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61.
62.
Regulating retrotransposon activity through the use of alternative transcription start sites 下载免费PDF全文
63.
Fabian Alperth Božena Mitić Stefanie Mayer Željan Maleš Olaf Kunert Dario Hruševar 《Plant biosystems》2019,153(2):317-324
Iris adriatica Trinajsti? ex Miti? (Iridaceae L.) is a strictly endemic taxon from Croatia. It is a rhizomatous dwarf plant from the I. pumila complex with a distribution area limited to the Croatian part of the Mediterranean area, mainly central Dalmatia. The genus Iris is known for its richness in isoflavonoids which also play a significant role in chemotaxonomy and biological activity. Hence, in the current study, different plant batches of I. adriatica collected in early spring of 2016 were analysed for their phytochemical profiles and qualitatively compared. UHPLC-PDA-ESI-MS analyses of methanolic rhizome extracts were performed. Altogether, 36 compounds, representing isoflavonoids (including 6,7-methylendioxy derivatives), benzophenones and xanthones were found as aglycones or in glycosidically bound form to be the main constituent groups of I. adriatica rhizomes. Qualitative results were identical between different batches of plant material from collection sites in central Dalmatia, they differed only in quantity. For some phenolic compounds of I. adriatica, chemotaxonomic relevance was detected. 相似文献
64.
Vilizzi Lorenzo Copp Gordon H. Adamovich Boris Almeida David Chan Joleen Davison Phil I. Dembski Samuel Ekmekçi F. Güler Ferincz Árpád Forneck Sandra C. Hill Jeffrey E. Kim Jeong-Eun Koutsikos Nicholas Leuven Rob S. E. W. Luna Sergio A. Magalhães Filomena Marr Sean M. Mendoza Roberto Mourão Carlos F. Neal J. Wesley Onikura Norio Perdikaris Costas Piria Marina Poulet Nicolas Puntila Riikka Range Inês L. Simonović Predrag Ribeiro Filipe Tarkan Ali Serhan Troca Débora F. A. Vardakas Leonidas Verreycken Hugo Vintsek Lizaveta Weyl Olaf L. F. Yeo Darren C. J. Zeng Yiwen 《Reviews in Fish Biology and Fisheries》2019,29(3):529-568
Reviews in Fish Biology and Fisheries - The freshwater Fish Invasiveness Screening Kit (FISK) has been applied in 35 risk assessment areas in 45 countries across the six inhabited continents (11... 相似文献
65.
Kristine von Bargen Mirella Scraba Ina Krmer Maren Ketterer Christian Nehls Sina Krokowski Urska Repnik Michaela Wittlich Anna Maaser Pia Zapka Madeleine Bunge Martin Schlesinger Gitta Huth Annette Klees Philipp Hansen Andreas Jeschke Gerd Bendas Olaf Utermhlen Gareth Griffiths Thomas Gutsmann Jens Wohlmann Albert Haas 《Cellular microbiology》2019,21(1)
Professional phagocytic cells such as macrophages are a central part of innate immune defence. They ingest microorganisms into membrane‐bound compartments (phagosomes), which acidify and eventually fuse with lysosomes, exposing their contents to a microbicidal environment. Gram‐positive Rhodococcus equi can cause pneumonia in young foals and in immunocompromised humans. The possession of a virulence plasmid allows them to subvert host defence mechanisms and to multiply in macrophages. Here, we show that the plasmid‐encoded and secreted virulence‐associated protein A (VapA) participates in exclusion of the proton‐pumping vacuolar‐ATPase complex from phagosomes and causes membrane permeabilisation, thus contributing to a pH‐neutral phagosome lumen. Using fluorescence and electron microscopy, we show that VapA is also transferred from phagosomes to lysosomes where it permeabilises the limiting membranes for small ions such as protons. This permeabilisation process is different from that of known membrane pore formers as revealed by experiments with artificial lipid bilayers. We demonstrate that, at 24 hr of infection, virulent R. equi is contained in a vacuole, which is enriched in lysosome material, yet possesses a pH of 7.2 whereas phagosomes containing a vapA deletion mutant have a pH of 5.8 and those with virulence plasmid‐less sister strains have a pH of 5.2. Experimentally neutralising the macrophage endocytic system allows avirulent R. equi to multiply. This observation is mirrored in the fact that virulent and avirulent R. equi multiply well in extracts of purified lysosomes at pH 7.2 but not at pH 5.1. Together these data indicate that the major function of VapA is to generate a pH‐neutral and hence growth‐promoting intracellular niche. VapA represents a new type of Gram‐positive virulence factor by trafficking from one subcellular compartment to another, affecting membrane permeability, excluding proton‐pumping ATPase, and consequently disarming host defences. 相似文献
66.
67.
Evaluation of a DC pulsed magnetic tracking system in neurosurgical navigation: technique, accuracies, and influencing factors] 总被引:1,自引:0,他引:1
Olaf Suess Silke Suess Sven Mularski Bj?rn Kühn Thomas Picht Sven Sch?nherr Theodoros Kombos 《Biomedizinische Technik》2007,52(3):223-233
Navigation systems are useful instruments in cranial neurosurgery. For specification of position, so-called sensor-based navigation techniques use: (a) a signal emitter that generates a defined electromagnetic field in the area of the operation site; and (b) small sensors that detect the position of various operating instruments in the electromagnetic field. For a long time, owing to a lack of clinical data and long-term studies, electromagnetic systems have been regarded as error-prone and imprecise. With the development of a pulsed direct current (DC) technique, precision levels can now be reached that are comparable with those of established optical and mechanical measuring procedures. However, it must be noted that the influence on the measuring accuracy within the operating field increases with increasing susceptibility of the various metals used in the operating theatre (titanium相似文献
68.
Metabolic profiling, metabolomic and metabonomic procedures for NMR spectroscopy of urine, plasma, serum and tissue extracts 总被引:2,自引:0,他引:2
Beckonert O Keun HC Ebbels TM Bundy J Holmes E Lindon JC Nicholson JK 《Nature protocols》2007,2(11):2692-2703
Metabolic profiling, metabolomic and metabonomic studies mainly involve the multicomponent analysis of biological fluids, tissue and cell extracts using NMR spectroscopy and/or mass spectrometry (MS). We summarize the main NMR spectroscopic applications in modern metabolic research, and provide detailed protocols for biofluid (urine, serum/plasma) and tissue sample collection and preparation, including the extraction of polar and lipophilic metabolites from tissues. 1H NMR spectroscopic techniques such as standard 1D spectroscopy, relaxation-edited, diffusion-edited and 2D J-resolved pulse sequences are widely used at the analysis stage to monitor different groups of metabolites and are described here. They are often followed by more detailed statistical analysis or additional 2D NMR analysis for biomarker discovery. The standard acquisition time per sample is 4-5 min for a simple 1D spectrum, and both preparation and analysis can be automated to allow application to high-throughput screening for clinical diagnostic and toxicological studies, as well as molecular phenotyping and functional genomics. 相似文献
69.
Michele T Guerin Wayne Martin Jarle Reiersen Olaf Berke Scott A McEwen Jean-Robert Bisaillon Ruff Lowman 《BMC veterinary research》2007,3(1):1-12
Background
The most predominant beta2-integrin lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2), expressed on all leukocytes, is essential for many adhesive functions of the immune system. Interestingly, RTX toxin-producing bacteria specifically target this leukocyte beta2-integrin which exacerbates lesions and disease development.Results
This study reports the sequencing of the wild boar beta2-integrin CD11a and CD18 cDNAs. Predicted CD11a and CD18 subunits share all the main structural characteristics of their mammalian homologues, with a larger interspecies conservation for the CD18 than the CD11a. Besides these strong overall similarities, wild boar and domestic pig LFA-1 differ by 2 (CD18) and 1 or 3 (CD11a) substitutions, of which one is located in the crucial I-domain (CD11a, E168D).Conclusion
As most wild boars are seropositive to the RTX toxin-producing bacterium Actinobacillus pleuropneumoniae and because they have sustained continuous natural selection, future studies addressing the functional impact of these polymorphisms could bring interesting new information on the physiopathology of Actinobacillus pleuropneumoniae-associated pneumonia in domestic pigs. 相似文献70.
Systems Biology is an emerging research area, which considers mathematical representations of inter- and intra-cellular dynamics. Among the many research problems that have been addressed, dynamic modeling of signal transduction pathways has received increasing attention. The usual approach to represent intra-cellular dynamics are nonlinear, usually ordinary, differential equations. The purpose of the models is to test and generate hypothesis of specific pathways and it is therefore required to estimate model parameters from experimental data. The experiments to generate data are complex and expensive, as a consequence of which the time series available are usually rather short, with few if any replicates. Almost certainly, not all variables one would like to include in a model can be measured. Parameter estimation is therefore an important research problem in Systems Biology and the focus of this paper. In particular, we are interested in optimizing the sampling time selection in order to minimize the variance of the parameter estimation error. With few sampling time points feasible, their selection is of practical importance in experimental design. Finally, the theoretical results are supported with an application. 相似文献