全文获取类型
收费全文 | 348篇 |
免费 | 17篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 4篇 |
2013年 | 15篇 |
2012年 | 21篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 21篇 |
2007年 | 19篇 |
2006年 | 24篇 |
2005年 | 20篇 |
2004年 | 20篇 |
2003年 | 14篇 |
2002年 | 16篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 4篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有365条查询结果,搜索用时 31 毫秒
41.
Ramicandelaber, a new genus of Zygomycetes is erected to accommodateRamicandelaber longisporus sp. nov. The fungus has hyphal septa with median plugs and forms homologous structures to sporocladia and pseudophialides.
These characteristics suggest that it belongs to the Kickxellales, Zygomycetes. 相似文献
42.
Shigeaki Nonoyama Mitsunobu Shimadzu Hano Toru Kuniaki Seyama Hiroyuki Nunoi Michael Neubauer Jun-ichi Yata Hans D. Ochs 《Human genetics》1997,99(5):624-627
X-linked hyper-IgM syndrome (XHIM) is a rare primary immunodeficiency caused by a defective CD40 ligand. We identified mutations
of the CD40 ligand gene in 13 unrelated Japanese XHIM patients. Of the four patients with missense mutations, one had a mutation
within the transmembrane domain, and the three others had mutations affecting the TNF homology region of the extracellular
domain. Two of the missense mutations resulted in the substitution of amino acids that are highly conserved in TNF family
proteins. Three patients had nonsense mutations, all of which resulted in the truncation of the TNF homology domain of the
CD40 ligand. Three patients had genomic DNA deletions of 2, 3 or 4 nucleotides, respectively. All of the deletions were flanked
by direct repeat sequences, suggesting that these deletions were caused by slipped mispairing. Three patients had mutations
within introns resulting in altered splicing, and multiple splicing products were found in one patient. Thus, each of the
13 Japanese patients had different mutations, 9 of them being novel mutations. These results indicate that mutations in XHIM
are highly heterogeneous, although codon 140 seems to be a hot spot of the CD40 ligand gene since two additional point mutations
were located at Trp 140, bringing the total numbers of mutations affecting codon 140 to six. In one XHIM family with a missense
mutation, prenatal diagnosis was performed by single-strand conformation polymorphism analysis of genomic DNA of a male fetus.
Received: 20 August 1996 相似文献
43.
M Minami Y Minami Y Emori H Kawasaki S Ohno K Suzuki N Ohishi T Shimizu Y Seyama 《FEBS letters》1988,229(2):279-282
The cDNA clone encoding human leukotriene A4 hydrolase was inserted into a vector pUC9 and expressed in Escherichia coli as a fusion protein containing the first 10 amino acid residues derived from a vector. The leukotriene A4 hydrolase activity was recovered in the soluble fraction of the transformants. The purified enzyme showed kinetic properties similar to the native enzyme, including inactivation by the substrate and sulfhydryl-modifying reagents. The results demonstrate that a protein with an Mr of 70,000 was expressed in Escherichia coli with a full enzyme activity and structural fidelity. Acquisition of the expression system makes it feasible to elucidate the reaction mechanism of the enzyme. 相似文献
44.
45.
Youhei Sohma Yoshio Hayashi Maiko Kimura Yousuke Chiyomori Atsuhiko Taniguchi Masato Sasaki Tooru Kimura Yoshiaki Kiso 《Journal of peptide science》2005,11(8):441-451
An efficient 'O-acyl isopeptide method' for the synthesis of difficult sequence-containing peptides was applied successfully to the synthesis of amyloid beta peptide (Abeta) 1-42 via a water-soluble O-acyl isopeptide of Abeta1-42, i.e. '26-O-acyl isoAbeta1-42' (6). This paper describes the detailed synthesis of Abeta1-42 focusing on the importance of resin selection and the analysis of side reactions in the O-acyl isopeptide method. Protected '26-O-acyl isoAbeta1-42' peptide resin was synthesized using 2-chlorotrityl chloride resin with minimum side reactions in comparison with other resins and deprotected crude 26-O-acyl isoAbeta1-42 was easily purified by HPLC due to its relatively good purity and narrow elution with reasonable water solubility. This suggests that only one insertion of the isopeptide structure into the sequence of the 42-residue peptide can suppress the unfavourable nature of its difficult sequence. The migration of O-acyl isopeptide to intact Abeta1-42 under physiological conditions (pH 7.4) via O--N intramolecular acyl migration reaction was very rapid and no other by-product formation was observed while 6 was stable under storage conditions. These results concluded that our strategy not only overcomes the solubility problem in the synthesis of Abeta1-42 and can provide intact Abeta1-42 efficiently, but is also applicable in the synthesis of large difficult sequence-containing peptides at least up to 50 amino acids. This synthesis method would provide a biological evaluation system in Alzheimer's disease research, in which 26-O-acyl isoAbeta1-42 can be stored in a solubilized form before use and then rapidly produces intact Abeta1-42 in situ during biological experiments. 相似文献
46.
FGF-2 suppresses cellular senescence of human mesenchymal stem cells by down-regulation of TGF-beta2 总被引:2,自引:0,他引:2
Ito T Sawada R Fujiwara Y Seyama Y Tsuchiya T 《Biochemical and biophysical research communications》2007,359(1):108-114
Human mesenchymal stem cells (hMSCs) are able to both self-replicate and differentiate into a variety of cell types. Fibroblast growth factor-2 (FGF-2) stimulates the growth of hMSCs in vitro, but its mechanisms have not been clarified yet. In this study, we investigated whether cellular senescence was involved in the stimulation of hMSCs growth by FGF-2 and the expression levels of transforming growth factor-beta1 and -beta2 (TGF-betas). Because hMSCs were induced cellular senescence due to long-term culture, FGF-2 decreased the percentage of senescent cells and suppressed G1 cell growth arrest through the suppression of p21(Cip1), p53, and p16(INK4a) mRNA expression levels. Furthermore, the levels of TGF-betas mRNA expression in hMSCs were increased by long-term culture, but FGF-2 suppressed the increase of TGF-beta2 mRNA expression due to long-term culture. These results suggest that FGF-2 suppresses the hMSCs cellular senescence dependent on the length of culture through down-regulation of TGF-beta2 expression. 相似文献
47.
Kathleen
Beverly
Alog Pe Kenji Yatsuzuka Hayase Hakariya Tomoki Kida Yousuke Katsuda Masatora Fukuda Shin-ichi Sato 《Nucleic acids research》2021,49(22):e132
Imaging the dynamics of proteins in living cells is a powerful means for understanding cellular functions at a deeper level. Here, we report a versatile method for spatiotemporal imaging of specific endogenous proteins in living mammalian cells. The method employs a bifunctional aptamer capable of selective protein recognition and fluorescent probe-binding, which is induced only when the aptamer specifically binds to its target protein. An aptamer for β-actin protein preferentially recognizes its monomer forms over filamentous forms, resulting in selective G-actin staining in both fixed and living cells. Through actin-drug treatment, the method permitted direct monitoring of the intracellular concentration change of endogenous G-actin. This protein-labeling method, which is highly selective and non-covalent, provides rich insights into the study of spatiotemporal protein dynamics in living cells. 相似文献
48.
Affinity labeling of a target protein is a powerful method for chemical biology studies. However, it is still difficult to label intracellular proteins efficiently in living cells. We propose the novel design strategy of a reactive group-embedded affinity labeling reagent for efficient protein labeling. With FKBP12 as the model target protein, the ligand binding pocket-oriented labeling reagent could label intracellular protein, whereas protein surface-oriented reagent was ineffective for labeling in living cells, partially because of the intracellular protein fluctuation under the macromolecular crowding effects. These results provide new insight for efficient intracellular protein labeling. 相似文献
49.
50.
Mio Nakamura Koji Nomura Jun-ichi P. Abe Yousuke Degawa Makoto Kakishima 《Mycoscience》2009,50(6):448-451
A simple method for isolating the nuclei from Basidiobolus ranarum was established. To improve the yield and purity of nuclei, we investigated maceration methods, buffer composition, and centrifugation
conditions to establish an optimal procedure. Basidiobolus ranarum cultured for 5 days was enzymatically macerated and then homogenized and filtrated through stainless steel sieves. The crude
cell homogenate was loaded on a layer of buffer containing 50% glycerol and centrifuged at 1500 g. The resultant pellet contained pure nuclei. 相似文献