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Pressure Wave

Jayaraj Joseph, Nabeel P M, Malay Ilesh Shah, Mohanasankar Sivaprakasam
OBJECTIVE: Assessment of local arterial properties has become increasingly important in cardiovascular research as well as in clinical domains. Vascular wall stiffness indices are related to local pulse pressure (ΔP) level, mechanical and geometrical characteristics of the arterial vessel. Non-invasive evaluation of local ΔP from the central arteries (aorta and carotid) is not straightforward in a non-specialist clinical setting. In this work, we present a method and system for real-time and beat-by-beat evaluation of local ΔP from superficial arteries-a non-invasive, cuffless and calibration-free technique...
2018: PloS One
Koen M van der Waaij, Maarten H G Heusinkveld, Tammo Delhaas, Abraham A Kroon, Koen D Reesink
BACKGROUND: Vascular research demonstrated that pulse wave velocity (PWV), a measure of arterial stiffness, is inherently blood pressure dependent. Considering the hypothesized pathophysiological chain of increased arterial stiffness leading to increased blood pressure load with consequent left ventricular hypertrophy (LVH) development, we conducted a systematic review of antihypertensive and lifestyle intervention studies to determine the association between, on the one hand, changes in arterial stiffness and blood pressure, and, on the other hand, changes in left ventricular mass (LVM)...
August 14, 2018: Journal of Hypertension
Agustin J Ramirez, Maria J Sanchez, Ramiro A Sanchez
INTRODUCTION: Hypertension control reduces cardiovascular and renal risks in type 2 diabetes. Sodium-glucose cotransporter-2 inhibitors prevent renal glucose reabsorption and decrease glucose plasma levels, blood pressure (BP) and weight reduction. Treatment of hypertension and sodium-glucose cotransporter-2 are able to improve arterial stiffness. AIMS: To evaluate, in patients with type 2 diabetes and hypertension, the effects of 6 months treatment with canagliflozin, or perindopril, an angiotensin converting enzyme inhibitor, on central BP and carotid-femoral pulse wave velocity (cfPWV)...
August 14, 2018: Journal of Hypertension
So Young Park, Sang Ook Chin, Sang Youl Rhee, Seungjoon Oh, Jeong Taek Woo, Sung Woon Kim, Suk Chon
BACKGROUND: Carotid artery intima medial thickness (IMT), brachial-ankle pulse wave velocity (baPWV), and ankle-brachial index (ABI) are commonly used surrogate markers of subclinical atherosclerosis in patients with type 2 diabetes mellitus (T2DM). The cardio-ankle vascular index (CAVI) is a complement to the baPWV, which is affected by blood pressure. However, it is unclear which marker is the most sensitive predictor of atherosclerotic cardiovascular disease (ASCVD). METHODS: This was a retrospective non-interventional study that enrolled 219 patients with T2DM...
July 27, 2018: Diabetes & Metabolism Journal
A L Velikovich, J L Giuliani
The classic self-similar solutions of the nonstationary compressible Euler equations obtained for a blast-wave propagation (Sedov, Taylor, and von Neumann), a shock-wave implosion (Guderley, Landau, and Stanyukovich), or an impulsive loading of a planar target (von Hoerner, Häfele, and Zel'dovich) have all been derived for a polytropic ideal gas. None of them can be generalized for a fluid with an arbitrary equation of state (EOS), such as the van der Waals EOS of a non-ideal-gas or a three-term EOS of a condensed material...
July 2018: Physical Review. E
Manuel S Brugger, Sarah Grundeen, Adele Doyle, Luke Theogarajan, Achim Wixforth, Christoph Westerhausen
For the investigation of cell-cell interaction in general and for neural communication and future applications of neural networks, a controllable and well-defined network structure is crucial. We here propose the implementation of an acoustically driven system for tunable and deliberate stimulation and manipulation of cell growth on a chip. This piezoelectric chip allows us to generate a checkerboard-like standing surface acoustic wave pattern coupled to a fluid layer in a microfluidic chamber on top. Such a dynamically induced patterning lattice is shown to allow for the active positioning of the neurons and subsequent guided neurite outgrowth, thus finally overcoming the limitations of static approaches...
July 2018: Physical Review. E
Joel Cameron Balmer, Christopher G Pretty, Shaun Davidson, Thomas Desaive, Shun Kamoi, Antoine Pironet, Philippe Morimont, Nathalie Janssen, Bernard Lambermont, Geoffrey M Shaw, J Geoffrey Chase

 Pulse wave velocity measurements are an indicator of arterial stiffness and possible cardiovascular dysfunction. It is usually calculated by measuring the pulse transit time (PTT) over a known distance through the arteries. In animal studies, reliable PTT measures can be obtained using two pressure catheters. However, such direct, invasive methods are undesirable in clinical settings. A less invasive alternative measure of PTT is pulse arrival time (PAT), the time between the Q-wave of an electrocardiogram (ECG) and the arrival of the foot of the beats pressure waveform at one pressure catheter...
August 15, 2018: Physiological Measurement
Jorge Alberto Arroyo Vázquez, Maria Bergström, Stephen Bligh, Barry P McMahon, Per-Ola Park
BACKGROUND: Perforated duodenal ulcers can be treated with a covered stent. Stent migration is a severe complication, sometimes requiring surgery. Pyloric physiology during stent treatment has not been studied and mechanisms for migration are unknown. The aim of this study was to investigate the pyloric response to distention, mimicking stent treatment, using the EndoFLIP. METHODS: A nonsurvival study in five pigs was carried out, followed by a pilot study in one volunteer...
August 15, 2018: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
Jing Wang, Meng-Meng Lv, Odeh Zach, Ling-Yu Wang, Meng-Ying Zhou, Gui-Rong Song, Xu Zhang, Hong-Li Lin
Hyperkalemia is a life-threatening emergency in maintenance hemodialysis (MHD) patients. This clinical trial investigated the efficacy and safety of calcium-polystyrene sulfonate (Ca-PS) in MHD patients with interdialytic hyperkalemia. A total of 58 hemodialysis patients with hyperkalemia (≥5.5 mol/L) were selected and administered either a 3-week Ca-PS (3 × 5 g/day) or a blank control following the model of a prospective, randomized, crossover clinical trial with a 1-week washout period. All patients were followed up for another 3 weeks for safety evaluations...
August 14, 2018: Therapeutic Apheresis and Dialysis
Dongming Zhang, Yushun Yang, Hao Wang, Xin Bai, Chen Ye, Shujian Li
The present experimental study on permeability characteristics for raw coal under different stress states is implemented by applying the triaxial self-made 'THM coupled with servo-controlled seepage apparatus for gas-containing coal'; the result indicates that the flow rate of gas in the coal sample gradually decreases with the nonlinear loading of axial pressure and increases with the nonlinear unloading of axial stress and confining pressure. The flow rate, axial stress and confining pressure curves all satisfy the negative exponential function relation...
July 2018: Royal Society Open Science
Ning Zhang, Bo Gao, Zhong Li, Qifeng Jiang
With the development of cavitation, the high-energy pressure wave from a cavitation bubble collapsing is detrimental to the stable operation of centrifugal pumps. The present paper concentrates on pressure pulsations under cavitation conditions, and pressure amplitudes at the blade-passing frequency ( f BPF ) and RMS values in the 0-500 Hz frequency band are combined to investigate cavitation-induced pressure pulsations. The results show that components at f BPF always dominate the pressure spectrum even at the full cavitation stage...
July 2018: Royal Society Open Science
Dong Gyu Kim, Jong Han Choi, Duck-Kyun Choi, Sang Woo Kim
Electromagnetic (EM) wave emissions from wearable or flexible smart display devices can cause product malfunction and have a detrimental effect on human health. Therefore, EM shielding strategies are becoming increasingly necessary. Consequently, herein, we prepared a transparent acrylic polymer-coated/reduced graphene oxide/silver nanowire (Ag NW) (A/RGO/SAW) EM interference (EMI) shielding film via liquid-to-vapor pressure-assisted wet sintering. The film exhibited enhanced Ag NW network formation and antireflection (AR) effects...
August 14, 2018: ACS Applied Materials & Interfaces
Javier García-Niebla, Andrés Ricardo Pérez-Riera, Raimundo Barbosa-Barros, Jorge Díaz-Muñoz, Rodrigo Daminello-Raimundo, Luiz Carlos de Abreu, Kjell Nikus
Right ventricular involvement in inferior myocardial infarction is a marker of poor prognosis. We present a case of a 62-year-old man with very recent onset of acute chest pain and cardiac shock with the triad of elevated jugular venous pressure, distension of the jugular veins on inspiration, and clear lung fields. In addition, the admission electrocardiogram showed a slurring J wave or lambda-like wave and conspicuous ST segment depression in several leads, predominantly in the lateral precordial (V4-V6), all clinical-electrocardiographic features of ominous prognosis...
August 14, 2018: Annals of Noninvasive Electrocardiology
Todd Ladanchuk, Seojung Kwak, Lucy Bates, Katrina Parkin, Katie Harris, Oisin Fitzgerald, William Lynch, Kate H Moore
AIM: The mechanisms leading to the development of detrusor overactivity (DO) are still relatively poorly understood, however, animal studies suggest that atherosclerosis and reduced blood flow to the bladder may be one etiological pathway. Thus, the aim of this study was to evaluate signs of atherosclerosis in a large cohort of women with detrusor overactivity, using two precise measures of atherosclerotic vascular impairment, Ankle Brachial Index (ABI), and Brachial-ankle Pulse Wave Velocity (baPWV)...
August 14, 2018: Neurourology and Urodynamics
Yun-Ning Tsai, Yi-Chia Huang, Sunny Jui-Shan Lin, Shen-Ming Lee, Yung-Yen Cheng, Yu-Hsin Chang, Yi-Chang Su
Purpose: This study aimed to clarify whether it is appropriate to choose any measurement location for pulse diagnosis research. Methods: A total of 37 subjects were recruited and measured for pulse pressure waves at 18 locations (9 per hand of "three positions and nine indicators"). These data were Fourier-transformed to the frequency spectrum, and the harmonics of C0-C10 of each location were obtained. Box plots of the harmonics were generated using SPSS v...
2018: Evidence-based Complementary and Alternative Medicine: ECAM
Sangmin An, Bongsu Kim, Soyoung Kwon, Geol Moon, Manhee Lee, Wonho Jhe
Mechanical sensors provide core keys for high-end research in quantitative understanding of fundamental phenomena and practical applications such as the force or pressure sensor, accelerometer and gyroscope. In particular, in situ sensitive and reliable detection is essential for measurements of the mechanical vibration and displacement forces in inertial sensors or seismometers. However, enhancing sensitivity, reducing response time and equipping sensors with a measurement capability of bidirectional mechanical perturbations remains challenging...
August 11, 2018: Sensors
Joshua C Tremblay, Taylor V Stimpson, Kristen M Murray, Kyra E Pyke
Prolonged sitting decreases lower limb endothelial function via sustained reductions in mean shear rate. We tested whether 30 minutes of sitting cross-legged differentially impacts superficial femoral artery shear rate pattern, flow-mediated dilation (FMD) and leg pulse-wave velocity (PWV) compared to sitting flat-footed. Sitting cross-legged attenuated the reduction in mean and antegrade shear rate and increased arterial pressure compared to sitting flat-footed. Superficial femoral artery FMD and leg PWV were unaltered following either sitting position...
August 13, 2018: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Xiaoxiong Wang, Wei-Zhi Song, Ming-Hao You, Jun Zhang, Miao Yu, Zhiyong Fan, Seeram Ramakrishna, Yun-Ze Long
Moravec's paradox shows that low-level sensorimotor skills are more difficult than high-level reasoning in artificial intelligence and robotics area. So simplifying every sensing unit on electronic skin is critical for endowing intelligent robots with tactile and temperature sense. The human nervous system is characterized by efficient single-electrode signal transmission, ensuring the efficiency and reliability of information transmission under big data conditions. In this work, we report a sensor based on single-electrode piezoelectric nanogenerator (SPENG) by electrospun polyvinylidene fluoride(PVDF) nanofibers that can realize steady state sensing of pressure integrating cold/heat sensing on a single unit...
August 13, 2018: ACS Nano
Alexandra M Coates, Philip J Millar, Jamie F Burr
PURPOSE: Moderate overtraining has been characterized by decreased exercising heart rate (HR) and recently, decreased exercising stroke volume (SV), independent of alterations to blood volume. The aim of this study was to assess changes in arterial stiffness and central hemodynamics, and their relationship to exercising SV, following three weeks of overload training. METHODS: Twenty-six cyclists and triathletes completed 3-weeks of either regular training (CON; n=13) or overload training (OL; n=13)...
August 10, 2018: Medicine and Science in Sports and Exercise
A Manduca, T L Rossman, D S Lake, K J Glaser, A Arani, S P Arunachalam, P J Rossman, J D Trzasko, R L Ehman, D Dragomir-Daescu, P A Araoz
Magnetic resonance elastography (MRE) is increasingly being applied to thin or small structures in which wave propagation is dominated by waveguide effects, which can substantially bias stiffness results with common processing approaches. The purpose of this work was to investigate the importance of such biases and artifacts on MRE inversion results in: (i) various idealized 2D and 3D geometries with one or more dimensions that are small relative to the shear wavelength; and (ii) a realistic cardiac geometry...
August 13, 2018: NMR in Biomedicine
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