全文获取类型
收费全文 | 10111篇 |
免费 | 959篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 280篇 |
妇产科学 | 183篇 |
基础医学 | 1345篇 |
口腔科学 | 263篇 |
临床医学 | 1135篇 |
内科学 | 1747篇 |
皮肤病学 | 207篇 |
神经病学 | 1061篇 |
特种医学 | 604篇 |
外科学 | 1430篇 |
综合类 | 305篇 |
一般理论 | 6篇 |
预防医学 | 1028篇 |
眼科学 | 239篇 |
药学 | 844篇 |
中国医学 | 13篇 |
肿瘤学 | 397篇 |
出版年
2022年 | 78篇 |
2021年 | 157篇 |
2020年 | 100篇 |
2019年 | 171篇 |
2018年 | 194篇 |
2017年 | 156篇 |
2016年 | 133篇 |
2015年 | 178篇 |
2014年 | 224篇 |
2013年 | 343篇 |
2012年 | 551篇 |
2011年 | 543篇 |
2010年 | 266篇 |
2009年 | 286篇 |
2008年 | 489篇 |
2007年 | 534篇 |
2006年 | 572篇 |
2005年 | 515篇 |
2004年 | 470篇 |
2003年 | 421篇 |
2002年 | 402篇 |
2001年 | 271篇 |
2000年 | 225篇 |
1999年 | 245篇 |
1998年 | 175篇 |
1997年 | 167篇 |
1996年 | 143篇 |
1995年 | 125篇 |
1994年 | 109篇 |
1993年 | 119篇 |
1992年 | 184篇 |
1991年 | 186篇 |
1990年 | 150篇 |
1989年 | 191篇 |
1988年 | 163篇 |
1987年 | 177篇 |
1986年 | 146篇 |
1985年 | 158篇 |
1984年 | 111篇 |
1983年 | 110篇 |
1982年 | 74篇 |
1981年 | 69篇 |
1980年 | 82篇 |
1979年 | 99篇 |
1978年 | 71篇 |
1977年 | 80篇 |
1976年 | 55篇 |
1975年 | 62篇 |
1974年 | 68篇 |
1973年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Macrae DJ 《Proceedings of the American Thoracic Society》2007,4(2):176-8, discussion 178-9
Numerous bodies from many countries, including governments, government regulatory departments, research organizations, medical professional bodies, and health care providers, have issued guidance or legislation on the ethical conduct of clinical trials. It is possible to trace the development of current guidelines back to the post-World War II Nuremburg war crimes trials, more specifically the "Doctors' Trial." From that trial emerged the Nuremburg Code, which set out basic principles to be observed when conducting research involving human subjects and which subsequently formed the basis for comprehensive international guidelines on medical research, such as the Declaration of Helsinki. Most recently, the Council for International Organizations and Medical Sciences (CIOMS) produced detailed guidelines (originally published in 1993 and updated in 2002) on the implementation of the principles outlined in the Declaration of Helsinki. The CIOMS guidelines set in an appropriate context the challenges of present-day clinical research, by addressing complex issues including HIV/AIDS research, availability of study treatments after a study ends, women as research subjects, safeguarding confidentiality, compensation for adverse events, as well guidelines on consent. 相似文献
952.
953.
954.
955.
956.
Christopher P. Derry A. Simon Harvey Matthew C. Walker John S. Duncan Samuel F. Berkovic 《Sleep》2009,32(12):1637-1644
Study Objectives.
To describe the semiological features of NREM arousal parasomnias in detail and identify features that can be used to reliably distinguish parasomnias from nocturnal frontal lobe epilepsy (NFLE).Design.
Systematic semiologial evaluation of parasomnias and NFLE seizures recorded on video-EEG monitoring.Patients.
120 events (57 parasomnias, 63 NFLE seizures) from 44 subjects (14 males).Interventions.
The presence or absence of 68 elemental clinical features was determined in parasomnias and NFLE seizures. Qualitative analysis of behavior patterns and ictal EEG was undertaken. Statistical analysis was undertaken using established techniques.Results.
Elemental clinical features strongly favoring parasomnias included: interactive behavior, failure to wake after event, and indistinct offset (all P < 0.001). Cluster analysis confirmed differences in both the frequency and combination of elemental features in parasomnias and NFLE. A diagnostic decision tree generated from these data correctly classified 94% of events. While sleep stage at onset was discriminatory (82% of seizures occurred during stage 1 or 2 sleep, with 100% of parasomnias occurring from stage 3 or 4 sleep), ictal EEG features were less useful. Video analysis of parasomnias identified three principal behavioral patterns: arousal behavior (92% of events); non-agitated motor behavior (72%); distressed emotional behavior (51%).Conclusions
Our results broadly support the concept of confusion arousals, somnambulism and night terrors as prototypical behavior patterns of NREM parasomnias, but as a hierarchical continuum rather than distinct entities. Our observations provide an evidence base to assist in the clinical diagnosis of NREM parasomnias, and their distinction from NFLE seizures, on semiological grounds.Citation:
Derry CP; Harvey AS; Walker MC; Duncan JS; Berkovic SF. NREM arousal parasomnias and their distinction from nocturnal frontal lobe epilepsy: a video EEG analysis. SLEEP 2009;32(12):1637-1644. 相似文献957.
958.
959.
Roopun AK Traub RD Baldeweg T Cunningham MO Whittaker RG Trevelyan A Duncan R Russell AJ Whittington MA 《Epilepsy & behavior : E&B》2009,14(Z1):39-46
Many types of electrographic seizures are readily identifiable by direct visual examination of electroencephalographic or electrocorticographic recordings. This process can, however, be painstakingly slow, and much effort has been expended to automate the process using various dynamic properties of epileptiform waveforms. As methods have become more subtle and powerful they have been used for seizure subclassification, seizure prediction, and seizure onset identification and localization. Here we concentrate on the last, with reference to seizures of neocortical origin. We briefly review some of the methods used and introduce preliminary results from a very simple dynamic model based on key electrophysiological properties found in some seizure types: occurrence of very fast oscillations (sometimes called ripples), excess gamma frequency oscillations, electroencephalographic/electrocorticographic flattening, and changes in global synchrony. We show how this multiscale analysis may reveal features unique to seizure onset and speculate on the underlying cellular and network phenomena responsible. 相似文献
960.
Bonelli SB Powell R Yogarajah M Thompson PJ Symms MR Koepp MJ Duncan JS 《Epilepsia》2009,50(2):217-227
Purpose: Anterior temporal lobe resections (ATLR) benefit 70% of patients with refractory mesial temporal lobe epilepsy (TLE), but may be complicated by emotional disturbances. We used functional magnetic resonance imaging (fMRI) to investigate the role of the amygdala in processing emotions in TLE and whether this may be a potential preoperative predictive marker for emotional disturbances following surgery.
Methods: We studied 54 patients with refractory mesial TLE due to hippocampal sclerosis (28 right, 26 left) and 21 healthy controls using a memory encoding fMRI paradigm, which included viewing fearful and neutral faces. Twenty-one TLE patients (10 left, 11 right) subsequently underwent ATLR. Anxiety and depression were assessed preoperatively and 4 months postoperatively using the Hospital Anxiety and Depression Scale.
Results: On viewing fearful faces, healthy controls demonstrated left lateralized, while right TLE patients showed bilateral amygdala activation. Left TLE patients had significantly reduced activation in left and right amygdalae compared to controls and right TLE patients. In right TLE patients, left and right amygdala activation was significantly related to preoperative anxiety and depression levels, and preoperative right amygdala activation correlated significantly with postoperative change of anxiety and depression scores, characterized by greater increases in anxiety and depression in patients with greater preoperative activation. No such correlations were seen for left TLE patients.
Discussion: The fearful face fMRI paradigm is a reliable method for visualizing amygdala activation in controls and patients with mesial TLE. Activation of the right amygdala preoperatively was predictive of emotional disturbances following right ATLR. 相似文献
Methods: We studied 54 patients with refractory mesial TLE due to hippocampal sclerosis (28 right, 26 left) and 21 healthy controls using a memory encoding fMRI paradigm, which included viewing fearful and neutral faces. Twenty-one TLE patients (10 left, 11 right) subsequently underwent ATLR. Anxiety and depression were assessed preoperatively and 4 months postoperatively using the Hospital Anxiety and Depression Scale.
Results: On viewing fearful faces, healthy controls demonstrated left lateralized, while right TLE patients showed bilateral amygdala activation. Left TLE patients had significantly reduced activation in left and right amygdalae compared to controls and right TLE patients. In right TLE patients, left and right amygdala activation was significantly related to preoperative anxiety and depression levels, and preoperative right amygdala activation correlated significantly with postoperative change of anxiety and depression scores, characterized by greater increases in anxiety and depression in patients with greater preoperative activation. No such correlations were seen for left TLE patients.
Discussion: The fearful face fMRI paradigm is a reliable method for visualizing amygdala activation in controls and patients with mesial TLE. Activation of the right amygdala preoperatively was predictive of emotional disturbances following right ATLR. 相似文献