Comparative investigation of the structure, phase composition, and mechanical properties of Ni-based high-temperature alloys manufactured by different methods

A comprehensive comparative study of the structure, phase composition, and mechanical properties of heat-resistant nickel-based Ni-Cr-(X) alloys produced by the methods of traditional metallurgy and self-propagating high-temperature synthesis (SHS metallurgy) is carrie

ON-LINE КОНЦЕНТРИРОВАНИЕ БИОГЕННЫХ АМИНОВ МЕТОДОМ КАПИЛЛЯРНОГО ЭЛЕКТРОФОРЕЗА С ИCПОЛЬЗОВАНИЕМ СИНТЕЗИРОВАННЫХ КОВАЛЕНТНЫХ ПОКРЫТИЙ НА ОСНОВЕ ИОННЫХ ЖИДКОСТЕЙ

Covalent coatings of internal quartz capillary walls based on the ionic liquids were synthesized within this research. The synthesis of the covalent coating included a step of silylation followed by the functionalization with imidazole and 1-bromobutane. The resulting coating created anodic electroosmotic flow (EOF) at pH = 2. The range of pH at which coatings do not change their properties was 2.0-5.5. The possibilities of different ways of on-line concentration (large volume sample stacking, head-column field-amplified sample stacking, sweeping, sweeping in combination with electrostacking) of catecholamines were examined. Stacking efficiency factors (SEF) were 105-135 and the detection limits were decreased to 11-17 ng/ml for analytes under the large volume sample stacking.  Under the sweeping conditions, sodium dodecyl sulfate (micelle forming agent) was sorbed on the modified walls, provided a negative charging surface and acted as a strong cation exchanger. This fact led to the additional reserves in the separation selectivity of catecholamines. Under the electrostacking, the values of SEF were above 1000 and the detection limits were reduced to 1-2 ng/ml. An approbation of established patterns in the analysis of urine samples was carried out.Keywords: covalent coating, ioniс liquids, biogenic amines, on-lineconcentration(Russian)DOI: http://dx.doi.org/10.15826/analitika.2017.21.1.006E.A. Kolobova1,2, L.A. Kartsova1, E.A. Bessonova1, A.V. Kravchenko1 1Saint-Petersburg State University, Institute of Chemistry, 26 Universitetskii prospect, St. Petersburg, Petergof 198504, Russian Federation2The Nikiforov Russian Center of Emergency and Radiation Medicine, 54 Optikov st.,St. Petersburg, 199034, Russian FederationВ работе предложен вариант синтеза ковалентных покрытий внутренних стенок кварцевого капилляра на основе имидазолиевой ионной жидкости (ИЖ), включающий стадию силилирования с последующей функционализацией имидазолом и 1-бромбутаном. Полученные покрытия создавали анодный электроосмотический поток (ЭОП) при рН = 2. Рабочий диапазон рН фонового электролита, при котором синтезированные покрытия не меняют своих характеристик, составляет 2.0-5.5. Выявлены возможности различных вариантов on-line концентрирования (стэкинг с большим объемом вводимой пробы и «водной пробкой», свипинг, свипинг в сочетании с электростэкингом) катехоламинов. При стэкинге с большим объемом вводимой пробы факторы концентрирования (SEF) аналитов составили 105-135, а пределы обнаружения снижены до 11-17 нг/мл. В варианте свипинга, мицеллообразующий агент – додецилсульфат натрия, сорбируясь на модифицированных стенках, обеспечивал поверхности отрицательный заряд и выполнял роль сильного катионообменника, что приводило к дополнительным резервам в селективности разделения аналитов. При электростэкинге значения факторов концентрирования биогенных аминов превысили 1000, а пределы обнаружения удалось снизить до 1-2 нг/мл. Проведена апробация установленных закономерностей при анализе образцов мочи.Ключевые слова: ковалентные покрытия, ионные жидкости, биогенные амины, on-lineконцентрированиеDOI: http://dx.doi.org/10.15826/analitika.2017.21.1.00

РАЗДЕЛЕНИЕ ЭНАНТИОМЕРОВ ТИРОЗИНА, ТРИПТОФАНА И β-БЛОКАТОРОВ МЕТОДОМ КАПИЛЛЯРНОГО ЭЛЕКТРОФОРЕЗА С УЧАСТИЕМ АМИНОКИСЛОТНОЙ ИОННОЙ ЖИДКОСТИ 1-бутил-3-метилимидазолий L-пролинат [C4MIm][L-Pro] В КАЧЕСТВЕ ХИРАЛЬНОГО СЕЛЕКТОРА

The current study is devoted to the synthesis of amino acid ionic 1-butyl-3-methylimidazolium L-prolinate [C4MIm][L-Pro] liquid and the investigation of its possibilities as a chiral selector for the separation of amino acids (tryptophan and tyrosine) and β-blockers (carvedilol and propranolol) enantiomers. The following factors affecting the resolution of amino acids stereoisomers under ligand exchange capillary electrophoresis were established: background electrolyte pH, concentration of chelate complex, molar ratio of metal and ligand and its nature. The enantioselectivity values of 1.25 for tryptophan enantiomers and 1.17 for tyrosine enantiomers were observed when the background electrolyte consisted of 50 mM borate buffer (pH = 12.2), 20 mM [C4MIm][L-Pro], and 10 mM CuSO4. The synergetic effect of the synthesized ionic liquid and (2-hydroxypropyl)-β-cyclodextrine when added to the background electrolyte content (20 мМ NaH2PO4, pH = 2.5) was discovered during the separation of carvedilol and propranolol enantiomers. The achieved resolution for carvedilol (Rs = 1.1) and propranolol (Rs = 1.6) enantiomers allowed determining the enantiomers ratio of active ingredients in drug formulations.Keywords: ligand exchange capillary electrophoresis, amino acid ionic liquids, chiral selector, amino acids, β-blockers, synergetic effect, enantioseparation(Russian)DOI: http://dx.doi.org/10.15826/analitika.2018.22.1.004 Kolobova E.A.1, Kartsova L.A.2, Alopina E.V.2, Smirnova N.A.2 1The Nikiforov Russian Center of Emergency and Radiation Medicine,54 Optikov st., St. Petersburg, 199034, Russian Federation2Saint-Petersburg State University, Institute of Chemistry, 26 Universitetskii prospect,  St. Petersburg, Petergof, 198504, Russian Federation Работа посвящена синтезу аминокислотной ионной жидкости (ИЖ) 1-бутил-3-метилимидазолий L-пролинат [C4MIm][L-Pro] и изучению ее возможностей в качестве хирального селектора при разделении энантиомеров аминокислот (триптофан и тирозин) и β-блокаторов (пропранолол и карведилол). Исследованы факторы, влияющие на разрешение стереоизомеров аминокислот в режиме лигандообменного капиллярного электрофореза (ЛОКЭ). Показано, что на разрешение энантиомеров влияют рН фонового электролита, концентрация хелатного комплекса, мольное соотношение «металл : лиганд», природа хирального селектора и металла-комплексообразователя. Значения энантиоселективности разделения, составившие 1.25 для энантиомеров триптофана и 1.17 для энантиомеров тирозина, были достигнуты с использованием фонового электролита, содержащего 50 мМ боратный буфер (рН = 12.2), 20 мМ [C4MIm][L-Pro], 10 мМ CuSO4. При разделении энантиомеров карведилола и пропранолола обнаружен синергетический эффект при совместном введении в фоновый электролит (20 мМ NaH2PO4, pH = 2.5) двух хиральных селекторов –  синтезированной аминокислотной ИЖ [C4MIm][L-Pro] и (2-гидроксипропил)-β-циклодекстрина. Достигнутые значения факторов разрешения для энантиомеров пропранолола (Rs = 1.1) и карведилола (Rs = 1.6)позволили определить соотношения энантиомеров действующих веществ в лекарственных препаратах.Ключевые слова: лигандообменный капиллярный электрофорез, аминокислотные ионные жидкости, хиральный селектор, аминокислоты, β-адреноблокаторы, синергетический эффект, разделение энантиомеровDOI: http://dx.doi.org/10.15826/analitika.2018.22.1.00

Laser-assisted fabrication and in vitro verification of functionalized surface for cells biointegration

The paper investigates how the surface relief of an implant affects cell behavior. Currently, most implant manufacturers claim the key impact biocompatibility factor to be surface micro-roughness. We suppose that the interaction between cells and implants also depends on such relief peculiarities as continuous or discontinuous topography, subcellular distance between peaks and presence of porous oxide layer. We have developed the laser processing conditions that provide three different reliefs: "open grooves", "grid" and "close grooves". Along with the micro-roughness characteristics the reliefs differ with their deepness and period of groove

ELECTRONIC STRUCTURE OF FeSi

The full set of high-energy spectroscopy measurements including X-ray photoelectron valence band spectra and soft X-ray emission valence band spectra of both components of FeSi (Fe K_beta_5, Fe L_alpha, Si K_beta_1,3 and Si L_2,3) are performed and compared with the results of ab-initio band structure calculations using the linearized muffin-tin orbital method and linearized augmented plane wave method.Comment: 11 pages + 3 PostScript figures, RevTex3.0, to be published in J.Phys.:Cond.Matte

The study of the sorghum genetic diversity using the mul¬tiplex microsatellite analysis

This study is focused on evaluation of the genetic structure and diversity of the national sorghum collection. Analyzing the genetic diversity of crop species is of great importance for genetic resources management and food security of any country. Huge genetic diversity of sorghum provides a great opportunity to improve the agronomic characteristics of this crop. The efficiency of microsatellite  analysis has been demonstrated in many studies on the genetic diversity of different races and geographical groups of sorghum plants. Development of multiplex PCR analysis systems based on a set of polymorphic microsatellite loci will facilitate genetic tests on a large number of plant samples, thus making the research on sorghum diversity more efficient and comprehensive. A system of multiplex PCR analysis based on 12 polymorphic microsatellite loci was developed to perform single-stage high-throughput screening of cultivated and wild forms preserved in the sorghum germplasm collection. As a result of the microsatellite analysis of 200 sorghum plants, 229 alleles were detected. The studied loci showed high polymorphism. More than 17 alleles were identified in most loci, their polymorphic index content (PIC) ranging from 0.694 to 0.954. The value of the effective multiplex ratio (EMR) in the developed system was estimated at 0.833. The microsatellite analysis of sorghum accessions resulted in obtaining quantized gene expressions profiles, with a DNA profile for each accession, and revealed significant polymorphism among the plants of different sorghum varieties (races). The developed multiplex PCR system was shown to be efficient for evaluation of the genetic diversity and genetic relationships of sorghum plants from different races. The analysis of the obtained data using three bioinformatic techniques, NJ cluster analysis, PCoA, and the Bayesian model-based clustering, helped to classify the analyzed sorghum accessions into cluster groups according to their morphological and agronomic traits

How Neanderthals gripped retouchers: experimental reconstruction of the manipulation of bone retouchers by Neanderthal stone knappers

When studying bone retouchers, researchers pay close attention to the morphological characteristics of the tool’s active zone, and the lithic raw material processed. In our research, we found that the orientation of the bone retoucher in the hand and the grip employed to retain and manipulate it are crucial factors that affect the morphological characteristics of the retoucher’s active zone. By examining two alternative grips for manipulating bone retouchers ((1) Using all the fingers of one hand in a power grip; (2) Using only the first three digits of one hand in a pinch grip), we found that when the retoucher is held in the first manner, the active area is larger, as is the amount of bone removed by the retoucher. When the retoucher was pinched with only three fingers in a precision grip, retouch damage was more densely concentrated and less bone was removed. The orientation of the retoucher in the hand and the grip employed have a greater influence on the active area than the extent of retoucher use, which we assessed by measuring the number of stone tool edges processed. By gripping the retoucher with all the fingers of one hand, the knapper automatically applies greater force, which results in the removal of more bone. Comparison of experimental bone retouchers with those recovered from Middle Paleolithic archaeological contexts in Chagyrskaya Cave (Altai, Russia) revealed that Altai Neanderthals practiced two methods of grasping bone retouchers, with a three-finger pinch grip being dominant. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature