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341.
Ken Keefover-Ring Maria Ahnlund Ilka Nacif Abreu Stefan Jansson Thomas Moritz Benedicte Riber Albrectsen 《PloS one》2014,9(10)
Salicinoids are well-known defense compounds in salicaceous trees and careful screening at the population level is warranted to fully understand their diversity and function. European aspen, Populus tremula, is a foundation species in Eurasia and highly polymorphic in Sweden. We exhaustively surveyed 102 replicated genotypes from the Swedish Aspen collection (SwAsp) for foliar salicinoids using UHPLC-ESI-TOF/MS and identified nine novel compounds, bringing the total to 19 for this species. Salicinoid structure followed a modular architecture of a salicin skeleton with added side groups, alone or in combination. Two main moieties, 2′-cinnamoyl and 2′-acetyl, grouped the SwAsp population into four distinct chemotypes, and the relative allocation of salicinoids was remarkably constant between different environments, implying a highly channeled biosynthesis of these compounds. Slightly more than half of the SwAsp genotypes belonged to the cinnamoyl chemotype. A fraction synthesized the acetyl moiety alone (∼7%) or in combination with cinnamoyl (∼2%), and close to forty percent lacked either of the two characteristic moieties, and thus resemble P. tremuloides in their salicinoid profile. The two most abundant chemotypes were evenly distributed throughout Sweden, unlike geographical patterns reported for SwAsp phenology traits, plant defense genes, and herbivore community associations. Here we present the salicinoid characterization of the SwAsp collection as a resource for future studies of aspen chemical ecology, salicinoid biosynthesis, and genetics. 相似文献
342.
Carolina Bernhardsson Kathryn M. Robinson Ilka N. Abreu Stefan Jansson Benedicte R. Albrectsen Pr K. Ingvarsson 《Ecology letters》2013,16(6):791-798
Plant–herbivore interactions vary across the landscape and have been hypothesised to promote local adaption in plants to the prevailing herbivore regime. Herbivores that feed on European aspen (Populus tremula) change across regional scales and selection on host defence genes may thus change at comparable scales. We have previously observed strong population differentiation in a set of inducible defence genes in Swedish P. tremula. Here, we study the geographic patterns of abundance and diversity of herbivorous insects, the untargeted metabolome of the foliage and genetic variation in a set of wound‐induced genes and show that the geographic structure co‐occurs in all three data sets. In response to this structure, we observe local maladaptation of herbivores, with fewer herbivores on local trees than on trees originated from more distant localities. Finally, we also identify 28 significant associations between single nucleotide polymorphisms SNPs from defence genes and a number of the herbivore traits and metabolic profiles. 相似文献
343.
Marten Szibor Rolf Schreckenberg Zemfira Gizatullina Eric Dufour Marion Wiesnet Praveen K. Dhandapani Grazyna Debska-Vielhaber Juliana Heidler Ilka Wittig Tuula A. Nyman Ulrich Gärtner Andrew R. Hall Victoria Pell Carlo Viscomi Thomas Krieg Michael P. Murphy Thomas Braun Frank N. Gellerich Klaus-Dieter Schlüter Howard T. Jacobs 《Journal of cellular and molecular medicine》2020,24(6):3534-3548
344.
Claudia Colesie T G Allan Green Ilka Haferkamp Burkhard Büdel 《The ISME journal》2014,8(10):2104-2115
Biological soil crusts (BSC) are the dominant functional vegetation unit in some of the harshest habitats in the world. We assessed BSC response to stress through changes in biotic composition, CO2 gas exchange and carbon allocation in three lichen-dominated BSC from habitats with different stress levels, two more extreme sites in Antarctica and one moderate site in Germany. Maximal net photosynthesis (NP) was identical, whereas the water content to achieve maximal NP was substantially lower in the Antarctic sites, this apparently being achieved by changes in biomass allocation. Optimal NP temperatures reflected local climate. The Antarctic BSC allocated fixed carbon (tracked using 14CO2) mostly to the alcohol soluble pool (low-molecular weight sugars, sugar alcohols), which has an important role in desiccation and freezing resistance and antioxidant protection. In contrast, BSC at the moderate site showed greater carbon allocation into the polysaccharide pool, indicating a tendency towards growth. The results indicate that the BSC of the more stressed Antarctic sites emphasise survival rather than growth. Changes in BSC are adaptive and at multiple levels and we identify benefits and risks attached to changing life traits, as well as describing the ecophysiological mechanisms that underlie them. 相似文献
345.
346.
Formation of the catalytic six-iron complex (H-cluster) of [FeFe]-hydrogenase (HydA) requires its interaction with a specific maturation protein, HydF. Comparison by X-ray absorption spectroscopy at the Fe K-edge of HydF from Clostridium acetobutylicum and HydA1 from Chlamydomonas reinhardtii revealed that the overall structure of the iron site in both proteins is highly similar, comprising a [4Fe4S] cluster (Fe–Fe distances of ∼2.7 Å) and a di-iron unit (Fe–Fe distance of ∼2.5 Å). Thus, a precursor of the whole H-cluster is assembled on HydF. Formation of the core structures of both the 4Fe and 2Fe units may require only the housekeeping [FeS] cluster assembly machinery of the cell. Presumably, only the 2Fe cluster is transferred from HydF to HydA1, thereby forming the active site. 相似文献
347.
348.
Age-related changes in breeding performance are likely to be mediated through changes in parental foraging performance. We investigated the relationship of foraging performance with age in female little penguins at Phillip Island, Australia, during the guard phase of the 2005 breeding season. Foraging parameters were recorded with accelerometers for birds grouped into three age-classes: (1) young, (2) middle age and (3) old females. We found the diving behaviour of middle-aged birds differed from young and old birds. The dive duration of middle age females was shorter than that of young and old birds while their dive effort (measure for dive and post-dive duration relation) was lower than that of young ones, suggesting middle-aged birds were in better physical condition than other ones. There was no difference in prey pursuit frequency or duration between age classes, but in the hunting tactic. Females pursued more prey around and after reaching the maximum depth of dives the more experienced they were (old > middle age > young), an energy saving hunting tactic by probably taking advantage of up-thrust momentum. We suggest middle age penguins forage better than young or old ones because good physical condition and foraging experience could act simultaneously. 相似文献
349.
Patrícia G. Lima Pedro F.N. Souza Cleverson D.T. Freitas Jose T.A. Oliveira Lucas P. Dias Joo X.S. Neto Ilka M. Vasconcelos Jos L.S. Lopes Daniele O.B. Sousa 《Journal of peptide science》2020,26(6)
Candida albicans has emerged as a major public health problem in recent decades. The most important contributing factor is the rapid increase in resistance to conventional drugs worldwide. Synthetic antimicrobial peptides (SAMPs) have attracted substantial attention as alternatives and/or adjuvants in therapeutic treatments due to their strong activity at low concentrations without apparent toxicity. Here, two SAMPs, named Mo‐CBP3‐PepI (CPAIQRCC) and Mo‐CBP3‐PepII (NIQPPCRCC), are described, bioinspired by Mo‐CBP3, which is an antifungal chitin‐binding protein from Moringa oleifera seeds. Furthermore, the mechanism of anticandidal activity was evaluated as well as their synergistic effects with nystatin. Both peptides induced the production of reactive oxygen species (ROS), cell wall degradation, and large pores in the C. albicans cell membrane. In addition, the peptides exhibited high potential as adjuvants because of their synergistic effects, by increasing almost 50‐fold the anticandidal activity of the conventional antifungal drug nystatin. These peptides have excellent potential as new drugs and/or adjuvants to conventional drugs for treatment of clinical infections caused by C. albicans. 相似文献
350.
Valdelaine Etelvina Miranda de Araújo Letícia Cavalari Pinheiro Maria Cristina de Mattos Almeida Fernanda Carvalho de Menezes Maria Helena Franco Morais Ilka Afonso Reis Renato Martins Assun??o Mariangela Carneiro 《PLoS neglected tropical diseases》2013,7(11)