全文获取类型
| 收费全文 | 1510087篇 |
| 免费 | 114259篇 |
| 国内免费 | 2996篇 |
专业分类
| 耳鼻咽喉 | 21022篇 |
| 儿科学 | 50354篇 |
| 妇产科学 | 39444篇 |
| 基础医学 | 212519篇 |
| 口腔科学 | 37913篇 |
| 临床医学 | 134705篇 |
| 内科学 | 306835篇 |
| 皮肤病学 | 31129篇 |
| 神经病学 | 122906篇 |
| 特种医学 | 58955篇 |
| 外国民族医学 | 668篇 |
| 外科学 | 231065篇 |
| 综合类 | 30314篇 |
| 现状与发展 | 1篇 |
| 一般理论 | 700篇 |
| 预防医学 | 115875篇 |
| 眼科学 | 33813篇 |
| 药学 | 110591篇 |
| 8篇 | |
| 中国医学 | 2759篇 |
| 肿瘤学 | 85766篇 |
出版年
| 2021年 | 13033篇 |
| 2019年 | 14015篇 |
| 2018年 | 18652篇 |
| 2017年 | 14122篇 |
| 2016年 | 15530篇 |
| 2015年 | 17726篇 |
| 2014年 | 25096篇 |
| 2013年 | 37127篇 |
| 2012年 | 52558篇 |
| 2011年 | 55451篇 |
| 2010年 | 32611篇 |
| 2009年 | 30543篇 |
| 2008年 | 51882篇 |
| 2007年 | 55217篇 |
| 2006年 | 55294篇 |
| 2005年 | 54291篇 |
| 2004年 | 52435篇 |
| 2003年 | 50227篇 |
| 2002年 | 48668篇 |
| 2001年 | 65880篇 |
| 2000年 | 67942篇 |
| 1999年 | 58489篇 |
| 1998年 | 17938篇 |
| 1997年 | 16107篇 |
| 1996年 | 16164篇 |
| 1995年 | 15332篇 |
| 1994年 | 14375篇 |
| 1993年 | 13228篇 |
| 1992年 | 45673篇 |
| 1991年 | 44465篇 |
| 1990年 | 43104篇 |
| 1989年 | 40977篇 |
| 1988年 | 37766篇 |
| 1987年 | 37083篇 |
| 1986年 | 34461篇 |
| 1985年 | 33135篇 |
| 1984年 | 25257篇 |
| 1983年 | 21274篇 |
| 1982年 | 12979篇 |
| 1981年 | 11897篇 |
| 1979年 | 21988篇 |
| 1978年 | 15524篇 |
| 1977年 | 13117篇 |
| 1976年 | 12233篇 |
| 1975年 | 13050篇 |
| 1974年 | 15092篇 |
| 1973年 | 14470篇 |
| 1972年 | 13251篇 |
| 1971年 | 11965篇 |
| 1970年 | 11260篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
1.
2.
3.
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
4.
5.
6.
7.
8.
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9.
M. Iachina P.M. Ljungdalh R.G. Sørensen L. Kaerlev J. Blaakær O. Trosko N. Qvist B.M. Nørgård 《Clinical oncology (Royal College of Radiologists (Great Britain))》2019,31(2):115-123
Aims
To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.Materials and methods
The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.Results
In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).Conclusions
We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis. 相似文献10.
Adilson Cunha Ferreira Edward Araujo Júnior Wellington P. Martins João Francisco Jordão Antônio Hélio Oliani Simon E. Meagher 《The journal of maternal-fetal & neonatal medicine》2015,28(14):1706-1710
Objective: To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.Methods: In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.Results: The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI?=?66.4–86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI?=?70.0–80.8%) the scores of transmitted image were considered the same as the original.Conclusion: We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality. 相似文献