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   26730篇
  免费   2764篇
  国内免费   764篇
耳鼻咽喉   172篇
儿科学   488篇
妇产科学   230篇
基础医学   1082篇
口腔科学   630篇
临床医学   3957篇
内科学   2161篇
皮肤病学   182篇
神经病学   841篇
特种医学   602篇
外国民族医学   7篇
外科学   1478篇
综合类   3542篇
现状与发展   1篇
一般理论   1篇
预防医学   8158篇
眼科学   119篇
药学   3522篇
  79篇
中国医学   2176篇
肿瘤学   830篇
  2024年   86篇
  2023年   634篇
  2022年   881篇
  2021年   1743篇
  2020年   1413篇
  2019年   1075篇
  2018年   1032篇
  2017年   1054篇
  2016年   1177篇
  2015年   1200篇
  2014年   1992篇
  2013年   2377篇
  2012年   1761篇
  2011年   1768篇
  2010年   1379篇
  2009年   1302篇
  2008年   1219篇
  2007年   1159篇
  2006年   1036篇
  2005年   820篇
  2004年   727篇
  2003年   608篇
  2002年   474篇
  2001年   446篇
  2000年   350篇
  1999年   342篇
  1998年   283篇
  1997年   240篇
  1996年   181篇
  1995年   180篇
  1994年   166篇
  1993年   144篇
  1992年   143篇
  1991年   110篇
  1990年   100篇
  1989年   92篇
  1988年   94篇
  1987年   52篇
  1986年   60篇
  1985年   76篇
  1984年   65篇
  1983年   30篇
  1982年   33篇
  1981年   31篇
  1980年   34篇
  1979年   14篇
  1978年   19篇
  1977年   16篇
  1975年   10篇
  1973年   6篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
21.
膳食炎症指数(DII)来源于将饮食和炎症联系起来的文献,被开发用来量化饮食的整体炎症潜能。饮食在调节慢性炎症中起着核心作用,是重要的调节因子,如果饮食的炎症潜能很高,则能够激发免疫调节作用,引起慢性炎症。DII可用于评估和指导个人饮食计划。本研究收集国外相关文献,就DII与炎症之间的相关性予以综述,以期通过减少饮食中的炎性成分而对慢性炎症引起的相关疾病进行一级预防。  相似文献   
22.
Objective: Longitudinal data on cardiometabolic effects of egg intake during adolescence are lacking. The current analyses aim to evaluate the impact of usual adolescent egg consumption on lipid levels, fasting glucose, and insulin resistance during late adolescence (age 17–20?years).

Methods: Data from 1392 girls, aged 9 to 10 at baseline and followed for 10?years, in the National Heart, Lung, and Blood Institute’s National Growth and Health Study were used to examine the association between usual egg intake alone and in combination with other healthy lifestyle factors and late adolescent lipid levels, fasting glucose, and insulin resistance, measured as homeostasis model assessment of insulin resistance (HOMA-IR). Diet was assessed using 3-day food records during eight examination cycles. Girls were classified according to usual weekly egg intake, ages 9–17?years:?<1 egg/wk (n?=?361), 1 to <3 eggs/wk (n?=?703), and ≥3 eggs/wk (n?=?328). Analysis of covariance modeling was used to control for confounding by other behavioral and biological risk factors.

Results: Girls with low, moderate, and high egg intakes had adjusted low-density lipoprotein cholesterol levels of 99.7, 98.8, and 95.5 mg/dL, respectively (p?=?0.0778). In combination with higher intakes of fiber, dairy, or fruits and vegetables, these beneficial effects were stronger and statistically significant. There was no evidence that ≥3 eggs/wk had an adverse effect on lipids, glucose, or HOMA-IR. More active girls who consumed ≥3 eggs/wk had the lowest levels of insulin resistance.

Conclusion: These results suggest that eggs may be included as part of a healthy adolescent diet without adverse effects on glucose, lipid levels, or insulin resistance.  相似文献   

23.
Although numerous studies have proven the medicinal values of Yulangsan polysaccharide (YLSP), the toxicity of this active ingredient is unknown. In the acute toxicity study, a single oral administration of 24 g/kg YLSP caused neither toxicological symptoms nor mortality, and the LD50 was estimated >24 g/kg. In the chronic toxicity study, we administered doses of 0, 0.6, 1.2 and 2.4 g/kg YLSP in rats by oral gavage for 26 weeks followed by a 3-week recovery period. There was no mortality or remarkable clinical signs observed during this 26-week study. Additionally, there were no toxic differences in the following parameters: body weight, food consumption, hematology, clinical biochemistry, organ weight, and macroscopic findings. There were no adverse effects on histopathology observed in males or female rats treated with YLSP. Based on the results, the no-observed-adverse-effect-level of YLSP in rats is greater than 2.4 g/kg when administered orally for 26 consecutive weeks.  相似文献   
24.
目的运用360度评价对我院住培学员的岗位胜任力进行评价,对学员岗位胜任力的现状进行探讨分析。方法使用问卷调查表分别从专业基地教学主任、学员指导教师、同专业学员及学员本人的角度,对2017级222名住培学员的岗位胜任力进行360度评价,利用SPSS22.0对数据进行统计分析。结果连续两年的测评,住院学员8类岗位胜任力的自评和他评得分低于满分,学员在临床基本能力、医患沟通能力、掌握与运用医学知识、团队合作能力4项内容的评分,差异有统计学意义(P<0.05);同时学员在临床基本能力、医生职业精神与素质、医患沟通能力、掌握与运用医学知识、团队合作能力5项内容的评分较上一年相比,差异也有统计学意义(P<0.05)。结论调查结果提示360度评价可帮助住培学员提高岗位胜任力,后续培训应围绕调查结果和以岗位胜任力为导向来调整与设置,需增加人文属性内容的培训以及再量化培训测评内容、指标和进一步完善考评反馈机制。  相似文献   
25.
随着我国医疗机构临床药师队伍的不断壮大,其在医疗服务中发挥着越来越重要的作用,对其工作进行绩效考核也是当今医疗领域的重要内容。以现有文献为基础,对国内外临床药师绩效考核体系进行分析,发现现有体系可分为为基于临床药师职责、基于临床药师业务流程、国外临床药师绩效考核体系三个方面;通过结合医疗机构的实际情况对现有绩效考核体系进行分析,发现存在考核指标和标准确定困难、考核难以做到实时性和延续性等问题,并针对这些问题提出清晰职责定位、重视临床药师价值体现等修改说明。  相似文献   
26.
Determining aortic stenosis (AS) severity is clinically important. Calculating aortic valve (AV) area by means of the continuity equation assumes a circular left ventricular outflow tract (LVOT). The full impact of this assumption in calculating AV area is unknown. Predictors of noncircular LVOT shape in patients with AS are undefined.In 109 adult patients with AS who underwent multiplanar transesophageal echocardiography, we calculated AV area by means of the standard continuity method and by a modified method involving planimetric LVOT area.We found 54 circular, 37 horizontal-oval, 8 vertical-oval, and 10 irregular LVOTs. Area derived by direct planimetry correlated better with the modified than the standard continuity method (r=0.89 vs r=0.85; both P=0.0001). Valve areas of patients with mild, moderate, or severe AS by planimetry were more often mischaracterized with use of the standard than modified method (29 vs 18; P <0.0001). Horizontal-oval AV area derived by planimetry (1.28 ± 0.55 cm2) was underestimated by the standard method (1.05 ± 0.47 cm2; P=0.001), but not by the modified method. Congenital AV morphology and low cardiac index were the only multivariate predictors of horizontal-oval shape. Low cardiac index was the only predictor of noncircular shape.More than half our patients with AS had noncircular LVOTs. Using the modified method reduces mischaracterizations of AS severity. Congenital AV morphology and low cardiac index predict horizontal-oval or noncircular shape. These data suggest the value of direct LVOT measurement to calculate AS severity in patients who have congenital AV or a low cardiac index.  相似文献   
27.
经典名方泽泻汤的HPLC指纹图谱及多指标含量测定研究   总被引:2,自引:0,他引:2  
目的建立经典名方泽泻汤的HPLC指纹图谱,结合化学模式识别技术对其进行分析,并测定泽泻汤中3种成分23-乙酰泽泻醇B、23-乙酰泽泻醇C和白术内酯Ⅲ的含量,为泽泻汤质量控制提供科学依据。方法采用Waters WAT054275C18色谱柱(250 mm×4.6 mm,5μm),以乙腈-水为流动相进行梯度洗脱,建立15批泽泻汤的HPLC指纹图谱,并采用"中药色谱指纹图谱相似度评价系统"、SPSS22.0及SIMCA14.1软件对15批泽泻汤的HPLC指纹图谱进行相似度评价及聚类分析(CA)、偏最小二乘判别分析(PLS-DA)等化学模式识别。同时测定23-乙酰泽泻醇B、23-乙酰泽泻醇C和白术内酯Ⅲ的含量。结果建立了15批泽泻汤的HPLC指纹图谱,相似度均0.94,标定了18个共有峰,指认出3个色谱峰,分别为11号峰白术内酯Ⅲ、15号峰23-乙酰泽泻醇C、16号峰23-乙酰泽泻醇B,CA和PLS-DA将15批泽泻汤样品分为2类,同时15批泽泻汤中23-乙酰泽泻醇B、23-乙酰泽泻醇C和白术内酯Ⅲ的质量分数分别为0.321~0.569、0.075~0.139、0.106~0.142 mg/g。结论 HPLC指纹图谱结合多成分同时测定的方法,快速、简便、重复性好,为泽泻汤及其制剂的质量评价提供参考。  相似文献   
28.
评价天津市各辖区基本公共卫生服务的资源配置效率,寻求有效的资源配置措施和方法,为进一步优化卫生资源配置提供参考依据。方法利用数据包络分析,对天津市16辖区的基本公共卫生服务进行效率评价。结果天津市基本公共卫生服务的资源配置效率整体不高,仅有5辖区达到了规模最优,多数区非DEA有效,且投入过剩与产出不足并存。结论为了达到最优的基本公共卫生服务效率,政府及各级基本公共卫生服务机构必须有效地完善、落实相关政策,优化资源投入结构,统筹地区差异,加强资源供给管理,提高资源利用效率。  相似文献   
29.
目的:系统评价宣白承气汤单用及联合用药治疗肺炎痰热壅肺证的临床疗效。方法:检索CNKI、万方、CBM、PubMed等数据库,筛选宣白承气汤治疗肺炎的随机对照试验(RCT),运用Cochrane协作网偏倚风险评价工具进行文献质量评价,使用Revman 5.3 软件进行Meta分析。结果:最终纳入16项研究,共1393例患者,纳入文献质量不高。Meta分析结果表明,与单纯西医治疗相比,使用宣白承气汤可明显提高肺炎痰热壅肺证的临床总有效率[RR=1.29,95%,CI(1.22,1.36),P<0.00001],且亚组分析显示单用或联用宣白承气汤的组间差异无统计学意义; 可明显改善APACHE II评分、CPIS评分,明显降低炎症因子水平,改善中医证候积分。结论:宣白承气汤可有效治疗肺炎痰热壅肺证,但鉴于纳入临床研究在质量上存在一定局限性,得出的阳性结果仅作为临床诊疗的提示与参考,急需开展更多的高质量大规模的RCT来进一步验证。  相似文献   
30.
Objective: A multidisciplinary vocational rehabilitation programme, the Vocational Enablement Protocol (VEP) was developed to address the specific needs of employees with hearing difficulties. In the current study we evaluated the process of implementing the VEP in audiologic care among employees with hearing impairment. Design: In conjunction with a randomized controlled trial, we collected and analysed data on seven process parameters: recruitment, reach, fidelity, dose delivered, dose received and implemented, satisfaction, and perceived benefit. Study sample: Sixty-six employees with hearing impairment participated in the VEP. The multidisciplinary team providing the VEP comprised six professionals. Results: The professionals performed the VEP according to the protocol. Of the recommendations delivered by the professionals, 31% were perceived as implemented by the employees. Compliance rate was highest for hearing-aid uptake (51%). Both employees and professionals were highly satisfied with the VEP. Participants rated good perceived benefit from it. Conclusions: Our results indicate that the VEP could be a useful treatment for employees with hearing difficulties from a process evaluation perspective. Implementation research in the audiological setting should be encouraged in order to further provide insight into parameters facilitating or hindering successful implementation of an intervention and to improve its quality and efficacy.  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