Influencia de un aditivo no comercial sobre la calidad de los yesos en construcción

At the present paper, it shows how has been studied the influence over the quality of a special sort of gypsum, when it has been added as "additive" 0,96% of potasium chlorurus (Kcl), it has been observed the variation on the mechanical proprieties and also over the time of the beginning and end of the set. Also with the use ot a scanner Electronic Microscopic (M.E.B.), it has been observed the results obtained using such additive and it has been made a comparison with the finded values for the standard specimen.En el presente trabajo se ha estudiado la influencia sobre la calidad de un determinado tipo de yeso, al incorporar como "aditivo" 0,96% de cloruro de potasio (KCI), comprobando la variación en el comportamiento mecánico, así como en los tiempos de principio y final de fraguado. También mediante el uso de la Microscopía Electrónica de Barrido (M.E.B.), se han observado los resultados obtenidos al emplear el citado aditivo y se han comparado con los valores encontrados para las probetas patrón

Serum ferritin level changes in children with sickle cell disease on chronic blood transfusion are nonlinear and are associated with iron load and liver injury

Chronic blood transfusion is increasingly indicated in patients with sickle cell disease. Measuring resulting iron overload remains a challenge. Children without viral hepatitis enrolled in 2 trials for stroke prevention were examined for iron overload (STOP and STOP2; n = 271). Most received desferrioxamine chelation. Serum ferritin (SF) changes appeared nonlinear compared with prechelation estimated transfusion iron load (TIL) or with liver iron concentrations (LICs). Averaged correlation coefficient between SF and TIL (patients/observations, 26 of 164) was r = 0.70; between SF and LIC (patients/observations, 33 of 47) was r = 0.55. In mixed models, SF was associated with LIC (P = .006), alanine transaminase (P = .025), and weight (P = .026). Most patients with SF between 750 and 1500 ng/mL had a TIL between 25 and 100 mg/kg (72.8% ± 5.9%; patients/observations, 24 of 50) or an LIC between 2.5 and 10 mg/g dry liver weight (75% ± 0%; patients/observations, 8 of 9). Most patients with SF of 3000 ng/mL or greater had a TIL of 100 mg/kg or greater (95.3% ± 6.7%; patients/observations, 7 of 16) or an LIC of 10 mg/g dry liver weight or greater (87.7% ± 4.3%; patients/observations, 11 of 18). Although SF changes are nonlinear, levels less than 1500 ng/mL indicated mostly acceptable iron overload; levels of 3000 ng/mL or greater were specific for significant iron overload and were associated with liver injury. However, to determine accurately iron overload in patients with intermediately elevated SF levels, other methods are required. These trials are registered at www.clinicaltrials.gov as #NCT00000592 and #NCT00006182