全文获取类型
收费全文 | 14431篇 |
免费 | 825篇 |
国内免费 | 212篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 125篇 |
妇产科学 | 61篇 |
基础医学 | 1601篇 |
口腔科学 | 267篇 |
临床医学 | 1173篇 |
内科学 | 2078篇 |
皮肤病学 | 250篇 |
神经病学 | 3012篇 |
特种医学 | 465篇 |
外国民族医学 | 1篇 |
外科学 | 1208篇 |
综合类 | 1282篇 |
预防医学 | 1801篇 |
眼科学 | 271篇 |
药学 | 1130篇 |
5篇 | |
中国医学 | 449篇 |
肿瘤学 | 227篇 |
出版年
2024年 | 43篇 |
2023年 | 332篇 |
2022年 | 492篇 |
2021年 | 705篇 |
2020年 | 634篇 |
2019年 | 701篇 |
2018年 | 594篇 |
2017年 | 386篇 |
2016年 | 381篇 |
2015年 | 369篇 |
2014年 | 872篇 |
2013年 | 745篇 |
2012年 | 711篇 |
2011年 | 800篇 |
2010年 | 662篇 |
2009年 | 633篇 |
2008年 | 621篇 |
2007年 | 623篇 |
2006年 | 505篇 |
2005年 | 402篇 |
2004年 | 354篇 |
2003年 | 330篇 |
2002年 | 279篇 |
2001年 | 233篇 |
2000年 | 216篇 |
1999年 | 190篇 |
1998年 | 190篇 |
1997年 | 167篇 |
1996年 | 166篇 |
1995年 | 144篇 |
1994年 | 138篇 |
1993年 | 141篇 |
1992年 | 135篇 |
1991年 | 132篇 |
1990年 | 133篇 |
1989年 | 105篇 |
1988年 | 105篇 |
1987年 | 110篇 |
1986年 | 124篇 |
1985年 | 193篇 |
1984年 | 142篇 |
1983年 | 106篇 |
1982年 | 89篇 |
1981年 | 84篇 |
1980年 | 68篇 |
1979年 | 55篇 |
1978年 | 24篇 |
1977年 | 41篇 |
1976年 | 21篇 |
1973年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Circumscribed low grade astrocytomas in the dominant opercular and insular region: A pilot study 总被引:4,自引:0,他引:4
Summary Intraoperative mapping techniques allow a reliable identification or exclusion of eloquent brain areas and are well tolerated by the patients. In dominant opercular tumours radical surgery can only be achieved without lasting deficits with intraoperative histological examination of the resection line and mapping. If an early post-operative MRI shows residual opercular tumour in non-eloquent areas re-operation is recommended.In large dominant insular or opercular-insular tumours only biopsy is recommended, because only an incomplete removal can be accomplished, because the trial of radical removal carries a high risk of postoperative deficits due to possible vascular damage of the lenticulo-striate arteries or internal capsule. Because subtotal removal of low grade gliomas does not increase the progression free interval, we would not recommend surgery in these cases, as they carry a significant risk of a further deficit. 相似文献
42.
Masako Nishizuka Hiroyuki Sumida† Yasuhiko Kano† Yasumasa Aral 《Journal of neuroendocrinology》1993,5(5):569-573
An examination was made of neurogenesis in the anteroventral periventricular nucleus (AVPv) of the preoptic area of the rat using bromodeoxyuridine (BrdU), a thymidine analog, and a BrdU-specific antibody. Cells in the AVPv of adult rats were labeled with the antibody when BrdU was injected into pregnant rats once during day 13 to 18 of gestation, but not during day 10 to 12 nor 19 to 20 of gestation nor on postnatal day 1, indicating that neurogenesis of the AVPv occurs during a limited period from day 13 to 18 of gestation. Next, to examine the effects of androgen on neurogenesis, BrdU was injected once on day 15 into pregnant rats that also received injections of testosterone propionate (TP). The number of BrdU-labeled cells in the AVPv was similar in control female and male fetuses and female fetuses from pregnant rats that received daily injections of TP during days 14 to 16, when fetuses were examined on day 17 of gestation. These results suggest that the neurogenesis that was recognized by labeling with BrdU was not affected by the treatment with TP. On day 21 of gestation, BrdU-labeled cells in the AVPv of control male fetuses and female fetuses that received TP during days 14 to 18 were fewer in number than those in female fetuses of the control group, whereas treatments with TP during days 14 to 16 and during days 17 to 18 did not cause any significant decrease in number of BrdU-labeled cells. These findings support the hypothesis that elimination of a population of cells, for example, by cell death as described previously, is enhanced in male fetuses and in female fetuses treated with TP repetitively. 相似文献
43.
44.
P. Praamstra A. R. Cools D. F. Stegeman M. W. I. M. Horstink 《Journal of the neurological sciences》1996,140(1-2):67-74
Movement-related potentials were recorded preceding self-paced voluntary movements in patients with Parkinson's disease and in healthy subjects of the same age group. We compared the Readiness Potential preceding joystick movements in a fixed direction and preceding joystick movements in freely selected directions. In normal subjects the Readiness Potential amplitude was higher preceding freely selected movements than preceding movements in a fixed direction. The Readiness Potential in Parkinson patients failed to be modified by the different modes of movement selection. The modulation of the Readiness Potential by different ways of preparing for movement might be due to the supplementary motor area (SMA) being more strongly engaged by tasks requiring internal control of movements than by tasks that are externally structured. The results suggest that this task-dependent variation of SMA activity is reduced in Parkinson's disease. A failing capacity to adapt SMA activity to different task demands has previously been suggested by evidence from positron emission tomography studies using similar tasks. 相似文献
45.
Surgeon perspectives on options for ventral abdominal wall hernia repair: results of a postal questionnaire 总被引:3,自引:0,他引:3
Background: Ventral abdominal wall hernias are a common cause of morbidity and mortality. Opinion varies as to appropriate management.
A recent consensus meeting on incisional hernia identified the need to standardise repair. On this background, a survey of
current practice was performed. Method: A questionnaire was sent to 101 practicing general surgeons within the West of Scotland. Incisional, epigastric and para-umbilical
defects were subdivided into defect size <2, 2–5 and >5 cm. The surgeons were asked to indicate the most appropriate repair
(suture, mayo or mesh) for each. The influence of reducibility on the decision to repair was also assessed. Results: Sixty-one of 101 questionnaires were returned valid giving a response rate of 60%. Suture repair was significantly more
likely to be used in all defects <2 cm (P<0.001). Mesh repair was significantly more likely to be recommended in all defects >5 cm (P<0.001). Of defects >5-cm, mesh was recommended for 90% of incisional hernia compared with 81% of epigastric and 76% of para-umbilical
hernia (P<0.001). There was no significant difference in choice of repair for defect size 2–5 cm with opinion divided between suture
and mesh. Irreducibility increased the likelihood of recommendation for repair. Conclusion: This survey shows a lack of consensus on the appropriate repair of ventral abdominal wall hernia amonge practicing consultant
general surgeons. This reflects the contrasting views within the current literature. 相似文献
46.
H. J. Maragkowitsch E. Irle 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1981,41(3-4):233-246
Summary Thirty-three cat brains with injections of horseradish peroxidase in various regions of the cerebral cortex were screened for afferent projections from the ventral tegmental area, the locus ceruleus, and the parabrachial nuclei. All three structures were found to project to rather divergent parts of the cortex, including regions in the posterior half of the hemisphere. These results, especially for the ventral tegmental area and, to a lesser degree, for the parabrachial neurons, disagree with most of the target loci of established cortical afferents in the rat. Though our results might be attributed to species differences in the cortical innervation of brain stem structures, we prefer explanations which emphasize different densities in the distribution of brain stem afferents to the cortex, and/or which suggest different cortical targets of catecholaminergic and noncatecholaminergic neurons.Supported in part by grant Ma 795 from the Deutsche Forschungsgemeinschaft (DFG) 相似文献
47.
目的介绍一种简单实用而较精确的测量狭窄气管截面积的方法.方法利用纤维支气管镜、测长器、模拟气管等制作并校正测量标尺,并利用该标尺测量了3例气管状况异常患者的气管某一截面面积.结果用校正过的4种测量标尺测量了10个模拟气管的直径,和实测真值比较经t检验分析无显著性差异,利用上述标尺测量的3个患者的目的截面面积分别为约96 mm2、 105 mm2和192 mm2.结论本方法提供了一种简单、快速而又较精确的测量大气道某一截面面积的方法,为定量评价患者的通气功能、选择气管支架或采用其他干预手段处理气管病变提供了数据参考. 相似文献
48.
49.
目的探讨体表面积(BS)、体质量、体质量指数(BMI)对老年人骨密度(BMD)的影响。方法用双能X线骨密度仪测定1794例老年人腰椎、髋关节的BMD值,并对其与BS等指标进行相关回归分析。结果BS大的老年人其BMD大于BS小者,有显著性差异。在各种指标与BMD的相关性比较中,BS与BMD的相关性最好,其后依次为:体质量、身高、OSTA得分(亚洲人自我骨质疏松筛查工具)、BMI。结论BS比BMI等指标更能反映出人体体型对老年人BMD的影响。 相似文献
50.