Neutral Beam Current Drive in Globus-M Compact Spherical Tokamak

Plasma Physics Reports - The article presents research on neutral beam current drive in Globus-M compact spherical tokamak. The experiments were performed in the plasma current range of...     

Bacterial endotoxinemia in children with intestinal dysbacteriosis

34 children with gastrointestinal diseases of infectious, allergic and mixed etiology were examined. The state of normal microflora in the large intestine as indicated by fecal bacterial charts and the level of secretory immunoglobulin A (sIgA) in the contents of the intestine as indicated by the results of radial immunodiffusion were studied. In addition, the content of endotoxin in the children's plasma was determined with the use of the Limulus (LAL) test. The presence of endotoxin in the plasma of children with intestinal dysbiosis was determined in 71.1% of cases. The frequency of the detection of antigenemia was found to be related to the severity of manifestations of dysbiotic changes in the intestine and to the level of sIgA in fecal supernatants. The inclusion of the probiotic preparation Bifidumbacterin forte containing live bifidobacteria adsorbed on activated charcoal into the complex therapy of digestive tract diseases ensured a decrease in the detection rate of endotoxinemia, which correlated with the tendency towards the normalization of defective intestinal microflora.     

A theoretical study of the dioxygen activation by glucose oxidase and copper amine oxidase

Glucose oxidase (GO) and copper amine oxidase (CAO) catalyze the reduction of molecular oxygen to hydrogen peroxide. If a closed-shell cofactor (like FADH(2) in GO and topaquinone (TPQ) in CAO) is electron donor in dioxygen reduction, the formation of a closed-shell species (H(2)O(2)) is a spin forbidden process. Both in GO and CAO, formation of a superoxide ion that leads to the creation of a radical pair is experimentally suggested to be the rate-limiting step in the dioxygen reduction process. The present density functional theory (DFT) studies suggest that in GO, the creation of the radical pair induces a spin transition by spin orbit coupling (SOC) in O(2)(-)(rad), whereas in CAO, it is induced by exchange interaction with the paramagnetic metal ion (Cu(II)). In the rate-limiting step, this spin-transition is suggested to transform the O(2)(-)(rad)-FADH(2)(+)(rad) radical pair in GO and the Cu(II)-TPQ (triplet) species in CAO, from a triplet (T) to a singlet (S) state. For CAO, a mechanism for the O[bond]O cleavage step in the biogenesis of TPQ is also suggested.     

Ulysses - an application for the projection of molecular interactions across species

We developed Ulysses as a user-oriented system that uses a process called Interolog Analysis for the parallel analysis and display of protein interactions detected in various species. Ulysses was designed to perform such Interolog Analysis by the projection of model organism interaction data onto homologous human proteins, and thus serves as an accelerator for the analysis of uncharacterized human proteins. The relevance of projections was assessed and validated against published reference collections. All source code is freely available, and the Ulysses system can be accessed via a web interface .     

Pegasys: software for executing and integrating analyses of biological sequences

Background  

We present Pegasys – a flexible, modular and customizable software system that facilitates the execution and data integration from heterogeneous biological sequence analysis tools.     

Antibiotic resistance of Campylobacter and its epidemiologic significance

Sensitivity of 179 strains of thermophilic Campylobacter to 21 chemotherapeutic drugs was studied. Activity of the antibacterial agents against the pathogens was estimated by the MICs. The MIC50 and MIC90 were also determined. All the Campylobacter strains were sensitive to gentamicin, chloramphenicol, neomycin, furazolidone and furagin and resistant to cefazolin, polymyxin E, rifampicin, vancomycin and bacitracin. Differences in the attitude of the Campylobacter isolates from various sources and patients of various age groups to the chemotherapeutic drugs were detected. Possible consideration of the results of comparison of R spectra of Campylobacter strains and the levels of their resistance to antimicrobial drugs as epidemiological markers is discussed.     

Study of fast-ion losses in experiments on neutral beam injection on the Globus-M spherical tokamak

The paper presents a review of the main results on the heating of plasma ions and behavior of fast ions in experiments on neutral beam injection (NBI) carried out in 2003–2010 on the Globus-M spherical tokamak. It is noticed that, along with significant success achieved in NBI plasma heating, there is experimental evidence indicating significant losses of the power injected into the plasma. Most probably, the power is lost due to so-called first-orbit losses, i.e., losses of fast ions that are produced in plasma after ionization of beam atoms and occur in unconfined trajectories. Until recently, the absence of appropriate diagnostic equipment did not allow one to verify this hypothesis. The use of the ACORD-M charge-exchange analyzer directed tangentially to the plasma column made it possible to measure the spectra of fast ions slowed down in plasma and confirm the assumption on the presence of substantial orbit losses of fast particles (～25–50% of the beam power). In addition to the review of the experimental results, the paper presents analysis of orbit losses on the basis of 3D simulations of fast-ion trajectories in plasma. The results of experiments on studying the influence of the magnitude of the tokamak magnetic field on the confinement of fast ions are also presented. Along with computer simulations, these experiments made it possible to formulate recommendations on the reduction of orbit losses in the Globus-M tokamak.     

First Globus-M2 Results

Plasma Physics Reports - Globus-M2—a new 1-Tesla spherical tokamak—was recently launched. The main features and research directions of this machine in scope of fusion–fission...     

A Nanoscale Modification of Materials at Thermoplasmonic Laser-Induced Backside Wet Etching of Sapphire

Plasmonics - Laser-induced backside wet etching using water solution of plasmon precursor (AgNO3) as an absorbing medium provides effective structuring of such a complex material as sapphire. At...