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31.
Asish Ray Chaudhuri Isao Tomita Fukutaro Mizuhashi Kyoji Murata Richard F. Ludue?a 《Journal of Protein Chemistry》1998,17(7):685-690
IKP104 is one of a group of tubulin-binding drugs whose interaction with tubulin suggests that it may bind to the protein
at or close to the region where vinblastine binds. By itself IKP104 is a potent enhancer of tubulin decay as evidenced by
the fact that it induces the exposure of the sulfhydryl groups and hydrophobic areas on tubulin. In this respect, IKP104 differs
from vinblastine and other drugs such as phomopsin A, dolastatin 10, rhizoxin, and maytansine which are competitive or noncompetitive
inhibitors of vinblastine binding. In contrast, however, in the presence of colchicine, IKP104 behaves differently and strongly
stabilizes tubulin, to an extent much greater than does colchicine alone. IKP104 appears to have two classes of binding site
on tubulin, differing in affinity; the acceleration of decay appears to be mediated by the low-affinity site (Chaudhuriet al., 1998,J. Protein Chem., in press). We investigated the relationship of the binding of IKP104 and vinblastine. We found that the high-affinity site
or sites of IKP104 overlap with or interact with the vinblastine-binding sites, but that the low-affinity site is distinctly
different. 相似文献
32.
Saito M Matsuura T Nagatsuma K Tanaka K Maehashi H Shimizu K Hataba Y Kato F Kashimori I Tajiri H Braet F 《The Journal of membrane biology》2007,217(1-3):115-121
Functional intact liver organoid can be reconstructed in a radial-flow bioreactor when human hepatocellular carcinoma (FLC-5),
mouse immortalized sinusoidal endothelial M1 (SEC) and A7 (HSC) hepatic stellate cell lines are cocultured. The structural
and functional characteristics of the reconstructed organoid closely resemble the in vivo liver situation. Previous liver organoid studies indicated that cell-to-cell communications might be an important factor
for the functional and structural integrity of the reconstructed organoid, including the expression of fenestrae. Therefore,
we examined the possible relationship between functional intact gap junctional intercellular communication (GJIC) and fenestrae
dynamics in M1-SEC cells. The fine morphology of liver organoid was studied in the presence of (1) irsogladine maleate (IM),
(2) oleamide and (3) oleamide followed by IM treatment. Fine ultrastructural changes were studied by transmission electron
microscopy (TEM) and scanning electron microscopy (SEM) and compared with control liver organoid data. TEM revealed that oleamide
affected the integrity of cell-to-cell contacts predominantly in FLC-5 hepatocytes. SEM observation showed the presence of
fenestrae on M1-SEC cells; however, oleamide inhibited fenestrae expression on the surface of endothelial cells. Interestingly,
fenestrae reappeared when IM was added after initial oleamide exposure. GJIC mediates the number of fenestrae in endothelial
cells of the liver organoid. 相似文献
33.
34.
Zhang X Li C Gao H Nabeka H Shimokawa T Wakisaka H Matsuda S Kobayashi N 《Cellular & molecular biology letters》2011,16(2):279-295
We investigated the effects of Rho-associated kinase (ROCK) on migration and cytoskeletal organization in primary human osteoblasts
and Saos-2 human osteosarcoma cells. Both cell types were exposed to two different ROCK inhibitors, Y-27632 and HA-1077. In
the improved motility assay used in the present study, Y-27632 and HA-1077 significantly increased the migration of both osteoblasts
and osteosarcoma cells on plastic in a dose-dependent and reversible manner. Fluorescent images showed that cells of both
types cultured with Y-27632 or HA-1077 exhibited a stellate appearance, with poor assembly of stress fibers and focal contacts.
Western blotting showed that ROCK inhibitors reduced myosin light chain (MLC) phosphorylation within 5 min without affecting
overall myosin light-chain protein levels. Inhibition of ROCK activity is thought to enhance the migration of human osteoblasts
through reorganization of the actin cytoskeleton and regulation of myosin activity. ROCK inhibitors may be potentially useful
as anabolic agents to enhance the biocompatibility of bone and joint prostheses. 相似文献
35.
36.
Yu Kitadate David J. Jörg Moe Tokue Ayumi Maruyama Rie Ichikawa Soken Tsuchiya Eri Segi-Nishida Toshinori Nakagawa Aya Uchida Chiharu Kimura-Yoshida Seiya Mizuno Fumihiro Sugiyama Takuya Azami Masatsugu Ema Chiyo Noda Satoru Kobayashi Isao Matsuo Yoshiakira Kanai Shosei Yoshida 《Cell Stem Cell》2019,24(1):79-92.e6
37.
38.
Distinct DNA methylation activity of Dnmt3a and Dnmt3b towards naked and nucleosomal DNA 总被引:6,自引:0,他引:6
Takeshima H Suetake I Shimahara H Ura K Tate S Tajima S 《Journal of biochemistry》2006,139(3):503-515
In mammals, the resetting of DNA methylation patterns in early embryos and germ cells is crucial for development. De novo type DNA methyltransferases Dnmt3a and Dnmt3b are responsible for creating DNA methylation patterns during embryogenesis and in germ cells. Although their in vitro DNA methylation properties are similar, Dnmt3a and Dnmt3b methylate different genomic DNA regions in vivo. In the present study, we have examined the DNA methylation activity of Dnmt3a and Dnmt3b towards nucleosomes reconstituted from recombinant histones and DNAs, and compared it to that of the corresponding naked DNAs. Dnmt3a showed higher DNA methylation activity than Dnmt3b towards naked DNA and the naked part of nucleosomal DNA. On the other hand, Dnmt3a scarcely methylated the DNA within the nucleosome core region, while Dnmt3b significantly did, although the activity was low. We propose that the preferential DNA methylation activity of Dnmt3a towards the naked part of nucleosomal DNA and the significant methylation activity of Dnmt3b towards the nucleosome core region contribute to their distinct methylation of genomic DNA in vivo. 相似文献
39.
40.
Shigekiyo Matsumoto Chihiro Shingu Hironori Koga Satoshi Hagiwara Hideo Iwasaka Takayuki Noguchi Isao Yokoi 《Neurochemical research》2010,35(7):1010-1016
Electron spin resonance (ESR)-silent ascorbate solutions generate a detectable, likely concentration-dependent signal of ascorbyl
free radicals (AFR) immediately upon addition of a molar excess of dimethyl sulfoxide (DMSO). We aimed to perform quantitative
ESR analysis of AFR in real time after addition of DMSO (AFR/DMSO) to evaluate ascorbate concentrations in fresh hippocampus
or plasma following systemic administration of kainate in mice. Use of a special tissue-type quartz cell allowed immediate
detection of AFR/DMSO ESR spectra in fresh tissues from mice. AFR/DMSO content was increased significantly in fresh hippocampus
or plasma obtained during kainate-induced seizures of mice, reaching maximum levels at 90 min after intraperitoneal administration
of 50 mg/kg kainic acid. This suggests that oxidative injury of the hippocampus resulted from the accumulation of large amounts
of ascorbic acid in the brain after kainic acid administration. AFR/DMSO content measured on an ESR spectrometer can be used
for real-time evaluation of ascorbate content in fresh tissue. Due to the simplicity, good performance, low cost and real-time
monitoring of ascorbate, this method may be applied to clinical research and treatment in the future. 相似文献