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排序方式: 共有342条查询结果,搜索用时 31 毫秒
61.
Maxia A Frau MA Foddis C Lancioni MC Kasture V Kasture S 《Natural product research》2012,26(5):438-445
In the traditional Sardinian system of medicine, Rubia peregrina L. (Rubiaceae) is reported as an aphrodisiac herb. Since the aphrodisiacs may also have antioxidant and dopaminergic activities, the aim of this study was to study the effect of ethanolic extract of aerial parts of R. peregrina for the scavenging of free DPPH radicals and the inhibition of haloperidol-induced catalepsy in mice and reserpine-induced orofacial dyskinesia in rats. The extract exhibited significant antioxidant activity in a free radical DPPH assay with IC(50)?=?55.6?μg?mL(-1), which was very close to IC(50) of ascorbic acid. The extract of R. peregrina (100 and 200?mg?kg(-1) intraperitoneally, i.p.) significantly inhibited haloperidol (1?mg?kg(-1) i.p.) - induced catalepsy in mice (p?0.01). In rats, the extract (200?mg?kg(-1) i.p.) significantly (p?0.01) inhibited the orofacial dyskinesia induced by intraperitoneal administration of reserpine (1?mg?kg(-1) on days 1, 3 and 5). This study demonstrates that R. peregrina has antioxidant activity and improves the dopaminergic function. Results therefore justify the development of further experiments to investigate the psychopharmacological profile of R. peregrina. 相似文献
62.
Giacomo Aletti Caterina May Piercesare Secchi 《Journal of Theoretical Probability》2012,25(4):1207-1232
We study a functional equation whose unknown maps a Euclidean space into the space of probability distributions on [0,1]. We prove existence and uniqueness of its solution under suitable regularity and boundary conditions, we show that it depends continuously on the boundary datum, and we characterize solutions that are diffuse on [0,1]. A canonical solution is obtained by means of a Randomly Reinforced Urn with different reinforcement distributions having equal means. The general solution to the functional equation defines a new parametric collection of distributions on [0,1] generalizing the Beta family. 相似文献
63.
Bellussi G Millini R Montanari E Carati A Rizzo C Parker WO Cruciani G de Angelis A Bonoldi L Zanardi S 《Chemical communications (Cambridge, England)》2012,48(59):7356-7358
ECS-14, a crystalline microporous hybrid organic-inorganic aluminosilicate, has been synthesized by using 1,4-bis-(triethoxysilyl)-benzene (BTEB) as a source of silica. Its structure contains a system of linear channels with 12-membered ring openings, running along the [001] direction, resembling the pore architecture of the AFI framework type. 相似文献
64.
We study power series and analyticity in the quaternionic setting. We first consider a function f defined as the sum of a power series \({\sum\nolimits_{n \in \mathbb{N}} q^n a_n}\) in its domain of convergence, which is a ball B(0, R) centered at 0. At each \({p \in B(0,R)}\), f admits expansions in terms of appropriately defined power series centered at p, namely \({\sum\nolimits_{n \in \mathbb{N}} (q-p)^{*n} b_n}\). The expansion holds in a ball Σ(p, R ? |p|) defined with respect to a (non-Euclidean) distance σ. We thus say that f is σ-analytic in B(0, R). Furthermore, we remark that Σ(p, R ? |p|) is not always a Euclidean neighborhood of p; when it is, we say that f is strongly analytic at p. It turns out that f is strongly analytic in a neighborhood of \({B(0,R) \cap \mathbb{R}}\) that can be strictly contained in B(0, R). We then relate these notions of analyticity to the class of quaternionic functions introduced in Gentili and Struppa (Adv. Math. 216(1):279–301, 2007), and recently extended in Colombo et al. (Adv. Math. 222(5):1793–1808, 2009) under the name of slice regular functions. Indeed, σ-analyticity proves equivalent to slice regularity, in the same way as complex analyticity is equivalent to holomorphy. Hence the theory of slice regular quaternionic functions, which is quickly developing, reveals a new feature that reminds the nice properties of holomorphic complex functions. 相似文献
65.
Caterina Fraschetti Matthias C. Letzel Marlene Paletta Jochen Mattay Maurizio Speranza Antonello Filippi Massimiliano Aschi Alexander B. Rozhenko 《Journal of mass spectrometry : JMS》2012,47(1):72-78
The effect of cyclochirality of rccc‐2,8,14,20‐tetra‐n‐decyl‐4,10,16,22‐tetra‐O‐methylresorcin[4]arene (C) on the enantiodiscrimination of a number of chiral bidentate and tridentate aromatic and aliphatic biomolecules (G) has been investigated by nano‐electrospray ionization (nano‐ESI)‐Fourier transform ion cyclotron resonance mass spectrometry. The experimental approach is based on the formation of diastereomeric proton‐bound [C·H·G]+ complexes by nano‐ESI of solutions containing an equimolar amount of quasi‐enantiomers (C) together with the chiral guest (G) and the subsequent measurement of the rate of the G substitution by the attack of several achiral and chiral amines. In general, the heterochiral complexes react faster than the homochiral ones, except when G is an aminoalcoholic neurotransmitter whose complexes, beyond that, exhibit the highest enantioselectivity. The kinetic results were further supported by both collision‐induced dissociation experiments on some of the relevant [C2·H·G]+ three‐body species and Density functional theory (DFT) calculations performed on the most selective systems. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
66.
Networks are characterized by a variety of topological features and dynamics. Classifying nodes into communities, community structure, is important when exploring networks. This paper explores the community detection metric called modularity. The theoretical definitions of modularity are connected with intuitive insights into the compositions of communities. Local modularity costs/benefits are explored and an efficient stochastic algorithm, Bloom, is introduced, based on growing communities using local improvement measures. Three extensions of Bloom are presented that build upon the basic version. A numerical analysis compares Bloom with the popular fast-greedy algorithm and demonstrates the successful performance of the three modifications of Bloom. 相似文献
67.
Eleonora Truzzi Caterina Durante Davide Bertelli Benedetta Catellani Samuele Pellacani Stefania Benvenuti 《Molecules (Basel, Switzerland)》2022,27(17)
In the present work, the applicability of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, coupled with chemometric tools in recognizing essential oils (EOs) for routine control, was evaluated. EOs belonging to Mentha, Cymbopogon, and Lavandula families and to S. rosmarinus and T. vulgaris species were analyzed, and the performance of several untargeted approaches, based on the synergistic combination of ATR-FTIR and Partial Least Squares Discriminant Analysis (PLS-DA), was tested to classify the species and chemotypes. Different spectra pre-processing methods were employed, and the robustness of the built models was tested by means of a Receiver Operating Characteristic (ROC) curve and random permutations test. The application of these approaches revealed fruitful results in terms of sensitivity and specificity, highlighting the potentiality of ATR-FTIR and chemometrics techniques to be used as a sensitive, cost-effective, and rapid tool to differentiate EO samples according to their species and chemotype. 相似文献
68.
Francesca Cicogna Emilia Bramanti Beatrice Campanella Stefano Caporali Luca Panariello Caterina Cristallini Randa Ishak Niccoletta Barbani Elisa Passaglia Serena Coiai 《Molecules (Basel, Switzerland)》2022,27(23)
To improve the capability of non-woven polypropylene-based fabric (NWF-PP) used for face mask production to retain active biomolecules such as polyphenols, the surface functionalization of NWF-PP–directly cut from face masks–was carried out by employing cold plasma with oxygen. The nature/structure of the functional groups, as well as the degree of functionalization, were evaluated by ATR-FTIR and XPS by varying the experimental conditions (generator power, treatment time, and oxygen flow). The effects of plasma activation on mechanical and morphological characteristics were evaluated by stress–strain measurements and SEM analysis. The ability of functionalized NWF-PP to firmly anchor polyphenols extracted from cloves was estimated by ATR-FTIR analysis, IR imaging, extractions in physiological solution, and OIT analysis (before and after extraction), as well as by SEM analysis. All the results obtained converge in showing that, although the plasma treatment causes changes–not only on the surface–with certain detriment to the mechanical performance of the NWF-PP, the incorporated functionalities are able to retain/anchor the active molecules extracted from the cloves, thus stabilizing the treated surfaces against thermo-oxidation even after prolonged extraction. 相似文献
69.
70.
Caterina Gattuso Philomène Gattuso Jolanda Mastroianni Valentina Roviello Luigi Campanella 《Natural product research》2019,33(7):1078-1084
AbstractTo achieve adequate restoration project, the moment of choice of the type of intervention is a very delicate phase that necessarily involves a thorough understanding of the asset in all its aspects, as the location, the history, the architecture, the state of preservation, the pathologies causing the degradation, the degradation in itself, the analysis of constituent materials. The set of all that can be investigated on a product (cultural), to obtaining important information for subsequent maintenance, conservation and/or restoration actions, is what is called a diagnostic plan. In this case it was applied directly on a monument of national importance: the Royal Villa in Naples (today the Municipal Villa). The analysis were performed in situ and in the laboratory (SEM-EDS) on samples taken directly at the Villa, which allowed the creation of a series of analytical cards, containing digital data, required for the selection of expense future of intervention. 相似文献