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961.
962.
Masaya Yamaguchi Kenji Satoo Hironori Suzuki Yuko Fujioka Yoshinori Ohsumi Fuyuhiko Inagaki Nobuo N. Noda 《Journal of molecular biology》2018,430(3):249-257
Atg8 is a unique ubiquitin-like protein that is covalently conjugated with a phosphatidylethanolamine through reactions similar to ubiquitination and plays essential roles in autophagy. Atg7 is the E1 enzyme for Atg8, and it activates the C-terminal Gly116 of Atg8 using ATP. Here, we report the crystal structure of Atg8 bound to the C-terminal domain of Atg7 in an unprecedented mode. Atg8 neither contacts with the central β-sheet nor binds to the catalytic site of Atg7, both of which were observed in previously reported Atg7–Atg8 structures. Instead, Atg8 binds to the C-terminal α-helix and crossover loop, thereby changing the autoinhibited conformation of the crossover loop observed in the free Atg7 structure into a short helix and a disordered loop. Mutational analyses suggested that this interaction mode is important for the activation reaction. We propose that Atg7 recognizes Atg8 through multiple steps, which would be necessary to induce a conformational change in Atg7 that is optimal for the activation reaction. 相似文献
963.
964.
965.
966.
Shibata H Kamada H Kobayashi-Nishibata K Yoshioka Y Nishibata T Abe Y Nomura T Nabeshi H Minowa K Mukai Y Nakagawa S Mayumi T Tsunoda S Tsutsumi Y 《Biochimica et biophysica acta》2007,1774(8):1029-1035
We have previously produced two bioactive lysine-deficient mutants of TNF-alpha (mutTNF-K90R,-K90P) and found that these mutants have bioactivity superior to wild-type TNF (wtTNF). Because these mutants contained same amino acid except for amino acid 90, it is unclear which amino acid residue is optimal for showing bioactivity. We speculated that this amino acid position was exchangeable, and this amino acid substitution enabled the creation of lysine-deficient mutants with enhanced bioactivity. Therefore, we produced mutTNF-K90R variants (mutTNF-R90X), in which R90 was replaced with other amino acids, to assay their bioactivities and investigated the importance of amino acid position 90. As a result, mutTNF-R90X that replaced R90 with lysine, arginine and proline were bioactive, while other mutants were not bioactive. Moreover, these three mutants showed bioactivity as good as or better than wtTNF. R90 replaced with lysine or arginine had especially superior binding affinities. These results suggest that the amino acid position 90 in TNF-alpha is important for TNF-alpha bioactivity and could be altered to improve its bioactivity to generate a "super-agonist". 相似文献
967.
Yamaguchi T Yamaguchi S Hirai T Kitano T 《Biochemical and biophysical research communications》2007,359(4):935-940
968.
Sasakawa H Sakata E Yamaguchi Y Masuda M Mori T Kurimoto E Iguchi T Hisanaga S Iwatsubo T Hasegawa M Kato K 《Biochemical and biophysical research communications》2007,363(3):795-799
Although biological importance of intrinsically disordered proteins is becoming recognized, NMR analyses of this class of proteins remain as tasks with more challenge because of poor chemical shift dispersion. It is expected that ultra-high field NMR spectroscopy offers improved resolution to cope with this difficulty. Here, we report an ultra-high field NMR study of alpha-synuclein, an intrinsically disordered protein identified as the major component of the Lewy bodies. Based on NMR spectral data collected at a 920 MHz proton frequency, we performed epitope mapping of an anti-alpha-synuclein monoclonal antibody, and furthermore, characterized conformational effects of phosphorylation at Ser129 of alpha-synuclein. 相似文献
969.
Takefuji M Mori K Morita Y Arimura N Nishimura T Nakayama M Hoshino M Iwamatsu A Murohara T Kaibuchi K Amano M 《Biochemical and biophysical research communications》2007,355(3):788-794
Rho family GTPases are key regulators of various physiological processes. Several recent studies indicated that the antagonistic relationship between Rho and Rac is essential for cell polarity and that the Rac activity is negatively regulated by Rho. In this study, we found that Rho-kinase, an effector of Rho, counteracted the Rac GEF STEF-induced Rac1 activation in COS7 cells. Rho-kinase phosphorylated STEF at Thr1662 in vitro, and Y-27632, a Rho-kinase inhibitor, suppressed lysophosphatidic acid-induced phosphorylation of STEF in PC12D cells. STEF interacted with specific molecules such as microtubule-associated protein 1B, and the phosphorylation of STEF by Rho-kinase diminished its interaction with these molecules. STEF promoted nerve growth factor-induced neurite outgrowth in PC12D cells, while the phosphomimic mutant of STEF had a weakened ability to enhance neurite outgrowth. Taken together, these results suggest that the phosphorylation of STEF by Rho-kinase exerts the inhibitory effect on the function of STEF. 相似文献
970.
Kohji Ishihara Nobuyoshi Nakajima Toshiyuki Itoh Hitomi Yamaguchi Kaoru Nakamura Tsutomu Furuya Hiroki Hamada 《Journal of Molecular Catalysis .B, Enzymatic》1999,7(5-6):307-310
The practical synthesis of vinyl p-coumarate (vinyl 4-hydroxycinnamate) and vinyl ferulate (vinyl 4-hydroxy-3-methoxycinnamate) was accomplished via a transesterification to the corresponding aromatic acid using vinyl acetate and a catalytic amount of PdCl2, followed by the lipase-catalyzed regioselective alcoholysis in EtOH. 相似文献