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   14748篇
  免费   2254篇
  国内免费   554篇
耳鼻咽喉   95篇
儿科学   295篇
妇产科学   149篇
基础医学   1287篇
口腔科学   267篇
临床医学   1582篇
内科学   2195篇
皮肤病学   148篇
神经病学   1082篇
特种医学   307篇
外国民族医学   5篇
外科学   758篇
综合类   2724篇
一般理论   8篇
预防医学   3096篇
眼科学   165篇
药学   1538篇
  10篇
中国医学   1120篇
肿瘤学   725篇
  2024年   105篇
  2023年   386篇
  2022年   896篇
  2021年   1147篇
  2020年   1057篇
  2019年   740篇
  2018年   658篇
  2017年   724篇
  2016年   783篇
  2015年   718篇
  2014年   1243篇
  2013年   1191篇
  2012年   1070篇
  2011年   1076篇
  2010年   818篇
  2009年   679篇
  2008年   641篇
  2007年   581篇
  2006年   463篇
  2005年   403篇
  2004年   320篇
  2003年   269篇
  2002年   203篇
  2001年   195篇
  2000年   175篇
  1999年   128篇
  1998年   104篇
  1997年   71篇
  1996年   70篇
  1995年   68篇
  1994年   63篇
  1993年   65篇
  1992年   39篇
  1991年   32篇
  1990年   46篇
  1989年   35篇
  1988年   32篇
  1987年   35篇
  1986年   25篇
  1985年   28篇
  1984年   25篇
  1983年   28篇
  1982年   26篇
  1981年   15篇
  1980年   19篇
  1979年   18篇
  1978年   10篇
  1977年   11篇
  1976年   15篇
  1974年   4篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
BackgroundObesity in children contributes to higher risks of various chronic diseases in adulthood and the prevalence has increased worldwide including Japan.ObjectivesThis study aims to examine the association between sleep duration at night in children aged 2.5 years and the subsequent risk of obesity at age 5.5 years.MethodsThis study is embedded in the Longitudinal Survey on Babies Born in the 21st Century, which recruited families who had a child born in Japan in 2001. The multivariable logistic regression models were applied to calculate odds ratios (OR) and 95 % confidence intervals (CI) of childhood obesity at 5.5 years, defined as percentage of overweight (POW) ≥ 20 % and body mass index (BMI) ≥ 95th percentile of this study population according to sleep duration at night collected at 2.5 years child age.ResultsAmong 25,378 children, 2.6 % and 3.7 % were obese at age 5.5 years defined by POW and BMI respectively. Compared with night sleep duration > 11 h/d, shorter sleep durations in 2.5 years-old children were associated with higher risk of obesity at 5.5 years; the multivariable ORs (95 %CI) were 1.05 (0.81–1.35), 1.23 (0.93–1.62) and 1.54 (1.04–2.31) for sleep duration 10, 9 and ≤ 8 h/d, respectively; p-trend = 0.03. The observed association differed according to the children (child’s sex, napping habits, and children frequently play at park), and family characteristics (mother’s age at delivery and mother’s level of education).ConclusionShort night sleep duration among girls aged 2.5 years was associated with risk of obesity at age 5.5 years, suggesting the importance of sufficient sleep duration at night for the prevention of obesity.  相似文献   
93.
通过对小儿阳气特点的探讨,认为小儿阳多阴少乃是小儿生长发育过程中的需要,而阳气郁遏往往成为小儿疾患常见的原因,通阳法通过使郁遏之阳气得以舒展、畅通,宣泄、从而达到阳通阴和,重新获得阴阳平衡的目的。  相似文献   
94.
目的明确人SR-AI转基因小鼠的一些形态、脏器、血液学和血浆脂质参数,为人SR-AI转基因小鼠模型的应用提供相关依据.方法用游标卡尺和电子称量天平测量人SR-AI转基因小鼠的吻长、眶间距、体长、尾长及12个脏器系数并与C57BL/6J小鼠进行比较分析;用SysmexK-4500型全血自动多参数血液分析仪检测其血液学指标;并用酶法分别测定血浆总胆固醇、甘油三酯和高密度脂蛋白胆固醇含量.结果人SR-AI转基因小鼠外部形态指标和脏器系数与C57BL/6J小鼠比较差异没有显著意义(P>0.05);转基因小鼠的各项血液学指标无明显改变,血脂蛋白成分的改变亦未显示统计学意义(P>0.05),甘油三酯的浓度略有增高(P<0.05).结论人SR-AI转基因小鼠的外部形态指标、脏器系数及各项血液学指标均无明显改变,适合用作动脉粥样硬化模型的研究.  相似文献   
95.
96.
目的 通过挖掘整理含丹参-当归的方剂,利用统计软件系统分析其用药规律。方法 检索筛选《中医方剂大辞典》中含丹参-当归药对的方剂,利用Excel软件分析中药使用频次、频率及丹参-当归配伍特征和主治中医病证频次,运用SPSS Modeler 18.0软件关联规则Apriori算法进行数据挖掘。结果 通过统计共筛选出含丹参-当归药对的方剂390首,频次统计分析发现涉及中药504味,使用频次≥60的中药共22味,除丹参、当归外,核心高频药物为川芎、甘草、白芍、肉桂、地黄、牛膝6味。通过组方规律分析得到常用中药组合有丹参-当归-川芎、丹参-当归-甘草、丹参-当归-白芍。主治病证涉及105种,频次≥10的中医病证10种,以瘀血疼痛病症、妇科病症为主。通过网络可视化得到治疗月经病的核心中药组合为丹参-当归-川芎-白芍-香附,治疗痹证的核心中药组合为丹参-当归-川芎-肉桂,治疗虚劳病核心中药组合为丹参-当归-牛膝-肉桂-防风。结论 与丹参-当归配伍的高频中药为白芍、川芎、肉桂等,优势病证为月经病、痹证和虚劳病,揭示了丹参-当归药对的用药规律,为该药对在临床合理用药及深入研究与开发提供科学依据。  相似文献   
97.
霍山石斛Dendrobium huoshanense作为一种名贵的滋补类中药,收载于《中国药典》2020年版。多糖为其主要活性成分之一,具有免疫调节、保肝、抗肿瘤、抗氧化和抗炎等药理活性。通过查阅国内外文献,基于中国知网及PubMed等中英文文献数据库分析当前研究现状及研究热点;总结霍山石斛多糖(Dendrobium huoshanense polysaccharide,DHP)的提取分离、结构解析及其生物活性;分析其多糖成分与其他常用石斛品种的差异性。以期更好地开发利用DHP,为DHP产品的深入开发与研究及质量标准完善提供参考和思路。  相似文献   
98.
ObjectiveTo analyze the clinical characteristics and controllable risk factors of osteoporosis in elderly men with type‐2 diabetes mellitus (T2DM).MethodsA total of 250 elderly OP patients with T2DM were included in the present study. Patients with one or more common chronic diseases (including hypertension, coronary heart disease, heart failure, chronic bronchitis, chronic nephrosis, and cirrhosis), and a course of more than 3 years were defined as complicated with chronic diseases. Blood glucose, cholesterol, triglyceride, low‐density lipoprotein, high‐density lipoprotein, calcium, phosphorus, glycosylated hemoglobin, urea nitrogen, creatinine, fasting insulin, liver function, and 25‐hydroxy vitamin D3 levels were measured. Bone mineral density was also measured.ResultsA total of 16 patients (6.4%) had severe osteoporosis. Furthermore, 66 patients (26.4%) had blood glucose control that reached the standard, while 176 patients (70.4%) used more than two anti‐diabetic drugs. The serum testosterone level was lower than the median in 87 patients (34.8%) and in 56 smokers (22.4%). Furthermore, 138 patients (55.2%) were overweight and obese, six patients (2.4%) were underweight, 197 patients (78.8%) had chronic diseases, 88 patients (35.2%) were sticking to exercise, and 117 patients (46.8%) had less exercise. In addition, 92 patients (36.8%) were treated with osteotrophy‐protective agents, and 24 patients (9.6%) received anti‐osteoporosis therapy. Smoking, poor glycemic control, low testosterone levels, less exercise, and complications with chronic diseases were the most relevant controllable risk factors.ConclusionFor elderly male osteoporosis patients with type‐2 diabetes, smoking cessation, blood sugar control up to the standard, regular exercise, active prevention and treatment of complications, and appropriate testosterone supplementation are necessary for preventing and curing osteoporosis.  相似文献   
99.
Existing studies have established several individual drivers of health facility delivery in many developing countries. However, the community characteristics that drive health facility delivery have been less studied across developing countries. This study thus examines the extent to which community characteristics drives health facility delivery among women who had recent live births in Nigeria based on data from the 2018 Nigeria Demographic and Health Survey (NDHS). A weighted sample size of 7,342 women was analysed. The outcome variable was health facility delivery. The explanatory variables were selected individual and community characteristics. Results show 39.7% prevalence of health facility delivery among the women. Findings further reveals that the community characteristics have significant effects on the variations in health facility delivery across the communities. Community characteristics significantly drive health facility delivery in Nigeria. More community-based priority actions are required to improve demand for health facility delivery in the country.  相似文献   
100.
目的 总结2019冠状病毒病(coronavirus disease 2019, COVID-19)待排患者的临床特征和鉴别诊断体会,提高COVID-19的诊断技能。方法 回顾性分析53例COVID-19待排患者的临床资料,包括流行病学史,以及白细胞计数、淋巴细胞计数、PLT、CRP、LDH、胸部高分辨CT(high resolution CT, HRCT)等检查结果。结果 本研究的53例COVID-19待排患者中,男32例,女21例;年龄15~79岁,平均年龄(53.5±8.4)岁。首诊时病程为1~12 d不等,病程中位数4 d。所有患者均否认COVID-19流行病学史。21例患者具有慢性基础病。首发症状主要为发热、乏力、咳嗽、咳痰、咽痛等。实验室检查外周血白细胞计数多为正常或减少;部分患者LDH、ALT、CK升高。胸部HRCT均呈现多发小斑片影、磨玻璃影及间质改变,以肺外带明显。53例患者均经间隔至少24 h的2次新冠病毒核酸检测为阴性,排除COVID-19,诊断为轻症社区获得性肺炎(community acquired pneumonia, CAP),经治疗后患者无发热及呼吸道症状。结论 COVID-19待排患者的临床表现以及肺部影像学与COVID-19相似,与CAP鉴别亦缺乏特异性;结合流行病学史以及新型冠状病毒核酸检测可以提高COVID-19诊断准确率。  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