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   2253篇
  免费   117篇
  国内免费   5篇
耳鼻咽喉   27篇
儿科学   87篇
妇产科学   35篇
基础医学   272篇
口腔科学   119篇
临床医学   209篇
内科学   418篇
皮肤病学   42篇
神经病学   237篇
特种医学   46篇
外科学   410篇
综合类   28篇
一般理论   1篇
预防医学   90篇
眼科学   42篇
药学   161篇
中国医学   15篇
肿瘤学   136篇
  2023年   15篇
  2022年   37篇
  2021年   89篇
  2020年   51篇
  2019年   81篇
  2018年   82篇
  2017年   54篇
  2016年   48篇
  2015年   58篇
  2014年   86篇
  2013年   113篇
  2012年   183篇
  2011年   167篇
  2010年   105篇
  2009年   87篇
  2008年   163篇
  2007年   128篇
  2006年   118篇
  2005年   114篇
  2004年   99篇
  2003年   83篇
  2002年   74篇
  2001年   29篇
  2000年   31篇
  1999年   30篇
  1998年   20篇
  1997年   14篇
  1996年   9篇
  1995年   11篇
  1994年   7篇
  1993年   8篇
  1992年   9篇
  1991年   21篇
  1990年   12篇
  1989年   16篇
  1988年   11篇
  1987年   17篇
  1986年   8篇
  1985年   11篇
  1984年   8篇
  1983年   10篇
  1982年   3篇
  1981年   8篇
  1980年   3篇
  1979年   5篇
  1974年   3篇
  1917年   4篇
  1916年   3篇
  1905年   2篇
  1879年   2篇
排序方式: 共有2375条查询结果,搜索用时 15 毫秒
81.

Background

Robotic surgery is increasingly adopted into surgical practice, but it remains unclear what level of robotic training general surgery residents receive. The purpose of our study was to assess the variation in robotic surgery training amongst general surgery residency programs in the United States.

Methods

A web-based survey was sent to 277 general surgery residency programs to determine characteristics of resident experience and training in robotic surgery.

Results

A total of 114 (41%) programs responded. 92% (n?=?105) have residents participating in robotic surgeries; 68%(n?=?71) of which have a robotics curriculum, 44%(n?=?46) track residents’ robotic experience, and 55%(n?=?58) offer formal recognition of training completion. Responses from university-affiliated (n?=?83) and independent (n?=?31) programs were not significantly different.

Conclusions

Many general surgery residencies offer robotic surgery experience, but vary widely in requisite components, formal credentialing, and case tracking. There is a need to adopt a standardized training curriculum and document resident competency.  相似文献   
82.

Introduction

Thoracic trauma comprises 10–15 % of all traumas. The incidence and etiological pattern of chest trauma varies from region to region and is related to cultural and socio-political circumstances. This paper details our experience with thoracic trauma in a North Indian state.

Material & methods

All patients who were hospitalized for thoracic trauma from June 2010 to June 2012 in our hospital were enrolled. Data was collected prospectively and analysed. Factors analysed were age, gender, mode of injury, type of thoracic injury, associated injuries, management modalities, and outcome.

Results

The total number of patients was 250. The male to female ratio was about 10:1. The mean age of patients was 36.62 years. Road Traffic Accident (RTA) was the most common mode of chest injury. Motor-bike accident was the most common type of RTA. Majority of patients were managed with tube thoracostomy (183, 73.2 %). One hundred and eighty nine (75.6 %) patients were discharged after recovery. Ten (4.0 %) patients absconded. In all, 29 (11.6 %) patients died, while 22 (8.8 %) patients left the hospital against medical advice. A significant association between presence of associated injury and outcome was observed (p?<?0.001). We found mortality rate was significantly higher in chest injury associated with neurotrauma and abdominal visceral injury.

Conclusion

Chest trauma is a major health problem since it has high morbidity and mortality rate. The majority of patients with simple chest injuries can be managed by tube thoracostomy. According to our analysis; mortality predictors were: RTAs, blunt chest trauma, unstable hemodynamic status upon arrival, neurotrauma, abdominal visceral injury, flail chest, ventilator use, cardiac contusion and complications of therapy.  相似文献   
83.
84.
BackgroundPrevious data has shown that severe traumatic injury is associated with bone marrow dysfunction, which manifests as persistent injury-associated anemia. This study sought to identify whether the expression of erythropoiesis-related microRNAs were altered in the bone marrow of trauma patients to determine if these microRNAs play a role in persistent injury-associated anemia.MethodsBone marrow was collected from severely injured trauma patients who underwent fracture fixation as well as patients who underwent elective hip replacement. There were 27 trauma patients and 10 controls analyzed. Total RNA and microRNA were isolated from CD34-positive cells using the RNeasy Plus Mini kit, and genome-wide microRNA expression patterns were assayed. Genes with significant expression differences were found using BRB-ArrayTools with a significance of P < .01.ResultsThere were marked differences in expression of 108 microRNAs in the trauma group when compared with hip replacement patients. Four of these microRNAs play a role in regulating erythropoiesis: microRNA-150, microRNA-223, microRNA15a, and microRNA-24. These microRNAs were all upregulated significantly, with trauma/hip replacement fold changes of 1.7, 1.8, 1.2, and 1.2 respectively, and all act to suppress or regulate erythropoiesis.ConclusionAssessment of the bone marrow microRNA profile in trauma patients compared to those undergoing elective hip replacement revealed the differential expression of microRNA-150, microRNA-223, microRNA-15a, and microRNA-24. These microRNAs all play a role in decreased erythroid progenitor cell growth and provide important insight to the erythropoietic dysfunction seen after trauma.  相似文献   
85.
BackgroundThe prevalence of total joint arthroplasty (TJA) in the United States has drawn the attention of health care stakeholders. The payers have also used a variety of strategies to regulate the medical necessity of these procedures. The purpose of this study was to examine the level of evidence of the coverage policies being used by commercial payers in the United States.MethodsThe references of the coverage policies of four commercial insurance companies were reviewed for type of document, level of evidence, applicability to a TJA population, and success of nonoperative treatment in patients with severe degenerative joint disease.Results282 documents were reviewed. 45.8% were primary journal articles, 14.2% were level I or II, 41.2% were applicable to patients who were candidates for TJA, and 9.9% discussed the success of nonoperative treatment in patients who would be candidates for TJA.ConclusionMost of the references cited by commercial payers are of a lower level of scientific evidence and not applicable to patients considered to be candidates for TJA. This is relatively uniform across the reviewed payers. The dearth of high-quality literature cited by commercial payers reflects the lack of evidence and difficulty in conducting high level studies on the outcomes of nonoperative versus operative treatment for patients with severe, symptomatic osteoarthritis. Patients, surgeons, and payers would all benefit from such studies and we encourage professional societies to strive toward that end through multicenter collaboration.  相似文献   
86.
We conducted a randomized trial to evaluate effectiveness of Centchroman in control of mastalgia and compared it with Danazol. Research Question- Is proportion of pain relief achieved by Centchroman similar to or inferior to that achieved by Danazol? In a randomized controlled trial of Centchroman vs. Danazol in mastalgia, 81 patients with mastalgia were studied. Thirty-nine patients were randomized to Danazol arm and 42 in Centchroman arm. The treatment was given for 12 weeks, followed by observation for 12 weeks. The pain was measured by visual analogue scale (VAS) of 0–10. At 12 weeks 89.7% women achieved reduction in pain score to ≤3 in Centchroman group (pvalue 0.001). In Danazol group 69.44% women achieved reduction in pain score to ≤ 3 (p = 0.001). Three months after stopping therapy, Centchroman was more effective in pain score reduction at 24 weeks as compared to Danazol (p = 0.019). Centchroman is an effective, safe and inexpensive alternative to Danazol for treatment of mastalgia.

Electronic supplementary material

The online version of this article (doi:10.1007/s12262-010-0216-z) contains supplementary material, which is available to authorized users.  相似文献   
87.
88.
Dextrocardia is a rare congenital condition which presents important challenges for surgical management. We discuss a patient with dextrocardia, atrial septal defect, and Eisenmenger syndrome, which ultimately led to decompensated end‐stage lung disease and heart‐lung transplant. Venous‐venous extracorporeal membrane oxygenation was an important strategy to bridge the patient until donor organs became available. Transplantation of a heart‐lung block allowed for the treatment of the patient's underlying congenital heart defect, anatomic reversal of dextrocardia with appropriate venous and arterial connections, and management of pulmonary damage from pulmonary hypertension.  相似文献   
89.
90.

Purpose

To evaluate the role of SWE in characterizing breast masses and ascertain whether additional use of SWE to ultrasound for evaluating BI-RADS 3 and 4a masses could help reduce long-term follow-up and unnecessary biopsies of these suspicious breast masses.

Materials and methods

This prospective, cross-sectional study was performed between June 2013 and November 2014. All enrolled patients underwent clinical breast examination, ultrasound, SWE and ultrasound-guided core biopsy of the breast mass. Breast Imaging Reporting and Data System (BI-RAD) categories were assigned to breast masses. For qualitative and quantitative variables of SWE, cut-off values for differentiation between benign and malignant breast masses were estimated. Modified BIRADS’ (up/downgrading of BIRADS category) was done for BI-RADS 3/4a masses by combining individual SWE parameters and ultrasound findings. Sensitivity, specificity, positive and negative predictive value of modified BI-RADS’ and ultrasound BI-RADS were compared.

Results

A total of 119 women (mean age, 42.3 ± 13.6 [SD] years; range: 13–87 years) with a single breast mass each were enrolled. Histopathologically, 57/119 (48%) breast masses were benign and 62 (52%) were malignant. On ultrasound, 42 breast masses were BI-RADS3 and 77 were BI-RADS 4 (4a, n = 10; 4b, n = 24; 4c, n = 43) leading to 96.8% sensitivity and 70.2% specificity. On SWE, benign breast masses were oval/round, homogenous/reasonably homogenous, blue/green with lower elasticity values and malignant breast masses were irregular, inhomogeneous, red/orange with high elasticity values. On modified BI-RADS’ using E-color and E-mean/E-max, specificity improved to 78.9% and 75.4% respectively.

Conclusion

Addition of SWE to ultrasound improves characterization of BI-RADS 3 and 4a masses. E-max, E-mean and E-color are the most useful SWE parameters to differentiate between malignant and benign breast masses.  相似文献   
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