Search Results
Results 501 - 550 of 2480
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Sipkens Laura M - - 2011
OBJECTIVE: Evaluation of autonomic function responses is increasingly important for risk prediction and hemodynamic evaluation in the ambulant and perioperative setting, but requires a noninvasive arterial blood pressure measurement device. This study describes whether a novel noninvasive beat-to-beat arterial blood pressure measurement device (Nexfin HD) is able to reproducibly reflect ...
Ebare M N - - 2011
OBJECTIVE: To assess the level of noise generated by music shops in an urban city in Nigeria. STUDY DESIGN: Cross-sectional, descriptive study. METHODOLOGY: The study involved music shops in three out of eight identified clusters of market areas in Benin City. A semi-structured, researcher-administered questionnaire was also used to collect ...
Wohlfahrt P - - 2011
Central blood pressure (BP) has been shown to be a better predictor of target organ damage and cardiovascular events than brachial BP. Whether central BP is a better predictor of left ventricular hypertrophy (LVH) determined by electrocardiography (ECG) is not known. Radial applanation tonometry and ECG were performed in 728 ...
Eiken Ola - - 2011
OBJECTIVE: The aim was to investigate whether repeated exposures to moderate pressure elevations in the blood vessels of the arms (pressure training) affect pressure distension in arteries/arterioles of healthy individuals. METHODS: Pressure training and vascular pressure-distension determinations were conducted with the participant (n = 11) seated in a pressure chamber with one ...
Wilhelm Matthias - - 2011
Veteran endurance athletes have an increased risk of developing atrial fibrillation (AF), with a striking male predominance. We hypothesized that male athletes were more prone to atrial and ventricular remodeling and investigated the signal-averaged P wave and factors that promote the occurrence of AF. Nonelite athletes scheduled to participate in ...
Samiotaki Gesthimani - - 2012
Focused ultrasound in conjunction with the systemic administration of microbubbles has been shown to open the blood-brain barrier (BBB) selectively, noninvasively and reversibly. In this study, we investigate the dependence of the BBB opening's reversibility on the peak-rarefactional pressure (0.30-0.60 MPa) as well as the microbubble size (diameters of 1-2, ...
Pauser Johannes - - 2011
Pauser J, Jendrissek A, Swoboda B, Gelse K, Carl H-D. Inaccuracy of a physical strain trainer for the monitoring of partial weight bearing. OBJECTIVE: To investigate the use of a physical strain trainer for the monitoring of partial weight bearing. DESIGN: Case series with healthy volunteers. SETTING: Orthopedic clinic. PARTICIPANTS: ...
Qin Jihong - - 2011
Within the two-leg t-J ladder, the spin dynamics of the pressure-induced two-leg ladder cuprate superconductor Sr(14-x)Ca(x)Cu(24)O(41) is studied based on the kinetic energy driven superconducting mechanism. It is shown that in the pressure-induced superconducting state, the incommensurate spin correlation appears in the underpressure regime, while the commensurate spin fluctuation emerges ...
Marcus Justin - - 2011
Elevated blood pressure (BP) is a risk factor for stroke and dementia, but the effect of BP, and change in BP over time, on white matter hyperintensity volume (WMHV) is not fully understood. Few studies have included Hispanics, who are at greater risk of stroke and dementia than non-Hispanic whites. ...
Yuda Satoshi - - 2011
Background: Two-dimensional speckle tracking imaging (2DS) enables quantitative measurement of left ventricular strain. However, application of 2DS for measurement of circumferential carotid arterial strain (CAS) is not fully elucidated. We investigated the feasibility and reproducibility of measuring CAS by 2DS and determinants of CAS in healthy subjects. Methods: Fifty-one healthy ...
Heffernan Kevin S - - 2011
Persons with multiple sclerosis (MS) have reduced gait performance and this is associated with disability and disease progression. The current study sought to test the hypothesis that higher central (aortic and carotid) and peripheral (brachial) pulse pressure (PP), manifestations of ventricular-vascular uncoupling related to increased arterial stiffness and pressure from ...
Constantinides C - - 2011
This study examines (a) the temporal stability of hemodynamic indices of systolic and diastolic function in C57BL/6 mice under 1.5% isoflurane (ISO) (v/v) anesthesia conditions in 50:50 O(2)/N(2)O (v/v) within 90 min post-induction, and (b) the effects of Mn(2+) on the mouse hemodynamic response in male C57BL/6 mice (n = ...
Mitchell E S - - 2011
The combination of theobromine and caffeine, methylxanthines found in chocolate, has previously been shown to improve mood and cognition. However, it is unknown whether these molecules act synergistically. This study tested the hypothesis that a combination of caffeine and theobromine has synergistic effects on cognition, mood and blood pressure in ...
Brock David W DW Department of Exercise and Movement Science, University of Vermont, Burlington, VT 05405-0068, USA. - - 2012
Two recent examinations reported a strong association between blood pressure (BP) and resting energy expenditure (REE), independent of body mass and body composition. Both reports postulate that neurohumoral processes that contribute to variation in REE may partly mediate the body mass effect on BP. Therefore, we examined the relationship of ...
Ramazanoglu M - - 2011
Neutron diffraction is used to show that small (∼7  MPa, or 70 bar) uniaxial pressure produces significant changes in the populations of magnetic domains in a single crystal of 2% Nd-doped bismuth ferrite. The magnetic easy plane of the domains converted by the pressure is rotated 60° relative to its original position. ...
Zhang Guanqun - - 2011
We compared pulse arrival time (PAT) and pulse transit time (PTT) in terms of their ability to track diastolic pressure (DP). We performed the comparison using high fidelity, invasive arterial waveforms recorded from six dogs during multiple interventions. On average, DP ranged from 40 to 106 mmHg and therefore varied ...
Singh Aditya - - 2011
The use of a Continuous Wave (CW) quadrature Doppler radar is proposed here for continuous non-invasive Pulse Pressure monitoring. A correspondence between the variation in systemic pulse and variation in the displacement of the chest due to heart is demonstrated, establishing feasibility for the approach. Arctangent demodulation technique was used ...
Mafi Majid - - 2011
A novel pulse morphology-based approach for estimation of blood pressure from non-invasive oscillometric blood pressure measurement is presented. Quantitative measures that describe the pulse morphology are utilized to obtain the estimates of mean arterial, systolic, and diastolic pressures. Preliminary results obtained from a small set of measurements are used to ...
Moslehpour Mohsen - - 2011
We previously developed a technique for estimating relative cardiac output (CO) change by long time interval analysis of a radial arterial blood pressure waveform. This technique analyzes the slow, beat-to-beat changes in the waveform to circumvent the confounding wave reflections but assumes constant arterial compliance (AC). Here, we sought to ...
Xu Ke - - 2011
With increasing interest in the effect of postural changes on arterial blood pressure and vascular properties, it is important to understand effects of pressure-dependent arterial compliance. This study investigates effects of pressure-dependent compliance on pulse wave velocity (PWVar), pressure wave shape, and transmission characteristics in an arterial model of the ...
Gregory Shaun D - - 2011
Mock circulation loops (MCLs) are used to evaluate cardiovascular devices prior to in-vivo trials; however they lack the vital autoregulatory responses that occur in humans. This study aimed to develop and implement a left and right ventricular Frank-Starling response in a MCL. A proportional controller based on ventricular end diastolic ...
Delles Michael - - 2011
In cardiovascular diagnostics, phase-contrast MRI is a valuable technique for measuring blood flow velocities and computing blood pressure values. Unfortunately, both velocity and pressure data typically suffer from the strong image noise of velocity-encoded MRI. In the past, separate approaches of regularization with physical a-priori knowledge and data representation with ...
Shyu Liang-Yu - - 2011
This study develops a system to obtain continuous blood pressure signal and impedance plethysmography (IPG) signal, simultaneously. Based on the principle of impedance measurement, the peripheral vessel volume change can be computed from the IPG signal. Equipped with simultaneous information of pressure and volume, a pressure-volume (PV) loop can be ...
Kobayashi Masato - - 2011
Head elevation can restore airway patency during anesthesia, although its effect may be offset by concomitant bite opening or accidental neck flexion. The aim of this study is to examine the effect of head elevation on the passive upper airway collapsibility during propofol anesthesia. Twenty male subjects were studied, randomized ...
Hoyt David W - - 2011
A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges ...
Kotsis Vasilios - - 2011
Differences in 24h blood pressure (BP) monitoring parameters such as average 24h BP, day to night BP ratio and BP variability could have an impact in arterial stiffness. The study hypothesis was that despite similar average BP values in ambulatory blood pressure monitoring subjects with increased 24h BP variability may ...
Lengyel E - - 2011
We carried out specific-heat and ac-susceptibility experiments under hydrostatic pressure to investigate the interplay of spin-density-wave antiferromagnetism (A) and superconductivity (S) in single-crystalline AS-type CeCu_{2}Si_{2}. We find evidence for a line of magnetic-field- and pressure-tuned quantum critical points in the normal state in the zero-temperature magnetic field-pressure plane. Our analysis ...
Roman Mary J - - 2011
The relative impacts of lowering blood pressure versus lowering low-density lipoprotein (LDL) cholesterol on regression of ventricular and arterial mass have not been systematically examined. Changes in left ventricular mass and arterial mass (common carotid artery cross-sectional area) after 36 months of simultaneous lowering of systolic blood pressure and LDL ...
Pavelescu Adriana - - 2011
Sildenafil and epoprostenol are effective therapies in pulmonary arterial hypertension (PAH). Both drugs increase cardiac output, which has been in part attributed to improved right ventricular (RV) contractility. We therefore used tissue Doppler imaging (TDI) to test whether sildenafil and epoprostenol might differently affect RV function in normal subjects before ...
Kaya Semira - - 2011
PURPOSE: To compare dynamic autoregulation in the Central Retinal Artery (CRA) and the Posterior Ciliary Arteries (PCAs) after a step decrease in systemic blood pressure. METHODS: Ten healthy male young subjects were studied. Flow velocities in retrobulbar vessels and systemic blood pressure were recorded in each subject before, during, and ...
Kremer Werner - - 2011
The introduction of the multidimensional NMR spectroscopy was a breakthrough in biological NMR me-thodology since it allowed the unequivocal correlation of different spin states of the system. The introduction of large pressure perturbations in the corresponding radio frequency (RF) pulse sequences adds an extra structural dimension into these experiments. We ...
Schumann S - - 2011
Background: Heartbeat-related pressure oscillations appear at the airway opening. We investigated whether these cardiogenic oscillations (COS) - extracted from spontaneous breathing signals - reflect the compliance of the respiratory system. Methods: Fifteen volunteers breathed spontaneously at normal or reduced chest wall compliance, i.e. with and without thorax strapping, and at ...
Nishihara Makoto - - 2011
To test the hypothesis that the N1 component of auditory evoked potentials (AEPs) is one form of the change-related response elicited by an abrupt change in sound pressure from a silent background, two AEP experiments were conducted. Change-N1 was evoked by a test stimulus at 70dB following a 3-s conditioning ...
Szafrański Marek - - 2011
A guanidinium compound, [C(NH2)3]5SO4(SO3-OC2H5)2F, with complex anionic sublattice has been synthesized and characterized by calorimetric and dielectric measurements at ambient and high hydrostatic pressures, as well as by single-crystal X-ray diffraction at varied temperatures. At room temperature the crystal structure is orthorhombic, space group Pnma. In this phase each of ...
Bai Yongyi - - 2011
The mechanisms of non-hypertensive intracerebral hemorrhages (ICH), which may have different pathologies, mechanisms and genetic background from hypertensive ICH, are not clear. MicroRNAs are a new class of endogenous small RNAs that negatively regulate gene expression at the posttranscriptional level. Previous studies indicate that vascular smooth muscle cell (VSMC) function ...
Samudrala Gopi K - - 2011
High pressure x-ray diffraction studies have been performed on the heavy rare earth metal erbium (Er) in a diamond anvil cell at room temperature to a pressure of 151 GPa and Er has been compressed to 40% of its initial volume. The rare earth crystal structure sequence [Formula: see text] fcc ...
Mills Nicholas L NL The BHF/University Centre for Cardiovascular Science, Edinburgh University, The Queens Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, - - 2011
Exposure to road traffic and air pollution may be a trigger of acute myocardial infarction, but the individual pollutants responsible for this effect have not been established. We assess the role of combustion-derived-nanoparticles in mediating the adverse cardiovascular effects of air pollution. To determine the in vivo effects of inhalation ...
Mesquida Jaume J Cardiopulmonary Research Laboratory, Department of Critical Care Medicine, University of Pittsburgh Medical Center, 606 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15261, - - 2011
We evaluated the impact of increasing tidal volume (V (t)), decreased chest wall compliance, and left ventricular (LV) contractility during intermittent positive-pressure ventilation (IPPV) on the relation between pulse pressure (PP) and LV stroke volume (SV(LV)) variation (PPV and SVV, respectively), and intrathoracic blood volume (ITBV) changes. Sixteen pentobarbital-anesthetized thoracotomized ...
Wykrętowicz Magdalena - - 2011
OBJECTIVES: Pregnancy is accompanied by different physiological adaptations in the cardiovascular system. However, information on central blood pressures, wave reflection, arterial stiffness in uncomplicated pregnancy compared with nonpregnant women is limited. STUDY DESIGN: Forty-six women (mean age 28 years) in the third trimester of pregnancy and 45 healthy age- and ...
Sobotka Kristina S - - 2011
A sustained inflation (SI) facilitates lung aeration after birth but may impair the neonatal cardiovascular transition. We aimed to determine the effect of an initial SI on pulmonary arterial and carotid blood flow (PBF and CBF) after preterm birth. Fetal sheep were instrumented at ∼122 d of gestation (d). Lambs ...
Arregui-Dalmases C - - 2011
While rupture of the aorta is a leading cause of sudden death following motor vehicle crashes, the specific mechanism that causes this injury is not currently well understood. Aortic ruptures occurring in the field are likely due to a complex combination of contributing factors such as acceleration, compression of the ...
Disotell Kevin J - - 2011
A pressure-sensitive paint (PSP) system capable of measuring high-frequency acoustic fields with non-periodic, acoustic-level pressure changes is described. As an optical measurement technique, PSP provides the experimenter with a global distribution of pressure on a painted surface. To demonstrate frequency response and enhanced sensitivity to pressure changes, a PSP system ...
Breskovic Toni - - 2011
Limited information exists concerning arterial blood pressure (BP) changes in underwater breath-hold diving. Simulated chamber dives to 50 m of freshwater (mfw) reported very high levels of invasive BP in two divers during static apnea (SA), whereas a recent study using a noninvasive subaquatic sphygmomanometer reported unchanged or mildly increased ...
Poliacek Ivan - - 2011
We tested the hypothesis, motivated in part by a coordinated computational cough network model, that alterations of mean systemic arterial blood pressure (BP) influence the excitability and motor pattern of cough. Model simulations predicted suppression of coughing by stimulation of arterial baroreceptors. In vivo experiments were conducted on anesthetized spontaneously ...
Lim Tae Sung - - 2011
BACKGROUND: Although an early neurological deterioration after lacunar infarction is not rare, its therapeutic options are still undetermined. We investigated the effect of induced-hypertension in lacunar infarction with motor progression. METHODS: We reviewed 82 lacunar infarction patients who experienced motor progression [≥1-point increase of NIH stroke scale (NIHSS) during hospitalization]. ...
Kim Ji Young - - 2011
Abstract Background: Several ventilatory strategies have been introduced to minimize the respiratory and hemodynamic effects of carbon dioxide pneumoperitoneum during laparoscopic surgery. The purpose of this study was to compare the effects of pressure-controlled ventilation (PCV) with that of volume-controlled ventilation (VCV) on the ventilatory and hemodynamic parameters in children ...
Vriz Olga - - 2011
BACKGROUND: The aim of this study was to investigate the relationship between carotid artery stiffness and diastolic function in a cohort of subjects without known cardiovascular risk factors and/or overt cardiovascular disease. METHODS: Ninety-two healthy subjects underwent transthoracic echocardiographic Doppler and carotid echo-tracking studies. Measurements of local arterial stiffness were ...
Sanchez-Gonzalez M A - - 2011
The augmentation index (AIx), a marker of wave reflection, decreases following acute leg exercise. Passive vibration (PV) causes local vasodilation that may reduce AIx. This study investigated the effects of acute PV on wave reflection and aortic hemodynamics. In a crossover fashion 20 (M=9, F=11) healthy young (22±3 year) participants were ...
Veit Lena - - 2011
How do animals with learned vocalizations coordinate vocal production with respiration? Songbirds such as the zebra finch learn their songs, beginning with highly variable babbling vocalizations known as subsong. After several weeks of practice, zebra finches are able to produce a precisely timed pattern of syllables and silences, precisely coordinated ...
Allet Lara - - 2011
PURPOSE: Joint moments have been acknowledged as key factors in understanding gait abnormalities. Gait velocity is further known to affect joint moments and foot pressures. Keeping gait velocity constant is thus a strategy to cancel out the influence of different preferred gait speed between groups. But even if gait velocity ...
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