68 research outputs found

    Multiple Gamma Function and Its Application to Computation of Series

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    The multiple gamma function Γn\Gamma_n, defined by a recurrence-functional equation as a generalization of the Euler gamma function, was originally introduced by Kinkelin, Glaisher, and Barnes around 1900. Today, due to the pioneer work of Conrey, Katz and Sarnak, interest in the multiple gamma function has been revived. This paper discusses some theoretical aspects of the Γn\Gamma_n function and their applications to summation of series and infinite products.Comment: 20 pages, Latex, uses kluwer.cls, will appear in The Ramanujan Journa

    A Gauge-Gravity Relation in the One-loop Effective Action

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    We identify an unusual new gauge-gravity relation: the one-loop effective action for a massive spinor in 2n dimensional AdS space is expressed in terms of precisely the same function [a certain multiple gamma function] as the one-loop effective action for a massive charged scalar in 4n dimensions in a maximally symmetric background electromagnetic field [one for which the eigenvalues of F_{\mu\nu} are maximally degenerate, corresponding in 4 dimensions to a self-dual field, equivalently to a field of definite helicity], subject to the identification F^2 \Lambda, where \Lambda is the gravitational curvature. Since these effective actions generate the low energy limit of all one-loop multi-leg graviton or gauge amplitudes, this implies a nontrivial gauge-gravity relation at the non-perturbative level and at the amplitude level.Comment: 6 page

    Universality of finite-size corrections to the number of critical percolation clusters

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    Monte-Carlo simulations on a variety of 2d percolating systems at criticality suggest that the excess number of clusters in finite systems over the bulk value of nc is a universal quantity, dependent upon the system shape but independent of the lattice and percolation type. Values of nc are found to high accuracy, and for bond percolation confirm the theoretical predictions of Temperley and Lieb, and Baxter, Temperley, and Ashley, which we have evaluated explicitly in terms of simple algebraic numbers. Predictions for the fluctuations are also verified for the first time.Comment: 13 pages, 2 figs., Latex, submitted to Phys. Rev. Let

    Choice of method of diagnosis hypogonadism in obesity and metabolic syndrome in men

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    Nowadays, obesity and metabolic syndrome are considered as symptoms of male hypogonadism, which underlines the need for hormonal screening in these patients. However, remain unsolved some questions of laboratory diagnostics testosterone deficiency. In particular, there are contradictions in the choice of research method of free testosterone. The objectives of our work was to conduct a comparative evaluation of methods for studying androgen status of young and middle-aged men with obesity and metabolic syndrome, and determining the relationship between hormonal indicators and metabolic profile, blood pressure, anthropometric characteristics of obesity. The study included 51 patients with symptoms of obesity and metabolic syndrome, aged from 20 to 50 years, the control group consisted of 19 equal-age men with normal body weight. A significant decrease in total testosterone in men with metabolic syndrome was revealed. The dependence of the concentration of total testosterone with age and content sex-steroid-binding globulin was found. The role of free testosterone in the formation of the metabolic syndrome was shown. It was found that free saliva testosterone significantly correlated with the level of calculated serum free testosterone. In patients with obesity and metabolic syndrome there are a statistically significant increase in saliva testosterone indicators compared to calculated serum free testosterone, while at normal body weight differences are absent. It is concluded that saliva testosterone is more sensitive and appropriate marker for obesity and metabolic syndrome

    Получение и анти-ВИЧ активность β-галактозилсфингозина

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    Β-Galactosylsphingosine a potential anti-HIV agent, has been prepared from pig brain cerebrosides and tested for antiviral activity. HIV-inhibitory properties of this compound, predicted previously by molecular modeling, have been confirmed. Consequently, the glycolipid obtained is considered as a promising basic structure for designing its more efficient derivatives.На основе цереброзидов, выделенных из мозга свиньи, получен гликолипид β-галактозилсфингозин - потенциальный анти-ВИЧ-агент - и проведено его тестирование на противовирусную активность, которое подтвердило ВИЧ-ингибирующие свойства соединения, предсказанные ранее методами молекулярного моделирования. В связи с этим полученный гликолипид рассматривается как перспективная базовая структура для создания его более эффективных модифицированных форм

    Структура и функции ароматазы и ее нестероидные ингибиторы

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    The analysis of the structure and function of aromatase (SYP19) - enzyme from the family of cytochrome P-450 that catalyzes the aromatization of six-membered ring A of the steroidal skeleton, namely transformation of androgens into estrogens peripheral and tumor tissues in the body, has been performed, and data in its non-steroidal inhibitors have been summarized.Проведен анализ структуры и функции ароматазы (СYP19) - фермента семейства цитохромов Р-450, кодируемого расположенным на коротком плече 15-й хромосомы (локус 15q21) геном CYP19A1, катализирующего ароматизацию шестичленного цикла А стероидного скелета и обуславливающего метаболизм стероидных гормонов, а именно трансформацию андрогенов в эстрогены периферическими и опухолевыми тканями организма. Обобщены данные по ее нестероидным ингибиторам. Обсуждены особенности первичной и пространственной структуры СYP19, обуславливающие взаимодействие с мембраной клетки и субстратом, обеспечивающие транспорт последнего между липидным бислоем мембраны и активным центром фермента. Показано, что наиболее эффективными ингибиторами СYP19 в настоящее время являются соединения, содержащие в составе молекулы азольные и азиновые гетероциклические фрагменты

    Dexmedetomidine is neuroprotective in an in vitro model for traumatic brain injury

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    <p>Abstract</p> <p>Background</p> <p>The α<sub>2</sub>-adrenoreceptor agonist dexmedetomidine is known to provide neuroprotection under ischemic conditions. In this study we investigated whether dexmedetomidine has a protective effect in an <it>in vitro </it>model for traumatic brain injury.</p> <p>Methods</p> <p>Organotypic hippocampal slice cultures were subjected to a focal mechanical trauma and then exposed to varying concentrations of dexmedetomidine. After 72 h cell injury was assessed using propidium iodide. In addition, the effects of delayed dexmedetomidine application, of hypothermia and canonical signalling pathway inhibitors were examined.</p> <p>Results</p> <p>Dexmedetomidine showed a protective effect on traumatically injured hippocampal cells with a maximum effect at a dosage of 1 μM. This effect was partially reversed by the simultaneous administration of the ERK inhibitor PD98059.</p> <p>Conclusion</p> <p>In this TBI model dexmedetomidine had a significant neuroprotective effect. Our results indicate that activation of ERK might be involved in mediating this effect.</p

    Birth, growth and computation of pi to ten trillion digits

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