全文获取类型
收费全文 | 428篇 |
免费 | 86篇 |
出版年
2018年 | 13篇 |
2016年 | 5篇 |
2015年 | 17篇 |
2014年 | 15篇 |
2013年 | 18篇 |
2012年 | 13篇 |
2011年 | 18篇 |
2010年 | 18篇 |
2009年 | 10篇 |
2008年 | 17篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 20篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 9篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 7篇 |
1992年 | 15篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 13篇 |
1987年 | 8篇 |
1986年 | 3篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1979年 | 4篇 |
1977年 | 3篇 |
1976年 | 7篇 |
1974年 | 6篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 6篇 |
1970年 | 7篇 |
1969年 | 4篇 |
1968年 | 5篇 |
1967年 | 8篇 |
1966年 | 3篇 |
1964年 | 3篇 |
排序方式: 共有514条查询结果,搜索用时 15 毫秒
81.
The industry of next-generation sequencing is constantly evolving, with novel library preparation methods and new sequencing machines being released by the major sequencing technology companies annually. The Illumina TruSeq v2 library preparation method was the most widely used kit and the market leader; however, it has now been discontinued, and in 2013 was replaced by the TruSeq Nano and TruSeq PCR-free methods, leaving a gap in knowledge regarding which is the most appropriate library preparation method to use. Here, we used isolates from the pathogenic fungi Cryptococcus neoformans var. grubii and sequenced them using the existing TruSeq DNA v2 kit (Illumina), along with two new kits: the TruSeq Nano DNA kit (Illumina) and the NEBNext Ultra DNA kit (New England Biolabs) to provide a comparison. Compared to the original TruSeq DNA v2 kit, both newer kits gave equivalent or better sequencing data, with increased coverage. When comparing the two newer kits, we found little difference in cost and workflow, with the NEBNext Ultra both slightly cheaper and faster than the TruSeq Nano. However, the quality of data generated using the TruSeq Nano DNA kit was superior due to higher coverage at regions of low GC content, and more SNPs identified. Researchers should therefore evaluate their resources and the type of application (and hence data quality) being considered when ultimately deciding on which library prep method to use. 相似文献
82.
83.
84.
Karpe A. V. Dunn M. S. Taylor M. C. Nguyen T. Ong C. Karla T. Rockman S. Beale D. J. 《Metabolomics : Official journal of the Metabolomic Society》2018,14(12):1-1
Metabolomics - The identification of metabolomic dysregulation appears promising for the prediction of type 1 diabetes and may also reveal metabolic pathways leading to beta-cell destruction.... 相似文献
85.
Pyrodiversity interacts with rainfall to increase bird and mammal richness in African savannas
下载免费PDF全文
![点击此处可从《Ecology letters》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Colin M. Beale Colin J. Courtney Mustaphi Thomas A. Morrison Sally Archibald T. Michael Anderson Andrew P. Dobson Jason E. Donaldson Gareth P. Hempson James Probert Catherine L. Parr 《Ecology letters》2018,21(4):557-567
Fire is a fundamental process in savannas and is widely used for management. Pyrodiversity, variation in local fire characteristics, has been proposed as a driver of biodiversity although empirical evidence is equivocal. Using a new measure of pyrodiversity (Hempson et al.), we undertook the first continent‐wide assessment of how pyrodiversity affects biodiversity in protected areas across African savannas. The influence of pyrodiversity on bird and mammal species richness varied with rainfall: strongest support for a positive effect occurred in wet savannas (> 650 mm/year), where species richness increased by 27% for mammals and 40% for birds in the most pyrodiverse regions. Range‐restricted birds were most increased by pyrodiversity, suggesting the diversity of fire regimes increases the availability of rare niches. Our findings are significant because they explain the conflicting results found in previous studies of savannas. We argue that managing savanna landscapes to increase pyrodiversity is especially important in wet savannas. 相似文献
86.
Of 33 cases of naturally occurring human malaria 32 were found to have significant thrombocytopenia. Only one patient showed signs of bleeding. The lowest platelet levels were found between the day of diagnosis and the fourth day of treatment. Thereafter they returned to normal values. No other factors could be found to correlate with the presence or depth of thrombocytopenia, and no evidence of intravascular coagulation was found in any case. A rise in the immunoglobulin IgM was found in all 13 cases in which it was estimated. Since thrombocytopenia can occur independently of intravascular coagulation the latter should be diagnosed and heparin given only after clotting factors have been shown to be depleted. 相似文献
87.
The Abolition of the Lag Phase in Greening Cucumber Cotyledons by Exogenous delta-Aminolevulinic Acid
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Etiolated cucumber cotyledons treated with δ-aminolevulinic acid accumulated protochlorophyllide which was phototransformable to chlorophyll (ide). The phototransformation process in the δ-aminolevulinic acid-treated tissue was markedly temperature-dependent, consistent with the view that this protochlorophyllide must combine with the holochrome apoenzyme before phototransformation can occur. 相似文献
88.
Retrotransposon BARE-1 and Its Role in Genome Evolution in the Genus Hordeum. 总被引:11,自引:0,他引:11
下载免费PDF全文
![点击此处可从《The Plant cell》网站下载免费的PDF全文](/ch/ext_images/free.gif)
CM Vicient A Suoniemi K Anamthawat-Jnsson J Tanskanen A Beharav E Nevo AH Schulman 《The Plant cell》1999,11(9):1769-1784
89.
Cassava is infected by numerous geminiviruses in Africa and India that cause devastating losses to poor farmers. We here describe the molecular diversity of seven representative cassava mosaic geminiviruses (CMGs) infecting cassava from multiple locations in Tanzania. We report for the first time the presence of two isolates in East Africa: (EACMCV-[TZ1] and EACMCV-[TZ7]) of the species East African cassava mosaic Cameroon virus, originally described in West Africa. The complete nucleotide sequence of EACMCV-[TZ1] DNA-A and DNA-B components shared a high overall sequence identity to EACMCV-[CM] components (92% and 84%). The EACMCV-[TZ1] and -[TZ7] genomic components have recombinations in the same genome regions reported in EACMCV-[CM], but they also have additional recombinations in both components. Evidence from sequence analysis suggests that the two strains have the same ancient origin and are not recent introductions. EACMCV-[TZ1] occurred widely in the southern part of the country. Four other CMG isolates were identified: two were close to the EACMV-Kenya strain (named EACMV-[KE/TZT] and EACMV-[KE/TZM] with 96% sequence identity); one isolate, TZ10, had 98% homology to EACMV-UG2Svr and was named EACMV-UG2 [TZ10]; and finally one isolate was 95% identical to EACMV-[TZ] and named EACMV-[TZ/YV]. One isolate of African cassava mosaic virus with 97% sequence identity with other isolates of ACMV was named ACMV-[TZ]. It represents the first ACMV isolate from Tanzania to be sequenced. The molecular variability of CMGs was also evaluated using partial B component nucleotide sequences of 13 EACMV isolates from Tanzania. Using the sequences of all CMGs currently available, we have shown the presence of a number of putative recombination fragments that are more prominent in all components of EACMV than in ACMV. This new knowledge about the molecular CMG diversity in East Africa, and in Tanzania in particular, has led us to hypothesize about the probable importance of this part of Africa as a source of diversity and evolutionary change both during the early stages of the relationship between CMGs and cassava and in more recent times. The existence of multiple CMG isolates with high DNA genome diversity in Tanzania and the molecular forces behind this diversity pose a threat to cassava production throughout the African continent. 相似文献
90.
Rupert CM Jones Maria Dickson-Spillmann Martin JC Mather Dawn Marks Bryanie S Shackell 《Respiratory research》2008,9(1):62