ARTIFICIAL HYPOBIOSIS AS A METHOD TO MITIGATE THE NEGATIVE EFFECT OF OXYGEN AT AN ELEVATED PARTIAL PRESSURE

2021 ◽  
Vol 55 (5) ◽  
pp. 64-68
Author(s):  
A.F. Makarov ◽  
◽  
M.A. Kotsky ◽  
А.А. Ton'shin ◽  
I.V. Bukhtiyarov ◽  
...  

To assess how hypobiosis modifies the negative effect of a high partial pressure of oxygen, goldhamsters were put into artificial hypobiosis followed by a simulated O2 poisoning at absolute gas pressure of 7 kgf/cm2. The experiment showed an increase in 1.4 times (p = 0.0579) of the period preceding convulsions; reduction in 3.7 times (p = 0.0009) of the period of stabilization on return to normal O2 pressure, reduction of the total convulsions period in 2.3 times (p = 0.0003).

1998 ◽  
Vol 84 (1) ◽  
pp. 351-356 ◽  
Author(s):  
R. E. Reinertsen ◽  
V. Flook ◽  
S. Koteng ◽  
A. O. Brubakk

Reinertsen, R. E., V. Flook, S. Koteng, and A. O. Brubakk.Effect of oxygen tension and rate of pressure reduction during decompression on central gas bubbles. J. Appl. Physiol. 84(1): 351–356, 1998.—Reduction in ascent speed and an increase in the O2 tension in the inspired air have been used to reduce the risk for decompression sickness. It has previously been reported that decompression speed and O2 partial pressure are linearly related for human decompressions from saturation hyperbaric exposures. The constant of proportionality K( K = rate/partial pressure of inspired O2) indicates the incidence of decompression sickness. The present study investigated the relationship among decompression rate, partial pressure of inspired O2, and the number of central gas bubbles after a 3-h dive to 500 kPa while breathing nitrox with an O2 content of 35 kPa. We used transesophageal ultrasonic scanning to determine the number of bubbles in the pulmonary artery of pigs. The results show that, for a given level of decompression stress, decompression rate and O2 tension in the inspired air can be traded off against each other by using pulmonary artery bubbles as an end point. The results also seem to confirm that decompressions that have a high K value are more stressful.


1931 ◽  
Vol 54 (6) ◽  
pp. 827-845 ◽  
Author(s):  
P. E. Gregoire

1. Methylene blue injected intravenously in white rats is hyperthermizing or hypothermizing according to the environmental temperature. 2. It causes an increase in metabolism at 28°C. or above. At lower temperature it does not affect, or rather depresses, metabolism. 3. It does not seem likely that its hypermetabolic action is due to catalysis of cell oxidations. 4. In animals exposed to an atmosphere with a high partial pressure of oxygen, methylene blue causes pulmonary edema, much more rapidly than does oxygen alone.


1972 ◽  
Vol 18 (8) ◽  
pp. 1191-1195 ◽  
Author(s):  
A. G. McLee ◽  
Agnes C. Kormendy ◽  
M. Wayman

Fifteen bacterial strains and four molds capable of growth on n-butane were isolated and partially classified. The bacteria were mostly Arthrobacter sp. and Brevibacterium sp.; among the molds, Penicillium nigricans, Allescheria boydii, and Graphium cumeiferum were identified, while the remaining mold had the appearance of Gliocladium, but was not firmly identified. Although able to grow on other alkanes and orthodox media, the bacterial isolates could not use methane. Growth rates on n-butane were unaffected by varying air or substrate partial pressures in the range of 10–90% atmosphere. High partial pressure of oxygen was inhibitory to most bacterial isolates, the degree of inhibition varying widely, however. Growth rates on n-butanol and on glucose were significantly higher than those on n-butane. Among the molds, only the Graphium would grow well in submerged, shaking culture.


2012 ◽  
Vol 1 (0) ◽  
pp. 43-46 ◽  
Author(s):  
Yoshihiro TANGE ◽  
Heihachi MIGITA ◽  
Shigenori YOSHITAKE ◽  
Yutaka ISAKOZAWA ◽  
Shingo TAKESAWA ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1062
Author(s):  
Tomohiro Okudera ◽  
Takayuki Nagata ◽  
Miku Kasai ◽  
Yuji Saito ◽  
Taku Nonomura ◽  
...  

The effects of the oxygen mole fraction on the static properties of pressure-sensitive paint (PSP) were investigated. Sample coupon tests using a calibration chamber were conducted for poly(hexafluoroisopropyl methacrylate)-based PSP (PHFIPM-PSP), polymer/ceramic PSP (PC-PSP), and anodized aluminum PSP (AA-PSP). The oxygen mole fraction was set to 0.1–100%, and the ambient pressure (Pref) was set to 0.5–140 kPa. Localized Stern–Volmer coefficient Blocal increased and then decreased with increasing oxygen mole fraction. Although Blocal depends on both ambient pressure and the oxygen mole fraction, its effect can be characterized as a function of the partial pressure of oxygen. For AA-PSP and PHFIPM-PSP, which are low-pressure- and relatively low-pressure-type PSPs, respectively, Blocal peaks at PO2ref<12 kPa. In contrast, for PC-PSP, which is an atmospheric-pressure-type PSP in the investigated range, Blocal does not have a peak. Blocal has a peak at a relatively high partial pressure of oxygen due to the oxygen permeability of the polymer used in the binder. The peak of SPR, which is the emission intensity change with respect to normalized pressure fluctuation, appears at a lower partial pressure of oxygen than that of Blocal. This is because the intensity of PSP becomes quite low at a high partial pressure of oxygen even if Blocal is high. Hence, the optimal oxygen mole fraction depends on the type of PSP and the ambient pressure range of the experiment. This optimal value can be found on the basis of the partial pressure of oxygen.


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