We examined the value of impedance monitoring in measuring bolus volume compared with videoesophagram. Eighty consecutive subjects were studied with simultaneous impedance-manometry-videoesophagram. A catheter with both an impedance electrode pair and a pressure transducer at four sites (5, 10, 15, 20 cm above lower esophageal sphincter) was passed per nares. Six ...

BACKGROUND:Acute normovolemic hemodilution (ANH) is an alternative to blood transfusion in surgeries involving blood loss. This experimental study was designed to evaluate whether pulse pressure variation (PPV) would be an adequate tool for monitoring changes in preload during ANH, as assessed by transesophageal echocardiography. METHODS: Twenty-one anesthetized and mechanically ventilated ...

BACKGROUND: Hindfoot trauma including ankle and subtalar sprains may be followed by osteochondral lesions and persisting pain originating from posttraumatic arthritis. HYPOTHESIS: "Acute severe" supination sprains and "mild supination sprains with increasing ligamentous incompetence" of the hindfoot lead to medial ankle and subtalar stress concentrations that may contribute to osteochondral ...

ABSTRACT: BACKGROUND: The Bramwell-Hill model describes the relation between vascular wall stiffness expressed in aortic distensibility and the pulse wave velocity (PWV), which is the propagation speed of the systolic pressure wave through the aorta. The main objective of this study was to test the validity of this model locally ...

OBJECTIVE: To describe for the first time a method of recording of Eustachian tube (ET) function by simultaneous and synchronous endoscopy and sonotubometry and explore its advantages compared with the performance of these tests independently. STUDY DESIGN: Observational study. SETTING: Academic tertiary medical center. PATIENTS: Eighteen healthy subjects. INTERVENTION: Endoscopic ...

The present study investigated processing strategies and matrix effects on antioxidant capacity (AC) and polyphenols (PP) content of fruit-based beverages: 1) Strawberry powder (Str) + Dairy, D-Str; 2) Str + Water, ND-Str; 3) Dairy + no Str, D-NStr. Beverages were subjected to high temperature-short time (HTST) and high pressure processing ...

The pressure dependence of the Curie temperature T(C)(P) in La(0.75)Ca(0.25)MnO(3) was determined by neutron diffraction up to 8 GPa, and compared with the metallization temperature T(IM)(P) (Postorino et al 2003 Phys. Rev. Lett. 91 175501). The behavior of the two temperatures appears similar over the whole pressure range, suggesting a key ...

The cerebrovascular time constant (τ) describes the time to establish a change in cerebral blood volume after a step transient in arterial blood pressure (ABP). We studied the relationship between τ, ABP, intracranial pressure (ICP), and end-tidal carbon dioxide concentration (EtCO(2)). Recordings from 46 anaesthetized, paralysed and ventilated New Zealand ...

Obstructive sleep apnoea (OSA) has been linked to hypertension in sleep clinic populations, but little is known about the symptom profile of undiagnosed OSA in hypertensive outpatients in primary care. To explore characteristics associated with undiagnosed OSA in hypertensive primary care patients. Cross-sectional design, including 411 consecutive patients (52% women), ...

There are very few data on the relationship between systolic blood pressure (SBP), diastolic blood pressure (DBP), arterial compliance, and left ventricular structure and function, particularly left ventricular hypertrophy (LVH), in the very elderly (>75 years). SBP and arterial stiffness increase with age, and the question is: which of the ...

Previous studies have shown a good agreement between central venous pressure (CVP) measurements from catheters placed in superior vena cava and catheters placed in the abdominal cava/common iliac vein. However, the influence of intra-abdominal pressure on such measurements remains unknown. We conducted a prospective, observational study in a tertiary teaching ...

Baroreflex failure results in wide excursions of blood pressure and heart rate. We report two cases that developed severe postoperative hypertension after radical neck dissection. Carotid sinus denervation during neck dissection may be the cause of the reflex hypertension once general anesthesia-induced vasodilatation has ended.

The health systems designed to cater for patients with chronic illnesses like hypertension have not fully evaluated the burden of long term therapy and its effect on patient outcome. This study assessed the financial implication and cost effectiveness of hypertension treatment in a rural Nigerian town. A chart review of ...

The purpose of this study was to identify the effects of essential oil inhalation on the 24-hour ambulatory blood pressure (BP) and salivary cortisol level in 83 prehypertensive and hypertensive subjects. The experimental group (n = 28) was asked to inhale an essential oil blended with lavender, ylang-ylang, marjoram, and ...

  To determine the effect of cholecystectomy on the motility of the sphincter of Oddi (SO).   Pressures of common bile duct (CBD), SO motility and its response to bolus injections of cholecystokinin (CCK, 20 ng/kg and 100 ng/kg) were detected respectively by manometry in eight Beagle dogs before and after cholecystectomy. ...

We assessed the relationship between pulse pressure and intermediate cardiovascular phenotypes in a middle-aged cohort with high prevalence of hypertension. It has been suggested that central pulse pressure (cPP) is a better predictor of cardiovascular outcome than peripheral pulse pressure (pPP), particularly in the elderly. Yet, it is unclear if ...

While moderate and vigorous leisure time physical activities are well documented to decrease the risk for cardiovascular disease, several studies have demonstrated an increased risk for cardiovascular disease in workers with high occupational activity. Research on the underlying causes to the contrasting effects of occupational and leisure time physical activity ...

To develop a new noninvasive approach to quantify left ventricular (LV) pressures using subharmonic emissions from microbubbles, an ultrasound scanner was used in pulse inversion grayscale mode; unprocessed radiofrequency data were obtained with pulsed wave Doppler from the aorta and/or LV during Sonazoid infusion. Subharmonic data (in dB) were extracted ...

The purpose of this research was to investigate the influence of sock addition and removal on residual-limb fluid volume in people using prosthetic limbs. We used bioimpedance analysis to measure residual-limb extracellular fluid volume on 28 transtibial amputee subjects during 30 min test sessions. Upon addition of a one-ply polyester ...

This study aimed to compare foot plantar pressure distribution while jogging and running in highly trained adolescent runners. Eleven participants performed two constant-velocity running trials either at jogging (11.2±0.9km/h) or running (17.8±1.4km/h) pace on a treadmill. Contact area (CA in cm(2)), maximum force (F(max) in N), peak pressure (PP in ...

BACKGROUND: Despite routine ultrasound mapping of upper extremity arteries and veins, early thrombosis and nonmaturation remain frequent complications following vascular access (VA) surgery. Besides vascular diameters, brachial artery stiffness is assumed to play an important role; however, reproducibility of measurements has never been established. The purpose of this study was ...

BACKGROUND:: The current standard for arterial stiffness assessment, aortic pulse wave velocity (aPWV), is measured at diastolic pressure. Arterial stiffness, however, is pressure dependent. At the carotid artery level, the degree of this dependency can be quantified as the difference (ΔPWV) between systolic and diastolic (cPWVd) carotid pulse wave velocity. ...

Background:  Studies of dietary sodium on vascular function and blood pressure (BP) in normotensive volunteers have shown conflicting results. There is very limited data available on the effect of chronic sodium loading from a low-sodium diet to a high-sodium diet on vascular function and BP in normotensive volunteers. Objective:  To ...

Pressure has a profound effect on the paraelectric and ferroelectric properties of perovskite crystals. In this paper we theoretically investigate the effect of pressure on the cubic-to-tetragonal phase transition and on the soft mode dynamics of some classical perovskite crystals: BaTiO(3), PbTiO(3), and KNbO(3). We use a model consisting of ...

BACKGROUND: /st>In the intensive care unit, intra-abdominal hypertension (IAH) is a frequently encountered, life-threatening condition. The aim of this animal study was to evaluate the effect of IAH on left ventricular (LV) relaxation (i.e. the active phase of diastole). METHODS: /st>Seven male rabbits were anaesthetized before mechanical ventilation. A 20 ...

The study addressed the hypothesis that soluble epoxide hydrolase (sEH) inhibition, which increases cardiovascular protective epoxyeicosatrienoic acids (EETs), exerts beneficial effects in an established chronic heart failure (CHF) model. In CHF rats, left ventricular (LV) function, perfusion and remodeling were assessed using MRI and invasive hemodynamics after 42-day (starting 8days ...

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 ...

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 ...

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 ...

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, ...

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 ...