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Search Results: 1 - 10 of 509432 matches for " Fernando; Cortés Marín "
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CORRELACIóN ENTRE PROPIEDADES ANATóMICAS, RESISTENCIA A FLEXIóN ESTáTICA Y ENERGíA REQUERIDA PARA EL CORTE DE LA CA?A DE AZúCAR (Saccharum officinarum L.)
González Sánchez,Hugo Alberto; Toro Betancur,Alejandro; álvarez Mejía,Fernando; Cortés Marín,Elkin Alonso;
Revista Facultad Nacional de Agronomía, Medellín , 2008,
Abstract: the microstructure, anatomical structure, bending resistance and the energy required to cut stems of three varieties of sugar cane cultivated in the valle del cauca ( colombia ), were studied in order to have useful data for the development of cutting blades. microestructural and anatomical characterization tasks were performed by optical microscopy ( om), and scanning electron microscopy (sem). the physical and mechanical properties were determined after adaptation of astm standards (which were developed for wood), while the consumption of energy during cutting was evaluated by using a modified charpy type impact pendulum. the fibers and silica particles showed different geometry and distribution in the stems of the three studied varieties, and a relation was established between the microstructure of the stems and the energy required to cut them in the modified charpy pendulum. generally speaking, cutting the internodes required higher specific energy than cutting the nodes, and the use of blades with cutting angle of 20° led to lower levels of energy consumption. also, a relation of proportionality between the effective cross-sectional area of fibers (atef) and the specific energy consumed in cutting, as well as between the flexibility coefficient and the modulus of elasticity in bending were found.
CORRELACIóN ENTRE PROPIEDADES ANATóMICAS, RESISTENCIA A FLEXIóN ESTáTICA Y ENERGíA REQUERIDA PARA EL CORTE DE LA CA A DE AZúCAR (Saccharum officinarum L.) CORRELATIONS AMONG ANATOMIC PROPERTIES, BENDING RESISTANCE AND ENERGY REQUIRED TO CUT SUGAR CANE (Saccharum officinarum L.)
Hugo Alberto González Sánchez,Alejandro Toro Betancur,Fernando álvarez Mejía,Elkin Alonso Cortés Marín
Revista Facultad Nacional de Agronomía, Medellín , 2008,
Abstract: La microestructura, estructura anatómica, la resistencia a la flexión y la energía requerida durante el corte de los tallos de tres variedades de ca a de azúcar cultivadas en el Valle del Cauca (Colombia), fueron estudiados con el propósito de adquirir información útil para el desarrollo de cuchillas para corte de esta especie. Las labores de caracterización microestructural y anatómica se apoyaron en las técnicas de microscopía óptica y electrónica de barrido. Las propiedades mecánicas se determinaron adaptando algunas normas ASTM para maderas, mientras que la energía al corte se evaluó usando un péndulo de impacto tipo Charpy modificado. En los tallos de las tres variedades estudiadas se observaron diferentes distribuciones y dimensiones geométricas de las fibras y se verificó la presencia de partículas de sílice. Se presentó en general mayor requerimiento de energía específica al corte en los entrenudos que en los nudos y un menor consumo específico de energía al corte con las cuchillas con ángulo de afilado de 20°. Se establecieron relaciones entre la microestructura de los tallos, comportamiento a la flexión y al corte, destacándose la relación proporcional entre el área transversal efectiva de fibra (ATEF) y la energía específica al corte, así como entre el coeficiente de flexibilidad y el módulo de elasticidad en flexión. The microstructure, anatomical structure, bending resistance and the energy required to cut stems of three varieties of sugar cane cultivated in the Valle del Cauca ( Colombia ), were studied in order to have useful data for the development of cutting blades. Microestructural and anatomical characterization tasks were performed by optical microscopy ( OM), and scanning electron microscopy (SEM). The physical and mechanical properties were determined after adaptation of ASTM standards (which were developed for wood), while the consumption of energy during cutting was evaluated by using a modified Charpy type impact pendulum. The fibers and silica particles showed different geometry and distribution in the stems of the three studied varieties, and a relation was established between the microstructure of the stems and the energy required to cut them in the modified Charpy pendulum. Generally speaking, cutting the internodes required higher specific energy than cutting the nodes, and the use of blades with cutting angle of 20° led to lower levels of energy consumption. Also, a relation of proportionality between the effective cross-sectional area of fibers (ATEF) and the specific energy consumed in cutting, as well as between the fl
Epidemiología molecular de la infección por VHB y VHD en comunidades indígenas del departamento del Amazonas, Colombia
Diana Di Filippo-Villa,Fabián Cortés-Mancera,Fernando de la Hoz,María C Navas
Actualidades Biológicas , 2012,
Abstract:
Memory AND effector cells in children with bacterial infections of the gastrointestinal and respiratory tracts  [PDF]
Monika Palacios-Martínez, María Cristina González-Torres, Leonor Rodríguez-Cruz, Oralia Nájera-Medina, Rubén D. Martínez-Pérez, Consuelo del Carmen Cortés-Bejar, Fernando Valencia-Chavarria, Daniel Martínez-Gómez
Open Journal of Immunology (OJI) , 2012, DOI: 10.4236/oji.2012.24024
Abstract:

Infections in infants and children under five years of age are a public health in México and are one of the major causes of death. Methods In this study, lymphocyte immunophenotyping for CD3+ (T-cells), CD3+CD4+, CD3+CD8+,
CD3+CD19+, CD3+CD16/56+, CD45RA+,
CD45RO+, CD62L
- and CD28- were determined in the whole blood of gastrointestinal and respiratory bacterial infected children, using a four-color flow cytometry technique. Results: Our data showed that the percentages and the absolute numbers of monocytes and granulocytes are increased in infected children, when compared to the control group. Similarly, we observed increases in the percentages of B lymphocytes, CD8+ cells, memory T cells
(CD4+CD45RO+ and CD8+CD45RO+) and effector lymphocytes (CD4+CD62L? and CD8+CD28?) in infected children compared with the control group. In contrast, naive T cells were decreased in the bacterial infected children relative to the control group. Additionally, we used ELISA assays to identify the pathogen agent in gastrointestinal and respiratory infection. Comparing different types of infection, we found that the children with respiratory bacterial infections had higher percentages of B lymphocytes, and cytotoxic lymphocytes (CD8+CD28-); and the children with gastrointestinal infections had higher percentages of CD3+ lymphocytes and effector cells (CD4+CD62L-). Conclusions The increase in B lymphocytes and CD8+CD28- cells in the children with respiratory infections and the increase of T lymphocytes and CD4+CD62L- cells in the children with gastrointestinal bacterial infections indicate that both cellular and humoral responses coincide, and both responses are necessary for eliminating the pathogen.

Seroprevalencia de infección por virus de la hepatitis B y por virus de la inmunodeficiencia humana en una población de pacientes con múltiples transfusiones en cuatro hospitales, Colombia, Sur América
Beltrán,Mauricio; Navas,María Cristina; Arbeláez,María Patricia; Donado,Jorge; Jaramillo,Sergio; De la Hoz,Fernando; Estrada,Cecilia; Cortés,Lucía del Pilar; de Maldonado,Amalia; Rey,Gloria; ,;
Biomédica , 2009,
Abstract: introduction. although the transfusion of blood products is a common therapy, it carries risk of transmission of infections, especially hepatitus b virus (hbv) and human immunodeficiency virus (hiv). objective. as part of the blood safety initiative, the pan american health organization supported studies to estimate the prevalence of human immunodeficiency virus and hepatitis b virus infection in colombia. materials and methods. between february and september 2003, a cross sectional study examined 500 multiply-transfused patients at four hospital centers in the cities of bogotá and medellín. the serum samples were analyzed by enzyme immunoassay (eia) using commercial kits. results. the seroprevalence of hiv infection was 1.8% (ci 95% 0.5-3.1). the seroprevalence of hbv infection was 18.6% (ci 95% 15.1-22.1). six risk factors were associated with hiv and hbv infection: (1) receiving more than 48 units of blood or blood components, (2) diagnosis of hemophilia, (3) receiving transfusions for more than one year, (4) receiving whole blood, (5) co-infection with hepatitis c virus and (6) receiving transfusions before 1993. conclusions. this is the first epidemiological study with a significant sample size performed in multiply-transfused patients in colombia. the principal finding was the high prevalence of hbv and hiv infection in patients with diagnosis of hemophilia compared with the other five groups of multiply-transfused patients.
Digestion and energy value of macerated sudangrass hay used in growing-finishing diets for feedlot cattle
Jorquera, Alejandro Plascencia;Ponce, José Gerardo Serrano;Sánchez-Mendoza, Berenice;Serrano, Alberto Barreras;Calderón-Cortés, José Fernando;López-Soto, María Alejandra;Monta?o Gómez, Martín Francisco;Zinn, Richard Avery;
Scientia Agricola , 2011, DOI: 10.1590/S0103-90162011000600001
Abstract: mechanical maceration enhances site and extent of digestion of low-moisture, low-quality forages. four holstein steers (172 ± 8 kg) with cannulas in rumen and proximal duodenum were used in 4x4 latin square design to evaluate the process of mechanical maceration of sudangrass hay on the characteristics of ruminal and total tract digestion. treatments consisted of a steam-flaked corn-based growing diet supplemented with 21 % forage (dm basis) as: i) wheat straw (triticum aestivum, strw), ii) sudangrass hay (sorghum sudanense, sg), iii) macerated sg at intensity of 4,134 kpa (mac600) and 4) macerated sg at intensity of 6,200 kpa (mac900). all forages were ground to pass through a 3.8 cm screen before incorporation into complete mixed diets (21:79 forage to concentrate ratio). maceration did not affect (p ≥ 0.17) on site and extent of om, n and adf, and de of sudangrass supplemented diets. characteristics of ruminal digestion of om, adf, starch, as well as, microbial efficiency (microbial n, g kg-1 of om fermentad) and protein efficiency (nonammonia n, g g-1 of n intake) were not different (p ≥ 0.11) for wheat straw versus sudangrass supplemented diets. however, total tract digestion of om, adf, n, and de diet were greater (p ≤ 0.05) for sudangrass than for wheat straw supplemented diets. using the replacement technique, de value of sg averaged 9.59 mj kg-1, very close to the expected value given its chemical composition. mechanical maceration did not enhance the feeding value of sudangrass hay. increase the intensity of maceration from 4,134 to 6,200 kpa did not altered ruminal or total tract digestion of om, ndf or energy value of processed hay
Head-to-Head Comparison of Three Vaccination Strategies Based on DNA and Raw Insect-Derived Recombinant Proteins against Leishmania
Felicitat Todolí, Alhelí Rodríguez-Cortés, María del Carmen Nú?ez, Márcia D. Laurenti, Silvia Gómez-Sebastián, Fernando Rodríguez, Eva Pérez-Martín, José M. Escribano, Jordi Alberola
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0051181
Abstract: Parasitic diseases plague billions of people among the poorest, killing millions annually, and causing additional millions of disability-adjusted life years lost. Leishmaniases affect more than 12 million people, with over 350 million people at risk. There is an urgent need for efficacious and cheap vaccines and treatments against visceral leishmaniasis (VL), its most severe form. Several vaccination strategies have been proposed but to date no head-to-head comparison was undertaken to assess which is the best in a clinical model of the disease. We simultaneously assayed three vaccination strategies against VL in the hamster model, using KMPII, TRYP, LACK, and PAPLE22 vaccine candidate antigens. Four groups of hamsters were immunized using the following approaches: 1) raw extracts of baculovirus-infected Trichoplusia ni larvae expressing individually one of the four recombinant proteins (PROT); 2) naked pVAX1 plasmids carrying the four genes individually (DNA); 3) a heterologous prime-boost (HPB) strategy involving DNA followed by PROT (DNA-PROT); and 4) a Control including empty pVAX1 plasmid followed by raw extract of wild-type baculovirus-infected T. ni larvae. Hamsters were challenged with L. infantum promastigotes and maintained for 20 weeks. While PROT vaccine was not protective, DNA vaccination achieved protection in spleen. Only DNA-PROT vaccination induced significant NO production by macrophages, accompanied by a significant parasitological protection in spleen and blood. Thus, the DNA-PROT strategy elicits strong immune responses and high parasitological protection in the clinical model of VL, better than its corresponding naked DNA or protein versions. Furthermore, we show that naked DNA coupled with raw recombinant proteins produced in insect larvae biofactories –the cheapest way of producing DNA-PROT vaccines– is a practical and cost-effective way for potential “off the shelf” supplying vaccines at very low prices for the protection against leishmaniases, and possibly against other parasitic diseases affecting the poorest of the poor.
Detección de hepatitis B oculta en donantes de bancos sangre, Colombia 2008-2009
Beltrán,Mauricio; Berrío-Pérez,Maritza; Bermúdez,María Isabel; Rey-Benito,Gloria; Camacho,Bernardo; Forero,Patricia; Molina,Gloria Cristina; Fals,Orlando; Pisciotti,Isabel; Oliveros,Yulieth; Cortés,Armando; De La Hoz,Fernando;
Biomédica , 2011,
Abstract: introduction. in colombian blood banks, screening for the surface antigen of hepatitis b is mandatory in all units collected. testing of antibody against core antigens is not administered, although this method may be useful to detect donors infected with the hepatitis b virus. objective. the prevalence of occult hepatitis b was determined by applying a full-serological profile of hepatitis b virus to blood samples of blood donors. materials and methods. between april 2008 and october 2009, a prospective cross sectional study was conducted using 628 samples from donors to blood banks located in four colombian cities. prevalence for hepatitis b had been previously recorded for these cities. serological screening was performed for the complete virus; then nucleic acid amplification was tested in sera that were anti-hb creactive and with a titer of anti-hbs a?¤30 mui/ml. results. of the 628 samples tested, 129 met the serological criteria established to be tested nucleic acid amplification. none of them demonstrated evidence of nucleic acid amplification of hepatitis b virus. conclusions. this is the first study in colombia to detect the presence of blood donors that may be occult hepatitis b carriers. none was detected.
Incidencia, factores de riesgo y tratamiento de las complicaciones biliares del trasplante hepático
GABRIELLI N,MAURICIO; NORERO M,ENRIQUE; FIGUEROA R,EDUARDO; CORTéS G,PABLO; PIMENTEL M,FERNANDO; HUETE G,áLVARO; MENESES Q,LUIS; LOYOLA Z,SOLEDAD; ARRESE J,MARCO; SOZA R,ALEJANDRO; PéREZ A,ROSA MARíA; DOMíNGUEZ B,PILAR; GUERRA C,JUAN FRANCISCO; JARUFE C,NICOLáS; MARTíNEZ C,JORGE;
Revista chilena de cirugía , 2010, DOI: 10.4067/S0718-40262010000400006
Abstract: biliary tract complications (bc) are cause of mortality after liver transplantation (lt). there are different treatment alternatives for this complication. aim: to determínate incidence, risk factors and treatment of biliary complications after lt. materials and methods: a retrospective descriptive cohort of patients undergoing lt between march 1994 and march 2009. risk factors and incidence for bc were ex-plored. also the bc impact on overall survival on lt patients was assessed. we used spss 15.0 for statistical analysis and considered a significant p value less than 0.05. results: 107 lt were performed in 102 patients. in 30 (28%) there was some biliary complication. ten (33.3%) were early complications (< 3 months) and 20 (66.7%) were late (≥ 3 month). anastomotic stricture was the more frequent bc. the gender male recipient, the cold ischemic time and biliary reconstruction technique without tutor were associated with an increased risk for bc. endoscopic treatment of biliary stricture was successful in 91% of cases at one year follow up. three (10%) patients died due to bc or their long-term treatment. conclusions: biliary complications after liver transplantation are frequent and are cause of mortality. decrease cold ischemic time and improve te-chniques for biliary reconstruction could reduce the high incidence of this complication.
Diagnóstico ecográfico prenatal de la pentalogía de Cantrell
Cortés Y,Hernán; Vélez V,José Fernando;
Revista Colombiana de Obstetricia y Ginecología , 2003,
Abstract: in 1958, cantrell described a syndromic complex characterized by five defects, these included: ectopia cordis, omphalocele, disruption of the distal sternum, anterior diaphragm, and diaphragmatic pericardium. we present a case of pentalogy of cantrell with a late sonographic diagnosis with echocardiography after birth and post-mortem examination. we do a short review of literature.
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