Lamellar structure and nanomechanical properties of quasicrystalline Al-Cu-Fe alloys

The kinetics of structural phase transformations in quasicrystal-forming Al-Cu-Fe alloys with compositions in the region of stability of the icosahedral (i) phase has been investigated. It has been shown that, depending on the development of metastable transformations i → pentagonal phases P1 and P2, a homogeneous lamellar structure (i + P1 + P2) or a polygrain i-phase is formed in the alloys. The P-h diagrams obtained upon nanoindentation, atomic force microscopy, and scanning electron microscopy of indentations have demonstrated signs of elasto-plastic deformation of the alloys with lamellar and polygrain icosahedral structures. It has been found that, in contrast to the polygrain icosahedral alloys with a normal size effect of nanoindentation, the alloys with a lamellar structure are characterized by a nonmonotonic dependence of the hardness (H) on the maximum load (P max) and exhibit the effect of strain hardening in the range of loads 50 mN ≤ P max < 500 mN. The strain hardening is considered as the result of resistance exerted by boundaries of the lamellar structure to the development of plastic deformation. © 2013 Pleiades Publishing, Ltd

Visible light photoluminescence in TiO2/CdS nanopowders synthesized by sol-gel route: Effect of gel aging time

A series of sol-gel TiO2/CdS, TiO2 powders and coagulated CdS nanoparticles were studied by XRD, HRTEM and Raman spectroscopy to elucidate the effect of low-temperature gel aging time on visible photoluminescence (PL) emission of the TiO2/CdS composites. With an increase in aging time a content of amorphous titania and incorporated CdS nanoparticles decreases in composites. For all composites, visible PL emission includes bands attributed to surface oxygen vacancies and hydroxyl group of TiO2 nanocrystals, as well as yellow-green and red bands related to lattice defect states of CdS nanoparticles. It was found that gel aging time is a crucial parameter to influence visible PL emission in composites. This emission is suppressed with increasing aging time, and its evolution shows that healing of oxygen vacancy defects and hydroxyl group affect visible emission more significantly than improving crystallinity degree. The correlation between visible PL emission in TiO2/CdS and their visible-light photocatalytic activity was discussed. © 2020, ITMO University. All rights reserved.The research was carried out in accordance with the state assignment for ISSC UB RAS and financial support from ISSC UB RAS (theme AAAA-A19-119031890025-9). TEM study was supported by RFBR (grant No. 20-02-00906). The authors are grateful to Dr. Kozhevnikova N. S. and Dr. Gorbunova T. I. for the provided samples TiO2/CdS and CdS

Supramolecular systems based on amidoammonium and amidoaminocalix[4]resorcinarenes and polyacrylic acid

© 2015 Elsevier B.V. In the solutions of polyacrylic acid (PAA) the amphiphilic calix[4]resorcinarenes 1-. 10 and their complexes with Methyl Orange (MO) form binary (. 1-. 10)-PAA and tertiary (. 2-. 10). -MO-PAA supramolecular complexes which are water-soluble in the case of amidoammonium (. 1-. 5) and water-insoluble in the case of amidoamino (. 6, 7) or amido(dimethylamino) (. 8-. 10) calixresorcinarenes. Almost 90% of removal of MO from the aqueous solution is achieved by the formation of the water-insoluble systems (. 6-. 10)-m{cyrillic}O{cyrillic}-PAA. In aqueous solution the particles of the (. 1-. 5)-PAA systems have average hydrodynamic diameters which values vary depending on the length of the alkyl substituents of macrocycles

Supramolecular nanoscale systems based on amphiphilic tetramethylensulfonatocalix[4]resorcinarenes and cationic polyelectrolyte with controlled guest molecule binding

© 2016 Informa UK Limited, trading as Taylor & Francis GroupThe water-soluble tetramethylensulfonatocalix[4]resorcinarene with methyl (C1) and pentyl (C5) substitutes on the lower rim forms colloid nanoscale aggregates with poly(diallyldimethylammonium chloride) (PDDA) in aqueous solutions. The size and stability of nanoparticles depend on concentrations of the components and their ratio in the ‘calixarene-polymer’ system. Ternary supramolecular complexes «polymer–macrocycle–guest molecule L-tryptophan (Trp) in conditions of spontaneous pH (3.80 and 4.78 for C1-PDDA and C5-PDDA systems, respectively) in an aqueous solution and in phosphate buffer (pH 7) were investigated by fluorescence method. The addition of the third component – PDDA – to the «non-aggregated C1–Trp» associates leads to the release of Trp in all studied conditions. The possibility of the «binding–release» process of L-tryptophan in «C5–Trp» associates after PDDA addition in the ternary complex is achieved and controlled by the structure of the macrocyclic self-associates and pH conditions

Supramolecular nanoscale systems based on amphiphilic tetramethylensulfonatocalix[4]resorcinarenes and cationic polyelectrolyte with controlled guest molecule binding

© 2016 Informa UK Limited, trading as Taylor & Francis Group.The water-soluble tetramethylensulfonatocalix[4]resorcinarene with methyl (C1) and pentyl (C5) substitutes on the lower rim forms colloid nanoscale aggregates with poly(diallyldimethylammonium chloride) (PDDA) in aqueous solutions. The size and stability of nanoparticles depend on concentrations of the components and their ratio in the ‘calixarene-polymer’ system. Ternary supramolecular complexes «polymer–macrocycle–guest molecule L-tryptophan (Trp) in conditions of spontaneous pH (3.80 and 4.78 for C1-PDDA and C5-PDDA systems, respectively) in an aqueous solution and in phosphate buffer (pH 7) were investigated by fluorescence method. The addition of the third component–PDDA–to the «non-aggregated C1–Trp» associates leads to the release of Trp in all studied conditions. The possibility of the «binding–release» process of L-tryptophan in «C5–Trp» associates after PDDA addition in the ternary complex is achieved and controlled by the structure of the macrocyclic self-associates and pH conditions

ENDOBILIARY INTERVENTIONS AT ACUTE NECROTIC PANCREATITIS

The study included patients with acute necrotic pancreatitis and confirmed biliary hypertension. The endoscopic retrograde cholangiopancreatography (ERSP) and endoscopic papillosphincterotomy (EPST) supplemented with lithoextrac- tion were conducted immediately. We concluded that in cases when intraduct pathology causes biliary hypertension and initial severity of patient's condition doesn't exceed 11 physiological status severity (PSS) scale conducting ERSP with EPST and lithoextraction is more preferable than drainage of gall bladder

Novel thermoresponsive water-soluble oligomers based on amphiphilic calixresorcinarenes

© 2017 Informa UK Limited, trading as Taylor & Francis Group.Novel water-soluble thermoresponsive oligomers TO1 and TO2 were obtained by reaction of amidoamine tetramethylcalixresorcinarenes (C1) and tetrapentylcalixresorcinarenes (C5) with ethylene glycol diglycidyl ether. The compounds were characterised by 1H and FT-PGSE NMR, FTIR, static light scattering and elemental analysis. The thermoresponsive properties of oligomers were investigated by spectrophotometry, DLS, FT-PGSE NMR and TEM. The cloud points of oligomers (43 °C for TO1 (5 mg/ml) and 41 °C for TO2 (1.2 mg/ml), respectively) were determined. The influence of salts effect on TO2 cloud points was investigated. The binding of anti-inflammatory drug naproxen (Nap) at 20 °C by TO1 and TO2 and its partial release at cloud points of oligomers in aqueous solution are observed using fluorescence and FT-PGSE NMR methods. New example of creating of thermoresponsive macrocyclic systems on the basis of amidoamine calixresorcinarenes with possibility of substrate binding and release under the influence of termo-stimuli in an aqueous solution was shown

ТЕКТОНИКА И МОДЕЛЬ ФОРМИРОВАНИЯ ОНЕЖСКОГО СИНКЛИНОРИЯ В ПАЛЕОПРОТЕРОЗОЕ

Consideration is being given to the Onega Paleoproterozoic structure (Onega synclinorium, OS) as a tectonotype of intraplate negative structures, which experience intermittent subsidence over a long period of time. The paper presents a model of the OS and discusses its tectonic evolution. The model is based on the geological and structural data, already published and collected so far by the authors, as well as on the data concerning the OS deep structure, particularly on the interpretation of the 1-EV seismic profile and potential fields. The proposed model illustrates an example of conjectured interaction between different geodynamic factors and explains reasons for the development of the OS throughout the Paleoproterozoic, including the periods of intense subsidence and magmatism, inversions of local basins comprising the Onega trough, and deformations of the Paleoproterozoic strata. An important role in the formation of the OS was played by shear dislocations within an imbricate fan of its controlling Central-Karelian shear zone. The shear dislocations were accompanied by rotation of a large block located to the west of the OS, which led to the rotational-indentational interaction between adjacent blocks and to compensated coexistence among transtensional and transpressional regimes along their separating shear zone. Compensatory dynamic mechanism also manifested itself in crustal layers at the base of the OS. Horizontal flow of the mid-crustal masses and their outflow from the depression were compensated by the development of deep-seated thrust duplexes and uplifts around the depression as well as by the upper crustal extension associated with low-angle dilatant normal faulting. Successive propagation of these faults, dynamically related to shear dislocations within an imbricate fan of the Central Karelia zone, controlled the formation features and southward migration of the OS-contained basins as well as magmatic and syllogenesis-related occurrences. Multilayered subhorizontal flow of low-viscosity rocks at the base and inside the OS section against the background of shear dislocations gave rise to the occurrence of crest-like and diapir-like folding. The processes of OS formation occurred amid the development and localization of active mantle plumes and asthenospheric diapirs. One of the factors of their development and localization were the phenomena of relative decompression within the imbrication fan of the Central Karelian shear zone.Охарактеризовано строение и разработана модель тектонической эволюции Онежской палеопротерозойской структуры (синклинория, ОС), представляющей собой тектонотип внутриплитных отрицательных структур, испытывавших периодическое прогибание на протяжении длительного времени. Модель разработана на основе обобщения опубликованных и авторских геолого-структурных материалов, а также сведений о глубинном строении ОС, в частности интерпретации сейсмического разреза 1-ЕВ и потенциальных полей. Модель иллюстрирует пример сопряженного взаимодействия различных геодинамических факторов и объясняет причины длительного формирования ОС на протяжении всего палеопротерозоя, включая периоды интенсивного прогибания и магматизма, инверсии составляющих Онежский прогиб локальных бассейнов и деформации палеопротерозойских толщ. При формировании ОС большое значение имели сдвиговые дислокации, проявленные в пределах имбрикационного веера Центрально-Карельской зоны сдвига, контролирующего позицию этой структуры. Сдвиговые перемещения были сопряжены с вращением крупного блока, расположенного западнее ОС, что привело к ротационно-инденторному взаимодействию смежных блоков и компенсационному сосуществованию областей транспрессии и транстенсии вдоль разделяющей их зоны сдвига. Компенсационный динамический механизм проявился и в коровых слоях основания ОС. Горизонтальное течение и отток среднекоровых масс из области депрессии компенсировались формированием глубинных надвиговых дуплексов и поднятий в обрамлении депрессии, а также растяжением верхней коры с развитием систем пологих дилатансионных сбросов. Последовательная пропагация этих сбросов, динамически сопряженных со сдвиговыми нарушениями имбрикационного веера Центрально-Карельской зоны, контролировала особенности формирования и миграцию бассейнов ОС в южном направлении, а также проявления магматизма и силлогенеза. Многоярусное субгоризонтальное течение маловязких пород в основании и внутри разреза ОС, проявившееся на фоне сдвиговых дислокаций, привело к развитию гребневидной и диапироподобной складчатости. Процессы формирования ОС проходили на фоне высокой активности мантийных плюмов и астеносферных диапиров. Одним из факторов их развития и локализации были явления относительной декомпрессии в пределах имбрикационного веера Центрально-Карельской зоны сдвига

Multiplexed set of 10 microsatellite markers for identification of potato varieties

Genetic identification of potato varieties is a demanded instrument for development of new cultivars registration system, protection of plant breeders’ rights, and variety homogeneity control. The most perspective approach for distinction and identification of varieties continues to remain the use of short tandem repeats. STR amplification with the subsequent high resolution electrophoresis allows such a unique characteristic of a variety to be obtained as the DNA profile. A large scale of samples requires the creation of a robust and time-saving technique based on fragment sizing. We selected 10 polymorphic STR loci of potato: STI0032, STG0016, STI0001, STI0004, STM1104, STM5127, STI0030, STI0033, STI0014, STM5114 and designed a multiplex panel for potato DNA profiling. Fluorescent labelling of primers and size distinction of amplicones allowed us to use one tube for PCR and capillary electrophoresis. We also modified the CTAB-protocol for DNA extraction from tubers and other parts of potato plants, the PCR mix recipe and the amplification protocol for good results. Using Genetic Analyzer allows the length of alleles to be defined with an accuracy of one nucleotide and digitized genetic profiles to be developed. We created a unique DNA profile for each of 40 varieties and 23 breeding lines from Russia and other countries and evaluated the homogeneity of 8 varieties. The proposed technique оf potato DNA profiling allows a large number of samples to be rapidly analyzed in the 96-well plate format