Search Results
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Ahmed Salim - - 2008
Although oximetric analysis of blood from the right heart chambers is the most commonly used method for assessing the presence of intracardiac left-to-right shunting, it sometimes provides misleading information because a patient with a left-to-right shunt in only 1 location sometimes manifests a significant oxygen step-up (1) in >1 chamber ...
van Bel Frank - - 2008
This review focuses on the clinical use of near infrared spectroscopy (NIRS) to assess brain oxygenation by the tissue oxygenation index (TOI), and monitoring regional cerebral oxygen saturation (rScO(2)), cerebral fractional tissue oxygen extraction (cFTOE), which is derived from rScO(2), and systemic oxygen saturation. Its precision and pitfalls are discussed. ...
Jung Christian - - 2008
Extracorporeal membrane oxygenation (ECMO) provides pulmonary and circulatory support in critically ill patients (Cardiopulmonary Resuscitation, Acute Respiratory Distress Syndrome, or low output syndrome). Hemodynamic parameters are used for evaluation of the macrocirculation, while the microcirculation is monitored by blood-lactate as a surrogate parameter. We evaluated the microcirculation by orthogonal polarization ...
Rosenthal Guy - - 2008
OBJECTIVE: Previous studies have demonstrated that periods of low brain tissue oxygen tension (PbtO2) are associated with poor outcome after head trauma but have primarily focused on cerebral and hemodynamic factors as causes of low PbtO2. The purpose of this study was to investigate the influence of lung function on ...
Arieli Ran - - 2008
INTRODUCTION: Humans may be accidentally trapped in a confined atmosphere in which oxygen availability is limited. If acclimation would extend survival, hypoxic acclimation in confined spaces would be recommended. METHODS: After hypoxic acclimation, an immature pig was transferred into an experimental sealed chamber. The O2, CO2, chamber temperature, and pressure ...
Li Jia - - 2008
OBJECTIVE: Induced hypometabolism may improve the balance between oxygen delivery and consumption and may help sustain tissue viability in critically ill patients with low cardiac output state. Inhaled hydrogen sulfide (H2S) has been shown to induce a suspended animation-like state in mice with a 90% decrease in oxygen consumption. We ...
Ronda Luca - - 2008
The determination of accurate oxygen-binding curves for heme-containing proteins is a demanding task. In fact, great care is required in the (i) preparation of accurate gas mixtures at defined oxygen partial pressures, (ii) precise measurement of changes in protein absorbance, (iii) calculation of the fraction of oxygen-containing sites, and (iv) ...
Bateman Ryon M - - 2008
OBJECTIVE: Although nitric oxide (NO) is a known regulator of cardiovascular function, the effect of NO overproduction during sepsis on capillary oxygen transport and local tissue oxygen consumption is not well understood. The objectives of this study were to determine whether sepsis-induced NO overproduction increased capillary stopped-flow and modulated tissue ...
Wilson David F DF Department of Biochemistry and Biophysics, Medical School, University of Pennsylvania, Philadelphia, PA 19104, - - 2008
A new Oxyphor (Oxyphor G3) has been used to selectively determine the oxygen pressure in interstitial (pericellular) spaces. Oxyphor G3 is a Pd-tetrabenzoporphyrin, encapsulated inside generation 2 poly-arylglycine (AG) dendrimer, and therefore is a true near infrared oxygen sensor, having a strong absorption band at 636nm and emission near 800nm. ...
Abdu Amgad - - 2008
The right-shifted oxyhemoglobin dissociation curve of sickle cell disease (SCD) has been thought to result in abnormally low arterial oxygen saturation (S(o)(2)), even when oxygen partial pressure (P(o)(2)) is normal. However, without polymer formation (minimal under normoxic conditions), HbS oxygen affinity is normal. We hypothesized that in SCD, in vivo ...
van Bommel Jasper - - 2008
Organ systems do not respond uniformly to changes in systemic oxygen delivery because of global and local redistributive mechanisms. We hypothesized that progressive hemodilution would evoke a different response in the microvascular oxygenation of the heart compared with kidney and gut. To evaluate this hypothesis, we studied the effect of ...
Hiltebrand Luzius B - - 2008
BACKGROUND: Oxidative killing is the primary defense against surgical pathogens; risk of infection is inversely related to tissue oxygenation. Subcutaneous tissue oxygenation in obese patients is significantly less than in lean patients during general anesthesia. However, it remains unknown whether reduced intraoperative tissue oxygenation in obese patients results from obesity ...
Lai Wei - - 2008
The AC impedance response of mixed ionic and electronic conductors (MIECs) exposed to a chemical potential gradient is derived from first principles. In such a system, the chemical potential gradient induces a gradient in the carrier concentration. For the particular system considered, 15% samarium doped ceria (SDC15) with Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-delta) (BSCF) ...
Ganter Michael T - - 2007
STUDY OBJECTIVES: To continuously measure arterial blood gases (ABGs), to calculate the percentage of anticipated changes over time, and to develop recommendations for sampling frequencies of arterial blood gases in patients undergoing thoracoscopic surgery. DESIGN: Prospective, observational clinical trial. SETTING: University hospital. PATIENTS: 43 consecutive elective patients undergoing thoracoscopic surgery ...
Denault André - - 2007
Near-infrared spectroscopy (NIRS) is a technique that can be used as a noninvasive and continuous monitor of the balance between cerebral oxygen delivery and consumption. The authors develop and propose an algorithm for the use of NIRS based on optimizing factors that can affect cerebral oxygen supply/demand. These factors are ...
Golczewski T - - 2007
AIMS: The aim of this study was to supplement a previously developed virtual respiratory system (RS) with gas exchange and gas transfer in airways and circulation (GETAC); and to analyze arterial blood oxygenation during apnea when pure O2 is the ambient gas, with and without extracorporeal CO2 removal (ER), for ...
Liang Yunfeng - - 2007
The transformation of SiO2 from low pressure tetrahedral phases into denser octahedral phases takes place via the collapse of the oxygen sublattice into a close-packed arrangement. The transition paths and the resulting products are known to be affected by the presence of anisotropic stresses, which are difficult to control, so ...
Wong Vivian K - - 2007
The mechanism of heel pressure ulcers after hip surgery is not entirely understood. The purpose of this one-group, prospective, repeated-measures design study was to examine how the external pressure of the bed surface affects heel skin oxygen tension in adults on the first 3 days after hip surgery. Transcutaneous oxygen ...
Belzberg Howard - - 2007
OBJECTIVES: The aims of the present study were to describe the temporal hemodynamic and oxygen transport patterns of patients with head injuries as well as the patterns of those who became brain dead to better understand the role of underlying central regulatory hemodynamic mechanisms and ultimately to improve rates of ...
Gennser M - - 2008
Raised internal pressure in a distressed submarine increases the risk of bubble formation and decompression illness after submarine escape. The hypothesis that short periods of oxygen breathing before submarine escape would reduce decompression stress was tested, using Doppler-detectable venous gas emboli as a measure. Twelve goats breathed oxygen for 15 ...
Putnam Brant - - 2007
Alterations in regional tissue perfusion may precede global indications of shock. This study compared regional tissue oxygenation saturation (StO2) using near-infrared spectroscopy with standard hemodynamic and biochemical variables in 40 patients undergoing cardiopulmonary bypass (CPB). Mean arterial pressure, cardiac output, oxygen delivery, arterial blood gases, and lactate were recorded at ...
El-Khatib Mohamad F - - 2007
PURPOSE: We describe the use of noninvasive bilevel positive airway pressure (BiPAP) in a critically ill, hypoxemic and morbidly obese patient for preoxygenation prior to rapid sequence induction of anesthesia. CLINICAL FEATURES: A critically ill morbidly obese patient (body mass index: 49 kg.m(-2)) was scheduled for urgent laparoscopic cholecystectomy. Preoxygenation ...
Nunes Silvia - - 2007
BACKGROUND: Deep sedation is often necessary after major reconstructive plastic surgery in the face and neck regions to prevent sudden spontaneous movements capable of inflicting mechanical injury to the transplanted musculocutaneous flap(s). An adequate positioning may help to optimize oxygenation and perfusion of the transplanted tissues. We hypothesized that dexmedetomidine, ...
Miyamoto J - - 2007
OBJECTIVE: The present study revealed the changes in cerebral oxygen metabolism before and after ventriculo-peritoneal shunt (VPS) using (15)O positron emission tomography ((15)O-PET). METHODS: Eight patients with idiopathic normal pressure hydrocephalus (i-NPH) underwent VPS. A (15)O-PET study was undertaken before and approximately 3 months after VPS. In five patients, the ...
Lurman Glenn J - - 2007
Much previous research has demonstrated the plasticity of myoglobin concentrations in both cardiac and skeletal myocytes in response to hypoxia and training. No study has yet looked at the effect of thermal acclimation on myoglobin in fish. Atlantic cod (Gadus morhua) from two different populations, i.e. the North Sea and ...
Dekura Haruhiko - - 2007
It was previously predicted that doping Li into semiconducting boron (α-rhombohedral) brought metallic character to the matrix and possibility a high-T(c) superconductor. However, experiments show that Li doping of α-rhombohedral boron is difficult. In this paper, the potential for Li doping of boron is re-examined using the ab initio pseudopotential ...
Dani Carlo - - 2007
AIM: To evaluate the hypothesis that increasing levels of nasal continuous positive airway pressure (NCPAP) may decrease cerebral blood volume (CBV) and cerebral oxygenation in infants with gestational age (GA) less than 30 weeks. METHODS: We prospectively studied a cohort of preterm infants treated with NCPAP using near-infrared spectroscopy (NIRS). ...
Cunningham Peter - - 2007
In this study, we tested the hypothesis that elite dinghy sailing is a whole-body, dynamic, repeated-effort sport, and that increased heart rate and oxygen consumption reflect its dynamic element. Six elite male Laser sailors (mean age 19.7 years, s = 1.82; height 1.81 m, s = 0.03; body mass 78.0 ...
Chin Kelly M - - 2007
BACKGROUND: IV epoprostenol is a highly effective therapy for pulmonary arterial hypertension (PAH). However, monitoring the efficacy and adjusting the dose of epoprostenol often requires serial invasive hemodynamic measurements. This study investigated whether superior vena cava (SVC) oxygen saturation measured from the indwelling catheter and brain natriuretic peptide (BNP) level ...
Muhm J Michael - - 2007
BACKGROUND: Acute mountain sickness occurs in some unacclimatized persons who travel to terrestrial altitudes at which barometric pressures are the same as those in commercial aircraft during flight. Whether the effects are similar in air travelers is unknown. METHODS: We conducted a prospective, single-blind, controlled hypobaric-chamber study of adult volunteers ...
Raven J A - - 2007
It has recently been shown that, in subthylakoid particles prepared using detergent, there is inhibition of oxygen production reactions in photosynthesis by thermodynamic feedback from oxygen build-up, with 50% inhibition at 230 kPa partial pressure of oxygen. This article presents a comprehensive analysis of laboratory data on the effects of ...
Inuzuka Kazunori - - 2007
BACKGROUND: Perfluorochemicals (PFC) are chemical substances that have a higher oxygen solubility under hyperbaric oxygen (HBO) pressure. This study investigated the effect of cold HBO-PFC/University of Wisconsin (UW) solution on preservation of rat small intestinal graft. METHODS: We manufactured an air-tight, pressure-resistant tank made of stainless steel with high thermal ...
Hua Ling - - 2007
Enzymatic oxidation of lactose to lactobionic acid (LBA) by a carbohydrate oxidase from Microdochium nivale was studied in a pilot-scale batch reactor of 600 L working volume using a rotary jet head (RJH) for mixing and mass transfer (Nordkvist et al., 2003, Chem Eng Sci 58:3877-3890). Both lactose and whey ...
Díaz-Barrera A - - 2007
The influence of oxygen transfer rate (OTR) on the molecular mass of alginate was studied. In batch cultures without dissolved oxygen tension (DOT) control and at different agitation rates, the DOT was nearly zero and the OTR was constant during biomass growth, hence the cultures were oxygen-limited. The OTR reached ...
Knoll Arnd - - 2007
This study demonstrates the applicability of pressurized stirred tank bioreactors for oxygen transfer enhancement in aerobic cultivation processes. The specific power input and the reactor pressure was employed as process variable. As model organism Escherichia coli, Arxula adeninivorans, Saccharomyces cerevisiae and Corynebacterium glutamicum were cultivated to high cell densities. By ...
Hiltebrand L B - - 2007
BACKGROUND AND OBJECTIVE: Insufficient blood flow and oxygenation in the intestinal tract is associated with increased incidence of postoperative complications after bowel surgery. High fluid volume administration may prevent occult regional hypoperfusion and intestinal tissue hypoxia. We tested the hypothesis that high intraoperative fluid volume administration increases intestinal wall tissue ...
Limbo Sara - - 2007
The aim of this work was to investigate the reaction kinetics of beta-carotene in an aqueous medium as a function of exposure to commercial lights (halogen and fluorescent sources) and oxygen partial pressures. The evolution of the pigment concentration, the changes in color, and the accumulation of a volatile compound ...
Rodway George W - - 2007
INTRODUCTION: The most effective treatment for high altitude sickness is prompt descent. However, rapid descent is sometimes impossible and alternative solutions are desirable. Supplemental oxygen at ambient pressure and hyperbaric oxygen in a hyperbaric tent have both been demonstrated to improve symptoms and increase arterial oxygenation (SaO2) in those with ...
Yu Mihae - - 2007
Transcutaneous pressure of oxygen (PtcO2) correlates with arterial pressure of oxygen (PaO2) in nonshock states, but in shock states, PtcO2 approximates cardiac output with no response to increasing fraction of inspired oxygen (FiO2) and PaO2. An incremental change of more than 21 mmHg in PtcO2 in response to an FiO2 ...
Wittenberg Jonathan B - - 2007
The heart, red skeletal muscles and the nitrogen-fixing legume root nodule function in steady states of high oxygen influx, partial oxygenation of cytoplasmic myoglobin or leghemoglobin and correspondingly low oxygen partial pressure. Here, we ask: what conditions are required at the surface of actively respiring, state III, tightly coupled mitochondria ...
Kiekkas Panagiotis - - 2007
OBJECTIVE: To investigate the effect of fever episodes and fever characteristics on heart rate, arterial blood pressure and arterial oxygen saturation of intensive care unit (ICU) patients. METHODS: This was a prospective study conducted in the medical-surgical ICU of General University Hospital of Patras, Greece. All patients who were consecutively ...
Bak Z - - 2007
AIM: The aim of the study was to examine the central and peripheral cardiovascular adaptation and its coupling during increasing levels of hyperoxaemia. We hypothesized a dose-related effect of hyperoxaemia on left ventricular performance and the vascular properties of the arterial tree. METHODS: Oscillometrically calibrated arterial subclavian pulse trace data ...
Liu Z J - - 2007
The thermodynamic and elastic properties of CaSiO(3) perovskite are investigated at high pressures and temperatures using the plane wave pseudopotential method within the local density approximation. The athermal elastic moduli of CaSiO(3) perovskite are calculated as a function of pressure up to 200 GPa. The calculated results are in excellent agreement ...
Golub Aleksander S - - 2007
A scanning phosphorescence quenching microscopy technique, designed to prevent accumulated O(2) consumption by the method, was applied to Po(2) measurements in mesenteric tissue. In an attempt to further increase the accuracy of the measurements, albumin-bound probe was topically applied to the tissue and an objective-mounted pressurized bag was used to ...
Berenbrink Michael - - 2007
The ability of some fishes to inflate their compressible swimbladder with almost pure oxygen to maintain neutral buoyancy, even against the high hydrostatic pressure several thousand metres below the water surface, has fascinated physiologists for more than 200 years. This review shows how evolutionary reconstruction of the components of such ...
Melsom M N - - 2007
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by airway narrowing that is most frequently inhomogeneously distributed. Ventilation/perfusion (V/Q) mismatch may explain much of the hypoxemia in patients with advanced disease. A potential treatment strategy would be to redistribute blood flow to well-ventilated lung regions in order to decrease V/Q ...
Rossi Pascal - - 2007
OBJECTIVE: In critically ill patients, a decrease in whole body oxygen consumption under hyperoxia has been reported and this could be related to hyperoxia-induced arterial changes. We investigated changes in brachial artery circulation and tone during short-term hyperoxic ventilation in septic patients. DESIGN AND SETTING: Prospective clinical study in the ...
Wei Z H - - 2007
Metabolism and hatchability are impaired when chicken eggs laid at sea level are incubated at high altitude. The Tibetan chicken is an excellent local poultry breed that inhabits altitudes of 2,900 m and has a hatchability of approximately 75% at that altitude. To understand how Tibetan chicken embryos develop successfully ...
Varotsos P - - 2007
The pressure-volume relation in sodium has been measured up to 100 GPa using high-resolution angle-dispersive synchrotron x-ray diffraction (Hanfland et al 2002 Phys. Rev. B 65 184109). In the light of these data, we show that a model suggested long ago (e.g., Varotsos et al 1978 J. Phys. C: Solid State ...
Rytter D - - 2007
In heart muscle from mammals, catecholamines frequently evoke an oxygen waste and reduce efficiency. It was examined if this also applies to fish in which heart muscle activity is often restricted by oxygen availability. In the isolated perfused heart from rainbow trout, adrenaline (0.5 microM) increased power output by approximately ...
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