67 research outputs found

    Review of developments in corneal transplantation in the regions of Brazil - Evaluation of corneal transplants in Brazil

    Get PDF
    The aim of this study was to identify inequalities in corneal donation and transplantation among the regions of Brazil. A transversal and retrospective study was specifically conducted using data from the Brazilian Transplant Registry collected by the Brazilian Association of Organ Transplantation between January 2002 and December 2014. The collected data were processed using descriptive statistical methods, and

    Elliptic integral evaluations of Bessel moments

    Get PDF
    We record what is known about the closed forms for various Bessel function moments arising in quantum field theory, condensed matter theory and other parts of mathematical physics. More generally, we develop formulae for integrals of products of six or fewer Bessel functions. In consequence, we are able to discover and prove closed forms for cn,k:=0tkK0n(t)dtc_{n,k}:=\int_0^\infty t^k K_0^n(t) {\rm d}t with integers n=1,2,3,4n=1,2,3,4 and k0k\ge0, obtaining new results for the even moments c3,2kc_{3,2k} and c4,2kc_{4,2k}. We also derive new closed forms for the odd moments sn,2k+1:=0t2k+1I0(t)K0n1(t)dts_{n,2k+1}:=\int_0^\infty t^{2k+1}I_0^{}(t) K_0^{n-1}(t) {\rm d}t with n=3,4n=3,4 and for tn,2k+1:=0t2k+1I02(t)K0n2(t)dtt_{n,2k+1}:=\int_0^\infty t^{2k+1}I_0^2(t) K_0^{n-2}(t) {\rm d}t with n=5n=5, relating the latter to Green functions on hexagonal, diamond and cubic lattices. We conjecture the values of s5,2k+1s_{5,2k+1}, make substantial progress on the evaluation of c5,2k+1c_{5,2k+1}, s6,2k+1s_{6,2k+1} and t6,2k+1t_{6,2k+1} and report more limited progress regarding c5,2kc_{5,2k}, c6,2k+1c_{6,2k+1} and c6,2kc_{6,2k}. In the process, we obtain 8 conjectural evaluations, each of which has been checked to 1200 decimal places. One of these lies deep in 4- dimensional quantum field theory and two are probably provable by delicate combinatorics. There remains a hard core of five conjectures whose proofs would be most instructive, to mathematicians and physicists alike.Comment: 51 pages, 1 Postscript figure, uses amsmath.sty, added reference

    Estudo quantitativo da lágrima pelo teste de fenol vermelho na população brasileira Quantitative tear study using the red phenol test in the Brazilian population

    No full text
    OBJETIVO: Determinar parâmetros normais do teste de fenol vermelho na população brasileira, e comparar entre diferentes raças, idade e sexo. MÉTODOS: Foram avaliados, com o teste de fenol vermelho, 280 indivíduos (560 olhos) da raça branca e 280 indivíduos (560 olhos) da raça não branca, que foram divididos de acordo com a idade e o sexo. Foram excluídos indivíduos com qualquer doença ocular, usuários de lente de contato e que usavam medicação ocular. RESULTADOS: Dos 1.120 olhos avaliados, o resultado médio foi de 19,77±7,90 mm. CONCLUSÃO: O resultado médio encontrado foi um valor intermediário entre as duas populações previamente estudadas (japonesa e norte-americana).<br>PURPOSE: To detect normal values of red phenol thread test in the Brazilian population and compare it between different races, age and sex. METHODS: 280 white individuals (560 eyes) and 280 non-white individuals (560 eyes) were analyzed regarding sex and age, and analyzed using the Phenol Red test. Individuals with ocular diseases, contact lens or ocular drug users were excluded from this study. RESULTS: Of the 1,120 evaluated eyes, the mean ± standard deviation result was 19,77±7,90 mm. CONCLUSIONS: The mean result found in this study was an intermediate value compared to the previously studied populations (Japanese and American)
    corecore