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Approximate formulas of the phosphorescence decay kinetics have been obtained for the statistical distribution of molecules over the rate constants of radiative and non-radiative deactivations of triplet excitations. It is shown that the characters of the phosphorescence decay differ for these two cases. The obtained difference in the kinetics has been used to establish a reason for the deviation from the exponential law and a faster decay of the sensitized phosphorescence of naphthalene and diphenyl in n-paraffin matrices (at T = 77 K) in the presence of heavy dibromo-diphenylene sulfide atoms in the donor.

The effects of the 5′-(4-ethoxybenzoyl)-5′,7′-dihydrospiro[cyclopentane-1,6′-[1,2,3]-triazolo[5,1-b][1,3,4]-thiadiazine]-3′-carboxylic acid ethyl ester oon the healing of linear skin wounds were studied in rats. This compound was found to have a stimulatory action on skin fibroblast proliferation, increasing the regenerative potential of damaged tissue. Assessment of the course of the wound process showed that use of test substance clearly accelerated the course of repair regeneration of the integument as compared with controls; inflammatory processes were moderate, without involvement of the deep layers of the skin; a cellular and fibrous component formed in the lesion zone.

Triplet-level population distributions of organic molecules in glassy matrices were studied by computer simulation for various exciting-light intensities and compound concentrations. The dependence of the triplet-level population distribution on these variables was found. A consequence of the established relationship was that the exciting-light intensity affected the concentration dependence of the luminescence intensity where the population change of the molecular ground state resulting from their transition into the triplet state could not be neglected.

The method of slow cooling from melting temperature is used to obtain coarse-grain ingots of (FexCo1 – x)2B with columnar structure. It is shown that at room temperature the configuration of the domain structure of the specimens of (FexCo1 – x)2B corresponds to magnetocrystalline anisotropy (MCA) of different types. Alloys Fe2B, (Fe0.4Co0.6)2B, (Fe0.2Co0.8)2B and Co2B exhibit MCA of the type of a “plane of easy axes.” Alloy (Fe0.92Co0.08)2B has a state with spin-reorientation transition of type “easy axis” – “plane of easy axes”.

The special features of the multiplet structure in spectra of sensitized acenaphthene phosphorescence caused by triplet-triplet energy transfer from 2,7-dibromodiphenylen sulfide (the energy donor) molecules in n-hexane matrices are investigated at 77 K. It is demonstrated that the distribution of intensities between components of the multiplet in quasi-line spectrum of sensitized acenaphthene phosphorescence depends on the freezing rate of the solution and the exciting pulse duration. The possible reasons for these dependences are discussed.

ObjectiveF-spondin is part of a group of evolutionarily conserved extracellular matrix proteins in vertebrates. It is highly expressed in the embryonic floor plate, and it can bind to the ECM and promote neuronal outgrowth. A characterization of F-spondin expression patterns in the adult zebrafish brain was previously reported by our group. However, given its importance during development, we aimed to obtain a detailed description of green fluorescent protein (GFP) expression driven by thespon1bpromotor, in the developing zebrafish brain of the transgenicTg(spon1b:GFP)line, using light sheet fluorescence microscopy (LSFM).ResultsImages obtained in live embryos from 22 to 96 h post fertilization confirmed our earlier reports on the presence ofspon1b:GFPexpressing cells in the telencephalon and diencephalon (olfactory bulbs, habenula, optic tectum, nuclei of the medial longitudinal fasciculus), and revealed newspon1b:GFPpopulations in the pituitary anlage, dorso-rostral cluster, and ventro-rostral cluster. LSFM made it possible to follow the dynamics of cellular migration patterns during development.Conclusionsspon1b:GFPlarval expression patterns starts in early development in specific neuronal structures of the developing brain associated with sensory-motor modulation. LSFM evaluation of the transgenicTg(spon1b:GFP)line provides an effective approach to characterize GFP expression patterns in vivo.

Theoretical analysis of the processes of magnetization of uniaxial ferromagnetic materials is performed within the Neel theory of magnetic phases. Relations are obtained for the constants of magnetic crystal anisotropy K 1, K 2, the form factor N, and the saturation magnetization I s , at which the magnetization curves exhibit jumps (FOMP). Formulas for computing the saturation fields H s and the jump fields H FOMP are derived for crystals with different types of magnetocrystalline anisotropy MCA. It is shown that the Sucksmith–Thompson method is applicable for computing the first too MCAconstants of uniaxial ferromagnets with any type of MCA. Constants K 1 and K 2 are computed with allowance for the form factor of the specimen. Model magnetization curves are plotted for uniaxial ferromagnets with different types of MCA along and perpendicularly to crystallographic axis c. The analytical results match the model curves well.

Processes of magnetization of orthorhombic single crystals of FeB are studied and the magnetocrystalline anisotropy is analyzed theoretically. The domain structure of the FeB single crystals is determined and its theoretical model is suggested.

Temperature dependence of the intensity of annihilation slowed-down fluorescence is studied for aromatic molecules in frozen n-paraffin solutions. With increasing temperature, regions with increased slowed-down fluorescence intensity are established for molecules expelled to the surface of small crystals of the solvent in the process of its freezing. It is assumed that this effect is caused by the increasing number of annihilating pairs involved in slowed-down fluorescence emission. The number of annihilating pairs increases due to rotation of pairs of triplet molecules with parallel directions of magnetic moments in the position with antiparallel direction of the magnetic moments.

Reduction of the carbonyl groups in cyclic and acyclic 2-diazo-1,3-diketones with sodium tetrahydridoborate in aqueous–alcoholic medium, followed by hydrolysis of the reaction mixture over wet silica gel and chromatographic purification on neutral aluminum oxide, afforded 1,3-dialkyl-3-hydroxy-2-diazoketones in 58–87% yield. Bulky substituents at the carbonyl group considerably reduce the efficiency of the process, and the reduction of cis- and trans-4,6-di-tert-butyl-2-diazocyclohexane-1,3-diones is characterized by low stereoselectivity (de 40–49%). In the IR spectra of 3-hydroxy-2-diazocyclohexanes, absorption bands corresponding to stretching vibrations of “free” axial hydroxy groups are located at higher frequencies (by 20-45 cm-1) than those belonging to equatorial hydroxy groups. These parameters may be useful for conformational analysis of cyclic hydroxy diazo ketones. Stabilization of the E conformation of acyclic hydroxy diazo ketones via intramolecular hydrogen bonding is likely to occur only in nonpolar solvents (CCl4, cyclohexane).

Experimental data show a close relationship among melatonin, circadian rhythms, and sleep. Low-dose melatonin treatment, increasing circulating melatonin levels to those normally observed at night, promotes sleep onset and sleep maintenance without changing sleep architecture. Melatonin treatment can also advance or delay the phase of the circadian clock if administered in the evening or in the morning, respectively. If used in physiologic doses and at appropriate times, melatonin can be helpful for those suffering from insomnia or circadian rhythm disorders. This may be especially beneficial for individuals with low melatonin production, which is established by measuring individual blood or saliva melatonin levels. However, high melatonin doses (over 0.3 mg) may cause side effects and disrupt the delicate mechanism of the circadian system, dissociating mutually dependent circadian body rhythms. A misleading labeling of the hormone melatonin as a "food supplement" and lack of quality control over melatonin preparations on the market continue to be of serious concern.

We studied biological rhythms of immunological parameters and absorption and digestive activities of neutrophils and monocytes in women during the menstrual cycle. Circadian rhythms of phagocytosis were evaluated. The phagocytic system was characterized by highest activity during ovulation and early luteal phase of the menstrual cycle accompanied by physiological immunosuppression. It was shown that macrophages determine the spatial and temporal organization of specific and nonspecific resistance in women. We evaluated phases of the menstrual cycle optimal for studying rhythms of the immune system and phagocytosis.

Biorhythms of iron metabolism in healthy women and patients with iron deficiency were studied during lactation. Healthy nursing women were characterized by circadian variations in the concentrations of iron, alpha-tocopherol, and malonic dialdehyde in breast milk. Diurnal variations in iron concentration, antioxidant potential, and lipid peroxidation in breast milk depended on iron metabolism in nursing women. Iron deficiency was accompanied by a decrease in the concentrations of alpha-tocopherol and iron, increase in malonic dialdehyde content, and suppression of circadian variations in these parameters in breast milk.

The effect of two cyclic enkephalin analogs (IVS-43 and IVS-46) on the group and individual behavior of rhesus macaques and hamadryas baboons has been studied. A pronounced influence of IVS-46 on competitive and operant goal-directed behavior of the monkeys was identified.

We previously observed tht low oral doses of melatonin given at noon increase blood melatonin concentrations to those normally occurring nocturnally and facilitate sleep onset, as assessed using and involuntary muscle relaxation test. In this study we examined the induction of polysomnographically recorded sleep by similar doses given later in the evening, close to the times of endogenous melatonin release and habitual sleep onset. Volunteers received the hormone (oral doses of 0.3 or 1.0 mg) or placebo at 6, 8, or 9 PM. Latencies to sleep onset, to stage 2 sleep, and to rapid eye movement (REM) sleep were measured polysomnographically. Either dose given at any of the three time points decreased sleep onset latency and latency to stage 2 sleep. Melatonin did not suppress REM sleep or delay its onset. Most volunteers could clearly distinguish between the effects of melatonin and those of placebo when the hormone was tested at 6 or 8 PM. Neither melatonin dose induced "hangover" effects, as assessed with mood and performance tests administered on the morning after treatment. These data provide new evidence that nocturnal melatonin secretion may be involved in physiologic sleep onset and that exogenous melatonin may be useful in treating insomnia.

Methods for the synthesis ofO-alkylS-(N-acyl-N-alkoxycarbonylalkyl)aminomethyl (methyl)thio- and -dithiophosphonates based on the reaction between alkaline-metal salts ofO-alkyl (methyl)thio- and -dithiophosphonates and N-alkoxycarbonyl-N-chloromethylglycine or -β-alanine esters and by treatment ofO-alkyl (methyl)dithiophosphonoates andN-acylated amino acids or their esters with paraform in the presence of HCl were developed. The compounds obtained exhibit high insectoacaricide activity and selectivity.

Biorhythms of absorption capacity of neutrophils and monocytes were studied in women with latent iron deficiency. We revealed disorders in circadian organization of the mononuclear phagocyte system and decreased reserve capacity of nonspecific organism's resistance against the background of tissue iron deficiency. Informative value of desynchronosis in circadian structure of the phagocyte absorption capacity as the early marker of prelatent iron deficiency was established.

The antioxidant properties of humic substances of low-mineralization sulfidic muds (peloids) were investigated using initiated oxidation of 1,4-dioxane as a model reaction. Four groups of substances including humic, himatomelanic, fulvic, and humus acids were studied. Kinetic characteristics of the oxidation of humic substances were determined in terms of effective inhibition rate constants fk In . It is established that himatomelanic acids of peloids exhibit the maximum antioxidant activity among the studied substances.

Trajectories of light rays in a gravitational field created by a homogeneous distribution of pointlike masses are considered in the framework of General Relativity. A method of approximate computation of statistical characteristics of such trajectories is suggested, with the accuracy up to first order in the gravitational constant. The estimates of the shift in the direction of a light ray and of the change in the angular coordinates of the light source are obtained.

1. A general method has been developed for the oxidation of sulfide sulfur in S-mercaptoalkyl esters of thio- and dithioacids of phosphorus to the sulfoxides and sulfones. 2. The oxidative activation metabolites of O-ethyl-S-(methoxycarbonylmethylmercaptomethyl) methyldithiophosphonate and its monothio analog, and the hydrolytic detoxification metabolite of the former, have been synthesized.

The selective properties of hollow fibres used in the separation of solutions of poly-ethylene glycols and proteins have been investigated. It has been shown that the increase in retention coefficient and specific permeability as the velocity of the stream increases, in the separation of solutions of kinetically relatively flexible polyethylene glycol molecules, is not connected with the phenomenon of concentration polarization. but can be explained by the deformability of the tangles of polyethylene glycol macromolecules on flow of the solution in thin capillaries (hollow fibres). Optimum ultrafiltration conditions have been determined. Complete retention curves have been constructed for the hollow fibre, which make it possible to determine its region of use.

1. A study was made of the liquid-phase oxidation of dicyclohexylethane with oxygen at 110–140°, and from the experimental data the activation energy of the initial stage of reaction was calculated (29-30 kcal/mole). 2. A scheme is proposed for a radical-chain mechanism for the reactions; it explains all the main experimental results obtained in the liquid-phase oxidation of dicyclohexylethane. 3. The first stage of the oxidation of dicyclohexylethane is attack by oxygen on the tertiary carbon atom of one cyclohexane ring with subsequent opening of this ring and formation of a cyclohexyl-substituted keto carboxylic acid.

1. A number of methylpropyldithiophosphinic acid esters, which possess acaricidal properties, was obtained by the aikylation of sodium methylpropyldithiophosphinate with halo derivatives. 2. Replacement of the ethoxy group in methyldithiophosphonic acaricides by the propyl group causes profound changes in the physiological activity.

A biologically active RNA which, when transferred to chick embryonic cells, produced an antiviral state in them, was isolated from cultures of chick embryonic cells treated with interferon. The level of reproduction of vesicular stomatitis virus in these cells was 2–30% of the level of reproduction observed in cells treated with control RNA. Maximal activity of the experimental RNA was observed after exposure to interferon for 3 h.

Transition of the water circulation loop to a nonblow-off operational regime with subsequent treatment with reagents and inhibition of the circulation water increases the technical and economic efficiency of operation of the water circulation system and of the ammonia cooling and compressor works.

The r-centroid method is used to find semiempirically the dependence of the electronic transition moment Re on the internuclear separation for the principal system of the SnO molecule.