全文获取类型
收费全文 | 241394篇 |
免费 | 17536篇 |
国内免费 | 6637篇 |
专业分类
耳鼻咽喉 | 3085篇 |
儿科学 | 3906篇 |
妇产科学 | 4915篇 |
基础医学 | 34143篇 |
口腔科学 | 4737篇 |
临床医学 | 26006篇 |
内科学 | 42616篇 |
皮肤病学 | 5466篇 |
神经病学 | 16479篇 |
特种医学 | 11138篇 |
外国民族医学 | 53篇 |
外科学 | 30265篇 |
综合类 | 12932篇 |
现状与发展 | 26篇 |
一般理论 | 100篇 |
预防医学 | 14805篇 |
眼科学 | 7290篇 |
药学 | 21849篇 |
67篇 | |
中国医学 | 5699篇 |
肿瘤学 | 19990篇 |
出版年
2024年 | 358篇 |
2023年 | 2216篇 |
2022年 | 5943篇 |
2021年 | 8893篇 |
2020年 | 5493篇 |
2019年 | 6420篇 |
2018年 | 7444篇 |
2017年 | 5754篇 |
2016年 | 6782篇 |
2015年 | 9369篇 |
2014年 | 11511篇 |
2013年 | 12389篇 |
2012年 | 18637篇 |
2011年 | 18702篇 |
2010年 | 11205篇 |
2009年 | 9097篇 |
2008年 | 13384篇 |
2007年 | 13084篇 |
2006年 | 12483篇 |
2005年 | 11936篇 |
2004年 | 9795篇 |
2003年 | 8622篇 |
2002年 | 7376篇 |
2001年 | 6140篇 |
2000年 | 5775篇 |
1999年 | 5294篇 |
1998年 | 2592篇 |
1997年 | 2250篇 |
1996年 | 1904篇 |
1995年 | 1755篇 |
1994年 | 1511篇 |
1993年 | 1118篇 |
1992年 | 2162篇 |
1991年 | 2062篇 |
1990年 | 1823篇 |
1989年 | 1645篇 |
1988年 | 1522篇 |
1987年 | 1331篇 |
1986年 | 1257篇 |
1985年 | 1095篇 |
1984年 | 774篇 |
1983年 | 646篇 |
1982年 | 440篇 |
1981年 | 427篇 |
1980年 | 363篇 |
1979年 | 582篇 |
1978年 | 428篇 |
1977年 | 399篇 |
1976年 | 356篇 |
1974年 | 384篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Functional renal insufficiency during long-term therapy with captopril and enalapril in severe chronic heart failure 总被引:4,自引:0,他引:4
Renal function was evaluated in 104 patients with severe chronic heart failure whom we treated with captopril or enalapril. Seventy patients showed no change or an improvement in renal function (group A), and 34 patients developed functional renal insufficiency (group B). Before converting-enzyme inhibition, group B patients received higher doses of furosemide (p less than 0.02) and had lower central venous pressures (p less than 0.05) than group A patients. After 1 to 3 months of converting-enzyme inhibition, an excessive reduction in left ventricular filling pressure (to less than 15 mm Hg) or mean arterial pressure (to less than 60 mm Hg) was noted in 28 of 34 (82%) patients in group B but in only 22 of 70 patients in group A (31%) (p less than 0.001). At the end of the study, drug-induced azotemia resolved after a reduction in the dosage of diuretics, despite unaltered treatment with captopril and enalapril. Hence, the deterioration of renal function after converting-enzyme inhibition in heart failure is not a toxic or immunologic reaction to therapy but results from specific hemodynamic events that can be ameliorated by sodium repletion. 相似文献
102.
103.
用视诱发电位和富里叶变换作视力客观估计 总被引:2,自引:0,他引:2
目的:研究用图形视觉诱发电位(PVEP)和离散富里叶变换(DFT)作视力客观估计的方法。方法:检测对象为33只正常眼。用翻转频率为10次/秒,条纹张角分别为30、20、18、12、10、6、4和2弧分的垂直方波光栅图形刺激,记录相应的稳态图形视诱发电位。用离散富里叶交换提取WEP频谱中10Hz成分的幅值。以光栅条纹张角为横坐标、相应的VEP频谱幅值为纵坐标作关系曲线,取阈值附近的近似线性部分的数据点作直线回归,用外推法求得阈值和视力。结果:比较VEP所测之视力与用国际标准视力表所测之视力,可见在本研究中70%的受检眼VEP视力估计较准确。结论:用本研究中的VEP技术客观地测量视力可靠性较高。眼科学报1997;13:59~61。 相似文献
104.
105.
小儿肾积水Anderson-Hynes手术后并发症及其治疗 总被引:1,自引:0,他引:1
对52例(54侧)先天性肾盂输尿管连接部梗阻性肾积水患者行Anderson-Hynes手术,对其手术的并发症进行分析,主要并发症为吻合口梗阻(39%)和泌尿系感染(28%).经腹进行手术,肠梗阻发生率为13%(3/23).患儿手术时年龄与手术后并发症发生率无显著性意义. 相似文献
106.
107.
Immunoelectron microscopic studies of exfoliative iris tissue (seven specimens) revealed the presence of laminin in the fibrillar component of exfoliation material. The immunogold label was uniformly distributed on the exfoliation fibres. Deposition of laminin labelled exfoliation material in the dilator muscle was a noteworthy feature, as was an apparent depletion of laminin in the basement membranes of ostensibly unaffected vessels. In control iris tissue (five enucleated eyes) laminin was identified in the basement membrane round vascular contractile cells, but not beneath the endothelium. 相似文献
108.
通过半年对35名7~12岁轻度碘缺乏病儿童进行补碘,并与同龄、同地的正常儿童和缺碘未补碘儿童进行比较,以观察补碘对儿童脑功能及生长发育的影响。结果发现:①补碘可使儿童碘营养状况恢复正常,尿碘值由(83.2±3.5)μg/L上升到(162.2±1.6)μg/L,血清T4、FT4I和rT3:也与正常儿童一致而与未补碘儿童有显著性差异(P<0.05).②轻度碘缺乏病儿童智商低于正常儿童(P<0.01),补碘在一定程度上改善其智商水平。③轻度碘缺乏病及补碘未能明显影响儿童的生长发育,可能与儿童总营养水平较差有关。 相似文献
109.
W W Wong W J Cochran W J Klish E O Smith L S Lee M L Fiorotto P D Klein 《European journal of clinical nutrition》1988,42(3):233-242
We estimated body fat in 20 normal adults (10 males and 10 females) from 18O- and 2H-dilution spaces and from the equations of Durnin & Womersley and Pollock, Schmidt & Jackson based on skinfold thickness measurements. Differences between methods for body fat estimation were found to be sex-dependent: subsequent analyses indicated significant differences between methods within each sex. Regardless of sex, the highest fat estimates were obtained with the 18O-dilution method, followed by those obtained with the 2H-dilution method or the Durnin & Womersley equation. The lowest fat estimates were obtained using the Pollock, Schmidt & Jackson equation. The 18O-dilution method and the Durnin & Wormersley anthropometric method are both suitable and appropriate for body fat estimation in adults studied under field conditions. 相似文献
110.
M E Lee 《Journal of the American Optometric Association》1988,59(7):567-571
Beta adrenergic blocking agents have gained wide acceptance among practitioners and patients alike as extremely useful drugs for the treatment of open-angle glaucoma. This new class of antiglaucoma agents usually is effective in reducing elevated intraocular pressure and is generally well tolerated. This paper is intended to provide an understanding of the ophthalmic beta adrenergic blocking agents to optometrists who are actively involved in the treatment of glaucoma and/or in the monitoring of glaucoma patients. The clinical pharmacology of the three FDA-approved beta blockers -- timolol, levobunolol, and betaxolol, is evaluated and the drugs are compared. 相似文献