scholarly journals Protoplasmic movement in the avena coleoptile as related to oxygen pressure and age

PROTOPLASMA ◽  
1938 ◽  
Vol 29 (1) ◽  
pp. 629-629
Keyword(s):  
Oxygen Pressure ◽  
Avena Coleoptile ◽  
Protoplasmic Movement

Comparison of two devices for measuring exercise transcutaneous oxygen pressures in patients with claudication

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Marie Urban ◽  
Alban Fouasson-Chailloux ◽  
Isabelle Signolet ◽  
Christophe Colas Ribas ◽  
Mathieu Feuilloy ◽  
...  
Keyword(s):  
Oxygen Pressure ◽  
Optical Sensors ◽  
Chemical Sensors ◽  
Transcutaneous Oxygen ◽  
Starting Values ◽  
Two Systems ◽  
Transcutaneous Oxygen Pressure ◽  
New Sensors ◽  
Changes Over Time ◽  
Over Time

Abstract. Summary: Background: We aimed at estimating the agreement between the Medicap® (photo-optical) and Radiometer® (electro-chemical) sensors during exercise transcutaneous oxygen pressure (tcpO2) tests. Our hypothesis was that although absolute starting values (tcpO2rest: mean over 2 minutes) might be different, tcpO2-changes over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. Patients and methods: Forty seven patients with arterial claudication (65 + / - 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simultaneously, one of each system on the chest, on each buttock and on each calf. Results: Seventeen Medicap® probes disconnected during the tests. tcpO2rest and DROPmin values were higher with Medicap® than with Radiometer®, by 13.7 + / - 17.1 mm Hg and 3.4 + / - 11.7 mm Hg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70 % for classification of test results from DROPmin. Conclusions: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturisation and weight reduction of the new sensors are possible.

Gravitropic responses of the Avena coleoptile in space and on clinostats. II. Is reciprocity valid?

1995 ◽  
Vol 95 (1) ◽  
pp. 34-38
Author(s):  
Anders Johnsson ◽  
Allan H. Brown ◽  
David K. Chapman ◽  
David Heathcote ◽  
Christina Karlsson
Keyword(s):  
Avena Coleoptile

Interaction of human hemoglobin with oxygen in the presence of benzene and use of computer for construction of saturation curves

1986 ◽  
Vol 51 (8) ◽  
pp. 1795-1801
Author(s):  
Hana Hájková ◽  
Zdeněk Pavlíček ◽  
Vítěz Kalous
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Pressure ◽  
Time Profile ◽  
Partial Oxygen Pressure ◽  
Human Hemoglobin ◽  
Allosteric Interaction ◽  
Partial Oxygen

The time profile of changes in the oxygen saturation curves of human hemoglobin in the presence of benzene was investigated. The partial oxygen pressure p50, necessary for a half saturation, decreases during the first 3.5 h of interaction of hemoglobin with benzene and did not change afterwards. The character of changes in Hill's coefficient was similar. The oxygen saturation was modeled both for hemoglobin alone and, using MWC as a model of allosteric interaction, also for hemoglobin and benzene in a computer.

scholarly journals Mismatch between Tissue Partial Oxygen Pressure and Near-Infrared Spectroscopy Neuromonitoring of Tissue Respiration in Acute Brain Trauma: The Rationale for Implementing a Multimodal Monitoring Strategy

2021 ◽  
Vol 22 (3) ◽  
pp. 1122
Author(s):  
Mario Forcione ◽  
Mario Ganau ◽  
Lara Prisco ◽  
Antonio Maria Chiarelli ◽  
Andrea Bellelli ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Oxygen Pressure ◽  
Near Infrared ◽  
Optical Signal ◽  
Brain Trauma ◽  
Partial Oxygen Pressure ◽  
Tissue Respiration ◽  
The Brain ◽  
Partial Oxygen

The brain tissue partial oxygen pressure (PbtO2) and near-infrared spectroscopy (NIRS) neuromonitoring are frequently compared in the management of acute moderate and severe traumatic brain injury patients; however, the relationship between their respective output parameters flows from the complex pathogenesis of tissue respiration after brain trauma. NIRS neuromonitoring overcomes certain limitations related to the heterogeneity of the pathology across the brain that cannot be adequately addressed by local-sample invasive neuromonitoring (e.g., PbtO2 neuromonitoring, microdialysis), and it allows clinicians to assess parameters that cannot otherwise be scanned. The anatomical co-registration of an NIRS signal with axial imaging (e.g., computerized tomography scan) enhances the optical signal, which can be changed by the anatomy of the lesions and the significance of the radiological assessment. These arguments led us to conclude that rather than aiming to substitute PbtO2 with tissue saturation, multiple types of NIRS should be included via multimodal systemic- and neuro-monitoring, whose values then are incorporated into biosignatures linked to patient status and prognosis. Discussion on the abnormalities in tissue respiration due to brain trauma and how they affect the PbtO2 and NIRS neuromonitoring is given.

Effects of Bi:V ratio and oxygen pressure on BiVO4(010) epitaxial thin film preparation

2021 ◽  
pp. 413174
Author(s):  
Yuxin Shi ◽  
Pengwei Zhai ◽  
Lixiang Meng ◽  
Zongyin Huang ◽  
Guoqiang Li
Keyword(s):  
Thin Film ◽  
Oxygen Pressure ◽  
Epitaxial Thin Film ◽  
Thin Film Preparation ◽  
Film Preparation

Effect of Oxygen Pressure on the Surface Roughness and Intergranular Behavior of YBCO Thin Films

2016 ◽  
Vol 29 (6) ◽  
pp. 1483-1489 ◽  
Author(s):  
S. Aghabagheri ◽  
M. R. Mohammadizadeh ◽  
P. Kameli ◽  
H. Salamati
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Oxygen Pressure ◽  
Ybco Thin Films ◽  
Effect Of Oxygen

Microvascular damage in the cortex of cat brain from middle cerebral artery occlusion and reperfusion

1993 ◽  
Vol 74 (2) ◽  
pp. 580-589 ◽  
Author(s):  
D. F. Wilson ◽  
S. Gomi ◽  
A. Pastuszko ◽  
J. H. Greenberg
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Oxygen Pressure ◽  
Video Camera ◽  
Artery Occlusion ◽  
Microvascular Damage ◽  
Excitation Light ◽  
Irreversible Brain Damage ◽  
Dynamic Time ◽  
Cerebral Artery Occlusion

Oxygen-dependent quenching of phosphorescence provides an extraordinarily powerful method for examining the effects of ischemia/hypoxia on the cortex of the brain. Video camera technology has permitted imaging, through a window in the skull, of the phosphorescence of an oxygen probe, Pd meso-tetra-(4-carboxyphenyl)-porphine, bound to albumin in the blood of anesthetized animals. Images of the phosphorescence taken at different times after the flash of excitation light were used to generate high-resolution two-dimensional maps of the oxygen pressure. These maps show that cortical oxygenation is spatially heterogeneous and that there is dynamic time-dependent modulation of regional oxygen pressures. When the middle cerebral artery was occluded, the region for which it supplied blood became hypoxic, the severity of the hypoxia varying among animals. Release after 60 min of occlusion resulted in a rapid rise of the oxygen pressure to above-normal levels followed by onset of a delayed period of hypoxia. This period is characterized by generally low tissue oxygen pressures with local regions of more severe hypoxia. The delayed period of hypoxia appears to result from damage to the microvasculature, and this microvascular damage is proposed to be an important determinant of the extent of irreversible brain damage.

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