收费全文 | 113638篇 |
免费 | 7698篇 |
国内免费 | 3898篇 |
耳鼻咽喉 | 424篇 |
儿科学 | 2269篇 |
妇产科学 | 520篇 |
基础医学 | 7483篇 |
口腔科学 | 578篇 |
临床医学 | 17182篇 |
内科学 | 22726篇 |
皮肤病学 | 350篇 |
神经病学 | 12792篇 |
特种医学 | 4246篇 |
外国民族医学 | 2篇 |
外科学 | 7212篇 |
综合类 | 22532篇 |
现状与发展 | 1篇 |
预防医学 | 6604篇 |
眼科学 | 445篇 |
药学 | 11627篇 |
112篇 | |
中国医学 | 6124篇 |
肿瘤学 | 2005篇 |
2024年 | 89篇 |
2023年 | 1531篇 |
2022年 | 2520篇 |
2021年 | 3803篇 |
2020年 | 3669篇 |
2019年 | 2917篇 |
2018年 | 3157篇 |
2017年 | 3147篇 |
2016年 | 3943篇 |
2015年 | 4241篇 |
2014年 | 8341篇 |
2013年 | 7996篇 |
2012年 | 7322篇 |
2011年 | 7449篇 |
2010年 | 6299篇 |
2009年 | 5751篇 |
2008年 | 5612篇 |
2007年 | 5615篇 |
2006年 | 5288篇 |
2005年 | 4606篇 |
2004年 | 4140篇 |
2003年 | 3307篇 |
2002年 | 2773篇 |
2001年 | 2582篇 |
2000年 | 2177篇 |
1999年 | 1877篇 |
1998年 | 1572篇 |
1997年 | 1592篇 |
1996年 | 1294篇 |
1995年 | 1164篇 |
1994年 | 1252篇 |
1993年 | 924篇 |
1992年 | 876篇 |
1991年 | 848篇 |
1990年 | 748篇 |
1989年 | 621篇 |
1988年 | 589篇 |
1987年 | 433篇 |
1986年 | 430篇 |
1985年 | 512篇 |
1984年 | 431篇 |
1983年 | 283篇 |
1982年 | 349篇 |
1981年 | 321篇 |
1980年 | 225篇 |
1979年 | 173篇 |
1978年 | 125篇 |
1977年 | 95篇 |
1976年 | 69篇 |
1975年 | 46篇 |
Background
Aneurysmal subarachnoid hemorrhage is an important cause of premature death and disability worldwide. Magnesium sulphate is shown to have a neuroprotective effect and it reverses cerebral vasospasm. Milrinone is also used in the treatment of cerebral vasospasm. The aim of the present study was to compare the effect of prophylactic magnesium sulphate and milrinone on the incidence of cerebral vasospasm after subarachnoid hemorrhage.Methods
The study included 90 patients with aneurysmal subarachnoid hemorrhage classified randomly (by simple randomization) into two groups: magnesium sulphate was given as an infusion of 500 mg.day?1 without loading dose for 21 days. Group B: milrinone was given as an infusion of 0.5 μg.kg?1.min?1 without loading dose for 21 days. The cerebral vasospasm was diagnosed by mean cerebral blood flow velocity in the involved cerebral artery (mean flow velocity ≥ 120 cm.s?1), neurological deterioration by Glasgow coma scale, or angiography (the decrease in diameter of the involved cerebral artery >25%).Results
The mean cerebral blood flow velocity decreased significantly in the magnesium group compared to milrinone group through Day 7, Day 14 and Day 21 (p < 0.001). The incidence of cerebral vasospasm decreased significantly with magnesium compared to milrinone (p = 0.007). The Glasgow coma scale significantly improved in the magnesium group compared to milrinone group through Day 7, Day 14 and Day 21 (p = 0.036, p = 0.012, p = 0.016, respectively). The incidence of hypotension was higher with milrinone than magnesium (p = 0.012).Conclusions
The incidence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage was significantly lower and Glasgow coma scale significantly better with magnesium when compared to milrinone. Milrinone was associated with a higher incidence of hypotension and requirement for dopamine and norepinephrine when compared to magnesium. 相似文献Objective
Acute mesenteric ischemia (AMI) is an emergent event with a high mortality rate; survivors have high rates of intestinal failure. Restoration of blood flow using endovascular or surgical revascularization is associated with better outcome in terms of survival rate and intestinal resection. Retrograde open mesenteric stenting (ROMS), which is a hybrid technique, combines two benefits: prompt blood flow restoration with an endovascular approach and inspection and resection of the small bowel. The aim of the study was to assess the results of ROMS in thrombotic AMI in a retrospective multicenter study.Methods
We retrospectively enrolled all consecutive patients who underwent ROMS revascularization for occlusive thrombotic AMI in three participating tertiary care centers between November 2012 and March 2017.Results
Twenty-five patients (14 men and 11 women; mean age, 64.9 ± 11.6 years) were included. In two patients, ROMS was not possible because of failure of re-entry in the aortic lumen (technical success, 92%). One patient required revascularization of two visceral arteries and underwent an aortohepatic bypass. Five patients (20%) underwent endarterectomy and patch angioplasty of the superior mesenteric artery before retrograde stenting. Thirteen patients (52%) required bowel or colon resection (11 patients required both resections) during the initial procedure with a mean length of small bowel resection of 52 ± 87 cm. The 30-day operative mortality rate was 25%, and the overall 1-year survival rate was 65%. The 1-year primary patency rate was 92%. In one patient, postoperative imaging at 1 month showed stent migration in the aortic bifurcation.Conclusions
ROMS for thrombotic AMI has a high technical success rate and a high midterm primary patency rate. It could be an alternative procedure to retrograde superior mesenteric artery bypass for patients when percutaneous endovascular revascularization is not indicated or has failed. 相似文献Methods: Fifty-four patients with ACI and 51 healthy controls were included in our study. Baseline characteristics and blood samples were collected for further analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the serum miR-124 levels. The dual-luciferase reporter assay was used to evaluate the effect of miR-124 on iASPP, a protein that inhibits apoptosis stimulating proteins in the p53 family.
Results: Compared with normal controls, the miR-124 levels in the ACI group rapidly decreased at phase 1 (within 24?h after ischemia) (p?<?0.001) and then gradually increased at phase 2 (48?~?72?h after ischemia) (p?<?0.001) and phase 3 (the 7th day after ischemia) (p?<?0.001). The dual-luciferase reporter assay showed that miR-124 down-regulates iASPP expression in 293T cells.
Conclusion: The miR-124 levels are down-regulated in ACI patients. The dynamic changes of miR-124 might provide a possible method for the detection of ischemic stroke.
- Highlights
The difference in miR-124 expression levels between ACI patients and normal controls.
Dynamic changes of miR-124 expression levels in ACI patients.
The down-regulation of miR-124 upon iASPP expression.