全文获取类型
收费全文 | 28619篇 |
免费 | 6059篇 |
国内免费 | 170篇 |
专业分类
耳鼻咽喉 | 704篇 |
儿科学 | 803篇 |
妇产科学 | 873篇 |
基础医学 | 1376篇 |
口腔科学 | 2965篇 |
临床医学 | 4746篇 |
内科学 | 6323篇 |
皮肤病学 | 574篇 |
神经病学 | 2578篇 |
特种医学 | 1487篇 |
外科学 | 4880篇 |
综合类 | 90篇 |
现状与发展 | 12篇 |
一般理论 | 2篇 |
预防医学 | 3081篇 |
眼科学 | 526篇 |
药学 | 710篇 |
中国医学 | 20篇 |
肿瘤学 | 3098篇 |
出版年
2024年 | 167篇 |
2023年 | 1132篇 |
2022年 | 466篇 |
2021年 | 836篇 |
2020年 | 1356篇 |
2019年 | 647篇 |
2018年 | 1500篇 |
2017年 | 1445篇 |
2016年 | 1720篇 |
2015年 | 1803篇 |
2014年 | 2261篇 |
2013年 | 2810篇 |
2012年 | 1329篇 |
2011年 | 1287篇 |
2010年 | 1691篇 |
2009年 | 2240篇 |
2008年 | 1229篇 |
2007年 | 968篇 |
2006年 | 1068篇 |
2005年 | 855篇 |
2004年 | 672篇 |
2003年 | 628篇 |
2002年 | 578篇 |
2001年 | 439篇 |
2000年 | 316篇 |
1999年 | 435篇 |
1998年 | 555篇 |
1997年 | 519篇 |
1996年 | 584篇 |
1995年 | 437篇 |
1994年 | 342篇 |
1993年 | 290篇 |
1992年 | 208篇 |
1991年 | 180篇 |
1990年 | 157篇 |
1989年 | 164篇 |
1988年 | 140篇 |
1987年 | 151篇 |
1986年 | 121篇 |
1985年 | 124篇 |
1984年 | 107篇 |
1983年 | 110篇 |
1982年 | 109篇 |
1981年 | 85篇 |
1980年 | 66篇 |
1979年 | 46篇 |
1978年 | 47篇 |
1977年 | 59篇 |
1976年 | 41篇 |
1974年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Monitoring left ventricular dilation in mice with PET. 总被引:3,自引:0,他引:3
Lars Stegger Klaus P Sch?fers Ulrich Fl?gel Lefteris Livieratos Sven Hermann Christoph Jacoby Petra Keul Edward M Conway Otmar Schober Jürgen Schrader Bodo Levkau Michael Sch?fers 《Journal of nuclear medicine》2005,46(9):1516-1521
Molecular imaging by small-animal PET is an important noninvasive means to phenotype transgenic mouse models in vivo. When investigating pathologies of the left ventricular (LV) myocardium, the serial assessment of LV volumes is important. By this, the presence of LV dilation as a sign of developing heart failure can be detected. Whereas PET is usually used to derive biochemical and molecular information, functional parameters such as ventricular volumes are generally measured using echocardiography or MRI. In this study, a novel method to monitor LV dilation in mice with PET is presented and evaluated using cardiac MRI. METHODS: A semiautomatic 3-dimensional algorithm was used to delineate the LV myocardial wall on static PET images depicting myocardial glucose metabolism ((18)F-FDG PET) for 20 mice: 10 wild-type and 10 genetically modified littermates designed to develop a dilative cardiomyopathy phenotype (cardiomyocyte-specific knockout of survivin). The volume enclosed by the 3-dimensional midmyocardial contour was calculated as a measure for LV volume for each mouse. Data were compared with ventricular volumes measured by MRI in the same animals. RESULTS: LV volumes obtained by PET and MRI correlated well (R = 0.89) for hearts with small and large left ventricles. In accordance with the hypothesis, the LV volumes were increased significantly for transgenic mice examined at an older age compared with those examined at a younger age (MRI: 160.5 +/- 25.7 microL vs. 114.7 +/- 15.2 microL [P = 0.012]; PET: 129.3 +/- 15.3 microL vs. 73.8 +/- 15.0 microL [P < 0.001], all values shown as mean +/- SD; for MRI, mean of end-diastolic and end-systolic volumes are given), whereas they did not for their wild-type littermates (MRI: 106.2 +/- 12.3 microL vs. 94.7 +/- 14.6 microL [P = 0.214]; PET: 82.6 +/- 20.9 microL vs. 65.0 +/- 16.9 microL [P = 0.185]). CONCLUSION: Evaluation and quantitation of LV dilation in both control and cardiomyopathic mice can be reliably and serially performed using small-animal PET and (18)F-FDG, yielding useful functional information in addition to metabolic data. 相似文献
62.
Andrew R. Hoellein MD Christopher A. Feddock MD Charles H. Griffith III MD MSPH John F. Wilson PhD Donald R. Barnett MD MSPH Pat F. Bass III MD MS T. Shawn Caudill MD MSPH 《Journal of general internal medicine》2004,19(5P2):562-565
Due to recent public debate and newly imposed resident work hour restrictions, we decided to investigate the relationship of resident call status to their ambulatory patients' satisfaction. Resident continuity clinic patients were asked to rate their level of satisfaction on a 10-point Likert-type scale. Using multiple regression approaches, these data were then assessed as a function of resident call status. We found that in 646 patient encounters, patient satisfaction scores were significantly less when the resident was postcall, 8.99 ± 1.8, than when not postcall, 9.31 ± 1.3. We herein discuss etiologies and implications of these findings for both patient care and medical education. 相似文献
63.
64.
65.
66.
Kuo-Sheng Hung MD Phd Chung-Ling Liang MD Cheng-Haung Wang MD Hsueh-Wen Chang PhD Naeun Park MS Suh-Hang Hank Juo MD PhD 《Journal of clinical neuroscience》2004,11(8):849-853
Frontal intracerebral haemorrhage (ICH) is a common result of cranial trauma. Outcome differences between bilateral and unilateral frontal ICH are not well studied but would be valuable to predict prognosis in clinical practice. Two aims are proposed in this study: first to compare the risk of developing delayed ICH after bilateral or unilateral frontal ICH, and second to determine the variables helpful to predict outcome according to the Glasgow Outcome Scale (GOS). Between January 1993 and December 1997, 694 consecutive patients with traumatic ICH were admitted to the Chang Gung Medical Center within 24 h of the trauma. Patients with ICH in sites other than the frontal lobes were excluded. A total of 161 cases (mean age 46.3+/-20.3 years), including 57 bilateral (mean age 52.5+/-18.7 years) and 104 unilateral (mean age 42.9+/-20.5 years) traumatic frontal ICH were studied. Twenty-eight of 57 patients (49%) with bifrontal ICH versus 17 of 104 patients (16%) with unilateral frontal ICH had a further, delayed ICH. In 42 of 45 patients (93%) with delayed ICH, this occurred within 5 days of the initial trauma. Multivariate logistic regression was used to select significant predictors of outcome. We found that delayed ICH (p<0.001), age (p=0.004) and mechanism of injury (p=0.001) explained the worse outcome in patients with bifrontal ICH. The best-fitting logistic regression model included three variables: delayed ICH (p=0.011), initial GCS (p=0.023), and a sum score of clinical and radiological variables (p=0.003). Bifrontal ICH tended to occur in older patients after a fall and was associated with a higher risk of developing delayed ICH or brain stem compression compared to unilateral ICH damage. Using these three variables - delayed ICH, initial GCS, and the sum score - in a logistical regression model is useful to predict outcome in patients with traumatic frontal ICH and may aid patient management. 相似文献
67.
68.
JENNIFER ORLET FISHER PhD DIANE C. MITCHELL MS RD HELEN SMICIKLAS- WRIGHT PhD LEANN LIPPS BIRCH PhD 《Journal of the American Dietetic Association》2002,102(1)
Objective To evaluate parents’ fruit and vegetable intake and their use of pressure to eat in child feeding as predictors of their 5-year-old daughters’ fruit and vegetable, micronutrient, and fat intakes.Subjects Data were obtained from 191 non-Hispanic white families with 5-year-old girls.Design Parent data included reports of pressure in child feeding and their own fruit and vegetable intake. Girls’ intakes of fruits and vegetables, selected micronutrients, and fat were the main outcomes of interest.Statistical analysis Structural equation modeling was used to test a model describing relationships among parents’ fruit and vegetable intake, parents’ use of pressure in child feeding, and daughters’ fruit and vegetable, micronutrient, and fat intakes.Results The model provided a good fit to the data, revealing that girls’ fruit and vegetable intake was positively related to their parents’ reported fruit and vegetable intake. Parents who consumed fewer fruits and vegetables tended to report greater pressure in child feeding and had daughters who consumed fewer fruits and vegetables. Girls’ reported fruit and vegetable intakes were positively related to their micronutrient intakes and negatively associated with fat intake.Applications/conclusions This research demonstrates that parents’ own fruit and vegetable intake may encourage fruit and vegetable intake in their daughters, leading to higher micronutrient intakes and lower dietary fat intakes. Conversely, pressure to eat may discourage fruit and vegetable intake among young girls. J Am Diet Assoc. 2002;102:58–64. 相似文献
69.
P Vanhaesebrouck K Vanneste C de Praeter Y Van Trappen M Thiery 《Archives of disease in childhood》1987,62(12):1276-1277
Two neonates who went into acute hypovolaemic shock due to a tight nuchal cord were successfully resuscitated. The occurrence of this life threatening complication in two low risk pregnancies emphasises the importance of having staff trained in resuscitation immediately available in the delivery unit. 相似文献
70.