SEARCH · Search PubMed
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.
A personal computer program in BASIC for the two-factor factorial analysis of variance has been developed. The factorial design is based on and combined with previous one-way and two-way ANOVA programs. The performance of the program is tested on data obtained from 3 months' consumption of three proprietary antibiotic products in four Saudi hospitals.
Physiologically-based pharmacokinetic (PB-PK) models are each defined as a set of mathematical equations offering a fairly comprehensive time course of a chemical's disposition in several pre-selected anatomical compartments. Each of these compartments has its characteristic blood flow, volume, tissue-blood partition coefficient, and metabolic or clearance rate constants that together are deemed responsible for a chemical's disposition in that region. Numerous investigators have used these models to predict tissue dose in the animal or human body in recent years. This simulation technique, if proven effective, will eventually reduce the large number of animals that are required in the costly classic, in vivo studies to be conducted for chemical disposition or metabolism. This communication offers 2 affordable micro-computer programs which can be used as a practical simulation tool in further exploring the application of PB-PK modeling in chemical risk assessment. These 2 programs are written especially for investigators who prefer to have some appreciation of the required computer simulation first before committing themselves to using more advanced, expensive simulation software packages that are commercially available.
An animation is described to assist in the visualization of the relationship between the Fischer and Haworth projections of monosaccharides. The animation helps the understanding of two quite different, commonly used representations of the same molecule. The animation runs on a 386-based PC with VGA graphics. The method for realizing such an animation on this hardware is described in detail; C code is provided in the Appendix.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The paper describes a package of programmes designed to store, retrieve and search simple descriptive data on burn patients. The computer system used is a Commodore Pet 8032 with 8050 disk drive and compatible printer. The programmes also have the ability to produce summary tables of certain patient characteristics either on a yearly or cumulative basis.
The design and implementation of a computer-based training system for radiation oncology was undertaken. A frame-based system was chosen, with factual information from Principles and Practices of Radiation Oncology, by Perez and Brady, as the body of knowledge. Each unit of the system was based on a site (chapter) and consists of three sections: text, review questions, and patient management problems. The text section contains text, tables, and references and defines the information upon which the review questions and clinical cases are based. The review questions are multiple choice and true-false, and immediate feedback is given for both correct and incorrect responses. The patient management problems are interactive and provide alternative methods of presenting information and stimulating problem-oriented thought. The emphasis in all sections is on learning rather than testing. Advantages of a computer-based tutorial include the ability to present large volumes of information easily, the capacity for immediate feedback, and the flexibility of format in presentation of material. Potential applications are discussed.
Explore the source record for details and available documents.
A versatile digital filtering system is described which enables separation of wave components of evoked potentials based on their frequencies. The utility of this technique is exemplified by application of digital filtering to hippocampal field potentials. Separation of population spikes from lower frequency synaptic potentials provides less ambiguous interpretation of the compound slope of the field potential during the first 5 milliseconds of the response. The entire procedure of stimulation, data acquisition, and digital filtering was implemented on a PC-compatible computer.
VOSTORG is a new, versatile package of programs for the inference and presentation of phylogenetic trees, as well as an efficient tool for nucleotide (nt) and amino acid (aa) sequence analysis (sequence input, verification, alignment, construction of consensus, etc.). On appropriately equipped systems, these data can be displayed on a video monitor or printed as required. They are implemented on IBM PC/XT/AT/PS-2 or compatible computers and hardware graphic support is recommended. The package is designed to be easily handled by occasional computer users and yet it is powerful enough for experienced professionals.
A simple and self-explanatory program in BASIC for the statistical evaluation of potential pharmacokinetic drug interactions is described. This program, using the data (times and drug concentrations) obtained from two different populations, and with the help of graphic computing techniques, allows the determination and statistical comparison of pharmacokinetic parameters (disposition constants, transfer rate constants, area under the concentration-time curves, etc.) for one- and two-compartment open models after intravenous or extravasal administration. The program is organized in subroutines so that it can be easily modified or extended to other pharmacokinetic models by the user.
A number of software routines were written for the public domain Macintosh-based video-densitometry program, Image, to facilitate in situ hybridization analysis. These routines utilize fiducial marks drilled in unused portions of the brain to rotate high-magnification images of individual sections so that they may be placed in register. The regions of interest within the registered sections are outlined and intermediate sections interpolated to produce a data set representing a three-dimensional volume. This shell is then filled with the original density data obtained with one or more in situ hybridization probes. The final object can be viewed in various degrees of translucency and examined from different angles or computationally resectioned to yield new information concerning activity changes within the region and relationships between reactive sites. These static images can be collected and rapidly displayed as a movie. These routines have been used in this paper to display the differential hybridization of three different mRNA probes in the hypothalamic paraventricular nucleus.
A dedicated nonlinear regression based curve-fitting packages has been developed for quantitative analysis of beta-adrenoceptor subtypes. A feature of this package is the provision to obtain initial parameter estimates using a conversational graphical technique where the user is prompted for parameter estimates, and the resulting curve is displayed over the data. Data are then fitted to a one- or two-binding site model with user-selected weighting and constraints on the parameters. A novel feature is the provision to estimate the nonspecific binding component in the assays as a parameter in the model. The printout for each model consists of the parameters and their standard deviations, estimates of the goodness of fit, an analysis of residuals, and a graph of the data points overlayed with the fitted curve. The nonlinear regression algorithm is based on that of Gauss-Newton. When unweighted, the values determined by RECFIT are essentially the same as those found using the BMDPAR programs on an ICL 2976 mainframe computer. The implementation is reasonably efficient; a typical run for a two-site fit, using nine data points and estimating nonspecific binding, took a total time of about 8 min, excluding data entry and derivation of initial estimates, 4 min for the fitting, 30 sec for graph generation, and 2-3 min for printing of the graph and data.
The relationship between brain tumor size and survival has been studied since the advent of CT and magnetic resonance imaging (MRI), however, all published studies are based on tumor sizes measured by the less accurate geometric method, with results that are inconsistent. For example, the influence of the extent of tumor resection on patient survival has been debated. Jelsma and Bucy advocated extensive resection based on their analysis of patients with glioblastoma multiforme, however, Green et al. produced conflicting results, showing that the extent of resection was not statistically significant when all variables were considered simultaneously. The present study investigates whether or not the study inconsistency is largely due to the use of the less accurate geometric tumor volume measurement. The study demonstrates that the geometric tumor volume and the planimetry tumor volume have significantly different prognostic effects.
Chromatograms of pesticide residues in food include peaks produced by pesticides and matrix compounds. Pesticide peaks are recognized by means of relative retention times and response factors; two detectors are used and internal standard methods are applied. Chromatograms of reference samples for all types of food are stored as raw data in a reduced format, together with tables of all chromatographic data for the matrix compounds. MATRIXCOMP provides the analyst with the chromatograms of the actual sample and the reference in parallel on a visual display screen for visual comparison. Simultaneously, the relevant chromatographic data for the sample, the reference and the calibration tables are displayed on a second screen page in a condensed form.
Explore the source record for details and available documents.
Explore the source record for details and available documents.