全文获取类型
收费全文 | 415392篇 |
免费 | 22630篇 |
国内免费 | 1305篇 |
专业分类
耳鼻咽喉 | 5943篇 |
儿科学 | 12841篇 |
妇产科学 | 9059篇 |
基础医学 | 55517篇 |
口腔科学 | 9456篇 |
临床医学 | 37422篇 |
内科学 | 82116篇 |
皮肤病学 | 8464篇 |
神经病学 | 40347篇 |
特种医学 | 19051篇 |
外国民族医学 | 61篇 |
外科学 | 66760篇 |
综合类 | 3641篇 |
现状与发展 | 1篇 |
一般理论 | 222篇 |
预防医学 | 25155篇 |
眼科学 | 10194篇 |
药学 | 28075篇 |
1篇 | |
中国医学 | 667篇 |
肿瘤学 | 24334篇 |
出版年
2023年 | 2013篇 |
2022年 | 2430篇 |
2021年 | 6703篇 |
2020年 | 4273篇 |
2019年 | 6509篇 |
2018年 | 8956篇 |
2017年 | 6835篇 |
2016年 | 8183篇 |
2015年 | 9408篇 |
2014年 | 12258篇 |
2013年 | 16838篇 |
2012年 | 25636篇 |
2011年 | 25910篇 |
2010年 | 14772篇 |
2009年 | 13225篇 |
2008年 | 23594篇 |
2007年 | 25246篇 |
2006年 | 24861篇 |
2005年 | 25095篇 |
2004年 | 23706篇 |
2003年 | 22361篇 |
2002年 | 21619篇 |
2001年 | 8830篇 |
2000年 | 8374篇 |
1999年 | 8095篇 |
1998年 | 4656篇 |
1997年 | 3719篇 |
1996年 | 3117篇 |
1995年 | 2744篇 |
1994年 | 2444篇 |
1993年 | 2336篇 |
1992年 | 3743篇 |
1991年 | 3604篇 |
1990年 | 3450篇 |
1989年 | 3194篇 |
1988年 | 2822篇 |
1987年 | 2738篇 |
1986年 | 2623篇 |
1985年 | 2605篇 |
1984年 | 2400篇 |
1983年 | 1980篇 |
1982年 | 1864篇 |
1981年 | 1725篇 |
1980年 | 1578篇 |
1979年 | 2041篇 |
1978年 | 1669篇 |
1977年 | 1450篇 |
1975年 | 1525篇 |
1974年 | 1544篇 |
1973年 | 1413篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
HIV risk in vulnerable groups such as itinerant male street labourers is often examined via a focus on individual determinants. This study provides a test of a modified Information-Motivation-Behavioral Skills (IMB) model to predict condom use behaviour among male street workers in urban Vietnam. In a cross-sectional survey using a social mapping technique, 450 male street labourers from 13 districts of Hanoi, Vietnam were recruited and interviewed. Collected data were first examined for completeness; structural equation modelling was then employed to test the model fit. Condoms were used inconsistently by many of these men, and usage varied in relation to a number of factors. A modified IMB model had a better fit than the original IMB model in predicting condom use behaviour. This modified model accounted for 49% of the variance, versus 10% by the original version. In the modified model, the influence of psychosocial factors was moderately high, whilst the influence of HIV prevention information, motivation and perceived behavioural skills was moderately low, explaining in part the limited level of condom use behaviour. This study provides insights into social factors that should be taken into account in public health planning to promote safer sexual behaviour among Asian male street labourers. 相似文献
93.
94.
95.
Miguel A. Sanz Pau Montesinos Haesook T. Kim Guillermo J. Ruiz-Argüelles María S. Undurraga María R. Uriarte Lem Martínez Rafael H. Jacomo Homero Gutiérrez-Aguirre Raul A. M. Melo Rosane Bittencourt Ricardo Pasquini Katia Pagnano Evandro M. Fagundes Edo Vellenga Alexandra Holowiecka Ana J. González-Huerta Pascual Fernández Javier De la Serna Salut Brunet Elena De Lisa José González-Campos José M. Ribera Isabel Krsnik Arnold Ganser Nancy Berliner Raul C. Ribeiro Francesco Lo-Coco Bob L?wenberg Eduardo M. Rego 《Annals of hematology》2015,94(8):1347-1356
96.
Gastroesophageal reflux is the most common benign disorder of the esophagus and laparoscopic Nissen fundoplication has become the standard surgical treatment for its treatment. In our area, where the use of bougie calibration is debatable, postoperative dysphagia is encountered often after this surgery although it is usually not permanent. The aim of this study was to investigate the effect of using a soft silicone tube 39 F in diameter for esophageal calibration during laparoscopic Nissen fundoplication on the incidence of postoperative dysphagia. We divided cases scheduled to undergo laparoscopic Nissen fundoplication between January 2009 and November 2010 into two groups, each consisting 25 patients. Esophageal calibration with a 39 F silicone orogastric tube was used for the first group while there was no operative calibration in the second group. The surgical duration was recorded; the presence and severity of the postoperative dysphagia was calculated by using a dysphagia severity scoring system during the 1-year postoperative follow-up. The dysphagia severity scores were significantly lower in group 1 than group 2 on the postoperative second day and at the end of the first week and first month. We did not find a significant difference at the end of the 6-month and first year. There was also no significant difference regarding surgery duration. The use of a soft orogastric tube 39 F in diameter for esophagus calibration during laparoscopic Nissen fundoplication has significantly decreased the incidence of postoperative transient dysphagia without affecting the duration of surgery. Although dysphagia gradually resolves in the majority of patients, a safe and easy calibration method for its prevention is worth developing, and we believe that the use of our method in larger series could be beneficial. 相似文献
97.
98.
99.
Anna C. Rienmüller Sandro M. Krieg Franziska A. Schmidt Elias L. Meyer Bernhard Meyer 《The spine journal》2019,19(1):113-120
Background Context
The concept of dynamic stabilization (DS) of the lumbar spine for treatment of degenerative instability has been introduced almost two decades ago. Dynamic stabilization follows the principle of controlling movement in the coronal plane by providing load transfer of the spinal segment without fusion and, at the same time, reducing side effects such as adjacent segment disease (ASD). So far, only little is known about revision rates after DS due to ASD and screw loosening (SL).Purpose
The present study aimed to evaluate the longitudinal revision rates following dynamic pedicle screw stabilization in the lumbar spine and to determine specific risk factors predictive for ASD, SL, and overall reoperation in a large cohort with considerable follow-up.Design
We carried out a post hoc analysis of a prospectively collected database in a level I spine center.Patients Example
The patient sample comprised 283 (151 female/132 male) consecutive patients suffering from painful degenerative lumbar segmental instability with or without spinal stenosis who underwent DS of the lumbar spine (Ulrich Cosmic, Ulrich Medical, Ulm, Germany) between January 2008 and December 2011.Outcome Measures
Longitudinal reoperation rate and risk factors predictive for revision surgery were evaluated.Methods
We analyzed the longitudinal reoperation rate due to ASD and SL and overall reoperation. Risk factors such as age, gender, body mass index, lumbar lordosis (LL), number of segments, and number of previous surgeries were taken into account. Regular and mixed model logistic regressions were performed to determine risk factors for revision surgery on a patient and on a screw level.Results
The mean age was 65.7±10.2 years (range 31–88). One hundred thirty-two patients were stabilized in 1 segment, 134 in 2 segments, 15 in 3 segments, and 2 patients in 4 segments. Reoperation rate for ASD and SL after 1 year was 7.4 %, after 2 years was 15.0%, and after a mean follow-up of 51.4±15 months was 22.6%. Reasons for revision were SL in 19 cases (6.6%), ASD in 39 cases (13.7%), SL and ASD in 6 cases, hematoma in 2 cases (0.7%), cerebrospinal fluid fistulae in 3 cases (1.1%), infection in 6 cases (2.1%), and implant failure in 1 case (0.4%). The patients' age, the number of stabilized segments, and the number of previous surgeries and postoperative LL had a significant influence on the probability for revision surgery.Conclusions
Reoperation rates after DS of the lumbar spine are comparable with rigid fixations. The younger the patient and the more segments are involved, the lower the LL and the more previous surgeries were found, the higher was the risk of revision. Risk of revision was almost twice as high in men compared with women. We therefore conclude that for clear clinical indication and careful evaluation of preoperative imaging data, DS using the Cosmic system seems to be a possible option. The presented data will help to further tailor indication and patient selection. 相似文献100.
Krisztina Emeriewen Shwan Kadare Michael Tsatsos Yannis Athanasiadis Cheryl MacGregor Sal Rassam 《Neuro-ophthalmology (Aeolus Press)》2016,40(5):225-228
We present the case of a 74-year-old Caucasian female who suffered sudden visual loss after routine phacoemulsification cataract surgery. The patient was subsequently diagnosed with non-arteritic anterior ischaemic optic neuropathy. The case is described in detail, and a concise review of the literature is presented together with the authors’ view on the subject outlined. This is a very rare complication after cataract surgery even in high-risk patients with associated systemic co-morbidities. We suspect that the previous history of obesity, coronary artery disease, and arteriosclerosis contributed to the development of this serious ocular complication. We suggest appropriate measures to reduce the risk of its occurrence. 相似文献