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71.
Rufus Turner Tobias Baron Siegfried Wolffram Anne Marie Minihane Aedin Cassidy Gerald Rimbach 《Free radical research》2013,47(2):209-216
Soy isoflavones are thought to have a cardioprotective effect that is partly mediated by an inhibitory influence on the oxidation of low density lipoprotein (LDL). However, the aglycone forms investigated in many previous studies do not circulate in appreciable quantities because they are metabolised in the gut and liver. We investigated effects of various isoflavone metabolites, including for the first time the sulphated conjugates formed in the liver and the mucosa of the small intestine, on copper-induced LDL oxidation. The parent aglycones inhibited oxidation, although only 5% as well as quercetin. Metabolism increased or decreased their effectiveness. Equol inhibited 2.65-fold better than its parent compound daidzein and 8-hydroxydaidzein, not previously assessed, was 12.5-fold better than daidzein. However, monosulphated conjugates of genistein, daidzein and equol were much less effective and disulphates completely ineffective. Since almost all isoflavones circulate as conjugates, these data suggest that despite the increased potency produced by some metabolic changes, isoflavones may not be effective antioxidants in vivo unless they are deconjugated again. 相似文献
72.
Marrit Putker Tobias Madl Harmjan R. Vos Hesther de Ruiter Marieke Visscher Maaike C.W. van den Berg Mohammed Kaplan Hendrik C. Korswagen Rolf Boelens Michiel Vermeulen Boudewijn M.T. Burgering Tobias B. Dansen 《Molecular cell》2013,49(4):730-742
Highlights? FOXO forms redox-sensitive, disulfide-dependent complexes with several proteins ? Transportin-1 binds to FOXO via a disulfide and regulates its nuclear localization ? Redox and insulin signaling govern FOXO nuclear localization via distinct pathways ? Redox control of longevity protein FOXO/DAF-16 is evolutionarily conserved 相似文献
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Choimaa Dulamsuren Tobias Wommelsdorf Fengjun Zhao Yaoqin Xue Bulat Z. Zhumadilov Christoph Leuschner Markus Hauck 《Ecosystems》2013,16(8):1536-1549
The larch forests at the southern limit of the Siberian boreal forest in Central Asia have repeatedly experienced strong recent growth declines attributed to decreasing summer precipitation in the course of climate warming. Here, we present evidence from the southernmost Larix sibirica forests in eastern Kazakhstan that these declines are primarily caused by a decrease in effective moisture due to increasing summer temperatures, despite constant annual, and summer precipitation. Tree-ring chronologies (>800 trees) showed a reduction by 50–80% in mean ring width and an increase in the frequency of missing rings since the 1970s. Climate-response analysis revealed a stronger (negative) effect of summer temperature (in particular of the previous year’s June and July temperature) on radial growth than summer precipitation (positive effect). It is assumed that a rise in the atmospheric vapor pressure deficit, which typically increases with temperature, is negatively affecting tree water status and radial growth, either directly or indirectly through reduced soil moisture. Larch rejuvenation ceased in the 1950s, which is partly explained by increasing topsoil desiccation in a warmer climate and a high drought susceptibility of larch germination, as was demonstrated by a germination experiment with variable soil moisture levels. The lack of regeneration and the reduced annual stem increment suggest that sustainable forest management aiming at timber harvesting is no longer feasible in these southern boreal forests. Progressive climate warming is likely to cause a future northward shift of the southern limit of the boreal forest. 相似文献
77.
Sara Borin Francesca Mapelli Eleonora Rolli Bongkeun Song Craig Tobias Markus C. Schmid Gert J. De Lange Gert J. Reichart Stefan Schouten Mike Jetten Daniele Daffonchio 《Extremophiles : life under extreme conditions》2013,17(2):289-299
To extend the knowledge of anaerobic ammonium oxidation (anammox) habitats, bacterial communities were examined in two hypersaline sulphidic basins in Eastern Mediterranean Sea. The 2 m thick seawater–brine haloclines of the deep anoxic hypersaline basins Bannock and L’Atalante were sampled in intervals of 10 cm with increasing salinity. 15N isotope pairing incubation experiments showed the production of 29N2 and 30N2 gases in the chemoclines, ranging from 6.0 to 9.2 % salinity of the L’Atalante basin. Potential anammox rates ranged from 2.52 to 49.65 nmol N2 L?1 day?1 while denitrification was a major N2 production pathway, accounting for more than 85.5 % of total N2 production. Anammox-related 16S rRNA genes were detected along the L’Atalante and Bannock haloclines up to 24 % salinity, and the amplification of the hydrazine synthase genes (hzsA) further confirmed the presence of anammox bacteria in Bannock. Fluorescence in situ hybridisation and sequence analysis of 16S rRNA genes identified representatives of the marine anammox genus ‘Candidatus Scalindua’ and putatively new operational taxonomic units closely affiliated to sequences retrieved in marine environments that have documented anammox activity. ‘Scalindua brodae’ like sequences constituted up to 84.4 % of the sequences retrieved from Bannock. The anammox community in L’Atalante was different than in Bannock and was stratified according to salinity increase. This study putatively extends anammox bacterial habitats to extremely saline sulphidic ecosystems. 相似文献
78.
Jan Plue Pieter De Frenne Kamal Acharya Jrg Brunet Olivier Chabrerie Guillaume Decocq Martin Diekmann Bente J. Graae Thilo Heinken Martin Hermy Annette Kolb Isgard Lemke Jaan Liira Tobias Naaf Anna Shevtsova Kris Verheyen Monika Wulf Sara A. O. Cousins 《Global Ecology and Biogeography》2013,22(10):1106-1117
79.
Dani?l P Melters Keith R Bradnam Hugh A Young Natalie Telis Michael R May J Graham Ruby Robert Sebra Paul Peluso John Eid David Rank José Fernando Garcia Joseph L DeRisi Timothy Smith Christian Tobias Jeffrey Ross-Ibarra Ian Korf Simon WL Chan 《Genome biology》2013,14(1):R10