全文获取类型
| 收费全文 | 252969篇 |
| 免费 | 17927篇 |
| 国内免费 | 1131篇 |
专业分类
| 耳鼻咽喉 | 2806篇 |
| 儿科学 | 6512篇 |
| 妇产科学 | 4636篇 |
| 基础医学 | 33121篇 |
| 口腔科学 | 4593篇 |
| 临床医学 | 25409篇 |
| 内科学 | 53824篇 |
| 皮肤病学 | 3409篇 |
| 神经病学 | 24371篇 |
| 特种医学 | 8432篇 |
| 外国民族医学 | 11篇 |
| 外科学 | 38534篇 |
| 综合类 | 3458篇 |
| 一般理论 | 319篇 |
| 预防医学 | 21501篇 |
| 眼科学 | 6577篇 |
| 药学 | 17016篇 |
| 6篇 | |
| 中国医学 | 361篇 |
| 肿瘤学 | 17131篇 |
出版年
| 2023年 | 1343篇 |
| 2022年 | 2416篇 |
| 2021年 | 5449篇 |
| 2020年 | 3265篇 |
| 2019年 | 5310篇 |
| 2018年 | 5959篇 |
| 2017年 | 4480篇 |
| 2016年 | 4968篇 |
| 2015年 | 5839篇 |
| 2014年 | 8626篇 |
| 2013年 | 11826篇 |
| 2012年 | 18073篇 |
| 2011年 | 18956篇 |
| 2010年 | 10612篇 |
| 2009年 | 9461篇 |
| 2008年 | 16637篇 |
| 2007年 | 17492篇 |
| 2006年 | 17347篇 |
| 2005年 | 17307篇 |
| 2004年 | 16220篇 |
| 2003年 | 15087篇 |
| 2002年 | 14088篇 |
| 2001年 | 2134篇 |
| 2000年 | 1629篇 |
| 1999年 | 2348篇 |
| 1998年 | 3075篇 |
| 1997年 | 2565篇 |
| 1996年 | 2187篇 |
| 1995年 | 2097篇 |
| 1994年 | 1748篇 |
| 1993年 | 1576篇 |
| 1992年 | 1264篇 |
| 1991年 | 1164篇 |
| 1990年 | 1008篇 |
| 1989年 | 986篇 |
| 1988年 | 973篇 |
| 1987年 | 957篇 |
| 1986年 | 969篇 |
| 1985年 | 980篇 |
| 1984年 | 1226篇 |
| 1983年 | 1128篇 |
| 1982年 | 1379篇 |
| 1981年 | 1321篇 |
| 1980年 | 1157篇 |
| 1979年 | 718篇 |
| 1978年 | 765篇 |
| 1977年 | 651篇 |
| 1976年 | 598篇 |
| 1975年 | 478篇 |
| 1974年 | 483篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
1.
2.
Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments. 相似文献
3.
4.
5.
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6.
7.
Daniel J. Snyder Thomas R. Kroshus Aakash Keswani Evan B. Garden Karl M. Koenig Kevin J. Bozic David S. Jevsevar Jashvant Poeran Calin S. Moucha 《The Journal of arthroplasty》2019,34(4):613-618
Background
Nursing Home Compare (NHC) ratings, created and maintained by Medicare, are used by both hospitals and consumers to aid in the skilled nursing facility (SNF) selection process. To date, no studies have linked NHC ratings to actual episode-based outcomes. The purpose of this study was to evaluate whether NHC ratings are valid predictors of 90-day complications, readmission, and bundle costs for patients discharged to an SNF after primary total joint arthroplasty (TJA).Methods
All SNF-discharged primary TJA cases in 2017 at a multihospital academic health system were queried. Demographic, psychosocial, and clinical variables were manually extracted from the health record. Medicare NHC ratings were then collected for each SNF. For patients in the Medicare bundle, postacute and total bundle cost was extracted from claims.Results
Four hundred eighty-eight patients were discharged to a total of 105 unique SNFs. In multivariate analysis, overall NHC rating was not predictive of 90-day readmission/major complications, >75th percentile postacute cost, or 90-day bundle cost exceeding the target price. SNF health inspection and quality measure ratings were also not predictive of 90-day readmission/major complications or bundle performance. A higher SNF staffing rating was independently associated with a decreased odds for >75th percentile 90-day postacute spend (odds ratio, 0.58; P = .01) and a 90-day bundle cost exceeding the target price (odds ratio = 0.69; P = .02) but was similarly not predictive of 90-day readmission/complications.Conclusion
Results of our study suggest that Medicare's NHC tool is not a useful predictor of 90-day costs, complications, or readmissions for SNFs within our health system. 相似文献8.
9.
Maggie L. Westfal David C. Chang Cassandra M. Kelleher 《Journal of pediatric surgery》2019,54(1):140-144
Purpose
The purpose of this study was to evaluate trends in demographics and outcomes of pediatric breast cancer in a United States population-based cohort.Methods
The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify all pediatric patients with malignant breast tumors between 1973 and 2014. Analysis was performed using Stata Statistical Software version 13.1. Associations between categorical variables were made using X2 test. Log-rank test was used for univariate survival analysis. Kaplan–Meier analysis investigated five-year survival rates across several variables. Adjusted analysis was performed using a Cox Proportional-Hazards regression.Results
134 patients with breast malignancies were identified. Carcinoma was the most prevalent histology (48.5%), followed by fibroepithelial tumors (FETs) (35.1%), and sarcoma (14.2%). FETs were twice as common in black compared to nonblack patients (56.3% vs. 29.0%, p?<?0.01). Analyzing histology by stage revealed that 100% of FETs were early stage disease (p?<?0.0001). 46.7% of the tumors tested were ER/PR negative, more than twice as many compared to the published adult estimate of 20.0%. Unadjusted survival analysis revealed worse survival for patients with adenocarcinoma/sarcomas, advanced stage, and high grade disease, without a survival difference between races.Conclusion
Breast cancer remains a rare malignancy among pediatric patients. Although black patients were found to have more noncarcinomatous tumors with less advanced disease, this did not confer a survival advantage.Type of study
Retrospective cohort study.Level of evidence
Level III. 相似文献10.
Béla Nagy Zsolt Bene Zsolt Fejes Sonya L. Heltshe David Reid Nicola J. Ronan Yvonne McCarthy Daniel Smith Attila Nagy Elizabeth Joseloff György Balla János Kappelmayer Milan Macek Scott C. Bell Barry J. Plant Margarida D. Amaral István Balogh 《Journal of cystic fibrosis》2019,18(2):271-277