Search results for "Aggregation"
showing 10 items of 566 documents
A BoD Composite Indicator to Measure the Italian “Sole 24 Ore” Quality of Life
2023
The measure of Quality of Life (QoL) is still a topic widely discussed in literature. In Italy, the newspaper “Il Sole 24 Ore” publishes a famous ranking that highlights strong disparities among provinces. In this paper, “Il Sole 24 Ore” and BoD-DEA methods are compared in order to show how different types of normaliza- tion and aggregation significantly influence the results making these rankings very fragile and questionable.
Dibenzocycloheptatriene as end-group of Thiele and tetrabenzo-Chichibabin hydrocarbons
2020
The authors are grateful for the financial support from: MICIU/FEDER/AEI, Spain (PG2018-101181-B-I00, PGC2018-095808B-I00, MAT2016-80826-R, FIP-2018-HECTIC-PTM, Prometeo2019/076 and the "Severo Ochoa" Programme for Centres of Excellence in R & D; SEV-2015-0496), the European Research Council (ERC) (677023), DGR (Catalunya) (2017-SGR-918), and SNSF (Switzerland, TS., PZ00P2_174175). We thank the CSIRC-Alhambra and SciCore (Basel, Switzerland) for supercomputing facilities and the Servei de RMN, UAB, for instrument time.
Structure, stability, and fragmentation of sodium bis(2-ethylhexyl)sulfosuccinate negatively charged aggregates in vacuo by MD simulations.
2014
Negatively charged supramolecular aggregates formed in vacuo by n bis(2-ethylhexyl)sulfosuccinate (AOT(-)) anions and n + n(c) sodium counterions (i.e., [AOT(n) Na(n+nc)](nc)) have been investigated by molecular dynamics (MD) simulations for n = 1 to 20 and n(c) = -1 to -5. By comparing the maximum excess charge values of negatively and positively charged AOTNa aggregates, it is found that the charge storage capability is higher for the latter systems, the difference decreasing as the aggregation number increases. Statistical analysis of physical properties like gyration radii and moment of inertia tensors of aggregates provides detailed information on their structural properties. Even for …
Entrapment of amino acids in gas phase surfactant assemblies: The case of tryptophan confined in positively charged (1R,2S)-dodecyl (2-hydroxy-1-meth…
2017
The ability of positively charged aggregates of the surfactant (1R,2S)‐dodecyl (2‐hydroxy‐1‐methyl‐2‐phenylethyl))dimethylammonium bromide (DMEB) to incorporate D-tryptophan or L-tryptophan in the gas phase has been investigated by electrospray ion mobility mass spectrometry (ESIâIMâMS). Strongly impacted by the pH of the electrosprayed solutions, both protonated (T+) and deprotonated (T-) tryptophan are effectively included into the aggregates, whereas, tryptophan in zwitterionic (T0) form is practically absent in singly charged DMEB aggregates but can be found in multiply charged ones. The ability to incorporate tryptophan increases with the aggregation number and charge state of aggr…
Effect of T-R conformational change on sickle-cell hemoglobin interactions and aggregation
2004
We compare the role of a conformational switch and that of a point mutation in the thermodynamic stability of a protein solution and in the consequent propensity toward aggregation. We study sickle-cell hemoglobin (HbS), the beta6 Glu-Val point mutant of adult human hemoglobin (HbA), in its R (CO-liganded) conformation, and compare its aggregation properties to those of both HbS and HbA in their T (unliganded) conformation. Static and dynamic light scattering measurements performed for various hemoglobin concentrations showed critical divergences with mean field exponents as temperature was increased. This allowed determining spinodal data points T(S)(c) by extrapolation. These points were …
Stochastic model for the epitaxial growth of two-dimensional islands in the submonolayer regime
2016
The diffusion-based growth of islands composed of clusters of metal atoms on a substrate is considered in the aggregation regime. A stochastic approach is proposed to describe the dynamics of island growth based on a Langevin equation with multiplicative noise. The distribution of island sizes, obtained as a solution of the corresponding Fokker-Planck equation, is derived. The time-dependence of island growth on its fractal dimension is analysed. The effect of mobility of the small islands on the growth of large islands is considered. Numerical simulations are in a good agreement with theoretical results.
Studies on DNA interaction of organotin(IV) complexes of meso-tetra(4-sulfonatophenyl)porphine that show cellular activity.
2016
PubMedID: 27393277 The interaction of the diorgano- and triorganotin(IV) derivatives of meso-tetra-(4-sulfonatophenyl)porphine (Me2Sn)2TPPS, (Bu2Sn)2TPPS, (Me3Sn)4TPPS and (Bu3Sn)4TPPS to natural DNA was analysed (together with free meso-tetra-(4-sulfonatophenyl)porphine (TPPS4 -) for comparison purposes). Particular attention was paid to (Bu3Sn)4TPPS, a species that shows significant cellular action. Preliminary tests were done on the solution properties of the organotin(IV) compounds (pKA and possible self-aggregation). Spectrophotometric and spectrofluorometric experiments showed that all the investigated organotin(IV) derivatives strongly interact with DNA, the binding energy depending …
Effect of structural engineering of π-spacers on anti-aggregation of D–A–π–A dyes
2019
In this paper, the encapsulated insulated molecular wire (EIMW) and 2′,7′-bis(hexyloxy)spiro[cyclopenta[2,1-b:3,4-b′]dithiophene-4,9′-fluorene] (SPDF) were specifically designed as efficient anti-aggregation π-bridges for two novel D–A–π–A metal-free sensitizers (IBT1 and IBT2). Compared with the reference dye IBT3 with 3,3′-dihexyl-2,2′-bithiophene (DHBT) as an anti-aggregation π-bridge, both the dyes IBT1 with EIMW and IBT2 with SPDF as π-bridges can suppress intermolecular aggregation more efficiently. The π-bridge of SPDF shows the strongest anti-aggregation ability due to the rigid ‘T’ configuration among these dyes. Meanwhile, the π-bridge of EIMW shows better anti-aggregation ability…
Thermal Aggregation of Bovine Serum Albumin in Trehalose and Sucrose Aqueous Solutions
2012
We report results of static and dynamic light scattering measurements performed on bovine serum albumin (BSA) in saccharide (trehalose and sucrose) solutions. Our aim is to study the effects of the two disaccharides on the first steps of thermal aggregation of BSA in aqueous solutions at two protein concentrations (1 and 30 mg/mL) at increasing sugar/water ratio. Results show that sugars modify early stages of aggregation mainly by perturbing the thermodynamic behavior of the solvent (i.e., general solvent effects) without involving direct, specific sugar-protein interactions. This agrees with current hypotheses on sugar action in protein solutions. (1-3) The linear correlation detected bet…
Stroke subtypes and their possible implication in stroke prevention drug strategies
2014
Thrombotic strokes can affect large or small arteries in the brain. Drugs to prevent atherosclerosis complication such as thrombotic strokes, should be drugs able to prevent the accumulation of intravascular fat, reduce vascular proliferation, decrease blood pressure levels with the resulting shear stress, reduce platelet aggregation, and possibly partially or totally reverse carotid plaques. Any of the commonly used antihypertensive drugs lower the incidence of stroke, with larger reductions in BP resulting in larger reductions in risk. Experimental and clinical data suggest that reducing the activity of the renin-angiotensin aldosterone system (RAAS) may have beneficial effects beyond the…