719 research outputs found
Thiol-linked peroxidase activity of human ceruloplasmin
AbstractHuman ceruloplasmin exhibited different antioxidant effects according to the electron donors in a metal-catalyzed oxidation system. Purified ceruloplasmin did not play a significant role in the protection of DNA strand breaks in the ascorbate/Fe3+/O2 system. However, when ascorbates were replaced with a thiol-reducing equivalent such as dithiothreitol, DNA strand breaks were significantly prevented by the same amount of ceruloplasmin. Ceruloplasmin did not catalyze the decomposition of H2O2 in the absence of reduced glutathione. On the contrary, ceruloplasmin showed a potent peroxidase ability to destroy H2O2 in the presence of reduced glutathione. In conclusion, the removal of H2O2 by human ceruloplasmin is not simply stoichiometric but thiol-dependent
Endoplasmic Reticulum Stress and Insulin Biosynthesis: A Review
Insulin resistance and pancreatic beta cell dysfunction are major contributors to the pathogenesis of diabetes. Various conditions play a role in the pathogenesis of pancreatic beta cell dysfunction and are correlated with endoplasmic reticulum (ER) stress. Pancreatic beta cells are susceptible to ER stress. Many studies have shown that increased ER stress induces pancreatic beta cell dysfunction and diabetes mellitus using genetic models of ER stress and by various stimuli. There are many reports indicating that ER stress plays an important role in the impairment of insulin biosynthesis, suggesting that reduction of ER stress could be a therapeutic target for diabetes. In this paper, we reviewed the relationship between ER stress and diabetes and how ER stress controls insulin biosynthesis
GaAs droplet quantum dots with nanometer-thin capping layer for plasmonic applications
We report on the growth and optical characterisation of droplet GaAs quantum
dots with extremely-thin (11 nm) capping layers. To achieve such result, an
internal thermal heating step is introduced during the growth and its role in
the morphological properties of the quantum dots obtained is investigated via
scanning electron and atomic force microscopy. Photoluminescence measurements
at cryogenic temperatures show optically stable, sharp and bright emission from
single quantum dots, at near-infrared wavelengths. Given the quality of their
optical properties and the proximity to the surface, such emitters are ideal
candidates for the investigation of near field effects, like the coupling to
plasmonic modes, in order to strongly control the directionality of the
emission and/or the spontaneous emission rate, crucial parameters for quantum
photonic applications.Comment: 1 pages, 3 figure
Assessment in marine environment for a hypothetic nuclear accident based on the database of tidal harmonic constants
The eleven nuclear power plants in operation, under construction and a well-planned plant in the east coast of China
generally use seawater for reactor cooling. In this study, an oceanic dispersion assessment system based on a database
of tidal harmonic constants is developed. This system can calculate the tidal current without a large computational
cost, and it is possible to calculate real-time predictions of pollu-tant dispersions in the ocean. Calculated amplitudes
and phases have maximum errors of 10% and 20%with observations, respectively. A number of hypothetical
simulations were performed according to vary-ing of the release starting time and duration of pollutant for the six
nuclear sites in China. The developed system requires a computational time of one hour for one month of real-time
forecasting in Linux OS. Thus, it can use to evaluate rapidly the dispersion characteristics of the pollutants
released into the sea from a nuclear accident.European Union FP7 EURATOM project PREPARE 32328
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