全文获取类型
收费全文 | 176117篇 |
免费 | 17631篇 |
国内免费 | 13212篇 |
专业分类
耳鼻咽喉 | 1559篇 |
儿科学 | 1738篇 |
妇产科学 | 1576篇 |
基础医学 | 19475篇 |
口腔科学 | 3408篇 |
临床医学 | 23293篇 |
内科学 | 24168篇 |
皮肤病学 | 1839篇 |
神经病学 | 8537篇 |
特种医学 | 6611篇 |
外国民族医学 | 105篇 |
外科学 | 18003篇 |
综合类 | 34117篇 |
现状与发展 | 58篇 |
一般理论 | 12篇 |
预防医学 | 13194篇 |
眼科学 | 4747篇 |
药学 | 18886篇 |
201篇 | |
中国医学 | 11701篇 |
肿瘤学 | 13732篇 |
出版年
2024年 | 717篇 |
2023年 | 2939篇 |
2022年 | 7640篇 |
2021年 | 9714篇 |
2020年 | 7513篇 |
2019年 | 6021篇 |
2018年 | 6146篇 |
2017年 | 5932篇 |
2016年 | 5470篇 |
2015年 | 8445篇 |
2014年 | 10358篇 |
2013年 | 9650篇 |
2012年 | 14180篇 |
2011年 | 15306篇 |
2010年 | 10382篇 |
2009年 | 8407篇 |
2008年 | 10178篇 |
2007年 | 9627篇 |
2006年 | 9015篇 |
2005年 | 8461篇 |
2004年 | 5504篇 |
2003年 | 4840篇 |
2002年 | 4004篇 |
2001年 | 3457篇 |
2000年 | 3541篇 |
1999年 | 3533篇 |
1998年 | 2274篇 |
1997年 | 2276篇 |
1996年 | 1761篇 |
1995年 | 1651篇 |
1994年 | 1398篇 |
1993年 | 891篇 |
1992年 | 1074篇 |
1991年 | 867篇 |
1990年 | 740篇 |
1989年 | 678篇 |
1988年 | 566篇 |
1987年 | 499篇 |
1986年 | 433篇 |
1985年 | 323篇 |
1984年 | 143篇 |
1983年 | 124篇 |
1982年 | 73篇 |
1981年 | 76篇 |
1980年 | 51篇 |
1979年 | 59篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Polytetrafluoroethylene (PTFE) microvascular prostheses with a fibril length of 30 microns were pretreated with alcohol (n = 18), implanted into the abdominal aorta of rats and were evaluated at 1 day (n = 3), 1 week (n = 3), 3 weeks (n = 6) and 6 weeks (n = 6) to determine whether alcohol-pretreatment might improve their healing. Untreated PTFE microvascular prostheses (n = 18) functioned as controls (all prostheses: length 10 mm, I.D. 1.5 mm). The alcohol-pretreated PTFE microarterial prostheses were initially completely filled and covered with clot and showed fast and complete healing within 6 weeks: endothelial cells and smooth muscle cells on the luminal surface, and the interstices filled with fibrous-like tissue. In contrast, the untreated PTFE prostheses were initially not filled or covered with clot and showed only healing near the anastomotic sites and scarce tissue ingrowth into the wall. These results demonstrate that alcohol-pretreatment improves the healing characteristics of PTFE microarterial prostheses with a fibril length of 30 microns. The alcohol-pretreatment renders the PTFE material more accessible to clot and subsequently to cells. 相似文献
72.
J Lin Z-H Liu W Chen Z Jia D Pan Y Fu F Zhang A Xu 《European journal of immunogenetics》2002,29(4):335-336
A new DRB1 allele, DRB1*0902, has been identified in an individual of the Jing ethnic minority. Its sequence was confirmed by sequencing of PCR products and clones. This allele differed by three nucleotides from DRB1*09012 at positions 157, 161 and 166, and resulted in amino acid motif substitution from VAES to DAEY. 相似文献
73.
高效液相色谱法测定右旋儿茶素血浆浓度及药代动力学参数 总被引:1,自引:0,他引:1
本文建立了体液中右旋儿茶素的RP-HPLC测定方法。采用C_(18)键合相硅胶为填料的固相提取柱进行样品预处理,右旋儿茶素的提取回收率为79.8%.应用二极管阵列检测器对色谱峰纯度进行鉴定。该法精密度好,方法回收率近100%,日内、日间的变异系数为2.4~5.6%,血浓69.6~1160 ng/ml范围内呈线性关系,r=0.9993。家兔静注右旋儿茶素18mg/kg,其药代动力学过程符合二室模型,分布相半衰期为0.129 h,消除相半衰期为1.19h。 相似文献
74.
61 patients with cerebellar hemorrhage were studied. The age at onset ranged from 15 to 84 years with a mean of 57.4 years. 49 cases were treated conservatively and 12 surgically and the mortality rates of the two groups were 32.5% and 25% respectively. Based on this study, it is suggested that the clinical and CT indications of surgical treatment of hematoma are as follows; Severe disturbance of consciousness; Bilateral eyeball fixation; Volume of hematoma over 10 ml; Size of hematoma over 4 cm in diameter; Marked acute obstructive hydrocephalus; Compression of cisterna ambieus and quadrigeminus. 相似文献
75.
利用仿生化学的原理,本文设计并合成了两个儿茶酚胺类和两个羟基吡啶酮类八配位的螯合剂,初步动物试验表明,具有较强的钚促排能力。 相似文献
76.
用二甲苯所致的急性炎症模型观察了神效止痛膏的抗急性炎症作用.用扭体法、热板法观察了神效止痛膏对小鼠的镇痛作用.结果表明,神效止痛膏有很好的镇痛作用. 相似文献
77.
QuantitativerelationshipbetweenpupillaryreflexfeatureanditsdiopterinretinoscopyXuShang(徐上);JiShangnian(计尚年)(DepartmentofOphth... 相似文献
78.
Zhenfeng Xu Dajoie R Croslan Adalynn E Harris Gregory D Ford Byron D Ford 《Journal of cerebral blood flow and metabolism》2006,26(4):527-535
We have previously shown that neuregulin-1 (NRG-1) protects neurons from ischemic brain injury if administered before focal stroke. Here, we examined the therapeutic window and functional recovery after NRG-1 treatment in rats subjected to 90 mins of middle cerebral artery occlusion (MCAO) and 24 h of reperfusion. Neuregulin-1 (2.5 ng/kg bolus, 1.25 ng/kg/min infusion) reduced infarct volume by 89.2%+/-41.9% (mean+/-s.d.; n=8; P<0.01) if administered immediately after the onset of reperfusion. Neuroprotection was also evident if NRG-1 was administered 4 h (66.4%+/-52.6%; n=7; P<0.01) and 12 h (57.0%+/-20.8%; n=8; P<0.01) after reperfusion. Neuregulin-1 administration also resulted in a significant improvement of functional neurologic outcome compared with vehicle-treated animals (32.1%+/-5.7%; n=9; P<0.01). The neuroprotective effect of the single administration of NRG-1 was seen as long as 2 weeks after treatment. Neurons labeled with the neurodegeneration marker dye Fluoro-JadeB were observed after MCAO in the cortex, but the numbers were significantly reduced after NRG-1 treatment. These results indicate that NRG-1 is a potent neuroprotective compound with an extended therapeutic window that has practical therapeutic potential in treating individuals after ischemic brain injury. 相似文献
79.
尼卡地平控制性降压对家犬脊髓血流的影响 总被引:2,自引:1,他引:1
目的 观察尼卡地平控制性降压对家犬脊髓血流的影响。方法 成年杂种犬 6只 ,体重 12 5~ 16kg ,以 2 5 %硫喷妥钠麻醉。股动脉置管监测MAP。以尼卡地平 8μg·kg 1·min 1持续静脉注射控制性降压。以激光多普勒血流仪测定脊髓血流 (SCBF)。结果 降压前MAP为 (12 5 7±10 6 )mmHg ,降压后为 (72 0± 11 2 )mmHg ,平均下降 4 2 8%。降压前SCBF为 (9 80± 1 0 5 )v ,降压后为 (8 0 4± 0 96 )v ,降低幅度为 18%。结论 尼卡地平控制性降压对SCBF影响较小 ,可安全用于脊髓手术。 相似文献
80.
病理性近视眼的研究进展 总被引:5,自引:4,他引:1
通过复习近年来相关文献,对近视眼发生发展机制与形觉剥夺之间的关系进行综合评述。认为近视眼的发生及眼轴延长与形觉剥夺有一定关系,深入研究其相关机制,对近视眼的早期防治具有重要意义。 相似文献