Добірка наукової літератури з теми "Mousse de biomasse"

Anthropogenic water sources (AWS) are developed water sources used as a management tool for desert wildlife species. Studies documenting the effects of AWS are often focused on game species; whereas, the effects on non-target wildlife are less understood. We used live trapping techniques to investigate rodent abundance, biomass, and diversity metrics near AWS and paired control sites; we sampled vegetation to determine rodent-habitat associations in the Sauceda Mountains of the Sonoran Desert in Arizona. A total of 370 individual mammals representing three genera and eight species were captured in 4,800 trap nights from winter 2011 to spring 2012. A multi-response permutation procedure was used to identify differences in small mammal community abundance and biomass by season and treatment. Rodent abundance, biomass, and richness were greater at AWS compared to control sites. Patterns of abundance and biomass were driven by the desert pocket mouse (Chaetodipus penicillatus) which was the most common capture and two times more numerous at AWS compared to controls. Vegetation characteristics, explored using principal components analysis, were similar between AWS and controls. Two species that prefer vegetation structure, Bailey’s pocket mouse (C. baileyi) and white-throated woodrat (Neotoma albigula), had greater abundances and biomass near AWS and were associated with habitat having high cactus density. Although small mammals do not drink free-water, perhaps higher abundances of some species of desert rodents at AWS could be related to artificial structure associated with construction or other resources. Compared to the 30-year average of precipitation for the area, the period of our study occurred during a dry winter. During dry periods, perhaps AWS provide resources to rodents related to moisture.

In the present study, the cytotoxicity and the antimicrobial activity of two silver citrate-based irrigant solutions were investigated. Cytotoxicity of various concentrations (0.25%, 0.5%, 1%, 2.5%, 5%) of both solutions (BioAKT and BioAKT Endo) was assessed on L-929 mouse fibroblasts using the MTT assay. For the quantitative analysis of components, an infrared (I.R.) spectroscopy was performed. The minimum inhibitory and minimal bactericidal concentrations (M.I.C. and M.B.C., respectively) were ascertained on Enterococcus faecalis strain ATCC 4083. For biofilm susceptibility after treatment with the irrigating agent, a minimum biofilm eradication concentration (M.B.E.C.) and confocal laser scanning microscope (C.L.S.M.) assays were performed. Quantification of E. faecalis cell biomass and percentage of live and dead cells in the biomass was appraised. Normality of data was analyzed using the D’Agostino & Pearson’s test and the Shapiro–Wilk test. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey’s test. Both silver citrate solutions showed mouse fibroblasts viability >70% when diluted to 0.25% and 0.5%. Conversely, at higher concentrations, they were extremely cytotoxic. F.T.-IR spectroscopy measurements of both liquids showed the same spectra, indicating similar chemical characteristics. No substantial contrast in antimicrobial activity was observed among the two silver citrate solutions by using broth microdilution methods, biofilm susceptibility (MBEC-HTP device), and biomass screening using confocal laser scanning microscopy (C.L.S.M.) technique. Both solutions, used as root canal irrigants, exhibited significant antimicrobial activity and low cytocompatibility at dilutions greater than 0.5%.

Transfer by mobilization of a pBR derivative recombinant plasmid lacking transfer functions (oriT+, tra−, mob−) from one E. coli K12 strain to another was investigated in seven sterile microcosms corresponding to different environments. These microcosms were chosen as representative of environments that genetically engineered microorganisms (GEMOs) encounter after accidental release, namely attached biomass in aquatic environments (biofilm), soil, seawater, freshwater, wastewater, mouse gut, and mussel gut. GEMOs survived in the same way as the host strains in all microcosms. Recombinant DNA mobilization occurred in the mouse gut, in sterile soil, and in biofilm. The plasmid transfer rates principally reflected the environmental conditions encountered in each microcosm.Key words: recombinant DNA, plasmid transfer, mobilization, conjugation, microcosm.

The present study represents an investigation of a novel stirred bioreactor for culture of a transformed cell line under defined hydrodynamic conditions in vitro. Cell colonies of the EL-4 mouse lymphoma cell line grown for the first time in a rotating disc bioreactor (RDB), were observed to undergo changes in phenotype in comparison to standard, static flask cultures. RDB cultures, with or without agitation, promoted the formation of adherent EL-4 cell plaques that merged to form contiguous tumor-like masses in longer-term cultures, unlike the unattached spheroid aggregates of flask cultures. Plaques grown under agitated conditions were further altered in morphology and distribution in direct response to fluid mechanical stimuli. Plaque colonies growth in RDBs with or without agitation also exhibited significant increases in production of interleukin-4 (IL-4) and lactate, suggesting an inducible “Warburg effect.” Increases in cell biomass in RDB cultures were no different to flask cultures, though a trend toward a marginal increase was observed at specific rotational speeds. The RDB may therefore be a suitable alternative method to study mechanisms of tumor progression and invasiveness in vitro, under more complex physicochemical conditions that may approximate natural tissue environments.

In addition to the previously developed recombinant modified human glucagon-like peptide 1 (rmglp1, Glypin), a recombinant modified human glucose-dependent insulinotropic peptide (RMGIP) has been obtained. A new universal reverse-phase HPLC technique has been proposed allowing quantitative analysis of rmGlp1 and rmGip separately and as part of a two-component preparation. The data show that the design of recombinant human rmGip according to the Glypine formula makes it possible to produce one-component and two-component preparations containing various rmGip and rmGlp1 protein ratios ranging from 1:0 to 20:1, using cell biomass samples mixed in predetermined proportions. Studies of human rmGip activity in a mouse model revealed reduced specific activity and signs of weak antagonistic effects. In this regard, there is a need for further study of human rmGip activity in a mouse model, including the use of alternative mouse or rat rmGip. type 2 diabetes mellitus; two-component drug, glucose-dependent insulinotropic peptide, glucagon-like peptide-1 The work was supported by the Internal Grant from National Research Center Kurchatov Institute.

We examined the flow of mercury (Hg) from benthic invertebrates to fishes in lakes with contrasting fish community structure. The study was carried out in two whole lakes in southcentral Ontario in 1992. Both were remote from direct sources of contamination and were chosen because of their physical and chemical similarities. Although the fish communities in the two lakes were qualitatively similar, the total number of fishes in Ranger Lake was an order of magnitude smaller than that in Mouse Lake. As a result of the lower net predation from benthivorous fishes, documented in earlier studies, Ranger Lake benthic invertebrate populations were significantly higher. However, benthic invertebrate taxa in Mouse Lake were generally larger and had higher Hg concentrations. This was partly attributed to the stunted growth of Mouse Lake fishes, which did not allow them to prey on larger benthos as a result of gape limitations. Despite the lower Hg concentrations in Ranger Lake benthos, total benthic invertebrate Hg pools were higher in this lake as a result of its higher total benthic invertebrate biomass. However, the transfer of total Hg from benthic invertebrates to fishes was higher in Mouse Lake due to the higher consumption rates of benthivorous fishes.

The respiratory tract has a resident microbiome with low biomass and limited diversity. This results in difficulties with sample preparation for sequencing due to uneven bacteria-to-host DNA ratio, especially for small tissue samples such as mouse lungs. We compared effectiveness of current procedures used for DNA extraction in microbiome studies. Bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected to test different forms of sample pre-treatment and extraction methods to increase bacterial DNA yield and optimize library preparation. DNA extraction using a pre-treatment method of mechanical lysis (lung tissue) and one-step centrifugation (BALF) increased DNA yield and bacterial content of samples. In contrast, a significant increase of environmental contamination was detected after phenol chloroform isoamyl alcohol (PCI) extraction and nested PCR. While PCI has been a standard procedure used in microbiome studies, our data suggests that it is not efficient for DNA extraction of frozen low biomass samples. Finally, a DNA Enrichment kit was tested and found to improve the 16S copy number of lung tissue with a minor shift in microbial composition. Overall, we present a standardized method to provide high yielding DNA and improve sequencing coverage of low microbial biomass frozen samples with minimal contamination.

Abstract Mucus hypersecretion is a pathological feature of acute inflammatory and chronic obstructive pulmonary diseases. Exposure to air pollutants can be a cause of pathological mucus overproduction, but mechanisms by which different forms of air pollutants elicit this response are not fully understood. In this study, particulate matter (PM) generated from burning pine wood and other types of biomass was used to determine mechanisms by which these forms of PM stimulate mucin gene expression and secretion by primary human bronchial epithelial cells (HBECs). Biomass PM < 2.5 μm generated from pine wood and several other fuels stimulated the expression and secretion of the gel-forming glycoprotein MUC5AC by HBECs. Muc5ac gene induction was also observed in mouse airways following subacute oropharyngeal delivery of pine wood smoke PM. In HBECs, MUC5AC was also induced by the transient receptor potential ankyrin-1 (TRPA1) agonists’ coniferaldehyde, a component of pine smoke PM, and allyl isothiocyanate, and was attenuated by a TRPA1 antagonist. Additionally, inhibition of epidermal growth factor receptor (EGFR/ErbB1) and the EGFR signaling partners p38 MAPK and GSK3β also prevented MUC5AC overexpression. Collectively, our results suggest that activation of TRPA1 and EGFR, paired with alterations to p38 MAPK and GSK3β activity, plays a major role in MUC5AC overproduction by bronchial epithelial cells exposed to biomass smoke PM. These results reveal specific processes for how biomass smoke PM may impact the human respiratory system and highlight potential avenues for therapeutic manipulation of lung diseases that are affected by air pollutants.

The diet of the Common Kestrel in the urban environment of the city of Nitra The diet of the urban Common Kestrel population was studied in Nitra during 2003-2005. Totally, 671 prey items were identified by the analysis of pellets and prey remains collected under the nesting sites. Insect, mainly represented by order Coleoptera, was found to be the most abundant prey. Regarding biomass, the Common Vole (Microtus arvalis) was predominated. In comparison with other articles published, the studied sample was rather rich in the Lesser White-toothed Shrew (Crocidura suaveolens) and the House Mouse (Mus cf. musculus).

Cette recherche s'est concentrée sur les bioressources, notamment le tanin, la lignine, les protéines de soja, les humines, pour préparer des adhésifs et des mousses à base de bois bio. Il y a quatre parties principales, dont deux types de préparation de colles à bois en utilisant des bio-ressources, à savoir les colles à bois NIPU biosourcées et les colles à bois biosourcées (tanin, SPI et lignine) sans formaldéhyde toxique ; deux types de produits de mousse de tanin, c'est-à-dire une mousse de tanin-furanique typique et des mousses de polyuréthane sans isocyanate. (1) Les humines commerciales, l'isolement de protéines de soja (SPI) et le tanin de mimosa ont été utilisés pour préparer des adhésifs pour bois, basés sur la formulation de polyuréthanes non-isocyanates (NIPU). Les propriétés de base des adhésifs ont été déterminées. Des techniques telles que MALDI-ToF et FTIR ont été utilisées pour détecter les produits obtenus et pour analyser les mécanismes réactionnels impliqués. Une analyse thermomécanique (TMA) a été utilisée pour étudier le comportement thermique des adhésifs. Enfin, des contreplaqués ou des panneaux de particules de laboratoire ont été préparés pour évaluer les performances de collage des adhésifs. (2) Un nouvel adhésif pour bois à base de biomasse a été préparé avec un extrait de tanin de mimosa commercial et de l'éther diglycidylique de glycérol (GDE) par mélange mécanique pratique. Le GDE a servi d'agent de réticulation du tanin sans aucune addition d'aldéhyde, produisant des réseaux tridimensionnels durcis. Différents rapports pondéraux tanin/GDE ont été étudiés par plusieurs techniques pour déterminer leur influence sur les propriétés finales. Deux types d'adhésifs à base de lignine ont été préparés, c'est-à-dire (ⅰ) la lignine modifiée au glyoxal et l'amidon dialdéhyde réticulé par l'urée; (ⅱ) oxydation du periodate en deux étapes. Les espèces moléculaires formées et le mécanisme réactionnel impliqué ont été déterminés par FT-IR, RMN 13C et spectrométrie de masse MALDI-ToF. Les adhésifs basés sur cette réaction ont été testés par collage de contreplaqué ou de panneaux de particules de laboratoire, par calorimétrie différentielle à balayage (DSC) et analyse thermomécanique (TMA).(3) Une mousse rigide de polyuréthane sans isocyanate (NIPU) à base de tanin a été obtenue. Le mélange d'acide citrique et de glutaraldéhyde a servi d'agent d'expansion et de réticulation utilisé pour fournir de l'énergie moussante et réticuler la résine à base de tanin pour préparer les mousses NIPU. Le mécanisme de réaction des mousses NIPU à base de tanin a été étudié par FT-IR, MALDI-TOF et 13C RMN. De plus, le tanin a également été utilisé comme ignifuge naturel pour améliorer les propriétés finales des mousses NIPU à base de glucose, y compris la résistance au feu et la résistance à la compression. (4) Un déchet de bioraffinerie, des humines et un insolat de protéine de soja (SPI) ont été sélectionnés comme agents de réticulation biosourcés de substitution du formaldéhyde pour deux types de formulations de mousse à base de tanin. Comme attendu, les propriétés ont été améliorées en utilisant ces réticulants biosourcés. Les propriétés de base des mousses de tanin en série ont été étudiées. Les caractéristiques de morphologie et de structure ont été observées par microscopie électronique à balayage (MEB). De plus, les mécanismes de réaction de réticulation entre le tanin avec les deux réticulants bio-sourcés, à savoir les humines et le SPI, ont été déterminés par spectrométrie MALDE-ToF et FTIR. Enfin, la stabilité thermique, les propriétés mécaniques, le caractère ignifuge et l'émission de formaldéhyde ont été évalués par les techniques appropriées
This research was focus on bioresources, including tannin, lignin, soybean protein, humins, to prepare bio-based wood adhesives and foams. There are four main parts, including two kinds of wood adhesives preparation by using bio-resources, i.e., bio-sourced NIPU wood adhesives and bio-based (tannin, SPI, and lignin) wood adhesives without toxic formaldehyde; two kinds of tannin-foam products, i.e., typical tannin-furanic foam and non-isocyanate polyurethane foams. (1) Commercial humins, soybean protein isolation (SPI), and mimosa tannin have been utilized to prepare wood adhesives, based on the formulation of non-isocyanate polyurethanes (NIPU). The basic properties of the adhesives were determined. Techniques such as MALDI-ToF and FTIR were used to detect the products obtained and for analyzing the reaction mechanisms involved. Thermomechanical analysis (TMA) was utilized to investigate the thermal behavior of the adhesives. Finally, the laboratory plywood or particleboard were prepared for evaluating the bonding performances of adhesives. (2) A novel biomass-based wood adhesive was prepared with commercial mimosa tannin extract and glycerol diglycidyl ether (GOE) by convenient mechanical mixing. GOE served as the crosslinker of the tannin without any aldehyde addition yielding hardened three­dimensional networks. Oifferent weight ratios of tannin/GOE were investigated by several techniques to determine their influence on final properties. Two kinds of lignin-based adhesives were prepared, i.e., ( i ) glyoxal modified lignin and dialdehyde starch cross-linked by urea; ( ii ) periodate oxidation by two-steps. The molecular species formed and the reactions mechanism involved were determined by FT-IR, 13C NMR and MALDI-ToF mass spectrometry. The adhesives based on this reaction were tested by bonding laboratory plywood or particleboard, by differential scanning calorimetry (DSC), and thermomechanical analysis (TMA). (3) A tannin-based non-isocyanate polyurethane (NIPU) rigid foam was obtained. Citric acid and glutaraldehyde mixture served as a blowing and crosslinker agent used to provide foaming energy and cross-link the tannin-based resin to prepare the NIPU foams. The reaction mechanism of the tannin-based NIPU foams were investigated by FT-IR, MALDI-TOF, and 13C NMR. Additionally, tannin was also used as a natural tire-retardant to improve the final properties of glucose-­based NIPU foams, including fire retardancy and compression strength. (4) A biorefinery waste, humins, and soybean protein insolate (SPI) were selected as formaldehyde substitute bio-sourced crosslinkers for two kinds of tannin-based foam formulations. As expected, the properties were improved by using these bio-sourced crosslinkers. The basic properties of series tannin foams were investigated. The morphology and structure characteristics were observed by scanning electron microscopy (SEM). Additionally, the crosslinking reaction mechanisms between tannin with the two bio-sourced crosslinkers, i.e., humins and SPI, were determined by MALDE-ToF and FTIR spectrometry. Finally, the thermal stability, mechanical properties, fire retardancy and formaldehyde emission were evaluated by the relevant techniques

Le projet Européen UNIfHY a vu le jour dans une optique de production d’hydrogène à partir de biomasse pour le remplacement des énergies fossiles. La purification des gaz produits par la gazéification de la biomasse permet l’obtention d’hydrogène pur pour une utilisation dans les piles à combustible. Cette thèse s’inscrit dans ce projet avec pour but le développement de catalyseurs Fe/CeO2 et Cu/CeO2 déposés sur des supports de mousse céramique pour la réaction de conversion du gaz à l’eau à haute et basse températures, de manière à augmenter la production d’hydrogène et diminuer la perte de charge dans le système. Les principaux objectifs de la thèse sont la synthèse et les caractérisations des catalyseurs à base de fer et de cuivre, l’optimisation des conditions réactionnelles dans la limite du cadre fixé par le projet, la modélisation cinétique en présence des catalyseurs Fe/CeO2 et Cu/CeO2 et la transposition à grande échelle des catalyseurs pour une utilisation en réacteur pilote
The UNIfHY European project was launched in an optic of producing hydrogen from biomass to replace fossil fuels. Purification of gases produced by biomass gasification allows obtaining pure hydrogen which can be used in fuel cells. This thesis takes part in this project with the development of Fe/CeO2 and Cu/CeO2 catalysts deposited on ceramic foam supports for high temperature and low temperature water gas shift reaction to increase the production of hydrogen and decrease the pressure drop in the system. The main objectives of this thesis are the synthesis and characterizations of iron and copper based catalysts, the optimization of reaction conditions within the limits of the framework set by the project, the kinetic modeling of the reaction in the presence of Fe/CeO2 and Cu/CeO2 catalysts and the scale-up of catalysts to use them in a pilot reactor