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排序方式: 共有1344条查询结果,搜索用时 15 毫秒
71.
M Kodama K Akiyama H Ujike Y Shimizu Y Tanaka S Kuroda 《Canadian Metallurgical Quarterly》1998,796(1-2):273-283
The effect of acute and chronic administration of methamphetamine (METH) on the levels of activity-regulated cytoskeleton-associated protein (arc), an effector-immediate early gene, mRNA has been investigated in rat brain using in situ hybridization. Levels of arc mRNAs in the brain regions examined increased significantly from 0.5-1 h after an acute METH (4 mg/kg) administration compared with basal levels. The increase in arc mRNA continued by 3 h, and then subsided to basal levels by 6 h. The degree of increase in arc mRNA and the peak time after METH administration varied according to brain area. Arc mRNA in cerebral cortices showed robust increase 1 h after METH administration. In the striatum and hippocampus, it showed earlier and later increase, respectively, and its degree of both was less than in the cortices. Microscopic examination revealed that the METH-induced arc mRNAs in the parietal cortex were enriched in layers IV and VI, and those in the striatum existed mainly in the medium-sized neuron. Pretreatment with either 0.5 mg/kg SCH23390 or 0.25 mg/kg MK-801 almost completely blocked the enhanced striatal arc mRNA levels induced by acute METH administration, whereas such pretreatments only partially reduced the effect of METH in the cerebral cortical regions. In the chronic treatment experiment, the arc mRNA levels of the group that received chronic treatment with METH followed by a METH challenge showed an increase like seen after acute METH administration. Since previous studies proposed that arc is one of cytoskeleton-associated proteins and is selectively localized in neural dendrites, the results of the present study suggested that arc may play an important role in the synaptic plasticity underlying METH-induced adaptational changes including behavioral sensitization. 相似文献
72.
BACKGROUND: To evaluate the antitumor activity in patients with T3b, T4 or metastatic urothelial carcinoma treated with MEC or M-VAC chemotherapy, by performing a multi-center randomized prospective study. METHODS: From 1991 to 1995, 89 patients with T3b, T4 or metastatic urothelial carcinoma were randomly allocated to a methotrexate, epirubicin and cisplatin chemotherapy group (arm 1: S-MEC therapy; n = 29), a dose-intensified MEC therapy combined with G-CSF group (arm 2: I-MEC therapy; n = 30) or a methotrexate, vinblastine, doxorubicin and cisplatin chemotherapy (arm 3: M-VAC therapy; n = 30). At the registration center, the patients were stratified into previously untreated patients and patients with recurrence after radical operation and then randomly allocated to the treatment groups. In each arm, two or more courses of chemotherapy (4-week cycles) were performed. RESULTS: Of the 88 eligible patients, four treated with S-MEC therapy and two treated with I-MEC therapy showed CR. The response rates (CR + PR) were 52% (15/29) with S-MEC therapy, 76% (22/29) with I-MEC therapy and 47% (14/30) with M-VAC therapy. The response rate with I-MEC therapy was significantly higher than that with M-VAC therapy (P = 0.02). Although the incidence of leukopenia was low with I-MEC therapy, the incidence of thrombocytopenia was high with this therapy. CONCLUSION: MEC therapy used in this study is promising in terms of the antitumor effects. 相似文献
73.
A Seth I Ourmanov MJ Kuroda JE Schmitz MW Carroll LS Wyatt B Moss MA Forman VM Hirsch NL Letvin 《Canadian Metallurgical Quarterly》1998,95(17):10112-10116
The utility of modified vaccinia virus Ankara (MVA) as a vector for eliciting AIDS virus-specific cytotoxic T lymphocytes (CTL) was explored in the simian immunodeficiency virus (SIV)/rhesus monkey model. After two intramuscular immunizations with recombinant MVA-SIVSM gag pol, the monkeys developed a Gag epitope-specific CTL response readily detected in peripheral blood lymphocytes by using a functional killing assay. Moreover, those immunizations also elicited a population of CD8+ T lymphocytes in the peripheral blood that bound a specific major histocompatibility complex class I/peptide tetramer. These Gag epitope-specific CD8+ T lymphocytes also were demonstrated by using both functional and tetramer-binding assays in lymph nodes of the immunized monkeys. These observations suggest that MVA may prove a useful vector for an HIV-1 vaccine. They also suggest that tetramer staining may be a useful technology for monitoring CTL generation in vaccine trials in nonhuman primates and in humans. 相似文献
74.
The fine specificity of the cellular immune response to Candida albicans (i.e., recognition of different antigenic components) between normal controls and human immunodeficiency virus-infected patients in various stages of disease was compared. C. albicans-specific T cells, enriched by antigen stimulation and interleukin-2 expansion, were challenged with antigenic fractions of different molecular weight obtained by SDS-gel fractionation of C. albicans extracts in the presence of autologous mononuclear cells as antigen-presenting cells. Proliferative responses showed similar patterns of reactivity between controls and category A and B seropositive subjects. Category C patients with concurrent C. albicans infections did not give rise to C. albicans-specific T cell lines, confirming the T cell defect. Patients without clinically evident C. albicans infection had a low but broad reactivity pattern of C. albicans-specific T cells. These results suggest that depletion of C. albicans-specific T cells, independent of their fine specificity, occurs along with disease progression. 相似文献
75.
A polyorganosiloxane retaining a SiO4 tetrahedral framework has been synthesized by the reaction of an inosilicate mineral (para-wollastonite) with a trimethylsilylating reagent. The glassy product dissolved in a wide range of organic solvents but was insoluble in water. The analyses of the product by means of infra-red spectroscopy, X-ray powder diffraction and elemental analysis indicated that trimethylsilyl side groups were linked to the SiO4 framework. The thermal stability of the product was determined by thermal analysis. 相似文献
76.
Tominaga J Michizoe J Kamiya N Ichinose H Maruyama T Goto M 《Journal of Bioscience and Bioengineering》2004,98(1):14-19
Catalytic oxidation of biphenyl derivatives was investigated using laccase in a homogeneous aqueous-organic system. A thermostable laccase from Trametes sp. showed the highest catalytic activity for the oxidation of 4-hydroxybiphenyl (4-HB) at a reaction temperature of 60 degrees C when dimethylsulfoxide (DMSO) was employed as a co-solvent. Furthermore, the catalytic performance was successfully enhanced by the incorporation of a laccase mediator system (LMS) into the aqueous-DMSO media. The catalytic performance strongly depended on the type of mediator, and the highest activity was observed with 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as mediator, suggesting the importance of the selection of a suitable mediator. It was verified that this mediator system is applicable to the oxidation of several biphenyl derivatives with hydroxyl groups. 相似文献
77.
The locations of process-induced defects in hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs), which are used as elements of active-matrix liquid crystal displays, were investigated by combining focused ion beam techniques with cross-sectional transmission electron microscopy (X-TEM). The FIB technique is applied to TFT failure analysis problems, which require considerable localised etching without inducing mechanical stress or damage at fragile failure locations. We demonstrate the manner in which these techniques are used to characterise TFT defects such as pinholes and portions of the multilayer damaged by mechanical stress. A dramatic improvement brought about by the FIB technique is the increase in temporal efficiency of sample preparations. X-TEM observations also lead to identification of the fault and analysis of its cause, which in turn lead to a marked yield improvement. 相似文献
78.
Kamino T Yaguchi T Kuroda Y Ohnishi T Ishitani T Miyahara Y Horita Z 《Journal of electron microscopy》2004,53(5):459-463
Transmission electron microscopy (TEM) samples of an Mg-Al alloy has been prepared using a Ga-focused ion beam (FIB) milling at two different operating voltages of 10 kV and 40 kV to investigate the influence of the FIB energy on the sample quality. The fine structures of the samples have been studied using a high resolution TEM, and the concentration of the implanted Ga was analysed using an energy dispersive X-ray (EDX) analysis. The result of the TEM observation revealed that point defects were introduced to the sample finally milled at 40 kV but not at 10 kV. However, crystal lattice images and electron diffraction patterns were clearly observed on both the samples. The typical influence of the FIB energy was indicated in the elemental analysis. The relative Ga concentration in the thin sample finally milled at 10 kV was 1.0-2.0 at% that is less than half of 4.0-6.0 at% of the Ga concentration in the sample finally milled at 40 kV. A comparison between the experimental results of the Ga concentration measurement with simulation was also discussed. 相似文献
79.
Silica films with a single-crystalline mesoporous structure 总被引:1,自引:0,他引:1
Miyata H Suzuki T Fukuoka A Sawada T Watanabe M Noma T Takada K Mukaide T Kuroda K 《Nature materials》2004,3(9):651-656
Films of mesoporous materials attract broad interest because of their wide applicability in the fields of optics and electronics. Although many of these films have a regular local porous structure, the structural regularity has not been used practically yet because of difficulties in its control on macroscopic scales. Here, we demonstrate the preparation of mesoporous silica films whose porous structure can be described as a single crystal, that is, a long-range order of cage-like pores is maintained over centimetre scales. These films have a three-dimensional hexagonal (space group P6(3)/mmc) porous structure, and the in-plane arrangement of the pores is strictly controlled by a polymeric substrate surface that has been treated by rubbing. This new class of single-crystalline films with mesoscopic periodic structure is a significant breakthrough in bottom-up nanotechnology, and could lead to novel devices, for example, optics in a soft X-ray region, and quantum electronics. 相似文献
80.
Wind flows over the 8.2-m Subaru Telescope at Mauna Kea in Hawaii were analyzed with a correlation method. Three or four wind flows were detected from our measurements. Spatial and temporal resolution of the wind-flow analysis across the 8.2 m pupil were investigated experimentally. A three-dimensional spatiotemporal-frequency analysis was also applied to the wind-flow data. 相似文献