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821.
Liu DeguiBeijing Institute of Computer Application Simulation Technology. P. O. Box Beijing . China 《系统工程与电子技术(英文版)》1993,(4)
In this paper two classes of equivalence transform methods for solving ordinary differential equations are proposed. One class of method is the equivalence integral transform method for special differential algebraic problems. The advantage of this class of method is such that the amount of work calculating one integration with parameters becomes that of two interpolations, when the system of nonlinear equations is solved on the right hand side function. The other class of method is the equivalence substitution method tor avoiding calculating derivative on the right hand side function. In order to avoid calculation derivatives, two equivalence substitution methods are proposed here. The application instances of some special effect of the equivalence substitution methods are given. 相似文献
822.
1,2,4-Triazolidine-3,5-diones and the 3,5-isoxazolidinedione were observed to be potent inhibitors of rat lens aldose reductase activity. In vivo in streptozotocin-diabetic rats, selected agents at 20 mg/kg/day, orally for 21 days reduced significantly the sorbitol levels of rbc, lens and sciatic nerves, suggesting that these derivatives may have some usefulness to treat clinical complications of diabetes mellitus. 相似文献
823.
O. Hoffmann-Ostenhof H. Moser E. Putz 《Cellular and molecular life sciences : CMLS》1948,4(9):352-352
Summary The authors describe a monophosphoesterase isolated from yeast which acts strongly on sodium phenolphthaleinphosphate, phenolphosphate, and-glycerophosphate in an alkaline medium (p
H 8,5–9,1). The enzyme does not need magnesium ions for its activity. 相似文献
824.
Identification of a widespread nuclear actin binding protein 总被引:16,自引:0,他引:16
825.
An explanation for the protective effect of the MHC class II I-E molecule in murine diabetes 总被引:26,自引:0,他引:26
Insulin-dependent diabetes mellitus is widely believed to be an autoimmune disease. Recent onset diabetics show destruction of insulin-secreting pancreatic beta-cells associated with a lymphocytic infiltrate (insulitis), with autoantibodies to beta-cells being found even before the onset of symptoms. Susceptibility to the disease is strongly influenced by major histocompatibility complex (MHC) class II polymorphism in both man and experimental animal models such as the non-obese diabetic (NOD) mouse. As MHC class II molecules are usually associated with dominant immune responsiveness, it was surprising that introduction of a transgenic class II molecule, I-E, protected NOD mice from insulitis and diabetes. This could be explained by a change either in the target tissue or in the T cells presumed to be involved in beta-cell destruction. Recently, several studies have shown that I-E molecules are associated with ontogenetic deletion of T cells bearing antigen/MHC receptors encoded in part by certain T-cell receptor V beta gene segments. To determine the mechanism of the protective effect of I-E, we have produced cloned CD4+ and CD8+ T-cell lines from islets of recently diabetic NOD mice. These cloned lines are islet-specific and pathogenic in both I-E- and I-E+ mice. Both CD4+ and CD8+ cloned T cells bear receptors encoded by a V beta 5 gene segment, known to be deleted during development in I-E expressing mice. Our data provide, therefore, an explanation for the puzzling effect of I-E on susceptibility to diabetes in NOD mice. 相似文献
826.
Based on a large data base from 69 ionosonde stations distributed worldwide a comparative study is made on the global behavior
of ionospheric responses to three great magnetic storms occurring nearly at low and high activity phase of the 22nd solar
cycle. Depending on the season of storn occurrence, the global morphology of the ionospheric response to major magnetic storm
is very different. For the February 1986 storm, hemispheric asymmetry of storm effects is remarkable, and positive storm effects
are dominant in the winter hemisphere. Instead, for the two magnetic storms taking place near equinox in 1989, longlasting
decreases in Nm were observed in both hemispheres Large-scale TIDs propagating equatorward were seen during the main phases of the October
1989 magnetic storm at evening-night sector. On the other hand, short-lasting positive storm effects appearing as wave-like
disturbances in Nm were observed during the primary main phase of the 1986 storm in winter hemisphere. They seem to originate near the equatorial
region and travel polarward.
Supported by the National Natural Science Foundation of China and the Science Foundation of State Education Commitee of China
Xu Jisheng: born in Nov. 1946, Professor 相似文献
827.
828.
Androgenic control of a sex-dependent protein in the rat 总被引:7,自引:0,他引:7
829.
830.