全文获取类型
收费全文 | 2267篇 |
免费 | 263篇 |
出版年
2021年 | 16篇 |
2019年 | 18篇 |
2018年 | 24篇 |
2016年 | 37篇 |
2015年 | 67篇 |
2014年 | 63篇 |
2013年 | 88篇 |
2012年 | 102篇 |
2011年 | 97篇 |
2010年 | 50篇 |
2009年 | 53篇 |
2008年 | 99篇 |
2007年 | 100篇 |
2006年 | 89篇 |
2005年 | 84篇 |
2004年 | 98篇 |
2003年 | 69篇 |
2002年 | 75篇 |
2001年 | 89篇 |
2000年 | 64篇 |
1999年 | 57篇 |
1998年 | 36篇 |
1997年 | 36篇 |
1996年 | 26篇 |
1995年 | 27篇 |
1994年 | 22篇 |
1993年 | 22篇 |
1992年 | 39篇 |
1991年 | 33篇 |
1990年 | 55篇 |
1989年 | 48篇 |
1988年 | 39篇 |
1987年 | 32篇 |
1986年 | 39篇 |
1985年 | 36篇 |
1984年 | 29篇 |
1983年 | 29篇 |
1982年 | 21篇 |
1981年 | 19篇 |
1979年 | 29篇 |
1978年 | 30篇 |
1977年 | 20篇 |
1976年 | 32篇 |
1975年 | 23篇 |
1974年 | 23篇 |
1973年 | 26篇 |
1972年 | 24篇 |
1971年 | 17篇 |
1970年 | 21篇 |
1969年 | 15篇 |
排序方式: 共有2530条查询结果,搜索用时 39 毫秒
111.
112.
113.
114.
Amino sugars in the cell walls of Pseudomonas species 总被引:3,自引:0,他引:3
115.
Kaitlyn M. Price Karen G. Wigg Yu Feng Kirsten Blokland Margaret Wilkinson Gengming He Elizabeth N. Kerr Tasha‐Cate Carter Sharon L. Guger Maureen W. Lovett Lisa J. Strug Cathy L. Barr 《Genes, Brain & Behavior》2020,19(6)
Reading disabilities (RD) are the most common neurocognitive disorder, affecting 5% to 17% of children in North America. These children often have comorbid neurodevelopmental/psychiatric disorders, such as attention deficit/hyperactivity disorder (ADHD). The genetics of RD and their overlap with other disorders is incompletely understood. To contribute to this, we performed a genome‐wide association study (GWAS) for word reading. Then, using summary statistics from neurodevelopmental/psychiatric disorders, we computed polygenic risk scores (PRS) and used them to predict reading ability in our samples. This enabled us to test the shared aetiology between RD and other disorders. The GWAS consisted of 5.3 million single nucleotide polymorphisms (SNPs) and two samples; a family‐based sample recruited for reading difficulties in Toronto (n = 624) and a population‐based sample recruited in Philadelphia [Philadelphia Neurodevelopmental Cohort (PNC)] (n = 4430). The Toronto sample SNP‐based analysis identified suggestive SNPs (P ~ 5 × 10?7) in the ARHGAP23 gene, which is implicated in neuronal migration/axon pathfinding. The PNC gene‐based analysis identified significant associations (P < 2.72 × 10?6) for LINC00935 and CCNT1, located in the region of the KANSL2/CCNT1/LINC00935/SNORA2B/SNORA34/MIR4701/ADCY6 genes on chromosome 12q, with near significant SNP‐based analysis. PRS identified significant overlap between word reading and intelligence (R2 = 0.18, P = 7.25 × 10?181), word reading and educational attainment (R2 = 0.07, P = 4.91 × 10?48) and word reading and ADHD (R2 = 0.02, P = 8.70 × 10?6; threshold for significance = 7.14 × 10?3). Overlap was also found between RD and autism spectrum disorder (ASD) as top‐ranked genes were previously implicated in autism by rare and copy number variant analyses. These findings support shared risk between word reading, cognitive measures, educational outcomes and neurodevelopmental disorders, including ASD. 相似文献
116.
Hansford Kayleigh M. McGinley Liz Wilkinson Samantha Gillingham Emma L. Cull Ben Gandy Sara Carter Daniel P. Vaux Alexander G. C. Richards Simon Hayes Alister Medlock Jolyon M. 《Experimental & applied acarology》2021,84(3):593-606
Experimental and Applied Acarology - Assessing the risk of tick-borne disease in areas with high visitor numbers is important from a public health perspective. Evidence suggests that tick presence,... 相似文献
117.
118.
Ana G. Crisostomo Raphael B. Moreno Suppiah Navaratnam James A. Wilkinson 《Free radical research》2013,47(6):730-737
Three potential routes to generation of reactive oxygen species (ROS) from α-tocopherolquinone (α-TQ) have been identified. The quinone of the water-soluble vitamin E analogue Trolox C (Trol-Q) is reduced by hydrated electron and isopropanol α-hydroxyalkyl radical, and the resulting semiquinone reacts with molecular oxygen to form superoxide with a second order rate constant of 1.3 × 108 dm3/mol/s, illustrating the potential for redox cycling. Illumination (UV-A, 355 nm) of the quinone of 2,2,5,7,8-pentamethyl-6-hydroxychromanol (PMHC-Q) leads to a reactive short-lived (ca. 10? 6 s) triplet state, able to oxidise tryptophan with a second order rate constant greater than 109 dm3/mol/s. The triplet states of these quinones sensitize singlet oxygen formation with quantum yields of about 0.8. Such potentially damaging reactions of α-TQ may in part account for the recent findings that high levels of dietary vitamin E supplementation lack any beneficial effect and may lead to slightly enhanced levels of overall mortality. 相似文献
119.
Alexandra M. Allen Gary L. A. Barker Paul Wilkinson Amanda Burridge Mark Winfield Jane Coghill Cristobal Uauy Simon Griffiths Peter Jack Simon Berry Peter Werner James P. E. Melichar Jane McDougall Rhian Gwilliam Phil Robinson Keith J. Edwards 《Plant biotechnology journal》2013,11(3):279-295
Globally, wheat is the most widely grown crop and one of the three most important crops for human and livestock feed. However, the complex nature of the wheat genome has, until recently, resulted in a lack of single nucleotide polymorphism (SNP)‐based molecular markers of practical use to wheat breeders. Recently, large numbers of SNP‐based wheat markers have been made available via the use of next‐generation sequencing combined with a variety of genotyping platforms. However, many of these markers and platforms have difficulty distinguishing between heterozygote and homozygote individuals and are therefore of limited use to wheat breeders carrying out commercial‐scale breeding programmes. To identify exome‐based co‐dominant SNP‐based assays, which are capable of distinguishing between heterozygotes and homozygotes, we have used targeted re‐sequencing of the wheat exome to generate large amounts of genomic sequences from eight varieties. Using a bioinformatics approach, these sequences have been used to identify 95 266 putative single nucleotide polymorphisms, of which 10 251 were classified as being putatively co‐dominant. Validation of a subset of these putative co‐dominant markers confirmed that 96% were true polymorphisms and 65% were co‐dominant SNP assays. The new co‐dominant markers described here are capable of genotypic classification of a segregating locus in polyploid wheat and can be used on a variety of genotyping platforms; as such, they represent a powerful tool for wheat breeders. These markers and related information have been made publically available on an interactive web‐based database to facilitate their use on genotyping programmes worldwide. 相似文献
120.
David T. Williams N. Straw M. Townsend A. S. Wilkinson A. Mullins 《Agricultural and Forest Entomology》2013,15(2):126-134
- 相似文献