oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 456 )

2018 ( 828 )

2017 ( 759 )

2016 ( 1111 )

Custom range...

Search Results: 1 - 10 of 467022 matches for " Arturo Navarro-Oca?a "
All listed articles are free for downloading (OA Articles)
Page 1 /467022
Display every page Item
Application of Metabolic Engineering to the Production of Scopolamine
Javier Palazón,Arturo Navarro-Ocaa,Liliana Hernandez-Vazquez,Mohammad Hossein Mirjalili
Molecules , 2008, DOI: 10.3390/molecules13081722
Abstract: Scopolamine is an alkaloid widely used in medicine for its anticholinergic activity. The aim of this review is to show that metabolic engineering techniques constitute a suitable tool to improve the production of tropane alkaloids, focusing in particular on scopolamine. We present an overview of results obtained by various research groups, including our own, who have studied the overexpression of genes involved in the biosynthesis of scopolamine in different plant species that produce tropane alkaloids. Experiments carried out to improve production in hairy root cultures will also be described, as well as those attempting to biotransform hyoscyamine into scopolamine in roots and transgenic tobacco cells.
Growth Inhibition of Streptococcus from the Oral Cavity by α-Amyrin Esters
Gloria Díaz-Ruiz,Liliana Hernández-Vázquez,Héctor Luna,María del Carmen Wacher-Rodarte,Arturo Navarro-Ocaa
Molecules , 2012, DOI: 10.3390/molecules171112603
Abstract: Five terpenoids were tested by the macrodilution broth method to determine their inhibition activity on cariogenic bacterial growth. In general, α-, β-amyrin and α-amyrin phenylacetate proved to be active, reducing the bacterial viability to less than 20%.
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-Ocaa,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
Antioxidant and free radical scavenging activities of plant extracts used in traditional medicine in Mexico
F Ruiz-Terán, A Medrano-Martínez, A Navarro-Oca a
African Journal of Biotechnology , 2008,
Abstract: Twenty-two species of medicinal plants collected in the Mexican state of Morelos were selected to evaluate their free radical scavenging and antioxidant activities. The extracts from the aerial parts of the plants were obtained using hexane, acetone and methanol (66 extracts). The initial qualitative screening of antioxidants was made using two TLC methods against the stable DPPH (1,1-diphenyl-2- picrylhydrazyl-hydrate) and -carotene-linoleic acid bleaching assay. All the extracts displayed antioxidant activity. However, the methanol extracts appeared to have the highest antioxidant activity, so they were examined further. The quantitative assays against DPPH radical, -carotene-linoleic acid bleaching and total amount of phenols in the methanol extracts (TPME) showed nine plants as having the highest scavenging and antioxidant activities. For the nine methanolic extracts analysed, a clear relation between the total phenolic content of the extracts and their antioxidant activity was found. Plants such as Annona squamosa and Sapium macrocarpum showed two times more antioxidant activity than the commercial BHA (butylated hydroxyanisole) antioxidant. Moreover, some methanolic extracts of the plants showed activities comparable to commercial antioxidants BHA and TBHQ (tertbutylhydroquinone), thus making it possible to consider some of the studied plants as a potential source of antioxidants of natural origin.
Serotypes of Vibrio cholerae Non-O1 Isolated from Water Supplies for Human Consumption in Campeche, México and their Antibiotic Susceptibility Pattern
Isaac-Márquez, Angélica P;Lezama-Dávila, Claudio M;Eslava- Campos, Carlos;Navarro-Ocaa, Armando;Cravioto-Quintana, Alejandro;
Memórias do Instituto Oswaldo Cruz , 1998, DOI: 10.1590/S0074-02761998000100004
Abstract: the presence of vibrio cholerae non-o1 in water supplies for human consumption in the city of campeche and rural locality of bécal was investigated. v. cholerae non-o1 was detected in 5.9% of the samples obtained in deep pools of campeche. studies conducted in bécal and neighbourhood of morelos in campeche indicated that collected samples harbored v. cholerae non-o1 in 31.5% and 8.7% respectively. there was a particular pattern of distribution of v. cholerae non-o1 serotypes among different studied regions. accordingly, v. cholerae non-o1 serotype o14 predominated in the deep pools of campeche and together with v. cholerae non-o1, o155 were preferentially founds in samples taken from intradomiciliary faucets in the neighbourhood of morelos. samples from bécal predominantly presented the serotype o112. 60% and 53.8% of all studied strains of v. cholerae non-o1 proved to be resistant to ampicillin and carbenicillin. 3.1%, 7.7% and 6.2% presented resistant to doxycycline, trimethoprim-sulfamethoxazole and erythromycin respectively. the study showed the necessity of performing a strong epidemiologic surveillance for emergence and distribution of v. cholerae non-o1
Serotypes of Vibrio cholerae Non-O1 Isolated from Water Supplies for Human Consumption in Campeche, México and their Antibiotic Susceptibility Pattern
Isaac-Márquez Angélica P,Lezama-Dávila Claudio M,Eslava- Campos Carlos,Navarro-Ocaa Armando
Memórias do Instituto Oswaldo Cruz , 1998,
Abstract: The presence of Vibrio cholerae non-O1 in water supplies for human consumption in the city of Campeche and rural locality of Bécal was investigated. V. cholerae non-O1 was detected in 5.9% of the samples obtained in deep pools of Campeche. Studies conducted in Bécal and neighbourhood of Morelos in Campeche indicated that collected samples harbored V. cholerae non-O1 in 31.5% and 8.7% respectively. There was a particular pattern of distribution of V. cholerae non-O1 serotypes among different studied regions. Accordingly, V. cholerae non-O1 serotype O14 predominated in the deep pools of Campeche and together with V. cholerae non-O1, O155 were preferentially founds in samples taken from intradomiciliary faucets in the neighbourhood of Morelos. Samples from Bécal predominantly presented the serotype O112. 60% and 53.8% of all studied strains of V. cholerae non-O1 proved to be resistant to ampicillin and carbenicillin. 3.1%, 7.7% and 6.2% presented resistant to doxycycline, trimethoprim-sulfamethoxazole and erythromycin respectively. The study showed the necessity of performing a strong epidemiologic surveillance for emergence and distribution of V. cholerae non-O1
Evaluation of the Hydroxynitrile Lyase Activity in Cell Cultures of Capulin (Prunus serotina)
Evaluation of the Hydroxynitrile Lyase Activity in Cell Cultures of Capulin (Prunus serotina)

Liliana Hemandez Hector Luna Arturo Navarro-Ocafia Ma Teresa de Jesus Olivera-Flores Ivon Ayala,
Liliana Hernández
,Héctor Lun,Arturo Navarro-Oca?,Ma Teresa de Jesús Olivera-Flores,Ivon Ayala

生物工程学报 , 2008,
Abstract: Enzymatic preparations obtained from young plants and cell cultures of capulin were screened for hydroxynitrile lyase activity. The threeweek old plants, grown under sterile conditions, were used to establish a solid cell culture. Crude preparations obtained from this plant material were evaluated for the transformation of benzaldehyde to the corresponding cyanohydrin (mandelonitrile). The results show that the crude material from roots, stalks, and leaves of young plants and calli of roots, stalks, internodes and petioles biocatalyzed the addition of hydrogen cyanide (HCN) to benzaldehyde with a modest to excellent enantioselectivity.
Inmigración y dinámicas demográficas andaluzas a comienzos del siglo XXI. Una perspectiva territorial
Navarro Rodríguez, Susana,Ocaa Ocaa, Carmen,Larrubia Vargas, Remedios
Estudios Geográficos , 2012,
Abstract: The presence of foreign immigration in Andalusia has prompted a new phase in the evolution of the region’s geographic dynamics, characterised by different spatial traits due to pre-existing population imbalances in the region and the manner in which these are affected by foreign immigration which concentrates in the most dynamic areas but also has a significant local impact in areas in decline where its presence is more diffused. This paper identifies the different models of demographic dynamics that this combination of circumstances has generated, as well as the territorial factors of their distribution throughout the region. La presencia de la inmigración extrajera en Andalucía ha propiciado una fase nueva en la evolución de su dinámica geográfica, cuya manifestación espacialmente tiene rasgos diferentes, por los desequilibrios poblacionales propios de la región y por la forma en que incide sobre ellos la inmigración extranjera, que si bien se concentra en las áreas más dinámicas, tiene también una presencia difuminada en áreas en declive, de alto impacto local. El artículo procede a identificar los modelos distintos de dinámicas demográficas que esta conjunción de circunstancias ha generado, y los factores territoriales de su distribución en la región. [fr] La présence de l'immigration étrangère en Andalousie a conduit a une nouvelle phase dans l'évolution de sa dynamique géographique, dont la manifestation spatiale a des traits différents, à cause des déséquilibres des populations propres à la région et de la facon par laquelle l'immigration étrangère les affecte, qui, bien qu'elle se concentre dans les zones les plus dynamiques, elle a aussi une présence diffuse dans des zones en déclin, avec un impacte local élevé. L'article vise à identifier les différentes modèles des dynamiques démographiques que cette conjonction de circonstances a générées, ainsi que les facteurs territoriaux de leur distribution dans la région.
Higiene contra la anemia de los mineros. La lucha contra la anquilostomiasis en Espa a (1897-1936)
Rodríguez Ocaa, Esteban,Menéndez Navarro, Alfredo
Asclepio : Revista de Historia de la Medicina y de la Ciencia , 2006,
Abstract: This study analyses the Spanish participation in the international campaign against ancylostomiasis during the period of the establishing and hegemony of Social Medicine. Through study of the main interventions carried out, including the agreement with the Rockefeller Foundation, its effects are observed on the popularization of laboratory medicine, the introduction of health concerns into employment legislation and the genesis of new rural health structures. Este trabajo analiza la participación espa ola en la campa a internacional contra la anquilostomiasis durante el periodo de constitución y hegemonía de la Medicina social. A través del estudio de las principales intervenciones realizadas, incluyendo el acuerdo con la Fundación Rockefeller, se observan sus efectos sobre la popularización de la medicina de laboratorio, la introducción de la preocupación por la salud en la legislación laboral y la génesis de estructuras nuevas para la sanidad rural.
Evaluación del proceso educativo de un posgrado en salud mediante la participación de los estudiantes
Rillo,Arturo G.; Arceo Guzmán,Mario E.; Ocaa Servín,Héctor;
Educaci?3n M??dica Superior , 2009,
Abstract: objective: to assess the educational process of a mastery program in health area by student perception regarding the level of participation during its stay in the program. methods: a cross-sectional prospective, observational and descriptive study was conducted applied to 14 students of health sciences mastery, a questionnaire by each subject of study plan (with o total of 88 questionnaires). study variables included the perception of participation level in educational process and mastery program; like tool we used questionnaire measurement on situations and judgments on educational process (sjep) created and validated by viniegra et al. statistical analysis included descriptive statistics and the spearman rank correlation test. results: the student participation level is high in research workshop of a 78,56%, for a of 64,29% for research seminar, and of 50% for other subjects. the higher frequency in participation level is in the following domains of educational process: conditions and use of means in above mentioned process, extracurricular activities; the lower frequency is in the diversity and types of learning situations; activities characteristic of professor and student; assessment features. conclusions: we conclude that the sjep questionnaire allows to assessment of educational process in mastery programs, the perception of mastery educational process members on educational process is high. educational process performed in research workshop is a strength area and in other subjects they are opportunity areas.
Page 1 /467022
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.