New indicator reactions involving sulfur-containing organic compounds for the kinetic determination of selenium

New indicator reactions were proposed for the determination of selenium by the kinetic method based on the reduction of Methylene Blue by some sulfur-containing organic compounds. It was demonstrated that a high sensitivity of the determination of selenium is attained using unithiol and thiomalic, 2,3-dithiomercaptopropionic, and rubeanic acids as reducing agents. In the presence of unithiol, down to 4 ng/mL selenium can be determined. © 2001 MAIK "Nauka/Interperiodica"

FTIR study of H-bonds cooperativity in complexes of 1,2-dihydroxybenzene with proton acceptors in aprotic solvents: Influence of the intramolecular hydrogen bond

FTIR spectroscopic study of hydrogen bonding of 1,2-dihydroxybenzene (catechol) with proton acceptors has been carried out. The influence of intramolecular and intermolecular hydrogen bonds on the strengths of each other in complexes of 1,2-dihydroxybenzene with various proton acceptors has been analyzed. It was shown that intramolecular hydrogen bond is strengthened when 1,2-dihydroxybenzene interacts with bases (ethers, amines, nitriles, etc.) in inert solvents. The contribution of the cooperativity of intramolecular hydrogen bonds in the frequency of stretching vibrations of O-H groups linearly depends on the proton acceptor ability of the bases. The solvent effect on hydrogen bond cooperativity in 1,2-dihydroxybenzene-base complexes has been studied. The approach to determine the influence of cooperative effects on the formation of intermolecular complexes with 1,2-dihydroxybenzene is proposed. It was shown that the strength of intramolecular hydrogen bonds in the complexes of 1,2-dihydroxybenzene with bases due to cooperativity of interactions increases by 30-70%, and the strength of intermolecular hydrogen bond by 7-22%. © 2010 Elsevier B.V. All rights reserved

Reaction of 2,3-dimethylmercaptopropionic acid with methylene blue as an indicator reaction for the kinetic determination of selenium

A new indicator reaction between 2,3-dimethylmercaptopropionic acid and Methyl Blue was proposed for the kinetic determination of selenium. The optimal reaction conditions were found. A linear relationship was observed between the induction period and the Se(IV) concentration in the range between 0.9 and 9.6 ng/mL Se. Masking with EDTA and solvent extraction with diethyldithiophosphoric acid can be used for the separation of interfering elements forming complexes with the reagent. © 2001 MAIK "Nauka/Interperiodica"

Calorimetric determination of the enthalpy of specific interaction of chloroform with a number of proton-acceptor compounds

Calorimetry was used to measure the enthalpies of solution of chloroform in various proton-acceptor solvents and, vice versa, proton-acceptors in chloroform. Based on a previously proposed equation, the enthalpies of specific interaction were calculated and compared with the published data on the enthalpy of hydrogen bonding of chloroform with various proton-acceptor solvents. The composition of the H-bonded complexes mainly formed during the dissolution of proton-acceptor solutes in chloroform was established. It was demonstrated that the dissolution of ethers in chloroform is predominantly accompanied by the formation of 1: 1 complexes, while the dissolution of acetone, dimethylformamide, and dimethyl sulfoxide in chloroform gives rise to more complex associates. © Nauka/Interperiodica 2006

The effects of changes in extracellular calcium concentrations on the electrical properties of command neurons after acquisition of a defensive conditioned reflex in snails

Studies of the electrical characteristics of the command neurons of a defensive reflex showed that the membrane potential showed no significant changes in response to changes in the calcium concentration in the perfusing solution in either intact or trained snails. Increases in the calcium ion concentration in intact snails were accompanied by increases in the threshold potential, from 14 ± 0.7 mV at 2.5 mM Ca2+ to 21.8 ± 0.9 mV at 20 mM Ca2+. The threshold potential in trained snails decreased in response to both increases and decreases in calcium concentrations, from 16.8 ± 0.6 mV (physiological saline containing 10 mM Ca2+) to 13.3 ± 0.6 mV at 20 mM Ca2+ and 11.8 ± 0.8 mV at 2.5 mM Ca2+. The critical depolarization level changed correspondingly: in intact snails, this decreased with increases in calcium concentration, while in trained snails it increased in response to both increases and decreases in the calcium concentration. © 2006 Springer Science+Business Media, Inc

The features of the language of representation of humour in the texts of American and Russian stand-up comedians

Based on the definition of the research object and the subject of sociolinguistics, which is considered an independent scientific discipline, in this article we assume to study the features of the language representation and perception of humour in performances of stand-up comedians from American and Russian linguocultures. We will also consider the similarities and differences of the topics of the texts of American and Russian comedians. In consideration of the genre of special interest is the attitude of the audience (in fact - the society) to the obscene and non-obscene language ("black humor"; "jokes below the belt", etc.) used by stand-up comedians in their performances in the United States and Russia. The relevance of this study is related to the overall underexplored genre"standup" fromlinguistics point of view and originality of their language. Research methodology –set of methods of textual, contextual, linguistic and linguostylistic analysis of the content of the texts of public performances ofthe comedians in the United States and Russia. Material for the study consists of texts of performances of stand-up comedians. The results of our research will help to identify the specifics of the language means of representation of humour in the texts of stand-up comedians.Key words: text, research, speech, language, translation, humour, linguistics, linguoculture,sociolinguistics

Astana experience: department of oncohematology and bone marrow transplantation, National Research Center of Oncology and Transplantation

The Unit of Oncohematology and Bone Marrow Transplantation (BMT) was arranged on basis of the Republican Research Center of Hospital Emergencies SC (Astana, Republic of Kazakhstan) in August 2010. Since July 2014, a Clinical Department with 69 beds was arranged, and National Research Center for Oncology and Transplantation SC was arranged. From 2010 to 2016, the modalities of hematopoietic stem cell transplantation have been advanced, from autologous BMT to allogeneic hematopoietic stem cell transplants (HSCT) from matched donors (33%), and haploidentical HSCTs (43% in 2016), a total of 186 transpants. Bone marrow was used as a source of stem cells in 71 cases (71 donors for allo-HSCT in 69 recipients), whereas peripheral stem cells were harvested in 73 cases (15 donors for 15 recipients of allo-BMT, and 58 marrow harvests for autologous BMT)

New indicator reactions involving sulfur-containing organic compounds for the kinetic determination of selenium

New indicator reactions were proposed for the determination of selenium by the kinetic method based on the reduction of Methylene Blue by some sulfur-containing organic compounds. It was demonstrated that a high sensitivity of the determination of selenium is attained using unithiol and thiomalic, 2,3-dithiomercaptopropionic, and rubeanic acids as reducing agents. In the presence of unithiol, down to 4 ng/mL selenium can be determined. © 2001 MAIK "Nauka/Interperiodica"

Kinetic determination of selenium using the reduction of Nile Blue with sulfide ions

The catalytic effect of Se(IV) was first observed in the reaction of the reduction of Nile Blue with sulfide ions. Optimal conditions for the determination of selenium by this reaction were found. The dependence of the reaction rate on the concentration of Se(IV) was linear in the concentration range 0.008-0.16 μg/mL. Solvent extraction with dithiophosphoric acids was proposed for the separation of selenium from the interferents. A procedure for the extraction-kinetic determination of selenium with the detection limit 0.006 μg/mL was developed