检索结果-南通市图书馆

Microhabitat heterogeneity associated with Vanilla *** its influences on the microbial community of leaf litter and soil

引用

Soil Ecology Letters 2020年第3期2卷 195-208页

作者： Gabriela Montes de Oca-Vasquez frank Solano-Campos Bernal Azofeifa-Bolanos Amelia Paniagua-Vasquez Jose Vega-Baudrit Antonio Ruiz-navarro Ruben Lopez-Mondejar Felipe Bastida national nanotechnology Laboratory National Center for High Technology10109 PavasSan JoseCosta Rica School of Biological Sciences Universidad NacionalCampus Omar Dengo86-3000 HerediaCosta Rica Asociacion nacional de Vainilleros Unidos San JoseCosta Rica Instituto de Investigacion y Servicios Forestales Universidad Nacional86-3000 HerediaCosta Rica Laboratory of Polymer Science and Technology School of ChemistryUniversidad NacionalCampus Omar Dengo86-3000 HerediaCosta Rica CEBAS-CSIC Department of Soil and Water ConservationCampus Universitario de Espinardo30100MurciaSpain Laboratory of Environmental Microbiology Institute of Microbiology of the CASVidenska 1083Praha 414220Czech Republic

The impact of forest microhabitats on physiochemical properties of the soil and that of microbial communities on tropical soils remain poorly *** elucidate the effect of tropical forest stand on leaf litter and soil microbial communities,we studied enzyme activities,microbial biomass,and diversity in three distinct microhabitats in terms of plant richness,diameter at breast height(DBH),and physiochemical properties of soil and litter,each associated with a different Vanilla *** the soil,positive correlations were found between electrical conductivity(EC)and total organic carbon(TOC)with phosphatase activity,and between nitrogen(n)and water-soluble carbon(WSC)content with urease activity(UA).In the litter,the water content was positively correlated with bacterial and fungal biomass,and n and WSC contents were positively correlated with fungal *** correlations were found between plant richness and UA in the soil,plant richness and fungal biomass in the soil and litter,and DBH and fungal biomass in the *** sequencing revealed differences between microhabitats in the relative abundance of some fungal and bacterial taxa and in the bacterial community composition of both litter and *** richness and diversity were different between microhabitats,and,in litter samples,they were negatively correlated with DBH and plant richness,*** contrast,none of the soil and litter physiochemical properties were significantly correlated with microbial *** results show that significant shifts in enzyme activity,microbial biomass,and diversity in the microhabitats were driven by key abiotic and biotic factors depending on the soil or litter sample type.

关键词： Tropical rainforest Enzyme activity Microbial community composition Microbial biomass Plant richness

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

Delineation of Shallow Aquifers of Umuahia and Environs, Imo River Basin, nigeria, Using Geo-Sounding Data

引用

Journal of Water Resource and Protection 2013年第11期5卷 1097-1109页

作者： Uchenna Ugada Alexander I. Opara Theophilus T. Emberga frank D. Ibim Alexander I. Omenikoro Edwin n. Womuru Department of Geosciences School of Sciences Federal University of Technology Owerri Nigeria Department of Physics Federal Polytechnic Nekede Owerri Nigeria Department of Physics Ignatius Ajuru University of Education Port Harcourt Nigeria

This work was undertaken to study the hydrogeophysical characteristics of Umuahia and environs,ImoRiver Basinusing geophysical data. Thirty (30) vertical electrical sounding data with a maximum electrode spacing of (AB/2) of 500 meters were acquired using the Schlumberger electrode configuration. The VES data were interpreted using the conventional partial curve matching technique to obtain initial model parameters, which were used as input for computer iterative modelling using the OFFIX software. The study revealed three (3) to six (6) geo-electric layers with underlying shale beds. Aquifer apparent resistivity in the study area ranges from about 50 to 850 Ωm with the aquifer depth varying between 0.53 - 82.67 m. Similarly, the aquifer thickness in the study area ranges from 0.8 - 110 m, with very low thicknesses around Ajata Ibeku. These shallow aquifers with very small thicknesses in the western areas around Ajata Ibeku are believed to be perched or fractured shale units with very low or no yield. Finally, transverse resistances in the study area range from 200 - 3400 Ωm2 with low values in the western part. Information extracted from iso-resistivity models, geoelectric cross sections, litho logs and electric logs revealed a sandy clay lithology at very shallow depths with a thick layer of shale/clay extending to over 300 m within the western part. These shallow aquiferous units are however perched, partially saturated and may not have sufficient yield. Finally, this study has helped to delineate the aquifers of the study into two distinct zones, thus revealing a groundwater divide.

关键词： Geo-Sounding Aquifer Units Resistivity Transverse Resistance Longitudinal Conductance nigeria

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

过磷酸钙添加剂对猪粪堆肥温室气体和氨气减排的作用

引用

农业工程学报 2012年第22期28卷 235-242页

作者：罗一鸣李国学 frank Schuchardt 王坤江滔罗文海中国农业大学资源与环境学院北京100193 德国联邦农业科学院农业技术与生态系统工程研究所布伦瑞克38116 乐山师范学院化学与生命科学学院乐山614004

为研究不同比例过磷酸钙添加剂对畜禽粪便高温堆肥氨挥发和温室气体减排的作用,该文以猪粪和玉米秸秆为试验材料,以市售过磷酸钙肥料作为添加剂,在发酵仓中(单仓体积1.2m3)进行56d的好氧堆肥试验,监测堆肥过程中的温室气体和氨排放速率... 详细信息

为研究不同比例过磷酸钙添加剂对畜禽粪便高温堆肥氨挥发和温室气体减排的作用,该文以猪粪和玉米秸秆为试验材料,以市售过磷酸钙肥料作为添加剂,在发酵仓中(单仓体积1.2m3)进行56d的好氧堆肥试验,监测堆肥过程中的温室气体和氨排放速率及堆体碳、氮损失率。结果表明:在初始物料中添加干质量3.3%～13.2%的过磷酸钙添加剂对减少堆体碳、氮损失,降低温室气体排放均有明显效果,但超过初始物料干质量的9.9%的过磷酸钙添加剂会对堆肥腐熟进程产生显著抑制作用;该试验中添加初始物料干质量3.3%～6.6%分别使堆肥56d的nH3、n2O和CH4排放量减少了24.1%～43.4%、22.2%～27.7%和22.4%～62.9%,总温室气体排放当量减少30%。猪粪和玉米秸秆堆肥中较适宜的过磷酸钙添加量是初始物料干质量的3.3%～6.6%。该文为过磷酸钙添加剂应用于实际堆肥工程提供理论依据。

关键词：堆肥温室气体粪便氨气过磷酸钙

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

水飞蓟素的肝脏保护作用研究(英文)

引用

中南大学学报（医学版） 2012年第1期37卷 6-10页

作者： frank J.Burczynski 汪谷奇 David nguyen 陈宇非 Howard J.Smith 巩跃文马尼托巴大学药学院加拿大马尼托巴温尼伯R3E OT5 马尼托巴大学医学院药理学与药物治疗系加拿大马尼托巴温尼伯R3E OT5 卡罗林医学中心美国北卡罗莱那州夏洛特28203 Howard J Smith联合公司澳大利亚墨尔本VIC3000

目的:研究水飞蓟素对人正常肝细胞(Chang细胞株)的保护作用,尤其是其抗氧化活性和对细胞抗凋亡的保护作用。方法:采用400μmol/L H2O2处理Chang细胞20 min后,通过二氯荧光黄(dichlorofluorescein,DCF)荧光强度检测细胞内自由基水平,并... 详细信息

目的:研究水飞蓟素对人正常肝细胞(Chang细胞株)的保护作用,尤其是其抗氧化活性和对细胞抗凋亡的保护作用。方法:采用400μmol/L H2O2处理Chang细胞20 min后,通过二氯荧光黄(dichlorofluorescein,DCF)荧光强度检测细胞内自由基水平,并检测了细胞活性及细胞内Bax表达水平和ATP水平。结果:水飞蓟素明显降低了DCF荧光信号,显示细胞内自由基生成减少。MTT实验结果显示水飞蓟素可增强细胞活性,增加细胞内ATP水平,而减少促凋亡蛋白Bax的转录和表达水平。结论:水飞蓟素可抑制Bas表达,具有保护细胞抗氧化应激所致自由基损伤的作用。水飞蓟素可作为治疗特异性肝脏疾病的有效辅助药物。

关键词：水飞蓟素肝脏疾病肝脏保护作用凋亡

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

基于重组人胶原构建角膜替代物

引用

高分子通报 2010年第8期 1-6页

作者：刘文广 May Griffith frank Li 天津大学材料科学与工程学院天津300072 Department of Cellular and Molecular Medicine University of Ottawa

作为细胞外基的重要成分,胶原在组织工程支架中应用广泛。但目前报道的动物胶原存在传播病毒和免疫原反应等隐患。而基因工程方法生产的重组人胶原(RHC)具有生物安全性和性能优异等特点。本文主要介绍近几年以碳二亚胺和n-羟基琥珀酰亚... 详细信息

作为细胞外基的重要成分,胶原在组织工程支架中应用广泛。但目前报道的动物胶原存在传播病毒和免疫原反应等隐患。而基因工程方法生产的重组人胶原(RHC)具有生物安全性和性能优异等特点。本文主要介绍近几年以碳二亚胺和n-羟基琥珀酰亚胺对重组人Ⅰ型(RHC-Ⅰ)和重组人Ⅲ型(RHC-Ⅲ)胶原浓溶液进行交联构建的RHC角膜替代物、重组胶原/磷酸胆碱互穿聚合物网络水凝胶角膜替代物、重组胶原/含糖聚合物互穿聚合物网络水凝胶角膜替代物的研究进展,并概述了RHC-Ⅲ角膜替代物的I期临床实验结果。

关键词：重组人胶原角膜替代物水凝胶

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

Hetero-trans-β-Glucanase Produces Cellulose-Xyloglucan Covalent Bonds in the Cell Walls of Structural Plant Tissues and Is Stimulated by Expansin

引用

Molecular Plant 2020年第7期13卷 1047-1062页

作者： Klaus Herburger Lenka frankova Martina Picmanova Jia Wooi Loh Marcos Valenzuela-Ortega frank Meulewaeter Andrew D.Hudson Christopher E.French Stephen C.Fry The Edinburgh Cell Wall Group Institute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburgh EH93BFUnited Kingdom Institute of Quantitative Biology Biochemistry and BiotechnologySchool of Biological SciencesThe University of EdinburghEdinburgh EH93BFUnited Kingdom BASF BBCC Innovation Center Gent-Trait Research9052 Gent(Zwijnaarde)Belgium Zhejiang University-University of Edinburgh Joint Research Centre for Engineering Biology Zhejiang UniversityHainingZhejiang 314400China Present address:Section for Plant Glycobiology Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg 1871Denmark

Current cell-wall models assume no covalent bonding between cellulose and hemicelluloses such as xyloglu-can or mixed-linkageβ-D-glucan(MLG).However,Equisetum hetero-trans-β-glucanase(HTG)grafts cellu-lose onto xyloglucan oligosaccharides(XGOs)-and,we now show,xyloglucan polysaccharide-in vitro,thus exhibiting CXE(cellulose:xyloglucan endotransglucosylase)*** addition,HTG also catalyzes MLG-to-XGO bonding(MXE activity).In this study,we explored the CXE action of HTG in native plant cell walls and tested whether expansin exposes cellulose to HTG by disrupting hydrogen *** quantify and visu-alize CXE and MXE action,we assayed the sequential release of HTG products from cell walls pre-labeled with substrate *** demonstrated covalent cellulose--xyloglucan bonding in plant cell walls and showed that CXE and MXE action was up to 15%and 60%of total transglucanase action,respectively,and peaked in aging,strengthening tissues:CXE in xylem and cells bordering intercellular canals and MXE in *** bacterial expansin(EXLX1)strongly augmented CXE activity in *** and MXE ac-tion in living Equisetum structural tissues potentially strengthens stems,while expansin might augment the HTG-catalyzed CXE reaction,thereby allowing efficient CXE action in *** methods will enable surveys for comparable reactions throughout the plant ***,engineering similar hetero-polymer formation into angiosperm crop plants may improve certain agronomic traits such as lodging tolerance.

关键词： cell wall cellulose hemicelluloses hetero-trans-p-glucanase hetero-transglycosylation xyloglucan

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

Assessing Lysine Requirement of Growing Chicken by Direct Comparison between Supplementation Technique and “Goettingen Approach”

引用

Open Journal of Animal Sciences 2017年第1期7卷 56-69页

作者： &nbsp Samadi Christian Wecke Anja Pastor frank Liebert Department of Animal Sciences Division Animal Nutrition Physiology Georg-August-University of Goettingen Goettingen Germany Animal Husbandry Department Agricultural Faculty Syiah Kuala University Banda Aceh Indonesia Phytobiotics Futterzusatzstoffe GmbH Eltville Germany

Validated procedures play an important role to obtain accurate information about individual amino acid requirement data. The aim of the present study was to assess lysine (Lys) requirement of growing chicken both by classical supplementation technique and principles of diet dilution technique as applied with “Goettingen approach”. During the starter period (1 - 21 d), a growth study with male meat type chicken (Ross 308) was conducted making use of five graded dietary Lys-levels (3 repetition boxes with 3 birds/box). L-Lys×HCl was gradually added to a diet based on wheat, soybean protein concentrate, wheat gluten and fishmeal to yield 80%, 87.5%, 95%, 102.5% and 110% of the expected requirement level (13 g Lys/kg as fed). Diets were iso-energetic (12.8 MJME/kg) and iso-nitrogenous (21.65% crude protein). Birds were fed on free choice level also to assess the feed intake (FI) effects as important factor on traditional response criteria. Analyzed body composition at start and end of the growth study yielded n deposition (nD) data for further data assessment using exponential approximations depending on dietary Lys content or observed Lys intake. The results indicated significant differences (p n response on body weight gain (BWG) and observed dietary protein quality with unexpected consequences for the derived Lys requirement data. According to the independent variable (Lys in % of diet versus daily Lys intake) and aimed level of daily nD, the needed in-feed content of Lys varied between 1.24% and 1.46%. Application of the exponential modelling by “Goettingen approach” overcame these misleading conclusions by modelling the relationship between required Lys intake and observed response data (BWG, nD) taking also into account the expected real feed intake to formulate the needed in-feed concentration.

关键词： Growing Chicken Lysine Requirement Supplementation Technique Diet Dilution Technique n Utilization Model Amino Acid Efficiency

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

An Elevated Dietary Cysteine to Methionine Ratio Does not Impact on Dietary Methionine Efficiency and the Derived Optimal Methionine to Lysine Ratio in Diets for Meat Type Chicken

引用

Open Journal of Animal Sciences 2015年第4期5卷 457-466页

作者： Daulat Rehman Khan Christian Wecke frank Liebert Department of Animal Sciences Division Animal Nutrition Physiology University of Goettingen Goettingen Germany

Optimal dietary methionine (Met) to lysine (Lys) ratio in presence of elevated dietary cysteine (Cys) levels was derived for meat type growing chicken. Twelve averaged weighed Ross 308 birds (each 50% of male and female per dietary treatment) were utilized in n balance trials. During starter (d10 - 20) and grower period (d25 - 35) five dietary treatments were used. Diets based on uniform mixtures of maize, wheat, soybean meal, potato protein and fish meal were supplemented with crystalline amino acids (AA). In diets 1 - 3, the dietary Cys to Met ratio was set as 85, 95 and 105 to 100, respectively. Diet 4, at a Cys to Met ratio of 105 to 100, was additionally supplemented with betaine (BET) as methyl group donor. Diets 1 - 4 were limiting in Met, diet 5 without L-Lys·HCl addition was limiting in Lys. Individual n-balance data per treatment were utilized for assessing protein quality and efficiency of dietary Met (Diets 1 - 4) or Lys (Diet 5) based on “Goettingen approach”. Elevated dietary Cys supply and supplemented BET failed to improve both dietary protein quality and Met efficiency. The established optimal Met to Lys ratio was on average 34 to 100 for growing chicken during starter and grower period, respectively.

关键词： Growing Chicken n Utilization Model Amino Acid Efficiency Methionine to Lysine Ratio Cysteine Betaine

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

InERTIA SETS OF SYMMETRIC SIGn PATTERn MATRICES

引用

numerical Mathematics A Journal of Chinese Universities(English Series) 2001年第2期10卷 226-240页

作者： frank J.Hall Li 李忠尚 Department of Mathematics and Statistics Georgia State University Atlanta GA 30303 USA

A sign pattern matrix is a matrix whose entries are from the set {+,-,0}. The symmetric sign pattern matrices that require unique inertia have recently been characterized. The purpose of this paper is to more generally investigate the inertia sets of symmetric sign pattern matrices. In particular, nonnegative tri-diagonal sign patterns and the square sign pattern with all + entries are examined. An algorithm is given for generating nonnegative real symmetric Toeplitz matrices with zero diagonal of orders n≥3 which have exactly two negative eigenvalues. The inertia set of the square pattern with all + off-diagonal entries and zero diagonal entries is then analyzed. The types of inertias which can be in the inertia set of any sign pattern are also obtained in the paper. Specifically, certain compatibility and consecutiveness properties are established.

关键词： inertia, sign pattern matrix, inertia set, unique inertia, Toeplitz matrix.

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

Pain sensation in pancreatic diseases is not uniform: The different facets of pancreatic pain

引用

World Journal of Gastroenterology 2014年第27期20卷 9154-9161页

作者： Jan G D'Haese Mark Hartel Ihsan Ekin Demir Ulf Hinz frank Bergmann Markus W Büchler Helmut Friess Güralp O Ceyhan Department of Surgery Klinikum Rechts der Isar Technische Universit?t München Unit for Documentation and Statistics Department of General Surgery University of Heidelberg Institute of Pathology University of Heidelberg Department of General Surgery University of Heidelberg

AIM: To systematically characterize specific pain patterns in the most frequent pancreatic diseases.

关键词： Abdominal pain Pancreatic neoplasm Chronic pancreatitis Intraductal papillary mucinous neoplasia Pancreatic cancer

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：