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At least 1,603 records · Page 89Linked to original sources
PubMed1997

Mononeuropathy of a distal branch of the femoral nerve in a body building champion.

A unique case of a body building champion with localised atrophy of the distal portion of the vastus lateralis muscle is reported; neurophysiological evaluation suggests a selective lesion of a distal branch of the vastus lateralis nerve (a motor branch of the femoral nerve). A necroscopic study in four cases was performed to better clarify the site and mechanism of nerve lesion. The data suggest that stretching and compression of the nerve has probably occurred during strenous exercise.

Adult↗
PubMed1995

Heteronuclear NMR pulse sequences applied to biomolecules.

Current concepts in heteronuclear multidimensional NMR spectroscopy are reviewed. Methods to improve the sensitivity and the efficiency of data collection include constant time, compression through the overlap of chemical shift evolution and dephasing and rephasing periods, and dual or time-shared evolution. Two classes of three-dimensional and four-dimensional triple-resonance experiments applied to proteins are considered. The first class correlates 1H, 15N, and 13C signals of the protein backbone. The second class correlates both backbone and side-chain signals. Application of triple resonance to RNA is also discussed. Heteronuclear cross polarization (HCP) is considered as an alternative to INEPT transfer, and its application to nucleic acids is presented. Finally, two methods of employing pulsed field gradients (PFGs) are reviewed.

Magnetic Resonance Spectroscopy↗
PubMed1985

Effect of filler content and size on properties of composites.

Two series of dental composites, along with the unfilled resin matrix, were examined to determine the effects of filler level and size on selected properties. Both series were prepared by incorporating a silanated barium borosilicate filler into a visible-light-activated polyphenylene polymethacrylate resin matrix. One series had a filler particle size of 2 microns, with filler levels of 20, 40, 45, 50, and 53% (vol). The second series contained a 15-microns filler in amounts of 20, 40, 50, 60, and 65% (vol). Tests conducted included: depth of cure as evaluated by hardness, water sorption, compressive strength, stress-strain behavior under slow compression, toothbrush abrasion, and wear by hydroxyapatite. Analysis of the data indicated that increased filler levels resulted in increased hardness, compressive strength and stiffness, and decreased water sorption. Also, there was a slight trend toward improved depth of cure. Incorporation of the 2-microns filler decreased the abrasion resistance of the resins to toothbrushing as compared with the unfilled resin, while addition of the 15-microns filler improved resistance. All filled resins exhibited a significant improvement in resistance to wear by hydroxyapatite as compared with the unfilled resin. There was a trend for increased wear with increased filler level. The particle size of the filler appeared to have a moderate influence on the properties. When compared with 15-microns filled resins of the same filler levels, the 2-micron filled series appeared to have inferior properties in terms of depth of cure, compressive strength, water sorption, and resistance to toothbrush abrasion. Properties which were less affected by particle size were hardness, stiffness, and wear resistance to hydroxyapatite.

Chemical Phenomena↗
PubMed2002

Application of a high-repetition-rate laser diagnostic system for single-cycle-resolved imaging in internal combustion engines.

High-repetition-rate laser-induced fluorescence measurements of fuel and OH concentrations in internal combustion engines are demonstrated. Series of as many as eight fluorescence images, with a temporal resolution ranging from 10 micros to 1 ms, are acquired within one engine cycle. A multiple-laser system in combination with a multiple-CCD camera is used for cycle-resolved imaging in spark-ignition, direct-injection stratified-charge, and homogeneous-charge compression-ignition engines. The recorded data reveal unique information on cycle-to-cycle variations in fuel transport and combustion. Moreover, the imaging system in combination with a scanning mirror is used to perform instantaneous three-dimensional fuel-concentration measurements.

Journal Article↗
PubMed1984

Evaluation of bronchodilation from aerosol beta 2 agonists delivered by the Inhal-Aid device to young children.

The Inhal-Aid is a device that combines a reservoir aerosol delivery system, two one-way valves, and an incentive spirometer to assist in the delivery of medication from metered-dose inhalers. It appears to result in bronchodilatory effect that is similar to that obtained from (9) compressed air driven nebulizer. Further data are needed to determine if the therapeutic advantages of an aerosol receiving chamber with metered-dose inhalers are matched by clinically important consequences for the patient with adequate coordination. For the patient unable to utilize metered-dose inhalers because of inability to coordinate inspiration with activation, however, the Inhal-Aid provides an effective means to conveniently deliver clinically important antiasthmatic medication.

Aerosols↗
PubMedDate not supplied

[Radiation diagnosis of uncomplicated compression spinal fractures in children].

Experiments on rabbits compared the X-ray, morphological, and magnetic resonance imaging of compression fractures of the vertebral body. Edema of the bone marrow of the vertebral body was ascertained to be a basic morphological substrate that evokes a modified MR signal. The data on 178 children with suspected compression fracture of the vertebral body were used to consider the potentialities of MRI and X-ray study in this pathology. The MRI semiotics of uncomplicated compression fractures of vertebral bodies is presented. The sensitivities of MRI and spondylography in the diagnosis of compression fractures of vertebral bodies were 100 and 62.5%, respectively.

Adolescent↗
PubMed1992

[Prospective study of echography versus phlebography in the detection of sural venous thrombosis].

Among all noninvasive techniques, high-resolution ultrasonography used alone has rarely been used for the diagnosis of thrombosis in the calf. Nineteen patients with suspected AVT were examined with ultrasonography and phlebography during 4 months. For each patient, a sonogram and a phlebogram were taken within less than 24 hours and interpreted independently. The sonographic exploration with a high-resolution (5 MHz) transducer covers all deep trunks and muscular veins (soleus or gastrocnemius muscles). The positivity criterion is the persistence of a hypoechogenic endoluminal image under moderate compression. According to the phlebographic data, 65% of the patients present with thrombosis. Ultrasonography has a sensitivity of 95% and a specificity of 99% for the study of the deep trunks. Ultrasonography screens more thromboses than phlebography (23 cases versus 17). On a whole, ultrasonography seems to be more sensitive than phlebography for the diagnosis of recent sural thrombosis.

Acute Disease↗
PubMed2003

Nonlinear and viscoelastic characteristics of skin under compression: experiment and analysis.

In physiological loading conditions, the soft tissues in the hands and fingers are predominantly in compression. The goal of the present study was to characterize the nonlinear and time-dependent behavior of skin in compression. The pigskin samples used in the study were collected from five different animals. The compression tests were performed in confined and unconfined loading configurations and at four different loading speeds (0.5, 1.0, 40, and 400 microm/s). A multi-axial material model was proposed to simulate the nonlinear and viscoelastic behavior of the skin in compression. The good agreement between the model predictions and experimental data suggests that the mechanical behavior of the skin in compression can be well characterized using the Ogden strain energy potential combined with a time-integration using a Prony series. Our results show that the stress/strain curve of the skin is much stiffer in confined compression compared to that in unconfined compression, indicating that the compressibility of the skin is small.

Animals↗
PubMed2002

The role of XML in medical informatics in Hungary.

Reforms in healthcare means frequent changes. The author focusing on flexible information systems and data structures in healthcare, that gives the chance to avoid costly deadlocks, incompatibilities and data chaos--keeping the financial and administrative burden of provider and reimbursement information systems at low level. He describes data and document exchange among health care providers (hospitals, GPs etc.) and the reimbursing insurance institute introducing XML (eXtensible Markup Language) technology and it's multimedia extension called SMIL (Synchronized Multimedia Integration Language) that well supports large textual and multimedia nature of data in healthcare. He presents the most frequent XML datasets for reimbursement in Hungary, the validation schemas (Data Type Definitions) and procedures, comparing the new and old data file sizes with different compressions. The comparison includes different schema file sizes, and validation times.

Humans↗
PubMed1990

[The image of intravertebral somatic gaseous dissection. Report of 9 cases one of which has a triple localization and review of the literature].

We report a series of 9 cases of vertebral somatic gaseous dissection studied between 1978 and 1989. We find most of the characteristics established from the literature data: advanced age, possible medullar compression contrary to the vertebral compression by common osteoporosis, predilection for the dorso-lumbar junction, frequency of the osteoporosis, possibility of metabolic disorders, of occurrence after radiotherapy. The context of the occurrence and the paraclinical examinations of the whole have enabled us to eliminate, in this series, a malignant pathology. However, when there exists a doubt on a malignant origin, it is preferable to carry out a vertebral biopsy with a trocar. In fact, the image may not be pathognomonic of a benign vertebral osteoporosis. Finally, we give the first description of a triple localization of vertebral gaseous dissection.

Aged↗
PubMed1982

Auditory perceptual abilities of formerly misarticulating children.

12 children who recently had satisfactorily completed therapy for 4+ phonemes, and normal controls, were given tasks of auditory perception consisting of (a) repeating 5-word recorded sentences (0, 1st- and 2nd-order approximations) at 0 and at 60% time compression, and (b) diotic and dichotic presentations at 40 db SL of the WIPI test split into 2 bandwidths (500-580 and 1950-2080 c/s). Results showed that the performance of the experimental Ss was significantly poorer than that of age-matched controls on time-compressed speech, but not on the binaural fusion task. The greatest diagnostic potential for time-compressed speech was at 60% compression. Results contrasted with previous data showing significantly poorer performance of severely misarticulating children on a binaural summation task (Flowers and Costello, J. Aud. Res., 1963, 3, 133-140). There is a need to monitor the auditory perceptual abilities of formerly misarticulating children with a battery of more than a single test.

Articulation Disorders↗
PubMed1995

[Glossary of terms used by radiologists in image processing].

We give the definition of 166 words used in image processing. Adaptivity, aliazing, analog-digital converter, analysis, approximation, arc, artifact, artificial intelligence, attribute, autocorrelation, bandwidth, boundary, brightness, calibration, class, classification, classify, centre, cluster, coding, color, compression, contrast, connectivity, convolution, correlation, data base, decision, decomposition, deconvolution, deduction, descriptor, detection, digitization, dilation, discontinuity, discretization, discrimination, disparity, display, distance, distorsion, distribution dynamic, edge, energy, enhancement, entropy, erosion, estimation, event, extrapolation, feature, file, filter, filter floaters, fitting, Fourier transform, frequency, fusion, fuzzy, Gaussian, gradient, graph, gray level, group, growing, histogram, Hough transform, Houndsfield, image, impulse response, inertia, intensity, interpolation, interpretation, invariance, isotropy, iterative, JPEG, knowledge base, label, laplacian, learning, least squares, likelihood, matching, Markov field, mask, matching, mathematical morphology, merge (to), MIP, median, minimization, model, moiré, moment, MPEG, neural network, neuron, node, noise, norm, normal, operator, optical system, optimization, orthogonal, parametric, pattern recognition, periodicity, photometry, pixel, polygon, polynomial, prediction, pulsation, pyramidal, quantization, raster, reconstruction, recursive, region, rendering, representation space, resolution, restoration, robustness, ROC, thinning, transform, sampling, saturation, scene analysis, segmentation, separable function, sequential, smoothing, spline, split (to), shape, threshold, tree, signal, speckle, spectrum, spline, stationarity, statistical, stochastic, structuring element, support, syntaxic, synthesis, texture, truncation, variance, vision, voxel, windowing.

Diagnostic Imaging↗
PubMed2005

Elastic anisotropy of bone and dentitional tissues.

The calculation of the scalar compressive and shear anisotropy factors developed for single crystal refractory compounds has been adapted to the anisotropic elastic stiffness coefficients determined by a number of ultrasonic measurements of bone based on transverse isotropic symmetry. Later, this work was extended to include the ultrasonic measurements of bone based on orthotropic symmetry. Recently, the five transverse isotropic elastic constants for both wet and dry human dentin were determined using resonant ultrasound spectroscopy. The five transverse isotropic elastic constants for wet bovine enamel and dentin had been calculated based on modeling of ultrasonic wave propagation measurements and related data in the literature. The scalar compressive and shear anisotropy factors have been calculated from both these sets of data and are compared with a representative set from those published previously for both human and bovine bone and both fluoro- and hydroxyl-apatites.

Animals↗
PubMed2002

Precision of estimates of mean and peak spinal loads in lifting.

A bootstrap procedure was used to determine the statistical precision of estimates of mean and peak spinal loads during lifting as function of the numbers of subjects and measurements per subject included in a biomechanical study. Data were derived from an experiment in which 10 subjects performed 360 lifting trials each. The maximum values per lift of the lumbar flexion angle, L5S1 sagittal plane moment, and L5S1 compression force were determined. From the data set thus compiled, 3000 samples were randomly drawn for each combination of number of subjects and number of measurements considered. The coefficients of variation of mean and peak (defined as mean plus 2 standard deviations) spinal loads across these samples were calculated. The coefficients of variation of the means of the three parameters of spinal load decreased as a linear function of the number of subjects to a power of about -0.48 and number of measurements to a power of about -0.06, while the corresponding powers for peak loads were about -0.44 and -0.11.

Analysis of Variance↗
PubMed2001

Feasibility and clinical value of "intelligent" compression and digital storage of transthoracic echocardiograms in day-to-day practice.

BACKGROUND: The aim of this study was to assess the clinical concordance of expert cardiologists' interpretation of echocardiographic studies recorded on Super-VHS videotape or stored in magneto-optical disk, as well as the feasibility and clinical value of intelligent compression and digital storage of echocardiographic data as cine-loops and still-frames for interpretation of transthoracic echocardiographic images in clinical practice. METHODS: All clinical cardiologists experienced in echocardiography in our department (n = 10) reported on a standardized worksheet checklist the echocardiographic data of 7 consecutive patients (140 reports), and recorded them on videotape or magneto-optical disks to compare the interpretation of videotaped studies, acquired in the usual way, with clinically compressed studies stored to magneto-optical disks using a standard (Italian Society of Echocardiography) image acquisition protocol. RESULTS: The time interval between analog and digital study readings was 50 +/- 15 days. Except for tricuspid valve regurgitation grading (k = 0.28) and for left ventricular global hypokinesia (k = 0.32), the intraobserver agreement in the interpretation of the 3290 cardiovascular morphological and functional findings found on analog and digitally stored images was good (k value ranging from 0.66 to 1.00). The wall motion score index was 1.56 +/- 0.53 when interpreting analog studies, and 1.52 +/- 0.54 on digital studies (p = 0.35). Conversely, the interobserver variability of the wall motion score index (Gini index ranging from 0 to 0.80) was significantly lower when interpreting studies stored digitally than when analog ones were examined (0.48 +/- 0.021 and 0.52 +/- 0.023 respectively, p = 0.006). In comparison to videotape recordings, digital storage of echocardiographic studies significantly shortened the time to image access for study review (327 +/- 62 and 30 +/- 4 s, respectively, p < 0.0001) and the reading time (600 +/- 300 and 540 +/- 300 s respectively, p = 0.034), rendered study accessibility easier (difficult or good: 73 vs 43% of observers, fast or optimal: 27 vs 57% of observers respectively, p = 0.0011) and improved the recorded image quality perception (poor: 25 vs 10% of observers, sufficient or good: 75 vs 90% of observers respectively, p = 0.022), without loss of study completeness (insufficient: 18 vs 17% of observers, adequate or complete: 82 vs 83% of observers, respectively; p = NS). Finally, from September 1, 1999, digital storage has become routine practice for patients admitted to our Department. By December 31, 1999, 411 echo studies had been stored: 7 +/- 3 cine-loop/study, 32 +/- 18 frames/cine-loop, and 3 +/- 2 still-frames/study. The average amount of memory needed for storage was 18.6 +/- 11.9 MB/study. CONCLUSIONS: Clinical compression of echocardiographic studies seems to be an accurate summary of the complete examination recorded to videotape for the assessment of patients admitted in the coronary care unit. In addition, digitally stored studies allow a significant improvement in the interobserver reproducibility of wall motion score assessment.

Analog-Digital Conversion↗
PubMed1982

Assessment of time-volume and flow-volume components of forced vital capacity. Measurement with spirometry, body plethysmography and respiratory inductive plethysmography in nonsmokers and smokers.

The purpose of this investigation was to assess the effectiveness of the time-volume and flow-volume components of the forced vital capacity measured by simultaneous spirometry, respiratory inductive plethysmography, and body plethysmography in detecting small airway disease. Spirometry measured the exit of gas from the lungs, whereas body plethysmography measured both the exit of gas and alveolar gas compression. Respiratory inductive plethysmography, which reflected change in thoracic volume, provided semi-quantitative data f both gas exit and alveolar gas compression which generally lay between spirometry and body plethysmography. In nine nonsmokers and 12 smokers (six with small airway disease as defined by abnormal closing volumes and alveolar uniformity), analysis of forced vital capacity revealed that the only test which differentiated nonsmokers from smokers was the higher spirometric estimation of maximum expiratory flow measured at 25 percent VC in nonsmokers. Combining flow measure at the mouth with volume referenced to change in alveolar gas volume as measured by body or respiratory inductive plethysmography did not differentiate nonsmokers from smokers. Moment analysis performed of forced vital capacity with all of the three devices did not distinguish nonsmokers from smokers. The data in this study and a review of other investigations indicate that the time-volume and flow-volume components of the forced vital capacity on air breathing are not very sensitive in detecting early lung disease in smokers.

Adolescent↗
PubMed2004

Highly scalable video compression with scalable motion coding.

A scalable video coder cannot be equally efficient over a wide range of bit rates unless both the video data and the motion information are scalable. We propose a wavelet-based, highly scalable video compression scheme with rate-scalable motion coding. The proposed method involves the construction of quality layers for the coded sample data and a separate set of quality layers for the coded motion parameters. When the motion layers are truncated, the decoder receives a quantized version of the motion parameters used to code the sample data. The effect of motion parameter quantization on the reconstructed video distortion is described by a linear model. The optimal tradeoff between the motion and subband bit rates is determined after compression. We propose two methods to determine the optimal tradeoff, one of which explicitly utilizes the linear model. This method performs comparably to a brute force search method, reinforcing the validity of the linear model itself. Experimental results indicate that the cost of scalability is small. In addition, considerable performance improvements are observed at low bit rates, relative to lossless coding of the motion information.

Algorithms↗
PubMed1980

A micro-computerised system to measure the colonic contractile activity: application to pharmacological tests in dogs.

This paper describes a rapid and reproducible technique for measuring the contractile activity of the colon, from strain-gauge signals, using a microcomputer data-processing PDS M 6800. This system can be used on-line, or after a 32 times compression, with only slight modifications of the data collection program. The motility index of the colon, calculated from the surface of the contractile waves, was automatically given at 5-min intervals. A series of comparative measurements of colonic motility and its changes after administration of drugs, such as morphinomimetics and spasmolytics, have been reported.

Animals↗