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   47691篇
  免费   4466篇
  国内免费   3639篇
耳鼻咽喉   298篇
儿科学   431篇
妇产科学   482篇
基础医学   5635篇
口腔科学   742篇
临床医学   6905篇
内科学   7469篇
皮肤病学   586篇
神经病学   2611篇
特种医学   1922篇
外国民族医学   23篇
外科学   4374篇
综合类   7687篇
现状与发展   15篇
一般理论   7篇
预防医学   2918篇
眼科学   1484篇
药学   5018篇
  81篇
中国医学   2836篇
肿瘤学   4272篇
  2024年   153篇
  2023年   858篇
  2022年   2039篇
  2021年   2622篇
  2020年   1965篇
  2019年   1650篇
  2018年   1756篇
  2017年   1513篇
  2016年   1456篇
  2015年   2166篇
  2014年   2636篇
  2013年   2332篇
  2012年   3460篇
  2011年   3887篇
  2010年   2361篇
  2009年   1854篇
  2008年   2475篇
  2007年   2549篇
  2006年   2473篇
  2005年   2571篇
  2004年   1484篇
  2003年   1331篇
  2002年   1110篇
  2001年   1099篇
  2000年   1145篇
  1999年   1208篇
  1998年   787篇
  1997年   800篇
  1996年   617篇
  1995年   568篇
  1994年   514篇
  1993年   300篇
  1992年   378篇
  1991年   308篇
  1990年   282篇
  1989年   242篇
  1988年   230篇
  1987年   208篇
  1986年   154篇
  1985年   110篇
  1984年   50篇
  1983年   38篇
  1982年   19篇
  1981年   12篇
  1980年   13篇
  1979年   12篇
  1966年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
A protein (Rp66) of 66 kDa was shown by DNA-binding protein blot assay to bind to a human repetitive DNA sequence (low-repeat sequence; LRS) in each of 10 transformed human cell lines examined. This protein-DNA interaction was not observed in 11 normal human cell cultures or in the Chinese hamster cell line CHO-K1. Gel retardation assay confirmed the specificity of the protein-DNA binding between Rp66 and LRS. In a histiocytic lymphoma human cell line, U937, that can be induced to differentiate in the presence of phorbol ester, this binding disappeared after cell differentiation. These together with other results cited suggest a regulatory role for these repetitive sequences in the human genome, with particular application to cancer.  相似文献   
32.
p16INK4A (p16) binds to cyclin-dependent kinase 4/6 and negatively regulates cell growth. Recent studies have led to an understanding of additional biologic functions for p16; however, the detailed mechanisms involved are still elusive. In this article, we show an unexpected expression of anion exchanger 1 (AE1) in the cytoplasm in poorly and moderately differentiated gastric and colonic adenocarcinoma cells and in its interaction with p16, thereby sequestrating the protein in the cytoplasm. Genetic alterations of p16 and AE1 were not detectable. Forced expression of AE1 in these cells sequestrated more p16 in the cytoplasm, whereas small interfering RNA-mediated silencing of AE1 in the cells induced the release of p16 from the cytoplasm to the nucleus, leading to cell death and growth inhibition of tumor cells. By analyzing tissue samples obtained from patients with gastric and colonic cancers, we found that 83.33% of gastric cancers and 56.52% of colonic cancers coexpressed AE1 and p16 in the cytoplasm. We conclude that AE1 plays a crucial role in the pathogenesis of gastric and colonic adenocarcinoma and that p16 dysfunction is a novel pathway of carcinogenesis.  相似文献   
33.
和谐是发展的条件,和谐产生动力。如何利用和谐因素消除不和谐因素,是中医发展值得重视和研究的问题。对中医发展中的和谐方面进行了探讨。  相似文献   
34.
利福喷汀治疗耐利福平肺结核的疗效分析   总被引:1,自引:0,他引:1  
目的分析增加利福喷汀的用药剂量对利福平耐药肺结核的疗效,以评价利福喷汀在治疗利福平耐药患者中的作用。方法根据药敏结果选取耐利福平肺结核患者101例,分为治疗1组(利福平低耐),治疗2组(利福平高耐),两组治疗方案中均含利福喷汀,对照组(利福平高耐)治疗方案中不合利福喷汀。观察治疗后3、18个月疗效。结果治疗1组在各阶段的痰菌阴转率、病灶吸收和空洞闭和情况明显优于治疗2组和对照组,两组差异有统计学意义;治疗2组的痰菌阴转率、病灶吸收和空洞闭和情况略优于对照组,两者差异无统计学意义。结论对利福平耐药的患者尤其在利福平低度耐药病例中,可以选择增加利福喷汀用药剂量的方案进行治疗,在利福平高度耐药病例中利福喷汀的作用不能确定。  相似文献   
35.
BACKGROUND: The impact of exercise programmes for heart failure on those close to the patient is largely unknown. We examined the effect of a hospital and home-based exercise intervention on burden, anxiety and depression of informal caregivers. DESIGN: The study was a randomized, controlled trial. Heart failure patients were randomized to a seated 12-week hospital-based exercise programme. Caregiver measures were gathered at baseline, 3 months later and 6 months following baseline. METHODS: Sixty caregivers (mean age 63.4 years, 65% female) of heart failure patients (n = 82, mean age 80.5 years, 44% female) participating in a trial of an exercise intervention were recruited. Caregiver burden, anxiety and depression were assessed. RESULTS: There were no differences in caregiver burden, depression or anxiety between the two groups of caregivers at baseline (caregiver burden, patient control 33.1 versus patient exercise 34.1; anxiety 4.1 versus 5.5; depression 2.8 versus 3.8). At 3 months there were no differences between caregivers in the two groups on outcomes. At 6-month follow-up caregivers of heart failure patients in the exercise group had burden scores that were significantly worse than the control group. There were no differences between the carers of exercise and control groups in anxiety and depression. Levels of anxiety and depression in the entire carer sample were marginally higher than reference values in a healthy non-clinical sample. CONCLUSION: The present exercise interventions for frail older patients did not benefit caregivers and was associated with an increase in caregiver burden. We suggest that future exercise interventions for heart failure patients should actively incorporate informal caregivers into research designs.  相似文献   
36.
高业霞  Xu Donghong  刘一鸣 《护理研究》2008,22(22):2024-2025
[目的]探讨颅脑损伤病人应用亚低温治疗仪时具体间隔多长时间翻身不发生压疮.[方法]随机选择45例颅脑损伤应用亚低温治疗的病人,采取3 h后开始翻身,侧卧位时每次均为1 h,以后平卧位时间每次逐渐递增1/2 h.[结果]在应用亚低温治疗期间除3例病人在不同时段内发生轻微紫色冻伤外,所有病例均未发生压疮,平均翻身间隔时间为11.31 h,应用单样本统计学处理,有统计学意义(t=8.867,P<0.005).[结论]颅脑损伤病人在使用亚低温治疗过程中翻身间隔时间可以延长至8 h不发生压疮.  相似文献   
37.
Advanced age has been associated with a wide range of defects in both the innate and adaptive immune systems including diminished specific antibody responses that increase the risk of invasive pneumococcal disease (IPD) and limit the effectiveness of vaccines. However, the elderly are a heterogeneous group and measures of overall frailty may be a better indicator of disease susceptibility (or vaccine response) than chronological age alone.  相似文献   
38.
小切口股骨近端解剖钢板治疗股骨转子间骨折   总被引:5,自引:4,他引:1  
目的 探讨股骨转子间骨折的治疗方法和疗效。方法小切口微创股骨近端解剖钢板内固定治疗股骨转子间骨折17例。结果 随访时间8个月~3年,平均1.6年,优良16例,占94%(16/17)。结论 小切口微创股骨近端解剖钢板内固定治疗股骨转子间骨折具有切口小、出血少等优点,是一种微创手术。  相似文献   
39.
40.
称量了14—38周共56例引产胎儿胸腺的重量并观察了6—38周共25例引产胎儿胸腺的组织结构,认为胸腺在胚胎时期生长速度较快。光镜观察,6周已出现胸腺的始基,第9周开始出现淋巴细胞,12周开始分叶,13周以后,皮质髓质渐趋分明并出现胸腺小体,15周后胸腺小叶增多变宽,新小叶形成旺盛,胸腺小体增多,至28周后结构已近似成熟。  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