Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Computer Terminals”

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 1,603 records · Page 89Linked to original sources
PubMed2002

Pacemaker interference by magnetic fields at power line frequencies.

Human exposure to external 50/60-Hz electric and magnetic fields induces electric fields within the body. These induced fields can cause interference with implanted pacemakers. In the case of exposure to magnetic fields, the pacemaker leads are subject to induced electromotive forces, with current return paths being provided by the conducting body tissues. Modern computing resources used in conjunction with millimeter-scale human body conductivity models make numerical modeling a viable technique for examining any such interference. In this paper, an existing well-verified scalar-potential finite-difference frequency-domain code is modified to handle thin conducting wires embedded in the body. The effects of each wire can be included numerically by a simple modification to the existing code. Results are computed for two pacemaker lead insertion paths, terminating at either atrial or ventricular electrodes in the heart. Computations are performed for three orthogonal 60-Hz magnetic field orientations. Comparison with simplified estimates from Faraday's law applied directly to extracorporeal loops representing unipolar leads underscores problems associated with this simplified approach. Numerically estimated electromagnetic interference (EMI) levels under the worst case scenarios are about 40 microT for atrial electrodes, and 140 microT for ventricular electrodes. These methods could also be applied to studying EMI with other implanted devices such as cardiac defibrillators.

Electromagnetic Fields↗
PubMed1979

Radiology management: the advantages of the dedicated mini-computer.

When planning to automate management functions, a department must choose between using a dedicated mini-computer and the hospital's large central computer facility. Rapid response times and ease of program modification are important advantages of the dedicated mini-computer; moreover, limitations on transmission speeds and the variety of terminals available are disadvantages of the central computer facility. The substantial reduction in the cost of computers coupled with the availability of well designed data-base management systems which allow communication with other systems are additional reasons for selecting the mini-computer. In selecting systems that are already programmed, the department minimizes risks and implementation difficulties.

Centralized Hospital Services↗
PubMed2004

Structure of the N-terminal domain of PEX1 AAA-ATPase. Characterization of a putative adaptor-binding domain.

Peroxisomes are responsible for several pathways in primary metabolism, including beta-oxidation and lipid biosynthesis. PEX1 and PEX6 are hexameric AAA-type ATPases, both of which are indispensable in targeting over 50 peroxisomal resident proteins from the cytosol to the peroxisomes. Although the tandem AAA-ATPase domains in the central region of PEX1 and PEX6 are highly similar, the N-terminal sequences are unique. To better understand the distinct molecular function of these two proteins, we analyzed the unique N-terminal domain (NTD) of PEX1. Extensive computational analysis revealed weak similarity (<10% identity) of PEX1 NTD to the N-terminal domains of other membrane-related type II AAA-ATPases, such as VCP (p97) and NSF. We have determined the crystal structure of mouse PEX1 NTD at 2.05-A resolution, which clearly demonstrated that the domain belongs to the double-psi-barrel fold family found in the other AAA-ATPases. The N-domains of both VCP and NSF are structural neighbors of PEX1 NTD with a 2.7- and 2.1-A root mean square deviation of backbone atoms, respectively. Our findings suggest that the supradomain architecture, which is composed of a single N-terminal domain followed by tandem AAA domains, is a common feature of organellar membrane-associating AAA-ATPases. We propose that PEX1 functions as a protein unfoldase in peroxisomal biogenesis, using its N-terminal putative adaptor-binding domain.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1975

Interactive simulator for pharmacokinetics of repetitive drug dosing.

DRUGSIM is a highly interactive program allowing simulation of the effects of repeated drug administration by a variety of routes on plasma concentrations of drugs over a period of time. Drug parameters are read from a data file; prescriptions are obtained from the user at various points during run time. The results for one or two compartment pharmacokinetics are plotted on a storage display tube, and the user is queried for further prescriptions. Simulation involves a point-slope method with a variable time step. The program is written in Fortran IV and run on a DEC PDP-10 computer using a Computek 611 display terminal.

Administration, Oral↗
PubMed1985

A molecular dynamics study of the C-terminal fragment of the L7/L12 ribosomal protein. Secondary structure motion in a 150 picosecond trajectory.

A 150 picosecond molecular dynamics computer simulation of the C-terminal fragment of the L7/L12 ribosomal protein from Escherichia coli is reported. The molecular dynamics results are compared with the available high-resolution X-ray data in terms of atomic positions, distances and positional fluctuations. Good agreement is found between the molecular dynamics results and the X-ray data. The form and parameters of the interaction potential energy function and the procedures for deriving it are discussed. Some current misunderstandings concerning the ways of evaluating the efficiency of molecular dynamics algorithms and of application of bond-length constraints in protein simulations are cleared up. The 150 picosecond trajectory has been scanned in a search for correlated motions within and between secondary structure elements. The beta-strands have diffusional stretching modes, and uncorrelated transversal displacements. The dynamic analysis of alpha-helices shows a variety of features. The atomic fluctuations differ between the helix ends; this effect reflects long time-scale motions. Two alpha-helices, alpha A and alpha C, show diffusive longitudinal stretching modes. The third helix, alpha B, has a correlated asymmetric longitudinal stretching; the N-terminal part dominates this behaviour. Furthermore, alpha B presents a librational motion with respect to the other parts of the molecule with a frequency of approximately 5 cm-1. This motion is coupled to helix stretching. Interestingly, the regions of highly conserved residues contain the most mobile parts of the molecule.

Bacterial Proteins↗
PubMed2000

SclA, a novel collagen-like surface protein of Streptococcus pyogenes.

Surface proteins of Streptococcus pyogenes are important virulence factors. Here we describe a novel collagen-like surface protein, designated SclA (streptococcal collagen-like surface protein). The sclA gene was identified in silico using the Streptococcal Genome Sequencing Project with the recently identified protein GRAB as the probe. SclA has a signal sequence and a cell wall attachment region containing the prototypic LPXTGX motif. The surface-exposed part of SclA contains a unique NH(2)-terminal domain of 73 amino acids, followed by a collagen-like region. The sclA gene was found to be positively regulated by Mga, a transcriptional activator of several S. pyogenes virulence determinants. A mutant lacking cell wall-associated SclA was constructed and was found to be as effective as wild-type bacteria in platelet aggregation, survival in fresh human blood, and adherence to pharyngeal cells. The sclA gene was found in all 12 S. pyogenes strains that were investigated using PCR. Sequence analysis revealed that the signal sequence and the cell wall attachment region are highly conserved. The collagen-like domain is variable in its NH(2)-terminal region and has conserved repeated domains in its COOH-terminal part. SclA proteins from most strains have additional proline-rich repeats spacing the collagen-like domain and the cell wall attachment sequence. The unique NH(2)-terminal region is hypervariable, but computer predictions indicate a common secondary structure, with two alpha helices connected by a loop region. Immune selection may explain the hypervariability in the NH(2)-terminal region, whereas the preserved secondary structure implies that this region has a common function. These features and the Mga regulation are shared with the M protein of S. pyogenes. Moreover, as with the gene encoding the M protein, phylogenetic analysis indicates that horizontal gene transfer has contributed to the evolution of sclA.

Animals↗
PubMed2026

Quantifying the control laws governing terminal attack in lions.

Intercepting an evasive, maneuvering target is among the most computationally demanding tasks a predator performs: in the terminal phase of a chase, it must continuously convert sensory information about the target into steering and speed commands, subject to its own biomechanical limits. How terrestrial predators solve this in real time has remained difficult to quantify. Here, we combine drone videography with AI-based markerless pose estimation to reconstruct the kinematics of 67 lion (Panthera leo) attacks on a mechanized lure programmed to move unpredictably. Lion steering is described by a combination of proportional navigation and proportional pursuit, which is a mixed guidance law previously identified only in the aerial pursuit of Harris's hawks (Parabuteo unicinctus), and speed is regulated within a defined kinematic envelope during turns, which declines at close range where the cost of overshooting is greatest. These findings reveal shared guidance principles across aerial and terrestrial pursuit, thus providing a quantitative framework for comparing pursuit strategies across species.

computational ethology↗
PubMedDate not supplied

Ileocolic intussusception in large cell lymphoma of the terminal ileum. Report of a case.

A case of an adult patient with ileocolic intussusception secondary to a lymphoma of the terminal ileum is reported. On the computed tomograms, a target mass, with the outer rim representing the annular tumour of the terminal ileum and the eccentric rim of low attenuation representing the mesentery, is described. Ultrasound patterns are those of parallel hypoechoic areas separated by hyperechoic stripes seen on longitudinal sections, and of a rounded mass of low echogenicity, exhibiting two hyperechoic concentric ring-like areas within it, on transverse scans. The appearances of the barium examinations are also described. The English literature is reviewed.

Humans↗
PubMed2005

[Blinking activity during visual display terminal work. 2: reduced blinking and therapeutic approaches].

New findings based on a noninvasive, automated long-term measurement method revealed interindividual differences in lid movement behavior, existence of blinking patterns, and the dominance of cognitive influence in the regulation of blinking frequency during increased concentration and especially visual attention. The development of an individual blinking animation promises long-lasting increase and harmonization of lid movements during visual display work. Maintenance of the integrity of the ocular surface by preventing surface evaporation and providing sufficient precorneal environment eradicates important pathogenic factors of ocular discomfort. An animation program for stimulation of blinking has been developed. First results showed that an increase in blinking rate initiated by the computer itself is feasible in principle during work at a visual display terminal. Further improvement of this new approach is promising.

Blinking↗
PubMed1985

QSAR application in chemical carcinogenesis. II. QSAR analysis of a class of carcinogenesis inhibitor: retinoids.

Quantitative structure-activity relationships for the reversion of keratinization of hamster tracheal cell organ culture by structurally related retinoids were formulated. Their biological activities (ED50 . M) were correlated with the following parameters: the minimal topological difference (describing the fit of the considered molecules with a possible receptor site) and the lipophilicity constants. For computation purposes the retinoids were divided in three series (A, B and C) according to structural modifications in the cyclic moiety of the molecule, in the polienic chain and in the terminal functional group, respectively. The computed regression equations suggested the importance of the stereochemical features of cyclic moiety (for series A, eq. 1, n = 19, r = 0.926, F = 48.19) and of the uninterrupted conjugation for the polienic chain (for series B, eq. 6, n = 11, r = 0.954, F = 39.39) for the biological activity. In order to check the prediction potential of the regression equation computed for the overall set of compounds (eq. 10, n = 53, r = 0.853, F = 32.11), it was used to calculate the ED50 for a test series of 15 retinoids. The correlation obtained between ED50 exp and ED50 calc for this series was r = 0.916, F = 60.25. The nature of the receptor site possibly involved in the interaction with retinoids was discussed.

Animals↗
PubMed1996

The use of yoked base-up and base-in prism for reducing eye strain at the computer.

BACKGROUND: Eye strain continues to be one of the chief complaints of people working at video display terminals. The increase in extorsion observed on elevation of gaze at near point may induce binocular disruption and strain. Binocular base-up and base-in prism might mitigate some of the visual complaints of computer users because they decrease the elevation and convergence required. A double blind study of 30 computer users indicates a significantly greater preference for a lens combining prism and plus power than for plus lenses having no prism.

Adult↗
PubMed2004

A quantitative study of nerve fiber density in the submandibular gland of rats.

The route and three dimensional distribution of nerve terminals in the submandibular gland were investigated in rats using immunohistochemistry for the protein gene product (PGP) 9.5, as a marker of neuronal elements. Thick fiber bundles were found along the wall of the excretory duct. Many fine fibers from these thick bundles were distributed each lobule of the submandibular gland. A large number of single fibers terminated in the area around the striated, intercalated ducts and the acini. The densities of PGP 9.5 immunoreactive terminals were measured by a computer aided analysis system in the three areas: the striated duct, the intercalated duct, and the acini, whose densities (microm/microm2) were 0.23, 0.39 and 0.05 respectively. The relatively high density of nerve terminals in the intercalated duct suggests that the duct system probably plays an unexpectedly important role in the functional aspects.

Animals↗
PubMed1981

Intraocular lens power formulas.

We have developed a FORTRAN digital computer program to evaluate intraocular lens power for any thin lens and combination of corneal curvature and axial length. Partial derivatives of the power with respect to cornea power, axial length, and lens position allow estimation of error in power of the lens. These derivatives are computed along with power of the lens for six far points which may be changed with the program running. The program is written for remote access so that an ordinary telephone and portable terminal provide the ability to compute lens power.

Computers↗
PubMed2005

The effect of antireflection film use on blink rate and asthenopic symptoms during visual display terminal work.

PURPOSE: To investigate the effect of visual display terminal antireflection (AR) films on blink rate and subjective symptoms of asthenopia. METHODS: This was a nonrandomized, prospective clinical trial in which 7 healthy volunteers underwent blink rate measurements with a blink rate recording system while viewing a DVD on a computer display for 10 minutes. The measurements were carried out without an AR film on terminal displays initially. The same tasks were performed on the next day with an AR film on the displays. The subjects were also required to score their symptoms of asthenopia on a visual analog scale before and just after DVD viewing. The changes in blink rate and asthenopia scores with AR film use were assessed by the Student t test. RESULTS: The mean baseline blink rate was 15.7 +/- 5.9 blinks /min, which decreased significantly to 9.6 +/- 4.3 blinks/min after DVD viewing without an AR film (P < 0.05). The mean baseline and final blink rates for DVD viewing with an AR film were 14.6 +/- 9.2 and 14.3 +/- 9.2 blinks/min, respectively. There were no significant differences between baseline and final blink rates after DVD viewing with an AR film (P > 0.05). The mean cumulative visual analog asthenopic symptom score after DVD viewing without an AR film was 72 +/- 18% compared with the mean cumulative symptom score of 52 +/- 11% after DVD viewing with an AR film. The difference was statistically significant (P < 0.05). CONCLUSIONS: Visual display terminal work appears to be associated with asthenopic symptoms and decreased blink rates. The use of AR films on computer displays may prevent both reflections of light from screen surfaces and reduction in blink rates resulting in fewer asthenopic symptoms.

Adult↗
PubMed1982

Structure and behaviour of the sperm terminal filament.

Light- and electron-microscopic observations of Ciona and Lytechinus spermatozoa show a thin terminal filament at the distal end. The terminal filament is 5-6 microns long and contains the two central microtubules and a variable number of A-tubule extensions of the peripheral doublet microtubules. The transition from the 9 + 2 region to the terminal filament is tapered more gradually in Lytechinus than in Ciona. Photographs of the movement of beating spermatozoa do not show any obvious discontinuity in curvature at the transition region. Bends are propagated smoothly off the end of the flagellum with no decrease in curvature. However, spermatozoa in which the terminal filament has been removed show a clear 'end effect'. This end effect involves a rapid unbending of bends that have reached the distal end of the flagellum. Computer simulations of flagellar models lacking a terminal filament show a similar end effect. Addition of a terminal filament to the end of the computer model can eliminate the end effect. Realistic bending behaviour of the model is obtained by using a terminal filament with a tapered elastic bending resistance in the basal portion of the terminal filament and a value of 0.03 x 10(9) pN nm2 in the remainder of the terminal filament. This leads to estimates of 0.01 x 10(9) pN nm2 for the elastic bending resistance of an individual microtubule, and 0.2 x 10(9) pN nm2 for the elastic bending resistance of the 9 + 2 region of the flagellum. An improvement in propulsive effectiveness by addition of a terminal filament remains to be demonstrated.

Animals↗
PubMed1972

Cable theory for finite length dendritic cylinders with initial and boundary conditions.

The cable equation is solved in the Laplace transform domain for arbitrary initial and boundary conditions. The cable potential is expressed directly in terms of the impedance of the terminations and the cable electrotonic length. A computer program is given to invert the transform. Numerical solutions may be obtained for any particular model by inserting expressions describing the terminations and parameter values into the program, without further computation by the modeler. For a finite length cable, sealed at one end, the solution is expressed in terms of the ratio of the termination impedance to the impedance of the finite length cable, a generalization of the steady-state conductance ratio. Analysis of a model of a soma with several primary dendrites shows that the dendrites may be lumped into one equivalent cylinder if they have the same electrotonic length, even though they may vary in diameter. Responses obtained under voltage clamp are conceptually predictable from measurements made under current clamp, and vice versa. The equalizing time constants of an infinite series expression of the solution are the negative reciprocals of the roots of the characteristic equation. Examination of computed solutions shows that solutions which differ theoretically may be indistinguishable experimentally.

Dendrites↗
PubMed2003

Computational docking of L-arginine and its structural analogues to C-terminal domain of Escherichia coli arginine repressor protein (ArgRc).

The arginine repressor (ArgR) of Escherichia coli binds to six L-arginine molecules that act as its co-repressor in order to bind to DNA. The binding of L-arginine molecules as well as its structural analogues is compared by means of computational docking. A grid-based energy evaluation method combined with a Monte Carlo simulated annealing process was used in the automated docking. For all ligands, the docking procedure proposed more than one binding site in the C-terminal domain of ArgR (ArgRc). Interaction patterns of ArgRc with L-arginine were also observed for L-canavanine and L-citrulline. L-lysine and L-homoarginine, on the other hand, were shown to bind poorly at the binding site. Figure A general overview of the sites found from docking the various ligands into ArgRc ( grey ribbons). Red coloured sticks: residues in binding site H that was selected for docking

Arginine↗
PubMed1994

Comparative morphometric analysis of terminal vascularization of hippocampal CA1 and CA3 sectors in Mongolian gerbils.

Comparative morphometric analysis of terminal vascularization (vessels with a diameter lower than 12.5 microns) in the ischemia-sensitive sector CA1 and the ischemia-resistant sector CA3 of Ammon's horn in Mongolian gerbils was performed. Basing on numerous computer-counted parameters characterizing the terminal vascular network in both hippocampal sectors and its relationship to the surrounding tissue, it was shown that a number of capillary vessels, their average diameter, and exchange and flow surfaces were to a statistically significant degree lower in the pyramidal layer of the CA1 sector as compared with those in CA3 sector. The number of pyramidal neurons in the pyramidal layer, counted per surface unit was in sector CA1 higher than in sector CA3. The obtained data indicate clearly an angioarchitectonically dependent lower microvascular capacity of sector CA1. However, these differences do not indicate per se a leading role of the vascular factor in the pathomechanism of selective vulnerability to ischemia. They may be a factor facilitating neuronal damage evoked by the excitotoxic action of glutamate, observed in CA1 sector as a result of forebrain ischemia.

Animals↗