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排序方式: 共有536条查询结果,搜索用时 31 毫秒
81.
Tetsuo Shimada Kazuyuki Kuwabara Saori Yamakoshi Tomomi Shichi 《Journal of Ethology》2002,20(2):87-88
The first observations of infanticide by a precocial avian species, Spot-billed Duck (Anas poecilorhyncha), were recorded on a small pond at Yatsu tidal flat, central Japan, from May to June 2000, where six families of conspecific
and one Gadwall A. strepera family, respectively, occupied territories. A female Spot-billed Duck with 11 ducklings attacked ducklings of all the other
families killing eight conspecifics and three of the Gadwall. High breeding density (15.0 families/ha) may have increased
the aggression of the female.
Electronic Publication 相似文献
82.
Yushi Saino Junji Eda Takao Nagoya Yoko Yoshimura Masahito Yamaguchi Fujio Kobayashi 《Microbiology and immunology》1976,20(1):17-25
Eighteen isolates of anaerobic coryneforms from human bone marrow and skin and four type strains of Propionibacterium were studied chemically, biochemically and antigenically. All of the isolates were identified as Propionibacterium acnes; of the 18 isolates, 16 belonged to serotype I and two to serotype II. By means of gas liquid chromatography and mass spectral analysis, a large amount of iso-type fatty acids, such as iso-pentadecanoic and iso-heptadecanoic acids were detected in whole cells of isolates and type strains. Antitumor and adjuvant effects of the isolates and type strains were found to differ considerably among the strains. One of the isolates, P. acnes C-7, which showed potent biological activities was fractionated by hot phenol-water extraction. The resulting insoluble middle layer was found the most effective in tumor protection, adjuvant action in immune response and phagocytic activity in mice. 相似文献
83.
84.
Characterization of lysine acetylation of a phosphoenolpyruvate carboxylase involved in glutamate overproduction in Corynebacterium glutamicum
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Megumi Nagano‐Shoji Yuma Hamamoto Yuta Mizuno Ayuka Yamada Masaki Kikuchi Mikako Shirouzu Takashi Umehara Minoru Yoshida Makoto Nishiyama Saori Kosono 《Molecular microbiology》2017,104(4):677-689
Protein Nε‐acylation is emerging as a ubiquitous post‐translational modification. In Corynebacterium glutamicum, which is utilized for industrial production of l ‐glutamate, the levels of protein acetylation and succinylation change drastically under the conditions that induce glutamate overproduction. Here, the acylation of phosphoenolpyruvate carboxylase (PEPC), an anaplerotic enzyme that supplies oxaloacetate for glutamate overproduction was characterized. It was shown that acetylation of PEPC at lysine 653 decreased enzymatic activity, leading to reduced glutamate production. An acetylation‐mimic (KQ) mutant of K653 showed severely reduced glutamate production, while the corresponding KR mutant showed normal production levels. Using an acetyllysine‐incorporated PEPC protein, we verified that K653‐acetylation negatively regulates PEPC activity. In addition, NCgl0616, a sirtuin‐type deacetylase, deacetylated K653‐acetylated PEPC in vitro. Interestingly, the specific activity of PEPC was increased during glutamate overproduction, which was blocked by the K653R mutation or deletion of sirtuin‐type deacetylase homologues. These findings suggested that deacetylation of K653 by NCgl0616 likely plays a role in the activation of PEPC, which maintains carbon flux under glutamate‐producing conditions. PEPC deletion increased protein acetylation levels in cells under glutamate‐producing conditions, supporting the hypothesis that PEPC is responsible for a large carbon flux change under glutamate‐producing conditions. 相似文献
85.
Tanimoto Y Iijima S Hasegawa Y Suzuki Y Daitoku Y Mizuno S Ishige T Kudo T Takahashi S Kunita S Sugiyama F Yagami K 《Comparative medicine》2008,58(4):347-352
Mouse embryonic stem (ES) cells with the C57BL/6 genetic background allow the generation of knockout mice without the need to backcross to C57BL/6. However, C57BL/6 ES cells whose pluripotency after homologous recombination has been confirmed are not yet available from public cell banks. To facilitate the use of ES cells derived from C57BL/6 sublines in both biologic and medical research, we demonstrated that the use of knockout serum replacement as a medium supplement and 8-cell blastomeres as recipient embryos allowed establishment of ES cells and production of germline chimeric mice, respectively. Under effective conditions, a large number of ES cell lines were established from C57BL/6J and C57BL/6N blastocysts. The majority of ES cells in many cell lines obtained from both strains showed a normal chromosome number. Germline chimeric mice were generated from C57BL/6J and C57BL/6N ES cells. Finally, the ES cell line B6J-S1UTR, derived from C57BL/6J, was used for successful production of gene knockout mice. C57BL/6J ES (B6J-S1UTR and B6J-23UTR) and C57BL/6N ES (B6N-22UTR) cells are available from the cell bank of the BioResource Center at RIKEN Tsukuba Institute (http://www.brc.riken.jp/lab/cell/english/). 相似文献
86.
Sakai M Tomita S Hirata H Asai T Dohra H Hara M Watanabe N 《Bioscience, biotechnology, and biochemistry》2008,72(1):219-221
Beta-glucosidase was partially purified from Rosa 'Hoh-Jun' petals. The enzyme was highly specific for such beta-D-glucopyranosides as 2-phenylethyl beta-D-glucopyranoside. The optimal activity was observed at pH 6.0 and 35 degrees C. The enzymes were composed with two proteins (160 and 155 kDa) by blue native-PAGE, and were classified in a family 1 glucosidase based on LC-MS/MS analyses. 相似文献
87.
Tashiro Y Nomura N Nakao R Senpuku H Kariyama R Kumon H Kosono S Watanabe H Nakajima T Uchiyama H 《Journal of bacteriology》2008,190(11):3969-3978
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that is one of the most refractory to therapy when it forms biofilms in the airways of cystic fibrosis patients. To date, studies regarding the production of an immunogenic and protective antigen to inhibit biofilm formation by P. aeruginosa have been superficial. The previously uncharacterized outer membrane protein (OMP) Opr86 (PA3648) of P. aeruginosa is a member of the Omp85 family, of which homologs have been found in all gram-negative bacteria. Here we verify the availability of Opr86 as a protective antigen to inhibit biofilm formation by P. aeruginosa PAO1 and several other isolates. A mutant was constructed in which Opr86 expression could be switched on or off through a tac promoter-controlled opr86 gene. The result, consistent with previous Omp85 studies, showed that Opr86 is essential for viability and plays a role in OMP assembly. Depletion of Opr86 resulted in streptococci-like morphological changes and liberation of excess membrane vesicles. A polyclonal antibody against Opr86 which showed reactivity to PAO1 cells was obtained. The antibody inhibited biofilm formation by PAO1 and the other clinical strains tested. Closer examination of early attachment revealed that cells treated with the antibody were unable to attach to the surface. Our data suggest that Opr86 is a critical OMP and a potential candidate as a protective antigen against biofilm formation by P. aeruginosa. 相似文献
88.
Oka S Toshida T Maruyama K Nakajima K Yamashita A Sugiura T 《Journal of biochemistry》2009,145(1):13-20
GPR55 is a G protein-coupled receptor. Recently, we obtained evidence that lysophosphatidylinositol (LPI) is a possible endogenous ligand for GPR55. However, no information is currently available concerning the biological activities of the individual molecular species of LPI. Furthermore, little is known concerning the levels as well as the molecular species of LPI in mammalian tissues. In this study, we first examined whether LPI is present in rat brain. We found that rat brain contains 37.5 nmol/g tissue of LPI; the most predominant fatty acyl moiety is stearic acid (50.5%) followed by arachidonic acid (22.1%). We next compared the biological activities of various molecular species of LPI and related molecules using HEK293 cells expressing GPR55. We found that the level of biological activity of the 2-arachidonoyl species is markedly higher than those of others. These results strongly suggest that the 2-arachidonoyl species of LPI is the true natural ligand for GPR55. 相似文献
89.
Saori Hata Sayaka Fujishige Yoichi Araki Naoko Kato Masahiko Araseki Masaki Nishimura Dieter Hartmann Paul Saftig Falk Fahrenholz Miyako Taniguchi Katsuya Urakami Hiroyasu Akatsu Ralph N. Martins Kazuo Yamamoto Masahiro Maeda Tohru Yamamoto Tadashi Nakaya Sam Gandy Toshiharu Suzuki 《The Journal of biological chemistry》2009,284(52):36024-36033
Alcadeins (Alcs) constitute a family of neuronal type I membrane proteins, designated Alcα, Alcβ, and Alcγ. The Alcs express in neurons dominantly and largely colocalize with the Alzheimer amyloid precursor protein (APP) in the brain. Alcs and APP show an identical function as a cargo receptor of kinesin-1. Moreover, proteolytic processing of Alc proteins appears highly similar to that of APP. We found that APP α-secretases ADAM 10 and ADAM 17 primarily cleave Alc proteins and trigger the subsequent secondary intramembranous cleavage of Alc C-terminal fragments by a presenilin-dependent γ-secretase complex, thereby generating “APP p3-like” and non-aggregative Alc peptides (p3-Alcs). We determined the complete amino acid sequence of p3-Alcα, p3-Alcβ, and p3-Alcγ, whose major species comprise 35, 37, and 31 amino acids, respectively, in human cerebrospinal fluid. We demonstrate here that variant p3-Alc C termini are modulated by FAD-linked presenilin 1 mutations increasing minor β-amyloid species Aβ42, and these mutations alter the level of minor p3-Alc species. However, the magnitudes of C-terminal alteration of p3-Alcα, p3-Alcβ, and p3-Alcγ were not equivalent, suggesting that one type of γ-secretase dysfunction does not appear in the phenotype equivalently in the cleavage of type I membrane proteins. Because these C-terminal alterations are detectable in human cerebrospinal fluid, the use of a substrate panel, including Alcs and APP, may be effective to detect γ-secretase dysfunction in the prepathogenic state of Alzheimer disease subjects. 相似文献
90.
Yuzuru Yamazoe Masanobu Tsubaki Hiroshi Matsuoka Takao Satou Tatsuki Itoh Takashi Kusunoki Yasuhiro Kidera Yoshihiro Tanimori Kaori Shoji Haruyuki Nakamura Mitsuhiko Ogaki Saori Nishiura Shozo Nishida 《Cell biology international》2009,33(10):1087-1094
NF-κB acts as a signal transducer during tumor progression, cell invasion, and metastasis. Dimethylfumarate (DMF) is reported to inhibit tumor necrosis factor-α-induced nuclear entry of NF-κB/p65. However, only a few reports suggest that DMF inhibits tumor metastasis; also the molecular mechanisms underlying the inhibition of metastasis are poorly understood. We investigated the inhibition of tumor invasion and metastasis by DMF in a melanoma cell line, B16BL6. DMF inhibited B16BL6 cell invasion and metastasis by suppressing the expression and activities of MMPs. DMF also inhibited the nuclear entry of NF-κB/p65, thus inhibiting B16BL6 cell invasion and metastasis. These results suggest that DMF is potentially useful as an anti-metastatic agent for the treatment of malignant melanoma. 相似文献