全文获取类型
收费全文 | 7345篇 |
免费 | 563篇 |
国内免费 | 547篇 |
出版年
2024年 | 6篇 |
2023年 | 88篇 |
2022年 | 208篇 |
2021年 | 443篇 |
2020年 | 258篇 |
2019年 | 323篇 |
2018年 | 282篇 |
2017年 | 244篇 |
2016年 | 315篇 |
2015年 | 436篇 |
2014年 | 531篇 |
2013年 | 547篇 |
2012年 | 664篇 |
2011年 | 568篇 |
2010年 | 338篇 |
2009年 | 360篇 |
2008年 | 383篇 |
2007年 | 306篇 |
2006年 | 285篇 |
2005年 | 208篇 |
2004年 | 220篇 |
2003年 | 214篇 |
2002年 | 136篇 |
2001年 | 136篇 |
2000年 | 128篇 |
1999年 | 143篇 |
1998年 | 83篇 |
1997年 | 70篇 |
1996年 | 81篇 |
1995年 | 70篇 |
1994年 | 61篇 |
1993年 | 31篇 |
1992年 | 62篇 |
1991年 | 43篇 |
1990年 | 40篇 |
1989年 | 22篇 |
1988年 | 24篇 |
1987年 | 28篇 |
1986年 | 16篇 |
1985年 | 33篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有8455条查询结果,搜索用时 15 毫秒
161.
研究菜籽饼肥对香蕉枯萎病的防治效果,探究菜籽饼肥施用后对土壤细菌群落的影响.设置2组实验,CN组为菜籽饼肥处理组,YN组为对照实验组.种植120d后,统计各组的发病率;利用qPCR技术检测2组中的FOC4孢子数量;采集2组土壤,利用Illumina Miseq高通量测序平台对CN处理组与YN对照组的土壤细菌群落结构和差异进行分析对比.实验研究发现:(1)施菜籽饼肥的CN处理组枯萎病发病率比YN对照组低63.33%;施用菜籽饼肥的处理土壤中FOC4的数量由2.94×104个/克土下降为1.96×103个/克土,YN对照组土壤中FOC4孢子的数量由2.94×104个/克土上升为4.55×105个/克土,CN处理组较YN对照组枯萎病菌数量下降了 2个数量级;(2)土壤细菌宏基因组微生物分类测序结果显示,CN处理组的Alpha多样性指数均优于YN对照组,这表明施用菜籽饼肥后增加了土壤细菌群落的丰度及多样性;(3)在门水平上,菜籽饼肥处理增加了变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)的相对丰度,同时也降低了酸杆菌门(Acidobact-eria)、厚壁菌门(Firmicutes)和Patescibacteria等菌门的相对丰度;在属水平,CN处理组中的不动杆菌属(Aci-netobacter)、水杆菌属(Aquabacterium)、热单胞菌属(Thermomonas)、产黄杆菌属(Rhodanobacter)、假单胞菌属(Pseudomonas)和奥托氏菌属(Ottowia)等菌属的相对丰度较YN对照组有明显提高,而酸热菌属(Acidother-mus)、Bryobacter菌属以及Acidipila等菌属相对丰度较YN对照组有所减少.施用菜籽饼肥可以改变土壤中细菌的群落结构,显著降低土壤中FOC4孢子数量,从而降低香蕉枯萎病的发病率.本研究结果为菜籽饼肥用于香蕉枯萎病综合防控提供了理论依据. 相似文献
162.
Taoli Liu Dongchang Zeng Zhiye Zheng Zhansheng Lin Yang Xue Tie Li Xianrong Xie Genglu Ma Yao‐Guang Liu Qinlong Zhu 《植物学报(英文版)》2021,63(9):1611-1619
The development of clustered regularly interspaced palindromic repeats (CRISPR)-associated protein (Cas) variants with a broader recognition scope is critical for further improvement of CRISPR/Cas systems. The original Cas9 protein from Streptococcus canis (ScCas9) can recognize simple NNG-protospacer adjacent motif (PAM) targets, and therefore possesses a broader range relative to current CRISPR/Cas systems, but its editing efficiency is low in plants. Evolved ScCas9+ and ScCas9++ variants have been shown to possess higher editing efficiencies in human cells, but their activities in plants are currently unknown. Here, we utilized codon-optimized ScCas9, ScCas9+ and ScCas9++ and a nickase variant ScCas9n++ to systematically investigate genome cleavage activity and cytidine base editing efficiency in rice (Oryza sativa L.). This analysis revealed that ScCas9++ has higher editing efficiency than ScCas9 and ScCas9+ in rice. Furthermore, we fused the evolved cytidine deaminase PmCDA1 with ScCas9n++ to generate a new evoBE4max-type cytidine base editor, termed PevoCDA1-ScCas9n++. This base editor achieved stable and efficient multiplex-site base editing at NNG-PAM sites with wider editing windows (C−1–C17) and without target sequence context preference. Multiplex-site base editing of the rice genes OsWx (three targets) and OsEui1 (two targets) achieved simultaneous editing and produced new rice germplasm. Taken together, these results demonstrate that ScCas9++ represents a crucial new tool for improving plant editing. 相似文献
163.
Junping Li Libin Liang Li Jiang Qian Wang Xia Wen Yuhui Zhao Pengfei Cui Yaping Zhang Guangwen Wang Qibing Li Guohua Deng Jianzhong Shi Guobin Tian Xianying Zeng Yongping Jiang Liling Liu Hualan Chen Chengjun Li 《PLoS pathogens》2021,17(2)
Posttranslational modifications, such as SUMOylation, play specific roles in the life cycle of invading pathogens. However, the effect of SUMOylation on the adaptation, pathogenesis, and transmission of influenza A virus (IAV) remains largely unknown. Here, we found that a conserved lysine residue at position 612 (K612) of the polymerase basic protein 1 (PB1) of IAV is a bona fide SUMOylation site. SUMOylation of PB1 at K612 had no effect on the stability or cellular localization of PB1, but was critical for viral ribonucleoprotein (vRNP) complex activity and virus replication in vitro. When tested in vivo, we found that the virulence of SUMOylation-defective PB1/K612R mutant IAVs was highly attenuated in mice. Moreover, the airborne transmission of a 2009 pandemic H1N1 PB1/K612R mutant virus was impaired in ferrets, resulting in reversion to wild-type PB1 K612. Mechanistically, SUMOylation at K612 was essential for PB1 to act as the enzymatic core of the viral polymerase by preserving its ability to bind viral RNA. Our study reveals an essential role for PB1 K612 SUMOylation in the pathogenesis and transmission of IAVs, which can be targeted for the design of anti-influenza therapies. 相似文献
164.
Zhou Yuanhao Ye Xiaolin Wang Baikui Ying Jiafu Zeng Zihan Tang Li Wang Qi Zou Peng Zhan Xiaoli Fu Luoqin 《International journal of peptide research and therapeutics》2021,27(3):1605-1613
International Journal of Peptide Research and Therapeutics - Pidotimod has been shown to exhibit immunomodulatory activities and exert protective effects against bacterial infections. This study... 相似文献
165.
Cui Liu Qian He Linlin Zeng Ling Shen Qiaomei Luo Wentao Zhang Xia Zhou Jun Wan 《化学与生物多样性》2021,18(12):e2100705
Emerging evidence suggests that a high-fat diet (HFD) can influence endoplasmic reticulum (ER) stress and gut microbiota. Crataegi Fructus is a traditional Chinese herb widely used in formulas for dyspepsia, with Dashanzha Pill composed of raw Crataegi Fructus (DR) being a representative drug. Processing products of Crataegi Fructus, however, have a stronger pro-digestive effect, and we hypothesized that Dashanzha Pill composed of charred Crataegi Fructus (DC) is more effective. We found that the contents of glucose 1-phosphate and luteolin in DR and DC were substantially different via ultra-high performance liquid chromatography-hybrid quadrupole-Orbitrap high-resolution mass spectrometry. DC outperformed DR in improving histopathological changes, increasing gastrin and motilin, and decreasing vasoactive intestinal peptides in rats with HFD induced dyspepsia. Fecal microbiota analysis revealed that DC could restore the disturbed intestinal microbiota composition, including that of Bacteroides, Akkermansia, and Intestinimonas to normal levels. Furthermore, DC significantly reduced the mRNA and protein levels of glucose-regulated protein 78, protein kinase R-like ER kinase, and eukaryotic initiation factor 2α. Taken together, DC outperformed DR in relieving dyspepsia by regulating gut microbiota and alleviating ER stress. 相似文献
166.
Li Jingyan Wang Yong Chen Juan Zhang Siyuan Zeng Ying 《International journal of peptide research and therapeutics》2021,27(4):2559-2570
International Journal of Peptide Research and Therapeutics - Atrial natriuretic peptide (ANP) is a type of peptide hormone secreted by atrial cells, which has many important biological functions... 相似文献
167.
Wei Liu Chunyu Wang Shengli Wang Kai Zeng Shan Wei Ning Sun Ge Sun Manlin Wang Renlong Zou Wensu Liu Lin Lin Huijuan Song Zining Jin Yue Zhao 《International journal of biological sciences》2021,17(1):188
Androgen receptor (AR) and its variants play vital roles in development and progression of prostate cancer. To clarify the mechanisms involved in the enhancement of their actions would be crucial for understanding the process in prostate cancer and castration-resistant prostate cancer transformation. Here, we provided the evidence to show that pre-mRNA processing factor 6 (PRPF6) acts as a key regulator for action of both AR full length (AR-FL) and AR variant 7 (AR-V7), thereby participating in the enhancement of AR-FL and AR-V7-induced transactivation in prostate cancer. In addition, PRPF6 is recruited to cis-regulatory elements in AR target genes and associates with JMJD1A to enhance AR-induced transactivation. PRPF6 also promotes expression of AR-FL and AR-V7. Moreover, PRPF6 depletion reduces tumor growth in prostate cancer-derived cell lines and results in significant suppression of xenograft tumors even under castration condition in mouse model. Furthermore, PRPF6 is obviously highly expressed in human prostate cancer samples. Collectively, our results suggest PRPF6 is involved in enhancement of oncogenic AR signaling, which support a previously unknown role of PRPF6 during progression of prostate cancer and castration-resistant prostate cancers. 相似文献
168.
Jun Zuo Lili Hu Wei Shen Jiaying Zeng Lin Li Lirong Song Nanqin Gan 《Environmental microbiology》2021,23(2):1066-1078
Lake Taihu in China has suffered serious harmful cyanobacterial blooms for decades. The algal blooms threaten the ecological sustainability, drinking water safety, and human health. Although the roles of abiotic factors (such as water temperature and nutrient loading) in promoting Microcystis blooms have been well studied, the importance of biotic factors (e.g. bacterial community) in promoting and meditating Microcystis blooms remains unclear. In this study, we investigated the ecological dynamics of bacterial community, the ratio of toxic Microcystis, as well as microcystin in Lake Taihu. High-throughput 16S rRNA sequencing and principal component analysis (PCA) revealed that the bacteria community compositions (BCCs) clustered into three groups, the partitioning of which corresponded to that of groups according to the toxic profiles (the ratio of toxic Microcystis to total Microcystis, and the microcystin concentrations) of the samples. Further Spearman's correlation network showed that the α-proteobacteria Phenylobacterium strongly positively correlated with the toxic profiles. Subsequent laboratory chemostats experiments demonstrated that three Phenylobacterium strains promoted the dominance of the toxic Microcystis aeruginosa PCC7806 when co-culturing with the non-toxic PCC7806 mcyB− mutant. Taken together, our data suggested that the α-proteobacteria Phenylobacterium may play a vital role in the maintenance of toxic Microcystis dominance in Lake Taihu. 相似文献
169.
Wang Yuhan Wang Dianhong Zhang Xiangli Huang Tianye Zhao Xiang Zeng Shuwen 《Plasmonics (Norwell, Mass.)》2021,16(2):463-469
Plasmonics - By introducing the sub-wavelength grating (SWG) waveguide in the long-range surface phonon resonance (LRSPhR) device, a mid-infrared Fano resonance is formed due to the coupling... 相似文献
170.
He Liming Xu Yungang Zeng Fansuo Tian Hongmei Xiao Ying Liu Hualing Yu Lei Zhan Yaguang 《In vitro cellular & developmental biology. Plant》2021,57(2):307-318
In Vitro Cellular & Developmental Biology - Plant - The interspecific hybridization can take advantage of heterosis and combine the double parental traits most extensively, and is an effective... 相似文献