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The screening for novel antibiotic producers by selection methods revealed the Streptomyces sp. strain No. 1278 producing the antibiotic INA-1278, which exhibits antimicrobial and antifungal activities. This compound was isolated from the liquid culture by extraction with organic solvents and purified by chromatographic methods. The structure of this antibiotic was studied by mass spectrometry and H and C NMR spectroscopy. An analysis of the results of the investigation indicate that the compound INA-1278 is structurally related to the antibiotic irumamycin, which has been studied earlier. However, the novel antibiotic may differ from irumamycin in the configurations of some asymmetric centers, which were not established at the present stage of our research. [ABSTRACT FROM AUTHOR]

Background: The best measure of body habitus as a risk factor for chronic disease is not well defined. Our intent was to examine the relation between waist-hip ratio (WHR) and body mass index (BMI) as a measurement of body habitus in patients with end-stage knee osteoarthritis (OA).Methods: We reviewed the data of 200 consecutive patients in our registry undergoing knee replacement surgery for demographic data of age, sex, BMI and WHR. We performed a stratified analysis by sex and calculated the risk ratios (RRs) to describe the risk of being classified as obese by WHR for those considered obese by the BMI criteria.Results: A similar percentage of male and female patients were classified as obese by the BMI criteria (38% v. 42%, respectively). Men were classified as obese more often than women by WHR (92% v. 82%). The RR of being obese as determined by WHR if classified as obese by the BMI criteria was 1.04 (95% confidence interval [CI]0.91-1.18) for men and 1.23 (95% CI 1.03-1.46) for women.Conclusion: Among patients with knee OA, the overlap between BMI and WHR is greater in women than men. This difference has implications for defining the prevalence of metabolic syndrome in this population. [ABSTRACT FROM AUTHOR]

The chemical diffusion coefficient of oxygen vacancies and oxygen ion conductivity in lanthanum cobaltite LaCoO3 were determined by the polarization method as functions of oxygen partial pressure $$ p_{O_2 } $$ (atm) and temperature T(K) over the ranges −4 ≤ log $$ p_{O_2 } $$ ≤ 0 and 1173 K ≤ T ≤ 1323 K. The mobilities (cm2/(V s)) of oxygen vacancies calculated over the temperature range studied satisfy the inequalities 1.8 × 10−5 ≤ $$ v_{v_0 } $$ ≤ 3.4 × 10−5. The transfer numbers of oxygen vacancies were calculated. These numbers change depending on oxygen partial pressure over the range 5 × 10−7 ≤ t 0 ≤ 1 × 10−5. The activation energy of self-diffusion of oxygen vacancies was found to be E a= 104 ± 10 kJ/mol (1.1 ± 0.1 eV). [ABSTRACT FROM AUTHOR]

The catalytic properties of iron complexes with monoethanolamine chemically immobilized on the surface of silica were studied in the reaction of CCl4 addition to 1-octene. Unlike the previously studied complexes of other transition metals, the activity of the iron complexes increased with increasing metal content. The analysis of the catalyst composition and reaction products demonstrated that the reaction occurred by a coordination mechanism at low metal concentrations. At high concentrations, the metal mainly occurred in the form of an oxychloride and the catalytic process occurred nonselectively, probably, by an ionic mechanism. The addition occurred in an analogous manner in the presence of iron chloride supported onto unmodified silica gel. [ABSTRACT FROM AUTHOR]

The paper presents the results obtained in studying the oxygen nonstoichiometry of undoped lanthanum cobaltite LaCoO3−δ as a function of temperature and oxygen pressure. A model analysis of the defect structure of the compound was performed. Two models were considered. For the first model, it was assumed that electrons and electron holes were quasi-free, whereas, in the second model, they were considered localized on cobalt ions. The internal electronic disordering and thermally excited disproportionation of cobalt were also taken into consideration in the first and second models, respectively. For both models, systems of nonlinear equations comprising the corresponding mass action law, mass balance, and electroneutrality equations were constructed. Verification equations were obtained for both models by solving these systems. The correspondence of the suggested models to experimental data was checked by the nonlinear regression method. Both models almost equally correctly described the data on the oxygen nonstoichiometry of LaCoO3−δ. The conclusion was drawn that these data were insufficient for selecting the most realistic model of the defect structure of this compound. [ABSTRACT FROM AUTHOR]

The luminescence properties of undoped epitaxial layers of gallium nitride grown on silicon carbide substrates by gas-phase epitaxy in a chloride system have been investigated. An edge band (361 nm, 96 K) and defect bands (380, 430, 560 nm, 96 K) were recorded in the photo- and cathodoluminescence spectra. It was observed that the parameters of the edge and defect luminescence bands for the GaN layers studied do not depend on the crystalline perfection of the substrate, but rather they are determined by the growth conditions, specifically, the position of the sample in the reactor. It is shown that there exists a characteristic symmetry of the distribution of the luminescence properties of a layer along the surface of the samples relative to the direction of the gas flow in the reactor. A correlation is established between the parameters of the edge and blue luminescence bands and the density of the electrically-active impurity in the epitaxial layer. [ABSTRACT FROM AUTHOR]

The work is devoted to the description of unsteady thermal processes in low-dimensional structures. To obtain the relationship between the microscopic and macroscopic descriptions of solids, it is necessary to understand the heat transfer mechanism at the micro-level. At the latter, in contrast to the macro-level, analytical, numerical, and experimental studies demonstrate significant deviations from the Fourier's law. The paper bases on the ballistic heat transfer model, according to which the heat is carried by the thermal waves. This effect can be applied, for example, to signal transmission and heat removal problems. The influence of non-nearest neighbors on processes in discrete media, as well as processes in polyatomic lattices, is investigated. To describe the evolution of the initial thermal perturbation, the dispersion characteristics and group velocities in one-dimensional crystal are analyzed for (i) a diatomic chain with variable masses or stiffnesses and for (ii) a monatomic chain with regard for interaction with second neighbors. A fundamental solution to the heat distribution problem for the corresponding crystal models is obtained and investigated. The fundamental solution allows to obtain a description of waves traveling from a point source, and can serve as the basis for constructing all other solutions. In both cases, the solution consists of two thermal fronts moving one after another with different speeds and intensities. Quantitative estimates of the intensity of the thermal wave front are given, and the dynamics of changes in the velocities and intensities of the waves depending on the parameters of the problem is analyzed. Thus, a simple method for estimating the wavefronts intensity is proposed and tested on two models. These results can be used to identify and analyze those parts of the wave processes that are of interest in terms of interpretation of the effects observed in the experiments. [ABSTRACT FROM AUTHOR]

Rotational Maker fringes, scaled with respect to χ11(2) of crystalline quartz, were used to determine the second order susceptibilities χ31(2) and χ33(2) for samples of thin AlxGa1-xN films, a thicker GaN film, and a free-standing GaN platelets. The pump wavelength was 1064 nm. The AlxGa1-xN samples, ranging in thickness from roughly 0.5 to 4.4 μm, were grown by metalorganic chemical vapor deposition (MOCVD) and hydride vapor-phase epitaxy (HVPE) on (0001) sapphire substrates. The Al mole fractions x were 0, 0.419, 0.507, 0.618, 0.660, and 0.666, for the MOCVD-grown samples, and x=0, 0.279, 0.363, and 0.593 for the HVPE-grown samples. An additional HVPE-grown GaN sample ∼70 μm thick was also examined. The free-standing bulk GaN platelets consisted of an HVPE grown film ∼226 μm thick removed from its growth substrate, and a crystal ∼160 μm thick grown by high-pressure techniques. For the AlxGa1-xN samples, the magnitudes of χ31(2) and χ33(2) decrease roughly linearly with increasing x and extrapolate to ∼0 for x=1. Furthermore, the constraint expected for a perfect wurtzite structure, namely χ33(2)=-2χ31(2), was seldom observed, and the samples with x=0.660 and x=0.666 showed χ31(2) and χ33(2) having the same sign. These results are consistent with the theoretical studies of nonlinear susceptibilities for AlN and GaN performed by Chen et al. [Appl. Phys. Lett. 66, 1129 (1995)]. The thicker bulk GaN samples displayed a complex superposition of high- and low-frequency Maker fringes due to the multiple-pass interference of the pump and second-harmonic generation beams, and the nonlinear coefficients were approximately consistent with those measured for the thin-film GaN sample. [ABSTRACT FROM AUTHOR]

Electrospray ionization mass spectra (MS and MS of protonated molecules) of dalargin, hexapeptide used in medicine are presented and all of the fragment ions in MS are assigned. [ABSTRACT FROM AUTHOR]

We study the effect of sublattice doping of cobalt on a crystal structure and oxygen nonstoichiometry of cobaltites GdBaCoFeO ( x = 0 − 0.6), which have considerable oxygen nonstoichiometry and show high values of oxygen-ionic and electronic conduction. These properties can be varied easily by a doping of oxide. We obtained the temperature dependences of the parameters of an elementary lattice in the range 25-800°C. [ABSTRACT FROM AUTHOR]

In order to determine whether there is an association between mumps orchitis and serum sperm antibodies, we tested patients at the time orchitis was diagnosed (n=7) and individuals who had had orchitis at least 1 month previously (n=14). Data were compared with the results for a control group of blood donors (n=20). Sperm antibodies were detected by the gelatin agglutination test of Kibrick, the tray agglutination test of Friberg and the ELISA. Clinically significant sperm antibody levels were not found in patients in the early stages of the disease. Four subjects tested post-disease were positive in the Friberg test and one was positive in the ELISA. One control serum was also positive in the latter test. Significant differences were not found between levels in patients in the early stages of the disease and levels in individuals post-disease, although the results of the Friberg test differed significantly between controls and former mumps orchitis cases. These data do not support the assumption of an involvement of humoral immunity against spermatozoa in mumps orchitis patients. [ABSTRACT FROM AUTHOR]

This paper is dedicated to the scientific and pedagogical activities of Nikolay Dmitrievich Kopachevsky (1940–2020) — a well-known mathematician, head of the Department of Mathematical Analysis of the V. I. Vernadsky Crimean Federal University, organizer and head of the Crimean Autumn Mathematical School-Symposium (KROMSH). [ABSTRACT FROM AUTHOR]

We consider unsteady heat transfer in a one-dimensional harmonic crystal surrounded by a viscous environment and subjected to an external heat supply. The basic equations for the crystal particles are stated in the form of a system of stochastic differential equations. We perform a continualization procedure and derive an infinite set of linear partial differential equations for covariance variables. An exact analytic solution describing unsteady ballistic heat transfer in the crystal is obtained. It is shown that the stationary spatial profile of the kinetic temperature caused by a point source of heat supply of constant intensity is described by the Macdonald function of zero order. A comparison with the results obtained in the framework of the classical heat equation is presented. We expect that the results obtained in the paper can be verified by experiments with laser excitation of low-dimensional nanostructures. [ABSTRACT FROM AUTHOR]

A correction to the article "In Vitro Effect of Knotolan, a New Lignan from Abies sibirica, on the Growth of Hormone-Dependent Breast Cancer Cells" that was published in the October 2010 issue is presented.

The specific conductivity logσ T and thermal electromotive force coefficient Q T of perovskite-like lanthanum cobaltite were measured over the temperature range 1173 K ≤ T ≤ 1323 K depending on the partial pressure of oxygen (10−8 atm ≤ p O 2 ≤ 1 atm). The p O 2- T-δ phase diagram of solid LaCoO3-δ studied earlier was used to recalculate the electric property data into the log σ T -δ and Q T -δ dependences. The isoconcentration temperature dependences of specific conductivity (logσ)δ-1/ T and Seebeck coefficient Q δ-1/ T for LaCoO3-δ were analyzed. The conclusion was drawn that charge transfer was activation in character and had a low activation energy. This was evidence that small-radius polarons (Co and Co) were responsible for charge transfer in perovskite-like lanthanum cobaltite. The calculated equilibrium constants for the formation of electronic defects and functional dependences of defect concentration [Co] T = f 1(δ) and [Co] T = f 2(δ) were used to analyze polaron transfer parameters in LaCoO3-δ. [ABSTRACT FROM AUTHOR]

Productive efficiency of technology of polysaccharide and lignin manufacturing from wood raw materials can be significantly improved by integration of purification stages of low molecular weight wood components widely used in applied chemistry into the technological cycle. In this connection, phenols including lignans and flavonoids, which have a practical application potential, are of a special interest. In the present work the results of a study of the content of (-)-secoisolariciresinol, dihydroquercetin and related polyphenols in different morphological parts and anatomical structures of larch wood from the Siberia are analyzed. Analysis of the content of the listed products by reversed-phase HPLC provides the selection of optimal raw material for organizing the manufacture of the listed compounds with predictable efficiency. Increased content of (-)-secoisolariciresinol (up to 3-4%) observed in wood of the trunk knot areas of larch from Khakassia evidences the prospects of raw material processing in this region for production of (-)-secoisolariciresinol from the wastes of larch wood refinery. [ABSTRACT FROM AUTHOR]

We present the results of a new stage of the long-term photometric study of FG Sge which is a quickly evolving central star of the planetary nebula Hen 1-5. Our new observations carried out on the SAI MSU telescopes in the optical () and infrared (IR) () regions in 2008–2021 and 2013–2021, respectively, allowed us to trace the evolution of the star's brightness in recent years. The most significant observations were performed in 2019 when the star suffered a short clearing of the dust shell and became visible in . Based on the spectral energy distribution of FG Sge in the 0.4–5 m wavelength range we derived the dust shell parameters: the size of dust grains m, the inner radius temperature K, optical depth (), the total mass of dust . After the short-term clearing of the dust shell in 2019, another dust structure was ejected that resulted in the star fading in all the observed bands. Based on the IR brightness and color curves, we estimated the dust depth growth in 2019–2020. [ABSTRACT FROM AUTHOR]

Complex perovskites BaCa(1+y)/3Nb(2−y)/3O3−δ (y = 0, 0.18 and 0.5) with 1:1-ordered structure ( F m 3 ¯ m space group) were synthesized by standard ceramic technique. The enthalpy increments for these oxides were measured in the temperature range of (295–1273) K by drop calorimetry, and experimental points were fitted with an integral of a single Einstein term. The hydration enthalpies for BaCa(1.18)/3Nb(1.82)/3O2.91 (BCN18), directly measured by calorimetry, were found to be equal to (− 86.7 ± 4.2) kJ (mol H2O)−1 and (− 88.8 ± 4.0) kJ (mol H2O)−1 at (673.8 ± 0.8) K and (872.8 ± 1.1) K, respectively. The calorimetrically determined enthalpies of hydration were found to be in agreement with those calculated using water vapor pressure–temperature–composition data. The increase in the off-stoichiometry index y in BaCa(1+y)/3Nb(2−y)/3O3−δ leads to more exothermic hydration heats. The enthalpies of formation from elements, determined by drop solution calorimetry for dehydrated BaCa(1+y)/3Nb(2−y)/3O3−δ with y = 0, 0.18 and 0.5, become less exothermic with increasing calcium content, and are equal to (− 1577.5 ± 14.5) kJ mol−1, (− 1533.6 ± 14.8) kJ mol−1 and (− 1492.2 ± 14.6) kJ mol−1, respectively. The thermodynamic data obtained allow calculating the enthalpies of formation and enthalpy increments for BaCa(1+y)/3Nb(2−y)/3O3−δ with arbitrary water content. [ABSTRACT FROM AUTHOR]

Hydride vapor-phase epitaxy (HVPE) was used to grow aluminum gallium nitride-based p–n diode structures on sapphire (0001) substrates. In the diode structure, an n-type AlGaN photon-emitting layer was sandwiched between n-type and p-type AlGaN cladding layers that contained higher AlN concentrations. These diode structures were processed and subsequently packaged into transistor outline cans. The light-emitting diodes (LEDs) were characterized using a state-of-the-art spectroradiometer. LED spectral emission occurred at a peak wavelength of 341 nm with a typical full width at half-maximum of approximately 14 nm. Pulsed injection currents of 110 mA resulted in greater than 2 mW of optical output power at a wavelength of 341 nm. This HVPE-grown LED’s pulsed optical power output level is comparable to reported results on similar sized metalorganic chemical vapor deposition grown ultraviolet LEDs with emission wavelengths near 340 nm. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]