Search Results
Results 401 - 450 of 937
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Shepherd Gordon M G - - 2003
Presynaptic terminals occur along unmyelinated axons in specialized compartments called axonal varicosities or synaptic boutons. Since the first descriptions of varicose axons by Cajal and others, the spatial organization of varicosities along axons has attracted the attention of neuroscientists. Quantitative light- and electron-microscopic analyses of varicosity spacing in the cerebellum ...
Vallarino Jose - - 2003
A reliable method for determining the distribution of synthetic vitreous fiber (SVF) densities found on building surfaces is presented with data collected from rooms in 40 office buildings in the United States. The initial survey of 20 buildings-complete with collection, counting, and analysis of SVF loading-found that nearly 60% of ...
Nahra Hicham - - 2003
This study examined the relative capacity of Adelta- and C-fibers to encode non-painful and painful brief CO(2) laser stimuli by comparing the effects of Adelta/C-fiber activation versus C-fiber activation alone. In nine normal subjects, brief CO(2) laser pulses of four different intensities (range 5.8-10.6mJ/mm(2)) were delivered at random on the ...
Mollenhauer Juergen - - 2003
The molecular substructure of human articular cartilage has been difficult to study because of its complex composition and high degree of hydration. Using newly available small-angle X-ray diffraction (SAX) instrumentation that allows very short exposure times (0.1 to 10 sec), we have obtained spatially resolved information concerning the disposition of ...
Gagnon Roy E - - 2003
New commercial liquid light guides have an advantage over fiberoptic bundles regarding breakage during clinical handling. We investigate the quality of clinical data collection using liquid versus fiber bundles as receivers. A four-wavelength NIRO-500 near-IR spectrophotometer is used with single-terminal fiber bundles, multiterminal fiber bundles, or a single-terminal liquid light ...
Lancry Matthieu - - 2002
Grating growths through exposure of presensitized standard fibers to KrF light were recorded in various experimental condition. It is shown that there exists an optimum sensitization fluence at which the efficiency of the sensitization process is higher. Isochronal thermal annealing of pre-exposed fibers led to a decrease in the sensitization-induced ...
Axer Hubertus - - 2002
A new neuroanatomic approach to evaluate the fiber orientation in gross histological sections of the human brain was developed. Serial sections of a human brainstem were used to derive fiber orientation maps by analysis of polarized light sequences of these sections. Fiber inclination maps visualize angles of inclination, and fiber ...
Nagase Shinobu - - 2002
The optical properties of hair fibers were studied, focusing on the reflections (highlights) from both the front and the back surfaces of the fiber in consideration and on the effect these have on the perceptions of hair appearance. The two reflections are distinguished from each other by sight, because only ...
Dimitrova N A - - 2002
To realize possible reasons for changes in EMG amplitude characteristics with fatigue, we analyzed motor unit potentials (MUPs) and M-waves under simultaneous variations of the intracellular action potential (IAP) amplitude, duration, and shape as well as of the muscle fiber propagation velocity and desynchronization in activation of individual muscle fibers. ...
Dam Jeppe Seidelin - - 2002
Using a fiber-based four-channel correlation scheme to investigate spatial and temporal correlations, we show that observations of period-doubling phenomena in single bubble sonoluminescence are primarily a result of spontaneously breaking the spherical symmetry in the bubble collapse and, at most, may show up as secondary effects in the flash-to-flash spatially ...
Schellart N A M - - 2002
The trout lateral line contains about 122 trunk scales and is tens of centimeters long. The difference in time of arrival in the hindbrain of simultaneously elicited afferent responses from the neuromasts is unknown. Propagation times of single-fiber afferent responses to water motion revealed that their mean conduction velocity was ...
Weidner Christian - - 2002
The microneurography technique was used to analyze use-dependent frequency modulation of action potential (AP) trains in human nociceptive peripheral nerves. Fifty-one single C-afferent units (31 mechano-responsive, 20 mechano-insensitive) were recorded from cutaneous fascicles of the peroneal nerve in awake human subjects. Trains of two and four suprathreshold electrical stimuli at ...
Jeong Yoonchan - - 2002
We demonstrate a multimode-fiber bundle reference scheme in a photorefractive volume hologram and discuss its angular/spatial selectivity both experimentally and theoretically. We measure the angular/spatial selectivity, changing distances between the photorefractive crystal and the output facet of the multimode-fiber bundle. The distance variation leads to a beam-size change in the ...
Johansson Jonas - - 2002
A system for fiber-optic probing in dissolution testing of solid pharmaceutical formulations has been constructed. The system is based on an imaging spectrometer and a charged coupled device (CCD) detector and includes 12 fiber-optic probes with a novel dual-path design. UV light was produced by a small arc deuterium lamp ...
Below Steven - - 2002
PURPOSE: To identify the surface collagen orientations of the distal femur and create a generic cartilage split-line map that could be used as a reference guide for the proper alignment of autogenous cartilage transplants. TYPE OF STUDY: Anatomic, cadaveric study. METHODS: Eight fresh cadaveric knee joints were used to determine ...
Finkel Julia C - - 2002
We used a neuroselective transcutaneous electrical stimulus to determine the onset time of cutaneous anesthesia with 4% liposomal lidocaine under occluded and nonoccluded conditions. The pain tolerance threshold (PTT) was used to atraumatically evaluate nociception. Twenty adult volunteers had liposomal lidocaine applied to the volar surface of each forearm for ...
La Rosa Andres H - - 2002
A tapered, metal-coated, optical fiber probe will elongate when heated by light input through a fiber. The induced motion can be used for data storage or nanostructuring of a surface. The elongation produced by this alignment-free system is measured with force feedback in a near-field scanning optical microscope (NSOM). The ...
Wada Hiroshi - - 2002
In spite of many studies concerning auditory nerve action potentials, the timing of neural excitation in relation to basilar membrane (BM) motion is still not well understood. In this study, therefore, BM vibrations in the basal region of the guinea pig cochlea were measured using a laser Doppler velocimeter, and ...
Van Wulfen Kimberly K - - 2002
OBJECTIVE: To describe microanatomic characteristics of the insertion of the aistal sesamoidean impar ligament (DSIL) and deep digital flexor tendon (DDFT) on the distal phalanx in horses. SAMPLE POPULATION: Healthy feet obtained from 62 horses of various breeds. PROCEDURE: Feet from 23 horses were used to histologically examine the insertion ...
Hämäläinen Minna M - - 2002
The purpose of this study was to examine which primary afferent fibers are sensitized to mechanical stimuli after an experimental surgical incision to the glabrous skin of the rat hindpaw. Afferent fibers teased from the L(5) dorsal root or the tibial nerve were recorded in anesthetized rats. The mechanical response ...
Park R - - 2001
Recent technological advances claim to allow quantitative measurement of the functional integrity of both large and small diameter sensory nerve fibers using the current perception threshold (CPT) sensory testing device. This device has yet to be validated against the corresponding gold standard references for sensory testing (thermal sensory testing [TST]) ...
Weir F W - - 2001
There has been considerable interest during the past 30 years regarding the potential for exposure to asbestos fibers generated during asbestos-containing automobile and light-duty truck brake replacement and repair operations. Less attention has been directed to asbestos fiber exposures resulting from servicing of brakes on heavy-duty trucks and other machinery. ...
Martin P - - 2001
The auditory system's ability to interpret sounds over a wide range of amplitudes rests on the nonlinear responsiveness of the ear. Whether measured by basilar-membrane vibration, nerve-fiber activity, or perceived loudness, the ear is most sensitive to small signals and grows progressively less responsive as stimulation becomes stronger. Seeking a ...
Tsai C L - - 2001
Lateral light-distribution images of biologic tissues were used to study the tissues' optical characteristics. Monte Carlo simulation with the same conditions was performed to simulate the light distribution for comparison. Simulation results showed that the lateral light distribution was similar to the internal light distribution in biologic tissue. The direction ...
Wheat H E - - 2001
When the flat faces of a coin are grasped between thumb and index finger, a "curved edge" is felt. Analogous curved edges were generated by our stimuli, which comprised the flat face of segments of annuli applied passively to immobilized fingers. Humans could scale the curvature of the annulus and ...
Ward A R - - 2001
We investigated the frequency dependence of motor thresholds over the frequency range 1 kHz to 25 kHz. Alternating current (AC), ramped in intensity, was applied transcutaneously, and the induced wrist extensor torque was measured. Plots of log torque versus stimulus voltage were used to accurately determine thresholds. Three kinds of ...
Qian H - - 2001
The effects of mechanical loads on the tooth-alveolus complex are of particular concern in orthodontics. The concepts of center of resistance (CRes) and center of rotation (CRot) are used to characterize tooth responses to orthodontic loads. The mechanical environment (stresses and strains) associated with orthodontic tooth movement is a unique ...
Binks A P - - 2001
Vagus nerve stimulation is used to reduce the frequency and intensity of seizures in patients with epilepsy. In the present study four such patients were studied while awake. We analyzed the physiological responses to vagus nerve stimulation over a broad range of tolerable stimulus parameters to identify vagal A-fiber threshold ...
Chen K P - - 2001
Long-period gratings were fabricated in standard telecommunication fiber (Corning SMF-28) by use of what is believed to be record short-wavelength light from a 157-nm F(2) laser. Strong loss peaks were formed without the need for enhancement techniques such as hydrogen loading. The magnitude of the attenuation peak was sensitive to ...
Coleman G T - - 2001
The marmoset monkey, Callithrix jacchus, has increasingly been the subject of experiments for the analysis of somatosensory system function in simian primates. However, as response properties of the mechanoreceptive afferent fibers supplying the skin have not been characterized for this primate, the present study was undertaken to classify fibers innervating ...
Cain D M - - 2001
The increasing use of transgenic mice for the study of pain mechanisms necessitates comprehensive understanding of the murine somatosensory system. Using an in vivo mouse preparation, we studied response properties of tibial nerve afferent fibers innervating glabrous skin. Recordings were obtained from 225 fibers identified by mechanical stimulation of the ...
Baron P A - - 2001
Current fiber measurement techniques arose primarily due to health concerns over asbestos exposure. Fiber toxicity appears to be primarily a function of fiber concentration, dimensions and durability in the lungs. There are two basic approaches to fiber measurement. Fibers can be collected on filters and counted or analyzed by light ...
Reng D - - 2001
Hair cells in the avian inner ear can regenerate after acoustic trauma or ototoxic insult, and significant functional recovery from hearing loss occurs. However, small residual deficits remain, possibly as a result of incomplete reestablishment of the hair cell neural synaptic contacts. The aim of the present study was to ...
Axer H - - 2001
Series of polarized light images can be used to achieve quantitative estimates of the angles of inclination (z-direction) and direction (in xy-plane) of central nervous fibers in histological sections of the human brain. (1) The corpus callosum of a formalin-fixed human brain was sectioned at different angles of inclination of ...
Vanwiggeren G D - - 2001
Azimuthal variations in the refractive index that are inherent in CO(2) -laser-induced long-period fiber gratings (LPFG's) coupled to small controlled flexure of the LPFG produce a wide variety of transmission characteristics as a function of LPFG curvature. The particularly useful cases of (1) wavelength tuning at a constant attenuation and ...
Gescheider G A - - 2001
The frequency selectivity of the P, NP I, and NP II channels of the four-channel model of mechanoreception for glabrous skin was measured psychophysically by an adaptation tuning curve procedure. The results substantially extend the frequency range over which the frequency selectivity of these channels is known and further confirm ...
Jabłoński P G - - 2001
The painted redstart Myioborus pictus uses visual displays to flush, pursue, and then capture an abundance of brachyceran Diptera that are equipped with giant fiber escape circuits. This paper investigates the relationships between features of the giant fiber system, the structure of visual stimuli produced by redstarts and their effectiveness ...
Miller C A - - 2001
Charge-balanced, biphasic stimulus pulses are commonly used in implantable cochlear prostheses as they can be safely delivered to living tissue. However, monophasic stimuli are more efficient (i.e. producing lower thresholds) and likely provide more spatially selective excitation of nerve fibers. We examined the neural responses to monophasic, 'pseudomonophasic', and biphasic ...
Urban N N - - 2001
The mossy fiber pathway has long been considered to provide the major source of excitatory input to pyramidal cells of hippocampal area CA3. In this review we describe anatomical and physiological properties of this pathway that challenge this view. We argue that the mossy fiber pathway does not provide the ...
Axer H - - 2000
Diffusion weighted magnetic resonance imaging (DWMRI) allows visualization of the orientation of the nervous fibers in the living brain. For comparison, a method was developed to examine the orientation of fibers in histological sections of the human brain. Serial sections through the entire human brain were analyzed regarding fiber orientation ...
Albanis V - - 2000
The reflectivity of a gallium/silica interface formed on an optical flat or at the tip of a cleaved optical fiber can be reduced in a reversible fashion when the interface is excited by a few milliwatts of laser power. This phenomenon occurs at temperatures just below gallium's melting point. We ...
Yamada H - - 2000
We studied stress fiber orientation under a wide range of uniaxial cyclic deformations. We devised and validated a hypothesis consisting of two parts, as follows: (1) a stress fiber aligns to avoid a mechanical stimulus in the fiber direction under cyclic deformation. This means that, among all allowable directions, a ...
Lewis E R - - 2000
We present examples of results from our studies of auditory primary afferent nerve fibers and populations of such fibers in the frog and gerbil. We take advantage of the natural dithering effect of internal noise, where it is sufficient, to construct highly predictive descriptive models (based on the Wiener series ...
Tung L - - 2000
Transmembrane potential (V(m)) responses in cardiac strands with different curvature were characterized during uniform electric-field stimulation with the use of modeling and experimental approaches. Linear and U-shaped strands (width 100-150 micrometer) were stained with voltage-sensitive dye. V(m) was measured by optical mapping across the width and at sites of beginning ...
Wang K - - 2000
A novel mode-filtered light detection method is described in which an unjacketed optical fiber is inserted into a transparent capillary tube and three or more detection channels are set on the capillary side for different distances from the port of the fiber. This new method is the basis of synchronization ...
Saito M - - 2000
Phosphorescent oxides and fluorescent dyes were used together to create a fiber-type illuminator that glows in the dark without the need for electric power. Dye-doped polymer fibers, which were bundled at one end, were linearly arrayed in a polysiloxane resin that contained phosphorescent oxide particles. The phosphorescent resin continued to ...
Geiger P C - - 2000
In the present study, myosin heavy chain (MHC) content per half sarcomere, an estimate of the number of cross bridges available for force generation, was determined in rat diaphragm muscle (Dia(m)) fibers expressing different MHC isoforms. We hypothesize that fiber-type differences in maximum specific force [force per cross-sectional area (CSA)] ...
Yuan H - - 2000
The dynamic stiffness (H), damping coefficient (G), and harmonic distortion (k(d)) characterizing tissue nonlinearity of lung parenchymal strips from guinea pigs were assessed before and after treatment with elastase or collagenase between 0.1 and 3.74 Hz. After digestion, data were obtained both at the same mean length and at the ...
Sato K - - 2000
An investigation of the ultrastructure of the vocal process of the arytenoid cartilage was performed on excised human adult larynges. The results are summarized as follows. 1) The size of the chondrocytes is small and their density is high at the tip of the vocal process. 2) The size of ...
Gusarov A I - - 2000
We have computed the contribution of UV-light-induced densification to the refractive-index modulation of fiber Bragg gratings. Our results confirm that, for strong gratings written in Ge-doped silica fibers with 248-nm UV light, density changes account for a major part of the photosensitivity effect.
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