全文获取类型
收费全文 | 14049篇 |
免费 | 1182篇 |
国内免费 | 480篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 171篇 |
妇产科学 | 173篇 |
基础医学 | 832篇 |
口腔科学 | 328篇 |
临床医学 | 1604篇 |
内科学 | 993篇 |
皮肤病学 | 209篇 |
神经病学 | 532篇 |
特种医学 | 241篇 |
外科学 | 837篇 |
综合类 | 2429篇 |
一般理论 | 5篇 |
预防医学 | 3521篇 |
眼科学 | 335篇 |
药学 | 1722篇 |
36篇 | |
中国医学 | 1331篇 |
肿瘤学 | 376篇 |
出版年
2024年 | 41篇 |
2023年 | 214篇 |
2022年 | 394篇 |
2021年 | 488篇 |
2020年 | 490篇 |
2019年 | 477篇 |
2018年 | 433篇 |
2017年 | 508篇 |
2016年 | 556篇 |
2015年 | 507篇 |
2014年 | 797篇 |
2013年 | 1120篇 |
2012年 | 823篇 |
2011年 | 866篇 |
2010年 | 629篇 |
2009年 | 593篇 |
2008年 | 695篇 |
2007年 | 740篇 |
2006年 | 637篇 |
2005年 | 500篇 |
2004年 | 458篇 |
2003年 | 403篇 |
2002年 | 359篇 |
2001年 | 312篇 |
2000年 | 257篇 |
1999年 | 245篇 |
1998年 | 199篇 |
1997年 | 176篇 |
1996年 | 142篇 |
1995年 | 145篇 |
1994年 | 148篇 |
1993年 | 102篇 |
1992年 | 120篇 |
1991年 | 128篇 |
1990年 | 105篇 |
1989年 | 108篇 |
1988年 | 85篇 |
1987年 | 79篇 |
1986年 | 105篇 |
1985年 | 62篇 |
1984年 | 71篇 |
1983年 | 66篇 |
1982年 | 71篇 |
1981年 | 56篇 |
1980年 | 52篇 |
1979年 | 51篇 |
1978年 | 26篇 |
1977年 | 16篇 |
1976年 | 22篇 |
1975年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
邓天权 《生物医学工程学杂志》1991,8(4):299-304
本文提出并研究了一种新型的电磁热疗系统-H面号角环形相控阵系统。推导出了适应性广的理论公式。以肺部CT图为模型,用矩量法计算得到了胸腔横断面内电场分布及吸收功率分布的计算机数值结果。结果表明,在200MHz的电磁波辐射下,适当调节阵列各单元的相位,振幅和位置,肺部肿瘤可得到优化的选择性加热,从而达到最佳的热疗效果。 相似文献
143.
Christopher M. Earls Ph.D. Vernon L. Quinsey Ph.D. Louis Georges Castonguay M.P.s 《Archives of sexual behavior》1987,16(6):493-500
There are presently three widely used methods of scoring penile circumference data. The present experiment attempted to determine the ability of each method to explain the variance within a data set. A total of 19 subjects were presented with 20 photographic slides assigned to five categories: neutral, female adult, female adolescent, male adult, and male adolescent. Erectile responses to each slide were recorded and the data analyzed in terms of the raw scores, percentage of full erection, and a z-score transformation. Results indicated that the z scores captured the highest proportion of the variance (52.7%), followed by the percentage scores (32.5%), and the raw scores (30.1%). Findings are discussed in terms of their research and clinical implications. 相似文献
144.
The study of individuals at "high" risk for developing psychiatric disorders is useful in confirming that a biological trait marker identified in patient populations is also present in genetically susceptible individuals who have never been ill, and predicts the future onset of illness. We outline a systematic method for deciding which variables to choose and how many individuals are required in order for a study to have sufficient power. We demonstrate how these decisions depend on the assumptions that can be made with regard to the mode of inheritance of the biological trait, the relationship of the biological trait to illness, and the magnitude of the mean difference observed between patients and controls. We also quantify the increased power of studying offspring of two affected parents rather than offspring of one affected parent. 相似文献
145.
van Rooij HH Pirovano IM Soudijn W 《Journal of pharmaceutical and biomedical analysis》1984,2(1):91-99
Methods have been developed for the determination of nicomorphine using reversed-phase HPLC with UV detection; for the simultaneous assay of morphine and mononicotinoylmorphine by a coupled normal-phase HPLC-radioimmunoassay method; and for conjugates of morphine and mononicotinoylmorphine by radioimmunoassay. The methods have been evaluated and applied to a pharmacokinetic study of nicomorphine administered intramuscularly. 相似文献
146.
《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
147.
《Health & place》2021
The distribution of food outlets within towns and cities and the provision of active travel infrastructure have been associated with health behaviours that can contribute to obesity risk. Decision-makers describe a lack of local data and research evidence as a barrier to policy adoption to improve the public's health. Online spatial data visualisation tools created by researchers can help to bridge this gap. We explored stakeholder experiences of using such tools for decision-support, with a focus on facilitators and barriers to use. We conducted 16 qualitative interviews with Public Health, Planning and Transport Planning professionals, who had used two recently-developed tools. Participants described the importance of tools being open access; their use in “story-telling”, particularly to non-experts; and more broadly their use even when imperfect. They expressed that ‘robustness’ of underpinning data was important, however this was not easily defined. Participants employed personal heuristics, principally based on endorsement and developer credibility, to determine suitability for use. We present key learning points for future developers to maximise engagement and impact. 相似文献
148.
《Health & place》2021
The features of the urban environment can support human health as well as harm it, but less is known about such influences in the context of middle eastern countries. The association between green space and the political classifications of the urban environment and the risk of chronic illness was investigated in a novel setting, the twin cities of Ramallah and Albireh in the occupied Palestinian territory. We used a generalised multi-level regression analysis to link the 2017 census data with Geographic Information System data. We modelled individuals at level one (n = 54693) and areas of residence at level two (n = 228), adjusting for individual demographic and socio-economic characteristics.The proportions of ‘mixed’ trees in residential areas had a significant inverse association with the risk of chronic illness. On the political dimension, only living in a refugee camp had a significant positive association with chronic illness; however, this was largely explained and rendered non-significant when green space variables were entered into the models. Our ability to differentiate between several types of green space was important, as findings demonstrated that not all types were associated with reduced risk of chronic illness. Our results from a middle eastern setting add to the largely Western existing evidence, that trees in urban settings are important and beneficial to human health. Researchers and policymakers should pay more attention to the health consequences of refugee camps but also the role of trees in benefiting individuals' health in such a disadvantaged context. 相似文献
149.
目的探讨红细胞免疫作用对胃癌BGC - 82 3细胞凋亡的影响 ,以及淋巴细胞的协同作用。方法应用红细胞免疫粘附肿瘤细胞花环试验、流式细胞术及放射免疫等方法 ,采用正常人外周血红细胞及红细胞 -淋巴细胞免疫粘附人胃腺癌BGC - 82 3细胞 ,检测红细胞及红细胞 -淋巴细胞免疫粘附胃癌细胞花环率 -胃癌细胞凋亡率、凋亡相关基因Fas、Bcl- 2以及凋亡相关信号传导物质cAMP、PKC的变化。结果红细胞组肿瘤红细胞花环率为 (2 8.41± 5 .0 1) % ,与对照组比较 ,红细胞组胃癌细胞凋亡率、Fas基因的表达、胃癌细胞内cAMP水平显著升高 ,蛋白激酶C(proteinkinaseC ,PKC)水平显著降低 (P <0 .0 1) ;与红细胞组相比 ,红淋混合组总花环率、胃癌细胞凋亡率、胃癌细胞内cAMP水平进一步增高 ,Bcl- 2基因的表达及PKC水平降低更为显著 (P <0 .0 1)。结论正常人红细胞可免疫粘附体外培养的胃癌BGC - 82 3细胞 ,通过红细胞的免疫作用 ,尤其是免疫粘附 ,可增加凋亡相关基因Fas的表达 ,增高胃癌细胞内cAMP水平 ,降低PKC水平 ,从而可能在诱导胃癌细胞凋亡方面起到某种作用 ;自身淋巴细胞有不同程度的促进和协同作用。 相似文献
150.
目的:探讨^99Tc^m-甲氧基异丁基异腈(^99Tc^m-methoxyisobutyl isonitrile,^99Tc^m-MIBI)心肌断层显像对病毒性心肌炎的诊断价值。方法对29例病毒性心肌炎患者及15例健康对照者进行负荷、静息^99Tc^m-MIBI心肌断层显像。结果13例(44.8%)表现为弥漫性放射性核素分布稀疏,15例(51.7%)表现为局灶性放射性核素分布稀疏。结论^99Tc^m-MIBI心肌断层显像对诊断病毒性心肌炎有临床实用价值。. 相似文献