Optical effects induced in silicon-doped wurtzite (0001) GaN epilayers by keV monatomic and molecular ion irradiation were experimentally investigated. Results were analyzed together with data on ...structure defect formation. In all the cases under consideration, an increase in the collision cascade density (the cases of molecular and heavy atomic ion bombardment) enhances the stable damage accumulation rate and, accordingly, intensifies quenching of luminescence. The processes of PL suppression were theoretically considered as an increase of surface recombination rate of nonequilibrium photo-excited charge carriers due to production of stable damage at the irradiated subsurface layer. It is shown that carrier diffusion determines PL decay time shortening in the shallow implantation cases studied.
The report reviews the options of drug supply for patients with chronic hepatitis C in the Russian Federation and elsewhere. The results of the Moscow regional program aimed at improving the quality ...of medical care in such patients are discussed. The proposed measures contribute to the reduced mortality rate in patients suffering from infections. The prospects of further improvements in the availability of antiviral medications for patients with chronic viral hepatitis C are outlined.
It reports results of the pump–probe experiment on colloidal solutions of semiconductor CdSe/ZnS quantum dots with 5 nm diameter for intense pulsed resonant excitation at 560 nm wavelength. The ...dependence of intensity of a transmitted probe pulse on time delay relative to the pump pulse was used to determine relaxation time τ
exc
of excited excitons in the QDs. The intensity of nonlinear reducing of QDs solution transmittance served the reason to set it for pump pulse. We found that the excited states in the QDs recombine within 300 ps after interaction with a 20-ps pump pulse.
Systemic lupus erythematosus (SLE) is a multisystem disease characterized by chronic inflammation and damage to vital organs and systems. Despite the great success achieved in the treatment of SLE, ...glucocorticoids (GC) remain one of the main methods of therapy. The GC toxicity index is an objective method for assessing adverse events associated with their use, and in future studies can be actively used to monitor the safety of various therapy regimens. Wider introduction of this index in the management of patients with SLE will allow to optimize approaches to the selection of GC doses, to consider earlier prescription of biologic disease modifying antirheumatic drugs, before the development of severe irreversible damage.
The causes of the occurrence and the method of the elimination of defects of non-bridging oxygen in multimode fluorosilicate optical fibers prepared by the modified method of chemical vapor ...deposition are considered. The solution is the use of support tubes obtained by quartz surfacing in a hydrogen atmosphere. In this case, there is no absorption band in a range of 630 nm caused by nonbridging oxygen in the spectrum of optical losses of gradient fluorosilicate optical fibers of W-type. Attenuation in a visible spectrum range is mainly determined by the level of Rayleigh scattering and the mode dispersions at a wavelength of 342 and 683 nm are 1.2 ± 0.1 and 0.7 ± 0.2 ps/m, respectively.
The paper presents data on the leaching efficiency of rare-earth (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and radioactive (Th and U) elements by various reagents from alkaline ...rocks of the Lovozero Massif. Element concentrations were analyzed by ICP-MS and instrumental neutral activation (INAA). A new complex technique is suggested for analyzing elements on the solid phase of polymer hydrogels. This technique makes it possible to enhance the sensitivity and selectivity of INAA when these elements are simultaneously contained in rocks. Data are presented on the selective leaching of trace elements and the application of environmentally safe reagents.
Listeria monocytogenes is motile at 22°C and non-motile at 37°C. In contrast, expression of L. monocytogenes virulence factors is low at 22°C and up-regulated at 37°C. Here, we studied a character of ...L. monocytogenes near surface swimming (NSS) motility and its effects on adhesion patterns and invasion into epithelial cells. L. monocytogenes and its saprophytic counterpart L. innocua both grown at 22°C showed similar NSS characteristics including individual velocities, trajectory lengths, residence times, and an asymmetric distribution of velocity directions. Similar NSS patterns correlated with similar adhesion patterns. Motile bacteria, including both pathogenic and saprophytic species, showed a preference for adhering to the periphery of epithelial HEp-2 cells. In contrast, non-motile bacteria were evenly distributed across the cell surface, including areas over the nucleus. However, the uneven distribution of motile bacteria did not enhance the invasion into HEp-2 cells unless virulence factor production was up-regulated by the transient shift of the culture to 37°C. Motile L. monocytogenes grown overnight at 22°C and then shifted to 37°C for 2 h expressed invasion factors at the same level and invaded human cells up to five times more efficiently comparatively with non-motile bacteria grown overnight at 37°C. Taken together, obtained results demonstrated that (i) NSS motility and correspondent peripheral location over the cell surface did not depend on L. monocytogenes virulence traits; (ii) motility improved L. monocytogenes invasion into human HEp-2 cells within a few hours after the transition from the ambient temperature to the human body temperature.
Sustainable product development of an automotive structure requires a balanced approach towards technological, economical and ecological aspects. Current paper shows the application of a structural ...optimization system to the optimal choice of foams as a core material for sandwiches with aluminum alloy faces, for the use as floor panels in the bottom structure of a concept car. The minimization problem for the weight of the entire bottom structure under static load conditions, including stiffness, strength and buckling constraints, is formulated and solved for each material application. In addition to optimal (minimized) mass and materials' price used for selection of foams, the assessment of an environmental impact of materials-candidates during the entire life cycle of the structure is considered.
Multiple lung pathogens such as chemical agents, H5N1 avian flu, or SARS cause high lethality due to acute respiratory distress syndrome. Here we report that Toll-like receptor 4 (TLR4) mutant mice ...display natural resistance to acid-induced acute lung injury (ALI). We show that TLR4-TRIF-TRAF6 signaling is a key disease pathway that controls the severity of ALI. The oxidized phospholipid (OxPL) OxPAPC was identified to induce lung injury and cytokine production by lung macrophages via TLR4-TRIF. We observed OxPL production in the lungs of humans and animals infected with SARS, Anthrax, or H5N1. Pulmonary challenge with an inactivated H5N1 avian influenza virus rapidly induces ALI and OxPL formation in mice. Loss of TLR4 or TRIF expression protects mice from H5N1-induced ALI. Moreover, deletion of
ncf1, which controls ROS production, improves the severity of H5N1-mediated ALI. Our data identify oxidative stress and innate immunity as key lung injury pathways that control the severity of ALI.
As is known, an increase of production extracted from raw material can be attained by mining of new deposits, on the one hand, and, on the other hand, by the development of new technologies including ...a decrease in the consumption of reagents and energy while providing ecologically safe works. It becomes apparent that one of the main problems in the industrial analysis of mineral raw materials is search for econom ical methods of trace element extraction from solutions that will provide completeness, required accuracy, and reproducibility. Problems that arise in determining the trace elements in multicomponent solutions by classical methods are primarily related to the high salt back ground of the solutions.
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