全文获取类型
收费全文 | 33299篇 |
免费 | 2403篇 |
国内免费 | 55篇 |
专业分类
耳鼻咽喉 | 303篇 |
儿科学 | 1187篇 |
妇产科学 | 963篇 |
基础医学 | 4291篇 |
口腔科学 | 434篇 |
临床医学 | 4351篇 |
内科学 | 5992篇 |
皮肤病学 | 473篇 |
神经病学 | 3548篇 |
特种医学 | 598篇 |
外国民族医学 | 4篇 |
外科学 | 3003篇 |
综合类 | 328篇 |
一般理论 | 45篇 |
预防医学 | 4632篇 |
眼科学 | 512篇 |
药学 | 2260篇 |
中国医学 | 23篇 |
肿瘤学 | 2810篇 |
出版年
2024年 | 44篇 |
2023年 | 296篇 |
2022年 | 524篇 |
2021年 | 1128篇 |
2020年 | 685篇 |
2019年 | 1040篇 |
2018年 | 1162篇 |
2017年 | 835篇 |
2016年 | 980篇 |
2015年 | 1010篇 |
2014年 | 1338篇 |
2013年 | 1881篇 |
2012年 | 2747篇 |
2011年 | 2970篇 |
2010年 | 1554篇 |
2009年 | 1301篇 |
2008年 | 2386篇 |
2007年 | 2389篇 |
2006年 | 2186篇 |
2005年 | 2063篇 |
2004年 | 1836篇 |
2003年 | 1589篇 |
2002年 | 1603篇 |
2001年 | 208篇 |
2000年 | 171篇 |
1999年 | 201篇 |
1998年 | 307篇 |
1997年 | 241篇 |
1996年 | 168篇 |
1995年 | 178篇 |
1994年 | 134篇 |
1993年 | 119篇 |
1992年 | 69篇 |
1991年 | 47篇 |
1990年 | 48篇 |
1989年 | 39篇 |
1988年 | 39篇 |
1987年 | 35篇 |
1986年 | 34篇 |
1985年 | 16篇 |
1984年 | 19篇 |
1983年 | 29篇 |
1982年 | 28篇 |
1981年 | 19篇 |
1980年 | 11篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1942年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Andrew F Shorr William L Jackson Brendan M Weiss Lisa K Moores 《Blood coagulation & fibrinolysis》2007,18(4):309-316
Multiple options exist for the prevention of deep vein thrombosis (DVT) in medical inpatients. We sought to determine the cost-effectiveness of low-molecular-weight heparin (LMWH) relative to unfractionated heparin (UFH) for DVT prevention in this setting. We conducted a cost-effectiveness analysis from the perspective of a third-party payer employing a decision model and literature-based estimates for inputs. In the base-case analysis, LMWH had little impact on the rate of DVT. Despite higher acquisition costs, however, LMWHs resulted in net savings. Routine use of LMWH saves approximately US$89 per patient. The lower rate of heparin-induced thrombocytopenia (HIT) with LMWH accounted for this differential. Univariate sensitivity analysis revealed the model was moderately sensitive to the odds ratio of HIT with LMWH and the cost of HIT. Multivariate sensitivity analysis confirmed the LMWH approach dominated financially. 'Worst-case' scenario modeling, where LMWH actually increased the risk for DVT, had little effect on the rate of HIT, and was substantially more costly than UFH, still demonstrated that LMWHs were economically superior. Monte-Carlo simulation indicated the 95% confidence interval around the estimate for savings with LMWH ranged from US$7 to US$373. We conclude that, despite their higher cost, LMWHs for thromboprophylaxis in medical patients result in savings. 相似文献
42.
Infections caused by extended-spectrum beta-lactamase (ESBL)-producing pathogens, particularly Klebsiella pneumoniae, are increasing. The epidemiology of ESBL-producing K. pneumoniae, the mechanisms of resistance, and treatment strategies for infections caused by these organisms are reviewed. 相似文献
43.
Gastrojejunostomy stricture after Roux-en-Y gastric bypass occurs in 3 to 27% of morbidly obese patients in the USA. We questioned
whether preoperative patient characteristics, including demographic attributes and comorbid disease, might be significant
factors in the etiology of stricture. In this study from November 2001 to February 2006 (51 months), at a high-volume bariatric
center, of the 1,351 patients who underwent laparoscopic gastric bypass, 92 developed stricture (6.8%). All but two were treated
successfully by endoscopic dilation. All patients stopped nonsteroidal anti-inflammatory medications 2 weeks prior to surgery
and did not restart them. The operative procedure included the use of a 21-mm transoral circular stapler to create the gastrojejunostomy;
the Roux limb was brought retrogastric, retrocolic. In an effort to reduce our center’s stricture rate, late in the study,
U-clips used at the gastrojejunostomy were replaced by absorbable sutures, and postoperative H2 antagonists were added to the treatment protocol. The change to absorbable polyglactin suture proved to be significant, resulting
in a lower stricture rate. The addition of H2 antagonists showed no significant effect. Following the retrospective review of the prospective database, univariate and
multivariate logistic regression analyses identified factors associated with the development of stricture. Gastroesophageal
reflux disease and age were each shown to be statistically significant independent predictors of stricture following laparoscopic
gastric bypass.
Presented at the 2006 Annual Meeting of the Society for Surgery of the Alimentary Tract, May 20–24, Los Angeles, CA (poster
presentation). 相似文献
44.
45.
Lisa Curtice 《Sociology of health & illness》1991,13(3):447-448
46.
Alok Bhargava Matthew Jukes Damaris Ngorosho Charles Khilma Donald A P Bundy 《American journal of human biology》2005,17(3):280-292
This paper models the proximate determinants of school attendance and scores on cognitive and educational achievement tests and on school examinations of over 600 schoolchildren from the Control group of a randomized trial in Tanzania, where children in the Intervention group heavily infected with hookworm and schistosomiasis received treatment. The modeling approach used a random effects framework and incorporated the inter-relationships between school attendance and performance on various tests, controlling for children's health status, socioeconomic variables, grade level, and the educational infrastructure. The empirical results showed the importance of variables such as children's height and hemoglobin concentration for the scores, especially on educational achievement tests that are easy to implement in developing countries. Also, teacher experience and work assignments were significant predictors of the scores on educational achievement tests, and there was some evidence of multiplicative effects of children's heights and work assignments on the test scores. Lastly, some comparisons were made for changes in test scores of treated children in the Intervention group with the untreated children in the Control group. 相似文献
47.
Jaime Guevara-Aguirre Arlan L Rosenbloom Marco Guevara-Aguirre Kemal Yariz Jeanette Saavedra Lisa Baumbach Jonathan Shuster 《Growth hormone & IGF research》2007,17(3):261-264
CONTEXT & OBJECTIVE: The Ecuadorian GH receptor deficiency (GHRD)/Laron syndrome population is the only large cohort with a single GHR mutation (E180 splice), permitting identification of numerous carrier and noncarrier first-degree relatives, to ascertain effects of heterozygosity on GH-dependent IGF-I and IGFBP-3 concentrations and on growth. DESIGN: First-degree relatives (n=212) of GHRD patients had specimens taken for IGF-I, IGFBP-3, and GHR genotyping. Normal statured (n=40) and short statured (n=40) unrelated controls had measurement of IGF-I, IGFBP-3, and stature. RESULTS: There were no significant differences between heterozygous and homozygous normal relatives in IGF-I or IGFBP-3 standard deviation scores (SDS). Heterozygous relatives had lower mean height SDS than did homozygous normals, but with extensive overlap between genotype groups in both child and adult relatives. Height SDS in general did not relate to IGF-I or IGFBP-3 concentrations. CONCLUSIONS: GH-dependent IGF-I and IGFBP-3 secretion is not affected by heterozygosity for the E180 splice mutation that causes GHRD/Laron syndrome in the Ecuadorian population. Heterozygosity is associated with reduction in mean statural SDS, but this is not sufficient to be clinically important and not mediated through measurable differences in circulating IGF-I or IGFBP-3 related to genotype. 相似文献
48.
49.
OBJECTIVES: To determine whether the increase in the incidence of injury found for the first summer season in which rugby league (RL) was played in the UK was repeated in subsequent summer seasons. DESIGN: A retrospective and prospective cohort study design. SETTING AND PARTICIPANTS: Injuries were recorded from all players who took part in 141 games over 3 summer seasons (1997 to 1999) for 1 professional team. These were compared against rates from previously collected data for 3 earlier winter and 1 summer season. ASSESSMENT OF RISK FACTORS: For each injury it was recorded in which season it occurred; how many games or training sessions, if any, were subsequently missed; the type, site and severity of injury. MAIN OUTCOME MEASURES: Injuries were reported as rate per 1000 hours, also broken down into severity according to the number of games missed and whether subsequent training sessions were missed. RESULTS: A sustained increase in injury incidence has been found comparing summer RL over RL played in the winter. There was an increase in injury rates for all sites and types, but not all reached significance. CONCLUSIONS: Data collected over 6 seasons indicate a higher risk of sustaining an injury playing summer RL, but the cause may be related to a combination of factors. These may include the ground or weather conditions associated with summer rugby, player characteristics or changes in the game itself and future research needs to investigate these further. 相似文献
50.