Investigation of the triboengineering characteristics of nanocomposites based on polymeric blends

Triboengineering tests of composites based on blends of fluoroplastics modified with magnesium nanospinel demonstrate the regularities of the appearance of friction surfaces on these metal-polymer pairs. The new materials are characterized by low and stable friction coefficients and wear rates and improved resistance to deformation, considerably expanding the range of their application in sealing systems and friction units.     

Noncanonical conformation of nucleic acids: structure with slipped-loops, occurring in DNA oligonucleotides

A HPLC method was developed and validated for the quantitation of 9-cis-retinoic acid (ALRT1057) and its major metabolite, 4-oxo-9-cis-retinoic acid (LG100182) in human plasma. Samples were buffered and extracted with methyl-tert-butyl-ether. The analytes and an I.S. were separated on a C18 HPLC column using a shallow gradient of 70-89% organic solvent. The analytes were quantitated by UV detection at 348 nm. Selectivity against endogenous compounds and potential metabolites (retinol, all trans-, 13-cis-, and 4-hydroxy-9-cis-retinoic acid) was demonstrated. The run time was 29 min. The standard curve was linear from 2.5 to 450 ng ml-1. Interassay precision for both analytes in quality control samples was less than 5.0% RSD. Accuracy was within 11.0% RE for both compounds. Analyte stability during sample storage, extraction processing, and chromatography was established. Method ruggedness was tested by two analysts and on two HPLC systems. This method has been applied to the quantitation of clinical samples.     

Dependence of the processing characteristics of a copper powder and its dendrite structure on electrolysis conditions at a constant overvoltage

Translated from Poroshkovaya Metallurgiya, No. 2(326), pp. 1–8, February, 1990.     

A Method for the Hermetic Connection of High-Pressure Tubing to a High-Pressure Apparatus

A method for the hermetic connection of small-diameter high-pressure tubing to a high-pressure apparatus without soldering is described.     

Application of the Luikov Approximate Solutions to Mathematical Description of the Process of Self-Freezing of Materials by Decreasing Pressure

A mathematical model for the process of self-freezing of moist materials in a continuously increasing vacuum which is developed on the basis of the approximate solutions obtained by A. V. Luikov for drying of capillary-porous media is presented. Results of experimental investigations into the self-freezing of a moist cloth are given, from which the temperature of supercooling of the surface material layer, the temperature coefficient, and the velocity of deepening of the freezing surface are determined; all of these parameters are used in mathematical simulation of the above process.     

Genetic Biomarkers of Antipsychotic-Induced Prolongation of the QT Interval in Patients with Schizophrenia

Antipsychotics (AP) induced prolongation of the QT interval in patients with schizophrenia (Sch) is an actual interdisciplinary problem as it increases the risk of sudden death syndrome. Long QT syndrome (LQTS) as a cardiac adverse drug reaction is a multifactorial symptomatic disorder, the development of which is influenced by modifying factors (APs’ dose, duration of APs therapy, APs polytherapy, and monotherapy, etc.) and non-modifying factors (genetic predisposition, gender, age, etc.). The genetic predisposition to AP-induced LQTS may be due to several causes, including causal mutations in the genes responsible for monoheme forms of LQTS, single nucleotide variants (SNVs) of the candidate genes encoding voltage-dependent ion channels expressed both in the brain and in the heart, and SNVs of candidate genes encoding key enzymes of APs metabolism. This narrative review summarizes the results of genetic studies on AP-induced LQTS and proposes a new personalized approach to assessing the risk of its development (low, moderate, high). We recommend implementation in protocols of primary diagnosis of AP-induced LQTS and medication dispensary additional observations of the risk category of patients receiving APs, deoxyribonucleic acid profiling, regular electrocardiogram monitoring, and regular therapeutic drug monitoring of the blood APs levels.     

Plasmids as Key Players in Acinetobacter Adaptation

This review briefly summarizes the data on the mechanisms of development of the adaptability of Acinetobacters to various living conditions in the environment and in the clinic. A comparative analysis of the genomes of free-living and clinical strains of A. lwoffii, as well as the genomes of A. lwoffii and A. baumannii, has been carried out. It has been shown that plasmids, both large and small, play a key role in the formation of the adaptability of Acinetobacter to their living conditions. In particular, it has been demonstrated that the plasmids of various strains of Acinetobacter differ from each other in their structure and gene composition depending on the lifestyle of their host bacteria. Plasmids of modern strains are enriched with antibiotic-resistant genes, while the content of genes involved in resistance to heavy metals and arsenic is comparable to plasmids from modern and ancient strains. It is concluded that Acinetobacter plasmids may ensure the survival of host bacteria under conditions of various types of environmental and clinical stresses. A brief overview of the main mechanisms of horizontal gene transfer on plasmids inherent in Acinetobacter strains is also given.     

γ-X-ray-spectrometric investigation of plutonium and241Am content in the soil in regions where peaceful nuclear explosions were conducted

A brief exposition of the γ-x-ray spectrometric method and apparatus for analyzing the content of plutonium and²⁴¹Am in samples of soil and vegetation is presented. The results of an analysis of some samples from the regions where peaceful nuclear explosions were conducted in Yakutiya and Perm oblast' are presented. It is concluded that the γ-x-ray spectrometric method can be used to perform large-scale measurements in regions where peaceful nuclear explosions have been conducted, 2 figures, 3 tables, 8 references. Translated from Atomnaya énergiya, Vol. 88, No. 1, pp. 52–55, January, 2000.