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En este trabajo se presentan los resultados del depósito de ZnO:Al sobre vidrio, por pulverizado catódico de RF. Se varió la temperatura, presión y potencia de RF con la finalidad de obtener las características electro-ópticas adecuadas para ser usado como película antirreflectante en celdas solares de película delgada de silicio policristalino. Se obtuvieron películas con resistencias de lámina de 13 Ω/cm2, transmitancias mayores al 80% en el visible y un factor de textura (Haze) del 14%. Se realizó un tratamiento térmico a 580 °C por 24 hs, para valorar la estabilidad térmica de sus propiedades, encontrando que las mismas no se modifican significativamente. Posteriormente se depositó sobre la capa de ZnO:Al una de a-Si:H por PECVD y se cristalizó por NIC para obtener p-Si. Resultados de DRX, muestran la estructura de p-Si con orientación preferencial en el plano (220). Finalmente se obtuvieron los espectros de reflectancia total para tres configuraciones, las propiedades como película antirreflectante del ZnO:Al no cambian significativamente acoplando a-Si:H o p-Si In this work we present results on the deposition of ZnO:Al films to be used as antireflective coating in solar cells. The films were deposited by RF Sputtering onto a glass substrate. To optimize the electro-optical properties of the films the substrate temperature, the pressure and the RF power were varied. The transmission and the haze factor were measured for the visible range. Resistances of the order of 13 Ω/cm2 and transmission higher than 80 % were obtained. To study the thermal stability of the ZnO films they were annealed at 580 °C during 24 hrs, its properties remain stable. Then on the top of the ZnO films a thin layer of a-Si:H was deposited by PECVD and crystallized following the NIC method, XRD analysis showed a polycrystalline film oriented in the (220) plane. Finally, the total reflectance was measured in three configurations, the antireflective properties of ZnO were similar for a-Si:H and p-Si. Fil: Mora, F.. Universidad Autónoma de Puebla. Centro de Investigación en Dispositivos Semiconductores (ICUAP-CIDS). Puebla. México Fil: Buitrago, Román Horacio. Instituto de Desarrollo Tecnológico para la industria Química (INTEC)-CONICET. Santa Fe. Argentina Fil: Urteaga, R.. Instituto de Desarrollo Tecnológico para la industria Química (INTEC)-CONICET. Santa Fe. Argentina Fil: Juárez, H.. Universidad Autónoma de Puebla. Centro de Investigación en Dispositivos Semiconductores (ICUAP-CIDS). Puebla. México Fil: Díaz, Tomás. Universidad Autónoma de Puebla. Centro de Investigación en Dispositivos Semiconductores (ICUAP-CIDS). Puebla. México

Se diseñó y construyó un sistema simple para la detección de analitos externos (AE) a la atmósfera empleando microcavidades ópticas de silicio poroso nanoestructurado. El sistema se basa en la medición de variaciones de la trasmitancia en función del ángulo de incidencia de un haz monocromático a través de la microcavidad. Utilizando un formalismo matricial y teorías de medio efectivo se realizaron cálculos que permitieron determinar las condiciones óptimas del sistema tales como el tipo de microcavidad a fabricar y la disposición del sistema para obtener la mayor sensibilidad de detección. En este trabajo se realizaron pruebas con vapor de alcohol isopropílico como AE diluído en una corriente de N2. Con el sistema propuesto se lograron medir cambios en la concentración de AE de hasta 1 ppm que equivale a un cambio en el índice de refracción de 10−6. Por debajo de estas cantidades es necesario controlar la temperatura del sistema A simple system for the detection of external analytes (EA) to the atmosphere employing nanostructured porous silicon optical microcavities was design and built. The system is based on the measurement of the transmittance changes as a function of the incidence angle of a monochromatic laser beam. Using a matrix formalism and effective medium theories we calculate the optimal conditions for the system so as to obtain the best sensitivity of the sensor. In this work we test the system with isopropyl alcohol vapor diluted in a N2 stream. With the system proposed we were able to detect changes in the concentration of the EA as small as 1 ppm, which is equivalent to a change in the refractive index of 10−6. Below this value, variations in temperature become significant and must be taken into account to obtain reliable measurements Fil: Acquaroli, Leandro Nicolás. Universidad Nacional del Litoral - CONICET. Instituto de Desarrollo Tecnológico para la Industria Química (INTEC). Santa Fe. Argentina Fil: Urteaga, R.. Universidad Nacional del Litoral - CONICET. Instituto de Desarrollo Tecnológico para la Industria Química (INTEC). Santa Fe. Argentina Fil: Koropecki, R. R.. Universidad Nacional del Litoral - CONICET. Instituto de Desarrollo Tecnológico para la Industria Química (INTEC). Santa Fe. Argentina

Zinc intake is well below recommendation among Chilean free living elderly adults of low socioeconomic level.To assess the effect of the consumption of a food supplement on plasma zinc concentrations in elderly adults (EA).Ambulatory EA (or = 70) with controlled type 2 diabetes mellitus or high blood pressure, ascribed to public family health centers were studied. They were separated in a control and intervention group, without blinding techniques. The intervention group consumed daily 50 g of a special nutritional supplement prepared as a soup or porridge, provided by the Government, for 3 months. The control group did not receive the supplement. A good compliance with the supplement was defined as a consumption of 7 portions per week. A fasting venous blood sample was obtained to determine plasma zinc at the beginning and end of the study.Forty three supplemented EA aged 76+/-5 years (21 women) and 31 non supplemented EA aged 78+/-5 years (20 women), completed 3 months of follow up. Mean compliance with the supplement was 40.5% (95% confidence intervals (CI) 40.3-40.6%). General characteristics of the study subjects upon recruitment were similar, except for the literacy that was higher in the intervention group. We fitted a multiple linear regression model which explained 39% of the variance, where the consumption of the nutritional supplement increased the concentration of plasmatic zinc by 4.14 microg/dL (95% CI 0.25-8.02) (p0.037), after controlling for sex, age, energy, vitamin E and calcium consumption.The consumption of a food supplement significantly increased plasma zinc concentrations in Chilean elderly adults.

Background: Zinc intake is well below recommendation among Chilean free living elderly adults of low socioeconomic level Aim: To assess the effect of the consumption of a food supplement on plasma zinc concentrations in elderly adults (EA). Material and Methods: Ambulatory EA (z70) with controlled type 2 diabetes mellitus or high blood pressure, ascribed to public family health centers were studied. They were separated in a control and intervention group, without blinding techniques. The intervention group consumed daily 50 g of a special nutritional supplement prepared as a soup or porridge, provided by the Government, for 3 months. The control group did not receive the supplement. A good compliance with the supplement was defined as a consumption of 7 portions per week. A fasting venous blood sample was obtained to determine plasma zinc at the beginning and end of the study. Results: Forty three supplemented EA aged 76±5 years (21 women) and 31 non supplemented EA aged 78±5 years (20 women), completed 3 months of follow up. Mean compliance with the supplement was 40.5% (95% confidence intervals (CI) 40.3-40.6%). General characteristics of the study subjects upon recruitment were similar, except for the literacy that was higher in the intervention group. We fitted a multiple linear regression model which explained 39% of the variance, where the consumption of the nutritional supplement increased the concentration ofplasmatic zinc by 4.14 fig/dL (95% CI 0.25-8.02) (p

Background: Zinc intake is well below recommendation among Chilean free living elderly adults of low socioeconomic level Aim: To assess the effect of the consumption of a food supplement on plasma zinc concentrations in elderly adults (EA). Material and Methods: Ambulatory EA (z70) with controlled type 2 diabetes mellitus or high blood pressure, ascribed to public family health centers were studied. They were separated in a control and intervention group, without blinding techniques. The intervention group consumed daily 50 g of a special nutritional supplement prepared as a soup or porridge, provided by the Government, for 3 months. The control group did not receive the supplement. A good compliance with the supplement was defined as a consumption of 7 portions per week. A fasting venous blood sample was obtained to determine plasma zinc at the beginning and end of the study. Results: Forty three supplemented EA aged 76±5 years (21 women) and 31 non supplemented EA aged 78±5 years (20 women), completed 3 months of follow up. Mean compliance with the supplement was 40.5% (95% confidence intervals (CI) 40.3-40.6%). General characteristics of the study subjects upon recruitment were similar, except for the literacy that was higher in the intervention group. We fitted a multiple linear regression model which explained 39% of the variance, where the consumption of the nutritional supplement increased the concentration ofplasmatic zinc by 4.14 fig/dL (95% CI 0.25-8.02) (p

Background: The prevalence of obesity is growing in Chile. The personal perception about the own nutritional status is associated to the risk of obesity. Aim: To analyze the personal perception about their nutritional status among adults living in Santiago and to compare it to the objective diagnosis obtained according to Chilean Health Ministry norms. Material and methods: The body image was explored in 735 people between the ages of 20 and 90. The weight and height were obtained under standard conditions, and the body mass index (BMI) was calculated (kg/m²) and classified according to the criteria of the Health Ministry. The concordance and Kappa index between both criteria in function of age, gender, nutritional status and height were analyzed. The model that best explained the weight subestimation was determined with multivariate logistic regressions. Results: Fifty two percent of subjects classified correctly their nutritional status, 30% subestimated, and 18% overstimated the nutritional status (Kappa 0.27). The multivariate analysis showed greater subestimation in obese (OR 5.8 95% IC 4.2-7.9), in men (OR 4.5 95% IC 2.7-7.3), people younger than 60 years old (OR 2.0 95% IC 1.3-3.1) and people of small stature (OR 3.1 95% IC 1.9-4.9). Conclusions: Half of the studied subjects had an inadequate perception of the body image. Educative campaigns are needed to reinforce the concept of adequate weight. This may contribute to promote health and reduce the risk of obesity

Background: The prevalence of obesity is growing in Chile. The personal perception about the own nutritional status is associated to the risk of obesity. Aim: To analyze the personal perception about their nutritional status among adults living in Santiago and to compare it to the objective diagnosis obtained according to Chilean Health Ministry norms. Material and methods: The body image was explored in 735 people between the ages of 20 and 90. The weight and height were obtained under standard conditions, and the body mass index (BMI) was calculated (kg/m²) and classified according to the criteria of the Health Ministry. The concordance and Kappa index between both criteria in function of age, gender, nutritional status and height were analyzed. The model that best explained the weight subestimation was determined with multivariate logistic regressions. Results: Fifty two percent of subjects classified correctly their nutritional status, 30% subestimated, and 18% overstimated the nutritional status (Kappa 0.27). The multivariate analysis showed greater subestimation in obese (OR 5.8 95% IC 4.2-7.9), in men (OR 4.5 95% IC 2.7-7.3), people younger than 60 years old (OR 2.0 95% IC 1.3-3.1) and people of small stature (OR 3.1 95% IC 1.9-4.9). Conclusions: Half of the studied subjects had an inadequate perception of the body image. Educative campaigns are needed to reinforce the concept of adequate weight. This may contribute to promote health and reduce the risk of obesity

Antecedentes: En Chile no existe criterio de evaluación nutricional de niños con Síndrome de Down (SD). Objetivo: Comparar la situación nutricional de niños con SD evaluados por distintos estándares antropométricos (uno norteamericano y otro español) y analizar su concordancia diagnóstica. Metodología: Se estudió en 116 niños con SD de ambos sexos entre 3 meses y 18 años la concordancia diagnóstica entregada por los indicadores peso/edad (P/E), talla/edad (T/E) e Índice de Masa Corporal (IMC) para la edad. Para el análisis estadístico se utilizó el X² y el Índice de Kappa, considerando significativo un p < 0,05. Resultados: Hay baja concordancia en la distribución obtenida con los diferentes estándares. En P/E y T/E la referencia española muestra un comportamiento más cercano a la curva Gaussiana y el IMC presenta un desplazamiento hacia el exceso de peso. Conclusiones: La curva española es la que parece ser más adecuada para discriminar déficit y excesos. Es necesario validar esta información con determinaciones de composición corporal Background: In Chile there is not a criteria for assessing the nutritional status of children with Down's syndrome (DS). Objective: To analyze the nutritional status of children with DS based on 2 specially designed growth charts (USA, Spain) and its comparison with the chart used in the infant population. Methods: The degree of agreement of the diagnosis given by weight/age (W/A), height/age (H/A) and body mass index (BMI) among the growth charts were determined in 116 children with DS, aged between 3 months and 18 years. Chi squared and kappa index were used for the statistical analysis. Results: A low agreement of the observed distributions among the growth charts was obtained. Regarding W/A and H/A the spanish growth chart showed the most symetrical distribution. BMI was displaced towards overweight values. Conclusions: The spanish curve seems to have the best discriminatory capacity for both deficent and excess values, it is necessary to validate the diagnoses obtained using the charts with determinations of body composition

Background: The Chilean Ministry of Health proposed the use of "Mini Nutritional Assessment", to identify elders at nutritional risk. This score considers anthropometric, dietary and quality of life items. Aim: To assess the concordance of the mini nutritional assessment with body mass index and dietary parameters in Chilean free living elders. Material and methods: Subjects aged 70 years old or more, coming from four public outpatient clinics were studied. In all, the mini nutritional assessment, dietary intake using 24 h recalls and anthropometric parameters, were measured. Energy intake was evaluated using FAO/WHO/UNU guidelines. Micronutrient intake was evaluated using the Dietary Recommended Intakes (DRI) from USA. Kappa index was used to determine diagnostic concordance. Results: Forty three percent of subjects were overweight or obese. There was a substandard intake of calcium, folate, zinc, vitamin A, C, E, B6, B12 and energy. Seventy nine percent of subjects had a deficient or regular food intake. Mini nutritional assessment score was normal in 66% of subjects. Fifty eight percent of those with a deficient food intake had a normal mini nutritional assessment. On the other hand, 73% of those considered at nutritional risk, had a normal or excessive weight. Conclusions: Mini nutritional assessment did not identify elders at nutritional risk in this sample (Rev Méd Chile 2001; 129: 871-6).

Background: Epidemiological studies have suggested that smoking, nutrition and sexual patterns are major risk factors for cervical cancer. Aim: To study the association between food consumption patterns, smoking and sexual behavior and the risk of cervical cancer. Material and methods: A matched case control study of 170 cases and 340 controls. Food and nutrient intakes were assessed by a food frequency questionnaire considering 58 antioxidant rich food items. Median daily intake of vegetables, fruits, antioxidant vitamins and fiber was calculated. A conditional logistic regression model was used to determine odds ratios associated with variations in nutritional intake and no nutritional factors (age at first delivery, parity, body mass index, family history of cancer and smoking). Results: High intakes of vegetables, fruits, beta carotene, vitamin C, E and fiber were associated with a lower risk of cervical cancer (Odds ratios ranging from 0.56 to 0.78). The risk for cancer was inversely associated with the age at first delivery and directly associated with the total number of pregnancies and smoking. Multivariate analysis model showed a protective effect for vegetable and vitamin E consumption (odds ratio of 0.6 with confidence intervals of 0.5 to 0.8 p

Background: Epidemiological studies suggest a relation between breast cancer, diet and life styles. Aim: To analyze the association between food patterns, obesity, smoking, alcohol consumption and breast cancer risk in women of Santiago. Patients and methods: A case-control study design (170 cases and 340 controls), matched by age and sex, was used. Through a food frequency questionnaire the average daily intake of vegetables, fruits, ß-carotene, vitamin A, C, E and fiber was analyzed. Other exposures to non-nutritional risks (parity, smoking, cancer history) were also studied. Conditional logistic regression was calculated to determine the odds ratio associated with variations in food and nutrient intake and nonnutritional factors. Results: Cases had a greater BMI and a higher prevalence of obesity than controls (p< 0.02). No differences were observed in either group food patterns. The ORs for breast cancer associated with obesity and alcohol consumption were 1.65 (95% CI 1.06-2.64) and 1.61 (95% CI 1.06-2.54) respectively (p< 0.05). Multiparity had a protective effect with 0.66 less risk (95% CI 0.44-0.99). No protective effect associated to a greater intake of vegetables, fruits or natural antioxidants was observed. Multivariate analysis model disclosed obesity as a risk factor (OR 1.79, p< 0.02) and parity ³ 4 as protective (OR 0.62, p

Objective: to assess food consumption and physical activity patterns of school children from the Aysen Region in order to develop an obesity prevention program. Patients and methods: the group studied was a representative sample from the school children from playground to fourth grade (n = 340). Sociodemographic, as well as food and physical activity patterns were obtained from interviews conducted at each participant’s house. Frequency and intake level of selected foods were studied and compared with Ministry of Health recommendations. An index of overall diet quality was developed based on Chilean food pyramid and food consumption guidelines. Results: average age was 7.7± 1.6 years. Vegetables, fruits, and dairy products were among foods with low frequency of consumption. On contrast, high consumption frequency of mayonnaise, lard, and soft drinks were observed. High-fat meats and lacteous products were commonly consumed. Adequacy by food groups showed low figures regarding vegetables, fruits and dairy products, and high values on fats (oils), sugar and meats, mainly in women. Median for quality index was 3 (p 25 = 2, p 75 = 4), over a maximum of 7, without significant differences neither by age, sex nor nutritional status. Median of physical activity was considered as low: 6 walked blocks/day (95% CI 4.5-6.0), sports and active games 4 hours/week (95% CI 4-4). Conclusion: the food and physical activity patterns of school children from Aysen are inadequate. It is necessary to elaborate plans to promote healthy life stiles as preventing measures for obesity

Resumen Objetivo: analizar la prevalencia de obesidad y el comportamiento del área grasa braquial en una muestra representativa de escolares de Aysén. Material y métodos: muestreo aleatorio simple, trietápico, estratificado, proporcional, en estudiantes de kinder a cuarto año básico de cinco comunas de la región. Se determinó peso, talla, perímetro braquial y pliegue tricipital en condiciones estandarizadas. Se calculó el puntaje Z para peso/edad, talla/edad y peso/talla en relación a NCHS/OMS y perímetro muscular braquial, área muscular braquial y área grasa braquial de acuerdo a Frisancho. Se clasificó el estado nutricional según normas del Ministerio de Salud. Se analizó la asociación de obesidad con tipo de escuela, sexo, edad, curso y comuna de residencia. Resultados: se estudiaron 1 022 niños con una edad promedio de 8,1 ± 1,5 años. La mediana de puntaje Z para talla/edad fue -0,2 (95% IC -0,3 y -0,1), para peso/edad 0,5 (0,4 y 0,6) y para peso/talla 1,0 (0,9 y 1,l). El 28,6% de la muestra presentó sobrepeso y 20,4% obesidad. La mediana de adecuación para el pliegue tricipital y área grasa braquial fue 117% (111 y 120) y 123% (117 y 128) respectivamente. La prevalencia de obesidad no se asoció con tipo de colegio, edad, curso, comuna o sexo. Conclusiones: sobrepeso y obesidad representan un problema de salud pública en todos los grupos estudiados. Es urgente desarrollar estrategias de promoción de la salud y prevención de la obesidad desde las primeras etapas de la vida. Prevalence of obesity in school children in the Aysén region Objective: to measure the prevalence of obesity, in particular the brachial adipose volume in a representative sample of Aysén school children. Methods and materials: simple random sample of 3 stages, stratified and proportional in students of kinder (6 yrs.) to 4º basic (10 yrs.) in 5 regional communities. Measurements taken included weight/height, biceps circumference, triceps fold under standard conditions. Z score was calculated for weight/age, height/age, weight/height in accor-dance with WHO/NCHS standards. Biceps muscular circumference, biceps muscular volume and adipose volume in accordance with the method of Frisancho. Nutritional status was classified according to Ministry of Health guidelines. The association of obesity with type of school, sex, age, year in school and community was evaluated. Results: 1 022 children with a mean age of 8.1 ± 1.5 yrs were studied, average Z scores were height/age -0.2 (95% CI -0.3 and -0.1), weight/age 0.5 (0.4 and 0.6) and weight/height 1.0 (0.9 and 1.1). 28.6% of the sample were overweight and 20.4% obese. The average triceps fold and biceps adipose volume were 117% (111-120) and 123% (117-128) respectively. Obesity was not associated with type of school, age, year in school, sex or community. Conclusions: The overweight or obese child is a problem of public health, en-compassing all the age groups studied. There is urgent need of health education and the prevention of obesity from an early stage of life.