| 1. |
- Grubin, C. E., et al.
(författare)
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A novel radioligand binding assay to determine diagnostic accuracy of isoform-specific glutamic acid decarboxylase antibodies in childhood IDDM
- 1994
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Ingår i: Diabetologia. - 0012-186X. ; 37:4, s. 344-350
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Tidskriftsartikel (refereegranskat)abstract
- Insulin-dependent diabetes mellitus (IDDM) is associated with autoreactivity against GAD but the diagnostic sensitivity (positivity in disease) and specificity (negativity in health) of isoform-specific GAD antibodies have yet to be defined in assay systems suitable for screening large number of samples. One set of IDDM patient (n=10) and control (n=50) standard sera were used to develop quantitative antibody assays with in vitro synthesized recombinant 35S-methionine-labelled GAD65 and GAD67, respectively, and protein A-Sepharose to separate free from antibody-bound ligand. Binding levels were not normally distributed (p<0.0001) and therefore, the diagnostic accuracy of GAD antibodies was analysed by the ROC plots in population-based, consecutively-diagnosed, recent onset, 0-14 year-old patients (n=105), and matched, healthy control subjects (n=157). The ROC plots showed that the diagnostic sensitivity of GAD65 antibodies was 77% and the specificity 92% compared with 8% and 98%, respectively for GAD67 antibodies. In the IDDM sera, GAD65 and GAD67 antibodies were concordant in 7% (6 of 81) and GAD65 antibodies and ICA in 89% (72 of 81) without a correlation between the autoantibody levels. Autoantibodies to recombinant human islet GAD65 are specific and sensitive markers for childhood IDDM in this immunoassay with in vitro synthesized 35S-methioninelabelled recombinant GAD.
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| 2. |
- Li, W.B., et al.
(författare)
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Mechanisms of indentation creep
- 1991
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Ingår i: Acta Metallurgica et Materialia. - 0956-7151. ; 39:12, s. 3099-3110
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Tidskriftsartikel (refereegranskat)abstract
- A physically-based theoretical model is developed for describing the phenomenon of indentation creep over the whole temperature range, from 300 K to melting. In agreement with experimental data collected, the model predicts that most materials, including ceramics, exhibit indentation creep at temperatures down to 300 K. It is established that the principal mechanism causing indentation creep is dislocation glide plasticity. The dominance of this mechanism over the whole temperature range is due to the very high stresses involved in indentation creep. If, however, the grain size is small (typically less than 0.3-0.4 μm) indentation creep may be dominated by grain boundary (Coble) diffusive creep instead. The implications of these results in terms of the design, forming and application of the so-called "hard materials" is discussed.
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