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Results 251 - 300 of 1547
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Xuan Xiangchun - - 2008
Electrokinetic flow is an efficient means to manipulate liquids and samples in lab-on-a-chip devices. It has a number of significant advantages over conventional pressure-driven flow. However, there exists inevitable Joule heating in electrokinetic flow, which is known to cause temperature variations in liquids and draw disturbances to electric, flow and ...
Groeneweg George - - 2008
BACKGROUND: In complex regional pain syndrome type 1 (CRPS1) vascular changes occur from the initial, inflammatory event onto the trophic signs during chronicity of the disease, resulting in blood flow disturbances and marked temperature changes. Pharmacotherapeutic treatment is generally inadequate. AIM: To determine whether local application of the nitric oxide ...
Davis Scott L - - 2008
The aim of this investigation was to test the hypothesis that skin grafting (5-9 months after surgery) impairs sympathetically mediated cutaneous vasoconstrictor responsiveness. Skin blood flow (laser-Doppler flowmetry) was assessed in grafted skin and adjacent healthy control skin in fourteen subjects (seven male, seven female) during indirect whole-body cooling (ie, ...
Cooper Joshua M - - 2008
INTRODUCTION:Titration of radiofrequency (RF) ablation energy to avoid steam pops while maximizing lesion size is difficult because of disparities between electrode and tissue temperature. We hypothesized that the variable contribution of local blood flow to electrode cooling contributes to electrode-tissue temperature disparity, even with an irrigated RF catheter. METHODS AND ...
Brown Angus - - 2008
There is currently no blood-based test that can rapidly and objectively distinguish between chest pain which is initiated by increased myocardial oxygen demand (stable angina pectoris (SAP)) and chest pain initiated due to decreased coronary blood flow (unstable angina pectoris (UAP)). Since leukocytes play an active role in the progression ...
Mahbub M H - - 2008
OBJECTIVE: The present study was designed to examine the simultaneous responses in digital circulation at both palmar and dorsal skin induced by acute exposure to short-term vibration while grasping a vibratory handle, and also to evaluate the importance of measurement site for such responses. METHODS: Finger blood flow (FBF) and ...
Nakagami Gojiro - - 2007
The effect of vibration on skin microcirculation was studied to investigate the possibility of clinical use of vibration to prevent and treat pressure ulcers. Vibrations at a vibrational intensity of 600, 800, or 1,000 mVpp with a fixed frequency of 47 Hz were applied horizontally to the ear of male ...
Petrofsky Jerrold S - - 2007
BACKGROUND: In a previous study, it was shown that placing a subject with chronic diabetic ulcers in a warm room prior to the use of electrical stimulation dramatically increased the healing rate. However, global heating is impractical in many therapeutic environments, and therefore in the present investigation the effect of ...
Anderson Don L - - 2007
Geophysical hotspots have been attributed to partially molten asthenosphere, fertile blobs, small-scale convection and upwellings driven by core heat. Most are short-lived or too close together to be deeply seated, and do not have anomalous heat flow or temperature; many are related to tectonic features. Bourdon et al. investigate the ...
Liao D - - 2008
The pain perception to distension of the oesophagus can be explained by activation of receptors responding to mechanical deformation or to distension-induced ischaemia. The aim of this study was to develop a new method for detection of changes in segmental blood flow during distension based on measurement of heat transfer. ...
Kohno Satoru - - 2007
We investigate whether the functional near-infrared spectroscopic (fNIRS) signal includes a signal from the changing skin blood flow. During a locomotor task on a treadmill, changes in the hemodynamic response in the front-parietal area of healthy human subjects are simultaneously recorded using an fNIRS imaging system and a laser Doppler ...
Severens Natascha M W - - 2007
OBJECTIVES: After cardiopulmonary bypass, patients often show redistribution hypothermia, also called afterdrop. Forced-air blankets help to reduce afterdrop. This study explores the effect of forced-air blankets on temperature distribution and peripheral perfusion. The blood perfusion data is used to explain the observed temperature effects and the reduction of the afterdrop. ...
Azman-Juvan Katja - - 2008
BACKGROUND/AIMS: Laser Doppler flowmetry (LDF) was used to determine the influence of acute myocardial infarction (AMI) and of successful reperfusion treatment on basal skin blood flow and its oscillatory components. METHODS: Skin LDF was performed on all extremities in 58 patients 4-9 days after AMI (Killip class I), and in ...
Weibel Lisa - - 2007
OBJECTIVE: Assessment of disease activity is a major challenge in the management of children with localized scleroderma. The aim of this study was to evaluate the role of laser Doppler flowmetry (LDF) in comparison with infrared thermography in the detection of scleroderma disease activity. METHODS: In 41 children with localized ...
Trotman Tara K - - 2007
A 6-year-old spayed female domestic shorthair cat with a 3-week history of inappetence, weight loss, and hiding was examined. A palpable abdominal fluid wave, dehydration, and a small tear on the left flank were noted during initial examination. When the cat was gently restrained for blood sampling, the skin on ...
Hodges Gary J - - 2007
Previous work showed that local cooling (LC) attenuates the vasoconstrictor response to whole body cooling (WBC). We tested the extent to which this attenuation was due to the decreased baseline skin blood flow following LC. In eight subjects, skin blood flow was assessed using laser-Doppler flowmetry (LDF). Cutaneous vascular conductance ...
Lorenzo Santiago - - 2007
Reactive hyperaemia is the increase in blood flow following arterial occlusion. The exact mechanisms mediating this response in skin are not fully understood. The purpose of this study was to investigate the individual and combined contributions of (1) sensory nerves and large-conductance calcium activated potassium (BKCa) channels, and (2) nitric ...
Yamazaki Fumio - - 2007
Hyperoxia induces skin vasoconstriction in humans, but the mechanism is still unclear. In the present study we examined whether the vasoconstrictor response to hyperoxia is through activated adrenergic function (protocol 1) or through inhibitory effects on nitric oxide synthase (NOS) and/or cyclooxygenase (COX) (protocol 2). We also tested whether any ...
Bryan Colleen E - - 2007
Several major unusual mortality events occurring in recent years have increased the level of concern for the health of bottlenose dolphin populations along the United States Atlantic and Gulf of Mexico coasts. Trace element concentrations were examined in a population of free-ranging dolphins in Sarasota Bay, Florida, in order to ...
Mavropoulos Antonios - - 2007
BACKGROUND: The aim of this study was to evaluate the gingival blood flow of smokers and non-smokers with periodontal disease before and after surgical periodontal treatment. METHODS: Nine smokers and six non-smokers with at least two periodontal lesions were included in the study. Laser Doppler flowmetry was used to measure ...
Nishidate Izumi - - 2007
A method is proposed for visualizing the depth and thickness distribution of a local blood region in skin tissue using diffuse reflectance images at three isosbestic wavelengths of hemoglobin: 420, 585, and 800 nm. Monte Carlo simulation of light transport specifies a relation among optical densities, depth, and thickness of ...
Loyd S J - - 2007
The thermal evolution of Earth is governed by the rate of secular cooling and the amount of radiogenic heating. If mantle heat sources are known, surface heat flow at different times may be used to deduce the efficiency of convective cooling and ultimately the temporal character of plate tectonics. We ...
Hsieh Ching-Hua - - 2007
BACKGROUND: Skin wrinkling on water immersion is a reliable and simple test of sympathetic innervation. The eutectic mixture of local anesthetic (EMLA) cream has been shown to induce near identical clinical wrinkling scores and reduction in digit blood flow as that following water immersion in people with normal sympathetic innervation. ...
Dawn Aerlyn - - 2007
BACKGROUND: Several studies using nailfold capillary microscopes have demonstrated capillary changes in patients with dermatomyositis (DM); however, no previous study has examined cutaneous blood flow in this disease. PURPOSE: To determine cutaneous blood flow in involved and non-involved skin surfaces of patients with DM and to assess possible correlation with ...
Guzman-Sanchez Daniela A - - 2007
BACKGROUND: Although patients with rosacea often complain of increased skin sensitivity, there has been no quantitative sensory testing of this phenomenon. Furthermore, cutaneous blood flow in these patients has not been assessed using state-of-the-art laser Doppler imaging (LDI). OBJECTIVES: To assess heat pain thresholds and skin blood flow using quantitative ...
Seebacher Frank - - 2007
Changes in blood flow are a principal mechanism of thermoregulation in vertebrates. Changes in heart rate will alter blood flow, although multiple demands for limited cardiac output may compromise effective thermoregulation. We tested the hypothesis that regional differences in blood flow during heating and cooling can occur independently from changes ...
Bezemer R - - 2007
The putative features of the (endo)vascular photothermal response, characterized by laser-induced thermal denaturation of blood and vessel wall constituents, have been elucidated individually, but not simultaneously in dynamic, isolated in vivo systems. A hamster dorsal skin fold model in combination with brightfield/fluorescence intravital microscopy was used to examine the effect ...
Janssen Francis-Paul E M - - 2007
Cooling the scalp during administration of chemotherapy can prevent hair loss. It reduces both skin blood flow and hair follicle temperature, thus affecting drug supply and drug effect in the hair follicle. The extent to which these mechanisms contribute to the hair preservative effect of scalp cooling remains unknown. The ...
Payne Gemma - - 2007
Hyperspectral (chemical) imaging collects spectroscopic data in a two-dimensional spatial format. The potential application for the determination of the age of bruises is demonstrated and compared to reflectance probe spectrophotometry as well as photography. Blood was deposited on white cotton cloth or injected subcutaneously into pig skin to simulate a ...
Iwase M - - 2007
AIMS: Although skin oxygenation is an important factor in the development and healing of foot ulcers, its regulation was not fully understood. We studied changes in foot skin oxygenation and blood flow during postural changes in patients with type 2 diabetes mellitus. METHODS: Skin oxygenation was measured using transcutaneous oxygen ...
Cankar Ksenija - - 2008
The K(ATP) channels play a crucial role in regulation of vascular tone in conditions of hypoxia. Whether they contribute to peripheral blood flow regulation in human cutaneous microcirculation during a non-hypoxic state is the matter of conflicting in vivo studies that have used plethysmographic method. Our aim was therefore to ...
Sandberg Margareta L - - 2007
BACKGROUND AND PURPOSE: Various researchers have studied the effects of transcutaneous electrical nerve stimulation (TENS) on hemodynamics. The purpose of this study was to examine the effects of TENS on local blood flow in the trapezius muscle and overlying skin. SUBJECTS: Thirty-three women who were healthy, aged 25 to 55 ...
Widlansky Michael E - - 2007
Multiple studies have documented an increased incidence of cardiovascular events in the winter, but the pathophysiologic mechanisms remain incompletely understood. It was hypothesized that brachial flow and flow-mediated dilation (FMD) would vary by season and temperature. Season and temperature were related to ultrasonic brachial artery endothelium-dependent FMD% (n = 2,587), ...
Lawson Daryl - - 2007
BACKGROUND: Decrease in skin blood flow (BF) due to diabetes may be one reason why only 31% of neuropathic diabetic ulcers heal in 20-weeks. Recent evidence shows that skin blood flow may be increased if therapy is done in a warm room. The purpose of this investigation was to compare ...
Staquet Pierre - - 2007
OBJECTIVE: The present study evaluated the usefulness of a real-time polymerase chain reaction (rtPCR) assay for the detection of Neisseria meningitidis (Nm) and genogrouping on skin lesion biopsies in patients with purpura fulminans (PF). DESIGN: Retrospective single-centre study. SETTING: Adult and paediatric intensive care units at the University Hospital of ...
Wascotte Valentine - - 2007
PURPOSE: To demonstrate the "skin reservoir" of urea by confocal Raman microspectroscopy in vivo and to evaluate its impact on the non-invasive monitoring of the analyte by reverse iontophoresis. METHODS: Urea was extracted iontophoretically over a 2-h period across the skin of adult volunteers and patients with chronic kidney disease. ...
Jin H Y - - 2007
AIMS: Multiple pathogenic pathways are involved in diabetic neuropathy and diverse treatments have been tried without success. The aim of this study was to assess the effect of alpha-lipoic acid on skin blood flow in patients with diabetic neuropathy. METHODS: We measured skin blood flow in 13 control subjects and ...
Chen Chih-Chung - - 2007
The aim of this study was to investigate the effects of transcutaneous electrical nerve stimulation (TENS) on blood flow and skin temperature following an elevation of baseline blood flow using infrared preheating. A randomized controlled approach was used whereby 66 healthy human subjects (33 male, 33 female) were allocated to ...
Wienzek Holger - - 2007
BACKGROUND: Ropivacaine is primarily a local anesthetic, but it also acts as a vasoactive agent. Case reports have described a critical reduction in blood flow when higher concentrations of ropivacaine were used for peripheral-nerve blocks. One hypothesis is that local application of ropivacaine in tissues supplied by end arteries reduces ...
Davis Scott L - - 2007
This study tested the hypothesis that postsynaptic cutaneous vascular responses to endothelial-dependent and -independent vasodilators, as well as sweat gland function, are impaired in split-thickness grafted skin 5 to 9 months after surgery. Intradermal microdialysis membranes were placed in grafted and adjacent control skin, thereby allowing local delivery of the ...
Wilkins Brad W - - 2007
In humans, vasoactive intestinal peptide (VIP) may play a role in reflex cutaneous vasodilation during body heating. We tested the hypothesis that the nitric oxide (NO)-dependent contribution to active vasodilation is enhanced in the skin of subjects with cystic fibrosis (CF), compensating for sparse levels of VIP. In 2 parallel ...
Terada Kazufumi - - 2007
The objective of this study was to evaluate the usefulness of laser Doppler imaging (LDPI) of the skin blood flow for assessing peripheral vascular impairment in the hand-arm vibration syndrome (HAVS). The subjects were 46 male patients with HAVS, aged 50 to 69 yr, and 31 healthy male volunteers of ...
Malty Abdul-Majeed A I - - 2007
BACKGROUND: Electrical stimulation (ES) shows promising results in increasing healing of decubitus ulcers. Recent studies show that skin blood flows (SBFs) are enhanced if the subject is exposed to a warm environment during treatment. The purpose of this investigation was to determine if blood flow would increase with ES in ...
Spigulis Janis - - 2007
A new technique for parallel recording of reflection photoplethysmography (PPG) signals in a broad spectral band (violet to near-infrared) has been developed, and its potential for assessment of blood microcirculation at various depths from the skin surface is discussed. PPG signals have been simultaneously detected at cw laser wavelength sets ...
Jia Fu - - 2007
In this in vivo study, we measured local temperature changes in rabbit pinnae, which were evoked by radiofrequency (RF) exposure for 20 min at localized SAR levels of 0 (sham exposure), 2.3, 10.0, and 34.3 W/kg over 1.0 g rabbit ear tissue. The effects of RF exposures on skin temperature ...
Deitrick George - - 2007
Skin breakdown lesions (SBLs) of the legs are common in spinal cord injury (SCI). It is assumed that the cause is deficient sensitivity and immobility of the limbs, which result in areas subjected to prolonged pressures. However, poor circulation may also be a significant factor. Indeed, strong reasons suggest that ...
Sokhadze Estate M - - 2007
The purpose of this study was to compare the effects of music and white noise on the recovery of physiological measures after stressful visual stimulation. Twenty-nine participants took part in the experiment. Visual stimulation with slides eliciting disgust was followed by subjectively pleasant music, sad music, and white noise in ...
Rossi M - - 2007
The aim of this study was to clarify whether the post-ischaemic amplification of skin blood flowmotion (SBF) influences the extent of skin post-ischaemic hyperaemia. Forearm skin perfusion was measured by means of laser Doppler flowmetry (LDF) and forearm SBF was examined using Fourier analysis of LDF signal, under basal conditions ...
Shitzer Avraham - - 2007
A model of facial heat exchange in cold and windy environments is presented. The tissue is depicted as a hollow cylinder and the model includes heat conduction and heat transport by blood circulation from the warmer core. A steady-state solution facilitating the estimation of wind chill equivalent temperature (WCET) as ...
Friedman E A - - 2007
Raynaud's phenomenon (RP) is a disorder characterized by episodic periods of vasoconstriction typically provoked by exposure to cold. Phosphodiesterase 5 (PDE5) inhibitors may improve digital blood flow and clinical symptoms in patients with RP, but the mechanisms are unknown. We examined the hypothesis that a PDE5 inhibitor, tadalafil, attenuates cold-induced ...
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