检索结果-内蒙古大学图书馆

A kinetic model of the thiazide-sensitive Na-Cl cotransporter

AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY 1999年第6期276卷 F952-F959页

作者： Chang, HG Fujita, T Univ Tokyo Hlth Serv Ctr Meguro Ku Tokyo 1538902 Japan Univ Tokyo Dept Internal Med 4 Tokyo 1538902 Japan

The aim of this study was to construct a numerical model of the thiazide-sensitive Na-Cl cotransporter (TSC) that can predict kinetics of thiazide binding and substrate transport of TSC. We hypothesized that the mechanisms underlying these kinetic properties can be approximated by a state diagram in which the transporter has two binding sites, one for sodium and another for chloride and thiazide. On the basis of the state diagram, a system of linear equations that should be satisfied in the steady state was postulated. Numerical solution of these equations yielded model prediction of kinetics of tkiazide binding and substrate transport. Rate constants, which determine transitional rates between states, were systematically adjusted to minimize a penalty function that was devised to quantitatively estimate the difference between model predictions and experimental results. With the resultant rate constants, the model could simulate the following experimental results: 1) dissociation constant of thiazide in the absence of sodium and chloride;2) inhibitory effect of chloride on thiazide binding;3) stimulatory effect of sodium on thiazide binding;4) combined effects of sodium and chloride on thiazide binding;5) dependence of sodium influx on extracellular sodium and chloride;and 6) inhibition of sodium influx by extracellular thiazide. We conclude that known kinetic properties of TSC can be predicted by a model which is based on a state diagram.

关键词： sodium-chloride cotransporter thiazide diuretics electrolyte metabolism kinetic model computer program

来源：评论

学校读者我要写书评

暂无评论

Rapid design of denaturing gradient-based two-dimensional electrophoretic gene mutational scanning tests

引用

NUCLEIC ACIDS RESEARCH 1998年第10期26卷 2398-2406页

作者： van Orsouw, NJ Dhanda, RK Rines, RD Smith, WM Sigalas, I Eng, C Vijg, J Beth Israel Deaconess Med Ctr Dept Med Gerontol Div Mol Genet Sect Boston MA 02115 USA Harvard Univ Sch Med Harvard Inst Med Boston MA 02115 USA Dana Farber Canc Inst Dept Adult Oncol Human Canc Genet Unit Boston MA 02115 USA Harvard Univ Sch Med Boston MA 02115 USA

With the current rapid pace at which human disease genes are identified there is a need for practical, cost-efficient genetic screening tests. Two-dimensional electrophoretic separation of PCR-amplified gene fragments on the basis of size and base pair sequence, in non-denaturing and denaturing gradient polyacrylamide gels respectively, provides a rapid parallel approach to gene mutational scanning. Accuracy of the denaturing gradient gel electrophoresis (DGGE) component of this system strongly depends on the design of the PCR primers and the melting characteristics of the fragments they encompass. We have developed a fully automated generally applicable procedure to generate optimal two-dimensional test designs at a minimum amount of time and effort. Designs were generated for the RB1, TP53, MLH1 and BRCA1 genes that can be readily implemented in research and clinical laboratories as low cost genetic screening tests.

关键词： .denaturing computer program Rapid design scanning tests van Orsouw TDGS

来源：评论

学校读者我要写书评

暂无评论

A DECISION SUPPORT SYSTEM FOR PLANNING AGROFORESTRY SYSTEMS

引用

FOREST ECOLOGY AND MANAGEMENT 1991年第1-4期45卷 199-206页

作者： GARCIADECECA, JL GEBREMEDHIN, KG CORNELL UNIV DEPT AGR & BIOL ENGNITHACANY 14853

A decision support system for planning small-scale agroforestry systems was developed (DESSAP). The program generates a set of feasible alternatives of culture combinations based on specified constraints. The constraints include land, labor, and cash. Labor used include own and/or hired, and cash is money spent for different items and activities such as fertilizer, harvesting, etc. The program utilizes a multiple objective linear programming model coupled with a management tool to generate alternatives. The system can be used by planners, managers, trainers, extension personnel, farmers, etc., to determine the optimum and desirable alternative(s) for an agroforestry farming system.

关键词： computer program Decision support system

来源：评论

学校读者我要写书评

暂无评论

Electron Diffraction Based Analysis of Phase Fractions and Texture in Nanocrystalline Thin Films, Part III: Application Examples

引用

MICROSCOPY AND MICROANALYSIS 2012年第2期18卷 406-420页

作者： Labar, J. L. Adamik, M. Barna, B. P. Czigany, Zs. Fogarassy, Zs. Horvath, Z. E. Geszti, O. Misjak, F. Morgiel, J. Radnoczi, G. Safran, G. Szekely, L. Szuets, T. Res Inst Tech Phys & Mat Sci H-1121 Budapest Hungary Polish Acad Sci Inst Met & Mat Sci PL-30059 Krakow Poland Harvard Univ Program Biophys Cambridge MA 02138 USA

In this series of articles, a method is presented that performs (semi) quantitative phase analysis for nanocrystalline transmission electron microscope samples from selected area electron diffraction (SAED) patterns. Volume fractions and degree of fiber texture are determined for the nanocrystalline components. The effect of the amorphous component is minimized by empirical background interpolation. First, the two-dimensional SAED pattern is converted into a one-dimensional distribution similar to X-ray diffraction. Volume fractions of the nanocrystalline components are determined by fitting the spectral components, calculated for the previously identified phases with a priori known structures. These Markers are calculated not only for kinematic conditions, but the Blackwell correction is also applied to take into account dynamic effects for medium thicknesses. Peak shapes and experimental parameters (camera length, etc.) are refined during the fitting iterations. Parameter space is explored with the help of the Downhill-SIMPLEX. The method is implemented in a computer program that runs under the Windows operating system. Part I presented the principles, while part II elaborated current implementation. The present part III demonstrates the usage and efficiency of the computer program by numerous examples. The suggested experimental protocol should be of benefit in experiments aimed at phase analysis using electron diffraction methods.

关键词： electron diffraction SAED ring patterns nanocrystals thin films phase fractions texture quantitative analysis TEM computer program

来源：评论

学校读者我要写书评

暂无评论

Automated Scoring System for the Early Assessment of Cost Performance for Construction of Buildings in Saudi Arabia

引用

ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2021年第11期46卷 11063-11087页

作者： Al-Saggaf, Abdullah Taha, Mahmoud King Abdulaziz Univ Dept Civil Engn Jeddah Saudi Arabia

Initial assessment of cost estimation for constructing a building is one of the most challenging and critical tasks by all involved participants across the fields of Architecture, Engineering, and Construction (A/E/C) industries. This may be contributed by the architects' subjectivity, owners' requirements, and a variety of possible design alternatives. Early decisions based on an estimate involve highly uncertain subsequent disputes between stakeholders. One of the most common uncertainty cost estimate factors of a project is selecting the building Architectural Design Variables (ADVs). Thus, this research identified seven ADVs with 40 design options that have conflicting contributions to the cost performance in construction. These options were quantitatively evaluated and combined to generate the cost of potential designs. Based on that, a novel Architectural-Based Construction Cost Impact Scoring System (ACCISS) was developed to reduce stakeholders' subjectivity, and accordingly, determine the most appropriate design decision that provides early cost advice and highlights the most cost-acceptable design alternatives. The proposed ACCISS is capable to automatically evaluate any combination of design alternatives, through its simple and user-friendly program. A case study of three design alternatives with three regression analyses models was incorporating to validate the ACCISS. The models' results showed the ability of ACCISS to work as an efficient assessing tool for providing cost-effective designs.

关键词： Buildings Architectural design Design variables Cost performance Scoring system Cost models Decision-making computer program Saudi Arabia

来源：评论

学校读者我要写书评

暂无评论

LEAST-SQUARES POLYNOMIAL CURVE-FITTING FOR CALIBRATION PURPOSES (STATCAL CALIBRA)

引用

ANALYTICA CHIMICA ACTA 1990年第1期241卷 1-13页

作者： KRAGTEN, J Laboratory for Analytical Chemistry University of Amsterdam Nieuwe Achtergracht 166 1018 WV Amsterdam The Netherlands

In a theoretical survey, the various advantages of orthogonal polynomial terms compared to ordinary powers of X are established. The coefficients in front of the polynomial terms are then not covariant. Simple formulae can be derived for the standard deviations of these coefficients. These standard deviations are proportional to the residual standard deviation and all have the same number of degrees of freedom. Additionally, matrix inversion is not necessary in the calculation procedure and so cannot boost computing errors. Testing whether these coefficients differ significantly from zero is shown to provide an excellent basis for cutting off the overall polynomial above a certain degree. The orthogonal polynomial terms are tested sequentially to see if their contribution is significant;in the procedure, the polynomial is cut off just before two adjacent terms which do not contribute significantly. This test proved to be far more robust than the usual F-tests which are based on changes of the overall polynomial. Possible outliers are detected earlier. For practical calibrations, five equidistant calibration levels should be selected to cover the orthogonal polynomial contributions adequately up to the fifth degree. During validation procedures, additional levels at 1/3 and 2/3 of the calibration range can be added. The use of other distributions of calibration levels should be discouraged. Replicate measurements at the different equidistant levels should be made at the ratio 3:1:2:1:3 (or at 8:3:2:4:2:3:8, in the other case). The absolute values of the calibration levels should be selected so that the unknown X falls in the upper part of the calibration range. The number of replicate measurements on the unknown should be at least 25% of the total number of measurements used in the calibration. In this way, the unknown can be evaluated optimally with minimal relative standard deviation. If the standard deviations of replicate standards do not change by more than a fa

关键词： CALIBRATION POLYNOMIAL CURVE-FITTING computer program

来源：评论

学校读者我要写书评

暂无评论

computer-AIDED METHOD FOR SIMULTANEOUS DETERMINATION OF SUBSTANCES IN SOLUTION BY SPECTROPHOTOMETRY

引用

ANALYTICA CHIMICA ACTA 1990年第2期234卷 381-386页

作者： LEPORATI, E Istituto di Chimica Generale ed Inorganica dell'Università degli Studi di Parma Viale delle Scienze 43100 Parma Italy

A computer program, LESSDAD (LEast-Squares Spectrophotometric Determination by Absorbance Data), is described for computation of the best set of analytical concentrations of two ligands and/or metal ions from absorbance measurements. At least-squares method is used to calculate the concentrations from the pH of the solution, spectrophotometric data (experimental absorbances and known molar absorptivities) and the relevant equilibtium constants. The Newton-Raphson iteration is used to solve the mass-balance equations. The program is rapid convenient to use and gives satisfactory results on a number of systems.

关键词： computer program

来源：评论

学校读者我要写书评

暂无评论

The EpiLink record linkage software - Presentation and results of linkage test on cancer registry files

引用

METHODS OF INFORMATION IN MEDICINE 2005年第1期44卷 66-71页

作者： Contiero, P Tittarelli, A Tagliabue, G Maghini, A Fabiano, S Crosignani, P Tessandori, R Ist Nazl Studio & Cura Tumori Canc Registry Div I-20133 Milan Italy Azienda Sanit Locale Prov Sondrio Sondrio Italy

Objectives: Record linkage, the process of bringing together separately compiled but related records from different databases, is essential in many area's of biomedical research. We developed a, record linkage program (EpiLink), which employs a simple mathematical approach. We describe the program and present results obtained testing it in a linkage task. Methods: EpiLink was designed to be flexible with user-friendly settings to tailor linkage and operating parameters to specific linkage tasks, and employ deterministic, probabilistic or sequential deterministic-probabilistic linkage strategies as required. The user con also standardize data format, examine linkage results and accept of discard them. We used EpiLink to link a subset of cases of the Lombardy Cancer Registry (20,724 records) with the Social Security file of the population (1,021,846 records) covered by the registry. I The linkage strategy was deterministic, followed by several probabilistic linkage steps. Results: Manual inspection of the-results showed that EpiLink achieved 98.8% specificity and 96.5% sensitivity. Conclusions. EpiLink is a practical and accurate means of linking records from different databases that con be used by non-statisticians and is efficient in terms of human and financial resources.

关键词： cancer registry record linkage computer program follow-up methods

来源：评论

学校读者我要写书评

暂无评论

Gene mapping by linkage and association analysis

引用

MOLECULAR BIOTECHNOLOGY 1999年第2期13卷 113-122页

作者： March, RE Astra Zeneca Res & Dev Genet Dept Macclesfield Cheshire England

Genetic analysis is used to map genes, including disease loci, to positions within the human genome. Linkage analysis depends on the co-segregation of a gene (locus) and a phenotype through a pedigree, while association analysis, or linkage disequilibrium mapping, depends on measuring deviation from the random occurrence of alleles in a haplotype in unrelated individuals or nuclear families. Complex computer programs may be used in both forms of analysis. In recent years most interest has focused on identifying genes involved in common, multifactorial diseases. Here I review some current and developing techniques of genetic analysis and give references to where further information can be obtained.

关键词： human genetics genetic analysis linkage allelic association linkage disequilibrium computer program

来源：评论

学校读者我要写书评

暂无评论

BINOMIAL 2X2 TEST FOR INDEPENDENT SAMPLES WITH INDEPENDENT PROPORTIONS

引用

COMMUNICATIONS IN STATISTICS PART A-THEORY AND METHODS 1981年第1期10卷 11-29页

作者： BURSTEIN, H New College of Hofstra University Hempstead N.Y. United States

For two independent samples with independent proportions, the significance level of the difference between them can be obtainedfrom joint binomial probabilities, assuming the population propor-tion is well estimated by the samples' pooled proportion. An efficient computer program can be written for this binomial test. The x2test, using a continuity correction of .25 for equal sample sizes and .1 for unequal sample sizes, is in close agreement with the binomial test.

关键词： sample proportions population proportion fisher's test normal test chi-square test barnard's test continuity correction computer program

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：