Effect of hyperbaric pressure on postharvest conservation of ‘Palmer’ mangoes

2021 ◽  
Author(s):  
Josiane Pereira da Silva ◽  
Carlos Inestroza‐Lizardo ◽  
José Sidnaldo Pinzetta Junior ◽  
Ben‐Hur Mattiuz
Keyword(s):  
Hyperbaric Pressure

Measurement of factors impairing gas exchange in man with hyperbaric pressure

1964 ◽  
Vol 19 (2) ◽  
pp. 189-194 ◽  
Author(s):  
C. Lenfant
Keyword(s):  
Sea Level ◽  
Venous Blood ◽  
Barometric Pressure ◽  
Bimodal Distribution ◽  
Arterial Oxygen ◽  
Dissociation Curve ◽  
Group Of Units ◽  
Hyperbaric Pressure ◽  
Oxygen Difference ◽  
Made In

Alveoli with very low ventilation/perfusion ratios (Va/Q) contribute capillary blood with venous saturation to the mixed arterial stream. The portion of the alveolar arterial oxygen difference (A-a Do2) due to these units with very low Va/Q ratios cannot be differentiated from that due to an anatomical shunt at ambient pressures. By raising the barometric pressure to such a level that venous blood is saturated, the O2 dissociation curve no longer affects the A-a Do2 measurement, and the differentiation can be made. In the present experiments 75% O2 was inspired at sea level and at a depth equivalent to 2.6 atm. The A-aD was measured for O2, CO2 and N2. In seven out of eight subjects A-a Do2 and A-a Dn2 varied when the barometric pressure was increased. A theoretical analysis showed that the results can be interpreted on the basis of a bimodal distribution of Va/Q composed of a large group of well-ventilated alveoli and of a small group of units having an undeterminable Va/Q. The shunt calculated from the total A-a Do2 at sea level was 3.47% of the total cardiac output. When the A-a Do2 due to Va/Q (i.e., A-a Dco2 + A-a Dn2) was subtracted from the total A-a Do2 the shunt was 1.78%. At 2.6 atm that part of the total A-a Do2 found to be due to shunt was 0.8%, or 25% of the shunt estimated at sea level from the pure O2 technique. pulmonary shunts; ventilation/perfusion distribution; diving; hyperbarism Submitted on June 24, 1963

Synaptic integrative properties at hyperbaric pressure

1988 ◽  
Vol 60 (4) ◽  
pp. 1497-1512 ◽  
Author(s):  
Y. Grossman ◽  
J. J. Kendig
Keyword(s):  
Synaptic Transmission ◽  
Motor Neurons ◽  
Repetitive Stimulation ◽  
Inhibitory Synapses ◽  
Synaptic Connections ◽  
Paired Pulse ◽  
Inhibitory Transmission ◽  
Inhibitory Synaptic Transmission ◽  
Hyperbaric Pressure ◽  
Per Se

1. Because hyperbaric pressure profoundly depresses excitatory synaptic transmission, it has proved difficult to account for its excitatory effects in the CNS. We tested the hypothesis that hyperbaric pressure might increase excitation by enhancing facilitation and potentiation during repetitive synaptic activation, and/or by selectively depressing inhibitory synaptic transmission. Intracellular microelectrode recordings were obtained from crustacean muscle fibers innervated by single identifiable excitor and inhibitor motor neurons; the preparations were exposed to pressures of 0.1-10.1 MPa. 2. Hyperbaric pressure reduced the amplitude of the singly evoked excitatory junctional potential (EJP), enhanced paired-pulse facilitation, and increased the potentiation elicited by trains of stimuli. The potentiated EJP at 10.1 MPa approached the comparable response evoked at normobaric pressure. 3. Hyperbaric pressure also depressed inhibitory synaptic transmission, measured as depression of the EJP by the inhibitor motor neuron. However, pressure depressed excitatory and inhibitory synaptic transmission to the same extent. Thus there appears to be no selective effect of pressure on the GABA-activated chloride channel. The amplitude of the inhibited EJP at 10.1 MPa remained below that at normobaric pressure, even during repetitive stimulation. 4. The results do not support the hypothesis that pressure increases central excitation by selectively depressing inhibitory transmission per se; enhancement of potentiation, however, probably plays an important role. In this preparation, in which inhibitory transmission also displays facilitation, pressure did not increase overall excitation or alter the balance between excitation and inhibition. 5. These results predict that a pressure-excitable network should encompass excitatory synaptic connections which exhibit pronounced facilitation and inhibitory synapses with little or no facilitation.

Hyperbaric pressure depresses potentiation of polysynaptic medullospinal reflexes in newborn rats

1989 ◽  
Vol 100 (1-3) ◽  
pp. 175-180 ◽  
Author(s):  
Ariel Tarasiuk ◽  
Yoram Grossman
Keyword(s):  
Newborn Rats ◽  
Hyperbaric Pressure

Characterizing the Active Opening of the Eustachian Tube in a Hypobaric/Hyperbaric Pressure Chamber

2015 ◽  
Vol 36 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Stefanie Mikolajczak ◽  
Moritz Friedo Meyer ◽  
Moritz Hahn ◽  
Christine Korthäuer ◽  
Masen Dirk Jumah ◽  
...  
Keyword(s):  
Eustachian Tube ◽  
Pressure Chamber ◽  
Hyperbaric Pressure ◽  
Active Opening

Pulmonary lipid peroxides and fatty acids of rats fed different lipids and exposed to oxygen at hyperbaric pressure

Lipids ◽  
1985 ◽  
Vol 20 (4) ◽  
pp. 248-251 ◽  
Author(s):  
Syed Q. Alam ◽  
Bassima S. alam
Keyword(s):  
Fatty Acids ◽  
Lipid Peroxides ◽  
Hyperbaric Pressure

Tomato shelf-life extension at room temperature by hyperbaric pressure treatment

2013 ◽  
Vol 86 ◽  
pp. 45-52 ◽  
Author(s):  
Pansa Liplap ◽  
Denis Charlebois ◽  
Marie Thérèse Charles ◽  
Peter Toivonen ◽  
Clément Vigneault ◽  
...  
Keyword(s):  
Shelf Life ◽  
Room Temperature ◽  
Life Extension ◽  
Pressure Treatment ◽  
Shelf Life Extension ◽  
Hyperbaric Pressure

Mesangial cell gelatinase A synthesis is attenuated by oscillating hyperbaric pressure

2002 ◽  
Vol 362 (3) ◽  
pp. 693-700 ◽  
Author(s):  
Abdelaziz EN-NIA ◽  
Julia REISDORFF ◽  
Ioannis STEFANIDIS ◽  
Juergen FLOEGE ◽  
Peter C. HEINRICH ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Cellular Response ◽  
Mesangial Cells ◽  
Gelatin Zymography ◽  
Regulatory Sequence ◽  
Gelatinase A ◽  
Binding Studies ◽  
Cellular Mechanisms ◽  
Hyperbaric Pressure ◽  
Matrix Accumulation

Glomerular hypertension has been established as a major factor contributing to glomerular scarring. Underlying cellular mechanisms leading to matrix accumulation are largely unknown. The isolated effect of oscillating hyperbaric pressure [OP; Pmax 50mmHg (1mmHg = 0.133kPa), Pmean 24mmHg, with a fixed oscillation of 60/min] on matrix-degrading protease secretion by rat mesangial cells (MCs) was analysed using a pressure chamber model described previously [Mertens, Espenkott, Venjakob, Heintz, Handt and Sieberth (1998) Hypertension 32, 945–952]. MCs were grown under atmospheric pressure (AP) or a controlled OP, and protease synthesis and gene transcription were analysed. A distinct biphasic cellular response to OP with stimulated gelatinase A protein expression and enzyme activity during the initial 24h, and subsequent inhibition, was apparent, as shown by gelatin zymography. Gelatinase B activity remained unchanged. The abundance of gelatinase A transcripts, determined by reverse transcriptase-PCR, indicated a concordant regulation of gene transcription. To elucidate underlying regu latory events, reporter constructs were transfected. In these experiments, a recently identified response element, RE-1, conferred a significant stimulatory effect within the initial 4h of OP. Nuclear protein/RE-1 binding studies revealed additional complexes from 5min up to 3h after OP exposure, with intensities dependent on Pmax. STAT3 was identified as a component of these novel complexes. Down-regulation of cis-activity after 48h of OP exposure was not transferred via the proximal 1686bp of the gelatinase A regulatory sequence. In conclusion, hyperbaric OP elicits time-dependent changes in rat MC gelatinase A gene transcription.

scholarly journals Mesangial cell gelatinase A synthesis is attenuated by oscillating hyperbaric pressure

2002 ◽  
Vol 362 (3) ◽  
pp. 693 ◽  
Author(s):  
Abdelaziz EN-NIA ◽  
Julia REISDORFF ◽  
Ioannis STEFANIDIS ◽  
Juergen FLOEGE ◽  
Peter C. HEINRICH ◽  
...  
Keyword(s):  
Mesangial Cell ◽  
Gelatinase A ◽  
Hyperbaric Pressure

scholarly journals Measurements of tube function of patients after laryngectomy in a hypobaric/hyperbaric pressure chamber

2020 ◽  
Author(s):  
P Wolber ◽  
M Meyer ◽  
Jan-Christoffer Lüers
Keyword(s):  
Pressure Chamber ◽  
Hyperbaric Pressure ◽  
Tube Function
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