全文获取类型
收费全文 | 13313篇 |
免费 | 963篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 93篇 |
儿科学 | 515篇 |
妇产科学 | 227篇 |
基础医学 | 1519篇 |
口腔科学 | 251篇 |
临床医学 | 1250篇 |
内科学 | 2988篇 |
皮肤病学 | 221篇 |
神经病学 | 1681篇 |
特种医学 | 456篇 |
外国民族医学 | 1篇 |
外科学 | 2000篇 |
综合类 | 190篇 |
一般理论 | 5篇 |
预防医学 | 1067篇 |
眼科学 | 202篇 |
药学 | 815篇 |
中国医学 | 9篇 |
肿瘤学 | 838篇 |
出版年
2021年 | 150篇 |
2020年 | 122篇 |
2019年 | 179篇 |
2018年 | 189篇 |
2017年 | 186篇 |
2016年 | 191篇 |
2015年 | 208篇 |
2014年 | 308篇 |
2013年 | 413篇 |
2012年 | 611篇 |
2011年 | 652篇 |
2010年 | 367篇 |
2009年 | 336篇 |
2008年 | 614篇 |
2007年 | 619篇 |
2006年 | 646篇 |
2005年 | 560篇 |
2004年 | 494篇 |
2003年 | 524篇 |
2002年 | 468篇 |
2001年 | 433篇 |
2000年 | 483篇 |
1999年 | 382篇 |
1998年 | 166篇 |
1997年 | 188篇 |
1996年 | 184篇 |
1995年 | 157篇 |
1994年 | 126篇 |
1993年 | 120篇 |
1992年 | 272篇 |
1991年 | 300篇 |
1990年 | 269篇 |
1989年 | 271篇 |
1988年 | 226篇 |
1987年 | 206篇 |
1986年 | 220篇 |
1985年 | 201篇 |
1984年 | 146篇 |
1983年 | 129篇 |
1982年 | 93篇 |
1981年 | 94篇 |
1979年 | 139篇 |
1978年 | 122篇 |
1977年 | 107篇 |
1976年 | 102篇 |
1975年 | 123篇 |
1974年 | 114篇 |
1973年 | 103篇 |
1972年 | 91篇 |
1970年 | 89篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Factors that determine the magnitude and time course of human H-reflexes in locomotion 总被引:7,自引:0,他引:7
The soleus H-reflex amplitude is deeply modulated during locomotion in humans (Capaday and Stein, 1986). Moreover, at a constant stimulus intensity, the slope of the relationship between the amplitude of the soleus H-reflex and the background electromyogram (EMG) changes with different locomotor tasks (Capaday and Stein, 1987a). Two further aspects are studied here. First, we recorded the reflex during overlapping speeds of walking (2.0-7.5 km/hr) and running (5-9 km/hr) to determine whether the speed, the motor output, or the form of locomotion was most important in setting the slope of this relationship between H-reflex and background EMG. Second, we determined the time course of change in the H-reflex amplitude and the possible site of action for the reflex depression during the transition from standing to walking. The primary determinant of the slope was found to be the form of locomotion. The differences between running and walking could not be explained entirely by either movement speed or motor output. For walking, the slope varied inversely with the speed and the motor output of locomotion. This compensation in slope as a function of motor output may prevent saturation of the motoneuron pool. The appropriate reflex amplitudes for a particular locomotor pattern are activated rapidly and completely within a reaction time, and simultaneously with the activation of muscle activity for the initiation of walking. Mechanisms for the rapid change seen during the initiation of locomotion most likely act presynaptically on the muscle spindle afferents. The time course and magnitude of this change are correlated with the activity of the tibialis anterior muscle. 相似文献
33.
34.
35.
Paradoxical movement in Parkinson's disease. 总被引:6,自引:0,他引:6
Patients with Parkinson's disease, although impaired, can sometimes move effectively under visual guidance. The stimuli that often elicit such paradoxical movement are similar to those that relay visual information to the cerebellum. We suggest that many instances of paradoxical movement may be explained by the fact that the pathways relaying those visual stimuli can bypass the damaged basal ganglia and allow an intact cerebellar circuit to be used for visuomotor control. 相似文献
36.
37.
A cancer-specific self-reporting quality of life questionnaire has been validated. The questionnaire is designed to assess physical functioning, role functioning, cognitive functioning, emotional functioning, social functioning, pain, fatigue, emesis and quality of life by means of multi-item scales, and other disease- and treatment-related symptoms by means of single items. The questionnaire was completed by 126 head and neck cancer patients with a mean age of 67 years. The internal consistency (scale reliability) was satisfactory for all scales but one. Correlations between scales and items assessing the same underlying dimension were also satisfactory. The questionnaire discriminates between patient subgroups and between acute, subacute and late toxicity. Patient compliance was high. The questionnaire provided valuable information, and most of the scales/items functioned well. A few problems were found, especially with the modified visual analogue scales, and minor modifications will be made. 相似文献
38.
39.
Summary. The increasing spectrum of therapeutic options for tumors of the gastrointestinal tract has resulted in a refinement of the
pretherapeutic diagnostic strategies. The diagnostic approach in surgical institutions that are focused on primary surgical
resection will therefore be much less sophisticated than in institutions who propose a selective therapeutic approach based
on the pretherapeutic tumor stage and prognostic parameters. Pretherapeutic assessment of the depth of tumor infiltration,
i. e. the T-category, is essential because most further diagnostic and therapeutic decisions are based on this information.
This can today be achieved with a high degree of accuracy by endoscopy and endoscopic ultrasonography. Early T-stages (T1–2)
are usually an indication for primary surgical resection and, after exclusion of distant metastases, no further diagnostic
studies are required. In patients with locally advanced esophageal, gastric or rectum tumors (T3–4) multimodal therapeutic
concepts should be considered. This usually requires additional diagnostic studies. None of the available diagnostic imaging
modalities today allows satisfactory pretherapeutic assessment of lymph node metastases. The assumed nodular status should
therefore currently not influence therapeutic decisions. Essential is, however, the assessment of distant metastases, since
the documentation of distant tumor spread will change the therapeutic approach to a palliative situation. Detailed histologic
and molecular-biologic assessment of tumor characteristics is growing in importance. This not only provides therapeutically
relevant information regarding tumor grading, but opens the door towards a modern molecular diagnostic approach. It can be
expected that in the near future a vast amount of relevant prognostic information can be obtained from endoscopic tumor biopsies,
which may soon alter our therapeutic concepts.
相似文献
40.