Evolution of level density step structures from 56,57-Fe to 96,97-Mo

Level densities have been extracted from primary gamma spectra for 56,57-Fe and 96,97-Mo nuclei using (3-He,alpha gamma) and (3-He,3-He') reactions on 57-Fe and 97-Mo targets. The level density curves reveal step structures above the pairing gap due to the breaking of nucleon Cooper pairs. The location of the step structures in energy and their shapes arise from the interplay between single-particle energies and seniority-conserving and seniority-non-conserving interactions.Comment: 9 pages, including 5 figure

Важность бизнес-инкубаторов в развитии современного образования

Развитие малого и среднего бизнеса, является одним из наиболее важных в решение вопросов развития экономики России.The development of small and medium business is one of the most important in the decision of questions of development of economy of Russia

Sex-related variation in compact bone microstructure of the femoral diaphysis in juvenile rabbits

<p>Abstract</p> <p>Background</p> <p>While gross morphological changes in the skeleton between males and females are well know, differences between sexes in the histomorphology are less known. It is important to have knowledge on the bone structure of rabbits, as this is a widely used species in biomedical research. A study was performed to evaluate the association between sex and the compact bone morphology of the femoral diaphysis in juvenile rabbits.</p> <p>Methods</p> <p>Seventeen clinically healthy 2–3 month-old rabbits (9 females, 8 males) were included in the study. The rabbits were euthanized and the right femur was sampled for analysis. 70–80 microns thick bone sections of the femoral diaphysis were prepared using standard histological equipment. The qualitative histological characteristics were determined according to internationally accepted classification systems while the quantitative parameters were assessed using the software Scion Image. Areas, perimeters, minimum and maximum diameters of primary osteons' vascular canals, Haversian canals and secondary osteons were measured. Additionally, blood plasma concentrations of progesterone, corticosterone, IGF-I, testosterone and estradiol were analyzed.</p> <p>Results</p> <p>Qualitative histological characteristics were similar for both sexes. However, variations of certain quantitative histological characteristics were identified. Measured parameters of the primary osteons' vascular canals were higher in males than for females. On the other hand, females had significant higher values of secondary osteons parameters. Differences in Haversian canals parameters were only significant for minimum diameter.</p> <p>Conclusion</p> <p>The study demonstrated that quantitative histological characteristics of compact bone tissue of the femoral diaphysis in juvenile rabbits were sex dependent. The variations may be associated with different growth and modeling of the femur through influence by sex-specific steroids, mechanical loads, genetic factors and a multitude of other sources. The results can be applied in experimental studies focusing on comparison of the skeletal biology of the sexes.</p

ИОНОХРОМАТОГРАФИЧЕСКОЕ ОПРЕДЕЛЕНИЕ ХЛОРУКСУСНЫХ КИСЛОТ С ПРЕДВАРИТЕЛЬНЫМ МИКРОЭКСТРАКЦИОННЫМ КОНЦЕНТРИРОВАНИЕМ

In order to increase the sensitivity of the ion chromatographic determination of chlorinated acetic acids (CAAs) in water, an emulsion microextraction preconcentration was proposed. The emulsification of extractants was performed by the ultrasonic irradiation. Diethyl and methyl tert-butyl ethers were used as extractants. The comparison of extractants showed the advantages of methyl tert-butyl ether: stable aggregation into a separate phase after the dispersion, no loss of extractant at the analysis stages due to volatility. To reduce the detection limits and improve the chromatographic separation of analytes, the organic matrix of the extract was replaced by water. It was achieved by evaporating the extractant at room temperature and dissolving the dry residue in the eluent. Also, this operation eliminated the difficulties associated with the analysis of organic extracts using the ion chromatography with conductivity detector. The absence of loss of the analytes at this stage was experimentally proven. The dependences of the efficiency of microextraction preconcentration on the various process parameters (ultrasonic exposure time, centrifugation time, volume of extractant, salt additive concentration) were established. The detection limits reached were 1∙10-3 ‒ 8∙10-3 mg/l, which are 20-600 times lower than the maximum permissible values for CAAs. In addition, the advantages of this preconcentration technique over the published works were the simultaneous removal of interfering impurities, small volume of water samples (4.1 ml) and chromatograph injected volume (50 μl). The relative standard deviation did not exceed 25%. The proposed method was tested by analyzing the samples of tap water. Mono- and dichloroacetic acids were detected, their content did not exceed the MAC values. Keywords: chlorinated acetic acids, ion chromatography, microextraction preconcentrationDOI: http://dx.doi.org/10.15826/analitika.2020.24.1.004  R.G. Sirotkin, E.V. Elipasheva, V.A. Krylov, R.E. Grubov, K.A. Lutoshkina National Research Lobachevsky State University of Nizhny Novgorod (UNN)Gagarin pr., 23, Nizhny Novgorod, 603950, Russian FederationС целью повышения чувствительности ионохроматографического определения моно-, ди-, и трихлоруксусной кислот (ХУК) в воде предложено предварительное эмульсионное микроэкстракционное концентрирование. Эмульгирование экстрагентов осуществляли с помощью ультразвукового воздействия. В качестве экстрагентов использованы диэтиловый и метил-трет-бутиловый эфиры. Проведенное сравнение экстрагентов показало преимущества метил-трет-бутилового эфира: стабильную агрегацию в отдельную фазу после диспергирования, отсутствие потерь экстрагента на стадиях анализа вследствие летучести. Для снижения пределов обнаружения и улучшения ионохроматографического разделения ХУК проводили замену органической матрицы экстракта на водную путем испарения экстрагента при комнатной температуре и растворения сухого остатка в элюенте. Осуществление данной операции позволило также устранить сложности, связанные с анализом органических экстрактов методом ионной хроматографии с кондуктометрическим детектированием. Экспериментально доказано отсутствие потерь искомых аналитов на данной стадии. Установлены зависимости эффективности микроэкстракционного концентрирования от различных параметров процесса (время ультразвукового воздействия, время центрифугирования, объем экстрагента, концентрация солевой добавки). Достигнуты пределы обнаружения 1·10-3 ‒ 8·10-3 мг/л, что в 20–600  раз ниже, чем предельно допустимые значения для ХУК в питьевой воде. Преимуществами методики перед опубликованными работами являются также удаление мешающих примесей на стадии концентрирования ХУК, малые объемы используемой воды (4.1 мл) и вводимой в хроматограф пробы (50 мкл). Относительная погрешность определения не превышает 25 %. Предлагаемая методика апробирована анализом образцов водопроводной воды. Обнаружены моно- и дихлоруксусная кислоты, их содержание не превышало значений ПДК.Ключевые слова: хлоруксусные кислоты, ионная хроматография, микроэкстракционное концентрированиеDOI: http://dx.doi.org/10.15826/analitika.2020.24.1.00

Level density and thermal properties in rare earth nuclei

A convergent method to extract the nuclear level density and the gamma-ray strength function from primary gamma-ray spectra has been established. Thermodynamical quantities have been obtained within the microcanonical and canonical ensemble theory. Structures in the caloric curve and in the heat capacity curve are interpreted as fingerprints of breaking of Cooper pairs and quenching of pairing correlations. The strength function can be described using models and common parameterizations for the E1, M1 and pygmy resonance strength. However, a significant decrease of the pygmy resonance strength at finite temperatures has been observed.Comment: 15 pages including 8 figures. Proceedings article for the conference Nuclear Structure and Related Topics, Dubna, Russia, June 6-10, 200

The association of two single nucleotide polymorphisms (SNPs) in growth hormone (GH) gene with litter size and superovulation response in goat-breeds

Two active mutations (A 781 G and A 1575 G) in growth hormone (GH) gene, and their associations with litter size (LS), were investigated in both a high prolificacy (Matou, n = 182) and a low prolificacy breed (Boer, n = 352) by using the PCR-RFLP method. Superovulation experiments were designed in 57 dams, in order to evaluate the effect of different genotypes of the GH gene on superovulation response. Two genotypes (AA and AB, CC and CD) in each mutation were detected in these two goat breeds. Neither BB nor DD homozygous genotypes were observed. The genotypic frequencies of AB and CC were significantly higher than those of AA and CD. In the third parity, Matou dams with AB or CC genotypes had significantly larger litter sizes than those with AA and CD (p < 0.05). On combining the two loci, both Matou and Boer dams with ABCD genotype had the largest litter sizes when compared to the other genotypes (p < 0.05). When undergoing like superovulation treatments, a significantly higher number of corpora lutea and ova, with a lower incidence of ovarian cysts, were harvested in the AB and CC genotypes than in AA and CD. These results show that the two loci of GH gene are highly associated with abundant prolificacy and superovulation response in goat breeds

Three Stages of Lysozyme Thermal Stabilization by High and Medium Charge Density Anions

Addition of high and medium charge density anions (phosphate, sulfate, and chloride) to lysozyme in pure water demonstrates three stages for stabilization of the protein structure. The first two stages have a minor impact on lysozyme stability and are probably associated with direct interaction of the ions with charged and partial charges on the protein’s surface. There is a clear transition between the second and third stages; in the case of sodium chloride, disodium sulfate and disodium hydrogen phosphate this is at 550, 210, and 120 mM, respectively. Stabilization of lysozyme can be explained by the free energy required to hydrate the protein as it unfolds. At low ion concentrations, the protein’s hydration layer is at equilibrium with the bulk water. After the transition, bulk water is depleted and the protein is competing for water with the ions. With competition for water between the protein and the ions at higher salt concentrations, the free energy required to hydrate the interior of the protein rises and it is this that stabilizes the protein structure

Determination of chloroacetic acids using ion chromatography with liquid-phase microextraction preconcentration

С целью повышения чувствительности ионохроматографического определения моно-, ди-, и трихлоруксусной кислот (ХУК) в воде предложено предварительное эмульсионное микроэкстракционное концентрирование. Эмульгирование экстрагентов осуществляли с помощью ультразвукового воздействия. В качестве экстрагентов использованы диэтиловый и метил-трет-бутиловый эфиры. Проведенное сравнение экстрагентов показало преимущества метил-трет-бутилового эфира: стабильную агрегацию в отдельную фазу после диспергирования, отсутствие потерь экстрагента на стадиях анализа вследствие летучести. Для снижения пределов обнаружения и улучшения ионохроматографического разделения ХУК проводили замену органической матрицы экстракта на водную путем испарения экстрагента при комнатной температуре и растворения сухого остатка в элюенте. Осуществление данной операции позволило также устранить сложности, связанные с анализом органических экстрактов методом ионной хроматографии с кондуктометрическим детектированием. Экспериментально доказано отсутствие потерь искомых аналитов на данной стадии. Установлены зависимости эффективности микроэкстракционного концентрирования от различных параметров процесса (время ультразвукового воздействия, время центрифугирования, объем экстрагента, концентрация солевой добавки). Достигнуты пределы обнаружения 1·10-3 ‒ 8·10-3 мг/л, что в 20–600 раз ниже, чем предельно допустимые значения для ХУК в питьевой воде. Преимуществами методики перед опубликованными работами являются также удаление мешающих примесей на стадии концентрирования ХУК, малые объемы используемой воды (4.1 мл) и вводимой в хроматограф пробы (50 мкл). Относительная погрешность определения не превышает 25 %. Предлагаемая методика апробирована анализом образцов водопроводной воды. Обнаружены моно- и дихлоруксусная кислоты, их содержание не превышало значений ПДК.In order to increase the sensitivity of the ion chromatographic determination of chlorinated acetic acids (CAAs) in water, an emulsion microextraction preconcentration was proposed. The emulsification of extractants was performed by the ultrasonic irradiation. Diethyl and methyl tert-butyl ethers were used as extractants. The comparison of extractants showed the advantages of methyl tert-butyl ether: stable aggregation into a separate phase after the dispersion, no loss of extractant at the analysis stages due to volatility. To reduce the detection limits and improve the chromatographic separation of analytes, the organic matrix of the extract was replaced by water. It was achieved by evaporating the extractant at room temperature and dissolving the dry residue in the eluent. Also, this operation eliminated the difficulties associated with the analysis of organic extracts using the ion chromatography with conductivity detector. The absence of loss of the analytes at this stage was experimentally proven. The dependences of the efficiency of microextraction preconcentration on the various process parameters (ultrasonic exposure time, centrifugation time, volume of extractant, salt additive concentration) were established. The detection limits reached were 1∙10-3 ‒ 8∙10-3 mg/l, which are 20-600 times lower than the maximum permissible values for CAAs. In addition, the advantages of this preconcentration technique over the published works were the simultaneous removal of interfering impurities, small volume of water samples (4.1 ml) and chromatograph injected volume (50 μl). The relative standard deviation did not exceed 25%. The proposed method was tested by analyzing the samples of tap water. Mono- and dichloroacetic acids were detected, their content did not exceed the MAC values