Potential benefits of melatonin in organ transplantation: a review

Organ transplantation is a useful therapeutic tool for patients with end-stage organ failure; however, graft rejection is a major obstacle in terms of a successful treatment. Rejection is usually a consequence of a complex immunological and nonimmunological antigen-independent cascade of events, including free radical-mediated ischemia-reperfusion injury (IRI). To reduce the frequency of this outcome, continuing improvements in the efficacy of antirejection drugs are a top priority to enhance the long-term survival of transplant recipients. Melatonin (N-acetyl-5-methoxytryptamine) is a powerful antioxidant and ant-inflammatory agent synthesized from the essential amino acid L-tryptophan; it is produced by the pineal gland as well as by many other organs including ovary, testes, bone marrow, gut, placenta, and liver. Melatonin has proven to be a potentially useful therapeutic tool in the reduction of graft rejection. Its benefits are based on its direct actions as a free radical scavenger as well as its indirect antioxidative actions in the stimulation of the cellular antioxidant defense system. Moreover, it has significant anti-inflammatory activity. Melatonin has been found to improve the beneficial effects of preservation fluids when they are enriched with the indoleamine. This article reviews the experimental evidence that melatonin is useful in reducing graft failure, especially in cardiac, bone, otolaryngology, ovarian, testicular, lung, pancreas, kidney, and liver transplantation

Subleading Shape Functions in Inclusive B Decays

The contributions of subleading shape functions to inclusive decay distributions of B mesons are derived from a systematic two-step matching of QCD current correlators onto soft-collinear and heavy-quark effective theory. At tree-level, the results can be expressed in terms of forward matrix elements of bi-local light-cone operators. Four-quark operators, which arise at O(g^2), are included. Their effects can be absorbed entirely into a redefinition of other shape functions. Our results are in disagreement with some previous studies of subleading shape-function effects in the literature. A numerical analysis of B->X_u+l+nu decay distributions suggests that power corrections are small, with the possible exception of the endpoint region of the charged-lepton energy spectrum.Comment: 22 pages, 2 figures; several typos corrected; version published in JHE

Efficient boundary integral-resonant mode expansion method implementation for full-wave analysis of passive devices based on circular waveguides with arbitrary perturbations

This paper is a preprint of a paper submitted to IET Microwaves Antennas and Propagation and is subject to Institution of Engineering and Technology Copyright. If accepted, the copy of record will be available at IET Digital LibraryIn this study, the efficient full-wave analysis of passive devices composed of circular and arbitrarily-shaped waveguides is considered. For this purpose, the well-known boundary integral-resonant mode expansion (BI RME) method has been properly extended. Circular waveguides are used for resonant mode expansion, whereas the arbitrary contour is defined by any combination of straight, circular and elliptical segments, thus allowing the exact representation of the most widely used geometries. The proposed algorithm extends previous implementations of the BI RME method based on circular waveguides by considering circular and elliptical arcs for defining arbitrary geometries. Similarly, it allows the efficient analysis of passive devices based on circular waveguides with arbitrary perturbations, thus providing more accurate results with less computational efforts than a rectangular waveguide-based BI RME approach. The extended method has been successfully tested with several practical application examples, having compared its performance with the BI RME method based on rectangular waveguides.This work was supported by Ministerio de Ciencia e Innovacion, Spanish Government, under Research Project TEC2010-21520-C04-01.Carceller Candau, C.; Cogollos Borras, S.; Soto Pacheco, P.; Gil Raga, J.; Boria Esbert, VE.; Vicente Quiles, CP.; Gimeno Martinez, B. (2013). Efficient boundary integral-resonant mode expansion method implementation for full-wave analysis of passive devices based on circular waveguides with arbitrary perturbations. IET Microwaves Antennas and Propagation. 7(1):44-53. https://doi.org/10.1049/iet-map.2012.0603S44537

Carbono orgânico dissolvido e biodisponibilidade de N e P como indicadores de qualidade do solo

Nas últimas décadas, qualidade do solo tem se tornado um tópico importante na ciência do solo. Embora esforços consideráveis tenham sido dedicados com o intuito de definir "qualidade do solo", ainda não há um conceito amplamente aceito pela comunidade cientifica. A seleção de índices qualitativos para definir qualidade do solo é uma tarefa extremamente difícil, e diversas propriedades químicas, físicas e biológicas tem sido sugeridas como potenciais indicadores. A matéria orgânica do solo está associada com processos químicos, físicos e biológicos no solo, e, portanto, é considerada um dos melhores indicadores de qualidade do solo. O manejo do solo pode influenciar significativamente a dinâmica do carbono orgânico e o ciclo de N, P, e S. Entretanto, mudanças na concentração total da matéria organica em resposta ao manejo pode ser dificil de ser detectada devido à variabilidade natural do solo. Quando comparada com a matéria orgânica total do solo, a fração mais prontamente disponível, como o carbono orgânico dissolvido (COD), é mais sensível às mudanças no manejo do solo a curto e médio prazo e, portanto, pode ser utilizada como indicador fundamental de qualidade do solo ou das alterações das condições naturais. Embora a fração dissolvida represente apenas uma pequena porção da matéria orgânica total do solo, o COD é móvel no solo e constitui uma importante fonte de C para os microorganismos, podendo facilmente refletir os efeitos de diferentes sistemas de manejo. Inúmeros métodos são utilizados para caracterizar o COD, mas os processos que influenciam sua mineralização e a disponibilidade dos elementos associado com a matéria orgânica (N, P, e S) ainda não são completamente entendidos. Pesquisas futuras devem buscar entender os processos que governam a dinâmica de nutrientes e do COD e como os mesmos afetam a qualidade do solo.Soil quality has become an important issue in soil science. Considerable attempts have been made to define soil quality, but a general concept has not yet been accepted by the scientific community. The selection of quantitative indices for soil quality is extremely difficult, and a considerable number of chemical, physical, and biochemical properties have been suggested as potential indicators of soil quality. Because soil organic matter (SOM) can be associated with different soil chemical, physical and biological processes, it has been widely considered as one of the best soil quality indicator. Land use can significantly influence dynamics of organic carbon and N, P, and S cycle. However, changes in total soil organic carbon (SOC) contents in response to land use may be difficult to detect because of the natural soil variability. In the short to medium term, biological properties and readily decomposable fractions of SOC, such as dissolved organic carbon (DOC), are much more sensitive to soil management than is SOM as a whole, and can be used as a key indicator of soil natural functions. Despite the fact that labile C accounts for a small portion of the total organic matter in the soils, DOC is the most mobile and important C-source for microorganisms, and can easily reflect the effects of land use on soil quality. Although several methods are used to characterize DOC, the factors influencing mineralization and bioavailability of elements associated with organic matter (N, P, and S) remains unclear. Future research should focus on the processes that govern DOC and nutrient dynamics and how they affect soil quality

Adiciones al catálogo de algas marinas bentónicas para el Archipiélago Canario. II.

The catalogue of benthic algae in the Canarian Archipelago is extended to include eigth new species; two Chlorophyta: Cladophoropsis macromeres Taylor and var. exigua of Caulerpa peltata Lamouroux; two Phaeophyta: Pilinia rimosa Kützing and Sporochnus gaetnera C.Ag., and four Rhodophyta: Dasya rigidula (Kützing) Ardissone, Cryptonemia crenulata (J.Ag.) J.Ag., Rhododiscus puicherrimus Crouan frat., and Botryooladia occidentalis (Boergesen) Kylin.The regional corology for fourty nine species is also extended.Se amplía el catálogo de algas marinas bentónicas para el Archipiélago Canario en ocho especies; dos Chlorophyta: Cladophoropsis macromeres Taylor y la variedad exigua de Caulerpa peltata Lamouroux ; dos Phaeophy­ta: Pilinia rimosa Kützing y Sporochnus gaetnera C.Ag. y cuatro Rhodophyta: Dasya rigidula (Kützing) Ardissone, Crtptonemia crenulata (J.Ag. )J.Ag., Rhododiscus pulcherrimus Crouan frat. y Botryocladia occidentalis (Boergesen) Kylin. Así mismo se amplía la corología regional de cuarenta y nueve especies

Sobre la estructura y reproducción de Cottoniella Boergesen (Rhodophyta, Ceramiales) en las Islas Canarias

The sexual structures of the genus Cottoniella in the Macaronesian endemic C. filamentosa (Howe) Boergesen var. fusiformis (Boergesen) Cormaci, Furnari & Scammacca are described for the first time, and the main taxonomic characters of the Canary Islands plants are particularized. The asexual structures, previously known only in var. algeriensis (Schotter) Womersley & Shepley, are confirmed and the basic life-history of the genus is presumed.Se describen por primera vez las estructuras sexuales del género Cottoniella en el endemismo macaronésico C. filamentosa (Howe) Boergesen var. fusiformis (Boergesen) Cormaci, Furnari & Scammacca y se detalla la estructura de las plantas canarias, resaltando los caracteres vegetativos más importantes desde el punto de vista de la taxonomía. Se confirman las estructuras asexuales, conocidas sólo en la var. algeriensis (Schotter) Womersley & Shepley. Con estos datos puede presumirse el ciclo biológico básico del género

Iniciación al estudio taxonómico ecológico del género Sargassum C. Agardh (Phaeophyta) en las Islas Canarias

We start to study the genus Sargassum in the Canary Islands, presenting some ecological and taxonomical remarks of some species. The different taxa recorded up to now for the Canaries are compared with that existing in the Mediterranean and the Atlantic coasts of Europe, Africa and America.Se inicia el estudio del género Sargassum en el Archipiélago Canario. comentando los caracteres ecológicos y taxonómicos de algunas especies. Se comparan los táxones citados hasta el presente para las Islas con los que crecen en las costas Atlántico-Europeas,Atlántico-Africanas, Atlántico-Americanas y Mediterráneas