首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1743篇
  免费   52篇
  国内免费   15篇
耳鼻咽喉   24篇
儿科学   132篇
妇产科学   77篇
基础医学   118篇
口腔科学   61篇
临床医学   128篇
内科学   326篇
皮肤病学   37篇
神经病学   135篇
特种医学   113篇
外科学   394篇
综合类   11篇
预防医学   39篇
眼科学   85篇
药学   71篇
肿瘤学   59篇
  2024年   1篇
  2023年   12篇
  2022年   21篇
  2021年   23篇
  2020年   16篇
  2019年   15篇
  2018年   18篇
  2017年   28篇
  2016年   52篇
  2015年   52篇
  2014年   60篇
  2013年   113篇
  2012年   132篇
  2011年   151篇
  2010年   78篇
  2009年   73篇
  2008年   146篇
  2007年   168篇
  2006年   158篇
  2005年   145篇
  2004年   110篇
  2003年   68篇
  2002年   57篇
  2001年   26篇
  2000年   14篇
  1999年   13篇
  1998年   7篇
  1997年   7篇
  1996年   4篇
  1995年   3篇
  1994年   5篇
  1993年   3篇
  1992年   2篇
  1991年   2篇
  1990年   2篇
  1989年   6篇
  1985年   10篇
  1983年   2篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1973年   2篇
  1970年   1篇
排序方式: 共有1810条查询结果,搜索用时 15 毫秒
991.
Objective:To determine the effect of Ankaferd Blood Stopper (ABS) on the shear bond strength (SBS) of orthodontic attachments.Materials and Methods:The study material consisted of 60 freshly extracted bovine permanent mandibular incisor teeth. All teeth were cleaned and randomly divided into three groups of 20 specimens and etched with 37% phosphoric acid for 15 seconds, washed, and air-dried. Teeth in groups 1 and 2 were contaminated with ABS and blood, respectively. Teeth in group 3 were only air-dried. Roth Generous maxillary central incisor brackets were bonded with Transbond XT to all teeth. SBS was applied using a universal test machine. The one-way analysis of variance (ANOVA) test was used to determine significant differences in SBS between the three groups, and Tukey honestly significant post hoc test was used to compare subgroups.Results:The mean bond strengths and standard deviations of groups 1, 2, and 3 were 9.58 ± 0.95, 4.04 ± 0.69, and 19.56 ± 1.84 MPa, respectively.Conclusions:Specimens contaminated with blood showed a statistically significant lower in vitro SBS than those contaminated with ABS. ABS may be used clinically for obtaining a blood-free tooth surface during application of the brackets on surgically exposed, impacted teeth.  相似文献   
992.
993.
994.

Objective

To determine the most efficient route and timing of oxytocin administration for active management of the third stage of labor.

Methods

A prospective randomized study was done at one center in Ankara, Turkey, between January and October 2010. Women with a singleton pregnancy (> 37 weeks) who had a live vaginal birth were randomly allocated to four groups: iv-A (intravenous oxytocin after delivery of the fetus), iv-B (when anterior shoulder seen), im-A (intramuscular oxytocin after delivery), and im-B (when anterior shoulder seen). Postpartum blood loss within the first hour, hemoglobin, hematocrit, and duration of the third stage were compared.

Results

A total of 600 eligible women were recruited; 150 were assigned to each group. Postpartum blood loss, prepartum and postpartum hemoglobin and hematocrit, and need for additional uterotonics were similar among groups (P > 0.05). The duration of the third stage of labor and changes in hemoglobin and hematocrit were significantly reduced in group iv-B (P < 0.05). Among women not exposed to oxytocin before delivery, postpartum blood loss was significantly lower in group iv-B (P = 0.019). Labor augmentation was related to significantly increased postpartum blood loss in all groups except iv-A.

Conclusion

Although postpartum blood loss was similar in all groups, early intravenous administration seemed to have beneficial effects.ClinicalTrials.gov: NCT01954186.  相似文献   
995.
A 17-year-old female patient presented with chronic symmetrical oligoarthritis of both knees and ankles, xerostomia, xerophthalmia, multiple bilateral lymphadenopathies in the cervical region, and bilateral parotid enlargement with the histological finding of chronic sialoadenitis. She had been already given methotrexate, chloroquine, and corticosteroids with the diagnosis of rheumatoid arthritis (RA) before referral to our outpatient clinic. Because her complaints and the lumps did not remit and she could be classified as neither RA nor primary Sjögren’s syndrome (SS) according to 1987 ACR RA criteria or European preliminary criteria for SS, lymph node biopsy was repeated and revealed the diagnosis of Rosai–Dorfman disease (RDD) with the histological findings of histiocytes, phagocyting lymphocytes in enlarged sinuses, and mature plasma cells infiltrating the pulpa. All the medications were stopped after the pathological diagnosis of RDD and consulting with the Division of Hematology. She was reevaluated with magnetic resonance imaging, which showed dense infiltrative areas around knee and ankle joints, and computed tomography that showed a soft tissue mass surrounding the descending aorta and upper part of the abdominal aorta. Activated partial thromboplastin time was found to be prolonged in prebiopsy examinations, and factor XII deficiency was detected after detailed hematological evaluation. The symptoms of joint involvement were relieved with nonsteroidal antiinflammatory drugs. She has been followed-up without medication without obvious clinical or laboratory change. We herein report a patient with RDD mimicking RA and SS. We consider that RDD should be kept in mind especially in patients with resistant symptoms to conventional therapies, younger disease onset, and predominant parotid and lymph node enlargement.  相似文献   
996.
997.

Background

The risk of developing a second primary tumour in patients with gastric carcinoma is higher than among the general population. The aim was to investigate the clinicopathological characteristics of the second primary cancers in patients with gastric cancer in this study.

Patients and methods

In the retrospective study, patients with gastric cancers were evaluated between 1995 and 2005 for primary tumours according to Warren and Gates’ criteria related with the second primary cancers.

Results

Nine of the 112 patients with gastric cancer had second primary cancers. Seven of the patients were males and two females. Six patients with gastric cancers had synchronous, and three had metachronous tumours. The age of the patients ranged from 53 to 78 years, and the mean age was 61 ± 8.3 years. The most frequent site of occurrence of the second tumours was the colo-rectum (33%) followed by the upper respiratory system (22%), and the urogenital system (22%) in descending order of frequency.

Conclusions

The incidence of the second primary cancer in gastric cancer patients was 8% in the current report. It is recommended that careful preoperative and postoperative examinations for other primary cancers, as well as for the extent of the primary gastric carcinoma, are carried out. Because colorectal cancer was the most common carcinoma combined with gastric carcinoma, the surveillance for this carcinoma (e.g., colonoscopy, abdominopelvic CT) would be appropriate after the diagnosis of gastric carcinoma.  相似文献   
998.
Anomalous systemic arterial supply to the lungs with normal bronchial branching and pulmonary arterial supply is an unusual variant of the sequestration spectrum. Pseudosequestration is referred as the combination of systemic arterial supply to lung with normal bronchial connection. Thorax computed tomography (CT) and CT angiography are non‐invasive and useful techniques in making the definitive diagnosis. Herein, we report two paediatric patients with anomalous systemic arterial supply to normal basal segments of the lower lobes.  相似文献   
999.
1000.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号