Gaseous Oxygen for Hypothermic Preservation of Predamaged Liver Grafts: Fuel to Cellular Homeostasis or Radical Tissue Alteration?

Cryobiology ◽  
2000 ◽  
Vol 40 (2) ◽  
pp. 182-186 ◽  
Author(s):  
Thomas Minor ◽  
Martina Kötting
Keyword(s):  
Gaseous Oxygen ◽  
Cellular Homeostasis ◽  
Hypothermic Preservation ◽  
Tissue Alteration

Mitochondrial hyperfusion: a friend or a foe

2020 ◽  
Vol 48 (2) ◽  
pp. 631-644 ◽  
Author(s):  
Rajdeep Das ◽  
Oishee Chakrabarti
Keyword(s):  
Negative Impact ◽  
Cellular Stress ◽  
Cellular Homeostasis ◽  
Mitochondrial Population

The cellular mitochondrial population undergoes repeated cycles of fission and fusion to maintain its integrity, as well as overall cellular homeostasis. While equilibrium usually exists between the fission–fusion dynamics, their rates are influenced by organellar and cellular metabolic and pathogenic conditions. Under conditions of cellular stress, there is a disruption of this fission and fusion balance and mitochondria undergo either increased fusion, forming a hyperfused meshwork or excessive fission to counteract stress and remove damaged mitochondria via mitophagy. While some previous reports suggest that hyperfusion is initiated to ameliorate cellular stress, recent studies show its negative impact on cellular health in disease conditions. The exact mechanism of mitochondrial hyperfusion and its role in maintaining cellular health and homeostasis, however, remain unclear. In this review, we aim to highlight the different aspects of mitochondrial hyperfusion in either promoting or mitigating stress and also its role in immunity and diseases.

Downregulation of Hemeoxygenase-1 and Altered Cellular Homeostasis in Cystic Fibrosis

Pneumologie ◽  
2014 ◽  
Vol 68 (06) ◽  
Author(s):  
SP Chillappagari ◽  
S Venkatesan ◽  
V Garapati ◽  
P Mahavadi ◽  
A Munder ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Cellular Homeostasis

DEFLAGRATION-TO-DETONATION TRANSITION IN A STRATIFIED SYSTEM “GASEOUS OXYGEN-LIQUID FILM OF N-DECANE”

2020 ◽  
Author(s):  
S. M. FROLOV ◽  
◽  
V. S. AKSENOV ◽  
I. O. SHAMSHIN ◽  
◽  
...  
Keyword(s):  
Liquid Film ◽  
Ignition Source ◽  
Gaseous Oxygen ◽  
Deflagration To Detonation Transition ◽  
Operation Process ◽  
Continuous Detonation ◽  
Smooth Channel ◽  
Detonation Transition ◽  
Run Up ◽  
X 24

Deflagration-to-detonation transition (DDT) in the system “gaseous oxygen- liquid film of n-decane” ' with a weak ignition source was obtained experimentally. In a series of experiments with ignition by an exploding wire that generates a weak primary shock wave (SW) with a Mach number ranging from 1.03 to 1.4, the DDT with the detonation run-up distances 1 to 4 m from the ignition source and run-up time 3 ms to 1.7 s after ignition was observed in a straight smooth channel of rectangular 54 x 24-millimeter cross section, 3 and 6 m in length with one open end. The DDT is obtained for relatively thick films with a thickness of 0. 3-0.5 mm, which corresponds to very high values of the overall fuel-to-oxygen equivalence ratios of 20-40. The registered velocity of the detonation wave (DW) was 1400-1700 m/s. In a number of experiments, a high-velocity quasi-stationary detonation-like combustion front was recorded running at an average velocity of 700-1100 m/s. Its structure includes the leading SW followed by the reaction zone with a time delay of 90 to 190 s. The obtained results are important for the organization of the operation process in advanced continuous-detonation and pulsed-detonation combustors of rocket and air-breathing engines with the supply of liquid fuel in the form of a wall film.

Biological Activity of Trans-Membrane Anion Carriers

2018 ◽  
Vol 25 (30) ◽  
pp. 3560-3576 ◽  
Author(s):  
Massimo Tosolini ◽  
Paolo Pengo ◽  
Paolo Tecilla
Keyword(s):  
Biological Activity ◽  
Membrane Transport ◽  
Anticancer Agents ◽  
Biological Effects ◽  
Structure Activity Relationship ◽  
New Drugs ◽  
Activity Relationship ◽  
Anion Channels ◽  
Cellular Homeostasis ◽  
Structure Activity

Natural and synthetic anionophores promote the trans-membrane transport of anions such as chloride and bicarbonate. This process may alter cellular homeostasis with possible effects on internal ions concentration and pH levels triggering several and diverse biological effects. In this article, an overview of the recent results on the study of aniontransporters, mainly acting with a carrier-type mechanism, is given with emphasis on the structure/activity relationship and on their biological activity as antibiotic and anticancer agents and in the development of new drugs for treating conditions derived from dysregulation of natural anion channels.

Preliminary Studies on Non-Reactive Flow Vortex Cooling

2019 ◽  
Vol 12 (3) ◽  
pp. 262-271
Author(s):  
T.N. Rajesh ◽  
T.J.S. Jothi ◽  
T. Jayachandran
Keyword(s):  
Combustion Chamber ◽  
Inner Core ◽  
Rocket Engine ◽  
Injection Pressure ◽  
Chamber Pressure ◽  
Reactive Flow ◽  
Stoichiometric Ratio ◽  
Gaseous Oxygen ◽  
Mixture Ratio ◽  
Vortex Combustion

Background: The impulse for the propulsion of a rocket engine is obtained from the combustion of propellant mixture inside the combustion chamber and as the plume exhausts through a convergent- divergent nozzle. At stoichiometric ratio, the temperature inside the combustion chamber can be as high as 3500K. Thus, effective cooling of the thrust chamber becomes an essential criterion while designing a rocket engine. Objective: A new cooling method of thrust chambers was introduced by Chiaverni, which is termed as Vortex Combustion Cold-Wall Chamber (VCCW). The patent works on cyclone separators and confined vortex flow mechanism for providing high propellant mixing with improved degree of turbulence inside the combustion chamber, providing the required notion for studies on VCCW. The flow inside a VCCW has a complex structure characterised by axial pressure losses, swirl velocities, centrifugal force, flow reversal and strong turbulence. In order to study the flow phenomenon, both the experimental and numerical investigations are carried out. Methods: In this study, non-reactive flow analysis was conducted with real propellants like gaseous oxygen and hydrogen. The test was conducted to analyse the influence of mixture ratio and injection pressure of the propellants on the chamber pressure in a vortex combustion chamber. A vortex combustor was designed in which the oxidiser injected tangentially at the aft end near the nozzle spiraled up to the top plate and formed an inner core inside the chamber. The fuel was injected radially from injectors provided near the top plate and the propellants were mixed in the inner core. This resulted in enhanced mixing and increased residence time for the fuel. More information on the flow behaviour has been obtained by numerical analysis in Fluent. The test also investigated the sensitivity of the tangential injection pressure on the chamber pressure development. Results: All the test cases showed an increase in chamber pressure with the mixture ratio and injection pressure of the propellants. The maximum chamber pressure was found to be 3.8 bar at PC1 and 2.7 bar at PC2 when oxidiser to fuel ratio was 6.87. There was a reduction in chamber pressure of 1.1 bar and 0.7 bar at PC1 and PC2, respectively, in both the cases when hydrogen was injected. A small variation in the pressure of the propellant injected tangentially made a pronounced effect on the chamber pressure and hence vortex combustion chamber was found to be very sensitive to the tangential injection pressure. Conclusion: VCCW mechanism has been to be found to be very effective for keeping the chamber surface within the permissible limit and also reducing the payload of the space vehicle.

scholarly journals CISD2 maintains cellular homeostasis

2021 ◽  
pp. 118954
Author(s):  
Zhao-Qing Shen ◽  
Yi-Long Huang ◽  
Yuan-Chi Teng ◽  
Tai-Wen Wang ◽  
Cheng-Heng Kao ◽  
...  
Keyword(s):  
Cellular Homeostasis
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