153 research outputs found

    Surface-enhanced optical third-harmonic generation in Ag island films

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    Surface-enhanced optical third-harmonic generation (THG) is observed in silver island films. The THG intensity from Ag nanoparticles is enhanced by more than two orders of magnitude with respect to the THG intensity from a smooth and homogeneous silver surface. This enhancement is attributed to local plasmon excitation and resonance of the local field at the third-harmonic wavelength. The diffuse and depolarized component of the enhanced THG is associated with the third-order hyper-Rayleigh scattering in a 2-D random array of silver nanoparticles.Comment: 4 pages, 2 figure

    Optical second harmonic generation probe of two-dimensional ferroelectricity

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    Optical second harmonic generation (SHG) is used as a noninvasive probe of two-dimensional (2D) ferroelectricity in Langmuir-Blodgett (LB) films of copolymer vinylidene fluoride with trifluorethylene. The surface 2D ferroelectric-paraelectric phase transition in the topmost layer of LB films and a thickness independent (almost 2D) transition in the bulk of these films are observed in temperature studies of SHG.Comment: 9 pages, 2 figures, Optics Letters, in prin

    The effect of rs776746 polymorphism in the <i>CYP3A5</i> gene on heart rate when using bisoprolol in patients with acute coronary syndrome

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    Aim. The aim of this work was to study the occurrence of the rs776746 allelic variant of the CYP3A5 gene and its effect on heart rate (HR) when using bisoprolol in patients hospitalized with acute coronary syndrome (ACS).Materials and methods. The study included patients with ACS who were prescribed bisoprolol for clinical indications. All patients underwent molecular genetic testing. In order to evaluate the effectiveness of the therapy with bisoprolol, all patients underwent Holter electrocardiogram (ECG) monitoting on days 10, the following parameters were assessed: minimum, average, maximum heart rate and heart rate during an exercise test. The stress test was performed as a ladder test.Results. The study involved 97 patients (63,5±10,5 years), including 60 men and 37 women. The frequency of occurrence of the desired alleles of the CYP3A5 gene was: CYP3A5*3 - 93%, and CYP3A5*1 - 7%, which corresponds to its prevalence in the European population. 84 carriers of the CYP3A5*3*3 genotype (87%), 12 heterozygous carriers of the *1 allele (12%) and one patient with the *1*1 genotype (1%) were identified. In order to search for differences in the effects of bisoprolol depending on the genetically predetermined activity of CYP3A5, we divided the general group of patients into two subgroups: subgroup 1 (CYP3A5*3*3), represented by carriers of the genotype associated with the synthesis of the inactive form of CYP3A5, and subgroup 2 (CYP3A5*1*3 and CYP3A5*1*1), represented by carriers of at least one allele encoding the synthesis of a fully functional protein CYP3A5, coupled with an increased metabolic rate. Patients did not differ in clinical and demographic characteristics. By the time of daily ECG monitoring, both groups reached comparable heart rate values. In carriers of at least one CYP3A5*1 allele (n = 13), associated with an increased metabolic rate, the daily dose of bisoprolol on the 10th day of hospitalization was significantly higher (p &lt;0.05). The only carrier of the homozygous CYP3A5 *1*1 variant receives bisoprolol at a daily dose of 10 mg. Taking into account the close to significant differences in glomerular filtration rate (GFR) in patients in the groups with the studied genetic variants, and the known eliminating role of the kidneys for bisoprolol, a linear regression model was built with the inclusion of factors that could affect the dose of bisoprolol: GFR, functional class of chronic heart failure, gender, age, number of simultaneously assigned CYP3A5 substrates. Of the parameters listed, only the CYP3A5 genotype significantly predicted the dose of bisoprolol (F=8.5; p&lt;0.005; R2=0.096).Conclusion. In this study, it was demonstrated for the first time that patients with different genetic variants of CYP3A5, in particular with respect to the rs776746 polymorphism, may differ in individual requirements for the dose of bisoprolol

    Model for determining the competitive identity of cities in a digital economy

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    The term competitive identity of cities was introduced by Enholt [1] when considering the notion of territory marketing. Such an indicator is significant for determining the investment attractiveness of the territorial entity, and as a consequence of the opportunities for the development of the Territory and its directions. The assessment and prospects for the development of territories are determined by a set of indicators that are quite stable in time, then it is necessary to determine how to predict the directions for improving the efficiency of investment policy, including in the transition to the digital economy. © 2020 American Institute of Physics Inc.. All rights reserved

    Hormone therapy - as a method of treatment of patients with breast cancer over 70 years

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    In article there are results of treatment of breast cancer by antiestrogen (Tamoxifen) in 213 patients older than 70 years without a preliminary assessment of receptor status. Objective response (complete response + partial response) was 33.44% (71 patient), stable disease - 34.64 % (74 patients), progressive disease - 31.92 % (68 patients). Objective response was observed only in the group of operable breast cancer. Progressive disease was observed mainly in groups of locally advanced and inoperable primary cancer. In all patients with edematous- infiltrative cancer (9 cases) and in 7 of 8 patients with N +- status during treatment reported progressive disease.В статье приведены результаты лечения рака молочной железы антизстрогенами (Тамоксифен) у 213 пациенток старше 70 лет без предварительной оценки рецепторного статуса. Объективный ответ (полная резорбция + частичная резорбция) составил 33,44% (71 пациентка), стабилизация процесса - 34,64% (74 пациентки), прогрессирование заболевания — 31,92% (68 пациенток). Объективный ответ был отмечен только в группе операбельного рака молочной железы. Прогрессирование заболевания наблюдалось преимущественно в группах местно-распространенного и первично-неоперабельного рака. У всех пациенток с отечно-инфильтративной формой рака (9 случаев) и у 7 из 8 пациенток с М+-статусом на фоне лечения зарегистрировано прогрессирование заболевания

    Estimation of antimicrobial activities and fatty acid composition of actinobacteria isolated from water surface of underground lakes from Badzheyskaya and Okhotnichya caves in Siberia

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    Extreme and unusual ecosystems such as isolated ancient caves are considered as potential tools for the discovery of novel natural products with biological activities. Actinobacteria that inhabit these unusual ecosystems are examined as a promising source for the development of new drugs. In this study we focused on the preliminary estimation of fatty acid composition and antibacterial properties of culturable actinobacteria isolated from water surface of underground lakes located in Badzheyskaya and Okhotnichya caves in Siberia. Here we present isolation of 17 strains of actinobacteria that belong to the Streptomyces, Nocardia and Nocardiopsis genera. Using assays for antibacterial and antifungal activities, we found that a number of strains belonging to the genus Streptomyces isolated from Badzheyskaya cave demonstrated inhibition activity against bacteria and fungi. It was shown that representatives of the genera Nocardia and Nocardiopsis isolated from Okhotnichya cave did not demonstrate any tested antibiotic properties. However, despite the lack of antimicrobial and fungicidal activity of Nocardia extracts, those strains are specific in terms of their fatty acid spectrum. When assessing fatty acid profile, we found that polyunsaturated fatty acids were quantitatively dominant in extracts of Nocardia sp. and Streptomyces sp. grown in different media. Saturated fatty acids were the second most abundant type in the fatty acid profile. It was due to palmitic acid. Also, a few monounsaturated fatty acids were detected. The obtained materials can become a basis for development of approaches to use bacteria isolated from caves as a biological sources of bioactive compounds to create medical and veterinary drugs

    The role of polymorphic variants of arginase genes (<i>ARG1, ARG2</i>) involved in beta-2-agonist metabolism in the development and course of asthma

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    Asthma is a common severe disease of the respiratory tract, it leads to a significant impairment in the quality of a patient’s life unless effectively treated. Uncontrolled asthma symptoms are a cause of disease progression and development, they lead to an increase in the patient’s disability. The sensitivity to asthma therapy largely depends on the interaction of genetic and epigenetic factors, which account for about 50–60 % of variability of therapeutic response. Beta-2-agonists are some of the major class of bronchodilators used for asthma management. According to published data, allelic variants of the arginase ARG1 and ARG2 genes are associated with a risk of asthma development, spirometry measures and efficacy of bronchodilator therapy. High arginase activity results in a low level of plasma L-arginine and in a decrease in nitric oxide, and, as a result, in an increase in airway inflammation and remodeling. Arginase genetic polymorphisms (rs2781667 of the ARG1 gene, rs17249437, rs3742879, rs7140310 of the ARG2 gene) were studied in 236 children with asthma and 194 unrelated healthy individuals of Russian, Tatar and Bashkir ethnicity from the Republic of Bashkortostan. Association analysis of the studied polymorphisms with asthma development and course, the sensitivity to therapy in patients was carried out. It was found that the rs2781667*C allele of the ARG1 gene is a marker of an increased risk of asthma in Tatars. In Russians, the association of rs17249437*TT and rs3742879*GG genotypes of the ARG2 gene with a decrease in spirometry measures (FEV1, MEF25) was established. In Russians and Tatars receiving glucocorticoid monotherapy or combination therapy, the association of the rs17249437*T allele and rs17249437*TT genotype of the ARG2 gene with a partially controlled and uncontrolled course of asthma was shown
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