1,721,189 research outputs found
Conformational changes of neuromedin B and delta sleep-inducing peptide induced by their interaction with lipid membranes as revealed by spectroscopic techniques and molecular dynamics simulation.
No full textStatic and dynamic spectroscopic properties of the tryptophanil emission in conjunction with circular dichroism (CD) spectroscopy and molecular dynamics are used to investigate the interactions of the neuropeptide neuromedin B (NMB) and the membrane-permeable δ sleep-inducing peptide (DSIP) with the membrane lipid phase. Our data indicate that in solution both peptides exist in energetically equivalent conformations, whereas in the presence of the membrane specific conformational states are stabilized. By changing from the aqueous to the lipid phase, the static and the dynamic fluorescence properties of the NMB's tryptophan residue are clearly affected: the fluorescence steady-state spectrum as well as the resolved fluorescence decay-associated spectra (DAS) are shifted to the blue with a significant increase of the fluorescence intensity of the second lifetime component (τ2-DAS). On the other hand, in the lipid environment the same parameters of DSIP are negligibly affected as compared to the aqueous buffer. The CD and molecular dynamics analyses are consistent with these results and indicate that, while NMB assumes a helix-like conformation with the tryptophan residue in the apolar surface, DSIP adopts a globule-like structure with the indole ring that is surface-exposed. As previously found for neuromedin C (Polverini, E., Neyroz, P., Fariselli, P., Casadio, R., and Masotti, L., Biochem. Biophys. Res. Commun. 214, 663-668, 1995), for NMB the stabilized 'lipophilic' structure also may favor the correct peptide-receptor contact and recognition. For DSIP, the lipid-stabilized conformation does not support an amphiphilic structure-driven peptide-membrane interaction and suggests a hydrophobicity-driven diffusion across the bilayer
Pharmacology of new oral anticoagulants: Mechanism of action, pharmacokinetics, pharmacodynamics
No full textDepurazione naturale e depurazione “impiantistica” nelle piccole comunità
No full textNell'ambito di importanti scadenze legislative che
stanno ormai maturando a livello nazionale, viene
affrontato il tema generale della depurazione delle
acque reflue delle piccole comunità, in una sintesi che
cerca di cogliere aspetti significativi connessi con
varie tecniche di trattamento. Considerazioni
specifiche sono sviluppate sui pretrattamenti, mirati
alla massima semplicità operativa, e sui trattamenti
centralizzati del fango. Elementi di confronto e di
scelta concludono il rapport
Timeresolved fluorescence studies of single-tryptophan containing neuropeptides: evidence of the rotamer model
No full textTime resolved fluorescence studies of small neuropeptides: clues for their membrane interaction modes.
No full textDevelopment of innovative steels and thermo-mechanical treatments for DEMO high operating temperature blanket options
No full textAmong the options currently taken into account for the realization of the first DEMO reactor there are the “helium-cooled” and the “dual coolant” breeding blanket. Therefore the high temperature (650 °C) behavior of the proposed innovative martensitic alloys should be improved, namely the frame of the hereby reported activities is the development of martensitic alloys more resistant to creep, suitable to tolerate such a high operating temperature. In order to improve the high temperature mechanical properties, concerning the alloy design strategies, two alternative routes are proposed; the effect of Nitrogen and Tungsten increase are taken into account as well as the addition of carbo-nitride forming elements, like Vanadium, combined with the “ausforming” thermo-mechanical treatments. Two alloys have been designed and a special thermo-mechanical treatment on Eurofer 97-2 is proposed. The “ausforming” treatment, consisting in a sort of hot-working at a lower temperature with respect to the austenitization one after the austenitization stage, is aimed at the achievement of a beneficial dislocation “pinning” at high temperature due to carbide precipitation. Generally the improvement of tensile properties is associated to the hardening of the steel due to dislocation network and precipitation effects. This hardening is accompanied by a DBTT increase to markedly higher values with respect to Standard Eurofer. The proposed materials should be, in any case, at least room temperature ductile in order to undergo safe manufacturing and assembling processes. Therefore the issue of the DBTT increase has been taken into account by tuning the tempering temperature adequately. The two variations from chemical composition of Eurofer 97 have been casted and the thermo-mechanical treatments have been selected by means of SEM and hardness measurements to tune grain size and precipitation of carbides. The outcomes of the preliminary mechanical characterization (tensile, creep and impact tests) will be discussed in this paper. © 201
Wastewater Polishing Index: a tool for a rapid quality assessment of reclaimed wastewater
No full textA new index, the Wastewater Polishing Index (WW.P.I.), has been defined for the rapid assessment of the quality achieved by different polishing treatments for water discharged into surface water bodies and for reuse purposes. The index is defined by a weighted average of six parameters (SS, BOD5 COD, ammonia, total phosphorus and E. coli), each transformed onto a sub-index scaled from 0 to 100. E. coli has been assigned a greater weight than the other indicators. The index is equal to 0 if none of the six pollutants are present in the effluent and to 100 when all six parameters equal their corresponding Italian legal limits for discharge into surface water bodies. When all 6 of them equal their corresponding Italian legal limits for reuse, the WW.P.I. is 36.
The index has been validated and tested on a pilot plant including a rapid sand filtration, a slow filtration through a horizontal subsurface flow system and a lagooning, in addition to their combinations. The experimental investigation showed that the index is a good tool for (i) rapidly comparing the water quality achieved by different treatment sequences, particularly natural systems; (ii) rapidly evaluating whether the proposed sequence is able to produce an effluent adequate for reuse and (iii) rapidly evaluating the water quality improvement achieved by different systems.
The proposed index could be of great help for managers and decision makers when planning for water resources, in particular, for comparing the quality level achieved by different wastewater treatment sequences
New receiving water body foe a large WWTP in a sensitive area in Northern Italy: refitting with natural systems and water reuse
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