全文获取类型
收费全文 | 1080篇 |
免费 | 82篇 |
出版年
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 16篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 14篇 |
2017年 | 17篇 |
2016年 | 21篇 |
2015年 | 34篇 |
2014年 | 43篇 |
2013年 | 63篇 |
2012年 | 76篇 |
2011年 | 73篇 |
2010年 | 49篇 |
2009年 | 40篇 |
2008年 | 77篇 |
2007年 | 69篇 |
2006年 | 66篇 |
2005年 | 65篇 |
2004年 | 78篇 |
2003年 | 62篇 |
2002年 | 63篇 |
2001年 | 17篇 |
2000年 | 14篇 |
1999年 | 11篇 |
1998年 | 10篇 |
1997年 | 18篇 |
1996年 | 14篇 |
1995年 | 4篇 |
1994年 | 12篇 |
1993年 | 6篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1969年 | 2篇 |
排序方式: 共有1162条查询结果,搜索用时 31 毫秒
131.
Izu A Kumai T Tohno Y Tohno S Minami T Yamada G Yamada MO 《Biological trace element research》2006,113(3):297-316
Vertebral columns were dissected and analyzed after birth with oral administration of silicon for 4 wk and for 8 wk. The silicon
level was lower (20 μg/g) at the beginning. It remains unchanged after 4 wk and then increases twice as much as that for those
mice bred for 8 wk than those bred for 4 wk. This increase depends remarkably on the mass ratio of Si/Ca (M/M). The ratio increases to three times higher than that of the control at the beginning of the experiments (5 wk after birth).
Although the S and P contents appeared to be lower, these increased when Si was administered in combination with phosphopeptide.
Other elements, such as Ca, Mg, Fe, and Zn, appeared to be unchanged as the weeks proceeded. These findings seem to support
a proposal that silicon is necessary for the growth of backbones in mice. 相似文献
132.
133.
134.
Dynamic polymorphism of Ras observed by single molecule FRET is the basis for molecular recognition 总被引:3,自引:0,他引:3
Arai Y Iwane AH Wazawa T Yokota H Ishii Y Kataoka T Yanagida T 《Biochemical and biophysical research communications》2006,343(3):809-815
Ras regulates signal transduction pathway function by dynamically interacting with various effectors. To understand the basis for Ras function, its conformational dynamics were measured in the absence and presence of effectors using single molecule fluorescence resonance energy transfer (FRET) between probes located on the Switch II region and GTP. The time trajectories of FRET efficiency from GTP-bound Ras showed that this conformation spontaneously varies among multiple states. Among them, a low FRET state was identified as an inactive state. The transition involving the inactive conformational state occurred in the time range of seconds. In contrast, fluctuation occurring most probably between multiple active high FRET conformational states lasted approximately 30 ms but converged to a specific conformational state upon binding to an effector. Thus, Ras conformation spontaneously fluctuates to readily interact with various effectors. 相似文献
135.
Hirano M Ogita-Nakanishi H Miyachi W Hannya N Yamamoto-Kimoto Y Sakurai K Miyoshi-Higashino M Tashiro-Yamaji J Kato R Ijiri Y Tanaka K Kanazawa A Terada T Kawata R Takenaka H Kubota T Yoshida R 《Microbiology and immunology》2012,56(6):392-405
The production of allergen-specific IgE antibodies (Abs) in allergen-sensitized patients or animals has a mutual relationship with the immunologic response leading to allergic rhinitis. We recently reported that, after an intranasal injection of cedar pollen into mice, an interleukin-4 (IL-4)-dependent increase in serum nonspecific IgE Abs was a prerequisite for the production of serum allergen-specific IgE Abs. Here, we explored which lymphoid organs were responsive to the intranasally injected allergen and how IL-4 and IgE Abs were produced in the lymphocytes. Time-dependent changes in the total cell numbers and in in vitro IgE Ab production in various lymphoid organs revealed that the submandibular lymph nodes were the main responsible organ. After treatment with allergen (for IgE production) or allergen and complete Freund's adjuvant (for IgG production), we separated submandibular lymph node cells into macrophage-, lymphocyte-, and granulocyte-rich populations by discontinuous Percoll density-gradient centrifugation. Unexpectedly, bulk cells, but not the lymphocyte- or macrophage-rich populations, produced significant amounts of IL-4, IgE, and IgG; whereas production was restored by addition of Mac-1(+) cells from the macrophage-rich to the lymphocyte-rich fraction. Furthermore, a combination of the lymphocyte-rich population (for IgG [or IgE]) production) and the macrophage-rich population (for IgE [or IgG]) production) produced a large amount of IgE (or IgG). These results indicate that, in the initiation of allergic rhinitis, macrophages in the submandibular lymph nodes are essential not only for IL-4 or immunoglobulin production, but also for class switching of immunoglobulin in lymphocytes. 相似文献
136.
Hiroaki Matsubara Yasunobu Shibasaki Mitsuhiko Okigaki Yasukiyo Mori Hiroya Masaki Atsushi Kosaki Yoshiaki Tsutsumi Yoko Uchiyama Soichiro Fujiyama Atsuko Nose Osamu Iba Eriko Tateishi Takamasa Hasegawa Masatsugu Horiuchi Clara Nahmias Toshiji Iwasaka 《Biochemical and biophysical research communications》2012,417(4):1316-1317
137.
Morita A Nakahira K Hasegawa T Uchida K Taniguchi Y Takeda S Toyoda A Sakaki Y Shimada A Takeda H Yanagihara I 《Development, growth & differentiation》2012,54(5):588-604
Roberts syndrome and SC phocomelia (RBS/SC) are genetic autosomal recessive syndromes caused by establishment of cohesion 1 homolog 2 ( ESCO 2) mutation. RBS/SC appear to have a variety of clinical features, even with the same mutation of the ESCO2 gene. Here, we established and genetically characterized a medaka model of RBS/SC by reverse genetics. The RBS/SC model was screened from a mutant medaka library produced by the Targeting Induced Local Lesions in Genomes method. The medaka mutant carrying the homozygous mutation at R80S in the conserved region of ESCO2 exhibited clinical variety (i.e. developmental arrest with craniofacial and chromosomal abnormalities and embryonic lethality) as characterized in RBS/SC. Moreover, widespread apoptosis and downregulation of some gene expression, including notch1a, were detected in the R80S mutant. The R80S mutant is the animal model for RBS/SC and a valuable resource that provides the opportunity to extend knowledge of ESCO2. Downregulation of some gene expression in the R80S mutant is an important clue explaining non-correlation between genotype and phenotype in RBS/SC. 相似文献
138.
Yoneda A Lendorf ME Couchman JR Multhaupt HA 《The journal of histochemistry and cytochemistry》2012,60(1):9-21
Tumor markers are widely used in pathology not only for diagnostic purposes but also to assess the prognosis and to predict the treatment of the tumor. Because tumor marker levels may change over time, it is important to get a better understanding of the molecular changes during tumor progression. Occurrence of breast and ovarian cancer is high in older women. Common known risk factors of developing these cancers in addition to age are not having children or having children at a later age, the use of hormone replacement therapy, and mutations in certain genes. In addition, women with a history of breast cancer may also develop ovarian cancer. Here, the authors review the different tumor markers of breast and ovarian carcinoma and discuss the expression, mutations, and possible roles of cell surface heparan sulfate proteoglycans during tumorigenesis of these carcinomas. The focus is on two groups of proteoglycans, the transmembrane syndecans and the lipid-anchored glypicans. Both families of proteoglycans have been implicated in cellular responses to growth factors and morphogens, including many now associated with tumor progression. 相似文献
139.
140.
Yoneda A Morgan-Fisher M Wait R Couchman JR Wewer UM 《Molecular and cellular biology》2012,32(10):1788-1804
Collapsin response mediator protein 2 (CRMP-2) is known as a regulator of neuronal polarity and differentiation through microtubule assembly and trafficking. Here, we show that CRMP-2 is ubiquitously expressed and a splice variant (CRMP-2L), which is expressed mainly in epithelial cells among nonneuronal cells, regulates myosin II-mediated cellular functions, including cell migration. While the CRMP-2 short form (CRMP-2S) is recognized as a substrate of the Rho-GTP downstream kinase ROCK in neuronal cells, a CRMP-2 complex containing 2L not only bound the catalytic domain of ROCK II through two binding domains but also trapped and inhibited the kinase. CRMP-2L protein levels profoundly affected haptotactic migration and the actin-myosin cytoskeleton of carcinoma cells as well as nontransformed epithelial cell migration in a ROCK activity-dependent manner. Moreover, the ectopic expression of CRMP-2L but not -2S inhibited fibronectin matrix assembly in fibroblasts. Underlying these responses, CRMP-2L regulated the kinase activity of ROCK II but not ROCK I, independent of GTP-RhoA levels. This study provides a new insight into CRMP-2 as a controller of myosin II-mediated cellular functions through the inhibition of ROCK II in nonneuronal cells. 相似文献