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   25673篇
  免费   2584篇
  国内免费   1320篇
耳鼻咽喉   260篇
儿科学   281篇
妇产科学   453篇
基础医学   5500篇
口腔科学   491篇
临床医学   1283篇
内科学   2932篇
皮肤病学   549篇
神经病学   1249篇
特种医学   395篇
外国民族医学   13篇
外科学   1546篇
综合类   3840篇
现状与发展   6篇
预防医学   667篇
眼科学   230篇
药学   2617篇
  2篇
中国医学   612篇
肿瘤学   6651篇
  2024年   51篇
  2023年   375篇
  2022年   572篇
  2021年   979篇
  2020年   807篇
  2019年   591篇
  2018年   546篇
  2017年   632篇
  2016年   663篇
  2015年   943篇
  2014年   1289篇
  2013年   1322篇
  2012年   1216篇
  2011年   1546篇
  2010年   1356篇
  2009年   1442篇
  2008年   1472篇
  2007年   1515篇
  2006年   1364篇
  2005年   1341篇
  2004年   1287篇
  2003年   1247篇
  2002年   1084篇
  2001年   1009篇
  2000年   915篇
  1999年   721篇
  1998年   633篇
  1997年   544篇
  1996年   446篇
  1995年   361篇
  1994年   228篇
  1993年   173篇
  1992年   108篇
  1991年   90篇
  1990年   52篇
  1989年   55篇
  1988年   63篇
  1987年   42篇
  1986年   47篇
  1985年   56篇
  1984年   58篇
  1983年   27篇
  1982年   45篇
  1981年   39篇
  1980年   41篇
  1979年   28篇
  1978年   30篇
  1977年   31篇
  1976年   20篇
  1973年   15篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
3.
4.
5.
6.
Profilin 1 (PFN1) is a critical actin-regulatory protein; however, its functional role in hepatocellular carcinoma (HCC) progression remains to be further elucidated. In the present study, we observed that the expression levels of PFN1 were significantly decreased in HCC tissues and cell lines. Low PFN1 expression was significantly correlated with aggressive clinicopathological characteristics and poor prognosis of HCC patients. Further in vitro experiments demonstrated that overexpression of PFN1 remarkably inhibited the proliferation, migration, invasion and EMT of HCC cells. Moreover, we also found that PFN1 was a direct target gene of miR-19a-3p, and in HCC tissues, and there was a significantly inverse correlation between PFN1 mRNA and miR-19a-3p expression. Collectively, our results showed that PFN1 functions as a tumor suppressor in HCC, and might serve as a diagnostic and therapeutic target for HCC patients.  相似文献   
7.
Neuronal growth regulator 1 (NEGR1), a member of the immunoglobulin superfamily cell adhesion molecule subgroup IgLON, has been involved in neuronal growth and connectivity. Genetic variants, in or near the NEGR1 locus, have been associated with obesity and, more recently, with learning difficulties, intellectual disability, and psychiatric disorders.Here, we described the only second report of NEGR1 gene disruption in 1p31.1 microdeletion in two patients. Patient 1 is a 14-year-old female with neurological and psychiatric features present also in her family. Patient 2 is a 5-month-old infant showing global hypotonia as unique neurological features till now. This patient also carries 7p22.1 duplication, of paternal origin, that could be responsible for some malformations present in the child.We hypothesize a role of NEGR1 in producing the phenotype of our patients and compare them with other cases previously reported in the literature and DECIPHER database to better identify a possible genotype-phenotype correlation.  相似文献   
8.
目的 探讨类风湿关节炎患者外周血miR-150-5p、细胞因子信号抑制因子1(suppressor of cytokine signaling 1,SOCS1)mRNA的表达及对类风湿关节炎(Rheumatoid Arthritis,RA)疾病诊断、中医证型判断的意义。方法 纳入符合诊断标准的RA患者57例及健康对照组19例,根据《22个专业95个病种中医诊疗方案》有关RA的中医证候诊断标准,判断RA的中医证型。qPCR检测RA患者及健康对照组miR-150-5p、SOCS1mRNA的相对表达水平,同时检测血常规、肝功能、肾功能等常规指标。双荧光素酶分析方法判断两者是否存在靶向关系。统计分析miR-150-5p、SOCS1 mRNA对RA疾病的诊断意义及其与中医证型的相关性。结果 RA患者外周血miR-150-5p的相对表达水平下调,低于正常人群(t = -19.019,P < 0.05);其表达水平随疾病活动度升高,有下降趋势;患者外周血SOCS1 mRNA的相对表达水平上调,低于正常人群(t = 5.333,P < 0.05);其表达水平随疾病活动度升高,有上升趋势。MiR-150-5p与SOCS1 mRNA有靶向结合关系(P < 0.05)。通过AUC曲线比较,miR-150-5p的相对表达水平区分RA的敏感性及特异性分别为98.1%、92.1%(AUC = 0.972,P < 0.05);SOCS1 mRNA的相对表达水平无法区分RA(AUC = 0.472,P > 0.05)。RA患者中miR-150-5p的相对表达水平低于3.06,RA患者风湿痹阻证、寒湿痹阻证的相对风险分别为8.33、250.00(P < 0.05)。结论 miR-150-5p、SOCS1 mRNA在RA患者中有差异性表达,且有靶向结合关系。miR-150-5p可能是RA的疾病诊断及中医风湿痹阻证、寒湿痹阻证证型诊断的潜在生物标志物。  相似文献   
9.
Conventional chemotherapy fails to cure metastatic hepatoma mainly due to its high hepatotoxicity. Currently, doxorubicin is the most widely used drug against liver cancer either as single agent or in combination with other chemotherapeutics such as cisplatin. It is limited due to their severe toxicity on normal hepatocytes. Therefore, alternative therapeutic agents without or with low hepatotoxicity are highly desirable. Interferons are a family of cytokines that potently demonstrate antiviral, immunomodulatory, and antiproliferative activities. It also exerts direct cytotoxic effects on tumor cells. The purpose of this study was to examine the in vitro cytotoxicity of interferon‐β on HepG2 cells. We revealed the presence of binding receptor of interferon‐β in HepG2 cells. The dose‐dependent inhibition on cell proliferation was observed. We demonstrated that IFN‐β exhibited significant cytotoxicity in HepG2 cells mainly through phosphorylation of signal transducers and activators of transcription 2. The activation of Akt was suppressed. The stimulation of pro‐apoptotic protein expression of Bax, inhibition of anti‐apoptotic protein expression of Bcl‐2, activation of cleaved caspases 9 and 3 was found at increasing concentrations. In conclusion, our results suggest that interferon‐β has potential to inhibit cell proliferation dose dependently. Increased concentrations of interferon‐β influenced apoptosis via mitochondrial pathway through inhibition of p‐Akt.  相似文献   
10.
目的探讨奥沙利铂如何调控MAPK通路,抑制胃癌细胞的增殖。方法NCBI检索文献,利用TargetScan、StarBase和miRBase数据库,进行GO分析与KEGG通路富集,找到相关miRNAs,预测靶基因。应用Real-time PCR、MTT、Hoechst33258、流式细胞术、细胞划痕实验、Western blot等方法分析人胃癌SGC-7901细胞的增殖、细胞周期、侵袭及蛋白表达情况。结果胃癌细胞中miR-7-5p显著低表达,RAF1与miR-7-5p存在互靶关系。miR-7-5p mimics与奥沙利铂均可促进SGC-7901细胞的凋亡,提高G1期细胞百分率(P<0.05),降低侵袭、迁移速度。caspase3、caspase9蛋白表达升高,Bcl-2/Bax比值降低(P<0.05)。结论过表达miR-7-5p与奥沙利铂均可促进胃癌SGC-7901细胞的凋亡,提示奥沙利铂可能通过上调miRNA-7-5p促进SGC-7901细胞的凋亡,降低侵袭、迁移速度。  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