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991.
A toy model is proposed in which the cosmological constant and the baryon number density of the Universe are interrelated. The model combines the mechanism of Dimopoulos and Susskind [S. Dimopoulos, L. Susskind, Phys. Rev. D 18 (1978) 4500] in which the baryon number density of the Universe is generated by the time-dependence of the phase of a complex scalar field, i.e. its ‘angular momentum’ in the two-dimensional complex field space, with that of Yoshimura [M. Yoshimura, Phys. Lett. B 608 (2005) 183, hep-ph/0410183] in which the ‘centrifugal force’ due to the ‘angular momentum’ pushes the vacuum expectation value of the scalar field out of a negative potential minimum and provides a small but positive cosmological constant. Unfortunately, our model fails to relate the smallness of the two numbers directly, requiring a fine-tuning of the negative potential minimum. 相似文献
992.
993.
Discovery of N-(3-{4-[(3-fluorobenzyl)oxy]phenoxy}propyl)-2-pyridin-4-ylacetamide as a potent and selective reverse NCX inhibitor 总被引:1,自引:0,他引:1
Kuramochi T Kakefuda A Yamada H Ogiyama T Taguchi T Sakamoto S 《Chemical & pharmaceutical bulletin》2005,53(8):1043-1047
In the setting of heart failure and myocardial ischemia-reperfusion, the sodium-calcium exchanger (NCX) can lead to calcium overload, which is responsible for contractile dysfunction and arrhythmia. NCX is an attractive target for treatment in heart failure and myocardial ischemia-reperfusion. We have designed and synthesized a series of benzyloxyphenyl derivatives based on compound 3. These derivatives have been evaluated for their inhibitory activity against both the reverse and forward modes of NCX. We have discovered a novel potent and selective reverse NCX inhibitor (12) with an IC50 value of 0.085 microM against reverse NCX. 相似文献
994.
Inamoto K Yamamoto A Ohsawa K Hiroya K Sakamoto T 《Chemical & pharmaceutical bulletin》2005,53(11):1502-1507
We have developed a highly regioselective synthesis of heterocycles via palladium-catalyzed annulation reaction of heteroatom-substituted allenes. Various aryl halides were reacted and one regioisomer was observed exclusively in all reactions. In addition, subsequent functionalizations of annulated products were carried out using alkyl metal reagents, and the introduction of alkyl moieties was accomplished. 相似文献
995.
996.
Yoji Imai Tatsuo Tsunoda Kiyoshi Kobayashi Akio Watanabe 《Applied Surface Science》2006,252(8):2858-2866
The preparation of palladium (Pd) films has been investigated using KrF or ArF laser irradiation on a Pd acetate (PdAc) coated substrate. A crystalline Pd film could be obtained by KrF laser irradiation (fluence = 15-40 mJ/cm2) but PdAc was found to remain in the film. An increase in the substrate temperature to 423 K decreased the inclusion of the unreacted precursor and produced a better crystallinity. An amorphous and uniform Pd film composed of very fine particles was found to be formed by this process under reduced pressure, which is probably due to the preferential ablation of the crystalline nuclei. ArF laser irradiation is more effective for decomposing the PdAc and for producing a Pd film with a better crystallinity and no (or smaller) organic inclusion. 相似文献
997.
Hideshi Nakamura Kazuhiro Fujimaki Osamu Sampei Akio Murai 《Tetrahedron letters》1993,34(52):8481-8484
Gonyol, 3S-5-dimethylsulfonio-3-hydroxylpentanoate, was isolated from a dinoflagellate Gonyaulax polyedra cultured in a medium containing methionine and the structure was elucidated by spectroscopic method and confirmed by chemical synthesis. Gonyol was shown to be biogenetically derived from methionine and acetic acid. 相似文献
998.
Shigeru Mase 《Probability Theory and Related Fields》1992,92(1):51-67
Summary A parametric model of planar point patterns in a bounded region is constructed using grand canonical Gibbsian point processes with soft-core potential functions. A simple and explicit condition that this model becomes a uniform locally asymptotic normal (ULAN) family will be given. From this result we can conclude that the maximum likelihood estimator of the potential function is asymptotically efficient for a wide class of loss functions. 相似文献
999.
1000.