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Search Results: 1 - 10 of 414344 matches for " Hernán R.;Martínez "
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Funciones termodinámicas relativas a la transferencia del ketoprófen desde el agua hasta algunos sistemas orgánicos
Lozano, Hernán R.;Martínez, Fleming;
Química Nova , 2006, DOI: 10.1590/S0100-40422006000400015
Abstract: the thermodynamics of molal partitioning of ketoprofen (ktp) was studied in cyclohexane/buffer (ch/w), octanol/buffer (roh/w), and dimyristoyl phosphatidylcholine (dmpc), dipalmitoyl phosphatidylcholine (dppc), and egg lecithin (egg/w) liposome systems. in all cases the partition coefficients (kmo/w)were greater than unity; therefore the standard free energies of transfer were negative indicating affinity of ktp for organic media. the kmo/w values were approximately seventy-fold higher in the roh/w system compared with the ch/w system. on the other hand, the kmo/w values were approximately ten or fifty-fold higher in the liposomes compared with the roh/w system. in all cases, the standard enthalpies and entropies of transfer of ktp were positive indicating some degree of participation of the hydrophobic hydration on partitioning processes.
Aspectos termodinámicos de la miscibilidad parcial entre el n-octanol y el agua
Mora, Carolina P.;Lozano, Hernán R.;Martínez, Fleming;
Revista Brasileira de Ciências Farmacêuticas , 2005, DOI: 10.1590/S1516-93322005000100003
Abstract: in the present work the thermodynamic analysis for those data presented by dallos and liszi on mole fraction n-octanol-water liquid-liquid equilibria was made. the values were analyzed using the van't hoff method (ln s as a function of t-1) and those presented by grant et al. (ln s as a function of t-1 and ln t). a non-lineal behavior was found in all cases studied by the van't hoff method, which lead us to apply a parabolic regression model derived in order to calculate the enthalpic changes. endothermic processes were obtained for all temperatures studied. in both systems the free energy changes were positive, whereas the entropic changes were negative indicating some kind of organization in the saturated solutions. in the case of n-octanol-saturated water this result would be explained as the hydrophobic hydration around the aliphatic groups and on the other hand, in the case of water-saturated n-octanol, it could be due to organization of n-octanol molecules around water molecules by hydrogen bonds as it has been presented in literature. the thermodynamic values calculated were compared with those presented by other authors, which were obtained by calorimetry and also by means of equilibrium constants as a function of temperature.
Prevalencia de caries en una población escolar de doce a os Prevalence of caries in an school population of twelve year-old
M.A. Tapias Ledesma,L. Martín-Pero,V. Hernández,R. Jiménez
Avances en Odontoestomatología , 2009,
Abstract: El objetivo de este estudio es conocer la prevalencia de caries en una población escolar de 12 a os y factores asociados a la misma. Población y métodos: Se ha efectuado un estudio transversal en 452 escolares de 12 a os edad de Móstoles. Para determinar el estado dental se ha efectuado una exploración odontológica siguiendo los criterios de la OMS. Medimos la prevalencia de caries en dentición temporal y permanente, así como los índices de caries en dentición temporal (cod, cos) y en dentición permanente (CAOD, CAOS), también medimos el índice SiC, calcularemos los intervalos de confianza al 95%. Utilizamos el programa estadístico SPSS V 13 para realizar todos los cálculos estadísticos y epidemiológicos necesarios del estudio. Resultados: La prevalencia en dentición permanente es del 28,8% (IC 95%: 26,94-31,06). El índice CAOD es del 0,61 (IC 95%: 0,48-0,73) y el índice cod 0,33 (IC 95%: 0,24-0,42). El índice SiC es de 1,82 (IC 95%: 1,55-2,09). Como conclusión podemos resaltar que prevalencia de caries en la población de 12 a os de Móstoles ha disminuido. Un 71% de los escolares esta libre de caries en dentición permanente. The objective of study is to know the prevalence of dental caries in schoolchildren 12 year-old and associated factors. Population and Methods: A cross sectional observational study has been carried out in 542 twelve year old schoolchildren in Móstoles. We conducted a dental exploration using the World Health Organization criteria. We then measure the caries prevalence permanent and deciduas and the dmt, dmts, DMFT, DMFS index and its confidence limits at 95%. We used programs SPPS V.13 to carry out all the statistic calculations of the study. Results: The caries prevalence in permanent teeth is 28,8% (IC95%: 26,94-31,06). The DMTF index is 0,61 (IC 95%: 0,48-0,73) and the dmt index is 0,33 (IC 95%: 0,24-0,42). SiC index is 1,82 (IC 95%: 1,55-2,09). In conclusion, the caries prevalence in the 12 year old population from Mostoles to decreed. 71% the schoolchildren are caries free.
Synthesis and Characterization of Organic Bio-Absorbents Coming from Sugarcane Bagasse  [PDF]
Israel Hernández Romero, Juan Rodrigo Laguna Camacho, Raúl Enrique Contreras Bermúdez, Francisca Sandoval Reyes, Erika Gaona Santiago, Celia María Calderón Ramón, Lizeth Ríos Velasco, Jesús Enrique Escalante Martínez
Journal of Surface Engineered Materials and Advanced Technology (JSEMAT) , 2016, DOI: 10.4236/jsemat.2016.63012
Abstract: In this work, a modification of the sugarcane bagasse is performed, in order to obtain organic catalysts. The bagasse analysis is performed using X-ray diffraction (XRD) and Fourier Transformer Infrared Spectroscopy (FTIR), which indicated that characteristic peaks determined its chemical compounds. In addition, Scanning Electron Microscopy (SEM) is used to know the morphology. Finally, a discoloration test is conducted on an azo compound (methylene blue) in an aqueous medium, obtaining an efficiency of 98.6%.
Producción de Biogás a Nivel Laboratorio Utilizando Estiércol de Cabras Producción de Biogás a Nivel Laboratorio Utilizando Estiércol de Cabras
J. L. Maga?a R.,Ernestina Torres,Martín T. Martínez G.,Rosalía Hernández Cantero
Acta Universitaria , 2012,
Abstract: Se aplicó el proceso de digestión anaerobia para la obtención de biogás a partir de estiércol de cabras. Para ello se implementaron dos tipos de experimentos: El primero se efectuó mediante dos lotes utilizando matraces kitazato de cristal con una capacidad de 1 litro como depósito de la mezcla agua-excremento. Los matraces kitazato se introdujeron dentro de una tina con agua calentada por una resistencia eléctrica para mantener la temperatura adecuada para el crecimiento de las bacterias metanogénicas. El objetivo de esta experimentación fue determinar la producción diaria de biogás al utilizar estiércol de cabras. El segundo se efectuó mediante un biodigestor a escala de laboratorio. Para ello se procedió primero a pesar las bolitas de estiércol de cabras. En seguida se pasaron a un recipiente en donde se les agregó agua. Luego se procedió a deshacer las bolitas hasta alcanzar una mezcla homogénea y en estas condiciones cargar el biodigestor. Elobjetivo de esta experimentación fue determinar la cantidad de metano del biogás mediante análisis cromatográfico. The anaerobic digestion process was applied in order to get biogas from goat’s manure. Two experiments were implemented. The first one was carried out by means of two lots, using matraces kitazatos of crystal with a capacity of 1 liter, as deposit of the mixture water - excrement. The kitazatos were put inside a tub with water warmed by an electrical resistance in order to supply the adapted temperature for the growth of the methanogenic bacteriums. The aim of this experimentation was to determine the daily production of biogas when goats’ manure is used. The second one was carried out by means of a biodigestor at laboratory scale. The small balls of goats’ manure were weighted and immediately were passed to a container where water was added. Then, these were dissolved in order to obtain a homogeneous mixture that could be loaded into the biodigestor. The aim of this experimentation was to determine the methane’s amount of biogas by means of chromatographic analyses.
Uso de las leguminosas arbustivas en los sistemas de producción animal en el trópico
Jaime Olivares Pérez; Saúl Rojas Hernández;,Régulo Jiménez Guillén,Pedro Arturo Martínez Hernández.
REDVET , 2005,
Abstract: Este trabajo es una revisión bibliográfica del como podrían utilizarse las leguminosas arbustivas como un recurso natural en los sistemas de producción animal, con reportes del impacto en el recurso suelo, animal y de manera general en el medio ambiente, donde se han introducido estas especies vegetales.
Crisis de secuestro hepático en pacientes con anemia drepanocítica Hepatic sequestration crisis in patients with drepanocytic anemia
Edgardo Espinosa Martínez,Carlos Hernández Padrón,Rafael Losada Buchillón,José R Mesa Cuervo
Revista Cubana de Hematolog?-a, Inmunolog?-a y Hemoterapia , 1999,
Abstract: Se estudiaron 120 pacientes adultos con anemia drepanocítica que por diferentes causas ingresaron en el Instituto de Hematología e Inmunología durante los a os 1996-1997. En 16 (13,3 %) de estos enfermos se encontraron los criterios diagnósticos de la crisis de secuestro hepático. Hubo disminución significativa de la cifra de hemoglobina (p<0,01) y aumento significativo de la hepatomegalia (p<0,01), el incremento de la reticulocitosis no fue estadísticamente significativo. Los síntomas clínicos más frecuentes fueron la fiebre (62,5 %) y la crisis vasooclusiva (50 %). Las variables que miden la función hepática no se modificaron significativamente durante la crisis. Los hallazgos histológicos más frecuentes fueron la dilatación de los sinusoides hepáticos con hematíes falciformados y la hiperplasia de las células de Kupffer con eritrofagocitosis. Estos resultados indican que la crisis de secuestro hepático es una complicación relativamente frecuente y que está relacionada con atrapamiento agudo de hematíes falciformados en los sinusoides hepáticos 120 adult patients with sickle cell anemia that were admitted in the Institute of Hematology and Immunology due to different causes from 1996 to 1997 were studied. The diagnostic criteria of the hepatic sequestration crisis were found in 16 (13,3 %) of these individuals. A significant decrease of the figure of hemoglobin (p<0,01) and a marked increase of hepatomegaly (p < 0,01) were observed. The rise of reticulocytosis was not statistically important. The most frequent clinical symptoms were fever (62,5 %) and vasoocclusive crisis. The variables that measure the hepatic function were not significantly modified, during the crisis. The commonest histological findings were the dilatation of the hepatic sinusoids with falciform erythrocytes and hyperplasia of the kupffer cells with eritrophagocytosis. These results show that the hepatic sequestration crisis is a relatively frequent complication and it is related to acute catching of falciform erythrocytes in the hepatic sinusoids
Canales y márgenes de comercialización del queso a?ejo en Zacazonapan, México
Rebollar Rebollar,S.; Hernández Martínez,J.; González Razo,F.J.; García Martínez,A.; Albarrán Portillo,B.; Rojo Rubio,R.;
Archivos de Zootecnia , 2011,
Abstract: in order to analyze margins and commercialization channels of a?ejo cheese, during 2007 a research was carried out in zacazonapan, mexico. the commercialization channel more used by producers in this kind of cheese was identified, and relative and absolute margins were obtained using equivalent values, revenues, and cost of each agent. results indicates that 83.3% of cheese makers obtained the first step of consumptionproduction chain and 16.7% was occupied by brokers, in the same way, first of them get 100% of price that final consumer paid and the seconds 33.4%. the gross total commercialization margin of a?ejo cheese in its modalities mature (8 days of mature) was 5.59 us$/kg; in relative words it means that the cheese producer give him 58.29% of final price that the consumer paid and the brokers 45.16%. respect to the same value of cheese mature, the cheese producer give him 41.71% and the difference was obtained by brokers. commercialization channel most common was producer-final consumer.
Implantación en el laboratorio de un algoritmo para el diagnóstico diferencial de la proteinuria
Albaladejo Otón,M. D.; González Cueva,M. M.; álvarez López,R.; Martínez Hernández,P.;
Anales de Medicina Interna , 2005, DOI: 10.4321/S0212-71992005001000002
Abstract: background and objective: when proteinuria appears, a differential diagnosis must determine its origin. the object of this work has been to evaluate the results after the laboratory implantation of an algorithm for the screening and diagnosis of proteinuria. material and methods: from a total of 30,718 processed urines, a 30 mg/dl or higher protein concentration was obtained in 639, recommending a new sample to confirm and differenciate proteinuria. we received 207, to which total protein, creatinine, albumin and alpha-1-microglobulin were quantificated, together with pseudoperoxidase and leucocite esterase from dipstick. the results were introduced in an expert system (upes and its application protis), allowing differenciate hematuria, leucocituria and proteinuria and suggesting the assessment of other parameters, like igg, alpha-2-macroglobulin, light chain kappa/lambda, when necessary. results: from 207 urinalysis assayed for selective proteinuria, 39 were normal, 96 were classified as primary glomerulopathy, 26 as secondary glomerulopathy and 5 as tubulo-interstitial nephropathy. a differential diagnosis of hematuria was made in 58 of these urines. besides, kappa light chains were detected in a sample from a patient with a normal serum protein graph, which were confirmed by inmune fixation. conclusion: with the proposed algorithm, the information obtained from a urine sample increases substantially, allowing detection and differentiation of proteinuria and providing suggestions for the clinical evaluation of the patient.
Prevalencia de caries en una población escolar de doce a?os
Tapias Ledesma,M.A.; Martín-Pero,L.; Hernández,V.; Jiménez,R.; Gil de Miguel,A.;
Avances en Odontoestomatología , 2009, DOI: 10.4321/S0213-12852009000400003
Abstract: the objective of study is to know the prevalence of dental caries in schoolchildren 12 year-old and associated factors. population and methods: a cross sectional observational study has been carried out in 542 twelve year old schoolchildren in móstoles. we conducted a dental exploration using the world health organization criteria. we then measure the caries prevalence permanent and deciduas and the dmt, dmts, dmft, dmfs index and its confidence limits at 95%. we used programs spps v.13 to carry out all the statistic calculations of the study. results: the caries prevalence in permanent teeth is 28,8% (ic95%: 26,94-31,06). the dmtf index is 0,61 (ic 95%: 0,48-0,73) and the dmt index is 0,33 (ic 95%: 0,24-0,42). sic index is 1,82 (ic 95%: 1,55-2,09). in conclusion, the caries prevalence in the 12 year old population from mostoles to decreed. 71% the schoolchildren are caries free.
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