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Insecticidal effects of plant extracts on immature whitefly Bemisia tabaci Genn. (Hemiptera: Aleyroideae)
Cruz-Estrada,Angel; Gamboa-Angulo,Marcela; Borges-Argáez,Rocío; Ruiz-Sánchez,Esaú;
Electronic Journal of Biotechnology , 2013, DOI: 10.2225/vol16-issue1-fulltext-6
Abstract: background: the whitefly (bemisia tabaci genn.) is a widely distributed and highly harmful plant pest species. the management of b. tabaci has been typically carried out by chemical pesticides. in the last decade however, there has been an increasing interest in natural products, particularly those of plant origin, to control this pest species. in the present work, aqueous and ethanolic extracts of native plants from the flora of the yucatán peninsula (acalypha gaumeri, annona squamosa, carlowrightia myriantha, petiveria alliaceae and trichilia arborea) and the introduced plant azadirachta indica were collected and evaluated for insecticidal activity against eggs and nymphs bemisia tabaci. results: most of the aqueous and ethanolic extracts showed high insecticidal effects on b. tabaci eggs. the lowest lc50 values were recorded in the aqueous extracts of a. gaumeri (0.39% w/v), a. squamosa (0.36% w/v), p. alliaceae (0.42% w/v) and a. indica (0.30% /v), as well as in the ethanolic extracts of p. alliaceae (2.09 mg ml-1) and t. arborea (2.14 mg ml-1). on the other hand, b. tabaci nymphs were not affected by the aqueous extracts, but were highly sensitive to the ethanolic extracts of the tested plants. the lowest lc50 values were recorded in the ethanolic extracts of p. alliaceae (1.27 mg ml-1) and t. arborea (1.61 mg ml-1). the gc-ms analysis showed that phytol was the major component of the ethanolic extract of p. alliaceae and fatty acids were the major components of ethanolic extract of t. arborea. conclusions: overall, results suggest that ethanolic extracts of p. alliaceae and t. arborea leaves showed the highest insecticidal effects on eggs and nymphs b. tabaci. the extracts from p. alliaceae and t. arborea are good candidates to be developed as sources of natural insecticides for the management of immature b. tabaci since their effects were comparable with that showed by the extracts of a. indica, a well-known plant species for its insecticidal activity.
STUDY OF MECHANICAL BEHAVIOR OF TEXTILE REINFORCED COMPOSITE MATERIALS
CARLOS ROLANDO RIOS-SOBERANIS,RICARDO HERBE CRUZ-ESTRADA,JOSE RODRIGUEZ-LAVIADA,EMILIO PEREZ-PACHECO
DYNA , 2012,
Abstract: La relación entre la geometría del entramado de las fibras y los mecanismos de fractura bajo cargas de tensión ha sido evaluada para materiales compuestos reforzados con textiles de diferente arquitectura tales como colchoneta (fibras al azar) y petatillo (biaxial). Estos materiales están manufacturados empleando como matriz polimérica resina epóxica curada a altas temperaturas. El sistema elegido para este trabajo consiste en resina epóxica bifuncional diglicidil éter de bisfenol A (DGEBA) curada con una amina tetrafuncional diaminodifenil sulfona (DDS). Este sistema asegura la obtención de un material rígido transparente con excelentes propiedades mecánicas que permite observar, analizar e identificar el proceso y el progreso del da o generado así como los mecanismos de fractura que conllevan a la ruptura del material. Los resultados demostraron que la arquitectura/geometría de los textiles de refuerzo influye en la generación de sitios de concentración de esfuerzos donde se incrementa la posibilidad de iniciación de fallas y la propagación de grietas.
Rese a de "Las universidades modernas: espacios de investigación y docencia", de Burton R. Clark.
Mariana Arteaga Estrada,Minerva Cruz Saldívar
Perfiles educativos , 1999,
Abstract:
Propuesta metodológica para la ubicación de áreas de disposición de residuos sólidos urbanos
J. Teodoro Silva,Francisco Estrada,Salvador Ochoa,Gustavo Cruz
Revista internacional de contaminación ambiental , 2006,
Abstract: Se propone una metodología encaminada a la localización de sitios ambientalmente seguros para la disposición de Residuos Sólidos Urbanos (RSU), que deberán cumplir con todos los requerimientos indicados en la Norma Oficial Mexicana NOM-083-SEMARNAT- 2003, como son: afectaciones a obras civiles (autopistas, aeropuertos, oleoductos, gasoductos, torres de energía eléctrica, áreas naturales protegidas), distancias mínimas a poblaciones, cuerpos de agua, zonas de inundación, fallas geológicas, taludes inestables e hidrogeología. Esta investigación se realizó en la región del Bajío Michoacano, comprendiendo los municipios de Zináparo, Numarán, Penjamillo, Ecuandureo, Churintzio y La Piedad. Los factores considerados fueron: vulnerabilidad acuífera, uso actual del suelo, densidad de fracturamiento, infraestructura urbana e industrial y áreas de inundación. El análisis de cada uno de los factores anteriores se realizó en áreas de 0.25 km2; a cada factor se le asignó un rango y peso, integrándolos posteriormente en rangos normalizados en escala de 0-1. Los pesos varían de 1 a 5 y representan la influencia en el impacto ambiental y social del factor considerado, siendo el valor de 5, el de mayor relevancia y 1 el de menor impacto. El proceso de la información implicó álgebra de mapas para obtener como producto final un mapa paramétrico denominado índice de Riesgo Ambiental (IRA). Los valores obtenidos estuvieron en el rango de 16-160, proponiéndose con ello, seis niveles de riesgo ambiental que son: Extremadamente alto, Muy alto, Alto, Medio, Bajo y Muy bajo.
Use of Propolis for Topical Treatment of Dermatophytosis in Dog  [PDF]
Tonatiuh Alejandro Cruz Sánchez, Perla Alejandra Estrada García, Cristian Ismael López Zamora, Marcela Autran Martínez, Víctor Pérez Valencia, Amparo Londo?o Orozco
Open Journal of Veterinary Medicine (OJVM) , 2014, DOI: 10.4236/ojvm.2014.410028
Abstract:

Here we present three clinical cases of canine dermatophytosis resolved with topical propolis treatment that involved alopecia and well-demarcated erythematous lesions. These cases were positively identified by direct observation of samples from the affected zones with 10% KOH. Each sample was cultured, leading to the isolation of Microsporum gypseum in one case and Microsporum canis in the other two cases. The animals’ subsequent treatment included bathing using a commercial soap with propolis every seven days for 3 to 8 weeks, as well as the use of a propolis-containing ointment elaborated in our laboratory, which was applied to the lesions once a day for three weeks. From the second week of treatment, all cultures were negative. At the end of treatment, all cases displayed full recovery of the injuries and hair growth in these areas. In these clin-ical cases, treatment with propolis was effective, supporting the use of propolis as a promising natural alternative with no known collateral effects.

Aptitud combinatoria general y específica del contenido de azúcares en maíces criollos eloteros
Couti?o Estrada, Bulmaro;Vidal Martínez, Víctor A.;Cruz Gómez, Bertha;Cruz Vázquez, Carolina;
Revista fitotecnia mexicana , 2010,
Abstract: six open-pollinated corn (zea mays l.) landraces outstanding for the quality of their sweet green ears, and their 15 direct crosses, were evaluated at two locations in chiapas. general and specific combining ability for grain sugar content, measured in °brix, as well as heterosis of their crosses was evaluated. it was found that only additive gene effects were significant (p ≤ 0.05). thus this ear sweetness related trait could be improved in parental varieties having the largest general combining ability by using recurrent selection methods that exploit the additive genetic variance. parental varieties 'campechano' and 'paloma' had the highest values of gca effects (0.781 and 0.581) and produced the sweetest green ears with 13.1 and 12.9 °brix. all crosses showed low values of heterosis.
Remineralización in vivo del esmalte desmineralizado artificialmente
Gispert Abreu,Estela; Cantillo Estrada,Elena; Rivero López,Aracelys; Cruz Rodríguez,Miriam;
Revista Cubana de Estomatolog?-a , 2001,
Abstract: a technique to measure the individual capacity of remineralization in the course of time of an enamel area which had been artificially demineralized before and also to measure enamel's resistance in 65 children aged 8 to 11 years was evaluated in this paper. this technique was developed by the provincial research group of materials , methods and drugs for preventive dentistry (grimep in spanish). a significant variation was observed (p=0.001) in the average individual capacity of remineralization (icr) at 96h and 120h as compared to that recorded at 72 h, which meant a rise in icr and a significant increase (x2=p< 0,001) in the percentage of children showing good icr as time went by. at 120 h, the majority of children showed good icr (93.4%), therefore this is the ideal moment for measuring it because maybe those having poor icr exhibit greater susceptibility to caries.
Lista sistemática de la ictiofauna de Bahía de Banderas, México
Moncayo-Estrada, Rodrigo;Castro-Aguirre, José Luis;De La Cruz Agüero, José;
Revista mexicana de biodiversidad , 2006,
Abstract: the bahía de banderas located in the central mexican pacific, contains an important ichthyological richness, which is described for the first time in the present systematic checklist, which includes a total of 210 species, belonging to 145 genera and 74 families. in the inventory 205 species were collected between 1997 and 1998, and the remainder five were observed and positively identified but not captured. the results had shown an important tropical component (117) over the temperate one (7), and the rest of the species (76) with a wider distribution along the eastern pacific ocean. the best represented families by number of species were: carangidae (19), haemulidae (16), sciaenidae (13), serranidae (11) and paralichthyidae (8). accordingly to revision of recent bibliographic records, eleven species reported here have extended their known distribution range to bahía de banderas.
Vulnerabilidad acuífera como herramienta de política ambiental para la protección de manantiales en Michoacán, México
SILVA, José Teodoro;ESTRADA, Francisco;RODRíGUEZ, Ramiro;OCHOA, Salvador;VILLALPANDO, Fabián;CRUZ, Gustavo;
Revista internacional de contaminación ambiental , 2010,
Abstract: in michoacán state, méxico, the use of aquifer vulnerability assessment methods is growing. their results can be incorporated in environmental public policies of sustainable development for aquifer protection programs as well as for protection of water bodies related to springs, especially when these bodies are been threatened by anthropogenic activities. the study carried out in valle de los reyes, michoacán, based on the sintacs method, permitted the proposal of increasing the protection area of the protected natural area chorros del varal. such proposal was based on the vulnerability assessment, on the role of this area in the local aquifer recharge and on its relevance in the local and regional fow transit. the obtained aquifer vulnerability map shows six contamination risk levels in the range of 26-260 points. the area shows medium to high vulnerability. the surrounding area has a very high vulnerability (186-210 points). low values refected clayed aquifer environments and scarce fracturing. the vulnerability map was incorporated to the management program of the chorros del varal park as a strategic planning tool. its incorporation insures a more adequate administration of this protected area as well as its natural resources.
Galactosemia: diagnóstico de 5 casos con deficiencia de transferasa
Gutiérrez García,Enna; Barrios garcía,Bárbara; Carrillo Estrada,úrsula; Lantigua Cruz,Aracely;
Revista Cubana de Pediatr?-a , 2001,
Abstract: the biochemical study of 5 children who were referred to the national center of medical genetics because they were clinically suspected of suffering from an inborn error of the carbohydrate metabolism is presented. thin layer chromatography was carried out to detect these substances in urine and a band was found at the galactose level. a high level of metabolites in blood was found on quantifying them. the final diagnosis consited in demonstrating the deficiency of erythrocytic galactose-1-phosphate uridyltransferase by the spectrophotometric method. the character of carriers of the deficient gene was also proved among the parents of the 5 children.
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