Search results for "PC"
showing 10 items of 2805 documents
Polychlorinated Biphenyls in Sediments from Sicilian Coastal Area (Scoglitti) using Automated Soxhlet, GC-MS, and Principal Component Analysis
2014
A methodology for the PAHs and PCBs congener determination in sediment samples has been revised. We determined the distributions of PAHs and PCBs in the superficial sediments of the Scoglitti (Italy) coastal area to provide data for comparison with other marine systems and to hypothesize the sources. Extraction yield, for PCB, was never less than 60% in most cases, while for PAHs, utilizing perdeuterated surrogate standard (benz[a]anthracene-d12 and anthracene-d10) was never less than 72%. The total concentration of the 16 PAHs investigated, expressed as the sum of concentrations, PAHs, varied from 1–5087 μg/kg of dry matrix, while the PCBs ranged from detection limit to 36 μg/kg of dry mat…
Estimation of the density of the protocatechuate-degrading bacterial community in soil by real-time PCR
2008
Summary The β-ketoadipate pathway is the major route for degradation of aromatic compounds by various soil microorganisms. Protocatechuate 3,4-dioxygenase, a key enzyme of this pathway and which is encoded by pcaGH genes, catalyses the ring cleavage of protocatechuate. Microorganisms harbouring pcaGH genes are widely distributed in the environment but little is known about their relative abundance within the total microflora. Hence, this paper reports the development of a real-time PCR assay to quantify the bacterial pcaH sequence that encodes the β sub-unit of the protocatechuate 3,4-dioxygenase. This real-time PCR assay was linear over seven orders of magnitude with a calculated efficienc…
Functional Nanohybrids Based on Dyes and Upconversion Nanoparticles
2020
Upconversion nanoparticles (UCNPs) and dyes are combined to make nanohybrid systems, which take advantage of the synergic relationship between lanthanide (Ln)-based UCNPs and dyes. Ln-UCNPs are inorganic nanophosphors which absorb NIR light and emit narrow emission bands in the UV-NIR region with long luminescence lifetimes. These unique properties, when coordinated properly with dyes of the appropriate photophysical features, produce nanosystems with new photophysical properties. In this context, the UCNP-dye nanohybrids are very promising for potential sensing (ions and biomolecules) and theragnosis (imaging and therapy, e.g. photodynamic therapy).
Polymer mechanical recycling: downcycling or upcycling?
2004
Recycled plastics are considered as materials with physical, mechanical and aesthetic properties worse than the virgin ones. In fact, this is true because degradation during lifetime and during the recycling operations changes the structure and the morphology of the polymers and then the final properties of the secondary material. Several “strategies” are under investigation, and in some cases also applied, in order to avoid further degradation during recycling and, if possible, to repair the macromolecules broken during lifetime and then to restore or to improve the initial properties. In this paper the more important techniques, already used in industry or under investigation, according …
Soil solarization with biodegradabile materials and its impact on soil microbial communities.
2008
Soil solarization (SS) seems one of the most promising techniques to control soilborne pathogens, but an important limitation to the diffusion of this technique is due to the drawback regarding the disposal of the used plastic materials. A possible solution to this problem is the use of biodegradable plastics. The aim of this study was compare the impact of SS with biodegradable materials with SS with plastic film and others pest management techniques (i.e. organic matter amendment, calcium cyanamide and Dazomet fungicide application) on crop productivity, soilborne disease incidence, weed suppression, and soil chemical (total N, ammonium, nitrate, available phosphorus, organic matter, hydr…
Glycoproteins In Large And Small Airways And In Lung Parenchyma Of COPD Patients
2011
Membrane-Perturbing Activities of KL4-Related Surfactant Peptides
2013
KL4 is a 21-residue peptide proposed as a potential substitute of pulmonary surfactant protein SP-B in synthetic surfactants, intended for the treatment of respiratory pathologies. The peptide, composed by leucines interrupted by lysine every four residues, was synthesized to simulate C-terminal amphipathic helical segments of SP-B. Once incorporated into lipid-protein complexes, KL4 promotes formation of interfacial films that produce and maintain surface tensions below 5 mN/m during compression-expansion cycling. Although KL4 was designed as an amphipathic helix at the membrane surface, the data on orientation and interactions of the peptide in membranes are contradictory. In the present …
Cucurbit[n]uril-capped upconversion nanoparticles as highly emissive scaffolds for energy acceptors.
2015
Spontaneous adsorption of cucurbit[n]uril CB[n] (n = 6, 7, and 8) on the surface of naked upconversion nanoparticles (UCNPs), in particular, NaYF4:Er3+(2%),Yb3+(18%) gave rise to UCNP@CB[n] exclusion complexes. These complexes proved to be highly stable as well as highly emissive under near-infrared excitation. By using two tricyclic basic dyes (specifically, methylene blue and pyronin Y) as a proof of concept, we demonstrate that the UCNP@CB[n] (n = 6, 7) nanohybrids can form exclusion complexes with this type of dyes via the CB carbonyl free portal, i.e., UCNP@CB@dye hybrids, thus making it possible to locate a high concentration of the dyes close to the UCNP and, consequently, leading to…
Les enfants difficiles à table : conceptualisation et évolution
2022
L'objectif du présent article est de proposer un état des lieux des études récentes permettant d'offrir un cadre conceptuel et opérationnel au concept de comportement difficile à table, tout en mettant en lumière les conséquences psychologiques pour l'enfant, ainsi que les pratiques éducatives parentales associées. L'article ambitionne aussi de déterminer dans quelle mesure un enfant difficile est un mangeur à risque de développer ultérieurement des troubles du comportement alimentaire (anorexie mentale, ARFID), et quelles seraient les pistes à privilégier, en termes de guidance parentale, pour accompagner l'enfant.