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Pollock Neal W - - 2002
OBJECTIVE: To evaluate the performance of the System O2 portable non-pressurized delivery system (SysO2). This device produces oxygen through chemical reaction and might have utility for emergency/field use. METHODS: Performance was evaluated with 10 unmanned trials conducted under standard laboratory conditions. Measures included oxygen flow (mean and peak), total oxygen ...
Kleinsasser Axel - - 2002
At extreme altitude, air has an almost identical composition compared to air at sea level, while its pressure is altitude-dependently lower. When supplementary oxygen is used to achieve an acceptable inspiratory pressure of oxygen (PI(O2)) during climbing, the barometric pressure difference to lower altitudes is not compensated for. In this ...
Cogliano M S - - 2002
We investigated the necessity for administration of supplementary oxygen to mothers undergoing elective Caesarean section under spinal anaesthesia. Sixty-nine women undergoing elective Caesarean section were randomly allocated to one of three groups to be given either oxygen (40%) by facemask, air by facemask or oxygen at 2 l x min(-1) ...
Huang Wei-Cho - - 2002
Aeration plays an important role in the production of glycerol by fermentation with yeast. Effective aeration depends on a number of factors, such as amount of air, fineness of air dispersion, rate of agitation, and time of gas-liquid contact. This investigation dealt with the effect of periodic variation in gas ...
Bobick T G - - 2001
This study investigated the effect of wearing a back belt on subjects' heart rate, oxygen consumption, systolic and diastolic blood pressure, and respiratory frequency during asymmetric repetitive lifting. Thirty subjects with materials-handling experience utilized three different belts (ten subjects per belt). Subjects completed six 30-min lifting sessions--three while wearing a ...
Schenkman K A - - 2001
Critical intracellular myocardial oxygen tension was determined by optical spectroscopic measurement of myoglobin oxygen saturation in crystalloid-perfused guinea pig hearts. Accurate end-point determinations of the maximally oxygenated and deoxygenated myoglobin were made. Hearts were subjected to a steady decrease in perfusate oxygen tension while left ventricular developed pressure, maximal left ...
Weind K L - - 2001
To maintain tissue oxygenation, normal aortic valves contain a vascular bed where tissue thickness is greatest. Avascular "living" tissue-engineered heart valves have been proposed, yet little information exists regarding the magnitude of valve tissue metabolic activity or oxygen requirements. We therefore set out to measure the oxygen diffusivity (DO(2)) and ...
Farmery A D - - 2001
A simple mathematical model of electron flow along the mitochondrial respiratory cytochrome assembly and the transfer of electrons to molecular oxygen is presented. First, an expression for the current-voltage relationship for a biological oxygen electrode is derived, and from this the relationship between oxygen consumption rate and oxygen partial pressure ...
Massabuau J C - - 2001
The primitive atmosphere where aerobic life started on earth was hypoxic and hypercapnic. Remarkably, an adaptation strategy whereby O(2) partial pressure, P(O(2)), in the arterial blood is maintained within a low and narrow range of 1-3 kPa, largely independent of inspired P(O(2)), has also been reported in modern water-breathers. In ...
Trujillo-Roldán M A - - 2001
The effect of oscillating dissolved oxygen tension (DOT) on the metabolism of an exopolysaccharide-producing bacteria (Azotobacter vinelandii) was investigated, particularly on the mean molecular weight (MMW) of the alginate produced. Sinusoidal DOT oscillations were attained by manipulating the oxygen and nitrogen partial pressures at the inlet of a 1.0 L ...
Read M R - - 2001
Hypoxemia is a commonly observed complication during the chemical immobilization of wild ruminants. If severe and left untreated, it can predispose animals to arrhythmias, organ failure, and capture myopathy. The following prospective study was designed to measure the degree of hypoxemia in wapiti that were immobilized with a combination of ...
Fernandes C J CJ - - 2001
Red blood cell (RBC) transfusion is commonly used to increase oxygen transport in patients with sepsis. However it does not consistently increase oxygen uptake at either the whole-body level, as calculated by the Fick method, or within individual organs, as assessed by gastric intra-mucosal pH. This study evaluates the hemodynamic ...
Chiang B B - - 2001
The aim of this study is to investigate blood lactic acid levels after the placement of the AbioCor implantable replacement heart to determine whether circulatory support with the AbioCor device results in adequate tissue perfusion. Tissue perfusion may not be adequate during cardiac surgery, especially with the use of cardiopulmonary ...
Webber D M - - 2001
We report the results of an experiment designed to investigate the feasibility of using differential pressure to estimate the swimming speed and metabolic rate of Atlantic cod (Gadus morhua). Seven cod were fitted with a miniature differential pressure sensor mounted on one side of the caudal peduncle immediately anterior to ...
Sussmane J B - - 2001
OBJECTIVE: To evaluate hemodynamic stability and gas exchange in a neonatal animal model of pumpless arteriovenous extracorporeal membrane oxygenation (AV-ECMO) with extracorporeal shunt flow of up to 15% of cardiac output during variable ventilation and oxygenation. DESIGN: Prospective study. SETTING: Research laboratory in a hospital. SUBJECTS: Seven lambs (5.5 +/- ...
Solås A B - - 2001
OBJECTIVE: To determine whether reoxygenation with 21% oxygen is preferable to 100% oxygen in normalizing extracellular levels of excitatory amino acids in the brains of hypoxic-ischemic newborn piglets and to compare this model of combined hypoxemia-ischemia to a previously used model of global hypoxemia. DESIGN: Prospective, randomized animal study. SETTING: ...
Platzack B - - 2001
We investigated the effects of vagal reductions in O(2) delivery on oxygen consumption (VO(2)) in the anesthetized freshwater turtle Trachemys scripta. Specifically, these experiments tested the hypothesis that reductions in arterial oxygen partial pressure (PO(2)) and/or systemic oxygen transport (SOT) trigger a metabolic downregulation. During electric stimulation of the efferent ...
Tobias S W - - 2001
This study examines a method to rapidly rewarm the core using total liquid ventilation with warmed, oxygenated perfluorocarbon. Yucatan miniswine were splenectomized and surgically implanted with telemetry devices to transmit electrocardiographic response, arterial pressure, and core temperature. Hypothermia (core temperature = 25.9 +/- 1.3 degrees C) was induced by placing ...
Fioretto J R - - 2001
AIM: To establish a protocol for the early introduction of inhaled nitric oxide (iNO) therapy in children with acute respiratory distress syndrome (ARDS) and to assess its acute and sustained effects on oxygenation and ventilator settings. PATIENTS AND METHODS: Ten children with ARDS, aged 1 to 132 months (median, 11 ...
Frey B - - 2001
The World Health Organisation recommends nasopharyngeal catheters as a safe and efficient method of oxygen administration in infants. However, little is known about the mechanisms of the improvement in oxygenation. The aim of the present study was to determine whether nasopharyngeal oxygen therapy produces positive end-expiratory pressure (PEEP). Nine spontaneously ...
Donnelly S - - 2001
Erythropoietin is distinct among the hematopoietic growth factors because it is produced primarily in the kidneys rather than the bone marrow. The kidney functions as a critmeter in that it senses oxygen tension and extracellular volume. By regulating red cell mass through erythropoietin and plasma volume through excretion of salt ...
Banasik J L - - 2001
OBJECTIVE: The purpose of this study was to assess the effect of lateral positions on tissue oxygenation in critically ill patients. DESIGN: The study design was prospective and quasi-experimental, and we used a convenience sample with random assignment. SETTING: The study took place in the intensive care unit and the ...
Trines S A - - 2001
OBJECTIVE: We investigated whether an increased oxygen cost of contractility and/or a decreased myofibrillar efficiency contribute to oxygen wastage of stunned myocardium. Because Ca(2+)-sensitizers may increase myofibrillar Ca(2+)-sensitivity without increasing cross-bridge cycling, we also investigated whether EMD 60263 restores myofibrillar efficiency and/or the oxygen cost of contractility. METHODS: Regional fiber ...
Hansen U - - 2001
Cartilage cells are normally studied under atmospheric pressure conditions and without loading. However, since cartilage exists in a condition of reduced oxygen and intermittent hydrostatic pressure we hypothesized lower partial oxygen pressures (PO2) and different intermittent hydrostatic pressures (IHP) would increase articular chondrocyte proliferation and matrix production and to stabilize ...
Ohlsson A - - 2001
BACKGROUND: Implantable sensors that monitor haemodynamics over time may be useful in patients with heart failure. This multicentre study assessed the feasibility of a system that has one sensor measuring absolute pressure and another measuring mixed venous oxygen saturation (SvO(2)). Both sensors were mounted on leads that were implanted in ...
Chetta A - - 2001
BACKGROUND AND AIM OF THE WORK: In patients with interstitial lung disease (ILD), the six-minute walk test (6MWT) has been rarely used, and up till now, the relationship between outcome measures of the test and baseline lung function has not yet been examined. Therefore, we assessed walk distance, oxygen desaturation, ...
Birchard G F - - 2001
The interrelationship of metabolic rate and cardiovascular function has been well documented in vertebrates through allometric analyses. However, similar studies are lacking in insects. Unlike vertebrates, the cardiovascular system of insects does not play a significant role in oxygen transport. A comparison of the interrelationship in insects and vertebrates might ...
Tservistas M - - 2001
Investigations of enzymatic reactions in supercritical CO(2) are often hindered by the high pressure involved in these processes, making reaction monitoring extremely difficult. This paper describes the implementation of a fiber optic based oxygen sensor into a high pressure reactor for supercritical carbon dioxide. The sensor is pressure resistant, working ...
Meisner F G - - 2001
BACKGROUND: Normovolemic hemodilution is an effective strategy to limit perioperative homologous blood transfusions. The reduction of hematocrit related to hemodilution results in reduced arterial oxygen content, which initially is compensated for by an increase in cardiac output and oxygen extraction ratio. To increase the efficacy of hemodilution, a low hematocrit ...
Cakar N - - 2001
OBJECTIVE: To determine the time required for the partial pressure of arterial oxygen (PaO2) to reach equilibrium after a 0.20 increment or decrement in fractional inspired oxygen concentration (FIO2) during mechanical ventilation. SETTING: A multi-disciplinary ICU in a university hospital. PATIENTS AND METHODS: Twenty-five adult, non-COPD patients with stable blood ...
Bormann G - - 2001
We report a 5-month-old infant with cutis marmorata telangiectatica congenita (CMTC) without associated abnormalities and unusual hemicorporal vascular markings. Laser Doppler fluxmetry of the involved skin, carried out for the first time, and the measurement of the transcutaneous partial pressure of oxygen indicate a functional disturbance, which may be the ...
Möller H E - - 2001
Hyperpolarized (3)He spin-lattice relaxation was investigated in the guinea pig lung using spectroscopy and imaging techniques with a repetitive RF pulse series. T(1) was dominated by interactions with oxygen and was used to measure the alveolar O(2) partial pressure. In animals ventilated with a mixture of 79% (3)He and 21% ...
Hentschel R - - 2001
Measurements of functional residual capacity (FRC) by the nitrogen (N(2)) washout technique yield low N(2) signals in neonates and preterm infants, especially when they are on high fractions of inspired oxygen (FiO(2)). Thus, recorded values often lie in the low range of detectability. We hypothesized that using heliox instead of ...
Vesovic D - - 2001
Ergometrics, using both treadmill (T) and bicycle-ergometer (B), plays an important role in assessing physical work capacity. In addition to the other important parameters (blood pressure, heart rate, oxygen consumption, oxygen and carbon dioxyde-partial pressure in blood, etc.), it is of interest to follow, measure and compare values of certain ...
Ding Y - - 2001
Lead-induced hypertension has previously been shown to be closely associated with an increase in reactive oxygen species in low lead (100 ppm)-treated rats. The present study has attempted to define the specific moiety involved by noting the blood pressure (BP), reactive oxygen species (MDA-TBA), hydroxyl radical, and nitrotyrosine responses to ...
Lin S S - - 2001
Wet air oxidation (WAO) of a prepared direct dye solution was tested by using the CoAIPO4 -5 catalyst. Addition of CoAIPO4 -5 could effectively improve rate of color removal and the activation energy of color removal could decrease from about 110 kJ/mole to about 75 kJ/mole as the catalyst loading ...
Nelson N - - 2001
BACKGROUND: The haemodynamic as well as the ventilatory consequences of mechanical ventilation can be harmful in critically ill neonates. Newly developed ventilatory lung protective strategies are not always available immediately and in an acute situation the haemodynamic changes caused by mechanical ventilation can affect the oxygen delivery considerably. We report ...
Rymarz E - - 2001
The aim of the paper was assessing the influence of polarizing GIK mixture on the selected indicators of acid-base equilibrium in patients with acute myocardial infarction treated fibrinolytically. The patients had arterial blood taken in order to check pH, partial pressure of oxygen and carbon dioxide, and the content of ...
Lustbader D - - 2000
Novel therapies for the next decade include hyperbaric oxygen, nitric oxide, and extracorporeal membrane oxygenation. Hyperbaric oxygen delivers oxygen at a pressure greater than one atmosphere and has been used in diseases ranging from decompression sickness to carbon monoxide poisoning. Inhaled nitric oxide, a potent vasodilator, has been used in ...
Devlin J W - - 2000
OBJECTIVE AND IMPORTANCE: Nimodipine is commonly used to improve neurological outcomes after subarachnoid hemorrhage. Although nimodipine reportedly has high specificity for the cerebral vasculature, adverse systemic effects such as hypotension have been described. This case report describes a patient with traumatic subarachnoid hemorrhage who experienced two episodes of previously undescribed, ...
Brodholt JP - - 2000
Although aluminium is the fifth most abundant element in the Earth's mantle, its effect on the physical properties of perovskite, the main mineral phase in the lower mantle, has largely been ignored. It is becoming clear, however, that many properties of MgSiO3 perovskites are remarkably sensitive to small amounts of ...
Benner J D - - 2000
PURPOSE: To study three patients with glaucoma caused by sickle cell hyphema who were successfully treated with transcorneal oxygen therapy. METHODS: Case reports. Three patients with increased intraocular pressure caused by sickle cell hyphema were administered transcorneal oxygen therapy using humidified oxygen at a flow rate that ranged from 1 ...
Meyer B - - 2000
The objective of this study was to generate data that allow for estimation of the validity of oxygen saturation (SO2) values in superficial cortical capillaries as calculated by a microreflectometric system (EMPHO II). Capillary SO2 and tissue oxygen pressure (PtO2) were measured simultaneously in the cortex of n = 13 ...
Ickx B E - - 2000
BACKGROUND: The maintenance of adequate tissue oxygenation during acute anemia depends on an increase in both cardiac output and tissue oxygen extraction. This study tested the hypothesis that anesthesia blunts the cardiac output response associated with acute normovolemic hemodilution. METHODS: Forty patients undergoing major abdominal surgery were prospectively randomized to ...
Hoffman W E - - 2000
Brain tissue oxygen reactivity is a measure of the increase in tissue oxygen pressure (PtO2) relative to an increase in arterial oxygen pressure (PaO2). Clinical studies show that PtO2 reactivity is increased after cerebral injury. However, the impact of patient ventilation on these measures is not known. We determined whether ...
Maitre B - - 2000
Fiberoptic bronchoscopy (FOB) may worsen oxygenation and clinical status in severely hypoxemic patients. We conducted a prospective, randomized double-blind trial to compare the delivery of continuous positive airway pressure (CPAP) as a tool for maintaining oxygenation during FOB, to the delivery of oxygen only. Thirty consecutive patients who needed FOB ...
Kuwagata Y - - 2000
When systemic oxygen delivery (DO2) is reduced, oxygen consumption (VO2) is maintained until a critical level is reached (DO2crit). Sepsis is thought to shift DO2crit to the right and lengthen the supply-dependent portion. We tested the effect of interleukin (IL)-1beta, which is one of the key cytokines related to sepsis, ...
Müller M - - 2000
BACKGROUND: Pulmonary resection may result in a reduction in arterial oxygen pressure as well as in cardiac output. Since cardiac index, oxygen delivery, and oxygen consumption are considered as important determinants of patients' outcome, we evaluated the effects of dopexamine and volume loading on cardiopulmonary variables in patients undergoing pulmonary ...
Secomb T W - - 2000
OBJECTIVE: Simulations of oxygen delivery by a three-dimensional network of microvessels in rat cerebral cortex were used to examine how the distribution of partial pressure of oxygen (PO2) in tissue depends on blood flow and oxygen consumption rates. METHODS: Network geometry was deduced from previously published scanning electron micrographs of ...
Wohlrab J - - 2000
In the present study, the acute vasoactive effect of a dried hydrophilic extract of garlic with 600 mg active substance (Alliosan) was investigated in 10 healthy volunteers. Laser-Doppler fluxmetry, video capillary microscopy and transcutaneous partial pressure of oxygen measurements were used for the objective assessment of functional and morphological parameters. ...
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