163 research outputs found

    Kaluza-Klein 5D Ideas Made Fully Geometric

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    After the 1916 success of General relativity that explained gravity by adding time as a fourth dimension, physicists have been trying to explain other physical fields by adding extra dimensions. In 1921, Kaluza and Klein has shown that under certain conditions like cylindricity (gij/x5=0\partial g_{ij}/\partial x^5=0), the addition of the 5th dimension can explain the electromagnetic field. The problem with this approach is that while the model itself is geometric, conditions like cylindricity are not geometric. This problem was partly solved by Einstein and Bergman who proposed, in their 1938 paper, that the 5th dimension is compactified into a small circle S1S^1 so that in the resulting cylindric 5D space-time R4×S1R^4\times S^1 the dependence on x5x^5 is not macroscopically noticeable. We show that if, in all definitions of vectors, tensors, etc., we replace R4R^4 with R4×S1R^4\times S^1, then conditions like cylindricity automatically follow -- i.e., these conditions become fully geometric.Comment: 14 page

    Social adaptation of children without parental care

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    The article presents an analysis of the specificity of children without parental care, as a special category of minors. Сertain particularities in social adaptation of given category of non-adults are observed.В статье представлен анализ специфики детей, оставшихся без попечения родителей, как особой категории несовершеннолетних. Проанализированы особенности социальной адаптации данной категории

    Influence of single amino acid substitutions in the hemagglutinin on the antigenic and receptor-binding properties of influenza virus B/Florida/04/2006 of Yamagata-like evolutionary lineage

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    Influenza A and B viruses use sialylated oligosaccharide chains expressed on the surface of a host cell as the cell entry receptors. The type of the bond between sialic acid (SA) and the neighboring galactose residue (Gal) is one of the main characteristics that define the type of receptor. Influenza viruses recognize SAα2-3Gal- or SAα2-6Gal-structures on the surface of the cells. Influenza A viruses of avian origin bind α2-3-sialylated glycans, while the human strains bind preferentially α2-6-sialylated ones. However, the receptor-binding specificity of influenza B viruses has not been characterized sufficiently so far. In this study, we selected the escape mutants of influenza B/Florida/04/2006 strain (Yamagata-like lineage) using monoclonal antibodies (mAb) to hemagglutinin (HA). The analysis of the amino acid sequences of mAb-induced escape mutants revealed the single amino acid substitutions 40Tyr→His, 85His→Tyr, 202Asn→Lys and 242Ser→Arg in 10F4-, 8Н11-, 8Н3- and 9А3-induced HA variants, correspondingly. It was shown that the single amino acid substitutions 202Asn→Lys and 242Ser→Arg alter the receptor-binding specificity of the influenza B virus. These findings are important for the understanding of the influence of individual amino acid residues in HA on the receptor-binding properties of influenza B Yamagata-like lineage viruses and allow us to predict the possible ways of their evolution.Influenza A and B viruses use sialylated oligosaccharide chains expressed on the surface of a host cell as the cell entry receptors. The type of the bond between sialic acid (SA) and the neighboring galactose residue (Gal) is one of the main characteristics that define the type of receptor. Influenza viruses recognize SAα2-3Gal- or SAα2-6Gal-structures on the surface of the cells. Influenza A viruses of avian origin bind α2-3-sialylated glycans, while the human strains bind preferentially α2-6-sialylated ones. However, the receptor-binding specificity of influenza B viruses has not been characterized sufficiently so far. In this study, we selected the escape mutants of influenza B/Florida/04/2006 strain (Yamagata-like lineage) using monoclonal antibodies (mAb) to hemagglutinin (HA). The analysis of the amino acid sequences of mAb-induced escape mutants revealed the single amino acid substitutions 40Tyr→His, 85His→Tyr, 202Asn→Lys and 242Ser→Arg in 10F4-, 8Н11-, 8Н3- and 9А3-induced HA variants, correspondingly. It was shown that the single amino acid substitutions 202Asn→Lys and 242Ser→Arg alter the receptor-binding specificity of the influenza B virus. These findings are important for the understanding of the influence of individual amino acid residues in HA on the receptor-binding properties of influenza B Yamagata-like lineage viruses and allow us to predict the possible ways of their evolution

    Peculiarities of the treatment of children with intestinal intussusception

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    The purpose of the study. is to study the specifities of patient management and the choice of a method for treating intestinal intussusception in different age groups, depending on alternating factors.Цель исследования – изучить особенности ведения пациентов и выбора метода лечения инвагинации кишечника в разных возрастных группах

    Foreign bodies of the gastrointestinal tract in the practice of a pediatric surgeon

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    The article presents an analysis of the results of treatment of 70 children with foreign bodies of the gastrointestinal tract. The distribution of the frequency of occurrence of pathology by age and sex characteristics, type of foreign bodies, by methods of treatment has been studied. In the case of performing surgical treatment, the methods and volumes of the performed surgical interventions were analyzedВ статье представлен анализ результатов лечения 70 детей с инородными телами желудочно-кишечного тракта. Изучено распределение частоты встречаемости патологии по возрастному и половому признаку, характеру инородных тел, по способам лечения. В случае выполнения оперативного лечения проанализированы способы и объемы проведенных оперативных вмешательст

    The approach of medical university students to reproductive health

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    The article considers the approach of medical university students to reproductive health, as well as their attitude to modern methods of contraception, which indicates the awareness of students and is a criterion for the correct reproductive behavior of medical university studentsВ статье рассмотрен подход студентов медицинского вуза к репродуктивному здоровью, а также их отношение к современным методам контрацепции, что свидетельствует об информированности студентов и является критерием правильного репродуктивного поведения студентов медицинских вузов

    Vitamin content of athletes of various sports: assessment of the diet and blood serum level

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    Objective: to study the vitamins level in athletes of various sports. Materials and methods: during the training process, 400 athletes of various sports and specializations were examined: martial artists, game sport athletes, cyclic, complex coordination sports. We assessed the dietery intake of vitamins A, C, B1, B2 and PP and the blood serum level of vitamins A, E, C, B2 and beta-carotene. Results: The assessement the dietary intake of vitamins in relation to the energy value revealed insufficient intake of vitamins B1, B2 and PP in vast majority of the athletes. Only 15.2% of athlets demonstrated adequate level of all vitamins. Most frequently we found a reduced blood serum riboflavin concentration. Conclusions: An increase of B vitamins dietary intake by athletes through a high level of dietary vitamin supplements

    Changes in the antigenic and genetic structure of influenza viruses: analysis of surveillance data of influenza A and B in Russia in 2006-2013

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    The goal of this research project was to study the natural variability of human influenza A and B viruses based on the analysis of the population structure of influenza viruses, circulating in Russia in 2006-2013, in order to determine the direction of their genetic and antigenic drift by comparison to the WHO reference strains. Our results proved that during that period significant changes occurred in the genetic structure of influenza viruses, their phylogenetic affiliation, as well as their sensitivity to antiviral drugs. According to the surveillance data, the percentage of influenza A(H1N1) viruses among patients with influenza-like illness or acute respiratory infection gradually decreased from 42% of the total number of influenza viruses in 2006-2007 to 19% in 2008- 2009. Influenza A(H1N1) viruses are characterized by «silent» variability that manifests in the gradual accumulation of amino acid substitutions in the minor undetectable group of viruses.The share of influenza A(H3N2) viruses varied from 10% in the 1st post pandemic year to approx. 60% in 2008-2009 and 2011- 2012 epidemic seasons. All of the influenza A strains isolated during the last years of the period, covered in this study, were found to be susceptible to neuraminidase inhibitors and resistant to adamantane antivirals.Influenza B viruses of both Yamagata and Victoria lineages circulated in Russia in the period from 2006 to 2013. The vast majority of these influenza B viruses belonged to the Victoria lineage. Phylogenetic and antigenic analyses of influenza B viruses have demonstrated a gradual drift of Russian isolates from the reference strains. No changes leading to resistance to oseltamivir or zanamivir were found in influenza B strains isolated until 2013.The goal of this research project was to study the natural variability of human influenza A and B viruses based on the analysis of the population structure of influenza viruses, circulating in Russia in 2006-2013, in order to determine the direction of their genetic and antigenic drift by comparison to the WHO reference strains. Our results proved that during that period significant changes occurred in the genetic structure of influenza viruses, their phylogenetic affiliation, as well as their sensitivity to antiviral drugs. According to the surveillance data, the percentage of influenza A(H1N1) viruses among patients with influenza-like illness or acute respiratory infection gradually decreased from 42% of the total number of influenza viruses in 2006-2007 to 19% in 2008- 2009. Influenza A(H1N1) viruses are characterized by «silent» variability that manifests in the gradual accumulation of amino acid substitutions in the minor undetectable group of viruses. The share of influenza A(H3N2) viruses varied from 10% in the 1st post pandemic year to approx. 60% in 2008-2009 and 2011- 2012 epidemic seasons. All of the influenza A strains isolated during the last years of the period, covered in this study, were found to be susceptible to neuraminidase inhibitors and resistant to adamantane antivirals. Influenza B viruses of both Yamagata and Victoria lineages circulated in Russia in the period from 2006 to 2013. The vast majority of these influenza B viruses belonged to the Victoria lineage. Phylogenetic and antigenic analyses of influenza B viruses have demonstrated a gradual drift of Russian isolates from the reference strains. No changes leading to resistance to oseltamivir or zanamivir were found in influenza B strains isolated until 2013

    Effect of Solid Dispersions on the Dissolution of Ampicillin

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    © 2016, Springer Science+Business Media New York.In this work, we studied water solubility of ampicillin trihydrate and its solid dispersions (SD) with polyethylene glycol-1500, polyvinylpyrrolidone-10000, and β-cyclodextrin. It was found that SD formation increases the solubility by a factor of 1.34–1.73 and the rate of ampicillin dissolution by a factor of 3.43–7.40. The results of complex physicochemical studies suggest that the improved release of ampicillin from SD is due to its micronization and solubilization by the polymer

    Antioxidant vitamin status of obese patients in terms of the risk of comorbidities

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    BACKGROUND: Synchronously optimized concentrations of vitamins C, E, A, carotenoids and their ratios in blood plasma help to prevent or slow down the development of many alimentary-dependent diseases and their complications. AIMS: to characterize the vitamin status of obese patients from the standpoint of the risk of progression of existing and development of associated diseases. MATERIALS AND METHODS: An observational single-site cross-sectional study of the sufficiency with antioxidant vitamins in 81 patients (21 men, 60 women) aged 20–75 years with body mass index 40,7±1,2 kg/m2, enrolled for treatment from April to June in Federal Research Centre of Nutrition, Biotechnology had been conducted. The concentration of α- and γ-tocopherols, retinol, ascorbic acid, β-carotene was determined in blood serum and their ratios with lipid profile were calculated. RESULTS: Indicators of vitamin status were determined in 35 patients with obesity, 27 patients with obesity and cardiovascular diseases (CVD), 19 patients with obesity and type 2 diabetes mellitus (T2DM). The concentration of ascorbic acid in more than 50% of patients did not reach the optimal level (50 µmol/l). Compared to patients of other groups, patients with T2DM were better supplied with vitamin E, but worse with other vitamins. They have a non-optimal ratio of concentrations of vitamin C and E more often compared with patients of other groups (p≤0.050). Among them, the combined suboptimal level of vitamin C and β-carotene (<0.4 µmol/l) was detected 1.6–1.8 fold more often. The lack of antioxidants in patients with T2DM according to simultaneously reduced vitamin C/vitamin E ratio (<1.5) and β-carotene level was detected 3.3-fold more often, synchronously lowered vitamin C/vitamin E ratio and vitamin C level – 2.4-fold. γ-tocopherol level in serum of patients with T2DM tended to increase compared with that in patients with obesity (p=0.063) and CVD (p=0.081), γ-tocopherol/triacylglycerides ratio was 1.5-fold higher (respectively р=0.009 и р=0.076). Only in 2 patients with obesity and 2 patients with CVD all serum indicators corresponded to the optimal level of all vitamins. In terms of α-tocopherol/cholesterol (<5 µmol/mol), an increased risk of myocardial infarction was detected in 10.5–42.9% of the examined patients. Glucose level was positively associated with serum levels of α- and γ-tocopherols, as well as cholesterol-adjusted individual tocopherols; while glycemia was inversely associated with triacylglycerides-standardized individual tocopherols, as well as β-carotene and vitamin C/vitamin E ratio. CONCLUSIONS: In most patients, a non-optimal serum vitamin content was found according to one or several parameters. In order to vitamin C/vitamin E ratio, patients with T2DM need to increase vitamin C intake. Increasing serum β-carotene and achieving an optimal C/E ratio will help to prevent an increase in glycemia
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