During leg flexion from erect posture, postural stability along the medio-lateral direction is organized in advance during "anticipatory postural adjustments" (APAs). This study aimed to investigate the influence of temporal pressure on this anticipatory postural control of medio-lateral stability. Eight young healthy participants performed series of leg flexions (1) as ...

Abstract Background: Cold stimulation (CS) accompanied by vasoconstriction can increase the stiffness of the arterial system. The vascular responses during CS have been studied using photoplethysmography (PPG), but most have focused on time-domain waveform indexes. Focusing on the radial arterial blood pressure (BPW) and the finger PPG waveforms, we aimed ...

The aim of this paper is to clarify some physical-mechanical aspects involved in the carbon dioxide angiography procedure (CO(2) angiography), with a particular attention to a possible damage of the vascular wall. CO(2) angiography is widely used on patients with iodine intolerance. The injection of a gaseous element, in most ...

Atomistic simulation of initial ⟨100⟩ oriented FCC Cu nanowires shows a novel coupled temperature-pressure dependent reorientation from ⟨100⟩ to ⟨110⟩ phase. A temperature-pressure-induced solid-solid ⟨100⟩ to ⟨110⟩ reorientation diagram is generated for Cu nanowire with varying cross-sectional sizes. A critical pressure is reported for Cu nanowires with varying cross-sectional sizes, ...

A device is presented for efficiently enriching parahydrogen by pulsed injection of ambient hydrogen gas. Hydrogen input to the generator is pulsed at high pressure to a catalyst chamber making thermal contact with the cold head of a closed-cycle cryocooler maintained between 15 and 20K. The system enables fast production ...

The study was performed to characterize the influence of tibial tuberosity realignment on the pressure applied to cartilage on the patella in the intact condition and with lesions on the lateral and medial facets. Ten knees were loaded in vitro through the quadriceps (586 N) and hamstrings (200 N) at ...

Pulse examination by palpation of a peripheral artery against a bony prominence is the most commonly used and widely accepted method. However this is subjective and thus prone to errors. Although pulse waveform was recorded in the 19th century, it did not gain popularity because of inconvenience in using the ...

Despite the popularity of Rapid Rhino packs, there are no clear guidelines regarding the volume of air to be inflated when used in the management of epistaxis. The manufacturers suggest that subjective assessment by pilot cuff palpation is used to guide inflation. However, studies have clearly demonstrated that clinicians are ...

Early evidence from long-duration flights indicated general cardiovascular deconditioning including reduced arterial baroreflex gain. The current study investigated the spontaneous baroreflex and markers of cardiovascular control in 6 male astronauts living from 2 to 6-months on the International Space Station. Measurements were made from the finger arterial pressure waves during ...

The cerebral metabolic and vascular effects of intravenous norepinephrine have been shown in an animal model using somatosensory-evoked potentials (SSEPs). A case of intravenous norepinephrine resulting in a decrease in SSEP amplitude (of greater than 50%) despite no significant change in blood pressure, prior to cross-clamping during a carotid endarterectomy ...

The analysis of cerebrospinal fluid (CSF) pulse pressure waveform has been considered as a reliable method to investigate the intracranial system (ICS) dynamics. We have examined the morphological changes of the CSF pulse wave and of the sagittal sinus pressure (SSP) wave during a progressive increase in intracranial pressure (ICP) ...

Subacute and chronic cardiac adaptations to marathon running may increase risk for sudden death. Herein, it is proposed that cardiac arrhythmogenic remodeling resulting from prolonged strenuous exertion may also have a systemic vascular component. Marathon running reduces coronary pulse pressure and causes acute endothelial damage, possibly via altering concentrations of ...

A finite elements model was developed in order to evaluate the combined influence of the head lateral microseparation and the cup abduction angle on the contact pressure in Ceramic-on-Ceramic Total Hip Arthroplasty. The model's parameters were those used on the Leeds II hip simulator. A 32mm head diameter and a ...

Chimaera (Holocephali) are cartilaginous fishes with flexible operculi rather than external gill slits, suggesting ventilation occurs in a manner different from other fishes. We examined holocephalan ventilation morphology, behavior, and performance by anatomical investigations, high-speed video, and in vivo pressure measurements from the buccal and parabranchial cranial cavities in Hydrolagus ...

Bismuth ferrite (BiFeO$_3$) nanocrystalline films with the crystalline size of 27-40 nm have been grown on {\it c}-sapphire substrates under various oxygen pressures of 10$^{-4}$-1 Pa by pulsed laser deposition. The X-ray diffraction spectra show that the films are polycrystalline and present the pure rhombohedral phase. It was found that ...

The present study investigated factors that modify or affect arterial stiffness as assessed by brachial-ankle pulse wave velocity (baPWV) in the general population. Subjects had previously participated in a physical checkup program (n=911), and baPWV and urinary albumin and sodium excretion were also measured. Urine albumin was expressed as the ...

The AV delay optimization of biventricular pacemakers (cardiac resynchronization therapy) may maximize hemodynamic benefit but consumes specialist time to conduct echocardiographically. Noninvasive BP monitoring is a potentially automatable alternative, but it is unknown whether it gives the same information and similar precision (signal/noise ratio). Moreover, the immediate BP increment on ...

The cerebrospinal fluid (CSF) is contained in the brain ventricles and the cranial and spinal subarachnoid spaces. The mean CSF volume is 150ml, with 25ml in the ventricles and 125ml in subarachnoid spaces. CSF is predominantly, but not exclusively, secreted by the choroid plexuses. Brain interstitial fluid, ependyma and capillaries ...

Abstract Plantar pressure characteristics during fencing movements may provide more specific information about the influence of foot loading on overload injury patterns. Twenty-nine experienced fencers participated in the study. Three fencing-specific movements (lunge, advance, retreat) and normal running were performed with three different shoe models: Ballestra (Nike, USA), Adistar Fencing ...

OBJECTIVE:: Our objective was to compare response time, pressure time product as a reflection of work of breathing, and incidence and type of asynchrony in neurally vs. pneumatically triggered breaths in a spontaneously breathing animal model with resolving lung injury. DESIGN:: Prospective animal study. SETTING:: Experimental laboratory. SUBJECTS:: Male Yorkshire ...

OBJECTIVES:: During mechanical ventilation, air flows may play a role in mucus transport via two-phase gas liquid flow. The aim of this study was to evaluate effects of duty cycles and positive end-expiratory pressure on mucus clearance in pigs using mechanical ventilation, and to assess their safety. DESIGN:: Prospective randomized ...

We examined the influence of partial meniscectomy of 10 mm width on 10 human cadaveric knee joints, as it is performed during the treatment of radial tears in the posterior horn of the medial meniscus, on maximum contact pressure, contact area (CA), and meniscal hoop strain in the lateral and medial ...

OBJECTIVE: The photoplethysmographic (PPG) waveforms are modulated by the respiratory, cardiac and autonomic nervous system. Lower body negative pressure (LBNP) has been used as an experimental tool to simulate loss of central blood volume in humans. The aim of our research is to understanding PPG waveform changes during progressive hypovolemia. ...

Hypertension is a complex, multifactorial disease, and its development is determined by a combination of genetic susceptibility and environmental factors. Several mechanisms have been implicated in the pathogenesis of hypertension: increased activity of the sympathetic nervous system, overactivation of the renin-angiotensin aldosterone system (RAAS), dysfunction of vascular endothelium, impaired platelet ...

Background: Cerebral blood flow disturbance is a major contributor to brain injury in the preterm infant. The initiation of ventilation may be a critical time for cerebral haemodynamic disturbance leading to brain injury in preterm infants, particularly if they are exposed to inflammation in utero. We aimed to determine whether ...

Using a manikin, equivalent free-field sound pressure level measurements were made from the portable digital audio players of 219 subjects, aged 10 to 17 years (93 males) at their typical and "worst-case" volume levels. Measurements were made in different classrooms with background sound pressure levels between 40 and 52 dBA. ...

To determine the mechanical upper airway properties and compensatory neuromuscular responses to obstruction during propofol anesthesia in the follicular and luteal phases of the menstrual cycle. Prospective, randomized study. University-affiliated hospital. 12 premenopausal female volunteers for studies of upper airway collapse throughout their menstrual cycle during the follicular phase (6 ...

The effect of static pressure on acoustic emissions including shock-wave emissions from cavitation bubbles in viscous liquids under ultrasound has been studied by numerical simulations in order to investigate the effect of static pressure on dispersion of nano-particles in liquids by ultrasound. The results of the numerical simulations for bubbles ...

Several randomized controlled trials comparing negative-pressure therapy to standard wound care for chronic wounds have been published. Although these studies suggest a benefit for negative-pressure therapy, the majority of the review articles on the topic conclude that the studies are inconclusive. The authors conducted a quantitative meta-analysis of the effectiveness ...

To demonstrate feasibility of using MR elastography (MRE) to identify hypertensive changes in the abdominal aorta when compared with normotensives based on the stiffness measurements. MRE was performed on eight volunteers (four normotensives and four hypertensives) to measure the effective stiffness of the abdominal aorta. MRE wave images are directionally ...

Bubble dynamics is investigated numerically with special emphasis on the static pressure and the positional stability of the bubble in a standing sound field. The bubble habitat, made up of not dissolving, positionally and spherically stable bubbles, is calculated in the parameter space of the bubble radius at rest and ...

The activation of bubbles by an acoustic field has been shown to temporarily open the blood-brain barrier (BBB), but the trigger cause responsible for the physiological effects involved in the process of BBB opening remains unknown. Here, the trigger cause (i.e., physical mechanism) of the focused ultrasound-induced BBB opening with ...

Aortic stiffness increases with age and vascular risk factor exposure and is associated with increased risk for structural and functional abnormalities in the brain. High ambient flow and low impedance are thought to sensitize the cerebral microcirculation to harmful effects of excessive pressure and flow pulsatility. However, haemodynamic mechanisms contributing ...

OBJECTIVE: To test the hypothesis that an educational intervention would improve the resuscitator's ability to provide on-target volume ventilation during pulmonary compliance changes. STUDY DESIGN: Neonatal professionals (n = 27) ventilated an electromechanical lung model simulating a 3-kg baby while targeting a tidal volume of 4-6 mL/kg. In this preintervention ...

We report neutron scattering measurements of critical magnetic excitations in the weakly ferromagnetic superconductor UCoGe. The strong non-Landau damping of the excitations we observe, although unusual, has been found in another related ferromagnet, UGe_{2} at zero pressure. However, we also find that there is a significant anisotropy of the magnetic ...

To characterize hydraulic right ventricle (RV) afterload by pulmonary arterial pressure waveform analysis in an acute pulmonary hypertension (PH) model. Pulmonary artery (PA) flow and pressure were recorded in six anesthetized sheep. Acute isobaric PH was induced by phenylephrine (active) and PA mechanical constriction (passive). We estimated the amplitude of ...

Decrease in arterial compliance leads to an increased pulse pressure, as explained by the Windkessel effect. Pressure waveform is the sum of a forward running and a backward running or reflected pressure wave. When the arterial system stiffens, as a result of aging or disease, both the forward and reflected ...

BackgroundPulse pressure (an indirect measure of arterial stiffness) is a robust predictor of cardiovascular events, but its pathophysiology remains poorly understood. To gain insight into the pathophysiology of arterial stiffness we conducted an exploratory investigation of the associations of 47 circulating biomarkers in etiologic pathways of arteriosclerosis with brachial artery ...

Proprioceptive neuromuscular facilitation (PNF) is an attractive method to increase strength and proprioception of elderly individuals. However, a major clinical concern about the prescription of PNF is the belief that it can cause a cardiovascular overload, because it involves close-to-maximal loads and isometric contractions. Yet the acute effect of a ...

We have shown that obese Zucker rats with orthopedic trauma (OZT) exhibit a loss of arteriolar tone in skeletal muscle. We hypothesize that the loss of arteriolar tone in OZT blunts vasoconstrictor responses to hemorrhage, resulting in an impaired blood pressure recovery. Orthopedic trauma was induced with soft tissue injury ...

The exact role of arousal in central and peripheral hemodynamic responses to passive limb movement in humans is unclear but has been proposed as a potential contributor. Thus, we used a human model with no lower limb afferent feedback to determine the role of arousal on the hemodynamic response to ...

Abstract In this study, we compared the effects of accumulated and continuous running on resting arterial blood pressure. Ten normotensive/pre-hypertensive men, aged 25.0 ± 4.2 years (mean ± s), participated in three 2-day trials at least one week apart in a randomized, repeated-measures design. On Day 1, participants rested (control) or ran at 70% ...

BackgroundA phenomenon of endothelial impairment, independent of classical cardiovascular risk factors, has been observed in young people. We identified subjects with persistently reduced, or declining, endothelial function during adolescence and early adulthood, without apparent cardiovascular risk, and investigated the clinical relevance of this finding.MethodsEndothelial vasomotor responses were assessed by brachial ...

BackgroundThere is a high burden of premature cardiovascular disease (CVD) among African Americans. Measures of central aortic blood pressure (CASP) and wave reflection are predictive of CVD risk in adults, but there is a paucity of data regarding the relation of these measures to target organ damage among adolescents. The ...

Vocal attack time (VAT) is the time lag between the growth of the sound pressure signal and the development of physical contact of vocal folds at vocal initiation. It can be derived by a cross-correlation of short-time amplitude changes occurring in the sound pressure and electroglottographic (EGG) signals. Cantonese is ...

It was hypothesized that tongue-palate pressure generation might directly facilitate hyoid movement in swallowing through the anatomical connections of the extrinsic tongue muscles. If true, non-invasive measures of tongue-palate pressure timing might serve as a proxy measure of hyoid excursion. The timing relationships between events in the tongue-palate pressure and ...

A significant link has been reported between aortic stiffening and renal microvascular damage, but the underlying mechanism remains poorly understood. We hypothesized that alterations in central and renal hemodynamics are responsible for this link. In 133 patients with hypertension, pressure waveforms were recorded on the radial, carotid, femoral, and dorsalis ...

The waveform morphology of intracranial pressure (ICP) pulses holds essential informations about intracranial and cerebrovascular pathophysiological variations. Most of current ICP pulse analysis frameworks process each pulse independently and therefore do not exploit the temporal dependency existing between successive pulses. We propose a probabilistic framework that exploits this temporal dependency ...

The purpose of this study was to develop and validate a noninvasive pressure estimation technique based on subharmonic emissions from a commercially available ultrasound contrast agent and scanner, unlike other studies that have either adopted a single-element transducer approach and/ or use of in-house contrast agents. Ambient pressures were varied ...

Ambulatory blood pressure monitoring (ABPM) is more accurate than clinic and home monitoring in diagnosing hypertension. A diagnostic strategy for hypertension using ABPM following an initial raised clinic reading would reduce misdiagnosis and NHS costs. If the first and second measurements taken during a consultation are both > or = ...