全文获取类型
收费全文 | 9823篇 |
免费 | 714篇 |
国内免费 | 808篇 |
出版年
2024年 | 19篇 |
2023年 | 137篇 |
2022年 | 361篇 |
2021年 | 630篇 |
2020年 | 356篇 |
2019年 | 470篇 |
2018年 | 463篇 |
2017年 | 317篇 |
2016年 | 447篇 |
2015年 | 686篇 |
2014年 | 794篇 |
2013年 | 782篇 |
2012年 | 925篇 |
2011年 | 852篇 |
2010年 | 500篇 |
2009年 | 454篇 |
2008年 | 497篇 |
2007年 | 414篇 |
2006年 | 326篇 |
2005年 | 266篇 |
2004年 | 232篇 |
2003年 | 244篇 |
2002年 | 197篇 |
2001年 | 151篇 |
2000年 | 114篇 |
1999年 | 135篇 |
1998年 | 75篇 |
1997年 | 68篇 |
1996年 | 67篇 |
1995年 | 53篇 |
1994年 | 38篇 |
1993年 | 27篇 |
1992年 | 42篇 |
1991年 | 25篇 |
1990年 | 22篇 |
1989年 | 39篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 14篇 |
1985年 | 22篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 9篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 4篇 |
1974年 | 5篇 |
1973年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Chiyu Li Jia Chen Xiaoyan Li Xin Zhang Ying Liu Sirui Zhu Long Wang Heping Zheng Sheng Luan Jiada Li Feng Yu 《植物学报(英文版)》2022,64(10):1901-1915
Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1(phot1) senses light direction, but how this leads to auxin gradient formation and growth regulation remains poorly understood. Previous studies have suggested phot1’s role for regulated apoplastic acidification, but its relation to phototropin and hypocotyl phototropism is unclear. Herein, we show that blue light can cause phot1 to interact with... 相似文献
92.
93.
在实验室控制条件下,以转Bt基因棉花GK12、33B、SGK321上的烟粉虱为食料饲养龟纹瓢虫,研究转Bt基因棉花上的烟粉虱对龟纹瓢虫生长发育及捕食的影响,同时利用Y型嗅觉仪,观察龟纹瓢虫对来自不同类型棉花的棉叶及其烟粉虱的嗅觉反应和视觉反应。结果表明,转Bt基因棉花和对应的常规棉亲本上的烟粉虱对龟纹瓢虫的发育历期和存活率没有明显的影响。龟纹瓢虫对棉花叶片、烟粉虱若虫、蜜露、蜕等4种物质的视觉反应之间没有明显的差异。对4种嗅源物质的嗅觉选择性的大小依次为:烟粉虱若虫>蜕>棉花>蜜露;在两类不同的棉花之间,转基因棉花和常规棉,龟纹瓢虫对GK12、33B、SGK321等三种转基因棉花上的烟粉虱若虫的嗅觉选择性明显较对应的常规棉亲本SM3、33、SY321上的烟粉虱若虫小;对烟粉虱若虫的蜕,两种转单价基因棉花GK12、33B较对应的常规棉亲本上的小,而转双价基因的棉花SGK321上与对应的常规棉之间没有明显的差异。烟粉虱密度大于200头.皿-1时,龟纹瓢虫捕食转基因棉花上烟粉虱的数量大于对应的常规棉花亲本,但烟粉虱密度小于200头.皿-1时,龟纹瓢虫捕食转基因棉花上烟粉虱的数量小于对应的常规棉花亲本。龟纹瓢虫对烟粉虱的捕食符合HollingⅡ型反应。龟纹瓢虫取食转基因棉花上的烟粉虱的理论极限值、瞬间攻击率均大于常规棉花。 相似文献
94.
叶色突变体往往伴随着叶绿素含量变化及叶绿体结构异常,是研究叶绿体发育与光合作用相关基因功能的重要材料。该研究通过甲基磺酸乙酯(EMS)诱变籼稻(Oryzasativasubsp.indica)品种华占(HZ)获得黄绿叶突变体,将其命名为ygl18 (yellow-green leaf 18)。与野生型相比,黄绿叶突变体ygl18自三叶期起叶片开始变黄且程度不断加深,同时伴随着光合速率与叶绿素含量下降,且结实率、千粒重及有效穗数均显著降低。透射电镜观察结果显示, ygl18的叶绿体结构紊乱,基质片层疏松,发育受到抑制,与叶片出现黄绿色表型一致。遗传分析表明, ygl18突变性状受1对隐性等位核基因控制,这对等位基因位于水稻第3号染色体长臂标记InDel2和InDel3之间115.2 kb范围内。进一步研究发现该突变体表型是编码铁氧还蛋白FdC2的基因LOC_Os03g48040的5’UTR发生突变所致。通过CRISPR转基因实验验证了该基因对表型的控制作用。研究结果揭示了叶色调控网络的遗传基础,可为今后选育高光效水稻品种提供新线索。 相似文献
95.
Ruijun Liu Ruili Liu Zhiyi Guo Jianghao Ren Jia Huang Qingquan Luo Qiang Tan 《Cell death & disease》2022,13(8)
In view of the important roles played by Kinetochore proteins in mitosis, we believed that they may contribute to the development and progression of human cancers, which has been reported recently elsewhere. Kinetochore-associated 1 (KNTC1) participates in the segregation of sister chromatids during mitosis, the effects of which on non-small-cell lung cancer (NSCLC) remain unclear. Here, we sought to identify the biological significance of KNTC1 in NSCLC. KNTC1 protein expression in NSCLC tissues was investigated by immunohistochemistry. Lentivirus delivered short hairpin RNA (shRNA) was utilized to establish KNTC1 silence NSCLC cell lines. The effects of KNTC1 depletion on NSCLC cell proliferation, migration, apoptosis, and tumor formation were analyzed by MTT assay, wound-healing assay, transwell assay, flow cytometry assay, and in nude mouse models in vivo. After KNTC1 reduction, NSCLC cell viability, proliferation, migration, and invasion were restrained. A xenograft tumor model was also provided to demonstrate the inhibited tumorigenesis in NSCLC. In addition, the downstream mechanism analysis indicated that KNTC1 depletion was positively associated with PSMB8. The findings of the present study suggested that KNTC1 may have a pivotal role in mediating NSCLC progression and may act as a novel therapeutic target for NSCLC.Subject terms: Non-small-cell lung cancer, Cell migration 相似文献
96.
Chang Xu Liang Yan Xiaoya Guan Zhen Wang Jianhui Wu Ang Lv Daoning Liu Faqiang Liu Bin Dong Min Zhao Ling Jia Xiuyun Tian Chunyi Hao 《International journal of biological sciences》2022,18(13):5038
Retroperitoneal liposarcoma (RLPS) is the most common subtype of retroperitoneal soft tissue sarcoma, characterized by a high recurrence rate and insensitivity to radiotherapy and chemotherapy. The function of tumor microenvironmental components, especially tumor-associated fibroblasts (TAFs), remains unclear in RLPS. The crosstalk between tumor cells and stromal cells should be clarified for therapy target discovery in RLPS. In this study, we demonstrated that TAFs from dedifferentiated liposarcoma (DDLPS) could attract LPS cells and promote their proliferation and migration. However, although α-SMA is positively expressed in RLPS, its expression does not indicate prognosis. By screening differentially expressed genes, performing Oncomine visualization, TCGA gene expression correlation analysis and qPCR verification, we determined that thrombospondin-2 (THBS2) gene expression was related to TAFs. The expression of Tsp2 protein, which was encoded by THBS2, was correlated with α-SMA expression, and it was an independent predictive factor for disease-free survival and recurrence-free survival in patients with RLPS. In vitro, Tsp2 facilitated the transformation of bone marrow-derived fibroblasts (BMFs) to TAFs and promoted the malignant biological behaviors of LPS cells by activating the MAPK/MEK/ERK pathway. Therefore, suppression of Tsp2 is expected to be a promising treatment method for RLPS patients. 相似文献
97.
98.
Jia Huang Xiaobo Zhou Wenbo Wang Guangdong Zhou WenJie Zhang Zhen Gao Xiaoli Wu Wei Liu 《PLoS genetics》2022,18(6)
Keloid disorder is a tumour-like disease with invasive growth and a high recurrence rate. Genetic contribution is well expected due to the presence of autosomal dominant inheritance and various genetic mutations in keloid lesions. However, GWAS failed to reveal functional variants in exon regions but single nucleotide polymorphisms in the non-coding regions, suggesting the necessity of innovative genetic investigation. This study employed combined GWAS, RNA-sequence and Hi-C analyses to dissect keloid disorder genetic mechanisms using paired keloid tissues and normal skins. Differentially expressed genes, miRNAs and lncRNAs mined by RNA-sequence were identified to construct a network. From which, 8 significant pathways involved in keloid disorder pathogenesis were enriched and 6 of them were verified. Furthermore, topologically associated domains at susceptible loci were located via the Hi-C database and ten differentially expressed RNAs were identified. Among them, the functions of six molecules for cell proliferation, cell cycle and apoptosis were particularly examined and confirmed by overexpressing and knocking-down assays. This study firstly revealed unknown key biomarkers and pathways in keloid lesions using RNA-sequence and previously reported mutation loci, indicating a feasible approach to reveal the genetic contribution to keloid disorder and possibly to other diseases that are failed by GWAS analysis alone. 相似文献
99.
100.
Yu Shang Li Li Tengfei Zhang Qingping Luo Qingzhong Yu Zhe Zeng Lintao Li Miaomiao Jia Guoyi Tang Sanlin Fan Qin Lu Wenting Zhang Yuhan Xue Hongling Wang Wei Liu Hongcai Wang Rongrong Zhang Chan Ding Huabin Shao Guoyuan Wen 《PLoS pathogens》2022,18(6)
The development of thermostable vaccines can relieve the bottleneck of existing vaccines caused by thermal instability and subsequent poor efficacy, which is one of the predominant reasons for the millions of deaths caused by vaccine-preventable diseases. Research into the mechanism of viral thermostability may provide strategies for developing thermostable vaccines. Using Newcastle disease virus (NDV) as model, we identified the negative surface charge of attachment glycoprotein as a novel determinant of viral thermostability. It prevented the temperature-induced aggregation of glycoprotein and subsequent detachment from virion surface. Then structural stability of virion surface was improved and virus could bind to and infect cells efficiently after heat-treatment. Employing the approach of surface charge engineering, thermal stability of NDV and influenza A virus (IAV) vaccines was successfully improved. The increase in the level of vaccine thermal stability was determined by the value-added in the negative surface charge of the attachment glycoprotein. The engineered live and inactivated vaccines could be used efficiently after storage at 37°C for at least 10 and 60 days, respectively. Thus, our results revealed a novel surface-charge-mediated link between HN protein and NDV thermostability, which could be used to design thermal stable NDV and IAV vaccines rationally. 相似文献