全文获取类型
收费全文 | 42670篇 |
免费 | 4162篇 |
国内免费 | 2401篇 |
专业分类
耳鼻咽喉 | 260篇 |
儿科学 | 957篇 |
妇产科学 | 369篇 |
基础医学 | 3084篇 |
口腔科学 | 782篇 |
临床医学 | 6357篇 |
内科学 | 4764篇 |
皮肤病学 | 493篇 |
神经病学 | 1525篇 |
特种医学 | 1342篇 |
外国民族医学 | 7篇 |
外科学 | 3009篇 |
综合类 | 9640篇 |
现状与发展 | 10篇 |
一般理论 | 4篇 |
预防医学 | 4919篇 |
眼科学 | 888篇 |
药学 | 5031篇 |
59篇 | |
中国医学 | 3310篇 |
肿瘤学 | 2423篇 |
出版年
2024年 | 96篇 |
2023年 | 419篇 |
2022年 | 1066篇 |
2021年 | 1474篇 |
2020年 | 1378篇 |
2019年 | 1026篇 |
2018年 | 1114篇 |
2017年 | 1257篇 |
2016年 | 1121篇 |
2015年 | 1848篇 |
2014年 | 2597篇 |
2013年 | 2851篇 |
2012年 | 4182篇 |
2011年 | 4576篇 |
2010年 | 3606篇 |
2009年 | 2985篇 |
2008年 | 3151篇 |
2007年 | 2924篇 |
2006年 | 2600篇 |
2005年 | 1950篇 |
2004年 | 1412篇 |
2003年 | 1291篇 |
2002年 | 979篇 |
2001年 | 804篇 |
2000年 | 624篇 |
1999年 | 445篇 |
1998年 | 254篇 |
1997年 | 249篇 |
1996年 | 175篇 |
1995年 | 132篇 |
1994年 | 128篇 |
1993年 | 70篇 |
1992年 | 79篇 |
1991年 | 48篇 |
1990年 | 38篇 |
1989年 | 46篇 |
1988年 | 31篇 |
1987年 | 34篇 |
1986年 | 26篇 |
1985年 | 30篇 |
1984年 | 14篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 17篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1975年 | 8篇 |
1974年 | 5篇 |
1973年 | 8篇 |
1970年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
目的:探讨喉癌患者术后出现迟发性感染的原因和治疗方法。方法:患者均为男性,平均58岁;声门上区21例(T1N0M0 5例、T1N1M0 6例、T1N2M0 4例、T2N0M0 2例、T2N0M0 3例、T3N2M0 1例),声门区10例(T2N0M0 3例、T3N0M04例、T3N1M0 3例),外院全喉切除术后1例(TNM分期不详);喉重建术31例,术后18例(56.25%)患者接受放疗。迟发性感染发生在术后1~10个月,平均术后5.6个月;1~3个月13例,4~6个月16例,7~10个月3例,合并颌下隙感染2例。静脉应用广谱抗生素同时切开排脓或行局部扩大清创术,32例中23例(72.5%)切口内发现缝合丝线头。结果:10例10d左右完全愈合,22例愈合时间为15d~0,5年,平均2个月。随访2月~8年,失访5例,20例患者存活,9例患者拔管保留喉功能,死亡7例。结论:迟发性感染的主要原因是颈部切口留有缝线、细菌感染、手术局部血运差、放射治疗等。 相似文献
32.
Objective To investigate the value of statistical parametric mapping 5 (SPM5) and its parameter settings in analysis of PET imaging for epilepsy patients. Methods Seventeen epilepsy patients and seventeen controls were scanned with PET. The datns were analyzed using PET and SPM5 with qualitative and semiquantitative analysis, statistical analysis of the percentage (numbers of agent distribution decreasing in focus to brain) for different parameters combinations, which were value adjustment to contral-p and voxels-k. Results There was decreasing of agent distribution at temporal lobe in epilepsy patients detecting with PET; the T/NT of focus to cerebellum was 1.07±0.24, the T/NT of normal tissue in opposite side to cerebellum was 1.27±0.18, there was a significant difference (t=1.87, P<0.05). Dealing with SPM5, there was more significant decreasing of agent in regions 19, 21, 39 of temporal lobe, regions 7, 19, 31, 40, 47 of parietal lobe and occipital lobe in epilepsy patients. With different value of k, the percentage was (27±22)%, (29±24)%, (32±23)%, (35±27)%, (39±31)%respectively, there was not significant difference (F=0.59, P>0.05) ; for different value of p, the percentage was (42±30) %, (29±25) %, (26±21) % respectively, with a significant difference (F=3.60, P<0.05); there was linear regression in value adjustment to contral-p and the percentage(b=-18.24, t=2.57, P<0.05). Conclusions Semiquantitative analysis by SPM5, the setting of value adjustment to contral-p would affect the results, the smaller of value adjustment to contral-p, the better of the result. SPM5 would be more objective and accurate to locate the focuses. 相似文献
33.
34.
目的 :对比根充糊剂 牙胶尖、Vitapex 牙胶尖、Thermafil热熔牙胶三种根管充填材料对离体人牙根管的密封性能。方法 :将 5 0个新鲜拔除的人单根管牙 ,在釉牙骨质界处切除牙冠。将所有牙根随机分为 5组 ,每组 10个。 3个实验组分别用上述三种材料充填根管 ;剩余 2组 ,一组根管预备后不进行充填 ,另一组不进行根管预备 ,也不进行根管充填。用印度墨水染色法对比三种根管充填材料对离体人牙根管的密封性能 ,体视显微镜下测量染色线长度并进行统计学分析。结果 :根充糊剂 牙胶尖组、Vitapex 牙胶尖组和Thermafil热熔牙胶组的平均染色线长度分别为 3 .3 6± 0 .42mm、2 .0 9± 0 .19mm、1.0 5± 0 .3 7mm。Vitapex糊剂 牙胶尖或Thermafil热熔牙胶进行根管充填 ,产生的根管封闭性明显优于用根充糊剂 牙胶尖组根管充填 (P <0 .0 5 ) ;而Vitapex糊剂 牙胶尖和Thermafil热熔牙胶比较时 ,统计学无显著性差异 (P >0 .0 5 )。结论 :Thermafil热熔牙胶的密封性能最强 ,Vitapex糊剂 牙胶尖次之 ,根充糊剂 牙胶尖最弱。 相似文献
35.
T.G. van Kooten J.M. Schakenraad H.C. van der Mei A. Dekker C.J. Kirkpatrick H.J. Busscher 《Medical engineering & physics》1994,16(6):506-512
In this study, human umbilical vein and human saphenous vein endothelial cells were seeded on glass and exposed to fluid shear in a parallel-plate flow chamber. Cell retention, morphology and migration were studied as a function of shear stress and of adhesion time prior to exposure to shear. Three-hour and 24-h adhesion times gave rise to comparable cell retention values after 2 h of flow for both cell types. Cell retention decreased from 85 to 20% as shear stress increased from 88 to 264 dynes cm−2 (8.8 to 26 Pa). Mean spreading areas decreased after the onset of flow, but subsequently stabilized to plateau values, which were smaller at higher shear stresses. Shape factors increased faster to higher values as cells were exposed to higher shear stresses, without any obvious preference in orientation of the cells with respect to the direction of flow. Migration was unidirectional with flow and linear with time. Migration was faster for cells which had adhered for 24 h than for cells which had adhered for 3 h and was accompanied by the presence of fibrillar structures left behind on the surface upstream of migrating cells. It is concluded that after 3 h adhesion to glass, cells have adhered with an adhesion strength that does not substantially increase during the next 21 h. However, during this time changes in cell-substratum interactions seem to occur judging by the differences in, e.g., migration rates. 相似文献
36.
Through a critical study of herbalogy, it is concluded that the mature seeds of Alpinia zermubet were used as caodoukou in ancient times. The original plant of Yutao recorded in Zhiwu Mingshi Tukao may be the species of Alpinia katsumadai. Baidukou used in ancient times may be the seeds of Alpinia katsumadai found in the south of China, or Amomum compactum and Am. kravanh imported from foreign countries. 相似文献
37.
控制性降压在临床麻醉中的应用进展 总被引:6,自引:0,他引:6
控制性低血压是指在某些手术麻醉期间,用药物等方法降低血压,以达到减少手术野出血,便于手术操作的一种方法,通常采用血管扩张剂,钙通道阻断剂及麻醉来控制血压,现就这一领域的研究进展作一综述。 相似文献
38.
笔者提出了对Reed-Frost模型的学术评论,并新建了一种Reed-Frost模型的改进模型。该改进模型全面考虑了隐性感染者的产生、传染作用及向免疫者的转化。应用这个模型,模拟了NewEngland的麻疹流行和中国上海市某保育院的水痘流行,结果颇为理想。该模型包括了基本的流行要因,故能用以解释流行过程,并可帮助流行病学工作者理解隐性感染在传染病流行过程中的作用。 相似文献
39.
肝硬化病人施行胆道手术35例分析 总被引:2,自引:0,他引:2
本文对我院近10年来收治的肝硬化病人施行胆道手术35例进行分析,术前漏诊肝硬化12例,占3O%以上,死亡5例,有3例死于胆囊床大出血与术前漏诊有关。作者就术前漏诊原因、术前准备和手术处理体会进行讨论。 相似文献
40.
To evaluate changes in matrix molecules of the joint capsule, the right knees of 24 skeletally mature female NZW rabbits were immobilized while the contralateral limb served as an unoperated control. The immobilization was discontinued at 8 weeks and the rabbits were divided among four groups (n = 6) based on the number of weeks the right knees were remobilized: 0, 8, 16, or 32. Three rabbits (six knees) that did not have operations provided normal control joint capsules. The mRNA levels for collagen types I, II, and III, and MMP-1 and -13 were significantly increased in the joint capsules of the contracture knees in all groups when compared to normal and contralateral limb joint capsules. In contrast, the mRNA levels for TIMP-1, -2, and -3 were decreased in the joint capsules of the contracture knees in all groups when compared to normal and contralateral limb joint capsules. The mRNA levels for lumican and decorin were increased in the joint capsules of the contracture knees in all groups when compared to normal capsules. Many of the changes observed in this animal model are similar to those observed in human joint capsules from posttraumatic elbow contractures, supporting the value of this rabbit model. 相似文献