全文获取类型
收费全文 | 45940篇 |
免费 | 3144篇 |
国内免费 | 2167篇 |
专业分类
耳鼻咽喉 | 71篇 |
儿科学 | 555篇 |
妇产科学 | 206篇 |
基础医学 | 3607篇 |
口腔科学 | 157篇 |
临床医学 | 5307篇 |
内科学 | 7755篇 |
皮肤病学 | 156篇 |
神经病学 | 4870篇 |
特种医学 | 1825篇 |
外国民族医学 | 2篇 |
外科学 | 5811篇 |
综合类 | 9268篇 |
预防医学 | 1545篇 |
眼科学 | 1284篇 |
药学 | 4488篇 |
44篇 | |
中国医学 | 3939篇 |
肿瘤学 | 361篇 |
出版年
2024年 | 137篇 |
2023年 | 583篇 |
2022年 | 1248篇 |
2021年 | 1704篇 |
2020年 | 1490篇 |
2019年 | 1203篇 |
2018年 | 1199篇 |
2017年 | 1305篇 |
2016年 | 1441篇 |
2015年 | 1502篇 |
2014年 | 3024篇 |
2013年 | 3012篇 |
2012年 | 2931篇 |
2011年 | 3186篇 |
2010年 | 2577篇 |
2009年 | 2400篇 |
2008年 | 2573篇 |
2007年 | 2480篇 |
2006年 | 2260篇 |
2005年 | 1988篇 |
2004年 | 1752篇 |
2003年 | 1618篇 |
2002年 | 1327篇 |
2001年 | 1235篇 |
2000年 | 1004篇 |
1999年 | 824篇 |
1998年 | 663篇 |
1997年 | 659篇 |
1996年 | 479篇 |
1995年 | 469篇 |
1994年 | 382篇 |
1993年 | 331篇 |
1992年 | 330篇 |
1991年 | 267篇 |
1990年 | 233篇 |
1989年 | 166篇 |
1988年 | 193篇 |
1987年 | 125篇 |
1986年 | 139篇 |
1985年 | 156篇 |
1984年 | 127篇 |
1983年 | 66篇 |
1982年 | 89篇 |
1981年 | 78篇 |
1980年 | 69篇 |
1979年 | 56篇 |
1978年 | 47篇 |
1977年 | 39篇 |
1976年 | 23篇 |
1973年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Kazumichi Yamada Satoshi Goto Taro Oyama Makoto Yoshikawa Shinji Nagahiro Yukitaka Ushio 《Acta neuropathologica》1995,89(2):172-177
The present study concerns the vulnerability of striatal interneurons immunopositive for the Ca2+-binding protein calretinin to ischemic neuronal injury. An immunohistochemical study was carried out on the striata of rats which had undergone transient middle cerebral artery occlusion. Two weeks after the ischemia, there was a marked reduction in the number of calretinin-positive neurons in the ipsilateral ischemic lesion, although the striatal interneurons positive for parvalbumin, which are a neuronal population distinct from the calretinin-immunoreactive cells in the striatum, were spared in the insulted areas. The present data indicate that the striatal calretinin-positive neurons are less resistant to transient ischemia, suggesting that there may exist vulnerability differences among the striatal interneurons in ischemia-induced neuronal injury. 相似文献
33.
34.
S.L. Atkin A.M. Coady D. Horton N. Sutaria L. Sellars C. Walton 《Diabetic medicine》1995,12(3):267-270
A 15-year-old girl presented de novo in diabetic ketoacidosis having been comatose for 24 h (day 1). A CT scan and lumbar puncture performed on admission were normal and her conscious level slowly improved over several days. On day 7 she had central neurological signs of bilateral knee clonus and an extensor plantar response. In addition, she had developed lower motor neurological signs of an ulnar nerve palsy of the left forearm, and ulnar, median, and radial nerve palsies of the right forearm. Magnetic resonance imaging (MRI), performed on day 12, showed multiple small cerebral haematomata with appearances at least several days of age. The scattered lesions were localized particularly to the parieto-occipital region, with sparing of the basal ganglia and without cerebral oedema, a novel feature not previously described in juvenile ketoacidosis. Four months later there was minimal residual disability of her right arm. The clinical findings together with the MRI images suggested that the peripheral nerve and central lesions were temporally related, suggesting a common aetiology. However, it is likely that MRI showed cerebral lesions which may have been missed by the conventional CT scanning performed initially. 相似文献
35.
甲基强的松龙对低温保存大鼠肝脏的保护作用 总被引:2,自引:1,他引:1
应用Wistar大鼠肝脏离体灌流模型,用CMU—1号液,含有甲基强的松龙的CMU—1号液,以及缺血前预用甲基强的松龙后再用CMU—1号液分别对肝脏进行灌洗保存。检测LDH、ALT、肝组织匀浆SOD活性和MDA含量,并观察肝组织结构。结果表明:甲基强的松龙对低温保存的离体大鼠肝脏具有保护作用 相似文献
36.
1992~1993年间为180例冠脉病变的病人施行冠脉搭桥术,全部病人均采用核甙抑制剂利多氟嗪预处理和低温(28℃)间断缺血心停搏进行术中心肌保护。平均每例病人作冠状动脉端吻合3~4个,每个吻合口用9分钟,主动脉阻断累加时间约25分钟,体外循环时间90分钟,术后医院死亡率1.6%(3/180),无术后心梗发生。作者认为,冠脉搭桥术的术中心肌保护可采用核甙抑制剂和间断缺血心停搏方法,而不用心肌停搏液。 相似文献
37.
38.
Objective:To explore the effect of thrombolysis with anticoagulation treatment forearly stage of deep vein thrombosis of lower extremity.Methods:The clinical data of 10 patients at the early stage of deep vein thrombosis(DVT)in the lower extremuites treated by thrombolysis with anticoagulation and dispersion drugs were analyzed retrospectively.Results:The thrombolytic effect was significant.After treatment,the deep veins were recanalized without regurgitation in 75.3% of the patients.The total effective rate was 100%.Only three patients had hemorrhagic complication,but none of the patients died.Conclusion:Thrombolysis with anticoagulation treatment is an effective and safe method for DVT at the early stage. 相似文献
39.
The brief anesthesia with isoflurane induces rapid tolerance against focal cerebral ischemia in rats and aden-osine A1 receptor antagonist, DPCPX, attenuates the beneficial effect of isoflurane preconditioning. 相似文献
40.
Prevalence of silent myocardial ischemia in asymptomatic individuals with subclinical atherosclerosis detected by electron beam tomography 总被引:3,自引:0,他引:3
Anand D. Vijay Lim Eric Raval Usha Lipkin David Lahiri Avijit 《Journal of nuclear cardiology》2004,11(4):450-457
BACKGROUND: Electron beam tomography coronary calcium imaging is an evolving technique for the early detection of coronary atherosclerosis, and recent studies have established its prognostic value in asymptomatic individuals. The relationship of coronary artery calcium scores (CAC) to obstructive coronary artery disease (CAD) has been poorly studied but is clinically relevant because it determines which individuals are likely to benefit from revascularization procedures. Hence, we prospectively evaluated the prevalence of myocardial ischemia in asymptomatic patients with cardiovascular risk factors and subclinical atherosclerosis. METHODS AND RESULTS: We studied 864 asymptomatic patients with no previous CAD but with cardiovascular risk factors, referred for electron beam tomography coronary calcium imaging to our institution over an 18-month period. From this group, 220 consecutive patients (85% men; mean age, 61 +/- 9 years; age range, 31-84 years) with moderate to severe atherosclerotic disease (coronary calcium score > or =100 Agatston units) were prospectively evaluated by technetium 99m sestamibi single photon emission computed tomography (SPECT). Patients were followed up (mean follow-up, 14 months) and data regarding their subsequent clinical management recorded. Of the 220 patients, 119 had moderate atherosclerosis (CAC score of 100-400 Agatston units) and 101 had severe atherosclerosis (CAC score > or =400 Agatston units). Abnormal SPECT findings were seen in 18% of patients with moderate atherosclerosis (n = 21) and 45% of patients with severe atherosclerosis (n = 45). Increasing severity of atherosclerosis was related to increasing ischemic burden (summed difference score = 1 +/- 0.2 for CAC score of 100-400 Agatston units and 3.2 +/- 0.5 for CAC score > or =400 Agatston units). In a multivariate linear regression model incorporating risk factors, CAC was the only predictor of silent ischemia. CONCLUSION: In comparison to previously published data, we detected a higher prevalence of silent ischemia even in patients with moderate coronary atherosclerosis (18%). This may reflect the differing risk factor profile of our patient population. When coronary calcium screening is used to preselect asymptomatic patients with cardiovascular risk factors for myocardial perfusion imaging, the optimum coronary calcium score threshold will depend on the population prevalence of risk factors and asymptomatic obstructive CAD. 相似文献