全文获取类型
收费全文 | 1412篇 |
免费 | 157篇 |
出版年
2023年 | 16篇 |
2022年 | 34篇 |
2021年 | 41篇 |
2020年 | 25篇 |
2019年 | 42篇 |
2018年 | 31篇 |
2017年 | 37篇 |
2016年 | 42篇 |
2015年 | 85篇 |
2014年 | 103篇 |
2013年 | 90篇 |
2012年 | 112篇 |
2011年 | 90篇 |
2010年 | 73篇 |
2009年 | 60篇 |
2008年 | 66篇 |
2007年 | 65篇 |
2006年 | 80篇 |
2005年 | 52篇 |
2004年 | 55篇 |
2003年 | 62篇 |
2002年 | 68篇 |
2001年 | 16篇 |
2000年 | 12篇 |
1999年 | 16篇 |
1998年 | 16篇 |
1997年 | 12篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 12篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1980年 | 3篇 |
1978年 | 7篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1969年 | 3篇 |
1963年 | 4篇 |
排序方式: 共有1569条查询结果,搜索用时 468 毫秒
101.
Metallic nanoparticles of gold functionalized with oligonucleotides conventionally use a terminal thiol modification and have been used in a wide range of applications. Although readily available, the oligonucleotide–nanoparticle conjugates prepared in this way suffer from a lack of stability when exposed to a variety of small molecules or elevated temperatures. If silver is used in place of gold then this lack of stability is even more pronounced. In this study we report the synthesis of highly stabilized oligonucleotide–nanoparticle conjugates using a simple oligonucleotide modification. A modified solid support was used to generate 3′-thioctic acid modified oligonucleotides by treatment with an N-hydroxysuccimidyl ester of thioctic acid. Unusually, both gold and silver nanoparticles have been investigated in this study and show that these disulphide-modified oligonucleotide probes offer significant improvements in nanoparticle stability when treated with dithiothreitol (DTT) compared with monothiol analogues. This is a significant advance in oligonucleotide–nanoparticle conjugate stability and for the first time allows silver nanoparticles to be prepared that are more stable than standard gold-thiol functionalized nanoparticles. This opens up the possibility of using silver nanoparticles functionalized with oligonucleotides as an alternative to gold. 相似文献
102.
Rainer Seitz Friedger von Auer Johannes Blümel Reinhard Burger Anne Buschmann Klaus Dietz Margarethe Heiden Walter E Hitzler Horst Klamm Thomas Kreil Hans Kretzschmar Micha Nübling Ruth Offergeld Georg Pauli Volkmar Schottstedt Peter Volkers Inga Zerr 《Biologicals》2007,35(2):79-97
Variant Creutzfeldt-Jakob disease (vCJD) is an at present inevitably lethal neurodegenerative disease which can only be diagnosed definitely post mortem. The majority of the approximately 200 victims to date have resided in the UK where most contaminated beef materials entered the food chain. Three cases in the UK demonstrated that vCJD can be transmitted by blood transfusion. Since BSE and vCJD have spread to several countries outside the UK, it appears advisable that specific risk assessments be carried out in different countries and geographic areas. This review explains the approach adopted by Germany in assessing the risk and considering precautionary measures. A fundamental premise is that the feeding chain of cattle and the food chain have been successfully and permanently cleared from contaminated material. This raises the question of whether transmissions via blood transfusions could have the potential to perpetuate vCJD in mankind. A model calculation based on actual population data showed, however, that this would not be the case. Moreover, an exclusion of transfusion recipients from blood donation would add very little to the safety of blood transfusions, but would have a considerable impact on blood supply. Therefore, an exclusion of transfusion recipients was not recommended in Germany. 相似文献
103.
104.
Tiffany A. Bougie M. Zachariah Peery Carly N. Lapin James E. Woodford Jonathan N. Pauli 《The Journal of wildlife management》2022,86(5):e22234
Management generally targets the most tractable life stage to rescue declining populations; however, that stage may not have the largest influence on recovery. Freshwater turtles are declining globally and early stages are frequently targeted for management, although the effectiveness of these actions on population growth are relatively unknown because of incomplete demographic data. We estimated the hatchling yearly survival rate for a freshwater turtle in the field using in situ enclosures to collect missing demographic information. We used these data to develop demographic models to calculate growth rate for a hypothetical, declining population of wood turtles (Glyptemys insculpta) in Wisconsin, USA, 2014–2019. We modeled growth for populations across a range of scenarios from no management to combinations of nest protection and head-starting at varying levels of effort. Nest protection alone did not increase population growth rate, while head-starting alone increased population growth by 0.07, with the largest increase in growth rate, 0.11, resulting from combinations of both approaches. No combination of nest protection and head-starting, without an increase in adult survival rate from the observed 0.88 to ≥0.95, led to population stabilization or increase. Populations of freshwater turtles, like the wood turtle, will likely only recover with a multi-faceted approach that targets multiple life stages simultaneously. 相似文献
105.
Ward Delphi Melbourne-Thomas Jessica Pecl Gretta T. Evans Karen Green Madeline McCormack Phillipa C. Novaglio Camilla Trebilco Rowan Bax Narissa Brasier Madeleine J. Cavan Emma L. Edgar Graham Hunt Heather L. Jansen Jan Jones Russ Lea Mary-Anne Makomere Reuben Mull Chris Semmens Jayson M. Shaw Janette Tinch Dugald van Steveninck Tatiana J. Layton Cayne 《Reviews in Fish Biology and Fisheries》2022,32(1):65-100
Reviews in Fish Biology and Fisheries - Marine ecosystems and their associated biodiversity sustain life on Earth and hold intrinsic value. Critical marine ecosystem services include maintenance of... 相似文献
106.
Bax Narissa Novaglio Camilla Maxwell Kimberley H. Meyers Koen McCann Joy Jennings Sarah Frusher Stewart Fulton Elizabeth A. Nursey-Bray Melissa Fischer Mibu Anderson Kelli Layton Cayne Emad Gholam Reza Alexander Karen A. Rousseau Yannick Lunn Zau Carter Chris G. 《Reviews in Fish Biology and Fisheries》2022,32(1):189-207
Reviews in Fish Biology and Fisheries - Humans have relied on coastal resources for centuries. However, current growth in population and increased accessibility of coastal resources through... 相似文献
107.
Endosomes are known to undergo budding and fission reactions that separate regions destined for lysosomal degradation from carriers to be recycled to the plasma membrane. A recent paper (Rowland et al, 2014 ) shows that contact sites between endosomes and the endoplasmic reticulum (ER) define the position and timing for fission. This uncovers an unanticipated role for the ER in controlling endosomal sorting and maturation. 相似文献
108.
Zhang Yang Catharina Steentoft Camilla Hauge Lars Hansen Allan Lind Thomsen Francesco Niola Malene B. Vester-Christensen Morten Fr?din Henrik Clausen Hans H. Wandall Eric P. Bennett 《Nucleic acids research》2015,43(9):e59
The nuclease-based gene editing tools are rapidly transforming capabilities for altering the genome of cells and organisms with great precision and in high throughput studies. A major limitation in application of precise gene editing lies in lack of sensitive and fast methods to detect and characterize the induced DNA changes. Precise gene editing induces double-stranded DNA breaks that are repaired by error-prone non-homologous end joining leading to introduction of insertions and deletions (indels) at the target site. These indels are often small and difficult and laborious to detect by traditional methods. Here we present a method for fast, sensitive and simple indel detection that accurately defines indel sizes down to ±1 bp. The method coined IDAA for Indel Detection by Amplicon Analysis is based on tri-primer amplicon labelling and DNA capillary electrophoresis detection, and IDAA is amenable for high throughput analysis. 相似文献
109.
110.