973 research outputs found
Electrocatalytic behavior of tetrathiafulvalene (TTF) and extended tetrathiafulvalene (exTTF) [FeFe] hydrogenase mimics
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
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
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
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
Papel de la linfadenectomía ampliada tipo R2 en el tratamiento quirúrgico del cáncer gástrico resecable
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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