Paul Sabatier University

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.

Cannibalism and fratricide: mechanisms and raisons d'être.

Abstract: Cannibalism and fratricide refer to the killing of genetically identical cells (siblings) that was recently documented in two Gram-positive species, Bacillus subtilis and Streptococcus pneumoniae, respectively. Cannibalism occurs during the early stages of sporulation in B. subtilis, whereas fratricide occurs in S. pneumoniae during natural genetic transformation. Here, we compare and contrast these two phenomena and discuss whether these processes are fundamentally different from the more traditional 'chemical warfare' among bacteria.

Sintering and densification of nanocrystalline ceramic oxide powders: a review

Abstract: Observation of the unconventional properties and material behaviour expected in the nanometre grain size range necessitates the fabrication of fully dense bulk nanostructured ceramics. This is achieved by the application of ceramic nanoparticles and suitable densification conditions, both for the green and sintered compacts. Various sintering and densification strategies were adopted, including pressureless sintering, hot pressing, hot isostatic pressing, microwave sintering, sinter forging, and spark plasma sintering. The theoretical aspects and characteristics of these processing techniques, in conjunction with densification mechanisms in the nanocrystalline oxides, were discussed. Spherical nanoparticles with narrow size distribution are crucial to obtain homogeneous density and low pore-to-particle-size ratio in the green compacts, and to preserve the nanograin size at full densification. High applied pressure is beneficial via the densification mechanisms of nanoparticle rearrangement and sli...

Synthesis of single-walled carbon nanotube–Co–MgO composite powders and extraction of the nanotubes

Abstract: A carbon nanotube–Co–MgO composite powder is prepared by reducing a Mg0.9Co0.1O solid solution in H2–CH4 atmosphere. The oxide matrix and part of the Co catalyst are dissolved by acid treatment without damage to the nanotubes. More than 80% of the carbon nanotubes have either one or two walls. The diameters of the nanotubes are in the range 0.5–5 nm. The utilized method may be a real improvement in the low-cost, large-scale synthesis of single- and double-walled carbon nanotubes.