Objective: To evaluate the influence of air pressure, water flow rate, and pulse frequency on the removal speed of enamel and dentin as well as on their surface morphology. Method and Materials: Twenty-four bovine incisors were horizontally cut in slices. Each sample was mounted on an experimental assembly, allowing precise ...

Background and study aims: Endoscopic submucosal injection of epinephrine may cause systemic effects on the cardiovascular system. The aim of this experimental study was to assess systemic hemodynamic changes after submucosal injection of epinephrine during upper gastrointestinal endoscopy in a porcine model.Methods: Measurements were taken from 12 pigs under general ...

The pressure induced structural and mechanical properties of nanocrystalline ZnO, ZnS, ZnSe, GaN, CoO, CdSe, CeO(2), SnO(2), SiC, c-BC(2)N, and β-Ga(2)O(3) with different grain sizes have been analyzed under high pressures. The molecular dynamics simulation model has been used to compute isothermal equation of state, volume collapse and bulk modulus ...

Previously studies have shown that nature improves mood and self-esteem and reduces blood pressure. Walking within a natural environment has been suggested to alter autonomic nervous system control, but the mechanisms are not fully understood. Heart rate variability (HRV) is a non-invasive method of assessing autonomic control and can give ...

Absolute (pulsed laser photolysis, 4 - 639 Torr N2 or air, 240-357 K) and relative rate methods (50 and 760 Torr air, 296 K) were used to measure rate coefficients k1 for the title reaction, OH + C4H5N -> products (R1). Whilst the pressure and temperature dependent rate coefficient is ...

We summarize the latest results on the rapid changes that are occurring to Arctic sea ice thickness and extent, the reasons for them, and the methods being used to monitor the changing ice thickness. Arctic sea ice extent had been shrinking at a relatively modest rate of 3-4% per decade ...

The severity of injury to cardiovascular autonomic pathways following clinical spinal cord injury (SCI) can be evaluated with spectral analyses. Whether this technique provides a translatable assessment of cardiovascular autonomic function in rodent SCI is unknown. Beat-to-beat blood pressure and pulse interval were measured in male rats one month after ...

OBJECTIVE: To describe physiologic alterations in runners competing in a 160-km endurance event and to evaluate the utility of weight and blood pressure measurements in the assessment of runner performance. DESIGN: Prospective cohort study. SETTING: 160-km ultramarathon. PARTICIPANTS: Ninety-one of the 101 participants in the 2010 Tahoe Rim 100 Mile ...

1. Indirect interactions resulting from changes in organismal traits such as behaviour [i.e. trait-mediated indirect interactions (TMIIs)] are widespread in biological communities, yet few studies have explored the potential for mutualisms to initiate TMIIs. 2. This study used a combination of behavioural observations and manipulative field experiments to investigate potential TMIIs resulting ...

There is little information about the hemodynamic and exercise-response implications of renin-angiotensin system blocker combinations. After a 3-week lisinopril (L; 40 mg/day) run-in, carvedilol (C; 20 then 40 mg/day) or valsartan (V; 160 then 320 mg/day) was added to L for 4 weeks each in a forced-titration, random order-entry crossover ...

The significance of white-coat hypertension in older persons with isolated systolic hypertension remains poorly understood. We analyzed subjects from the population-based 11-country International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes database who had daytime ambulatory blood pressure (BP; ABP) and conventional BP (CBP) measurements. After excluding ...

ABSTRACT: INTRODUCTION: Cyclic alveolar recruitment (R/D) is an important mechanism of ventilator associated lung injury. In experimental models this process can be measured with high temporal resolution by detection of respiratory-dependent oscillations of the paO2 ([increment] paO2). A previous study showed that end-expiratory collapse can be prevented by an increased ...

High-pressure behavior of tetramethylsilane, one of the Group IVa hydrides, was investigated by Raman scattering measurements at pressures up to 142 GPa and room temperature. Our results revealed the phase transitions at 0.6, 9, and 16 GPa from both the mode frequency shifts with pressure and the changes of the ...

Convective clearance during hemodialysis (HD) improves dialysis outcomes in kidney failure patients, and, thus, trials have been undertaken to increase convective mass transfer, which is directly related to internal filtration rates. The authors designed a new hemodialyzer to increase the internal filtration rates, and here describe the hemodialytic efficacy of ...

In situ characterization of phase transitions and direct microscopic observations of a low-melting ionic liquid, 1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM][BF4]), has been performed in details by Raman spectroscopy. Compression of [BMIM][BF4] was measured under hydrostatic pressure up to about 30.0 GPa at room temperature by using a high pressure diamond anvil ...

BACKGROUND AND PURPOSE: Stroke-related tissue pressure increase in the core and penumbra determines regional cerebral perfusion pressure (rCPP) defined as a difference between local inflow pressure and venous or tissue pressure, whichever is higher. We previously showed that venous pressure reduction below the pressure in the core causes blood flow ...

BACKGROUND:: Direct identification of second systolic peaks of peripheral upper limb pulses (pSBP2) has been used to represent central systolic blood pressure (cSBP), but its accuracy at low SBP was questioned. OBJECTIVES:: We investigated the relationship of pSBP2 with characteristics of central pressure waveforms. METHODS:: High-fidelity central aortic and right ...

BackgroundTo perform the first European overview of educational inequalities in the use of blood pressure and cholesterol screening.MethodsData were obtained on the use of screening services according to educational level from nationally representative cross-sectional surveys in Belgium, Czech Republic, Denmark, Estonia, Finland, Hungary, Italy, Latvia and Lithuania. Screening rates were ...

Plate tectonics, which shapes the surface of Earth, is the result of solid-state convection in Earth's mantle over billions of years. Simply driven by buoyancy forces, mantle convection is complicated by the nature of the convecting materials, which are not fluids but polycrystalline rocks. Crystalline materials can flow as the ...

INTRODUCTION: Intraosseous (IO) access is an important alternative to conventional intravenous access when intravenous access is difficult. METHODS: A nonrandomized, prospective, observational study comparing flow rates with distal and proximal tibia IO access in adults using the EZ-IO-powered drill device. The proximal tibia was the first site of insertion, and ...

OBJECTIVE: Previous work studying vegetarians has often found that they have lower blood pressure (BP). Reasons may include their lower BMI and higher intake levels of fruit and vegetables. Here we seek to extend this evidence in a geographically diverse population containing vegans, lacto-ovo vegetarians and omnivores. DESIGN: Data are ...

Background. The purpose of the study was to determine the associations between blood pressure, body mass index and smoking habits, recorded at routine health check-ups with the occupational health officer, and life expectancy and cause-specific mortality through several decades. Material and methods. Participants in the Linseed Oil Study were followed ...

Baroreflex sensitivity (BRS) is reduced in humans during snoring, however the mechanisms are unknown. We used an anaesthetised rabbit induced snoring (IS) model, to test: (1) whether IS was associated with reduced BRS; and (2) if snoring related vibration transmission to peri-carotid tissues influenced BRS levels. BRS was quantified using ...

We show experimentally that gaseous CO₂ intercalates into the interlayer space of the synthetic smectite clay Na-fluorohectorite at conditions not too far from ambient. The mean interlayer repetition distance of the clay when CO₂ is intercalated is found to be for the conditions 20 °C and 15 bar. The magnitude ...

ABSTRACT: Study Design. This in vitro human cadaveric study measured adjacent-level kinematics following posterior cervical decompression and fixation.Objective. Quantify adjacent-level changes in ROM and intradiscal pressure following posterior cervical decompression and fixation.Summary of Background Data. Optimal length of instrumentation following posterior decompression is unclear. Longer posterior cervical fixation constructs may ...

Effortful swallow and the Mendelsohn maneuver are two common strategies to improve disordered swallowing. We used high-resolution manometry (HRM) to quantify the effects of these maneuvers on pressure and timing characteristics. Fourteen normal subjects swallowed multiple, 5-ml water boluses using three techniques: normal swallow, effortful swallow, and the Mendelsohn maneuver. ...

The objective of the study was to assess the prognostic value of variability in home-measured blood pressure (BP) and heart rate (HR) in a general population. We studied a representative sample of the Finnish adult population with 1866 study subjects aged 45-74 years. BP and HR self-measurements were performed on ...

PURPOSE: The purpose of the study was to determine if the conditions during scuba diving without exercise (e.g. submersion, restricted breathing) stimulate the activities of the sympathoadrenergic system and the hypothalamic-pituitary-adrenal axis. This might facilitate panic reactions in dangerous situations. METHODS: 15 experienced rescue divers participated in 3 experiments with ...

BACKGROUND: Living kidney donor selection has become more liberal with acceptation of hypertensive donors. Here, we evaluate short-term and 1- and 5-year renal outcome of living kidney donors with preexistent hypertension. METHODS: We compared outcome of hypertensive donors by gender, age, and body mass index with matched control donors. Hypertension ...

A series of laboratory experiments was conducted under realistic environmental conditions to test the ability of the Diffusive Gradient in Thin film (DGT) technique to mimic monomethylmercury (MMHg) bioaccumulation by a clam (Macoma balthica, Baltic clam). Using isotope enriched MMHg as tracers, bioavailability was determined by comparing the rate of ...

Little is known about transient effects of foods and nutrients on reactivity to mental stress. In a randomized crossover study of healthy adults (n = 20), we measured heart rate variability (respiratory sinus arrhythmia), blood pressure, and other hemodynamic variables after three test meals varying in type and amount of fat. Measurements ...

Objective  To investigate the influence of a dexmedetomidine constant rate infusion (CRI) in horses anaesthetized with isoflurane. Study design  Prospective, randomized, blinded, clinical study. Animals  Forty adult healthy horses (weight mean 491 ± SD 102 kg) undergoing elective surgery. Methods  After sedation [dexmedetomidine, 3.5  μg  kg(-1) intravenously (IV)] and induction IV (midazolam 0.06 mg kg(-1) ...

Decisions based on invasive functional diagnostic measurements are often made in the setting of fluctuating hemodynamic variables that may alter resting or hyperemic measurements. The purpose of this investigation is to analyze the effect of myocardial contractility (CY) on invasive functional parameters. We hypothesize that the pressure drop coefficient (CDPe; ...

To examine associations between neuroretinal rim area, pressure related factors and anthropometric parameters in a population-based setting. The population-based cross-sectional Beijing Eye Study 2006 included 3251 subjects with an age of 45+ years. The participants underwent a detailed ophthalmic examination. Exclusion criteria for our study were high myopia of more ...

Although several studies have shown that enhanced cardiovascular reactivity can predict hypertension development in African Americans, these findings have not been consistent among all studies examining reactivity and hypertension susceptibility. This inconsistency may be explained by the influence of anxiety (state and trait) on the blood pressure response to stress. ...

High hydrostatic pressure (HHP) treatment can eliminate cholesteatoma cells from explanted human ossicles prior to re-insertion. We analyzed the effects of HHP treatment on the microbial flora on ossicles and on the planktonic and biofilm states of selected isolates. Twenty-six ossicles were explanted from cholesteatoma patients. Five ossicles were directly ...

INTRODUCTION AND OBJECTIVES: To analyze the factors associated with knowledge and control of hypertension in the adult population of the Canary Islands (18-75 years). METHODS: We recruited a random sample of the general population aged ≥18 years. Hypertension was defined as systolic/diastolic blood pressure ≥140/90 mmHg or known hypertension (self-declared, ...

Global left ventricular (LV) isovolumic relaxation rate has been characterized: 1) via the time-constant of isovolumic relaxation τ or 2) via the logistic time-constant τ(L). An alternate kinematic method, characterizes isovolumic relaxation (IVR) in accordance with Newton's Second Law. The model's parameters - stiffness E(k), and damping/relaxation μ result from ...

ABSTRACT: BACKGROUND: Ingestion of a meal increases the blood flow to the gastrointestinal organs and affects the heart rate (HR), blood pressure and cardiac output (CO), although the mechanisms are not known. The aim of this study was to evaluate the effect of endogenously released glucose, insulin, glucagon-like peptide 1 ...

The prevalence of urinary symptoms increases with age, and is a significant source of distress, morbidity, and expense in the elderly. Recent findings suggest symptoms in the aged may be the result of sensory dysfunction, rather than abnormalities of detrusor performance. We therefore tested the hypothesis that in-vivo detrusor voiding ...

Molecular dynamics simulations evidenced a structural transition of the flexible MIL-53(Cr) under a relatively moderate applied pressure ∼50 MPa. The incorporation of CO(2) within its porosity significantly shifts the onset of such a transformation at lower pressure while it decreases the bulk modulus of this solid.

PURPOSE: The purpose of this study is to assess the relationship between tongue strength and rate of articulation in two speech tasks, diadochokinetic rates and reading aloud, in healthy men and women between 20 and 78 years of age. METHOD: Diadochokinetic rates were measured for the syllables /p/, /t/, /k/, ...

OBJECTIVE: Cardiovascular reactivity is associated with carotid artery intima-media thickness as early as childhood. Excess cardiovascular responses relative to the metabolic demand during psychological stress have been proposed as a mechanism for this association. However, it is not known whether excess cardiovascular responses in relation to the metabolic demand correlate ...

Background  We previously showed that changes in intra-abdominal content induce a volume-dependent muscular response of the anterior abdominal wall and the diaphragm. We aimed to determine the contribution of the thorax to abdominal accommodation and the influence of the intra-abdominal expansion rate. Methods  Gas (1440 mL total load) was infused into ...

Autogenerative High Pressure Digestion (AHPD) is a novel configuration of anaerobic digestion, in which micro-organisms produce autogenerated biogas pressures up to 90 bar with >90% CH4-content in a single step reactor (Lindeboom et al., 2011). The less than 10% CO2-content was postulated to be resulting from proportionally more CO2 dissolution ...

BACKGROUND: Emotional stress is considered a risk factor for cardiovascular events, the underlying pathophysiology remains unclear. METHODS: To evaluate how emotional stress effects hemodynamics, thirteen healthy German soccer fans (mean 37.6years, 24-56years) were studied during live TV coverage of the finals with German national team participation (GP) and the respective ...

Chronic pressure-mediated baroreflex activation suppresses renal sympathetic nerve activity. Recent observations indicate that chronic electric activation of the carotid baroreflex produces sustained reductions in global sympathetic activity and arterial pressure. Thus, we investigated the effects of global and renal specific suppression of sympathetic activity in dogs with sympathetically mediated, obesity-induced ...

To assess an impact of vascular risk factors on ambulatory blood pressure measurement (ABPM) in the elderly, we followed up a population-based cohort of men from 68 until 82 years, when 104 survivors underwent ABPM. Results. At age 68, hypertension and high clinic blood pressure (CBP) did not predict ABPM ...

AIM OF THE STUDY: This work aims to investigate the effects of HSYA on cardiac function and blood pressure. MATERIALS AND METHODS: To evaluate changes in mean arterial pressure (MAP) and heart rate (HR), different groups of pentobarbitone-anesthetized normotensive and spontaneously hypertensive rats (SHR) were treated with intravenous HSYA (0.1-3mg/kg). ...

In heart failure, diastolic dysfunction is responsible for about 50% of the cases, with higher prevalence in women and elderly persons and contributing similarly to mortality as systolic dysfunction. Whereas the cardiac systolic diagnostics in ventricular assist device patients from pump parameters have been investigated by several groups, the diastolic ...