全文获取类型
收费全文 | 56534篇 |
免费 | 4560篇 |
国内免费 | 182篇 |
专业分类
耳鼻咽喉 | 511篇 |
儿科学 | 1521篇 |
妇产科学 | 1076篇 |
基础医学 | 7466篇 |
口腔科学 | 978篇 |
临床医学 | 6272篇 |
内科学 | 10833篇 |
皮肤病学 | 812篇 |
神经病学 | 4862篇 |
特种医学 | 2304篇 |
外科学 | 9382篇 |
综合类 | 804篇 |
一般理论 | 57篇 |
预防医学 | 5590篇 |
眼科学 | 1261篇 |
药学 | 4062篇 |
1篇 | |
中国医学 | 53篇 |
肿瘤学 | 3431篇 |
出版年
2023年 | 321篇 |
2022年 | 451篇 |
2021年 | 1154篇 |
2020年 | 655篇 |
2019年 | 1088篇 |
2018年 | 1309篇 |
2017年 | 953篇 |
2016年 | 1029篇 |
2015年 | 1231篇 |
2014年 | 1799篇 |
2013年 | 2497篇 |
2012年 | 3802篇 |
2011年 | 3892篇 |
2010年 | 2111篇 |
2009年 | 1879篇 |
2008年 | 3397篇 |
2007年 | 3653篇 |
2006年 | 3542篇 |
2005年 | 3451篇 |
2004年 | 3182篇 |
2003年 | 3031篇 |
2002年 | 2861篇 |
2001年 | 888篇 |
2000年 | 840篇 |
1999年 | 841篇 |
1998年 | 663篇 |
1997年 | 542篇 |
1996年 | 507篇 |
1995年 | 521篇 |
1994年 | 455篇 |
1993年 | 424篇 |
1992年 | 545篇 |
1991年 | 489篇 |
1990年 | 506篇 |
1989年 | 484篇 |
1988年 | 443篇 |
1987年 | 386篇 |
1986年 | 388篇 |
1985年 | 440篇 |
1984年 | 375篇 |
1983年 | 306篇 |
1982年 | 261篇 |
1981年 | 244篇 |
1980年 | 216篇 |
1979年 | 246篇 |
1978年 | 239篇 |
1977年 | 191篇 |
1974年 | 210篇 |
1973年 | 194篇 |
1972年 | 188篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
54.
55.
56.
Sheryl A. Scott Seth Dinowitz Kristen Terhaar Diane Sherlock Maurice A. Campbell Dreania Levine 《The Journal of comparative neurology》1994,350(2):302-310
The goal of the present study was to identify cytochemical markers characteristic of muscle afferents in hatchling chicks. To this end, we stained neurons in the trigeminal mesencephalic nucleus with a variety of markers that label subsets of neurons in avian dorsal root ganglia. We found that trigeminal mesencephalic neurons are surprisingly heterogeneous in their cytochemical make-up, expressing, to varying degrees, substance P, cholecystokinin, carbonic anhydrase, calbindin D-28k, parvalbumin, and S-100β. Calbindin D28k and S-100β appeared to be expressed equally in medial and lateral divisions of the trigeminal mesencephalic nucleus. In contrast, substance P- and cholecystokinin-immunoreactive neurons were more abundant in the medial division, whereas carbonic anhydrase activity and parvalbumin immunoreactivity were stronger in the lateral division. We were unable to detect met-enkephalin, neuropeptide Y, calcitonin gene-related peptide, vasoactive intestinal peptide, somatostatin, γ-aminobutyric acid, or tyrosine hydroxylase in the trigeminal mesencephalic nucleus. Moreover, these neurons did not appear to bind the lectin Dolichos biflorus agglutinin. The heterogeneity of expression of markers among trigeminal mesencephalic nucleus neurons, especially between neurons in the medial and lateral divisions, suggests that these neurons are functionally diverse. 相似文献
57.
B. Silke J. P. Spiers S. Boyd E. Graham G. McParland M. E. Scott 《Clinical autonomic research》1994,4(1-2):49-56
The accuracy and precision of the Finapres in recording rest and exercise blood pressure compared with the intra-arterial (aortic and brachial) and random-zero sphygmomanometer methods was assessed in 84 ischaemic patients in three different studies. Firstly, comparison at rest with the aortic intraarterial pressure in 50 ischaemic patients demonstrated that the Finapres systolic (136.5 ± 21.1 vs. 129.3 ± 19.0 mmHg;p < 0.001) and mean (92.4 ± 13.4 vs. 90.7 ± 11.4 mmHg;p < 0.001) arterial pressures were higher and diastolic pressures lower (70.4 ± 11.5 vs. 71.5 ± 9.8 mmHg;p < 0.001). The reproducibility of the Finapres and invasive method was similar for systolic (4.6% vs. 4.0%), diastolic (2.8% vs. 2.7%) and mean (3.3% vs. 3.0%) blood pressures. Second, in seven subjects studied twice at rest and during 4 min supine bicycle exercise, the exercise increase in blood pressure was greater on the Finapres compared with the brachial intra-arterial pressure (systolic +10.2 ± 6.3 vs. +3.6 ± 9.8 mmHg; diastolic +9.6 ± 11.1 vs. +0.2 ± 2.1 mmHg;p = 0.02 for each); however, at steady-state the peak/trough differences in pressure between the methods were similar. Thirdly, compared under rest conditions, to random zero sphygmomanometer (RZO), the Finapres systolic pressure was higher (6.8 ± 3.5 mmHg) and diastolic pressure lower (–6.0 ± 1.9 mmHg). During upright bicycle exercise, the difference between the Finapres and RZO in systolic blood pressure increased at each level of exercise (+14.3 ± 4.2, +17.9 ± 4.0 and +22.2 ± 4.1 mmHg respectively at each exercise stage:p < 0.01). For RZO, diastolic blood pressure fell as exercise workload increased whereas Finapres diastolic blood pressure increased on exercise (3.1 ± 2.6, 7.0 ± 2.1 and 8.1 ± 2.0 mmHg respectively:p < 0.01). Thus there were systematic differences between the values recorded by the Finapres and proximal blood pressure methods and limited agreement in the rest to exercise increments related to light exercise. Calibration of the Finapres values in terms of the other methods is limited by the variable relationship to these related changes in arterial distensibility. 相似文献
58.
59.
60.
A mother affected with Apert's syndrome was diagnosed by ultrasound scan at 16-17 weeks to have a fetus similarly affected. The typical features of acrocephaly and symmetrical syndactyly were seen. This is probably the first time that this condition has been diagnosed at such a gestation by ultrasound scan. The patient decided to continue the pregnancy, and intrauterine death occurred at 34 weeks. The diagnosis was confirmed by pathological examination. 相似文献