全文获取类型
收费全文 | 90212篇 |
免费 | 41628篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 1752篇 |
儿科学 | 4627篇 |
妇产科学 | 799篇 |
基础医学 | 16922篇 |
口腔科学 | 5669篇 |
临床医学 | 13536篇 |
内科学 | 25514篇 |
皮肤病学 | 7748篇 |
神经病学 | 14062篇 |
特种医学 | 2666篇 |
外国民族医学 | 1篇 |
外科学 | 16088篇 |
综合类 | 333篇 |
一般理论 | 39篇 |
预防医学 | 5179篇 |
眼科学 | 1517篇 |
药学 | 6488篇 |
中国医学 | 1044篇 |
肿瘤学 | 7922篇 |
出版年
2023年 | 176篇 |
2022年 | 412篇 |
2021年 | 1905篇 |
2020年 | 5330篇 |
2019年 | 11217篇 |
2018年 | 10605篇 |
2017年 | 11753篇 |
2016年 | 12438篇 |
2015年 | 12320篇 |
2014年 | 12329篇 |
2013年 | 13006篇 |
2012年 | 5048篇 |
2011年 | 5069篇 |
2010年 | 9484篇 |
2009年 | 5734篇 |
2008年 | 2790篇 |
2007年 | 1620篇 |
2006年 | 1608篇 |
2005年 | 1365篇 |
2004年 | 1291篇 |
2003年 | 1218篇 |
2002年 | 1237篇 |
2001年 | 959篇 |
2000年 | 861篇 |
1999年 | 398篇 |
1998年 | 122篇 |
1997年 | 101篇 |
1996年 | 105篇 |
1995年 | 94篇 |
1994年 | 69篇 |
1993年 | 75篇 |
1992年 | 89篇 |
1991年 | 52篇 |
1990年 | 66篇 |
1989年 | 68篇 |
1988年 | 74篇 |
1987年 | 70篇 |
1986年 | 57篇 |
1985年 | 65篇 |
1984年 | 58篇 |
1983年 | 38篇 |
1982年 | 46篇 |
1981年 | 38篇 |
1980年 | 24篇 |
1979年 | 29篇 |
1978年 | 28篇 |
1977年 | 23篇 |
1974年 | 23篇 |
1973年 | 29篇 |
1967年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
The association between family affluence and smoking among 15‐year‐old adolescents in 33 European countries,Israel and Canada: the role of national wealth 下载免费PDF全文
43.
Kota Sahara Rin Yamada Takashi Fujiwara Koichi Koizumi Shin‐ichiro Horiguchi Tsunekazu Hishima Tatsuro Yamaguchi 《Digestive endoscopy》2015,27(7):768-771
Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood ischemic colitis that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. A 76‐year‐old Japanese man presented to our hospital with a 1‐year history of worsening diarrhea, lower abdominal pain, and weight loss (−6 kg). Laboratory evaluation revealed white blood cell count of 13 200/μL, C‐reactive protein level of 2.0 mg/dL (normal range, 0.0–0.3), and negative results for stool culture (including Clostridium difficile). Colonoscopy showed circumferential and edematous narrowing of the sigmoid colon with deep longitude ulceration. Biopsy was done and examination of the specimen demonstrated no specific ischemia. The patient was treated with bowel rest, antibiotics, and i.v. fluids; however, his symptoms worsened. Finally, sigmoidectomy was carried out. Histological examination demonstrated significant myointimal hyperplasia of mesenteric veins leading to thickening and stenosis of the venous lumen. Therefore, the final diagnosis was IMHMV. Three months following sigmoidectomy, he was asymptomatic. 相似文献
44.
45.
46.
47.
Melatonin induces apoptosis of colorectal cancer cells through HDAC4 nuclear import mediated by CaMKII inactivation 下载免费PDF全文
Melatonin induces apoptosis in many different cancer cell lines, including colorectal cancer. However, the precise mechanisms involved remain largely unresolved. In this study, we provide evidence to reveal a new mechanism by which melatonin induces apoptosis of colorectal cancer LoVo cells. Melatonin at pharmacological concentrations significantly suppressed cell proliferation and induced apoptosis in a dose‐dependent manner. The observed apoptosis was accompanied by the melatonin‐induced dephosphorylation and nuclear import of histone deacetylase 4 (HDAC4). Pretreatment with a HDAC4‐specific siRNA effectively attenuated the melatonin‐induced apoptosis, indicating that nuclear localization of HDAC4 is required for melatonin‐induced apoptosis. Moreover, constitutively active Ca2+/calmodulin‐dependent protein kinase II alpha (CaMKIIα) abrogated the melatonin‐induced HDAC4 nuclear import and apoptosis of LoVo cells. Furthermore, melatonin decreased H3 acetylation on bcl‐2 promoter, leading to a reduction of bcl‐2 expression, whereas constitutively active CaMKIIα(T286D) or HDAC4‐specific siRNA abrogated the effect of melatonin. In conclusion, the present study provides evidence that melatonin‐induced apoptosis in colorectal cancer LoVo cells largely depends on the nuclear import of HDAC4 and subsequent H3 deacetylation via the inactivation of CaMKIIα. 相似文献
48.
49.
50.