1,017 research outputs found
Organizing Pneumonia by Paragonimiasis and Coexistent Aspergilloma Manifested as a Pulmonary Irregular Nodule
Organizing pneumonia by paragonimiasis and coexistent aspergilloma as a pulmonary nodule is a rare case of lung disease. Its radiographic or CT feature has not been described before in the radiologic literature. We present organizing pneumonia by paragonimiasis and coexistent aspergilloma manifested as a pulmonary irregular nodule on CT
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
The Evaluation of CP-001 (a Standardized Herbal Mixture of Houttuynia cordata
In the present study, the effect of CP-001, a standardized herbal mixture of Houttuynia cordata, Rehmannia glutinosa, Betula platyphylla, and Rubus coreanus, on cytochrome P450 (CYP) enzyme-mediated drug metabolism was investigated in vitro to evaluate the potential for herb-drug interactions. CP-001 was tested at concentrations of 1, 3, 10, 30, and 100 μg/mL. A CYP-specific substrate mixture was incubated with CP-001 in human liver microsomes, and the metabolites generated by each CYP-specific metabolic reaction were measured by liquid chromatography-tandem mass spectrometry. CP-001 seemed to slightly inhibit some CYP isozymes, but the IC50 values for all CYP isozymes were greater than 100 μg/mL. Furthermore, CP-001 did not exhibit time-dependent CYP inhibitory activities, indicating that it does not act as a mechanism-based inactivator of CYP enzymes. In conclusion, the effects of CP-001 on CYP isozyme activities were negligible at the concentrations tested. Therefore, the likelihood of herbal mixture-drug interaction is considered minimal
Crack-Resistance Behavior of an Encapsulated, Healing Agent Embedded Buffer Layer on Self-Healing Thermal Barrier Coatings
In this work, a novel thermal barrier coating (TBC) system is proposed that embeds silicon particles in coating as a crack-healing agent. The healing agent is encapsulated to avoid unintended reactions and premature oxidation. Thermal durability of the developed TBCs is evaluated through cyclic thermal fatigue and jet engine thermal shock tests. Moreover, artificial cracks are introduced into the buffer layer’s cross section using a microhardness indentation method. Then, the indented TBC specimens are subject to heat treatment to investigate their crack-resisting behavior in detail. The TBC specimens with the embedded healing agents exhibit a relatively better thermal fatigue resistance than the conventional TBCs. The encapsulated healing agent protects rapid large crack openings under thermal shock conditions. Different crack-resisting behaviors and mechanisms are proposed depending on the embedding healing agents
Crack-Growth Behavior in Thermal Barrier Coatings with Cyclic Thermal Exposure
Crack-growth behavior in yttria-stabilized zirconia-based thermal barrier coatings (TBCs) is investigated through a cyclic thermal fatigue (CTF) test to understand TBCs’ failure mechanisms. Initial cracks were introduced on the coatings’ top surface and cross section using the micro-indentation technique. The results show that crack length in the surface-cracked TBCs grew parabolically with the number of cycles in the CTF test. Failure in the surface-cracked TBC was dependent on the initial crack length formed with different loading levels, suggesting the existence of a threshold surface crack length. For the cross section, the horizontal crack length increased in a similar manner as observed in the surface. By contrast, in the vertical direction, the crack did not grow very much with CTF testing. An analytical model is proposed to explain the experimentally-observed crack-growth behavior
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
- …