oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 4 )

2018 ( 9 )

2017 ( 9 )

2016 ( 17 )

Custom range...

Search Results: 1 - 10 of 6040 matches for " Contreras Escudero Lorena "
All listed articles are free for downloading (OA Articles)
Page 1 /6040
Display every page Item
Dise?o y puesta en marcha de un sistema de vigilancia epidemiológica en salud mental
Goldenberg,Judith Scharager; Contreras Escudero,Lorena;
Revista Panamericana de Salud Pública , 2002, DOI: 10.1590/S1020-49892002000200004
Abstract: objective. to design and test a surveillance system to detect and rank the most significant mental health problems in a community and to establish their association with the living conditions in that community. methods. the system was designed and tested at a primary health care center in the community of la florida, which is in the metropolitan region of santiago, the capital of chile. the health problems that were under surveillance, with monthly monitoring, were: addiction (to alcohol, tobacco, and benzodiazepines or other drugs), violence (domestic violence and sexual abuse, real or suspected), and disorders in children (attention deficit and behavioral disorders). by means of a computerized geographical information system (gis), those surveillance data were combined with other data. these other data included sociodemographic information on the persons who went to the health center for care as well as data on local risk factors and protective factors for health problems, some of which are indicators of the local residents' living conditions. results. the proposed epidemiological surveillance system, which takes into account local living conditions and environmental variables, is a good tool for health action. the proposed system also complements the incomplete perspective of monitoring systems, which do not include variables describing the local context and that focus only on health problems. the information synthesized in the gis maps makes it possible to simultaneously display different layers of information on factors related to the health problems studied, linked to a specific area and all its environmental variables, in an easy-to-read, self-explanatory format. conclusions. these results and the concurring opinions of the participating physicians show that the experimental system effectively met the basic requirements of an epidemiological surveillance system of this kind.
Dise o y puesta en marcha de un sistema de vigilancia epidemiológica en salud mental
Goldenberg Judith Scharager,Contreras Escudero Lorena
Revista Panamericana de Salud Pública , 2002,
Abstract: Objetivos. Dise ar y poner a prueba un sistema de vigilancia que permita detectar y jerarquizar los problemas más relevantes de salud mental y establecer su asociación con las condiciones de vida de la comunidad estudiada. Métodos. El sistema se dise ó y puso a prueba en un centro de salud de la comuna La Florida, región metropolitana de Chile. Los problemas de salud que se sometieron a vigilancia con seguimiento mensual fueron: adicción (al alcohol, tabaco, drogas y benzodiazepinas), violencia (violencia o sospecha de violencia intrafamiliar y abuso sexual) y trastornos en ni os (déficit de atención y trastornos de conducta). Mediante un sistema computacional de información geográfica se combinaron estos elementos con datos sociodemográficos de las personas que acudieron a consulta y con datos territoriales que pueden considerarse factores protectores o de riesgo de los problemas de salud, y algunos de los cuales constituyen indicadores de las condiciones de vida de las personas. Resultados. Se probó que el sistema de vigilancia epidemiológica propuesto --que incorpora las condiciones de vida y las variables ambientales-- es una buena herramienta para la acción en salud y complementa la visión parcial de los sistemas de seguimiento, que no incluyen variables de contexto y se centran sólo en los problemas de salud. La información sintetizada en mapas permite visualizar simultáneamente diferentes capas de información sobre los factores relacionados con los problemas de salud estudiados, asociados a un territorio específico, con todas las variables ambientales que implican, en un formato de lectura ágil y evidente por sí mismo. Conclusiones. Estos resultados y la opinión convergente de los médicos participantes y usuarios permiten afirmar que el sistema de vigilancia epidemiológica puesto a prueba en fase experimental logró cumplir los requerimientos básicos de un método de esta naturaleza.
Factores asociados a consumo de tabaco durante el último a o en estudiantes de educación superior Fatores associados a consumo do cigarro durante o último ano em estudantes de educa o superior Smoking associated factors in students during their last year of higher education
María Soledad Zuzulich Pavez,Báltica Cabieses Valdés,Nuria Pedrals Gibbons,Lorena Contreras Escudero
Investigación y Educación en Enfermería , 2010,
Abstract: Objetivo. Determinar los factores de riesgo asociados al consumo de tabaco en el último a o en una población universitaria chilena. Metodología. Estudio observacional analítico, de corte transversal. Se realizó muestreo aleatorio estratificado según unidad académica y a o de carrera, siendo el tama o muestral de 2 045 estudiantes de cuatro Campus de la Universidad Católica de Chile. La toma de la información se hizo con ayuda de un cuestionario autoaplicado. Se realizaron análisis descriptivo, bivariado y de regresión logística. Resultados. El promedio de edad fue 20.4±1,6 a os, el 46.6% eran de sexo masculino y el 70.3% tenían nivel socioeconómico alto. Un 91.0% había iniciado el consumo después de los 18 a os. La prevalencia mensual de consumo de tabaco fue de 40.5%, un 20.0% de los encuestados estaría a riesgo de tener diagnóstico de tabaquismo. Se encontró asociación positiva entre consumo de tabaco durante último a o y: la edad (p < 0.05), el sexo femenino (p < 0.001), el nivel socioeconómico (p < 0.05) y la percepción de consumo de droga por parte de padres (p < 0.001). Se encontró asociación negativa entre consumo de tabaco y la religiosidad (p < 0.001). Conclusión. En el grupo universitario en el que se realizó el estudio se encontró que el problema de tabaquismo merece especial atención por su magnitud, estando asociado a factores de riesgo como la edad, el sexo femenino, el estrato socioeconómico y una baja religiosidad. Objetivo. Determinar os fatores de risco associados ao consumo do cigarro no último ano numa popula o universitária chilena. Metodologia. Estudo observacional analítico, de corte transversal. Realizouse amostragem aleatória estratificado segundo unidade acadêmica e ano de carreira, sendo o tamanho da mostra de 2 045 estudantes de quatro Campus da Universidade Católica de Chile. A tomada da informa o se fez com ajuda de um questionário auto-aplicado. Realizaramse análise descritiva, bivariado e de regress o logística. Resultados. A média de idade foi 20.4±1,6 anos, o 46.6% eram de sexo masculino e o 70.3% tinham nível socioecon mico alto. Um 91% tinha iniciado o consumo depois dos 18 anos. A prevalência mensal de consumo do cigarro foi de 40.5%, um 20% dos interrogados estaria a risco de ter diagnóstico de tabagismo. Encontrou-se associa o positiva entre consumo de fumo durante último ano e: a idade (p< 0.05), o sexo feminino (p< 0.001), o nível socioecon mico (p< 0.05) e a percep o de consumo de droga por parte de pais (p< 0.001). Encontrou-se associa o negativa entre consumo de fumo e a religiosidade (p< 0.001). Conclus o
Factores asociados a consumo de tabaco durante el último a?o en estudiantes de educación superior
Zuzulich Pavez,María Soledad; Cabieses Valdés,Báltica; Pedrals Gibbons,Nuria; Contreras Escudero,Lorena; Martínez Aldunate,Daniel; Mu?oz Serrano,Mónica; Espinoza Sepúlveda,Manuel;
Investigación y Educación en Enfermería , 2010,
Abstract: objective. to determine the risk factors associated to smoking in the last year of school in a chilean university population. methodology. analytical, observational, transversal cut study. stratified randomized sampling was conducted according to academic unit and year of career; the size of the sample was of 2045 students from four campuses of the catholic university of chile. the information was collected with a self-applied questionnaire. a descriptive, bivariate and logistic regression analysis was made. results. the average age was 20.4±1.6, 46% were males and 70.3% had a high socioeconomic status. 91% had started cigarette consumption before the age of 18. the smoking monthly prevalence was of 40.5%, 20% of the surveyed would be at risk of having diagnosis of smoking. a positive association was found between smoking during the last year of university and: age (p< 0.05), female sex (p< 0.001), socioeconomic status (p< 0.05) and parents drug consumption perception (p< 0.001). a negative association was found between smoking and religiosity (p< 0.001). conclusion. in the studied university group it was found that the smoking problem requires special attention due to its magnitude and association to risk factors as age, female gender, socioeconomic status and a low religiosity.
CONFORMATIONAL PREFERENCE OF 4-ETHYL- 6-METHYL-1,3-DITHIANES
CONTRERAS,J. GUILLERMO; GERLI,LORENA A.;
Journal of the Chilean Chemical Society , 2007, DOI: 10.4067/S0717-97072007000300018
Abstract: interconversion reaction of i ? ii conformers of 4-ethyl-6-methyl-1,3-dithiane (metdit) has been studied by means of ab initio methods on the frame of mo theory. optimized geometries at hf/6-31g** level correlate well with that found for the parent 1,3-dithianefrom an x-ray diffraction study. both conformers possess similar bond distances, but differ in up 12° in some dihedrals. conformer i geometry presents the larger distortion from the regular 1,3-dithiane mainly due to difference between angles κ1 and κ2 (ca. 14°). in conformer ii this difference is just ca. 3°. the energetics and thermodynamics were obtained with basis sets that include diffuse, polarization functions and electronic correlations at the second-order perturbation meller plesset theory. gas phase thermodynamic predicts ii to be in a 98% concentration. low and medium high polarity solvents seem to exert no influence on the conformers concentrations. thus the i ? ii interconversion reaction is largely displaced to ii formation, both in the gas phase and solution. the calculated 1h-nmr data, i.e., chemical shifts and one-bond c-h spin-spin coupling constants are predicted on the basis of the consistent results obtained for the parent 1,3-dithiane. for both conformers reverse perlin effect takes place at c2 and c5. the c2 - hax and c2 - heq bond distances are similar ( ca. 1.092 ?), whereas the c5- heq are larger than the axial ones yielding smaller 1jc-h coupling constants
CONFORMATIONAL PREFERENCE IN 4,6-DIMETHYL-l,3-THIOXANE
CONTRERAS,J. GUILLERMO; GERLI,LORENA A.;
Journal of the Chilean Chemical Society , 2008, DOI: 10.4067/S0717-97072008000100014
Abstract: trans-4,6-dimethyl-l,3-thioxane shows two conformations as a result of the heterocyclic ring inversion. the i and ii conformers interconversion process has been studied by means of ab initio methods. the thermodynamics of this reaction calculated at the mp2/6-311+g**// hf/6-31g" and b3lyp/6-311+g"// b3lyp/6-31g" levels yield ag° values of ca. -1.5 kcal/mol in the gas phase, implying that ii is the most important species in the gas phase and that its relative concentration is ca. 93%. in solution of low and medium polarity solvents, pcm method predicts an 85% concentration for this species, consistent with an 83% estimated from 'h-nmr spectra. the experimental nmr properties ( 8 and 'jc_h ) have not been reported since i and ii separation could not be achieved. the results obtained for two long range "j2ax6e and 6j2e je coupling constants of ca. 0.5 hz are in good agreement with 0.41 hz, calculated in the present work. the calculated chemical shifts for the c2 and c5 protons show that 8heq < 8hax implying that some anomalous effects are operating, though the 8 seems to be moderately insensitive c-h bond distances changes. the spin-spin coupling constants are much more sensitive to changes occurring in the ring. thus, normal and reverse perlin effects for 'j are predicted for c2 -h and c5-h are operating, respectively. the cc5 - heq -> (7*c - s interaction would be the responsible for the very small elongation of the c5 - heq over the c5 - hax bond distances
CONFORMATIONAL PREFERENCE IN 4,6-DIMETHYL-l,3-THIOXANE
J. GUILLERMO CONTRERAS,LORENA A. GERLI
Journal of the Chilean Chemical Society , 2008,
Abstract: Trans-4,6-dimethyl-l,3-thioxane shows two conformations as a result of the heterocyclic ring inversion. The I and II conformers interconversion process has been studied by means of ab initio methods. The thermodynamics of this reaction calculated at the MP2/6-311+G**// HF/6-31G" and B3LYP/6-311+G"// B3LYP/6-31G" levels yield AG° values of ca. -1.5 kcal/mol in the gas phase, implying that II is the most important species in the gas phase and that its relative concentration is ca. 93%. In solution of low and medium polarity solvents, PCM method predicts an 85% concentration for this species, consistent with an 83% estimated from 'H-NMR spectra. The experimental NMR properties ( 8 and 'J C_H ) have not been reported since I and II separation could not be achieved. The results obtained for two long range "J2ax6e and 6J2e Je coupling constants of ca. 0.5 Hz are in good agreement with 0.41 Hz, calculated in the present work. The calculated chemical shifts for the C2 and C5 protons show that 8Heq < 8Hax implying that some anomalous effects are operating, though the 8 seems to be moderately insensitive C-H bond distances changes. The spin-spin coupling constants are much more sensitive to changes occurring in the ring. Thus, normal and reverse Perlin effects for 'J are predicted for C2 -H and C5-H are operating, respectively. The cC5 - Heq -> (7*C - S interaction would be the responsible for the very small elongation of the C5 - Heq over the C5 - Hax bond distances
CONFORMATIONAL PREFERENCE OF 4-ETHYL- 6-METHYL-1,3-DITHIANES
J. GUILLERMO CONTRERAS,LORENA A. GERLI
Journal of the Chilean Chemical Society , 2007,
Abstract: Interconversion reaction of I II conformers of 4-ethyl-6-methyl-1,3-dithiane (METDIT) has been studied by means of ab initio methods on the frame of MO theory. Optimized geometries at HF/6-31G** level correlate well with that found for the parent 1,3-dithianefrom an x-ray diffraction study. Both conformers possess similar bond distances, but differ in up 12° in some dihedrals. Conformer I geometry presents the larger distortion from the regular 1,3-dithiane mainly due to difference between angles κ1 and κ2 (ca. 14°). In conformer II this difference is just ca. 3°. The energetics and thermodynamics were obtained with basis sets that include diffuse, polarization functions and electronic correlations at the second-order perturbation Meller Plesset theory. Gas phase thermodynamic predicts II to be in a 98% concentration. Low and medium high polarity solvents seem to exert no influence on the conformers concentrations. Thus the I II interconversion reaction is largely displaced to II formation, both in the gas phase and solution. The calculated 1H-NMR data, i.e., chemical shifts and one-bond C-H spin-spin coupling constants are predicted on the basis of the consistent results obtained for the parent 1,3-dithiane. For both conformers reverse Perlin effect takes place at C2 and C5. The C2 - Hax and C2 - Heq bond distances are similar ( ca. 1.092 ), whereas the C5- Heq are larger than the axial ones yielding smaller 1J C-H coupling constants
LiMnPO4: Review on Synthesis and Electrochemical Properties  [PDF]
Joel O. Herrera, Héctor Camacho-Montes, Luis E. Fuentes, Lorena álvarez-Contreras
Journal of Materials Science and Chemical Engineering (MSCE) , 2015, DOI: 10.4236/msce.2015.35007
Abstract: The olivine structured mixed lithium-transition metal phosphates LiMPO4 (M = Fe, Mn, Co) have attracted tremendous attention of many research teams worldwide as a promising cathode material for lithium batteries and for studying their magnetic and electrical properties. High energy density is required for mind- to large-scale batteries because the mounting spaces are quite small for vehicles and other energy storage applications. This constraint necessitates synthesis to yield high volumetric energy density and reliable battery performance. Development of eco-friendly, low cost and high energy density, LiMnPO4 cathode material became attractive due to its high operating voltage, which can be located inside of the electrochemical stability window of conventional electrolyte solutions and it offers more safety features due to the presence of a strong P-O covalent bond. This review is an overview of current research activities on LiMnPO4 cathodes and its carbon coating synthesized by various synthetic techniques.
Morbimortalidad del traumatismo de recto extraperitoneal
Barillaro, Guillermo;Gatica, Sandra;Escudero, Ezequiel;Jimenez, Lorena;Martini, Mariano;
ABCD. Arquivos Brasileiros de Cirurgia Digestiva (S?o Paulo) , 2008, DOI: 10.1590/S0102-67202008000100002
Abstract: background: extraperitoneal rectal injuries represent 3 to 5% of all traumatisms and abdominal injuries, and they are highlighted by their high morbidity/mortality presented if not early and appropriately diagnosed and treated. nowadays there is not a consensus related to an optimal surgical management. aim: to relate the experience in treating this disease, evaluating factors that influence mortality and morbidity. methods: it consisted in a descriptive retrospective study where it was reviewed handbooks of all extraperitoneal rectal trauma patients operated between january 1998 and december 2007. the abdominal trauma rate, the interval between trauma and surgery and the initial surgery's type were related to infectious complications and mortality. results: there were evaluated 13 patients: 5 injured by firearms, 5 autoimpalament and 3 by closed trauma. the abdominal trauma mean rate of infected and dead was more than 25. 61% of patients (n=8) underwent surgery before 8 hours. the infection rate was 61.5% and 90% of infected patients required additional surgeries. the series' mortality was 38.5% (5 patients). in patients operated after 8 hours there was perirectal infection in 80% of them, and 80% of mortality regardless of surgery performed type. conclusions: the delay over 8 hours in treating and the abdominal trauma rate over 25 were the main factors associated with perirectal infection and mortality in this series. absence of presacral drainage and distal rectal wash were correlated with increased incidence of perirectal infection.
Page 1 /6040
Display every page Item


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