Four European national asbestos fibre counting proficiency testing schemes have been studied in order to compare their criteria for the assessment of laboratory performance. Performance assessment is ...based on each laboratory's results after counting a certain number of samples. Two methods are currently being applied. To be classified ‘satisfactory’ laboratories must obtain at least 75% of normalised counts lying within defined performance limits (in three schemes), or the median and coefficient of variation of normalised counts must be within performance limits (in the fourth scheme). Differences in the numbers of test samples mean that the schemes are operating with different selectivity in assessing their laboratories' performances. Differences in the percentage of laboratory results falling within performance limits indicate that the schemes do not operate the same confidence probability in correctly assessing individual counts. It means that some schemes may be more lenient than others. This paper discusses two proposals to move towards harmonisation of the asbestos fibre counting proficiency testing schemes: (i) standardisation of the number of samples used for laboratory assessment and (ii) changes to the criteria to establish the limits of satisfactory performance.
El objetivo de este estudio fue determinar la validez y fiabilidad del instrumento de calidad percibida y satisfacción del servicio deportivo (EPOD2) en el contexto mexicano, así como invarianza de ...medición en función del sexo y de institutos del deporte. Participaron 1510 usuarios de servicios deportivos (Medad = 20.40, DT= 1 Al). El valor de la medida de adecuación muestral del Análisis Factorial Exploratorio (AFE) fue óptimo, la prueba de Bartlett resultó estadísticamente significativa, por lo que el AFE es pertinente. El Análisis Factorial Confirmatorio (AFC) corroboró la estructura factorial de las escalas, el ajuste de los índices fue adecuado. La invarianza factorial indicó que la estructura es estable tanto para sexo como por instituto del deporte. Se concluye que el instrumento EPOD2 es válido y fiable para el estudio de la calidad percibida y satisfacción de servicios deportivos en población mexicana, además de ser un instrumento de fácil aplicación e interpretación.
Abstract
The sarkinite, Mn
2
(OH)AsO
4
, mineral has been synthesized in laboratory as pure phase under mild hydrothermal conditions. The decomposition process of the hydroxiarsenate compound is ...strongly dependent on the atmospheric conditions. The results of the thermal treatment in air or argon are quite different. In this way, a new black phase appears in air atmosphere in the 400‐630 °C temperature range whereas under inert atmosphere the structure of Mn
2
(OH)AsO
4
at room temperature is maintained up to 560 °C. The weight loss is attributed to the partial decomposition of Mn
2
(OH)AsO
4
above 400 °C with removal of OH groups and the oxidation of Mn
II
to Mn
III
that occur simultaneously. Above 650 °C, the structures of the intermediate compounds are broken and the evolution of the inorganic residues gives rise to the formation of arsenates and oxides of Mn
II
and Mn
III
in inert and air atmospheres.
A variant of the murine CD4
+ T helper cell clone D10.G4.1 (D10) has been isolated and cloned. This line, which we have named "syngeneic-reactive D10", or SR.D10, maintains the I-A
k-restricted ...specificity for Conalbumin and the allogeneic specificities characteristic of D10 cells. However, it is hyperreactive to TCR-dependent and-independent stimuli, indicating a lower activation threshold than the original D10.G4.1 clone. The hyperreactivity of SR.D10 runs in parallel with the acquisition of a reactive phenotype against syngeneic antigen presenting cells (APCs). As in antigen activation, reactivity to syngeneic APCs can be inhibited by anti-TCR, anti-CD4, or anti-class II monoclonal antibodies. The role of CD4 in this phenomenon is highlighted as "syngeneic reactivity" disappears in CD4
- mutants of SR.D10 and is recovered in CD4 transfectants. The expression of several cell surface molecules involved in T cell activation show qualitative and/or quantitative differences between SR/D10 and the original D10. No significant differences in quantity and activity of p56
lck and p59
fyn were detected between the hyperreactive and the original clone. Our results suggest that high sensitivity to activation, concomitant with expression of CD4, might allow the acquisition of an autoreactive phenotype and confirm the important contribution of coreceptors to determine the activation threshold of the cells. The characteristics of SR.D10 and the possibility of growing them in the presence of interleukins make this cell line a experimental model of great interest for analyzing activation mechanisms in T cells.
We report on the temperature dependence of the relaxation properties of a Mn perovskite with overall composition (La0.97Ca0.03)0.96(Mn4+0.07Mn3+0.93)0.96O2.90. Our data are correlated with the ...simultaneous occurrence in the sample of metallic double-exchange magnetically coupled, Mn4+ clusters and of insulating superexchange coupled regions.
The pheochromocytoma is a catecholamine secreting tumour derived from chromaffin cells of the sympathetic nervous system. Eighty to eighty-five percent of these tumours are localized in the adrenal ...medulla. When pheocromocytomas are found outside the adrenal gland they are referred to as extra-adrenal pheochromocytomas or paragangliomas. The diagnosis is confirmed by elevation of catecholamines and the metanephrines in blood plasma and urine. Localization of the tumour should be done following biochemical diagnosis by means of CT scan and/or MRI. The treatment of choice is tumour resection by laparoscopic surgery.
A review was made of all patient medical histories diagnosed with pheochromocytoma confirmed by the pathology reports of Pathological anatomy of the Navarre hospital Complex (Anatomía patológica del Complejo hospitalario de Navarra A y B) between 1996 to 2010. Descriptive analysis was made using the IBM SPSS statistics program.
Our series consists of 43 patients diagnosed with pheochromocytoma over a span of 15 years. The average age on presentation was 47 years. Among the younger patients specific genetic syndromes were found. Computerized tomography was the most widely used method of localization. Contradictory results were found regarding perioperative medical management protocols. All pheocromocytoma tumours in this series were benign.
It is advisable to carry out a genetic study on patients under twenty. The biochemical indicators with the greatest diagnostic sensitivity were the levels of normetanephrine and metanephrine in urine. Surgery was the only treatment option.
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