Search results for "stability"
showing 10 items of 3085 documents
Elementi di pericolosità geologica dell’offshore del margine calabro-ionico
2008
Nitrogen-Doped Carbon Nanodots-Ionogels: Preparation, Characterization, and Radical Scavenging Activity
2018
Hybrid diimidazolium-based ionogels were obtained by dispersing nitrogen-doped carbon nanodots (NCNDs) in ionic liquid (IL) solutions and by using dicationic organic salts as gelators. The properties of the NCND-ionogels were studied in terms of thermal stability, mechanical strength, morphology, rheological, and microscopic analyses. Insights into the formation of the hybrid soft material were attained from kinetics of sol-gel phase transition and from estimating the size of the aggregates, obtained from opacity and resonance light-scattering measurements. We demonstrate that, on one hand, NCNDs were able to favor the gel formation both in the presence of gelating and nongelating ILs. On t…
Influence of Anion and Cation Structure of Ionic Liquids on Carboxylic Acids Extraction
2019
A recently proposed new mechanism and a model of reactive extraction of carboxylic acids by hydrophobic ionic liquids (ILs) was tested on five systems from published as well as from new equilibrium data on liquid-liquid extraction of butyric and lactic acids (BA and LA) from aqueous solutions. Two phosphonium and one ammonium ILs were used. The model describes experimental data for all systems with a good fit. The mechanism of acid extraction by ILs is very similar for all tested systems. This indicates a more general validity of the developed model. The model allows deeper understanding of regularities in carboxylic acid extraction by hydrophobic ILs. Stability constants of the first acid-…
Beyond Subsidies: A Study of Sustainable Public Subordinated Debt in Spain
2019
Evidence from business shows that small- and medium-sized enterprises (SMEs) are fragile. They suffer from a high mortality rate that primarily owes to difficulties in securing financing as a result of major information asymmetries. Despite these difficulties, SMEs provide the economic backbone of all economically developed countries. Aware of the key role of SMEs in national economic stability and of the financial problems that SMEs face, governments have designed a range of financial and tax measures to protect them. These financial measures include a highly specific form of public financing called subordinated debt. This concept refers to debt with the lowest credit seniority, just befor…
Stability and marginal bone loss in implants placed using piezoelectric osteotomy versus conventional drilling: systematic review and meta-analysis.
2021
Background The main objective of this systematic review was to compare primary and secondary implant stability between placement with piezoelectric osteotomy and conventional drilling, comparing marginal bone losses as a secondary objective. Material and Methods An electronic search was conducted using PubMed (MEDLINE), Scopus, and Cochrane Library (Wiley) databases, besides a manual search. Results A total of 153 articles were retrieved, 39 from Pubmed, 44 from Scopus, and 70 from the Cochrane Library. After removing duplicates, 112 articles (1 from the manual search) were screened, and 9 were finally selected for qualitative and statistical analyses. Conclusions Piezoelectric surgery is a…
High pressure processing of food-grade emulsion systems: Antimicrobial activity, and effect on the physicochemical properties
2019
Abstract The use of high pressure processing (HPP) for development of stable emulsion-based delivery systems has been recently increased. Under adequate conditions, application of high pressures modifies the functionality of protein and polysaccharide molecules and significantly promotes the emulsifying activities. Application of high pressures also modulates the emulsion microstructure without any destabilization and gelation of protein molecules. The lipid oxidation in HPP-treated emulsions can be accelerated, particularly with higher pressure levels, while the HPP utilization on emulsions in acidic conditions can highly inhibit the growth of spoilage and pathogenic microorganisms. In thi…
Kinetically Controlled Stepwise Self-Assembly of AuI-Metallopeptides in Water
2018
The combination of attractive supramolecular interactions of a hydrophobic AuI-metallopeptide with the shielding effect of flexible oligoethylene glycol chains provides access to a stepwise self-assembly of a AuI-metalloamphiphile in water. Kinetic control of the supramolecular polymer morphology is achieved using a temperature-dependent assembly protocol, which yields low dispersity supramolecular polymers (metastable state I) or helical bundled nanorods (state II).
N ‐Annulated Perylene Bisimides to Bias the Differentiation of Metastable Supramolecular Assemblies into J‐ and H‐Aggregates
2020
The unique self-assembling features of N-annulated perylene bisimides (PBIs) 1 and 2 are reported. The stability of the aggregates of diester 1, in which no H-bonding interactions are operative, corroborates the significance of long-range van der Waals and dipole-dipole electrostatic interactions in the construction of stable supramolecular assemblies. The incorporation of amide functional groups within the N-annulated PBI in 2 stimulates pathway differentiation to achieve up to three J-type aggregates and a fourth H-type aggregate depending on the experimental conditions. The results presented demonstrate unprecedented levels of control over synthetic supramolecular self-assembly and the r…
Substrate-Independent Stable and Adherent Reactive Surface Coatings and their Conversion with Amines
2007
To create stable, adherent and reactive surface coatings, a hybrid polymer composed of poly(methylsilsesquioxane) (PMSSQ) and poly(pentafluorophenyl acrylate) PFPA with a M n of 32000 g/mol was prepared by a RAFT polymerization procedure. These hybrid polymer has been used for coating experiments. The PFPA part enabled a variable functionalization of the coating afterwards. The stability on various substrates (e.g. glass, PMMA, steel) was tested in an ISO tape test. These reactive surface coatings were modified using different amines, such as amino-terminated PEG, dodecyl amine and N-isopropyl amine. The conversion was analyzed by FT-IR and contact angle measurements.
Ability of Kocuria varians LTH 1540 To Degrade Putrescine: Identification and Characterization of a Novel Amine Oxidase.
2015
This work describes the identification and characterization of an amine oxidase from Kocuria varians LTH 1540 (syn. Micrococcus varians) primarily acting on putrescine. Data from MALDI-TOF MS/MS and the identification of Δ(1)-pyrroline as degradation product from putrescine indicate that the enzyme is a flavin-dependent putrescine oxidase (PuO). Properties of partially purified enzyme have been determined. The enzyme oxidizes diamines, putrescine and cadaverine, and, to a lesser extent, polyamines, such as spermidine, but not monoamines. The kinetic constants (Km and Vmax) for the two major substrates were 94 ± 10 μM and 2.3 ± 0.1 μmol/min·mg for putrescine and 75 ± 5 μM and 0.15 ± 0.02 μmo…