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排序方式: 共有774条查询结果,搜索用时 15 毫秒
71.
Kylliki Tarvainen Riitta Jolanki Maj-Len Henriks Eckerman Tuula Estlander 《Contact dermatitis》1998,39(1):46-47
Formaldehyde is a ubiquitous and potent sensitizer. Formaldehyde-sensitive patients may have long-lasting hand eczema (1). Contact dermatitis from formaldehyde is often chronic, probably because it is so difficult to avoid exposure to formaldehyde-containing products. An investigation in Denmark showed that 1/3 of all cosmetic products contained formaldehyde or formaldehyde-releasing preservatives (2). Formaldehyde can also be found in many houshold products. In recent years, the use of moistened baby toilet tissues has greatly increased. 相似文献
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Effects of temperature and aldehyde fixation on tissue water diffusion properties, studied in an erythrocyte ghost tissue model. 总被引:1,自引:0,他引:1
Peter E Thelwall Timothy M Shepherd Greg J Stanisz Stephen J Blackband 《Magnetic resonance in medicine》2006,56(2):282-289
Ex vivo biological sample imaging can complement in vivo MRI studies. Since ex vivo studies are typically performed at room temperature, and samples are frequently preserved by fixation, it is important to understand how environmental and chemical changes dictated by ex vivo studies alter the physical and MR properties of a sample. Diffusion and relaxation time measurements were used to assess the effects of temperature change and aldehyde fixation on the biophysical and MR properties of a model biological tissue comprised of erythrocyte ghosts suspended in buffer or agarose gel. Sample temperature was varied between 10 degrees C and 37 degrees C. Diffusion MRI data were analyzed with a biophysically appropriate two-compartment exchange model. Temperature change resulted in a complex alteration of water diffusion properties due to the compartmental nature of tissues and alteration in membrane permeability. Formaldehyde, Karnovsky's solution, and glutaraldehyde all caused statistically significant changes to the biophysical and MR properties of the samples. Fixation caused large decreases in water proton T2, which was restored to near prefixation values by washing free fixative from the samples. Water membrane permeability was also significantly altered by fixation. This study demonstrates that relating in vivo MR data to chemically fixed ex vivo data requires an understanding of the effects of sample preparation. 相似文献
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室内装修后空气中甲醛浓度的变化趋势 总被引:6,自引:1,他引:5
目的 :研究室内装修后空气中甲醛浓度的变化趋势。方法 :选择装修后不同时间段的居民住宅 5 4家和公共场所经营单位 5 2家进行室内空气中甲醛浓度的测定。结果 :甲醛浓度在居民住宅装修 1年之内的超标率为 79.9%~ 85 .4 % ,1年~ 2年之间的超标率为 5 0 .0 % ,2年之后为18.3% ,3个时间段甲醛浓度超标率有显著性差异 (P<0 .0 5 )。公共场所装修半年之内甲醛含量的超标率为 6 5 .5 %~ 81.3% ,半年~ 1年为 36 .84 % ,1年之后 <15 .4 % ,3个时间段甲醛浓度超标率有显著性差异 (P<0 .0 5 )。结论 :室内装修后甲醛浓度随着装修时间的延长而逐渐降低 ,居民住宅大约需要 2年、公共场所大约需要 1年才能达到国家卫生标准。 相似文献
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旅店室内空气甲醛污染对从业人员健康影响的调查报告 总被引:10,自引:0,他引:10
本文以甲醛平均浓度为0.058mg/m3的高级宾馆为接触组和平均浓度为0.020mg/m3的普通招待所为对照组,对其从业人员的健康状况进行调查比较,结果表明:接触组的眼、鼻、咽刺激征、呼吸道症状、头晕、疲劳感、皮肤干燥、月经不调、多汗等自觉症状阳性检出率明显高于对照组,差异具有显著性。提示,旅店业甲醛污染对从业人员健康的影响不能忽视。改善室内环境、降低空气中甲醛浓度,对于保护人体健康具有重要意义。 相似文献
80.
Mari-Ann Flyvholm Barbara M. Hall Tove Agner Eva Tiedemann Peter Greenhill Walter Vanderveken Fred E. Freeberg Torkil Menné 《Contact dermatitis》1997,36(1):26-33
Our purpose was to investigate the eliciting threshold concentration of formaldehyde in formaldehyde-sensitive individuals in the occluded and non-occluded patch teat and to evaluate the relationship in repeated open application test (ROAT) with a product containing a formaldehyde releaser. 20 formaldehyde-sensitive patients and a control group of 20 healthy volunteer were included in the study. Occluded and non-occluded patch tests with formaldehyde solutions form 25 to 10,000 ppm. and ROAT for I week with a leave-on cosmetic product containing on average 300 ppm formaldehyde. Were carried out simultaneously on each subject. In the occluded patch test. 1/2 of the 20 patients only reacted to 10,000 ppm formaldehyde. 9 reacted to 5,000 ppm. 3 reacted to 1.000 ppm. 2 reacted to 500 ppm and I reacted to 25 ppm. No definite positive reactions were observed in the non-occluded patch test or in the ROAT No positive reactions were observed in the control group to any of the test procedures. We concluded that the threshold concentration for occluded patch test to formaldehyde in formaldehyde-sensitive patients was 250 ppm. The threshold in occluded patch test corresponded to the degree of sensitivity Definite positive reactions in the ROAT were not seen, either indicating that they are unlikely to happen with the type of product used or that the exposure time was too short. 相似文献