全文获取类型
收费全文 | 25101篇 |
免费 | 2515篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 228篇 |
儿科学 | 692篇 |
妇产科学 | 590篇 |
基础医学 | 3431篇 |
口腔科学 | 609篇 |
临床医学 | 2940篇 |
内科学 | 5203篇 |
皮肤病学 | 352篇 |
神经病学 | 2516篇 |
特种医学 | 782篇 |
外科学 | 3274篇 |
综合类 | 581篇 |
一般理论 | 16篇 |
预防医学 | 2583篇 |
眼科学 | 457篇 |
药学 | 2163篇 |
1篇 | |
中国医学 | 29篇 |
肿瘤学 | 1194篇 |
出版年
2021年 | 370篇 |
2020年 | 209篇 |
2019年 | 367篇 |
2018年 | 417篇 |
2017年 | 340篇 |
2016年 | 323篇 |
2015年 | 378篇 |
2014年 | 532篇 |
2013年 | 793篇 |
2012年 | 1141篇 |
2011年 | 1197篇 |
2010年 | 686篇 |
2009年 | 572篇 |
2008年 | 1026篇 |
2007年 | 1203篇 |
2006年 | 1127篇 |
2005年 | 1172篇 |
2004年 | 1033篇 |
2003年 | 1092篇 |
2002年 | 978篇 |
2001年 | 689篇 |
2000年 | 695篇 |
1999年 | 599篇 |
1998年 | 284篇 |
1997年 | 228篇 |
1996年 | 214篇 |
1995年 | 252篇 |
1994年 | 229篇 |
1992年 | 522篇 |
1991年 | 483篇 |
1990年 | 462篇 |
1989年 | 457篇 |
1988年 | 417篇 |
1987年 | 425篇 |
1986年 | 373篇 |
1985年 | 438篇 |
1984年 | 379篇 |
1983年 | 298篇 |
1982年 | 290篇 |
1981年 | 237篇 |
1980年 | 242篇 |
1979年 | 347篇 |
1978年 | 296篇 |
1977年 | 211篇 |
1976年 | 242篇 |
1975年 | 213篇 |
1974年 | 276篇 |
1973年 | 284篇 |
1972年 | 232篇 |
1971年 | 214篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Matthew S Lewis Paul Maruff Brendan S Silbert Lis A Evered David A Scott 《Archives of clinical neuropsychology》2006,21(5):421-427
The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of post-operative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. These rules are applied to 160 patients undergoing coronary artery bypass graft (CABG) surgery who completed neuropsychological assessments preoperatively and 1 week post-operatively using error and reliability data from a comparable healthy non-surgical control group. The rules all identify POCD in a similar proportion of patients, but the use of the within subject standard deviation, expressing the effects of random error, as an error estimate is a theoretically appropriate denominator when a constant error correction, removing the effects of systematic error, is deducted from the numerator in a RCI. 相似文献
2.
Improved graft survival for flow cytometry and antihuman globulin crossmatch-negative retransplant recipients 总被引:1,自引:0,他引:1
R H Kerman C T Van Buren R M Lewis V DeVera V Baghdahsarian K Gerolami B D Kahan 《Transplantation》1990,49(1):52-56
We compared our standard NIH (extended incubation) crossmatch (XM) with antihuman globulin (AHG) and flow cytometry XMs and correlated the results with rejection episodes and graft survivals. For 89 CsA-Pred, primary renal allograft recipients, AHG and/or FCXM results did not improve on the NIH-XM-negative (NEG) graft survival results, whether testing pretransplant or historical (Hx) sera. Similarly, there was no association of a positive (POS) AHG or FCXM with increased rejection episodes in these primary recipients. However, for retransplant (Re-Tx) recipients a neg AHG or FCXM did discriminate fewer rejections and an improved graft survival compared with the NIH-XM-neg. results. The overall one-year graft survival for the 47 Re-Tx recipients studied herein was 66% (based on a neg pre-Tx NIH-XM). Pre-Tx AHG-NEG, Re-Tx recipients displayed an improved graft survival compared with NIH-XM NEG recipients (77% vs. 66%, P less than 0.05) and with AHG-POS recipients (77% vs. 47%, P less than 0.05). Similarly, pre-Tx, FCXM-NEG, Re-Tx recipients displayed improved graft survivals compared with NIH-XM-NEG recipients (83% vs. 66%, P less than 0.05) and FCXM-POS recipients (83% vs. 48%, P less than 0.05). Re-Tx recipients displaying a POS AHG and/or FCXM experienced a significantly greater number of rejections than NEG-XM recipients (P less than 0.05, respectively). The AHG and FCXM results correlated with rejections and graft survivals whether testing pre-Tx or Hx high-PRA sera. Re-Tx recipients who were AHG-XM-NEG but FCXM-POS, experienced more rejection episodes than recipients who displayed a negative XM reactivity for both AHG and FCXM (P less than 0.02), but with no resulting differences in graft survival. HLA matching, pre-Tx blood transfusions and PRA did not impact on these crossmatch and graft survival results. Use of AHG and/or FCXMs for Re-Tx, but not primary, recipients should help to improve graft survival for these high-risk recipients. 相似文献
3.
The Brief Symptom Inventory (BSI), a 53-item psychiatric symptom checklist, was administered to 57 alcoholic inpatients on days 2, 10, 18 and 26 of their 28-day stay in an alcoholism rehabilitation unit at a Veterans Administration hospital. The results of the test show a steady decline in the patients' psychiatric symptomatology from week 1 to week 4 with the most dramatic improvement evidenced between weeks 1 and 2. 相似文献
4.
5.
P J Landrigan M G Cherniack F A Lewis L R Catlett R W Hornung 《Scandinavian journal of work, environment & health》1986,12(1):32-39
An industrial hygiene and medical survey was conducted in an iron foundry to study the occurrence of silicosis. Breathing zone exposures to respirable crystalline silica had been very high in 1977 [1 045 micrograms/m3 (geometric mean) for coremakers and 198 micrograms/m3 for fettlers]; exposures in 1980 and 1982 were substantially lower. A radiographic evaluation of 188 workers revealed silicosis in 18 (9.6%). Eight had category 1 profusion of small rounded pulmonary lesions (by the 1980 classification of the International Labour Office); two had category 2; and eight had category 3. Two had progressive massive fibrosis. Four workers without silicosis in 1977 had developed lesions by 1980. The prevalence increased from 1.5% among workers employed less than 20 years to 53% among longer term workers. No association was found between the prevalence of silicosis and cigarette smoking. Chronic cough was more common in workers with heavy current dust exposure than in those with light exposure, more common in smokers than in nonsmokers, and more common in silicotics than in nonsilicotics. A multiplicative interaction existed between dust exposure and smoking in the etiology of cough. Silicosis continues to exist in American foundries. Cigarette smoking does not contribute to the causation of silicosis, but it aggravates the attendant respiratory symptoms. 相似文献
6.
7.
A G Lewis 《Postgraduate medicine》1989,86(3):141-4, 147-51
Initial assessment of common forefoot deformities by the primary care physician is quite feasible. A thorough history, examination of the foot with the patient standing and seated, assessment of the patient's footwear, and radiographic evaluation can often lead to gratifying relief with use of simple office measures. Even in cases that require referral to an orthopedic surgeon, interim relief of symptoms and the patient's increased awareness of the problem and its cause enhance the patient's understanding and the final outcome as well. 相似文献
8.
Scalp electrical recording during paralysis: quantitative evidence that EEG frequencies above 20 Hz are contaminated by EMG. 总被引:2,自引:0,他引:2
Emma M Whitham Kenneth J Pope Sean P Fitzgibbon Trent Lewis C Richard Clark Stephen Loveless Marita Broberg Angus Wallace Dylan DeLosAngeles Peter Lillie Andrew Hardy Rik Fronsko Alyson Pulbrook John O Willoughby 《Clinical neurophysiology》2007,118(8):1877-1888
OBJECTIVE: To identify the possible contribution of electromyogram (EMG) to scalp electroencephalogram (EEG) rhythms at rest and induced or evoked by cognitive tasks. METHODS: Scalp EEG recordings were made on two subjects in presence and absence of complete neuromuscular blockade, sparing the dominant arm. The subjects undertook cognitive tasks in both states to allow direct comparison of electrical recordings. RESULTS: EEG rhythms in the paralysed state differed significantly compared with the unparalysed state, with 10- to 200-fold differences in the power of frequencies above 20 Hz during paralysis. CONCLUSIONS: Most of the scalp EEG recording above 20 Hz is of EMG origin. Previous studies measuring gamma EEG need to be re-evaluated. SIGNIFICANCE: This has a significant impact on measurements of gamma rhythms from the scalp EEG in unparalysed humans. It is to be hoped that signal separation methods will be able to rectify this situation. 相似文献
9.
10.
A technique for arthrodesis of small joints of the hand is described that uses a tenon to secure apposition that has good intrinsic stability as well as a large surface area of cancellous bony contact. A minimum of postoperative immobilization is required. The tenon arthrodesis method has been employed in 85 joints. The literature shows pseudoarthrosis rates of 0 to 33%. This technique had a 2.3% failure rate that compares favorably with those in other published series. 相似文献