全文获取类型
收费全文 | 287篇 |
免费 | 19篇 |
专业分类
306篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 7篇 |
2017年 | 1篇 |
2016年 | 8篇 |
2015年 | 16篇 |
2014年 | 10篇 |
2013年 | 19篇 |
2012年 | 18篇 |
2011年 | 23篇 |
2010年 | 16篇 |
2009年 | 14篇 |
2008年 | 19篇 |
2007年 | 12篇 |
2006年 | 28篇 |
2005年 | 13篇 |
2004年 | 13篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有306条查询结果,搜索用时 0 毫秒
131.
Rogier Bodewes Joke van der Giessen Bart L. Haagmans Albert D. M. E. Osterhaus Saskia L. Smits 《Journal of virology》2013,87(13):7758-7764
Red foxes (Vulpes vulpes) are the most widespread members of the order of Carnivora. Since they often live in (peri)urban areas, they are a potential reservoir of viruses that transmit from wildlife to humans or domestic animals. Here we evaluated the fecal viral microbiome of 13 red foxes by random PCR in combination with next-generation sequencing. Various novel viruses, including a parvovirus, bocavirus, adeno-associated virus, hepevirus, astroviruses, and picobirnaviruses, were identified. 相似文献
132.
Joke Van den Berge Kim Naudts Costanza Zavalloni Ivan A. Janssens Reinhart Ceulemans Ivan Nijs 《Plant and Soil》2011,345(1-2):375-385
Few studies have investigated whether responses to nutrient supply of mixed plant communities change under combined elevated CO2 and climate warming. In this study we analyzed the response of constructed temperate grassland communities to five levels of nitrogen (N) supply, ranging from 0 to 150 kg N ha?1, under two climate scenarios. Biomass of the plant communities responded positively to N supply in the current climate, but was insensitive to N supply in the future climate. This altered response was not the result of a changing response from a single species, but all species seemed to contribute to it. The weaker response in the future climate was caused by changes in N uptake rather than by changes in nitrogen use efficiency, as community N stocks showed the same response pattern as community biomass. Climate change apparently modified the relation between fertilizer N addition and plant available N. 相似文献
133.
134.
Associations between marine seaweeds and bacteria are widespread, with endobiotic bacterial-algal interactions being described for over 40 years. Also within the siphonous marine green alga Bryopsis, intracellular bacteria have been visualized by electron microscopy in the early '70s, but were up to now never molecularly analyzed. To study this partnership, we examined the presence and phylogenetic diversity of microbial communities within the cytoplasm of two Bryopsis species by combining fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone libraries. Sequencing results revealed the presence of Arcobacter, Bacteroidetes, Flavobacteriaceae, Mycoplasma, Labrenzia, Phyllobacteriaceae and Xanthomonadaceae species. Although the total diversity of the endobiotic communities was unique to each Bryopsis culture, Bacteroidetes, Mycoplasma, Phyllobacteriaceae, and in particular Flavobacteriaceae bacteria, were detected in several Bryopsis samples collected hundreds of kilometres apart. This suggests that Bryopsis closely associates with well-defined endophytic bacterial communities of which some members possibly maintain an endosymbiotic relationship with the algal host. 相似文献
135.
Nelson AG Kokkonen J Winchester JB Kalani W Peterson K Kenly MS Arnall DA 《Journal of strength and conditioning research / National Strength & Conditioning Association》2012,26(3):832-836
It was questioned whether a unilateral stretching program would induce a crosstraining effect in the contralateral muscle. To test this, 13 untrained individuals participated in a 10-week stretching program while 12 other untrained individuals served as a control group. For the experimental group, the right calf muscle was stretched 4 times for 30 seconds, with a 30-second rest between stretches, 3 d·wk(-1) for 10 weeks. Strength, determined via 1 repetition maximum (1RM) unilateral standing toe raise, and range of motion (ROM) were measured pre-post. In the treatment group, the stretched calf muscle had a significant (p < 0.05) 8% increase in ROM, whereas the nonstretched calf muscle had a significant 1% decrease in ROM. The 1 RM of the stretched calf muscle significantly increased 29%, whereas the 1RM of the nonstretched calf muscle significantly increased 11%. In the control group, neither 1RM nor ROM changed for either leg. The results indicate that 10 weeks of stretching only the right calf will significantly increase the strength of both calves. Hence, chronic stretching can also induce a crosstraining effect for strength but not for the ROM. This study also validates earlier findings suggesting that stretching can elicit strength gains in untrained individuals. 相似文献
136.
The primary function of the skin is to protect the body for unwanted influences from the environment. The main barrier of the skin is located in the outermost layer of the skin, the stratum corneum. The stratum corneum consists of corneocytes surrounded by lipid regions. As most drugs applied onto the skin permeate along the lipid domains, the lipid organization is considered to be very important for the skin barrier function. It is for this reason that the lipid organization has been investigated quite extensively. Due to the exceptional stratum corneum lipid composition, with long chain ceramides, free fatty acids and cholesterol as main lipid classes, the lipid organization is different from that of other biological membranes. In stratum corneum, two lamellar phases are present with repeat distances of approximately 6 and 13 nm. Moreover the lipids in the lamellar phases form predominantly crystalline lateral phases, but most probably a subpopulation of lipids forms a liquid phase. Diseased skin is often characterized by a reduced barrier function and an altered lipid composition and organization. In order to understand the aberrant lipid organization in diseased skin, information on the relation between lipid composition and organization is crucial. However, due to its complexity and inter-individual variability, the use of native stratum corneum does not allow detailed systematic studies. To circumvent this problem, mixtures prepared with stratum corneum lipids can be used. In this paper first the lipid organization in stratum corneum of normal and diseased skin is described. Then the role the various lipid classes play in stratum corneum lipid organization and barrier function has been discussed. Finally, the information on the role various lipid classes play in lipid phase behavior has been used to interpret the changes in lipid organization and barrier properties of diseased skin. 相似文献
137.
138.
Defoliation Induces Fructan 1-Exohydrolase II in Witloof Chicory Roots. Cloning and Purification of Two Isoforms, Fructan 1-Exohydrolase IIa and Fructan 1-Exohydrolase IIb. Mass Fingerprint of the Fructan 1-Exohydrolase II Enzymes 下载免费PDF全文
139.
140.