全文获取类型
收费全文 | 72109篇 |
免费 | 6617篇 |
国内免费 | 1538篇 |
专业分类
耳鼻咽喉 | 993篇 |
儿科学 | 1441篇 |
妇产科学 | 1202篇 |
基础医学 | 10377篇 |
口腔科学 | 1203篇 |
临床医学 | 7402篇 |
内科学 | 13511篇 |
皮肤病学 | 2005篇 |
神经病学 | 5614篇 |
特种医学 | 3640篇 |
外国民族医学 | 5篇 |
外科学 | 8539篇 |
综合类 | 3988篇 |
现状与发展 | 6篇 |
一般理论 | 24篇 |
预防医学 | 5090篇 |
眼科学 | 1648篇 |
药学 | 6577篇 |
10篇 | |
中国医学 | 1490篇 |
肿瘤学 | 5499篇 |
出版年
2023年 | 413篇 |
2022年 | 487篇 |
2021年 | 2017篇 |
2020年 | 1321篇 |
2019年 | 1793篇 |
2018年 | 2008篇 |
2017年 | 1650篇 |
2016年 | 2252篇 |
2015年 | 2875篇 |
2014年 | 3441篇 |
2013年 | 4039篇 |
2012年 | 5548篇 |
2011年 | 5513篇 |
2010年 | 3640篇 |
2009年 | 3116篇 |
2008年 | 4006篇 |
2007年 | 4020篇 |
2006年 | 3642篇 |
2005年 | 3380篇 |
2004年 | 3090篇 |
2003年 | 2930篇 |
2002年 | 2671篇 |
2001年 | 1709篇 |
2000年 | 1416篇 |
1999年 | 1140篇 |
1998年 | 556篇 |
1997年 | 533篇 |
1996年 | 427篇 |
1995年 | 389篇 |
1994年 | 334篇 |
1993年 | 312篇 |
1992年 | 669篇 |
1991年 | 682篇 |
1990年 | 588篇 |
1989年 | 633篇 |
1988年 | 617篇 |
1987年 | 618篇 |
1986年 | 529篇 |
1985年 | 517篇 |
1984年 | 420篇 |
1983年 | 350篇 |
1982年 | 264篇 |
1981年 | 244篇 |
1980年 | 215篇 |
1979年 | 317篇 |
1978年 | 284篇 |
1977年 | 213篇 |
1974年 | 220篇 |
1973年 | 239篇 |
1972年 | 192篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
Clinical usefulness of intraductal ultrasonography for the management of acute biliary pancreatitis 下载免费PDF全文
24.
25.
Yaobin Ouyang Gongmeizi Liu Wenting Xu Zhen Yang Nianshuang Li Chuan Xie Chun Zhou Jiang Chen Yin Zhu Junbo Hong Nonghua Lu 《Oncology Letters》2021,21(2)
Helicobacter pylori (H. pylori) is a main risk factor for gastric cancer (GC). Epithelial-mesenchymal transition (EMT) is involved in the development and progression of H. pylori-associated GC. However, the exact molecular mechanism of this process remains unclear. The AKT/GSK3β signaling pathway has been demonstrated to promote EMT in several types of cancer. The present study investigated whether H. pylori infection induced EMT, and promoted the development and metastasis of cancer in the normal gastric mucosa, and whether this process was dependent on AKT activation. The expression levels of the EMT-associated proteins, including E-cadherin and N-cadherin, were determined in 165 gastric mucosal samples of different disease stages by immunohistochemical analysis. The expression levels of E-cadherin, N-cadherin, AKT, phosphorylated (p-)AKT (Ser473), GSK3β and p-GSK3β (Ser9) were further determined in H. pylori-infected Mongolian gerbil gastric tissues and cells co-cultured with H. pylori by immunohistochemical analysis and western blotting. The results indicated that the expression levels of the epithelial marker E-cadherin were decreased, whereas the expression levels of the mesenchymal marker N-cadherin were increased during gastric carcinogenesis. Their expression levels were associated with H. pylori infection. Furthermore, H. pylori infection resulted in downregulation of E-cadherin expression and upregulation of N-cadherin expression in Mongolian gerbils and GES-1 cells. In addition, an investigation of the associated mechanism of action revealed that p-AKT (Ser473) and p-GSK3β (Ser9) were activated in GES-1 cells following co-culture with H. pylori. Furthermore, following pretreatment of the cells with the AKT inhibitor VIII, the expression levels of E-cadherin, N-cadherin, p-AKT and p-GSK3β did not show significant differences between GES-1 cells that were co-cultured with or without H. pylori. The levels of p-AKT and p-GSK3β were increased in H. pylori-infected Mongolian gerbils. In conclusion, the present study demonstrated that H. pylori infection activated AKT and resulted in the phosphorylation and inactivation of GSK3β, which in turn promoted early stage EMT. These effects were AKT-dependent. This mechanism may serve as a prerequisite for GC development. 相似文献
26.
27.
28.
Growth Hormone Induces Recurrence of Infantile Hemangiomas After Apparent Involution: Evidence of Growth Hormone Receptors in Infantile Hemangioma 下载免费PDF全文
Naikhoba C. O. Munabi B.A. Qian Kun Tan H.S. Maria C. Garzon M.D. Gerald G. Behr M.D. Carrie J. Shawber Ph.D. June K. Wu M.D. 《Pediatric dermatology》2015,32(4):539-543
Infantile hemangiomas (IHs) are the most common benign tumor of infancy, characterized by a natural history of early proliferation in the first months of life to eventual involution during childhood, often with residual fibrofatty tissue. Once involution has been achieved, IHs do not typically recur. We present two cases of exogenous growth hormone therapy resulting in the recurrence of IHs in late childhood, supported by radiological, immunohistochemical, in vitro, and in vivo evidence. 相似文献
29.
30.
Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case–control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan–Meier analysis with log-rank test (P = 0.008). The AF group''s adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16–1.57; P = 0.009) according to Cox''s proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF. 相似文献