全文获取类型
收费全文 | 1335篇 |
免费 | 151篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 46篇 |
妇产科学 | 37篇 |
基础医学 | 208篇 |
口腔科学 | 39篇 |
临床医学 | 142篇 |
内科学 | 246篇 |
皮肤病学 | 14篇 |
神经病学 | 109篇 |
特种医学 | 89篇 |
外科学 | 225篇 |
综合类 | 31篇 |
预防医学 | 135篇 |
眼科学 | 8篇 |
药学 | 65篇 |
肿瘤学 | 84篇 |
出版年
2021年 | 25篇 |
2020年 | 12篇 |
2019年 | 15篇 |
2018年 | 20篇 |
2016年 | 15篇 |
2015年 | 17篇 |
2014年 | 29篇 |
2013年 | 43篇 |
2012年 | 39篇 |
2011年 | 45篇 |
2010年 | 38篇 |
2009年 | 38篇 |
2008年 | 31篇 |
2007年 | 62篇 |
2006年 | 49篇 |
2005年 | 50篇 |
2004年 | 26篇 |
2003年 | 27篇 |
2002年 | 38篇 |
2001年 | 38篇 |
2000年 | 30篇 |
1999年 | 33篇 |
1998年 | 34篇 |
1997年 | 24篇 |
1996年 | 31篇 |
1995年 | 32篇 |
1994年 | 23篇 |
1993年 | 24篇 |
1992年 | 38篇 |
1991年 | 29篇 |
1990年 | 29篇 |
1989年 | 54篇 |
1988年 | 47篇 |
1987年 | 45篇 |
1986年 | 26篇 |
1985年 | 23篇 |
1984年 | 18篇 |
1983年 | 14篇 |
1982年 | 17篇 |
1981年 | 22篇 |
1980年 | 16篇 |
1979年 | 29篇 |
1978年 | 20篇 |
1977年 | 17篇 |
1974年 | 12篇 |
1973年 | 19篇 |
1970年 | 14篇 |
1969年 | 11篇 |
1968年 | 12篇 |
1967年 | 11篇 |
排序方式: 共有1488条查询结果,搜索用时 15 毫秒
91.
Taylor SL Morgan DL Denson KD Lane MM Pennington LR 《American journal of surgery》2005,189(2):219-222
BACKGROUND: Systems for evaluating acute pancreatitis are useful in hospitalized patients. Traditional systems of evaluation are well established but might be outdated. We propose a Multiple Organ System Score (MOSS) containing data that are more consistently collected and which are accurate in predicting patient outcome. METHODS: A retrospective chart review of 49 patients was completed. We determined if the physician obtained all of the variables necessary to calculate Ranson, Glasgow, or APACHE II scores, if these scores were predictive of patient outcome in the form of length of hospital stay (LOS), and if new, more frequently evaluated variables could be used. RESULTS: None of the patients could be assigned complete scores. According to Spearman rank correlation, both Glasgow and MOSS showed correlation with patient outcome when APACHE II and Ranson did not. CONCLUSIONS: Although larger studies should be performed, the MOSS is useful in predicting outcomes of patients with acute pancreatitis. 相似文献
92.
Scott-Cawiezell J Main DS Vojir CP Jones K Moore L Nutting PA Kutner JS Pennington K 《Health care management review》2005,30(4):372-380
Exploring selected working conditions and performance in nursing homes suggests that high and low performers can be determined based on both quantitative and qualitative findings. 相似文献
93.
Background
Variance of peak bone mass has a substantial genetic component, as has been shown with twin studies examining quantitative measures such as bone mineral density (BMD) and quantitative ultrasound (QUS). Evidence implicating single nucleotide polymorphisms (SNPs) of the transforming growth factor beta-1 (TGFB1) gene is steadily accumulating. However, a comprehensive look at multiple SNPs at this locus for their association with indices of peak bone mass has not been reported. 相似文献94.
An in vitro is described that attempts to detect patients with a potential for adverse systemic reactions to contrast material. This test involves measuring the rate of conversion of prekallikrein to kallikrein under certain standard conditions. In a preliminary retrospective study, the test could be used to identify such patients with a sensitivity of 88%, a specificity of 82%, and a predictive value of 79%. 相似文献
95.
Patient dosage in computed tomography 总被引:1,自引:0,他引:1
96.
M S Schaffer S Nouri S C Chen A D Waggoner D G Pennington P L Monteleone 《Clinical pediatrics》1985,24(4):216-218
An adolescent female with occult cystic medial necrosis died following spontaneous aortic rupture. A large saccular aortic aneurysm that had ruptured into the pericardial space was demonstrated by two-dimensional echocardiography and confirmed at surgery. Echocardiographic screening of the patient's family members revealed a 13-year-old brother with unsuspected aortic root dilatation. He is now being followed for possible progression of his disease. This case demonstrates the role of echocardiography in cystic medial necrosis. It can aid the acute management of patients with aortic dissection or aneurysm. It can also define patients with occult disease who require serial follow-up and genetic counseling. 相似文献
97.
98.
Are endophenotypes based on measures of executive functions useful for molecular genetic studies of ADHD? 总被引:6,自引:0,他引:6
Doyle AE Faraone SV Seidman LJ Willcutt EG Nigg JT Waldman ID Pennington BF Peart J Biederman J 《Journal of child psychology and psychiatry, and allied disciplines》2005,46(7):774-803
BACKGROUND: Behavioral genetic studies provide strong evidence that attention-deficit/hyperactivity disorder (ADHD) has a substantial genetic component. Yet, due to the complexity of the ADHD phenotype, questions remain as to the specific genes that contribute to this condition as well as the pathways from genes to behavior. Endophenotypes, or phenotypes that are more closely linked to the neurobiological substrate of a disorder, offer the potential to address these two issues simultaneously (Freedman, Adler, & Leonard, 1999). Thus far, potential endophenotypes for ADHD have not been systematically studied. METHOD: The current paper reviews evidence supporting the use of deficits on neurocognitive measures of executive functions for this purpose. RESULTS: Such deficits are a correlate of ADHD and show preliminary evidence of heritability and association with relevant candidate genes. Nonetheless, studies that have assessed the familial and genetic overlap of neurocognitive impairments with ADHD have yielded inconsistent results. CONCLUSIONS: In order for executive function deficits to be used as an endophenotype for ADHD, we recommend greater attention to the neurocognitive heterogeneity of this disorder and to the precision of measurement of the neuropsychological tests employed. We also discuss empirical strategies that may be necessary to allow such research to progress prior to full resolution of the pathophysiological basis of ADHD. 相似文献
99.
The purpose of this research was to describe the kinds of pain assessments nursing home staff use with nursing home residents and the characteristics and behaviors of residents that staff consider as they assess pain. Twenty-one focus groups were held in 12 nursing homes. Nurses and other nursing home staff attended the focus groups. Coding techniques consistent with ethnographic methodology were used for data analysis. Four themes identified an underlying uncertainty in assessing residents' pain, the staff relationship-centered approach to pain assessment, the resident cues that alert staff to pain, and residents' characteristics important to the nursing assessment. Composition of focus groups made a difference in participation of certified nursing assistants in focus group discussion. Urban and rural differences were noted across the focus groups. Research is needed to further refine pain assessment techniques specifically for nursing home settings. 相似文献
100.
DiCesare D DuPont HL Mathewson JJ Ashley D Martinez-Sandoval F Pennington JE Porter SB 《The American journal of gastroenterology》2002,97(10):2585-2588
OBJECTIVE: The study was designed to evaluate the effectiveness of SP-303 (Provir), a plant-derived product with novel antisecretory properties, in the treatment of travelers' diarrhea. METHODS: A total of 184 persons from the United States who acquired diarrhea in Jamaica or Mexico were enrolled in a double-blind, placebo-controlled study examining the effectiveness of three doses of SP-303 in reducing illness. Subjects were treated with 125 mg, 250 mg, or 500 mg SP-303 or a matching placebo four times a day for 2 days. Subjects kept daily diaries of symptoms and were seen each day for 3 days. Of the subjects, 169 (92%) were included in the efficacy analysis. RESULTS: The most common etiological agent identified was enterotoxigenic Escherichia coli, found in 19% of subjects. The mean time interval from taking the first dose of medication until passage of the last unformed stool during 48 h therapy (TLUS48) was 38.7 h for the placebo group. TLUS48 was shortened by SP-303: 30.6 h for the 125-mg dose group (p = 0.005); 30.3 h for the 250-mg group; and 32.6 h for the 500-mg group (p = 0.01). Treatment failures were seen in 29.3% in the placebo group compared with 7.3% (p = 0.01), 4.3 (p = 0.002), and 9.8 (p = 0.026) in the three treatment groups. SP-303 was well tolerated at all doses. CONCLUSIONS: SP-303 was effective in shortening the duration of travelers' diarrhea by 21%. This antisecretory approach works directly against the pathophysiology of travelers' diarrhea and is not likely to potentiate invasive forms of diarrhea or to produce posttreatment constipation. 相似文献