Femtosecond energy transfer between chromophores in allophycocyanin trimers

Ultrafast energy-transfer processes in allophycocyanin (APC) trimers from Mastigocladus laminosus have been examined by a femtosecond absorption technique. Isotropic absorption recovery kinetics with τ=440±30 fs were observed in APC trimers at 615 nm. In APC monomers such a fast process was not observed. The anisotropy in both samples was constant and close to 0.4 during the first few picoseconds. The results are consistent with a model of the APC trimer in which the two APC chromophores have different absorption spectra with maxima about 600 and 650 nm. The transfer of energy from the 600 nm chromophore to the 650 nm chromophore occurs in 440 fs and is dominated by the Förster dipole—dipole energy-transfer mechanism

CompHEP-PYTHIA interface: integrated package for the collision events generation based on exact matrix elements

CompHEP, as a partonic event generator, and PYTHIA, as a generator of final states of detectable objects, are interfaced. Thus, integrated tool is proposed for simulation of (almost) arbitrary collision processes at the level of detectable particles. Exact (multiparticle) matrix elements, convolution with structure functions, decays, partons hadronization and (optionally) parton shower evolution are basic stages of calculations. The PEVLIB library of event generators for LHC processes is described.Comment: Standard LaTeX, 4 pages. To appear in the proceedings of the Seventh International Workshop on Advanced Computing and Analysis Technics in Physics Research (ACAT2000, Fermilab, October 16-20, 2000

Identification of Trace Element-Containing Proteins in Genomic Databases

Development of bioinformatics tools provided researchers with the ability to identify full sets of trace element–containing proteins in organisms for which complete genomic sequences are available. Recently, independent bioinformatics methods were used to identify all, or almost all, genes encoding selenocysteine-containing proteins in human, mouse, and Drosophila genomes, characterizing entire selenoproteomes in these organisms. It also should be possible to search for entire sets of other trace element–associated proteins, such as metal-containing proteins, although methods for their identification are still in development

Some Aspects of Oxidation-Reduction Reactions under Carbon-Bearing Flux Welding

The authors have completed thermodynamic calculations of oxidation-reduction processes under submerged arc welding with application of carbon containing additive. The calculations have shown that carbon, due to its high reducing properties under Т=1950-2200 K, introduced into the system can significantly decrease the amount of non-metallic inclusions in the weld metal and so improve its mechanical properties

Optimal choice of prophylactic anticoagulant therapy for nonvalvular atrial fibrillation in the context of COVID-19 pandemic

Already at the very beginning of COVID-19 pandemic, it became known about the key clinical and pathogenetic significance of immunopathological reactions and disorders of hemostasis. Specific coagulopathy, microvascular thromboinflammatory organ damage, macrothrombosis and thromboembolism in the acute period of COVID-19, as well as secondary hemostasis disorders in convalescents, actualize the issues of caring patients with cardiovascular disease. COVID-19 not only increases the risk of thromboembolic events for patients with previously identified arrhythmias, but can also indirectly cause it (as a complication of infection or therapy). The aim of this work was to summarize the data and substantiate the optimal choice of prophylactic anticoagulant therapy for nonvalvular atrial fibrillation during the COVID-19 pandemic. Atrial fibrillation is not only the most common type of supraventricular tachyarrhythmia, but it is also the main underlying cause of more than half of cardioembolic stroke cases, which requires effective thromboprophylaxis. While maintaining the infectious danger for patients, the anticoagulant selection should take into account the possible dysfunctions and drug interactions during the initial infection or reinfection of COVID-19, as well as the possibility of rapid anticoagulant action reverse if surgery is required or bleeding develops. The optimal choice seems to be the use of dabigatran, which is characterized by the best safety profile for hepato- and nephrotoxicity, cytochrome P450-independent metabolism, and the presence of an antidote