全文获取类型
收费全文 | 1171篇 |
免费 | 103篇 |
出版年
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 31篇 |
2020年 | 17篇 |
2019年 | 29篇 |
2018年 | 22篇 |
2017年 | 19篇 |
2016年 | 45篇 |
2015年 | 69篇 |
2014年 | 65篇 |
2013年 | 90篇 |
2012年 | 85篇 |
2011年 | 112篇 |
2010年 | 61篇 |
2009年 | 47篇 |
2008年 | 72篇 |
2007年 | 76篇 |
2006年 | 60篇 |
2005年 | 73篇 |
2004年 | 61篇 |
2003年 | 39篇 |
2002年 | 50篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 13篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 9篇 |
1984年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1958年 | 1篇 |
1957年 | 1篇 |
1889年 | 1篇 |
1882年 | 1篇 |
排序方式: 共有1274条查询结果,搜索用时 109 毫秒
21.
Saeed Najafi Yanxian Lin Andrew P. Longhini Xuemei Zhang Kris T. Delaney Kenneth S. Kosik Glenn H. Fredrickson JoanEmma Shea Songi Han 《Protein science : a publication of the Protein Society》2021,30(7):1393
The liquid–liquid phase separation (LLPS) of Tau has been postulated to play a role in modulating the aggregation property of Tau, a process known to be critically associated with the pathology of a broad range of neurodegenerative diseases including Alzheimer''s Disease. Tau can undergo LLPS by homotypic interaction through self‐coacervation (SC) or by heterotypic association through complex‐coacervation (CC) between Tau and binding partners such as RNA. What is unclear is in what way the formation mechanisms for self and complex coacervation of Tau are similar or different, and the addition of a binding partner to Tau alters the properties of LLPS and Tau. A combination of in vitro experimental and computational study reveals that the primary driving force for both Tau CC and SC is electrostatic interactions between Tau‐RNA or Tau‐Tau macromolecules. The liquid condensates formed by the complex coacervation of Tau and RNA have distinctly higher micro‐viscosity and greater thermal stability than that formed by the SC of Tau. Our study shows that subtle changes in solution conditions, including molecular crowding and the presence of binding partners, can lead to the formation of different types of Tau condensates with distinct micro‐viscosity that can coexist as persistent and immiscible entities in solution. We speculate that the formation, rheological properties and stability of Tau droplets can be readily tuned by cellular factors, and that liquid condensation of Tau can alter the conformational equilibrium of Tau. 相似文献
22.
Leen Depauw Michael P. Perring Dries Landuyt Sybryn L. Maes Haben Blondeel Emiel De Lombaerde Guntis Brūmelis Jörg Brunet Déborah Closset-Kopp Guillaume Decocq Jan Den Ouden Werner Härdtle Radim Hédl Thilo Heinken Steffi Heinrichs Bogdan Jaroszewicz Martin Kopecký Ilze Liepiņa Martin Macek František Máliš Wolfgang Schmidt Simon M. Smart Karol Ujházy Monika Wulf Kris Verheyen 《应用植被学》2021,24(1):e12532
23.
Exotic perennial grasses (EPGs) pose a significant risk to native communities globally. With over 2,200 species in Australia, understanding which characteristics enable high threat invasions, and comparing between functionally similar EPGs, can help prioritise species management. We developed a framework of risk and used the literature to rank 21 EPGs considered a threat to plant communities in New South Wales, while also evaluating the reliability of information currently available. Characteristics were scored within five broad categories that distinguish invasiveness: Arrival, Establishment, Persistence, Impact and Distribution. These included aspects of reproductive biology, competitive ability and environmental tolerance. The risk assessment was effective in assessing key characteristics of invasion. EPGs with an economic benefit (trade‐off species) were more likely to have reliable research and frequently ranked as high‐risk invaders in natural habitats due to the overlap of characteristics important in invasion with those considered important in agriculture. Lack of formal scientific research hindered assessment for some species, and some traits had been poorly assessed in the literature. High uncertainty was associated with key characteristics for Establishment, Persistence and Impact. Uncertainty in key characteristics revealed a need for improved integration of less formal research validated by more formal scientific research. This may lead to more informed decisions in the management of EPGs in native habitats and assist in early control of EPGs not yet assessed. 相似文献
24.
Liana Tsiatsiani Evy Timmerman Pieter-Jan De Bock Dominique Vercammen Simon Stael Brigitte van de Cotte An Staes Marc Goethals Tine Beunens Petra Van Damme Kris Gevaert Frank Van Breusegem 《The Plant cell》2013,25(8):2831-2847
Metacaspases are distant relatives of the metazoan caspases, found in plants, fungi, and protists. However, in contrast with caspases, information about the physiological substrates of metacaspases is still scarce. By means of N-terminal combined fractional diagonal chromatography, the physiological substrates of METACASPASE9 (MC9; AT5G04200) were identified in young seedlings of Arabidopsis thaliana on the proteome-wide level, providing additional insight into MC9 cleavage specificity and revealing a previously unknown preference for acidic residues at the substrate prime site position P1′. The functionalities of the identified MC9 substrates hinted at metacaspase functions other than those related to cell death. These results allowed us to resolve the substrate specificity of MC9 in more detail and indicated that the activity of phosphoenolpyruvate carboxykinase 1 (AT4G37870), a key enzyme in gluconeogenesis, is enhanced upon MC9-dependent proteolysis. 相似文献
25.
26.
27.
Torsten Wronski Timothy Wacher Robert L. Hammond Bruce Winney Kris J. Hundertmark Mark J. Blacket 《分类学与生物多样性》2013,11(1):119-129
Mountain gazelles (Gazella gazella) rank among the most critically endangered mammals on the Arabian Peninsula. Past conservation efforts have been plagued by confusion about the phylogenetic relationship among various ‘phenotypically discernable’ populations, and even the question of species boundaries was far from being certain. This lack of knowledge has had a direct impact on conservation measures, especially ex situ breeding programmes, hampering the assignment of captive stocks to potential conservation units. Here, we provide a phylogenetic framework, based on the analysis of mtDNA sequences (360 bp cytochrome b and 213 bp Control Region) of 126 individuals collected from the wild throughout the Arabian Peninsula and from captive stocks. Our analyses revealed two reciprocally monophyletic genetic lineages within the presumed species Gazella gazella: one ‘northern clade’ on the Golan Heights (Israel/Syrian border) and one genetically diverse larger clade from the rest of the Arabian Peninsula including the Arava Valley (Negev, Israel). Applying the Strict Phylogenetic Species Concept (sensu Mishler & Theriot, 2000) allows assigning species status to these two major clades. 相似文献
28.
29.
The finding that a variety of chemicals display oestrogenic activity has resulted in the development of in vitro and in vivo assays to assess oestrogenic activity. One such assay, the yeast oestrogen assay (YES) makes use of recombinant yeast cells that harbour an oestrogen receptor expression cassette and a reporter construct, coding for bgalactosidase. The induction mechanism starts with the binding of oestrogenic compounds to the oestrogen receptor. This complex activates the production of β-galactosidase. The β-galactosidase activity is thus a measure of the oestrogenic activity of chemical compounds. In the YES assay, the β-galactosidase activity may be quantified with the chromogenic substrate chlorophenol red-β-d-galactopyranoside (CPRG). In the present study it is reported that CPRG or its β-galactosidase degradation product chlorophenol red act in the YES as an oestrogenic compound itself. The implications of this finding are described. It is especially argued that chlorophenol red production after prolonged incubation of the assay might be misinterpreted as an oestrogenic effect of the test compound. 相似文献
30.
Jan Plue Pieter De Frenne Kamal Acharya Jrg Brunet Olivier Chabrerie Guillaume Decocq Martin Diekmann Bente J. Graae Thilo Heinken Martin Hermy Annette Kolb Isgard Lemke Jaan Liira Tobias Naaf Anna Shevtsova Kris Verheyen Monika Wulf Sara A. O. Cousins 《Global Ecology and Biogeography》2013,22(10):1106-1117