全文获取类型
收费全文 | 5712篇 |
免费 | 533篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 195篇 |
妇产科学 | 162篇 |
基础医学 | 810篇 |
口腔科学 | 57篇 |
临床医学 | 755篇 |
内科学 | 988篇 |
皮肤病学 | 109篇 |
神经病学 | 644篇 |
特种医学 | 111篇 |
外科学 | 563篇 |
综合类 | 48篇 |
一般理论 | 6篇 |
预防医学 | 702篇 |
眼科学 | 324篇 |
药学 | 334篇 |
中国医学 | 3篇 |
肿瘤学 | 371篇 |
出版年
2024年 | 16篇 |
2023年 | 127篇 |
2022年 | 164篇 |
2021年 | 425篇 |
2020年 | 268篇 |
2019年 | 337篇 |
2018年 | 333篇 |
2017年 | 273篇 |
2016年 | 289篇 |
2015年 | 236篇 |
2014年 | 320篇 |
2013年 | 363篇 |
2012年 | 465篇 |
2011年 | 487篇 |
2010年 | 234篇 |
2009年 | 209篇 |
2008年 | 296篇 |
2007年 | 247篇 |
2006年 | 226篇 |
2005年 | 214篇 |
2004年 | 165篇 |
2003年 | 190篇 |
2002年 | 158篇 |
2001年 | 24篇 |
2000年 | 10篇 |
1999年 | 11篇 |
1998年 | 33篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1975年 | 2篇 |
1973年 | 7篇 |
1972年 | 4篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有6254条查询结果,搜索用时 312 毫秒
11.
12.
13.
14.
15.
Martha L. Neighbor MD Samantha Honner MD Michael A. Kohn MD MPP 《Academic emergency medicine》2004,11(12):1290-1296
OBJECTIVES: Studies of emergency department (ED) pain management in patients with trauma have been mostly restricted to patients with fractures, yet the potential for undertreatment of more severely injured patients is great. The authors sought to identify factors associated with failure to receive ED opioid administration in patients with acute trauma who subsequently required hospitalization. METHODS: At an urban Level 1 trauma center and teaching hospital, a retrospective cohort study of trauma team activation patients requiring hospitalization between January 1 and December 31, 1999, was conducted. The authors excluded patients receiving opioids only within ten minutes of chest tube insertion or fracture manipulation. The main outcome measure was ED opioid administration. RESULTS: A total of 540 charts of hospitalized first-tier trauma team activation patients were reviewed. A total of 258 (47.8%) received intravenous opioid analgesia within three hours of ED arrival. The median time to receiving the first dose of opioids was 95 minutes. Patients were independently less likely to receive opioids if they were younger or older, were intubated, had a lower Revised Trauma Score, or did not require fracture manipulation. Patients with these factors were less likely to receive opioids independent of the amount of time they spent in the ED. CONCLUSIONS: Many trauma activation patients requiring hospitalization do not receive opioid analgesia in the ED. Patients at particular risk for oligoanalgesia include those who are younger or older and those who are more seriously injured, as defined by a lower Revised Trauma Score, lower Glasgow Coma Scale score, and intubation. 相似文献
16.
Shirley Kobar Coni C Francis Samantha MaWhinney Teresa Sharp 《Nutrition in clinical practice》2003,18(5):417-421
BACKGROUND: Development of an acclimation protocol for use when measuring resting energy expenditure (REE) would simplify and standardize data collection. The purpose of this study was to determine if our 2 metabolic carts could be used interchangeably and to determine if excluding the first 3 or 5 minutes of data collected as an acclimation period would significantly improve the coefficients of variation (CVs) for oxygen consumed (VO(2)) and carbon dioxide produced (VCO(2)) when performing REE assessments with our metabolic cart systems. METHODS: Thirteen healthy, nonsmoking adults ranging in age from 32 to 45 years, with activity levels ranging from sedentary to highly active, participated. Indirect calorimetry was performed twice in the morning after 30 minutes of supine resting. Subjects had fasted for 12 hours, and did not exercise within the last 24 hours. The system order for testing was randomized for the first measurement. When the first measurement was completed, subjects were crossed over for measurement using a second metabolic cart. RESULTS: The CVs for VO(2) and VCO(2) were significantly lower when excluding the first 3 (VO(2), p = .0005), (VCO(2), p = .0024) or 5 minutes (VO(2), p = .0001, VCO(2), p = .0021) of data compared with no exclusions. No significant differences in CVs between the 3- and 5-minute exclusions were found for VO(2) (p = .3224) or VCO(2) (p = .2255). CONCLUSIONS: Clearly, our machines cannot be used interchangeably within a study. An acclimation period improves CVs of VO(2) and VCO(2.) The similarities in CVs led us to adopt a 3-minute acclimation period for measuring REE. 相似文献
17.
18.
Sensitivity and specificity of screening for Down syndrome with alpha-fetoprotein, hCG, unconjugated estriol, and maternal age. 总被引:4,自引:0,他引:4
The sensitivity and specificity of maternal serum screening for Down syndrome with different biochemical markers were evaluated. Detection rates with different combinations of maternal serum alpha-fetoprotein (MSAFP), hCG, and unconjugated estriol (uE3) were established by retrieving and analyzing 54 serum specimens from women with confirmed Down syndrome pregnancies, compared with 657 specimens from women with normal outcomes. With a risk cutoff of 1:270 at the second trimester, the detection rate with MSAFP, hCG, and uE3 was two to three times higher than with MSAFP alone. With all three markers, the detection rate for Down syndrome increased from 50 to 77% as maternal age increased, and was 60% in a representative screened population. If uE3 was omitted, the detection rate decreased from 60 to 48%. One thousand women were screened prospectively, either with MSAFP or with all three markers prospectively, either with MSAFP or with all three markers and 4.1% with MSAFP. With the three markers, the positive predictive value for Down syndrome was 2.2% overall and as high as 5.9% in older women. Therefore, the addition of hCG and uE3 to the maternal serum screen increases the positive predictive value by 50-300%, depending on maternal age. These results confirm the efficacy of screening for Down syndrome using maternal age and three serum markers. 相似文献
19.
Further experience with division of the left renal vein 总被引:2,自引:0,他引:2
The left renal vein (LRV) has numerous tributaries including, but not limited to, the inferior phrenic, suprarenal, and gonadal veins. The resultant potential for collateral LRV outflow through these tributaries in instances of LRV division is obvious. One of us has previously reported 10 such cases of LRV division (close to its confluence with the inferior vena cava and without reanastomosis) for the purpose of facilitating proximal abdominal aortic exposure for reconstructive procedures. One of the 10 patients had moderate renal insufficiency at follow-up. We present herein an additional 19 patients who underwent LRV division predominantly for aneurysmal disease of the abdominal aorta. Sixteen patients were available for follow-up. Three patients died in the intraoperative and early postoperative periods. Multivariate analysis of variance of preoperative, postoperative, and follow-up laboratory data--serum creatinine and BUN--showed no significant change in renal function as assessed. 相似文献
20.