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Circumnutation, the helical movement of organs, has been observed in diverse species of land plants. Whether circumnutation arises purely from internal growth oscillations or as a response to exogenous forces such as gravity is a subject of active debate. By observing rice seedlings grown under microgravity at the International Space Station (ISS) and analyzing the agravitropic lazy1 mutant, Kobayashi et al. (2019) propose gravity as the causal force that regulates circumnutation of rice coleoptiles.  相似文献   
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Interesting optical and photochemical properties make microbial rhodopsin a promising biological material suitable for various applications, but the cost-prohibitive nature of production has limited its commercialization. The aim of this study was to explore the natural biodiversity of Indian solar salterns to isolate natural bacteriorhodopsin (BR) variants that can be functionally expressed in Escherichia coli. In this study, we report the isolation, functional expression and purification of BRs from three pigmented haloarchaea, wsp3 (water sample Pondicherry), wsp5 and K1T isolated from two Indian solar salterns. The results of the 16S rRNA data analysis suggest that wsp3, wsp5 and K1T are novel strains belonging to the genera Halogeometricum, Haloferax and Haloarcula respectively. Overall, the results of our study suggest that 17 N-terminal residues, that were not included in the gene annotation of the close sequence homologues, are essential for functional expression of BRs. The primary sequence, secondary structural content, thermal stability and absorbance spectral properties of these recombinant BRs are similar to those of the previously reported Haloarcula marismortui HmBRI. This study demonstrates the cost-effective, functional expression of BRs isolated from haloarchaeal species using E. coli as an expression host and paves the way for feasibility studies for future applications.  相似文献   
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A member of the nematophagous anamorph genus Arthrobotrys was isolated from its teleomorph Orbilia blumenaviensis comb. nov. (= Orbilia fici), a species closely related to O. auricolor but deviating in having lanceolate paraphyses. In the presence of nematodes, the anamorph forms three-dimensional adhesive networks. A trimorphism in its conidia was observed which vary in shape and number of septa. In the first isolate, two types of heteropolar conidia were obtained. These differ markedly from the type strain of A. vermicola, which forms mainly homopolar (fusoid) conidia. In a further ascospore isolate of O. blumenaviensis, however, mainly fusoid conidia referable to A. vermicola occurred. Combining morphological and phylogenetic analysis, we conclude that these isolates with differently shaped conidia and/or differences in the ITS rDNA (ca. 2–4%) belong to a single anamorph species, A. vermicola. Both teleomorph and anamorph are illustrated and described.  相似文献   
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This study addresses for the first time the movement patterns of the globally near-threatened Bearded Vulture Gypaetus barbatus in its most important stronghold, the high-altitude mountain ranges of Asia. Tracked individuals (n = 8) in the Annapurna Himalayan range (Nepal) foraged over a vast range of 60 715.9 km2 and our results indicated age-class differences in the use of space. Territorial adults showed very small annual home-ranges (K90 = 150.3 km2), whereas immatures wandered extensively and covered vast ranges of the mountains (K90 = 23 930.8 km2). For adults and immatures, these values are notably larger than the other two studied populations in the world (Pyrenees and South Africa). This suggests that the studied Annapurna population might exhibit lower breeding density than in the Pyrenees or South Africa, possibly due to lower food availability.  相似文献   
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Quantitative studies on nesting habitat selection are important to understand and predict the resource requirements for breeding habitat. In this study, we analysed nest-site (cliff) and territory selection patterns of the Bearded Vulture in the Annapurna Range of the Himalayas (Nepal). Our study area represents high-elevation mountain range systems, where information on nest selection is lacking, despite having the largest remaining populations of Bearded Vultures in the world. Our models indicated selection patterns at both nest and territory spatial scales that are consistent with previous studies at lower altitudes (Pyrenees, the Caucasus), such as a preference for landscape patches with greater food availability. However, our models also indicated selection patterns that are probably a response to the higher altitudes and sheer reliefs of the Annapurna massif, such as avoidance of the steepest slopes and selection of cliffs facing south and west for nest-sites. We did not detect an impact of human activities on the distribution of nests or territories. However, the Annapurna massif is experiencing development of infrastructures (e.g. road construction). Further research efforts will be needed to monitor human impacts on Bearded Vulture populations in the Annapurna Range, as this is a global stronghold for this species.  相似文献   
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