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In the complex multicomponent formulation of standard commercial varistors used in high tension devices, those based in the ZnO-Bi2O3-Sb2O3 (ZBS) ternary system, the presence of iron is ordinarily prevented in any of its plausible sources: dopant, impurity and/or unwanted contamination. Otherwise the material undergoes a systematic degradation in its electrical performance which rapidly disallows it for practical uses. In order to understand the origin of such degradation phenomena, we have deliberately doped the ZBS varistor composition with different amounts of Fe2O3. The research here presented evidences that the prime reason for the varistor electrical ruination is the progressive incorporation of iron inside the spinel secondary grains, which eventually leads to the formation of a highly conductive skeleton of secondary phases with an unbearable level of leakage currents below the varistor breakdown voltage. [ABSTRACT FROM AUTHOR]

Abstract: 3β,11β-Dihydroxy-9α-fluor-5α-androstane-17-one (2), 3β-acetoxy-9α-fluor-11β-hydroxy-5α-androstane-17-one (3), 3β-acetoxy-9α-fluor-11β,17β-dihydroxy-5α-androstane (4), 3β,17β-diacetoxy-9α-fluor-11β-hydroxy-5α-androstane (5), 3β-acetoxy-9α-fluor-11β-hydroxy-5α-androstane 17β-propionate (6), 3β-acetoxy-9α-fluor-11β-hydroxy-5α-androstane 17β-enanthate (7), 3β-acetoxy-9α-fluor-11β-hydroxy-5α-androstane 17β-isobutyrate (8) were synthesized in the present study. Compounds 2 and 8 exhibited higher anabolic activity than the rest of the synthesized compounds. The structure of all these newly synthesized compounds was confirmed by analytic spectral data (mass, 1H NMR and 13C NMR). [Copyright &y& Elsevier]

The efficiency and performance of electrodialytic cells is based on the flow pattern and mass transfer characteristics, hence, evaluation of cell design, spacers and turbulence promoters (TP), is needed in order to obtain optimal operation. In this, work we compare the mass transfer performance of several plastic nets and cell orientation by means of experimental test and CFD simulation. Excellent agreement in terms of mass transfer was obtained between the two methods. From CFD analysis, it is possible to conclude that the electrochemical reactor design presented in this work, favors the formation of jet flow and stagnant zones in all reactor configurations affecting mass transport flux distribution; this behavior is associated with inlet design and TP orientation. Velocity fields and mass transport flux distributions visualized by CFD analysis, affect the mass transport coefficients values and of course the exact form of dimensionless mass transport correlations here obtained. Finally, 0273R oriented TP configuration seems to have the highest mass transport coefficients, attributed to high contribution of limiting current densities at jet flow zones. A low efficiency under operational conditions is expected. [ABSTRACT FROM AUTHOR]

Objectives: Our objective is to carry out a clinical study of the performance of the preliminary European classification criteria for Sjögren Syndrome and that of the criteria proposed by the American European Consensus Group.Methods: Eighty-eight patients who had undergone a biopsy of the salivary gland on suspicion that they were suffering from Sjögren Syndrome were studied by two independent rheumatologists. Two pathologists independently revised the biopsies without knowing the diagnosis. With all of this information, the clinicians established, or did not establish, a diagnosis of primary Sjögren Syndrome or secondary Sjögren Syndrome. Finally, it was analysed whether or not the patients met the American European Consensus Group classification criteria and the preliminary European criteria for primary Sjögren Syndrome and secondary Sjögren Syndrome, and their sensitivity and specificity with respect to the clinical diagnosis were determined.Results: Clinicians estimated that 35 cases (39.8%) had primary Sjögren Syndrome (kappa 0.718) and 17 cases (19.3%) had secondary Sjögren Syndrome (kappa 0.761). The specificity and sensitivity of American European Consensus Group criteria, with regard to the clinical diagnosis, for primary Sjögren Syndrome were 97.2% and 48.6%, respectively. For secondary Sjögren Syndrome, the specificity was 97.2% and the sensitivity 64.7%. The preliminary European criteria for primary Sjögren Syndrome demonstrated a lesser specificity (75%), but a higher sensitivity (65.7%). In secondary Sjögren Syndrome the specificity reached 97.2% with sensitivity at 70.6%.Conclusions: These results underline the difficulty in applying the Sjögren Syndrome classification criteria from the American European Consensus Group and the preliminary European criteria, in the diagnosis of individual patients. [ABSTRACT FROM AUTHOR]