Results 61 to 70 of about 499,118 (196)

Aortic Pressure Levels and Waveform Indexes in People Living With Human Immunodeficiency Virus: Impact of Calibration Method on the Differences With Respect to Non-HIV Subjects and Optimal Values

Frontiers in Cardiovascular Medicine, 2021
Background: There are scarce and controversial data on whether human immunodeficiency virus (HIV) infection is associated with changes in aortic pressure (aoBP) and waveform-derived indexes.
Alejandro Diaz, Marina Grand, Marina Grand, Juan Torrado, Federico Salazar, Yanina Zócalo, Daniel Bia   +6 more
doaj   +1 more source

Photon pair generation using four-wave mixing in a microstructured fibre: theory versus experiment

, 2006
We develop a theoretical analysis of four-wave mixing used to generate photon pairs useful for quantum information processing. The analysis applies to a single mode microstructured fibre pumped by an ultra-short coherent pulse in the normal dispersion ...
Alibart, O., Fulconis, J., Murdoch, S. G., Rarity, J. G., Wadsworth, W. J., Wong, G. K. L.   +5 more
core   +1 more source

Analysis of pulse-wave propagation characteristics in abdominal aortic sclerosis disease

Theoretical and Applied Mechanics Letters
In this work, a bidirectional fluid‒structure coupling finite element analysis model of the abdominal aorta was established, with the various vascular elastic modulus as the main parameters for atherosclerosis, taking into consideration blood's dynamic ...
Xuehang Sun, Bensen Li, Yicheng Lu, Xiabo Chen, Wenbo Gong, Fuxing Miao   +5 more
doaj   +1 more source

Attosecond streaking enables the measurement of quantum phase

, 2010
Attosecond streaking, as a measurement technique, was originally conceived as a means to characterize attosecond light pulses, which is a good approximation if the relevant transition matrix elements are approximately constant within the bandwidth of the
Gagnon, Justin, Karpowicz, Nicholas, Krausz, Ferenc, Yakovlev, Vladislav S.   +3 more
core   +1 more source

A second-order class-D audio amplifier [PDF]

, 2011
Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time)
Jun Yu, Mellor P. H., Meng Tong Tan, Stephen M. Cox, Tan M. T.   +4 more
core   +2 more sources

Attosecond electron spectroscopy using a novel interferometric pump-probe technique [PDF]

, 2010
We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP.
A. L’Huillier, E. Benedetti, F. Ferrari, F. Kelkensberg, F. Lépine, G. Sansone, I. Znakovskaya, J. Mauritsson, K. J. Schafer, K. Klünder, L. Argenti, M. F. Kling, M. J. J. Vrakking, M. Nisoli, M. Swoboda, O. Ghafur, P. Johnsson, S. Zherebtsov, T. Remetter, T. Uphues, W. Siu   +20 more
core   +3 more sources

Pulse wave propagation rate and dynamics of matrix metalloproteinase in patients with myocardial infarction and arterial hypertension in the presence or absence of diabetes mellitus

Медицинский вестник Юга России
Objective: to study the pulse wave propagation rate and the level of matrix metalloproteinase type 9 in patients with ST-segment elevation myocardial infarction who underwent percutaneous coronary intervention in the presence of hypertension and diabetes
V. A. Suroedov, A. A. Pirozhenko, L. A. Khaisheva, K. A. Khaishev   +3 more
doaj   +1 more source

Inter-operator Reliability for Measuring Pulse Wave Velocity and Augmentation Index

Frontiers in Cardiovascular Medicine, 2020
Background: Arterial stiffness is a reversible precursor to hypertension. However, research is needed to determine the minimum amount of training required before acceptable arterial stiffness measurements are collected by novice operators.Objective: To ...
Catherine A. Elliot, Michael J. Hamlin, Catherine A. Lizamore, Catherine A. Lizamore   +3 more
doaj   +1 more source

Numerical study of acoustic oscillations and combustion instabilities in solid propellant rocket [PDF]

, 1997
A numerical analysis of unsteady motions in solid rocket motors has been conducted. A fully coupled implicit scheme based on a dual time-stepping integration algorithm has been adopted to solve the governing equations and associated boundary conditions.
Culick, F. E. C., Roh, T. S.
core  

Aortic frequency response determination via bioimpedance plethysmography

, 2019
Objective: Arterial stiffness is an important marker to predict cardio vascular events. Common measurement techniques to determine the condition of the aorta are limited to the acquisition of the arterial pulse wave at the extremities.
Hauschild, Sebastian, Kusche, Roman, Lindenberg, Arthur-Vincent, Ryschka, Martin   +3 more
core   +1 more source