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351.
352.
Gosetti F Chiuminatto U Zampieri D Mazzucco E Robotti E Calabrese G Gennaro MC Marengo E 《Journal of chromatography. A》2010,1217(50):7864-7872
A rapid on-line solid phase extraction ultra high performance liquid chromatography tandem mass spectrometry method was developed for the identification and quantitation of nine perfluorinated compounds in matrices of environmental, biological and food interest. Pre-treatment, solid phase extraction, chromatographic and mass detection conditions were optimised, in order to apply the whole methodology to the analysis of different matrices. Particular attention was devoted to the evaluation of matrix effect and the correlated phenomena of ion enhancement or suppression in mass spectrometry detection. LOD and LOQ range from 3 to 15ngL(-1) and from 10 to 50ngL(-1), respectively. Method detection limits (MDLs) were also calculated for each kind of matrix. The recovery, evaluated for each analyte, does not depend on analyte concentration in the explored concentration range: average Rˉ% values are always greater than 82.9%. In the whole, the results obtained for samples of river waters, blood serum, blood plasma, and fish confirm the ubiquitous presence of perfluorinated compounds, as recently denounced by many sources. 相似文献
353.
Bonifacio A Beleites C Vittur F Marsich E Semeraro S Paoletti S Sergo V 《The Analyst》2010,135(12):3193-3204
Raman mapping in combination with uni- and multi-variate methods of data analysis is applied to articular cartilage samples. Main differences in biochemical composition and collagen fibers orientation between superficial, middle and deep zone of the tissue are readily observed in the samples. Collagen, non-collagenous proteins, proteoglycans and nucleic acids can be distinguished on the basis of their different spectral characteristics, and their relative abundance can be mapped in the label-free tissue samples, at so high a resolution as to permit the analysis at the level of single cells. Differences between territorial and inter-territorial matrix, as well as inhomogeneities in the inter-territorial matrix, are properly identified. Multivariate methods of data analysis prove to be complementary to the univariate approach. In particular, our partial least squares regression model gives a semiquantitative mapping of the biochemical constituents in agreement with average composition found in the literature. The combination of hierarchical and fuzzy cluster analysis succeeds in detecting variations between different regions of the extra-cellular matrix. Because of its characteristics as an imaging technique, Raman mapping could be a promising tool for studying biochemical changes in cartilage occurring during aging or osteoarthritis. 相似文献
354.
Ivan Guryanov Dr. Francesca Maria Toma Dr. Alejandro Montellano López Dr. Mauro Carraro Dr. Tatiana Da Ros Dr. Guido Angelini Dr. Eleonora D'Aurizio Dr. Antonella Fontana Prof. Michele Maggini Prof. Maurizio Prato Prof. Marcella Bonchio Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(46):12837-12845
The effect of microwave (MW) irradiation and ionic liquids (IL) on the cycloaddition of azomethine ylides to [60]fullerene has been investigated by screening the reaction protocol with regard to the IL medium composition, the applied MW power, and the simultaneous cooling of the system. [60]Fullerene conversion up to 98 % is achieved in 2–10 min, by using a 1:3 mixture of the IL 1‐methyl‐3‐n‐octyl imidazolium tetrafluoroborate ([omim]BF4) and o‐dichlorobenzene, and an applied power as low as 12 W. The mono‐ versus poly‐addition selectivity to [60]fullerene can be tuned as a function of fullerene concentration. The reaction scope includes aliphatic, aromatic, and fluorous‐tagged (FT) derivatives. MW irradiation of IL‐structured bucky gels is instrumental for the functionalization of single‐walled carbon nanotubes (SWNTs), yielding group coverages of up to one functional group per 60 carbon atoms of the SWNT network. An improved performance is obtained in low viscosity bucky gels, in the order [bmim]BF4> [omim]BF4> [hvim]TF2N (bmim=1‐methyl‐3‐n‐butyl imidazolium; hvim=1‐vinyl‐3‐n‐hexadecyl imidazolium). With this protocol, the introduction of fluorous‐tagged pyrrolidine moieties onto the SWNT surface (1/108 functional coverage) yields novel FT‐CNS (carbon nanostructures) with high affinity for fluorinated phases. 相似文献
355.
Annamaria Cattaneo Luisella Bocchio-Chiavetto Roberta Zanardini Eleonora Marchina Daniela Bellotti Elena Milanesi Stefania Moraschi Francesca Calabrese Sergio Barlati Marco Andrea Riva Massimo Gennarelli 《BMC neuroscience》2010,11(1):1-5
Background
Brain-Derived Neurotrophic Factor (BDNF) is a neurotrophin which plays survival- and growth-promoting activity in neuronal cells and it is involved in cellular plasticity mechanisms as it controls activity dependent synaptic transmission. A functional polymorphism (Val66Met) in the pro-region of BDNF, which affects the intracellular trafficking of proBDNF has been associated with memory and cognitive deficits as well as to an increased susceptibility for several psychiatric disorders especially those with a neurodevelopmental origin. To date, no study has evaluated the influence of the Val66Met polymorphism on BDNF levels in a peripheral system that may reflect fetal neurodevelopment. Therefore we investigated in amniotic fluids (AF) obtained from 139 healthy women during 15-17 week of pregnancy, BDNF protein levels in correlation with the Val66Met polymorphism.Results
Interestingly we found a significant BDNF protein levels reduction in 55 Met carriers (Val/Met and Met/Met) (p = 0.002) as compared to 84 non carriers (Val/Val), and no effect of fetus gender, maternal age or gestation week on BDNF levels has been observed.Conclusion
These results, although explorative, indicate that during fetal life the Val66Met genotype might influences BDNF protein levels in AF supporting the involvement of this polymorphism in behavioral and functional brain individual differences in the adulthood. 相似文献356.
Sylwia Zieliska Magdalena Dzigwa-Becker Adam Junka Ewelina Pitczak Anna Jezierska-Domaradzka Malwina Broyna Justyna Paleczny Aleksandra Sobiecka Wojciech Supski Eleonora Mess Mariusz Kucharski Serhat Sezai iek Christian Zidorn Adam Matkowski 《Molecules (Basel, Switzerland)》2021,26(16)
The antimicrobial properties of herbs from Papaveraceae have been used in medicine for centuries. Nevertheless, mutual relationships between the individual bioactive substances contained in these plants remain poorly elucidated. In this work, phytochemical composition of extracts from the aerial and underground parts of five Papaveraceae species (Chelidonium majus L., Corydalis cava (L.) Schweigg. and Körte, C. cheilanthifolia Hemsl., C. pumila (Host) Rchb., and Fumaria vaillantii Loisel.) were examined using LC-ESI-MS/MS with a triple quadrupole analyzer. Large differences in the quality and quantity of all analyzed compounds were observed between species of different genera and also within one genus. Two groups of metabolites predominated in the phytochemical profiles. These were isoquinoline alkaloids and, in smaller amounts, non-phenolic carboxylic acids and phenolic compounds. In aerial and underground parts, 22 and 20 compounds were detected, respectively. These included: seven isoquinoline alkaloids: protopine, allocryptopine, coptisine, berberine, chelidonine, sanguinarine, and chelerythrine; five of their derivatives as well as non-alkaloids: malic acid, trans-aconitic acid, quinic acid, salicylic acid, trans-caffeic acid, p-coumaric acid, chlorogenic acid, quercetin, and kaempferol; and vanillin. The aerial parts were much richer in phenolic compounds regardless of the plant species. Characterized extracts were studied for their antimicrobial potential against planktonic and biofilm-producing cells of S. aureus, P. aeruginosa, and C. albicans. The impact of the extracts on cellular metabolic activity and biofilm biomass production was evaluated. Moreover, the antimicrobial activity of the extracts introduced to the polymeric carrier made of bacterial cellulose was assessed. Extracts of C. cheilanthifolia were found to be the most effective against all tested human pathogens. Multiple regression tests indicated a high antimicrobial impact of quercetin in extracts of aerial parts against planktonic cells of S. aureus, P. aeruginosa, and C. albicans, and no direct correlation between the composition of other bioactive substances and the results of antimicrobial activity were found. Conclusively, further investigations are required to identify the relations between recognized and unrecognized compounds within extracts and their biological properties. 相似文献
357.
Ludmila I. Chaikovskaya Eleonora P. Zege 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(8):506-525
We present a semi-analytical approach to determine angular patterns of a polarized intensity that form lidar signals from multiply scattering media registered by a monostatic multiple-field-of-view receiver or CCD camera for any polarization state of incident light and any analyzer state at a receiver. Multiply scattering media with a highly forward elongated phase functions are considered. The model of lidar signal formation includes the single near-backscattering and small-angle multiple scattering of light. The developed approach allows computation and analysis of polarized images, including the Mueller matrix images, formed by the laser light backscattered by multiply scattering media, for example, from atmospheric clouds, ocean waters, tissue, etc. 相似文献
358.
Stefan Mijatovic Jelena Antic Stankovic Ivana Colovic Calovski Eleonora Dubljanin Dejan Pljevljakusic Dubravka Bigovic Aleksandar Dzamic 《Molecules (Basel, Switzerland)》2022,27(19)
The aim of our study was to determine the susceptibility of 15 Candida albicans sputum isolates on fluconazole and caspofungin, as well as the antifungal potential of Lavandula angustifolia essential oil (LAEO). The commercial LAEO was analyzed using gas chromatography-mass spectrometry. The antifungal activity was evaluated using EUCAST protocol. A killing assay was performed to evaluate kinetics of 2% LAEO within 30 min treatment. LAEO with major constituents’ linalool (33.4%) and linalyl acetate (30.5%) effective inhibited grows of C. albicans in concentration range 0.5–2%. Fluconazole activity was noted in 67% of the isolates with MICs in range 0.06–1 µg/mL. Surprisingly, 40% of isolates were non-wild-type (non-WT), while MICs for WT ranged between 0.125–0.25 µg/mL. There were no significant differences in the LAEO MICs among fluconazole-resistant and fluconazole-susceptible sputum strains (p = 0.31) and neither among caspofungin non-WT and WT isolates (p = 0.79). The 2% LAEO rapidly achieved 50% growth reduction in all tested strains between 0.2 and 3.5 min. Within 30 min, the same LAEO concentration exhibited a 99.9% reduction in 27% isolates. This study demonstrated that 2% solution of LAEO showed a significant antifungal activity which is equally effective against fluconazole and caspofungin susceptible and less-susceptible strains. 相似文献
359.
For a finite non cyclic group G, let γ(G) be the smallest integer k such that G contains k proper subgroups H 1, . . . , H k with the property that every element of G is contained in \({H_i^g}\) for some \({i \in \{1,\dots,k\}}\) and \({g \in G.}\) We prove that for every n ≥ 2, there exists a finite solvable group G with γ(G) = n. 相似文献
360.