Physicochemical investigation of NiAl with small molybdenum additions

Specimens of four cast NiAl alloys, three of them containing 0.5, 1.0 and 1.5 at. % Mo., were homogenized for 10, 10, and 140 hr at 1373, 1523 and 1273 K, respectively, then kept at 1073, 1173 and 1323 K for 60, 120 and 3 hr, respectively, and quenched in icy water. The precipitation of a metastable Ni3Mo phase was observed at temperatures between 1073 and 1523 K. Molybdenum substituted for nickel was found to inhibit the lattice disordering in NiAl at 1073 and 1523 K

Prospects for the creation of antimicrobial preparations based on copper and copper oxides nanoparticles

The spread of strains of microorganisms that are multidrug resistant to modern antimicrobial drugs is still an urgent problem in the treatment and prevention of infectious diseases and public health in general.Currently, the possibility of using metal nanopreparations in various fields of medicine is being actively studied. Nanoparticles of metals and metal oxides are promising antimicrobial agents and are attracting growing interest due to their effectiveness. Nanoscale copper metal particles have shown high antimicrobial activity againstvarious types of gram-positive and gram-negative bacteria, as well as fungi. Taking into account the potential of copper nanoparticles in antimicrobial therapy, we present an overview of the current state of research related to their antimicrobial properties, consideration of the mechanisms of action, key factors affecting antimicrobial activity, including the polymer matrix. The issues of toxicity and resistance to copper are considered. The advantage of copper nanoparticles over other metal nanoparticles is shown.The studies summarized in this review have shown the promise of copper nanoparticles in the creation of new antimicrobial drugs that can be used in the future to control, prevent, and treat various diseases

Analysis of the SXT Constin of Antibiotic-Sensitive <I>Vibrio cholerae </I>Strain of Non-O1/ Non-O139 Serogroup

In the genome of antibiotic-sensitive Vibrio cholerae strain belonging to O50 serogroup, isolated in the territory of the Russian Federation in 1974, detected is the SXT conjugative trasposone – SXT constin. Analysis if its structure revealed that it does not contain genes of resistance to such antibiotics as streptomycin, sulfamethoxasole, trimethoprim, chloramphenicol, and kanamycin, being, probably, one of the predecessors of antibiotic-resistant SXT constins which spread out within the genomes of epidemic Vibrio cholerae O139 strains in 1992

Personalized medicine in the treatment of inflammatory bowel diseases

Personalized medicine (personalized medicine, individualized medicine) represents the totality of methods of prevention of a pathological condition, diagnosis and treatment in the event of its occurrence, based on individual patient characteristics. Such individual characteristics include genetic, epigenetic, and transcript, proteome, metabolomic and metagenomic markers, as well as a set of variable phenotypic traits - both of the patient's body and its separate tissues or cells. For example, treatment of inflammatory bowel diseases (IBD) can most clearly show the importance of applying personalized approaches. Currently in the treatment of patients with IBD paid great attention to genetic studies, monitoring of the concentration of the biological drugs and the level of antibodies to them, the role of microbiota as a predictor of effectiveness of therapy of IBD. Used clinical, laboratory, instrumental methods, as well as new biomarkers to assess the forecasting efficiency of conservative therapy in IBD patient. In the future treatment of patients with IBD will include a number of personalized data in order to better predict outcomes of the disease in each patient and more accurately select the appropriate treatment regimen

ОПРЕДЕЛЕНИЕ МАТРИЧНОГО СОСТАВА ХАЛЬКОГЕНИДНЫХ СТЕКОЛ СИСТЕМЫ GE-SE-TE МЕТОДОМ АЭС-ИСП

One of the most important stages of the high-purity chalcogenide glasses’ analytical control is the determination of matrix elements’ content with the uncertainty at the levels of 0.1–0.2 mol.%.  The content of the macro-components may differ from the composition of the initial charge; therefore, an important task is the macro-composition determination of the final materials. This article describes the development of the technique for determining the matrix elements of high-purity Ge-Se-Te glasses in the range of germanium content from 10 to 35 mol. %, selenium and tellurium content from 20 to 50 mol. % with the expanded uncertainty within 0.01–0.2 mol. % (P = 0.95) using the inductively coupled plasma atomic emission spectrometry (ICP-AES). A simple technique for the preparation of primary calibration solutions from pure elementary Ge, Se and Te is proposed. The correctness of the analysis results is confirmed by comparing the calculated matrix composition of model glass samples, prepared by direct synthesis from high-purity simple substances in the sealed quartz glass ampoule, with the analysis results.  The main advantage of the proposed analysis technique is the absence of the need for the reference samples identical to the analyzed material, which is especially important for determination of new materials’ matrix composition. The minimum sample mass for the determination of matrix elements is about 1 mg, which makes it possible to analyze not only bulk glass samples, but also fibers and expensive materials.Key words: Ge-Se-Te chalcogenide glasses, determination of matrix elements, high accuracy, inductively coupled plasma atomic emission spectrometry.DOI: http://dx.doi.org/10.15826/analitika.2020.24.4.002 D.A. Fadeeva, I.I. Evdokimov, V.G. PimenovG.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, Box-75, 49 Tropinin Str., Nizhny Novgorod, 603951, Russian FederationОдин из важнейших этапов аналитического контроля высокочистых халькогенидных стекол, используемых для изготовления оптоволоконных устройств, является установление содержания матричных элементов с неопределенностью на уровне 0.1–0.2 % мол. Необходимость данного этапа аналитического контроля возникает из-за сложности получения высокочистых халькогенидных стекол с необходимой точностью задания матричного состава, что связано, отчасти, с возможными потерями матричных элементов на многочисленных стадиях синтеза и очистки. Методик определения матричных элементов стекол системы Ge-Se-Te с необходимыми метрологическими характеристиками найти не удалось. В статье описана разработка методики определения матричных элементов высокочистых стекол вышеуказанной системы в диапазоне содержания германия от 10 до 35 % мол., селена и теллура – от 20 до 50 % мол. с расширенной неопределенностью результатов анализа на уровне 0.01–0.2 % мол. (P = 0.95) с использованием атомно-эмиссионной спектрометрии с индуктивно связанной плазмой. Предложен способ приготовления первичных градуировочных растворов, необходимых для достижения заявленного уровня неопределенности, с использованием германия, селена и теллура в форме чистых простых веществ. Корректность оценки точности результатов анализа подтверждена сопоставлением расчетного матричного состава модельных образцов стекол, изготовленных прямым синтезом из высокочистых простых веществ в запаянной ампуле из кварцевого стекла, с результатами анализа. Главное достоинство предложенной методики анализа – отсутствие потребности в образцах сравнения, идентичных анализируемому материалу, что особенно важно при установлении матричного состава новых материалов (т.е. когда образцы сравнения, и даже способы их изготовления отсутствуют в принципе). Минимальная для определения матричных элементов масса пробы составляет около 1 мг, что позволяет проводить анализ не только массивных образцов стекол, но и изготавливаемых из них волокон, а также дорогостоящих материалов.Ключевые слова: халькогенидные стекла Ge-Se-Te, определение матричных элементов, высокая точность, атомно-эмиссионная спектрометрия с индуктивно связанной плазмой.DOI: http://dx.doi.org/10.15826/analitika.2020.24.4.00

ICP-AES analysis of high-purity arsenic

В настоящее время практически отсутствуют экспрессные многоэлементные методики анализа мышьяка, позволяющие определять широкий круг примесей на уровне 10⁻⁷-10⁻⁵ % мас. (в соответствии с современными требованиями), включая близкие по летучести к матрице элементы: P, S, Sb, Se и Te. Это связано с тем, что искровая масс-спектрометрия и нейтронно-активационный анализ сейчас труднодоступны, а атомно-эмиссионная спектрометрия с дуговым разрядом в сочетании с предварительным концентрированием примесей, позволяющая определять примеси до уровня 10⁻⁸-10⁻⁴ % мас., сокращает число определяемых примесей (например, P, S, Sb, Se, Te теряются при концентрировании отгонкой матрицы), отличается повышенной трудоёмкостью и длительностью анализа. В данной работе оценены возможности анализа высокочистого мышьяка доступным и широко распространённым методом атомно-эмиссионной спектрометрии с индуктивно связанной плазмой. Исследованы матричные помехи при распылении в индуктивно связанную плазму растворов с концентрацией мышьяка до 150 мг/мл. Установлено, что для достижения низких пределов определения примесей целесообразно анализировать растворы проб с концентрацией мышьяка ~100 мг/мл, что не вызывает технических трудностей. Проведение пробоподготовки в химически стойкой посуде из PFA (PerFluoroAlkoxy polymer) и использование доочищенных реактивов (вода, азотная кислота) позволило снизить влияние загрязнений на пределы определения большинства примесей. Разработана методика определения 39 элементов-примесей в высокочистом мышьяке, включая наиболее распространённые металлы (Al, Ca, Cu, Mg, Fe) и Si, и обычно теряемые при концентрировании отгонкой матрицы элементы (B, P, S, Sb, Se, Te). Пределы определения примесей в мышьяке составили ~10⁻⁷-10⁻⁵ % мас. При необходимости круг определяемых примесей может быть расширен, исходя из возможностей определения конкретных элементов методом атомно-эмиссионной спектрометрии с индуктивно связанной плазмой с учётом предложенной методики пробоподготовки и наличия соответствующих стандартных растворов солей определяемых элементов.The arc discharge atomic emission spectrometry method with pre-concentration of impurities is mainly used for multi-element analysis of high-purity arsenic. Spark ionization mass-spectrometry and neutron activation analysis are applied less often. The use of spark ionization mass-spectrometry and neutron activation analysis is quite problematic at the present time. Arc discharge atomic emission spectrometry in combination with pre-concentration of impurities makes it possible to determine the impurities at the level of 10⁻⁸-10⁻⁴ % mass. At the same time the number of the determined impurities is reduced (e.g., P, S, Sb, Se, Te are getting lost during concentration by matrix sublimation) with the increase in the duration of the analysis. Thus, at the present time the express multi-element techniques of analysis of arsenic which can provide the determination of wide range of impurities at the level of 10⁻⁷-10⁻⁵ % mass. (according to the modern requirements), including the elements P, S, Sb, Se and Te (with volatility close to that of the matrix) are actually absent. In the present paper the capabilities of available and widely used method of inductively-coupled plasma atomic emission spectrometry are estimated for analysis of high-purity arsenic. The matrix interference was investigated in the process of spraying the solutions with arsenic concentration up to 150 mg/mL into inductively-coupled plasma. It was found that in order to attain low limits of quantification of impurities it is expedient to analyze sample solutions with arsenic concentration ~100 mg/mL. It does not present a problem technically. Preparation of samples in chemically resistant vials of PFA (PerFluoroAlkoxy polymer) and the use of additionally purified reagents (water, nitric acid) made it possible to decrease the effect of contaminations on the limits of quantification of most impurities. A technique for determination of 39 elements in high-purity arsenic has been developed. The diapason of determined impurities includes the most abundant metals (Al, Ca, Cu, Mg, Fe) and Si, as well as the elements usually getting lost during concentration by matrix sublimation (B, P, S, Sb, Se, Te). The limits of quantification (as well as the limits of detection) of impurities in arsenic are equal ~10⁻⁷-10⁻⁵ % mass. If necessary, the range of impurities can be widened in view of the possibilities of inductively-coupled plasma atomic emission spectrometry, the possibilities of the suggested sample preparation technique and the availability of the corresponding standard solutions of the determined elements

Development of the PCR Assay with Universal Primers for the Detection of Different <i>tcpA</i> Gene Variants

Developed is the PCR assay for the detection of the structural genes of toxin co-regulated adhesion piluses - tcpA of different types. Determined are the universal primers, the usage of which provides for the detection of the stated above genes in V. cholerae of various serogroups. With the help of this PCR assay identified is a new variant of tcpA gene in toxigenic cholera vibrio of non-O1/non-O139 serogroup

Study of anxiety and self-assessment of adolescents

В статье представлены результаты исследования тревожности и самооценки у подростков. Подтверждены гипотезы что, существуют различия в выраженности тревожности и самооценки в группах мальчиков и девочек и существует взаимосвязь между тревожностью и самооценкой подростков.The article presents the results of a study of anxiety and self-esteem in adolescents. The hypotheses were confirmed that there are differences in the severity of anxiety and self-esteem in groups of boys and girls, and there is a relationship between anxiety and self-esteem of adolescents

Description of the latin names of viruses, used in pediatrics

The article is devoted to the study of the influence of indoor plants on the human body. While working on this article, we studied some types of indoor plants that have a negative effect on people's health, and can even threaten their lives. Further, in the research results, specific plants will be presented in detail, and their mechanism of damaging action will be describedСтатья посвящена изучению влияния комнатных растений на организм человека. Во время работы над данной статьёй нами были исследованы некоторые виды комнатных растений, которые оказывают отрицательное влияние на здоровье людей, и даже могут угрожать жизни. Далее в результатах исследования подробно будут представлены конкретные растения, и описан их механизм поражающего действи

Experimental Modeling of General Purulent Peritonitis

General purulent peritonitis takes one of the first places in the structure of purulent complications. Despite the im provement of methods of diagnosis and treatment, mortality in postoperative purulent peritonitis remains quite high.Aim of the study: develop a reproducible model of postoperative general peritonitis to study the pathophysiological mechanisms of its development and the development of pathogenetically substantiated therapy.Materials and methods. The study was performed on 18 Wistar male rats aged 6 months, weighing 250–300 grams. Animals underwent laparotomy and modeling of postoperative general peritonitis according to the proposed method. Hospital strains of Escherichia coli BRLS 109 and Bacteroides fragilis 109 (strain ISCST1982, registered in Genbank), which we isolated from patients with acute appendicitis, with a total volume of 1.0 ml per animal, were used as infectious agents. Animals were taken out of the experiment under anesthesia with compliance with the rules of euthanasia at 1st, 3rd, 7th days after surgery. For morphological studies, samples of a fragment of the abdominal wall and cecum were taken. Bacteriological studies were performed on the 3rd, 7th day from the beginning of the experiment.Results. It was established that all animals developed peritonitis with the progression of purulent-destructive changes in the abdominal cavity and the development of adhesions, which was confirmed by the data of the morphological method of research. According to the results of bacteriological studies on the 3rd day, exudate infection was detected in all rats (in 100 % of observations). E. coli BLS were isolated in all cases at concentrations of 103–104 CFU/ml. The strain B. fragilis is inoculated in 3 animals at a concentration of 103 CFU/ml, which made 50 %. By the 7th day, only an aerobic E. coli strain of BLS was detected in peritoneal exudate at concentrations of 103 CFU/ml in the complete absence of growth of B. fragilis.Conclusion. We have developed a model of postoperative general peritonitis, which allows us to study the dynamics of the development of the inflammatory process in the abdominal cavity and, in terms of its clinical manifestations, is close to a real human disease. The reproducibility of the model is 100 %, which is confirmed by microbiological and morphological data