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Results 251 - 300 of 937
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Kishen Anil - - 2008
In this study, a Fiber Optic Backscatter Spectroscopic Sensor (FOBSS) is used to monitor demineralization and remineralization induced changes in the enamel. A bifurcated fiber optic backscatter probe connected to a visible light source and a high resolution spectrophotometer was used to acquire the backscatter light spectrum from the tooth ...
Short Michael A - - 2008
A near-infrared Raman system was developed to collect real-time in vivo human lung spectra. The excitation light and the emission were guided to and from the tissue surface by a reusable fiber catheter passed down the instrument channel of a bronchoscope. Two-stage filtering was used to reduce laser noise, fluorescence, ...
Zhao Li - - 2008
OBJECTIVE: To investigate the effect on intramuscular connective tissue and passive range of joint motion by the stress produced in limb lengthening. METHODS: An animal model of limb lengthening was established in the tibia of rabbits. Distraction was initiated at a rate of 1 mm/d and 2 mm/d in two ...
Demb Jonathan B - - 2008
Synaptic depression at conventional synapses is usually caused by strong or prolonged stimuli, like tetanic bursts of afferent fiber discharge at high frequencies. In this issue of Neuron, Dunn and Rieke report that, in the retina, even the weakest stimuli, single photons, can lead to synaptic depression at ribbon-type synapses ...
Falk Peter - - 2008
We experimentally study the generation of broadband light at approximately 1300 nm from an 810 nm Ti:sapphire femtosecond pump laser. We use two photonic crystal fibers with a second infrared zero-dispersion wavelength (lambda Z2) and compare the efficiency of two schemes: in one fiber lambda Z2=1400 nm and the light ...
Yuan Libo - - 2008
By using specially designed three-core fiber, a microstructured light-pattern generator for sensing 3-D shapes has been demonstrated. The square or hexagon grid-interferometric fringe pattern formed by the fiber-optic interferometric grid generator is projected onto an object's surface. The deformed grid pattern containing information of the object's surface topography is captured ...
Hartmann Daniel M - - 2008
Microfluidic chips require connections to larger macroscopic components, such as light sources, light detectors, and reagent reservoirs. In this article, we present novel methods for integrating capillaries, optical fibers, and wires with the channels of microfluidic chips. The method consists of forming planar interconnect channels in microfluidic chips and inserting ...
Stone J M - - 2008
We report on visibly white supercontinuum generation in photonic crystal fibers using a sub ns pump source at 1064 nm. The spectra extend from below 400 nm to 2450 nm, some 50 nm further into the blue than previously reported spectra. The extra bandwidth which is achieved by a simple ...
Schiek Manuela - - 2008
A new route to bottom-up organic nanotechnology is presented. Molecular building blocks with specific optoelectronic properties are designed and grown via directed self-assembly arrays of morphologically controlled light-emitting organic nanofibers on template surfaces. The fibers can be easily transferred from the growth substrate to device platforms either as single entities ...
Seyama Tomoko - - 2008
A unique fiber spinning was found in protoplasts from white birch (Betula platyphylla) leaves under an acidic medium containing high concentration of Ca(2+). After expanding from 10 to 100 microm in diameter under the culture condition, the protoplast started secreting a gigantic fiber while moving in a spiral way. Real ...
de Almeida Hiram Larangeira HL - - 2008
Cutis laxa is a rare condition characterized by diminished elastic tissue. We report the histological changes from a 22-year-old male patient, who presented since 4 years hanging and inelastic facial skin, giving him an older appearance. The palpebral, preauricular and submandibular skin obtained after a facelift were examined. Conventional light ...
Matsuura Motoharu - - 2007
We investigate discrete wavelength tuning characteristics of a single-frequency fiber laser locked to either of two external lights. Frequency locking is achieved by the cooperatively induced spatial-hole burning (SHB) of a saturable absorber in the laser cavity. We show that lasing frequency is well locked to either of the two ...
Smith Lachlan J - - 2008
The anulus fibrosus of the human lumbar intervertebral disc has a complex, hierarchical structure comprised of collagens, proteoglycans, and elastic fibers. Recent histological studies have suggested that the elastic fiber network may play an important functional role. In this study, it was hypothesized that elastic fibers enhance the mechanical integrity ...
Huang Ruey-Song - - 2008
Imaging the neural basis of visuomotor actions using fMRI is a topic of increasing interest in the field of cognitive neuroscience. One challenge is to present realistic three-dimensional (3-D) stimuli in the subject's peripersonal space inside the MRI scanner. The stimulus generating apparatus must be compatible with strong magnetic fields ...
Campagnola Luke - - 2008
Channelrhodopsin-2 (ChR2) is a blue-light-gated ion channel that can be used to stimulate genetically defined neurons reproducibly, rapidly and non-invasively. Existing approaches for delivering light to cells expressing ChR2 rely upon microscopes, lasers, arc lamps and shutters, all of which are relatively expensive and are not readily scalable for use ...
Swanson Brook O - - 2007
Spiders and their silk are an excellent system for connecting the properties of biological materials to organismal ecology. Orb-weaving spiders spin sticky capture threads that are moderately strong but exceptionally extensible, resulting in fibers that can absorb remarkable amounts of energy. These tough fibers are thought to be adapted for ...
Frazão O - - 2007
A novel Mach-Zehnder interferometer based on a fiber multimode interference structure combined with a long-period fiber grating (LPG) is proposed. The multimode interference is achieved through the use of a MMF section spliced between two single-mode fibers, with a length adjusted to couple a fraction of light into the cladding ...
Bar-Shir Amnon - - 2008
In recent years, much effort has been made to increase our ability to infer nerve fiber direction through the use of diffusion MR. The present study examines the effect of the rotational angle (alpha), i.e. the angle between the diffusion sensitizing gradients and the main axis of the fibers in ...
Mouraux A - - 2007
There is experimental evidence indicating that, in humans, avoiding the concurrent activation of non-nociceptive A beta-fibers is a necessary condition for slower A delta-fiber nociceptive input to elicit reproducible event-related brain potentials (ERPs). Similarly, numerous studies have shown that for unmyelinated C-fiber nociceptive input to elicit ERPs, the concurrent activation ...
Tomaru Tatsuya - - 2007
Antisqueezed light is a possible resource to apply quantum information technologies to the real world. When antisqueezed light is used in secure optical communications, an LD is a preferable light source from an engineering point of view. Although LD output power is low, LD light can be antisqueezed with the ...
Allsop Tom - - 2007
We demonstrate the use of tilted fiber gratings to assist the generation of localized infrared surface plasmons with short propagation lengths and a sensitivity of dlambda/dn = 3,365 nm in the aqueous index regime. It was also found that the resonances could be spectrally tuned over 1,000 nm at the ...
Ying Diqing - - 2007
A resonator fiber-optic gyro (R-FOG) is a high-accuracy inertial rotation sensor based on the Sagnac effect. A fiber ring resonator is the core sensing element in the R-FOG. When the frequency of the fiber ring resonator input laser is swept linearly with time, ringing of the output resonance curve is ...
Reddy Narendra - - 2007
We report the production and characteristics of natural cellulose fibers obtained from the leaves and stems of switchgrass. In this paper, the composition, structure and properties of fibers obtained from the leaves and stem of switchgrass have been studied in comparison to the common natural cellulose fibers, such as cotton, ...
Heil Peter - - 2007
In several sensory systems, the conversion of the representation of stimuli from graded membrane potentials into stochastic spike trains is performed by ribbon synapses. In the mammalian auditory system, the spiking characteristics of the vast majority of primary afferent auditory-nerve (AN) fibers are determined primarily by a single ribbon synapse ...
Schulmerich Matthew V - - 2007
Different spatial separations between an illumination ring and a bundle of 50 collection fibers focused to collect light in the center of the ring were used to investigate the recovery of subsurface Raman spectra. The depth of Raman signal recovery and the preservation of spatial information in the recovered signal ...
Zhang B - - 2007
We conceptually compare the advantages of the proposed slow-light-based tunable OTDM to conventional fiber-based fixed OTDM multiplexer. We experimentally demonstrate continuously-controllable OTDM of two 2.5-Gb/s return-to-zero (RZ) signals using broadband SBS-based slow-light as the tunable optical delay line. We show that the time slot of one signal path can be ...
Levitan Richard M - - 2007
STUDY OBJECTIVE: Laryngoscopy and tracheal intubation requires laryngeal exposure and illumination. The objective of this study is to assess variation in laryngoscope lights across different emergency departments (EDs). METHODS: A convenience sample of 3 Mac #4 blade and handle pairs in each of 17 Philadelphia area EDs was tested with ...
Vassalle Mario - - 2007
The mechanisms underlying the pacemaker current in cardiac tissues is not agreed upon. The pacemaker potential in Purkinje fibers has been attributed to the decay of the potassium current I (Kdd). An alternative proposal is that the hyperpolarization-activated current I (f) underlies the pacemaker potential in all cardiac pacemakers. The ...
Bleys Ronald L A W - - 2007
The perichondrial envelopes of the septal cartilage and the lateral crus of the lobular cartilage were studied in serial coronal sections of five human noses. To differentiate between the various tissue components, the sections were stained according to Mallory-Cason, Azan, Herovici, Verhoeff-van Gieson, and Lawson. Collagen types I and II ...
Jiang Yi - - 2007
A four-element hydrophone array system using a fiber Bragg grating laser system is described. The demodulation technique for the array combines a 3x3 coupler-based interferometer and three wavelength division multiplexers (WDMs). It is believed to be a new passive approach to use a WDM and a unique arithmetic method. The ...
Labruyere A - - 2007
In standard optical fibers with constant chromatic dispersion, modulational instability (MI) sidebands execute undesirable frequency shifts due to fiber losses. By means of a technique based on average-dispersion-decreasing dispersion-managed fibers, we achieve both complete suppression of the sideband frequency shifts and fine control of the MI frequencies, without any compromise ...
Watkins Neil J - - 2007
We report a compact light collection scheme suitable for retrofitting a scanning tunneling microscope (STM) for STM-induced light emission experiments. The approach uses a pair of optical fibers with large core diameters and high numerical apertures to maximize light collection efficiency and to moderate the mechanical precision required for alignment. ...
Juarez Juan C - - 2007
Field tests in desert terrain of a distributed sensor system for detecting and locating intruders based on the phase-sensitive optical-time-domain reflectometer (phi-OTDR) are described. The sensing element is a single-mode telecommunications fiber in a 4.5 mm diameter cable buried in a trench filled with loose sand. Light pulses from a ...
Dupriez P - - 2007
We report the generation of white light from a picosecond pump by efficient four-wave mixing processes. A 530 nm green source based on a frequency-doubled Yb-doped fiber laser generates strong red and blue sidebands in the secondary cores of a holey fiber with large air-filling factor. Phase matching is attributed ...
Valderrábano Miguel M Methodist DeBakey Heart Center, The Methodist Hospital Research Institute, Houston, TX 77030, USA. - - 2007
Anisotropy, the property of being directionally dependent, is ubiquitous in nature. Propagation of the electrical impulse in cardiac tissue is anisotropic, a property that is determined by molecular, cellular, and histological determinants. The properties and spatial arrangement of connexin molecules, the cell size and geometry, and the fiber orientation and ...
Fan Jingyun - - 2007
After characterizing the Raman scattering in a fused silica polarization-maintaining microstructure optical fiber, we built a fiber-based two-photon light source of high spectral brightness, broad spectral range, and very low noise background at room temperature. The resulting bright low-noise two-photon light can be used for a number of quantum information ...
Abu-Hijleh Marwan F - - 2007
This study revisits the anatomy of the deep fascia over the distal leg, ankle, and dorsum of the foot. The arrangement of the deep fascia in these regions was recorded in 14 lower limbs of adult cadavers using photographs and drawings. The fascial layer from all three sites was subsequently ...
Skedros John G - - 2007
Experimental models are needed for resolving relative influences of genetic, epigenetic, and nonheritable functionally induced (extragenetic) factors in the emergence of developmental adaptations in limb bones of larger mammals. We examined regional/ontogenetic morphologic variations in sheep calcanei, which exhibit marked heterogeneity in structural and material organization by skeletal maturity. Cross-sections ...
Manek-Hönninger I - - 2007
We studied the temporal evolution of the photodarkening effect in an Yb-doped silica LMA fiber. The absorption spectra exhibit an increase in absorption in the visible and in the near infrared spectral range when the fiber is exposed to pump light around 980 nm. We show the influence of the ...
Bydder Mark - - 2007
This review provides a formalism for understanding magic angle effects in clinical studies. It involves consideration of the fiber-to-field angle for linear structures such as tendons, ligaments, and peripheral nerves, disc-like and circular structures such as menisci and labra, as well as complex three-dimensional structures. There may be one or ...
Herskind Peter - - 2007
We report external cavity second-harmonic generation of light at 544 and 272 nm based on an ytterbium-doped distributed-feedback fiber laser. The nonlinear crystal used to generate light at 544 nm is LiNbO3, and the maximum output of the cavity is 845 mW, corresponding to a conversion efficiency of 55%. In ...
Moran-Mirabal José M - - 2007
We have electrospun light-emitting nanofibers from ruthenium(II) tris(bipyridine)/polyethylene oxide mixtures. The electroluminescent fibers were deposited on gold interdigitated electrodes and lit in a nitrogen atmosphere. The fibers showed light emission at low operating voltages (3-4 V), with turn-on voltages approaching the band gap limit of the organic semiconductor. Because of ...
Imoto Kenshi - - 2007
A Neurometer device is an electrical nerve stimulator used to determine the current perception threshold (CPT) evoked by stimulating A-beta fibers at 2,000 Hz, A-delta fibers at 250 Hz and C fibers at 5 Hz. CPT evaluation is used for analyzing peripheral nerve dysfunction. In this study, the sensory disturbance ...
Franchi Marco - - 2007
A tendon is a tough band of fibrous connective tissue that connects muscle to bone, designed to transmit forces and withstand tension during muscle contraction. Tendon may be surrounded by different structures: 1) fibrous sheaths or retinaculae; 2) reflection pulleys; 3) synovial sheaths; 4) peritendon sheaths; 5) tendon bursae. Tendons ...
Sellaro Tiffany L - - 2007
In the present study, the effects of initial collagen fiber orientation on the medium-term (up to 50 x 10(6) cycles) fatigue response of heart valve soft tissue biomaterials was investigated. Glutaraldehyde treated bovine pericardium (GLBP), preselected for uniform structure and collagen fiber orientation, was used as the representative heart valve ...
Mitsumune Norihiko - - 2007
The rotary undulation pump is believed to be a good candidate for the next-generation artificial heart. Due to its complex movement, it is desirable to magnetically levitate the rotor and dynamically control the gap. In this article, the applicability of a fiber-optic gap sensor to the dynamic position control of ...
Rengle A A CREATIS-LRMN, CNRS, UMR 5220, Villeurbanne, - - 2007
Respiratory and cardiac motion must be overcome if MRI of the thorax or abdomen is to be performed satisfactorily. An optical-based device designed to synchronize MRI acquisition on small animal was developed using a pair of optical fibers. Light from a laser diode was focused into the transmit fiber and ...
Fay Jonathan P - - 2006
At frequencies above 3 kHz, the tympanic membrane vibrates chaotically. By having many resonances, the eardrum can transmit the broadest possible bandwidth of sound with optimal sensitivity. In essence, the eardrum works best through discord. The eardrum's success as an instrument of hearing can be directly explained through a combination ...
Lin Q - - 2006
The commonly used Lorentzian form of the Raman response function for studying propagation of ultrashort pulses in silica fibers does not properly account for the shoulder in the Raman gain spectrum originating from the Boson peak. We propose a more accurate form of this response function and show that its ...
Hoffman Brian B 1108 Dresser Court, Raleigh, NC 27609, USA. - - 2006
Achilles tendon lengthening is an important part of the operative management of numerous foot and ankle disorders. The most commonly used percutaneous technique involves three hemitenotomies: medial, lateral, and medial. The discovery that Achilles tendon fibers may undergo external torsion created concern that improper consideration of this feature could result ...
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