全文获取类型
收费全文 | 242092篇 |
免费 | 16271篇 |
国内免费 | 1472篇 |
专业分类
耳鼻咽喉 | 2457篇 |
儿科学 | 6673篇 |
妇产科学 | 4999篇 |
基础医学 | 32644篇 |
口腔科学 | 5535篇 |
临床医学 | 21906篇 |
内科学 | 52428篇 |
皮肤病学 | 4774篇 |
神经病学 | 23064篇 |
特种医学 | 9644篇 |
外国民族医学 | 29篇 |
外科学 | 35748篇 |
综合类 | 3524篇 |
现状与发展 | 2篇 |
一般理论 | 185篇 |
预防医学 | 16142篇 |
眼科学 | 4617篇 |
药学 | 17877篇 |
3篇 | |
中国医学 | 750篇 |
肿瘤学 | 16834篇 |
出版年
2023年 | 1072篇 |
2022年 | 1368篇 |
2021年 | 4440篇 |
2020年 | 2995篇 |
2019年 | 4303篇 |
2018年 | 5290篇 |
2017年 | 4090篇 |
2016年 | 4526篇 |
2015年 | 5261篇 |
2014年 | 7341篇 |
2013年 | 10198篇 |
2012年 | 15010篇 |
2011年 | 15844篇 |
2010年 | 9434篇 |
2009年 | 8724篇 |
2008年 | 14362篇 |
2007年 | 15211篇 |
2006年 | 14501篇 |
2005年 | 14554篇 |
2004年 | 14283篇 |
2003年 | 13671篇 |
2002年 | 13140篇 |
2001年 | 5154篇 |
2000年 | 4739篇 |
1999年 | 4516篇 |
1998年 | 3203篇 |
1997年 | 2495篇 |
1996年 | 2205篇 |
1995年 | 2050篇 |
1994年 | 1802篇 |
1993年 | 1754篇 |
1992年 | 2533篇 |
1991年 | 2525篇 |
1990年 | 2085篇 |
1989年 | 2021篇 |
1988年 | 1870篇 |
1987年 | 1740篇 |
1986年 | 1665篇 |
1985年 | 1561篇 |
1984年 | 1395篇 |
1983年 | 1253篇 |
1982年 | 1197篇 |
1981年 | 1081篇 |
1980年 | 949篇 |
1979年 | 928篇 |
1978年 | 788篇 |
1977年 | 768篇 |
1975年 | 705篇 |
1974年 | 727篇 |
1973年 | 676篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
992.
Jos F M de Jonghe Kees J Kalisvaart Marty Dijkstra Huib van Dis Ralph Vreeswijk Martin G Kat Piet Eikelenboom Tjeerd van der Ploeg Willem A van Gool 《The American journal of geriatric psychiatry》2007,15(2):112-121
OBJECTIVES: The authors investigated prodromal delirium symptoms in elderly patients undergoing hip surgery. METHODS: This was a prospective cohort study in the setting of a large medical school-affiliated general hospital in Alkmaar, The Netherlands. Participants were patients undergoing hip surgery aged 70 and older at risk for delirium. Before surgery, patients were randomized to low-dose prophylactic haloperidol treatment or placebo. Daily assessments were based on patient interviews with the Mini-Mental State Examination and Digit Span test. The Delirium Rating Scale-Revised (DRS-R-98) was used to measure early symptoms during the prodromal phase before the onset of delirium. RESULTS: Data of 66 patients with delirium were compared with those of 35 at-risk patients who did not develop delirium: 14 of 66 patients (21%) had delirium on the day of surgery or early the day after, 32 of 66 (48%) on the second day, 14 of 66 on the third, and six of 66 (9%) on the fourth. The average DRS-R-98 total scores on day -4 to day -1 before delirium were 1.9 for the comparison group patients and 5.0, 4.3, 5.8, and 10.7 for patients with postoperative delirium. Multivariate analysis showed that the early symptoms memory impairments, incoherence, disorientation, and underlying somatic illness predict delirium. CONCLUSIONS: Most elderly patients undergoing hip surgery with postoperative delirium already have early symptoms in the prodromal phase of delirium. These findings are potentially useful for screening purposes and for optimizing prevention strategies targeted at reducing the incidence of postoperative delirium. 相似文献
993.
R. Parker Ward MD Mouaz H. Al-Mallah MD Gabriel B. Grossman MD PhD Christopher L. Hansen MD Robert C. Hendel MD Todd C. Kerwin MD Benjamin D. McCallister Jr MD Rupa Mehta MD Donna M. Polk MD MPH Peter L. Tilkemeier MD Aseem Vashist MD Kim Allan Williams MD David G. Wolinsky MD Edward P. Ficaro PhD 《Journal of nuclear cardiology》2007,14(6):911-e38
994.
BACKGROUND: Long-term intra-oesophageal acid suppression with proton pump inhibitors represents a management option for Barrett's oesophagus and severe reflux oesophagitis, but its stability over time has not been adequately assessed. AIM: Our aim was to evaluate prospectively the efficacy of proton pump inhibitors in suppressing intra-oesophageal acidity after 2-year continuous treatment. METHODS: Forty-five patients with Barrett's oesophagus or severe reflux oesophagitis on a proton pump inhibitor regimen (once or twice daily) that normalised the total percentage acid exposure time were re-evaluated by means of 24-h oesophageal pH-monitoring after 2-year of continuous unmodified treatment. RESULTS: A significant rise in the total percentage acid exposure time was observed at 2-year follow-up (P=0.029), owing to an increased value in 27 (60%) cases (9 on a twice daily regimen), higher than normal in 10 of them (22% of the whole group) (3 on a twice daily regimen). In 18 patients (40%) the total percentage acid exposure time was stable or decreased. Heartburn remained efficiently suppressed in all patients. CONCLUSIONS: The efficacy of proton pump inhibitors in suppressing intra-oesophageal acidity during continuous treatment may decrease over time, up to abnormal levels of oesophageal acid exposure in a minority of cases. This may occur without heartburn recurrence and with both once and twice daily regimens. 相似文献
995.
Virginia L Willour Peter P Zandi Judith A Badner Jo Steele Kuangyi Miao Victor Lopez Dean F MacKinnon Francis M Mondimore Barbara Schweizer Melvin G McInnis Erin B Miller J Raymond Depaulo Elliot S Gershon Francis J McMahon James B Potash 《Neuropsychopharmacology》2007,61(5):725-727
BACKGROUND: We are interested in identifying susceptibility genes that predispose subjects to attempted suicide. METHODS: We conducted a secondary analysis of genome-wide linkage data from 162 bipolar pedigrees that incorporated attempted suicide as a clinical covariate. RESULTS: The strongest covariate-based linkage signal was seen on 2p12 at marker D2S1777. The logarithm of odds (LOD) score at marker D2S1777 rose from 1.56 to 3.82 after inclusion of the suicide covariate, resulting in significant chromosome-wide empirically derived p-values for the overall linkage finding (p = .01) and for the change in LOD score after the inclusion of the covariate (p = .02). CONCLUSIONS: The finding on chromosome 2 replicates results from two previous studies of attempted suicide in pedigrees with alcohol dependence and in pedigrees with recurrent early-onset depression. Combined, these three studies provide compelling evidence for a locus influencing attempted suicide on 2p12. 相似文献
996.
Jean-Marie Boeynaems Anne De Leener Barbara Dessars Hector Rodriguez Villa-Lobos Jean-Claude Aubry Frédéric Cotton Philippe Thiry 《Clinical chemistry and laboratory medicine》2004,42(1):67-71
Polyethylene terephthalate (PET) tubes have several advantages over glass tubes: they are unbreakable, lighter and more easily disposed of. Despite a steady increase in their use and an expansion of the range of available tubes, few studies validating their use have been published in the literature. This paper describes the various studies that have been performed to compare VENOJECT glass, VENOSAFE PET and VENOSAFE PET/heparin tubes for the assay of a panel of analytes in routine clinical chemistry, immunochemistry, hormone and tumor marker analysis and trace metal determination. These studies demonstrate that VENOSAFE PET tubes are a suitable alternative to glass tubes. 相似文献
997.
998.
Oluseun A Sowemimo Steven M Yood John Courtney Jessie Moore Miriam Huang Rebecca Ross Ursula McMillian Peter Ojo Randolph B Reinhold 《Surgery for obesity and related diseases》2007,3(1):73-7; discussion 77
BACKGROUND: To study the mortality among morbidly obese patients qualifying for bariatric surgery. Mortality from bariatric surgery for morbid obesity has been widely reported; however, little is known about the mortality in morbidly obese patients who defer surgery. METHODS: Consecutive patients evaluated for bariatric surgery with an initial encounter between 1997 and 2004 were identified. The Social Security Death Index and office records were used to identify mortality through 2006. We conducted telephone interviews to determine whether the 305 patients who did not undergo bariatric surgery at our institution had undergone the surgery elsewhere. Using Cox proportional hazards models, we compared the mortality in patients undergoing surgery with that of those who did not. To evaluate bias resulting from missing data, we conducted analyses assuming that all patients with missing data had (1) undergone surgery and (2) not undergone surgery. RESULTS: A total of 908 patients underwent bariatric surgery (880 patients at our institution and 28 patients elsewhere). A total of 112 patients did not undergo surgery. Data regarding surgery on 165 patients could not be obtained. The mortality in those patients who did not undergo surgery was 14.3% compared with 2.9% for those who did undergo surgery. Adjusting for age, gender, and body mass index, patients who had undergone surgery had an 82% reduction in mortality (hazard ratio 0.18, 95% confidence interval 0.09-0.35, P <.0001). Sensitivity analysis, assuming that all patients with missing data received surgery resulted in an 85% mortality reduction (P <.001) and assuming that patients did not receive surgery resulted in a 50% mortality reduction (P = .04). CONCLUSIONS: Mortality among morbidly obese patients without surgery was 14.3% during the study period. Surgical intervention offered a 50%-85% mortality reduction benefit. 相似文献
999.
Characterization of a functional promoter polymorphism of the human tryptophan hydroxylase 2 gene in serotonergic raphe neurons. 总被引:2,自引:0,他引:2
1000.