全文获取类型
收费全文 | 18644篇 |
免费 | 1703篇 |
国内免费 | 1397篇 |
出版年
2023年 | 208篇 |
2022年 | 383篇 |
2021年 | 887篇 |
2020年 | 602篇 |
2019年 | 685篇 |
2018年 | 727篇 |
2017年 | 537篇 |
2016年 | 699篇 |
2015年 | 1148篇 |
2014年 | 1263篇 |
2013年 | 1364篇 |
2012年 | 1561篇 |
2011年 | 1498篇 |
2010年 | 981篇 |
2009年 | 833篇 |
2008年 | 905篇 |
2007年 | 875篇 |
2006年 | 770篇 |
2005年 | 656篇 |
2004年 | 617篇 |
2003年 | 544篇 |
2002年 | 515篇 |
2001年 | 393篇 |
2000年 | 390篇 |
1999年 | 360篇 |
1998年 | 169篇 |
1997年 | 161篇 |
1996年 | 158篇 |
1995年 | 119篇 |
1994年 | 146篇 |
1993年 | 90篇 |
1992年 | 155篇 |
1991年 | 147篇 |
1990年 | 122篇 |
1989年 | 98篇 |
1988年 | 82篇 |
1987年 | 96篇 |
1986年 | 83篇 |
1985年 | 92篇 |
1984年 | 48篇 |
1983年 | 48篇 |
1982年 | 48篇 |
1981年 | 36篇 |
1980年 | 37篇 |
1979年 | 52篇 |
1978年 | 41篇 |
1977年 | 45篇 |
1976年 | 33篇 |
1975年 | 35篇 |
1974年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
991.
Delfine Cheng Marco Morsch Gerald J. Shami Roger S. Chung Filip Braet 《Experimental cell research》2019,374(1):162-171
Although liver transport routes have been extensively studied in rodents, live imaging under in situ and in vivo conditions of large volumes is still proven to be difficult. In this study, we took advantage of the optical transparency of zebrafish and their small size to explore their usefulness for correlative imaging studies and liver transport experimentations. First, we assessed the micro-architecture of the zebrafish liver and compared its fine structure to the rodent and humans’ literature. Next, we investigated the transport routes and cellular distribution of albumin using combined and correlative microscopy approaches. These methods permitted us to track the injected proteins at different time points through the process of liver uptake and clearance of albumin.We demonstrate strong structural and functional resemblance between the zebrafish liver and its rodents and humans’ counterparts. In as short as 5?min post-injection, albumin rapidly accumulated within the LSECs. Furthermore, albumin entered the space of Disse where it initially accumulated then subsequently was taken up by the hepatocytes. We propose the zebrafish as a viable alternative experimental model for hepatic transport studies, allowing swift multimodal imaging and direct quantification on the hepatic distribution of supramolecular complexes of interest. 相似文献
992.
Zimei Dong Fangfang Cheng Yibo Yang Fenxi Zhang Guangwen Chen Dezeng Liu 《Experimental cell research》2019,374(1):76-84
FLOTILLIN-1 and FLOTILLIN-2 are membrane rafts associated proteins that have been implicated in insulin and growth factor signaling, endocytosis, cell migration, proliferation, differentiation, cytoskeleton remodeling and membrane trafficking. Furthermore, FLOTILLINs also play important roles in the progression of cancer and neurodegenerative diseases. In this study, the roles of flotillins are investigated in planarian Dugesia japonica. The results show that Djflotillin-1 and Djflotillin-2 play a key role in homeostasis maintenance and regeneration process by regulating the proliferation of the neoblast cells, they are not involved in the maintenance and regeneration of the central nervous system in planarians. 相似文献
993.
994.
995.
Shan Huang Yong Xu Wen-Fang Peng Jie Cheng Hui-Hua Li Li-Sha Shen Li-Li Xia 《Journal of cellular physiology》2019,234(7):10640-10645
Asymmetric dimethylarginine (ADMA) plays a vital role in the regulation of insulin sensitivity and has been shown as a potential marker for various disease, including type 2 diabetes mellitus (DM2). However, the correlation between ADMA and impaired glucose tolerance (IGT) and obesity has not been studied. A total of 195 subjects were involved in our study. The characteristics of the subjects in the study cohort were measured and analyzed. We found that the serum ADMA and C-reactive protein levels were significantly increased in IGT and diabetic patients, whereas the levels of lipoprotein A and adiponectin were decreased, especially in diabetic patients with obesity. The serum ADMA level was positively correlated to a homeostatic model assessment for insulin resistance, and multivariate regression analysis further indicated that ADMA was an independent factor for DM patients with obesity. Our study expands the understanding of the complicated relationship between obesity, insulin resistance, IGT, and ADMA. In addition, we demonstrated that the serum ADMA level could serve as a diagnositic biomarker of the early signs for IGT patients with obesity. 相似文献
996.
Mingjun Wang Jian Wu Erye Zhou Xin Chang Jianhe Gan Tao Cheng 《Journal of cellular physiology》2019,234(11):20139-20148
997.
998.
Jinhui Liu Sipei Nie Mei Gao Yi Jiang Yicong Wan Xiaoling Ma Shulin Zhou Wenjun Cheng 《Journal of cellular physiology》2019,234(11):21260-21273
Cervical cancer is the fourth most common malignancy in women worldwide and cervical squamous cell carcinoma (CESC) is the most common histological type of cervical cancer. The dysregulation of genes plays a significant role in cancer. In the present study, we screened out differentially expressed genes (DEGs) of CESC in the GSE63514 data set from the Gene Expression Omnibus database. An integrated bioinformatics analysis was used to select hub genes, as well as to investigate their related prognostic signature, functional annotation, methylation mechanism, and candidate molecular drugs. As a result, a total of 1907 DEGs were identified (944 were upregulated and 963 were downregulated). In the protein–protein interaction network, three hub modules and 30 hub genes were identified. And two hub modules and 116 hub genes were screened out from four CESC-related modules by the weighted gene coexpression network analysis. The gene ontology term enrichment analysis and Kyoto encyclopedia of genes and genomes pathway analysis were performed to better understand functions and pathways. Genes with a significant prognostic value were found by prognostic signature analysis. And there were five genes (EPHX2, CHAF1B, KIAA1524, CDC45, and RMI2) identified as significant CESC-associated genes after expression validation and survival analysis. Among them, EPHX2 and RMI2 were noted as two novel key genes for the CESC-associated methylation and expression. In addition, four candidate small molecule drugs for CESC (camptothecin, resveratrol, vorinostat, and trichostatin A) were defined. Further studies are required to explore these significant CESC-associated genes for their potentiality in diagnosis, prognosis, and targeted therapy. 相似文献
999.
Shengsong Xu Rui Guo Pei-Zhi Li Ke Li Yu Yan Jianlong Chen Guang Wang Beate Brand-Saberi Xuesong Yang Xin Cheng 《Journal of cellular physiology》2019,234(9):15167-15181
Dexamethasone (Dex), a synthetic glucocorticoid (GC) with long-lasting treatment effects, has been proved to exert a modulatory effect on osteoblast proliferation and differentiation during embryonic osteogenesis. However, it is still controversial if Dex exposure influences endochondral ossification and the underlying mechanism. In this study, chick embryos in vivo and preosteoblast cell cultures in vitro were utilized to investigate the effects of Dex on osteoblast formation and differentiation during the skeletal development. We first demonstrated that Dex exposure could shorten the long bones of 17-day chick embryos in vivo, and also downregulated the expressions of osteogenesis-related genes. Next, we established that Dex exposure inhibited the proliferation and viability of preosteoblasts-MC3TC-E1 cells, and the addition of insulin-like growth factor 1 (IGF-1) could dramatically rescue these negative effects. On the basis of remarkable changes in the rescue experiments, we next verified the important role of angiogenesis in osteogenesis by culturing isolated embryonic phalanges in Dulbecco's modified Eagle's medium culture or on the chick chorioallantoic membrane (CAM). Then, we transplanted MC3T3-E1 cell masses onto the CAM. The data showed that Dex exposure reduced the vessel density within the developed cell mass, concomitantly with the downregulation of IGF-1 pathway. We verified that the inhibition of blood vessel formation caused by Dex could be rescued by IGF-1 treatment using the CAM angiogenesis model. Eventually, we demonstrated that the shortened length of the phalanges in the presence of Dex could be reversed by IGF-1 addition. In summary, these findings suggested that the inhibition of Igf-1 signal caused by Dex exposure exerts a detrimental impact on the formation of osteoblasts and angiogenesis, which consequently shortens long bones during osteogenesis. 相似文献
1000.