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排序方式: 共有65条查询结果,搜索用时 218 毫秒
1.
Rectal absorption of morphine from various kinds of suppository bases was investigated. The extent of bioavailability of morphine by rectal administration varied with the bases used (30.5-97.5%), but every value was higher than that in the case of oral administration (13.5%). Witepsol bases were preferable to macrogol base for the rectal absorption of morphine. In particular, Witepsol S-55 or W-35 gave a higher plasma peak level than H-15 or E-75, whereas the difference in the mean residence times obtained from these bases could not be regarded as significant. Sustained-release suppositories of morphine could be prepared simply by mixing alginic acid (Alg) with morphine in a suppository base. Further, prolonged rectal absorption could be obtained by using these sustained-release suppositories, and the absorption rate was controlled by the amount of Alg added. It seems likely that the sustained release was due to the binding of morphine to Alg from the results of partition coefficient and binding ratio measurements in aqueous solution. The rapid initial absorption and the subsequent prolonged absorption of morphine simultaneously obtained from the morphine-Alg suppository may be useful in the clinical context. 相似文献
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The methodology for a copper-catalyzed preparation of diaryl chalcogenide compounds from aryl iodides and diphenyl dichalcogenide molecules is reported. Unsymmetrical diaryl sulfide or diaryl selenide can be synthesized from aryl iodide and PhYYPh (Y = S, Se) with a copper catalyst (CuI or Cu(2)O) and magnesium metal in one pot. This reaction can be carried out under neutral conditions according to an addition of magnesium metal as the reductive reagent. Furthermore, it is efficiently available for two monophenylchalcogenide groups generated from diphenyl dichalcogenide. 相似文献
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5.
Nobukazu Taniguchi 《Tetrahedron》2009,65(14):2782-1357
A copper-catalyzed synthesis of β-haloalkenyl sulfides or selenides was carried out by addition of dichalcogenides and tetrabutylammonium halides to internal alkynes. The present reaction anti- and regio-selectively afforded the corresponding alkenyl chalocogenides, and took advantage of both organochalcogenide-groups on dichalcogenide. Furthermore, the reaction under oxygen atmosphere could employ thiols. The use of the procedure could easily synthesize (Z)-tamoxifen from diphenyl acetylene in three steps. 相似文献
6.
Xiang L Ishii T Hosoda K Kamiya A Enomoto M Nameki N Inoue Y Kubota K Kohno T Wakamatsu K 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2008,194(1):147-151
Prevention of aggregation is critical for analyzing protein structure. Non-detergent sulfobetaines (NDSBs) are known to prevent protein aggregation, but the molecular mechanisms of their anti-aggregation effect are poorly understood. To elucidate the underlying mechanisms, we analyzed the effects of dimethylethylammonium propane sulfonate (NDSB-195) on acidic fibroblast growth factor (aFGF). NDSB-195 (0.5M) increased both aggregation and denaturation temperatures of aFGF by 4 degrees C. Chemical shift perturbation analyses indicated that many affected residues were located at the junction between a beta-strand (or 3(10)-helix) and a loop, irrespective of the chemical properties of the residue. The apparent dissociation constants of the interaction ranged from 0.04 to 3M, indicating weak interactions between NDSB and protein molecules. 相似文献
7.
Abdominal apparent diffusion coefficient measurements: effect of diffusion-weighted image quality and usefulness of anisotropic images 总被引:1,自引:0,他引:1
Yoshikawa T Ohno Y Kawamitsu H Ku Y Seo Y Zamora CA Aoyama N Sugimura K 《Magnetic resonance imaging》2008,26(10):1415-1420
This study aimed to assess the effect of diffusion-weighted image (DWI) quality on abdominal apparent diffusion coefficient (ADC) measurements and the usefulness of anisotropic images. Twenty-six patients (10 men and 16 women; mean, 58.1 years) who underwent DW imaging and were diagnosed not to have any abdominal diseases were analyzed. Single-shot spin-echo echo-planar DW imaging was performed, and one isotropic and three orthogonal anisotropic images were created. ADCs were calculated for liver (four segments), spleen, pancreas (head, body, tail) and renal parenchyma. Image quality for each organ part was scored visually. We estimated the correlation between ADC and image quality and evaluated the feasibility of using anisotropic images. ADCs and image quality were affected by motion probing gradient directions in the liver and pancreas. A significant inverse correlation was found between ADC and image quality. The r values for isotropic images were −.46, −.48, −.70 and −.28 for the liver, spleen, pancreas and renal parenchyma, respectively. Anisotropic images had the best quality and lowest ADC in at least one organ part in 17 patients. DWIs with the best quality among isotropic and anisotropic images should be used in the liver and pancreas. 相似文献
8.
Takei T Yonesaki Y Kumada N Kinomura N 《Langmuir : the ACS journal of surfaces and colloids》2008,24(16):8554-8560
The preparation of hybrid films of metal (Ti and Sn) phosphate nanosheets and polyaniline by simultaneous electrophoretic and electrolytic deposition was performed in an acetonitrile solvent. Emeraldine polyaniline was intercalated between the phosphate nanosheets with a monolayer arrangement. The obtained hybrid films were several tens of micrometers in thickness. The ratio of incorporated polyaniline to metal phosphate in the hybrid films reaches to around 0.45 and 0.30 at suitable concentrations of tetrabutylammonium hydroxide (TBAOH). These amounts correspond with occupancy of polyaniline in the interlayer gallery of several tens percent. Fractions of voids in a horizontal direction were around 22 and 1% in titanium phosphate/polyaniline and tin phosphate/polyaniline hybrid films, respectively. Thus, anodic electrodeposition makes it possible to form thick films of intercalation compounds of alpha-titanium and tin phosphates with polyaniline. These hybrid films were examined for redox activity. The cyclic voltammetry results of these films confirmed that the hybrid films have redox activity by polyaniline. For these voltammograms, the maximum current was observed in the tin phosphate/polyaniline hybrid deposited for 15 min. The redox activity of these hybrids possibly depends on the mesoscopic texture of the film, especially on the amount of voids in a horizontal direction. 相似文献
9.
[structure: see text] The addition of oligothiophene into a dendritic structure causes a self-association behavior by intermolecular pi-pi interactions in a solution and in a solid state. Increasing the generation of the dendritic structure gives not only a high association constant but also sufficient field-effect hole mobility, which indicates that the charge-transporting passes are formed by the strong pi-pi interactions. 相似文献
10.
Katsuhiro Munakata Kenji Harada Nobukazu Yoshikawa Masahide Itoh Shinsuke Umegaki Toyohiko Yatagai 《Optical Review》1999,6(6):518-521
Two fabrication methods of surface relief electro-optic (EO) gratings in azo-polymer films are described: surface deformation by a continuous wave laser and laser ablation by a pulse laser. In the fabrication process, the periodic intensity modulation of laser beams is formed by an interference fringe or a phase mask. The surface relief EO grating is fabricated by poling the surface relief grating (SRG) after the SRG fabrication process. The linear dependence of an applied voltage in the modulation efficiency of the first-order diffraction beam is observed. The proposed methods are effective for highly-efficient surface relief EO grating fabrication. 相似文献