45 research outputs found
Observable effects caused by vacuum pair creation in the field of high-power optical lasers
We consider the possibility of an experimental proof of vacuum e+e- pair
creation in the focus of two counter-propagating optical laser beams with an
intensity of the order of 10^20 - 10^22 W/cm^2. Our approach is based on the
collisionless kinetic equation for the distribution function of the e+e- pairs
with the source term for particle production. As a possible experimental signal
of vacuum pair production we consider the refraction of a high-frequency probe
laser beam by the produced e+e- plasma to be observed by an interference
filter. The generation of higher harmonics of the laser frequency in the
self-consistent electric field is also investigated.Comment: 7 pages, 7 figures; typos corrected, Eq.(16) corrected, reference
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Effect of zinc doping on electrical properties of LaAlO3 perovskite
New solid solution with the general formula of LaAl1-xZnxO3-1/2x was prepared by a solid-state reaction route. According to XRD, the crystal structure of LaAlO3 is rhombohedral, while the solid solution possesses cubic symmetry. Homogeneity region of the solid solution LaAl1-xZnxO3-1/2x was narrow and limited to the maximum concentration of 5 mol. %. Computer simulations using crystalochemistry and density functional theory approaches showed that LaAlO3 has high energy barriers for O2–-ion transport (2.79 eV). These results are in good agreement with the low values of electrical conductivity obtained experimentally. The electrical conductivity of LaAl1-xZnxO3-1/2x was measured by impedance spectroscopy in the temperature range of 200–1000 °C. The partial substitution of Al3+ by Zn2+ was found to increase the electrical conductivity by ~2 order of magnitude. The electrical conductivity of doped phase LaAl0.95Zn0.05O2.975 as a function of oxygen partial pressure was measured, and the partial contributions (oxygen-ionic and electronic) were determined. It was found that the sample has mixed ionic and p-type electronic conductivity, while the electronic contribution increases with the rise of the temperature
A Novel C1q Domain-Containing Protein Isolated from the Mollusk Modiolus kurilensis Recognizing Glycans Enriched with Acidic Galactans and Mannans
C1q domain-containing (C1qDC) proteins are a group of biopolymers involved in immune response as pattern recognition receptors (PRRs) in a lectin-like manner. A new protein MkC1qDC from the hemolymph plasma of Modiolus kurilensis bivalve mollusk widespread in the Northwest Pacific was purified. The isolation procedure included ammonium sulfate precipitation followed by affinity chromatography on pectin-Sepharose. The full-length MkC1qDC sequence was assembled using de novo mass-spectrometry peptide sequencing complemented with N-terminal Edman’s degradation, and included 176 amino acid residues with molecular mass of 19 kDa displaying high homology to bivalve C1qDC proteins. MkC1qDC demonstrated antibacterial properties against Gram-negative and Gram-positive strains. MkC1qDC binds to a number of saccharides in Ca(2+)-dependent manner which characterized by structural meta-similarity in acidic group enrichment of galactose and mannose derivatives incorporated in diversified molecular species of glycans. Alginate, κ-carrageenan, fucoidan, and pectin were found to be highly effective inhibitors of MkC1qDC activity. Yeast mannan, lipopolysaccharide (LPS), peptidoglycan (PGN) and mucin showed an inhibitory effect at concentrations three orders of magnitude greater than for the most effective saccharides. MkC1qDC localized to the mussel hemal system and interstitial compartment. Intriguingly, MkC1qDC was found to suppress proliferation of human adenocarcinoma HeLa cells in a dose-dependent manner, indicating to the biomedical potential of MkC1qDC protein
CRISPR/Cas9-generated mouse model with humanizing single-base substitution in the Gnao1 for safety studies of RNA therapeutics
The development of personalized medicine for genetic diseases requires preclinical testing in the appropriate animal models. GNAO1 encephalopathy is a severe neurodevelopmental disorder caused by heterozygous de novo mutations in the GNAO1 gene. GNAO1 c.607 G>A is one of the most common pathogenic variants, and the mutant protein Gαo-G203R likely adversely affects neuronal signaling. As an innovative approach, sequence-specific RNA-based therapeutics such as antisense oligonucleotides or effectors of RNA interference are potentially applicable for selective suppression of the mutant GNAO1 transcript. While in vitro validation can be performed in patient-derived cells, a humanized mouse model to rule out the safety of RNA therapeutics is currently lacking. In the present work, we employed CRISPR/Cas9 technology to introduce a single-base substitution into exon 6 of the Gnao1 to replace the murine Gly203-coding triplet (GGG) with the codon used in the human gene (GGA). We verified that genome-editing did not interfere with the Gnao1 mRNA or Gαo protein synthesis and did not alter localization of the protein in the brain structures. The analysis of blastocysts revealed the off-target activity of the CRISPR/Cas9 complexes; however, no modifications of the predicted off-target sites were detected in the founder mouse. Histological staining confirmed the absence of abnormal changes in the brain of genome-edited mice. The created mouse model with the “humanized” fragment of the endogenous Gnao1 is suitable to rule out unintended targeting of the wild-type allele by RNA therapeutics directed at lowering GNAO1 c.607 G>A transcripts
Diabetes mellitus type 2 in adults
Public organization “Russian Association of Endocrinologists”. Clinical guidelines. 
Diabetes mellitus type 1 in adults
Public organization “Russian Association of Endocrinologists”. Clinical guidlines
Energetic particle influence on the Earth's atmosphere
This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally
galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere
are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere
WSES guidelines for management of Clostridium difficile infection in surgical patients
In the last two decades there have been dramatic changes in the epidemiology of Clostridium difficile infection (CDI), with increases in incidence and severity of disease in many countries worldwide. The incidence of CDI has also increased in surgical patients. Optimization of management of C difficile, has therefore become increasingly urgent. An international multidisciplinary panel of experts prepared evidenced-based World Society of Emergency Surgery (WSES) guidelines for management of CDI in surgical patients.Peer reviewe