Mechanisms of photosensitization PY1983 glutathione IR95
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Photochem Photobiol
. 1983 Dec;38(6):745-51. doi: 10.1111/j.1751-1097.1983.tb03610.x.
Mechanisms of photosensitization
A W Girotti
PMID: 6366837 DOI: 10.1111/j.1751-1097.1983.tb03610.x
No abstract available
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S-Glutathionylation: From Molecular Mechanisms to Health Outcomes PY2011 IR95 Glutathione as a biological redox buffer
資訊來源：
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3110090/
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Glutathione as a biological redox buffer.
重要重點
Glutathione as a biological redox buffer. The ratio of GSH/GSSG reflects the redox capacity of the cell. The ratio is kept in balance through oxidation/reduction reactions involving GSH peroxidase and GSH reductase. Reactive oxygen species-/reactive nitrogen species-induced changes that decrease GSH lead to cell death via apoptosis or necrosis.
GP, GSH peroxidase; GR, GSH reductase; GSH, reduced glutathione; GSSG, oxidized glutathione.
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重要重點
Intracellular GSH levels are governed by the rate of de novo GSH synthesis and export. GSH cannot freely cross the cell membrane and as such there are GSH transporters in some tissues and enzymes that facilitate catalysis and uptake. In general, GSH must be catabolized via a salvage pathway and the constitutive amino acids brought into the cell for subsequent de novo synthesis.
重點
To date, only one enzyme is known to facilitate this process. Gamma-glutamyltransferase (GGT) is a cell surface heterodimeric glycoprotein expressed at high levels in kidney tubules, biliary epithelium, and brain capillaries (112). GGT catalyzes the degradation of extracellular GSH, hydrolyzing the γ-glutamyl bond between glutamate and cysteine and releasing the product cysteinyl-glycine (CG) and glutamate. CG is cleaved by the membrane-bound dipeptidase to cysteine and glycine (Fig. 2). The resulting cysteine can be transported into the cell. This salvage supplements the constitutive amino acids required for de novo synthesis, achieved by sequential catalytic steps involving γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase. The γ-GCS reaction represents the committed step in the biosynthesis and is subject to feedback inhibition by GSH, but cysteine is rate limiting. Reactions of GSH can be subdivided into those involving the γ-glutamyl and those of the sulfhydryl of cysteine. The amino terminal peptide bond is formed through the γ-carboxyl of the glutamate residue. This bond is resistant to degradation by serum proteolytic enzymes and this allows interorgan transport of GSH.
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Measurement of electron density and temperature in an annular magnetically confined cold-cathode plasma of helium by optical emission spectroscopy PY2022 中國，氦氣，氦原子，電子的密度
資訊來源：
德國的博士論文：
Electron Density in a Helium Discharge Plasma
https://www.uni-frankfurt.de/49398667/bachelorarbeit_christian_kuechler.pdf
關鍵字詞：
electron density map, helium
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RESEARCH ARTICLE JANUARY 28 2022
Measurement of electron density and temperature in an annular magnetically confined cold-cathode plasma of helium by optical emission spectroscopy
Hao Sun ; Yushi Zhang ; Lingxiao Li ; Yi Wu; Mingzhe Rong
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Author to whom correspondence should be addressed: wuyic51@mail.xjtu.edu.cn
Physics of Plasmas 29, 013511 (2022)
https://doi.org/10.1063/5.0067380
Magnetically confined cold-cathode plasmas in monatomic gases like helium can be used in a variety of devices and applications. In this paper, the radial distribution of electron temperature and electron density in cold-cathode helium plasmas constrained by an annular magnetic field were studied by optical emission spectroscopy. Helium plasma was generated under different pressures (7.5, 10, and 20 Pa) and values of current (23.5 and 33 mA). The spectral lines of He I 667.8 and He I 501.6 nm were studied and the Stark broadening method was applied to obtain the radial distributions of electron temperature and electron density. The results indicate that higher radial gradients or peak values of both electron density and electron temperature could be achieved with increasing operating pressures and discharge currents. It was found that the electrons were mainly concentrated in the area of the localized cusp magnetic field near the cathode surface and the electron density decreased rapidly as with the decrease in the magnetic field.
Topics
Electron density, Doppler effect, Integral transforms, Stark effect, Chemical elements, Cold cathodes, Optical emission spectroscopy, Gaussian broadening, Gas discharges, Plasmas
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