Institution
Paul Sabatier University
Education•Toulouse, France•
About: Paul Sabatier University is a education organization based out in Toulouse, France. It is known for research contribution in the topics: Population & Adipose tissue. The organization has 15431 authors who have published 23386 publications receiving 858364 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this article, the authors estimate the magnitude and distribution of the dominant sources of nitrogen oxides in the troposphere and some minor sources which may play a specific role in tropospheric chemistry such as NOx emission from aircraft in the upper troposphere or input from production in the stratosphere from N2O photodissociation.
Abstract: Nitrogen oxides are key compounds for the oxidation capacity of the troposphere. NOx concentrations depend on the proximity of sources because of their short atmospheric lifetime. An accurate knowledge of the distribution of their sources and sinks is therefore crucial. At global scale, the dominant sources of nitrogen oxides - combustions of fossil fuel (∼50%) and biomass burning (∼20%) - are basically anthropogenic. Natural sources, including lightning and microbial activity in soils, represent therefore less than 30% of total emissions. Fertilizer use in agriculture constitutes an anthropogenic perturbation to the microbial source. The methods to estimate the magnitude and distribution of these dominant sources of nitrogen oxides are discussed. Some minor sources which may play a specific role in tropospheric chemistry such as NOx emission from aircraft in the upper troposphere or input from production in the stratosphere from N2O photodissociation are also considered.
170 citations
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TL;DR: Pol η–dependent DNA synthesis at stalled replication forks during S phase suppresses chronic fragile site instability by preventing checkpoint-blind under-replicated DNA in mitosis.
Abstract: Human DNA polymerase η (Pol η) is best known for its role in responding to UV irradiation–induced genome damage. We have recently observed that Pol η is also required for the stability of common fragile sites (CFSs), whose rearrangements are considered a driving force of oncogenesis. Here, we explored the molecular mechanisms underlying this newly identified role. We demonstrated that Pol η accumulated at CFSs upon partial replication stress and could efficiently replicate non-B DNA sequences within CFSs. Pol η deficiency led to persistence of checkpoint-blind under-replicated CFS regions in mitosis, detectable as FANCD2-associated chromosomal sites that were transmitted to daughter cells in 53BP1-shielded nuclear bodies. Expression of a catalytically inactive mutant of Pol η increased replication fork stalling and activated the replication checkpoint. These data are consistent with the requirement of Pol η–dependent DNA synthesis during S phase at replication forks stalled in CFS regions to suppress CFS instability by preventing checkpoint-blind under-replicated DNA in mitosis.
170 citations
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TL;DR: In this paper, it is shown that the second wall can grow inside the first one but that subsequent ones are formed outside, and it is also possible that under given experimental conditions, the smallest (<2 nm) catalyst particles preferentially produce double-walled rather than singlewalled carbon nanotubes.
Abstract: The reduction in H2/CH4 atmosphere of aluminum-iron oxides produces metal particles small enough to catalyze the formation of single-walled carbon nanotubes. Several experiments have been made using the same temperature profile and changing only the maximum temperature (800-1070 °C). Characterizations of the catalyst materials are performed using notably 57Fe Mo¨ssbauer spectroscopy. Electron microscopy and a macroscopical method are used to characterize the nanotubes. The nature of the iron species (Fe3+, R-Fe, c-Fe-C, Fe3C) is correlated to their location in the material. The nature of the particles responsible for the high-temperature formation of the nanotubes is probably an Fe-C alloy which is, however, found as Fe3C by postreaction analysis. Increasing the reduction temperature increases the reduction yield and thus favors the formation of surface-metal particles, thus producing more nanotubes. The obtained carbon nanotubes are mostly single-walled and double-walled with an average diameter close to 2.5 nm. Several formation mechanisms are thought to be active. In particular, it is shown that the second wall can grow inside the first one but that subsequent ones are formed outside. It is also possible that under given experimental conditions, the smallest (<2 nm) catalyst particles preferentially produce double-walled rather than single-walled carbon nanotubes.
170 citations
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TL;DR: It is shown by genetic transfer and virulence experiments that specific mutations in a virulence regulator contribute to lower fitness and virosity of M. bovis and related strains for the human host, likely obstructing the capacity of causing overt disease needed for efficient human-to-human transmission.
Abstract: Although the bovine tuberculosis (TB) agent, Mycobacterium bovis, may infect humans and cause disease, long-term epidemiological data indicate that humans represent a spill-over host in which infection with M. bovis is not self-maintaining. Indeed, human-to-human transmission of M. bovis strains and other members of the animal lineage of the tubercle bacilli is very rare. Here, we report on three mutations affecting the two-component virulence regulation system PhoP/PhoR (PhoPR) in M. bovis and in the closely linked Mycobacterium africanum lineage 6 (L6) that likely account for this discrepancy. Genetic transfer of these mutations into the human TB agent, Mycobacterium tuberculosis, resulted in down-regulation of the PhoP regulon, with loss of biologically active lipids, reduced secretion of the 6-kDa early antigenic target (ESAT-6), and lower virulence. Remarkably, the deleterious effects of the phoPR mutations were partly compensated by a deletion, specific to the animal-adapted and M. africanum L6 lineages, that restores ESAT-6 secretion by a PhoPR-independent mechanism. Similarly, we also observed that insertion of an IS6110 element upstream of the phoPR locus may completely revert the phoPR-bovis–associated fitness loss, which is the case for an exceptional M. bovis human outbreak strain from Spain. Our findings ultimately explain the long-term epidemiological data, suggesting that M. bovis and related phoPR-mutated strains pose a lower risk for progression to overt human TB, with major impact on the evolutionary history of TB.
169 citations
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TL;DR: A useful prediction of antioxidant capacity could be achieved from calculated molecular properties and the kinetic parameter developed here, derived from initial second-order rate constants and antioxidant/DPPH ratios.
169 citations
Authors
Showing all 15486 results
Name | H-index | Papers | Citations |
---|---|---|---|
Yury Gogotsi | 171 | 956 | 144520 |
Tobin J. Marks | 159 | 1621 | 111604 |
L. Montier | 138 | 403 | 97094 |
Jean-Paul Kneib | 138 | 805 | 89287 |
Olivier Forni | 137 | 548 | 95819 |
J. Aumont | 131 | 299 | 95006 |
Julian I. Schroeder | 120 | 315 | 50323 |
Bruno Vellas | 118 | 1011 | 70667 |
Christopher G. Goetz | 116 | 651 | 59510 |
Didier Dubois | 113 | 742 | 54741 |
Alain Dufresne | 111 | 358 | 45904 |
Henri Prade | 108 | 917 | 54583 |
Louis Bernatchez | 106 | 568 | 35682 |
Walter Wahli | 105 | 365 | 49372 |
Patrice D. Cani | 100 | 370 | 49523 |