Magnetic properties of ferro-antiferromagnetic spin triangle chain.

Frustrated spin-12model consisting of a linear chain of triangles with ferro (F)- and antiferromagnetic interactions connected by ferromagnetic interactions (triangles chain) is studied. The ground state phase diagram depending on the interaction ratios consists of ferromagnetic, two ferrimagnetic and singlet phases. The magnetic properties in these phases are analyzed both analytically and numerically.

Magnetic properties of delta- and kagome-like chains with competing interactions.

We study the delta-chain with spin-1 on basal sites and spin-12on apical sites. The Heisenberg interaction between neighbor basal spins is antiferromagnetic (AF) and the interaction between basal and apical spins is ferromagnetic (F). We show that the magnetization curve of this model is the same as that of the spin-12kagome-like chain with competing Heisenberg interactions.

Oxidative damage to β-crystallin in vitro by iron compounds formed in physiological buffers.

β-crystallin aggregation due to oxidative damage in the presence of HO and ferric chloride was studied in-vitro under conditions close to physiological. It was shown that the protein aggregation characterized by the nucleation time and the aggregation rate significantly depended on the composition of the isoosmotic buffers used, and decreased in the series HEPES buffer > Tris buffer > PBS. Ferric chloride at neutral pH was converted into water-insoluble iron hydroxide III (≡FeOH).

Inflammation Regulation by Bacterial Molecular Patterns.

Stimulation of innate immunity by bacterial molecular patterns can induce an enhanced cellular immune response to pathogens that are associated with innate immune memory shaped by epigenetic changes. Immunological memory can be expressed in the acceleration/intensification of inflammation, as well as in the exact opposite-to maintain tolerance and non-response to a repeated stimulus. Tolerance is one of the central concepts of immunity and is ensured by the consistency of all parts of the immune response.

Spin triangle chain with ferromagnetic and antiferromagnetic interactions on the transition line.

We investigate spin-12anisotropic model of a linear chain of triangles with competing ferro- and antiferromagnetic interactions and ferromagneic Heisenberg interactions between triangles. For a certain ratio between interactions the one-magnon excitation band is dispersionless leading to an existence of localized-magnon states which form macroscopically degenerated ground states. The spectrum of excitations has a specific structure depending on the value of the triangle-triangle interaction.

Tunable Single-Atomic Charges on a Cleaved Intercalated Transition Metal Dichalcogenide.

Control of a single ionic charge state by altering the number of bound electrons has been considered as an ultimate testbed for atomic charge-induced interactions and manipulations, and such subject has been studied in artificially deposited objects on thin insulating layers. We demonstrate that an entire layer of controllable atomic charges on a periodic lattice can be obtained by cleaving metallic CoNbS, an intercalated transition metal dichalcogenide. We identified a metastable charge state of Co with a different valence and manipulated atomic charges to form a linear chain of the metastable charge state.

Chromosome Folding Promotes Intrachromosomal Aberrations under Radiation- and Nuclease-Induced DNA Breakage.

The long-standing question in radiation and cancer biology is how principles of chromosome organization impact the formation of chromosomal aberrations (CAs). To address this issue, we developed a physical modeling approach and analyzed high-throughput genomic data from chromosome conformation capture (Hi-C) and translocation sequencing (HTGTS) methods. Combining modeling of chromosome structure and of chromosomal aberrations induced by ionizing radiation (IR) and nuclease we made predictions which quantitatively correlated with key experimental findings in mouse chromosomes: chromosome contact maps, high frequency of cis-translocation breakpoints far outside of the site of nuclease-induced DNA double-strand breaks (DSBs), the distinct shape of breakpoint distribution in chromosomes with different 3D organizations.

Two-dimensional spin models with macroscopic degeneracy.

We consider a class of anisotropic spin-12models with competing ferro- and antiferromagnetic interactions on two-dimensional Tasaki and kagome lattices consisting of corner sharing triangles. For certain values of the interactions the ground state is macroscopically degenerated in zero magnetic field. In this case the ground state manifold consists of isolated magnons as well as the bound magnon complexes.

Slow-binding inhibitors of acetylcholinesterase of medical interest.

Certain ligands slowly bind to acetylcholinesterase. As a result, there is a slow establishment of enzyme-inhibitor equilibrium characterized by a slow onset of inhibition prior reaching steady state. Three mechanisms account for slow-binding inhibition: a) slow binding rate constant k, b) slow ligand induced-fit following a fast binding step, c) slow conformational selection of an enzyme form.

On the Edge of Bilayered Graphene: Unexpected Atomic Geometry and Specific Electronic Properties.

The tendency of bilayered graphene edges to connect with each other allows to create hollow sp-hybridized material with specific electronic properties. However, the unknown geometry of the formed edges hinders further investigation. Here we show that a closed bigraphene edge can be represented as a connection of generally misoriented graphene domains with topological defects and can be further described by grain boundary theory.

Stability and gas sensing properties of TaXM (X = Pd, Pt; M = S, Se) nanoribbons: a first-principles investigation.

One dimensional Ta2(Pd/Pt)3(S/Se)8 nanoribbons (TPS-NR) are considered as a promising material in nanoelectronics due to their intrinsic semiconducting electronic properties. In this article, we study the stability of TPS-NR by considering their oxidation process. Our calculations showed that the Ta2(Pd/Pt)3Se8 nanoribbons are more environmentally stable than Ta2(Pd/Pt)3S8-NR.

Electric field effect in bilayered graphene nanomeshes.

The effect of applying an external electric field on the electronic properties of nanoporous bilayered graphene is reported. Such an effect was demonstrated on bilayered graphene structures with various types of stacking and relative arrangements of nanopores. The direct-indirect band gap transformation combined with significant changes of electronic band structure behavior was predicted.

Cationic penetrating antioxidants switch off Mn cluster of photosystem II in situ.

Mitochondria-targeted antioxidants (also known as 'Skulachev Ions' electrophoretically accumulated by mitochondria) exert anti-ageing and ROS-protecting effects well documented in animal and human cells. However, their effects on chloroplast in photosynthetic cells and corresponding mechanisms are scarcely known. For the first time, we describe a dramatic quenching effect of (10-(6-plastoquinonyl)decyl triphenylphosphonium (SkQ1) on chlorophyll fluorescence, apparently mediated by redox interaction of SkQ1 with Mn cluster in Photosystem II (PSII) of chlorophyte microalga Chlorella vulgaris and disabling the oxygen-evolving complex (OEC).

Heisenberg-Ising delta-chain with bond alternation.

The spin-[Formula: see text] delta-chain (sawtooth chain) with antiferromagnetic Heisenberg basal chain and Ising apical-basal interactions is studied. The basal-apical interactions involve the bond alternation. The limiting cases of the model include the symmetrical delta-chain and the antiferromagnetic chain in the staggered magnetic field.

How regularities of mortality statistics explain why we age despite having potentially ageless somatic stem cells.

Researchers working in the area of ageing have found numerous manifestations of this process at the molecular biological level, including DNA and protein damage, accumulation of metabolic by-products, lipids peroxidation, macromolecular cross-linking, non-enzymatic glycosylation, anti-oxidant/pro-oxidant misbalance, rising of pro-inflammatory cytokines, etc. This results in an increase in the proportion of cells in growth arrest, reduction of the rate of information processing, metabolic rate decrease, and decrease in rates of other processes characterizing dynamic aspects of the organism's interaction with its environment. Such staggering multilevel diversity in manifestation of senescence precludes (without methodology of systems biology) development of a correct understanding of its primary causes and does not allow for developing approaches capable of postponing ageing or reducing organisms' ageing rate to attain health preservation.

[Detection of effective treatment of amnestic mild cognitive impairement with cereton by testing of lipids markers].

Aim: Determination of effectivity and safety of Cereton (Choline alfoscerate, production by Sotex) 1200 mg/day in the treatment of cognitive functioning disorders in patients with amnestic mild cognitive impairment (aMCI) and determining its influence in the process (after a 3 month course of taking the drug) and 3 months after the end of treatment of aMCI on the change in the content of phosphatidylcholine, sphingomyelin, ceramide-metabolite sphingolipids and the activity of genes controlling the synthesis of enzymes, which control ithe metabolism of sphingomyelin and ceramide (sphingomyelinase and ceramidase).

Material And Methods: The study involved a group of elderly patients (20 people), consisting of 14 women and 6 men, aged 51 to 82 years (mean age 70.3±9.

Kagome-like chains with anisotropic ferromagnetic and antiferromagnetic interactions.

We consider a spin-[Formula: see text] kagome-like chain with competing ferro- and antiferromagnetic anisotropic exchange interactions. The ground state phase diagram of this model consists of the ferromagnetic and ferrimagnetic phases. We study the ground state and the low-temperature properties on the phase boundary between these phases.

Bilayered graphene/h-BN with folded holes as new nanoelectronic materials: modeling of structures and electronic properties.

The latest achievements in 2-dimensional (2D) material research have shown the perspective use of sandwich structures in nanodevices. We demonstrate the following generation of bilayer materials for electronics and optoelectronics. The atomic structures, the stability and electronic properties of Moiré graphene (G)/h-BN bilayers with folded nanoholes have been investigated theoretically by ab-initio DFT method.

Ferrimagnetism in delta chain with anisotropic ferromagnetic and antiferromagnetic interactions.

We consider analytically and numerically an anisotropic spin-[Formula: see text] delta-chain (sawtooth chain) in which exchange interactions between apical and basal spins are ferromagnetic and those between basal spins are antiferromagnetic. In the limit of strong anisotropy of exchange interactions this model can be considered as the Ising delta chain with macroscopic degenerate ground state perturbed by transverse quantum fluctuations. These perturbations lift the ground state degeneracy and the model reduces to the basal XXZ spin chain in the magnetic field induced by static apical spins.

Bilayered graphene as a platform of nanostructures with folded edge holes.

The stability and the electronic properties of new AB-stacking and moiré bilayer graphene superlattices with closed edge nanoholes are studied using DFT calculations. The closing of the edges is made of C-C bonds that form after folding the borders of the holes. Superlattices with periodic hexagonal symmetry are considered in more detail.

Heterostructures based on graphene and MoS2 layers decorated by C60 fullerenes.

Here we present a comprehensive investigation of various novel composite structures based on graphene (G) and molybdenum disulphide (MoS2) monolayers decorated by C60 fullerenes, which can be successfully applied in photovoltaics as a solar cell unit. Theoretical studies of the atomic structure, stability and electronic properties of the proposed G/C60, MoS2/C60 and G/MoS2/C60/G nanostructures were carried out. We show that making the G/MoS2/C60/G heterostructure from the 2D films considered here will lead to the appearance of particular properties suitable for application in photovoltaics due to the broad energetic region of high electronic density of states.

The Mitochondria-Targeted Plastoquinone-Derivative SkQ1 Promotes Health and Increases Drosophila melanogaster Longevity in Various Environments.

Mitochondria play an important role in aging. Strongly reduced function of the mitochondria shortens life span, whereas moderate reduction prolongs life span, with reactive oxygen species production being the major factor contributing to life span changes. Previously, picomolar concentrations of the mitochondria-targeted antioxidant SkQ1 were shown to increase the life span of Drosophila by approximately 10%.

Slow-binding inhibition of cholinesterases, pharmacological and toxicological relevance.

Slow-binding inhibition (SBI) of enzymes is characterized by slow establishment of enzyme-inhibitor equilibrium. Cholinesterases (ChEs) display slow onset of inhibition with certain inhibitors. After a survey of SBI mechanisms, SBI of ChEs is examined.

MoS₂ decoration by Mo-atoms and the MoS₂-Mo-graphene heterostructure: a theoretical study.

Here we propose a completely new covalent heterostructure based on graphene and self-decorated MoS2 monolayers. Detailed investigation of the decoration process of the MoS2 surface by Mo adatoms was performed using first principles DFT methods. Comparison between valence-only and semicore pseudopotentials was performed to correctly describe the interaction between Mo adatoms and the MoS2 surface.

[Carriage of A Allele of Polymorphic Marker G(-238)A of TNF-alfa Gene Is Associated With Unfavorable Prognosis in Patients With Chronic Systolic Heart Failure].

Aim: to elucidate association between polymorphic markers of interleukin- 6 (Il-6) and tumor necrosis factor (TNF) genes and unfavorable outcomes in patients with chronic heart failure (CHF).

Material And Methods: We determined levels of TNF and Il-6 and genotypes of polymorphic markers G(-238)A of TNF gene (rs361525) and G(-174)C of IL-6 gene (rs1800795) in 151 patients (mean age 64.5 years) hospitalized because of decompensation of systolic CHF (left ventricular ejection fraction less or equal 40%) after stabilization of their state.