Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Computer Graphics”

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 91 records · Page 5Linked to original sources
PubMed2003

Fiswidgets: a graphical computing environment for neuroimaging analysis.

Current fMRI neuroimaging software programs offer the researcher a wealth of analysis methods and tools. However, the incompatibilities in user interface, data format, and computing environment in these tools make it difficult if not impossible for most researchers to take advantage of the full set of resources available for neuroimaging analyses. We describe a graphical computing environment, Functional Imaging Software Widgets (fiswidgets), which was developed to address these interoperability and usability problems. This environment provides a desktop style framework into which 100 subcomponents from a number of widely used fMRI analysis software packages (e.g., AFNI, AIR) are incorporated. It is an open-source, extensible environment available for reuse and modification by other software developers. A discussion of the design criteria (open architecture, modularity, wrapper technology, commercial utilities) that support such loosely integrative computing environments, and the problems entailed in maintaining them (development overhead, distribution logistics, format incompatibilities, graphics vs scripting tradeoffs, and appropriate acknowledgment of software developers) follows.

Computer Graphics↗
PubMed1987

Interactive computer graphics: a new technology to improve judgment in rhinoplasty.

A teaching system has been developed that employs interactive computer graphics to simulate the surgical experience of rhinoplasty, allowing the surgeon to experiment within a model of nasal behavior. The ability to experiment without risk and to safely learn the laws governing nasal behavior should augment the development of surgical judgment in rhinoplasty.

Computer Graphics↗
PubMed1989

Serial section reconstruction using a computer graphics system: applications to intracellular structures in yeast cells and to the periodontal structure of dogs' teeth.

A computer graphics system for reconstruction from serial section micrographs was applied to intracellular details of a yeast target cell (Saccharomyces cerevisiae cell) induced by the alpha factor mating pheromone and was also applied to a periodontal structure of a dog tooth moved orthodontically. In the former, intracellular organelles and a distribution of vesicles could be clearly observed through the cell membrane using the transparent display method in which the smoothing of the reconstructed outer cell membrane surface by computer processing was applied to the transparent display. In the latter case, by cutting through a reconstructed dog tooth and its periodontal tissues, labiolingual and mesiodistal cut surfaces of the tooth and of adjacent alveolar bone could be observed with fine details (232 sections were used).

Animals↗
PubMed1993

Computer graphic analysis of endosteal expansion after total hip arthroplasty.

Femoral endosteal expansion is known to occur naturally with aging and may contribute to femoral component loosening after cemented total hip arthroplasty (THA). Previous roentgenographic models used to quantify femoral expansion have used a limited number of measurements at arbitrary axial sites in one roentgenographic view. A computer graphic model is introduced, which uses standard anteroposterior (AP) and lateral roentgenograms to reconstruct a three-dimensional model of the femur between the lesser trochanter and the distal end of a cemented prosthesis. The model was used retrospectively to calculate endosteal and periosteal surface area and volume at the time of surgery and at follow-up examination for 22 patients who had been treated with hip arthroplasty (average, 9.3-year follow-up observation). Endosteal surface area and volume were found to increase an average of 3.1 cm2 and 1.7 cm3, respectively. Periosteal dimensions did not change significantly. Overall endosteal expansion occurs in the vicinity of the implanted prosthesis. The extremely low interobserver variability indicates that this model provides a reliable method of following surface area and volume changes around a cemented hip prosthesis.

Aged↗
PubMed1988

Three-dimensional reconstruction from serial section images by computer graphics.

A method is described which allows a three-dimensional object to be reconstructed from micrographs of serial sections using computer graphic techniques. The reconstructed object, which can be rotated three-dimensionally, is displayed on a color CRT and the surface of the object is shaded in order that it can be observed to provide an illusion of a three-dimensional structure. Using biological samples, some useful representation methods are demonstrated, which are a transparent display, smoothing of a reconstructed surface, cuts through a reconstructed model and a three-dimensional distribution representation of particles, and so forth. Furthermore, an example measuring the volume and surface area of reconstructed objects is shown.

Animals↗
PubMed1989

A computer graphics study of multistranded DNA models.

A range of related nucleic acid models has been built using the computer graphics system at EMBL (Heidelberg). The relationship between these models is considered in terms of a simple "core" structure. One of these models is a four-strand structure in which two duplexes of the Watson-Crick kind are specifically related by a twofold rotation axis and which has already been discussed in some detail. The models fall into two principal classes. In one, each sugar phosphate chain is attached to every layer of bases in the "core" structure; in the other, each chain is attached to alternate layers of bases. Several of the models discussed have specificity both of complementarity and of identity.

Computer Graphics↗
PubMed1986

Computer graphics presentation modes for biologic data. Types and examples.

New advances in automated cytology, computer microscopy, densitometry and other instrumentation for feature/scene acquisition or analysis have resulted in higher information densities than heretofore encountered. Two-, three- and four-space computer graphics provide favorable bandwidth conditions for transforming complex, large-scale data sets into visual displays that allow a human observer, utilizing the brain's efficient processing of visual information, to rapidly grasp relationships and synthesize concepts. Examples of multidimensional displays are presented, all developed by neuroscientists who are not computer specialists. Because modern graphics and image-synthesis techniques can now be implemented on any one of several commercially available very-high-speed integrated-circuit-based display systems, at moderate cost, exploitation of specifically visual presentation should be carefully considered in any system generating information in high density.

Animals↗
PubMed1989

A computer graphics program for measuring two- and three-dimensional form change in developing craniofacial cartilages using finite element methods.

Allometric analysis of chondrocranial growth seeks to provide objective measures of morphogenetic form change during ontogeny of the primordial skull. Linear measures, typically employed to study differential growth, become problematic at the histological level since an external referencing system is impossible to achieve for microscopic anatomies in embryos. The purpose of this paper is to describe a computer graphics program which generates spatially invariant measures of two- and three-dimensional form change using finite element methods. Anatomical form change is viewed as a continuous deformation of an initial finite element representing an anatomical unit into a second configuration. The algorithm consists of isoparametric scaling of finite elements, strain matrix formulation, and size/shape variable derivation. The routine includes four segments serving to extract nodal data, generate the strain matrix relating the two morphologies as well as deriving corresponding size/shape variables, reference the major and minor axes of form change, and provide graphic display of the anatomical geometries. Applications are provided measuring two- and three-dimensional form change in the developing craniofacial cartilages of rats subjected to treatment with the known teratogen diazo-oxo-norleucine (DON). The finite element routine provides craniofacial form change variables which are expected in light of cellular alterations induced by DON administration. Finally, computational differences between this routine and similar approaches using finite element methods for analyzing biological form change are examined.

Animals↗
PubMed1986

Representation of the path of a non-disintegrating capsule in the gastrointestinal tract using external scintigraphy and computer graphics.

The intestinal transit rate of a single non-disintegrating object has been measured using gamma scintigraphy. Using computer graphics, a three-dimensional visualization of the data has been developed. The display enables viewing from any angle and should be of value in assessing the effect of variables on the transit of pharmaceuticals and other materials.

Capsules↗
PubMed2006

Three-dimensional computer graphics for surgical procedure learning: Web three-dimensional application for cleft lip repair.

OBJECTIVE: In surgical procedures for cleft lip, surgeons attempt to use various skin incisions and small flaps to achieve a better and more natural shape postoperatively. They must understand the three-dimensional (3D) structure of the lips. However, they may have difficulty learning the surgical procedures precisely from normal textbooks with two-dimensional illustrations. Recent developments in 3D computed tomography (3D-CT) and laser stereolithography have enabled surgeons to visualize the structures of cleft lips from desired viewpoints. However, this method cannot reflect the advantages offered by specific surgical procedures. To solve this problem, we used the benefits offered by 3D computer graphics (3D-CG) and 3D animation. DESIGN AND RESULTS: By using scanning 3D-CT image data of patients with cleft lips, 3D-CG models of the cleft lips were created. Several animations for surgical procedures such as incision designs, rotation of small skin flaps, and sutures were made. This system can recognize the details of an operation procedure clearly from any viewpoint, which cannot be acquired from the usual textbook illustrations. This animation system can be used for developing new skin-flap design, understanding the operational procedure, and using tools in case presentations. The 3D animations can also be uploaded to the World Wide Web for use in teleconferencing.

Cleft Lip↗
PubMed1986

Computer graphic display method for visualizing three-dimensional biological structures.

A computer graphic display method that produces two-dimensional perspective views of three-dimensional objects is presented. The method is applied to the reconstruction at a resolution of 2.2 nanometers of the neck of bacteriophage phi 29, obtained from transmission electron micrographs processed by the direct Fourier method. The combined use of directed illumination, reflectance models, color, and different levels of transparency provides a powerful tool for a better interpretation of the three-dimensional structure, allowing improved correlation with genetic, structural, and biochemical data.

Bacteriophages↗
PubMed1991

Computer graphic modeling in drug design--conformational analysis of antifolate binding to avian dihydrofolate reductase: crystal and molecular structures of 2,4-diamino-5-cyclohexyl-6-methylpyrimidine and 5-cyclohexyl-6-methyluracil.

The results of crystal structure determinations of the antifolate 2,4-diamino-5-cyclohexyl-6-methylprimidine (I), and its uracil derivative (II), show that the 5-cyclohexyl ring is gauche to the planar pyrimidine ring with torsion angles 82.4 (3) degrees and 63.7 (3) degrees for (I) and (II), respectively. Hydrogen bond patterns observed for these free base pyrimidines indicate a preference for N...N or N...O dimer formation around inversion centers, as observed in other antifolate structures. Computer graphic modeling studies were carried out comparing the avian dihydrofolate reductase active site interactions of the cyclohexyl antifolate (I) with the more potent 5-adamantyl analog and the less potent 5-hexyl and 5-heptyl antifolates. These data showed that although the cyclohexyl ring fits into the same conformational space as adamantyl, it makes fewer hydrophobic contacts. Similarly, cyclohexyl fills the active site better than either the 5-n-hexyl or heptyl side chains. These data are consistent with the increased potency of the adamantyl and cyclohexyl antifolates compared to n-alkyl analogs with similar hydrophobicities. These data indicate that the rigid structure of these ring systems increases their hydrophobic interactions, thus enhancing their biochemical activity.

Animals↗
PubMed1987

A computer-aided three-dimensional reconstruction of brain structures using high level computer graphics.

This paper describes how line drawings and continuous tone shaded images of a three-dimensional solid model of a brain structure are generated using a powerful general purpose computer graphics package. The model is built from a series of serial sections. We developed a software interface to convert the data entered by a section oriented way into a brain structure oriented file. We point out particularly the modular approach which consists of separating the tasks on small microcomputers or on bigger machines according to their computing cost. An example of a thalamic structure in a stereotaxic referential is presented.

Animals↗
PubMed1992

Computer graphics presentations and analysis of hydrogen bonds from molecular dynamics simulation.

To obtain better insights into the dynamic nature of hydrogen bonding, computer graphics representations were introduced as an aid for the analysis of molecular dynamics trajectories. A schematic representation of hydrogen bonding patterns is generated to reflect the frequency and the type of hydrogen bonding occurring during the simulation period. Various trajectory plots for monitoring geometrical parameters and for analyzing three-center hydrogen bonding were also generated. The methods proposed are applicable to a variety of biopolymers. In this study, hydrogen bonding in the d(G)6.d(C)6 system was examined. For the nucleic acid fragments examined, three-center hydrogen bonds can be classified as in-plane and major or minor groove types. The in-plane three-center hydrogen bond represents a stable state in which both bonds simultaneously satisfy the relaxed hydrogen bonding criteria for a measurable period. On the other hand, groove three-center hydrogen bonds behave as a transient intermediate state in a flip-flop hydrogen bonding system.

Computer Graphics↗
PubMed1991

Association of cytoskeletons with the Golgi apparatus: three-dimensional observation and computer-graphic reconstruction.

The association of cytoskeletons with the Golgi apparatus (GA) in cultured 3Y1 cells was investigated by stereo electron microscopy of thick sections and computer-graphic reconstruction of serial thin sections. The 3-dimensional analysis has demonstrated that: 1) both microtubules (MT) and vimentin intermediate filaments (IF) were abundantly present in close vicinity to GA, and some of them were closely associated with GA; and 2) such GA-associated cytoskeletons were attached to GA either at their termini or at their lateral side. The present observations suggest that both MT and vimentin IF are responsible for maintaining the structural integrity of GA.

Animals↗
PubMed1982

Computer graphics in drug design: molecular modeling of thyroid hormone-prealbumin interactions.

Computer graphics modeling of the thyroxine-prealbumin complex provides a detailed picture of the interactions between thyroxine and prealbumin. A wide variety of thyroid hormone analogue-prealbumin complexes were modeled by calculating the molecular surfaces of the analogues and the prealbumin hormone-binding site. Analogues with high binding affinity were observed to fill more of the hormone-binding site than low-affinity analogues. These surface models described many aspects of the hormone-protein interaction which were not obvious using simple wire models and led us to develop a model which accounts for thyroid hormone-prealbumin structure-activity relationships and ultimately to predict and measure the relative binding affinities of four previously untested thyroid hormone analogues to prealbumin.

Chemical Phenomena↗
PubMed2001

Optical design using computer graphics.

For decades the computer has been the primary tool used for optical design. Typical tasks include performing numerical calculations for ray tracing and analysis and rendering graphics for system drawings. As machines become faster with each new generation, the time needed for a particular design task has greatly reduced, allowing multiple assignments to be performed with little noticeable delay. This lets the designer modify a system and then immediately see the results rendered in graphics with a single motion. Such visual design methods are discussed here, where graphics of systems and plots relating to their performance are produced in real time, permitting the optical designer to design by pictures. Three examples are given: an educational tutorial for designing a simple microscope objective, an unobstructed reflective telescope composed of three spherical mirrors, and a modified Offner relay with an accessible pupil.

Journal Article↗