首页 | 官方网站   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   162329篇
  免费   15477篇
  国内免费   9668篇
医药卫生   187474篇
  2024年   645篇
  2023年   2518篇
  2022年   6491篇
  2021年   8180篇
  2020年   5973篇
  2019年   5268篇
  2018年   5580篇
  2017年   5067篇
  2016年   4842篇
  2015年   7036篇
  2014年   8634篇
  2013年   8501篇
  2012年   11959篇
  2011年   12687篇
  2010年   8919篇
  2009年   7261篇
  2008年   8819篇
  2007年   8818篇
  2006年   8096篇
  2005年   7265篇
  2004年   5688篇
  2003年   5538篇
  2002年   4743篇
  2001年   3906篇
  2000年   3441篇
  1999年   3025篇
  1998年   1901篇
  1997年   1986篇
  1996年   1406篇
  1995年   1369篇
  1994年   1217篇
  1993年   834篇
  1992年   1094篇
  1991年   990篇
  1990年   870篇
  1989年   796篇
  1988年   724篇
  1987年   628篇
  1986年   578篇
  1985年   467篇
  1984年   405篇
  1983年   325篇
  1982年   286篇
  1981年   242篇
  1980年   213篇
  1979年   229篇
  1978年   201篇
  1977年   227篇
  1976年   200篇
  1974年   161篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
European Archives of Oto-Rhino-Laryngology - Several polymorphisms in a disintegrin and metalloproteinase 33 (ADAM33) have been implicated in susceptibility to allergic rhinitis (AR), but the...  相似文献   
2.
3.
1. To investigate Genkwa Flos hepatotoxicity, a cell metabolomics strategy combined with serum pharmacology was performed on human HL-7702 liver cells in this study.

2. Firstly, cell viability and biochemical indicators were determined and the cell morphology was observed to confirm the cell injury and develop a cell hepatotoxicity model. Then, with the help of cell metabolomics based on UPLC-MS, the Genkwa Flos group samples were completely separated from the blank group samples in the score plots and seven upregulated as well as two down-regulated putative biomarkers in the loading plot were identified and confirmed. Besides, two signal molecules and four enzymes involved in biosynthesis pathway of lysophosphatidylcholine and the sphingosine kinase/sphingosine-1-phosphate pathway were determined to investigate the relationship between Genkwa Flos hepatotoxicity and these two classic pathways. Finally, the metabolic pathways related to specific biomarkers and two classic metabolic pathways were analyzed to explain the possible mechanism of Genkwa Flos hepatotoxicity.

3. Based on the results, lipid peroxidation and oxidative stress, phospholipase A2/lysophosphatidylcholine pathway, the disturbance of sphingosine-1-phosphate metabolic profile centered on sphingosine kinase/sphingosine-1-phosphate pathway and fatty acid metabolism might be critical participators in the progression of liver injury induced by Genkwa Flos.  相似文献   

4.
5.
Objective: Acute graft-versus-host disease (aGVHD) is a common and life-threatening complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). The extent to which aGVHD increases inpatient costs associated with allo-HSCT has not been thoroughly evaluated. In this analysis, mortality, hospital length of stay (LOS) and costs associated with aGVHD during allo-HSCT admissions are evaluated.

Methods: This is a retrospective analysis of discharge records from the National Inpatient Sample database for patients receiving allo-HSCT between 1 January 2009 and 31 December 2013. Allo-HSCT discharges with an aGVHD diagnosis were included in the aGVHD group and those without any graft-versus-host disease (GVHD) diagnosis comprised the non-GVHD group. Mortality, LOS and costs were compared between the two groups, as well as within subgroups, including age (<18 vs. ≥18 years) and survival status (alive vs. deceased) at discharge.

Results: Overall, mortality (16.2% vs. 5.3%; p?<?.01), median hospital LOS (42.0 vs. 26.0 days; p?<?.01) and median total costs ($173,144 vs. $98,982; p?<?.01) were significantly increased in patients with aGVHD versus those without GVHD during hospitalizations for allo-HSCT, irrespective of age group. Patients with aGVHD who were <18 years of age had a lower mortality rate but greater hospital LOS and total costs versus patients aged ≥18 years. Patients who died during allo-HSCT hospitalization had longer LOS and incurred greater costs than those who survived in both the aGVHD and non-GVHD groups.

Conclusion: Occurrence of aGVHD during allo-HSCT admissions resulted in a tripling of the mortality rate and a near doubling of hospital LOS and total costs. In addition, death during allo-HSCT hospitalizations was associated with greater healthcare utilization and costs. Effectively mitigating aGVHD may improve survival and substantially reduce hospital LOS and costs for allo-HSCT.  相似文献   

6.
目的探讨化浊解毒方治疗溃疡性结肠炎(UC)的治疗作用及机制。方法120例UC患者按照随机数字表法分为观察组、对照组各60例。观察组予中药化浊解毒方口服,每日1剂,早晚2次温服;对照组予美沙拉嗪肠溶片口服,1.0 g/次,3次/d。2组疗程均4周。对比2组治疗前后Geboes指数、结肠镜下黏膜表现、生活质量评分、疾病活动指数及血清炎性因子IL-8、IL-35水平,凝血指标血清FIB水平,统计治疗后1年内复发情况。结果治疗后,观察组Geboes指数、疾病活动指数及血清炎性因子IL-8水平、凝血指标血清FIB水平均较本组治疗前降低,生活质量评分、血清炎性因子IL-35水平升高(P<0.05);且观察组治疗后疾病活动指数及血清炎性因子IL-8水平、凝血指标血清FIB水平均低于对照组,生活质量评分、血清炎性因子IL-35水平均高于对照组(P<0.05)。与对照组相比,治疗组糜烂、溃疡改善不明显(P>0.05),充血水肿、颗粒样变等肠镜表现改善情况均优于对照组(P<0.05)。治疗结束1年观察组复发率为10.64%,对照组为23.53%,2组差异有统计学意义(P<0.05)。结论化浊解毒方能改善UC患者临床症状,修复肠黏膜病理损伤,降低复发率;其机制可能与调节血清炎性因子IL-8、IL-35和凝血因子FIB水平有关。  相似文献   
7.
目的:通过对21例髋臼爆裂性骨折伴股骨头脱位的手术治疗,探讨处理此类损伤应注意的几个问题。方法:术前 X片及CT片明确骨折及脱位类型,采用患侧扩大的髂股入路或Langenbeck-Kocher入路,显露髂骨内外板及小骨盆内壁、髋臼前后柱,必要时显露坐骨大切迹,保持股骨头于脱位状态,直视下复位各骨折块尽量达到髓关节内软骨面光滑圆弧,在骨折复位状态下行内固定,之后使股骨头复位入髋臼,术后皮牵引,早期锻炼。结果:术后21例随访12~36个月, 骨折均愈合好,髋臼内壁形态光滑,元再脱位或创伤性关节炎症状出现。结论:髋臼爆裂性骨折伴股骨头脱位的病例,早期手术恢复髋臼内壁软骨面光滑圆弧可最大限度的恢复患肢功能,能有效地防止髓关节创伤性关节炎的发生,手术切口的选择是复位成功的关键,同时深静脉栓塞、坐骨神经的损伤及异位骨化的预防应予以重视。  相似文献   
8.
9.
10.
1 建立新型师生关系是实施素质教育的需要 传统教学中,教师是知识的载体,是教学活动的主宰。学生是教师知识传授的对象。课堂上,教师站在讲台上严肃认真地讲解。学生规规矩矩地坐在座位上专心听讲。教师讲的知识点,学生掌握了,就达到教学目的了。教师对学生最为关注的是其学习成绩。学生对教师则敬而远之,甚至关系紧张,很难向教师敞开心扉、畅所欲言。素质教育的核心就是创新教育。而这种师生关系严重阻碍了学生个性的发展和创新意识的培养。  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-23

京公网安备 11010802026262号