全文获取类型
收费全文 | 1247篇 |
免费 | 98篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 88篇 |
妇产科学 | 21篇 |
基础医学 | 192篇 |
口腔科学 | 30篇 |
临床医学 | 102篇 |
内科学 | 244篇 |
皮肤病学 | 29篇 |
神经病学 | 66篇 |
特种医学 | 172篇 |
外科学 | 136篇 |
综合类 | 46篇 |
预防医学 | 98篇 |
眼科学 | 31篇 |
药学 | 43篇 |
肿瘤学 | 52篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 28篇 |
2017年 | 15篇 |
2016年 | 33篇 |
2015年 | 32篇 |
2014年 | 41篇 |
2013年 | 52篇 |
2012年 | 48篇 |
2011年 | 41篇 |
2010年 | 49篇 |
2009年 | 55篇 |
2008年 | 43篇 |
2007年 | 49篇 |
2006年 | 43篇 |
2005年 | 60篇 |
2004年 | 29篇 |
2003年 | 43篇 |
2002年 | 28篇 |
2001年 | 21篇 |
2000年 | 36篇 |
1999年 | 25篇 |
1998年 | 47篇 |
1997年 | 51篇 |
1996年 | 45篇 |
1995年 | 38篇 |
1994年 | 29篇 |
1993年 | 32篇 |
1992年 | 25篇 |
1991年 | 15篇 |
1990年 | 11篇 |
1989年 | 26篇 |
1988年 | 31篇 |
1987年 | 21篇 |
1986年 | 20篇 |
1985年 | 26篇 |
1984年 | 20篇 |
1983年 | 17篇 |
1982年 | 7篇 |
1981年 | 15篇 |
1980年 | 9篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 11篇 |
1976年 | 13篇 |
1975年 | 4篇 |
1972年 | 5篇 |
排序方式: 共有1354条查询结果,搜索用时 31 毫秒
1.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia. 相似文献
2.
VISUOMOTOR PERFORMANCE OF NORMAL AND CLUMSY CHILDREN. II: ARM-TRACKING WITH AND WITHOUT VISUAL FEEDBACK 总被引:2,自引:2,他引:0
J. H. P. van der Meulen J. J. Denier van der Gon C. C. A. M. Gielen R. H. J. M. Gooskens J. Willemse 《Developmental medicine and child neurology》1991,33(2):118-129
Tracking performance was investigated in normal and clumsy children in two age-groups, six to seven and 10 to 11 years. Target signals moving unpredictably along a straight line had to be tracked, both with and without visual feedback. Performance was described in three ways: (1) performance in the low-frequency range (LF); (2) the delay between target signal and tracking movement (DL); and (3) a measure of tracking quality or over-all similarity in the shape of target signal and tracking movement (Q). Clumsy children in both age-groups had a lower tracking quality (Q) and longer delay (DL) than the normal children. Disturbances in the regulation of attention seemed to affect tracking performance, particularly of the six- to seven-year-old clumsy children. There was no significant difference between normal and clumsy children in the effect of visual feedback on tracking performance. This suggests that clumsiness is not linked to disturbance of integration of visual feedback information and motor processes. 相似文献
3.
Automatic assessment of levodopa-induced dyskinesias in daily life by neural networks. 总被引:1,自引:0,他引:1
We developed an objective and automatic procedure to assess the severity of levodopa-induced dyskinesia (LID) in patients with Parkinson's disease during daily life activities. Thirteen patients were continuously monitored in a home-like situation for a period of approximately 2.5 hours. During this time period, the patients performed approximately 35 functional daily life activities. Behavior of the patients was measured using triaxial accelerometers, which were placed at six different positions on the body. A neural network was trained to assess the severity of LID using various variables of the accelerometer signals. Neural network scores were compared with the assessment by physicians, who evaluated the continuously videotaped behavior of the patients off-line. The neural network correctly classified dyskinesia or the absence of dyskinesia in 15-minute intervals in 93.7, 99.7, and 97.0% for the arm, trunk, and leg, respectively. In the few cases of misclassification, the rating by the neural network was in the class next to that indicated by the physicians using the AIMS score (scale 0-4). Analysis of the neural networks revealed several new variables, which are relevant for assessing the severity of LID. The results indicate that the neural network can accurately assess the severity of LID and could distinguish LID from voluntary movements in daily life situations. 相似文献
4.
Bis[di-n-butyl (4-aminosalicylato)tin] oxide [NSC: 628561] (compound 1), bis [diphenyl(4-aminosalicylato)tin] oxide [NSC: 628562] (compound 2), and six other analogous compounds of the type [n-Bu2 (XYZ-C6H2COO)Sn]2O (compounds 3 to 8), were tested in vitro at the National Cancer Institute, Bethesda, Maryland, USA, for cytotoxic activity against a series of human cell lines. Compounds 1, 6 and 8 score globally satisfactorily since four of the five relevant sensitivity or selectivity parameters, DGI50, DTGI or DLC50, DH and MGDH, are statistically significant. Compounds 3 and 7 are less satisfactory because only three such parameters are statistically significant. For compound 2, only two of the parameters are significant. 相似文献
5.
G. Zambruno V. Gielen D. Schmitt C. Dezutter-Dambuyant J. Thivolet 《Journal of cutaneous pathology》1987,14(6):331-336
In this work the role of trypsin in revealing epidermal cell surface antigens, with the use of immunological markers, was investigated. Two monoclonal antibodies (MCA) were used, the first: D47, belongs to the first cluster of differentiation and recognizes a membrane antigen of human thymocytes; the second HLA-ABC-m3, is an anti-HLA-B27 MCA. Preliminary treatment with various concentrations of trypsin was performed on frozen skin sections and followed by indirect immunofluorescence. D47 reacted with epidermal dendritic cells only after trypsin pretreatment of skin sections. In addition a mild preliminary trypsinization was shown to increase in situ immunoreactivity of MCA HLA-ABC-m3 with epidermal cells. Best results were obtained when trypsin concentrations ranging from 2.5 to 5 micrograms/ml were applied for 10 min at 37 degrees C. Preliminary trypsinization may be of interest for a better exposure of some surface antigens to immunohistochemical markers. 相似文献
6.
The immunomodulator interleukin-1 beta (IL-1) is one of the major inflammatory mediators. In vivo, it has been reported to depress some rat liver cytochromes P-450 (cytochrome P-450). Our aim was to study those effects in vitro, using cultured fetal rat hepatocytes as a model. Testosterone 6 beta-hydroxylase (cytochrome P-450 IIIA family activity) was not depressed by IL-1 treatments, but its induction by dexamethasone was prevented. The effect was time- and dose-dependent. Ethoxyresorufine-O-deethylase (cytochrome P-450 IA1 activity) decreased after IL-1 treatment, and dexamethasone partially prevented this inhibition. Acute phase effects of IL-1 were assayed by albumin and transferrin secretions. The cell's sensitivity to glucocorticoids was determined by tyrosine-aminotransferase activity. Our data demonstrate that IL-1 was able to prevent the glucocorticoid induction of cytochrome P-450 IIIA involving at least two different mechanisms. This is in agreement with the theory suggesting that the induction of CYPIIIA family by glucocorticoids requires the presence of the glucocorticoid receptor and some other regulatory elements. Other cytochrome P-450-dependent activities (IIA1, IIB1/2, and IIC11) were inhibited by IL-1 treatments, depending on dose and time, but some were also protected by dexamethasone. 相似文献
7.
8.
9.
10.