全文获取类型
收费全文 | 48946篇 |
免费 | 3185篇 |
国内免费 | 188篇 |
专业分类
耳鼻咽喉 | 524篇 |
儿科学 | 1235篇 |
妇产科学 | 858篇 |
基础医学 | 6395篇 |
口腔科学 | 1252篇 |
临床医学 | 4751篇 |
内科学 | 9949篇 |
皮肤病学 | 725篇 |
神经病学 | 4778篇 |
特种医学 | 2551篇 |
外国民族医学 | 6篇 |
外科学 | 7227篇 |
综合类 | 592篇 |
一般理论 | 40篇 |
预防医学 | 4018篇 |
眼科学 | 1199篇 |
药学 | 2925篇 |
中国医学 | 69篇 |
肿瘤学 | 3225篇 |
出版年
2023年 | 206篇 |
2022年 | 348篇 |
2021年 | 807篇 |
2020年 | 612篇 |
2019年 | 810篇 |
2018年 | 951篇 |
2017年 | 773篇 |
2016年 | 914篇 |
2015年 | 1050篇 |
2014年 | 1468篇 |
2013年 | 2043篇 |
2012年 | 3102篇 |
2011年 | 3285篇 |
2010年 | 1866篇 |
2009年 | 1708篇 |
2008年 | 3054篇 |
2007年 | 3146篇 |
2006年 | 3104篇 |
2005年 | 3037篇 |
2004年 | 2843篇 |
2003年 | 2758篇 |
2002年 | 2655篇 |
2001年 | 619篇 |
2000年 | 573篇 |
1999年 | 637篇 |
1998年 | 601篇 |
1997年 | 468篇 |
1996年 | 421篇 |
1995年 | 403篇 |
1994年 | 322篇 |
1993年 | 292篇 |
1992年 | 371篇 |
1991年 | 338篇 |
1990年 | 308篇 |
1989年 | 325篇 |
1988年 | 292篇 |
1987年 | 309篇 |
1986年 | 279篇 |
1985年 | 300篇 |
1984年 | 305篇 |
1983年 | 292篇 |
1982年 | 318篇 |
1981年 | 297篇 |
1980年 | 263篇 |
1979年 | 225篇 |
1978年 | 233篇 |
1977年 | 195篇 |
1976年 | 168篇 |
1975年 | 177篇 |
1974年 | 183篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Unique variant of partial anomalous pulmonary venous connection with intact atrial septum 总被引:1,自引:0,他引:1
Summary Partial anomalous pulmonary venous connections (PAPVCs) are rare in association with an intact atrial septum. However, the diagnosis should be considered in patients with otherwise unexplained findings of left-to-right shunt and right heart enlargement. An unusual variant is presented, which we considered unsuitable for operative repair, based on findings at catheterization. Developmental, hemodynamic, and surgical considerations are discussed. 相似文献
42.
43.
Abstract: Lobular carcinoma in situ (LCIS) has gone from a rare form of mammary cancer to a marker of increased risk. Treatment options have undergone a corresponding change from ipsilateral mastectomy with axillary node dissection to observation once it became clear that the majority of patients did not progress to invasive cancer. However, recent events suggest a re-evaluation of LCIS management options. It is clear that even meticulous observation may fail to detect invasive cancer before systemic spread has taken place. This fact plus the identification of breast cancer genes have brought a renewed interest in prophylactic mastectomy. At the same time pathologists feel that it is possible to identify microscopic features of LCIS pointing to an increased likelihood of developing invasive cancer. As a result physicians are being asked to better quantitate risks for individual patients. Most patients with LCIS do not need bilateral mastectomies, but we are coming closer to identifying the minority that would be better served by prophylactic surgery. 相似文献
44.
45.
46.
Frank de Vocht Berna van-Wendel-de-Joode Hans Engels Hans Kromhout 《Magnetic resonance in medicine》2003,50(4):670-674
The interactive use of magnetic resonance imaging (MRI) techniques is increasing in operating theaters. A study was performed on 17 male company volunteers to assess the neurobehavioral effects of exposure to magnetic fields from a 1.5 Tesla MRI system. The subjects' neurobehavioral performances on a neurobehavioral test battery were compared in four 1-hr sessions with and without exposure to magnetic fields, and with and without additional movements. Adverse effects were found for hand coordination (-4%, P < 0.05; Pursuit Aiming II) and near visual contrast sensitivity (-16% and -15%, P < 0.10; Vistech 6000). The results from the remaining tests were inconclusive due to a strong learning effect. No additional effect from gradient fields was detected. The results indicate that working near a 1.5 Tesla MRI system may lead to neurobehavioral effects. Further research is recommended, especially in members of operating teams using interactive MRI systems. 相似文献
47.
G L Garamoni C F Reynolds M E Thase E Frank S R Berman A L Fasiczka 《Psychiatry research》1991,39(2):99-108
The States of Mind (SOM) model provided a framework for assessing the balance between self-reported positive and negative affects in a sample of 39 outpatients with major depression and 43 healthy control subjects. The SOM model proposes that healthy functioning is characterized by an optimal balance of positive (P) and negative (N) cognitions or affects (P/(P + N) approximately 0.63), and that psychopathology is marked by deviations from the optimal balance. Research thus far has focused on the functional significance of cognitive rather than affective balance. Within this framework, we hypothesized that patients in untreated episodes of major depression would balance their positive and negative affects at the same level where depressed patients in other studies have balanced their positive and negative cognitions--namely, at P/(P + N) approximately 0.37. Points and confidence interval (CI) estimation procedures yielded results (mean = 0.35, 95% CI = 0.30 - 0.40) consistent with this hypothesis in a sample of 39 depressed male outpatients. Correlational analysis indicated that affect balance is inversely related to symptom severity as measured by self-report (Beck) and clinician-rating (Hamilton) scales. 相似文献
48.
49.
Burst-suppression EEG (BS-EEG) after cardiopulmonary resuscitation implies a bad prognosis, but little is known of the temporal dynamics of postanoxic BS-EEG. The authors studied 24 consecutive patients who developed BS-EEG within 24 hours after cardiopulmonary resuscitation, and followed 20 of these patients with serial EEGs. Except for one patient, BS-EEG was followed by another EEG pattern within 1 day, mainly areactive alpha EEG (n = 6), isoelectric EEG (n = 5), generalized continuous epileptiform discharges (n = 4), or theta; EEG (n = 3). The coexistence of different EEG patterns in the same recording was seen in 10 patients. Serial recordings disclosed a variety of EEG sequences with (often subtle) transitions between the different EEG patterns, including reappearance of BS-EEG. Postanoxic BS-EEG is followed by a variety of EEG sequences composed of different EEG patterns, each of which is recognized as an unfavorable sign in and of itself. The coexistence of different unfavorable EEG patterns in the same recording, and transitions between these EEG patterns in subsequent recordings, are common in patients with postanoxic BS-EEG. It seems reasonable to speculate that BS-EEG and subsequently evolving EEG patterns in anoxic encephalopathy reflect different forms of neocortical dysfunction, which occur at different stages of a dynamic process, leading ultimately to severe neuronal loss. 相似文献
50.