全文获取类型
收费全文 | 22274篇 |
免费 | 2164篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 209篇 |
儿科学 | 538篇 |
妇产科学 | 466篇 |
基础医学 | 3209篇 |
口腔科学 | 408篇 |
临床医学 | 2077篇 |
内科学 | 4609篇 |
皮肤病学 | 289篇 |
神经病学 | 2079篇 |
特种医学 | 773篇 |
外科学 | 3217篇 |
综合类 | 646篇 |
一般理论 | 65篇 |
预防医学 | 2359篇 |
眼科学 | 668篇 |
药学 | 1625篇 |
中国医学 | 24篇 |
肿瘤学 | 1234篇 |
出版年
2023年 | 134篇 |
2022年 | 207篇 |
2021年 | 467篇 |
2020年 | 262篇 |
2019年 | 427篇 |
2018年 | 483篇 |
2017年 | 364篇 |
2016年 | 364篇 |
2015年 | 498篇 |
2014年 | 612篇 |
2013年 | 905篇 |
2012年 | 1125篇 |
2011年 | 1260篇 |
2010年 | 703篇 |
2009年 | 590篇 |
2008年 | 1113篇 |
2007年 | 1127篇 |
2006年 | 968篇 |
2005年 | 1025篇 |
2004年 | 993篇 |
2003年 | 910篇 |
2002年 | 872篇 |
2001年 | 567篇 |
2000年 | 559篇 |
1999年 | 549篇 |
1998年 | 276篇 |
1997年 | 229篇 |
1996年 | 211篇 |
1995年 | 226篇 |
1994年 | 202篇 |
1993年 | 192篇 |
1992年 | 390篇 |
1991年 | 406篇 |
1990年 | 383篇 |
1989年 | 401篇 |
1988年 | 317篇 |
1987年 | 341篇 |
1986年 | 317篇 |
1985年 | 378篇 |
1984年 | 306篇 |
1983年 | 248篇 |
1982年 | 162篇 |
1980年 | 151篇 |
1979年 | 209篇 |
1978年 | 164篇 |
1977年 | 134篇 |
1975年 | 141篇 |
1974年 | 145篇 |
1973年 | 140篇 |
1972年 | 150篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Leonardo Bonilha MD PhD Paulien M. de Vries Diana J. Vincent MD PhD Chris Rorden MD PhD Paul S. Morgan Mark W. Hurd PhD Nada Besenski MD Kenneth J. Bergmann MD Vanessa K. Hinson MD PhD 《Movement disorders》2007,22(8):1110-1116
We investigated whether structural white matter abnormalities, in the form of disruption of axonal coherence and integrity as measured with diffusion tensor imaging (DTI), constitute an underlying pathological mechanism of idiopathic dystonia (ID), independent of genotype status. We studied seven subjects with ID: all had cervical dystonia as their main symptom (one patient also had spasmodic dysphonia and two patients had concurrent generalized dystonia, both DYT1‐negative). We compared DTI MR images of patients with 10 controls, evaluating differences in mean diffusivity (MD) and fractional anisotropy (FA). ID was associated with increased FA values in the thalamus and adjacent white matter, and in the white matter underlying the middle frontal gyrus. ID was also associated with increase in MD in adjacent white matter to the pallidum and putamen bilaterally, left caudate, and in subcortical hemispheric regions, including the postcentral gyrus. Abnormal FA and MD in patients with ID indicate that abnormal axonal coherence and integrity contribute to the pathophysiology of dystonia. These findings suggest that ID is not only a functional disorder, but also associated with structural brain changes. Impaired connectivity and disrupted flow of information may contribute to the impairment of motor planning and regulation in dystonia. © 2006 Movement Disorder Society 相似文献
32.
33.
34.
B D Royston D Royston S B Coade D M Morgan J D Pearson 《Thrombosis and haemostasis》1992,67(1):172-175
The release of prostacyclin (PGI2) and von Willebrand factor (vWF) from human umbilical vein endothelial cells (HUVEC) was examined to determine if aprotinin had any effects on these endothelial cell reactions. These end-points were chosen to indicate if this serine protease inhibitor caused alterations in the control of haemostatic function by endothelium, in the light of the improvement in haemostasis seen in patients given aprotinin therapy at the time of open heart surgery. Stimuli used to promote secretion of prostacyclin and vWF were human alpha-thrombin, histamine, protamine sulphate, poly-L-lysine and phorbol myristate acetate. Aprotinin (30 microMs) had no significant effect on the basal or stimulated release of PGI2 or vWF from HUVEC. 相似文献
35.
We have previously described the development of new hepatic surgical techniques using the ultrasonic surgical dissector. With 10 years' experience, we have found that major liver resections have been simplified and that the technique is repeatable in hands other than our own. Thirty-three patients had 37 tumors, averaging 5.65 cm in size, resected with an average blood loss of only 1,020 mL per case, which included 5 right trisegmentectomies, 12 lobectomies, 15 segmental resections, and 4 subsegmental resections. Twenty-two patients had metastatic colorectal cancer. Blood transfusion requirements averaged only 2.24 units in long-term survivors, which was significantly less than the 3.5 units received by patients who have since died (p = 0.092). There were no operative deaths. The median survival of these 22 patients was 56 months, and the 5-year actuarial survival rate was 35%. All of the early deaths occurred in patients with more than four tumors, and no patient with less than four tumors died before 42 months with recurrent disease. Six patients had bilateral tumors, and the fact that patients survived into the fourth and fifth post-resectional year indicates that resection was worthwhile. All these patients had Dukes' C primary tumors, but we found no statistical difference in survival between patients with Dukes' B and Dukes' C lesions. The results indicate that hepatic resection with the ultrasonic surgical dissector decreases blood loss, requires few transfusions, is safe to perform, and is associated with excellent long-term survival. 相似文献
36.
Assessment of attitudes amongst health care professionals to suicide prevention reveals a considerable degree of doubt with regards to its feasibility and appropriateness. The various professional groups may vary considerably in the degree of negative attitudes which they exhibit. Such findings suggest that there is an urgent need to ensure that health care professionals are fully informed about the key facts concerning suicide and preventive strategies. Key elements of clinical practice and service organization with regards to suicide prevention are discussed. 相似文献
37.
38.
39.
Victoria L Morgan Benoit M Dawant Yong Li David R Pickens 《Computerized medical imaging and graphics》2007,31(6):436-446
The objectives of this study were to use computer-generated phantoms containing real subject motion to: (1) compare the sensitivity of four commonly used fMRI software packages and (2) compare the sensitivity of three statistical analysis strategies with respect to motion correction. The results suggest that all four packages perform similarly in fMRI statistical analysis with SPM2 having slightly higher sensitivity. The most sensitive analysis technique was to perform motion correction and include the realignment parameters as regressors in the general linear model. This approach applies to all four packages examined and can be most beneficial when stimulus-correlated motion is present. 相似文献
40.