic activity,with the CO and H2 evolution rates reaching 1665.74μmol g^(−1) h^(−1) and 1293.18μmol g^(−1) h^(−1),respectively,far surpassing those of Co nanoparticles anchored CTF and pure CTF.A variety of instrumental analyses collectively indicated that Co single atoms sites served as the reaction center for activating the adsorbed CO_(2) molecules,which significantly improved the CO_(2) reduction ***,the introduction of Co single atoms could accelerate the separation/transfer of photogenerated charge carriers,thus boosting the photocatalytic *** study envisions a novel strategy for designing efficient photocatalysts for energy conversion and showcases the application of CTFs as attractive support for confining metal single atoms.

关键词： Covalent triazine-based frameworks Co single atoms Photocatalysis CO_(2)reduction Hydrogen evolution

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

Fused Autonomous Navigation for Spacecrafts around Mars using Optical Measurements

Fused Autonomous Navigation for Spacecrafts around Mars usin...

引用

新型导航技术及应用研讨会

作者： Maodeng Li Dayi Wang Xiangyu huanga aScience and Technology on Space Intelligent Control and Laboratory Beijing Institute of Control Engineering

This paper focuses on the autonomous optical navigation problems for surrounded phase of Mars *** measurement equations using optical sensors are developed, and a fused navigation scheme is proposed based on state-vector fusion methods. In this scheme, each measurement equation is processed into individual Kalman filters to form local estimates, and a linear fusion rule is applied to fuse local estimates. The proposed fusion rule is derived from covariance-intersection algorithm to cope with unknown correlations and redundant information of local estimates. At last, the performance of all the navigation strategies are analyzed through numerical simulations.

关键词： Mars Exploration Autonomous Navigation Sensor Fusion Covariance Intersection Algorithm

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

Electrospun Supramolecular Hybrid Microfibers from Conjugated Polymers:Color Transformation and Conductivity Evolution

引用

Chinese Journal of Polymer Science 2021年第7期39卷 824-830页

作者： Wei Xue Man Xu Meng-Na Yu Hua-Min Sun Jin-Yi Lin Rong-Cui Jiang Ling-Hai Xie Nai-En Shi Wei huanga Center for Molecular Systems and Organic Devices(CMSOD) Key Laboratory for Organic Electronics and Information Displays&Institute of Advanced Materials(IAM)Nanjing University of Posts&TelecommunicationsNanjing 210023China Center for Supramolecular Optoelectronics(CSO) Key Laboratory of Flexible Electronics(KLOFE)and Institute of Advanced Materials(IAM)Nanjing Tech University(NanjingTech)Nanjing 211816China Frontiers Science Center for Flexible Electronics(FSCFE) Shaanxi Institute of Flexible Electronics(SIFE)&Shaanxi Institute of Biomedical Materials and Engineering(SIBME)Northwestern Polytechnical University(NPU)Xi'an 710072China

A type of novel electrospun supramolecular hybrid microfibers comprising poly(9-(4-(octyloxy)-phenyl)-2,7-fluoren-9-ol)(PPFOH)and poly(A/-vinylcarbazole)(PVK)are successfully prepared for intriguing multi-color emission *** supramolecular tunable PPFOH aggregation in PVK matrix endows the complex with a smart energy transfer behavior to obtain the multi-color *** stark contrast to PVK fibers,the emission color of PPFOH/PVK fibers with an efficient dispersion of PPFOH fluorophores at a proper dope ratio can be tuned in a wide spectrum of blue(0.1%),sky blue(0.5%),nearly white(1%),cyan(2%),green(5%)and yellow(10%).Besides,conductive behaviors of the microfiber were demonstrated in accompany with the increment of the doping ratio of PPFOH to *** fabrication of polymer light-emitting diode(PLED)based on the blended electrospun fiber provided a further evidence of its excellent electrical property for potential applications in optoelectronic devices.

关键词： Supramolecular approach Electrospinningπ-conjugated fibers Multi-color emissions Conductivity Polymer light-emitting diodes

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

Fingerprint analysis of placenta polypeptide injection by high performance liquid chromatography

引用

Journal of Pharmaceutical Analysis 2012年第1期2卷 71-75页

作者： Li huanga, Xiao-Man Wub, Yu Jib, Yu Wanga,baChina Pharmaceutical University, Nanjing 210009, China bJiangsu Institute for Food and Drug Control, Nanjing 210008, China China Pharmaceutical University Nanjing 210009 China. Jiangsu Institute for Food and Drug Control Nanjing 210008 China.

Objective: To develop the representative fingerprint for the quality control of placenta polypeptide injection. Methods: The chromatographic separation was performed using a Phenomenex Gemini C18 column (250 mm 4.6 mm, 5 mm) maintained at 30 1C. 0.1% aqueous trifiuoroacetic acid (Solvent A) and acetonitrile contained 0.1% TFA (Solvent B) were used as mobile phase with a gradient elution. Detection wavelength was 280 nm with the sample injection volume of 50 mL; the fiow rate was 1.0 mL/min. The fingerprints of different samples were investigated by similarity analysis. Results: Nine peaks were identified as the characteristic common peaks. The similarities of the fingerprints of the 10 batches of samples were above 0.992. Conclusion: This method showed high precision and good repeatability, and provided the basis for the improvement of the quality control of placenta polypeptide injection.

关键词： Placenta polypeptide injection Fingerprint Similarity analysis High performance liquid chromatography

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

Simulating a typhoon storm surge in the East Sea of China using a coupled model

引用

Progress in Natural Science:Materials International 2009年第1期19卷 65-71页

作者： Baoshu Yin a,Zhenhua Xua,b,Yong huanga,b,Xiang Linc a Institute of Oceanology,Chinese Academy of Sciences,7# Nanhai Road,Qingdao 266071,China b Graduate School of Chinese Academy of Sciences,Beijing 100039,China c Traffic and Ocean Engineering College,Hohai University,Nanjing 210098,China Institute of Oceanology Chinese Academy of Sciences 7# Nanhai Road Qingdao 266071 China Graduate School of Chinese Academy of Sciences Beijing 100039 China Traffic and Ocean Engineering College Hohai University Nanjing 210098 China

A coupled numerical model with a 20 20 resolution grid has been developed and used to simulate five typical typhoon storm surges(5612,7413,7910,8114,and 9711) in the East Sea of *** main driving forces have been considered in this coupled model:wave radiation stress,combined wave-current bottom shear stress and wave-state-dependent surface wind *** model has then been compared with in situ measurements of the storm *** effect of different driving force components on the total storm surge has also been *** study has found that the coupled model with high resolution is capable of simulating the five typical typhoons better than the uncoupled models,and that the wave-dependent surface wind stress plays an important role in typhoon storm surge-wave coupling in this area and can increase the storm set-up by 1 *** study of the five typhoon cases has shown that the general coupling effects could increase storm set-up by 20-32%.Thus,it is suggested that to predict typhoon storm surges in the East Sea of China,a storm surge-wave coupled model be adopted.

关键词： East Sea of China Coupled model Typhoon storm surges Wave effects

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

粉末X射线衍射内标法研究丙酮溶液中β-HMX的晶习

引用

含能材料 2018年第2期26卷 161-166页

作者：关羽翔黄石亮刘渝徐金江曹雄中北大学化工与环境学院山西太原030051 中国工程物理研究院化工材料研究所四川绵阳621999

为了研究β-HMX晶体在丙酮溶液中的晶习,采用丙酮溶剂挥发法制备了β-HMX大单晶,利用粉末Ge O_2作为内标物质,通过粉末X射线衍射内标法,确定了β-HMX晶体所有显露面的晶面指数,从实验上建立了β-HMX在丙酮溶液中的晶习模型,并与文献报... 详细信息

为了研究β-HMX晶体在丙酮溶液中的晶习,采用丙酮溶剂挥发法制备了β-HMX大单晶,利用粉末Ge O_2作为内标物质,通过粉末X射线衍射内标法,确定了β-HMX晶体所有显露面的晶面指数,从实验上建立了β-HMX在丙酮溶液中的晶习模型,并与文献报道的利用不同生长模型模拟得到的晶习模型进行了比较。β-HMX晶体各个显露面的晶面指数分别为(1 0 0)、(0 1 1)、(-1 1 1)和(0 2 0),其中(1 0 0)晶面为最优生长面,其次为(0 1 1)、(-1 1 1)晶面,再次为(0 2 0)晶面,与溶剂校正后的AE模型模拟得到的β-HMX晶体在丙酮溶液中的晶习模型相符。丙酮分子与β-HMX晶体的(1 1 0)和(0 2 0)晶面的相互作用较弱,导致随晶体生长,(1 1 0)和(0 2 0)晶面逐渐消失,证明溶剂环境对HMX的晶体形貌具有很大的影响。

关键词： β-奥克托今(β-HMX) 晶习粉末X射线衍射内标法

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

Generation of endostatin by matrix metalloproteinases and cathepsins in human limbo-corneal epithelial cells cultivated on amniotic membrane

Generation of endostatin by matrix metalloproteinases and ca...

引用

第三届全球华人眼科学术大会暨中华医学会第十一届全国眼科学术大会

作者： David Hui-Kang Maa Jan-Kan Chenc Kuei-Ying Lina Samuel Chao-Ming huanga Ken-Kuo Lina Department of Ophthalmology Chang Gung Memorial Hospital Taoyuan Taiwan

Purpose: Previously, we found that human limbo - corneal epithelial cells (HLCECs) secreted more endostatin (EN), a potent angiogenic inhibitor, when HLE are cultured on am-niotic membrane (AM) (IOVS45: 2586, 2004). The purpose of this study is to understand proteolytic mechanism by which EN production is increased following cultivating HLCECs on AMMethods: We examined the level of MMP-7, - 9, cathepsin--B, - K, - L, and -V in the conditioned

关键词：

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

Quassinoids from the Root Barks of Ailanthus altissima:Isolation,Configurational Assignment,and Cytotoxic Activities

引用

Chinese Journal of Chemistry 2021年第4期39卷 879-886页

作者： Ye-Qing Du Ming Bai Xiao-Qi Yu Tian-Ming Lv Bin Lin Xiao-Xiao Huang Shao-Jiang Song Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research&Development Liaoning ProvinceSchool of Traditional Chinese Materia MedicaShenyang Pharmaceutical UniversityShenyangLiaoning 110016China School of Pharmaceutical Engineering Shenyang Pharmaceutical UniversityShenyangLiaoning 110016China

Main observation and conclusion Quassinoids,a class of highly oxygenated triterpenes,have been isolated as bitter principles from the plants of Simaroubaceae *** new quassinoids,chouchunlactone A-E(1-5),and two known ones were identified from the root barks of Ailanthus altissima Swingle(Simaroubaceae).The chemical structures of the new compounds were deduced by spectroscopic data analyses,NMR calculations and DP4+probability *** absolute configurations were defined by comparison of their experimental and calculated electronic circular dichroism(ECD)spectra data,and compounds 1-2 were further confirmed by single-crystal X-ray ***,compound 5 showed potencies equivalent to sorafenib(IC50 value,9.70μmol·L–1)against HepG2 *** Hoechst 33342 staining,JC-1 fluorescent dye and Annexin V/PI analysis studies demonstrated that 5 can induce apoptosis and attenuate mitochondrial membrane potential(MMP)in HepG2 cells.

关键词： Ailanthus altissima Simaroubaceae Quassinoids Cytotoxicity Apoptosis

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

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：