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排序方式: 共有492条查询结果,搜索用时 15 毫秒
121.
Uchiyama T Kumaki S Ishikawa Y Onodera M Sato M Du W Sasahara Y Tanaka N Sugamura K Tsuchiya S 《Biochemical and biophysical research communications》2006,341(2):391-398
Recently, a serious adverse effect of uncontrolled clonal T cell proliferation due to insertional mutagenesis of retroviral vector was reported in X-SCID gene therapy clinical trial. To offset the side effect, we have incorporated a suicide gene into therapeutic retroviral vector for selective elimination of transduced cells. In this study, B-cell lines from two X-SCID patients were transduced with bicistronic retroviral vector carrying human gamma c chain cDNA and Herpes simplex virus thymidine kinase gene. After confirmation of functional reconstitution of the gamma c chain, the cells were treated with ganciclovir (GCV). The gamma c chain positive cells were eliminated under low concentration without cytotoxicity on untransduced cells and have not reappeared at least for 5 months. Furthermore, the gamma c chain transduced cells were still sensitive to GCV after five months. These results demonstrated the efficacy of the suicide gene therapy although further in vivo studies are required to assess feasibility of this approach in clinical trial. 相似文献
122.
Takashi Yanagida Tomoaki Minowa Yoshihisa Shimizu Yukihiko Matsumura Yoji Noda 《Bioresource technology》2009,100(20):4884-4886
A new method for suspending a fine, activated carbon catalyst in a biomass feedstock used for a supercritical water gasification (SCWG) continuous reactor is proposed. In a previous study, the organic matter in poultry manure was shown to be completely converted into gases such as H2, CO2 and CH4 using SCWG. In practice, however, since the feedstock is not only composed of organic matter, but also contains inorganic material, water and catalyst, products such as gas, solid and liquid are produced during SCWG. The aim of this work was to investigate SCWG by-product utilization. This paper describes fundamental studies on the recovery of materials from SCWG products to develop a novel and simple recycling process that utilizes the by-products. A major portion of the activated carbon, monetite and ammonium sulfate can be isolated from the SCWG effluent. 相似文献
123.
The mechanisms of cell death induced by hypoxia or ischemia are not yet fully understood. We have previously demonstrated that cell death induced by hypoxia occurs independently of caspases, and is mediated by phospholipase A2 (PLA2).Here, we show that p38 mitogen-activated protein kinase is activated under hypoxia. A selective inhibitor of p38 or decrease in the p38alpha protein level prevents hypoxia-induced cell death. The p38 inhibitor abolishes PLA2 activation by hypoxia, indicating that p38 acts upstream of PLA2. The antioxidant N-acetyl-cysteine inhibits activation of p38 and cell death induced by hypoxia, indicating that reactive oxygen species (ROS) are responsible for p38 activation. These results demonstrate that the ROS/p38/PLA2 signaling axis has a crucial role in caspase-independent cell death induced by hypoxia. 相似文献
124.
Ken Horii Takashi Adachi Takanori Tanino Tsutomu Tanaka Hiroshi Sahara Seiji Shibasaki Chiaki Ogino Yoji Hata Mitsuyoshi Ueda Akihiko Kondo 《Biotechnology letters》2009,31(8):1259-1264
A molecular display technology that uses the displayed proteins on cell surfaces has many applications in microbiology and
molecular biology. Here, we describe the resistance of displayed proteins to proteases using simulated gastric fluid (SGF),
which included pepsin at pH 2. The displayed β-glucosidase resisted pepsin digestion compared with secreted, free β-glucosidase.
In SDS-PAGE and Western blotting analysis, the secreted β-glucosidase was immediately digested within 1 min following SGF
treatment, although the displayed β-glucosidase was stable for more than 60 min following SGF treatment. In addition, the
residual activity of secreted β-glucosidase was completely destroyed after 10 min SGF treatment. However, displayed β-glucosidase
retained 14% of its residual activity following the same treatment. These results clearly show that cell surface display technology
using enzymes can reveal the protease resistance of a protein of interest under various conditions. 相似文献
125.
Ken Horii Takashi Adachi Takanori Tanino Tsutomu Tanaka Atsushi Kotaka Hiroshi Sahara Tsuneharu Hashimoto Nobuyuki Kuratani Seiji Shibasaki Chiaki Ogino Hideo Noda Yoji Hata Mitsuyoshi Ueda Akihiko Kondo 《Enzyme and microbial technology》2010,46(3-4):194-199
We used cutinase from the filamentous fungi Aspergillus oryzae to produce dairy flavors. Secretory and displayed forms of cutinase were investigated using salt-free butter, which is composed mostly of triacylglycerides, as the substrate. The secretory form of cutinase, which was produced in recombinant A. oryzae, was suitable for producing butyric acids (16.8 mol%). Also, cutinase displayed on the cell surface of the yeast Saccharomyces cerevisiae as a fusion protein with α-agglutinin released butyric acid at a 2.7-fold rate (45.4 mol%) higher than that of the secreted form. Yeasts carrying two copies of cutinase genes into their chromosomes, which were constructed using the HELOH method, released free fatty acids rapidly and showed 2-fold higher lipase activity compared with yeasts carrying one copy of the cutinase gene. 相似文献
126.
Takashi Asahi Hajime Kondo Mitsuharu Masuda Hoyoku Nishino Yasuaki Aratani Yuji Naito Toshikazu Yoshikawa Shinsuke Hisaka Yoji Kato Toshihiko Osawa 《The Journal of biological chemistry》2010,285(12):9282-9291
Myeloperoxidase (MPO) generates reactive halogenating species that can modify DNA. The aim of this study was to investigate the formation of 8-halogenated 2′-deoxyguanosines (8- halo-dGs) during inflammatory events. 8-Bromo-2′-dG (8-BrdG) and 8-chloro-2′-dG (8-CldG) were generated by treatment of MPO with hydrogen peroxide at physiological concentrations of Cl− and Br−. The formation of 8-halo-dGs with other oxidative stress biomarkers in lipopolysaccharide-treated rats was assessed by liquid chromatography tandem mass spectrometry and immunohistochemistry using a novel monoclonal antibody (mAb8B3) to 8-BrdG-conjugated keyhole limpet hemocyanin. The antibody recognized both 8-BrdG and 8-CldG. In the liver of lipopolysaccharide-treated rats, immunostaining for 8-halo-dGs, halogenated tyrosines, and MPO were increased at 8 h, whereas those of 8-oxo-2′-dG (8-OxodG) and 3-nitrotyrosine were increased at 24 h. Urinary excretion of both 8-CldG and 8-BrdG was also observed earlier than those of 8-OxodG and modified tyrosines (3-nitrotyrosine, 3-chlorotyrosine, and 3- bromotyrosine). Moreover, the levels of the 8-halo-dGs in urine from human diabetic patients were 8-fold higher than in healthy subjects (n = 10, healthy and diabetic, p < 0.0001), whereas there was a moderate difference in 8-OxodG between the two groups (p < 0.001). Interestingly, positive mAb8B3 antibody staining was observed in liver tissue from hepatocellular carcinoma patients but not in liver tissue from human cirrhosis patients. These data suggest that 8-halo-dGs may be potential biomarkers of early inflammation. 相似文献
127.
Seiichi Kanzaki Akira Yamaguchi Kayoko Yamaguchi Yoshitsugu Kojima Kyoko Suzuki Noriko Koumitsu Yoji Nagashima Kiyotaka Nagahama Michiko Ehara Yoshio Hirayasu Akihide Ryo Ichiro Aoki Shoji Yamanaka 《PloS one》2010,5(8)
Background
Sandhoff disease is a lysosomal storage disorder characterized by the absence of β-hexosaminidase and storage of GM2 ganglioside and related glycolipids. We have previously found that the progressive neurologic disease induced in Hexb −/− mice, an animal model for Sandhoff disease, is associated with the production of pathogenic anti-glycolipid autoantibodies.Methodology/Principal Findings
In our current study, we report on the alterations in the thymus during the development of mild to severe progressive neurologic disease. The thymus from Hexb −/− mice of greater than 15 weeks of age showed a marked decrease in the percentage of immature CD4+/CD8+ T cells and a significantly increased number of CD4+/CD8− T cells. During involution, the levels of both apoptotic thymic cells and IgG deposits to T cells were found to have increased, whilst swollen macrophages were prominently observed, particularly in the cortex. We employed cDNA microarray analysis to monitor gene expression during the involution process and found that genes associated with the immune responses were upregulated, particularly those expressed in macrophages. CXCL13 was one of these upregulated genes and is expressed specifically in the thymus. B1 cells were also found to have increased in the thy mus. It is significant that these alterations in the thymus were reduced in FcRγ additionally disrupted Hexb −/− mice.Conclusions/Significance
These results suggest that the FcRγ chain may render the usually poorly immunogenic thymus into an organ prone to autoimmune responses, including the chemotaxis of B1 cells toward CXCL13. 相似文献128.
129.
130.
Characterization of the solution properties of Pichia farinosa killer toxin using PGSE NMR diffusion measurements 总被引:1,自引:1,他引:0
William S. Price Fumihiko Tsuchiya Chise Suzuki Yoji Arata 《Journal of biomolecular NMR》1999,13(2):113-117
The solution behaviour with respect to pH and NaCl concentration of the tertiary structure and propensity for aggregation of salt- mediated killer toxin (SMKT) from Pichia farinosa was examined using pulsed-gradient spin-echo NMR diffusion measurements. It was found that in 0.15m NaCl the tertiary structure of SMKT was constant below pH 5.0, with the native SMKT existing as an unaggregated heterodimer containing the -subunit in a compactly folded form. However, above pH 5.0 the -subunit dissociated and lost its compact structure, becoming a random coil with an 37% increase in effective hydrodynamic radius. To determine the effects of NaCl concentration on the tertiary structure of SMKT, diffusion measurements were performed at pH 3.5 and NaCl concentrations up to 2M. Both the tertiary structure and aggregation state of SMKT were found to be insensitive to the salt concentration which indicates that the activity of the toxin is not a direct result of salt–protein interactions. 相似文献