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人体β-胡萝卜素的肠转化和吸收后转化的研究 总被引:5,自引:1,他引:4
目的 :为了解部分中国人体内 β 胡萝卜素 ( β carotene ,以下简称 β C)转化维生素A (vitaminA ,以下简称VA)的效率 ,开展了本研究。方法 :使用稳定同位素稀释法对 15名 5 0 60岁健康农村志愿者 (男 9,女6)进行β C人体代谢实验。 2周适应期和 5 6天实验期内 ,志愿者接受常规膳食 ,避免大量VA和 β C摄入以及烟、酒和营养补充剂。实验第 1天 ,给受试者含 6mg氘标记 β C( 2 H8β C)玉米油胶丸 ,随半流质早餐 (脂肪热能比 2 5 % )一起摄入。实验第 4天 ,受试者以同样方法摄入含 3mg氘标记醋酸视黄醇 ( 2 H8RAC)油剂胶丸。实验第 1天和第 4天摄入标记物后 0 ,3 ,5 ,7,9,11,13h时 ,实验第 2 ,3 ,5 ,6,7,8,9,10 ,14,2 1,2 8,3 5 ,42 ,49,5 6天晨空腹时 ,采静脉血。用高效液相色谱仪 (HPLC)分离血清 β C和VA组分 ,再分别使用气相质谱仪(GC MS)和液相质谱仪 (LC MS)测定VA和 β C组分的同位素丰度。根据VA和 β C的浓度和同位素丰度 ,描述标记VA和β C在体内应答的血液动力学曲线。 结果 :所有 15名受试者对2 H8RAC应答明显 ;但是在对2 H8β C的应答方面 ,只有 11名受试者2 H4视黄醇应答曲线明显 ,有 4名受试者血清2 H4视黄醇应答曲线非常微弱。经过对备份血清样品进行的多次重复GC MS测定 ,我们目前初步? 相似文献
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The mould collection of the Centraalbureau voor Schimmelcultures, Baarn, The Netherlands, was screened for isolates originating from warm-blooded animals. The range of species indicates that distribution of clinically relevant, pathogenic or opportunistic strains over the fungal kingdom is non-random. Some opportunistic fungi possess adaptations to life under hostile environmental conditions, enabling them to survive inside the human body. Presence of melanin or carotene seems to be an important virulence factor. Opportunistic fungi which sporulate in submersion are able to disseminate or cause severe local mycoses when the aspecific immune system of the host is impaired. Mycoses caused by a few dimorphic fungi, mostly in their natural ecological niche living in association with vertebrates, are promoted by specific immune deficiencies. 相似文献
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摘要:包装内气氛与包装材料选择性透气性是影响果蔬气调包装质量的主要因素。对青豌豆采用6组不同初始气体组分、3种包装材料进行气调包装,在5℃,相对湿度85%的环境下贮藏7d后,测定青豌豆的相关质量指标,并与未包装产品进行比较,结果表明气调包装对青豌豆保鲜效果显著;在此基础上,用主成分分析法构造了气调包装产品质量的综合评价模型,对气调包装青豌豆质量进行综合评价,得出青豌豆气调包装的最佳初始气体组分,分析了不同包装材料对青豌豆气调包装质量的影响。 相似文献
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Astrid A. M. Poelman Maeva Cochet-Broch Janne Beelen Bonnie Wiggins Jessica E. Heffernan David N. Cox 《Nutrients》2021,13(5)
The teacher-led implementation of healthy eating programs in schools is cost-effective and potentially impactful. Teacher acceptability is important for uptake; however, process evaluations are scarce. This study evaluated the effect of two intensities of teacher training on the evaluation of a vegetable education program for Australian primary schools by teachers. The teachers (n = 65) who implemented the program as part of a cluster RCT (25 schools in two states, New South Wales and South Australia) received either low- (provision with materials and online training) or high (additional face-to-face (F2F) training)-intensity training prior to implementing a 5-week vegetable education program. They evaluated the acceptability of a digital training module and program by indicating the level of agreement with 15 and 18 statements, respectively, using 5-point Likert scales. The average item scores ranged from 3.0 to 4.2. All but one item, including student engagement, alignment to the curriculum and intent for reuse of the program, had a rounded average or median score of 4. The level of training intensity did not impact the teacher acceptability ratings. In conclusion, the teacher acceptability was good, and additional F2F training does not add value above the solely digital training of the teachers. 相似文献
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Plasma levels of antioxidant vitamins and cholesterol in a large population sample in Central-Northern Italy 总被引:2,自引:0,他引:2
D. Palli A. Decarli A. Russo F. Cipriani A. Giacosa D. Amadori R. Salkeld S. Salvini E. Buiatti 《European journal of nutrition》1999,38(2):90-98
Background:
In a population-based multicenter case-control study of diet, life-style, and gastric cancer a large series of adults, aged
30–75 years (mean 58.9 yearss), were randomly sampled from the general population in 3 areas of Central-Northern Italy.
Aim of the study: To evaluate the relationship between plasma levels of antioxidant vitamins and cholesterol, and sociodemographic characteristics,
life-style factors, and dietary intake of selected nutrients in a sample of the Italian population.
Methods: A fasting blood sample was available for 945 subjects (553 men, 392 women). The plasma concentrations of ascorbic acid,
carotene, retinol, alpha-tocopherol, and cholesterol were determined by a centralized laboratory. All participants answered
to a detailed questionnaire collecting information on sociodemographic and anthropometric characteristics, smoking, alcohol
drinking, and dietary habits. Covariance analysis models, with post hoc Dunnett tests, including terms for age, sex, study
center, and period of blood drawing, were used for selected multiple-way comparisons of mean values of plasma nutrients.
Results: Mean plasma values of retinol were higher among men while women had higher levels of plasma carotene, ascorbic acid, alpha-tocopherol,
and cholesterol. Plasma carotene levels showed an inverse association with body mass index, alcohol consumption, and smoking
and a positive association with social class. Carotene concentrations were higher in plasma samples obtained in spring/summer,
while ascorbic acid levels were higher in autumn/winter. Partial correlation coefficients between carotene and ascorbic acid
(0.69 in men; 0.74 in women), between carotene and alpha-tocopherol (0.44; 0.37), and between alpha-tocopherol and ascorbic
acid (0.45; 0.41). Plasma alpha-tocopherol and retinol correlated with plasma cholesterol. On the other hand, plasma carotene
and ascorbic acid were correlated with their estimated dietary intakes, while the intakes of other nutrients, as expected,
correlated rather poorly with the respective plasma concentrations.
Conclusions: Socio-economic factors, life-style, and specific nutrient intake, in addition to gender, are related to nutrient plasma
levels in Italian adults and may provide specific suggestions for the prevention of chronic diseases.
Received: 8 December 1998, Accepted: 25 February 1999 相似文献
8.
目的建立同时测定果蔬中11种有机磷的气相色谱法。方法以丙酮为萃取剂提取残留在样品中的有机磷农药,用HP-5毛细管色谱柱附氮磷检测器(NPD)对其进行测定。结果采用程序升温,所测定的11种有机磷在HP-5(30 m×0.32 mm×0.25μm)毛细管柱上得到很好的分离。加标回收率82.5%~102.0%,相对标准偏差(RSD)为1.9%~6.0%,在0.1~10.0 mg/L范围内有良好的线性关系。结论该方法具有灵敏度高,操作简单、快捷,结果准确、可靠等优点,适用于各种蔬菜水果样品的测定分析。 相似文献
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