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2020, Publications.


  • Abbès B, Lacoste C, Bliard C, et al. Novel Extruded Starch-Beet Pulp Composites for Packaging Foams. Materials 2020; 13: 1571.
    Résumé : This article concerns the elaboration and the characterization of a novel biobased potato starch-beet pulp composite for packaging applications as cushion foams. A twin-screw extruder was used to elaborate composite foams. SEM observations of these materials were conducted, and thermomechanical properties were studied in terms of thermal transitions (TGA, DSC) and viscoelastic properties (DMA). The effect of relative humidity content on viscoelastic properties was analyzed as a function of frequency. The different test results show that the composite structures are homogeneously mixed. The sponge-like structure of the beet-pulp disappears indicating a good compatibility between the two mixed constituents. The DSC curve of starch-beet pulp foam shows a single thermal transition at 153.6 °C, indicating the thermal homogeneity of the obtained composite material. The density value of starch-beet pulp foam is higher than conventional foams, but this can be optimized by adjusting the technological parameters of the extruder. The viscoelastic properties of the developed materials depend on the relative humidity.
    Mots-clés : beet pulp, biobased composite, extrusion, starch.

  • Achkar TE, Moufawad T, Ruellan S, Landy D, Greige-Gerges H, Fourmentin S. Cyclodextrins: from solute to solvent. Chemical Communications 2020; 56: 3385-3388.
    Résumé : A supramolecular solvent based on cyclodextrin (CD) is presented here for the first time. Indeed, a low melting mixture was obtained by mixing levulinic acid and a CD derivative, which retained its inclusion ability in the resulting solvent. This new system gives rise to a new family of solvents that could be called SUPRADES (supramolecular deep eutectic solvents).

  • Al-Mohamadawi A, Benhabib K, Dheilly R-M, Goullieux A. Hygric Behavior of Cement Composites Elaborated with Flax Shives, a Byproduct of the Linen Industry. Waste and Biomass Valorization 2020; 11: 5053-5066.
    Résumé : The reuse of flax shives, an agricultural waste, in the elaboration of cement composites offers an interesting alternative to meet the challenge of their elimination and solve an environmental problem. The composites studied are developed by adding flax shives to Portland cement and water. Due to their honeycomb structure the flax shives are used as lightweight aggregates and provide insulating properties to the composites. However they are hygroscopic and can release water-soluble molecules responsible for setting retardation, large dimensional variations and low mechanical strengths. In previous works these drawbacks have been reduced by the development of coating processes using lime, linseed oil and paraffin as coating substances. When coated shives are used the composites exhibited compressive strength 8 to 27-fold higher, drying shrinkage two to threefold lower compared to the raw shives composite, and belong to the insulating class of the lightweight concrete. The thermal conductivity of the composites may be negatively affected by environment humidity, so their hygric behavior must be determined. The establishment of the sorption isotherms and the evaluation of the water vapor transport allow the assessment of the hygric behavior. The treatment of the flax shives involves a decrease in the moisture adsorption capacity of the composites up to 48% for a paraffin coating. The composites can be ranked in descending order of hygroscopicity: raw, lime-coated, linseed oil-coated and paraffin-coated shive composites. Only the water vapor permeability and resistance factor of the paraffin-coated shive composite are significantly lower (46%) and higher (73%) compared to those of the raw shive composite. The analytical models (GAB, Janssen and Roels) adjust the experimental results and the influence of flax shives treatment on the composites hygric behavior is demonstrated.

  • Alkoussa S, Hulo S, Courcot D, Billet S, Martin PJ. Extracellular vesicles as actors in the air pollution related cardiopulmonary diseases. Critical Reviews in Toxicology 2020; 50: 402-423.
    Résumé : Many associations were reported between air pollution and daily mortality rates for cardiopulmonary diseases. Humans are exposed to a mixture of oxidizing gases and particles, both anthropogenic and natural. Exposure to air toxics causes or exacerbates cardiovascular damages and respiratory diseases. Numerous studies have identified the induction of oxidative stress and sustained inflammatory response as among the main known underlying pathophysiological mechanisms of air pollutants. More recently, the relationship between these mechanisms of action and the secretion of extracellular vesicles (EVs) by lung cells has been revealed. EVs have been shown to be important mediators of cellular communication in the body. The purpose of this review is to first recall the main air pollutants. Then, the cardiopulmonary diseases caused by exposure to air pollution and the pathophysiological mechanisms are presented before showing, through an exhaustive review of the literature, the involvement of EVs in the toxicity of air pollutants and the initiation of cardiopulmonary diseases.
    Mots-clés : air pollutants, cardiopulmonary diseases, cigarette smoke, COPD, Extracellular vesicles, lung cancer, particulate matter.

  • Asghari S, Harighi B, Ashengroph M, et al. Induction of systemic resistance to Agrobacterium tumefaciens by endophytic bacteria in grapevine. Plant Pathology 2020; 69: 827-837.
    Résumé : Crown gall disease of grapevine, caused by Agrobacterium tumefaciens, often results in severe economic loss to grape production worldwide. This study demonstrated the ability of the endophytic bacteria Pseudomonas sp. Sn48 and Pantoea sp. Sa14 isolated from domesticated and wild grapevines to induce resistance in both above- and belowground tissues of grapevines infected with A. tumefaciens. Our results provide evidence that both strains can colonize roots and/or shoots. We showed that the strains Pseudomonas sp. Sn48 and Pantoea sp. Sa14 are capable of inducing stilbenic phytoalexin production in grapevine tissues and to further prime plantlets for enhanced phytoalexin production after A. tumefaciens inoculation. We also showed that in the majority of treatments, polyamine accumulation remained unchanged or slightly increased in plantlets treated with Pseudomonas sp. Sn48 and Pantoea sp. Sa14 compared with the control. Our findings indicated that the levels of polyamines remain unchanged or significantly decrease in plantlets treated with endophytic bacteria after A. tumefaciens challenge compared to the control and plantlets treated with individual endophytic bacterial strains. PR1, PR2, and PR4 gene expression levels of plantlets treated with Pseudomonas sp. Sn48 and Pantoea sp. Sa14 significantly increased after A. tumefaciens inoculation. The findings revealed the efficacy of the selected endophytic bacteria in triggering grapevine resistance against A. tumefaciens and the possible use of these strains as an alternative to chemical control methods in grapevine crown gall disease management.
    Mots-clés : endophytic bacteria, induced resistance, pathogenesis-related protein, phytoalexin, polyamine, Vitis vinifera.

  • Auezova L, Najjar A, Kfoury M, Fourmentin S, Greige‐Gerges H. Antibacterial activity of free or encapsulated selected phenylpropanoids against Escherichia coli and Staphylococcus epidermidis. Journal of Applied Microbiology 2020; 128: 710-720.
    Résumé : Aims Antibacterial activities of phenylpropenes (PPs) (eugenol, isoeugenol, estragole and trans-anethole) and hydroxycinnamic acids (HCAs) (p-coumaric, caffeic and ferulic acids) were assessed against Escherichia coli and Staphylococcus epidermidis. Effect of cyclodextrin and liposome encapsulation on the PPs activity was also evaluated. Methods and Results All PPs inhibited the bacterial growth in the hundred micromolar range, while HCAs did not, as determined by broth macrodilution. Anethole and estragole showed a higher efficiency than eugenol and isoeugenol, and E. coli was more susceptible than S. epidermidis. Hydroxypropyl-β-cyclodextrin/PP complexes and anethole-loaded Lipoid S100-liposomes were prepared by freeze-drying and ethanol injection respectively. Both formulations were substantially less active than free PPs. For instance, E. coli growth inhibition was about 14% for all HP-β-CD/PP complexes evaluated at MIC50 values of free PPs (P < 0·05), and about 12% for liposomal anethole evaluated at minimal bactericidal concentration value of free anethole (P < 0·05). Conclusions Hydrophobicity appears to be crucial for PPs antibacterial activity. Encapsulation in cyclodextrin and liposome seems to retain the PPs preventing their interaction with bacteria. Significance and Impact of the Study This study highlights the structural features of simple phenylpropanoids related to their antibacterial activity. The limitations of conventional encapsulation systems on the activity of PPs should be considered in future applications.
    Mots-clés : antibacterials, cyclodextrin, Escherichia coli, liposomes, phenylpropanoids, Staphylococcus epidermidis.

  • Augustin P, Billet S, Crumeyrolle S, et al. Impact of Sea Breeze Dynamics on Atmospheric Pollutants and Their Toxicity in Industrial and Urban Coastal Environments. Remote Sensing 2020; 12: 648.
    Résumé : Sea breeze (SB) phenomena may strongly influence air quality and lead to important effects on human health. In order to study the impact of SB dynamics on the properties and toxicity of aerosols, an atmospheric mobile unit was deployed during a field campaign performed in an urbanized and industrialized coastal area in Northern France. This unit combines aerosol samplers, two scanning lidars (Doppler and elastic) and an air-liquid interface (ALI, Vitrocell&reg;) in vitro cell exposure device. Our study highlights that after the passage of an SB front, the top of the atmospheric boundary layer collapses as the thermal internal boundary layer (TIBL) develops, which leads to high aerosol extinction coefficient values (&gt;0.4 km&minus;1) and an increase of PM2.5 and NOx concentrations in the SB current. The number-size distribution of particles indicates a high proportion of fine particles (with diameter below 500 nm), while the volume-size distribution shows a major mode of coarse particles centered on 2&ndash;3 &micro;m. Individual particle analyses performed by cryo-transmission scanning electron microscopy (cryo-TSEM)-EDX highlights that submicronic particles contained a high fraction of secondary compounds, which may result from nucleation and/or condensation of condensable species (vapors or gaseous species after photo-oxidation). Secondary aerosol (SA) formation can be enhanced in some areas, by the interaction between the SB flow and the upper continental air mass, particularly due to the effect of both turbulence and temperature/humidity gradients between these two contrasting air masses. Potential areas of SA formation are located near the ground, during the SB front passage and in the vicinity of the SB current top. During the sea breeze event, an increase in the oxidative stress and inflammation processes in exposed lung cells, compared to the unexposed cells, can also be seen. In some instances, short singularity periods are observed during SB, corresponding to a double flow structure. It consists of two adjacent SB currents that induce an important increase of the TIBL top, improving the pollutants dispersion. This is associated with a substantial decrease of aerosol mass concentrations.
    Mots-clés : aerosols, air quality, atmospheric boundary layer, atmospheric dynamics, lidar, sea breeze, toxicology.

  • Backes A, Hausman J-F, Renaut J, Ait Barka E, Jacquard C, Guerriero G. Expression Analysis of Cell Wall-Related Genes in the Plant Pathogenic Fungus Drechslera teres. Genes 2020; 11: 300.
    Résumé : Drechslera teres (D. teres) is an ascomycete, responsible for net blotch, the most serious barley disease causing an important economic impact. The cell wall is a crucial structure for the growth and development of fungi. Thus, understanding cell wall structure, composition and biosynthesis can help in designing new strategies for pest management. Despite the severity and economic impact of net blotch, this is the first study analyzing the cell wall-related genes in D. teres. We have identified key genes involved in the synthesis/remodeling of cell wall polysaccharides, namely chitin, &beta;-(1,3)-glucan and mixed-linkage glucan synthases, as well as endo/exoglucanases and a mitogen-activated protein kinase. We have also analyzed the differential expression of these genes in D. teres spores and in the mycelium after cultivation on different media, as well as in the presence of Paraburkholderia phytofirmans strain PsJN, a plant growth-promoting bacterium (PGPB). The targeted gene expression analysis shows higher gene expression in the spores and in the mycelium with the application of PGPB. Besides analyzing key cell-wall-related genes, this study also identifies the most suitable reference genes to normalize qPCR results in D. teres, thus serving as a basis for future molecular studies on this ascomycete.
    Mots-clés : <i>Drechslera teres</i>, barley net blotch, cell-wall-related genes, gene expression.

  • Batiha GE-S, Alqahtani A, Ojo OA, et al. Biological Properties, Bioactive Constituents, and Pharmacokinetics of Some Capsicum spp. and Capsaicinoids. International Journal of Molecular Sciences 2020; 21: 5179.
    Résumé : Pepper originated from the Capsicum genus, which is recognized as one of the most predominant and globally distributed genera of the Solanaceae family. It is a diverse genus, consisting of more than 31 different species including five domesticated species, Capsicum baccatum, C. annuum, C. pubescen, C. frutescens, and C. chinense. Pepper is the most widely used spice in the world and is highly valued due to its pungency and unique flavor. Pepper is a good source of provitamin A; vitamins E and C; carotenoids; and phenolic compounds such as capsaicinoids, luteolin, and quercetin. All of these compounds are associated with their antioxidant as well as other biological activities. Interestingly, Capsicum fruits have been used as food additives in the treatment of toothache, parasitic infections, coughs, wound healing, sore throat, and rheumatism. Moreover, it possesses antimicrobial, antiseptic, anticancer, counterirritant, appetite stimulator, antioxidant, and immunomodulator activities. Capsaicin and Capsicum creams are accessible in numerous ways and have been utilized in HIV-linked neuropathy and intractable pain.
    Mots-clés : <i>Capsicum</i> spp., bioactive constituents, pharmacokinetics.

  • Baumberger S, Bellon-Fontaine M-N. Chimie verte et industries agroalimentaires. 2020. (consulté 7 avr.2020).
    Résumé : Aujourd’hui, l’un des principaux enjeux de l’industrie et de l’économie consiste à répondre aux besoins d’une population mondiale croissante tout en préservant l’environnement. En effet, l’utilisation depuis plusieurs décennies des ressources énergétiques fossiles a généré, outre la diminution des réserves de ces ressources, un phénomène de réchauffement climatique dû à la libération dans l’atmosphère de gaz à effet de serre. De plus en plus de secteurs industriels, dont la chimie, s’inscrivent dans une substitution du carbone fossile par le carbone renouvelable ; ainsi se développe la bioéconomie, fondée sur la chimie verte et les biotechnologies, comme levier pour réduire l’empreinte écologique des activités humaines. L’objectif de Chimie verte et industries agroalimentaires est de présenter une utilisation raisonnée des matières premières renouvelables qui exploite la complémentarité entre filières alimentaires et non alimentaires, sans les opposer. Parmi ces matières premières figurent les ressources agricoles et forestières et les déchets issus de leurs transformations et usages. L’ouvrage comporte un ensemble de 21 chapitres articulés autour de 6 parties, chacune correspondant à un concept identifié comme clé de voûte de l’interface chimie verte-IAA : • De la chimie verte aux biotechnologies • Ressources agricoles et coproduits des IAA : sources de polymères, carburants et molécules pour la chimie • Chimie verte et matériaux polymères : vers de nouveaux emballages alimentaires • Vers des systèmes intégrés de bioraffinerie : lien avec le territoire et les autres filières de production • Apport des biotechnologies végétales à l’élaboration de la qualité de la biomasse • Les scénarios pour 2050 : comment concilier les différentes filières

  • Chouikhi N, Brandani F, Pullumbi P, Perre P, Puel F. Biomethane production by adsorption technology: new cycle development, adsorbent selection and process optimization. Adsorption 2020. doi:10.1007/s10450-020-00250-3.
    Résumé : Gas separation by adsorption processes such as pressure swing adsorption (PSA) presents an attractive alternative for upgrading biogas to biomethane. A new vacuum pressure swing adsorption (VPSA) cycle is proposed for a unit designed to purify pre-cleaned biogas (40% CO2 and 60% CH4) in industrial conditions (feed flow rate more than 500 Nm3/h and large-volume equipment). The process simulations performed to optimize the VPSA unit consider the kinetic separation of the feed components by using an appropriate carbon molecular sieve (CMS) adsorbent having a high kinetic separation selectivity for CO2 with respect to CH4. The designed VPSA unit is composed of five columns that perform three equalization steps. Minimizing methane losses during the regeneration steps necessitates injecting part of the off-gas rich in CO2 at the bottom of the column during the production step to push the CH4 forward. The produced biomethane meets the specification (97% CH4) of grid injection purity. The developed cycle allows a CH4 recovery of 92% to be obtained with a specific energy consumption of 0.35 kWh/Nm3, thus meeting the initial requirements for industrial exploitation of VPSA technology for biomethane purification from biogas sources.

  • Cochard M, Ledoux F, Landkocz Y. Atmospheric fine particulate matter and epithelial mesenchymal transition in pulmonary cells: state of the art and critical review of the in vitro studies. Journal of Toxicology and Environmental Health, Part B 2020; : 1-26.
    Résumé : Exposure to fine particulate matter (PM2.5) has been associated with several diseases including asthma, chronic obstructive pulmonary disease (COPD) and lung cancer. Mechanisms such as oxidative stress and inflammation are well-documented and are considered as the starting point of some of the pathological responses. However, a number of studies also focused on epithelial-mesenchymal transition (EMT), which is a biological process involved in fibrotic diseases and cancer progression notably via metastasis induction. Up until now, EMT was widely reported in vivo and in vitro in various cell types but investigations dealing with in vitro studies of PM2.5 induced EMT in pulmonary cells are limited. Further, few investigations combined the necessary endpoints for validation of the EMT state in cells: such as expression of several surface, cytoskeleton or extracellular matrix biomarkers and activation of transcription markers and epigenetic factors. Studies explored various cell types, cultured under differing conditions and exposed for various durations to different doses. Such unharmonized protocols (1) might introduce bias, (2) make difficult comparison of results and (3) preclude reaching a definitive conclusion regarding the ability of airborne PM2.5 to induce EMT in pulmonary cells. Some questions remain, in particular the specific PM2.5 components responsible for EMT triggering. The aim of this review is to examine the available PM2.5 induced EMT in vitro studies on pulmonary cells with special emphasis on the critical parameters considered to carry out future research in this field. This clarification appears necessary for production of reliable and comparable results.
    Mots-clés : EMT, epithelial-mesenchymal transition, Particulate matter, PM2.5, pulmonary cells.

  • Costantine G, Maalouf C, Moussa T, Kinab E, Polidori G. Hygrothermal evaluation of hemp concrete at wall and room scales: Impact of hysteresis and temperature dependency of sorption curves. Journal of Building Physics 2020; : 1744259119896380.
    Résumé : In the context of global warming associated with the excess of energy consumption, energy saving and environmental sustainability in buildings have become significant issues at both national and European levels. Therefore, the adoption of energy-efficiency measures in new and renovated dwellings will increase the demand for thermal insulation, which is crucial to improve the housing comfort by reducing the heat loss through the building envelope. Over the past two decades, several bio-based materials have been used in building thermal insulation, such as hemp concrete. Promoting the use of hemp concrete in new constructions and restoration of existing buildings first requires a validation of its hygrothermal behavior at both wall and building scales. For this, several models dealing with various physical aspects of hemp concrete were developed to understand their impact on the prediction of changes in temperature and relative humidity. These physical phenomena include hemp concrete hygroscopic hysteresis and thermal dependency of sorption curves. The preliminary results show that hysteresis has a significant influence on the numerical prediction in the short-term, while temperature dependency has less influence at the wall scale. The next part of this article is devoted to the study of these phenomena at the room scale by monitoring the internal conditions and energy consumption of a virtual hemp concrete office. The results highlight the fact that hysteresis and thermal dependency have low impact on indoor conditions, which could probably be related to the other parameters at the room scale.
    Mots-clés : Hemp concrete, hysteresis, numerical validation, room scale, SPARK, temperature dependency, wall scale.

  • Crouzet J, Arguelles-Arias A, Dhondt-Cordelier S, et al. Biosurfactants in Plant Protection Against Diseases: Rhamnolipids and Lipopeptides Case Study. Frontiers in Bioengineering and Biotechnology 2020; 8. doi:10.3389/fbioe.2020.01014.
    Résumé : Biosurfactants are amphiphilic surface-active molecules that are produced by a variety of microorganisms including fungi and bacteria. Pseudomonas, Burkholderia and Bacillus species are known to secrete rhamnolipids and lipopeptides that are used in a wide range of industrial applications. Recently, these compounds have been studied in a context of plant-microbe interactions. This mini-review describes the direct antimicrobial activities of these compounds against plant pathogens. We also provide the current knowledge on how rhamnolipids and lipopeptides stimulate the plant immune system leading to plant resistance to phytopathogens. Given their low toxicity, high biodegradability and ecological acceptance, we discuss the possible role of these biosurfactants as alternative strategies to reduce or even replace pesticide use in agriculture.
    Mots-clés : antimicrobial, elicitor, Lipopeptides, Plant Immunity, Plant Pathogen, rhamnolipids.

  • Dib H, El Khawaja R, Rochard G, Poupin C, Siffert S, Cousin R. CuAlCe Oxides Issued from Layered Double Hydroxide Precursors for Ethanol and Toluene Total Oxidation. Catalysts 2020; 10: 870.
    Résumé : CuAlCe oxides were obtained from hydrotalcite-type precursors by coprecipitation using a M2+/M3+ ratio of 3. The collapse of the layered double hydroxide structure following the thermal treatment leads to the formation of mixed oxides (CuO and CeO2). The catalytic performance of the copper-based catalysts was evaluated in the total oxidation of two Volatile Organic Compounds (VOCs): ethanol and toluene. XRD, SEM Energy-Dispersive X-ray Spectrometry (EDX), H2-temperature programmed reduction (TPR) and XPS were used to characterize the physicochemical properties of the catalysts. A beneficial effect of combining cerium with CuAl-O oxides in terms of redox properties and the abatement of the mentioned VOCs was demonstrated. The sample with the highest content of Ce showed the best catalytic properties, which were mainly related to the improvement of the reducibility of the copper species and their good dispersion on the surface. The presence of a synergetic effect between the copper and cerium elements was also highlighted.
    Mots-clés : catalytic oxidation, ethanol, layered double hydroxide, toluene, VOC.

  • Dulaurent-Mercadal A-M, Houben D. Sensibiliser les jeunes au sol à l'aide de la démarche scientifique : retour d'expérience d'un atelier conduit dans le cadre de la Fête de la Science. 2020; 27: 9-22.
    Résumé : Cet article traite de l'organisation d'un atelier de sensibilisation au sol à destination d'élèves âgés d'entre 8 et 11 ans organisé à Beauvais (France) dans le cadre de la Fête de la Science 2017, et discute de l'efficacité de ce type d'action sur base des retours collectés. L'approche adoptée pour l'élaboration des ateliers a été basée sur la démarche scientifique d'investigation. A travers différentes observations et expérimentations, les élèves sont partis à la découverte des organismes du sol et ont appréhendé le rôle du sol dans la régulation du cycle de l'eau. De manière plus générale, ils ont été amenés à se questionner sur l'importance du sol pour les écosystèmes et le bien-être humain. Les retours très positifs collectés à l'issue de ces ateliers ainsi que lors d'une journée ouverte aux citoyens suggèrent que la méconnaissance du sol en tant que réalité multifonctionnelle est davantage liée à un manque d'information qu'à un manque d'intérêt du grand public. L'engouement suscité par cet évènement encourage à conduire des actions de sensibilisation similaires ainsi qu'à promouvoir l'intégration du sol dans les programmes scolaires.

  • El-Alam I, Raveau R, Fontaine J, et al. Antifungal and Phytotoxic Activities of Essential Oils: In Vitro Assays and Their Potential Use in Crop Protection. Agronomy 2020; 10: 825.
    Résumé : (1) Background: The use of natural products based on essential oils (EO) is nowadays arousing great interest as an alternative method to control plant pathogens and weeds. However, EO possess low bioavailability and are highly volatile, and their encapsulation in hydroxypropyl-&szlig;-cyclodextrin (HP-&beta;-CD) could be a means to enhance their stability and maintain their bioactivity. Thus, the current study aims at investigating, in the presence and the absence of HP-&beta;-CD, the antifungal and phytotoxic activities of nine EO, distilled from plant species belonging to Alliaceae, Apiaceae, and Cupressaceae families, with considerations for their chemical composition. (2) Methods: EO antifungal activity was assessed by direct contact and volatility assays against Fusarium culmorum, a major phytopathogenic fungi, while phytotoxic effects were evaluated against lettuce (Lactuca sativa L.) and rye-grass (Lolium perenne L.), by seedling&rsquo;s emergence and growth assays. (3) Results: These EO inhibit fungal growth in both direct contact and volatility assays, with half-maximal inhibitory concentrations (IC50) ranging from 0.01 to 4.2 g L&minus;1, and from 0.08 up to 25.6 g L&minus;1, respectively. Concerning phytotoxicity, these EO have shown great potential in inhibiting lettuce (IC50 ranging from 0.0008 up to 0.3 g L&minus;1) and rye-grass (IC50 ranging from 0.01 to 0.8 g L&minus;1) seedlings&rsquo; emergence and growth. However, the EO encapsulation in HP-&beta;-CD has not shown a significant improvement in EO biological properties in our experimental conditions. (4) Conclusion: All tested EO present antifungal and phytotoxic activities, with diverse efficacy regarding their chemical composition, whilst no increase of their biological effects was observed with HP-&beta;-CD.
    Mots-clés : <i>Fusarium culmorum</i>, <i>Lactuca sativa</i> L., <i>Lolium perenne</i> L., bioassays, essential oils.

  • Ephraim A, Pozzobon V, Lebonnois D, et al. Pyrolysis of wood and PVC mixtures: thermal behaviour and kinetic modelling. Biomass Conversion and Biorefinery 2020. doi:10.1007/s13399-020-00952-2.
    Résumé : Wood waste containing halogenated compounds such as polyvinyl chloride (PVC) is in abundant supply, although the pyrolysis of such waste feedstock for energy production may cause corrosion and environmental problems due to the release of HCl gas. Hence, there is a need to understand the pyrolysis behaviour of chlorine-contaminated wood in order to develop methods that minimise the impact of chloride species on pyrolysis equipment and product quality. In literature, few studies exist on the kinetic analysis of wood and PVC co-pyrolysis. The existing models assume a single-step reaction with an n-order reaction mechanism for the entire process, which may lead to large errors in the kinetic parameters estimated. Therefore, in this paper, we develop and validate a multi-step kinetic model that predicts the pyrolysis behaviour and reaction mechanism of poplar wood (PW) pellet with different contents of PVC (0, 1, 5, 10, 100 wt%). Using data from thermogravimetric analysis of the pellets at heating rates of 5, 10 and 20 °C/min, we determined the apparent kinetic parameters by combining Fraser-Suzuki deconvolution, isoconversional methods and master plot procedures. Our model fitted the experimental data well with a deviation of less than 4.5%. Our results show that the addition of 1 wt% PVC to PW decreases the activation energy of hemicellulose and cellulose pyrolysis in PW from 136.3 to 101.6 kJ/mol and from 216.7 to 108.2 kJ/mol, respectively. This demonstrates the importance of acid hydrolysis reactions between the cellulosic fibres of PW and HCl released from PVC dehydrochlorination. Furthermore, we found that a nucleation and growth mechanism best represents the rate-limiting interactions between PVC and PW, which we linked to the formation of metal chloride crystals from acid-base reactions between HCl and PW minerals. Our kinetic model is an improvement of current models for the co-pyrolysis of wood and PVC, and can be readily used in a reactor-scale model of a pyrolyser or gasifier due to its relative simplicity.

  • Fauvergue X, Rusch A, Barret M, et al. Biocontrôle - Éléments pour une protection agroécologique des cultures. Librairie Quae. 2020. (consulté 7 avr.2020).
    Résumé : Biocontrôle - Éléments pour une protection agroécologique des cultures - (EAN13 : 9782759230778)

  • Flissi A, Ricart E, Campart C, et al. Norine: update of the nonribosomal peptide resource. Nucleic Acids Research 2020; 48: D465-D469.
    Résumé : Abstract. Norine, the unique resource dedicated to nonribosomal peptides (NRPs), is now updated with a new pipeline to automate massive sourcing and enhance an

  • Gharib R, Jemâa JMB, Charcosset C, Fourmentin S, Greige‐Gerges H. Retention of Eucalyptol, a Natural Volatile Insecticide, in Delivery Systems Based on Hydroxypropyl-β-Cyclodextrin and Liposomes. European Journal of Lipid Science and Technology 2020; 122: 1900402.
    Résumé : Eucalyptol (Euc) is a natural monoterpene with insecticide effects. Being highly volatile and sensitive to ambient conditions, its encapsulation would enlarge its application. Euc-loaded conventional liposomes (CL), cyclodextrin/drug inclusion complex, and drug-in-cyclodextrin-in-liposomes (DCL) are prepared to protect Euc from degradation, reduce its evaporation, and provide its controlled release. The liposomal suspension is freeze-dried using hydroxypropyl-β-cyclodextrin (HP-β-CD) as cryoprotectant. The liposomes are characterized before and after freeze-drying. The effect of Euc on the fluidity of liposomal membrane is also examined. A release study of Euc from delivery systems, in powder and reconstituted forms, is performed by multiple head extraction at 60 °C after 6 months of storage at 4 °C. CL and DCL suspensions are homogeneous, show nanometric vesicles size, spherical shape, and negative surface charge before and after freeze-drying. Moreover, HP-β-CD does not affect the fluidity of liposomes. CL formulations present a weak encapsulation for Euc. The loading capacity of eucalyptol in DCL is 38 times higher than that in CL formulation. In addition, freeze-dried DCL and HP-β-CD/Euc inclusion complex show a higher retention of eucalyptol than CL delivery system. Both carrier systems HP-β-CD/Euc and Euc-loaded DCL decrease Euc evaporation and improve its retention. Practical Applications: Eucalyptol is a natural insecticide. It is highly volatile and poorly soluble in water. To enlarge its application, its encapsulation in three delivery systems (conventional liposomes, cyclodextrin/drug inclusion complex, combined system composed of cyclodextrin inclusion complex and liposome) is studied. In this paper it is proved that cyclodextrin/eucalyptol inclusion complex and eucalyptol-in-cyclodextrin-in-liposome are effective delivery systems for encalyptol encapsulation, retention, and release.
    Mots-clés : conventional liposomes, drug-in-cyclodextrin-in-liposomes, eucalyptol, freeze-drying, hydroxypropyl-β-cyclodextrin.

  • Goemaere E, Blieck A, Coen-Aubert M, et al. Le géopatrimoine du massif ardennais. Géochronique 2020; : 56-60.
    Mots-clés : Géopatrimoine, massif ardennais, patrimoine géologique.

  • Hadad C, Husson E, Nguyen Van Nhien A. Encyclopedia of Ionic Liquids : Conversion of Chitin in Ionic Liquids. , Springer Singapore, 2020 (consulté 3 févr.2020).

  • Hai TAP, Nguyen DM, Zhang J, et al. The effects of low-profile additives on shrinkage and mechanical properties of cultured marble materials. Plastics, Rubber and Composites 2020; 49: 357-367.
    Résumé : Cultured marble is a blend of unsaturated polyester and calcium carbonate that is combined with pigments and additives to produce a wide range of colours and realistic, natural-looking patterns. This study aims to investigate process conditions (catalyst, temperature, cured time, etc …) of cultured marble at high temperatures. The optimized process conditions are obtained by thermal analysis from DSC with a temperature of 110°C and curing time of 20 min, respectively. The optimum catalyst for process conditions in a bulk moulding compound (BMC) machine is 2 phr of benzoyl peroxide (BPO). The styrene amount in UP resin is determined at 37.40% by the Gas chromatography-mass spectroscopy – headspace (GCMS-HS) technique. Anhydride maleic (MA) is found to improve outstanding mechanical properties in terms of flexural properties, the strength of impact, and the resistance of volume shrinkage of UP resin in cultured marble material.
    Mots-clés : and volume shrinkage, bulk moulding compound, Cultured marble materials, low-profile additives, mechanical properties.

  • Hawila AA-W, Merabtine A, Troussier N. Metamodeling of mean radiant temperature to optimize glass facade design in PMV-based comfort controlled space. Building Simulation 2020; 13: 271-286.
    Résumé : In recent years, glass facades and extensive glassing areas have gained popularity in the built environment. However, thermal comfort and energy-savings in such buildings are still questionable. Advanced comfort-based control strategies have been proposed in order to fulfill a tradeoff between energy-saving and occupants’ thermal comfort. Yet, they could consume energy as the conventional control approach if the building is poorly designed. Thus, an adequate design of building envelope, namely glass facades, is essential to achieve the desired trade-off. The objective of this study is to understand and formulate the relationship between the mean radiant temperature (MRT) and glass facades design parameters in a comfort-controlled space in order to optimize building design for a trade-off between energy savings and thermal comfort. The combined use of numerical simulations, the design of experiments (DoE) technique and an optimization approach is adopted. For the investigations, a previously developed and validated dynamic simulation model is used. The combined use of numerical simulation and DoE aims to identify the significant parameters affecting the MRT, as well as to develop a metamodeling relationship between the considered design factors and MRT. Lastly, the developed meta-models are validated and used to determine a set of optimal solutions using the desirability function approach. The results indicate that the optimized design case allowed about 26% reduction of heating energy consumption compared to the base case design. Finally, the results show that an adequate design of the glazed envelope leads to improved thermal comfort conditions and reduce heating energy consumption.

  • Hocq L, Guinand S, Habrylo O, et al. The exogenous application of AtPGLR, an endo-polygalacturonase, triggers pollen tube burst and repair. The Plant Journal 2020; 103: 617-633.
    Résumé : Plant cell wall remodeling plays a key role in the control of cell elongation and differentiation. In particular, fine-tuning of the degree of methylesterification of pectins was previously reported to control developmental processes as diverse as pollen germination, pollen tube elongation, emergence of primordia or elongation of dark-grown hypocotyls. However, how pectin degradation can modulate plant development has remained elusive. Here we report the characterization of a polygalacturonase (PG), AtPGLR, the gene for which is highly expressed at the onset of lateral root emergence in Arabidopsis. Due to gene compensation mechanisms, mutant approaches failed to determine the involvement of AtPGLR in plant growth. To overcome this issue, AtPGLR has been expressed heterologously in the yeast Pichia pastoris and biochemically characterized. We showed that AtPGLR is an endo-PG that preferentially releases non-methylesterified oligogalacturonides with a short degree of polymerization (< 8) at acidic pH. The application of the purified recombinant protein on Amaryllis pollen tubes, an excellent model for studying cell wall remodeling at acidic pH, induced abnormal pollen tubes or cytoplasmic leakage in the subapical dome of the pollen tube tip, where non-methylesterified pectin epitopes are detected. Those leaks could either be repaired by new β-glucan deposits (mostly callose) in the cell wall or promoted dramatic burst of the pollen tube. Our work presents the full biochemical characterization of an Arabidopsis PG and highlights the importance of pectin integrity in pollen tube elongation.
    Mots-clés : Amaryllis belladonna, Arabidopsis thaliana, elongation, oligogalacturonides, pectins, pollen tube, polygalacturonase.

  • Huby E, Napier JA, Baillieul F, Michaelson LV, Dhondt-Cordelier S. Sphingolipids: towards an integrated view of metabolism during the plant stress response. New Phytologist 2020; 225: 659-670.
    Résumé : Plants exist in an environment of changing abiotic and biotic stresses. They have developed a complex set of strategies to respond to these stresses and over recent years it has become clear that sphingolipids are a key player in these responses. Sphingolipids are not universally present in all three domains of life. Many bacteria and archaea do not produce sphingolipids but they are ubiquitous in eukaryotes and have been intensively studied in yeast and mammals. During the last decade there has been a steadily increasing interest in plant sphingolipids. Plant sphingolipids exhibit structural differences when compared with their mammalian counterparts and it is now clear that they perform some unique functions. Sphingolipids are recognised as critical components of the plant plasma membrane and endomembrane system. Besides being important structural elements of plant membranes, their particular structure contributes to the fluidity and biophysical order. Sphingolipids are also involved in multiple cellular and regulatory processes including vesicle trafficking, plant development and defence. This review will focus on our current knowledge as to the function of sphingolipids during plant stress responses, not only as structural components of biological membranes, but also as signalling mediators.
    Mots-clés : abiotic stress, biotic stress, pathogens, plant defence, programmed cell death, sphingolipid.

  • Jiang W, Levasseur W, Casalinho J, et al. Shear stress computation in a millimeter thin flat panel photobioreactor: Numerical design validated by experiments. Biotechnology and Applied Biochemistry 2020; n/a. doi:10.1002/bab.1894.
    Résumé : Flat panels are the most spread type of photobioreactors for studying light effects on a microalgae culture. Their low thickness, usually between 1 and 3 cm, aims at ensuring light homogeneity across the culture. Yet because optical density has to remain very low, studies are still limited to low cell density cultures. To alleviate this problem, even thinner photobioreactors can be designed. Nevertheless, thin flat panel reactors are very prone to induce high shear stress. This work aimed at designing a new millimeter thin panel photobioreactor to study light effects on Chlorella and Scenedesmus genera. We proposed a numerical workflow that is capable of assessing the shear stress intensity in such a reactor. The numerical predictions were validated at three different levels: 2D preliminary simulations were able to reproduce bubble commonly known behaviors; close to the nozzle, the predictions were successfully confronted to shadowgraphy experimental reference; at the mini bioreactor scale, experimental and numerical mixing were found to be close. After these throughout validations, shear stress intensity in the photobioreactor was calculated over 1000 Lagrangian tracers. The experienced shear stress was agglomerated at the population level. From the computed shear stress, it was possible to choose the minimal reactor thickness that would not hinder cell growth.
    Mots-clés : OpenFOAM, shear stress, VOF.

  • Kabir MT, Uddin MS, Mamun AA, et al. Combination Drug Therapy for the Management of Alzheimer’s Disease. International Journal of Molecular Sciences 2020; 21: 3272.
    Résumé : Alzheimer&rsquo;s disease (AD) is the leading cause of dementia worldwide. Even though the number of AD patients is rapidly growing, there is no effective treatment for this neurodegenerative disorder. At present, implementation of effective treatment approaches for AD is vital to meet clinical needs. In AD research, priorities concern the development of disease-modifying therapeutic agents to be used in the early phases of AD and the optimization of the symptomatic treatments predominantly dedicated to the more advanced AD stages. Until now, available therapeutic agents for AD treatment only provide symptomatic treatment. Since AD pathogenesis is multifactorial, use of a multimodal therapeutic intervention addressing several molecular targets of AD-related pathological processes seems to be the most practical approach to modify the course of AD progression. It has been demonstrated through numerous studies, that the clinical efficacy of combination therapy (CT) is higher than that of monotherapy. In case of AD, CT is more effective, mostly when started early, at slowing the rate of cognitive impairment. In this review, we have covered the major studies regarding CT to combat AD pathogenesis. Moreover, we have also highlighted the safety, tolerability, and efficacy of CT in the treatment of AD.
    Mots-clés : Alzheimer’s disease, combination therapy, dementia, multi-target-directed ligands.

  • Kervroëdan L, Armand R, Saunier M, Faucon M-P. Functional Diversity Effects of Vegetation on Runoff to Design Herbaceous Hedges for Sediment Retention. Diversity 2020; 12: 131.
    Résumé : Background: Functional diversity effects on ecosystem processes, like on soil erosion, are not fully understood. Runoff and soil erosion in agricultural landscapes are reduced by the hydraulic roughness (HR) of vegetation patches, which furthers sediment retention. Vegetation with important stem density, diameters, leaf areas, and density impact the HR. A functional structure composed of these negatively correlated traits involved in the increase of the HR would constitute a positive effect of the functional diversity. Methods: Runoff simulations were undertaken on four mono-specific and two multi-specific communities, using herbaceous plant species from North-West Europe, presenting six contrasting aboveground functional traits involved in the HR increase. Results: An effect of dominant traits in the community was found on the HR, identified as the community-weighted leaf density. The non-additive effect of functional diversity on the HR could be explained by the presence of species presenting large stems in the communities with high functional diversity. Conclusion: We argued that functional diversity effect on the HR could change due to idiosyncratic effects of the plant traits, which would be influenced by soil properties, phylogeny diversity, and plant species interactions. These findings constitute an advancement in the understanding of plant trait assemblage on runoff and soil erosion processes.
    Mots-clés : functional diversity, herbaceous vegetation, hydraulic roughness, leaf and stem functional traits, plant–runoff interaction, soil erosion control.

  • Landoulsi A, Hennebelle T, Bero J, et al. Antimicrobial and Light-Enhanced Antimicrobial Activities, Cytotoxicity and Chemical Variability of All Tunisian Eryngium Species. Chemistry & Biodiversity 2020; 17: e1900543.
    Résumé : This study was performed on all Eryngium species growing in Tunisia in order to evaluate their intra and interspecies variabilities and to investigate their biological activities. These species are used in traditional medicine, and literature about the phytochemical investigations of most of them is scarce. Antimicrobial and light-enhanced activities were tested against multiresistant microorganisms and extended spectrum beta-lactamase producing bacteria (ESBL). All studied species showed antimicrobial effect with several MIC values lower than 70 μg/ml. Tested Eryngium species have proven to be a promising source of photoactive compounds, while light-enhanced activity offers an alternative for the inactivation of pathogenic microorganisms which is currently subjected to a great interest. This is the first report of this activity in genus Eryngium. A significant improvement of antimicrobial activity with UV irradiation was observed, mainly for E. dichotomum, E. ilicifolium and E. triquetrum. Cytotoxicity, studied for the first time for the most species, was evaluated against cancer (J774) and non-cancer (WI38) human cell lines. Chemical composition of volatile compounds presented in the most active crude extracts (petroleum ether extracts) of the aerial parts was investigated using GC/MS analysis and was submitted to statistical analyses. It revealed their high content of bioactive phytochemicals, particularly oxygenated sesquiterpenes like spathulenol, ledol and α-bisabolol but also hydrocarbon sesquiterpenes such as β-bisabolene and copaene, as well as polyacetylene derivatives such as falcarinol. Statistical analyses permitted to evaluate the interrelations between all Tunisian Eryngium species.
    Mots-clés : antimicrobial, chemical variability, cytotoxicity, Eryngium, photoactivation.

  • Lorreyte C, Lea P, Henry J-F, et al. Morphological and effective transport properties of fixed beds of wood chips: Toward realistic modeling of low-temperature pyrolysis. Journal of Renewable and Sustainable Energy 2020; 12: 013101.
    Résumé : A detailed understanding of heat transfer and flow is critically important for the pyrolysis of carbonaceous feedstock in fixed bed reactors. In this paper, multimode transport phenomena are simulated by direct pore level simulation on representative digitized samples to retrieve the heat-transfer and pressure-drop properties of highly porous fixed beds of oak-wood chips, which exhibit anisotropic solid-phase tortuosity. A comparison of the direct pore level simulation and simple models of porous media with simple morphologies shows that simple models cannot be used to determine the transport properties of a material with a complex morphology, such as fixed beds of wood chips. Because of drying and devolatilization, the effective thermal conductivity of wood chips decreases with increasing temperature. Heat conduction passes preferentially through the fluid because wood chips have very low thermal conductivity. This study also shows that the shrinking and cracking phenomena resulting from pyrolysis lead to a decrease in the porosity and solid-phase tortuosity and an increase in the specific area. At a high Reynolds number, the pyrolysis also diminishes the permeability but increases the inertial resistance to flow and the interfacial heat transfer.

  • Mallard I, Landy D, Fourmentin S. Evaluation of Polyethylene Glycol Crosslinked β-CD Polymers for the Removal of Methylene Blue. Applied Sciences 2020; 10: 4679.
    Résumé : The environment is at the heart of global worldwide discussion. This study describes the synthesis of ecofriendly polymers by a crosslinking reaction between &beta;-cyclodextrin as the monomer and polyethylene glycol diglycidyl ether (PEDGE) as well as ethylene diglycidyl ether (EDGE) as the crosslinking agents. The studied polymers were characterized by several techniques, such as SEM, FTIR, TGA-TDA and XRD. Their adsorption properties for methylene blue under various conditions of pH, contact time and initial concentration of dye were assessed in order to find the optimal conditions. The results indicate that the polymers are good nominates for methylene blue adsorption with adsorption capacities up to 15 mg/g. The adsorption mechanism was demonstrated to follow the Langmuir model. Finally, the regeneration of the polymers was investigated using Soxhlet extraction with ethanol. The absorption capacities of the adsorbent were stable after three cycles.
    Mots-clés : adsorption, dye, methylene blue, polymer, β-cyclodextrin.

  • Martin B, Colin J, Lu P, et al. Water migration in wood during imbibition assessed by X-ray imaging. E3S Web of Conferences 2020; 172: 14007.
    Résumé : In the wooden construction, structural elements are particularly exposed to external climatic conditions during the construction phase. To ensure their durability over their expected lifespan, the required drying time have to be known after a rain shower and before closing the timber structures. This question, involving coupled heat and mass transfer, can be investigated through numerical tools. The aim of this work is to provide experimental data through X-ray imaging to validate the prediction potential of computational models simulating transfer in porous media. Two complementary methods were developed to access the water migration in Norway spruce. The first one allowed to quantitatively measure spatial distribution of moisture content over time. It is based on a rigorous treatment of the X-ray beam attenuation. The second method, using a high-resolution 3D reconstruction, highlighted the role of wood rays on liquid migration within the porous network.

  • Meglouli H, Fontaine J, Sahraoui AL-H. Dioxins/furans disturb the life cycle of the arbuscular mycorrhizal fungus, Rhizophagus irregularis and chicory root elongation grown under axenic conditions. International Journal of Phytoremediation 2020; : 1-8.
    Résumé : Arbuscular mycorrhizal fungi (AMF)-assisted phytoremediation is a promising technology for sustainable removal of hazardous pollutants like dioxins/furans (PCDD/F) from the soil. However, little is known on AMF development in the presence of the persistent organic pollutants, PCDD/F. Thus, the present work aims at investigating the impact of increasing PCDD/F concentrations on the development of both partners of the symbiosis: the AMF, Rhizophagus irregularis and the chicory roots, Cichorium intybus L. grown under axenic conditions. Our results show that even R. irregularis spore germination is not affected by PCDD/F, it occurred mainly in linear way. However, root colonization, extra-radical hyphal elongation and sporulation are reduced by 40, 30, and 75%, respectively, at the highest PCDD/F concentration. In addition, while non-mycorrhizal root growth (length and dry weight) decreased at the highest PCDD/F concentration, no negative effect was observed on the dry weight of mycorrhizal roots. In conclusion, our findings show that although high PCDD/F concentrations disturb the main stages of R. irregularis development, the AMF remains able to fulfill its life cycle in the presence of PCDD/F. Moreover, the mycorrhizal inoculation protects the host plant against PCDD/F phytotoxicity. AMF could thus represent an interesting amendment option to assist phytoremediation of PCDD/F contaminated soils.
    Mots-clés : Arbuscular mycorrhizal fungus, development cycle, dioxins/furans, ecotoxicity, in vitro culture, Rhizophagus irregularis.

  • Mirzaei H, Bagheri H, Ghasemi F, et al. Anti-Cancer Activity of Curcumin on Multiple Myeloma. Anti-Cancer Agents in Medicinal Chemistry 2020. doi:10.2174/1871520620666200918113625.
    Résumé : Multiple Myeloma (MM) is the third most common and deadly hematological malignancy, which is characterized by a progressive monoclonal proliferation within the bone marrow. MM is cytogenetically heterogeneous with numerous genetic and epigenetic alterations, which lead to a wide spectrum of signaling pathways and cell cycle checkpoint aberrations. MM symptoms can be attributed to CRAB features (hyperCalcemia, Renal failure, Anemia and Bone lesion), which profoundly affect both the Health-Related Quality of Life (HRQoL) and the life expectancy of patients. Despite all enhancement and improvement in therapeutic strategies, MM is almost incurable, and patients faced to this disease eventually relapse. Curcumin is an active and nontoxic phenolic compound, isolated from the rhizome of Curcuma longa L. It has been widely studied and has a confirmed broad range of therapeutic properties, especially anticancer activity, including anti-proliferation, anti-angiogenesis, antioxidant and anti-mutation activities. Curcumin induces apoptosis in cancerous cells and prevents Multidrug Resistance (MDR). Growing evidence concerning the therapeutic properties of curcumin caused a pharmacological impact on MM. It is confirmed that curcumin interferes with various signaling pathways and cell cycle checkpoints, and with oncogenes. In this paper, we summarized the anti-MM effects of curcumin.
    Mots-clés : CRAB features., Curcumin, HRQoL, multidrug resistance, multiple myeloma, therapy.

  • Morvan S, Meglouli H, Sahraoui AL-H, Hijri M. Into the wild blueberry (Vaccinium angustifolium) rhizosphere microbiota. Environmental Microbiology 2020; 22: 3803-3822.
    Résumé : The ability of wild blueberries to adapt to their harsh environment is believed to be closely related to their symbiosis with ericoid mycorrhizal fungi, which produce enzymes capable of organic matter mineralization. Although some of these fungi have been identified and characterized, we still know little about the microbial ecology of wild blueberry. Our study aims to characterize the fungal and bacterial rhizosphere communities of Vaccinium angustifolium (the main species encountered in wild blueberry fields). Our results clearly show that the fungal order Helotiales was the most abundant taxon associated with V. angustifolium. Helotiales contains most of the known ericoid mycorrhizal fungi which are expected to dominate in such a biotope. Furthermore, we found the dominant bacterial order was the nitrogen-fixing Rhizobiales. The Bradyrhizobium genus, whose members are known to form nodules with legumes, was among the 10 most abundant genera in the bacterial communities. In addition, Bradyrhizobium and Roseiarcus sequences significantly correlated with higher leaf-nitrogen content. Overall, our data documented fungal and bacterial community structure differences in three wild blueberry production fields.

  • Nguyen DM, Vu TN, Nguyen TML, et al. Synergistic Influences of Stearic Acid Coating and Recycled PET Microfibers on the Enhanced Properties of Composite Materials. Materials 2020; 13: 1461.
    Résumé : This study aims to produce novel composite artificial marble materials by bulk molding compound processes, and improve their thermal and mechanical properties. We employed stearic acid as an efficient surface modifying agent for CaCO3 particles, and for the first time, a pretreated, recycled, polyethylene terephthalate (PET) fibers mat is used to reinforce the artificial marble materials. The innovative aspects of the study are the surface treatment of CaCO3 particles by stearic acid. Stearic acid forms a monolayer shell, coating the CaCO3 particles, which enhances the compatibility between the CaCO3 particles and the matrix of the composite. The morphology of the composites, observed by scanning electron microscopy, revealed that the CaCO3 phase was homogeneously dispersed in the epoxy matrix under the support of stearic acid. A single layer of a recycled PET fibers mat was pretreated and designed in the core of the composite. As expected, these results indicated that the fibers could enhance flexural properties, and impact strength along with thermal stability for the composites. This combination of a pretreated, recycled, PET fibers mat and epoxy/CaCO3-stearic acid could produce novel artificial marble materials for construction applications able to meet environmental requirements.
    Mots-clés : composite artificial marble, fiber-reinforced composite, pretreatment calcium carbonate, recycled PET fibers, SEM analysis, stearic acid.

  • Nguyen NH, Trotel-Aziz P, Villaume S, et al. Bacillus subtilis and Pseudomonas fluorescens Trigger Common and Distinct Systemic Immune Responses in Arabidopsis thaliana Depending on the Pathogen Lifestyle. Vaccines 2020; 8: 503.
    Résumé : Plants harbor various beneficial bacteria that modulate their innate immunity, resulting in induced systemic resistance (ISR) against various pathogens. However, the immune mechanisms underlying ISR triggered by Bacillus spp. and Pseudomonas spp. against pathogens with different lifestyles are not yet clearly elucidated. Here, we show that root drenching of Arabidopsis plants with Pseudomonas fluorescensPTA-CT2 and Bacillus subtilis PTA-271 can induce ISR against the necrotrophic fungus B. cinerea and the hemibiotrophic bacterium Pseudomonas syringae Pst DC3000. In the absence of pathogen infection, both beneficial bacteria do not induce any consistent change in systemic immune responses. However, ISR relies on priming faster and robust expression of marker genes for the salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) signaling pathways upon pathogen challenge. These responses are also associated with increased levels of SA, JA, and abscisic acid (ABA) in the leaves of bacterized plants after infection. The functional study also points at priming of the JA/ET and NPR1-dependent defenses as prioritized immune pathways in ISR induced by both beneficial bacteria against B. cinerea. However, B. subtilis-triggered ISR against Pst DC3000 is dependent on SA, JA/ET, and NPR1 pathways, whereas P. fluorescens-induced ISR requires JA/ET and NPR1 signaling pathways. The use of ABA-insensitive mutants also pointed out the crucial role of ABA signaling, but not ABA concentration, along with JA/ET signaling in primed systemic immunity by beneficial bacteria against Pst DC3000, but not against B. cinerea. These results clearly indicate that ISR is linked to priming plants for enhanced common and distinct immune pathways depending on the beneficial strain and the pathogen lifestyle.
    Mots-clés : <i>Arabidopsis</i>, <i>Bacillus subtilis</i>, <i>Pseudomonas</i> <i>fluorescens</i>, induced immunity, induced resistance, pathogens, priming.

  • Nguyen TH, Doré J, Ait Barka E, et al. Development of a DNA based real time PCR assay to quantify Allorhizobium vitis over time in grapevine (Vitis vinifera L.) plantlets. Plant Disease 2020. doi:10.1094/PDIS-04-20-0732-RE.
    Résumé : Allorhizobium vitis is the primary causal pathogen of grapevine crown gall disease. As this endophytic bacterium can survive as systemic latent (symptomless) infections in grapevine, there is a great importance to detect and monitor its development in planta. In plant-bacteria studies, plate counting is routinely used as a simple and reliable method to evaluate the level of bacterial populations in planta. However, isolation techniques present some disadvantages such as necessity of working on fresh samples, time-consuming and risk of contamination. In this study, we developed a DNA-based real-time PCR assay that can replace the classical method to monitor the development of A. vitis in grapevine plantlets. Primers targeting A. vitis chromosomic genes and the virulent Ti plasmid were validated. The proposed qPCR technique is highly reliable and reproducible to assess A. vitis numeration at the earliest stage of infection until tumor development in grapevine plantlets. Moreover, this is a low-cost technique which provides rapid and robust in planta quantification of the pathogen, suitable for fundamental research to monitor bacterial development over time.

  • Pozzobon V, Levasseur W, Viau E, Michiels E, Clément T, Perré P. Machine learning processing of microalgae flow cytometry readings: illustrated with Chlorella vulgaris viability assays. Journal of Applied Phycology 2020. doi:10.1007/s10811-020-02180-7.
    Résumé : A flow cytometry viability assay protocol is proposed and applied to model microalgae Chlorella vulgaris. The protocol relies on concomitant dual staining of the cells (fluorescein diacetate (FDA), propidium iodide (PI)) and machine learning processing of the results. Protocol development highlighted that working at 4 °C allows to preserve the stained sample for 15 min before analysis. Furthermore, the inclusion of an extracellular FDA washing step in the protocol improves the signal-to-noise ratio, allowing better detection of active cells. Once established, this protocol was validated against 7 test cases (controlled mixtures of active and non-viable cells). Its performances on the test cases are good: − 0.19%abs deviation on active cell quantification (processed by humans). Furthermore, a machine learning workflow, based on DBSCAN algorithm, was introduced. After a calibration procedure, the algorithm provided very satisfactorily results with − 0.10%abs deviation compared to human processing. This approach permitted to automate and speed up (15 folds) cytometry readings processing. Finally, the proposed workflow was used to assess Chlorella vulgaris cryostorage procedure efficiency. The impact of freezing protocol on cell viability was first investigated over 48-h storage (− 20 °C). Then, the most promising procedure (pelleted, − 20 °C) was tested over 1 month. The observed trends and values in viability loss correlate well with literature. This shows that flow cytometry is a valid tool to assess for microalgae cryopreservation protocol efficiency.

  • Quintela-Sabarís C, Faucon M-P, Repin R, et al. Plant Functional Traits on Tropical Ultramafic Habitats Affected by Fire and Mining: Insights for Reclamation. Diversity 2020; 12: 248.
    Résumé : Biodiversity-rich tropical ultramafic areas are currently being impacted by land clearing and particularly by mine activities. The reclamation of ultramafic degraded areas requires a knowledge of pioneer plant species. The objective of this study is to highlight the functional traits of plants that colonize ultramafic areas after disturbance by fire or mining activities. This information will allow trait-assisted selection of candidate species for reclamation. Fifteen plots were established on ultramafic soils in Sabah (Borneo, Malaysia) disturbed by recurrent fires (FIRE plots) or by soil excavation and quarrying (MINE plots). In each plot, soil samples were collected and plant cover as well as species abundances were estimated. Fifteen functional traits related to revegetation, nutrient improvement, or Ni phytomining were measured in sampled plants. Vegetation of both FIRE and MINE plots was dominated by perennials with lateral spreading capacity (mainly by rhizomes). Plant communities displayed a conservative growth strategy, which is an adaptation to low nutrient availability on ultramafic soils. Plant height was higher in FIRE than in MINE plots, whereas the number of stems per plant was higher in MINE plots. Perennial plants with lateral spreading capacity and a conservative growth strategy would be the first choice for the reclamation of ultramafic degraded areas. Additional notes for increasing nutrient cycling, managing competition, and implementing of Ni-phytomining are also provided.
    Mots-clés : community weighted means, functional traits, soil reclamation, technosols, ultramafic.

  • Raveau R, Fontaine J, Lounès-Hadj Sahraoui A. Essential Oils as Potential Alternative Biocontrol Products against Plant Pathogens and Weeds: A Review. Foods 2020; 9: 365.
    Résumé : Naturally produced by aromatic plants, essential oils (EO) contain a wide range of volatile molecules, including mostly secondary metabolites, which possess several biological activities. Essential oils properties such as antioxidant, antimicrobial and anti-inflammatory activities are known for a long time and hence widely used in traditional medicines, cosmetics and food industries. However, despite their effects against many phytopathogenic fungi, oomycetes and bacteria as well as weeds, their use in agriculture remains surprisingly scarce. The purpose of the present review is to gather and discuss up-to-date biological activities of EO against weeds, plant pathogenic fungi, oomycetes and bacteria, reported in the scientific literature. Innovative methods, potentially valuable to improve the efficiency and reliability of EO, have been investigated. In particular, their use towards a more sustainable agriculture has been discussed, aiming at encouraging the use of alternative products to substitute synthetic pesticides to control weeds and plant diseases, without significantly affecting crop yields. An overview of the market and the recent advances on the regulation of these products as well as future challenges to promote their development and wider use in disease management programs is described. Because of several recent reviews on EO insecticidal properties, this topic is not covered in the present review.
    Mots-clés : biological properties, crop protection, essential oils, sustainable agriculture.

  • Robineau M, Le Guenic S, Sanchez L, et al. Synthetic Mono-Rhamnolipids Display Direct Antifungal Effects and Trigger an Innate Immune Response in Tomato against Botrytis Cinerea. Molecules 2020; 25: 3108.
    Résumé : Natural rhamnolipids are potential biocontrol agents for plant protection against bacterial and fungal diseases. In this work, we synthetized new synthetic mono-rhamnolipids (smRLs) consisting in a rhamnose connected to a simple acyl chain and differing by the nature of the link and the length of the lipid tail. We then investigated the effects of these ether, ester, carbamate or succinate smRL derivatives on Botrytis cinerea development, symptoms spreading on tomato leaves and immune responses in tomato plants. Our results demonstrate that synthetic smRLs are able to trigger early and late immunity-related plant defense responses in tomato and increase plant resistance against B. cinerea in controlled conditions. Structure-function analysis showed that chain length of the lipidic part and type of acyl chain were critical to smRLs immune activity and to the extent of symptoms caused by the fungus on tomato leaves.
    Mots-clés : <i>Botrytis</i>, elicitors, induced resistance, innate immunity, tomato.

  • Saleh E, Morshdy AE, El-Manakhly E, et al. Effects of Olive Leaf Extracts as Natural Preservative on Retailed Poultry Meat Quality. Foods 2020; 9: 1017.
    Résumé : Poultry meat is commonly marketed at refrigerated temperatures (2&ndash;5 &deg;C). The major concern for retailers and consumers is the quality and safety of refrigerated poultry meat. During the chilling period, poultry meat undergoes too many undesirable changes due to microbial growth that leads to spoilage and economic loss. Therefore, this study was conducted to assess the effects of olive leaf extracts (OLE) used at three concentrations (0.25, 0.5, and 1%) on the sensory attributes, as well as the chemical and microbiological quality of raw poultry meat stored at 4 &plusmn; 1 &deg;C for 15 days. The results revealed that the OLE addition reduced microbial growth successfully, and maintained the chemical quality and sensory attributes of poultry meat. Moreover, OLE extended the shelf-life of the poultry meat that held under proper refrigeration conditions up to 15 days compared to the control group, that was completely spoiled by the sixth day of storage. This study concludes that OLE could be used both as a natural antioxidant and an antimicrobial preservative for chilled poultry meat held at refrigerated temperature.
    Mots-clés : microbial quality, natural preservative, olive leaf extract, poultry meat.

  • Segado Centellas M, Piot M, Salles R, et al. Exploring the self-assembly of dumbbell-shaped polyoxometalate hybrids, from molecular building units to nanostructured soft materials. Chemical Science 2020. doi:10.1039/D0SC03243C.
    Résumé : The formation of hierarchical nanostructures using preformed dumbbell-like species made of covalent organic–inorganic polyoxometalate (POM)-based hybrids is herein described. In this system, the presence of charged subunits (POM, metal linkers, and counter ions) in the complex molecular architecture can drive their aggregation, which results from a competition between the solvation energy of the discrete species and intermolecular electrostatic interactions. We show that the nature of the POM and the charge of the metal linker are key parameters for the hierarchical nanoorganization. The experimental findings were corroborated with a computational investigation combining DFT and molecular dynamics simulation methods, which outlines the importance of solvation of the counter ion and POM/counter ion association in the aggregation process. The dumbbell-like species can also form gels, in the presence of a poorer solvent, displaying similar nanoorganization of the aggregates. We show that starting from the designed molecular building units whose internal charges can be controlled by redox trigger we can achieve their implementation into soft nanostructured materials through the control of their supramolecular organization.

  • Souissi D, Zouhri L, Hammami S, Msaddek MH, Zghibi A, Dlala M. GIS-based MCDM – AHP modeling for flood susceptibility mapping of arid areas, southeastern Tunisia. Geocarto International 2020; 35: 991-1017.
    Résumé : Floods are considered as a major natural disaster due to their devastating effects that lead to socio-economic losses. The present study is an attempt to prepare a flood hazard susceptibility map of the Gabes region using ‘multi-criteria decision making – analytical hierarchy process’ model in geographic information system environment. Eight factors have been used in the flood modeling: elevation, land use/land cover, lithology, rainfall intensity, drainage density, distance from the drainage network, slope, and groundwater depth. The impact of each factor contributing in the flood risk was examined by weights using analytical hierarchy process method. The results obtained shows that the most prominent flood occurrence factor is the elevation (22.5%), around 15% of the total area is flooded and the flood hazard index is equal 6.30. The validation of results by a susceptibility zones histogram showed that 74.51% of the observed flood areas are mainly concentrated in a moderate to very high susceptibility zone.
    Mots-clés : analytical hierarchy process (AHP), Correction, Flood susceptibility, GIS analysis, multi-criteria decision making (MCDM), sensitivity analysis.

  • Terryn C, Habrant A, Paës G, Spriet C. Measuring Interactions between Fluorescent Probes and Lignin in Plant Sections by sFLIM Based on Native Autofluorescence. JoVE (Journal of Visualized Experiments) 2020; : e59925.
    Résumé : In lignocellulosic biomass (LB), the activity of enzymes is limited by the appearance of non-specific interactions with lignin during the hydrolysis process, which maintains enzymes far from their substrate. Characterization of these complex interactions is thus a challenge in complex substrates such as LB. The method here measures molecular interactions between fluorophore-tagged molecules and native autofluorescent lignin, to be revealed by Förster resonance energy transfer (FRET). Contrary to FRET measurements in living cells using two exogenous fluorophores, FRET measurements in plants using lignin is not trivial due to its complex autofluorescence. We have developed an original acquisition and analysis pipeline with correlated observation of two complementary properties of fluorescence: fluorescence emission and lifetime. sFLIM (spectral and fluorescent lifetime imaging microscopy) provides the quantification of these interactions with high sensitivity, revealing different interaction levels between biomolecules and lignin.

  • Tong SS, Deroin J-P, Pham TL. An optimal waterline approach for studying tidal flat morphological changes using remote sensing data: A case of the northern coast of Vietnam. Estuarine, Coastal and Shelf Science 2020; : 106613.
    Résumé : Tidal flats on the north coast of Vietnam suffer diurnal tide with a tide range varying between 0.3 m and 3.5 m. Along the 350 km long coastline, the diversity of environmental conditions induces various tidal flats with different characteristics. This study applies the waterline method for multi-temporal satellite images to build Digital Elevation Models (DEMs) of tidal flats during the last 25 years. 117 Landsat images acquired with TM, ETM+, and OLI have been processed to construct tidal flat DEMs in 1989, 2000, and 2014. Waterlines extracted from single spectral bands (near-infrared [NIR], short wave infrared [SWIR]) or band ratios (normalized difference water index [NDWI], normalized difference vegetation index [NDVI], Green/SWIR) of the Landsat data have been compared with waterlines digitalized on Spot, Aster and Worldview 2 images. This experiment allows us to determine the best band (or band ratio) for extracting waterlines depending on local conditions. Consequently, the study shows that the Green/SWIR ratio image is a good solution for extracting waterlines in the black coal tidal flats of Cam Pha. However, the NDWI index appears to be a better choice for the other parts of the study area. The vertical accuracy of the tidal flat DEMs reaches 0.144 m. The change analysis of the DEMs also emphasizes the tidal flat evolution in both vertical and horizontal dimensions, i.e. erosion or accretion. The erosion of the tidal flats along the northern coast of Vietnam is particularly developed in the area extending from Yen Hung to Mong Cai, especially in Mong Cai with an amount of about 50 × 106 m3 of sediments lost between 1989 and 2014. On the contrary, the tidal flats in the south of the study area show a high rate of deposition due to the sediments fed by Red and Thai Binh rivers. About 35 × 106 m3 of sediments deposited in the tidal flat surrounding the Red River mouth between 1989 and 2014. This study represents a development of the waterline extraction method to investigate the evolution of tidal flat at a large scale and a diversified coastal environment using optical satellite images and fieldwork.
    Mots-clés : Gulf of tonkin, Landsat, Morphological change, Tidal flats, Waterlines extraction.

  • Tzortzakis N, Chrysargyris A, Aziz A. Adaptive Response of a Native Mediterranean Grapevine Cultivar Upon Short-Term Exposure to Drought and Heat Stress in the Context of Climate Change. Agronomy 2020; 10: 249.
    Résumé : The impact of climate change on viticulture is of major importance. Several international and indigenous grapevine cultivars have been examined for their adaptive performance to drought and heat stresses. However, the underlying physiological mechanisms are not well known. In the present study we examined the short-term effects of light and moderate drought stress (DS) as well as heat stress (HS) on physiological and biochemical attributes in two grapevine cultivars: Chardonnay (international) and Xynisteri, an indigenous adapted to the specific Cypriot microclimate. Xynisteri plants exhibited decreasing leaf stomatal conductance and photosynthetic rate as well as increasing total phenols and antioxidant capacity under DS conditions. These reactions were concomitant to a rapid accumulation of hydrogen peroxide and lipid peroxidation in leaves, associated to an increase of the antioxidant superoxide dismutase activity. However, Chardonnay plants did not exhibit the same responses as Xynisteri against DS (i.e., stomatal closure, total phenolics and antioxidants) over the first four days. Additionally, Chardonnay showed leaf damage with increased lipid peroxidation levels and activation of catalase and peroxidase. Interestingly, HS increased leaf stomatal conductance and decreased total phenolic content, flavonoids and antioxidant capacity in Chardonnay after 20 d of stress. In both cultivars, HS had milder effects compared to DS, and again Xynisteri showed better performance than Chardonnay in terms of damage index and antioxidative activities. Overall, Xynisteri adaptation to DS and HS was higher than that of Chardonnay, and both cultivars reacted more to the short-term DS than to HS. Although the Xynisteri performances under stress conditions provide an important resource for adaptation to stressful conditions, the impacts on earliness, yield and grape quality remain to be explored.
    Mots-clés : antioxidants, climate change, drought stress, heat stress, lipid peroxidation, photosynthesis.

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