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   14875篇
  免费   703篇
  国内免费   92篇
耳鼻咽喉   329篇
儿科学   590篇
妇产科学   527篇
基础医学   1393篇
口腔科学   495篇
临床医学   1159篇
内科学   3393篇
皮肤病学   255篇
神经病学   853篇
特种医学   569篇
外科学   3026篇
综合类   356篇
一般理论   5篇
预防医学   716篇
眼科学   347篇
药学   937篇
中国医学   57篇
肿瘤学   663篇
  2023年   144篇
  2022年   259篇
  2021年   552篇
  2020年   305篇
  2019年   403篇
  2018年   486篇
  2017年   334篇
  2016年   487篇
  2015年   557篇
  2014年   671篇
  2013年   806篇
  2012年   1093篇
  2011年   1095篇
  2010年   629篇
  2009年   525篇
  2008年   954篇
  2007年   1061篇
  2006年   1033篇
  2005年   969篇
  2004年   820篇
  2003年   684篇
  2002年   609篇
  2001年   126篇
  2000年   111篇
  1999年   103篇
  1998年   87篇
  1997年   59篇
  1996年   60篇
  1995年   46篇
  1994年   30篇
  1993年   35篇
  1992年   34篇
  1991年   34篇
  1990年   35篇
  1989年   50篇
  1988年   36篇
  1987年   31篇
  1986年   31篇
  1985年   26篇
  1984年   21篇
  1983年   25篇
  1982年   13篇
  1981年   22篇
  1980年   19篇
  1979年   12篇
  1977年   13篇
  1976年   15篇
  1973年   13篇
  1972年   13篇
  1971年   12篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
Abdominal Radiology - Metastatic involvement of the ovaries is not rare. The most common tumor types metastasizing to the ovaries, from non-gynecological organs, are breast, colorectal, gastric,...  相似文献   
3.
4.
5.
6.

Background

Multiple myeloma (MM) is a hematologic malignancy of plasma cell origin. MM primarily affects bone marrow, but extramedullary sites can also be involved. Myelomatous pleural effusion (MPE) is an atypical and rare complication of MM. We aimed to systematically study the incidence and clinicopathologic profile of patients with MPE in a real-world setting.

Patients and Methods

In this retrospective study, 415 consecutive patients with MM managed at a tertiary care center in North India during a study period of January 1, 2010 to December 31, 2015 were evaluated for MPE. The patients with MPE were analyzed for their clinical profile, diagnosis, treatment, and outcomes.

Results

Of these 415 patients, 11 (2.65%) patients had MPE. The median age of the study population was 50 years with male preponderance. The majority of these patients had immunoglobin (Ig)G Kappa disease. All patients had higher than International Staging System stage I disease. MPE was a presenting feature at MM diagnosis in 45.45% (n = 5) of the patients, whereas the rest developed MPE during follow-up. MPE presented predominantly (81.8%) as a unilateral effusion. Concurrent extramedullary involvement at other site was seen in 45.45% (n = 5), with 3 (27%) patients having concurrent myelomatous ascites. Six of these were managed aggressively, whereas 5 patients opted for palliation. The outcomes were dismal (90.9% mortality), with a median survival of 2.47 months.

Conclusion

MPE is a rare entity, and positive outcomes of therapy remain low with dismal prognosis.  相似文献   
7.
Purpose: To study, with computational models, the utility of power modulation to reduce tissue temperature heterogeneity for variable nanoparticle distributions in magnetic nanoparticle hyperthermia.

Methods: Tumour and surrounding tissue were modeled by elliptical two- and three-dimensional computational phantoms having six different nanoparticle distributions. Nanoparticles were modeled as point heat sources having amplitude-dependent loss power. The total number of nanoparticles was fixed, and their spatial distribution and heat output were varied. Heat transfer was computed by solving the Pennes’ bioheat equation using finite element methods (FEM) with temperature-dependent blood perfusion. Local temperature was regulated using a proportional-integral-derivative (PID) controller. Tissue temperature, thermal dose and tissue damage were calculated. The required minimum thermal dose delivered to the tumor was kept constant, and heating power was adjusted for comparison of both the heating methods.

Results: Modulated power heating produced lower and more homogeneous temperature distributions than did constant power heating for all studied nanoparticle distributions. For a concentrated nanoparticle distribution, located off-center within the tumor, the maximum temperatures inside the tumor were 16% lower for modulated power heating when compared to constant power heating. This resulted in less damage to surrounding normal tissue. Modulated power heating reached target thermal doses up to nine-fold more rapidly when compared to constant power heating.

Conclusions: Controlling the temperature at the tumor-healthy tissue boundary by modulating the heating power of magnetic nanoparticles demonstrably compensates for a variable nanoparticle distribution to deliver effective treatment.  相似文献   

8.
9.
10.
Different methods have been used throughout the years for syndesmotic injury but there is no consensus on the ideal treatment. Some methods are expensive and some have more complications. The aim of this study is to compare single suture endobutton with double suture endobutton and screw fixation for syndesmotic injury.Sixty nine patients with syndesmotic injury with fibular fractures whom were treated with a single interosseous suture endobutton system (ZipTightTM, Zimmer Biomet), a double interosseous suture endobutton system (ZipTightTM, Zimmer Biomet) and 1 syndesmotic screw (TST, Istanbul, Turkey) were included in this study. Functional and radiological results from patient records between 2015 and 2018 were retrospectively evaluated.Twenty patients were treated with the double interosseous suture endobutton, 23 were treated with the single interosseous suture endobutton, and 26 were treated with traditional AO screw fixation. Three patients from the screw fixation group (11.5%) required revision surgery (P < .05). All the radiologic and clinical outcomes were statistical similar in all 3 groups.Our findings showed that the interosseous suture endobutton system is at least as safe as the screw fixation technique for treatment of syndesmosis joint injuries and can be used as an alternative to the screw method. The interosseous suture endobutton system eliminates the need for a second surgery to remove the hardware, which minimizes the probability of re-diastasis. Since our results showed no statistical difference between single and double interosseous suture endobutton systems, the less costly single endobutton system may be the better alternative.  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