348 research outputs found
The Changing Face of Heart Transplantation
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 -splits
Inspired by the split decomposition of graphs and rank-width, we introduce
the notion of -splits. We focus on the family of -splits of a graph of
order , and we prove that it forms a hypergraph with several properties. We
prove that such hypergraphs can be represented using only
of its hyperedges, despite its potentially exponential number of hyperedges. We
also prove that there exist hypergraphs that need at least
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
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}
10.4ââkW coherently combined ultrafast fiber laser
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 (M2â€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
Towards Speeding Up Graph-Relational Queries in RDBMSs
International audienc
0038: Addressing the controversy of estimating right ventricular systolic pressure by echocardiography: insights from 307 patients with advanced lung disease or pulmonary arterial hypertension
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 Pearsonâs 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 (mPAPâ„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.ConclusionEchocardiographyâs reliability for RVSP estimation can be improved when careful attention is paid to simple practical signal quality parameters, clearly identified by the present study
AnĂĄlisis crĂtico de los factores de riesgo del carcinoma oral de cĂ©lulas escamosa
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
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Tracking ultrafast solid-state dynamics using high harmonic spectroscopy
WWe establish time-resolved high harmonic generation (tr-HHG) as a powerful spectroscopy method for tracking photoinduced dynamics in strongly correlated materials through a detailed investigation of the insulator-to-metal phase transitions in vanadium dioxide. We benchmark the technique by comparing our measurements to established momentum-resolved ultrafast electron diffraction, and theoretical density functional calculations. Tr-HHG allows distinguishing of individual dynamic channels, including a transition to a thermodynamically hidden phase. In addition, the HHG yield is shown to be modulated at a frequency characteristic of a coherent phonon of the equilibrium monoclinic phase over a wide range of excitation fluences. These results demonstrate that tr-HHG is capable of tracking complex dynamics in solids through its sensitivity to the band structure
Endocarditis in Cattle Caused by Bartonella bovis
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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