Optimal electron, phonon, and magnetic characteristics for low energy thermally induced magnetization switching

Using large-scale computer simulations, we thoroughly study the minimum energy required to thermally induced magnetization switching (TIMS) after the application of a femtosecond heat pulse in transition metal-rare earth ferrimagnetic alloys. We find that for an energy efficient TIMS, a low ferrimagnetic net magnetization with a strong temperature dependence is the relevant factor for the magnetic system. For the lattice and electron systems, the key physics for efficient TIMS is a large electron-phonon relaxation time. Importantly, we show that as the cooling time of the heated electrons is increased, the minimum power required to produce TIMS can be reduced by an order of magnitude. Our results show the way to low power TIMS by appropriate engineering of magnetic heterostructures

Unified decoupling scheme for exchange and anisotropy contributions and temperature-dependent spectral properties of anisotropic spin systems

We compute the temperature-dependent spin-wave spectrum and the magnetization for a spin system using the unified decoupling procedure for the high-order Green's functions for the exchange coupling and anisotropy, both in the classical and quantum case. Our approach allows us to establish a clear crossover between quantum-mechanical and classical methods by developing the classical analog of the quantum Green's function technique. The results are compared with the classical spectral density method and numerical modeling based on the stochastic Landau-Lifshitz equation and the Monte Carlo technique. As far as the critical temperature is concerned, there is a full agreement between the classical Green's functions technique and the classical spectral density method. However, the former method turns out to be more straightforward and more convenient than the latter because it avoids any \emph{a priori} assumptions about the system's spectral density. The temperature-dependent exchange stiffness as a function of magnetization is investigated within different approaches

The possibility of hyperbaric oxygenation in the correction of the secretory impaired fertility in men

The infertility problem during a marriage affects demographic indicators significantly and has not only medical and biological but important social significance as well. In Russia, about 20 % of married couples remain infertile. With that, in half of cases this is caused with pathological changes in male reproductive system. Until now, a comprehensive andrologic examination is not capable of finding out the reason of pathospermia in 40–72 % of cases of male infertility and, as a result, of assigning the appropriate etiotropic treatment. A comparative dynamic study of spermograms of 107 patients with idiopathic pathozoospermia depending on various types of treatment has been held immediately, 1 month, and 2 months after completion of the therapy course. It has been determined that significantly greater and sustained improvement in quality and quantity of ejaculate is achieved in 1 month as compared to monotherapy with L-carnitine in combination with hyperbaric oxygenation by eliminating the effects of hypoxia and oxidativestress, and the effect is maintained during the whole term of observation

The use of microarrays for the identification of the origin of genes of avian influenza viruses in wild birds

Forty-two strains of avian influenza viruses were isolated from the wild waterfowls’ feces in the city of Moscow. These viruses, as well as reference strains and some experimental reassortants, were analyzed by microarrays. The microarrays contained 176 probes to the different segments of influenza virus genome. The microarray helps to determine 1) the hemagglutinin and neuraminidase proteins subtype; 2) the primary structure of the C-terminal sequence of the viral NS1 protein, which serves as a ligand for the PDZ domain; 3) the presence of stop codons in the reading frame of PB1-F2 as well as the N66S substitution in the PB1-F2 viral protein; 4) the presence of the polybasic site for hemagglutinin cleavage. The viruses of the H3N1, H3N6, H3N8, H4N6, H1N1, H5N3, and H11N9 subtypes were identified from the group of wild birds’ isolates. All isolates contained the ESEV sequence at the C-terminus of the NS1 protein and the full-length reading frame for the PB1-F2 protein. The replacement of N66S in PB1-F2 was found in six strains. However, the presence of the ESEV sequence (ligand of PDZ domain) in the NS1 virus protein and the N66S substitution in PB1-F2 did not lead to the pathogenicity of these viruses for mice. All isolates demonstrated high yield growth in chicken embryos and were infectious and immunogenic for mice, but did not induce any clinical symptoms.Forty-two strains of avian influenza viruses were isolated from the wild waterfowls’ feces in the city of Moscow. These viruses, as well as reference strains and some experimental reassortants, were analyzed by microarrays. The microarrays contained 176 probes to the different segments of influenza virus genome. The microarray helps to determine 1) the hemagglutinin and neuraminidase proteins subtype; 2) the primary structure of the C-terminal sequence of the viral NS1 protein, which serves as a ligand for the PDZ domain; 3) the presence of stop codons in the reading frame of PB1-F2 as well as the N66S substitution in the PB1-F2 viral protein; 4) the presence of the polybasic site for hemagglutinin cleavage. The viruses of the H3N1, H3N6, H3N8, H4N6, H1N1, H5N3, and H11N9 subtypes were identified from the group of wild birds’ isolates. All isolates contained the ESEV sequence at the C-terminus of the NS1 protein and the full-length reading frame for the PB1-F2 protein. The replacement of N66S in PB1-F2 was found in six strains. However, the presence of the ESEV sequence (ligand of PDZ domain) in the NS1 virus protein and the N66S substitution in PB1-F2 did not lead to the pathogenicity of these viruses for mice. All isolates demonstrated high yield growth in chicken embryos and were infectious and immunogenic for mice, but did not induce any clinical symptoms

In-vivo Studies of Ultrasound-activated Drug-loaded Porous Silicon Nanoparticles for Cancer Therapy Application

It is investigated the therapeutic efficacy of combined action of ultrasound and porous silicon nanoparticles loaded with anticancer drug doxorubicin by using an experimental cancer model of lung Lewis carcinoma in vivo. Time dependences of growth of the primary tumor with introduced nanoparticles and without them, as well as the life span of mice after exposure to therapeutic ultrasound with intensity of 1W/cm2 and frequency of 1 MHz were studied. The obtained results show the effectiveness of inhibiting the growth of primary tumor site, as well as slowing the process of metastasis, in the case of combined action of ultrasound and drug-loaded porous silicon nanoparticles that indicates the prospect of latter as sonosensitizers and nanocontainers for the delivery and controlled release of drugs in sonodynamic therapy of malignant tumors. Keywords: silicon nanoparticles, nanocontainers, medical ultrasound, sonodynamic therapy, sonosensitizer

Review on uranium in soil: levels, migration

The problems of radioactive contamination of biosphere with the 238U in recent years have attracted a large number of experts in various fields of knowledge. Natural radionuclides are an integral part of the biosphere. They are concentrated everywhere: in rocks, in soil, water, air and food. Various types of phosphorus fertilizers and other natural ameliorants used in agriculture are also an additional source of heavy natural radionuclides. The review describes the behaviour and migration of 238U in biosphere, which depend on various factors acting simultaneously. It is noted that the behaviour of 238U in the soil depends on the forms of its presence in it and the physical and chemical properties of the soil. The processes of sorption and desorption of 238U by different soil types are significant indicators

Radionuclide biological half-life values for terrestrial and aquatic wildlife

The equilibrium concentration ratio is typically the parameter used to estimate organism activity concentrations within wildlife dose assessment tools. Whilst this is assumed to be fit for purpose, there are scenarios such as accidental or irregular, fluctuating, releases from licensed facilities when this might not be the case. In such circumstances, the concentration ratio approach may under- or over-estimate radiation exposure depending upon the time since the release. To carrying out assessments for such releases, a dynamic approach is needed. The simplest and most practical option is representing the uptake and turnover processes by first-order kinetics, for which organism- and element-specific biological half-life data are required. In this paper we describe the development of a freely available international database of radionuclide biological half-life values. The database includes 1907 entries for terrestrial, freshwater, riparian and marine organisms. Biological half-life values are reported for 52 elements across a range of wildlife groups (marine = 9, freshwater = 10, terrestrial = 7 and riparian = 3 groups). Potential applications and limitations of the database are discussed

The role of the CNTNAP2 gene in the development of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder in which genetic and environmental factors interact in its development. Research suggests that the contactin associated protein 2 (CNTNAP2) gene may play a role in ASD pathophysiology, yet more studies involving human participants and animal models of autism are needed. One such model may be the use of prenatal valproic acid (VPA) model to induce autism-like behaviors in offspring rats. The aim of this study was twofold: (1) to examine the association of the CNTNAP2 gene rs2710102 variant with ASD in children; and (2) to examine the effect of prenatal exposure to VPA on Cntnap2 gene expression in the rat brain. The study included 167 children of European ancestry—81 diagnosed with ASD (20 girls, 61 boys; age 4.9±1.4 years) and 86 controls (44 girls, 42 boys; 5.1±1.2 years). In vivo experiments were conducted in 80 rats (40 with the VPA model of autism), with Cntnap2 gene expression analysis in the amygdala, hippocampus, prefrontal cortex, and cerebellum. Results demonstrated that the frequency of the CNTNAP2 gene rs2710102 GG genotype was significantly higher in children with ASD when compared with controls (33.3 vs 19.8%; OR=2.03, 95%CI [1.004, 4.102], p = 0.035), although, potentially due to bias in cohort selection, in the ASD children this polymorphism did not meet Hardy-Weinberg expectations (χ2 =5.40, p = 0.02). In addition, Cntnap2 gene expression was significantly lower (p < 0.01) in the amygdala and hippocampus of VPA rats when compared with controls, regardless of sex. These results support previous research and provide evidence for the CNTNAP2 gene as a risk factor for AS