全文获取类型
收费全文 | 2150篇 |
免费 | 163篇 |
国内免费 | 1篇 |
专业分类
2314篇 |
出版年
2022年 | 13篇 |
2021年 | 30篇 |
2020年 | 15篇 |
2019年 | 12篇 |
2018年 | 24篇 |
2017年 | 25篇 |
2016年 | 41篇 |
2015年 | 57篇 |
2014年 | 78篇 |
2013年 | 111篇 |
2012年 | 138篇 |
2011年 | 134篇 |
2010年 | 88篇 |
2009年 | 82篇 |
2008年 | 114篇 |
2007年 | 135篇 |
2006年 | 122篇 |
2005年 | 117篇 |
2004年 | 113篇 |
2003年 | 112篇 |
2002年 | 102篇 |
2001年 | 46篇 |
2000年 | 37篇 |
1999年 | 55篇 |
1998年 | 22篇 |
1997年 | 31篇 |
1996年 | 32篇 |
1995年 | 23篇 |
1994年 | 22篇 |
1993年 | 16篇 |
1992年 | 37篇 |
1991年 | 31篇 |
1990年 | 39篇 |
1989年 | 29篇 |
1988年 | 28篇 |
1987年 | 25篇 |
1986年 | 29篇 |
1985年 | 22篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 22篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1973年 | 4篇 |
1968年 | 3篇 |
排序方式: 共有2314条查询结果,搜索用时 15 毫秒
71.
Phosphorylation is an effective method of post-translational protein modification but understanding its significance is hindered by its biological complexity. Many protein kinases and phosphatases have been identified that connect signal perception mechanisms to plant defence responses. Recent studies of mitogen-activated protein kinases, calcium-dependent protein kinases and other kinases and phosphatases have revealed some important mechanisms, but have also raised new questions. The regulation of any phosphorylation pathway is complex and dynamic. There are many protein kinases and phosphatases in the plant genome, which makes it hard to delineate the phosphorylation machinery fully. Genomics and proteomics have already identified new components and will continue to influence the study of phosphorylation profoundly in plant-pathogen interactions. 相似文献
72.
Toshihiko Sudo Xiaoxian Zhao Yoko Wakamatsu Miki Shibahara Nobuhiko Nomura Tadaatsu Nakahara Akemi Suzuki Yoshiro Kobayashi Chunyuan Jin Takehide Murata Kazunari K. Yokoyama 《Cytotechnology》2000,33(1-3):259-264
Four analogs of succinoyl trehalose lipid-3 (STL-3)with saturated even-number or odd-number carbonchains, and unsaturated or halogenated fatty acidswere examined for their ability to inhibit the growthand induce the differentiation of HL-60 humanpromyelocytic leukemia cells. The optimalconcentration of STL-3 at which such activities wererecognized was closed to the critical micelleconcentration of STL-3. Analog of STL-3 witheven-number or odd-number carbon chain and unsaturatedfatty acids strongly inhibited growth and induced thedifferentiation of HL-60 cells, as evaluated in termsof nitroblue tetrazilium-reducing activity and theappearance of the CD36 antigen. An analog of STL-3with halogenated fatty acids significantly inhibitedproliferation but only induced the differentiation ofHL-60 cells. Our results indicate that the effects ofSTL-3 and its analogs on HL-60 cells depend on thestructure of the hydrophobic moiety of STL-3.These authors contributed equally to this work 相似文献
73.
74.
75.
Using food network unfolding to evaluate food–web complexity in terms of biodiversity: theory and applications 下载免费PDF全文
Yoshikazu Kato Michio Kondoh Naoto F. Ishikawa Hiroyuki Togashi Yukihiro Kohmatsu Mayumi Yoshimura Chikage Yoshimizu Takashi F. Haraguchi Yutaka Osada Nobuhito Ohte Naoko Tokuchi Noboru Okuda Takeshi Miki Ichiro Tayasu 《Ecology letters》2018,21(7):1065-1074
Food–web complexity often hinders disentangling functionally relevant aspects of food–web structure and its relationships to biodiversity. Here, we present a theoretical framework to evaluate food–web complexity in terms of biodiversity. Food network unfolding is a theoretical method to transform a complex food web into a linear food chain based on ecosystem processes. Based on this method, we can define three biodiversity indices, horizontal diversity (DH), vertical diversity (DV) and range diversity (DR), which are associated with the species diversity within each trophic level, diversity of trophic levels, and diversity in resource use, respectively. These indices are related to Shannon's diversity index (H′), where H′ = DH + DV ? DR. Application of the framework to three riverine macroinvertebrate communities revealed that D indices, calculated from biomass and stable isotope features, captured well the anthropogenic, seasonal, or other within‐site changes in food–web structures that could not be captured with H′ alone. 相似文献
76.
Shingo Izawa Kayo Ikeda Takeo Miki Yoshinori Wakai Yoshiharu Inoue 《Applied microbiology and biotechnology》2010,88(1):277-282
Although ethanol and osmotic stress affect the vacuolar morphology of Saccharomyces cerevisiae, little information is available about changes in vacuolar morphology during the processes of wine making and Japanese sake (rice wine) brewing. Here, we elucidated changes in the morphology of yeast vacuoles using Zrc1p-GFP, a vacuolar membrane
protein, so as to better understand yeast physiology during the brewing process. Wine yeast cells (OC-2 and EC1118) contained
highly fragmented vacuoles in the sake mash (moromi) as well as in the grape must. Although sake yeast cells (Kyokai no. 9 and no. 10) also contained highly fragmented vacuoles during the wine-making process, they showed quite a distinct
vacuolar morphology during sake brewing. Since the environment surrounding sake yeast cells in the sake mash did not differ much from that surrounding wine yeast cells, the difference in vacuolar morphology during sake brewing between wine yeast and sake yeast was likely caused by innate characters. 相似文献
77.
T Suzuki M Murakami N Onai E Fukuda Y Hashimoto M H Sonobe T Kameda M Ichinose K Miki H Iba 《Journal of virology》1994,68(6):3527-3535
78.
Tsutomu Enoki Tohru Nakashizuka Shin-ichi Nakano Takeshi Miki Yu-Pin Lin Masahiro Nakaoka Eri Mizumachi Hideaki Shibata 《Ecological Research》2014,29(3):357-368
The primary goal of the 60th anniversary symposium of the Ecological Society of Japan (ESJ) was to re-examine the role of the Society. The first of five lectures, “Development of Long-term Ecological Research in Japan,” discussed the increasingly important role of long-term and networked research studies. Ecological research in Asia faces many challenges, because Asia features natural and anthropogenic landscapes with highly diverse ecosystems. “Developing Strategies of the Ecological Society of Japan for Worldwide Societies of Ecology with Special Reference to Strategies for Asia” emphasized the role of ESJ in promoting ecological research and outreach in Asia. Ecosystem sustainability is a key issue in both the theory and practice of ecosystem management. A framework concept of an environmental and biodiversity cycle was proposed in the session “Linking Community and Ecosystem Dynamics” for understanding the mechanisms driving the sustainability of ecosystems. Ecosystem services are essential aspects of land use and conservation planning and management. “Integrating Models of Ecosystem Services and Land Use Changes” reviewed recently-developed models that simulate patterns of land-use change and analyze its effects on ecosystem services and also recommended future directions for collaboration among researchers. “Disaster Resilience and Coastal Ecology” highlighted the contributions of ecologists to evaluating the resilience of damaged coastal ecosystems and provided sound proposals to local communities and governments for rehabilitation plans. The past achievements and future directions of ESJ were discussed by the panelists and the audience in “Past and Future of the Ecological Society of Japan.” 相似文献
79.
KIT (c-kit oncogene product) pathway is constitutively activated in human testicular germ cell tumors 总被引:5,自引:0,他引:5
Nakai Y Nonomura N Oka D Shiba M Arai Y Nakayama M Inoue H Nishimura K Aozasa K Mizutani Y Miki T Okuyama A 《Biochemical and biophysical research communications》2005,337(1):289-296
We investigated the expression of KIT (product of c-kit oncogene), gain-of-function mutations, and activation of its downstream signal transduction in human testicular cancers. KIT was expressed in 88% (22/25) of seminomas and in 44.4% (4/9) of non-seminomas compared to adjacent normal testicular tissue. Nine of the KIT-expressing seminomas had mutations (40.9%; 9/22) in the c-kit gene; two cases in exon 11 and 7 cases in exon 17. Two of these mutations in exon 17 were novel, and the other seven mutations were identical to the already known gain-of-function mutations which cause activation of KIT without ligand stem cell factor. All of the mutant KIT and 53.8% (7/13) of wild-type KIT were phosphorylated (activated) and associated with phosphorylated phosphatidylinositol 3-kinase (PI3K). Akt was also phosphorylated in these seminomas, suggesting that the KIT-PI3K-Akt pathway is activated in seminoma. These findings suggest that the KIT-PI3K-Akt pathway is constitutively activated in testicular germ cell tumors, due to overexpression of KIT protein and/or gain-of-function mutations in the c-kit gene. 相似文献
80.
Akinobu Echigo Miki Hino Tadamasa Fukushima Toru Mizuki Masahiro Kamekura Ron Usami 《Aquatic biosystems》2005,1(1):1-13