全文获取类型
| 收费全文 | 1096473篇 |
| 免费 | 73059篇 |
| 国内免费 | 1516篇 |
专业分类
| 耳鼻咽喉 | 15276篇 |
| 儿科学 | 35261篇 |
| 妇产科学 | 29282篇 |
| 基础医学 | 155522篇 |
| 口腔科学 | 30191篇 |
| 临床医学 | 96748篇 |
| 内科学 | 208296篇 |
| 皮肤病学 | 24855篇 |
| 神经病学 | 82434篇 |
| 特种医学 | 43707篇 |
| 外国民族医学 | 210篇 |
| 外科学 | 167070篇 |
| 综合类 | 22306篇 |
| 现状与发展 | 2篇 |
| 一般理论 | 283篇 |
| 预防医学 | 76096篇 |
| 眼科学 | 25139篇 |
| 药学 | 88042篇 |
| 7篇 | |
| 中国医学 | 2954篇 |
| 肿瘤学 | 67367篇 |
出版年
| 2021年 | 8822篇 |
| 2019年 | 8620篇 |
| 2018年 | 12447篇 |
| 2017年 | 9594篇 |
| 2016年 | 10797篇 |
| 2015年 | 12038篇 |
| 2014年 | 16253篇 |
| 2013年 | 23414篇 |
| 2012年 | 32211篇 |
| 2011年 | 33985篇 |
| 2010年 | 19818篇 |
| 2009年 | 18539篇 |
| 2008年 | 30983篇 |
| 2007年 | 33192篇 |
| 2006年 | 33677篇 |
| 2005年 | 31880篇 |
| 2004年 | 30524篇 |
| 2003年 | 29231篇 |
| 2002年 | 28153篇 |
| 2001年 | 60270篇 |
| 2000年 | 61716篇 |
| 1999年 | 51156篇 |
| 1998年 | 12583篇 |
| 1997年 | 11102篇 |
| 1996年 | 11095篇 |
| 1995年 | 10411篇 |
| 1994年 | 9400篇 |
| 1993年 | 8904篇 |
| 1992年 | 37896篇 |
| 1991年 | 36372篇 |
| 1990年 | 35829篇 |
| 1989年 | 34370篇 |
| 1988年 | 30945篇 |
| 1987年 | 30060篇 |
| 1986年 | 28294篇 |
| 1985年 | 26523篇 |
| 1984年 | 19241篇 |
| 1983年 | 16188篇 |
| 1982年 | 8853篇 |
| 1979年 | 17079篇 |
| 1978年 | 11436篇 |
| 1977年 | 10261篇 |
| 1976年 | 8872篇 |
| 1975年 | 10103篇 |
| 1974年 | 11685篇 |
| 1973年 | 11292篇 |
| 1972年 | 10775篇 |
| 1971年 | 10111篇 |
| 1970年 | 9265篇 |
| 1969年 | 8952篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
1.
M. R. D. Maslin S. K. Lloyd S. Rutherford S. Freeman A. King D. R. Moore K. J. Munro 《Journal of the Association for Research in Otolaryngology》2015,16(5):631-640
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis. 相似文献
2.
3.
4.
Stelter K. Theodoraki M. N. Becker S. Tsekmistrenko V. Olzowy B. Ledderose G. 《European archives of oto-rhino-laryngology》2015,272(3):639-639
European Archives of Oto-Rhino-Laryngology - 相似文献
5.
6.
Accuracy and Precision of Acetabular Component Placement With Imageless Navigation in Obese Patients
Leonard T. Buller Alexander S. McLawhorn Jose A. Romero Peter K. Sculco David J. Mayman 《The Journal of arthroplasty》2019,34(4):693-699
Background
Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.Methods
A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon’s institutional review board–approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m2) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.Results
The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).Conclusion
Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.Level of Evidence
Therapeutic Level IV. 相似文献7.
Stephan Koter Tina U. Cohnert Korbinian B. Hindermayr Jörg Lindenmann Maximilian Brückner Wolfgang K. Oswald Georg Werkgartner Doris Wagner 《Journal of vascular surgery》2019,69(4):1227-1232
Objective
Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.Methods
Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.Results
We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.Conclusions
Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients. 相似文献8.
Alexander Real Chierika Ukogu Divya Krishnamoorthy Nicole Zubizarreta Samuel K. Cho Andrew C. Hecht James C. Iatridis 《The spine journal》2019,19(2):225-231
Background Context
Low back pain (LBP) is a common complaint in clinical practice of multifactorial origin. Although obesity has been thought to contribute to LBP primarily by altering the distribution of mechanical loads on the spine, the additional contribution of obesity-related conditions such as diabetes mellitus (DM) to LBP has not been thoroughly examined.Purpose
To determine if there is a relationship between DM and LBP that is independent of body mass index (BMI) in a large cohort of adult survey participants.Study Design
Retrospective analysis of prospectively collected National Health and Nutrition Examination Survey (NHANES) data to characterize associations between LBP, DM, and BMI in adults subdivided into 6 subpopulations: normal weight (BMI 18.5–25), overweight (BMI 25–30), and obese (BMI >30) diabetics and nondiabetics. Diabetes was defined with glycohemoglobin A1c (HbA1c) ≥6.5%.Patient Sample
11,756 participants from NHANES cohort.Outcome Measures
Percentage of LBP reported.Methods
LBP reported in the 1999-2004 miscellaneous pain NHANES questionnaire was the dependent variable examined. Covariates included HbA1c, BMI, age, and family income ratio to poverty as continuous variables as well as race, gender, and smoking as binary variables. Individuals were further subdivided by weight class and diabetes status. Regression and graphical analyses were performed on the study population as a whole and also on subpopulations.Results
Increasing HbA1c did not increase the odds of reporting LBP in the full cohort. However, multivariate logistic regression of the 6 subpopulations revealed that the odds of LBP significantly increased with increasing HbA1c levels in normal weight diabetics. No other subpopulations reported significant relationships between LBP and HbA1c. LBP was also significantly associated with BMI for normal weight diabetics and also for obese subjects regardless of their DM status.Conclusions
LBP is significantly related to DM status, but this relationship is complex and may interact with BMI. These results support the concept that LBP may be improved in normal weight diabetic subjects with improved glycemic control and weight loss, and that all obese LBP subjects may benefit from improved weight loss alone. 相似文献9.
Objectives
Iatrogenic injury of the Profunda Femoris Artery (PFA) at time of hip fixation surgery can increase morbidity and mortality and prolong the hospital stay. This is an injury that tends to pass unnoticed as a cause of postoperative deterioration despite being frequently reported in the literature. Our study aims to describe the anatomy of the PFA in relation to the medial femoral cortex with specific emphasis on its orientation relative to the position of a sliding hip screw side plate construct. By doing so we are able to present clear guidance to orthopaedic surgeons on how to avoid iatrogenic PFA injury at the time of hip fracture fixation.Methods
Using Computed Tomography Angiographic (CTA) studies, the course of the PFA in relation to the medial femoral cortex was traced in 44 patients (28 males and 16 females) with mean age of 65.6 years. Coronal and axial CT sections were cross-linked to specify the position of the PFA at 1?cm intervals.Results
The course of the artery could be divided into three parts relative to a fixed reference point. Proximal and distal parts of the artery were in a safer position in comparison to the middle part of the artery that was found very close to the femoral cortex and along the coronal axis of the femur (mean angle 2.9° from the femoral coronal axis and 13.8?mm from the medial femoral cortex). Using the commercially available side plate constructs, this part of the artery corresponded to the distal part of the plate (third and fourth holes).Conclusion
Special attention needs to be practiced by the operating surgeon while drilling into the third and fourth holes of the side plate. 相似文献10.
Stress Testing Versus CT Angiography in Patients With Diabetes and Suspected Coronary Artery Disease
Abhinav Sharma Adrian Coles Nishant K. Sekaran Neha J. Pagidipati Michael T. Lu Daniel B. Mark Kerry L. Lee Hussein R. Al-Khalidi Udo Hoffmann Pamela S. Douglas 《Journal of the American College of Cardiology》2019,73(8):893-902