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141.
We have investigated the effect of ionic strength on the aggregation behavior of n-dodecyl phosphocholine. On the basis of the classical Corrin–Harkins relation, the critical micellar concentration of this
detergent decreases with a biphasic trend on lithium chloride addition. It is nearly constant below 150 mM salt, with a mean
value of 0.91 mM, whereas it undergoes a dramatic 80-fold decrease in 7 M LiCl. Such a drop in the critical micellar concentration
could be explained by the effect of salting out and the implication of phosphocholine head groups on the organization of surrounding
water. Knowledge of the effective critical micellar concentration of n-dodecyl phosphocholine could be useful in the purification of membrane proteins in non-denaturing conditions. 相似文献
142.
Gianfranco Carotenuto Cornelia L. Hison Filomena Capezzuto Mariano Palomba Pietro Perlo Pellegrino Conte 《Journal of nanoparticle research》2009,11(7):1729-1738
An effective method of preparation of bismuth nanopowders by thermal decomposition of bismuth dodecyl-mercaptide Bi(SC12H25)3 and preliminary results on their thermoelectric properties are reported. The thermolysis process leads to Bi nanoparticles
due to the efficient capping agent effect of the dodecyl-disulfide by-product, which strongly bonds the surface of the Bi
clusters, preventing their aggregation and significantly reducing their growth rate. The structure and morphology of the thermolysis
products were investigated by differential scanning calorimetry, thermogravimetry, X-ray diffractometry, 1H nuclear magnetic resonance spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. It has been shown
that the prepared Bi nanopowder consists of spherical shape nanoparticles, with the average diameter depending on the thermolysis
temperature. The first results on the thermoelectric characterization of the prepared Bi nanopowders reveal a peculiar behavior
characterized by a semimetal–semiconductor transition, and a significant increase in the Seebeck coefficient when compared
to bulk Bi in the case of the lowest grain size (170 nm). 相似文献
143.
144.
145.
Filomena Monica Vella Francesco La Cara Alessandra Morana 《Natural product research》2018,32(9):1022-1032
The underutilised forest and industrial biomass of Castanea sativa (Mill.) is generally discarded during post-harvest and food processing, with high impact on environmental quality. The searching on alternative sources of natural antioxidants from low-cost supplies, by methods involving environment-friendly techniques, has become a major goal of numerous researches in recent times. The aim of the present study was the set-up of a biomolecules extraction procedure from chestnut leaves, burs and shells and the assessing of their potential antioxidant activity. Boiling water was the best extraction solvent referring to polyphenols from chestnut shells and burs, whereas the most efficient for leaves resulted 60% ethanol at room temperature. Greatest polyphenol contents were 90.35, 60.01 and 17.68 mg gallic acid equivalents g?1 in leaves, burs and shells, respectively. Moreover, flavonoids, tannins and antioxidant activity were assessed on the best extract obtained from each chestnut by-product. 相似文献
146.
Valentina Hartwig Stefano Tassano Alessio Mattii Nicola Vanello Vincenzo Positano Maria Filomena Santarelli Luigi Landini Giulio Giovannetti 《Applied magnetic resonance》2013,44(3):389-400
Magnetic resonance imaging (MRI) is essential for the diagnosis and treatment of musculoskeletal conditions. Low-field (<0.5T) imaging is a cost-effective alternative to more expensive high-field strength imaging due to the inexpensive setting, greater patient comfort and better safety profile. On the other hand, if compared with high-field body scanners, the low-field scanners produce poor-quality images with lower signal-to-noise ratio. Especially in low-field MR, receiver coil performance plays a significant role in image quality. Coil performance is generally evaluated using classical electromagnetic theory, but when the coil is loaded with a sample, an analytical solution is extremely difficult to derive, so that a trial-and-error approach is often followed. Numerical methods have been proposed in literature as good alternatives to predict MRI coil performance. In this study the performance of a knee coil for low-field (0.5 T) MR scanners is analyzed using workbench tests and numerical simulation with a software program based on the finite difference time domain method. Parameter performances measured using the classical workbench test are compared with those obtained using numerical simulations. Finally, the knee coil performance is validated with images acquired in a commercial low-field MR system. 相似文献
147.
Mohamed Ben Ayed Khalil El Mehdi Filomena Pacella 《Journal of Functional Analysis》2007,250(2):347-373
In this paper we make the analysis of the blow up of low energy sign-changing solutions of a semilinear elliptic problem involving nearly critical exponent. Our results allow to classify these solutions according to the concentration speeds of the positive and negative part and, in high dimensions, lead to complete classification of them. Additional qualitative results, such as symmetry or location of the concentration points are obtained when the domain is a ball. 相似文献
148.
Filomena Pacella 《Milan Journal of Mathematics》2005,73(1):221-236
In this paper we survey some recent results about the uniqueness of the solution of some semilinear elliptic Dirichlet problems
in bounded domains. The presentation aims to emphasize the role of the geometrical properties of the second eigenfunction
of the linearized problem in the study of the above question. This motivates the analysis of the asymptotic behaviour of these
eigenfunctions and of the relative eigenvalues when the nonlinear term is a power with exponent close to the critical Sobolev
exponent.
Research supported by MIUR, project “Variational Methods and Nonlinear Differential Equations”.
Lecture held in the Seminario Matematico e Fisico on January 31, 2005 Received: June 2005 相似文献
149.
Rosanna Mallamaci Roberta Budriesi Maria Lisa Clodoveo Giulia Biotti Matteo Micucci Andrea Ragusa Francesca Curci Marilena Muraglia Filomena Corbo Carlo Franchini 《Molecules (Basel, Switzerland)》2021,26(4)
Extra-virgin olive oil (EVOO) contains many bioactive compounds with multiple biological activities that make it one of the most important functional foods. Both the constituents of the lipid fraction and that of the unsaponifiable fraction show a clear action in reducing oxidative stress by acting on various body components, at concentrations established by the European Food Safety Authority’s claims. In addition to the main product obtained by the mechanical pressing of the fruit, i.e., the EVOO, the residual by-products of the process also contain significant amounts of antioxidant molecules, thus potentially making the Olea europea L. an excellent example of the circular economy. In fact, the olive mill wastewaters, the leaves, the pomace, and the pits discharged from the EVOO production process are partially recycled in the nutraceutical and cosmeceutical fields also because of their antioxidant effect. This work presents an overview of the biological activities of these by-products, as shown by in vitro and in vivo assays, and also from clinical trials, as well as their main formulations currently available on the market. 相似文献
150.
Mónica Silva Isabel Martins Filomena Barreiro Madalena Dias Alírio E. Rodrigues 《International Journal of Polymer Analysis and Characterization》2017,22(8):709-724
The synthesis of poly(urethane–urea) shells (PUU) using poly(ethylene glycols) of different molecular weights and methylene-bis(4-cyclohexylisocyanate) was performed for the microencapsulation of limonene, using a step-growth polymerization process. The obtained microcapsules were structurally characterized by dynamic light scattering, optical microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The results showed that the core–shell microcapsules had spherical shape, a mean diameter in between 10 and 20?µm, and characteristic urethane-urea bonds. Furthermore, the molecular weight of polyol influences the entrapment efficiency, which ranged from 38 to 55%. The release data were analyzed by applying the Korsmeyer–Peppas model. 相似文献