Radiological characterization of the tailings of an abandoned copper mine using a neural network and geostatistical analysis through the Co-Kriging method.

The radiological characterization of soil contaminated with natural radionuclides enables the classification of the area under investigation, the optimization of laboratory measurements, and informed decision-making on potential site remediation. Neural networks (NN) are emerging as a new candidate for performing these tasks as an alternative to conventional geostatistical tools such as Co-Kriging. This study demonstrates the implementation of a NN for estimating radiological values such as ambient dose equivalent (H*(10)), surface activity and activity concentrations of natural radionuclides present in a waste dump of a Cu mine with a high level of natural radionuclides. The results obtained using a NN were compared with those estimated by Co-Kriging. Both models reproduced field measurements equivalently as a function of spatial coordinates. Similarly, the deviations from the reference concentration values obtained in the output layer of the NN were smaller than the deviations obtained from the multiple regression analysis (MRA), as indicated by the results of the root mean square error. Finally, the method validation showed that the estimation of radiological parameters based on their spatial coordinates faithfully reproduced the affected area. The estimation of the activity concentrations was less accurate for both the NN and MRA; however, both methods gave statistically comparable results for activity concentrations obtained by gamma spectrometry (Student's t-test and Fisher's F-test).

Increasing the recovery and selectivity of 238U, 235U, and 234U extraction with tri-n-butyl phosphate in mine tailing samples with a high copper content.

Abandoned Cu mine tailings may be associated high concentrations of U. However, the presence of stable cations such as Cu, Fe, Al, Ca, or Mg, etc. in high concentrations can reduce the chemical efficiency of the liquid-liquid extraction method with tri-n-butyl phosphate (TBP); it can also inhibit the electrodeposition of U on the stainless steel planchet where the sample is measured. In this work we studied an initial stage of complexation with ethylenediaminetetraacetic acid (EDTA) and a back extraction with different solutions: H2O, Na2CO3, and (NH4)2CO3 at room temperature and at 80 °C. The sensitivity of the method was 4.9·10-4 Bq for 238U and 234U, and 2.3·10-5 Bq for 235U. The validation of the method achieved 95% of the results when using a |ζ-score| ≤ ± 2.0 and a relative bias (RB[%]) ≤ ± 20% as the acceptance criteria. The recoveries obtained with the proposed method were higher than those achieved with the extraction method without initial complexation and re-extraction with H2O for water samples. Finally, this method was applied in practice to study the tailing of an abandoned Cu mine and the activity concentrations of 238U and 235U were compared with those obtained by gamma spectrometry for 234Th and 235U. The means and variances of both methods showed no significant differences between these two isotopes.

Variaciones de la configuración ductal pancreática: factor predisponente de pancreatitis recurrente / Variations of pancreatic ductal configuration: predisposing factor of recurrent pancreatitis

El páncreas es un órgano de origen endodérmico, que se desarrolla de dos esbozos intestinales separados, uno dorsal y otro ventral,a partir de la cuarta o quinta semana de gestación. El páncreas se origina en el intestino anterior en la parte correspondiente a lafutura segunda porción duodenal. Allí se originan dos brotes: uno posterior o dorsal que aparece a principios de la cuarta semanay crece rápidamente en el mesenterio dorsal y el otro brote es anterior o ventral. Este último da origen a dos brotes, uno origina unaparte del páncreas y otro a la vía biliar e hígado. Existen diferentes variantes anatómicas, derivadas de este desarrollo embrionario;su conocimiento es de vital importancia en pacientes con persistencia de dolor abdominal y episodios de pancreatitis recurrente.El objetivo de este artículo es una revisión de las variantes anatómicas del conducto pancreático que pueden manifestarse como pancreatitis idiopática recurrente. (AU)

The pancreas is an organ of endodermal origin, which develops from two separate intestinal sketches, one dorsal and one ventral,from the fourth or fifth week of gestation. The pancreas originates in the anterior intestine in the part corresponding to the futuresecond duodenal portion. There two shoots originate: one posterior or dorsal that appears at the beginning of the fourth week andgrows rapidly in the dorsal mesentery and the other outbreak is anterior or ventral. The latter gives rise to two outbreaks, oneoriginates a part of the pancreas and another to the bile duct and liver. There are different anatomical variants, derived from thisembryonic development; their knowledge is of vital importance in patients with persistent abdominal pain and episodes of recurrentpancreatitis. The objective of this article is a review of the anatomical variants of the pancreatic duct that can manifest as recurrent idiopathic pancreatitis. (AU)

Evaluation of pulse rate variability obtained by the pulse onsets of the photoplethysmographic signal.

This work presents the evaluation of pulse rate variability (PRV) obtained from pulse onsets of photoplethysmographic (PPG) signals. Three published algorithms were used to determine the pulse onsets: diastolic point, maximum second derivative and tangent intersection. Temporal series of pulse onsets were obtained for each method, and several variability indices were derived from these series. Simultaneous ECG and PPG records were acquired from 37 healthy volunteers to evaluate the interchangeability between PRV indices and heart rate variability (HRV) indices by the Bland-Altman method. Furthermore, the concordance correlation coefficient was used to correlate the indices. In all the cases, PRV indices obtained through the tangent intersection method showed better accuracy and precision (Bland-Altman analysis, bias ± 1.96 standard deviation: low frequency, LF(ms)(2) = -28.06 ± 72.68; high frequency, HF(ms)(2) = -68.23 ± 192.85; high frequency in normalized units, HF(nu) =-2.02 ± 7.08; LF/HF = 0.17 ± 0.71) and higher correlation (concordance correlation coefficients: low frequency, LF(ms)(2) = 0.99; high frequency, HF(ms)(2) = 0.98; high frequency in normalized units, HF(nu) = 0.97; LF/HF = 0.90) with HRV indices than other methods, and could be used as a good surrogate of HRV.

Cistectomía total: un mismo problema, distintas soluciones / No disponible

Dentro de los carcinomas del tracto urinario, los tumores de vejiga constituyen, junto con el de próstata, la causa principal de las derivacionesurinarias. Hablamos por lo tanto de un problema de salud más frecuente de lo que pensamos, cuya solución es quirúrgica:realización de una cistectomía total.Nuestro objetivo es conocer las distintas formas de realización y de elección de una cistectomía total, diferenciando entre los dos grandesgrupos principales: ureteroileostomía y neovejiga. Las diferencias entre un procedimiento u otro conllevarán unos cuidados enfermerosdistintos (AU)

Inside the urinary tract carcinomas, bladder tumors constitute together with that of prostate, the mainspring of the urinary derivations.Therefore, we talk about a problem of health more frequent than what we think, which solution is surgical: accomplishment of a totalcystectomy.Our goal is to know the different ways of accomplishment and of choice of a total cystectomy, differentiating between the two maingroups: ureteroileostomy and neobladder. The differences between a procedure or another will entail some different nursing cares (AU)

Effects of partial hepatectomy on the distal ileum in rats.

INTRODUCTION: hepatectomy, both partial resection and transplant, has greatly developed and advanced during the last years as a result of a better understanding of surgical anatomy and the progress of technological means; it has also allowed a widening of surgical indications, including living-donor liver transplantation. The aims of our study was to assess the morphological impact of partial hepatectomy on the distal ileum, since the liver and intestine behave as a unit from an anatomical, functional, and metabolic point of view. MATERIAL AND METHODS: twenty-four Wistar rats were used; they were divided into two groups, a control and an experimental group (30, 90, and 180 days). We studied changes occurred in the distal ileum after a 70% liver resection, taking 4 parameters into account. RESULTS: an important drop in total thickness occurred at the ileum wall in the experimental group (p < 0.001). There were no important differences in villus height with regard to the control group. Thickness at the villi fell significantly (p < 0.01), as did the depth of the crypts, which diminished significantly in relation to the control group (p < 0.001). CONCLUSIONS: a 70% hepatectomy induces trophic changes on the distal ileum that remain in both the short and longer term, and causes atrophy of the ileum wall and a drop in villus thickness.

A study of robustness with multivariate calibration. Application to the polarographic determination of benzaldehyde.

A procedure to evaluate the robustness of an analytical method when there are changes in some experimental variables, when using multivariate calibration, is proposed. The procedure consists of analysing the root mean square error of prediction (RMSEP) as a response to a Plackett-Burman experimental design, through which the influence of several experimental factors on the prediction capability of the multivariate partial least squares (PLS) models built is studied. Two different ways of analysing the experimental design response are considered: establishing the residual variance with replicates and using Lenth's method. The proposed methodology has been applied to estimate the robustness of the polarographic determination of benzaldehyde when PLS calibration is used.