全文获取类型
收费全文 | 22952篇 |
免费 | 2601篇 |
国内免费 | 7739篇 |
出版年
2024年 | 90篇 |
2023年 | 542篇 |
2022年 | 899篇 |
2021年 | 1443篇 |
2020年 | 1233篇 |
2019年 | 1400篇 |
2018年 | 1048篇 |
2017年 | 921篇 |
2016年 | 1087篇 |
2015年 | 1585篇 |
2014年 | 2062篇 |
2013年 | 1935篇 |
2012年 | 2458篇 |
2011年 | 2444篇 |
2010年 | 1668篇 |
2009年 | 1568篇 |
2008年 | 1745篇 |
2007年 | 1584篇 |
2006年 | 1443篇 |
2005年 | 1193篇 |
2004年 | 927篇 |
2003年 | 777篇 |
2002年 | 681篇 |
2001年 | 525篇 |
2000年 | 532篇 |
1999年 | 354篇 |
1998年 | 210篇 |
1997年 | 137篇 |
1996年 | 128篇 |
1995年 | 103篇 |
1994年 | 75篇 |
1993年 | 67篇 |
1992年 | 65篇 |
1991年 | 68篇 |
1990年 | 35篇 |
1989年 | 37篇 |
1988年 | 34篇 |
1987年 | 31篇 |
1986年 | 22篇 |
1985年 | 46篇 |
1984年 | 22篇 |
1983年 | 13篇 |
1982年 | 22篇 |
1981年 | 13篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1972年 | 1篇 |
1965年 | 2篇 |
1950年 | 6篇 |
1938年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
的:研究Fibulin-5蛋白在三阴性乳腺癌(TNBC)m胞转移中的作用。方法:以三阴性乳腺癌细胞系(MDA-MB-231)分化而来的三株高中低不同转移能力的子细胞系为模型,高表达和抑制Fibulin.5在其中的表达,研究其对细胞侵袭能力的影响。结果:三阴性乳腺癌细胞内本底的Fibulin.5与其转移能力正相关,另外上调和抑制Fibulin-5可以改变其原有的侵袭能力。结论:Fibulin-5在三阴性乳腺癌细胞转移中发挥重要作用,抑制Fibulin-5可以降低三阴性乳腺癌细胞的侵袭能力。 相似文献
932.
目的:探讨原发性肝细胞癌(HCC)组织中Beclin 1的表达及其在肝细胞癌发生发展中的作用。方法:应用免疫组化EnVision法检测54例肝细胞癌组织及其癌旁组织中Beclin 1的表达,分析其与肝细胞癌的病理分级、临床分期、侵袭及转移等临床病理因素的关系。结果:HCC组织中Beclin 1阳性表达率明显低于癌旁组织(X2=7.53,P〈0.01)。病理分级Ⅲ~Ⅳ、TNM分期Ⅲ~Ⅳ、存在静脉浸润和淋巴结转移的肝癌组织中的Beclin 1表达水平明显低于病理分级Ⅰ~Ⅱ、TNM分期Ⅰ~Ⅱ、无静脉浸润和淋巴结转移的肝癌组织(P〈0.01)。结论:HCC组织中存在Beclin 1表达缺失,可能与HCC的发生有着密切的关系,且对HCC的恶性生物学行为有重要影响。 相似文献
933.
934.
Xiao-Chen Chen Hao Sun Chang-Jun Zhang Ying Zhang Ke-Qin Lin Liang Yu Lei Shi Yu-Fen Tao Xiao-Qin Huang Jia-You Chu Zhao-Qing Yang 《遗传学报》2013,40(10):543-548
The ataxin-2 (ATXN2) gene is located on human chromo-some 12q24.1. In normal individuals, the coding region in exon 1 of this gene has fewer than 31 CAG repeats (Yu et al., 2005: Laffita-Mesa et al., 2012). However, an abnormal expansion of CAG trinucleotide repeats results in the aggre-gation of polyglutamine (polyQ), which causes spinocer-ebellar ataxia type 2 (SCA2) (Pulst et al., 1996). The expanded alleles have more than 32 repeats in the affected individuals, and generally there is an inverse correlation between CAG repeat length and age of onset (Pulst et al., 1996). SCA2 is an autosomal dominant inheritance neurodegenerative disease, whose major clinical feature is progressive cerebellar ataxia. Atrophies of the brainstem and frontal lobe have been frequently detected by magnetic resonance imaging (MRI) (Yamamoto-Watanabe et al., 2010). This disease has the strong effect on sensory and motor control. 相似文献
935.
YANG Lei RONG WeiQi XIAO Ting ZHANG Ying XU Bin LIU Yu WANG LiMing WU Fan QI Jun ZHAO XiuYing WANG HongXia HAN NaiJun GUO SuPing WU JianXiong GAO YanNing CHENG ShuJun 《中国科学:生命科学英文版》2013,56(7):638-646
For successful therapy, hepatocellular carcinoma (HCC) must be detected at an early stage. Herein, we used a proteomic approach to analyze the secretory/releasing proteome of HCC tissues to identify plasma biomarkers. Serum-free conditioned media (CM) were collected from primary cultures of cancerous tissues and surrounding noncancerous tissues. Proteomic analysis of the CM proteins permitted the identification of 1365 proteins. The enriched molecular functions and biological processes of the CM proteins, such as hydrolase activity and catabolic processes, were consistent with the liver being the most important metabolic organ. Moreover, 19% of the proteins were characterized as extracellular or membrane-bound. For validation, secretory proteins involved in transforming growth factor-β signaling pathways were validated in plasma samples. Alphafetoprotein (AFP), metalloproteinase (MMP)1, osteopontin (OPN), and pregnancy-specific beta-1-glycoprotein (PSG)9 were significantly increased in HCC patients. The overall performance of MMP1 and OPN in the diagnosis of HCC remained greater than that of AFP. In addition, this study represents the first report of MMP1 as a biomarker with a higher sensitivity and specificity than AFP. Thus, this study provides a valuable resource of the HCC secretome with the potential to investigate serological biomarkers. MMP1 and OPN could be used as novel biomarkers for the early detection of HCC and to improve the sensitivity of biomarkers compared with AFP. 相似文献
936.
937.
938.
Jing Lin Xiling Shou Xiaobo Mao Jiangchuan Dong Nilesh Mohabeer Kishan kumar Kushwaha Lei Wang Yousu Su Hongcheng Fang Dazhu Li 《PloS one》2013,8(4)
Background
Macrophage death in advanced lesion has been confirmed to play an important role in plaque instability. However, the mechanism underlying lesion macrophage death still remains largely unknown.Methods and Results
Immunohistochemistry showed that caspase-1 activated in advanced lesion and co-located with macrophages and TUNEL positive reaction. In in-vitro experiments showed that ox-LDL induced caspase-1 activation and this activation was required for ox-LDL induced macrophages lysis, IL-1β and IL-18 production as well as DNA fragmentation. Mechanism experiments showed that CD36 and NLRP3/caspase-1/pathway involved in ox-LDL induced macrophage pyroptosis.Conclusion
Our study here identified a novel cell death, pyroptosis in ox-LDL induced human macrophage, which may be implicated in lesion macrophages death and play an important role in lesion instability. 相似文献939.
940.
Wenhui Pang Hefeng Wang Lei Shi Yueqi Sun Xiaoting Wang Mingming Wang Jianfeng Li Haibo Wang Guanggang Shi 《PloS one》2013,8(3)