全文获取类型
收费全文 | 8482篇 |
免费 | 662篇 |
国内免费 | 524篇 |
出版年
2024年 | 17篇 |
2023年 | 79篇 |
2022年 | 228篇 |
2021年 | 393篇 |
2020年 | 255篇 |
2019年 | 334篇 |
2018年 | 366篇 |
2017年 | 238篇 |
2016年 | 364篇 |
2015年 | 507篇 |
2014年 | 624篇 |
2013年 | 581篇 |
2012年 | 779篇 |
2011年 | 707篇 |
2010年 | 417篇 |
2009年 | 387篇 |
2008年 | 446篇 |
2007年 | 379篇 |
2006年 | 337篇 |
2005年 | 298篇 |
2004年 | 262篇 |
2003年 | 255篇 |
2002年 | 242篇 |
2001年 | 140篇 |
2000年 | 123篇 |
1999年 | 130篇 |
1998年 | 94篇 |
1997年 | 72篇 |
1996年 | 63篇 |
1995年 | 65篇 |
1994年 | 55篇 |
1993年 | 45篇 |
1992年 | 53篇 |
1991年 | 50篇 |
1990年 | 46篇 |
1989年 | 39篇 |
1988年 | 24篇 |
1987年 | 23篇 |
1986年 | 23篇 |
1985年 | 25篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1976年 | 5篇 |
1972年 | 5篇 |
1969年 | 6篇 |
排序方式: 共有9668条查询结果,搜索用时 15 毫秒
1.
Caitlin M. Cossaboom Laura Córdoba Dianjun Cao Yan-Yan Ni Xiang-Jin Meng 《Journal of virology》2012,86(23):13124-13125
Hepatitis E virus (HEV) is a single-strand positive-sense RNA virus in the family Hepeviridae. The disease caused by HEV, hepatitis E, is an important public health problem in developing countries of Asia and Africa and is also endemic in many industrialized countries, including the United States. HEV has been identified from several other animal species in addition to humans, including the pig, chicken, mongoose, deer, rabbit, ferret, bat, and fish. Here we report the complete genome sequence of the first strain of HEV from rabbits in the United States. Sequence and phylogenetic analyses revealed that the U.S. rabbit HEV is a distant member of the zoonotic genotype 3 HEV, thus raising a concern for potential zoonotic human infection. A unique 90-nucleotide insertion within the X domain of the ORF1 was identified in the rabbit HEV, and this insertion may play a role in the species tropism of HEV. 相似文献
2.
Fang Chang An Yan Li-Na Zhao Wei-Hua Wu Zhenbiao Yang 《植物学报(英文版)》2007,49(8):1261-1270
A tip-focused Ca^2+ gradient is tightly coupled to polarized pollen tube growth, and tip-localized influxes of extracellular Ca^2+ are required for this process. However the molecular identity and regulation of the potential Ca^2+ channels remains elusive. The present study has implicated CNGC18 (cyclic nucleotide-gated channel 18) in polarized pollen tube growth, because its overexpression induced wider and shorter pollen tubes. Moreover, CNGC18 overexpression induced depolarization of pollen tube growth was suppressed by lower extracellular calcium ([Ca^2+]ex). CNGC18-yellow fluorescence protein (YFP) was preferentially localized to the apparent post-Golgi vesicles and the plasma membrane (PM) in the apex of pollen tubes. The PM localization was affected by tip-localized ROP1 signaling. Expression of wild type ROP1 or an active form of ROP1 enhanced CNGC18-YFP localization to the apical region of the PM, whereas expression of RopGAP1 (a ROP1 deactivator) blocked the PM localization. These results support a role for PM-Iocalized CNGC18 in the regulation of polarized pollen tube growth through its potential function in the modulation of calcium influxes. 相似文献
3.
4.
Jun‐juan Wang Qi‐min Zhang Wei‐wei Ni Xin Zhang Ying Li Ai‐li Li Peng Du Chun Li Su‐su Yu 《Microbiology and immunology》2019,63(8):303-315
We investigated the correlation between the beneficial effect of Lactobacillus acidophilus on gut microbiota composition, metabolic activities, and reducing cow's milk protein allergy. Mice sensitized with β‐lactoglobulin (β‐Lg) were treated with different doses of L. acidophilus KLDS 1.0738 for 4 weeks, starting 1 week before allergen induction. The results showed that intake of L. acidophilus significantly suppressed the hypersensitivity responses, together with increased fecal microbiota diversity and short‐chain fatty acids (SCFAs) concentration (including propionate, butyrate, isobutyrate, and isovalerate) when compared with the allergic group. Moreover, treatment with L. acidophilus induced the expression of SCFAs receptors, G‐protein–coupled receptors 41 (GPR41) and 43 (GPR43), in the spleen and colon of the allergic mice. Further analysis revealed that the GPR41 and GPR43 messenger RNA expression both positively correlated with the serum concentrations of transforming growth factor‐β and IFN‐γ (p < .05), but negatively with the serum concentrations of IL‐17, IL‐4, and IL‐6 in the L. acidophilus–treated group compared with the allergic group (p < .05). These results suggested that L. acidophilus protected against the development of allergic inflammation by improving the intestinal flora, as well as upregulating SCFAs and their receptors GPR41/43. 相似文献
5.
6.
7.
8.
9.
Genome‐wide detection of CNVs associated with beak deformity in chickens using high‐density 600K SNP arrays
下载免费PDF全文
![点击此处可从《Animal genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H. Bai Y. Sun N. Liu Y. Liu F. Xue Y. Li S. Xu A. Ni J. Ye Y. Chen J. Chen 《Animal genetics》2018,49(3):226-236
Beak deformity (crossed beaks) is found in several indigenous chicken breeds including Beijing‐You studied here. Birds with deformed beaks have reduced feed intake and poor production performance. Recently, copy number variation (CNV) has been examined in many species and is recognized as a source of genetic variation, especially for disease phenotypes. In this study, to unravel the genetic mechanisms underlying beak deformity, we performed genome‐wide CNV detection using Affymetrix chicken high‐density 600K data on 48 deformed‐beak and 48 normal birds using penncnv . As a result, two and eight CNV regions (CNVRs) covering 0.32 and 2.45 Mb respectively on autosomes were identified in deformed‐beak and normal birds respectively. Further RT‐qPCR studies validated nine of the 10 CNVRs. The ratios of six CNVRs were significantly different between deformed‐beak and normal birds (P < 0.01). Within these six regions, three and 21 known genes were identified in deformed‐beak and normal birds respectively. Bioinformatics analysis showed that these genes were enriched in six GO terms and one KEGG pathway. Five candidate genes in the CNVRs were further validated using RT‐qPCR. The expression of LRIG2 (leucine rich repeats and immunoglobulin like domains 2) was lower in birds with deformed beaks (P < 0.01). Therefore, the LRIG2 gene could be considered a key factor in view of its known functions and its potential roles in beak deformity. Overall, our results will be helpful for future investigations of the genomic structural variations underlying beak deformity in chickens. 相似文献
10.
Shi Fenghua Tan Muxiu Mo Qiaocheng Chen Xiaoying Zhao Yimin Guo Xiaoyun Jiang Ni 《Journal of plant biochemistry and biotechnology.》2020,29(3):528-538
Journal of Plant Biochemistry and Biotechnology - The dried buds of Lonicera hypoglauca Miq. have antipyretic, antidotal and anti-inflammatory properties and as Flos lonicerae are widely used in... 相似文献