全文获取类型
收费全文 | 2055篇 |
免费 | 156篇 |
国内免费 | 182篇 |
出版年
2024年 | 3篇 |
2023年 | 31篇 |
2022年 | 72篇 |
2021年 | 97篇 |
2020年 | 72篇 |
2019年 | 102篇 |
2018年 | 87篇 |
2017年 | 73篇 |
2016年 | 99篇 |
2015年 | 137篇 |
2014年 | 132篇 |
2013年 | 186篇 |
2012年 | 181篇 |
2011年 | 186篇 |
2010年 | 98篇 |
2009年 | 101篇 |
2008年 | 112篇 |
2007年 | 78篇 |
2006年 | 78篇 |
2005年 | 78篇 |
2004年 | 57篇 |
2003年 | 51篇 |
2002年 | 39篇 |
2001年 | 30篇 |
2000年 | 34篇 |
1999年 | 32篇 |
1998年 | 21篇 |
1997年 | 26篇 |
1996年 | 7篇 |
1995年 | 14篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 16篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有2393条查询结果,搜索用时 868 毫秒
991.
Stanley?G.?Kimani Sushil?Kumar Viralkumar?Davra Yun-Juan?Chang Canan?Kasikara Ke?Geng Wen-I?Tsou Shenyan?Wang Mainul?Hoque Andrej?Bohá? Anita?Lewis-Antes Mariana?S.?De Lorenzo Sergei?V.?Kotenko Raymond?B.?BirgeEmail author 《Cell communication and signaling : CCS》2016,14(1):19
Background
Tyro3, Axl, and Mertk (TAMs) are a family of three conserved receptor tyrosine kinases that have pleiotropic roles in innate immunity and homeostasis and when overexpressed in cancer cells can drive tumorigenesis.Methods
In the present study, we engineered EGFR/TAM chimeric receptors (EGFR/Tyro3, EGFR/Axl, and EGF/Mertk) with the goals to interrogate post-receptor functions of TAMs, and query whether TAMs have unique or overlapping post-receptor activation profiles. Stable expression of EGFR/TAMs in EGFR-deficient CHO cells afforded robust EGF inducible TAM receptor phosphorylation and activation of downstream signaling.Results
Using a series of unbiased screening approaches, that include kinome-view analysis, phosphor-arrays, RNAseq/GSEA analysis, as well as cell biological and in vivo readouts, we provide evidence that each TAM has unique post-receptor signaling platforms and identify an intrinsic role for Axl that impinges on cell motility and invasion compared to Tyro3 and Mertk.Conclusion
These studies demonstrate that TAM show unique post-receptor signatures that impinge on distinct gene expression profiles and tumorigenic outcomes.992.
993.
Shelan Liu Ta-Chien Chan Yu-Tseng Chu Joseph Tsung-Shu Wu Xingyi Geng Na Zhao Wei Cheng Enfu Chen Chwan-Chuen King 《PloS one》2016,11(3)
The largest nosocomial outbreak of Middle East respiratory syndrome (MERS) occurred in South Korea in 2015. Health Care Personnel (HCP) are at high risk of acquiring MERS-Coronavirus (MERS-CoV) infections, similar to the severe acute respiratory syndrome (SARS)-Coronavirus (SARS-CoV) infections first identified in 2003. This study described the similarities and differences in epidemiological and clinical characteristics of 183 confirmed global MERS cases and 98 SARS cases in Taiwan associated with HCP. The epidemiological findings showed that the mean age of MERS-HCP and total MERS cases were 40 (24~74) and 49 (2~90) years, respectively, much older than those in SARS [SARS-HCP: 35 (21~68) years, p = 0.006; total SARS: 42 (0~94) years, p = 0.0002]. The case fatality rates (CFR) was much lower in MERS-HCP [7.03% (9/128)] or SARS-HCP [12.24% (12/98)] than the MERS-non-HCP [36.96% (34/92), p<0.001] or SARS-non-HCP [24.50% (61/249), p<0.001], however, no difference was found between MERS-HCP and SARS-HCP [p = 0.181]. In terms of clinical period, the days from onset to death [13 (4~17) vs 14.5 (0~52), p = 0.045] and to discharge [11 (5~24) vs 24 (0~74), p = 0.010] and be hospitalized days [9.5 (3~22) vs 22 (0~69), p = 0.040] were much shorter in MERS-HCP than SARS-HCP. Similarly, days from onset to confirmation were shorter in MERS-HCP than MERS-non-HCP [6 (1~14) vs 10 (1~21), p = 0.044]. In conclusion, the severity of MERS-HCP and SARS-HCP was lower than that of MERS-non-HCP and SARS-non-HCP due to younger age and early confirmation in HCP groups. However, no statistical difference was found in MERS-HCP and SARS-HCP. Thus, prevention of nosocomial infections involving both novel Coronavirus is crucially important to protect HCP. 相似文献
994.
995.
Ran Cheng Gulaqa Anwari Zhu Jing Wang Xiaowei Zhang Siqi Geng Yanqiu Guo Liying Jin Feng Shao Xiwen 《Journal of Plant Growth Regulation》2020,39(1):370-377
Journal of Plant Growth Regulation - Saline–sodic is one of the major conditions threatening crop production. Biochar application could alleviate the adverse impacts of saline–sodic... 相似文献
996.
Jian Yang Hongchen Jiang Hailiang Dong Geng Wu Weiguo Hou Wanyu Zhao 《Geomicrobiology journal》2013,30(9):851-860
Sulfur-oxidizing bacteria (SOB) play important roles in the sulfur cycle and are widespread in a number of environments, but their occurrence and relationship to geochemical conditions in (hyper)saline lakes are still poorly understood. In this study, the abundance and diversity of SOB populations were investigated in four Qinghai-Tibetan lakes (Erhai Lake, Gahai Lake 1, Gahai Lake 2 and Xiaochaidan Lake) by using quantitative polymerase chain reaction (qPCR) and soxB gene- (encoding sulfate thiohydrolase) based phylogenectic analyses. qPCR analyses showed that in the studied lakes, the total bacterial 16S rRNA and soxB gene abundances in the sediments were distinctly higher than in the overlying waters. The 16S rRNA gene abundance in the waters ranged 5.27 × 106–6.09 × 108 copies per mL and 7.39 × 1010–2.9 × 1011 copies per gram sediment. The soxB gene abundance in the waters ranged from 1.88 × 104 to 5.21 × 105 per mL and 4.73 × 106–2.65 × 107 copies per gram sediment. The soxB gene in the waters of the two hypersaline lakes (Gahai Lake 2 and Xiaochaidan Lake) was more abundant (2.97 × 105 and 5.21 × 105 copies per mL) than that in the two low-salinity lakes (1.88 × 104 and 3.36 × 104 copies per mL). Phylogenetic analysis showed that Alpha- and Betaproteobacteria were dominant SOB in the investigated lakes, and the composition of proteobacterial subgroups varied with salinity: in freshwater Erhai Lake and low-salinity Gahai Lake 1, the SOB populations were dominated by the Betaproteobacteria, whereas in hypersaline Lake Gahai 2 and Xiaochaidan Lake, the SOB populations were dominated by Alphaproteobacteria. Overall, salinity played a key role in controlling the diversity and distribution of SOB populations in the investigated Qinghai-Tibetan lakes. 相似文献
997.
Recently,a class of about 22 nucleotides (nt)small RNA has been discovered in many eukaryotes,termed microRNAs (miRNAs),which have a variety of functions.Many recent findings have demonstrated that viruses can also encode their own miRNAs.Meanwhile,other findings reveal a relationship between host miRNA and viral infection.These findings suggest a tight relationship between host and viral infection via miRNA pathway.This article introduces the miRNAs encoded by viruses and reviews the advances of the interaction of the mammalian host miRNAs and viral infection. 相似文献
998.
High‐density interspecific genetic linkage mapping provides insights into genomic incompatibility between channel catfish and blue catfish 下载免费PDF全文
S. Liu Y. Li Z. Qin X. Geng L. Bao L. Kaltenboeck H. Kucuktas R. Dunham Z. Liu 《Animal genetics》2016,47(1):81-90
Catfish is the leading aquaculture species in the United States. The interspecific hybrid catfish produced by mating female channel catfish with male blue catfish outperform both of their parent species in a number of traits. However, mass production of the hybrids has been difficult because of reproductive isolation. Investigations of genome structure and organization of the hybrids provide insights into the genetic basis for maintenance of species divergence in the face of gene flow, thereby helping develop strategies for introgression and efficient production of the hybrids for aquaculture. In this study, we constructed a high‐density genetic linkage map using the hybrid catfish system with the catfish 250K SNP array. A total of 26 238 SNPs were mapped to 29 linkage groups, with 12 776 unique marker positions. The linkage map spans approximately 3240 cM with an average intermarker distance of 0.25 cM. A fraction of markers (986 of 12 776) exhibited significant deviation from the expected Mendelian ratio of segregation, and they were clustered in major genomic blocks across 15 LGs, most notably LG9 and LG15. The distorted markers exhibited significant bias for maternal alleles among the backcross progenies, suggesting strong selection against the blue catfish alleles. The clustering of distorted markers within genomic blocks should lend insights into speciation as marked by incompatibilities between the two species. Such findings should also have profound implications for understanding the genomic evolution of closely related species as well as the introgression of hybrid production programs in aquaculture. 相似文献
999.
Intensive groundwater extraction causes many environmental problems globally. Reducing groundwater extraction is a primary method for alleviating these problems. However, this reduction may create new pollution issues because of an increase in groundwater vulnerability. A case study was done using the DRAOTIC evaluation method (an improved DRASTIC method for organic pollutant in aquifer vulnerability; soil (S factor) has been updated by organic matter (O factor) in the method) for the Hun River Basin, northeastern China, where groundwater intensive extraction had caused serious environmental and hydrogeological problems. The assessment results show that moderate vulnerability level is the main vulnerability level in the Hun River Basin; high vulnerability level and low vulnerability level categories occupy a smaller area; while very high and very low vulnerability categories occupy the smallest area. By combining the predicted groundwater level distribution and DRAOTIC model, the responses of groundwater vulnerability to different groundwater extraction reductions could be studied. The results show that groundwater vulnerability levels increased as groundwater extraction was reduced; this is because the rising groundwater levels make it easier for pollution coming from the surface to reach the aquifer. The more the reduction in groundwater extraction, the greater the increase in the area with higher vulnerability levels, and the greater the increase in pollution risk. 相似文献
1000.