全文获取类型
收费全文 | 27727篇 |
免费 | 1361篇 |
国内免费 | 154篇 |
专业分类
耳鼻咽喉 | 360篇 |
儿科学 | 416篇 |
妇产科学 | 529篇 |
基础医学 | 3493篇 |
口腔科学 | 654篇 |
临床医学 | 2003篇 |
内科学 | 7494篇 |
皮肤病学 | 364篇 |
神经病学 | 2155篇 |
特种医学 | 1009篇 |
外科学 | 4782篇 |
综合类 | 129篇 |
一般理论 | 2篇 |
预防医学 | 812篇 |
眼科学 | 395篇 |
药学 | 1850篇 |
中国医学 | 53篇 |
肿瘤学 | 2742篇 |
出版年
2022年 | 184篇 |
2021年 | 504篇 |
2020年 | 288篇 |
2019年 | 336篇 |
2018年 | 482篇 |
2017年 | 391篇 |
2016年 | 467篇 |
2015年 | 461篇 |
2014年 | 638篇 |
2013年 | 811篇 |
2012年 | 1256篇 |
2011年 | 1393篇 |
2010年 | 778篇 |
2009年 | 697篇 |
2008年 | 1330篇 |
2007年 | 1389篇 |
2006年 | 1378篇 |
2005年 | 1314篇 |
2004年 | 1265篇 |
2003年 | 1221篇 |
2002年 | 1246篇 |
2001年 | 923篇 |
2000年 | 962篇 |
1999年 | 849篇 |
1998年 | 354篇 |
1997年 | 254篇 |
1996年 | 248篇 |
1995年 | 223篇 |
1994年 | 196篇 |
1993年 | 181篇 |
1992年 | 628篇 |
1991年 | 651篇 |
1990年 | 553篇 |
1989年 | 563篇 |
1988年 | 533篇 |
1987年 | 509篇 |
1986年 | 432篇 |
1985年 | 439篇 |
1984年 | 329篇 |
1983年 | 245篇 |
1979年 | 237篇 |
1978年 | 139篇 |
1977年 | 141篇 |
1974年 | 130篇 |
1973年 | 121篇 |
1972年 | 139篇 |
1971年 | 128篇 |
1970年 | 115篇 |
1969年 | 138篇 |
1967年 | 130篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Jun Agata Nobuyuki Ura Hideaki Yoshida Yasuyuki Shinshi Haruki Sasaki Masaya Hyakkoku Shinya Taniguchi Kazuaki Shimamoto 《Hypertension research》2006,29(11):865-874
Angiotensin II receptor blockers (ARBs) are widely used for the treatment of hypertension. It is believed that treatment with an ARB increases the level of plasma angiotensin II (Ang II) because of a lack of negative feedback on renin activity. However, Ichikawa (Hypertens Res 2001; 24: 641-646) reported that long-term treatment of hypertensive patients with olmesartan resulted in a reduction in plasma Ang II level, though the mechanism was not determined. It has been reported that angiotensin 1-7 (Ang-(1-7)) potentiates the effect of bradykinin and acts as an angiotensin-converting enzyme (ACE) inhibitor. It is known that ACE2, which was discovered as a novel ACE-related carboxypeptidase in 2000, hydrolyzes Ang I to Ang-(1-9) and also Ang II to Ang-(1-7). It has recently been reported that olmesartan increases plasma Ang-(1-7) through an increase in ACE2 expression in rats with myocardial infarction. We hypothesized that over-expression of ACE2 may be related to a reduction in Ang II level and the cardioprotective effect of olmesartan. Administration of 0.5 mg/kg/day of olmesartan for 4 weeks to 12-week-old stroke-prone spontaneously hypertensive rats (SHRSP) significantly reduced blood pressure and left ventricular weight compared to those in SHRSP given a vehicle. Co-administration of olmesartan and (D-Ala7)-Ang-(1-7), a selective Ang-(1-7) antagonist, partially inhibited the effect of olmesartan on blood pressure and left ventricular weight. Interestingly, co-administration of (D-Ala7)-Ang-(1-7) with olmesartan significantly increased the plasma Ang II level (453.2+/-113.8 pg/ml) compared to olmesartan alone (144.9+/-27.0 pg/ml, p<0.05). Moreover, olmesartan significantly increased the cardiac ACE2 expression level compared to that in Wistar Kyoto rats and SHRSP treated with a vehicle. Olmesartan significantly improved cardiovascular remodeling and cardiac nitrite/ nitrate content, but co-administration of olmesartan and (D-Ala7)-Ang-(1-7) partially reversed this anti-remodeling effect and the increase in nitrite/nitrate. These findings suggest that olmesartan may exhibit an ACE inhibitory action in addition to an Ang II receptor blocking action, prevent an increase in Ang II level, and protect cardiovascular remodeling through an increase in cardiac nitric oxide production and endogenous Ang-(1-7) via over-expression of ACE2. 相似文献
6.
Koji Saito Takashi Saito Sumio Kawada 《Nihon Shokakibyo Gakkai zasshi》2006,103(10):1176, 1179-1176, 1180
7.
Masahiro Yamauchi Hiroko Kusano Etsuko Saito Takeshi Iwata Masashi Nakakura Yasuki Kato Takaaki Uochi Shiro Akinaga Noboru Aoki 《Journal of controlled release》2006,114(2):268-275
Previously, we demonstrated that wrapping dextran fluorescein anionic/cationic lipid complexes with neutral lipids produced a stable formulation that markedly increased the duration of the compound in plasma after intravenous administration to rats. The improved drug-delivery properties of the wrapped liposomes (WL) relative to other formulations suggested that this technology could offer important advantages for the administration of other polyanionic drugs, including antisense oligodeoxynucleotides (ODN). In the present study, we investigated the value of WL for formulating fluorescence-labeled phosphorothioated ODN (F-ODN). WL encapsulating F-ODN/cationic lipid complexes were prepared efficiently using similar methodology to that used in our earlier study. Studies confirmed that these WL were stable in vitro. Following intravenous administration to mice, free F-ODN and naked F-ODN/cationic lipid complexes were rapidly eliminated whereas administration of the WL resulted in high blood concentrations of drug that were maintained for several hours. Additional studies were conducted in mice that were inoculated with tumor cells (Caki-1 xenograft model, human kidney); in these experiments, intravenous administration of WL delivered 13 times more F-ODN to the tumor site than achieved after injection of free F-ODN. 相似文献
8.
Akira Sawaki Nobumasa Mizuno Kuniyuki Takahashi Tsuneya Nakamura Masahiro Tajika Hiroki Kawai Toshifumi Isaka Hiroshi Imaoka Yasuyuki Okamoto Masatoshi Aoki Hiroyuki Inoue Ahmed AS Salem Yasushi Yatabe Kenji Yamao 《Digestive endoscopy》2006,18(1):40-44
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed. 相似文献
9.
10.
Yasuyuki Suzuki Kazuyuki Daitoku Masahito Minakawa Kozo Fukui Ikuo Fukuda 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(1):44-46
We report the case of a 4-year-old girl who had quadricuspid aortic valve regurgitation with tetralogy of Fallot and pulmonary
atresia. This combination is very uncommon. Aortic valve replacement was performed successfully due to aortic regurgitation
which had progressed one year after the total repair. The dilated aortic annulus plus quadricuspid aortic valve may result
in progressive aortic regurgitation for a short period. 相似文献