348 research outputs found

    The Changing Face of Heart Transplantation

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    It has been 40 years since the first human-to-human heart transplant performed in South Africa by Christiaan Barnard in December 1967. This achievement did not come as a surprise to the medical community but was the result of many years of early pioneering experimental work by Alexis Carrel, Frank Mann, Norman Shumway, and Richard Lower. Since then, refinement of donor and recipient selection methods, better donor heart management, and advances in immunosuppression have significantly improved survival. In this article, we hope to give a perspective on the changing face of heart transplantation. Topics that will be covered in this review include the changing patient population as well as recent advances in transplantation immunology, organ preservation, allograft vasculopathy, and immune tolerance

    Hypergraphs with Polynomial Representation: Introducing rr-splits

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    Inspired by the split decomposition of graphs and rank-width, we introduce the notion of rr-splits. We focus on the family of rr-splits of a graph of order nn, and we prove that it forms a hypergraph with several properties. We prove that such hypergraphs can be represented using only O(nr+1)\mathcal O(n^{r+1}) of its hyperedges, despite its potentially exponential number of hyperedges. We also prove that there exist hypergraphs that need at least Ω(nr)\Omega(n^r) hyperedges to be represented, using a generalization of set orthogonality

    Dual-sPLS: a family of Dual Sparse Partial Least Squares regressions for feature selection and prediction with tunable sparsity; evaluation on simulated and near-infrared (NIR) data

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    Relating a set of variables X to a response y is crucial in chemometrics. A quantitative prediction objective can be enriched by qualitative data interpretation, for instance by locating the most influential features. When high-dimensional problems arise, dimension reduction techniques can be used. Most notable are projections (e.g. Partial Least Squares or PLS ) or variable selections (e.g. lasso). Sparse partial least squares combine both strategies, by blending variable selection into PLS. The variant presented in this paper, Dual-sPLS, generalizes the classical PLS1 algorithm. It provides balance between accurate prediction and efficient interpretation. It is based on penalizations inspired by classical regression methods (lasso, group lasso, least squares, ridge) and uses the dual norm notion. The resulting sparsity is enforced by an intuitive shrinking ratio parameter. Dual-sPLS favorably compares to similar regression methods, on simulated and real chemical data. Code is provided as an open-source package in R: \url{https://CRAN.R-project.org/package=dual.spls}

    10.4  kW coherently combined ultrafast fiber laser

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    An ultrafast laser delivering 10.4 kW average output power based on a coherent combination of 12 step-index fiber amplifiers is presented. The system emits close-to-transform-limited 254 fs pulses at an 80 MHz repetition rate, and has a high beam quality (M2≀1.2) and a low relative intensity noise of 0.56% in the frequency range of 1 Hz to 1 MHz. Automated spatiotemporal alignment allows for hands-off operation

    0038: Addressing the controversy of estimating right ventricular systolic pressure by echocardiography: insights from 307 patients with advanced lung disease or pulmonary arterial hypertension

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    BackgroundThere is a controversy on the reliability of echocardiography in estimating right ventricular systolic pressure (RVSP) in advanced lung disease (ALD) and idiopathic pulmonary arterial hypertension (PAH) patients. This study aimed to develop a quality control method for echocardiographic RVSP assessment to provide guidance.MethodsWe selected consecutive patients referred from 2001 to 2012 for ALD or PAH, in whom an echocardiogram and a right heart catheterization (RHC) were performed within five days. In order to assess reader level influence on echo interpretation, three levels of readers (multi-reader echo-lab, level 2 and 3) estimated RVSP (based on the tricuspid regurgitation TR maximal velocity). Invasive and non-invasive RVSPs were compared using Pearson’s coefficient and Bland-Altman analysis. PH classification performance was also assessed. Reasons for under- and overestimation were systematically analysed.ResultsAmong the 307 patients included (mean age 50±13, 41% male), two-thirds had pulmonary hypertension (PH). RVSP was measurable in 56% of patients. There was a strong correlation between echo and RHC (r=0.84 for echo-lab; 0.86 level 2 and 0.96 level 3). For PH classification, areas under the curve of level 2 and 3 RVSPs were excellent (0.94 and 0.97);>45mmHg was associated with 86% sensitivity and 100% specificity. No severe PH (mPAP≄35mmHg) was missed. The main reason for underestimation was the absence of a well-defined TR envelope and for overestimation the inability to identify the complete envelope by decreasing the gain.ConclusionEchocardiography’s reliability for RVSP estimation can be improved when careful attention is paid to simple practical signal quality parameters, clearly identified by the present study

    Anålisis crítico de los factores de riesgo del carcinoma oral de células escamosa

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    El objetivo de este estudio fue identificar la producciĂłn cientĂ­fica sobre los factores de riesgo para el desarrollo del carcinoma oral de cĂ©lulas escamosas en un perĂ­odo de diez años. Se realizaron bĂșsquedas virtuales en las bases de datos MEDLINE, LILACS, BBO, Scielo y la biblioteca Cochrane. Los factores de riesgo asociados a estas neoplasias malignas fueron: el cigarrillo/tabaco, el alcohol, la raza, la ubicaciĂłn geogrĂĄfica, el nivel educativo, el estado dental, el nivel de higiene y las prĂĄcticas sexuales. Teniendo en cuenta la encuesta realizada, se pudo constatar que las neoplasias malignas orales afectan predominantemente a individuos de sexo masculino, pero en los Ășltimos años se ha notado un aumento en la apariciĂłn de casos en mujeres asĂ­ como, los factores de riesgo asociados a esta enfermedad fueron predominantemente el consumo de alcohol y tabaco.Analise crĂ­tica dos fatores de risco para o carcinoma oral de cĂ©lulas escamosas O objetivo deste trabalho foi identificar a produção cientĂ­fica a respeito dos fatores de riscos para o desenvolvimento do carcinoma oral de cĂ©lulas escamosas em um perĂ­odo de dez anos. Foram realizadas buscas virtuais nos bancos MEDLINE, LILACS, BBO, Scielo e Cochrane library. Os fatores de risco associados a essas neoplasias malignas foram: cigarro/tabaco, ĂĄlcool, raça, localização geogrĂĄfica, nĂ­vel educacional, estado da dentição, nĂ­vel de higiene e prĂĄticas sexuais. Considerando o levantamento realizado, pĂŽde-se notar que as neoplasias orais malignas afetam predominantemente indivĂ­duos do sexo masculino, mas nos Ășltimos anos tem-se notado um aumento da ocorrĂȘncia de casos em mulheres assim como, os fatores de risco associados a esta doença foram predominantemente as prĂĄticas etilistas e o uso do tabaco

    Endocarditis in Cattle Caused by Bartonella bovis

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    This study aimed to determine the role of Bartonella as an endocarditis agent in cattle. Bartonella bovis was identified by PCR, gene sequences analysis, and specific internal transcribed spacer amplicon product size in 2 bovine endocarditis cases with high antibody titers, which demonstrates that B. bovis is a pathogen for cattle
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