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Results 301 - 350 of 973
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Li Gai-Ru - - 2003
Oxygen is the most effective dynamic quencher in liquid room temperature phosphorimetry (LRTP). Using oxygen scavenger to achieve significant or more sensitive RTP signals may bring about kinds of trouble in many cases and is apparently not very convenient in procedures. To date a few examples on LRTP without deoxygenation ...
Chieregato A - - 2003
BACKGROUND: Normal values of the jugular bulb oxygen saturation were obtained in 1942 and in 1963. Correct catheter positioning was not confirmed radiologically. OBJECTIVES: To replicate the measurements during angiographic catheterisation of the jugular bulb. METHODS: Oxygen saturation in the jugular bulb (SjO(2)), inferior petrosal sinus (SipsO(2)), and internal jugular ...
Downs John B - - 2003
Modern clinical use of supplemental oxygen supposes that: (1) exposure to F(IO)(2) < or = 60% is without adverse effects, (2) an individual at risk of developing arterial hypoxemia can be protected by administering high F(IO)(2), and (3) routine administration of supplemental oxygen is useful, harmless, and clinically indicated. There ...
Boumphrey S M - - 2003
BACKGROUND: The administration of oxygen at a high-inspired concentration is often required in medicine, particularly in resuscitation of critically ill patients. However, there is a lack of evidence-based guidance on how to achieve this using currently available apparatus. The aim of this study was to assess how maximum inspired oxygen ...
Primhak R A - - 2003
This article deals with the discharge planning and continuing care of babies with chronic lung disease of the newborn (CLD), especially those with a continuing oxygen requirement, with some reference to longer term outcome. The pattern of CLD has changed since early descriptions, and the most useful definition for persisting ...
van Dongen Joost T - - 2003
We have investigated the consequences of endogenous limitations in oxygen delivery for phloem transport in Ricinus communis. In situ oxygen profiles were measured directly across stems of plants growing in air (21% [v/v] oxygen), using a microsensor with a tip diameter of approximately 30 microm. Oxygen levels decreased from 21% ...
Denninghoff Kurt R - - 2003
The objective was to test calibration of an eye oximeter (EOX) in a vitiligo swine eye and correlate retinal venous oxygen saturation (Srv(O(2))), mixed venous oxygen saturation (Sv(O(2))), and cardiac output (CO) during robust changes in blood volume. Ten anesthetized adult Sinclair swine with retinal vitiligo were placed on stepwise ...
Heyen U - - 2003
Media and growth conditions were optimized for the microaerobic cultivation of Magnetospirillum gryphiswaldense in flasks and in a fermentor, resulting in significantly increased cell and magnetosome yields, compared with earlier studies. A reliable method was established for the automatic control of low dissolved oxygen tensions (pO(2)) in the fermentor (oxystat). ...
Rajakumar A - - 2003
Pre-eclamptic (PE) placentae overexpress hypoxia inducible transcription factors-1alpha and -2alpha proteins (Biol. Repro. 64: 499-506, 2001; Ibid 1019-1020). Possible explanations include (a) impaired oxygen-dependent reduction, and/or (b) enhanced sensitivity to reduced oxygen. After 18 h equilibration under 21 per cent O(2) atmosphere, we subjected villous explants prepared from placentae of ...
Farrell A P - - 2003
For most teleost fish, the majority of the myocardial oxygen supply is provided by the oxygen reserve remaining in venous blood after other tissues have extracted oxygen. We examined the effect of graded exercise and water temperature on this venous blood oxygen supply to the heart (termed the cardiac circulation) ...
Land Stephen C - - 2003
Oxygen-sensing pathways have been extensively explored in the context of homeostatic responses to hypoxic episodes; however, little is known of their involvement in the morphogenesis of respiratory structures (mitochondria, placenta, lung) during development in utero. This review identifies four essential loci where oxygen signalling pathways may cue the development of ...
Wolff Christopher B - - 2003
Cardiac output (Q) changes linearly with oxygen consumption (VO2) in normal subjects undertaking submaximal exercise (Q = A + B x VO2 where A is the y intercept and B the slope). If (hypothesis 1) the increase in cardiac output above the resting state represents the blood flow to exercising ...
Radhakrishnan Krishnan - - 2003
An acute reduction in oxygen delivery to a tissue is associated with metabolic changes aimed at maintaining ATP homeostasis. However, given the complexity of the human bioenergetic system, it is difficult to determine quantitatively how cellular metabolic processes interact to maintain ATP homeostasis during stress (e.g., hypoxia, ischemia, and exercise). ...
Vasserot Y - - 2003
The capacity of yeast lees to remove thiols was investigated in a synthetic medium and in wine. In a synthetic medium, yeast lees are able to reduce thiol concentration with a concomitant production of a disulfide. In wine, thiol consumption is lower than in the synthetic medium and no disulfide ...
Edmark Lennart - - 2003
BACKGROUND: The use of 100% oxygen during induction of anesthesia may produce atelectasis. The authors investigated how different oxygen concentrations affect the formation of atelectasis and the fall in arterial oxygen saturation during apnea. METHODS: Thirty-six healthy, nonsmoking women were randomized to breathe 100, 80, or 60% oxygen for 5 ...
Sahoo Goloka Behari - - 2003
A one-dimensional bubble plume model is described to predict the gaseous mass transfer of air bubbles into ambient water and the appropriate design criteria of a bubbler for a linearly stratified reservoir. The bubble plume behavior is governed by two dimensionless parameters: G, the strength of stratification, and M, the ...
Hendeles Leslie - - 2003
Bronchospasm precipitated by exercise is often indistinguishable from bronchospasm produced by other stimuli. Symptoms result from airflow limitation and include wheezing, cough, chest tightness, dyspnea and sometimes hypoxemia. The prevalence of exercise-induced bronchospasm varies from 30%-90%, but virtually all patients with current asthma will experience a decrease in lung function ...
Yu Hyung Suk - - 2002
Bacterial aerotaxis is a rapid response towards or away from oxygen. Here we report on the use of computer-assisted motion analysis coupled to flash photolysis of caged oxygen to quantify aerotactic responses in bacteria. The caged compound (mu-peroxo)(mu-hydroxo)bis[bis(bipyridyl) cobalt(III)] perchlorate liberates molecular oxygen upon irradiation with near-UV light. A mixture ...
Madhani Melanie - - 2002
The effects of the antibacterial peptide PR-39 on nitric oxide (NO) and liver oxygenation (pO(2)) in a mouse model of endotoxaemia have been explored. In vivo electron paramagnetic resonance (EPR) spectroscopy was used to make direct measurements of liver NO and pO(2). Measurements of pO(2) were made at two different ...
Pridemore William Alex - - 2002
In Russia, rates of alcohol consumption and homicide are among the highest in the world, and already-high levels increased dramatically after the breakup of the Soviet Union. Rates of both, however, vary greatly among Russia's 89 regions. We took advantage of newly available vital statistics and socioeconomic data to examine ...
Hummler Helmut D - - 2002
OBJECTIVE: This study tested the effects of low perfusion caused by emerging sepsis on the reliability of a new pulse oximetry technology (Masimo SET; IVY 405T) compared with a standard pulse oximeter (Nellcor N-200). DESIGN: Randomized trial. SETTING: University animal research facility. SUBJECTS: Twenty-six anesthetized, ventilated (Fio, 1.0), adult rabbits. ...
Kalliokoski Kari K - - 2003
The purpose of this study was to compare the effects of intermittent and continuous static exercise on muscle perfusion, perfusion heterogeneity, and oxygen extraction. Perfusion and oxygen uptake of quadriceps femoris muscle were measured in 10 healthy men by using positron emission tomography and [(15)O]H(2)O and [(15)O]O(2) first during intermittent ...
Fournell Artur - - 2002
OBJECTIVE: To evaluate the impact of cardiopulmonary bypass (CPB) on gastric mucosal oxygen saturation assessed by reflectance spectrophotometry in patients undergoing coronary artery bypass graft surgery. DESIGN: Prospective, observational study. SETTING: A division of cardiothoracic anesthesia in a university hospital. PARTICIPANTS: Twelve consecutive patients undergoing CPB. INTERVENTIONS: Monitoring, anesthesia, surgical ...
Thavasothy M - - 2002
In this study cerebral oxygenation was measured using the NIRO 300 and the INVOS 5100 spectrophotometers in 10 healthy adult volunteers, exposed to varying degrees of hyperoxia and hypoxia. The results showed similar baseline values for tissue oxygenation index and regional cerebral oxygen saturation with mean (SD) values being 64.9% ...
Akça Ozan - - 2002
BACKGROUND: Wound infections are common, serious, surgical complications. Oxidative killing by neutrophils is the primary defense against surgical pathogens and increasing intraoperative tissue oxygen tension markedly reduces the risk of such infections. Since hypercapnia improves cardiac output and peripheral tissue perfusion, we tested the hypothesis that peripheral tissue oxygenation increases ...
Fantini Sergio - - 2002
We present a model that describes the effect of physiological parameters such as the speed of blood flow, local oxygen consumption, capillary recruitment, and vascular dilation/constriction on the concentration and oxygen saturation of haemoglobin in tissue. This model can be used to guide the physiological interpretation of haemodynamic and oximetric ...
Mokuolu Olugbenga A - - 2002
A 3-year experience of using an oxygen concentrator in a Nigerian newborn unit and economic appraisal of its effectiveness is reported. The oxygen concentrator is a device that absorbs nitrogen from ambient air, with a resultant oxygen concentration of 85 to 95% at different flow rates. The oxygen concentrator met ...
van Bommel Jasper - - 2002
BACKGROUND: During severe isovolemic hemodilution, determination of critical hematocrit levels for the microvascular oxygenation of different organs might provide more insight into the effect of the redistribution of blood flow and oxygen delivery on the oxygenation of different organs. The effect of an increased amount of dissolved oxygen on tissue ...
Zhang Wensheng - - 2002
In this model of oxygen transport in the renal medullary microcirculation, we predicted that the net amount of oxygen reabsorbed from vasa recta into the interstitium is on the order of 10(-6) mmol/s, i.e., significantly lower than estimated medullary oxygen requirements based on active sodium reabsorption. Our simulations confirmed a ...
Roast Stephen D - - 2002
Neomysis integer (Peracarida: Mysidacea) occupies the upper, low-salinity regions of estuaries in Europe, where it can experience periods of reduced oxygen concentration associated with the maximum turbidity zone. The present study reports the distribution of N. integer in response to gradients of dissolved oxygen in combination with environmentally realistic cadmium ...
Tiep Brian L - - 2002
BACKGROUND:Oxygen-conserving devices have been the foundation of highly portable oxygen systems that enable hypoxemic chronic lung disease patients to live active lives. Pulsing demand oxygen delivery systems (DODS) can adequately oxygenate most patients at rest and usually during exercise. However, some patients desaturate during exercise at DODS settings equivalent to ...
Tehrani Fleur - - 2002
OBJECTIVE: Supplemental oxygen treatment of patients on mechanical ventilation is crucial in maintaining the patients' oxygen levels in the normal range. The purpose of this study was to evaluate the effectiveness of a closed-loop controller for automatic adjustment of the fraction of inspired oxygen, FIO2. More specifically, the aim of ...
Farrell A P - - 2002
Studies in the laboratory with salmonids and now in the field with wild salmon clearly show that critical swimming performance has an optimum temperature. This temperature optimum is coincident with maximum aerobic scope and maximum cardiac scope. At a temperature that is higher than this optimum, however, whole animal performance ...
Oda Jun - - 2002
OBJECTIVE: To evaluate the effect of mild hypothermia on the relationship between systemic oxygen consumption and oxygen delivery. DESIGN: Prospective animal study. SETTING: University research laboratory. SUBJECTS: Anesthetized and ventilated rabbits. INTERVENTIONS: Rabbits were subjected to stepwise cardiac tamponade to reduce oxygen delivery while body temperature was maintained at 34 ...
Ntefidou Maria - - 2002
In the absence of other external stimuli the motile, unicellular freshwater flagellate Euglena gracilis normally swims upward in the water column (negative gravitaxis). This behavior is most likely triggered by active physiological orientation mechanisms. Recently it was found that negative gravitaxis often inverts to a positive one upon high light ...
Ward W K - - 2002
The primary objective was to develop a telemetric oxygen sensor designed for implantation in subcutaneous tissue. In the sensor, the platinum indicating electrode was covered with polythene to retard oxygen entry and avoid interference. Given the potential for large indicating electrodes to deplete oxygen in vivo, some sensors were made ...
Alegria Antonio E - - 2002
Four terpenylnaphthoquinones were found to enhance the rate of superoxide production in the presence of ascorbate as detected from the superoxide dismutase (SOD)-inhibitable initial oxygen consumption rates. Initial rates of oxygen consumption in the presence of ascorbate plus quinone increase with an increase in the half-wave reduction potentials of the ...
Rahardjo Yovita S P - - 2002
Oxygen transfer is for two reasons a major concern in scale-up and process control in industrial application of aerobic fungal solid-state fermentation (SSF): 1) heat production is proportional to oxygen uptake and it is well known that heat removal is one of the main problems in scaled-up fermenters, and 2) ...
Hourdez Stéphane - - 2002
Methanoaricia dendrobranchiata Blake (Polychaeta; Orbiniidae) occurs in large numbers in association with communities of the mussel Bathymodiolus childressi at hydrocarbon seeps on the Louisiana Slope of the Gulf of Mexico. Its microhabitat can be strongly hypoxic (oxygen is often undetectable) and sulfidic (sulfide concentrations can reach millimolar levels), which may ...
Dunham Rex A - - 2002
The survival and tolerance of F2 transgenic common carp (Cyprinus carpio) containing pRSVrtGH1 complementary DNA were compared with nontransgenic (control) common carp when subjected to low dissolved oxygen. The tolerance of low oxygen was evaluated in 8 families of common carp in rectangular tanks (3 x 1 x 1 m). ...
Arieli Yehuda - - 2002
It is accepted that gas bubbles grow from preexisting gas nuclei in tissue. The possibility of eliminating gas nuclei may be of benefit in preventing decompression sickness. In the present study, we examined the hypothesis that hyperbaric oxygen may replace the resident gas in the nuclei with oxygen and, because ...
Jensen Tina D - - 2002
BACKGROUND: The authors hypothesized that impaired oxygen extraction in mitochondrial myopathy (MM) results in a high oxygen saturation in venous effluent blood from working muscle and that this phenomenon can be used as a diagnostic tool for MM. METHODS: Twelve patients with MM, 10 patients with muscular dystrophy, and 12 ...
Tretinyak Alexander S - - 2002
Supplemental oxygen can reduce intimal hyperplasia (IH) after stent deployment in a rabbit model. Endovascular stent placement is technically feasible, but long-term durability in vessels outside the aortoiliac system is compromised with postinterventional IH, which causes restenosis and failure of the arterial conduit. Groups (n = 4 to 6) of ...
Higgins Rosemary D - - 2002
The goal of this study was to determine the effect of two somatostatin analogs, Woc4D and octreotide, on oxygen induced retinopathy in the mouse. Oxygen induced retinopathy was produced in C57BL6 mice. Octreotide and Woc4D were administered from post-natal day 12-16. Retinopathy was assessed by a retinal scoring system utilizing ...
Russell W C - - 2002
We investigated the effects of neuromuscular blockade with atracurium on oxygen consumption, oxygen delivery and total chest compliance in 20 sedated intensive care patients who required mechanical ventilation with an inspired oxygen fraction of at least 0.6. The reverse Fick method was used to measure oxygen consumption. Total chest compliance ...
Lavon Haim - - 2002
BACKGROUND: Many hyperbaric facilities use infusion pumps inside the chamber. It is therefore important to ensure that this equipment will perform accurately during hyperbaric conditions. The authors tested the function and accuracy of the Imed 965 and Infutec 520 volumetric infusion pumps, the Easy-pump MZ-257 peristaltic infusion pump, and the ...
Bäumer C - - 2002
To determine the contribution of circulatory convection to tissue oxygen supply in animals of Daphnia magna, heart rate ( f(H)), in-vivo Hb oxygen-saturation ( S(Hb)) and NADH fluorescence intensity ( I(NADH)) as a measure of the tissue oxygenation state were simultaneously measured using digital motion analysis, microabsorption spectroscopy and fluorescence ...
Ho Anthony M H - - 2002
Heliox has a lower density than oxygen and nitrogen, and can improve ventilation rapidly in patients with critical upper airway obstruction. The choice of the best helium:oxygen ratio depends on whether the predominant problem is hypercarbia or hypoxia. In the former situation, 80% helium should be used, and in the ...
Stitt David T - - 2002
A novel method utilizing the BD Oxygen Biosensor System has been developed to rapidly, simply, and accurately determine the growth rate of microorganisms in broth, with no needfor plate counts, standardized inocula, or technically difficult manipulations. The BD Oxygen Biosensor System incorporates an oxygen-sensitive material into the wells of standard ...
Kalinin A - - 2002
Relative to species such as rainbow trout, freshwater turtle shows a high tolerance to challenges involving acidosis and increases in extracellular K+. Therefore, the effects of acidosis or high K+ on twitch force and oxygen consumption were examined in ventricular ring preparations from these two species. The oxygen consumption associated ...
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