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141.
Shimanouchi K Takata K Yamaguchi M Murakami S Ishikawa G Takeuchi R Kanai Y Ruike T Nakamura R Abe Y Sakaguchi K 《Journal of biochemistry》2006,139(1):51-58
The damaged DNA-binding protein (DDB) complex consists of a heterodimer of p127 (DDB1) and p48 (DDB2) subunits and is believed to have a role in nucleotide excision repair (NER). We used the GAL4-UAS targeted expression system to knock down DDB1 in wing imaginal discs of Drosophila. The knock-down was achieved in transgenic flies using over-expression of inverted repeat RNA of the D-DDB1 gene [UAS-D-DDB1(650)-dsRNA]. As a consequence of RNA interference (RNAi), the fly had a shrunken wing phenotype. The wing spot test showed induced genome instability in transgenic flies with RNAi knock-down of D-DDB1 in wing imaginal discs. When Drosophila larvae with RNAi knock-down of D-DDB1 in wing imaginal discs were treated with the chemical mutagen methyl methanesulfonate (MMS), the frequency of flies with a severely shrunken wing phenotype increased compared to non-treated transgenic flies. These results suggested that DDB1 plays a role in the response to DNA damaged with MMS and in genome stability in Drosophila somatic cells. 相似文献
142.
Nishimura K Li W Hoshino Y Kadohama T Asada H Ohgi S Sumpio BE 《American journal of physiology. Cell physiology》2006,290(3):C812-C821
Endothelial cells (ECs) are exposed to repetitive cyclic strain (CS) in vivo by the beating heart. The aim of this study was to assess the influence of CS amplitude and/or frequency on EC proliferation and survival and to determine the role of AKT in CS-induced EC proliferation and survival. Cultured bovine aortic ECs were exposed to 10% strain at a frequency of 60 (60 cpm-10%) or 100 (100 cpm-10%) cycles/min or 15.6% strain at a frequency of 60 cycles/min (60 cpm-15.6%). AKT, glycogen synthase kinase (GSK)-3, BAD, and cleaved caspase-3 were activated by CS in ECs. Increasing the magnitude or frequency of strain resulted in an earlier phosphorylation of GSK-3, although the magnitude of phosphorylation was similar. After CS at 60 cpm-10% for 24 h, the number of nontransfected ECs was significantly increased by 8.5% (P < 0.05). We found that the number of apoptotic ECs was slightly decreased with exposure to CS. ECs transfected with kinase-dead AKT (KA179) as well as plasmids containing a point mutation in the pleckstrin homology domain of AKT (RC25) not only prevented AKT, GSK-3, and BAD phosphorylation but also inhibited the CS-induced increase in cell number as well as the CS-induced protection against apoptosis (both P < 0.05). The ratio of 5'-bromo-2'-deoxyuridine-positive cells was increased when ECs transfected with RC25 and KA179 as well as nontransfected ECs and ECs transfected with Lipofectamine 2000 were exposed to CS. We conclude that AKT is important in enhancing the survival of ECs exposed to CS but is not involved in EC proliferation. apoptosis; glycogen synthase kinase 相似文献
143.
Yamasaki T Deguchi M Fujimoto T Masumura T Uno T Kanamaru K Yamagata H 《Bioscience, biotechnology, and biochemistry》2006,70(5):1200-1209
The complete nucleotide sequences of the cDNA and its gene that encode a bifunctional alpha-amylase/subtilisin inhibitor of rice (Oryza sativa L.) (RASI) were analyzed. RASI cDNA (939 bp) encoded a 200-residue polypeptide with a molecular mass of 21,417 Da, including a signal peptide of 22 amino acids. Sequence comparison and phylogenetic analysis showed that RASI is closely related to alpha-amylase/subtilisin inhibitors from barley and wheat. RASI was found to be expressed only in seeds, suggesting that it has a seed-specific function. A coding region of RASI cDNA without the signal peptide was introduced into Escherichia coli and was expressed as a His-tagged protein. Recombinant RASI was purified to homogeneity in a single step by Ni-chelating affinity column chromatography and characterized to elucidate the target enzyme. The recombinant inhibitor had strong inhibitory activity toward subtilisin, with an equimolar relationship, comparable with that of native RASI, and weak inhibitory activity toward some microbial alpha-amylases, but not toward animal or insect alpha-amylases. These results suggest that RASI might function in the defense of the seed against microorganisms. 相似文献
144.
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146.
Kengo Uemura Christina M. Lill† Mary Banks† Megumi Asada‡ Nobuhisa Aoyagi Koichi Ando Masakazu Kubota‡ Takeshi Kihara§ Takaaki Nishimoto§ Hachiro Sugimoto§ Ryosuke Takahashi Bradley T. Hyman† Shun Shimohama¶ Oksana Berezovska† Ayae Kinoshita‡ 《Journal of neurochemistry》2009,108(2):350-360
In neurons, Presenilin 1(PS1)/γ-secretase is located at the synapses, bound to N-cadherin. We have previously reported that N-cadherin-mediated cell–cell contact promotes cell-surface expression of PS1/γ-secretase. We postulated that N-cadherin-mediated trafficking of PS1 might impact synaptic PS1-amyloid precursor protein interactions and Aβ generation. In the present report, we evaluate the effect of N-cadherin-based contacts on Aβ production. We demonstrate that stable expression of N-cadherin in Chinese hamster ovary cells, expressing the Swedish mutant of human amyloid precursor protein leads to enhanced secretion of Aβ in the medium. Moreover, N-cadherin expression decreased Aβ42/40 ratio. The effect of N-cadherin expression on Aβ production was accompanied by the enhanced accessibility of PS1/γ-secretase to amyloid precursor protein as well as a conformational change of PS1, as demonstrated by the fluorescence lifetime imaging technique. These results indicate that N-cadherin-mediated synaptic adhesion may modulate Aβ secretion as well as the Aβ42/40 ratio via PS1/N-cadherin interactions. 相似文献
147.
Kengo Usui Tei Maki Fuyu Ito Atsushi Suenaga Satoru Kidoaki Masayoshi Itoh Makoto Taiji Takehisa Matsuda Yoshihide Hayashizaki Harukazu Suzuki 《Protein science : a publication of the Protein Society》2009,18(5):960-969
Self‐assembly of artificially designed proteins is extremely desirable for nanomaterials. Here we show a novel strategy for the creation of self‐assembling proteins, named “Nanolego.” Nanolego consists of “structural elements” of a structurally stable symmetrical homo‐oligomeric protein and “binding elements,” which are multiple heterointeraction proteins with relatively weak affinity. We have established two key technologies for Nanolego, a stabilization method and a method for terminating the self‐assembly process. The stabilization method is mediated by disulfide bonds between Cysteine‐residues incorporated into the binding elements, and the termination method uses “capping Nanolegos,” in which some of the binding elements in the Nanolego are absent for the self‐assembled ends. With these technologies, we successfully constructed timing‐controlled and size‐regulated filament‐shape complexes via Nanolego self‐assembly. The Nanolego concept and these technologies should pave the way for regulated nanoarchitecture using designed proteins. 相似文献
148.
Takaaki Komatsu Mika Sasaki Kengo Sanai Hikari Kuwahata Chikai Sakurada Minoru Tsuzuki Yohko Iwata Shinobu Sakurada Tsukasa Sakurada 《Peptides》2009,30(9):1689-1696
The present study sought to examine the mechanism of substance P to modulate the antinociceptive action of intrathecal (i.t.) morphine in paw-licking/biting response evoked by subcutaneous injection of capsaicin into the plantar surface of the hindpaw in mice. The i.t. injection of morphine inhibited capsaicin-induced licking/biting response in a dose-dependent manner. Substance P (25 and 50 pmol) injected i.t. alone did not alter capsaicin-induced nociception, whereas substance P at a higher dose of 100 pmol significantly reduced the capsaicin response. Western blots showed the constitutive expression of endopeptidase-24.11 in the dorsal and ventral parts of lumbar spinal cord of mice. The N-terminal fragment of substance P (1–7), which is known as a major product of substance P by endopeptidase-24.11, was more effective than substance P on capsaicin-induced nociception. Combination treatment with substance P (50 pmol) and morphine at a subthreshold dose enhanced the antinociceptive effect of morphine. The enhanced effect of the combination of substance P with morphine was reduced significantly by co-administration of phosphoramidon, an inhibitor of endopeptidase-24.11. Administration of d-isomer of substance P (1–7), [d-Pro2, d-Phe7]substance P (1–7), an inhibitor of [3H] substance P (1–7) binding, or antisera against substance P (1–7) reversed the enhanced antinociceptive effect by co-administration of substance P and morphine. Taken together these data suggest that morphine-induced antinociception may be enhanced through substance P (1–7) formed by the enzymatic degradation of i.t. injected substance P in the spinal cord. 相似文献
149.
Kiyoshi Fujisawa Hiroaki Iwamoto Kengo Tobita Yoshitaro Miyashita Ken-ichi Okamoto 《Inorganica chimica acta》2009,362(12):4500-4509
Copper(II) coordination complexes of the neutral ligand, tris(3-tert-butyl-5-methyl-1-pyrazolyl)methane (L2′), i.e. the copper(II) nitrato complexes [Cu(L2′)(NO3)][Cu(NO3)4]1/2 (1) and [Cu(L2′)(NO3)](ClO4) (2) and the copper(II) chloro complex [Cu(L2′)(Cl)](ClO4) (3), and its anionic borate analogue, hydrotris(3-tert-butyl-5-methyl-1-pyrazolyl)borate (L2−), i.e. the copper(II) nitrato complex [Cu(L2)(NO3)] (4) and the copper(II) chloro complex [Cu(L2)(Cl)] (5), were synthesized in order to investigate the influence of ligand framework and charge on their structure and physicochemical properties. While X-ray crystallography did not show any definitive trends in terms of copper(II) atom geometry in four-coordinate copper(II) chloro complexes 3 and 5, different structural trends were observed in five-coordinate copper(II) nitrato complexes 1, 2, and 4. These complexes were also characterized by spectroscopic techniques, namely, UV-Vis, ESR, IR/far-IR, and X-ray absorption spectroscopy. 相似文献
150.
Sugawara H Iwabata K Koshiyama A Yanai T Daikuhara Y Namekawa SH Hamada FN Sakaguchi K 《Chromosoma》2009,118(1):127-139
Mer3 is an evolutionarily conserved DNA helicase that has crucial roles in meiotic recombination and crossover formation.
We have identified the MER3 homolog in Coprinus cinereus (Ccmer3) and show that it is expressed in zygotene and pachytene meiocytes. Immunostaining analysis indicated that CcMer3 was localized
on chromosomes at zygotene and pachytene and CcMer3 foci were more frequent on paired than unpaired chromosomes. We generated
a C. cinereus mer3 mutant (#1) and found that it showed abnormal meiosis progression and underwent apoptosis after prophase I. Basidiospore
production in #1 was reduced to 0.8% of the wild-type level; the spores showed slower germination at 25°C but were similar
to the wild type at 37°C. Electron microscopic analysis of chromosome spreads revealed that axial elements were formed in
the mutant but that synapsis was defective, resulting in a reduction in spore production. Our results demonstrate that CcMer3
is required for synaptonemal complex formation after axial elements align and is thus essential for homologous synapsis. 相似文献