Background  Esophageal motility abnormalities include a series of manometric findings that differ to a significant degree from findings in normal, asymptomatic volunteers. Methods  Current review summarizes conventional and high-resolution esophageal manometry criteria used to define and characterize esophageal hypertensive motility abnormalities. Key Results  In the conventional esophageal manometry classification scheme ...

Obesity is a risk factor for type 2 diabetes mellitus (DM) and is associated with chronic kidney disease. Activation of the renin-angiotensin-aldosterone system (RAAS) is common in obesity. The RAAS is an important mediator of hypertension. Mechanisms involved in activation of the RAAS in obesity include sympathetic stimulation, synthesis of ...

OBJECTIVES:: AMP-activated protein kinase (AMPK) activity may alter blood pressure by directly influencing vascular tone. The purpose of this study is to examine if these effects occur acutely in a model of hypertension. METHODS AND RESULTS:: Using distinct groups of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) we compare ...

A hallmark feature of Williams-Beuren Syndrome (WBS) is a generalized arteriopathy due to elastin deficiency, presenting as stenoses of medium and large arteries and leading to hypertension and other cardiovascular complications. Deletion of a functional NCF1 gene copy has been shown to protect a proportion of WBS patients against hypertension, ...

The computational fractal dimension of human colonic pressure activity acquired by a telemetric capsule robot under normal physiological conditions was studied using the box-counting method. The fractal dimension is a numeric value that quantifies to measure how rough the signal is from nonlinear dynamics, rather than its amplitude or other ...

Instrumented roll technology on Alexanderwerk(®) WP120 roller compactor was developed and utilized successfully for the measurement of normal stress on ribbon during the process. The effects of process parameters such as roll speed (4-12rpm), feed screw speed (19-53rpm), and hydraulic roll pressure (40-70bar) on normal stress and ribbon density were ...

The purpose of this experiment was to confirm the presence of positive subglottic air pressure during swallowing, known as deglutitive subglottic air pressure (DPsub), in a group of healthy individuals. We also sought to determine if respiratory system recoil is responsible for generating the pressure. Ten healthy volunteers underwent direct ...

Salt-sensitive hypertension is a characteristic of the metabolic syndrome. Given the links to cardiovascular events, the mechanisms underlying sodium metabolism may represent an important therapeutic target for this disorder. Angiotensin II (AII) is a key peptide underlying sodium retention. However, 5'AMP-activated protein kinase (AMPK) has also been reported to participate ...

BACKGROUND: The objective of the present study was to relate the dimensions and the intraluminal pressure of the pharyngoesophageal segment (PES) to the voice and speech proficiency of total laryngectomees with a tracheoesophageal prosthesis (TEP). METHODS: Twenty total laryngectomees with secondary TEP insertion underwent evaluation of voice and speech, manometry, ...

It is essential to select the optimal pressure gauge location for effective management and maintenance of water distribution systems. This study proposes an objective and quantified standard for selecting the optimal pressure gauge location by defining the pressure change at other nodes as a result of demand change at a ...

AIM: To investigate the effect of intravenous hydralazine infusion on maternal nitric oxide (NO) levels. METHODS: This pilot study comprised 40 (n = 40) gestations complicated with severe preeclampsia to whom maternal plasma NO levels were determined by chemiluminescence before and after hydralazine administration. Blood pressure values were concomitantly assessed. RESULTS: After ...

In this work, clusters of three or four spheres were used to examine intrusion pressure. Polytetrafluoroethylene (PTFE) or polyamide 66 (PA66) spheres were arranged horizontally to create a single pore. Liquid drops of water or ethylene glycol were gently introduced from above. If the spheres were too large, drops flowed ...

Due to its large pressure range of stability and inert nature, cubic boron nitride has been proposed as a potential pressure standard for high pressure experiments. It is extremely refractive upon compression, although its melting temperature is not known beyond 10 GPa. We apply first-principles molecular dynamics to evaluate the thermodynamics ...

Objective: Physiological effects of social evaluation are central in models of psychosocial influences on physical health. Experimental manipulations of evaluative threat evoke substantial cardiovascular and neuroendocrine responses in laboratory studies, but only preliminary evidence is available regarding naturally occurring evaluative threats in daily life. In such nonexperimental ambulatory studies, it ...

Experimentally, the effects of pressure on reaction rates are described by their pressure derivatives, known as volumes of activation. Transition state theory directly links activation volumes to partial molar volumes of reactants and transition states. We discuss a molecular dynamics method for the accurate calculation of molecular volumes, within which ...

Background  Recto-anal inhibitory reflex (RAIR) is an integral part of normal defecation. The physiologic characteristics of RAIR along anal length and anterior-posterior axis are unknown. The aim of this study was to perform topographic and vector-graphic evaluation of RAIR along anal canal using high definition manometry (HDM), and examine the ...

OBJECTIVE:: Although recent studies have indicated that both orthostatic hypotension and orthostatic hypertension (OHTN) independently predict cardiovascular events, the underlying mechanisms are still debatable. METHODS:: A total of 700 nondiabetic adults (43% men, age 64 years) were examined by orthostatic blood pressure (BP) test, carotid artery ultrasonography, and biochemical tests ...

ABSTRACT: BACKGROUND: Previous Italian paediatric blood pressure (BP) tables overestimated the prevalence of hypertension in adolescents of specific geographic areas, such as Sardinia, an island in the Mediterranean Sea. This is probably due to a not very homogeneous distribution of the subjects studied, most from Middle and Northern Italy, and ...

PURPOSE: The present study investigated lingual propulsive pressures generated in the normal swallow by the anterior and posterior lingual segments for various consistencies and maximum isometric tasks. METHOD: Lingual pressures for saliva, thin, and honey-thick liquid boluses were measured via the Iowa Oral Performance Instrument (IOPI) at both anteromedian and ...

Objectives.The aim of the present study was to investigate the prevalence of hypotension in older participants and to identify which 24-hour ambulatory blood pressure monitoring parameter better correlated with the occurrence of hypotension. METHODS: We studied 588 elderly participants (mean age 78.7 ± 7.1 years; 70% women) who underwent a ...

This paper presents a method for prediction of forces and displacements in the expansion screw of a modified mandibular Schwarz appliance and the contact pressure distributions on the mucosa during malocclusions treatment. A 3D finite element biomechanical model of the complete mandible-mucosa-apparatus set was built using computerised tomographic images of ...

A computational fluid dynamics model of a healthy, a stenotic and a post-operatory stented human trachea was developed to study the respiration under physiological boundary conditions. For this, outflow pressure waveforms were computed from patient-specific spirometries by means of a method that allows to compute the peripheral impedance of the ...

The assessment of cerebral autoregulation (CA) relies mostly on methods that modulate arterial blood pressure (ABP). Despite advances, the gold standard of assessment remains elusive and clinical practicality is limited. We investigate a novel approach of assessing CA, consisting of the intermittent application of thigh cuffs using square wave sequences. ...

BackgroundNoninvasive central blood pressure (BP) independently predicts mortality, but current methods are operator-dependent, requiring skill to obtain quality recordings. The aims of this study were first, to determine the validity of an automatic, upper arm oscillometric cuff method for estimating central BP (O(CBP)) by comparison with the noninvasive reference standard ...

PURPOSE: We investigated the contact pressure and area of the patellofemoral joint both before and after different meniscectomies to provide a biomechanical basis for selecting meniscectomy and its clinical application for meniscus injuries. METHODS: Six fresh cadaveric knees were used in the study. Using Staubli robots and an ultra-low-min-type pressure-sensitive ...

BACKGROUND: Short-term exposure to air pollution has been associated with changes in blood pressure (BP) and emergency hospital visits for hypertension, but little is known about effects of long-term exposure to traffic-related air pollution on BP and hypertension. OBJECTIVES: To study whether long-term exposure to air pollution is associated with ...

Oxygen is in many ways a unique element: It is the only known diatomic molecular magnet, and it exhibits an unusual O(8) cluster in its high-pressure solid phase. Pressure-induced molecular dissociation as one of the fundamental problems in physical sciences has been reported from theoretical or experimental studies of diatomic ...

OBJECTIVE: To compare the quality and accuracy of morning blood pressure (BP) readings as taken by automated office BP (AOBP) and morning home BP (mHBP) techniques using morning ambulatory BP (mABP) measurements as the gold standard. METHODS: A total of 139 individuals were included, 70 men and 69 women, mean ...

This article presents a computational and experimental study of contact pressure between six N95 filtering facepiece respirators (FFRs) and five newly developed digital headforms (small, medium, large, long/narrow, and short/wide). Contact interaction is simulated using the finite element method and validated by experiments using a pressure mapping system. The headform ...

Recently, endoscopic clip application devices have undergone redesign and improvements to optimize their clinical use and effectiveness. Initially designed for the treatment of bleeding nonvariceal lesions, these devices are also increasingly used for the closure of perforations, fistulas, and anastomotic leaks. Several clinical studies, both randomized and nonrandomized, have used ...

Object Shunt valves are intended to maintain physiological intracranial pressure (ICP). A variety of mechanisms have been designed to accomplish this goal but have had limited success. Siphoning, in particular, has been a problem not effectively solved by proposed or manufactured valves. Poor control of ICP results in headache, neurological ...

The association of physical activity (PA), measured 3 ways, and biomarkers were compared in a sample of adolescents. PA data were collected on 2 cohorts of adolescents (N = 700) in the Twin Cities, Minnesota, 2007-2008. PA was measured using 2 survey questions [Modified Activity Questionnaire (MAQ)], the 3-Day Physical ...

: The purpose of this study is to assess the utility of inferior orbital septum release compared with lateral canthotomy and inferior cantholysis for the treatment of orbital compartment syndrome. : An experimental study design using a cadaver model for orbital compartment syndrome was used to compare the efficacy of ...

OBJECTIVE: To study the prevalence of hypertension and its determinants among adolescents in rural areas of Wardha. METHODS: The cross-sectional study was carried out in villages under PHC Talegaon (Talatule) of Wardha district of central India. Out of total population of 37,946 in the PHC, 7435 were adolescents. For the ...

Accurate mechanics measurements during high frequency oscillatory ventilation (HFOV) facilitate optimizing ventilator support settings. Yet, these are substantially influenced by endotracheal tube (ETT) contributions which may dominate when leaks around uncuffed ETT are present. We hypothesized that 1) the effective removal of ETT leaks may be confirmed via direct comparison ...

Brominated flame retardants (BFRs) have been used in a variety of consumer products in the past four decades. The vapor pressures for three widely used BFRs, that is, tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), and octabromodiphenyl ethers (octaBDEs) mixtures, were determined using the Knudsen effusion method and compared to those of ...

Based on the Euler-Lagrange equation for ion density distribution in an inhomogeneous, charged, and hard-sphere fluid, a novel method is proposed to determine the interaction pressure between charged plates. The resulting expression is a sum of distinct physical contributions to the pressure, which involves different contributions to the single-particle direct ...

BACKGROUND: /st>This study was conducted to determine whether an alveolar recruitment strategy (ARS) applied during two-lung ventilation (TLV) just before starting one-lung ventilation (OLV) improves ventilatory efficiency. METHODS: /st>Subjects were randomly allocated to two groups: (i) control group: ventilation with tidal volume (VT) of 8 or 6 ml kg(-1) for ...

BACKGROUND: Betel quid is chewed by 600 million people worldwide and it has been linked to obesity and cardiovascular disease. The purpose of our study was to examine the prevalence and predictors of betel quid chewing in a rural area of Bangladesh, and determine its effects on body mass index ...

OBJECTIVES:: To determine the validity of electrical impedance tomography to detect and quantify the amount of tidal recruitment caused by different positive end-expiratory pressure levels in a porcine acute lung injury model. DESIGN:: Randomized, controlled, prospective experimental study. SETTING:: Academic research laboratory. SUBJECTS:: Twelve anesthetized and mechanically ventilated pigs. INTERVENTIONS:: ...

BACKGROUND: Bedside ultrasound has been suggested as a non-invasive modality to estimate central venous pressure (CVP). OBJECTIVE: Evaluate a simple bedside ultrasound technique to measure the diameter of the inferior vena cava (IVC) and correlate to simultaneously measured CVP. Secondary comparisons include anatomic location, probe orientation, and phase of respiration. ...

Background/Aims: Living donor nephrectomy can be associated with increases in blood pressure several years following the procedure, but the best method to assess blood pressure during the living donor evaluation process is unclear. Methods: Living kidney donors underwent casual clinic and ambulatory blood pressure monitoring (ABPM) and measurement of central ...

BACKGROUND: Pulmonary artery systolic pressure (PASP) is frequently measured noninvasively using transthoracic echocardiography. Normal values of PASP are based on studies performed in heterogeneous populations. The normal values of PASP in young healthy subjects are poorly defined. The aim of this study was to describe the distribution and clinical and ...

Dehiscence of median sternotomy wounds remains a clinical problem. Wall forces in thin-walled pressure vessels can be calculated by membrane stress theory. An ellipsoid pressure vessel model of sternal forces is presented together with its application for optimal wire placement in the sternum. Sternal forces were calculated by computational simulation ...

PURPOSE: We developed a prototype device using an automatically controlled inflatable penile cuff to measure bladder voiding pressure continuously and non-invasively in men. The purpose of this study was to validate the pressure measurements made by this device by comparison to those during simultaneous invasive PFS. METHODS: A device was ...

OBJECTIVE: To propose a novel noninvasive beat-to-beat arterial blood pressure measurement method based on the Korotkoff sound delay time (KDT) and evaluate its accuracy in preliminary experiments. METHODS: KDT decreases as the cuff pressure P deflates, which can be described by a function KDT=f (P). Actually, KDT is a function ...

INTRODUCTION: Non-Western cleaners have reported better psychosocial work environment but worse health compared with their Danish colleagues. The aim of this study was to compare the association between psychosocial work environment and hypertension among non-Western immigrant cleaners and Danish cleaners. METHODS: Two hundred and eighty-five cleaners from nine workplaces in ...

Purpose: Respiratory changes in the diameter of the inferior vena cava (IVC) have been validated as a measure of volume status and preload responsiveness during spontaneous breathing and mechanical ventilation. However, many intensive care patients are ventilated with triggered positive pressure ventilation (PPV). In this setting, there is no evidence ...

A convenient method has been developed, which allows for the direct transformation of aryl iodides into the corresponding carboxylic acid anhydrides via Pd-catalyzed carbonylation under atmospheric CO pressure.

BACKGROUND AND PURPOSE: Tested hypotheses from social action theory that (a) implicit and explicit measures of agonistic (social control) motives and transcendence (self-control) motives differentially predict cardiovascular risk; and (b) implicit motives interact with everyday self-regulation behaviors to magnify risk. METHODS: Implicit/explicit agonistic/transcendence motives were assessed in a multi-ethnic sample ...