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Search Results: 1 - 10 of 215361 matches for " Boada E. Luis Francisco "
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Procedimiento para el dise o de un sistema de calentamiento solar-mixto de aire que utiliza agua como fluido de trabajo
Boada E. Luis Francisco,Rodríguez A. Carlos Alfonso,Salazar L. Luz Marina
Ingeniería e Investigación , 1983,
Abstract: En este artículo se describe un sistema solar-mixto de calefacción de aire que incorpora colectores planos calentadores del agua, un tanque acumulador de calor y un dispositivo para el intercambio de calor agua-aire. Se presentan los ensayos que determinaron la disposición óptima del equipo para el intercambio de calor con flujo de agua por termosifón y el comportamiento térmico para diferentes flujos de aire, así como los ensayos para conocer el comportamiento del sistema de calentamiento solar de agua. Finalmente, el dise o se efectúa mediante un programa de computador adaptado para tal fin.
Evaluación de hidrogeles para aplicaciones agroforestales
Barón Cortés,Andrés; Barrera Ramírez,Ingrid Xiomara; Boada Eslava,Luis Francisco; Rodríguez Ni?o,Gerardo;
Ingeniería e Investigación , 2007,
Abstract: hydrogels synthesised by inverse suspension polymerisation (isp) technique consisting of acrylamide and potassium acrylate interlinked with n, n? methylene-bis-acrylamide and presenting different behaviour in terms of rooting ability and speed, elastic module and release properties were studied. markedly clayey soil properties were modified by drawing up moisture-retention curves using ceramic plate pressure waves and developing montages for evaluating modifications made to their retention, regarding prolonged and instantaneous irrigation-water dosage conditions. acacia and radish crops were grown in nursery phase in soil conditioned with different hydrogels. delayed specie withering was simultaneously evaluated in the first crop and difference in growth in the second one. follow-up of in situ soil moisture content was also evaluated over a fixed period of time. a method was achieved for measuring elastic module and release properties and model was established for predicting hydrogel behaviour in soil having known basic properties in free state. the results revealed the usefulness of hydrogels in such applications: greater facility in usable water release and retention by soil, notable delay in withering in hostile conditions and greater growth of species. guidelines were also established for defining the characteristics of hydrogel more adequately, depending on the desired application and a projection was made concerning reducing water consumption for maintaining a particular crop.
Evaluación de hidrogeles para aplicaciones agroforestales Evaluating hydrogels for agriforestry applications
Barón Cortés Andrés,Barrera Ramírez Ingrid Xiomara,Boada Eslava Luis Francisco,Rodríguez Ni?o Gerardo
Ingeniería e Investigación , 2007,
Abstract: Con hidrogeles sintetizados por medio de la técnica de polimerización en suspensión inversa (PSI), compuestos por acrilamida y acrilato de potasio entrecruzados con N, N’ metilen-bis-acrilamida y que presentan diferentes comportamientos desde el punto de vista de capacidad y velocidad de hinchamiento, módulo elástico y propie-dades de liberación, se estudia la modificación de las propiedades hidráulicas de un suelo tipo franco arcilloso realizando curvas de retención de humedad, empleando ollas de presión de plato cerámico, y se desarrollan montajes para evaluar la modificación en la retención de los mismos, ante condiciones de dosificación prolongada e instantánea de agua de irrigación. Adicionalmente, se realizan cultivos de acacia y rábano en fase vivero en suelos acondicionados con diferentes hidrogeles, en el primer cultivo se evalúa el retraso en la marchitez de la especie y en el segundo la diferencia en crecimiento; simultáneamente para los cultivos, se hace el seguimiento del contenido de humedad in situ del suelo con respecto al tiempo. Se logra un método para la medición del módulo elástico y las propiedades de liberación y se establece un modelo para predecir el comportamiento de los hidrogeles en el suelo con el conocimiento de sus propiedades básicas en el estado libre. Finalmente, los resultados muestran la bondad del uso de hidrogeles en estas aplicaciones: hay mayor facilidad de liberación y retención de agua aprovechable por el suelo, retraso notable del marchitamiento en condiciones hostiles, y es mayor el crecimiento de las especies, entre otros beneficios, además se establecen pautas para definir las características del hidrogel más adecuado dependiendo de la aplicación deseada y se realiza una proyección hacia la disminución del consumo de agua para el mantenimiento de un cultivo. Hydrogels synthesised by inverse suspension polymerisation (ISP) technique consisting of acrylamide and potassium acrylate interlinked with N, N’ methylene-bis-acrylamide and presenting different behaviour in terms of rooting ability and speed, elastic module and release properties were studied. Markedly clayey soil properties were mo-dified by drawing up moisture-retention curves using ceramic plate pressure waves and developing montages for evaluating modifications made to their retention, regarding prolonged and instantaneous irrigation-water dosage conditions. Acacia and radish crops were grown in nursery phase in soil conditioned with different hydrogels. Delayed specie withering was simultaneously evaluated in the first crop and difference in growth
PKR and PP1C Polymorphisms in Alzheimer’s Disease Risk  [PDF]
Ernest Palomer, Gerard ILL-Raga, Marta Tajes, Eva Ramos-Fernández, Mònica Bosch-Morató, Biuse Guivernau, José J. Galán, Jordi Clarimón, Carmen Antúnez, Mercé Boada, Luis M. Real, César Fandos, Francisco J. Mu?oz
Neuroscience & Medicine (NM) , 2011, DOI: 10.4236/nm.2011.23031
Abstract: Alzheimer’s disease (AD) is a neurodegenerative disease characterized by senile plaques and neurofibrillary tangles. Senile plaques are deposits of amyloid ß-peptide (Aß) produced by the cleavage of a transmembrane protein termed Amyloid Precursor Protein (APP). The amyloidogenic cleavage of APP is performed by γ-secretase complex and ß-site APP cleaving enzyme 1 (BACE1), a key enzyme in AD that can be activated by different noxious stimuli. Interestingly, some viruses could activate double-stranded RNA-activated protein kinase (PKR), which phosphorylates Eukaryotic Initiation Factor 2 alpha (eIF2α). This phosphorylation stops global translation to avoid any synthesis of viral infective proteins, but paradoxically up-regulates BACE1 translation. One of the viral mechanisms to circumvent eIF2α phosphorylation is the recruitment of protein phosphatase 1 (PP1), to fully dephosphorylate eIF2α and allow viral protein synthesis. Due to the functional relationship between BACE1, PKR, PP1 and AD we have performed a large (1122 cases and 1191 control individuals) case-control genetic analysis using two biallelic polymorphisms rs2254958 and rs7480390, located within the genes coding for PKR and the catalytic unit A of PP1, respectively. Although a trend to association of the rs2254958 TT genotype with AD risk was found, our results show that neither rs7480390 nor rs2254958 are associated with AD susceptibility.
Herpes Virus Bovino tipo 1 (BoHV-1) como posible causa de encefalitis en bovinos de la región del Magdalena Medio Colombiano: Estudio serológico y análisis epidemiológico
Piedrahita,Luis E; Montoya,Luis M; Pedraza,Francisco J;
Revista Colombiana de Ciencias Pecuarias , 2010,
Abstract: the bovine herpesvirus type 1 and type 5 (bohv-1 and bohv-5), causing diseases and significant economic losses in farms of worldwide. both affect the nervous system of cattle, although bohv-5 has been the most associated with this type of pathogenesis. given the death of animals with nervous symptoms and negative diagnoses for rabies virus in the area of study, this research focused on the detection of positive reactors to bovine herpes virus serum neutralization. we collected 518 blood samples from animals without herpesvirus vaccine, in the municipalities of caparrapi, cimitarra, honda and victoria, in the middle magdalena river region. in addition, epidemiological information useful to discuss neurological disease was collected through primary and secondary sources. for the analysis of data was used chi-square test by identification of relationship between evidence of viral infection and the variables recorded. the results revealed that 286 cases were positive for herpesvirus infection, corresponding to a prevalence of 55.5%, however, there was no statistical relationship (p < 0.05) between the presence of antibodies and the variables analyzed. in conclusion, some cases of neurological disease in cattle in this region could be due to infection with herpes viruses. we discussed about the presence of bohv-1 and bohv-5 in the ambient, diagnosis and monitoring plans, as well as economic losses, which may cause in herds in this area.
Herpes Virus Bovino tipo 1 (BoHV-1) como posible causa de encefalitis en bovinos de la región del Magdalena Medio Colombiano: Estudio serológico y análisis epidemiológico Herpes Vírus Bovino tipo 1 (BoHV-1) como uma possível causa de encefalite em bovinos da regi o do Magdalena Medio Colombiano: Estudo sorológico e análise epidemiológico Bovine Herpes Virus type 1 (BoHV-1) as a possible cause of e
Luis E Piedrahita,Luis M Montoya,Francisco J Pedraza
Revista Colombiana de Ciencias Pecuarias , 2010,
Abstract: Los herpesvirus bovino tipo 1 y 5 (BoHV-1 y BoHV-5), causan enfermedades que producen importantes pérdidas económicas en ganaderías de todo el mundo. Ambos afectan el sistema nervioso de los bovinos, aunque ha sido el BoHV-5 más asociado a este tipo de patogénesis. Teniendo en cuenta la muerte de animales con sintomas nerviosos y negativos a rabia en la zona de estudio, el objetivo de esta investigación se centró en la detección de reactores positivos por seroneutralización al herpesvirus bovino, recolectando 518 muestras de sangre en bovinos sin vacuna contra este agente, en los municipios de Caparrapi (Cundinamarca), Cimitarra (Santander), Honda (Tolima) y Victoria (Caldas). Además, información epidemiológica útil para discutir sobre enfermedad neurológica fue recolectada mediante fuentes de información primarias y secundarias. Para el análisis de los datos se utilizó la prueba chi-cuadrado identificando la relación entre la evidencia de infección viral y las variables registradas. Los resultados revelaron que 286 casos fueron positivos a infección con herpesvirus, correspondiendo a una prevalencia de 55.5%, sin embargo, no hubo relación estadística (p<0.05) entre la presencia de anticuerpos y las variables que se analizaron. En conclusión, algunos de los casos de enfermedad neurológica en bovinos del área pudieron deberse a la infección con los herpesvirus y se discute sobre la presencia de ellos en el medio, los planes de diagnóstico y control, así como las pérdidas económicas que puedan causar en ganaderías de la zona. Os herpesvirus bovino tipo 1 e 5 (BoHV-1 e BoHV-5), causam doen as que produzem importantes perdidas econ micas no gado de todo o mundo. Juntos afetam o sistema nervoso dos bovinos, embora tem sido o BoHV-5 mais associado a este tipo de patogênese. Tinindo em conta a morte de animais com sintomas nervosos e negativos à doen a da raiva na zona do estudo, objetivo-se esta pesquisa na detec o de reatores positivos pela soro neutraliza o ao herpesvirus bovino, coletando 518 amostras de sangue em bovinos sem vacina contra este agente, nos municípios de Caparrapi, Cimitarra, Honda e Victoria, zona conhecida como Magdalena Médio Colombiano. Alem disso, informa o epidemiológica útil para discutir sobre a doen a neurológica foi coletada mediante fontes de informa o primarias e secundarias. Para o análise dos dados utilizou-se o teste Ji quadrado, identificando a rela o entre a evidencia de infec o viral e as variáveis registradas. Os resultados revelaram que 286 casos foram positivos à infec o com herpesvirus, correspondendo a uma preva
Complex organochlorine pesticide mixtures as determinant factor for breast cancer risk: a population-based case–control study in the Canary Islands (Spain)
Luis D Boada, Manuel Zumbado, Luis Henríquez-Hernández, Maira Almeida-González, Eva E álvarez-León, Lluis Serra-Majem, Octavio P Luzardo
Environmental Health , 2012, DOI: 10.1186/1476-069x-11-28
Abstract: This population-based study was designed to evaluate the profile of mixtures of organochlorines detected in 103 healthy women and 121 women diagnosed with breast cancer from Gran Canaria Island, and the relation between the exposure to these compounds and breast cancer risk.The most prevalent mixture of organochlorines among healthy women was the combination of lindane and endrin, and this mixture was not detected in any affected women. Breast cancer patients presented more frequently a combination of aldrin, dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), and this mixture was not found in any healthy woman. After adjusting for covariables, the risk of breast cancer was moderately associated with DDD (OR?=?1.008, confidence interval 95% 1.001-1.015, p?=?0.024).This study indicates that healthy women show a very different profile of organochlorine pesticide mixtures than breast cancer patients, suggesting that organochlorine pesticide mixtures could play a relevant role in breast cancer risk.Breast cancer (BC) is the most common cancer diagnosed in women worldwide [1]. In Spain, BC is currently the most significant cause of death from malignancies in women [2]. Whereas BC mortality and incidence are lower in mainland Spain than in other European countries, there are alarming rates of mortality because of this type of cancer in the archipelago of the Canary Islands, specifically in Gran Canaria Island (Figure?1) [3,4].The etiology of BC is complex, with genetic, epigenetic and environmental factors contributing to the development of the disease. BC risk is significantly influenced by genetics, but over 70% of the women that are diagnosed have sporadic cancer or tumours not associated with inheritance of any major identified high risk genes. It is thought that the risk of BC can be modified by lifestyle and environment. Besides the genetic influence, the most established factors contributing to BC are related to cumulative exposure of t
El diálogo como encuentro: Aproximaciones a la relación profesional de la salud-paciente
Bohórquez G.,Francisco; Jaramillo E.,Luis Guillermo;
Index de Enfermería , 2005, DOI: 10.4321/S1132-12962005000200008
Abstract: health care is the central role of health?s professionals. in the health?s professional - patient relationships health care has left deteriorating in the measure that communication is restricted a more and more technical, distant and colds encounters that avoid the dialogue and they privilege the "information." this outlines a challenge to the health?s professional and to the health?s sciences schools. today, more than ever, in a world that succumbs in the conflict and the intolerance, is necessary recognizing the human illness, beyond the mere biological fact, as social and cultural fact. in this way is necessary to value the dialogue, like the best form of interpersonal communicating, that it allows the encounter, at once to give sense to our existence and to become human of making sick again and of healing.
El diálogo como encuentro: Aproximaciones a la relación profesional de la salud-paciente The dialogue like encounter: approaches to health`s professional-patient relationship
Francisco Bohórquez G.,Luis Guillermo Jaramillo E.
Index de Enfermería , 2005,
Abstract: El acto profesional de cuidar la salud se ha ido deteriorando en la medida que la comunicación con el paciente se restringe a encuentros cada vez más técnicos, distantes y fríos que esquivan el diálogo y privilegian la "información". Esto plantea un reto al personal de salud, particularmente, a las escuelas y facultades de ciencias de la salud. Hoy más que nunca, en un mundo que sucumbe en el conflicto y la intolerancia, resurge la necesidad de reconocer la enfermedad, más allá del mero hecho biológico, como hecho social y cultural; de volver a valorar el diálogo como estrategia que permite el encuentro, dando sentido a nuestra existencia y haciéndonos humanos en el acto de enfermar y de sanar. Health care is the central role of health’s professionals. In the health’s professional - patient relationships health care has left deteriorating in the measure that communication is restricted a more and more technical, distant and colds encounters that avoid the dialogue and they privilege the "information." This outlines a challenge to the health’s professional and to the health’s sciences schools. Today, more than ever, in a world that succumbs in the conflict and the intolerance, is necessary recognizing the human illness, beyond the mere biological fact, as social and cultural fact. In this way is necessary to value the dialogue, like the best form of interpersonal communicating, that it allows the encounter, at once to give sense to our existence and to become human of making sick again and of healing.
Activation of PKR Causes Amyloid ?-Peptide Accumulation via De-Repression of BACE1 Expression
Gerard ILL-Raga, Ernest Palomer, Matthew A. Wozniak, Eva Ramos-Fernández, Mònica Bosch-Morató, Marta Tajes, Francesc X. Guix, José J. Galán, Jordi Clarimón, Carmen Antúnez, Luis M. Real, Mercé Boada, Ruth F. Itzhaki, César Fandos, Francisco J. Mu?oz
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021456
Abstract: BACE1 is a key enzyme involved in the production of amyloid ?-peptide (A?) in Alzheimer's disease (AD) brains. Normally, its expression is constitutively inhibited due to the presence of the 5′untranslated region (5′UTR) in the BACE1 promoter. BACE1 expression is activated by phosphorylation of the eukaryotic initiation factor (eIF)2-alpha, which reverses the inhibitory effect exerted by BACE1 5′UTR. There are four kinases associated with different types of stress that could phosphorylate eIF2-alpha. Here we focus on the double-stranded (ds) RNA-activated protein kinase (PKR). PKR is activated during viral infection, including that of herpes simplex virus type 1 (HSV1), a virus suggested to be implicated in the development of AD, acting when present in brains of carriers of the type 4 allele of the apolipoprotein E gene. HSV1 is a dsDNA virus but it has genes on both strands of the genome, and from these genes complementary RNA molecules are transcribed. These could activate BACE1 expression by the PKR pathway. Here we demonstrate in HSV1-infected neuroblastoma cells, and in peripheral nervous tissue from HSV1-infected mice, that HSV1 activates PKR. Cloning BACE1 5′UTR upstream of a luciferase (luc) gene confirmed its inhibitory effect, which can be prevented by salubrinal, an inhibitor of the eIF2-alpha phosphatase PP1c. Treatment with the dsRNA analog poly (I:C) mimicked the stimulatory effect exerted by salubrinal over BACE1 translation in the 5′UTR-luc construct and increased A? production in HEK-APPsw cells. Summarizing, our data suggest that PKR activated in brain by HSV1 could play an important role in the development of AD.
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