全文获取类型
收费全文 | 7683篇 |
免费 | 687篇 |
国内免费 | 308篇 |
学科分类
医药卫生 | 8678篇 |
出版年
2024年 | 19篇 |
2023年 | 153篇 |
2022年 | 227篇 |
2021年 | 419篇 |
2020年 | 446篇 |
2019年 | 1003篇 |
2018年 | 740篇 |
2017年 | 472篇 |
2016年 | 257篇 |
2015年 | 338篇 |
2014年 | 469篇 |
2013年 | 752篇 |
2012年 | 374篇 |
2011年 | 442篇 |
2010年 | 314篇 |
2009年 | 375篇 |
2008年 | 284篇 |
2007年 | 223篇 |
2006年 | 209篇 |
2005年 | 162篇 |
2004年 | 120篇 |
2003年 | 112篇 |
2002年 | 85篇 |
2001年 | 74篇 |
2000年 | 72篇 |
1999年 | 70篇 |
1998年 | 31篇 |
1997年 | 25篇 |
1996年 | 50篇 |
1995年 | 86篇 |
1994年 | 64篇 |
1993年 | 22篇 |
1992年 | 15篇 |
1991年 | 16篇 |
1990年 | 12篇 |
1989年 | 16篇 |
1988年 | 25篇 |
1987年 | 17篇 |
1986年 | 10篇 |
1985年 | 23篇 |
1984年 | 16篇 |
1983年 | 13篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 5篇 |
1978年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有8678条查询结果,搜索用时 15 毫秒
51.
52.
H. Liu Y. Li Y. Mao 《European annals of otorhinolaryngology, head and neck diseases》2019,136(6):481-487
BackgroundProphylactic central neck dissection (CND) at the time of total thyroidectomy (TT) remains controversial in clinically node-negative (cN0) papillary thyroid carcinoma (PTC). This systematic review and meta-analysis was performed to compare the local recurrence between patients who underwent TT plus CND and those who underwent TT alone.MethodsThe publicly available literature published from January 1990 to October 2017 concerning TT plus prophylactic CND versus TT for PTC was retrieved by searching the national and international online databases. Meta-analysis was performed after the data extraction process.ResultsTwenty-five studies with comparison between TT + CND and TT alone were eligible and included in this meta-analysis. For both PTC and papillary thyroid microcarcinoma (PTMC), the overall recurrence in TT + CND group was significantly lower than that in TT alone group. The central compartment recurrence was significantly higher in TT alone group than TT + CND group (OR = 3.41, 95% Cl [2.00 ~ 5.80], P < 0.00001), while no significant difference of lateral compartment recurrence was observed between the two groups (OR = 1.19, 95%Cl [0.81 ~ 1.77], P = 0.38). We compared ipsilateral CND + TT with TT alone and found that the recurrence was not significantly different between the two groups (OR = 1.44, 95%Cl [0.74 ~ 2.81], P = 0.28). On the other hand, bilateral CND + TT showed significantly low recurrence (OR = 2.48, 95%Cl [1.75 ~ 3.53], P < 0.00001).ConclusionsThe addition of CND to TT resulted in a greater reduction in risk of local recurrence than TT alone, especially preventing central neck recurrences. Additionally, we discovered that bilateral CND in patients with PTC > 1 cm was necessary. 相似文献
53.
【目的】 探索建设世界一流科技期刊的策略,以助力中国科技期刊冲刺世界一流水平。【方法】 通过研读相关政策和研究文献,结合对Nature、Science、The Lancet、Cell等不同类型的世界一流科技期刊的分析,解析世界一流科技期刊的概念及内涵,探讨建设世界一流科技期刊的充分条件和必要条件,提出建设世界一流科技期刊的建议。【结果】 卓越的办刊理念、全方位的国际化水平、世界一流的人才队伍、先进的经营管理水平以及汇聚一流前沿成果、卓著的科学声望是建设世界一流科技期刊的必要条件。“高、精、尖”和“稳、准、狠”的办刊策略,是建设世界一流科技期刊的充分条件。建设世界一流科技期刊要理性且准确地认知其内涵,始终坚持卓越的办刊理念、国际化战略、人才战略、质量战略和集群化战略。【结论】 中国科技期刊既要扎根祖国大地,又要学习世界一流期刊的成功经验,从办刊的硬实力和软实力方面吸收借鉴,才能探索出具有中国特色的世界一流科技期刊建设路径。 相似文献
54.
The widely diverse impacts of SAR-CoV-2 infection resulting in the COVID-19 pandemic cannot be held in more stark relief when contrasting the devastating impact upon China, Italy, Great Britain, America and Brazil with the considerably milder course in the geographically isolated countries of Australia and New Zealand and the densely populated Vietnam. Children in the Asia-Pacific region, as with children all over the world to date, have fared better than older adults. Other countries in the Asia-Pacific region, including Indonesia and India have struggled to deal with the pandemic because of a lack of health infrastructure, inability to provide sufficient testing and isolation and widespread poverty. This article will provide a snapshot of the impact of COVID-19 upon countries in the Asia-Pacific region in the six months since the first case of the novel zoonotic coronavirus infection appeared in China. 相似文献
55.
目的 检测分析被诊断为X连锁视网膜色素变性(XLRP)的三个中国家系内的基因突变。设计 基因研究。研究对象 三个中国XLRP家系共27位受试者(其中18人为男性)。方法 由同一医生收集家系成员的详细临床资料并进行眼部检查,采集三个家系的先证者及有条件采血者的外周静脉血,提取基因组DNA。应用PCR技术扩增RPGR和RP2基因的全部外显子和内含子交界区序列,包括RPGR基因15号外显子开放阅读框,产物直接测序进行突变分析。主要指标 临床特征及基因测序结果。结果 基因筛查证实了两个RPGR基因的新型无义突变(c.1541C>G;p.S514X 和 c.2833G>T;p.E945X) 及一个错义突变(c.607G>C;p.A203P)。基因型-表型的相关性分析表明家系3患者在接近ORF15下游位置存在突变,这种突变导致视锥细胞功能的早期丧失。ORF15无义突变的女性携带者临床表型重,呈现出部分显性遗传的特点。结论 本研究证实了三种RPGR基因的新型突变,这一结果扩展了RPGR的突变谱及表型谱。 相似文献
56.
57.
刘洁荣 《中国医学教育技术》2015,(4)
世界各地均在加速推进教育信息化建设,但快速的 e 化发展,会因民众自身条件的不同造成不均的现象,并导致阶层、地域及群体间的“数位落差”。数位落差是世界各地政府在推动信息化的过程中都无法避免的,大陆地区也不例外。由于中国台湾地区具有与大陆相似的文化氛围和相近的教育发展历史,该文通过梳理和解读中国台湾地区现有的缩减数位落差政策,以期为大陆地区研制专门化政策来应对当前挑战,推进教育信息化的均衡发展提供借鉴。 相似文献
58.
Elanah Uretsky 《Critical public health》2015,25(1):78-88
Mention of the term sex work often invokes images of marginalized women at risk for HIV infection. Such images, however, are counterintuitive to the functional role intended by the movement that spawned use of the terms ‘sex work’ and ‘sex worker.’ This article looks at the sexual practices of men in urban China to argue for a return to a functional definition of ‘sex work’, which was originally meant to legitimize the role sex plays in work. The progenitors of this movement intended to use ‘sex work’ as a means to legitimize sex as an income-generating activity for women involved in prostitution. I show that sex can also serve a functional role in the work-related duties of men seeking economic and political success in contemporary urban China. Men in China utilize sex as one way for demonstrating the loyalty necessary to access state-owned and controlled resources in a market economy governed under a Leninist system. Overall, the article demonstrates that reclaiming perception of sex work as a functional rather than behavioral category can expand its use for preventing HIV among the broad subset of people who engage in sex as part of their work. 相似文献
59.
Haochu Li Xiaoming Li Lai Sze Tso Shan Qiao Eleanor Holroyd Yuejiao Zhou 《Vulnerable children and youth studies》2016,11(2):173-179
In HIV/AIDS research, few studies to date have evaluated ways to improve parental HIV disclosure practices using feedback from HIV-negative children who have recently experienced this event. We conducted semi-structured in-depth interviews with 20 children (aged 6–15) who were partially to fully aware of their parents’ HIV status in rural Guangxi, China. Of the 20 children, eight children who were of older age (11.38 years in average) endorsed parental HIV disclosure, five discouraged it and seven expressed uncertainty. Children’s different experiences and attitudes towards disclosure were seen to be associated with their family dynamics (especially the parent–child relationship), social support and care, experiences of stigma and discrimination, psychosocial suffering, comprehension of the disease and the children’s age. Our study contributes to building a child-centered comprehensive understanding for Chinese parental HIV disclosure. It is imperative that counselors and community advocates assess and help parents achieve optimal readiness preceding disclosure of their illness to their HIV-negative children. 相似文献
60.
Ju-Fang Shi PhD Le Wang PhD Jian-Chao Ran MPH Hong Wang MB Cheng-Cheng Liu MB Hai-Zeng Zhang MD Lin Yang MD Su-Sheng Shi MD Li-Ming Jiang MD Jin-Hu Fan BS Yue-Ming Zhang MD Wei-Hu Wang MD Jian-Song Ren PhD Lin Zhu MPH Zhao-Xu Zheng MD Yong-Kun Sun MD Shuang-Mei Zou MD Jun Jiang MD Bo Chen MD Hong-Da Chen PhD Guo-Xiang Liu PhD Li Yang PhD Yun-Chao Huang MD Lan-Wei Guo PhD De-Bin Wang PhD Yong-Zhen Zhang MPH A-Yan Mao MPH Jia-Lin Wang MD Ji-Yong Gong MD Dong-Hua Wei MD Wu-Qi Qiu PhD Bing-Bing Song MPH Kai Zhang MD Ni Li PhD Eleonora Feletto PhD Jie-Bin Lew PhD You-Lin Qiao PhD Wan-Qing Chen PhD Min Dai PhD Jie He MD 《Cancer》2021,127(11):1880-1893