Real-time microsensor measurement of internal oxygen partial pressure in tomato fruit under hypoxic conditions

2009 ◽  
Vol 52 (2) ◽  
pp. 240-242 ◽  
Author(s):  
Adrian D. Berry ◽  
Steven A. Sargent
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Real Time ◽  
Tomato Fruit ◽  
Hypoxic Conditions

scholarly journals Placental oxygen transfer reduces hypoxia-reoxygenation swings in fetal blood in a sheep model of gestational sleep apnea

2019 ◽  
Vol 127 (3) ◽  
pp. 745-752 ◽  
Author(s):  
Isaac Almendros ◽  
Paula Martínez-Ros ◽  
Nuria Farré ◽  
Mónica Rubio-Zaragoza ◽  
Marta Torres ◽  
...  
Keyword(s):  
Sleep Apnea ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Real Time ◽  
Oxygen Transfer ◽  
Umbilical Vein ◽  
Fetal Blood ◽  
Sheep Model ◽  
The Impact ◽  
Hypoxia Reoxygenation

Obstructive sleep apnea (OSA), characterized by events of hypoxia-reoxygenation, is highly prevalent in pregnancy, negatively affecting the gestation process and particularly the fetus. Whether the consequences of OSA for the fetus and offspring are mainly caused by systemic alterations in the mother or by a direct effect of intermittent hypoxia in the fetus is unknown. In fact, how apnea-induced hypoxemic swings in OSA are transmitted across the placenta remains to be investigated. The aim of this study was to test the hypothesis, based on a theoretical background on the damping effect of oxygen transfer in the placenta, that oxygen partial pressure (Po2) swings resulting from obstructive apneas mimicking OSA are mitigated in the fetal circulation. To this end, four anesthetized ewes close to term pregnancy were subjected to obstructive apneas consisting of 25-s airway obstructions. Real-time Po2 was measured in the maternal carotid artery and in the umbilical vein with fast-response fiber-optic oxygen sensors. The amplitudes of Po2 swings in the umbilical vein were considerably smaller [3.1 ± 1.0 vs. 21.0 ± 6.1 mmHg (mean ± SE); P < 0.05]. Corresponding estimated swings in fetal and maternal oxyhemoglobin saturation tracked Po2 swings. This study provides novel insights into fetal oxygenation in a model of gestational OSA and highlights the importance of further understanding the impact of sleep-disordered breathing on fetal and offspring development. NEW & NOTEWORTHY This study in an airway obstruction sheep model of gestational sleep apnea provides novel data on how swings in oxygen partial pressure (Po2) translate from maternal to fetal blood. Real-time simultaneous measurement of Po2 in maternal artery and in umbilical vein shows that placenta transfer attenuates the magnitude of oxygenation swings. These data prompt further investigation of the extent to which maternal apneas could induce similar direct oxidative stress in fetal and maternal tissues.

Real-Time Monitoring of Singlet Oxygen and Oxygen Partial Pressure During the Deep Photodynamic Therapy In Vitro

2016 ◽  
Vol 44 (9) ◽  
pp. 2737-2745 ◽  
Author(s):  
Weitao Li ◽  
Dong Huang ◽  
Yan Zhang ◽  
Yangyang Liu ◽  
Yueqing Gu ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Singlet Oxygen ◽  
Real Time ◽  
Real Time Monitoring

scholarly journals Effect of Hot-Dip Galvanizing Process on Selective Oxidation and Galvanizability of Medium Manganese Steel for Automotive Application

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1265
Author(s):  
Zhang Chen ◽  
Yanlin He ◽  
Weisen Zheng ◽  
Hua Wang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Surface Oxidation ◽  
Steel Sample ◽  
Dew Point ◽  
Manganese Steel ◽  
Automotive Application ◽  
Stable Phase ◽  
Annealing Atmosphere ◽  
Medium Manganese Steel

A medium manganese steel with 7.5 wt.% Mn for automobile application was galvanized in a continuous Hot Dip Galvanizing (HDG) simulator under different galvanizing conditions. It was shown that the effects of dew point, annealing temperature and annealing atmosphere on the surface oxidation of steel could be comprehensively evaluated by the consideration of oxygen partial pressure P(O2). Although Mn2SiO4 was a thermodynamic stable phase when P(O2) varied from 10−28 to 10−21 atm, it was difficult to form Mn–Si–O composite oxide because there was no enrichment of silicon on the steel surface. So, this oxide was generally formed in the Fe substrate and had little effect on the galvanizability. With the increase in P(O2) above 10−25 atm, MnO particles in the form of the thermodynamic stable phase became coarser and tended to aggregate, which hindered the formation of a continuous inhibition layer, resulting in the defects of bare spots on the galvanized surface of the steel. When the oxygen partial pressure greater than 10−22 atm, film-like MnO layer was formed on the surface of steel sample, which obviously deteriorated the galvanizability. The galvanizability of the steel can be improved by the regulation of oxygen partial pressure; based on this, the reasonable zinc plating process parameters can be developed.

Quantitative evaluation of the oxidation behavior of ZrB2-15 vol.%SiC at a low oxygen partial pressure

Vacuum ◽  
2013 ◽  
Vol 88 ◽  
pp. 98-102 ◽  
Author(s):  
Ai Momozawa ◽  
Rong Tu ◽  
Takashi Goto ◽  
Yuuki Kubota ◽  
Hiroshi Hatta ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Quantitative Evaluation ◽  
Oxidation Behavior ◽  
Low Oxygen
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