Generation of terahertz radiation with a specified spectral profile from a mosaic combined organic crystal.

We present a method for the generation of terahertz (THz) pulses with a high optical-to-THz conversion efficiency and a smooth spectrum. The method is based on the optical rectification of near-infrared femtosecond laser pulses with a wavelength of 1240 nm in a mosaic combined crystal, consisting of two pieces of nonlinear organic crystals, OH1 and DSTMS. The mosaic combined crystal produces a relatively smooth spectrum in the 0.

DFT Model of Elemental Sulfur in Sulfolane Solutions.

The structure and the thermodynamic and optical (UV) properties of elemental sulfur solution in sulfolane (Sl) have been studied using density functional theory methods. The cyclic molecular form of sulfur (S "crown") was found using PBE1PBE/6-311+G(d,p) approximation in combination with a polarizable continuum model (the integral equation formalism variant) to exist in sulfolane medium as a Sl-S-Sl solvate. It has been theoretically established that sulfur can form stable (S) clusters in concentrated solutions.

Properties and Activity of Peptide Derivatives of ACE2 Cellular Receptor and Their Interaction with SARS-CoV-2 S Protein Receptor-Binding Domain.

The aim of this work was to design and characterize peptides based on the α-helices h1 and h2 of the ACE2 receptor, forming the interaction interface between the receptor-binding domain (RBD) of the SARS-CoV-2 S protein and the cellular ACE2 receptor. Monomeric and heterodimeric peptides connected by disulfide bonds at different positions were synthesized. Solubility, RBD-binding affinity, and peptide helicity were experimentally measured, and molecular dynamics simulation was performed in various solvents.

Global Kinetics and Spectral Modeling of -Methoxyphenyl Azide Photooxidation.

The kinetics of photooxidation of -methoxyphenyl azide was studied by flash photolysis with spectrophotometric detection of the absorption of active intermediates in an aerated acetonitrile solution at 295 K. The holistic set of experimental data including the consumption of - isomers of -methoxyphenyl nitroso oxide and the accumulation of photooxidation products (2,4)-4-methoxy-6-oxo-hexa-2,4-diene-nitrile oxide and bis--methoxy-azobenzene monitored via the changes in the optical density of the solution in the wavelength range of 300-500 nm was treated to obtain the most complete information about the system under study. Flash photolysis of results in the formation of the corresponding triplet nitrene, which either recombines to azobenzene with a rate constant 2 = (8.

Chimeric Agonist of Galanin Receptor GALR2 Reduces Heart Damage in Rats with Streptozotocin-Induced Diabetes.

Neuropeptide galanin and its N-terminal fragments reduce the generation of reactive oxygen species and normalize metabolic and antioxidant states of myocardium in experimental cardiomyopathy and ischemia/reperfusion injury. The aim of this study was to elucidate the effect of WTLNSAGYLLGPβAH-OH (peptide G), a pharmacological agonist of the galanin receptor GalR2, on the cardiac injury induced by administration of streptozotocin (STZ) in rats. Peptide G was prepared by solid phase peptide synthesis using the Fmoc strategy and purified by preparative HPLC; its structure was confirmed by 1H-NMR spectroscopy and MALDI-TOF mass spectrometry.

Pb: Production Approaches and Targeted Therapy Applications.

Over the last decade, targeted alpha therapy has demonstrated its high effectiveness in treating various oncological diseases. Lead-212, with a convenient half-life of 10.64 h, and daughter alpha-emitter short-lived Bi ( = 1 h), provides the possibility for the synthesis and purification of complex radiopharmaceuticals with minimum loss of radioactivity during preparation.

BEP-Like Correction of Nonequilibrium Thermodynamic Parameters of the Solvent-Assisted Reactions: The DFT and Study of Hydration, Peroxidation, and Enolization of Acetone and 1,1,1-Trifluoroacetone in Aqueous Solutions.

The mechanisms of enolization and reactions of nucleophilic addition to carbonyl compounds were analyzed by density functional theory (DFT) (PBE1PBE) and (DLPNO-CCSD(T)) level of theory using the interaction of water and hydrogen peroxide with acetone and 1,1,1-trifluoroacetone (TFA) as the reference reactions. The transition states of the studied reactions were localized within the integrated approach that includes both the dielectric continuum theory (polarizable continuum model (PCM)) and the cyclic or two-cluster explicit solvation models. The considered models provide proton transfer in the enolization, hydration, and peroxidation reactions by the Grotthuss mechanism.

[MeArg, NLe]-apelin-12: Optimization of solid-phase synthesis and evaluation of biological properties in vitro and in vivo.

Chemically modified peptide apelin-12 ([MeArg, NLe]-apelin12, peptide M) is able to reduce reactive oxygen species (ROS) formation, cell death, and metabolic and ionic homeostasis disorders in experimental myocardial ischemia-reperfusion injury. These beneficial effects indicate the therapeutic potential of this compound in cardiovascular diseases. The goals of this work were to optimize the synthesis of peptide M, and to study its proteolytic stability and effect on the heart function of rabbits with doxorubicin (Dox) cardiomyopathy.

The substituent effects on the [3+2] cycloaddition of nitrile oxides generated by photooxidation of arylazides to acetonitrile.

The DFT approach in M06L/6-311 + G(d,p) approximation was used to study the transformation of unsaturated nitrile oxides (RCNO), which were generated by photooxidation of the corresponding aromatic azide, to oxadiazoles via [3 + 2]cyclization with acetonitrile. It was found that the cycloaddition activation enthalpy was within 60-93 kJ/mol, depending on the structure of the nitrile oxide. A significant mesomeric effect of the substituent and its position in the conjugated molecular system on the activation barrier of the reaction studied was identified.

Luminescent and DFT Study of Keto-Enol Tautomers of 5-Fluorouracil and Its Derivatives in Aqueous Solutions.

Fluorescence (FL) spectra were recorded and identified for the following 5-fluorouracil (FU) tautomers: 5-fluoropyrimidine-2,4(1,3)-dione (), 5-fluoro-2-hydroxypyrimidine-4(3)-one (), and 5-fluoro-4-hydroxypyrimidine-2(1)-one (), as well as the corresponding tautomers and of 1-(tetrahydrofuranyl-2)-5-fluorouracil and 1-methyl-5-fluorouracil, tautomers and of 3-methyl-5-fluorouracil, and the diketo tautomer of 1,3-dimethyl-5-fluorouracil. It was shown that the FL of rare tautomers of FU derivatives occurs by the excitation of uracil homoassociates followed by intramolecular proton transfer (IPT), formation of a pair of rare tautomers, and radiative deactivation of one of them. The FL quantum yields φ were estimated.

Galanin receptors activation modulates myocardial metabolic and antioxidant responses to ischaemia/reperfusion stress.

The mechanisms of protective action of the neuropeptide galanin and its N-terminal fragments against myocardial ischaemia/reperfusion (I/R) injury remain obscure. The aim of this work was to study effects of a novel peptide agonist of galanin receptors [βAla14, His15]-galanin (2-15) (G1) and the full-length galanin (G2) on energy and antioxidant status of the heart with acute infarction. The peptides were synthesized by the automatic solid phase method using Fmoc technology.

[Cardiometabolic efficacy and toxicological evaluation of a pharmacological galanin receptor agonist].

The goal of this study was to examine effects of a novel galanin receptor agonist GalR1-3 [bAla14, His15]-galanine 2-15 (G), obtained by automatic solid-phase synthesis, on the metabolic state of the area at risk and the size of acute myocardial infarction (MI) in rats in vivo and evaluate its toxicity in BALB /c mice. In anesthetized rats, regional ischemia was simulated by coronary artery occlusion and then coronary blood flow was restored. The peptide G was administered intravenously (i.

[Protective action of a modified fragment of galanine in rats with doxorubicin-induced heart failure].

The use of the anticancer drug doxorubicin (Dox) is limited due to its cardiotoxic effect. Using the method of automatic solid-phase peptide synthesis, we obtained a synthetic agonist of galanin receptors GalR1-3 [RAla14, His15]-galanine (2-15) (G), exhibiting cardioprotective properties. It was purified by high performance liquid chromatography (HPLC).

Galanin/GalR1-3 system: A promising therapeutic target for myocardial ischemia/reperfusion injury.

N-terminal fragments of galanin (2-11) and (2-15) are critical for binding to GalR1-3 receptors, members of the G-protein-coupled receptor superfamily, and are involved in myocardial protection against ischemia/reperfusion (I/R) injury. This study was designed to synthesize novel GalR1-3 agonists with improved properties and evaluate their efficiency as cardioprotective agents. Peptide agonists were synthesized by the automatic solid phase method using Fmoc technology and purified by preparative HPLC.

Protective Effects of a Novel Agonist of Galanin Receptors Against Doxorubicin-Induced Cardiotoxicity in Rats.

The clinical use of antineoplastic agent doxorubicin (DOX) is limited due to its cardiotoxic action. [βAla14, His15]-galanine (2-15) (G) is a novel synthetic agonist of galanin receptors GalR1-3 having cardioprotective properties in animal models in vivo. The aim of the present study was to explore effects of G on DOX-induced cardiotoxicity.

Galanin and its N-terminal fragments reduce acute myocardial infarction in rats.

Agonists and antagonists for galanin receptor subtypes GalR1-3 can be used as putative therapeutics targets for the treatment of various human diseases. However, effects of galanin and its N-terminal fragments on myocardial ischemia/reperfusion injury remain unclear. This study was designed to assess the ability of the full-length galanin (GWTLNSAGYLLGPHAIDNHRSFSDKHGLT-NH2, G1), the natural fragments WTLNSAGYLL-NH2 (G2) and WTLNSAGYLLGPHA (G3), and their modified analogs WTLNAAGYLL (G4) and WTLNSAGYLLGPβAH (G5) to limit acute myocardial infarction in rats in vivo.

Mechanism of gelation in low-concentration aqueous solutions of silver nitrate with l-cysteine and its derivatives.

We discuss the results of experimental studies of the processes of gelation in aqueous solutions of silver nitrate with l-cysteine and its derivatives. We focus on understanding what determines if these small molecules will self-assemble in water at their extremely low concentration to form a gel. A mechanism of gel formation in a cysteine-silver solution (CSS) is proposed.

Nature of Lewis Base Catalysis of 1,3-Dipolar Cycloaddition of Methyl Diazoacetate to Methyl Acrylate; NMR Kinetic Spectroscopy and DFT Study.

The effect of Lewis base (LB) in the domino reaction between methyl diazoacetate and methyl acrylate has been studied. This domino process is initialized by a [3+2]-cycloaddition reaction to generate 3H-pyrazoline followed by a subsequent 1,3-H shift reaction forming 1H-pyrazoline as the more stable isomer. The rate of the first step is not sensitive to the presence of LBs (THF, Py, DMAP, DBU, and triphenylphosphine) as it was evidenced by kinetic nuclear magnetic resonance spectroscopy and quantum chemical modeling.

Effects of Deltorphin II and Its Retroenantio Analog on Cardiac Tolerance to Ischemia and Reperfusion.

Selective agonist of δ-opioid receptors deltorphin II and its retroenantio analog (0.12 mg/kg intravenously) were preventively injected to male Wistar rats 15 min prior to 45-min coronary occlusion or 5 min before 120-min reperfusion. Administration of deltorphin II before artery occlusion and before reperfusion decreased the infarct size/area at risk ratio.

Aerosol indirect effect from turbulence-induced broadening of cloud-droplet size distributions.

The influence of aerosol concentration on the cloud-droplet size distribution is investigated in a laboratory chamber that enables turbulent cloud formation through moist convection. The experiments allow steady-state microphysics to be achieved, with aerosol input balanced by cloud-droplet growth and fallout. As aerosol concentration is increased, the cloud-droplet mean diameter decreases, as expected, but the width of the size distribution also decreases sharply.

[Study of neuroprotective, antihypoxic and antiamnesic effects of new mixture of tripeptides].

A new mixture of tripeptides (NMT: H-Lys-Asp-Glu-OH, H-Asp-Glu-Pro-OH, H-Asp-Glu-Arg-OH) in doses of 150 and 300 mg/kg per day produces clearly pronounced neuroprotective effect in rats with brain ischemia and decreases neurologic deficiency 1.1 times more effectively than reference drug semax. NMT (10, 50 and 150 mg/kg) had marked antihypoxic effect on mice in hermetic and altitude chamber.

Acoustic streaming of a sharp edge.

Anomalous acoustic streaming is observed emanating from sharp edges of solid bodies that are vibrating in fluids. The streaming velocities can be orders of magnitude higher than expected from the Rayleigh streaming at similar amplitudes of vibration. Acoustic velocity of fluid relative to a solid body diverges at a sharp edge, giving rise to a localized time-independent body force acting on the fluid.

Signatures of discrete breathers in coherent state quantum dynamics.

In classical mechanics, discrete breathers (DBs) - a spatial time-periodic localization of energy - are predicted in a large variety of nonlinear systems. Motivated by a conceptual bridging of the DB phenomena in classical and quantum mechanical representations, we study their signatures in the dynamics of a quantum equivalent of a classical mechanical point in phase space - a coherent state. In contrast to the classical point that exhibits either delocalized or localized motion, the coherent state shows signatures of both localized and delocalized behavior.

[Antibacterial activity of nanostructured silver gel].

Aim: Evaluation of antimicrobial activity of L-cysteine silver gel against various species of pathogenic and opportunistic microorganisms.

Materials And Methods: Antibacterial activity of L-cysteine silvergel with silver concentration from 1.28 x 10(-3) to 3.