Análisis cuantitativo y cualitativo de las ecografías del segundo y tercer trimestres en mujeres gestantes mexicanas / Quantitative and qualitative analysis of the ultrasound of the second and third trimester in Mexican pregnant women

Resumen OBJETIVO: cuantificar el número de ecografías durante la gestación y evaluar la calidad de los estudios del segundo y tercer trimestres en pacientes de bajo riesgo del área metropolitana de la Ciudad de México. MATERIALES Y MÉTODOS: estudio prospectivo, observacional y descriptivo de mujeres con control prenatal fuera de nuestra unidad que acudieron a la Clínica Perinatal de Embarazo de Alto riesgo, Hospital de la Mujer de la Ciudad de México, para la finalización del embarazo. Cuantificación de las ecografías tomadas durante la gestación, identificación del profesional encargado del estudio y evaluación de la calidad de los estudios del segundo y tercer trimestres mediante una lista de cotejo basada en guías internacionales; obtención del porcentaje de apego a las mismas. RESULTADOS: se estudiaron 199 pacientes a quienes se tomaron, en promedio, 3.7 ecografías; al 80% tres o más ultrasonidos. El análisis de las ecografías del segundo trimestre arrojó un promedio de 13.8 parámetros evaluados, con 43% de apego a las normas. En las ecografías del tercer trimestre, el promedio de parámetros evaluados fue de 10 con un porcentaje de apego de 66.7%. Los médicos ultrasonografistas fueron quienes realizaron el mayor número de estudios en ambos trimestres. CONCLUSIONES: la ecografía es un recurso accesible a la población del área metropolitana; sin embargo, debe insistirse en la calidad de los estudios.

Abstract OBJECTIVE: To quantify the number of ultrasound scans during pregnancy and evaluate the quality of ultrasound in the second and third trimester of gestation in the low risk obstetric population in the metropolitan area. MATERIAL AND METHODS: we conducted a prospective, observational and descriptive study in 199 women that arrived to the hospital for delivery without prenatal care in our unit, quantified the number of ultrasound scans performed during pregnancy, and evaluate the quality of the second and third trimester echographies with a check list based on international guidelines. The percentage of adherence was obtained and analyzed by the professional in health responsible of the study. RESULTS: The average scan per patient was 3.37, 80% had three or more. Analysis of ultrasound for the second trimester showed an average of 13.8 parameters evaluated with 43% of adherence to standards; in the ultrasounds of the third trimester, the evaluated parameters averaged 10 with a percentage of attachment of 66.7%. The largest number of studies was performed by sonographists. CONCLUSIONS: The ultrasound is a tool accessible to the population of the metropolitan area; however, it should be emphasized in the quality of studies.

Valoración nutricional de los menús escolares de los colegios públicos de la isla de Tenerife / Assessment of the nutritional value of the menus served in school canteens on the island of Tenerife, Spain

Objetivo: Conocer las características nutricionales de los menús ofertados en los colegios públicos de Tenerife y valorar si son adecuados para los escolares, según los distintos grupos de edad. Ámbito y métodos: El estudio se realiza en 52 comedores escolares, con una población de 8.411 comensales, con edades comprendidos entre 4 y 12 años. Del total de colegios 27 eran de gestión directa y 25 de gestión contratada, seleccionados mediante un muestreo aleatorio estratificado según las distintas zonas geográficas de la isla. En cada uno de ellos se recogió un menú completo: primer plato, segundo plato y postre (en algunas ocasiones un lácteo, normalmente una pieza de fruta). El registro de alimentos se realizó por pesada. Para la valoración de la ingesta en los centros de gestión directa, recogimos información acerca del menú, la forma de preparación, los ingredientes utilizados y la proporción de los mismos en cada plato, la cantidad de aceite y sal añadidos, etc. Se calcula así la proporción de los distintos ingredientes. Posteriormente se procede a la pesada de las distintas raciones ofrecidas a los escolares. En el caso de los menús ofertados por catering se pesa la cantidad de la ración en el comedor escolar y al aportarnos, el propio catering el desglose de todos los ingredientes de los platos podemos conocer la composición de los menú. Para la conversión de los alimentos en nutrientes hemos utilizado el programa Dietsource V 1.0. Con la gestión de dietas, platos y alimentos se desglosa el menú escolar dando las proporciones en principios activos y utilizando como referencia las Ingestas Recomendadas para la población española se evalúa la calidad nutricional de la dieta, tomando en cada uno de los parámetros, la media del valor recomendado para los distintos grupos de edad. Resultados: Los hidratos de carbono representan un 54% de la energía total, los lípidos un 27% y las proteínas un 19%. El contenido medio y desviación estándar del colesterol es de 77,53 ± 64,30 mg, por lo que el aporte medio de colesterol por 1.000 kcal es de 109 mg/1.000 kcal. Los ácidos grasos saturados contribuyen en un 8,6% a la ingesta calórica, los ácidos grasos monoinsaturados con un 11,7% y los poliinsaturados con un 9,7%. La ingesta de fibra por 1.000 kcal se sitúa en 11 g. Conclusiones: El aporte de energía del menú escolar es adecuado, el contenido porcentual de proteínas es algo elevado y de lípidos y carbohidratos están dentro de los límites. El contenido porcentual de ácidos grasos es adecuado, así como el colesterol y fibra. El aporte de vitaminas y minerales es apropiado, con excepción del yodo, zinc y hierro, vitaminas D, E y riboflavina que son deficitarios, sobre todo para los niños de mayor edad (AU)

Objective: To study the nutritional characteristics of the menus provided in the state primary schools of Tenerife and to assess whether they are adequate for the different age groups of school children. Scope and methods: The study is conducted in 52 school canteens, with a population of 8,411 diners aged between 4 and 12 years old. 27 of the 52 school dinner services were managed directly and 25 were contracted out to catering companies. They were selected through a random sampling that was stratified by the different geographic areas of the island. A full menu was taken from each of them: first course, second course and dessert (in some cases, a dairy product, normally a piece of fruit). The food was recorded by weight. For assessing the nutritional input in the directly managed dining rooms, we took information on the menu, how it was prepared, the ingredients used and the proportion of each of these in each dish, the amount of oil and salt added, etc. Hence we calculate the proportion of each ingredient. We then weigh the different rations offered to the school children. In the case of the menus offered by catering companies, the quantity of the ration is weighed in the school dining room and, as the catering company supplies us with the breakdown of all the ingredients used in the dishes, we can determine the composition of the menus. To convert the food into nutrients, we used the Dietsource V 1.0 programme. The school menu is broken down using the diet, dish and food management plan, to give the proportions of active ingredients used, and the Recommended Inputs for the Spanish population are used as a reference forevaluating the nutritional quality of the diet, taking the average of the recommended value for the different age groups for each of the parameters. Result: The carbohydrates account for 54% of the total energy, lipids 27% and proteins 19%. The mean content and standard error for cholesterol is 77.53 ± 64.30 mg, so the mean cholesterol input per 1,000 kcal is 109 mg/1,000 kcal. Saturated fatty acids contribute 8.6% of the calorie input, monounsaturated fatty acids 11.7% and polyunsaturated fatty acids 9.7%. The fibre input per 1,000 kcal is 11 g. Conclusion: The energy value of the school menu is adequate, the percentage content of proteins is slightly high and the lipid and carbohydrate contents are within the limits. The percentage content of fatty acids is adequate, as are the percentage contents of cholesterol and fibre. The vitamin and mineral contents are appropriate, with the exception of iodine, zinc, iron and vitamins D, E and riboflavin, where there is a deficit, especially for the older children (AU)

Homogeneous Precipitation of Uniform alpha-Fe2O3 Particles from Iron Salts Solutions in the Presence of Urea.

Uniform alpha-Fe2O3 particles within the nanometer range (100-300 nm) have been obtained by precipitation of iron (III) perchlorate in the presence of urea. Different morphology, from spheres to ellipsoidal particles with axial ratio up to approximately 10, was obtained by adding to the initial solution increasing amounts of phosphate anions up to 7 x 10(-3) M. The main targets of this work are the reduction in particle size and precipitation time and the increase of the particles axial ratio, keeping a narrow particle size distribution, in comparison to other methods previously developed to obtain homogenous alpha-Fe2O3 particles. A detailed analysis of the reaction products and a systematic study of the influence of the different precipitation conditions on the characteristics of the resulting particles have been carried out. Finally, some information on the formation mechanism of the ellipsoidal hematite particles in the iron (III) salt-urea-phosphate system is also given. Copyright 1999 Academic Press.

Interfacial and Rheological Characteristics of Maghemite Aqueous Suspensions.

The interfacial properties and rheological behavior of the maghemite/water system have been investigated in this work. It has been determined that the real pzc and iep values of maghemite immersed in aqueous solution, containing KNO3 as electrolyte, are very close to 6.6. It has also been shown that the triple-layer site-binding model likely describes the electrical double layer of the maghemite/water system. The parameters obtained from this model indicate that the mechanism responsible for charging involves complexation reactions and that the interfacial properties of aqueous suspensions containing maghemite are very similar to those containing magnetite. Finally, rheological characterization of three maghemite samples with different average particle size showed that the maximum yield stress, at a fixed solid concentration, decreases as the sample particle size decreases. This anomalous behavior is originated by the apparition of relaxation superparamagnetic phenomena as a consequence of the decrease in the sample particle size. Copyright 1998 Academic Press.