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71.
HLA-D region beta-chain DNA endonuclease fragments differ between HLA-DR identical healthy and insulin-dependent diabetic individuals 总被引:19,自引:0,他引:19
D Owerbach A Lernmark P Platz L P Ryder L Rask P A Peterson J Ludvigsson 《Nature》1983,303(5920):815-817
The human HLA-D histocompatibility region encodes class II antigens each of which consists of two polypeptide chains (alpha and beta) inserted in the plasma membrane. These molecules are implicated in the regulation of the immune response but several human diseases are also found to be associated with certain HLA-DR antigens. The occurrence of insulin-dependent (type I) diabetes (IDDM) is strongly associated with HLA-DR3 and/or 4 (ref. 5). The class II antigens, however, show a marked genetic polymorphism associated with the beta-chains which seem, from hybridization studies, to be encoded by several genes. We have therefore used the beta-chain cDNA probe, pDR-beta-1 (refs 8, 10) to test whether there are differences in hybridization pattern between DNA from healthy individuals and diabetic patients, after digestion with restriction endonucleases. Among the HLA-DR 4 and 3/4 individuals, the IDDM patients showed an increased frequency of a PstI 18 kilobase (kb) fragment. A BamHI 3.7 kb fragment, frequent among controls (30-40%), was rarely detected in the IDDM patients (0-2%). These differences may be related to susceptibility to develop the disease. 相似文献
72.
Addition of sodium/potassium alloy to THF solutions containing dodecamethylcyclohexasilane and a diene or a silane, affords silacyclopentenes and disilanes, respectively. 相似文献
73.
Host sensitized energy transfer in CaWO4 doped with Eu3+ and Sm3+ is investigated using pulsed laser time-resolved spectroscopy techniques. The excitation is into the long wavelength tail of the absorption edge and the results indicate that this selectively excites tungstate ions which are located next to activator impurity ions. The subsequent energy transfer is found to be consistent with a single step, nearest neighbor process. Both electric dipole-dipole and exchange interactions can predict strong enough transfer to account for the observed rates. These results are compared to those obtained previously for broad band excitation into the highest energy absorption bands of CaWO4 crystals. 相似文献
74.
S. F. Peterson F. Tera G. H. Morrison 《Journal of Radioanalytical and Nuclear Chemistry》1969,2(1-2):115-125
Isotopic ion exchange for the rapid separation of radioactive mixtures has been further extended through the use of an acetone-water-hydrochloric
acid system. Distribution data were obtained for 27 elements in the range of 15–90% acetone, 0.3N HCl indicating a number of new separations. The approach was used for the separation of several radioisotopes from short
half-life magnesium matrix for activation analysis. The separations were completed in less than 5 minutes.
Research supported by the Advanced Research Projects Agency. 相似文献
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76.
W.K. Chen N.L. Peterson L.C. Robinson 《Journal of Physics and Chemistry of Solids》1973,34(4):705-709
Diffusion of 51Cr in NiO single crystals in air has been studied by the tracer-sectioning technique. In the temperature range 1192–1642°C, the diffusion coefficient can be expressed by the Arrhenius expression D=Doexp(-Q/RT), with Do=(8·6±1·2)×10?3 cm2/sec and Q=67·4±1·1 kcal/mole. The use of a high specific-activity tracer and a special configuration for the diffusion anneal prevented the self-dopling effect found by Seltzer and the evaporation of chromium from the sample surface. The present results, in conjunction with published results on nickel self-diffusion in NiO and interdiffusion in the NiO?Cr2O3 system, are used to determine a chromium ion-vacancy binding energy of about 5 kcal/mole in pure NiO. 相似文献
77.
The inelastic scattering of protons, deuterons, τ and α from50Cr has been studied. Spins, parities and transition strengths have been inferred for many states. The 1.89 MeV 4+state is excited by a double-excitation process, but more weakly than expected for a two-phonon state. A weak 5? state is found at 4.37 MeV, and a 5+ state is inferred at 3.792 MeV. 相似文献
78.
D. W. Peterson 《Journal of Optimization Theory and Applications》1974,13(1):56-73
Two types of interpretations of multipliers in both static and dynamic optimization problems are described. It is snown that the Lagrange multipliers encountered in mathematical programming problems and the auxiliary functions arising in Pontryagintype optimal control problems sometimes have highly analogous interpretations as rates of change of the optimal attainable value of an objective function, or in some cases as bounds on average rates of change. 相似文献
79.
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