268 research outputs found

    Special Values of Generalized Polylogarithms

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    We study values of generalized polylogarithms at various points and relationships among them. Polylogarithms of small weight at the points 1/2 and -1 are completely investigated. We formulate a conjecture about the structure of the linear space generated by values of generalized polylogarithms.Comment: 32 page

    Multiple (inverse) binomial sums of arbitrary weight and depth and the all-order epsilon-expansion of generalized hypergeometric functions with one half-integer value of parameter

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    We continue the study of the construction of analytical coefficients of the epsilon-expansion of hypergeometric functions and their connection with Feynman diagrams. In this paper, we show the following results: Theorem A: The multiple (inverse) binomial sums of arbitrary weight and depth (see Eq. (1.1)) are expressible in terms of Remiddi-Vermaseren functions. Theorem B: The epsilon expansion of a hypergeometric function with one half-integer value of parameter (see Eq. (1.2)) is expressible in terms of the harmonic polylogarithms of Remiddi and Vermaseren with coefficients that are ratios of polynomials. Some extra materials are available via the www at this http://theor.jinr.ru/~kalmykov/hypergeom/hyper.htmlComment: 24 pages, latex with amsmath and JHEP3.cls; v2: some typos corrected and a few references added; v3: few references added

    Characteristics of Somatic Status and Individual Biochemical Markers in Patients with Retinal Vein Occlusion

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    Retinal vein occlusion is one of the most severe vascular lesions of the organ of vision, usually accompanied by somatic pathology.The aim of the study was to study the somatic status and individual biochemical markers in patients with retinal vein occlusion and comparison in groups opposing the effectiveness of anti-VEGF therapy.Methods. 84 patients with macular edema were examined on the background of retinal vein occlusion, who underwent intravitreal injections of an angiogenesis inhibitor for therapeutic purposes. Further, depending on the effectiveness of treatment, the patients were divided into 2 groups, in which a retrospective comparative analysis of somatic status and laboratory data was performed.Results. It was shown that patients with occlusion of the retinal veins have significant impairments in terms of somatic status, blood biochemical parameters and coagulogram. Moreover, there is a direct relationship between the severity of somatic changes and ocular manifestations of the disease. The data obtained reflect a clear tendency in patients with occlusion of the retinal veins to a high risk of cardiovascular complications, including occlusive lesions. In patients with an insufficient treatment effect, a more severe course of arterial hypertension with an increased risk of stratification was detected.Conclusion. The somatic status and laboratory parameters of patients with retinal vein occlusion are significantly different from the norm, which must be taken into account in the prognosis of the course of an ophthalmologic disease

    Making complex things simpler: modern tools to edit the plant genome

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    There are several technologies for plant genome editing, of which the most simple and universal is CRISPR/Cas. Currently, this technology is widely used for gene knockout, deleting genome fragments and inserting exogenous sequences in the plant genome. For each of these applications, many different types of genetic tools have been developed that are used by various research groups to solve specific problems. The CRISPR/Cas technology for plant genome editing is at an early stage of optimization, which is reflected by the ongoing search for the most effective, simple and flexible techniques. As a result, experimental work has to be preceded by a rather long and laborious process of selecting a genetic tool that will be optimal for a specific experimental task. In our review we describe the main variants of the CRISPR/Cas technology used to edit a plant genome. We classify them in terms of experimental tasks solved, major components and technology performance. In the first half of the review a detailed description of two major components of CRISPR/Cas technology – nuclease and guide RNA – is given, the effect of structural features of these elements on editing efficiency is analyzed. Experimental data on the relationship between editing efficiency and nucleotide sequence of guide RNA are generalized. We also give the characteristic for different variants of nucleases used for plant genome editing and discuss their benefits for different experimental purposes. In the second half of the review various strategies for expression of CRISPR/Cas elements in plant cells, in particular, advantages and disadvantages of stable transformation and transient expression, are discussed. The effect of various regulatory elements of genes encoding nuclease and guide RNA on editing efficiency is described. Special emphasis is placed on the techniques of increasing targeted gene replacement efficiency

    Integrals Over Polytopes, Multiple Zeta Values and Polylogarithms, and Euler's Constant

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    Let TT be the triangle with vertices (1,0), (0,1), (1,1). We study certain integrals over TT, one of which was computed by Euler. We give expressions for them both as a linear combination of multiple zeta values, and as a polynomial in single zeta values. We obtain asymptotic expansions of the integrals, and of sums of certain multiple zeta values with constant weight. We also give related expressions for Euler's constant. In the final section, we evaluate more general integrals -- one is a Chen (Drinfeld-Kontsevich) iterated integral -- over some polytopes that are higher-dimensional analogs of TT. This leads to a relation between certain multiple polylogarithm values and multiple zeta values.Comment: 19 pages, to appear in Mat Zametki. Ver 2.: Added Remark 3 on a Chen (Drinfeld-Kontsevich) iterated integral; simplified Proposition 2; gave reference for (19); corrected [16]; fixed typ

    Construction of Immune-Chromatographic Indicator Elements for Burnet Rickettsia Detection

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    mc/ml, and the elapsed time – 20 minutes. The IE is specific to other members of the family Ricketsiaceae, for instance to R. prowazekii , to antigen complexes of R. prowazekii and R. sibirika , as well as to vaccinia virus (L-IVP strain). The IE engineered can be used for rapid indication of Burnet Rickettsia at different stages of laboratory investigation. Span time reduction, lack of necessity to perform any accessory technological operations, visual and (or) automatic registration of the results build up premises to observe immune-chromatographic method for Burnet Rickettsia detection as one of the alternatives for identification of these microorganisms under field conditions when monitoring ambient environment objects
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