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   2661篇
  免费   160篇
  国内免费   12篇
耳鼻咽喉   11篇
儿科学   31篇
妇产科学   188篇
基础医学   349篇
口腔科学   32篇
临床医学   268篇
内科学   671篇
皮肤病学   28篇
神经病学   293篇
特种医学   70篇
外科学   459篇
综合类   9篇
预防医学   72篇
眼科学   15篇
药学   104篇
中国医学   4篇
肿瘤学   229篇
  2023年   22篇
  2022年   30篇
  2021年   59篇
  2020年   34篇
  2019年   62篇
  2018年   54篇
  2017年   56篇
  2016年   63篇
  2015年   61篇
  2014年   98篇
  2013年   114篇
  2012年   162篇
  2011年   165篇
  2010年   107篇
  2009年   97篇
  2008年   180篇
  2007年   156篇
  2006年   155篇
  2005年   146篇
  2004年   138篇
  2003年   132篇
  2002年   126篇
  2001年   72篇
  2000年   91篇
  1999年   66篇
  1998年   29篇
  1997年   22篇
  1996年   22篇
  1995年   18篇
  1994年   14篇
  1993年   11篇
  1992年   32篇
  1991年   29篇
  1990年   24篇
  1989年   12篇
  1988年   21篇
  1987年   10篇
  1986年   17篇
  1985年   10篇
  1984年   11篇
  1983年   12篇
  1982年   9篇
  1980年   7篇
  1979年   7篇
  1978年   5篇
  1974年   5篇
  1973年   9篇
  1972年   5篇
  1969年   8篇
  1968年   8篇
排序方式: 共有2833条查询结果,搜索用时 31 毫秒
1.
2.
A retrospective study of 1058 liver transplant recipients was performed to determine: (i) the incidence, etiology, timing, clinical features and treatment of refractory ascites (RA), (ii) risk factors for RA development, (iii) predictors of RA disappearance, (iv) predictors of survival following RA and (v) the impact of RA on patient survival. Sixty-two patients (5.9%) developed RA and its disappearance occurred in 27/62 cases. Patients having hepatitis C virus (HCV) had a significantly higher hazard rate of developing RA (p < 0.00001). No other baseline characteristic was associated with RA. Cox stepwise regression analysis of the hazard rate of RA disappearance found two significant factors: HCV recurrence as the reason for developing RA implied a poorer outcome (p = 0.006), whereas an unknown reason implied a favorable outcome (p = 0.02). In addition, survival following RA was significantly poorer among patients having bacterial peritonitis or HCV recurrence. Finally, the mortality rate was significantly (nearly 8.6 times) higher in patients following RA development while it was ongoing (p < 0.00001); however, if the RA disappeared, then the additional risk of death also disappeared. This study illustrates the importance of developing an optimal treatment strategy to (i) effectively treat RA if it develops and (ii) prevent hepatitis C recurrence.  相似文献   
3.
OBJECTIVES: To evaluate a novel method for localization of subdural electrodes in presurgical assessment of patients with drug-resistant focal epilepsy. METHODS: We studied eight consecutive patients with posterior epilepsy in whom subdural electrodes were implanted for presurgical evaluation. Electrodes were detected on post-implantation brain CT scans through a semiautomated procedure based on a MATLAB routine. Then, post-implantation CT scans were fused with pre-implantation MRI to localize the electrodes in relation to the underlying cortical structures. The reliability of this procedure was tested by comparing 3D-rendered MR images of the electrodes with electrode position as determined by intraoperative digital photography. RESULTS: In each patient, all electrodes could be correctly localized and visualized in a stereotactic space, thus allowing optimal surgery planning. The agreement between the procedure-generated images and the digital photographs was good according to two independent raters. The mean mismatch between the 3D images and the photographs was 2 mm. CONCLUSIONS: While our findings need confirmation on larger samples including patients with anterior epilepsy, this procedure allowed to localize subdural electrodes and to establish the spatial relationship of each electrode to the underlying brain structure, either normal or damaged, on brain convessity, basal and medial cortex. SIGNIFICANCE: Being simple, rapid, unexpensive, and reliable, this procedure holds promise to be useful to optimize epilepsy surgery planning.  相似文献   
4.
The most common surgical techniques performed for gluteal augmentation employ the use of implants and a combination of liposuction/lipo-injection procedures. We review the major literature concerning this subject with emphasis on gluteal implants, the various indications, surgical techniques and complications are discussed and we present some of our cases. Contour reconstruction, indications such as malformation, asymmetry, trauma and radiotherapy may require custom-made or regular implants, liposuction or lipo-injection procedures and sometimes free flaps. Gluteal implants for aesthetic purposes are widely used, particularly in South America, are easy to perform with a high success rate, whereas lipS200osuction and lipo-injection procedures require considerable experience in Coleman fat injection.  相似文献   
5.
6.
ESR response to gamma-irradiation (1-50 Gy) of blends containing alanine and either B(OH)(3) or Gd(2)O(3) is reported. The sensitivity of the alanine--B(OH)(3) blend is comparable to the sensitivity of pure alanine, although its lowest detectable dose, LDD, is smaller ( approximately 1.3 Gy) than that of pure alanine ( approximately 2.9 Gy). Alanine with Gd(2)O(3) is about two times more sensitive than pure alanine, and its LDD is 0.8 Gy. The better sensitivity and LDD are probably due to the high atomic number (Z=64) of gadolinium, which enhances the interaction probability with photons and, consequently, the radical yield. This study suggests that other high-Z atoms may be useful for increasing the sensitivity of the response of alanine to gamma-radiation.  相似文献   
7.
During the period from March to September 1989, 40 children suffering from primary nocturnal enuresis, aged between 5 and 14 years, were included in a study to assess the comparative therapeutical efficacy of DDAVP and acupuncture. Children were divided into four groups of 10: group A was treated with DDAVP, group B was treated with acupuncture, group C was treated with DDAVP and acupuncture and group D was treated with placebo (control). The trial design included 3 periods: observation (2 weeks), treatment (8 weeks) and follow-up (4 weeks). Nineteen children completed the study. The efficacy of treatment, which was expressed as a percentage of dry nights, was high in both the DDAVP and acupuncture groups, when used separately. The combined treatment of DDAVP and acupuncture appeared to be the most efficacious both in terms of the percentage of dry nights at the end of treatment and in relation to the stability of results, even after the end of the study. The paper gives a detailed analysis of correlations between type of treatment and urinary osmolarity.  相似文献   
8.
9.
10.
We investigated the role of donor bone marrow cell (DBMC) infusions in immunosuppression withdrawal in adult liver transplantation. Patients enrolled were at least 3 years post-transplantation, with stable graft function. Forty-five (study group: G1) received DBMC, and 59 (control group: G2) did not. Immunosuppression was reduced by one third upon enrollment, by another third the second year of the study and was completely withdrawn the third year. Patient and graft survival were similar between the two groups. Although rejection episodes were significantly less in G1 the first 2 years of the study (35% vs. 57%, p = 0.016), there was no significant difference overall (74% vs. 81%, p = 0.14). Until February 2004, 20 patients, 10 in each group, were immunosuppression free for 1-3 years. Approximately 20% of long-term survivors of liver transplantation can successfully discontinue their immunosuppression. DBMC infusions, do not increase this likelihood.  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