全文获取类型
收费全文 | 4957篇 |
免费 | 339篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 99篇 |
妇产科学 | 62篇 |
基础医学 | 762篇 |
口腔科学 | 43篇 |
临床医学 | 492篇 |
内科学 | 1240篇 |
皮肤病学 | 36篇 |
神经病学 | 479篇 |
特种医学 | 272篇 |
外科学 | 827篇 |
综合类 | 8篇 |
一般理论 | 6篇 |
预防医学 | 267篇 |
眼科学 | 38篇 |
药学 | 305篇 |
中国医学 | 2篇 |
肿瘤学 | 331篇 |
出版年
2023年 | 40篇 |
2022年 | 60篇 |
2021年 | 218篇 |
2020年 | 98篇 |
2019年 | 160篇 |
2018年 | 199篇 |
2017年 | 133篇 |
2016年 | 145篇 |
2015年 | 156篇 |
2014年 | 226篇 |
2013年 | 282篇 |
2012年 | 419篇 |
2011年 | 419篇 |
2010年 | 214篇 |
2009年 | 195篇 |
2008年 | 290篇 |
2007年 | 284篇 |
2006年 | 230篇 |
2005年 | 215篇 |
2004年 | 155篇 |
2003年 | 166篇 |
2002年 | 122篇 |
2001年 | 73篇 |
2000年 | 64篇 |
1999年 | 58篇 |
1998年 | 29篇 |
1997年 | 16篇 |
1996年 | 21篇 |
1995年 | 27篇 |
1994年 | 14篇 |
1993年 | 17篇 |
1992年 | 52篇 |
1991年 | 40篇 |
1990年 | 54篇 |
1989年 | 43篇 |
1988年 | 38篇 |
1987年 | 34篇 |
1986年 | 31篇 |
1985年 | 35篇 |
1984年 | 22篇 |
1983年 | 24篇 |
1980年 | 14篇 |
1979年 | 20篇 |
1978年 | 14篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1974年 | 12篇 |
1968年 | 12篇 |
1967年 | 12篇 |
排序方式: 共有5312条查询结果,搜索用时 31 毫秒
71.
Mathieu Van der Aerschot Faheema Mahomed-Asmail Herman Carel Myburgh Robert Henry Eikelboom 《International journal of audiology》2016,55(11):616-622
Objective: Evaluation of the Sennheiser HD 202 II supra-aural headphones as an alternative headphone to enable more affordable hearing screening. Design: Study 1 measured the equivalent threshold sound pressure levels (ETSPL) of the Sennheiser HD 202 II. Study 2 evaluated the attenuation of the headphones. Study 3 determined headphone characteristics by analyzing the total harmonic distortion (THD), frequency response and force of the headband. Study sample: Twenty-five participants were included in study 1 and 15 in study 2 with ages ranging between 18 and 25. No participants were involved in study 3. Results: The Sennheiser HD 202 II ETSPLs (250–16000?Hz) showed no significant effects on ETSPL for ear laterality, gender or age. Attenuation was not significantly different (p?>?0.01) to TDH 39 except at 8000?Hz (p?0.01). Maximum permissible ambient noise levels (MPANL) were specified accordingly. The force of the headband was 3.1N. THD measurements showed that between 500 and 8000?Hz intensities of 90?dB HL and higher can be reached without THD?>3%. Conclusion: Sennheiser HD 202 II supra-aural headphones can be used as an affordable headphone for screening audiometry provided reported MPANLs, maximum intensities and ETSPL values are employed. 相似文献
72.
Gerbaud E Harcaut E Coste P Erickson M Lederlin M Labèque JN Perron JM Cochet H Dos Santos P Durrieu-Jaïs C Laurent F Montaudon M 《The international journal of cardiovascular imaging》2012,28(4):783-794
To evaluate the incremental diagnostic and prognostic value of cardiac magnetic resonance (CMR) in patients with chest pain, raised troponin and unobstructed coronary arteries, and to compare subsequent event rates between diagnostic groups. 130 patients (mean age: 54?±?17) presenting with troponin-positive acute chest pain and unobstructed coronary arteries were included. All patients were managed according to European Society of Cardiology guidelines, including echocardiography, and had CMR within 6.2?±?5.3?days of presentation. During follow-up, major adverse cardiovascular events (MACE) were recorded. CMR provided a diagnosis in 100 of 130 patients (76.9%), with the remaining 30 (23.1%) having a normal examination. CMR diagnosed 37 (28.5%) acute myocardial infarctions, 34 (26.1%) myocarditis, 28 (21.5%) apical ballooning syndromes and 1 (0.8%) hypertrophic cardiomyopathy. When a single diagnosis was suspected by the referring physician, CMR validated this diagnosis in 32 patients (76.2%). CMR provided a formal diagnosis in 61 patients (69.3%) in which the clinical diagnosis was uncertain between at least two possibilities. CMR corrected a wrong diagnosis in 10 patients (7.7%). CMR-suggested diagnosis led to a modification of therapy in 42 patients (32.3%). Median follow-up was 34?months (interquartile range 24–49) in 124 patients. Sixteen patients (12.9%) experienced MACE. MACE rate was not different between patients with a conclusive CMR and normal CMR. In patients with acute troponin-positive chest pain and unobstructed coronary arteries, early CMR has important diagnostic and therapeutic implications. However its association with occurrence of MACE during mid term follow-up was not obvious. 相似文献
73.
74.
75.
76.
Mathieu Wurtz Elisa Ruhland XuanLi Liu Izzie-Jacques Namer Viola Mazzoleni Dan Lipsker Daniel Keller Gilles Prvost David Gaucher 《Investigative ophthalmology & visual science》2021,62(1)
PurposeEndophthalmitis models have reported the virulent role of Panton-Valentine leucocidin (PVL) secreted by Staphylococcus aureus on the retina. PVL targets retinal ganglion cells (RGCs), expressing PVL membrane receptor C5aR. Interactions between PVL and retinal cells lead to glial activation, retinal inflammation, and apoptosis. In this study, we explored oxidative stress and retinal neurotransmitters in a rabbit retinal explant model incubated with PVL.MethodsReactive oxygen species (ROS) production in RGCs has been assessed with fluorescent probes and immunohistochemistry. Nuclear magnetic resonance (NMR) spectroscopy quantified retinal concentrations of antioxidant molecules and neurotransmitters, and concentrations of neurotransmitters released in the culture medium. Quantifying the expression of some pro-inflammatory and anti-inflammatory factors was performed using RT-qPCR.ResultsPVL induced a mitochondrial ROS production in RGCs after four hours’ incubation with the toxin. Enzymatic sources of ROS, involving nicotinamide adenine dinucleotide phosphate–oxidase and xanthine oxidase, were also activated after four hours in PVL-treated retinal explants. Retinal antioxidants defenses, that is, glutathione, ascorbate and taurine, decreased after two hours’ incubation with PVL. Glutamate retinal concentrations and glutamate release in the culture medium remained unaltered in PVL-treated retinas. GABA, glycine, and acetylcholine (Ach) retinal concentrations decreased after PVL treatment. Glycine release in the culture medium decreased, whereas Ach release increased after PVL treatment. Expression of proinflammatory and anti-inflammatory cytokines remained unchanged in PVL-treated explants.ConclusionsPVL activates oxidative pathways and alters neurotransmitter retinal concentrations and release, supporting the hypothesis that PVL could induce a neurogenic inflammation in the retina. 相似文献
77.
A. St-Laurent M. M. Mony M. È. Mathieu 《Journal of medical engineering & technology》2018,42(4):259-264
Physical activity (PA) is a part of a healthy pregnancy. To date, no consumer-based activity monitors have been validated with this population. The aim of this study was to validate the Fitbit Zip and Fitbit Flex monitors in free-living conditions with pregnant women using the ActiGraph GT3X as the ?gold standard?. We compared the accuracy of the Fitbit Zip and Fitbit Flex devices in measuring steps, sedentary time and time spent in different activity intensities. Sixteen women in their third trimester of pregnancy wore the ActiGraph GT3X (hip) plus one Fibit Zip (hip) and one Fitbit Flex (wrist) during seven consecutive days. The validity of Fitbit Zip and Fitbit Flex is good, depending on measured parameters. Fitbit Zip is accurate to measure steps whereas Fitbit Flex is precise for MVPA. When choosing between Fitbit Zip and Fitbit Flex monitors, pregnant women should take into account their preferred PA and the parameters they want to measure.. 相似文献
78.
Liesbeth Ceelen Marusya Lieveld Ramses Forsyth Mathieu Vinken 《Hepatology International》2013,7(2):394-399
Hepatitis virus infections, mainly hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, constitute a major problem for public health since they have a worldwide distribution and because they are associated with hepatocellular carcinoma and death. Current anti-HBV vaccines seem to be effective in the majority of people. However, an important issue waiting to be tackled nowadays is how to cure patients with chronic hepatitis B. Moreover, no vaccine is available today for the prevention of HCV infection. Therefore, the use of adequate in vitro infection systems is a prerequisite for the molecular understanding of the infection events of these viruses, which could result in the development of novel powerful therapeutics. In this respect, the HepaRG cell line exhibits a hepatocyte-like morphology and displays drug metabolism capacity similar to that of primary hepatocytes. HepaRG cells have yet been proven to be a useful tool in the study of viral infections, particularly for deciphering the mechanism of HBV entry into hepatocytes. 相似文献
79.
M Gayda F Paillard P Sosner M Juneau M Garzon M Gonzalez M Bélanger A Nigam 《Journal of clinical hypertension (Greenwich, Conn.)》2012,14(8):553-560
J Clin Hypertens (Greenwich). 2012;00:00–00 ©2012 Wiley Periodicals, Inc. The effects of sauna alone vs exercise and sauna on ambulatory blood pressure monitoring and central hemodynamic variables were measured in 16 patients with untreated hypertension assigned to a control period, sauna, or exercise and sauna. Exercise and sauna had positive effects on 24‐hour systolic and mean blood pressure in patients with untreated hypertension. Exercise and sauna and sauna alone reduce total vascular resistance, with positive effects lasting up to 120 minutes after heat exposure. 相似文献
80.
Longitudinal stent deformation is a recently described complication of percutaneous coronary intervention. It can lead to serious adverse outcomes. The precipitating mechanisms and treatment strategies have been described. We report a case of longitudinal stent deformation that occurred with the removal of a trapped rotablation guide wire. 相似文献