全文获取类型
收费全文 | 973篇 |
免费 | 165篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 52篇 |
妇产科学 | 9篇 |
基础医学 | 140篇 |
口腔科学 | 16篇 |
临床医学 | 169篇 |
内科学 | 319篇 |
皮肤病学 | 9篇 |
神经病学 | 22篇 |
特种医学 | 164篇 |
外科学 | 43篇 |
综合类 | 22篇 |
预防医学 | 53篇 |
眼科学 | 8篇 |
药学 | 109篇 |
肿瘤学 | 37篇 |
出版年
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 6篇 |
2015年 | 11篇 |
2014年 | 15篇 |
2013年 | 26篇 |
2012年 | 27篇 |
2011年 | 25篇 |
2010年 | 43篇 |
2009年 | 45篇 |
2008年 | 30篇 |
2007年 | 50篇 |
2006年 | 26篇 |
2005年 | 36篇 |
2004年 | 22篇 |
2003年 | 29篇 |
2002年 | 25篇 |
2001年 | 36篇 |
2000年 | 31篇 |
1999年 | 22篇 |
1998年 | 62篇 |
1997年 | 52篇 |
1996年 | 55篇 |
1995年 | 47篇 |
1994年 | 45篇 |
1993年 | 38篇 |
1992年 | 19篇 |
1991年 | 26篇 |
1990年 | 19篇 |
1989年 | 39篇 |
1988年 | 32篇 |
1987年 | 15篇 |
1986年 | 28篇 |
1985年 | 22篇 |
1984年 | 16篇 |
1983年 | 19篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 12篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1971年 | 3篇 |
1964年 | 3篇 |
1962年 | 3篇 |
排序方式: 共有1176条查询结果,搜索用时 15 毫秒
1.
There has been a call for research on migrant and refugee women’s negotiation of diverse discourses and cultural constraints associated with sexual embodiment, including menopause, in order to facilitate sexual and reproductive health and understand gendered subjectivity. This study examined the construction and experience of menopause among migrant and refugee women who had settled in Australia or Canada in the last 10 years. Eighty-four individual interviews and 16 focus groups comprising 85 participants were conducted (total n?=?169), with women aged 18 years and over from Afghanistan, India (Punjab), Iraq, Somalia, South Sudan, Sri-Lanka (Tamil), Sudan and various South American (Latina) backgrounds. Thematic decomposition identified three discursive themes: Menopause as the Age of Despair; a Discourse of Silence and Secrecy; and Menopause as a Life Stage – or when Life Starts. Negative constructions of menopause, associated with silence and secrecy, were evident across different cultural groups, with implications for women’s positioning and experience of menopausal change and embodiment. However, resistance to negative discourse was also evident. This was primarily associated with having received menopause education and more open communication about menopausal change, suggesting that education and health information can facilitate affirming aspects of menopause. 相似文献
2.
Tessa Timmers Rik Ossenkoppele Denise Visser Hayel Tuncel Emma E Wolters Sander CJ Verfaillie Wiesje M van der Flier Ronald Boellaard Sandeep SV Golla Bart NM van Berckel 《Journal of cerebral blood flow and metabolism》2020,40(12):2464
The aim of this study was to investigate the test–retest (TRT) repeatability of various parametric quantification methods for [18F]Flortaucipir positron emission tomography (PET). We included eight subjects with dementia or mild cognitive impairment due to Alzheimer’s disease and six cognitively normal subjects. All underwent two 130-min dynamic [18F]Flortaucipir PET scans within 3 ± 1 weeks. Data were analyzed using reference region models receptor parametric mapping (RPM), simplified reference tissue method 2 (SRTM2) and reference logan (RLogan), as well as standardized uptake value ratios (SUVr, time intervals 40–60, 80–100 and 110–130 min post-injection) with cerebellar gray matter as reference region. We obtained distribution volume ratio or SUVr, first for all brain regions and then in three tau-specific regions-of-interest (ROIs). TRT repeatability (%) was defined as |retest–test|/(average (test + retest)) × 100. For all methods and across ROIs, TRT repeatability ranged from (median (IQR)) 0.84% (0.68–2.15) to 6.84% (2.99–11.50). TRT repeatability was good for all reference methods used, although semi-quantitative models (i.e. SUVr) performed marginally worse than quantitative models, for instance TRT repeatability of RPM: 1.98% (0.78–3.58) vs. SUVr80–100: 3.05% (1.28–5.52), p < 0.001. Furthermore, for SUVr80–100 and SUVr110–130, with higher average SUVr, more variation was observed. In conclusion, while TRT repeatability was good for all models used, quantitative methods performed slightly better than semi-quantitative methods. 相似文献
3.
4.
目的:临床局部辐射条件下会造成非辐射区域组织及细胞功能损害,最为突出的是对造血功能的影响。实验建立60Coγ射线左半身辐射动物模型,观察局部电离辐射对其非辐射区域骨髓巨核细胞的影响。方法:实验于2003-10/2005-03在解放军第三军医大学辐照中心和全军复合伤研究所完成。①实验动物:6~8周龄SPF级雄性昆明小鼠180只,随机数字表法分为正常对照组、全身辐射组、左半身辐射组、全身屏蔽辐射组,45只/组。②实验方法:全身辐射组小鼠固定于辐射架内;左半身辐射组小鼠麻醉后固定体位,用铅砖屏蔽右半身;全身屏蔽辐射组小鼠麻醉固定体位,用铅砖屏蔽全身。以60Coγ射线一次性辐射,剂量率68.46cGy/min。正常对照组不作任何干预。③实验评估:辐射后不同时相检测小鼠血清丙二醛含量及超氧化物歧化酶活性变化,计数外周血血小板,检测骨髓巨核祖细胞集落形成单位,观察骨髓组织病理改变及CD41a、CD61的表达。结果:全身辐射组第8天死亡2只,第9天死亡4只,其余各组无脱失。①外周血血小板计数:辐射后第2,7天,左半身辐射组外周血血小板数量显著低于正常对照组(P<0.01),但高于全身辐射组(P<0.01)。②血清丙二醛含量及超氧化物歧化酶活性变化:辐射后第2,9天,左半身辐射组血清丙二醛含量显著高于正常对照组(P<0.01),低于全身辐射组(P<0.01);血清超氧化物歧化酶活性显著低于正常对照组(P<0.01),高于全身辐射组(P<0.01)。③骨髓巨核祖细胞集落形成单位的变化:与正常对照组比较,辐射后6h左半身辐射组非辐射侧的巨核祖细胞集落形成单位显著降低(P<0.01),高于全身辐射组及左半身辐射组(P<0.01)。④骨髓组织病理改变:正常对照组有核细胞比例较高,分布均匀,并见多量散在分布的细胞龛;辐射2d后,左半身辐射组非辐射侧骨髓有核细胞较正常对照组减少,但好于全身辐射组、左半身辐射组。⑤骨髓CD41a及CD61表达的变化:辐射后2d与正常对照组比较,左半身辐射组非辐射侧骨髓CD41a及CD61阳性细胞数和相对荧光强度均显著降低(P<0.01),但高于全身辐射组、左半身辐射组(P<0.01)。结论:局部电离辐射作用后,可导致小鼠非辐射区域骨髓巨核细胞增殖能力降低,血小板减少,产生功能障碍。氧自由基激活可能参与了该损伤过程。 相似文献
5.
Guidelines for the laboratory diagnosis and susceptibility testing of methicillin-resistant Staphylococcus aureus (MRSA) 总被引:4,自引:0,他引:4
Brown DF Edwards DI Hawkey PM Morrison D Ridgway GL Towner KJ Wren MW;Joint Working Party of the British Society for Antimicrobial Chemotherapy;Hospital Infection Society;Infection Control Nurses Association 《The Journal of antimicrobial chemotherapy》2005,56(6):1000-1018
These evidence-based guidelines have been produced after a literature review of the laboratory diagnosis and susceptibility testing of methicillin-resistant Staphylococcus aureus (MRSA). We have considered the detection of MRSA in screening samples and the detection of reduced susceptibility to glycopeptides in S. aureus. Recommendations are given for the identification of S. aureus and for suitable methods of susceptibility testing and screening for MRSA and for S. aureus with reduced susceptibility to glycopeptides. These guidelines indicate what tests should be used but not when the tests are applicable, as aspects of this are dealt with in guidelines on control of MRSA. There are currently several developments in screening media and molecular methods. It is likely that some of our recommendations will require modification as the new methods become available. 相似文献
6.
Ensor VM Shahid M Evans JT Hawkey PM 《The Journal of antimicrobial chemotherapy》2006,58(6):1260-1263
OBJECTIVES: To determine occurrence, prevalence and CTX-M genotypes produced by Enterobacteriaceae from clinical samples from three geographically distant Indian hospitals and to detect linkage of IS26 with bla(CTX-M) and map its precise insertion position. METHODS: A total of 130, non-duplicate Escherichia coli and Klebsiella pneumoniae resistant to a third-generation cephalosporin (3GC) from three Indian centres were screened for extended-spectrum beta-lactamase (ESBL) production using phenotypic detection methods. All isolates were screened for bla(CTX-M) using multiplex PCR. Precise CTX-M genotype was identified using reverse-line hybridization. All CTX-M-producing isolates were screened for linkage of IS26 with bla(CTX-M). DNA sequencing was used to map the exact insertion position of this mobile element. RESULTS: Ninety-five of 130 3GC-resistant (73%) (73% of total E. coli, 72% of total K. pneumoniae) isolates were found to carry bla(CTX-M-15). No other CTX-M genotype was detected. IS26 linkage with bla(CTX-M-15) was detected in 31% of isolates carrying bla(CTX-M-15). DNA sequencing revealed variable insertion of this mobile element within tnpA of ISEcp1. RAPD-PCR typing demonstrated great diversity in isolates carrying bla(CTX-M-15); no predominant clone was identified. CONCLUSIONS: In contrast with other studies where greater diversity exists, CTX-M-15 was the only CTX-M ESBL produced in this Indian collection of unrelated E. coli and K. pneumoniae. This is the first systematic survey report from India detecting CTX-M-type beta-lactamases This is also the first report indicating such high mobility/diversity of insertion of IS26 in close association with bla(CTX-M) in a single bacterial collection. 相似文献
7.
Jessica C Fanzo Matthew M Graziose Klaus Kraemer Stuart Gillespie Jessica L Johnston Saskia de Pee Eva Monterrosa Jane Badham Martin W Bloem Alan D Dangour Richard Deckelbaum Achim Dobermann Patrizia Fracassi SM Moazzem Hossain John Ingram Johann C Jerling CJ Jones Stefanus Indrayana Jap Lynnda Kiess Quinn Marshall Keith Martin Anuradha Narayan Mary Amuyunzu-Nayamongo Fré Pepping Keith P West 《Advances in nutrition (Bethesda, Md.)》2015,6(6):639-647
Nearly all countries in the world today are burdened with malnutrition, manifesting as undernutrition, micronutrient deficiencies, and/or overweight and obesity. Despite some progress, efforts to alleviate malnutrition are hampered by a shortage in number, skills, and geographic coverage, of a workforce for nutrition. Here, we report the findings of the Castel Gandolfo workshop, a convening of experts from diverse fields in March 2014 to consider how to develop the capacity of a global cadre of nutrition professionals for the post-2015 development era. Workshop participants identified several requirements for developing a workforce for nutrition, including an ability to work as part of a multisectoral team; communication, advocacy, and leadership skills to engage decision makers; and a set of technical skills to address future challenges for nutrition. Other opportunities were highlighted that could immediately contribute to capacity development, including the creation of a consortium to link global North and South universities, online training modules for middle managers, and practical, hands-on experiences for frontline nutrition workers. Institutional and organizational support is needed to enable workshop recommendations on education and training to be effectively implemented and sustained. The findings from the Castel Gandolfo workshop can contribute to the delivery of successful nutrition-relevant actions in the face of mounting external pressures and informing and attaining the forthcoming Sustainable Development Goals. 相似文献
8.
Comparison of the Eder-Puestow and Celestin techniques for dilating benign oesophageal strictures 总被引:1,自引:0,他引:1 下载免费PDF全文
The Celestin and Eder-Puestow methods of dilating benign oesophageal strictures have been compared prospectively in a randomised trial. One hundred and thirty three dilatations were performed on 72 patients. There was no significant difference between the two techniques with regard to the long term relief of symptoms. Celestin dilatation was quicker, less likely to cause pharyngeal trauma, and less damaging to guide wires. It could not be used, however, in those patients in whom only a short length of guide wire could be passed through the stricture. 相似文献
9.
Tze Peng Lim Rick Twee-Hee Ong Pei-Yun Hon Jane Hawkey Kathryn E. Holt Tse Hsien Koh Micky Lo-Ngah Leong Jocelyn Qi-Min Teo Thean Yen Tan Mary Mah-Lee Ng Li Yang Hsu 《Antimicrobial agents and chemotherapy》2015,59(12):7899-7902
We studied polymyxin B resistance in 10 pairs of clinical Acinetobacter baumannii isolates, two of which had developed polymyxin B resistance in vivo. All polymyxin B-resistant isolates had lower growth rates than and substitution mutations in the lpx or pmrB gene compared to their parent isolates. There were significant differences in terms of antibiotic susceptibility and genetic determinants of resistance in A. baumannii isolates that had developed polymyxin B resistance in vivo compared to isolates that had developed polymyxin B resistance in vitro. 相似文献
10.
Sebaceous carcinoma is a rare cutaneous malignancy, commonly affecting the eyelids. This case highlights a patient who presented with sebaceous carcinoma of the right upper lip with extensive involvement of the soft tissues of the head and neck. As part of the initial investigation, ultrasound was requested. This case demonstrates the ultrasound features of sebaceous carcinoma as well as revising the normal ultrasound anatomy of the upper lip and muscles of the cheek. 相似文献