Search results for "GRI"
showing 10 items of 10209 documents
Prediction models based on soil properties for evaluating the uptake of eight heavy metals by tomato plant (Lycopersicon esculentum Mill.) grown in a…
2021
The aim of this study is to design de novo prediction models in order to gauge the likely uptake of eight heavy metals (Al, Cr, Cu, Fe, Mn, Ni, Pb and Zn) by Lycopersicon esculentum, the tomato plant. Uptake was assessed within the plant’s root, stem, leaf and fruit tissues, respectively. The plant was cultivated in soil amended by different application rates of sewage sludge, i.e. 0, 10, 20, 30 and 40 g/kg. The roots exhibited markedly elevated heavy metal concentrations compared to the above-ground plant components, with the exception of the quantity of Ni in the leaves. Apart from Al, Fe and Mn, a bioconcentration factor >1 was identified for all heavy metals. Excluding Ni in the leaves,…
Silver Oxide Mediated Monotosylation of Poly(ethylene glycol) (PEG): Heterobifunctional PEG via Polymer Desymmetrization
2017
Heterobifunctional poly(ethylene glycol)s (PEGs) are key structures for bioconjugation in the context of the “PEGylation” strategy to enhance blood circulation times of, for example, peptide drugs or “stealth” liposomes. The formation of heterobifunctional PEGs from symmetric PEG diols is challenging because of limited yields of the targeted monofunctional product and difficulties associated with separation steps. On the basis of a detailed comparison of reaction conditions, we have investigated a “polymer desymmetrization” strategy to maximize the yields of monofunctional PEG tosylate. The tosylation reaction in the presence of the heterogeneous catalyst silver oxide and potassium iodide i…
Characterization and biodistribution of Au nanoparticles loaded in PLGA nanocarriers using an original encapsulation process
2021
Due to their imaging and radiosensitizing properties, ultrasmall gadolinium chelate-coated gold nanoparticles (AuNP) represent a promising approach in the diagnosis and the treatment of tumors. However, their poor pharmacokinetic profile, especially their rapid renal clearance prevents from an efficient exploitation of their potential for medical applications. The present study focuses on a strategy which resides in the encapsulation of AuNP in large polymeric NP to avoid the glomerular filtration and then to prolong the vascular residence time. An original encapsulation procedure using the polyethyleneimine (PEI) was set up to electrostatically entrap AuNP in biodegradable poly(lactic-co-g…
Aggregation Behavior of Polystyrene-Nanoparticles in Human Blood Serum and its Impact on the in vivo Distribution in Mice
2014
The interactions between nanoparticles (NPs) and proteins in complex biological application media such as blood serum are capable of inducing aggregate formation which can lead to subsequent changes in biological activity. Here, we correlate surface charge, aggregation-tendency, and surface serum protein adsorption with cellular uptake and biodistribution in mice. Polystyrene-based NPs (80 - 170 nm) with different surface functionalizations were synthesized and incubated with human serum. Interaction of NPs with serum proteins and aggregate formation were analyzed by mass spectrometryanalysis and dynamic light-scattering. Influence of surface functionalization on specific cellular uptake an…
In vivo biodistribution and lifetime analysis of cy5.5-conjugated rituximab in mice bearing lymphoid tumor xenograft using time-domain near-infrared …
2008
Rituximab is a chimeric monoclonal antibody directed against human CD20 antigen, which is expressed on B-cell lymphocytes and on the majority of B-cell lymphoid malignancies. Herein we report the conjugate of rituximab with the near-infrared (NIR) fluorophore Cy5.5 (RI-Cy5.5) as a tool for in vitro, in vivo, and ex vivo NIR time-domain (TD) optical imaging. In vitro, RI-Cy5.5 retained biologic activity and led to elevated cell-associated fluorescence on tumor cells. In vivo, TD optical imaging analysis of RI-Cy5.5 injected into lymphoma-bearing mice revealed a slow tumor uptake and a specific long-lasting persistence of the probe within the tumor. Biodistribution studies after intraperiton…
Hot spots, indicator taxa, complementarity and optimal networks of taiga
2000
If hot spots for different taxa coincide, priority-setting surveys in a region could be carried out more cheaply by focusing on indicator taxa. Several previous studies show that hot spots of different taxa rarely coincide. However, in tropical areas indicator taxa may be used in selecting complementary networks to represent biodiversity as a whole. We studied beetles (Coleoptera), Heteroptera, polypores or bracket fungi (Polyporaceae) and vascular plants of old growth boreal taiga forests. Optimal networks for Heteroptera maximized the high overall species richness of beetles and vascular plants, but these networks were least favourable options for polypores. Polypores are an important gro…
Mapping and determinism of soil microbial community distribution across an agricultural landscape.
2015
Article en open access; International audience; Despite the relevance of landscape, regarding the spatial patterning of microbial communities and the relative influence of environmental parameters versus human activities, few investigations have been conducted at this scale. Here, we used a systematic grid to characterize the distribution of soil microbial communities at 278 sites across a monitored agricultural landscape of 13km(2). Molecular microbial biomass was estimated by soil DNA recovery and bacterial diversity by 16S rRNA gene pyrosequencing. Geostatistics provided the first maps of microbial community at this scale and revealed a heterogeneous but spatially structured distribution…
Flora e vegetazione della Valle di Castro e di Monte Barraù (Sicilia centro-occidentale)
2015
I paesaggi agricoli tradizionali sono l’espressione più significativa del rapporto tra attività umane e processi naturali. Essi sono il luogo dove, attraverso una gestione consapevole delle risorse, si è conservata nel tempo la biodiversità così come oggi la conosciamo. Nel presente contributo si riportano i risultati di uno studio condotto in un’area rurale dei Monti Sicani settentrionali compresa tra Corleone e Campofiorito (Palermo) di proprietà della società Bona Furtuna LLC che, a partire dall’autunno 2014, ha sostenuto lo studio della flora e della vegetazione finalizzato alla valorizzazione di “piante autoctone” di potenziale interesse aromatico e medicinale.
Cost-benefit analysis: A comparison between conventional and organic olive growing in the Mediterranean Area
2015
The conversion from conventional to organic management of olive growing has many benefits, such as increase of biodiversity, reduction of soil erosion and lower environmental impact. Since olive represents a main crop in the Mediterranean area, from a social, economic as well as environmental point of view, the aim of this paper has been to determine if the conversion from conventional to organic olive growing can increase the profitability of the farmer in Sicilian farms. Economic analysis has been carried out by means of cost-benefit analysis and financial indicators (NPV, B0/C0, IRR) show that organic growing would allow a better profitability for organic olive farms respect to conventio…
Impact des digestats de méthanisation sur la qualité biologique des sols agricoles : nécessité de générer de nouvelles données pour objectiver
2021
National audience; La méthanisation est une technologie basée sur la dégradation par des micro-organismes de la matière organique, en conditions contrôlées et en l'absence dioxygène. Cette dégradation aboutit à la production d'un biogaz utilisé comme énergie renouvelable et d'un co-produit riche en matière organique appelé digestat. Ce digestat est au cœur de nombreuses interrogations, concernant les impacts engendrés par son épandage sur les sols. Avec l'essor de la méthanisation, la recherche s'intéresse à ses effets, afin de conserver des sols de qualité.