全文获取类型
收费全文 | 5328篇 |
免费 | 660篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 245篇 |
妇产科学 | 156篇 |
基础医学 | 844篇 |
口腔科学 | 124篇 |
临床医学 | 672篇 |
内科学 | 1016篇 |
皮肤病学 | 128篇 |
神经病学 | 414篇 |
特种医学 | 224篇 |
外科学 | 618篇 |
综合类 | 210篇 |
一般理论 | 7篇 |
预防医学 | 493篇 |
眼科学 | 113篇 |
药学 | 416篇 |
中国医学 | 1篇 |
肿瘤学 | 301篇 |
出版年
2022年 | 34篇 |
2021年 | 98篇 |
2020年 | 39篇 |
2019年 | 86篇 |
2018年 | 79篇 |
2017年 | 71篇 |
2016年 | 67篇 |
2015年 | 98篇 |
2014年 | 116篇 |
2013年 | 184篇 |
2012年 | 199篇 |
2011年 | 206篇 |
2010年 | 121篇 |
2009年 | 155篇 |
2008年 | 180篇 |
2007年 | 218篇 |
2006年 | 200篇 |
2005年 | 200篇 |
2004年 | 212篇 |
2003年 | 212篇 |
2002年 | 229篇 |
2001年 | 235篇 |
2000年 | 222篇 |
1999年 | 181篇 |
1998年 | 84篇 |
1997年 | 83篇 |
1996年 | 80篇 |
1995年 | 64篇 |
1994年 | 74篇 |
1993年 | 87篇 |
1992年 | 117篇 |
1991年 | 134篇 |
1990年 | 150篇 |
1989年 | 143篇 |
1988年 | 134篇 |
1987年 | 133篇 |
1986年 | 120篇 |
1985年 | 103篇 |
1984年 | 89篇 |
1983年 | 79篇 |
1982年 | 59篇 |
1981年 | 53篇 |
1980年 | 47篇 |
1979年 | 60篇 |
1978年 | 56篇 |
1977年 | 52篇 |
1975年 | 37篇 |
1974年 | 42篇 |
1973年 | 30篇 |
1972年 | 32篇 |
排序方式: 共有6014条查询结果,搜索用时 31 毫秒
21.
The Workup for Bariatric Surgery Does Not Require a Routine Upper Gastrointestinal Series 总被引:1,自引:0,他引:1
Andrew J Ghassemian Kenneth G MacDonald MD Paul G Cunningham MD Melvin Swanson PhD Brenda M Brown MRA Patricia G Morris BSN Walter J Pories MD 《Obesity surgery》1997,7(1):16-18
Background: Morbid obesity is a serious disease that afflicts over five million Americans, threatening their health with such
co-morbidities as diabetes, arthritis, pulmonary failure and stroke. Surgery is the only effective therapy, providing long-term
control of weight, diabetes, pulmonary failure, and hypertension for as long as 14 years. Because the operation presents a
major expense, this study examined whether X-ray examination of the gut could be omitted safely as a cost-saving measure.
Methods: The records of 814 consecutive morbidly obese patients who underwent gastric bypass were reviewed to determine: (1)
whether these individuals had undergone an upper gastro-intestinal (GI) series, and (2) if these studies influenced therapy
or caused cancellation or postponement of surgery. Results: Of the 814 patients, 657 (80.7%) underwent a preoperative GI radiography.
Of these examinations, 393 (59.8%) were normal, with the following abnormalities in the remaining 264: hiatal hernia, 164;
esophageal reflux, 39; Schatzki's ring, 18; small bowel diverticula, four; renal stones, four; malrotation, three; gall stones,
two; pyloric ulcer, one; possible pelvic mass, one; calcified leiomyoma, one; and dysphagial lusoria, one. None of these findings
resulted in cancellation or a delay in surgery. Conclusions: The upper GI series can be safely omitted from the routine preoperative
evaluation of patients undergoing gastric bypass. At a cost of $741.00 per examination, this change represents significant
potential savings. Similar evaluations of other routine preoperative tests may well provide a better basis for the evaluation
of these complex patients. 相似文献
22.
A. MacDonald 《Journal of human nutrition and dietetics》1994,7(2):105-114
This article is a report of a meeting of dietitians held on 15 September 1992 in Birmingham to discuss the recommendations of a 'Medical Research Council Working Party on the Dietary Management of Phenylketonuria'. (Contributions on the day of the meeting came from Judith Houghton, Eleanor Weetch, Isabel Smith, Sheena Laing, Ruth Watling, John Walter, Rodney Pollitt.) 相似文献
23.
Martin V. Pusic MD George S. Pachev PhD Wendy A. MacDonald MD 《Academic emergency medicine》2007,14(2):138-148
Objectives
To explore medical students' use of computer tutorials embedded in a busy clinical setting; to demonstrate that such tutorials can increase knowledge gain over and above that attributable to the clinical rotation itself.
Methods
Six tutorials were installed on a computer placed in a central area in an emergency department. Each tutorial was made up of between 33 and 85 screens of information that include text, graphics, animations, and questions. They were designed to be brief (10 minutes), focused, interactive, and immediately relevant. The authors evaluated the intervention using quantitative research methods, including usage tracking, surveys of faculty and students, and a randomized pretest-posttest study.
Results
Over 46 weeks, 95 medical students used the tutorials 544 times, for an overall average of 1.7 times a day. The median time spent on completed tutorials was 11 minutes (average [SD], 14 [±12] minutes). Seventy-four students completed the randomized study. They completed 65% of the assigned tutorials, resulting in improved examination scores compared with the control (effect size, 0.39; 95% confidence interval = 0.15 to 0.62). Students were positively disposed to the tutorials, ranking them as "valuable." Fifty-four percent preferred the tutorials to small group teaching sessions with a preceptor. The faculty was also positive about the tutorials, although they did not appear to integrate the tutorials directly into their teaching.
Conclusions
Medical students on rotation in a busy clinical setting can and will use appropriately presented computer tutorials. The tutorials are effective in raising examination scores. 相似文献
To explore medical students' use of computer tutorials embedded in a busy clinical setting; to demonstrate that such tutorials can increase knowledge gain over and above that attributable to the clinical rotation itself.
Methods
Six tutorials were installed on a computer placed in a central area in an emergency department. Each tutorial was made up of between 33 and 85 screens of information that include text, graphics, animations, and questions. They were designed to be brief (10 minutes), focused, interactive, and immediately relevant. The authors evaluated the intervention using quantitative research methods, including usage tracking, surveys of faculty and students, and a randomized pretest-posttest study.
Results
Over 46 weeks, 95 medical students used the tutorials 544 times, for an overall average of 1.7 times a day. The median time spent on completed tutorials was 11 minutes (average [SD], 14 [±12] minutes). Seventy-four students completed the randomized study. They completed 65% of the assigned tutorials, resulting in improved examination scores compared with the control (effect size, 0.39; 95% confidence interval = 0.15 to 0.62). Students were positively disposed to the tutorials, ranking them as "valuable." Fifty-four percent preferred the tutorials to small group teaching sessions with a preceptor. The faculty was also positive about the tutorials, although they did not appear to integrate the tutorials directly into their teaching.
Conclusions
Medical students on rotation in a busy clinical setting can and will use appropriately presented computer tutorials. The tutorials are effective in raising examination scores. 相似文献
24.
25.
L MacDonald 《Canadian Medical Association journal》1991,145(9):1136-1138
26.
We evaluated the Kodak Ektachem clinical chemistry slide for assay of theophylline. Assay precision and accuracy were acceptable in the therapeutic range although precision was poor at low levels of theophylline. The assay performed well with patients' samples using the Abbott TDx as the reference procedure but, as indicated by the manufacturer, uremic samples gave a positive bias, particularly in the therapeutic range. Finally, the significant bias observed with Quality Control material, probably due to matrix sensitivity, is a possible drawback. 相似文献
27.
J. R. MacDonald J. H. Beckstead E. A. Smuckler 《International journal of experimental pathology》1987,68(2):189-199
The biochemical basis of the hepatitis-like liver injury produced by D(+)-galactosamine in rats is well-established and is linked to depletion of uridine nucleotides within parenchymal cells. However, the prominent inflammatory response that accompanies this lesion in vivo has been largely overlooked as a component of the hepatic damage. This study examines the cellular components of the inflammatory infiltrate of galactosamine-induced liver injury over time using histochemical and ultrastructural techniques. By 12 h after toxin administration, the infiltrate consisted largely of neutrophils and recently-mobilized monocytes. By 24 to 48 h after the toxin, when hepatocellular necrosis was maximal, few neutrophils were found in the infiltrate. At these times, the infiltrate consisted almost exclusively of large phagocytic cells, histochemically and morphologically consistent with active tissue macrophages apparently derived from circulating monocytes. The extent of the inflammatory response to this experimental hepatotoxin suggests that effects on the generation and development of the inflammatory response should be considered for treatments reported to alter the intrinsic hepatotoxicity of galactosamine. 相似文献
28.
29.
A B MacDonald 《Journal of clinical neuro-ophthalmology》1987,7(4):185-190
Lyme borreliosis is a spirochetal infection with a potential to produce a clinical disease in the human host with protean manifestations as diverse as the spectrum of disease caused by Treponema pallidum. Neuro-ophthalmologic manifestations of Lyme borreliosis are emphasized in this short review. A brief historical chronicle of Lyme disease is offered. Potential pitfalls in the diagnosis of Lyme disease with an emphasis on false negative serology and currently available diagnostic modalities are presented. Therapeutic options for Lyme borreliosis are briefly reviewed. 相似文献
30.