全文获取类型
收费全文 | 984篇 |
免费 | 58篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 25篇 |
妇产科学 | 54篇 |
基础医学 | 140篇 |
口腔科学 | 86篇 |
临床医学 | 107篇 |
内科学 | 197篇 |
皮肤病学 | 2篇 |
神经病学 | 85篇 |
特种医学 | 16篇 |
外科学 | 101篇 |
综合类 | 3篇 |
预防医学 | 110篇 |
眼科学 | 16篇 |
药学 | 32篇 |
肿瘤学 | 61篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 22篇 |
2013年 | 51篇 |
2012年 | 49篇 |
2011年 | 33篇 |
2010年 | 28篇 |
2009年 | 34篇 |
2008年 | 60篇 |
2007年 | 61篇 |
2006年 | 68篇 |
2005年 | 81篇 |
2004年 | 60篇 |
2003年 | 56篇 |
2002年 | 68篇 |
2001年 | 19篇 |
2000年 | 19篇 |
1999年 | 20篇 |
1998年 | 18篇 |
1997年 | 15篇 |
1996年 | 9篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 13篇 |
1992年 | 11篇 |
1991年 | 12篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 21篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1970年 | 4篇 |
1969年 | 3篇 |
1964年 | 6篇 |
1963年 | 4篇 |
排序方式: 共有1049条查询结果,搜索用时 15 毫秒
1.
2.
Association between craniomandibular disorders and occlusal interferences in children. 总被引:2,自引:0,他引:2
The association between clinical signs of craniomandibular disorders (CMD) and occlusal interferences was studied longitudinally in two cohorts of children, 5 and 10 years of age at baseline, representing the nonpatient population. They were followed up for 5 years. The range of active participants was 96 to 106 in the younger group, and 64 to 74 in the older group. The subjects were seen annually for registration of signs of CMD and for the presence of interferences, and for a real or placebo occlusal adjustment. The double-blind study design was applied. Baseline data showed no association between the variables studied; parts of data from second and third examinations disclosed significant associations; and fourth, fifth and sixth examinations disclosed a consistent pattern of significant associations. 相似文献
3.
Mäkinen KK Alanen P Isokangas P Isotupa K Söderling E Mäkinen PL Wenhui W Weijian W Xiaochi C Yi W Boxue Z 《International dental journal》2008,58(1):41-50
AIM: To investigate the use of xylitol-containing chewing-gums in public elementary schools as a means to affect the growth of salivary and plaque mutans streptococci and salivary lactobacilli. DESIGN: Over a period of 24 months, 750 8- to 9-year-old children chewed xylitol (X group; n = 255) or xylitol-sorbitol (XS group; n = 264) gum on school days (454 days over 2 years), or chewed no gum at all (C group; n = 231). Consumption of xylitol in the X and the XS groups was 6.6 and 5.4g per day, respectively. Use of gum took place at school in four daily episodes of which three were supervised by teachers. Following the 24-month chewing-gum period, the subjects were re-examined after 15 months (total follow-up period: 39 months) at which time an extraneous comparison group (ExC; n = 117) was also examined. The numbers of subjects examined after 39 months were: X, 239; XS, 248; C3 217. METHODS: Salivary and plaque levels of mutans streptococci and the salivary levels of aerobically cultured aciduric bacteria (mostly representing lactobacilli) were determined using the Orion Diagnostica Dentocult SM and LB test kits, respectively. RESULTS: There were statistically significant differences after 24 and 39 months between the two xylitol chewing-gum groups and the C group with regard to salivary and plaque mutans streptococci and salivary lactobacilli: the use of xylitol-containing chewing-gums significantly reduced these bacterial scores. The reductions were statistically more significant in the X group than in the XS group. The bacterial scores of groups C and ExC were similar. CONCLUSIONS: Long-term use of xylitol-containing chewing-gum can reduce the growth of mutans streptococci in saliva and dental plaque, and lactobacilli-type bacteria in saliva, even if xylitol is used only on school days. The results also suggest that xylitol gum use can have a long-term, delayed growth-retarding effect on these micro-organisms, since reduced bacterial growth was still observed 15 months following the termination of xylitol use. The results indicate a close biochemical relationship between xylitol and mutans streptococci, and suggest that a similar relationship may exist regarding aerobically cultured aciduric bacteria present in saliva. 相似文献
4.
Pihlajamäki M Jalava J Huovinen P Kotilainen P;Finnish Study Group for Antimicrobial Resistance 《Antimicrobial agents and chemotherapy》2003,47(6):1832-1835
The resistance patterns and macrolide resistance mechanisms of 910 Finnish invasive pneumococci isolated during 1999 and 2000 were studied. Macrolide resistance was detected in 6.9% of isolates. Penicillin resistance was detected in 1.5% of isolates, and penicillin intermediate resistance was detected in 4.0% of isolates. Active macrolide efflux, mediated by the mef(A) gene, was the most common macrolide resistance mechanism. Four macrolide-resistant isolates had mutations in rRNA or ribosomal protein L22. 相似文献
5.
A method for the diagnosis of nuchal coiling of the umbilical cord before labor using a combination of real-time and Doppler ultrasonic equipment is presented in this case report. The applicability of the method is discussed. Further evaluation in routine obstetric practice is still required. 相似文献
6.
Generation of GFAP::GFP astrocyte reporter lines from human adult fibroblast‐derived iPS cells using zinc‐finger nuclease technology 下载免费PDF全文
Ping‐Wu Zhang Amanda M. Haidet‐Phillips Jacqueline T. Pham Youngjin Lee Yuqing Huo Pentti J. Tienari Nicholas J. Maragakis Rita Sattler Jeffrey D. Rothstein 《Glia》2016,64(1):63-75
Astrocytes are instrumental to major brain functions, including metabolic support, extracellular ion regulation, the shaping of excitatory signaling events and maintenance of synaptic glutamate homeostasis. Astrocyte dysfunction contributes to numerous developmental, psychiatric and neurodegenerative disorders. The generation of adult human fibroblast‐derived induced pluripotent stem cells (iPSCs) has provided novel opportunities to study mechanisms of astrocyte dysfunction in human‐derived cells. To overcome the difficulties of cell type heterogeneity during the differentiation process from iPSCs to astroglial cells (iPS astrocytes), we generated homogenous populations of iPS astrocytes using zinc‐finger nuclease (ZFN) technology. Enhanced green fluorescent protein (eGFP) driven by the astrocyte‐specific glial fibrillary acidic protein (GFAP) promoter was inserted into the safe harbor adeno‐associated virus integration site 1 (AAVS1) locus in disease and control‐derived iPSCs. Astrocyte populations were enriched using Fluorescence Activated Cell Sorting (FACS) and after enrichment more than 99% of iPS astrocytes expressed mature astrocyte markers including GFAP, S100β, NFIA and ALDH1L1. In addition, mature pure GFP‐iPS astrocytes exhibited a well‐described functional astrocytic activity in vitro characterized by neuron‐dependent regulation of glutamate transporters to regulate extracellular glutamate concentrations. Engraftment of GFP‐iPS astrocytes into rat spinal cord grey matter confirmed in vivo cell survival and continued astrocytic maturation. In conclusion, the generation of GFAP::GFP‐iPS astrocytes provides a powerful in vitro and in vivo tool for studying astrocyte biology and astrocyte‐driven disease pathogenesis and therapy. GLIA 2016;64:63–75 相似文献
7.
Pentti Kuronen Esko Toppila Jukka Starck Rauno Pa¨a¨kko¨nen Martti J. Sorri 《International journal of audiology》2013,52(2):79-84
Noise is a significant risk factor in aviation, especially in military aviation. Even though our earlier studies have shown that the risk of noise-induced hearing loss (NIHL) among military pilots is small and the monitoring of their hearing is effective, we still need to develop methods of assessing the risk of NIHL more effectively at both the general and individual levels. In addition, many other risk factors are considered to contribute to the development of hearing impairment. The novel NoiseScan data management system enables assessment of the risk of developing hearing impairment on the basis of known risk factors. This study investigates the risk of hearing impairment among Finnish Air Force pilots using reasonably accurate noise exposure data and other risk factors for hearing impairment. This risk is also compared with that of industrial workers, whose risk followed the ISO 1999 prediction. Hearing among Finnish military pilots turned out to be better than predicted by the ISO 1999 model. The industrial workers had a larger number of risk factors than the pilots. Owing to the small number of risk factors, the hearing of pilots corresponds to approximately the 80th percentile, being 9-13 dB better than the 50th percentile obtained with the industrial population. 相似文献
9.