973 research outputs found

    Electrocatalytic behavior of tetrathiafulvalene (TTF) and extended tetrathiafulvalene (exTTF) [FeFe] hydrogenase mimics

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    TTF- and exTTF-containing [(μ-S2)Fe2(CO)6] complexes have been prepared by the photochemical reaction of TTF or exTTF and [(μ-S2)Fe2(CO)6]. These complexes are able to interact with PAHs. In the absence of air and in acid media an electrocatalytic dihydrogen evolution reaction (HER) occurs, similarly to analogous [(μ-S2)Fe2(CO)6] complexes. However, in the presence of air, the TTF and exTTF organic moieties strongly influence the electrochemistry of these systems. The reported data may be valuable in the design of [FeFe] hydrogenase mimics able to combine the HER properties of the [FeFe] cores with the unique TTF propertie

    In vitro Evaluation of Phthalimide Derivatives Against Cancer Cell lines

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    Los cánceres de pulmón, próstata e hígado se encuentran entre los más prevalentes en los hombres. El cáncer de mama, de cuello uterino y de tiroides se encuentran entre los más prevalentes en mujeres (OMS, 2019). El tratamiento del cáncer generalmente incluye quimioterapia y radioterapia; sin embargo, los medicamentos contra el cáncer disponibles tienen una selectividad baja y causan efectos adversos graves, como nefrotoxicidad, neurotoxicidad y mielosupresión (Matsuo et al., 2010). Por tanto, el diseño y desarrollo de compuestos como nuevos agentes anticancerígenos frente a los tipos de cáncer de mayor incidencia son de vital importancia en el campo de la salud. Los derivados de ftalimida son compuestos prometedores para el desarrollo de nuevos agentes anticancerígenos (Li et al., 2011; Grigalius y Petrikaite, 2017; Kamal et al., 2002). Basado en lo anterior, Este trabajo tuvo como objetivo evaluar la actividad antiproliferativa de 43 derivados de ftalimida contra una línea celular de cáncer principal en hombres (HepG2) y dos líneas celulares de cáncer principales en mujeres (HeLa y 4T1). Además, se determinó la citotoxicidad de los compuestos contra una línea celular de fibroblasto murino normal (3T3). Los resultados mostraron que los compuestos C16, E11 y E16 presentaron la mejor actividad antiproliferativa contra las líneas celulares HeLa y 4T1. El compuesto H16 solo disminuyó la proliferación celular en un 32% contra la línea celular HepG2. Los compuestos H5, H16, E2, E16 y C1 no afectaron a la proliferación de la línea celular 3T3. Demostrando que sería importante continuar con el análisis de este tipo de compuestos frente a diferentes cánceres para encontrar nuevos compuestos con mejor actividad que los actualmente disponibles en el mercado

    Immunosuppressive Minimization Strategies in Kidney Transplantation

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    The long-term graft survival in renal transplantation results is still controversial, the toxicity and adverse reactions of the immunosuppressive drugs are implicated, as well as cellular and humoral antigen-specific immune mechanisms; therefore, different strategies for adapting immunosuppression are used to reduce the complications associated with the use of these drugs. Calcineurin inhibitors (CNI) require an adequate dose-dependent concentration leading to the appearance of drug-related adverse reactions. The variability in the required dose of CNI leads to minimization strategies that do not result in a higher acute rejection (AR) incidence when compared to other immunosuppressive agents. Early steroid withdrawal is another strategy, although with an increase in AR, but without an impact on the function and survival of the renal graft. The reduction of mycophenolate mofetil to 1.5 g/day seems to be a therapeutic option, decreasing the infectious, hematological and gastrointestinal adverse reactions. Finally, alemtuzumab, bortezomib, belatacept and cellular therapies are in the search for the new treatments, whose premise is the induction of donor-specific nonresponse in the context of operational tolerance or mixed chimerism. The use of adapted and adequate immunosuppression has led to variable results and some are very encouraging; however, they must be validated with experimental studies

    Evolutionary discriminative confidence estimation for spoken term detection

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s11042-011-0913-zSpoken term detection (STD) is the task of searching for occurrences of spoken terms in audio archives. It relies on robust confidence estimation to make a hit/false alarm (FA) decision. In order to optimize the decision in terms of the STD evaluation metric, the confidence has to be discriminative. Multi-layer perceptrons (MLPs) and support vector machines (SVMs) exhibit good performance in producing discriminative confidence; however they are severely limited by the continuous objective functions, and are therefore less capable of dealing with complex decision tasks. This leads to a substantial performance reduction when measuring detection of out-of-vocabulary (OOV) terms, where the high diversity in term properties usually leads to a complicated decision boundary. In this paper we present a new discriminative confidence estimation approach based on evolutionary discriminant analysis (EDA). Unlike MLPs and SVMs, EDA uses the classification error as its objective function, resulting in a model optimized towards the evaluation metric. In addition, EDA combines heterogeneous projection functions and classification strategies in decision making, leading to a highly flexible classifier that is capable of dealing with complex decision tasks. Finally, the evolutionary strategy of EDA reduces the risk of local minima. We tested the EDA-based confidence with a state-of-the-art phoneme-based STD system on an English meeting domain corpus, which employs a phoneme speech recognition system to produce lattices within which the phoneme sequences corresponding to the enquiry terms are searched. The test corpora comprise 11 hours of speech data recorded with individual head-mounted microphones from 30 meetings carried out at several institutes including ICSI; NIST; ISL; LDC; the Virginia Polytechnic Institute and State University; and the University of Edinburgh. The experimental results demonstrate that EDA considerably outperforms MLPs and SVMs on both classification and confidence measurement in STD, and the advantage is found to be more significant on OOV terms than on in-vocabulary (INV) terms. In terms of classification performance, EDA achieved an equal error rate (EER) of 11% on OOV terms, compared to 34% and 31% with MLPs and SVMs respectively; for INV terms, an EER of 15% was obtained with EDA compared to 17% obtained with MLPs and SVMs. In terms of STD performance for OOV terms, EDA presented a significant relative improvement of 1.4% and 2.5% in terms of average term-weighted value (ATWV) over MLPs and SVMs respectively.This work was partially supported by the French Ministry of Industry (Innovative Web call) under contract 09.2.93.0966, ‘Collaborative Annotation for Video Accessibility’ (ACAV) and by ‘The Adaptable Ambient Living Assistant’ (ALIAS) project funded through the joint national Ambient Assisted Living (AAL) programme

    Trabajo comunitario y descolonización

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    Papel de la linfadenectomía ampliada tipo R2 en el tratamiento quirúrgico del cáncer gástrico resecable

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    The extended lymphadenectomy has been proposed as routine procedure in the surgical treatment of gastric cancer, although some controversies have been published. We present a retrospective analysis on the impact of extended lymph node dissection after total gastrectomy, in terms of post-operative course and histopathologic findings, in a group of 30 patients with R2 lymphadenectomy and in 16 patients with R1 lymphadenectomy. There were no significant differences in duration of operation, amount of blood trasfusion and length of hospital stay between the 2 groups. The only significant difference was found in the greater amount of drainage output after R2 lymphadenectomy as compared with R1. There were no mortalities in either group and morbidity rate was similar for both [43% in R1 and 40% in R2) mostly in the form of abdominal infections (18% in R1 and 16% in R2]). A significantly greater number of lymph nodes was identified after R2 gastrectomy. Fifty-three per cent of patients has positive lymph nodes, 12% of them being from the N2 echelon of nodes (including one case of early gastric cancer). Careful lymph node dissection in gastric cancer surgery allows a more precise staging of the tumor with no increase in postoperative morbidit
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