首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7212篇
  免费   586篇
  国内免费   518篇
  2023年   87篇
  2022年   108篇
  2021年   417篇
  2020年   253篇
  2019年   323篇
  2018年   282篇
  2017年   245篇
  2016年   317篇
  2015年   434篇
  2014年   533篇
  2013年   551篇
  2012年   662篇
  2011年   562篇
  2010年   332篇
  2009年   352篇
  2008年   381篇
  2007年   304篇
  2006年   284篇
  2005年   210篇
  2004年   219篇
  2003年   216篇
  2002年   139篇
  2001年   139篇
  2000年   128篇
  1999年   144篇
  1998年   86篇
  1997年   68篇
  1996年   81篇
  1995年   71篇
  1994年   62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   29篇
  1986年   17篇
  1985年   34篇
  1984年   8篇
  1983年   6篇
  1982年   2篇
  1981年   3篇
  1980年   2篇
  1979年   2篇
  1977年   1篇
排序方式: 共有8316条查询结果,搜索用时 203 毫秒
81.
Regeneration of pulmonary epithelial cells plays an important role in the recovery of acute lung injury (ALI), which is defined by pulmonary epithelial cell death. However, the mechanism of the regenerative capacity of alveolar epithelial cells is unknown. Using a lung injury mouse model induced by hemorrhagic shock and lipopolysaccharide, a protein mass spectrometry‐based high‐throughput screening and linage tracing technology to mark alveolar epithelial type 2 cells (AEC2s), we analyzed the mechanism of alveolar epithelial cells proliferation. We demonstrated that the expression of Hippo‐yes‐associated protein 1 (YAP1) key proteins were highly consistent with the regularity of the proliferation of alveolar epithelial type 2 cells after ALI. Furthermore, the results showed that YAP1+ cells in lung tissue after ALI were mainly Sftpc lineage‐labeled AEC2s. An in vitro proliferation assay of AEC2s demonstrated that AEC2 proliferation was significantly inhibited by both YAP1 small interfering RNA and Hippo inhibitor. These findings revealed that YAP functioned as a key regulator to promote AEC2s proliferation, with the Hippo signaling pathway playing a pivotal role in this process.  相似文献   
82.
Zhang  Zhe  Fan  Junxia  Long  Chuannan  He  Bin  Hu  Zhihong  Jiang  Chunmiao  Li  Yongkai  Ma  Long  Wen  Jingshang  Zou  Xiaojin  Chen  Yuan  Ge  Zhenxiang  Zeng  Bin 《Journal of industrial microbiology & biotechnology》2019,46(12):1769-1780
Journal of Industrial Microbiology & Biotechnology - The ZRT, IRT-like protein (ZIP) family exists in many species and plays an important role in many biological processes, but little is known...  相似文献   
83.
Journal of Industrial Microbiology & Biotechnology - Extremely thermoacidophilic Crenarchaeota belonging to the order Sulfolobales, such as Metallosphaera sedula, are metabolically versatile...  相似文献   
84.
Cheng  Zhuru  Zhu  Xiaonian  Zeng  Dan  Feng  Qiao  Tian  Baodong  Zheng  Haiqing  Tan  Shengkui  Zhu  Chunjiang 《Molecular biology reports》2022,49(7):6199-6205
Molecular Biology Reports - The hematological phenotype and genotype analysis of hemoglobin New York (Hb New York) combined with α or β thalassemia has been rarely reported, and whether...  相似文献   
85.
Song  Jiayue  Zhang  Fuqiang  Wang  Yu  Wang  Yuxiang  Zhang  Jingtian  Xiao  Zixuan  Fu  Xueqi  Xu  Xuemin  Zeng  Linlin 《Molecular and cellular biochemistry》2022,477(3):939-949
Molecular and Cellular Biochemistry - Bak is important for TNFα/CHX-induced neuronal death, but the precise molecular mechanism remains unclear. At the same time, TNFα/CHX concomitantly...  相似文献   
86.
The continuously arising of SARS-CoV-2 variants has been posting a great threat to public health safety globally, from B.1.17 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta) to B.1.1.529 (Omicron). The emerging or reemerging of the SARS-CoV-2 variants of concern is calling for the constant monitoring of their epidemics, pathogenicity and immune escape. In this study, we aimed to characterize replication and pathogenicity of the Alpha and Delta variant strains isolated from patients infected in Laos. The amino acid mutations within the spike fragment of the isolates were determined via sequencing. The more efficient replication of the Alpha and Delta isolates was documented than the prototyped SARS-CoV-2 in Calu-3 and Caco-2 cells, while such features were not observed in Huh-7, Vero E6 and HPA-3 cells. We utilized both animal models of human ACE2 (hACE2) transgenic mice and hamsters to evaluate the pathogenesis of the isolates. The Alpha and Delta can replicate well in multiple organs and cause moderate to severe lung pathology in these animals. In conclusion, the spike protein of the isolated Alpha and Delta variant strains was characterized, and the replication and pathogenicity of the strains in the cells and animal models were also evaluated.  相似文献   
87.
Gong  Chang  Cheng  Ziliang  Yang  Yaping  Shen  Jun  Zhu  Yingying  Ling  Li  Lin  Wanyi  Yu  Zhigang  Li  Zhihua  Tan  Weige  Zheng  Chushan  Zheng  Wenbo  Zhong  Jiajie  Zhang  Xiang  Zeng  Yunjie  Liu  Qiang  Huang  R. Stephanie  Komorowski  Andrzej L.  Yang  Eddy S.  Bertucci  François  Ricci  Francesco  Orlandi  Armando  Franceschini  Gianluca  Takabe  Kazuaki  Klimberg  Suzanne  Ishii  Naohiro  Toss  Angela  Tan  Mona P.  Cherian  Mathew A.  Song  Erwei 《中国科学:生命科学英文版》2022,65(11):2205-2217
Science China Life Sciences - Patients with hormone receptor (HR)-positive tumors breast cancer usually experience a relatively low pathological complete response (pCR) to neoadjuvant chemotherapy...  相似文献   
88.
Zhang  Lulu  Lin  Zhuohua  Zeng  Lan  Zhang  Fan  Sun  Lihong  Sun  Suhui  Wang  Ping  Xu  Menghong  Zhang  Jinxia  Liang  Xiaolong  Ge  Huiyu 《中国科学:生命科学英文版》2022,65(5):896-908

Ultrasound is widely used in biomedical engineering and has applications in conventional diagnosis and drug delivery. Recent advances in ultrasound-induced drug delivery have been summarized previously in several reviews that have primarily focused on the fabrication of drug delivery carriers. This review discusses the mechanisms underlying ultrasound-induced drug delivery and factors affecting delivery efficiency, including the characteristics of drug delivery carriers and ultrasound parameters. Firstly, biophysical effects induced by ultrasound, namely thermal effects, cavitation effects, and acoustic radiation forces, are illustrated. Secondly, the use of these biophysical effects to enhance drug delivery by affecting drug carriers and corresponding tissues is clarified in detail. Thirdly, recent advances in ultrasound-triggered drug delivery are detailed. Safety issues and optimization strategies to improve therapeutic outcomes and reduce side effects are summarized. Finally, current progress and future directions are discussed.

  相似文献   
89.
Welwitschia mirabilis, which is endemic to the Namib Desert, is the only living species within the family Welwitschiaceae. This species has an extremely long lifespan of up to 2,000 years and bears a single pair of opposite leaves that persist whilst alive. However, the underlying genetic mechanisms and evolution of the species remain poorly elucidated. Here, we report on a chromosome-level genome assembly for W. mirabilis, with a 6.30-Gb genome sequence and contig N50 of 27.50 Mb. In total, 39,019 protein-coding genes were predicted from the genome. Two brassinosteroid-related genes (BRI1 and CYCD3), key regulators of cell division and elongation, were strongly selected in W. mirabilis and may contribute to their long ever-growing leaves. Furthermore, 29 gene families in the mitogen-activated protein kinase signalling pathway showed significant expansion, which may contribute to the desert adaptations of the plant. Three positively selected genes (EHMT1, EIF4E, SOD2) may be involved in the mechanisms leading to long lifespan. Based on molecular clock dating and fossil calibrations, the divergence time of W. mirabilis and Gnetum montanum was estimated at ~123.5 million years ago. Reconstruction of population dynamics from genome data coincided well with the aridification of the Namib Desert. The genome sequence detailed in the current study provides insight into the evolution of W. mirabilis and should be an important resource for further study on gnetophyte and gymnosperm evolution.  相似文献   
90.
Zhu  Jing  Zeng  Zhaofu  Xiong  Mengqing  Mo  Huaheng  Jin  Meng  Hu  Ke 《Sleep and biological rhythms》2022,20(3):421-429
Sleep and Biological Rhythms - The relationship between plasma orexin A (OXA) levels and cognitive function in patients with obstructive sleep apnea (OSA) remains unclear. This study aimed to...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号