Oxygen Concentration In Plasma Research Articles

Putting Evidence Into Nursing Practice: Four Traditional Practices Not Supported by the Evidence

Evidence-based nursing practice is essential to the delivery of high-quality care that optimizes patients' outcomes. Studies continue to show improved outcomes when best evidence is used in the delivery of patient care. Despite awareness of the importance of practicing by using best evidence, achieving and sustaining evidence-based practice within practice environments can be challenging, and research suggests that integration of evidence-based practice into daily clinical practice remains inconsistent. This article addresses 4 practice issues that, first, are within the realm of nursing and if changed might improve care of patients and, second, are areas in which the tradition and the evidence do not agree and practice continues to follow tradition. The topics addressed are (1) noninvasive measurement of blood pressure in children, (2) oxygen administration for patients with chronic obstructive pulmonary disease, (3) intravenous catheter size and blood administration, and (4) infection control practices to prevent infections. The related beliefs, current evidence, and recommendations for practice related to each topic are described.

Thermodynamic approach to oxygen delivery in vivo by natural and artificial oxygen carriers

Oxygen is a toxic gas, still indispensable to aerobic life. This paper explores how normal physiology uses the physico-chemical and thermodynamic characteristics of oxygen for transforming a toxic gas into a non toxic indispensable metabolite. Plasma oxygen concentration is in the range of 10 − 5 M, insufficient to sustain metabolism. Oxygen carriers, present in blood, release oxygen into plasma, thereby replacing consumed oxygen and buffering PO 2 near their P 50. They are the natural cell-bound carriers, like hemoglobin inside red cells, myoglobin inside myocytes, and artificial cell-free hemoglobin-based oxygen carriers (HBOC) dissolved in plasma. Metabolic oxygen replacement can be defined as cell-bound and cell-free delivery. Cell-bound delivery is retarded by the slow diffusion of oxygen in plasma and interstitial fluids. The 40% hematocrit of normal blood compensates for the delay, coping with the fast oxygen consumption by mitochondria. Facilitated oxygen diffusion by HBOCs corrects for the slow diffusion, making cell-free delivery relatively independent from P 50. At all oxygen affinities, HBOCs produce hyperoxygenations that are compensated by vasoconstrictions. There is a strict direct correlation between the rate of oxygen replacement and hemoglobin content of blood. The free energy loss of the gradient adds a relevant regulation of tissues oxygenation. Oxygen is retained intravascularly by the limited permeability to gases of vessel walls.

Determination of the Elemental Composition of Hydrocarbon Mixtures by Gas Chromatography with Atomic Emission Detection: Increasing the Accuracy

In this work, the accuracy of the ratio of the numbers of carbon and hydrogen atoms (nC/nH) determined in the molecules of the components of aliphatic hydrocarbon mixtures by gas chromatography with atomic emission detection (GC-AED) is studied as a function of the oxygen concentration in helium. It is shown that the highest accuracy is achieved at about 9% of oxygen, which is the highest oxygen concentration possible for the Agilent model G2350A GC-AED device. At the standard oxygen concentration (about 1.5%) recommended by the manufacturer, the accuracy of the nC/nH ratios was five to ten times lower. It is shown that improving the accuracy of the nC/nH ratios at the maximum oxygen concentration in plasma is followed by an increase in the detection limit approximately by an order of magnitude.

Effects of the plasma oxygen concentration on the formation of SiO xC y films by low temperature PECVD

Experiments were made to produce SiO x C y coatings by PECVD on polycarbonate substrates at a temperature below 80 °C, using a gaseous mixture of methyltrimethoxy-silane (MTMOS) [CH 3Si(OCH 3) 3] with O 2 and CH 4. Under those conditions, the effects of the oxygen concentration in the plasma on the film thermal shock and long-term stability, hardness and growth rate were studied using Fourier transform infrared absorption spectrocopy (FTIR) and optical emission spectroscopy (OES). It is concluded that for given deposition conditions there is an optimum oxygen concentration in the plasma compatible with films presenting a best compromise in terms of the indicated properties, which is determined essentially by a competition between the reaction rates at the substrate surface for Si–O–Si formation and Si–OH elimination by dehydration reactions, and the deposition rate of silanol groups formed in the plasma phase. The overall results suggest that this competition is sensitive to the plasma electron temperature.

Modeling of oxygen diffusion and metabolism from capillary to muscle.

In the bioengineering and sports training field, there are interests in obtaining information on oxygen transport and metabolism during muscle exercise. The goal of our study was to develop a time-dependent model which can simulate the changes in oxygen diffusion and metabolism in muscle tissue, especially from capillary to mitochondria. We postulate that oxygen diffuses into the tissue at a rate proportional to the oxygen concentration in plasma when applied to a steady state condition. As we know, any build up of oxygen in the tissue is directly related to oxygen leaving the capillary into the tissue and the consumption of oxygen by the mitochondria, or the metabolic demand. We designed a model which consisted of four compartments: (1) capillary; (2) interstitial space between capillary and myofibril tissue cell; (3) parenchymal cell through myofibril to mitochondria in muscle tissue; (4) at mitochondria. Oxygen comes from arteriole to capillary, then diffuses to mitochondria through interstitial space and myofibril. Oxygen is reduced to water in mitochondria, and ATP is generated through proton transport. Our model simulates the measured oxygen uptake during rest and muscle exercise as the input oxygen uptake represented as H2O formation.KeywordsOxygen ConcentrationOxygen DiffusionInterstitial SpaceOxygen TransportDifferential Equation ModelThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Thermal Plasma Synthesis of BaFe12O19 (BaM) Films

Barium Ferrite (BaFe12O19) films have been successfully deposited on high silica glass substrates using an inductively coupled plasma source. Precursor of the metals used was a barium acetate and ferric nitrate solution of controlled concentration which was injected into the hot region of the plasma using a nebulizer. Variables studied included molar ratio of precursor liquid, substrate to plasma distance, plasma torch power, and oxygen concentration in plasma and carrier gas. Films were characterized for microstructure, composition and magnetic properties using scanning and transmission electron microscopy with energy dispersive spectroscopy, X-ray diffraction, and vibrating sample magnetrometry. Results indicate that barium ferrite forms under certain conditions of oxygen content in the plasma and substrate temperature above 800°C. Magnetic properties indicate that there is some degree of preferred orientation of the barium ferrite crystals on the substrate, and coercivity and magnetization correspond to that of a hard magnetic material.

Cerebral oxygenation and the recoverable brain

Oxygenation is the most critical function of blood flow and a sudden reduction in oxygen availability is an inevitable consequence of severe ischemia. The resulting cascade of events may result in the failure of membrane integrity of some cells and necrosis, but in the surrounding zone of tissue, less affected by hypoxia, cells survive to form the ischemic penumbra. The timing of these events is uncertain, but sufficient oxygen is available to these cells to maintain membrane ion pump mechanisms, but not enough for them to generate action potentials and therefore function as neurons. The existence of such area.s has been suspected for some time based upon the nature of clinical recovery, but has now been demonstrated by SPECT imaging with a high plasma oxygen concentration under hyperbaric conditions as a tracer. A course ofhyperbaric oxygen therapy frequently results in a permanent improvement in both flow and metabolism. These changes apparently represent a reversal ofthe changes that render neurones dormant and the activity of cells, previously undetectable by standard electrophysiological methods, can now be demonstrated. Three patients are presented in whom recoverable brain tissue has been identified using SPECT imaging and increased cerebral oxygenation under hyperbaric conditions. Improved perfusion from reoxygenation has correlated with clinical evidence of benefit especially with continued therapy. [Neural Res 1998; 20 (Suppl 1): 533-536]

Preparation of photovoltaic silicon by purification of metallurgical grade silicon with a reactive plasma process

The main methods of silicon purification involve physicochemical techniques of separation. They yield an ultrapure metal, but its price is not compatible with photovoltaic central power generation. The plasma zone melting process consists in the horizontal displacement of a melted zone under an argon-hydrogen-oxygen plasma. The melt zone is characterized by a vertical gradient of concentration and temperature which drains impurities toward the upper surface of the bar. Moreover, the displacement of the zone from the head to the tail of the bar ensures a horizontal drainage of impurities toward the tail. This technique has been used with success for purification of metallurgical grade silicon; for example, iron was reduced from 3500 ppm to 0.5 ppm at a displacement rate between 20 and 40 cm/h. The final impurity level was less than 1 ppm. The mass transfer was independent of the displacement rate at 40 cm/h, but dependent on the heat transfer rate. The segregation of the metals is caused by drainage toward the tail of the bar, while the plasma vaporizes impurities since the metallic and metalloidic impurities have high vapor pressures (e.g., S, P, C, O, Mn). Acid (HF-HNO3) is used to dissolve the impurities between each passage of the zone. Boron elimination depends directly on the plasma oxygen concentration. Classical mathematic models of zone melting are not valid for plasma melting zone processes.

Physiology and Management of Pulmonary Insufficiency due to Kyphoscoliosis.

s1 May 1961Physiology and Management of Pulmonary Insufficiency due to Kyphoscoliosis.M. Stein, M.D., I. Bruderman, M.D.M. Stein, M.D.Search for more papers by this author, I. Bruderman, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-54-5-1060_2 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptDetailed studies of pulmonary function were carried out in seven patients with severe thoracic deformity (kyphoscoliosis). The ages ranged from 31 to 79 years and included both acquired and congenital deformities. Six patients complained of moderate or severe dyspnea on mild exertion and five had histories consistent with cor pulmonale. The pulmonary function studies revealed vital capacities to be smaller than predicted, normal distribution of inspired gas, normal tidal volumes, alveolar hypoventilation, carbon dioxide retention, and arterial blood oxygen saturation disproportionately low for the degree of hypoventilation. On breathing 99.6% oxygen, plasma oxygen concentration failed to rise to predicted normal... This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics 1 May 1961Volume 54, Issue 5Page: 1060-1060KeywordsBlood plasmaBlood volumeBreathingCarbon dioxideDyspneaNormal distributionOxygenPulmonary functionRespiratory physiologyTidal volume ePublished: 1 December 2008 Issue Published: 1 May 1961 PDF downloadLoading ...