全文获取类型
收费全文 | 7159篇 |
免费 | 491篇 |
国内免费 | 142篇 |
专业分类
耳鼻咽喉 | 39篇 |
儿科学 | 109篇 |
妇产科学 | 68篇 |
基础医学 | 656篇 |
口腔科学 | 132篇 |
临床医学 | 1137篇 |
内科学 | 530篇 |
皮肤病学 | 30篇 |
神经病学 | 477篇 |
特种医学 | 364篇 |
外国民族医学 | 1篇 |
外科学 | 586篇 |
综合类 | 702篇 |
一般理论 | 4篇 |
预防医学 | 1364篇 |
眼科学 | 69篇 |
药学 | 943篇 |
1篇 | |
中国医学 | 396篇 |
肿瘤学 | 184篇 |
出版年
2023年 | 103篇 |
2022年 | 156篇 |
2021年 | 232篇 |
2020年 | 228篇 |
2019年 | 200篇 |
2018年 | 224篇 |
2017年 | 219篇 |
2016年 | 175篇 |
2015年 | 208篇 |
2014年 | 409篇 |
2013年 | 461篇 |
2012年 | 358篇 |
2011年 | 476篇 |
2010年 | 317篇 |
2009年 | 344篇 |
2008年 | 382篇 |
2007年 | 422篇 |
2006年 | 341篇 |
2005年 | 351篇 |
2004年 | 315篇 |
2003年 | 277篇 |
2002年 | 221篇 |
2001年 | 194篇 |
2000年 | 174篇 |
1999年 | 99篇 |
1998年 | 99篇 |
1997年 | 77篇 |
1996年 | 76篇 |
1995年 | 60篇 |
1994年 | 55篇 |
1993年 | 46篇 |
1992年 | 55篇 |
1991年 | 56篇 |
1990年 | 43篇 |
1989年 | 48篇 |
1988年 | 42篇 |
1987年 | 32篇 |
1986年 | 33篇 |
1985年 | 31篇 |
1984年 | 28篇 |
1983年 | 11篇 |
1982年 | 18篇 |
1981年 | 7篇 |
1980年 | 12篇 |
1979年 | 13篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1973年 | 8篇 |
1971年 | 7篇 |
排序方式: 共有7792条查询结果,搜索用时 15 毫秒
1.
乙型肝炎病毒感染为一种全球范围内疾病,HBV感染导致的肝硬化、肝衰竭与原发性肝细胞癌,严重威胁着人们生命健康。乙肝病毒DNA定量检测为乙型肝炎表面抗原最直接的病毒复制指标,临床可将其作为监测评估乙肝病毒的一个重要指标依据,但受实验室要求严格限制,不能快速检测,影响临床疾病诊断。随着临床研究深入,临床研究发现HBsAg水平可用于监控、预测抗病毒治疗效果。本文通过探究分析HBsAg定量水平与HBV DNA相关性,指导临床诊断乙肝病毒,并为后期临床治疗工作开展提供指导意见。 相似文献
2.
3.
4.
5.
《Saudi Dental Journal》2022,34(6):503-508
BackgroundThis study aimed to identify whether healthy older adults are at a high risk of osteoporosis based on the association between the T-score values of bone mineral density (BMD) and three panoramic indices.Materials and methodsAll participants (50–64 years old) underwent calcaneal quantitative ultrasound (QUS) bone densitometry. In total, 371 panoramic images were included in the analysis. The mandibular cortical width (MCW), mandibular cortical index (MCI), and panoramic mandibular index (PMI) were the three parameters assessed. The data were examined using one-way analysis of variance or Kruskal–Wallis H and post hoc tests. Spearman’s rho was used to measure correlation coefficients.ResultsT-score distributions in the normal, osteopenia, and osteoporosis categories were 80 (21.6%), 236 (63.6%), and 55 (14.8%), respectively. T-scores were significantly related to age, MCW, PMI, and MCI (p < 0.001). Participants with osteopenia and a risk of progression to osteoporosis had an average MCW value of < 3.38 mm, a PMI of < 0.31, and an MCI class 2 and 3 distribution in 211 (56.9%) participants. The highest to lowest correlation coefficients with a significant relationship to the T-score were for age (r = -0.844), MCI (r = 0.456), MCW (r = 0.359), sex (r = 0.354), and PMI value (r = 0.292).ConclusionsThis study found that healthy older people with Class 3 MCI, an MCW < 3 mm, and a PMI ratio < 0.3 had a significant association with lower BMD T-scores on QUS and were at higher risk of osteoporosis. 相似文献
6.
7.
《Value in health》2022,25(1):10-31
Health economic evaluations are comparative analyses of alternative courses of action in terms of their costs and consequences. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement, published in 2013, was created to ensure health economic evaluations are identifiable, interpretable, and useful for decision making. It was intended as guidance to help authors report accurately which health interventions were being compared and in what context, how the evaluation was undertaken, what the findings were, and other details that may aid readers and reviewers in interpretation and use of the study. The new CHEERS 2022 statement replaces the previous CHEERS reporting guidance. It reflects the need for guidance that can be more easily applied to all types of health economic evaluation, new methods and developments in the field, and the increased role of stakeholder involvement including patients and the public. It is also broadly applicable to any form of intervention intended to improve the health of individuals or the population, whether simple or complex, and without regard to context (such as healthcare, public health, education, and social care). This Explanation and Elaboration Report presents the new CHEERS 2022 28-item checklist with recommendations and explanation and examples for each item. The CHEERS 2022 statement is primarily intended for researchers reporting economic evaluations for peer-reviewed journals and the peer reviewers and editors assessing them for publication. Nevertheless, we anticipate familiarity with reporting requirements will be useful for analysts when planning studies. It may also be useful for health technology assessment bodies seeking guidance on reporting, given that there is an increasing emphasis on transparency in decision making. 相似文献
8.
《Journal of the Academy of Nutrition and Dietetics》2022,122(4):786-796.e4
BackgroundThe Child and Adult Care Food Program (CACFP) nutrition standards may present food purchasing, preparation, and feeding challenges for caregivers of young children.ObjectiveTo elucidate perceived barriers and facilitators faced by in-home childcare providers to following the CACFP food and beverage nutrition standards.DesignVirtual, semistructured individual interviews elicited perceptions from a cross section of low-income, in-home childcare providers in Michigan.Participants/settingsTwenty childcare providers of various races, ethnicity, urban and rural residence, and licensure status.AnalysisThematic coding analysis with NVivo (ver12.0) to organize and interpret data.ResultsFour primary barriers to adhering to the CACFP nutrition standards emerged including (1) noncompliant food preferences of children and providers; (2) higher cost and lower availability of CACFP-approved items; (3) celebrations and food rewards; (4) excessive time and effort needed to prepare foods and beverages, especially with dietary restrictions for some children. Ten perceived facilitators included (1) using nutrition education available through community organizations; (2) finding convenient and easy ways to prepare foods and beverages; (3) using CACFP and Special Supplemental Nutrition Program for Women, Infants, and Children guidelines and funding; (4) increasing variety of foods and beverages by using a menu or recalling items recently served; (5) modeling eating healthful foods and encouraging sampling of new foods and beverages; (6) mixing preferred foods/beverages with less preferred; (7) using nutrition information available from social media and from peers; (8) allowing children to choose foods and beverages; (9) serving the same eligible food and beverages to all children; and (10) provider concern about impact of foods and beverages on children’s health and behavior.ConclusionsResults from this study can inform nutrition education from community organizations that occurs in tandem with CACFP sponsor organizations. In addition, they can be utilized to address state-level licensure regulations and quality improvement rating systems that include nutrition standards childcare providers are encouraged or required to follow. 相似文献
9.
目的探讨超声造影定量评估脓毒症相关急性肾损伤(S-AKI)大鼠肾血流灌注及其参数对大鼠炎症反应的监测价值。 方法选取健康SD大鼠32只,平均分为模型组和对照组,模型组采用盲肠结扎穿孔术制作脓毒症大鼠,对照组仅开腹游离盲肠末端,不结扎穿孔,直接还纳关闭腹腔。于术后12 h、24 h两个时间点每组取8只大鼠行超声造影检查,并选取感兴趣区绘制时间强度曲线进行定量分析,下腔静脉取血检测血清肌酐(Scr)、尿素(Urea)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、白细胞介素10(IL-10),留取肾标本进行病理检查。采用独立样本t检验和非参数检验(Mann-Whitney U)统计不同时间点两组各指标的差异,采用Spearman相关分析超声造影定量参数[造影剂到达时间(AT)、达峰时间(TTP)、上升斜率(AS)、峰值强度(PI)、降半时间(DT/2)、下降斜率(DS)、曲线下面积(AUC)]与炎症因子的相关性。 结果(1)模型组肾功能指标Scr、Urea、炎症因子指标IL-6、TNF-α、IL-10于两个时间点均显著高于对照组,差异均具有统计学意义(P均<0.05)。(2)造影剂团注后2~4 s,肾血管快速增强,随后皮质、髓质依次显影,髓质、皮质依次消退。与对照组相比,模型组12 h肾皮质TTP增加[(10.47±1.25)s vs(8.30±1.53)s],DS、PI减小[(-0.13±0.02)dB/s vs(-0.17±0.04)dB/s;(23.90±1.36)dB vs(27.26±1.88)dB],髓质TTP、DT/2增加[(11.66±1.99)s vs(9.00±1.28)s;(62.49±4.56)s vs(52.15±7.70)s],DS减小[(-0.13±0.02)dB/s vs(-0.17±0.03)dB/s],差异均有统计学意义(t=-3.105、-3.121、4.102、-3.180、-3.268,-2.915,P=0.008、0.008、0.001、0.007、0.007、0.011),模型组24 h肾皮质AS、DS增加[(0.99±0.17)dB/s vs(0.61±0.19)dB/s;(-0.23±0.03)dB/s vs(-0.15±0.04)dB/s],DT/2、AUC减小[(42.41±3.03)s vs(61.07±6.52)s;(2477.89±113.37)dB·s vs(3024.93±253.81)dB·s],髓质AS、DS、AT增加[(1.00±0.27)dB/s vs(0.66±0.17)dB/s;(-0.23±0.06)dB/s vs(-0.15±0.04)dB/s;(4.30±0.34)s vs(3.77±0.29)s],DT/2、AUC减小[(42.73±7.02)s vs(59.64±9.23)s;(2335.75±189.77)dB·s vs(2689.72±285.45)dB·s],差异具有统计学意义(t=-4.262、5.138、7.344、5.566、-3.061、3.108、-3.349、4.124、2.921,P=0.001、<0.001、<0.001、<0.001、=0.008、=0.008、=0.005、=0.001、=0.011)。(3)肾皮质超声造影定量参数PI、AUC与血清IL-6、TNF-α、IL-10呈显著相关(r=-0.562、-0.398、-0.512;-0.540、-0.638、-0.430,P均<0.05)。(4)肾病理切片行过碘酸雪夫染色显示,模型组大鼠肾出现肾小管轮廓不清、扩张、刷状缘脱落、肾小管上皮细胞扁平化、脱落表现,24 h模型组部分肾小管管型形成;对照组大鼠病理表现正常。 结论超声造影可以实时动态观察大鼠肾血流灌注过程,定量评价血流灌注水平,初步监测机体的炎症反应状态。 相似文献
10.
一测多评法(quantitative analysis of multi-components by single marker,QAMS)已成熟应用于中药材、中药提取物及中成药领域等中药复杂体系的质量评价研究中,有效解决了因对照品缺乏而导致的多指标质控技术推广难问题。本文查阅近五年的国内外研究文献,重点总结了高效液相色谱、气相色谱和质谱等技术在QAMS法中药质量控制中的应用。高效液相色谱联用紫外检测器(UV)技术应用最为广泛,最适合于中药QAMS法定量,结果稳定、准确;而高效液相色谱联用蒸发光检测器在中药QAMS法应用中,其测定准确性和适用性仍然需进一步探索和验证。液质联用技术虽然具有灵敏度高、线性范围宽等优点,但易受仪器参数、基质效应等的影响。进一步发展HPLC-UV技术在中成药制剂质量评价中的应用,是QAMS法多成分定量值得关注的方向;探索LC-MS和GC技术在中药QAMS质量评价中的稳定性和普适性是未来将面临的挑战。 相似文献