scholarly journals Oxygen: A Stimulus, Not “Only” a Drug

Medicina ◽  
2021 ◽  
Vol 57 (11) ◽  
pp. 1161
Author(s):  
Costantino Balestra ◽  
Jacek Kot
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Hyperbaric Oxygen ◽  
Hyperbaric Oxygenation ◽  
Extreme Environments ◽  
Hypoxia Inducible Factors ◽  
Partial Pressure Of Oxygen ◽  
New Paradigm ◽  
Simple Substance ◽  
Shock Proteins

Depending on the oxygen partial pressure in a tissue, the therapeutic effect of oxygenation can vary from simple substance substitution up to hyperbaric oxygenation when breathing hyperbaric oxygen at 2.5–3.0 ATA. Surprisingly, new data showed that it is not only the oxygen supply that matters as even a minimal increase in the partial pressure of oxygen is efficient in triggering cellular reactions by eliciting the production of hypoxia-inducible factors and heat-shock proteins. Moreover, it was shown that extreme environments could also interact with the genome; in fact, epigenetics appears to play a major role in extreme environments and exercise, especially when changes in oxygen partial pressure are involved. Hyperbaric oxygen therapy is, essentially, “intermittent oxygen” exposure. We must investigate hyperbaric oxygen with a new paradigm of treating oxygen as a potent stimulus of the molecular network of reactions.

scholarly journals Combined Hyperbaric Oxygen Partial Pressure at 1.4 Bar with Infrared Radiation: A Useful Tool To Improve Tissue Hypoxemia?

2018 ◽  
Vol 24 ◽  
pp. 4009-4019 ◽  
Author(s):  
Tobias Dünnwald ◽  
Julia Held ◽  
Petru Balan ◽  
Otto Pecher ◽  
Thomas Zeiger ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Hyperbaric Oxygen ◽  
Infrared Radiation

SOME EFFECTS OF HYPERBARIC OXYGENATION ON BACTERIA AT INCREASED HYDROSTATIC PRESSURES

1967 ◽  
Vol 13 (10) ◽  
pp. 1311-1319 ◽  
Author(s):  
Claude E. ZoBell ◽  
Leslie L. Hittle
Keyword(s):  
Hydrostatic Pressure ◽  
Dissolved Oxygen ◽  
Partial Pressure ◽  
Oxygen Content ◽  
Hyperbaric Oxygenation ◽  
Bacterial Species ◽  
Partial Pressure Of Oxygen ◽  
Nutrient Media ◽  
Initial Oxygen Content ◽  
Initial Oxygen

The adverse effects of hyperbaric oxygenation on the reproduction and survival of bacteria are augmented by increased hydrostatic pressure. Different bacterial species differ considerably in their tolerance of increased hydrostatic pressure as well as for increased partial pressure of oxygen. Although their generation times may be lengthened and their reproduction rates retarded by increased pressures, most species of well-known bacteria are able to grow at hydrostatic pressures as high as 200–400 atm. In closed systems at 1 atm, certain aerobic bacteria grow well, or sometimes better, in nutrient media in which the partial pressure of oxygen is 5 to 10 times higher than that in the normal atmosphere (-Po2ca. 0.2 atm, equivalent to a dissolved oxygen content of ca. 7 μg/ml), but such increased concentrations of oxygen (35–70 μg/ml) are injurious at substantially increased hydrostatic pressures, for example, 5–25 atm. Escherichia coli, Bacillus subtilis, Bacillus megaterium, Pseudomonas enalia, Pseudomonas perfectomarinus, and Serratia marinorubra were sterilized within a day or two by compression to 100 atm in media having a dissolved oxygen content of 35 μg/ml. All six species thrived at 100 atm in nutrient media having an initial oxygen content of 7 μg/ml and they grew well in media with an oxygen content of 35 μg/ml at 1 atm.

Electrical Properties and Microstructures of Ultraviolet Transparent Ga2O3 Thin Films

2007 ◽  
Vol 561-565 ◽  
pp. 1233-1236
Author(s):  
Yasuhiro Shigetoshi ◽  
Susumu Tsukimoto ◽  
Hidehisa Takeda ◽  
Kazuhiro Ito ◽  
Masanori Murakami
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Optical Properties ◽  
Electrical Properties ◽  
Substrate Temperature ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Partial Pressure Of Oxygen ◽  
Electrical And Optical Properties ◽  
Sputtering Deposition

The electrical and optical properties, and microstructures of 100 nm-thick Ga2O3 films fabricated on Al2O3(0001) substrates by a sputtering deposition were investigated. The partial pressure of oxygen was controlled and the substrate temperature was kept to be 500 °C during deposition. With increasing the oxygen partial pressure, the structures of the Ga2O3 films deposited on the substrates were observed to change from amorphous to crystalline (monoclinic β-type Ga2O3). The transmittance of the Ga2O3 films was measured to be more than 80 % at the visible and ultraviolet regions although the electrical resistivity was high. In order to obtain both low electrical resistivity and high transmittance at the ultraviolet regions, the addition of active dopant elements such as Sn into the Ga2O3 films would be required.

Oxidation Behavior of ZrB2-15vol.%SiC at an Oxygen Partial Pressure of 57 Pa

2011 ◽  
Vol 484 ◽  
pp. 21-25 ◽  
Author(s):  
Ai Momozawa ◽  
Yuuki Kubota ◽  
Rong Tu ◽  
Takashi Goto ◽  
Ken-Ichi Takagi ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Cross Sections ◽  
Reaction Layer ◽  
Oxidation Behavior ◽  
Protective Layer ◽  
Partial Pressure Of Oxygen ◽  
Active Oxidation ◽  
Passive Oxidation ◽  
Zro2 Phase

The oxidation tests of the ZrB2-15vol.%SiC composite were carried out at 1673-1923 K under a low partial pressure of oxygen. Cross sections of the oxidized samples were studied using WDS. The reaction layer consists of ZrO2 and SiO2 at 1673 K. The SiO2 protective layer is formed on the surface. No apparent SiC depleted layer is observed. SiC depletion seems to occur at 1923 K and only the ZrO2 phase exists at the reaction layer. The passive oxidation occurs at 1673 K, whereas the active oxidation at 1923 K. The mass changes are quantitatively discussed by introducing a new emprical equation. The ZrB2-30 vol.%SiC composite is also discussed briefly.

Interaction of H2O, O2 and H2 with Proton Conducting Oxides Based on Lanthanum Scandates

2019 ◽  
pp. 88-100
Author(s):  
A. S. Farlenkov ◽  
N. A. Zhuravlev ◽  
Т. A. Denisova ◽  
М. V. Ananyev
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Gas Phase ◽  
Molecular Hydrogen ◽  
Proton Magnetic Resonance ◽  
Partial Pressure Of Oxygen ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Temperature Range ◽  
Apparent Level

The research uses the method of high-temperature thermogravimetric analysis to study the processes of interaction of the gas phase in the temperature range 300–950 °C in the partial pressure ranges of oxygen 8.1–50.7 kPa, water 6.1–24.3 kPa and hydrogen 4.1 kPa with La1–xSrxScO3–α oxides (x = 0; 0.04; 0.09). In the case of an increase in the partial pressure of water vapor at a constant partial pressure of oxygen (or hydrogen) in the gas phase, the apparent level of saturation of protons is shown to increase. An increase in the apparent level of saturation of protons of the sample also occurs with an increase in the partial pressure of oxygen at a constant partial pressure of water vapor in the gas phase. The paper discusses the causes of the observed processes. The research uses the hydrogen isotope exchange method with the equilibration of the isotope composition of the gas phase to study the incorporation of hydrogen into the structure of proton-conducting oxides based on strontium-doped lanthanum scandates. The concentrations of protons and deuterons were determined in the temperature range of 300–800 °C and a hydrogen pressure of 0.2 kPa for La0.91Sr0.09ScO3–α oxide. The paper discusses the role of oxygen vacancies in the process of incorporation of protons and deuterons from the atmosphere of molecular hydrogen into the structure of the proton conducting oxides La1–xSrxScO3–α (x = 0; 0.04; 0.09). The proton magnetic resonance method was used to study the local structure in the temperature range 23–110 °C at a rotation speed of 10 kHz (MAS) for La0.96Sr0.04ScO3–α oxide after thermogravimetric measurements in an atmosphere containing water vapor, and after exposures in molecular hydrogen atmosphere. The existence of proton defects incorporated into the volume of the investigated proton oxide from both the atmosphere containing water and the atmosphere containing molecular hydrogen is unambiguously shown. The paper considers the effect of the contributions of the volume and surface of La0.96Sr0.04ScO3–α oxide on the shape of the proton magnetic resonance spectra.

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