Influence of minerals on the taste of bottled and tap water: a chemometric approach.

Chemometric analysis was performed on two sets of sensory data obtained from two separate studies. Twenty commercially-available bottled mineral water samples (from the first study) and twenty-five drinking tap and bottled water samples (from the second study) were blind tasted by trained panelists. The panelists expressed their overall liking of the water samples by rating from 0 (worst flavor) to 10 (best flavor). The mean overall score was compared to the physicochemical properties of the samples. Thirteen different physicochemical parameters were considered in both studies and, additionally, residual chlorine levels were assessed in the second study. Principal component analysis performed on the physicochemical parameters and the panelists' mean scores generated models that explain most of the total data variance. Moreover, partial least squares regression of the panelists' sensory evaluations of the physicochemical data helped elucidate the main features underlying the panelists' ratings. The preferred bottled and tap water samples were associated with moderate (relatively to the parameters mean values) contents of total dissolved solids and with relatively high concentrations of HCO3⁻, SO4²â», Ca²âº and Mg²âº as well as with relatively high pH values. High concentrations of Na⁺, K⁺ and Cl⁻ were scored low by many of the panelists, while residual chlorine did not affect the ratings, but did enable the panel to distinguish between bottled mineral water and tap water samples.

Comparison between sampling and analytical methods in characterization of pollutants in biogas.

Different sampling methods involving the collection of biogas by Tedlar bags or adsorption tubes, and different GC-MS injection systems, loop injection or cold trap injection (with bags or by tube desorption), were compared to establish the best method to determine the minority compounds in biogas from sewage treatment plants (STPs). A study of parameters is included, such as the stability of compounds in Tedlar bags or cartridges and the adsorption effect of some less volatile compounds in the thermal desorption system (TD). The optimized methods allowed to determine most compounds at low mgm(-3) levels. Among them, maximum values of D5 (4.84 mg m(-3)), decane (95-118 mg m(-3)) and H(2)S (2223 mg m(-3)) were found in biogas samples.

Tratamiento hidroelectrolítico y ácido base en pacientes con cetoacidosis diabética: comparación de dos guías terapéuticas

Introducción. Objetivo: comparar 2 guías terapéuticas que difieren en el manejo de líquidos y bicarbonato de sodio para corregir la deshidratación y el desequilibrio ácido base en pacientes con cetoacidosis diabética (CAD). Material y métodos. Diseño: casos y controles. Se compararon 2 muestras a conveniencia de los registros de 16 pacientes con CAD tratados con una guía terapéutica que recomienda corregir la deshidratación, considerando los líquidos basales más las pérdidas insensibles de líquidos por respiración y las pérdidas secundarias a diuresis osmótica, y que no recomienda el uso de bicarbonato de sodio para corregir la acidosis, con un grupo de control de 16 registros de pacientes con CAD expuestos a una guía terapéutica que no considera las pérdidas insensibles por la taquipnea relacionada, y aquellas secundarias a diuresis osmótica para corregir la deshidratación, y recomienda el uso de bicarbonato de sodio para corregir la acidosis. Se incluyeron en el estudio a pacientes que a su ingreso tenían deshidratación grave con hiperglucemia igual o mayor a 300 mg/dL, pH igual o menor a 7.3 ó bicarbonato menor a 15 mmol/L, cetonemia, glucosurias y cetonurias. Resultados. La corrección de la deshidratación en 24 horas se logró en 81.2% del grupo de estudio y en 37.5% del grupo control (P =0.0005). Los líquidos suministrados en el grupo de estudio fueron de 5 287 ± 1 659 mL y el grupo control de 8 360 ± 7 391 mL (P =0.004). La glucemia al término de 24 horas fue de 292 ± 45 mg en el grupo de estudio y 310 ± 76.4 mg en el grupo control, sin significancia estadística (P =0.4). El pH de 7.32 ± 0.064 en el grupo de estudio y de 7.2 ± 0.146 en el grupo control, con significancia estadística (P =0.005). El anión gap mostró al término de 24 horas de 12.7 ± 1.57 en el grupo de estudio y de 29 ± 11.44 en el grupo control con alta significancia estadística (P =0.0001). El sodio sérico a las 24 horas fue de 133.9 ± 2.56 mEq/L en el grupo de estudio y de 147.8 ± 12.47 mEq/L en los controles (P =0.001). La osmolalidad para el grupo control fue de 276 ± 8.08, para el grupo de estudio de 296 ± 6.75 mOsmol/L, con alta significancia estadística (P =0.0003). El potasio sérico a las 24 horas en el grupo de estudio fue de 4.85 ± 1.15 mEq/L y de 4.2 ± 0.52 mEq/L en los controles (P =0.05). Conclusiones. Este protocolo ha demostrado ser muy práctico y efectivo para el tratamiento hidroelectrolítico y el equilibrio ácido base, mostrando mejor estabilización en 24 horas de tratamiento. El restablecimiento de la hidratación y del equilibrio electrolítico y ácido base son superiores en el grupo de estudio, no existen diferencias en cuanto a la corrección de la glucemia.

Introduction. The aim of this work was to compare 2 different therapeutic guidelines which recommend diverse amounts of fluids, and bicarbonate to correct dehydration and acid-base unbalance in children with diabetic ketoacidosis (DKA). Material and methods. A group (A) of patients (n= 16) with DKA treated with a guideline which recommend the reposition of basal plus negligible fluid loss without bicarbonate were compared with a second group (n =16) of DKA patients (group B) managed with another guideline which do not consider negligible fluid loss but recommend the use of bicarbonate. Patients with severe dehydratation, hyperglycemia > 300 mg/dL, pH > 7.3 or bicarbonate < 15 mmol/L, ketonemia, glycosuria, and ketonuria, were included. A bivariate test for each dependent variable, Z distribution, and Student's t test were used in the statistical analysis. Results. Correction of dehydration in a 24 h period was achieved in 81.2% of patients in group A and in 37.5% of group B (P =0.0005). Average fluid volume was 5 287 ± 1 659 mL in group B, and 8 360 ± 7 391 mL in group A. Glycemia was 292 ± 45 mg in group A, and 310 ± 76.4 mg in group B; pH was 7.32 ± 0.064 in group A, and 7.2 ± 0.146 in group B (P =0.005). After 24 h anion gap was 12.7 ± 1.57 in group A, and 29 ± 11.44 in group B (P =0.0001), serum Na was 133.9 ± 2.56 mEq/L in group A, and 147.8 ± 12.47 mEq/L in group B (P =0.001); serum K was 4.85 ± 1.15 mEq/L in group A, and 4.2 ± 0.52 mEq/L in group B (P =0.05). Osmolarity was 296 ± 6.75 mOsmol/L in group A, and 276 ± 8.08 in group B (P =0.0003). Conclusions. Stabilization after 24 h, rehydration, electrolyte and acid-base balance were more effectively achieved with the reposition of basal plus negligible losses of fluids without bicarbonate.