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Search Results: 1 - 10 of 107274 matches for " José Augusto Castro-Rodríguez "
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Immobilization and Biochemical Properties of the Enantioselective Recombinant NStcI Esterase of Aspergillus nidulans
Carolina Pe?a-Montes,María Elena Mondragón-Tintor,José Augusto Castro-Rodríguez,Ismael Bustos-Jaimes,Arturo Navarro-Oca?a,Amelia Farrés
Enzyme Research , 2013, DOI: 10.1155/2013/928913
Abstract: The recombinant NStcI A. nidulans esterase was adsorbed on Accurel MP1000, where protein yield and immobilization efficiency were 42.48% and 81.94%, respectively. Storage stability test at 4°C and RT showed 100% of residual activity after 40 days at both temperatures. The biocatalyst retains more than 70% of its initial activity after 3 cycles of repeated use. Biochemical properties of this new biocatalyst were obtained. Maximum activity was achieved at pH 11 and 30°C, while the best stability was observed with the pH between 9 and 11 at 40°C. NStcI thermostability was increased after immobilization, as it retained 47.5% of its initial activity after 1?h at 60°C, while the free enzyme under the same conditions displayed no activity. NStcI preserved 70% of its initial activity in 100% hexane after 72?h. Enzymatic kinetic resolution of (R,S)-1-phenylethanol was chosen as model reaction, using vinyl acetate as acyl donor. After optimization of reaction parameters, the highest possible conversion (42%) was reached at 37°C, of 0.07, and 120?h of bioconversion in hexane with an enantiomeric excess of 71.7%. NStcI has selectivity for (R)-enantiomer. The obtained E value (31.3) is in the range considered useful to resolve enantiomeric mixtures. 1. Introduction Carboxylic ester hydrolases (EC 3.1.1.x) (CEH) are a diverse group of hydrolases which split carboxylic acid esters in different types of molecules. Lipases (E.C. 3.1.1.3) and esterases (E.C. 3.1.1.1) are the main groups of natural biocatalysts that promote the ester bond cleavage and formation [1]. The most important feature that distinguishes lipases and esterases is the substrate specificity. Lipases preferentially hydrolyze water-insoluble esters such as triglycerides composed of long-chain fatty acids while esterases prefer short-chain acid triglycerides. Another distinction is based on protein structure, most lipases possess a hydrophobic domain (lid) covering the active site, a feature that is absent in esterases [2]. Moreover, esterases obey classical Michaelis-Menten kinetics, whereas lipases need a minimum substrate concentration before high activity is observed [3]. In this direction, esterases may offer advantages as catalysts over lipases in the absence of an interface. All aspects described above demonstrate how fundamentally significant esterases are for biotechnological processes and why the search for new biocatalysts has become very important. Enzyme immobilization ensures recycling of the biocatalyst, allows easy product separation, and may improve performance of the enzyme [4]. The
Neumonía eosinofílica crónica: A propósito de un caso y revisión de la literatura
Maggiolo M.,Julio; Paiva R.,Rebeca; Abara E.,Selim; Girardi B.,Guido; Benveniste D.,Samuel; Castro-Rodríguez,José A.;
Revista chilena de pediatría , 2005, DOI: 10.4067/S0370-41062005000100007
Abstract: introduction: pulmonary infiltrates with eosinophilia (pie) are a group of rare heterogeneous disorders in children, with systemic symptoms and common finding of lung disease and eosinophilia in peripheral blood, bronchoalveolar lavage fluid (bal) or pulmonary interstitium. the most frequent cause is parasite induced. however, chronic eosinophilic pneumonia can be confused with infectious pneumonia. case: a 14 year old girl with 2 months of fever, cough, dyspnea, weight loss and finally respiratory failure without resbronse to antibiotic therapy. chest x-ray and high resolution tomography (hrct) showed diffuse interstitial infiltrates and bilateral condensation involving mainly the superior lobes. bal showed eosinophilia (46%) and in peripheral blood 8 976/mm3. blood, sputum and bal cultures were negative. a diagnosis of chronic eosinophilic pneumonia was made and antibiotics were stooped. systemic steroids were started and after 5 days there was clinical improvement. chest x-ray was normal after 2 weeks and the hrct after 9 months. lung biopsy showed bronchiolitis obliterans with an organized pneumonia with diffuse cellular infiltrates, mainly histiocytes. conclusion: owing to the mortality of this disease, the diagnosis should be suspected in children with respiratory failure, failure to improve with antibiotics and diffuse infiltrates in the chest x-ray or hrct
Obesidad, dieta y asma infantil Obesity, diet and childhood asthma
J.A. Castro-Rodríguez
Boletín de Pediatría , 2010,
Abstract: Durante las últimas décadas, las prevalencias de obesidad y asma a nivel mundial han aumentado. Al comparar la fase III (2002-03) y la fase I (1994-95) del estudio internacional ISAAC, se aprecia que la prevalencia de asma se incrementó en alrededor de 1 error estandar en el 59% (para ni os 6-7 a os) y en el 77% (para los de 13-14 a os) de los centros en todo el mundo. LA OMS se ala que la obesidad y el asma están entre las enfermedades crónicas prioritarias a nivel de salud pública en el mundo. Este incremento paralelo de estas dos enfermedades ha dado origen a que se postule que ambas entidades podrían estar de algún modo relacionadas...
Producción de películas delgadas de CdS Te1-x con estructura cúbica para O _< X _< 1
M. Zapata-Torres,F. Chale-Lara,R. Castro-Rodríguez,O. Calzadilla Amaya
Revista mexicana de física , 2005,
Abstract: El sistema CdS/CdTe posee un gran potencial en la producción de sistemas fotovoltaicos de alta eficiencia, dado que aún se está muy lejos de alcanzar la eficiencia de 30%, predicha teóricamente. Una de las limitaciones para aumentar la eficiencia de esta heteroestructura es la diferencia en estructura cristalográfica del CdTe y CdS, cúbica y hexagonal, respectivamente. Adicionalmente, la presencia de una región con composición gradual en la interfaz CdS/CdTe limita la uniformidad del campo eléctrico interfacial necesario para tener una separación de carga eficiente. Para tener un mejor conocimiento de la aleación CdSTe y eventualmente aportar resultados para incrementar la eficiencia actual hemos crecido películas delgadas de CdSxTe1 x sobre substratos de vidrio utilizando la técnica de transporte de vapor en espacio reducido combinada con evaporación libre (CSVT-FE, por sus siglas en inglés) usando la coevaporación de CdTe y CdS. La incorporación del S fue controlada por medio de la temperatura de la fuente de CdS. Las muestras fueron caracterizadas utilizando difracción de rayos X, espectroscopías de análisis de la dispersión de energía de los rayos X y de transmisión óptica. Se encontró que las muestras tienen una estructura cúbica, para 0 < x < 1, con el parámetro de red siguiendo la aproximación de cristal virtual. El ancho de banda prohibida tiene un comportamiento cuadrático con el contenido de azufre, similar al reportado en la literatura. El comportamiento del ancho de la banda prohibida no fue afectado por la estructura cúbica de las películas CdSxTe1-x.
Annealing effects on the mass diffusion of the CdS/ITO interface deposited by chemical bath deposition
Ordaz-Flores, A.;Bartolo-Pérez, P.;Castro-Rodríguez, R.;Oliva, A.I.;
Revista mexicana de física , 2006,
Abstract: cadmium sulphide thin films prepared by chemical bath deposition (cbd) were deposited on indium tin oxide (ito) substrates with different deposition times (i.e. thickness) and characterised by their morphology and band gap energy. samples were analysed as deposited and after annealing at 90 and 150°c, in order to study the interface diffusion and its effects on the properties mentioned. auger depth profiles were used to determine the mass diffusivity coefficient in the cds/ito interface. the initial surface rms-roughness measured with afm, as well as the initial band gap energy, are reduced after the annealing process. we obtained very small diffusion coefficient values, around 10-21 m2/s, for the different elements analysed in the interface.
Annealing effects on the mass diffusion of the CdS/ITO interface deposited by chemical bath deposition
A. Ordaz-Flores,P. Bartolo-Pérez,R. Castro-Rodríguez,A.I. Oliva
Revista mexicana de física , 2006,
Abstract: Capas delgadas de sulfuro de cadmio, preparadas por ba o químico, fueron depositadas sobre sustratos de ITO (óxido de esta o impurificado con indio) con diferentes tiempos de depósito (i.e. espesor) y caracterizadas en su morfología y en su brecha de energía. Las muestras fueron analizadas tanto recién depositadas como después de ser recocidas a las temperaturas de 90 y 150±C, con el objetivo de estudiar la difusión en la interfaz CdS/ITO y sus efectos sobre las propiedades mencionadas. Con ayuda de los perfiles Auger, se determinaron los valores de la difusividad másica de dicha interfaz. El valor inicial rms de la rugosidad superficial medida usando imágenes de fuerza atómica, así como la brecha de energía, se ven reducidos después de los procesos de recocido. Se obtuvieron valores muy peque os en los coeficientes de difusión, del orden de 10 21 m2/s, para los diferentes elementos analizados en la interfaz.
The glutamine synthetase gene family in Populus
Vanessa Castro-Rodríguez, Angel García-Gutiérrez, Javier Canales, Concepción Avila, Edward G Kirby, Francisco M Cánovas
BMC Plant Biology , 2011, DOI: 10.1186/1471-2229-11-119
Abstract: The GS gene family consists of 8 different genes exhibiting all structural and regulatory elements consistent with their roles as functional genes. Our results indicate that the family members are organized in 4 groups of duplicated genes, 3 of which code for cytosolic GS isoforms (GS1) and 1 which codes for the choroplastic GS isoform (GS2). Our analysis shows that Populus trichocarpa is the first plant species in which it was observed the complete GS family duplicated. Detailed expression analyses have revealed specific spatial and seasonal patterns of GS expression in poplar. These data provide insights into the metabolic function of GS isoforms in poplar and pave the way for future functional studies.Our data suggest that GS duplicates could have been retained in order to increase the amount of enzyme in a particular cell type. This possibility could contribute to the homeostasis of nitrogen metabolism in functions associated to changes in glutamine-derived metabolic products. The presence of duplicated GS genes in poplar could also contribute to diversification of the enzymatic properties for a particular GS isoform through the assembly of GS polypeptides into homo oligomeric and/or hetero oligomeric holoenzymes in specific cell types.Glutamine synthetase (GS; EC 6.3.1.2, L-glutamate: ammonia ligase ADP-forming) catalyzes the ATP-dependent addition of ammonium (NH4+) to the γ-carboxyl group of glutamate to produce glutamine and acts as the center for nitrogen flow in plants. Glutamate synthase (Fd-GOGAT, EC 1.4.7.1; NADH-GOGAT, EC 1.4.1.1) then catalyzes the conversion of glutamine and 2-oxoglutarate to produce two molecules of glutamate, one of which participates in further ammonium assimilation via GS while the other donates reduced nitrogen for all nitrogen-containing biomolecules [1]. The ammonium assimilated by GS in the production of glutamine can come from various sources, including direct uptake from the soil, reduction of nitrate and nitrite, photoresp
GLACE survey: OSIRIS/GTC Tuneable Filter H$α$ imaging of the rich galaxy cluster ZwCl 0024.0+1652 at z = 0.395. Part I -- Survey presentation, TF data reduction techniques and catalogue
Miguel Sánchez-Portal,Irene Pintos-Castro,Ricardo Pérez-Martínez,Jordi Cepa,Ana M. Pérez García,Helena Domínguez-Sánchez,ángel Bongiovanni,Ana L. Serra,Emilio Alfaro,Bruno Altieri,Alfonso Aragón-Salamanca,Chantal Balkowski,Andrea Biviano,Malcom Bremer,Francisco Castander,Héctor Casta?eda,Nieves Castro-Rodríguez,Ana L. Chies-Santos,Daniela Coia,Antonaldo Diaferio,Pierre-Alain Duc,Alessandro Ederoclite,James Geach,Ignacio González-Serrano,Chris. P. Haines,Brian McBreen,Leo Metcalfe,Iván Oteo,Ismael Pérez-Fournón,Bianca Poggianti,Jana Polednikova,Marina Ramón-Pérez,José M. Rodríguez-Espinosa,Joana S. Santos,Ian Smail,Graham P. Smith,Sonia Temporin,Ivan Valtchanov
Physics , 2015, DOI: 10.1051/0004-6361/201525620
Abstract: The cores of clusters at 0 $\lesssim$ z $\lesssim$ 1 are dominated by quiescent early-type galaxies, whereas the field is dominated by star-forming late-type ones. Galaxy properties, notably the star formation (SF) ability, are altered as they fall into overdense regions. The critical issues to understand this evolution are how the truncation of SF is connected to the morphological transformation and the responsible physical mechanism. The GaLAxy Cluster Evolution Survey (GLACE) is conducting a study on the variation of galaxy properties (SF, AGN, morphology) as a function of environment in a representative sample of clusters. A deep survey of emission line galaxies (ELG) is being performed, mapping a set of optical lines ([OII], [OIII], H$\beta$ and H$\alpha$/[NII]) in several clusters at z $\sim$ 0.40, 0.63 and 0.86. Using the Tunable Filters (TF) of OSIRIS/GTC, GLACE applies the technique of TF tomography: for each line, a set of images at different wavelengths are taken through the TF, to cover a rest frame velocity range of several thousands km/s. The first GLACE results target the H$\alpha$/[NII] lines in the cluster ZwCl 0024.0+1652 at z = 0.395 covering $\sim$ 2 $\times$ r$_{vir}$. We discuss the techniques devised to process the TF tomography observations to generate the catalogue of H$\alpha$ emitters of 174 unique cluster sources down to a SFR below 1 M$_{\odot}$/yr. The AGN population is discriminated using different diagnostics and found to be $\sim$ 37% of the ELG population. The median SFR is 1.4 M$_{\odot}$/yr. We have studied the spatial distribution of ELG, confirming the existence of two components in the redshift space. Finally, we have exploited the outstanding spectral resolution of the TF to estimate the cluster mass from ELG dynamics, finding M$_{200}$ = 4.1 $\times$ 10$^{14}$ M$_{\odot} h^{-1}$, in agreement with previous weak-lensing estimates.
Carnitine Palmitoyltransferase 1B 531K Allele Carriers Sustain a Higher Respiratory Quotient after Aerobic Exercise, but β3-Adrenoceptor 64R Allele Does Not Affect Lipolysis: A Human Model
Eduardo Gómez-Gómez, Martín Efrén Ríos-Martínez, Elena Margarita Castro-Rodríguez, Mario Del-Toro-Equíhua, Mario Ramírez-Flores, Ivan Delgado-Enciso, Ana Lilia Pérez-Huitimea, Luz Margarita Baltazar-Rodríguez, Gilberto Velasco-Pineda, Jesús Mu?iz-Murguía
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0096791
Abstract: Carnitine palmitoyltransferase IB (CPT1B) and adrenoceptor beta-3 (ADRB3) are critical regulators of fat metabolism. CPT1B transports free acyl groups into mitochondria for oxidation, and ADRB3 triggers lipolysis in adipocytes, and their respective polymorphisms E531K and W64R have been identified as indicators of obesity in population studies. It is therefore important to understand the effects of these mutations on ADRB3 and CPT1B function in adipose and skeletal muscle tissue, respectively. This study aimed to analyze the rate of lipolysis of plasma indicators (glycerol, free fatty acids, and beta hydroxybutyrate) and fat oxidation (through the non-protein respiratory quotient). These parameters were measured in 37 participants during 30 min of aerobic exercise at approximately 62% of maximal oxygen uptake, followed by 30 min of recovery. During recovery, mean respiratory quotient values were higher in K allele carriers than in non-carriers, indicating low post-exercise fatty acid oxidation rates. No significant differences in lipolysis or lipid oxidation were observed between R and W allele carriers of ADRB3 at any time during the aerobic load. The substitution of glutamic acid at position 531 by lysine in the CPT1B protein decreases the mitochondrial beta-oxidation pathway, which increases the non-protein respiratory quotient value during recovery from exercise. This may contribute to weight gain or reduced weight-loss following exercise.
Ritmo circadiano y variaciones temporales en el paro cardiaco súbito extrahospitalario
López-Messa,J.B.; Alonso-Fernández,J.I.; Andrés-de Llano,J.M.; Garmendia-Leiza,J.R.; Ardura-Fernández,J.; Castro-Rodríguez,F. de; Gil-González,J.M.;
Medicina Intensiva , 2012, DOI: 10.1016/j.medin.2011.11.007
Abstract: objectives: to analyze the chronobiological and time variations of out- hospital cardiac arrest (ohca). design: a retrospective descriptive study was made. patients: all cases of ohca of cardiac origin registered over 18 months in the database of the emergency medical service (ems) of the autonomous community of castilla y león (spain) were evaluated. variables analyzed: age, sex, recovery of spontaneous circulation (rosc), first monitored rhythm (amenable / not amenable to defibrillation), alert site [(home, public place, primary care (pc) center], alerting person (family, witness, law enforcement member, pc center staff), alert time (0-8; 8-16; 16-24), emergency team activation time, care time and day of the week. univariate analysis (chi-squared), variance, and nonparametric tests comparing the variables in three periods of 8hours. chronobiological analysis by fast fourier transform and cosinor testing. results: we studied 1286 cases reported between january 2007 and june 2008. statistically significant differences were observed in terms of younger age, higher incidence in the victim's home, and greater frequency of family-cohabiting persons as witnesses in the period between 0 and 8hours. chronobiological analysis found daily rhythm (circadian) with acrophase at 11.16h (p<0.001) and weekly rhythm (circaseptan) with acrophase on wednesday (p<0.05). the median alert time-care time interval and emergency team activation time-care time were 11.7min and 8.0min, respectively, without differences between periods. conclusions: we have demonstrated the presence of a daily rhythm of emergence of ohca with a morning peak and a weekly rhythm with a peak on wednesdays. these results can guide the planning of resources and improvements in response in certain time periods.
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