To obtain the most accurate predictions for the Higgs masses in the minimal supersymmetric model (MSSM), one should compute the full set of one-loop radiative corrections, resum the large logarithms to all orders, and add the dominant two-loop effects. A complete computation following this procedure yields a complex set of formulae which must be analyzed numerically. We discuss a very simple approximation scheme which includes the most important terms from each of the three components mentioned above. We estimate that the Higgs masses computed using our scheme lie within 2 GeV of their theoretically predicted values over a very large fraction of MSSM parameter space. 相似文献
This work reports the radioiodination of human thyrotropin (hTSH) in our laboratory (IPEN) and evaluates its quality in comparison with a commercial product. The radioiodination yield obtained in 20 experiments ranged from 18.5 to 56.3%, while the purification recovery ranged from 75.5 to 124.0% and the specific activity ranged from 1.01 to 3.10 MBq g–1. The values for the distribution coefficient revealed in the purification of radioiodinated hTSH ranged from 0.232 to 0.371. When tested concomitantly in the same radioimmunoassay system, the IPEN and the commercial tracer presented parallel standard curves. A highly significant correlation ion was observed between the quality control samples estimated through both curves (p<0.001). These results confirm the quality of the hTSH radioiodinated at IPEN and suggest the acquirement of self-sufficiency in this in vitro nuclear technology. 相似文献
Due to their restricted conformational flexibility, cyclic peptides are of great interest in connection with structure-activity relationships, especially the elucidation of bioactive conformations. For linear peptides that do not contain turn structure-inducing amino acid residues, the cyclization reaction may be an inherently improbable or slow process, and side reactions, such as cyclodimerization and epimerization at the C-terminal residue, may dominate. A number of 1-hydroxy-7-azabenzotriazole-based onium salts were examined for cyclization of thymopentin-derived pentapeptides and the results compared with data from more conventional coupling reagents. The azabenzotriazol-derived coupling reagents stood out as being the most effective by far. The cyclizations proceed extremely rapidly, and in contrast to other coupling reagents, C-terminal epimerization was generally less than 10%. C-terminal D-amino acid residues favor the formation of monocyclic pentapeptide rings. A similar effect was observed for cyclization of linear N-methylamino acid-containing peptides, suggesting that reversible amide bond alkylation such as Hmb-modification should be useful in promoting the cyclization of pepitdes devoid of turn-inducing amino acid residues. 相似文献
Photoelectron spectra of Cu2Mo3O10 catalysts in different conditions of catalytic propylene oxidation show that in an oxidizing atmosphere reversible surface reconstruction takes place, directing the reaction to selective oxidation to acrolein, whereas in reducing atmosphere total oxidation takes place.
IR spectra of propylene adsorbed in CoO-MgO and CoO-MgO-MoO3 solid solutions show that a surface -complex with Co2+ ions is formed, strongly bonded in the former case and weakly in the latter. Thus, introduction of Mo strongly modifies the catalytic properties of Co2+ active centers. In the presence of oxygen, allylic species, aldehyde and carboxylate complexes appear.
For certain ranges of masses of the supersymmetric partners of the gluons, quarks and W-bosons, it is expected that a few events of production and decay of the partners could be observed at the CERN pp? collider. The characteristic signatures are events with where ?± is an isolated charged lepton, j is a hadron jet and stands for missing pT. Some recently reported events are of this type. 相似文献
Liquid phase catalytic oxidation of acrolein in the presence of Co(III) and Mo(VI) complexes was investigated. The addition of a Mo(VI) complex was found to accelerate the reaction at higher, and retard it at lower, Co(III) concentrations.