全文获取类型
收费全文 | 4419篇 |
免费 | 247篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 145篇 |
妇产科学 | 72篇 |
基础医学 | 633篇 |
口腔科学 | 86篇 |
临床医学 | 315篇 |
内科学 | 1164篇 |
皮肤病学 | 96篇 |
神经病学 | 354篇 |
特种医学 | 80篇 |
外科学 | 574篇 |
综合类 | 39篇 |
一般理论 | 2篇 |
预防医学 | 171篇 |
眼科学 | 190篇 |
药学 | 320篇 |
中国医学 | 30篇 |
肿瘤学 | 377篇 |
出版年
2023年 | 46篇 |
2022年 | 70篇 |
2021年 | 109篇 |
2020年 | 39篇 |
2019年 | 84篇 |
2018年 | 94篇 |
2017年 | 79篇 |
2016年 | 100篇 |
2015年 | 104篇 |
2014年 | 129篇 |
2013年 | 161篇 |
2012年 | 253篇 |
2011年 | 323篇 |
2010年 | 168篇 |
2009年 | 154篇 |
2008年 | 302篇 |
2007年 | 321篇 |
2006年 | 283篇 |
2005年 | 299篇 |
2004年 | 287篇 |
2003年 | 263篇 |
2002年 | 254篇 |
2001年 | 64篇 |
2000年 | 54篇 |
1999年 | 61篇 |
1998年 | 37篇 |
1997年 | 38篇 |
1996年 | 34篇 |
1995年 | 28篇 |
1994年 | 30篇 |
1993年 | 17篇 |
1992年 | 41篇 |
1991年 | 37篇 |
1990年 | 32篇 |
1989年 | 46篇 |
1988年 | 25篇 |
1987年 | 34篇 |
1986年 | 25篇 |
1985年 | 23篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 14篇 |
1979年 | 20篇 |
1978年 | 5篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1972年 | 7篇 |
排序方式: 共有4683条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
Soejima K Akaishi M Meguro T Oyamada K Yoshikawa T Mitamura H Ogawa S 《Japanese circulation journal》2000,64(1):32-38
The age-adjusted, heart rate variability (HRV) was evaluated as a parameter for the severity of heart failure and its prognosis. HRV was obtained by 24-h Holter monitoring in patients with left ventricular dysfunction (LVD). New York Heart Association (NYHA) functional classification, echocardiography, radioisotope ventriculography, and blood examination were performed, and compared between patients and normal subjects. The evaluation was repeated during the follow-up period. Finally, using the lower limit of HRV, patients were divided into either normal or abnormal group for each low-frequency power (LF) and high-frequency power (HF) (age-adjusted HRV). Other parameters of heart failure and prognosis were compared between these 2 groups. HRV tended to be lower in patients with LVD. HF decreased at the early stage of heart failure, but did not decrease progressively. LF decreased progressively. HRV change paralleled the change of NYHA. The abnormal HRV group showed a poor prognosis for cardiac death, but not for sudden cardiac death. In patients with LVD, HRV was decreased compared with the normal subjects. Change in HRV correlated with the change in NYHA classification. Age-adjusted HRV correlated with cardiac-death prognosis, but not for sudden cardiac death. 相似文献
66.
Ohfuji Satoko Matsuura Tomoka Tamori Akihiro Kubo Shoji Sasaki Satoshi Kondo Kyoko Ito Kazuya Fukushima Wakaba 《Digestive diseases and sciences》2021,66(6):2118-2128
Digestive Diseases and Sciences - Hepatocellular carcinoma develops in some patients with hepatitis C virus (HCV), even after achieving sustained virological response (SVR). We examined factors... 相似文献
67.
Although Helicobacter pylori have been identified in the liver, the role of Helicobacter sp. in human liver diseases remains unclear. This study explored whether H. pylori were internalized and could persist in hepatocytes. The majority of an inoculum of H. pylori (1 x 10(7) colony forming units) adhered to hepatocytes. Using the gentamicin invasion assay we found that approximately 2% were internalized and persisted following passage for more than 2 months. Electron microscopy confirmed the presence of intracellular Helicobacter. The number of adherent or internalized H. pylori was significantly greater with hepatocytes than with gastric epithelial cells (P < 0.05) and was also dependent on cag pathogenicity island (PAI), VacA, OipA, or BabA status. Transmission electron microscopy was used to confirm adherence and invasion of H. pylori into hepatocytes. Internalization of H. pylori was inhibited by antibodies to beta1-integrin receptors, genistein, and cytochalasin D (P < 0.05) consistent with beta1-integrin acting as a surface receptor with additional requirements for tyrosine kinase phosphorylation and actin polymerization. In summary, H. pylori both adhered to and invaded into hepatocytes in vitro, depending on the virulent factors, and persisted within hepatocytes during subcultures. beta1-integrin is likely a receptor involved in internalization of H. pylori into hepatocytes. 相似文献
68.
Ono Mayo Fukuda Izumi Nagao Mototsugu Tomiyama Keiko Okazaki-Hada Mikiko Shuto Yuki Kobayashi Shunsuke Yamaguchi Yuji Nagamine Tomoko Nakajima Yasushi Inagaki-Tanimura Kyoko Sugihara Hitoshi 《Pituitary》2022,25(4):615-621
Pituitary - Isolated adrenocorticotropic hormone deficiency is a rare disease; however, since immune check point inhibitors (ICIs) have become widely used, many more cases have been reported. In... 相似文献
69.
Effect of interleukin 1 polymorphisms on gastric mucosal interleukin 1beta production in Helicobacter pylori infection 总被引:20,自引:0,他引:20
Hwang IR Kodama T Kikuchi S Sakai K Peterson LE Graham DY Yamaoka Y 《Gastroenterology》2002,123(6):1793-1803
BACKGROUND & AIMS: Although epidemiological studies suggest that interleukin (IL)-1 genetic polymorphisms are involved in Helicobacter pylori-related gastric carcinogenesis, the data are conflicting regarding the effects of these polymorphisms on IL-1beta production. METHODS: IL-1B-511 polymorphism was genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism, and IL-1RN variable number of tandem repeats was determined by PCR. Mucosal IL-1beta levels were measured by enzyme-linked immunosorbent assay. To determine which factors influence mucosal IL-1beta levels, gastric inflammation, and atrophy, multiple regression analyses were performed. RESULTS: We studied 117 H. pylori-infected Japanese patients. Carriers of the IL-1B-511T/T genotype or IL-1RN*2 allele had higher mucosal IL-1beta levels than noncarriers (partial regression coefficient [PRC] +/- SE), TT versus CC: 37.6 +/- 6 [antrum] and 32.1 +/- 6 [corpus] pg/mg protein (P < 0.001 for each), *1/*2 versus *1/*1: 24 +/- 8 [antrum] (P <0.01) and 36.5 +/- 7 [corpus] (P <0.001). Simultaneous carriers of IL-1B-511T/T genotype and IL-1RN*2 allele had the highest IL-1beta levels (82.9 +/- 12 [antrum] and 87.2 +/- 11 [corpus]) and showed a synergistic effect between 2 loci. The *1/*2 carriers were closely related to atrophy (PRC +/- SE; 0.87 +/- 0.4 [antrum] and 0.93 +/- 0.4 [corpus], P < 0.05), whereas being a carrier of the -511T/T genotype was related to severe gastric inflammation. CONCLUSIONS: IL-1 genetic polymorphisms influenced H. pylori-related gastric mucosal IL-1beta levels and were related to gastric inflammation and atrophy, factors thought to be important in gastric carcinogenesis. 相似文献
70.
Valpha24+ natural killer T-cell responses against T-acute lymphoblastic leukaemia cells: implications for immunotherapy 总被引:1,自引:0,他引:1
Takahashi T Haraguchi K Chiba S Yasukawa M Shibata Y Hirai H 《British journal of haematology》2003,122(2):231-239
Human Valpha24+ natural killer T (NKT) cells correspond to mouse Valpha14+ NKT cells, both cell types use an invariant T-cell receptor-alpha chain and are activated by glycolipids in a CD1d-dependent manner. Mouse Valpha14+ NKT cells have been reported to have an antitumour effect in vivo. Human Valpha24+ NKT cells can kill a proportion of tumour cells in a CD1d-dependent manner in vitro. We report here that many human leukaemic T-cell lines express CD1d and can be directly killed by Valpha24+ NKT cells. This killing activity was enhanced in the presence of alpha-galactosylceramide (alpha-GalCer), a ligand of Valpha24+ NKT cells. Moreover, primary leukaemic T cells from five of eight T-cell acute lymphoblastic leukaemia (T-ALL) patients expressed CD1d and were good targets of Valpha24+ NKT cells. This cytotoxicity was increased in the presence of alpha-GalCer. Our results suggest that T-ALL is a good candidate for Valpha24+ NKT-cell-based immuno-cell therapy. 相似文献