Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Programming, Linear”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMed1989

[Retention index of essential oil in temperature-programmed capillary column gas chromatography].

Kovats retention indexes of more than 200 kinds of natural and synthetic compounds of alcohol, aldehyde, acetal, ketone, ether, alkene, nitrile, carboxylic acid, ester, etc. were determined on polar liquid phase (DB-WAX) and nonpolar liquid phase (DB-1) by linear temperature-program capillary column gas chromatography. Some rules of part of the homologous series of compounds were summed up from the retention indexes: the rules of RI vs carbon, RI vs boiling point and RI on two columns. In order to keep the retention indexes practical, effects of initial temperature (T0), program rate (r) and average linear carrier gas velocity (u), etc. on the retention indexes were investigated. The conclusion is that the retention indexes are highly reproducible so long as the program parameters change in a certain range. Two kinds of essences, Meigui and Linglan, were identified successfully on IBM-PC/XT microcomputer by the Data Base Management System of essential oil and essence by capillary column gas chromatography and the results are satisfactory.

Chromatography, Gas↗
PubMed2006

Synthesis of an elongated linear oligo(phenylene ethynylene)-based building block for application in DNA-programmed assembly.

The synthesis of an elongated linear oligonucleotide-functionalised module (ELOM) is described. The ELOM structure is based on an oligo(phenylene ethynylene) backbone substituted with two decyloxy groups. The two termini constitute two salicylaldehyde moieties acting as chemical cross-linkers. Before incorporation into an oligonucleotide sequence the organic part of the module, the elongated linear module (ELM), is functionalised with a dimethoxytrityl group and a phosphoramidite group. This enables incorporation into the middle of 30-mer oligonucleotide sequences by automated DNA synthesis. The obtained ELOMs were characterised by polyacrylamide gel electrophoresis and MALDI-TOF mass spectrometry. In analogy with previously reported LOM and TOM structures the coupling reactions of the ELOM modules were tested.

Aldehydes↗
PubMed1993

Sodium modeling ameliorates intradialytic and interdialytic symptoms in young hemodialysis patients.

Despite advances in the delivery of hemodialysis, significant dialytic morbidity persists. Sodium modeling in older adults has been shown to decrease some dialytic symptoms, but clear benefits in young patients without coexisting diabetes or advanced cardiovascular disease have not been shown. The effects of sodium modeling were evaluated in 16 adolescent and young adult hemodialysis patients (16 to 32 yr of age) treated with conventional hemodialysis for a median of 11.5 months. The 8-wk study was divided into four 2-wk blocks. During each block, one of three sodium programs or a constant (control) dialysate sodium of 138 mEq/L was used. During each sodium program, the initial dialysate sodium of 148 mEq/L was decreased by an exponential, linear, or step program to 138 mEq/L. Treatments with sodium modeling were significantly better than those with constant sodium dialysate. When all sodium programs were grouped and compared with constant dialysate sodium, the odds of improvement in dialytic cramps, headaches, and nausea were 1.8, 2.1, and 3.9, respectively (P < 0.05). Sodium modeling also significantly decreased the frequency of postdialysis hypotension and interdialytic fatigue, dizziness, and muscle cramping (P < 0.05). No differences were seen among the sodium protocols in the incidence of symptomatic hypotension, the amount of normal saline administered, the degree of hemo-concentration during treatments, or the decrease in serum osmolality. There was no increase in pretreatment or posttreatment serum sodium concentrations, interdialytic thirst, weight gain, or hypertension. Sodium modeling dramatically decreases both intradialytic and interdialytic morbidity in young hemodialysis patients. There was no increase in adverse events associated with sodium modeling.

Adolescent↗
PubMed1987

Inheritance and relationships of linear type traits for age groups of Holsteins.

Routine classifications from the linear type trait program of the Holstein Association were analyzed separately for age groups. Inheritance of linear type traits and their genetic and phenotypic relationships were evaluated. Estimates of genetic and phenotypic parameters were compared to other studies with experimental classifications from the Holstein Association and with data from artificial insemination organizations across age groups. Evaluation of sires for type traits across age groups may not properly rank sires if ages of daughters differ for sires. Future genetic evaluations of type by the Holstein Association will consider only classifications of cows closest to 30 mo, so heritabilities for linear type traits for only 2 yr olds from this study may have application. Some linear type traits are very similar genetically. Stature has substantial genetic association with final score as subjectively assigned by classifiers.

Aging↗
PubMed1985

An interactive computer program for the determination of the binding constants of monoclonal antibodies by non-linear regression analysis of radioimmunoassay data.

A computer program is presented for non-linear regression analysis of radioimmunoassay data, which allows the determination of the binding parameters of monoclonal antibodies, i.e., affinity constant and number of available binding sites. The program is based on the median method and gives the values of the binding constants and their 95% confidence limits, without the necessity for their preliminary, approximate evaluation. The program may also be used to determine the binding constants for the interaction of receptors with labelled ligands.

Antibodies, Monoclonal↗
PubMed1995

Computer-assisted instruction: MR imaging of the knee.

Computer-assisted education offers a unique method of learning that is complementary to conventional learning techniques. The regional anatomy of musculoskeletal magnetic resonance (MR) imaging lends itself well to discrete learning modules on the computer. This article describes a computer-assisted educational program for MR imaging of the knee. The program is divided into four sections: MR imaging physics, anatomy, pathology, and a quiz. The program has cross-references between the sections that allow comparison of normal versus pathologic findings, review of specified pathologic entities, and self-testing of comprehension. The student can progress through the program in a linear or nonlinear fashion at his or her own pace. All images in the program were digitally acquired with an MR imager and transferred directly to the computer used to develop the program. The program is available throughout the radiology department on a local area network and in the medical school library on stand-alone units. The program is currently being used at a medical school as a supplement to the recently implemented problem-based learning curriculum and for resident education.

Computer-Assisted Instruction↗
PubMed1985

Association of sire dystocia transmitting ability with progeny linear type traits in Holsteins.

Data on 13 traits of 11,260 progeny of 775 sires in the Carnation Genetics linear type appraisal program were analyzed to determine the association between sire dystocia transmitting ability and progeny linear type traits. Mean linear type scores ranged from 25.0 to 29.8 on a scale of 1 to 50. Parity, stage of lactation, and interactions of evaluator by parity and evaluator by stage were sources of variation for most traits. First quartile (easy) and fourth quartile (most difficult) sires grouped by dystocia transmitting ability differed in daughter linear type scores for stature, dairy character, rump angle, center ligament, udder depth, teat length, teat placement, and rump width. Differential use of easy calving bulls on heifers might result in progeny with lower type scores for stature, dairy character, rump angle, legs, and rump width. Average type scores differed by less than 1 unit for all traits, indicating little correlated response in linear type traits through use of bulls whose progeny are born with least difficulty.

Analysis of Variance↗
PubMed1976

A program for fitting of hypnograms and other biological data by orthogonal polynomials.

Many biological phenomenon are nonlinear and poorly approximated by linear regression. The program POLFIT calculates curvilinear regressions by fitting of orthogonal polynomials. This program, as well as two supporting programs (CORREC: disk storage, and CALCML: calculation of cumulated values of series of observations), was primarily designed for the study of the temporal organization of sleep components. They can be used as well for any other kind of biological data.

Computers↗
PubMed2004

Applicational possibilities of linear and non-linear (polynomial) regression and analysis of variance. III. Stability determination of pharmaceutical preparations: stability of diclofenac-sodium in Diclofen injections.

This paper presents the application of the regression analysis program and the program for comparing linear regressions (modified method for one-way, analysis of variance), writtens in BASIC program language, for instance, determination of content of Diclofenac-Sodium (active ingredient in DIKLOFEN injections, ampules á 75 mg/3 ml). Stability testing of Diclofenac-Sodium was done by isothermic method of accelerated aging at 4 different temperatures (30 degrees, 40 degrees, 50 degrees and 60 degrees C) as a function of time (4 different duration of treatment: (0-155, 0-145, 0-74 and 0-44 days). The decrease in stability (decrease in the mean value of the content of Diclofenac-Sodium (in %), at different temperatures as a function of time, is possible to describe by, linear dependance. According to the value for regression equation values, the times are assessed in which the content of Diclofenac-Sodium (in %) will decrease by 10%, of the initial value. The times are follows at 30 degrees C 761.02 days, at 40 degrees C 397.26 days, at 50 degrees C 201.96 days and at 60 degrees C 58.85 days. The estimated times (in days) in which the mean value for Diclofenac-Sodium content (in %) will by 10% of the initial values, as a junction of time, are most suitably described by 3rd order parabola. Based on the parameter values which describe the 3rd order parabola, the time was estimated in which Diclofenac-Sodium content mean value (in %) will fall by 10% of the initial one at average ambient temperatures of 20 degrees C and 25 degrees C. The times are: 1409.47 days (20 degrees C) and 1042.39 days (25 degrees C). Based on the value for Fischer's coefficien (F), the comparison of trenf of Diclofenac-Sodium content (in %) shows that, under the influence of different temperatures as a function of time, among them, depending on temperature value, there is: statistically very significant difference (P << .05) at 50 degrees C and lower toward 60 degrees C, i.e. statistically probably significant difference (P > 0.01) at 40 degrees C and lower towards 50 degrees C and there is no statistically significance difference (P >> 0.05) at 30 degrees C towards 40 degrees C.

Algorithms↗
PubMed1984

Pocket computer program for fitting the Hill equation.

This paper presents a program written in the BASIC language for the Radio Shack TRS-80 PC-1 or the Sharp PC 1211 pocket computers for fitting the Hill equation to experimental data. The program is based on a procedure involving a combination of an optimization technique and non-linear regression. The program determines precisely all three parameters of the Hill equation and in addition, it performs a simulation of the kinetic experiment using the parameter values previously estimated, calculating the sum of squares of residuals.

Allosteric Regulation↗
PubMed1990

A method for conforming the pH dependence of the michaelis parameters of nonallosteric enzymes to four kinetic schemes.

A nonlinear regression program for the analysis of the effect of pH on enzyme activity has been developed for the IBM micro range and compatible machines. The program conforms the V and Km pH profiles to one of four commonly occurring kinetic schemes. By using multiple linear regression the program computes initial estimates for the nonlinear search which are thus not required from the user. Two nonlinear optimization methods are included in order to effectively handle the nonnegativity constraints on the parameters. The program is user-friendly and provides plots of the fit and residual plots to help the user decide on the goodness of fit obtained. The program was coded in Turbo Pascal version 4.0 and runs on IBM micros or close compatibles with four types of graphics cards.

Algorithms↗
PubMed1996

A simple flexible program for the computational analysis of amino acyl residue distribution in proteins: application to the distribution of aromatic versus aliphatic hydrophobic amino acids in transmembrane alpha-helical spanners of integral membrane transport proteins.

We describe a simple, flexible program (AAD) with a primary function of depicting the distribution of aliphatic and aromatic amino acid residues along the linear aligned sequence of a family of homologous proteins and a secondary function of depicting the distribution of all amino acids along the same linear sequence. The program is used to examine the distribution of aromatic versus aliphatic residues in representative well-characterized families of polytopic membrane proteins. Many but not all such protein families are shown to exhibit a predominance of aliphatic residues in the central regions of their transmembrane spanners but a predominance of aromatic residues at the peripheries of their spanners. We propose that this distribution stabilizes the hydrophobic-hydrophilic interface and renders the centers of these integral membrane proteins more fluid than their peripheries.

Amino Acids↗
PubMed2005

Demonstration of software programs for estimating multilevel measurement model parameters.

A brief overview of the relevant parameterizations of the Rasch measurement model will first be provided. Next, the use of five different hierarchical linear modeling software programs (SAS, MLWIN, S-PLUS, R and HLM) using a heuristic data set will be demonstrated. For each program, researchers will be offered: 1) instructions describing the way to set up data sets, as well as 2) directions for running each program, 3) guidelines to assist with the appropriate interpretation of the output. Last, testing of the local independence assumption will be discussed. All data and code for each of the models run in this analysis may be downloaded from the website: http://www.hlm-online.com/papers/mmmpaper.htm/.

Data Interpretation, Statistical↗
PubMed1998

Interaction effects of client and treatment program characteristics on retention: an exploratory analysis using hierarchical linear models.

This paper applied a hierarchical linear modeling approach to explore the interaction effects of treatment program and client characteristics on client retention in treatment for drug users. Program characteristics included services provision, funding sources, and staff-client gender congruence, and client characteristics included gender, age at admission, and drug use level prior to admission. The same model was applied separately to three modalities: residential, methadone maintenance, and outpatient drug-free programs. Data were obtained from 59 treatment programs and 3,764 of their clients who had discharge records. The most noteworthy significant interaction effect detected was program's funding source and client's gender on treatment retention in the outpatient drug-free modality. For example, female clients remained less time in the programs that accepted only public funding than in the programs that accepted both public and private funding. Male clients remained in the treatment an average of 25.3 fewer days than female clients in drug-free programs that only accepted public fund, but stayed about the same time as females if the programs received mixed funding.

Adult↗
PubMed2006

Data analysis of kinetic modelling used in drug stability studies: isothermal versus nonisothermal assays.

PURPOSE: Kinetic modelling was applied to predict the stability of cholecystokinin fragment CCK-4 in aqueous solution, which was analyzed by isothermal and nonisothermal methods using a validated stability indicating HPLC method. METHODS: The isothermal studies were performed in the temperature range 40 to 80 degrees C at pH 12 and ionic strength 0.01 M as constants, whereas nonisothermal stability studies were performed using a linear increasing temperature program, heating rate 0.25 degrees C/h and a temperature interval 40-82 degrees C. The isothermal studies require two-step linear regression to estimate the parameters, resulting in a well-defined confidence interval. Nonisothermal kinetic studies require nonlinear or linear regression by previous transformation of data to estimate the parameters. In this case, the two most popular approaches, derivative and integral, were used and compared. RESULTS: Under isothermal conditions, an apparent first-order degradation process was observed at all temperatures. The linear Arrhenius plot suggested that the CCK-4 degradation mechanism was the same within the studied temperature range, with quite large uncertainties due to the small number of degrees of freedom based only on the scatter in the plot, and giving an estimated shelf life at 25 degrees C of 35.2 days. The derivative approach yields high variability in the Arrhenius parameters, since they are dependent on the number of polynomial terms chosen, so several statistical criteria were applied to select the best model. The integral approach allows activation parameters to be calculated directly from experimental data, and provides results in good agreement with those of the traditional method, but have the advantage that the uncertainty in the final result directly reflects the goodness of fit of the experimental data to the chosen kinetic model. The application of the bootstrap technique to estimating confidence limits for the Arrhenius parameters and shelf life is also illustrated, and shows there is no difference between the asymptotic and bootstrap confidence intervals. CONCLUSIONS: Nonisothermal studies give us fast and valuable information about drug stability, although their potential for predicting isothermal behaviour is conditioned by the data analysis method applied.

Drug Stability↗