Objective: To analyze the early response of uveal melanomas in patients treated with ruthenium-106 brachytherapy. Materials And Methods: In the period between April 2002 and July 2003, 20 patients diagnosed with uveal melanoma were submitted to ruthenium-106 brachytherapy. The calculated dose delivered at the apex of the tumor ranged between 55 Gy and 100 Gy. Patients with lesions greater than 5 mm were submitted to transpupillary thermotherapy concomitantly with ophthalmic plaque insertion. Results: As regards the lesions site, 75% of the lesions were located in the choroid, 15% in the iris, and the remainder 10% in the ciliary body. In a median 19-month-follow-up, the progression-free survival for brachytherapy was 69%, and 87% for associated brachytherapy and transpupillary thermotherapy. A significant tumor height reduction was observed after treatment. No patient was submitted to enucleation. Conclusion: Our preliminary results show that ruthenium-106 brachytherapy is an ...
The document describes the outcome of the CSN/CIEMAT-00 interlaboratory test comparison among environmental radioactivity laboratories. the exercise was organised according to the ISO-43 and the ISO/IUPAC/AOAC Harmonized Protocol for the proficiency testing of analytical laboratories. the test sample was a soil containing environmental levels of K-40, Ra-226, Ac-228, Sr-90, Cs-137, Cs-134, Pu (239-240) y Am-241. the Universidad Autonoma de Barcelona prepared the material and reported adequate statistical studies of homogeneity. The results of the exercise were computed for 30 participating laboratories, and their analytical performance was assessed using the u-score approach. A raised percentage of satisfactory laboratory performance has been obtained for all the analysis, being the best performance in gamma measurements. The exercise has drawn that several laboratories have difficulties in the evaluation of combined uncertainty, mainly in analysis involving radiochemical steps. The ...
Introduccion y objetivos La enfermedad renal oculta (ERO) es una entidad que define los estadios mas iniciales de insuficiencia renal y no se detecta con los metodos usados habitualmente. El objetivo es determinar la prevalencia de ERO en los pacientes hipertensos en consultas de cardiologia y su relacion con los distintos factores de riesgo y tratamientos cardiovasculares. Metodos. Estudio observacional, transversal, retrospectivo y multicentrico que se llevo a cabo en 1.214 hipertensos de consultas de cardiologia. Resultados . Se analizo a 1.190 pacientes (98%). El filtrado glomerular (FG) fue calculado (MDRD) por el cardiologo responsable en el 11% de los pacientes. Tras su determinacion a posteriori, el 9,5% presentaba ERO, mas probablemente mujeres, con mas edad, mas antecedents de di...
The purpose of this work is to investigate whether any morphometric or densitometric are detectable in the kidneys of type 2 diabetic patients. 40 diabetic patients were examined and of 20 non-diabetics (the control group) were submitted to triphasic helical CT for different abdominal conditions. The type 2 diabetic patients were 23 men and 17 women, mean age 62 years, while the nondiabetic controls were 12 men and 8 women, mean age 58 years. All the CT images were analyzed using the Multiplanar Reconstruction (MPR) software. It was evaluated morphometric features, such as the presence of parenchymal or vascular calcifications, axial and coronal renal diameters, coronal renal area, and cortico medullary ratio, and densitometric and functional features, such as unenhanced renal density, cortical and medullary density in the arterial phase, parenchymal density in the nephrographic phase, and contrast elimination. It was also compared the results in the subgroups of patients with those in ...
In this work a flat receiver of self construction is shown with relatively low cost and easy manufacture, but with a thermal efficiency superior to 40% for applications at temperatures less than 60 degrees Celsius, that allows satisfying international standards in this respect. The heater has been matter of study in open courses distributed in the Universidad Autonoma de la Ciudad de Mexico (UACM) oriented to that the participants construct their own system, in addition to its installation and tests. The obtained results have been excellent. The massive use of efficient solar receivers of self-construction can truly help to the decreasing of the gas discharges of greenhouse effect. [Spanish] En este trabajo se presenta un captador plano de auto construccion con relativamente bajo costo y facil manufactura, pero con un rendimiento termico superior a 40% para aplicaciones a temperatura menos de 60 grados centigrados que le permite satisfacer estandares internacionales a este respecto. El ...
A first, partial, assessment is included of the low- to medium-temperature geothermal reserves in 20 Mexican States and their aggregate value. The assessment covers about 29.16% of the identified geothermal-surface manifestations in the public database. For reserve assessments, we use the volumetric method, supplemented with Montecarlo simulations and statistics, to quantify inherent uncertainties. Our estimations are presented on a state-by-state basis. We estimate the aggregated reserves of the 20 states as between 7.7 x 1016 and 8.6 x 1016 kJ, with 90% confidence. The most likely reservoir temperatures range between 60-180 degrees Celsius, with a mean of 111 degrees Celsius. Such massive amounts of recoverable energy-and the associated temperatures-are potentially important for the economic development of nearby localities and the nation. [Spanish] En este trabajo se hace una primera estimacion, parcial, de las reservas geotermicas de temperatura intermedia a baja de Mexico. La ...
It turns out of interest to Comision Federal de Electricidad and Petroleos Mexicanos to reduce costs of fuel oil, reducing the viscosity of the residues petroleum of high vacuum distillation emulsifying these with water. The parameters that define the characteristics of the emulsions are mainly the relation of their components, viscosity, size and drop distribution and its stability. The experimental work began producing emulsions in form of lots, using samples of approximately 500 milliliters of vacuum residue. In this first stage, at different concentrations, were examined eight different surfactants, as well as combinations among them, also seven different stabilizers were used. With these tests it has been managed to identify the concentrations, as well as the most adequate relations of surfactants and stabilizers for the production of emulsions of vacuum residues in water. The size and drop distribution has been determined by means of an optical LEICA microscope, model DMLS, that ...