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排序方式: 共有1362条查询结果,搜索用时 31 毫秒
81.
Giulia Vallarino Annalisa Salis Elena Lucarini Federica Turrini Guendalina Olivero Alessandra Roggeri Gianluca Damonte Raffaella Boggia Lorenzo Di Cesare Mannelli Carla Ghelardini Anna Pittaluga 《Molecules (Basel, Switzerland)》2022,27(3)
A new formulation of a pomegranate-peel extract (PEm) obtained by PUAE (Pulsed Ultrasound-Assisted Extraction) and titrated in both ellagic acid (EA) and punicalagin is proposed, characterized and then analyzed for potential health properties in mice suffering from the experimental autoimmune encephalomyelitis (EAE). PEm effects were compared to those elicited by a formulation containing EA (EAm). Control and EAE mice were chronically administered EAm and Pem dissolved in the drinking water, starting from the day 10 post-immunization (d.p.i.), with a “therapeutic” protocol to deliver daily 50 mg/kg of EA. Treated EAE mice did not limit their daily access to the beverage, nor did they show changes in body weight, but they displayed a significant amelioration of “in vivo” clinical symptoms. “Ex vivo” histochemical analysis showed that spinal-cord demyelination and inflammation in PEm and EAm-treated EAE mice at 23 ± 1 d.p.i. were comparable to those in the untreated EAE animals, while microglia activation (measured as Ionized Calcium Binding Adaptor 1, Iba1 staining) and astrocytosis (quantified as glial fibrillar acid protein, GFAP immunopositivity) significantly recovered, particularly in the gray matter. EAm and PEm displayed comparable efficiencies in controlling the spinal pathological cellular hallmarks in EAE mice, and this would support their delivery as dietary supplementation in patients suffering from multiple sclerosis (MS). 相似文献
82.
Least-squares support vector machines and near infrared spectroscopy for quantification of common adulterants in powdered milk 总被引:5,自引:0,他引:5
This paper proposes the use of the least-squares support vector machine (LS-SVM) as an alternative multivariate calibration method for the simultaneous quantification of some common adulterants (starch, whey or sucrose) found in powdered milk samples, using near-infrared spectroscopy with direct measurements by diffuse reflectance. Due to the spectral differences of the three adulterants a nonlinear behavior is present when all groups of adulterants are in the same data set, making the use of linear methods such as partial least squares regression (PLSR) difficult. Excellent models were built using LS-SVM, with low prediction errors and superior performance in relation to PLSR. These results show it possible to built robust models to quantify some common adulterants in powdered milk using near-infrared spectroscopy and LS-SVM as a nonlinear multivariate calibration procedure. 相似文献
83.
NaClO2/NaI in the presence of HCl is a mild, cheap, and non-toxic reagent for the iodination of phenols, including estradiol and naphthol, aromatic amines, and heterocyclic substrates, e.g., indoles, 8-hydroxyquinoline, imidazole, in fair to excellent yields by a very simple isolation protocol. The scope of the procedure is exemplified by the first iodination of 5-nitroindole to 3-iodo-5-nitroindole in 75% yield. 相似文献
84.
Francesca?PelosiEmail author Rida?T.?Farouki Carla?Manni Alessandra?Sestini 《Advances in Computational Mathematics》2005,22(4):325-352
It is shown that, depending upon the orientation of the end tangents t0,t1 relative to the end point displacement vector p=p1–p0, the problem of G1 Hermite interpolation by PH cubic segments may admit zero, one, or two distinct solutions. For cases where two interpolants exist, the bending energy may be used to select among them. In cases where no solution exists, we determine the minimal adjustment of one end tangent that permits a spatial PH cubic Hermite interpolant. The problem of assigning tangents to a sequence of points p0,...,pn in R3, compatible with a G1 piecewise-PH-cubic spline interpolating those points, is also briefly addressed. The performance of these methods, in terms of overall smoothness and shape-preservation properties of the resulting curves, is illustrated by a selection of computed examples. 相似文献
85.
Francesca Felice Maria Michela Cesare Luca Fredianelli Marinella De Leo Veronica Conti Alessandra Braca Rossella Di Stefano 《Molecules (Basel, Switzerland)》2022,27(8)
Tomatoes and their derivates represent an important source of natural biologically active components. The present study aims to investigate the protective effect of tomato peel extracts, grown in normal (RED-Ctr) or in drought stress (RED-Ds) conditions, on an experimental model of sarcopenia. The phenolic profile and total polyphenols content (TPC) of RED-Ctr and RED-Ds were determined by Ultra High-Performance Liquid Chromatography (UHPLC) analyses coupled to electrospray ionization high-resolution mass spectrometry (ESI-HR-MS). Human skeletal muscle myoblasts (HSMM) were differentiated in myotubes, and sarcopenia was induced by dexamethasone (DEXA) treatment. Differentiation and sarcopenia were evaluated by both real-time PCR and immunofluorescent techniques. Data show that myosin heavy chain 2 (MYH2), troponin T (TNNT1), and miogenin (MYOG) were expressed in differentiated myotubes. 5 μg Gallic Acid Equivalent (GAE/mL) of TPC from RED-Ds extract significantly reduced muscle atrophy induced by DEXA. Moreover, Forkhead BoxO1 (FOXO1) expression, involved in cell atrophy, was significantly decreased by RED-Ds extract. The protective effect of tomato peel extracts depended on their qualitative polyphenolic composition, resulting effectively in the in vitro model of sarcopenia. 相似文献
86.
87.
Irene Bravo-Osuna Christine Vauthier Alessandra Farabollini Gioconda Millotti Gilles Ponchel 《Journal of nanoparticle research》2008,10(8):1293-1301
Surface modified nanoparticles composed of poly(isobutylcyanoacrylate) (PIBCA) cores surrounded by a chitosan and thiolated
chitosan gel layer were prepared and characterized in previous works. The presence of such biopolymers on the nanoparticle
surface conferred those nanosystems interesting characteristics that might partially overcome the gastrointestinal enzymatic
barrier, improving the oral administration of pharmacologically active peptides. In the present work, the antiprotease behaviour
of this family of core–shell nanoparticles was in vitro tested against two model metallopeptidases present in the gastrointestinal
tract (GIT): Carboxypeptidase A -CP A- (luminal protease) and Leucine Aminopeptidase M -LAP M- (membrane protease). As previous
step, the zinc-binding capacity of these nanoparticles was evaluated. Interestingly, an improvement of both the zinc-binding
capacity and the antiprotease effect of chitosan was observed when the biopolymers (chitosan and thiolated chitosan) were
used as coating component of the core–shell nanoparticles, in comparison with their behaviour in solution, thanks to the different
biopolymer chains rearrangement. The presence of amino, hydroxyl and thiol groups on the nanoparticle surface promoted zinc
binding and hence the inhibition of the metallopeptidases analysed. On the contrary, the occurrence of a cross-linked structure
in the gel layer surrounding the PIBCA cores of thiolated formulations, due to the formation of interchain and intrachain
disulphide bonds, partially limited the inhibition of the proteases. The low accessibility of cations to the active groups
of the cross-linked polymeric shell was postulated as a possible explanation of this behaviour. Results obtained in this work
make this family of surface-modified nanocarriers promising candidates for the successfull administration of pharmacologically
active peptides and proteins by the oral route. 相似文献
88.
Chlorofluorocarbons and their substitutes are anthropogenic compounds strongly involved in global change phenomena. Therefore, their atmospheric mixing-ratios are monitored on a worldwide scale. In order to evaluate source strength of these compounds in Southern Europe, in 1999 a research activity, monitoring these compounds in the atmosphere of the Monte Cimone (MO, Italy) was started. Air samples, collected on a weekly base, were analyzed using a GC-MS methodology recently devised by our group. The reported results, obtained after eighteen months of observation, are relative to four fully halogenated halocarbons and four hydrogenated halocarbons. 相似文献
89.
Microarrays are becoming a ubiquitous tool of research in life sciences. However, the working principles of microarray-based methodologies are often misunderstood or apparently ignored by the researchers who actually perform and interpret experiments. This in turn seems to lead to a common over-expectation regarding the explanatory and/or knowledge-generating power of microarray analyses. In this note we intend to explain basic principles of five (5) major groups of analytical techniques used in studies of microarray data and their interpretation: the principal component analysis (PCA), the independent component analysis (ICA), the t-test, the analysis of variance (ANOVA), and self organizing maps (SOM). We discuss answers to selected practical questions related to the analysis of microarray data. We also take a closer look at the experimental setup and the rules, which have to be observed in order to exploit microarrays efficiently. Finally, we discuss in detail the scope and limitations of microarray-based methods. We emphasize the fact that no amount of statistical analysis can compensate for (or replace) a well thought through experimental setup. We conclude that microarrays are indeed useful tools in life sciences but by no means should they be expected to generate complete answers to complex biological questions. We argue that even well posed questions, formulated within a microarray-specific terminology, cannot be completely answered with the use of microarray analyses alone. 相似文献
90.
The interaction of water with Si- and C- terminated beta-SiC(001) surfaces was investigated by means of ab initio molecular dynamics simulations. Irrespective of coverage, varied from 1/4 to 1 monolayer, we found that water dissociates on the Si-terminated surface, substantially modifying the clean surface reconstruction, while the C-terminated surface is nonreactive and hydrophobic. Based on our results, we propose that STM images and photoemission experiments may detect specific changes induced by water on both the structural and electronic properties of SiC(001) surfaces. 相似文献