49 research outputs found

    The influence of thermal cycles on the microstructure of grade 92 steel

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    The microstructure in the heat-affected zone (HAZ) of welds made from the 9 wt pct chromium martensitic Grade 92 steel is complex and has not yet been completely understood. There is a lack of systematic microstructural investigations to define the different regions of the microstructure across the HAZ of Grade 92 steel welds as a function of the welding process. In this study, the microstructure in the HAZ of an as-fabricated single-pass bead-on-plate weld on a parent metal of Grade 92 steel was systematically investigated by using an extensive range of electron and ion-microscopy-based techniques. A dilatometer was used to apply controlled thermal cycles to simulate the microstructures in the different regions of the HAZ. A wide range of microstructural properties in the simulated materials were then characterized and compared with the experimental observations from the weld HAZ. It was found that the microstructure in the HAZ of a single-pass Grade 92 steel weld can be categorized as a function of a decreasing peak temperature reached as (1) the completely transformed (CT) region, in which the original matrix is completely reaustenitized with complete dissolution of the pre-existing secondary precipitate particles; (2) the partially transformed (PT) region, where the original matrix is partially reaustenitized along with a partial dissolution of the secondary precipitate particles from the original matrix; and (3) the overtempered (OT) region, where the pre-xisting precipitate particles coarsen. The PT region is considered to be the susceptible area for damage in the commonly reported HAZ failures in weldments constructed from these types of steels

    Identification of a Small TAF Complex and Its Role in the Assembly of TAF-Containing Complexes

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    TFIID plays a role in nucleating RNA polymerase II preinitiation complex assembly on protein-coding genes. TFIID is a multisubunit complex comprised of the TATA box binding protein (TBP) and 14 TBP-associated factors (TAFs). Another class of multiprotein transcriptional regulatory complexes having histone acetyl transferase (HAT) activity, and containing TAFs, includes TFTC, STAGA and the PCAF/GCN5 complex. Looking for as yet undiscovered subunits by a proteomic approach, we had identified TAF8 and SPT7L in human TFTC preparations. Subsequently, however, we demonstrated that TAF8 was not a stable component of TFTC, but that it is present in a small TAF complex (SMAT), containing TAF8, TAF10 and SPT7L, that co-purified with TFTC. Thus, TAF8 is a subunit of both TFIID and SMAT. The latter has to be involved in a pathway of complex formation distinct from the other known TAF complexes, since these three histone fold (HF)-containing proteins (TAF8, TAF10 and SPT7L) can never be found together either in TFIID or in STAGA/TFTC HAT complexes. Here we show that TAF8 is absolutely necessary for the integration of TAF10 in a higher order TFIID core complex containing seven TAFs. TAF8 forms a heterodimer with TAF10 through its HF and proline rich domains, and also interacts with SPT7L through its C-terminal region, and the three proteins form a complex in vitro and in vivo. Thus, the TAF8-TAF10 and TAF10-SPT7L HF pairs, and also the SMAT complex, seem to be important regulators of the composition of different TFIID and/or STAGA/TFTC complexes in the nucleus and consequently may play a role in gene regulation

    Croissance à température constante de l'ancyloïde de Gundlachia wautieri (Mollusque basommatophore)

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    Wautier Jacques, Richardot M. Croissance à température constante de l'ancyloïde de Gundlachia wautieri (Mollusque basommatophore). In: Bulletin mensuel de la Société linnéenne de Lyon, 35ᵉ année, n°10, décembre 1966. pp. 463-467

    Notes sur les complexes neuro-endocriniens de Gundlachia sp. (Mollusque Ancylidae)

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    Wautier Jacques, Pavans de Ceccatty M., Richardot M., Buisson B., Hernandez M.-L. Notes sur les complexes neuro-endocriniens de Gundlachia sp. (Mollusque Ancylidae). In: Bulletin mensuel de la Société linnéenne de Lyon, 30ᵉ année, n°4, avril 1961. pp. 79-87

    Histo-physiologie des corrélations neuro-hormonales lors du cycle sexuel de Gundlachia

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    Wautier Jacques, Pavans de Ceccatty M., Hernandez M.-L., Richardot M., Buisson B. Histo-physiologie des corrélations neuro-hormonales lors du cycle sexuel de Gundlachia. In: Bulletin mensuel de la Société linnéenne de Lyon, 31ᵉ année, n°3, mars 1962. pp. 84-92

    Les étapes de la croissance chez Gundlachia sp.(Mollusque, Ancylidae)

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    Wautier Jacques, Pavans de Ceccatty M., Richardot M., Buisson B., Hernandez M.-L. Les étapes de la croissance chez Gundlachia sp.(Mollusque, Ancylidae). In: Bulletin mensuel de la Société linnéenne de Lyon, 31ᵉ année, n°3, mars 1962. pp. 70-73
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