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111.
Negro D Montesano V Grieco S Crupi P Sarli G De Lisi A Sonnante G 《Journal of food science》2012,77(2):C244-C252
Polyphenol compounds, particularly caffeoylquinic acids and flavonoids, were measured in different tissues and developmental stages of 6 artichoke varietal types diffused in the Mediterranean region. Flower heads were subdivided into external, intermediate, internal bracts, and receptacle, while leaves were collected at the vegetative and productive stages. The main polyphenols detected were chlorogenic acid, cynarin, luteolin 7-O-rutinoside, and luteolin 7-O-glucoside. "Violet de Provence" artichoke proved to retain the highest content of total phenols. Single polyphenols accumulated preferentially in specific parts of capitula. In leaves, most polyphenols were detected in the productive stage of the plant. Altogether, results provide useful indications for the promotion of artichoke as nutraceutical food and for the extraction of health-promoting substances in particular tissues/stages of the artichoke plant. PRACTICAL APPLICATION: We describe the content of phenolic compounds in various artichoke tissues, developmental stages, and varieties. Results indicate that artichoke leaves represent an important source of these health-promoting compounds, also useful for phytopharmaceutical applications. A wider utilization of specific artichoke types should be strongly encouraged not only as a food for the fresh market, as they are now used, but also for the pharmaceutical industry, since the content of phenolic compounds is abundant both in the heads and in the leaves. 相似文献
112.
Vera Lavelli Gabriella Giovanelli 《Journal of the science of food and agriculture》2003,83(9):966-971
Tomato products (pulp, puree and paste) submitted to accelerated aging (30, 40 and 50 °C for 3 months) were studied to evaluate variations in the kinetics of the degradation of antioxidants and antioxidant activity. The carotenoids lycopene and β‐carotene, ascorbic acid, rutin and total phenolics were analysed. The antioxidant activity was measured using (a) the xanthine oxidase (XOD)/xanthine system, which generates superoxide radicals and hydrogen peroxide, and (b) the linoleic acid/CuSO4 system, which promotes lipid peroxidation. The ascorbic acid content decreased even at 30 °C, following pseudo‐first‐order kinetics, with an activation energy of 105 200 J mol?1 for tomato pulp and 23 600 J mol?1 for tomato paste. The lower the initial ascorbic acid content, the higher was the degradation rate. Variations in phenolic compounds occurred at 40 °C and higher, following pseudo‐zero order kinetics. The antioxidant activity of the hydrophilic fraction of the tomato products depended on both antioxidant degradation and the Maillard reaction and could not be described by a kinetic model. The β‐carotene content decreased even at 30 °C, whereas the lycopene content was stable in all samples. The antioxidant activity of the lipophilic fraction of the tomato products decreased following pseudo‐first order kinetics, with an activation energy of 22 200 J mol?1 for tomato pulp and 20 200 J mol?1 for tomato paste. It is concluded that significant ‘oxidative damage’ can occur in tomato products during their commercial shelf‐life. Copyright © 2003 Society of Chemical Industry 相似文献
113.
Volpini R Marucci G Buccioni M Dal Ben D Lambertucci C Lammi C Mishra RC Thomas A Cristalli G 《ChemMedChem》2011,6(6):1074-1080
Guanosine, released extracellularly from neurons and glial cells, plays important roles in the central nervous system, including neuroprotection. The innovative DELFIA Eu‐GTP binding assay was optimized for characterization of the putative guanosine receptor binding site at rat brain membranes by using a series of novel and known guanosine derivatives. These nucleosides were prepared by modifying the purine and sugar moieties of guanosine at the 6‐ and 5′‐positions, respectively. Results of these experiments prove that guanosine, 6‐thioguanosine, and their derivatives activate a G protein‐coupled receptor that is different from the well‐characterized adenosine receptors. 相似文献
114.
Dal Ben D Antonini I Buccioni M Lambertucci C Marucci G Thomas A Volpini R Cristalli G 《ChemMedChem》2011,6(7):1163-1171
Neuropeptide?S (NPS) is a 20-amino acid peptide of great interest due to its possible involvement in several biological processes, including food intake, locomotion, wakefulness, arousal, and anxiety. Structure-activity relationship studies of NPS have identified key points for structural modifications with the goal of modulating NPS receptor (NPSR) agonist activity or achieving antagonism at the same receptor. Only limited information is available for nonpeptide NPSR antagonists. In the last year, several studies have been reported in literature which present various series of small molecules as antagonists of this receptor. The results allow a comparison of the structures and activities of these molecules, leading to the design of new ligands with increased potency and improved pharmacological and pharmacokinetic profiles. This work presents a brief overview of the available information regarding structural features and pharmacological characterization of published nonpeptide NPSR antagonists. 相似文献
115.
Gabriella Roventi Tiziano Bellezze Romeo Fratesi 《Journal of Applied Electrochemistry》2013,43(8):839-846
Zn–SiC composite coatings were obtained on mild steel substrate by electrodeposition technique with high-current efficiency. A slightly acidic chloride bath, containing SiC nanoparticles and gelatine as additive, was used. The electrodeposition was carried out under galvanostatic control with pulsed direct current; the effect of experimental parameters (temperature, average current density and particles concentration) on composition, morphology and structure of the deposit was studied. Coatings were characterized by means of scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffractometry and Vickers microhardness measurements. Zn–SiC electrodeposits with the best characteristics were obtained by performing electrodepositions at 45 °C, with 20 g L?1 SiC in the bath and with average current density in the range 100–150 mA cm?2. Under these experimental conditions, homogeneous and compact coatings, with low-grain size and SiC content ranging from 1.7 to 2.1 wt%, were found to be electrodeposited. Microhardness measurements showed for these deposits an increase of about 50 % with respect to those without nanoparticles obtained in the same experimental conditions. 相似文献
116.
Kai Tang Eivind J. Øvrelid Gabriella Tranell Merete Tangstad 《JOM Journal of the Minerals, Metals and Materials Society》2009,61(11):49-55
The diffusion of impurities in solid and liquid silicon is critically reviewed and assessed in this paper. The activation
energies and pre-exponential factors in theArrhenius equation have been evaluated using the least-squares analysis and semi-empirical
correlations. Impurity diffusion coefficients for Ag, Al, As, Au, B, Bi, C, Co, Cr, Cu, Fe, Ga, In, Li, Mn, N, Ni, 0, P, S,
Sb, Te, Ti, and Zn in both solid and liquid silicon have been obtained. The current assessed impurity diffusivities can be
coupled with the assessed thermochemical properties for the simulation of diffusion phenomena in the production of solar grade
cell silicon feedstock. The assessed diffusivities have been applied to simulate the impurity diffusion profiles and the denuded
zone in the intrinsic gettering annealing. 相似文献
117.
118.
Univ.-Prof. DI Dr. Helmut Habersack DI Marlene Haimann Ass. Prof. Dr. Sándor Baranya Prof. Dr. János Józsa Mag. Angelika Riegler Dr Christine Sindelar DI Marcel Liedermann Johanna Ficsor Gabriella Mohácsiné Simon HR DI Dr. Michael Hengl 《?sterreichische Wasser- und Abfallwirtschaft》2014,66(9-10):340-347
The multiple uses of the Danube River for navigation, hydropower production and as a drinking water supply influence its ecological quality. Flow restrictions due to regulation as well as impacts on the sediment regime such as retention in the catchment area and interruption of the sediment continuum result in changes of the hydromorphological structures and can produce major problems in the context of sediment management. In light of these facts, cross-border investigations of sediment transport at the Danube River are called for. As there are no uniform research approaches shared by Austria and Hungary, the EU-funded project SEDDON (Sediment Research and Management at the Danube River) aims to compare different monitoring and modeling techniques used to determine sediment transport, and to develop mutual solutions. Further, the laboratory equipment currently used for hydraulic model experiments is evaluated and a research channel with a free flowing discharge of up to 10 m3/s without pumping will be constructed, allowing large-scale joint laboratory tests concerning sediment to be performed. 相似文献
119.
120.
Gabriella Tranell Oleg Ostrovski Sharif Jahanshahi 《Metallurgical and Materials Transactions B》2002,33(1):61-67
The redox behavior of titanium in CaO-SiO2-TiO
x
melts was investigated using a slag-gas equilibrium technique. Titanium partitioning between Ti3+ and Ti4+ valency states and the ratio of activity coefficients of TiO1.5 and TiO2 were determined as functions of oxygen partial pressure, temperature, and slag composition. The equilibrium experiments were
carried out at temperatures between 1783 and 1903 K under CO-CO2-Ar gas atmosphere with oxygen partial pressure ranging from 10−12 to 10−7 atm (1.01×10−10 kPa to 1.01×10−5 kPa). The slags had CaO/SiO2 ratios between 0.55 and 1.35 and total titanium oxide concentrations from 7 to 50 mass pct. Experimental results showed that
the Ti3+/Ti4+ ratio in CaO-SiO2-TiO
x
slags, containing up to 50 mass pct TiO
x
, increased with decreasing oxygen partial pressure and decreased with increasing CaO/SiO2 ratio and decreasing temperature. Measured variation of the redox ratio Ti3+/Ti4+ with oxygen partial pressure closely followed the ideal behavior. Increasing the CaO/SiO2 ratio increased the ratio of activity coefficients of TiO1.5 and TiO2. The effect of total titania content on this ratio was more complex and in accord with Raman spectroscopy data. 相似文献