Épinal, France


Épinal, France
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Viguier J.,Arts et Metiers ParisTech | Pot G.,Arts et Metiers ParisTech | Bleron L.,ENSTIB LERMAB | Collet R.,Arts et Metiers ParisTech
WCTE 2016 - World Conference on Timber Engineering | Year: 2016

Strength grading of timber is dependent of the predictions accuracy of the bending modulus of elasticity and bending strength. Different models based on grain angle measurements and X-Ray imaging have already proved their efficiency for strength grading purpose. This study proposes a way to improve those models thanks to a better understanding of the phenomenon that occur due to the presence of singularities in wood using the comparison of fullfield measurements by Digital Image Correlation and a Finite Element Model. First results seem to show that the two strains fields in the longitudinal direction are similar and are influenced by the presence of knots.

Krifa M.,University of Monastir | Pizzi A.,ENSTIB LERMAB | Mousli M.,University of Strasbourg | Chekir-Ghedira L.,University of Monastir | And 2 more authors.
Tumor Biology | Year: 2014

Several studies have reported that plant-derived natural products have cancer chemopreventive and chemotherapeutic properties. The aim of the present study was to determine the antiproliferative and pro-apoptotic potential of Limoniastrum guyonianum aqueous gall extract (G extract) on human colorectal cancer BE cell line and, if so, to characterize the mechanism involved. The G extract-induced growth inhibitory effect was associated with an arrest of cell cycle progression in G2/M phase as shown by the cell phase distribution. In addition, G extract promoted in a concentration-dependent manner these cells towards apoptosis as indicated by the presence of cleaved poly(ADP-ribose) polymerase (PARP). In order to characterize the mechanism involved in the antiproliferative and pro-apoptotic signaling pathway activated by G extract, calpain activity and the expression of the cell cycle inhibitor p16INK4A were determined. The present findings indicated that G extract exhibited significant inhibitory activity against calpain and caused a marked and concentration-dependent upregulation of p16INK4A. These effects could be ascribed to the presence of condensed tannins and polyphenols such as epicatechin and epigallocatechin gallate in G extract. © 2014, International Society of Oncology and BioMarkers (ISOBM).

PubMed | University of Monastir, University of Strasbourg, Laboratory Cellular and Molecular Biology and ENSTIB LERMAB
Type: Journal Article | Journal: Journal of cellular biochemistry | Year: 2016

A large number of plants used in traditional medicines have been shown to possess antitumor activities. The aims of this study were to evaluate any anticancer effect of the essential oil (EO) extracted from P. tortuosus against B16F10 melanoma cancer cells in vitro as well as in vivo. In vitro, EO was shown to induce apoptosis and to inhibit migration and invasion processes. Further investigation revealed that EO decreased focal adhesion and invadopodia formation which was accompanied by a drastic downregulation of FAK, Src, ERK, p130Cas and paxillin. Moreover, EO treatment decreased the expression level of p190RhoGAP, and Grb2, which impair cell migration and actin assembly. Mice bearing the melanoma cells were used to confirm any in vivo effectiveness of the EO as an anti-tumor promoting agent. In mice dosed with 100mg EO/kg/d (for 27 days), tumor weight was inhibited by 98% compared to that in mice that did not receive the product. In conclusion, these data suggested to us that an EO of P. tortuosus could evolve to be a potential medicinal resource for use in the treatment of cancers.

Zhao W.,CNRS Jean Lamour Institute | Fierro V.,CNRS Jean Lamour Institute | Pizzi A.,ENSTIB LERMAB | Celzard A.,CNRS Jean Lamour Institute
Journal of Materials Science | Year: 2010

New cellular activated carbons mainly derived from tannins and furfuryl alcohol are introduced and suggested as adsorbents and catalyst supports. They present a bimodal porosity, based on a highly porous, reticulated vitreous carbon backbone, whose micro/meso-porosity was developed by steam activation. The macroporosity corresponds to the connected network of cells whose average diameter is close to 250 μm. In contrast, the micro/meso-porosity is located at the inner surface of the cells and is thus fully and easily accessible. Consequently, much higher adsorption kinetics than for usual granular activated carbons are expected. A burn-off close to 30% was shown to be optimal for getting a high proportion of microporosity without complete loss of mechanical resistance. In these conditions, the surface area is close to 850 m2 g-1, thus similar to that of many commercial carbonaceous adsorbents. © 2010 Springer Science+Business Media, LLC.

Krifa M.,University of Monastir | Krifa M.,Laboratory of Cellular and Molecular Biology | El Mekdad H.,ENSTIB LERMAB | Bentouati N.,University of Monastir | And 6 more authors.
Tumor Biology | Year: 2015

Many studies have been performed to assess potential utility of natural products as immunomodulants to enhance antitumor activity in situ. In this study, an essential oil (EO) from the aerial parts of Pituranthos tortuosus was prepared using hydrodistillation, its composition was characterized, and its immunomodulatory potential was assessed. The results indicated that the EO contained sabinene, α-pinene, limonene, and terpinen-4-ol as major constituents. EO was also found to be able to significantly promote lipopolysaccharide (LPS)-stimulated splenocyte proliferation, suggestive of a potential for activation of B cells and enhanced humoral immune responses in hosts given this product. Effects of EO on cell proliferation and apoptosis were also investigated in B16F10 melanoma cells. EO-induced tumor cell growth inhibition was associated with characteristic apoptotic changes in the cells, including nuclear condensation. In conclusion, these data suggested to us that an EO of P. tortuosus could evolve to be a potential medicinal resource for use in the treatment of cancers. © 2015, International Society of Oncology and BioMarkers (ISOBM).

Krifa M.,University of Monastir | Skandrani I.,University of Monastir | Pizzi A.,ENSTIB LERMAB | Nasr N.,University of Monastir | And 5 more authors.
Food and Chemical Toxicology | Year: 2014

The objectives of this study were to evaluate the in vitro and in vivo anti-tumor potential of the aqueous gall extract (G extract) from Limoniastrum guyonianum and to elucidate its immunological mechanisms, in part, by assessing its effects on the growth of transplanted tumors and the immune response in these tumor-bearing mice. Here, mice were inoculated with B16F10 mouse tumor cells and then treated intraperitoneally with G extract at 25 or 50. mg extract/kg. BW for 7, 14, or 21. days. At each timepoint, effects of the extract on the tumor growth, splenocytes proliferation, NK cell activity, and CTL activity among splenocytes isolated from the mice were measured. G extract-induced tumor growth inhibition was associated with characteristic apoptotic changes in the tumor cells, like nuclear condensation. In addition, the extract inhibited melanin synthesis and tyrosinase activity among melanoma cells in a concentration-related manner. G extract did not only significantly inhibit the growth of the transplantable tumor, but also remarkably increased splenocytes proliferation and both NK and CTL activities in tumor-bearing mice. The extract was also seen to have promoted lysosomal activity of host macrophages and gave rise to enhanced cellular anti-oxidant activity in several cell types in mice. © 2014 Elsevier Ltd.

Krifa M.,University of Monastir | Mustapha N.,University of Monastir | Ghedira Z.,University of Monastir | Ghedira K.,University of Monastir | And 2 more authors.
Drug and Chemical Toxicology | Year: 2015

Evaluation of the immunomodulatory activity of plant extracts is an interesting and growing area of research. In this study, effects of a methanolic extract of Limoniastrum guyonianum stems (M extract) on mice immune cell function in vitro were investigated. These studies showed that mitogen-induced lymphocyte proliferation was dose-dependently inhibited by the extract. Further, the lectin-induced response appeared to be more sensitive to the suppressive effects of the extract than were LPS-stimulated responses. In studies to assess any potential effects of extract on innate immunity, the results showed that the extract significantly enhanced the killing activity of isolated NK cells. In addition, studies here demonstrated that the extract could enhance lysosomal enzyme activity and inhibit nitrite oxide (NO) production by murine peritoneal macrophages ex vivo, suggesting a potential anti-inflammatory effect in situ. The anti-inflammatory activity was concomitant with the cellular anti-oxidant effect in macrophages and splenocytes. © 2015 Informa Healthcare USA, Inc. All rights reserved.

Girardon S.,ENSTIB Lermab | Barthram C.,ENSTIB Lermab | Resch L.,ENSTIB Lermab | Bocquet J.-F.,ENSTIB Lermab | Triboulot P.,ENSTIB Lermab
European Journal of Wood and Wood Products | Year: 2014

This paper presents a methodology to characterize the secant shearing stiffness of welding-through wood dowels used in multi-layer spruce beams. Welding-through wood dowel’s stiffness behaviour as well as isostatic multi-layer beams’ behaviour were investigated experimentally. These elements are made by a specifically designed machine to guarantee repeatability. A model of finite elements was developed to reproduce the bending behaviour of the beams tested from non-linear connection behaviour. This model is then used to study the influence of parameters such as: layer number, spacing of dowels, load type (concentrated or distributed), strength class and beam span. After a sensibility analysis, a parameterized regression model allows to obtain kser and ku fastener secant stiffness in compliance with EN 1995-1 standard to design multi-layer beams in an elastic analytical model way. This model is based on the work by Kreuzinger (1999). © 2014, Springer-Verlag Berlin Heidelberg.

Journal of Adhesion Science and Technology | Year: 2012

Successful experiments on high, medium and low density natural fiber reinforced composites made from tannin/hexamine resin and flax-hemp fibers have recently been carried out. This study focused on the high density composites. In this work composite panels have been made of three different tannin extracts: mimosa, sulfited mimosa and quebracho, each with their own properties. The panels were tested for modulus in elasticity (MOE) in bending, and for swelling in cold water, following the French standard NF EN 622-2. It appeared that a strong correlation exists between the density and the mechanical performances of the composites. Water, which is necessary for hardening resin, can, when in excess cause a strong drop in the mechanical performances by increasing the porosity in a composite structure. In the course of carrying out this work, some manufacturing problems were found: cracks appeared during the pressing of large panels resulting in the need for a specific pressing cycle; and deformations occurred during the cooling phase due to internal stresses. Experimental procedures were developed and tested to reduce these problems. © 2012 Copyright Taylor and Francis Group, LLC.

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