全文获取类型
收费全文 | 3839篇 |
免费 | 292篇 |
国内免费 | 201篇 |
专业分类
4332篇 |
出版年
2024年 | 15篇 |
2023年 | 80篇 |
2022年 | 89篇 |
2021年 | 176篇 |
2020年 | 187篇 |
2019年 | 216篇 |
2018年 | 190篇 |
2017年 | 165篇 |
2016年 | 171篇 |
2015年 | 255篇 |
2014年 | 344篇 |
2013年 | 464篇 |
2012年 | 196篇 |
2011年 | 177篇 |
2010年 | 138篇 |
2009年 | 147篇 |
2008年 | 146篇 |
2007年 | 125篇 |
2006年 | 119篇 |
2005年 | 122篇 |
2004年 | 110篇 |
2003年 | 86篇 |
2002年 | 65篇 |
2001年 | 44篇 |
2000年 | 31篇 |
1999年 | 36篇 |
1998年 | 38篇 |
1997年 | 26篇 |
1996年 | 31篇 |
1995年 | 35篇 |
1994年 | 41篇 |
1993年 | 22篇 |
1992年 | 22篇 |
1991年 | 19篇 |
1990年 | 22篇 |
1989年 | 15篇 |
1988年 | 11篇 |
1987年 | 19篇 |
1986年 | 8篇 |
1985年 | 17篇 |
1984年 | 24篇 |
1983年 | 18篇 |
1982年 | 25篇 |
1981年 | 16篇 |
1980年 | 11篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1973年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有4332条查询结果,搜索用时 15 毫秒
81.
82.
83.
随着高通量测序技术快速发展,Me RIP-seq(methylated RNA immunoprecipitation sequencing)测序技术开启了RNA表观遗传学研究新局面,能够在全基因组范围内描述RNA甲基化.从Me RIP-seq高通量数据中挖掘RNA甲基化模式,有助于揭示m RNA甲基化在调控基因表达、剪切等方面所发挥的潜在功能,有效指导癌症的干预治疗.本文从Me RIP-seq测序原理出发,较全面地综述Me RIP-seq数据处理和分析方法研究现状,并对其所面临的计算问题进行讨论和展望. 相似文献
84.
Parkinson disease (PD) is a multifactorial neurodegenerative disorder with high incidence in the elderly, where environmental and genetic factors are involved in etiology. In addition, epigenetic mechanisms, including deregulation of DNA methylation have been recently associated to PD. As accurate diagnosis cannot be achieved pre-mortem, identification of early pathological changes is crucial to enable therapeutic interventions before major neuropathological damage occurs. Here we investigated genome-wide DNA methylation in brain and blood samples from PD patients and observed a distinctive pattern of methylation involving many genes previously associated to PD, therefore supporting the role of epigenetic alterations as a molecular mechanism in neurodegeneration. Importantly, we identified concordant methylation alterations in brain and blood, suggesting that blood might hold promise as a surrogate for brain tissue to detect DNA methylation in PD and as a source for biomarker discovery. 相似文献
85.
Identification of resistance gene analogs linked to a powdery mildew resistance locus in grapevine 总被引:12,自引:6,他引:12
Donald TM Pellerone F Adam-Blondon AF Bouquet A Thomas MR Dry IB 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(4):610-618
Oligonucleotide primers, designed to conserved regions of nucleotide binding site (NBS) motifs within previously cloned pathogen
resistance genes, were used to amplify resistance gene analogs (RGAs) from grapevine. Twenty eight unique grapevine RGA sequences
were identified and subdivided into 22 groups on the basis of nucleic acid sequence-identity of approximately 70% or greater.
Representatives from each group were used in a bulked segregant analysis strategy to screen for restriction fragment length
polymorphisms linked to the powdery mildew resistance locus, Run1, introgressed into Vitis vinifera L. from the wild grape species Muscadinia rotundifolia. Three RGA markers were found to be tightly linked to the Run1 locus. Of these markers, two (GLP1–12 and MHD145) cosegregated with the resistance phenotype in 167 progeny tested, whereas
the third marker (MHD98) was mapped to a position 2.4 cM from the Run1 locus. The results demonstrate the usefulness of RGA sequences, when used in combination with bulked segregant analysis,
to rapidly generate markers tightly linked to resistance loci in crop species.
Received: 2 May 2001 / Accepted: 3 August 2001 相似文献
86.
Saze H 《Seminars in cell & developmental biology》2008,19(6):527-536
Gene activities can be regulated by epigenetic modifications of nucleotides and chromatin that are stably propagated through somatic cell divisions and, in some cases, across generations. The mechanisms that control epigenetic marks have recently been uncovered using model organisms, such as the flowering plant Arabidopsis thaliana. In Arabidopsis, perturbation of epigenetic gene activity often results in heritable developmental phenotypes. Stable, but potentially reversible, changes in epigenetic status can also be sources for phenotypic variations in natural plant populations. 相似文献
87.
88.
女性怀孕前后饮酒会对胎儿的发育及神经系统造成不利影响,称为“胎儿酒精综合征”(fetal alcohol spectrum disorders,FASD)。小鼠通常作为研究该病的动物模型。该实验采用体外培养技术及体内冲胚法研究雌鼠怀孕前后酒精摄入对各期植入前胚胎全基因组DNAT基化模式建立的影响。小鼠植入前胚胎体外培养实验发现,体外实验组I(怀孕前酒精处理组1,除8-cell外,其他各期胚胎的DNA甲基化水平明显低于体外对照组;体外实验组II(正常胚胎在含乙醇的培养基中培养),各期植入前胚胎DNA甲基化水平均明显低于体外对照组。体内实验发现,体内实验组I(怀孕前酒精处理组)与体内的实验组II(怀孕后酒精处理组),各期植入前胚胎DNA甲基化水平明显低于体内对照组。体内、外实验结果表明:受精前后酒精对各期植入前胚胎DNA甲基化模式的正确建立造成紊乱,该结果可为进一步揭示FSAD发病机制提供一定的实验基础。 相似文献
89.
Bibikova M Barnes B Tsan C Ho V Klotzle B Le JM Delano D Zhang L Schroth GP Gunderson KL Fan JB Shen R 《Genomics》2011,98(4):288-295
We have developed a new generation of genome-wide DNA methylation BeadChip which allows high-throughput methylation profiling of the human genome. The new high density BeadChip can assay over 480K CpG sites and analyze twelve samples in parallel. The innovative content includes coverage of 99% of RefSeq genes with multiple probes per gene, 96% of CpG islands from the UCSC database, CpG island shores and additional content selected from whole-genome bisulfite sequencing data and input from DNA methylation experts. The well-characterized Infinium® Assay is used for analysis of CpG methylation using bisulfite-converted genomic DNA. We applied this technology to analyze DNA methylation in normal and tumor DNA samples and compared results with whole-genome bisulfite sequencing (WGBS) data obtained for the same samples. Highly comparable DNA methylation profiles were generated by the array and sequencing methods (average R2 of 0.95). The ability to determine genome-wide methylation patterns will rapidly advance methylation research. 相似文献
90.