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   368篇
  免费   27篇
  国内免费   5篇
耳鼻咽喉   1篇
儿科学   25篇
妇产科学   3篇
基础医学   40篇
口腔科学   30篇
临床医学   41篇
内科学   69篇
皮肤病学   5篇
神经病学   15篇
特种医学   61篇
外科学   29篇
综合类   28篇
预防医学   20篇
药学   10篇
中国医学   4篇
肿瘤学   19篇
  2023年   1篇
  2022年   1篇
  2021年   10篇
  2020年   5篇
  2019年   3篇
  2018年   4篇
  2017年   6篇
  2016年   6篇
  2015年   9篇
  2014年   8篇
  2013年   18篇
  2012年   17篇
  2011年   18篇
  2010年   26篇
  2009年   12篇
  2008年   10篇
  2007年   8篇
  2006年   9篇
  2005年   8篇
  2004年   5篇
  2003年   5篇
  2002年   3篇
  2001年   3篇
  2000年   6篇
  1999年   3篇
  1998年   23篇
  1997年   14篇
  1996年   19篇
  1995年   8篇
  1994年   13篇
  1993年   9篇
  1992年   3篇
  1991年   8篇
  1990年   5篇
  1989年   11篇
  1988年   12篇
  1987年   15篇
  1986年   10篇
  1985年   6篇
  1984年   6篇
  1983年   3篇
  1982年   8篇
  1981年   2篇
  1980年   5篇
  1979年   1篇
  1978年   1篇
  1977年   3篇
  1976年   7篇
  1975年   2篇
  1971年   2篇
排序方式: 共有400条查询结果,搜索用时 9 毫秒
61.
目的探讨不同类型肾脏占位病变的超声造影特点。方法对照病理诊断结果分析76例肾脏占位病变Sono Vue超声造影特征。结果肾恶性肿瘤62例,良性肿瘤14例。肾恶性肿瘤超声造影剂的充盈和消退呈多样性,以同步增强和快增强多见,造影剂的快速消退和缓慢消退之间无明显差别,差异无统计学意义(P>0.05)。恶性肿瘤典型的表现是整个病灶弥漫增强,轮廓边界清晰,呈"亮球"征(95.2%),并多有假包膜(87.1%)。肾错构瘤表现为无假包膜的不均匀增强,而肾囊肿始终无增强。结论超声造影有助于肾占位病变的鉴别诊断和预后判断。  相似文献   
62.
63.
This systematic review examines critically the scientific basis for Canada's Physical Activity Guide for Healthy Active Living for adults. Particular reference is given to the dose-response relationship between physical activity and premature all-cause mortality and seven chronic diseases (cardiovascular disease, stroke, hypertension, colon cancer, breast cancer, type 2 diabetes (diabetes mellitus) and osteoporosis). The strength of the relationship between physical activity and specific health outcomes is evaluated critically. Literature was obtained through searching electronic databases (e.g., MEDLINE, EMBASE), cross-referencing, and through the authors' knowledge of the area. For inclusion in our systematic review articles must have at least 3 levels of physical activity and the concomitant risk for each chronic disease. The quality of included studies was appraised using a modified Downs and Black tool. Through this search we identified a total of 254 articles that met the eligibility criteria related to premature all-cause mortality (N = 70), cardiovascular disease (N = 49), stroke (N = 25), hypertension (N = 12), colon cancer (N = 33), breast cancer (N = 43), type 2 diabetes (N = 20), and osteoporosis (N = 2). Overall, the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified. Moreover, higher levels of physical activity reduce the risk for premature all-cause mortality. The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality.  相似文献   
64.
摘要:目的 探讨新疆乌鲁木齐市维吾尔族人群成人支气管哮喘的影响因素。方法 本研究采用成组匹配病例对照研究方法,病例组为新疆医科大学第一附属医院呼吸内科在2014年1-12月确诊的维吾尔族支气管哮喘成人患者(n=120例),对照组为同期体检中心健康维吾尔族体检者(n=126例),两组在年龄、性别相匹配。采用问卷调查的方法收集相关暴露资料,并采用单因素分析及多因素非条件Logistic回归模型分析成人支气管哮喘影响因素。结果 多因素Logistic回归分析显示,吸烟(OR=1.88,95% CI:1.28~2.96)、家族支气管哮喘史(OR=6.20,95% CI:2.10~18.31)、家中铺有纯毛地毯数量多(OR=1.87,95% CI:1.18~2.95),睡眠质量(OR=1.46,95% CI:1.22~1.75),患慢性支气管炎(OR=13.43,95% CI:6.65~25.34)及过敏性鼻炎(OR=6.27,95% CI:3.63~10.81)是维吾尔族成人支气管哮喘的主要影响因素。结论 维吾尔族成人支气管哮喘是生活方式、环境及遗传等多种因素共同作用的结果,应加强对相关影响因素的预防及治疗,减少哮喘的发生,改善哮喘患者生活质量。  相似文献   
65.
Aim:   Human epidermal growth factor receptor 2 (HER2) overexpression is associated with poor prognosis and the frequency of HER2 positivity in breast cancer patients varies among different regions of the world. We studied HER2 expression in Turkish breast cancer patients.
Methods:   HER 2 expression was evaluated immunohistochemically in 107 breast cancer patients. HER2 expression was reported as negative or positive (3+) according to cellular membrane staining characteristics. The frequency of HER2 overexpression, distribution according to clinical characteristics, effect on survival and effect of chemotherapy on survival in relation to HER2 overexpression was evaluated.
Results:   The median age of patients was 49 years (range 27–76). HER2 was 3+ in 34 patients (31.8%). There was no significant difference in age, menopausal status, histopathology, lymph node involvement, stage and estrogen and/or progesterone receptor positivity in relation to HER2 expression. Forty-three patients (40.2%) relapsed and 21 patients (19.6%) died during the follow-up period. There was no significant difference in the relapse rate, distribution of relapse sites and death rate in relation to HER2 expression. The 3- and 5-year disease free survival rates were 67.1 and 40.5%, and the overall survival rates were 87.5 and 66.1%, respectively. Survival rate and calculated survival time were relatively shorter in HER2 3+ patients than in non-HER2 3+ patients, but these differences were not statistically significant. HER2 status did not affect survival period according to chemotherapy group.
Conclusion:   Immunohistochemistry findings of HER2 expression in Turkish breast cancer patients were similar to those found in the published reports. A shorter survival period was observed in HER2 3+ patients, but the difference was not statistically significant.  相似文献   
66.
67.
68.
Caecal diverticulitis is an uncommon phenomenon in western countries. The clinical diagnosis is often difficult as it mimics other acute abdominal conditions like appendicitis, colitis or neoplasia. Diagnosis is often made at operation. Operative strategy has been controversial and there is no broad consensus emerging. We report the case of a 71-year-old woman, known to have chronic obstructive pulmonary disease, who presented acutely with right iliac fossa pain. A clinical diagnosis of appendicitis was made. At laparoscopy, a solitary, inflamed, gangrenous caecal diverticulum was found. A laparoscopic stapled diverticulectomy was performed. The patient made a steady post-operative recovery. Histology confirmed diverticulitis. We conclude that stapled diverticulectomy for solitary caecal diverticulitis is a safe and effective surgical strategy when confronted with this scenario.  相似文献   
69.
70.
B Wenz  ; ER Burns 《Transfusion》1991,31(9):829-834
The residual white cell (WBC) content of donated units of red cell concentrate rendered WBC-reduced by filtration through commercially available polyester filters was quantified and phenotypically analyzed. All studies were performed by flow cytometery. Quantification studies were performed with a DNA/RNA fluorophore, propidium iodide. WBC subset analyses were performed with fluorescence-labeled monoclonal antibodies directed against various cluster differentiation (CD) loci. The results indicate that the filter removes in excess of 3 log10 total WBCs from the red cell components and depletes granulocytes to or beyond the specific assay's sensitivity of 3 log10. Total T and B cells, T4 and T8 lymphocytes, and monocytes are reduced by approximately 4 log10. These analyses provide plausible explanations for the clinical success of the filter and suggest other potential applications.  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