全文获取类型
收费全文 | 5261篇 |
免费 | 820篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 183篇 |
妇产科学 | 105篇 |
基础医学 | 555篇 |
口腔科学 | 120篇 |
临床医学 | 601篇 |
内科学 | 1422篇 |
皮肤病学 | 69篇 |
神经病学 | 472篇 |
特种医学 | 427篇 |
外科学 | 655篇 |
综合类 | 108篇 |
预防医学 | 745篇 |
眼科学 | 106篇 |
药学 | 250篇 |
肿瘤学 | 240篇 |
出版年
2023年 | 56篇 |
2021年 | 54篇 |
2020年 | 57篇 |
2019年 | 50篇 |
2018年 | 78篇 |
2017年 | 62篇 |
2016年 | 72篇 |
2015年 | 96篇 |
2014年 | 142篇 |
2013年 | 191篇 |
2012年 | 153篇 |
2011年 | 173篇 |
2010年 | 132篇 |
2009年 | 148篇 |
2008年 | 150篇 |
2007年 | 173篇 |
2006年 | 168篇 |
2005年 | 186篇 |
2004年 | 167篇 |
2003年 | 110篇 |
2002年 | 124篇 |
2001年 | 123篇 |
2000年 | 115篇 |
1999年 | 125篇 |
1998年 | 101篇 |
1997年 | 123篇 |
1996年 | 117篇 |
1995年 | 90篇 |
1994年 | 104篇 |
1993年 | 92篇 |
1992年 | 120篇 |
1991年 | 107篇 |
1990年 | 149篇 |
1989年 | 167篇 |
1988年 | 147篇 |
1987年 | 157篇 |
1986年 | 161篇 |
1985年 | 152篇 |
1984年 | 127篇 |
1983年 | 145篇 |
1982年 | 103篇 |
1981年 | 108篇 |
1980年 | 91篇 |
1979年 | 115篇 |
1978年 | 87篇 |
1977年 | 87篇 |
1976年 | 60篇 |
1975年 | 60篇 |
1974年 | 49篇 |
1970年 | 48篇 |
排序方式: 共有6110条查询结果,搜索用时 31 毫秒
1.
2.
Lisa A. Lang DDS MS David C. Holmes DDS MS Craig Passon DDS MS Robert M. Trombly DDS JD Jeffrey D. Astroth DDS MSPH Arnold F. Tavel DMD 《Journal of prosthodontics》2003,12(3):206-210
Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience. 相似文献
3.
Hepatitis C virus (HCV) infection is a major health care issue in liver and kidney transplantation. Besides negatively affecting both patient and graft survival, HCV is associated with a heightened risk for new onset diabetes mellitus (NODM). The mechanisms underlying the diabetogenicity of HCV are complex but are likely to involve insulin resistance caused by inhibitory actions of the virus on insulin regulatory pathways in the liver. The resultant glucose dysregulation is an important determinant of increased morbidity and mortality in liver and kidney recipients. This review highlights the concerns for outcomes in HCV-positive liver and kidney transplant patients with particular focus on the interrelationship between hepatitis C and diabetes. Data about the potential role of calcineurin inhibitors, corticosteroids and mycophenolate mofetil in HCV infection and HCV-associated NODM will also be discussed. 相似文献
4.
R W Hertle A B Leahey S Bloom D B Schaffer S Bartlett 《Ophthalmic plastic and reconstructive surgery》1990,6(4):278-282
Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery. 相似文献
5.
6.
SNAP-25 immunoreactivity was translocated into the endings of the processes induced in PC12 cells by dibutyryl-cAMP-treatment. Conversely, the protein was not present in the endings of the processes seen after NGF-treatment unless dibutyryl-cAMP was used simultaneously. This redistribution of SNAP-25 immunoreactivity appeared to be dependent upon new protein synthesis. Finally, dibutyryl-cAMP was capable of inducing SNAP-25 expression. 相似文献
7.
D J Brooks J S Gibbs P Sharp S Herold D R Turton S K Luthra E M Kohner S R Bloom T Jones 《Journal of cerebral blood flow and metabolism》1986,6(2):240-244
Regional cerebral [11C]3-O-methyl-D-glucose ([11C]MeG) uptake kinetics have been measured in five insulin-dependent diabetic patients and four normal controls using positron emission tomography (PET). Concomitant measurement of regional cerebral blood volume and CBF enabled corrections for the presence of intravascular [11C]MeG signal in cerebral regions of interest to be carried out, and regional cerebral [11C]MeG unidirectional extraction fractions to be computed. Four of the five diabetic subjects were studied with their fasting plasma glucose level clamped at a normoglycaemic level (4 mM), and four were studied at hyperglycaemic plasma glucose levels (mean 13 mM). The four diabetic subjects whose fasting plasma glucose levels were clamped at a normoglycaemic level of 4 mM had mean fasting whole-brain, cortical, and white matter [11C]MeG extraction fractions of 15, 15, and 16%, respectively, values similar to those found for the four normal controls (whole brain, 14%; cortex, 13%; white matter, 17%). Mean regional cerebral [11C]MeG extraction fractions were significantly reduced in diabetic subjects during hyperglycaemia whether their plasma insulin levels were undetectable or whether they were raised by continuous intravenous insulin infusion. Such a reduction in [11C]MeG extraction under hyperglycaemic conditions can be explained entirely in terms of increased competition between [11C]MeG and D-glucose for the passive facilitated transport carrier system for hexoses across the blood-brain barrier (BBB). It is concluded that the number and affinity of D-glucose carriers present in the BBB are within normal limits in treated insulin-dependent diabetic subjects. In addition, insulin appears to have no effect on the transport of D-glucose across the BBB. 相似文献
8.
9.
Peter B. Richman MD Shari Dominguez MD David Kasper MD Frederick Chen MD Jeremy Friese MD Joseph Wood MD JD Joseph Collins MD Jeffrey A. Kline MD 《Academic emergency medicine》2006,13(3):295-301
Objectives: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis).
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography. 相似文献
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography. 相似文献
10.