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Aims To investigate changes in insulin action and insulin secretion in obese subjects with different categories of impaired glucose regulation (IGR): impaired glucose tolerance (IGT), impaired fasting glucose (IFG), and combined IFG/IGT (CGI). Methods A total of 222 subjects underwent an oral glucose tolerance test and a frequently sampled intravenous glucose tolerance test (FSIGTT); 100 had normal glucose tolerance (subdivided into 32 lean NGT, 68 obese NGT), and 122 were obese with IGR (82 IGT, 14 IFG and 26 CGI). The insulin sensitivity index (SI) was assessed by Bergman's minimal model method with FSIGTT; insulin secretion was determined by acute insulin response to glucose (AIRg). The disposition index (DI), the product of AIRg and SI, was used to determine whether AIRg was adequate to compensate for insulin resistance. Results SI was similar in NGT and IGR obese subgroups. AIRg was significantly increased in obese NGT as compared with lean NGT, significantly reduced in IGT, and further reduced in IFG and CGI subjects as compared with obese NGT subgroups. DI was reduced in NGT obese individuals. Within the obese IGR subgroups, IFG and CGI subjects had even lower DI value than IGT subjects. Conclusions Obese Chinese subjects with IGR have a similar degree of insulin resistance but differ in insulin secretion. Subjects with IFG and CGI have a more prominent deficiency in insulin secretion than subjects with IGT. [ABSTRACT FROM AUTHOR]

We calculated electron energy loss and angular distributions for electrons transmitted through masks for electron projection lithography by a Monte Carlo (MC) simulation method. After comparing the improved continuous slowing down approximation model, the direct MC model, and the intensive direct MC model, the last model was used. The energy loss distributions calculated by the latter two models are much better than by the first model and the intensive direct MC model can be applied to more materials than the direct MC model. The effect of mask thickness on energy loss, transmission, and contrast was analyzed. We found that, for a W/Cr/Si[sub 3]N[sub 4] mask, the thicker the scattering layer the wider the angular distribution, the lower the transmission, and the higher the contrast. But the thickness of the membrane Si[sub 3]N[sub 4] layer has less effect on the contrast. [ABSTRACT FROM AUTHOR]