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This report is based on the extraction of lignin from by-products of the Walloon wood industry using green processes (meeting the standards of green chemistry). The woody materials studied correspond to shredded wood of beech, spruce, poplar and a mixture of species supplied by Groupe François, which wishes to develop these by-products. A percentage of lignin varying between 22 and 29 % (w/w) of the dry mass was found in the different batches studied. 4 types of pretreatments were tested: 2 alkaline extractions (NaOH 3 % (w/v) and Ca(OH)2 3 % (w/v)) and 2 acid extractions (H2SO4 3% (w/v) and H3PO4 3% (w/v)).
The chemical composition of each of the phases produced during the pretreatments (a solid and a liquid phase after the acid pretreatments and a solid, a liquid and a precipitated phase after the alkaline pretreatments) was determined in order to envisage a utility for each of these phases. Specifically, the composition and mass of each of the phases involved in the pretreatments with NaOH and H2SO4 of spruce wood is presented in this document. In fact, these pretreatments are the most effective ones for each of the extraction pathways studied, according to the parameters chosen in this report, namely the recovery or extraction yield (the proportion of lignin found in the wood before pretreatment that was recovered after pretreatment, the recovery yield concerning the acid pretreatments and the extraction yield concerning the alkaline pretreatments) and the purity of this lignin. Thus, the water consumption of these 2 pretreatments was studied, as well as the possible uses of the related fluxes, according to their chemical composition.
The lignins obtained by alkaline pretreatment were then characterized by elemental analysis, infrared, high performance steric exclusion chromatography by ultraviolet and electrophoresis. After determining the absence of sulfur and nitrogen in the precipitated lignins, lignin structural analyses showed little differences between the lignins obtained from the 3 treated wood species (beech, poplar and spruce).
A special study has been made concerning the lignin molecular weight determination. This determination by HPSEC-UV analysis strongly depends on the hydrodynamic volume. However, this volume does not only depend on the lignin weight, but also on its chemical functions composition. Thus, to avoid this problem, a lignin molecular weight determination by SDS-PAG electrophoresis was carried out. The SDS (sodium dodecyl sulphate) was used to eliminate the involvement of non-covalent bonds on the hydrodynamic volume. This method seems to corroborate the results obtained by HPSEC-UV. However, the use of sodium polystyrene sulphonate as mass standards does not make it possible to establish a calibration curve. The determination of molecular weight by electrophoresis is rarely used in the study of lignin, it must be further improved to show a level of accuracy and precision, equivalent or superior to those of the HPSEC-UV analysis.

Shredded wood --- Lignin extraction --- Lignin characterization --- HPSEC-UV --- SDS-PAGE --- FTIR --- Ingénierie, informatique & technologie > Ingénierie chimique --- Sciences du vivant > Biotechnologie

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Pathogenic Escherichia coli strains cause a large number of diseases in humans, including diarrhea, hemorrhagic colitis, hemolytic uremic syndrome, urinary tract infections, and neonatal meningitis, while in animals they cause diseases such as calf scours and mastitis in cattle, post-weaning diarrhea and edema disease in pigs, and peritonitis and airsacculitis in chickens. The different E. coli pathotypes are characterized by the presence of specific sets of virulence-related genes. Therefore, it is not surprising that pathogenic E. coli constitutes a genetically heterogeneous family of bacteria, and they are continuing to evolve. Rapid and accurate molecular methods are critically needed to detect and trace pathogenic E. coli in food and animals. They are also needed for epidemiological investigations to enhance food safety, as well as animal and human health and to minimize the size and geographical extent of outbreaks. The serotype of E. coli strains has traditionally been determined using antisera raised against the >180 different O- (somatic) and 53 H- (flagellar) antigens. However, there are many problems associated with serotyping, including: it is labor-intensive and time consuming; cross reactivity of the antisera with different serogroups occurs; antisera are available only in specialized laboratories; and many strains are non-typeable. Molecular serotyping targeting O-group-specific genes within the E. coli O-antigen gene clusters and genes that are involved in encoding for the different flagellar types offers an improved approach for determining the E. coliO- and H-groups. Furthermore, molecular serotyping can be coupled with determination of specific sets of virulence genes carried by the strain offering the possibility to determine O-group, pathotype, and the pathogenic potential simultaneously. Sequencing of the O-antigen gene clusters of all of the known O-groups of E. coli is now complete, and the sequences have been deposited in the GenBank database. The sequence information has revealed that some E. coli serogroups have identical sequences while others have point mutations or insertion sequences and type as different serogroups in serological reactions. There are also a number of other ambiguities in serotyping that need to be resolved. Furthermore, new E. coli O-groups are being identified. Therefore, there is an essential need to resolve these issues and to revise the E. coli serotype nomenclature based on these findings. There are emerging technologies that can potentially be applied for molecular serotyping and detection and characterization of E. coli. On a related topic, the genome sequence of thousands of E. coli strains have been deposited in GenBank, and this information is revealing unique markers such as CRISPR (clustered regularly interspaced short palindromic repeats) and virulence gene markers that could be used to identify E. coli pathotypes. Whole genome sequencing now provides the opportunity to study the role of horizontal gene transfer in the evolution and emergence of pathogenic E. coli strains. Whole genome sequencing approaches are being investigated for genotyping and outbreak investigation for regulatory and public health needs; however, there is a need for establishing bioinformatics pipelines able to handle large amounts of data as we move toward the use of genetic approaches for non-culture-based detection and characterization of E. coli and for outbreak investigations.

whole genome sequencing --- detection --- pathogenic E. coli --- E. coli characterization --- Molecular serotyping --- Genetic Markers --- subtyping --- outbreak investigation --- Shiga toxin-producing E. coli --- virulence genes

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Pathogenic Escherichia coli strains cause a large number of diseases in humans, including diarrhea, hemorrhagic colitis, hemolytic uremic syndrome, urinary tract infections, and neonatal meningitis, while in animals they cause diseases such as calf scours and mastitis in cattle, post-weaning diarrhea and edema disease in pigs, and peritonitis and airsacculitis in chickens. The different E. coli pathotypes are characterized by the presence of specific sets of virulence-related genes. Therefore, it is not surprising that pathogenic E. coli constitutes a genetically heterogeneous family of bacteria, and they are continuing to evolve. Rapid and accurate molecular methods are critically needed to detect and trace pathogenic E. coli in food and animals. They are also needed for epidemiological investigations to enhance food safety, as well as animal and human health and to minimize the size and geographical extent of outbreaks. The serotype of E. coli strains has traditionally been determined using antisera raised against the >180 different O- (somatic) and 53 H- (flagellar) antigens. However, there are many problems associated with serotyping, including: it is labor-intensive and time consuming; cross reactivity of the antisera with different serogroups occurs; antisera are available only in specialized laboratories; and many strains are non-typeable. Molecular serotyping targeting O-group-specific genes within the E. coli O-antigen gene clusters and genes that are involved in encoding for the different flagellar types offers an improved approach for determining the E. coliO- and H-groups. Furthermore, molecular serotyping can be coupled with determination of specific sets of virulence genes carried by the strain offering the possibility to determine O-group, pathotype, and the pathogenic potential simultaneously. Sequencing of the O-antigen gene clusters of all of the known O-groups of E. coli is now complete, and the sequences have been deposited in the GenBank database. The sequence information has revealed that some E. coli serogroups have identical sequences while others have point mutations or insertion sequences and type as different serogroups in serological reactions. There are also a number of other ambiguities in serotyping that need to be resolved. Furthermore, new E. coli O-groups are being identified. Therefore, there is an essential need to resolve these issues and to revise the E. coli serotype nomenclature based on these findings. There are emerging technologies that can potentially be applied for molecular serotyping and detection and characterization of E. coli. On a related topic, the genome sequence of thousands of E. coli strains have been deposited in GenBank, and this information is revealing unique markers such as CRISPR (clustered regularly interspaced short palindromic repeats) and virulence gene markers that could be used to identify E. coli pathotypes. Whole genome sequencing now provides the opportunity to study the role of horizontal gene transfer in the evolution and emergence of pathogenic E. coli strains. Whole genome sequencing approaches are being investigated for genotyping and outbreak investigation for regulatory and public health needs; however, there is a need for establishing bioinformatics pipelines able to handle large amounts of data as we move toward the use of genetic approaches for non-culture-based detection and characterization of E. coli and for outbreak investigations.

whole genome sequencing --- detection --- pathogenic E. coli --- E. coli characterization --- Molecular serotyping --- Genetic Markers --- subtyping --- outbreak investigation --- Shiga toxin-producing E. coli --- virulence genes

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Un autor crea sus personajes, pero sólo puede ejercer su poder sobre ellos dentro de los límites de su obra. Más allá, en la imaginación de otros escritores, algunos personajes continúan viviendo aventuras. ¿Cómo los reconocemos? ¿Hay unos especialmente proclives a emigrar de una ficción a otra? ¿Dónde radica, en definitiva, su identidad? Los estudios reunidos en este volumen plantean estas y otras preguntas a golems y vampiros ; a Lázaro de Tormes y a Celestina ; al diablo cojuelo, a Gregor Samsa y al comisario Maigret. Unos proceden del patrimonio literario hispánico ; otros se aclimatan en él. El conjunto se cierra con una coda sobre la construcción del personaje en el cine biográfico.

Spanish literature --- Spanish fiction --- Characters and characteristics in literature --- History and criticism. --- History and criticism --- Character sketches --- Characterization (Literature) --- Literary characters --- Literary portraits --- Portraits, Literary --- #KVHA:Literaire kritiek; Spaans --- #KVHA:Personages --- #KVHA:Literaire genres; Spaans

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Challenges in Mechanics of Time-Dependent Materials, Volume 2 of the Proceedings of the 2017 SEM Annual Conference& Exposition on Experimental and Applied Mechanics, the second volume of nine from the Conference, brings together contributions to this important area of research and engineering.  The collection presents early findings and case studies on fundamental and applied aspects of Experimental Mechanics, including papers in the following general technical research areas:  Characterization Across Length Scales Extreme Environments & Environmental Effects Viscoelasticity Structure Function Performance Polymer Viscoplasticity Metallic Materials Fracture/Fatigue/Damage Composites Soft Materials.

Engineering. --- Continuum mechanics. --- Structural mechanics. --- Building materials. --- Materials science. --- Continuum Mechanics and Mechanics of Materials. --- Characterization and Evaluation of Materials. --- Structural Mechanics. --- Building Materials. --- Materials --- Mechanical properties --- Mechanics. --- Mechanics, Applied. --- Surfaces (Physics). --- Building construction. --- Solid Mechanics. --- Classical mechanics --- Newtonian mechanics --- Physics --- Dynamics --- Quantum theory --- Surface chemistry --- Surfaces (Technology) --- Applied mechanics --- Engineering, Mechanical --- Engineering mathematics --- Architectural materials --- Architecture --- Building --- Building supplies --- Buildings --- Construction materials --- Structural materials --- Material science --- Physical sciences --- Solids. --- Characterization and Analytical Technique. --- Analysis. --- Solid state physics --- Transparent solids