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   18615篇
  免费   1790篇
  国内免费   276篇
耳鼻咽喉   78篇
儿科学   762篇
妇产科学   247篇
基础医学   906篇
口腔科学   529篇
临床医学   2232篇
内科学   2217篇
皮肤病学   105篇
神经病学   1556篇
特种医学   231篇
外国民族医学   1篇
外科学   1201篇
综合类   1979篇
现状与发展   1篇
预防医学   5970篇
眼科学   102篇
药学   910篇
  33篇
中国医学   416篇
肿瘤学   1205篇
  2024年   49篇
  2023年   410篇
  2022年   636篇
  2021年   1174篇
  2020年   938篇
  2019年   816篇
  2018年   762篇
  2017年   757篇
  2016年   754篇
  2015年   692篇
  2014年   1225篇
  2013年   1517篇
  2012年   1117篇
  2011年   1198篇
  2010年   890篇
  2009年   962篇
  2008年   973篇
  2007年   896篇
  2006年   693篇
  2005年   551篇
  2004年   485篇
  2003年   427篇
  2002年   347篇
  2001年   287篇
  2000年   267篇
  1999年   212篇
  1998年   194篇
  1997年   163篇
  1996年   132篇
  1995年   161篇
  1994年   114篇
  1993年   112篇
  1992年   103篇
  1991年   83篇
  1990年   74篇
  1989年   77篇
  1988年   65篇
  1987年   47篇
  1986年   34篇
  1985年   67篇
  1984年   43篇
  1983年   31篇
  1982年   35篇
  1981年   25篇
  1980年   19篇
  1979年   17篇
  1978年   14篇
  1977年   8篇
  1976年   8篇
  1972年   6篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
The dietary history method was used to determine the total energy and macronutrient intake, the distribution of daily energy from the different meals and the energy contribution of various food groups, in a population of 299 boys, aged between 10 and 15 years. The effects of age, the social status of the father (SPS), the ponderal index, the importance of breakfast or lunch, and the level of energy intake on dietary indicators, were studied. In our population, energy intake increased with increasing age but the energy contribution of macronutrients did not vary. The diet of boys whose fathers were in the upper SPS classes differed from the diet of those boys whose fathers were manual workers: for example they consumed less energy and pastries, but more animal protein (in percentage of energy intake), more dairy products, and more fruit. The ponderal index was negatively related to energy intake but positively related to protein intake, especially from meat and meat products. The energy intake from protein, animal protein and the energy contribution of dairy products, meat and meat products, fish and vegetables was lower among large eaters than among small eaters. The energy contribution of pastries, sugar and sweets was higher among large eaters.
Similarily, the energy intake from morning and evening snacks was also higher among large eaters. It should be noted that boys who had a substantial breakfast took in less energy from all other meals (including snacks and main meals). Such informaton is necessary in order to develop an effective health programme.  相似文献   
52.
BACKGROUND: In maintenance haemodialysis patients, daily food intake is changeable; however, its relationship with nutritional status is unexplored. This study aimed to evaluate the isolated, long-term effect of daily nutrient intake on nutritional status in haemodialysis patients. METHODS: We performed a prospective 1-year controlled study in 27 chronic haemodialysis patients, without recognized risk factors for malnutrition. Each day for 1 week, four times in the year, we measured protein nitrogen appearance, and assessed dietary protein (DPI) and energy (DEI) intake from dietary diaries. We compared the nutritional outcome of patients spontaneously reducing nutrient intake below the threshold of 0.8 g/kg body weight/day for DPI and 25 kcal/kg body weight/day for DEI during the week (LOW, n = 8), with controls at adequate nutrient intake (CON, n = 19). An interventional 6-month study was then carried out in LOW to verify the cause-effect relationship. RESULTS: All patients showed a day-by-day reduction of whole nutrient intake during interdialytic period, which was mostly relevant in the third interdialytic day (L3). During the 1-year study, even in the presence of adequate dialysis dose and normal inflammatory indexes, body weight (68.0 +/- 5.5 to 65.8 +/- 5.9 kg), serum albumin (3.96 +/- 0.07 to 3.66 +/- 0.06 g/dl) and creatinine (9.2 +/- 1.1 to 8.1 +/- 0.7 mg/dl) significantly decreased in LOW but not in CON. Diaries evidenced in LOW a reduced number of meals at L3 that was explained by the fear of excessive interdialytic weight gain. During the interventional study, daily DPI and DEI increased at L3; this was associated with a significant increment of body weight, and serum albumin and creatinine levels. CONCLUSIONS: In maintenance haemodialysis patients the persistent, marked reduction of daily nutrient intake, even if limited to a single day of the week, is an independent determinant of reversible impairment of nutritional status.  相似文献   
53.
目的 探讨对小儿难治性惊厥持续状态的有效治疗方法。方法 对14例小儿难治性惊厥持续状态采用硫喷妥钠治疗并观察疗效。结果 硫喷妥钠治疗有效率为100%,1例出现呼吸抑制,3例于停药后复发。结论 硫喷妥钠对小儿难治性惊厥持续状态有明显疗效,但易发生呼吸抑制。惊止后应维持一段时间,以免复发。  相似文献   
54.
宁夏卫生人力资源现状分析   总被引:6,自引:0,他引:6  
目的 了解宁夏卫生人力现状 ,提出建设性意见。方法 采用普查分类统计分析的方法。结果 现有卫生人员 2 3485名 ,其中卫生专业技术人员 18838名 ,每千人拥有 4 .35名卫生人员和 3.36名卫生专业技术人员。结论 年龄和职称分布合理 ,卫生人力资源总量较 16年前明显增加 ,卫生专业技术人员增长了 83.5 7% ,研究生偏少 ,本科学历比例较小 ,卫生人力资源过于集中在银川市  相似文献   
55.
Background: Elder patients with acute coronary syndromes (ACS) are less likely to receive cardiac catheterization. The reasons for this are unclear.
Objectives: To assess whether elder patients who had a documented history of dementia, lived in extended care facilities, or had do not intubate–do not resuscitate (DNR-DNI) advance directives were less likely to receive cardiac catheterization, despite having ACS with high-risk features.
Methods: This was a medical record review conducted at an urban teaching hospital. DNR-DNI status before hospitalization, extended care facility (nursing home or assisted living) residence, and a previous diagnosis of dementia were obtained from the medical record. Patients 65 years and older who presented to the emergency department with acute myocardial infarction or with unstable angina with ST segment deviation were included. Univariate and multivariate logistic regression were performed, and odds ratios (ORs) were reported with their 95% confidence intervals (CIs).
Results: Of the 201 eligible patients, 66 (32.8%) patients did not undergo cardiac catheterization. In the univariate analysis, patients who had dementia, resided in extended care facilities, or were DNR-DNI were less likely to receive cardiac catheterization. Only extended care facility residence (OR, 0.18; 95% CI = 0.04 to 0.83) and DNR-DNI status (OR, 0.19; 95% CI = 0.04 to 0.92) remained significantly associated with decreased cardiac catheterization in the multivariate analysis.
Conclusions: Elder patients with ACS residing in extended care facilities or who are DNR-DNI are less likely to receive cardiac catheterization. Future studies concerning the quality of ACS care for elders should take these variables into account.  相似文献   
56.
航渡营养口粮抗疲劳实验研究   总被引:1,自引:0,他引:1  
目的:评价航渡营养口粮抗疲劳功能。方法:50只小鼠随机分成氨基酸低,中,高剂量组,混合饲料组和对照组,进行运动耐力测定,血清尿素氮浓度测定和血糖测定。结果:给予氨基酸的小鼠,与对照组比较负重游泳时间明显延长(P<0.05),小鼠负重游泳至力竭时血清尿素氮浓度明显降低(P<0.01),氨基酸高剂量组和混合饲料组小鼠血糖水平高于对照组。结论:航渡营养口粮能有效地提高小鼠机体运动耐力,维持血糖水平,降低血清尿素氮浓度,抗疲劳。  相似文献   
57.
广州市4770名小学生营养状况调查及分析   总被引:2,自引:1,他引:1  
颜君  刘可 《中国妇幼保健》2007,22(4):519-521
目的了解广州市东山区4770名小学生的营养状况。方法对2005年广州市东山区农林街的小学生健康检查结果进行分析和评价。结果广州市东山区各年龄组小学生营养不良和肥胖的比例均较高,其中男生肥胖的检出率明显高于女生,女生营养不良的比例明显高于男生,贫血患病率明显低于国内同类研究结果。结论整个社会应加强联系与协作,开展有效的健康教育,倡导良好的健康习惯,加强体育锻炼,改善小学生的营养状况。  相似文献   
58.
目的 观察初诊高血压病患者心理、个性和行为特征对控烟效果的影响.方法 对84例初诊高血压病吸烟患者行控烟治疗,连续3个月后评价控烟效果,并采用A型行为问卷、艾森克个性问卷(EPQ)及症状自评量表(SCL-90)对其进行测评.结果 控烟效果佳者38例,占45.24%;控烟效果差者46例,占54.76%.前者A型行为问卷、EPQ问卷(除外内外向性维度)评分均显著优于后者(P<0.05,P<0.01);SCL-90除偏执、阴性项目外,其余项目评分均显著优于后者(P<0.05,P<0.01).结论 A型行为类型、神经质和精神病性人格特征及负性情绪是影响控烟效果的重要因素,对此类患者实施控烟的同时予以针对性心理干预可望获得事半功倍的效果.  相似文献   
59.
南海某岛礁作业人员睡眠状况与身心健康状况关系的研究   总被引:2,自引:2,他引:0  
目的 研究南海某岛礁作业人员睡眠状况与身心健康状况的关系。方法 由经过统一培训的医务人员连续91d每日逐人逐项当面调查、记录。其中的“指数”指标,采用视觉模糊评分法。结果 随着在礁时阃的延长,作业人员睡眠状况明显变差,其主要影响因素依次为值勤(28.73%)、情绪(20.09%)、多梦(10.16%)、噪音(8.86%)和气候(7.73%)等。睡眠状况与身心健康状况明显相关,相关系数7=0.937~0.980,P<0.01;睡眠指数对身心健康状况各指标均有明显影响(P<0.01),睡眠时间主要影响体能指数、健康指数、工作质量指数、工作积极性指数、注意力指数及情绪指数等(P<0.05~0.01),对食欲指数、记忆力指数影响则不明显。结论 在岛礁期间,影响作业人员睡眠的主要因素是值勤和情绪,睡眠状况明显影响身心健康状况。  相似文献   
60.
北京农村居民健康状况及卫生服务需求调查   总被引:17,自引:5,他引:12  
目的了解北京农村居民健康状况及卫生服务需求特点。方法从昌平区、顺义区、大兴区、房山区随机抽取25~64岁农民1605人进行统一问卷调查。结果农民高血压自报患病率为22.4%,超重和肥胖率为56.1%;现在吸烟率为34.4%,缺乏运动率为41.6%;家庭主要经济支出为学生上学(35.3%),建房(25.4%)和疾病(21.2%);54.9%家庭医疗费用支出占总收入的10%以上;最关心的健康问题主要是慢性疾病防治(70.2%);最希望获得的健康知识是慢性病预防知识(72%);希望获得健康知识的途径是广播和电视(81%);家庭最希望获得的医疗保健服务是方便看病和获得药物(73.8%)。结论慢性病给农民带来沉重负担,并成为农民关心的主要健康问题。  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