全文获取类型
收费全文 | 4328篇 |
免费 | 332篇 |
国内免费 | 4篇 |
出版年
2022年 | 22篇 |
2021年 | 49篇 |
2020年 | 29篇 |
2019年 | 46篇 |
2018年 | 47篇 |
2017年 | 55篇 |
2016年 | 102篇 |
2015年 | 157篇 |
2014年 | 194篇 |
2013年 | 266篇 |
2012年 | 321篇 |
2011年 | 303篇 |
2010年 | 176篇 |
2009年 | 183篇 |
2008年 | 267篇 |
2007年 | 284篇 |
2006年 | 251篇 |
2005年 | 258篇 |
2004年 | 247篇 |
2003年 | 240篇 |
2002年 | 218篇 |
2001年 | 38篇 |
2000年 | 31篇 |
1999年 | 55篇 |
1998年 | 62篇 |
1997年 | 39篇 |
1996年 | 41篇 |
1995年 | 44篇 |
1994年 | 32篇 |
1993年 | 33篇 |
1992年 | 46篇 |
1991年 | 31篇 |
1990年 | 33篇 |
1989年 | 21篇 |
1988年 | 25篇 |
1987年 | 26篇 |
1986年 | 19篇 |
1985年 | 24篇 |
1984年 | 38篇 |
1983年 | 17篇 |
1982年 | 34篇 |
1981年 | 17篇 |
1980年 | 11篇 |
1979年 | 15篇 |
1978年 | 19篇 |
1977年 | 12篇 |
1976年 | 13篇 |
1975年 | 18篇 |
1974年 | 11篇 |
1969年 | 10篇 |
排序方式: 共有4664条查询结果,搜索用时 62 毫秒
131.
132.
Qiaomei Fu Alissa Mittnik Philip L.F. Johnson Kirsten Bos Martina Lari Ruth Bollongino Chengkai Sun Liane Giemsch Ralf Schmitz Joachim Burger Anna Maria Ronchitelli Fabio Martini Renata G. Cremonesi Jiří Svoboda Peter Bauer David Caramelli Sergi Castellano David Reich Johannes Krause 《Current biology : CB》2013,23(7):553-559
133.
Bradley J. Newhouse Steve Wenglowsky Jonas Grina Ellen R. Laird Walter C. Voegtli Li Ren Kateri Ahrendt Alex Buckmelter Susan L. Gloor Nathalie Klopfenstein Joachim Rudolph Zhaoyang Wen Xianfeng Li Bainian Feng 《Bioorganic & medicinal chemistry letters》2013,23(21):5896-5899
This Letter details the synthesis and evaluation of imidazo[4,5-b]pyridines as inhibitors of B-Raf kinase. These compounds bind in a DFG-in, αC-helix out conformation of B-Raf, which is a binding mode associated with significant kinase selectivity. Structure–activity relationship studies involved optimization of the ATP-cleft binding region of these molecules, and led to compound 23, an inhibitor with excellent enzyme/cell potency, and kinase selectivity. 相似文献
134.
Ojas A. Namjoshi Zhi-jian Wang Sundari K. Rallapalli Edward Merle Johnson Yun-Teng Johnson Hanna Ng Joachim Ramerstorfer Zdravko Varagic Werner Sieghart Samarpan Majumder Bryan L. Roth James K. Rowlett James M. Cook 《Bioorganic & medicinal chemistry》2013,21(1):93-101
Selective modulation of specific benzodiazepine receptor (BzR) gamma amino butyric acid-A (GABAA) receptor ion channels has been identified as an important method for separating out the variety of pharmacological effects elicited by BzR-related drugs. Importantly, it has been demonstrated that both α2β(2/3)γ2 (α2BzR) and α3BzR (and/or α2/α3) BzR subtype selective ligands exhibit anxiolytic effects with little or no sedation. Previously we have identified several such ligands; however, three of our parent ligands exhibited significant metabolic liability in rodents in the form of a labile ester group. Here eight analogs are reported which were designed to circumvent this liability by utilizing a rational replacement of the ester moiety based on medicinal chemistry precedents. In a metabolic stability study using human liver microsomes, four compounds were found to undergo slower metabolic transformation, as compared to their corresponding ester analogs. These compounds were also evaluated in in vitro efficacy assays. Additionally, bioisostere 11 was evaluated in a rodent model of anxiety. It exhibited anxiolytic activity at doses of 10 and 100 mg/kg and was devoid of sedative properties. 相似文献
135.
U Hofmann S Michaelis T Winckler J Wegener KH Feller 《Biosensors & bioelectronics》2013,39(1):156-162
This study presents the time-resolved detection of chemically induced stress upon intracellular signaling cascades by using genetically modified sensor cells based on the human keratinocyte cell line HaCaT. The cells were stably transfected with a HSP72-GFP reporter gene construct to create an optical sensor cell line expressing a stress-inducible reporter protein. The time- and dose-dependent performance of the sensor cells is demonstrated and discussed in comparison to a label-free impedimetric monitoring approach (electric cell-substrate impedance sensing, ECIS). Moreover, a microfluidic platform was established based on μSlidesI(0,4)Luer to allow for a convenient, sterile and incubator-independent time-lapse microscopic observation of the sensor cells. Cell growth was successfully achieved in this microfluidic setup and the cellular response to a cytotoxic substance could be followed in real-time and in a non-invasive, sensitive manner. This study paves the way for the development of micro-total analysis systems that combine optical and impedimetric readouts to enable an overall quantitative characterization of changes in cell metabolism and morphology as a response to toxin exposure. By recording multiple parameters, a detailed discrimination between competing stress- or growth-related mechanisms is possible, thereby presenting an entirely new in vitro alternative to skin irritation tests. 相似文献
136.
Elisabeth Breitenlechner Gert Goldenberg Joachim Lutz Klaus Oeggl 《Vegetation History and Archaeobotany》2013,22(4):351-366
The exploitation of copper ore deposits of the northern Greywacke Zone was initiated by the implementation of metallurgic technologies in the Eastern Alps thousands of years ago. This multi-proxy study aimed to detect prehistoric mining phases in the vicinity of a prominent copper ore deposit in the Lower Inn Valley. Therefore we studied a peat core from a fen using pollen, micro charcoal and geochemical analyses. In the same fen, an archaeological investigation revealed an ore beneficiation site, well dated by dendrochronological analysis to the Late Bronze Age (9th century b.c.). First hints of mining activities reflected by the occurrence of anthropogenic indicators in the pollen diagram, associated with elevated metal values, at the beginning of the Bronze Age might result from early mineral prospecting and metallurgical experiments around the use of fahlore. The local ore deposit was then abandoned until during the Bronze Age mining activities started to increase. This is reflected by an expansion of the pioneer species Pinus and Larix on mine spoil heaps in the proximity. Concomitantly metal ratios and micro charcoal increase. From about 1000 to 850 b.c. a strong impact of mining activities is displayed in the multi-proxy data. The local forest was partly cleared on and in the vicinity of the fen. According to dendrochronological data the ore beneficiation plant was in use from about 900 to 870 b.c. Until about 700 b.c. another period with moderate impact by mining activities in the further vicinity of the fen shows up. 相似文献
137.
138.
Marta Coll Philippe Cury Ernesto Azzurro Michel Bariche Giorgos Bayadas Jose Maria Bellido Christian Chaboud Joachim Claudet Abdel-Fattah El-Sayed Didier Gascuel Leyla Knittweis Carlo Pipitone Yianna Samuel-Rhoads Said Taleb Sergi Tudela Audrey Valls 《Reviews in Fish Biology and Fisheries》2013,23(4):415-434
139.
140.
Sebastian Ullrich Phillip Bremer Christine Neumann-Grutzeck Helge Otto Christoph Rüther Cay Uwe von Seydewitz Gerd Peter Meyer Keihan Ahmadi-Simab Joachim R?ther Barbara Hogan Wolfgang Schwenk Roman Fischbach J?rg Caselitz Jochen Puttfarcken Susanne Huggett Petra Tiedeken Jordan Pober Nancy C. Kirkiles-Smith Friedrich Hagenmüller 《PloS one》2013,8(2)