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   63600篇
  免费   4768篇
  国内免费   337篇
耳鼻咽喉   636篇
儿科学   1611篇
妇产科学   1543篇
基础医学   7862篇
口腔科学   1546篇
临床医学   6420篇
内科学   14474篇
皮肤病学   809篇
神经病学   5034篇
特种医学   2102篇
外国民族医学   2篇
外科学   9782篇
综合类   1020篇
现状与发展   1篇
一般理论   103篇
预防医学   5248篇
眼科学   1852篇
药学   4437篇
中国医学   139篇
肿瘤学   4084篇
  2023年   279篇
  2022年   388篇
  2021年   1161篇
  2020年   728篇
  2019年   1010篇
  2018年   1266篇
  2017年   857篇
  2016年   984篇
  2015年   1153篇
  2014年   1812篇
  2013年   2851篇
  2012年   3777篇
  2011年   4128篇
  2010年   2377篇
  2009年   2233篇
  2008年   4027篇
  2007年   4203篇
  2006年   4028篇
  2005年   4121篇
  2004年   3853篇
  2003年   3458篇
  2002年   3422篇
  2001年   738篇
  2000年   631篇
  1999年   729篇
  1998年   762篇
  1997年   632篇
  1996年   508篇
  1995年   504篇
  1994年   475篇
  1993年   455篇
  1992年   535篇
  1991年   512篇
  1990年   424篇
  1989年   459篇
  1988年   412篇
  1987年   386篇
  1986年   363篇
  1985年   431篇
  1984年   435篇
  1983年   398篇
  1982年   537篇
  1981年   449篇
  1980年   494篇
  1979年   305篇
  1978年   324篇
  1977年   327篇
  1976年   268篇
  1975年   291篇
  1974年   246篇
排序方式: 共有10000条查询结果,搜索用时 422 毫秒
951.
952.
953.
954.
Objectives: This study compared fentanyl vs. sufentanil in intrathecal pain pumps. H1: both reduce patient subjective pain ratings. H2: sufentanil is more effective than fentanyl. H3: overall satisfaction with pain control is greater with sufentanil. Materials/Method: This is an archival study of patients in tertiary pain management (N= 97, mean age = 58.77, standard deviation = 14.88). Pain was measured using the subjective units of discomfort scale. Satisfaction with pain control/relief was measured by asking patients each visit if they are satisfied with pain management and is recorded in a “yes”/ “no” manner. Pain ratings were analyzed with repeated measures analysis of variance and satisfaction was analyzed with chi square. Results/Discussion: Sufentanil was found to be marginally more effective, but both medications controlled a significant degree of variance in pain reduction over time. A significantly greater number of patients maintained on sufentanil were satisfied with care than patients on fentanyl.  相似文献   
955.
Breast implant associated anaplastic large cell lymphoma (BIA-ALCL) is a recently recognized clinical entity, with only 39 well-documented cases reported worldwide, including 3 fatalities. Because of its rarity, the clinical and pathologic features of this malignancy have yet to be fully defined. Moreover, the pathogenesis of ALCL in association with textured silicone gel breast implants is poorly understood. Here we report a case of BIA-ALCL arising in a 67-year-old woman with a mastectomy due to breast cancer followed by implantation of textured silicone gel breast prosthesis. The patient presented with breast enlargement and tenderness 8 years following reconstructive surgery. MRI revealed a fluid collection surrounding the affected breast implant. Pathologic examination confirmed the presence of malignant ALCL T cells that were CD30+, CD8+, CD15+, HLA-DR+, CD25+ ALK- and p53. A diagnosis of indolent BIA-ALCL was made since tumor cells were not found outside of the capsule. Interestingly, an extensive mixed lymphocytic infiltrate and ectopic lymphoid tissue (lymphoid neogenesis) adjacent to the fibrous implant capsule were present. The patient was treated with capsulectomy and implantation of new breast prostheses. Six months later, the patient was found to have BIA-ALCL involvement of an axillary lymph node with cytogenetic evolutionof the tumor. To our knowledge, this is the sixth reported case of aggressive BIA-ALCL. Unique features of this case include the association with lymphoid neogenesis and the in vivo cytogenetic progression of the tumor. This case provides insight into the potential role of chronic inflammation and genetic instability in the pathogenesis of BIA-ALCL.  相似文献   
956.
957.
958.
Background: Diabetes mellitus (DM) increases the risk for the development of both ischemic and nonischemic cardiomyopathy. We aimed to identify differences in response to cardiac resynchronization therapy with a defibrillator (CRT‐D) among DM patients with ischemic or nonischemic cardiomyopathy. Methods: Cox proportional hazards regression modeling was used to assess clinical response to CRT‐D (defined as CRT‐D vs. defibrillator‐only reduction in the risk of heart failure [HF] or death) and echocardiographic response (defined as percent reduction in left ventricular end diastolic and systolic volume [LVEDV and LVESV, respectively] at 12 month of follow‐up compared with baseline values) among 552 diabetic patients with ischemic (n = 367) or nonischemic (n = 185) cardiomyopathy enrolled in MADIT‐CRT. Results: The clinical benefit of CRT‐D was more pronounced among nonischemic patients (HR = 0.30 [P < 0.001] than among ischemic patients (HR = 0.59 [P = 0.004]; P for interaction = 0.10). Nonischemic patients also experienced significantly greater reductions in LVESV and LVEDV at 12 months with CRT‐D compared with ischemic patients (P < 0.001 for both). Subgroup analysis showed that the most pronounced reduction in HF or death with CRT‐D therapy occurred in nonischemic patients who were women (83% risk‐reduction [P < 0.001]), had a lower BMI (<30/kg/m2: 79% risk‐reduction [P < 0.001]), or had left bundle branch block at enrollment (82% risk‐reduction [P < 0.001]). Conclusions: The present study shows that treatment with CRT‐D in at‐risk cardiac patients with DM is associated with substantial reductions in the risk of HF or death and improvement in cardiac remodeling in those with ischemic and nonischemic cardiomyopathy, with a more pronounced benefit in patients with nonischemic disease. Ann Noninvasive Electrocardiol 2012;17(1):14–21  相似文献   
959.
960.
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