全文获取类型
收费全文 | 9233篇 |
免费 | 812篇 |
国内免费 | 1068篇 |
出版年
2024年 | 20篇 |
2023年 | 116篇 |
2022年 | 327篇 |
2021年 | 499篇 |
2020年 | 344篇 |
2019年 | 397篇 |
2018年 | 364篇 |
2017年 | 282篇 |
2016年 | 371篇 |
2015年 | 585篇 |
2014年 | 652篇 |
2013年 | 765篇 |
2012年 | 891篇 |
2011年 | 744篇 |
2010年 | 480篇 |
2009年 | 518篇 |
2008年 | 574篇 |
2007年 | 504篇 |
2006年 | 399篇 |
2005年 | 383篇 |
2004年 | 339篇 |
2003年 | 307篇 |
2002年 | 251篇 |
2001年 | 170篇 |
2000年 | 140篇 |
1999年 | 135篇 |
1998年 | 119篇 |
1997年 | 84篇 |
1996年 | 48篇 |
1995年 | 49篇 |
1994年 | 40篇 |
1993年 | 31篇 |
1992年 | 37篇 |
1991年 | 24篇 |
1990年 | 25篇 |
1989年 | 14篇 |
1988年 | 21篇 |
1987年 | 9篇 |
1986年 | 12篇 |
1985年 | 15篇 |
1984年 | 9篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1949年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Xiao Lei Na Ma Yanjie Liang Junyan Liu Pei Zhang Yanan Han Wei Chen Lehui Du Baolin Qu 《Journal of cellular and molecular medicine》2020,24(18):11018-11023
Radiotherapy is one of the most important treatments for chest tumours. Although there are plenty of strategies to prevent damage to normal lung tissues, it cannot be avoided with the emergence of radiation‐induced lung injury. The purpose of this study was to investigate the potential radioprotective effects of glucosamine, which exerted anti‐inflammatory activity in joint inflammation. In this study, we found glucosamine relieved inflammatory response and structural damages in lung tissues after radiation via HE staining. Then, we detected the level of epithelial‐mesenchymal transition marker in vitro and in vivo, which we could clearly observe that glucosamine treatment inhibited epithelial‐mesenchymal transition. Besides, we found glucosamine could inhibit apoptosis and promote proliferation of normal lung epithelial cells in vitro caused by radiation. In conclusion, our data showed that glucosamine alleviated radiation‐induced lung injury via inhibiting epithelial‐mesenchymal transition, which indicated glucosamine could be a novel potential radioprotector for radiation‐induced lung injury. 相似文献
92.
Jialing Rong Xianqun Xu Yang Xiang Guohua Yang Xinliang Ming Siying He Bin Liang Xiaokang Zhang Fang Zheng 《Journal of cellular and molecular medicine》2020,24(6):3560-3571
Numerous studies have demonstrated that thioredoxin-interacting protein (TXNIP) expression of peripheral blood leucocytes is increased in coronary artery disease (CAD). However, the molecular mechanism of this phenomenon remained unclear. DNA methylation plays important roles in the regulation of gene expression. Therefore, we speculated there might be a close association between the expression of TXNIP and methylation. In this study, we found that compared with controls, DNA methylation at cg19693031 was decreased in CAD, while mRNA expressions of TXNIP and inflammatory factors, NLRP3, IL-1β, IL-18, were increased. Methylation at cg19693031 was negatively associated with TXNIP expression in the cohort, THP-1 and macrophages/foam cells. Furthermore, Transwell assay and co-cultured adhesion assay were performed to investigate functions of TXNIP on the migration of THP-1 or the adhesion of THP-1 on the surface of endothelial cells, respectively. Notably, overexpressed TXNIP promoted the migration and adhesion of THP-1 cells and expressions of NLRP3, IL-18 and IL-1β. Oppositely, knock-down TXNIP inhibited the migration and adhesion of THP-1 and expressions of NLRP3, IL-18. In conclusion, increased TXNIP expression, related to cg19693031 demethylation orientates monocytes towards an inflammatory status through the NLRP3 inflammasome pathway involved in the development of CAD. 相似文献
93.
94.
95.
Dafeng Yang Zhousheng Yang Lei Chen Dabin Kuang Yang Zou Jie Li Xu Deng Songyuan Luo Jianfang Luo Jun He Miao Yan Guixia He Yang Deng Rong Li Qiong Yuan Yangzhao Zhou Pei Jiang Shenglan Tan 《Journal of cellular and molecular medicine》2020,24(10):5911-5925
Natural products were extracted from traditional Chinese herbal emerging as potential therapeutic drugs for treating cardiovascular diseases. This study examines the role and underlying mechanism of dihydromyricetin (DMY), a natural compound extracted from Ampelopsis grossedentata, in atherosclerosis. DMY treatment significantly inhibits atherosclerotic lesion formation, proinflammatory gene expression and the influx of lesional macrophages and CD4-positive T cells in the vessel wall and hepatic inflammation, whereas increases nitric oxide (NO) production and improves lipid metabolism in apolipoprotein E-deficient (Apoe−/−) mice. Yet, those protective effects are abrogated by using NOS inhibitor L-NAME in Apoe−/− mice received DMY. Mechanistically, DMY decreases microRNA-21 (miR-21) and increases its target gene dimethylarginine dimethylaminohydrolase-1 (DDAH1) expression, an effect that reduces asymmetric aimethlarginine (ADMA) levels, and increases endothelial NO synthase (eNOS) phosphorylation and NO production in cultured HUVECs, vascular endothelium of atherosclerotic lesions and liver. In contrast, systemic delivery of miR-21 in Apoe−/− mice or miR-21 overexpression in cultured HUVECs abrogates those DMY-mediated protective effects. These data demonstrate that endothelial miR-21-inhibited DDAH1-ADMA-eNOS-NO pathway promotes the pathogenesis of atherosclerosis which can be rescued by DMY. Thus, DMY may represent a potential therapeutic adjuvant in atherosclerosis management. 相似文献
96.
Yunjie Lu Yunfei Duan Qinghua Xu Li Zhang Weibo Chen Zhen Qu Baoqiang Wu Wensong Liu Longqing Shi Di Wu Yan Yang Donglin Sun Xuemin Chen 《Journal of cellular and molecular medicine》2020,24(2):1311-1318
Although the diagnosis and therapy approach developed, techniques for the early diagnosis of HCC remain insufficient which results in poor prognosis of patients. The traditional biomarker AFP, however, has been proved with low specificity. Circulating exosomal ncRNAs revealed different profiles reflecting the characteristics of tumour. In this study, we mainly focused on circulating exosomal ncRNAs which might be the fingerprint for HCC, especially for the diagnosis or metastasis prediction. A high throughput lncRNA microarray in exosomes extracted from cell‐free plasma was applied. The risk score analysis was employed to screen the potential exosome‐derived lncRNAs in two independent sets based on different clinical parameters in 200 paired HCC patients. After a multi‐stage validation, we finally revealed three lncRNAs, ENSG00000248932.1, ENST00000440688.1 and ENST00000457302.2, increased in HCC comparing with the both chronic hepatitis (CH) patients and cancer‐free controls. ROC curve revealed a higher sensitivity and specificity in predicting the occurrence of HCC from cancer‐free controls and CH patients with the area under curve (AUC) of 0.905 and 0.879 by combining AFP. The three lncRNA panel combined with AFP also indicted a fingerprint function in predicting the metastasis of HCC with the AUC of 0.870. In conclusion, ENSG00000248932.1, ENST00000440688.1 and ENST00000457302.2 might be the potential biomarker for the tumorigenesis prediction from CH patients or healthy controls and may also be applied for dynamic monitoring the metastasis of HCC. 相似文献
97.
Shuang Liu Yanjun Guan Yusong Sheng Yue Hu Yaoguang Rong Anyi Mei Hongwei Han 《Liver Transplantation》2020,10(13)
Additives are widely adopted for efficient, stable, and hysteresis‐free perovskite solar cells and play an important role in various breakthroughs of perovskite solar cells (PSCs). Herein the various additives adopted for PSCs are reviewed and their functioning mechanism and influence on device performance is described. The main roles of additives, modulating morphology of perovskite films, stabilizing phase of formamidinium (FA) and cesium (Cs)‐based perovskites, adjusting energy level alignment in PSCs, suppressing nonradiative recombination in perovskites, eliminating hysteresis, enhancing operational stability of PSCs, are summarized. 相似文献
98.
Kong Wen-Hua Zhao Rong Zhou Jun-Bo Wang Fang Kong De-Guang Sun Jian-Bin Ruan Qiong-Fang Liu Man-Qing 《中国病毒学》2020,35(6):752-757
Virologica Sinica - The immense patient number caused by coronavirus disease 2019 (COVID-19) global pandemic brings the urge for more knowledge about its immunological features, including the... 相似文献
99.
Tian Chan Deng Tao Zhu Xiuhuang Gong Chen Zhao Yangyu Wei Yuan Li Rong Xu Xiufeng He Miaonan Zhang Zhiwei Cheng Jing BenWillem Mol Qiao Jie 《中国科学:生命科学英文版》2020,63(3):319-328
In China,the medical guidelines recommend performing noninvasive prenatal testing (NIPT) with caution for pregnant women aged 35 years or older.However,the Mother and Child Health Care Law suggests that all primiparous women whose age is older than 35 years undergo prenatal diagnosis.These two inconsistent suggestions/recommendations have made obstetricians confused about whether to offer NIPT to these older pregnant women.To face this issue and find out the solution we performed a retrospective study of 189,809 NIPT samples collected from 28 provincial-leveled administrative units in China.Of 1,564women with high-risk pregnancies who underwent NIPT,459 (29.3%) did not participate in follow-up.The compound sensitivity and specificity of NIPT for trisomies 21,18 and 13 detection was 99.1%(95%CI,98.0%-99.6%) and 99.9%(95%CI,98.8%-99.9%),respectively.In secundiparous women,NIPT showed high sensitivity and specificity similar to that in primiparous women.The observed risk for trisomies 21 and 18 significantly increased when the maternal age was 39 and older.After the publication of the current NIPT policy,the follow-up rate at our center was 97.9%;however,a large number of women are not in maternal and infant care networks nationwide,and that makes the follow-up rate outside our center relatively low.Our study shows that to balance the prevention of major aneuploidies and the limited resources for prenatal diagnosis,the cut-off age of 35for invasive prenatal diagnosis might be unnecessary.Although the NIPT guidelines are well written,how to practice it effectively,especially in less industrialized areas,is worth discussing. 相似文献
100.
Molecular diversity of the 5S nuclear ribosomal DNA in Campeiostachys with StHY haplome constitution
Cai‐Rong Yang Bernard R. Baum Douglas A. Johnson Hai‐Qin Zhang Yong‐Hong Zhou 《植物分类学报:英文版》2020,58(1):69-76
To detect the genomic constitutions and investigate the evolutionary relationships between Campeiostachys Drobov and Elymus L. species, we have cloned and analyzed 271 5S nuclear ribosomal DNA sequences from 27 accessions of these species, mostly of Chinese origin. We identified Long H1, Short S1, and Long Y1 unit classes in nine Campeiostachys or Elymus species. The identification of the three orthologous unit classes was confirmed by the neighbor‐joining tree of each unit class from PAUP and the phylogeny tree of three unit classes from MrBayes. The results suggested that these Elymus species comprise StYH haplomes and should be included in Campeiostachys. The phylogeny tree showed a clear separation between the S1 unit class and Y1 unit class. However, Y1 unit class sequences formed a sister clade to the S1 unit class, implying that although the St and Y haplomes might have some affinity, they are distinct from one another. The phylogeny tree also indicated that the five species in sect. Turczaninovia (C. dahurica var. cylindrica, C. dahurica var. dahurica, C. dahurica var. tangutorum, E. purpuraristatus, and E. dahuricus Turcz. ex Griseb. var. violeus C. P. Wang & H. L. Yang) might share a more recent common ancestor, whereas the four species in sect. Elymus (C. nutans, E. breviaristatus (Keng) Keng ex Keng f., E. sinosubmuticus (Keng) Keng f., and E. atratus (Nevski) Hand.‐Mazz.) share a close relationship. By identifying only one type of unit class for each haplome, we propose that the 5S nuclear ribosomal DNA sequences of species within Campeiostachys might have undergone haplome‐specific concerted evolution. 相似文献