PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Computer Graphics”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 55 records · Page 3Linked to original sources
PubMed1978

Structure of methemerythrin at 2.8-Angstrom resolution: computer graphics fit of an averaged electron density map.

The crystal structure of methemerythrin from Themiste dyscritum has been determined at 2.8-Angstrom resolution by single isomorphous replacement technique combined with anomalous scattering from a K2HgI4 derivative. Noncrystallographic symmetry relating the four subunits in the asymmetric unit was used to obtain an average electron density map of the hemerythrin monomer, and a computer graphics system was used to fit a polypeptide model to the electron density. The average map was of sufficient quality to locate most of the amino acid side chains and to confirm the assignment of His-25, His-54, Glu-58, His-73, His-77, His-101, Asp-106, and Tyr-109 as the iron ligands. One of the mercury sites in the heavy atom derivative is located between two Cys-9 residues related by a noncrystallographic twofold axis, although no intersubunit disulfide bond is present in the native structure. The residues responsible for the binding of the subunits to form the octamer are identified.

Amino Acids↗
PubMed1990

The role of the vimentin intermediate filaments in rat 3Y1 cells elucidated by immunoelectron microscopy and computer-graphic reconstruction.

The three-dimensional arrangement of vimentin intermediate filaments (IF) was studied in 3Y1, rat fibroblastic cell line, to elucidate its biological role in the cell. While actin filaments were observed exclusively in the superficial part of the cell, vimentin IF were found to be abundantly present in the inside of the cell where microtubules were occasionally discovered. By whole-mount immunoelectron microscopy and computer-graphic reconstruction of serial thin sections, it was observed in more detail that vimentin IF are located very close to the nucleus, endoplasmic reticulum, and mitochondria. Vimentin IF were observed to be attached to these organelles laterally or terminally. Thus, we can reasonably assume that vimentin IF are major cytoskeletal structures deep inside the cell and that they play an important role in supporting the location of the organelles. This is the first report which has visualized the three-dimensional relationship between vimentin IF and the organelles of the cell.

Animals↗
PubMed1990

Computer graphics in medical illustration.

The advent of powerful personal computers (PC) has revolutionised the production of graphic illustrations in the various disciplines of medicine. This paper reviews the current hardware devices and software programmes available in the personal computer market for the generation, processing and production of graphic output in medical illustration for the purposes of teaching and presentation. A low-cost method of generating high quality presentation slides on IBM-PC based systems is also outlined.

Computer Graphics↗
PubMed1992

Drug interactions represented by high resolution computer graphics.

The amount of backward walking induced in mice by co-administration of clenbuterol, a beta-adrenoceptor agonist and putative antidepressant, and the benzodiazepine chlordiazepoxide was plotted as a three-dimensional surface, using modified Uniras software. The surface was compared with the theoretical surface to be expected if the interactions between the two drugs were merely additive. The difference between the theoretical and the obtained surfaces was plotted and a functional representation of statistical variability was 'draped' over the difference model. The computer methods can be applied to small amounts of irregularly distributed data, and results are apparent from simple inspection, e.g. the highest peak of backward walking is also the most reliable statistically. The technique is useful for both laboratory and clinical studies.

Animals↗
PubMed1990

Molecular conformational space analysis using computer graphics: going beyond FRODO.

The molecular graphics program FRODO has been modified to support analytical animation of molecular dynamics trajectories. The enhanced program, mdFRODO, supports all features available in FRODO and is interfaced to GROMOS. A variety of analytical animation modes is included. Extensive coloring and atom selection features are implemented to aid the user in distinguishing features of interest in a set of conformations. Molecular conformational space can be analyzed efficiently and comprehended. Animations may be viewed in stereo, and the animated object can be overlaid with any of the standard FRODO objects. The mdFRODO program is of wide use in molecular dynamics, X-ray crystallography and two-dimensional NMR work. Examples illustrating various aspects of collective motion in protein molecules are given and discussed.

Computer Graphics↗
PubMed1990

Prediction of total knee motion using a three-dimensional computer-graphics model.

Twenty-three knees were sectioned, digitized, and standardized to determine the 'average' three-dimensional bony geometry and ligamentous attachments. Data on normal knee motion were obtained from a cadaveric study. An algorithm was written to simulate three-dimensional patella motion. Verification of the knee model was achieved by determining femoro-tibial and patello-femoral contact locations, as well as ligament length patterns, and comparing the results with published data. The criterion for maximum predicted knee motion with a prosthesis in place was the length of the posterior cruciate ligament. Three total knee replacement surfaces were mathematically generated: flat, laxity and conforming. A greater flexion angle was obtained with a flat tibial surface than for the laxity or conforming. Posterior tibial component displacement increased the range of motion, but only slightly. For all tibial surfaces, increased range of motion was achieved with a 10 degrees posterior tilt of the tibial tray. Anterior femoral component displacement increased motion due to reduction in posterior cruciate tension during flexion. The results are applicable to the design and surgical technique of total knee replacement.

Algorithms↗
PubMedDate not supplied

Computer graphics for slide presentations.

This applications article describes the use of a computer to generate high-quality presentation materials. Different programs and methodologies are discussed.

Computer Graphics↗
PubMed1991

Hypertext and three-dimensional computer graphics in an all digital PC-based CAI workstation.

In the past several years there has been an enormous increase in the number of computer-assisted instructional (CAI) applications. Many medical educators and physicians have recognized the power and utility of hypertext. Some developers have incorporated simple diagrams, scanned monochrome graphics or still frame photographs from a laser disc or CD-ROM into their hypertext applications. These technologies have greatly increased the role of the microcomputer in education and training. There still remain numerous applications for these tools which are yet to be explored. One of these exciting areas involves the use of three-dimensional computer graphics. An all digital platform increases application portability.

Computer Graphics↗
PubMed1991

VESICA: computer graphics modeling of lipid vesicles.

A vesicle simulation and computer analysis program, VESICA, is described which employs spherical projections of triangularly tessellated icosahedra to produce molecular graphics models of the three-dimensional structures of lipid vesicles. The program is used to analyze the molecular architecture of small unilamellar vesicles of dipalmitoyl-phosphatidylcholine and is demonstrated as a worthwhile investigative tool for determining the factors that govern the minimum vesicle size.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1976

An on-line computer graphics terminal for radiotherapy treatment planning.

A programmed graphics terminal has been connected on-line to a large time-shared computer for calculating dose distributions in radiotherapy treatment planning and provides a viable alternative to dedicated systems and batch working. The terminal equipment is based on a mini-computer and includes a function-key devise for outline input, a large-screen refresh oscilloscope for viewing results and an X-Y plotter for hard-copy. Radiotherapy dose computation programs in standard Fortran are stored and run on a large remote computer with graphical interaction at the terminal. External beam programs can calculate dose distributions for most commonly used treatment situations and can compute in off-axis planes. Data input is fully interactive and easy to understnad. Dose distributions are displayed as isodose contours. Advantages of the system include accuracy, speed, ease of use and maintenance, and transferability of the programs between different host computers.

Data Display↗
PubMedDate not supplied

Use of computer graphic images in teaching dermatology.

A microcomputer-based system for copying, storing, retrieving, and displaying color still images was assembled from commercially available components. The system was tested against 35-mm color photographic transparencies by measuring the performance of 91 medical students in a task of identifying the primary morphology of eight skin lesion images from the displayed images. There was no significant difference in the students' performance between the two display media.

Computer Graphics↗
PubMed1991

An interactive computer graphics system for the design of molded and orthopedic shoe lasts.

The Department of Computer Science at North Carolina State University, with support from the Department of Veterans Affairs and National Aeronautics and Space Administration (NASA) Langley Research Center, has developed an interactive graphics program for the development of shoe lasts from digitized images of feet or digitized images of commercial shoe lasts. The program runs on a Sun 3/260 computer with a TAAC-1 graphics accelerator. The program contains operations for region addition and deletion, techniques for narrowing the ankle area, methods for toe extension, operations to allow for shoe inserts, etc. Once the operations by the user are complete, the program will resample the resulting last in a 512 x 512 array. The user is then allowed to select an error tolerance which will guide a data reduction program to represent the last as Coons patches. These patches are then transmitted to a milling machine which will cut the last.

Computer Graphics↗
PubMed1992

POCKET: a computer graphics method for identifying and displaying protein cavities and their surrounding amino acids.

A new interactive graphics program is described that provides a quick and simple procedure for identifying, displaying, and manipulating the indentations, cavities, or holes in a known protein structure. These regions are defined as, e.g., the xo, yo, zo values at which a test sphere of radius r can be placed without touching the centers of any protein atoms, subject to the condition that there is some x < xo and some x > xo where the sphere does touch the protein atoms. The surfaces of these pockets are modeled using a modification of the marching cubes algorithm. This modification provides identification of each closed surface so that by "clicking" on any line of the surface, the entire surface can be selected. The surface can be displayed either as a line grid or as a solid surface. After the desired "pocket" has been selected, the amino acid residues and atoms that surround this pocket can be selected and displayed. The protein database that is input can have more than one protein "segment," allowing identification of the pockets at the interface between proteins. The use of the program is illustrated with several specific examples. The program is written in C and requires Silicon Graphics graphics routines.

Algorithms↗