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   2544篇
  免费   217篇
  国内免费   6篇
耳鼻咽喉   20篇
儿科学   117篇
妇产科学   56篇
基础医学   371篇
口腔科学   31篇
临床医学   222篇
内科学   740篇
皮肤病学   112篇
神经病学   109篇
特种医学   200篇
外科学   289篇
综合类   20篇
预防医学   173篇
眼科学   41篇
药学   112篇
中国医学   19篇
肿瘤学   135篇
  2023年   15篇
  2022年   24篇
  2021年   57篇
  2020年   34篇
  2019年   56篇
  2018年   78篇
  2017年   57篇
  2016年   69篇
  2015年   54篇
  2014年   80篇
  2013年   87篇
  2012年   111篇
  2011年   152篇
  2010年   103篇
  2009年   70篇
  2008年   106篇
  2007年   116篇
  2006年   118篇
  2005年   117篇
  2004年   85篇
  2003年   92篇
  2002年   81篇
  2001年   82篇
  2000年   66篇
  1999年   60篇
  1998年   49篇
  1997年   56篇
  1996年   70篇
  1995年   53篇
  1994年   28篇
  1993年   29篇
  1992年   32篇
  1991年   40篇
  1990年   37篇
  1989年   38篇
  1988年   53篇
  1987年   41篇
  1986年   49篇
  1985年   34篇
  1984年   14篇
  1983年   15篇
  1981年   15篇
  1980年   9篇
  1979年   11篇
  1978年   15篇
  1977年   19篇
  1976年   10篇
  1975年   16篇
  1974年   10篇
  1971年   8篇
排序方式: 共有2767条查询结果,搜索用时 93 毫秒
1.

Background

Intramedullary nailing is considered a “gold standard” for treatment of tibial shaft fractures. However, some types of fractures are typically considered as “difficult for nailing”. This group includes the periarticular fractures, fractures of both bones at the same level, comminuted and segmental fractures of the tibia. Fixator-assisted nailing (FAN) is an effective method treatment of these types of fractures. The main requirements for the ideal reduction device are an ease of its installation and an ability of multiplanar fracture reduction. Fixator-assisted nailing (FAN) with the use of two perpendicular to each other monolateral tubular frames perfectly meets these requirements. In this study we present this new surgical technique and the analysis of first 30 cases.

Methods

A prospective analysis was conducted for 30 patients with “difficult for nailing” tibial fractures treated with fixator-assisted nailing in our institution between September 1st, 2017, and March 1st, 2018. The duration of surgery and its different stages, the time of fluoroscopy, difficulties encountered during surgery, were analyzed. Clinical and radiological methods were used to evaluated reduction quality.

Results

In all 30 cases the acceptable reduction was achieved. The mean duration of the surgical procedure was 73.7?±?3?min. The mean duration of fluoroscopy 85.9?±?4.8?s. In 7 cases we faced with technical difficulties, which were successfully addressed.

Conclusion

The described technique of FAN is an effective method for the treatment of “difficult for nailing” tibial fractures. Future multi-centered studies with a larger number of patients are needed to validate our results.  相似文献   
2.
Background and study aimsThe COVID-19 outbreak has reorganized surgical team conditions regarding endoscopy. The number of interventions has been reduced, the number of healthcare professionals must be limited, and both the patients and physicians are more protected than ever.Patients and MethodsIn the highest peak of contagion in Colombia, endoscopy, colonoscopy, and esophagogastroduodenoscopy were performed using a low-cost disposable device. A total of 1388 procedures were performed. Every patient was assessed for symptoms via a telephone call, at the health center, and after the procedure, following specific attention routes.ResultsAfter procedure follow-up, no positive cases of COVID-19 were noted.ConclusionThe methodology reduced the risk of infection during the COVID-19 pandemic.  相似文献   
3.
Definitive radiotherapy is an effective single-modality in T1 glottic cancer. Hypofractionated schemes could offer excellent results in a shorter treatment period. We aimed to evaluate the clinical outcomes and toxicity comparing conventional vs. hypofractionated radiotherapy treatment in T1N0M0-glottic cancer. Between Jan-1st, 2005 and August-1st, 2017, in a prospective cohort study, with 10-year follow-up, 138 patients were treated with conventional schedule 2 Gy/day, total dose 70 Gy/7 weeks (N = 71) or hypofractionated schedule 2, 2–2, 25 Gy/day, total dose 63, 8–63 Gy/5, 5 weeks (N = 67). Endpoints were clinical-response rate, local relapse-free survival (LRFS), laryngectomy-free survival (LFS), toxicity rates, relapse-free survival (RFS), metastasis-free survival (MFS), second tumour-free survival (2TFS), and overall survival (OS). All patients showed a complete clinical response. No differences were found for LRFS (p = 0.869), LFS (p = 0.975), RFS (p = 0.767), MFS (p = 0.601), 2TFS (p = 0.293), or OS (p = 0.685). Acute toxicity for skin and mucosae was similar (p = 0.550 and p = 0.698). Acute laryngeal toxicity was higher in the hypofractionation group (p = 0.004), due to an increase in slight moderate grade. No differences in late laryngeal edema were found (p = 0.989). Radiotherapy offers high rate survival, local control, and larynx preservation after 5–10-year follow-up. A hypofractionation could be preferable, since it offers the same results as conventional with fewer treatment sessions.  相似文献   
4.
5.
6.
7.
The observation that tumor cells of some neoplasms display major histocompatibility complex (MHC) class II molecules may be of functional significance, influencing the progression of malignancy by allowing the cancer cells to present antigen to the immune system. In the normal cervix, class II molecules are expressed by columnar but not squamous epithelium. The pattern of MHC class II expression in cervical carcinomas has been documented using immunohistochemical methods. Of 53 cervical squamous carcinomas examined for MHC class II expression, only 17% maintained a negative phenotype characteristic of the epithelium from which they were derived, while the remaining tumors exhibited either uniform (45%) or heterogeneous (38%) expression. Tumor areas which were class II positive also express class II associated invariant chain and the adhesion molecules lymphocyte function antigen 3 and intercellular adhesion molecule 1. The DR, DP, and DQ class II MHC subloci are differentially expressed, suggesting independent regulation. There is a trend for tumors with the uniform class II phenotype to predominantly express DR antigen, whereas tumors of the heterogeneous class II phenotype express with equal frequency either DR or DP antigens dominantly. There is no apparent influence of class II status on lymphocyte infiltration of the tumors. The presence of human papillomavirus 16 DNA in the cervical carcinoma specimens was analyzed by Southern blotting of restriction enzyme digested DNA and no correlation between the presence of human papilloma virus and MHC class II expression was found.  相似文献   
8.
9.
10.
A potential public health concern is the reported detection of the human T-lymphotropic virus (HTLV) tax gene in the lymphocytes of up to 11% of a low-risk group of New York City blood donors (NYBD). This study aimed to independently confirm the prevalence of HTLV tax sequences in 293 NYBD. All NYBD tested negative for antibodies to HTLV types 1 and 2 and HTLV Tax. HTLV tax sequences were not detected in the NYBD lymphocytes. These data demonstrate the lack of HTLV-1 tax in this group of NYBD at low risk for HTLV infection.  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