Search Results
Results 51 - 100 of 1530
1 2 3 4 5 6 7 8 9 10 >
Zhang Minmin - - 2013
Pressure retarded osmosis (PRO) is an osmotically-driven membrane process that can be used to harvest salinity-gradient power. The PRO performance (both water flux and power density) can be severely limited by membrane fouling. The current study, for the first time, investigates PRO scaling in a bench-scale pressurized system using calcium ...
Lancioni Giulio E - - 2013
Objective: To assess whether a man with amyotrophic lateral sclerosis could benefit from using (a) a mouth pressure microswitch instead of an optic microswitch activated via head movement and (b) a special word prediction function within a text messaging system. Method: Initially, both microswitches were used for operating the text ...
Siebenmann Christoph C Center for Integrative Human Physiology, Institute of Physiology, University of Zurich Zurich, - - 2013
During acute altitude exposure tachycardia increases cardiac output (Q) thus preserving systemic O2 delivery. Within days of acclimatization, however, Q normalizes following an unexplained reduction in stroke volume (SV). To investigate whether the altitude-mediated reduction in plasma volume (PV) and hence central blood volume (CBV) is the underlying mechanism we ...
Ferreira Lucas Lima - - 2013
Objective: To analyze the outcomes of increased or decreased intracranial pressure and/or the decrease in cerebral perfusion pressure resulting from respiratory physiotherapy on critically ill patients admitted to the intensive care unit. Methods: Through a systematic review of the literature, clinical trials published between 2002 and 2012 were selected. The ...
Tang Sung-Chun - - 2013
Mannitol is commonly used in patients with increased intracranial pressure (ICP), but its effect on cerebrovascular pressure reactivity (CVPR) is uncertain. We analyzed the changes of pressure reactivity index (PRx) during the course of mannitol treatment. Twenty-one patients who received mannitol treatment for increased ICP were recruited prospectively. Continuous waveforms ...
Dias Celeste - - 2013
Plateau waves are common in traumatic brain injury. They constitute abrupt increases of intracranial pressure (ICP) above 40 mmHg associated with a decrease in cerebral perfusion pressure (CPP). The aim of this study was to describe plateau waves characteristics with multimodal brain monitoring in head injured patients admitted in neurocritical care. ...
Larsen Rikke Hebo - - 2013
To investigate the neuroprotective potential of ciclosporin during acute liver failure. We evaluated the effect of intrathecally administered ciclosporin on intracranial pressure, brain water content and aquaporin-4 expression in a rat model with acute hyperammonaemia. Twenty-four male Wistar rats with portacaval anastomosis were randomised into four groups receiving ciclosporin or ...
Ogawa Yuki - - 2013
Abstract Purpose: To develop a new structure and function of alternating pressure air mattress (APAM) which reduces discomfort during head-of-bed (HOB) elevation and evaluate the effectiveness. Method: An observational study (Study 1) and randomized crossover experiment (Study 2) were conducted in healthy adult volunteers. External force (interface pressure and shear ...
Wang Sheng-Hao - - 2013
The study was conducted to achieve early detection of increased compartment pressure by comparing the changes between the thickness and pressure within the musculofascial compartments after lower leg injury. We included cases of a lower-leg fracture between January and December 2007. Bilateral lower leg compartment pressure and thickness were measured ...
Cremer Antoine - - 2013
We validated against invasive measurements a measure of central SBP based on the QKD interval. The present objective is a comparison to the SphygmoCor device. A first cohort was used to redefine an algorithm for estimating ascending aorta SBP (cSBP) with respect to SphygmoCor. This algorithm was then tested in ...
Xia Huijing - - 2013
Rationale: Over-activity of the brain Renin Angiotensin System (RAS) is a major contributor to neurogenic hypertension. While over-expression of Angiotensin-Converting Enzyme type 2 (ACE2) has been shown to be beneficial in reducing hypertension by transforming Angiotensin (Ang)-II into Ang-(1-7), several groups have reported decreased brain ACE2 expression and activity during ...
Rostami Elham - - 2013
Modulation in ventilatory settings is one of the approaches and interventions used to treat and prevent secondary brain damage after traumatic brain injury (TBI). Here we investigate the effect of hyperoxia in combination with hypoventilation on brain oxygenation, metabolism and intracranial pressure. Twelve pigs were divided into three groups; group1-100% ...
Marchi Andrea - - 2013
It is unknown whether modified head-up tilt (MTILT) with inclination of the back rest, thigh rest and shank rest of 60, 0 and 15° respectively challenges autonomic control as assessed from beat-to-beat variability of heart period (HP) and systolic arterial pressure (SAP). In 15 healthy adult humans we found that ...
Olson Daiwai M - - 2013
Background Intracranial pressure is a frequent target for goal-directed therapy to prevent secondary brain injury. In critical care settings, nurses deliver many interventions to patients having intracranial pressure monitored, yet few data documenting the immediate effect of these interventions on intracranial pressure are available. Objective To examine the relationship between ...
Andresen Morten - - 2013
Object Intracranial pressure (ICP) monitoring is used extensively in clinical practice, and as such, the accuracy of registered ICP values is paramount. Clinical observations of nonphysiological changes in ICP have called into question the accuracy of registered ICP values. Subsequently, the authors have tried to determine if the ICP monitors ...
Schaeffer Anne Marie J - - 2013
We studied the pressure-induced superconductivity of BaLi4 up to 53 GPa by means of electrical resistivity in a diamond anvil cell. Superconductivity in BaLi4 is first observed at a pressure of 5.4 GPa with a superconducting critical temperature (Tc) of 4.5 K. Below 2 GPa, superconductivity is not observed above the minimum temperature achievable ...
Nwachuku Enyinna L - - 2013
There is clinical equipoise regarding whether neurointensive care unit management of external ventricular drains (EVD) in severe traumatic brain injury (TBI) should involve an open EVD, with continuous drainage of cerebrospinal fluid (CSF), versus a closed EVD, with intermittent opening as necessary to drain CSF. In a matched cohort design, ...
Skoglund Karin - - 2013
The neurological wake-up test (NWT) is used to monitor the level of consciousness in patients with traumatic brain injury (TBI). However, it requires interruption of sedation and may elicit a stress response. We evaluated the effects of the NWT using cerebral microdialysis (MD), brain tissue oxygenation (PbtiO2), jugular venous oxygen ...
Boltz Agnes - - 2013
In the choroid, there is evidence that blood flow does not only depend on ocular perfusion pressure (OPP), but also on absolute mean arterial pressure (MAP) and intraocular pressure (IOP). The present study included 40 healthy subjects to investigate whether such behavior is also found in the optic nerve head ...
Younan Youliana - - 2013
Purpose: Low-intensity focused ultrasound has been shown to stimulate the brain noninvasively and without noticeable tissue damage. Such a noninvasive and localized neurostimulation is expected to have a major impact in neuroscience in the coming years. This emerging field will require many animal experiments to fully understand the link between ...
Lee Sungjoon - - 2013
Presented here is a 36-year-old male with arterial hypertension who developed brainstem edema and intracranial hemorrhage. Magnetic resonance scan revealed diffuse brainstem hyperintensity in T2-weighted and fluid-attenuated inversion-recovery images, with an increase in apparent diffusion coefficient values. After a reduction in blood pressure, rapid resolution of the brainstem edema was ...
Jadischke Ron - - 2013
On-field measurement of head impacts has relied on the Head Impact Telemetry (HIT) System, which uses helmet mounted accelerometers to determine linear and angular head accelerations. HIT is used in youth and collegiate football to assess the frequency and severity of helmet impacts. This paper evaluates the accuracy of HIT ...
Balou Matina - - 2013
The primary aim of this study was to investigate the immediate effects of partial versus complete head rotation and chin tuck on pharyngeal swallowing pressures and durations in the pharynx and UES of normal, healthy adults. Ten individuals (3 men and 7 women; age range 54-76 years) served as participants. Solid-state ...
Vrettou Charikleia S - - 2013
In acute respiratory distress syndrome (ARDS) combined high-frequency oscillation (HFO) and tracheal gas insufflation (TGI) improves gas-exchange compared to conventional mechanical ventilation (CMV). We evaluated the effect of HFO-TGI on PaO2/fractional inspired O2 (FiO2) and PaCO2, systemic hemodynamics, intracranial pressure (ICP), and cerebral perfusion pressure (CPP) in patients with traumatic ...
Ravid Sarit - - 2013
Pseudotumor cerebri or idiopathic intracranial hypertension is characterized by normal spinal fluid composition and increased intracranial pressure in the absence of a space-occupying lesion. This study describes a subgroup of 10 patients with the same typical presenting symptoms (headache, vomiting, and papilledema) but without nuchal rigidity, meningeal signs, or change ...
Haubrich Christina - - 2013
To anticipate an increase in intra-cranial pressure (ICP), information about pressure-volume (p/v) compliance is required. ICP monitoring often fails at this task after head injury. Could a test that transiently shifts intra-cranial blood volume produce consistent information about the p/v relationship? Doppler flow velocities in the middle cerebral arteries (left: 80.8 ± 34.7 cm/s; ...
Cecchetti C - - 2013
Background: Currently there is no clear evidence of how changes in hemodynamic parameters are involved in the onset of neurogenic pulmonary edema. Aim of the study has been to correlate the principal variations of the intracranial pressure and volumetric hemodynamic parameters with the variations of extravascular lung water following severe ...
Scott Jonathan P R - - 2013
Repeated exposure to +Gz acceleration provokes cardiovascular adaptations of potential benefit to pilots' +Gz tolerance, but whether such changes actually improve human tolerance to +Gz acceleration is uncertain. This study assessed +Gz tolerance before and after repeated exposure to +Gz at two different intensities as the role of frequency of ...
Weenink Robert P RP Diving Medical Center, Royal Netherlands Navy, Den Helder, The Netherlands. - - 2013
Hyperbaric oxygenation is the accepted treatment for cerebral arterial gas embolism. Although earlier start of hyperbaric oxygenation is associated with better outcome, it is unknown how much delay can be tolerated before start of hyperbaric oxygenation. This study investigates the effect of hyperbaric oxygenation on cerebral function in swine when ...
Rickard A C - - 2013
Rising intracranial pressure (ICP) is a poor prognostic indicator in traumatic brain injury (TBI). Both mannitol and hypertonic sodium solutions are used to treat raised ICP in patients with TBI. This meta-analysis compares the use of mannitol versus hypertonic sodium solutions for ICP control in patients with TBI. Randomised clinical ...
Beauchet Olivier - - 2013
High blood pressure (BP) levels may be associated with brain volume reduction and may contribute to brain atrophy in key brain regions involved in cognition and susceptible to neurodegeneration in Alzheimer's disease. The purpose of this work was to systematically review and quantitatively synthesize the association of BP levels with ...
Brockman Erik C - - 2013
Polynitroxylated-pegylated hemoglobin (PNPH), a bovine hemoglobin decorated with nitroxide and polyethylene glycol moieties, showed neuroprotection vs. lactated Ringer's (LR) in experimental traumatic brain injury plus hemorrhagic shock (TBI+HS). Hypothesis: Resuscitation with PNPH will reduce intracranial pressure (ICP) and brain edema and improve cerebral perfusion pressure (CPP) vs. LR in experimental ...
Asgari Shadnaz - - 2013
BACKGROUND: Although abnormally high Lactate/Pyruvate ratio (LPR) could indicate cerebral ischemia for brain injury patients, there is a debate on what is primary factor responsible for LPR increase. METHODS: A data analysis experiment is taken to test whether any association between cerebral vasodilatation/vasoconstriction and LPR increase exists. We studied 4,316 ...
Selvan Veera - - 2013
Blast waves generated in the field explosions impinge on the head-brain complex and induce mechanical pressure pulses in the brain resulting in traumatic brain injury. Severity of the brain injury (mild to moderate to severe) is dependent upon the magnitude and duration of the pressure pulse, which in turn depends ...
Metheny Norma A - - 2013
Clinicians are confused by conflicting guidelines about the use of head-of-bed elevation to prevent aspiration and pressure ulcers in critically ill patients. Research-based information in support of guidelines for head-of-bed elevation to prevent either condition is limited. However, positioning of the head of the bed has been studied more extensively ...
Ahmad Rufa'i Adamu - - 2013
Background: Movement dysfunction may be expressed in terms of symptoms experienced in non-physiological postures, and head-down crooked kneeling (HDCK) is a posture frequently assumed by Muslims during prayer activities. The purpose of this study was to investigate the cardiovascular responses in the HDCK posture. Methods: Seventy healthy volunteers, comprising 35 ...
Jaeger Matthias - - 2013
BACKGROUND: To investigate the relationship between cerebrovascular pressure reactivity and cerebral oxygen regulation after head injury. METHODS: Continuous monitoring of the partial pressure of brain tissue oxygen (PbrO2), mean arterial blood pressure (MAP), and intracranial pressure (ICP) in 11 patients. The cerebrovascular pressure reactivity index (PRx) was calculated as the ...
Kiehna Erin N - - 2013
Object The intrathoracic pressure regulator (ITPR) is a novel noninvasive device designed to increase circulation and blood pressure. By applying negative pressure during the expiratory phase of ventilation it decreases intrathoracic pressure and enhances venous return, which increases cardiac output. It is possible that the ITPR may both decrease intracranial ...
Kristiansson Helena - - 2013
Elevated intracranial pressure (ICP) is an important cause of secondary brain injury, and a measurement of ICP is often of crucial value in neurosurgical and neurological patients. The gold standard for ICP monitoring is through an intraventricular catheter, but this invasive technique is associated with certain risks. Intraparenchymal ICP monitoring ...
Eskandari Ramin R Department of Neurosurgery, University of Utah, Salt Lake City, UT, - - 2013
Normal intracranial pressure (ICP) and cerebral perfusion pressure (CPP) have been identified as favorable prognostic factors in the outcome of patients with traumatic brain injuries (TBIs). Osmotic diuretics and hypertonic saline (HTS) are commonly used to treat elevated ICP in patients with TBI; however, sustained effects of repeated high-concentration HTS ...
Jiang Xue - - 2013
Pressure-induced bond type switching and phase transformation in glassy carbon (GC) has been simulated by means of Density Functional Theory (DFT) calculations and the Stochastic Quenching method (SQ) in a wide range of pressures (0-79 GPa). Under pressure, the GC experiences a hardening transition from sp- and sp(2)-type to sp(3)-type bonding, ...
Facchini Alberto - - 2013
INTRODUCTION: Posterior reversible encephalopathy syndrome (PRES) is a largely reversible disease with long-term favorable outcome. A minority of patients, however, may develop progressive cerebral edema and ischemia resulting in severe disability or death. We report a case of severe intracranial hypertension associated with PRES that was successfully treated according to ...
Fortrat Jacques-Olivier - - 2013
Heart rate spontaneously fluctuates despite homeostatic regulatory mechanisms to stabilize it. Harmonic and fractal fluctuations have been described. Non-harmonic non-fractal fluctuation has not been studied because it is usually thought that it is caused by apparatus noise. We hypothesized that this fluctuation looking like apparatus noise (that we call "noisy ...
Lazaridis Christos - - 2013
: Intracranial hypertension and cerebral edema are known contributors to secondary brain injury and to poor neurologic outcomes. Small volume solutions of exceedingly high osmolarity, such as 23.4% saline, have been used for the management of intracranial hypertension crises and as a measure to prevent or reverse acute brain tissue ...
Pelisch Nicolas - - 2013
Recent studies have suggested that blood-brain barrier (BBB) abnormalities are present from an early stage in patients exhibiting mild symptoms of cognitive impairment during the development of hypertension. There is also growing body of evidence suggesting the potential role of the renin-angiotensin system (RAS) in the pathogenesis of small-vessel disease ...
Gocze Ivan - - 2013
INTRODUCTION: Adopting the 45degrees semirecumbent position in mechanically ventilated critically ill patients is recommended, as it has been shown to reduce the incidence of ventilator-associated pneumonia. Although the benefits to the respiratory system are clear, it is not known whether elevating the head of the bed results in hemodynamic instability. ...
Yuan Qiang - - 2013
Abstract Objective: To prospectively investigate the predictive value of initial intracranial pressure (ICP) for refractory intracranial hypertension and outcomes in persons with diffuse traumatic brain injury (TBI). Methods: A prospective observational study was conducted in 107 adult persons with diffuse TBI (Marshall CT Class II-IV). Initial ICP was defined as ...
Schmutzhard Joachim - - 2013
Intracranial pressure usually is measured with invasive techniques. The usability of transient evoked otoacoustic emissions as non-invasive approach has been evaluated only once by Frank et al. This article presents the case of a Kenyan boy with tuberculous meningitis and an active malresorptive hydrocephalus. At this stage, the otoacoustic emissions ...
Faes Luca - - 2013
The transition from the supine to the upright position requires a reorganization of the mechanisms of cardiovascular control that, if not properly accomplished, may lead to neurally mediated syncope. We investigated how the patterns of causality between systolic arterial pressure (SAP) and cardiac RR interval were modified by prolonged head-up ...
Freimann Florian Baptist - - 2013
BACKGROUND: A standardized large animal model for controlled ICP manipulation within a relevant range and repetitive ICP measurements is missing. We sought to develop such a model on the base of controlled IPP changes induced by capnoperitoneum. METHODS: We utilized six female pigs (mean body weight 59.5 ± 18.4 kg) for experiments. A ...
1 2 3 4 5 6 7 8 9 10 >