全文获取类型
收费全文 | 148490篇 |
免费 | 13291篇 |
国内免费 | 9867篇 |
专业分类
耳鼻咽喉 | 1334篇 |
儿科学 | 1833篇 |
妇产科学 | 2498篇 |
基础医学 | 16803篇 |
口腔科学 | 2483篇 |
临床医学 | 19110篇 |
内科学 | 23214篇 |
皮肤病学 | 1670篇 |
神经病学 | 7865篇 |
特种医学 | 5094篇 |
外国民族医学 | 73篇 |
外科学 | 15268篇 |
综合类 | 24351篇 |
现状与发展 | 28篇 |
一般理论 | 6篇 |
预防医学 | 9952篇 |
眼科学 | 4020篇 |
药学 | 15458篇 |
146篇 | |
中国医学 | 7913篇 |
肿瘤学 | 12529篇 |
出版年
2024年 | 458篇 |
2023年 | 2174篇 |
2022年 | 5515篇 |
2021年 | 7012篇 |
2020年 | 5167篇 |
2019年 | 4773篇 |
2018年 | 4805篇 |
2017年 | 4461篇 |
2016年 | 4073篇 |
2015年 | 6238篇 |
2014年 | 7816篇 |
2013年 | 7448篇 |
2012年 | 10757篇 |
2011年 | 11654篇 |
2010年 | 7488篇 |
2009年 | 5908篇 |
2008年 | 7817篇 |
2007年 | 7832篇 |
2006年 | 7673篇 |
2005年 | 7518篇 |
2004年 | 5311篇 |
2003年 | 5142篇 |
2002年 | 4490篇 |
2001年 | 3975篇 |
2000年 | 3782篇 |
1999年 | 3855篇 |
1998年 | 2432篇 |
1997年 | 2351篇 |
1996年 | 1724篇 |
1995年 | 1596篇 |
1994年 | 1390篇 |
1993年 | 873篇 |
1992年 | 1295篇 |
1991年 | 1136篇 |
1990年 | 977篇 |
1989年 | 858篇 |
1988年 | 745篇 |
1987年 | 694篇 |
1986年 | 534篇 |
1985年 | 479篇 |
1984年 | 253篇 |
1983年 | 181篇 |
1982年 | 123篇 |
1981年 | 119篇 |
1980年 | 77篇 |
1979年 | 122篇 |
1978年 | 59篇 |
1976年 | 52篇 |
1975年 | 55篇 |
1974年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
目的研究快速成型(RP)技术辅助下制作的个体化假体复合珊瑚羟基磷灰石(CHA)、重组人骨形成蛋白2(rhBMP-2)修复兔下颌骨缺损的成骨效果。
方法以27只新西兰大白兔为实验对象,随机数字表法平均分成3组(每组9只),全部建立下颌骨连续性缺损模型,并在兔下颌骨缺损区分别植入个体化假体+自体骨(A组)、个体化假体+CHA(B组)、个体化假体+CHA+rhBMP-2(C组)。分别于术后4、12、24周3个时间点处死动物取材,进行大体标本观察,以及骨钙素(OC)、Ⅰ型胶原(COL-1)的免疫组化观察,分别比较各组修复骨缺损的能力,并对实验数据进行重复测量设计资料的单因素方差分析。
结果术后24周各组实验兔外形均对称,通过OC及COL-1的吸光度检测,骨缺损区均有大量新骨形成,A组(0.537 ± 0.010)、C组(0.530 ± 0.010)可见大量骨小梁及编织骨结构,缺损区的新骨OC、COL-1的免疫组化观察基本一致,差异无统计学意义(t = 0.007,P>0.05);但A组强于B组(0.415 ± 0.009,t = 0.122,P<0.001);C组也强于B组(t = 0.121,P<0.001),差异均有统计学意义。
结论在兔下颌骨缺损修复中,通过RP技术和组织工程技术相结合,CHA复合rhBMP-2后成骨能力明显增强,成骨效能肯定,为后期的临床应用提供可靠的实验基础。 相似文献
66.
67.
68.
69.
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
70.
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