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151.
Marina Russo Filomena Cichello Carla Ragonese Paola Donato Francesco Cacciola Paola Dugo Luigi Mondello 《Analytical and bioanalytical chemistry》2013,405(13):4617-4626
In this work, a high-performance liquid chromatography with evaporative light scattering detection method has been developed and applied for quantification of the polar content of the lipid fraction in milk samples of different origin. From a chromatographic stand-point, a 4.6-mm I.D. hydrophilic interaction liquid chromatography column was employed to attain a baseline separation of major phospholipid classes contained in the various milk samples tested. Quantitative analysis was performed by the external calibration method using reference material solutions in the 5–100 mg/L concentration range. Analytical recoveries ranging from 57 to 100 %, and repeatability data lower than 8.04 % were obtained on a skimmed cow’s milk sample. The crude cow milk was the most abundant (0.04 %) in phospholipids and donkey milk was the poorest (0.004 %). Quantitative differences were determined in the phospholipid content of the milk samples tested. Finally, characterization of phospholipid profile and fatty acid composition of the different samples was carried out by an ion trap-time of flight mass spectrometer and gas chromatography coupled to flame ionization and mass spectrometry detection. A thorough screening of the polar lipid composition of milk samples of different origin is here outlined, for the first time. 相似文献
152.
Enrico Le Donne Gian Paolo Leonardi Roberto Monti Davide Vittone 《Geometric And Functional Analysis》2013,23(4):1371-1401
We classify extremal curves in free nilpotent Lie groups. The classification is obtained via an explicit integration of the adjoint equation in Pontryagin maximum principle. It turns out that abnormal extremals are precisely the horizontal curves contained in algebraic varieties of a specific type. We also extend the results to the nonfree case. 相似文献
153.
The synthesis of (±)10H-phenothiazine-10-propanoyl-1′-myo-inositol was accomplished in order to test it as inhibitor of phosphatidylinositol specfic phospholipase C (PI-PLC). 相似文献
154.
Kamel Abbas Izabela Cydzik Riccardo Del Torchio Massimo Farina Efrat Forti Neil Gibson Uwe Holzwarth Federica Simonelli Wolfgang Kreyling 《Journal of nanoparticle research》2010,12(7):2435-2443
Industrially manufactured titanium dioxide nanoparticles have been successfully radiolabelled with 48V by irradiation with a cyclotron-generated proton beam. Centrifugation tests showed that the 48V radiolabels were stably bound within the nanoparticle structure in an aqueous medium, while X-ray diffraction indicated
that no major structural modifications to the nanoparticles resulted from the proton irradiation. In vitro tests of the uptake
of cold and radiolabelled nanoparticles using the human cell line Calu-3 showed no significant difference in the uptake between
both batches of nanoparticles. The uptake was quantified by Inductively Coupled Plasma Mass Spectrometry and high resolution
γ-ray spectrometry for cold and radiolabelled nanoparticles, respectively. These preliminary results indicate that alterations
to the nanoparticles’ properties introduced by proton bombardment can be controlled to a sufficient extent that their further
use as radiotracers for biological investigations can be envisaged and elaborated. 相似文献
155.
156.
Paola Mura Gian Piero Bettinetti Maria Teresa Faucci Milena Sorrenti Alessandra Negri 《Supramolecular chemistry》2013,25(4):379-389
Abstract Interactions of naproxen (NAP) with amorphous, randomly methylated β-cyclodextrin at a degree of substitution per anhydroglucose unit of 1.8 (RAMEB) and with crystalline heptakis-(2,6-di-O-methyl)-β-cyclodextrin (DIMEB) were studied in aqueous solution and in the solid state using, respectively, phase-solubility analysis (at 25 °C, 37 °C and 47 °C) and differential scanning calorimetry (DSC) supported by X-ray powder diffractometry. RAMEB and DIMEB displayed similar solubilizing and complexing abilities towards NAP, suggesting analogous inclusion modes of the drug in the host cavity in aqueous solution. Differences were instead observed in interactions in the solid state, where the amorphizing capacity of RAMEB toward NAP (evaluated by DSC) was about twice that of DIMEB at each drug-to-carrier ratio. Assuming that inclusion complexation is also involved in solid-state interactions, molecular modelling accounted for the experimental results in terms of structural features of DIMEB, i.e. the particular inwards orientation of O-6-C-8 groups of three alternate glucoses on the primary hydroxyl side which hampers a deep penetration of NAP in the DIMEB cavity in the solid state. On the contrary, no obstruction of the cavity apparently occurs with RAMEB due its noncrystalline state. The aqueous dissolution rate of NAP from NAP-RAMEB and NAP-DIMEB blends containing 0.59, 0.73, 0.85, and 0.92 mass fraction of carrier linearly increased at decreasing drug-to-carrier ratios. The improvement was 5 to 20 times (from powders) and 50 to 200 times (from discs) the dissolution rate of NAP alone for both carrier. Therefore the choice of the amorphous RAMEB in pharmaceutical formulations can be recommended mainly for economic reasons, though the anhydrous and non-hygroscopic nature of crystalline DIMEB might be of particular advantage in case of moisture sensitive formulations. 相似文献
157.
Valeria van Axel Castelli Antonella Dalla Cort Luigi Mandolini Valentina Pinto David N. Reinhoudt Fabrizio Ribaudo 《Supramolecular chemistry》2013,25(2-3):211-219
The complexation of the salophen-uranyl metallocleft 2 and of its half-cleft analogue 3 with enones and other carbonyl compounds was assessed in chloroform by UV-Vis titration and, occasionally, by FT-IR measurements. Complexes with receptors 2 and 3 are in all cases more stable than those with the control unsubstituted uranyl-salophen 1 , showing that in addition to the primary binding force provided by coordination of the carbonyl oxygen to the uranium, a significant driving force for complexation, typically in the range of 2-3 kcal/mol, results from van der Waals interactions of the guest with the aromatic walls. Replacement of the phenyl group in 3 with larger aromatic residues to give 4 and 5 , led to enhanced complex stabilities, due to more extended contact surfaces between host and guest. 相似文献
158.
Marco Bellagamba Luigi Bencivenni Lorenzo Gontrani Leonardo Guidoni Claudia Sadun 《Structural chemistry》2013,24(3):933-943
In this work, we report a multitechnique (energy-dispersive X-ray diffraction, computational methods, and FTIR spectroscopy) study of the tautomeric equilibrium of 1,2,3-triazole, one of the few small nitrogen-containing eterocycles liquid at room temperature. The T-2H form (C 2v symmetry) is found to be strongly favored in gas and solid phases, whereas the neat liquid gives diffraction patterns that can be interpreted satisfactorily with the structure functions calculated from some molecular dynamics results for both T-2H and T-1H tautomers, although the T-2H form gives a slightly better agreement. 相似文献
159.
160.
Eduardo Sommella Giacomo Pepe Francesco Pagano Gian Carlo Tenore Paola Dugo Michele Manfra Pietro Campiglia 《Journal of separation science》2013,36(20):3351-3355
We have developed a fast ultra HPLC with ion‐trap TOF‐MS method for the analysis of flavonoids in Citrus bergamia juice. With respect to the typical methods for the analysis of these matrices based on conventional HPLC techniques, a tenfold faster separation was attained. The use of a core–shell particle column ensured high resolution within the fast analysis time of only 5 min. Unambiguous determination of flavonoid identity was obtained by the employment of a hybrid ion‐trap TOF mass spectrometer with high mass accuracy (average error 1.69 ppm). The system showed good retention time and peak area repeatability, with maximum RSD% values of 0.36 and 3.86, respectively, as well as good linearity (R2 ≥ 0.99). Our results show that ultra HPLC can be a useful tool for ultra fast qualitative/quantitative analysis of flavonoid compounds in citrus fruit juices. 相似文献