1,112 research outputs found
Left ventricular ejection time, not heart rate, is an independent correlate of aortic pulse wave velocity.
Salvi P, Palombo C, Salvi GM, Labat C, Parati G, Benetos A. Left
ventricular ejection time, not heart rate, is an independent correlate of
aortic pulse wave velocity. J Appl Physiol 115: 1610–1617, 2013. First
published September 19, 2013; doi:10.1152/japplphysiol.00475.2013.—
Several studies showed a positive association between heart rate and
pulse wave velocity, a sensitive marker of arterial stiffness. However, no
study involving a large population has specifically addressed the dependence
of pulse wave velocity on different components of the cardiac
cycle. The aim of this study was to explore in subjects of different age the
link between pulse wave velocity with heart period (the reciprocal of
heart rate) and the temporal components of the cardiac cycle such as left
ventricular ejection time and diastolic time. Carotid-femoral pulse wave
velocity was assessed in 3,020 untreated subjects (1,107 men). Heart
period, left ventricular ejection time, diastolic time, and early-systolic
dP/dt were determined by carotid pulse wave analysis with high-fidelity
applanation tonometry. An inverse association was found between pulse
wave velocity and left ventricular ejection time at all ages (25 years,
r2 0.043; 25–44 years, r2 0.103; 45–64 years, r2 0.079; 65–84
years, r2 0.044; 85 years, r2 0.022; P 0.0001 for all). A
significant (P 0.0001) negative but always weaker correlation between
pulse wave velocity and heart period was also found, with the exception
of the youngest subjects (P0.20). A significant positive correlation was
also found between pulse wave velocity and dP/dt (P 0.0001). With
multiple stepwise regression analysis, left ventricular ejection time and
dP/dt remained the only determinant of pulse wave velocity at all ages,
whereas the contribution of heart period no longer became significant.
Our data demonstrate that pulse wave velocity is more closely related to
left ventricular systolic function than to heart period. This may have
methodological and pathophysiological implications
Влияние автономного инвертора напряжения с синусоидальной широтно-импульсной модуляцией на устойчивость системы электропривода
A method for calculating conditions subharmonic stable AC systems, taking into account the discrete of voltage autonomous inverter with sinusoidal PWM based on which the stable area of AC engine drive
Іван Франко - публіцист
Проаналізовано соціально-економічну і культурно-освітню публіцистику І. Франка,
зокрема, його ставлення до податкової політики Австро-Угорщини, діяльності
банківської системи, еміграції з Галичини, кооперативного руху, майбутнього
української держави.The article analyses social and economic and cultural and educational publications by Ivan
Franko, as well as his attitude to tax policies in Austro-Hungarian Empire, banking system
activities, emigration from Halychyna, co-operative societies movement, and the future of
Ukraine
Future Practices and Technologies in Anthropometrics and Body Scanning
There have also been great strides in software development, to convert and manipulate 3D scan data, to make mannequins, lasts, patterns, tooling files, etc. The presenters invited to this special topic session are at the forefront of these research spaces, either through evaluating or utilizing these technologies for product design and developmen
Pulmonary hypertension in infants with congenital heart defects: are leukotrienes involved?
The circulating levels of leukotriene E4 in infants with congenital heart defects, increased pulmonary blood flow and pulmonary arterial hypertension, were determined and compared with infants with decreased pulmonary blood flow (Tetralogy of Fallot). There was no correlation (r=0.38) between the pulmonary arterial pressure
(56 ± 4 mmHg) and the leukotriene E4 levels (1.37 ± 0.67 ng/ml blood) measured in peripheral blood samples from the hypertensive group prior to surgery. There was considerable variation in the detectable leukotriene E4 levels in blood samples from different patients. The levels detected in the blood samples between the two groups of patients was similar. These data suggest that neither the surgical repair during cardiopulmonary bypass nor the pulmonary hypertension appeared to modify the leukotriene E4 blood levels in the small number of patients studied
Anti-IgE Response in Human Airways: Relative Contribution of Inflammatory Mediators
Heman airway preparations at resting tone were relaxed with either
the leukotriene synthesis inhibitor BAY x1005 (3 μM),
chlorpheniramine (1 μM) or the thromboxane receptor antagonist
BAY u3405 (0.1 μM). The response to anti-IgE (1:1000) was 58
± 8% of acetylcholine pre-contraction (2.19 ±
0.28 g). Indomethacin (3 μM) enhanced the anti-IgE-induced
contraction by 28%. The anti-IgE maximal response was not
modified by either chlorpheniramine, BAY x1005 or BAY u3405. When
the tissues were treated with either BAY xl005/indomethacin or
BAY x1005/chlorpheniramine, the anti-IgE-induced contraction was
reduced. In addition, in presence of BAY
xl005/indomethacin/chlorpheniramine the response was
completely blocked. These results suggest that mediatots released
during anti-IgE challenge cause airway contraction which may mask
the evaluation of the leukotriene component
Aggregation effects on pigment coatings: Pigment red 179 as a case study
Here, we have studied, with a combined experimental and computational approach, the effect of the crystal environment and aggregation on the electronic properties of Pigment Red 179, which affect both its color and optical energy gap. Spectra acquired in the near-infrared and visible range of energies suggest that this molecule is indeed a "cool" dye, which can be employed as a red pigment that provides effective color coverage to different substrates without contributing to their heating during light irradiation. Spectra acquired on different polymer mixtures at different pigment concentrations (i.e., 2.5-10 wt %) suggest that absorption features depend on chromophoric arrangements promoted by the strong intermolecular I -\u3c0interactions. Calculations, performed at the time-dependent density functional theory level, allowed to both attribute the nature of the electronic transitions causing the observed spectra involved and understand the effect of the environment. Indeed, the visible spectra of the pigment is dominated by two localized transitions, with negligible charge transfer for both a dye monomer and dimer either in vacuum or acetonitrile solution. Instead, models including the crystal environment of the pigment show the presence of a high-wavelength S1 \ue2 S0 charge transfer transition between two adjacent molecules, in quantitative agreement with the experimental absorption energy of the crystal pigment
The endothelial mineralocorticoid receptor regulates vasoconstrictor tone and blood pressure
Pathophysiological aldosterone (aldo)/mineralocorticoid receptor (MR) signaling has significant effects on the cardiovascular system, resulting in hypertension and cardiovascular remodeling; however, the specific contribution of the vascular MR to blood pressure regulation remains to be established. To address this question, we generated a mouse model with conditional overexpression of the MR in endothelial cells (MR-EC). In basal conditions, MR-EC mice developed moderate hypertension that could be reversed by canrenoate, a pharmacological MR antagonist. MR-EC mice presented increased contractile response of resistance arteries to vasoconstrictors (phenylephrine, thromboxane A(2) analog, angiotensin II, and endothelin 1) in the absence of vascular morphological alterations. The acute blood pressure response to angiotensin II or endothelin 1 infusion was increased in MR-EC mice compared with that in littermate controls. These observations demonstrate that enhanced MR activation in the endothelium generates an increase in blood pressure, independent of stimulation of renal tubular Na(+) transport by aldo/MR or direct activation of smooth muscle MR and establish one mechanism by which endothelial MR activation per se may contribute to impaired vascular reactivity
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