全文获取类型
收费全文 | 1740篇 |
免费 | 60篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 55篇 |
妇产科学 | 31篇 |
基础医学 | 156篇 |
口腔科学 | 39篇 |
临床医学 | 207篇 |
内科学 | 464篇 |
皮肤病学 | 19篇 |
神经病学 | 105篇 |
特种医学 | 243篇 |
外科学 | 185篇 |
综合类 | 16篇 |
预防医学 | 89篇 |
眼科学 | 37篇 |
药学 | 62篇 |
肿瘤学 | 81篇 |
出版年
2023年 | 9篇 |
2022年 | 7篇 |
2021年 | 22篇 |
2020年 | 12篇 |
2019年 | 30篇 |
2018年 | 35篇 |
2017年 | 26篇 |
2016年 | 28篇 |
2015年 | 29篇 |
2014年 | 36篇 |
2013年 | 62篇 |
2012年 | 65篇 |
2011年 | 79篇 |
2010年 | 70篇 |
2009年 | 60篇 |
2008年 | 83篇 |
2007年 | 103篇 |
2006年 | 90篇 |
2005年 | 71篇 |
2004年 | 84篇 |
2003年 | 57篇 |
2002年 | 65篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 16篇 |
1998年 | 51篇 |
1997年 | 53篇 |
1996年 | 52篇 |
1995年 | 45篇 |
1994年 | 44篇 |
1993年 | 26篇 |
1992年 | 20篇 |
1991年 | 14篇 |
1990年 | 18篇 |
1989年 | 22篇 |
1988年 | 38篇 |
1987年 | 20篇 |
1986年 | 31篇 |
1985年 | 28篇 |
1984年 | 20篇 |
1983年 | 18篇 |
1982年 | 16篇 |
1981年 | 7篇 |
1980年 | 12篇 |
1977年 | 9篇 |
1976年 | 11篇 |
1975年 | 7篇 |
1970年 | 9篇 |
1967年 | 8篇 |
1965年 | 9篇 |
排序方式: 共有1806条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
An increasing array of treatments such as immunosuppressive drugs and tumor necrosis factor inhibitors can offer patients with ulcerative colitis and Crohn disease improved relief from symptoms with fewer adverse effects. Several additional drugs have shown promise, including nicotine, antimicrobials, and heparin. 相似文献
65.
New biomarkers in the risk stratification of patients with suspected acute myocardial infarction 总被引:1,自引:0,他引:1
The acute coronary syndromes (ACS) remain a diagnostic and prognostic challenge for today’s physician. Over the past decade,
studies have identified several serologic biomarkers to aid the clinician in assessing risk and predicting outcomes in ACS.
Still others are being identified that show promise for increasing the accuracy with which this risk is assessed. However,
further research remains necessary to identify the perfect cardiac biomarker or combination of markers and to define their
roles in clinical management of ACS patients. 相似文献
66.
Cerebral metastases as first symptom of bronchogenic carcinoma. A prospective study of 37 cases 总被引:1,自引:0,他引:1
V Trillet J F Catajar B Croisile F Turjman G Aimard C Bourrat P Bret C Carrie J L Chassard F Chauvin 《Cancer》1991,67(11):2935-2940
Among the patients showing evidence of cerebral metastases without previously known cancer history, lung cancer has been found 37 times as the primary tumor in our institution. There were 34 men and three women and all but two were heavy smokers. Only one presented at diagnosis with thoracic symptoms but the chest radiograph was abnormal in 34. The histologic type of the primary tumor was obtained in 32 cases as a result of thoracic investigations and in five cases from metastatic tumor tissue. The primary tumor appeared to be non-small cell lung carcinoma in 26 cases and small cell lung carcinoma in 11 cases. These results show that patients treated with surgery (20 cases) have a better survival (median 10 months versus 4.5) than the others, and among surgically treated patients only those treated with bifocal resection (eight patients) are long-term survivors. Also, in four of six patients, objective regression of the neurologic symptoms was seen after radiation therapy alone. Central nervous system relapse was seen in 12 patients, but in none of the patients treated with postoperative radiation therapy. Conventional chemotherapy (11 patients) induced objective responses only in the small cell type and proved to be too toxic when used simultaneously with radiation therapy in inoperable patients. 相似文献
67.
Anna Marie Chang Judd E. Hollander Erica Su Robert E. Weiss Annick N. Yagapen Susan E. Malveau David H. Adler Aveh Bastani Christopher W. Baugh Jeffrey M. Caterino Carol L. Clark Deborah B. Diercks Bret A. Nicks Daniel K. Nishijima Manish N. Shah Kirk A. Stiffler Alan B. Storrow Scott T. Wilber Benjamin C. Sun 《The American journal of emergency medicine》2019,37(5):869-872
Almost 20% of patients with syncope will experience another event. It is unknown whether recurrent syncope is a marker for a higher or lower risk etiology of syncope. The goal of this study is to determine whether older adults with recurrent syncope have a higher likelihood of 30-day serious clinical events than patients experiencing their first episode.
Methods
This study is a pre-specified secondary analysis of a multicenter prospective, observational study conducted at 11 emergency departments in the US. Adults 60?years or older who presented with syncope or near syncope were enrolled. The primary outcome was occurrence of 30-day serious outcome. The secondary outcome was 30-day serious cardiac arrhythmia. In multivariate analysis, we assessed whether prior syncope was an independent predictor of 30-day serious events.Results
The study cohort included 3580 patients: 1281 (35.8%) had prior syncope and 2299 (64.2%) were presenting with first episode of syncope. 498 (13.9%) patients had 1 prior episode while 771 (21.5%) had >1 prior episode. Those with recurrent syncope were more likely to have congestive heart failure, coronary artery disease, previous diagnosis of arrhythmia, and an abnormal ECG. Overall, 657 (18.4%) of the cohort had a serious outcome by 30?days after index ED visit. In multivariate analysis, we found no significant difference in risk of events (adjusted odds ratio 1.09; 95% confidence interval 0.90–1.31; p?=?0.387).Conclusion
In older adults with syncope, a prior history of syncope within the year does not increase the risk for serious 30-day events. 相似文献68.
69.
Kenneth Wengler Brandon K. Ashinoff Elena Pueraro Clifford M. Cassidy Guillermo Horga Bret R. Rutherford 《Neuropsychopharmacology》2021,46(7):1233
Late-life depression (LLD) is a prevalent and disabling condition in older adults that is often accompanied by slowed processing and gait speed. These symptoms are related to impaired dopamine function and sometimes remedied by levodopa (L-DOPA). In this study, we recruited 33 older adults with LLD to determine the association between a proxy measure of dopamine function—neuromelanin-sensitive magnetic resonance imaging (NM-MRI)—and baseline slowing measured by the Digit Symbol test and a gait speed paradigm. In secondary analyses, we also assessed the ability of NM-MRI to predict L-DOPA treatment response in a subset of these patients (N = 15) who received 3 weeks of L-DOPA. We scanned a further subset of these patients (N = 6) with NM-MRI at baseline and after treatment to preliminarily evaluate the effects of L-DOPA treatment on the NM-MRI signal. We found that lower baseline NM-MRI correlated with slower baseline gait speed (346 of 1807 substantia nigra–ventral tegmental area (SN-VTA) voxels, Pcorrected = 0.038), particularly in the more medial, anterior, and dorsal SN-VTA. Secondary analyses failed to show an association between baseline NM-MRI and treatment-related changes in gait speed, processing speed, or depression severity (all Pcorrected > 0.361); we however found preliminary evidence of increases in the NM-MRI signal 3 weeks post-treatment with L-DOPA compared to baseline (200 of 1807 SN-VTA voxels; Pcorrected = 0.046), although the small sample size of these preliminary analyses warrants caution in their interpretation and future replications. Overall, our findings indicate that NM-MRI is sensitive to variability in gait speed in patients with LLD, suggesting this non-invasive MRI measure may provide a promising marker for dopamine-related psychomotor slowing in geriatric neuropsychiatry.Subject terms: Cognitive neuroscience, Depression, Biomarkers 相似文献
70.