In the present work we embrace a three scales asymptotic homogenization approach to investigate the effective behavior of hierarchical linear elastic composites reinforced by cylindrical, uniaxially aligned fibers and possessing a periodic structure at each hierarchical level of organization. We present our novel results assuming isotropy of the constituents and focusing on the effective out-of-plane shear modulus, which is computed exploiting the solution of the arising anti-plane problems. The latter are solved semi-analytically by means of complex variables and successfully benchmarked against the results obtained by finite elements. Our findings can pave the way for multiscale modeling of complex hierarchical materials (such as bone and tendons) at a negligible computational cost.
In this work, bee pollen samples from different botanical origin were investigated for antioxidant capacity. Thereafter, a phenolic profiling was produced through a mass spectrometric untargeted metabolomic approach. Marked differences were identified in TPC, ranging from 4.2 (Magnolia) to 29.6 mg g−1 GAE (Lamium). Wide differences were also recorded in antioxidant capacity (ORAC, ABTS and DPPH assays). Untargeted profiling allowed annotating 467 compounds with flavonoids being the most frequent class of phenolics followed by phenolic acids, tyrosols, lignans and other. OPLS-DA clearly discriminated the most represented floral families (Umbelliferae, Rosaceae and Fabaceae), suggesting, thus, that botanical origin leaves a characteristic phenolic signature in pollen. Overall, 35 phenolics accounted for most of the discrimination, with flavonoids being the most represented class. Despite the fact that further research is needed, the phenolic profile of bee pollen is a promising tool to investigate the botanical origin. 相似文献
Sizeable scientific evidence indicates the health benefits related to phenolic compounds and dietary fiber. Various phenolic compounds-rich foods or ingredients are also rich in dietary fiber, and these two health components may interrelate via noncovalent (reversible) and covalent (mostly irreversible) interactions. Notwithstanding, these interactions are responsible for the carrier effect ascribed to fiber toward the digestive system and can modulate the bioaccessibility of phenolics, thus shaping health-promoting effects in vivo. On this basis, the present review focuses on the nature, occurrence, and implications of the interactions between phenolics and food components. Covalent and noncovalent interactions are presented, their occurrence discussed, and the effect of food processing introduced. Once reaching the large intestine, fiber-bound phenolics undergo an intense transformation by the microbial community therein, encompassing reactions such as deglycosylation, dehydroxylation, α- and β-oxidation, dehydrogenation, demethylation, decarboxylation, C-ring fission, and cleavage to lower molecular weight phenolics. Comparatively less information is still available on the consequences on gut microbiota. So far, the very most of the information on the ability of bound phenolics to modulate gut microbiota relates to in vitro models and single strains in culture medium. Despite offering promising information, such models provide limited information about the effect on gut microbes, and future research is deemed in this field. 相似文献
DNA G-quadruplexes (G4s) form in relevant genomic regions and intervene in several biological processes, including the modulation of oncogenes expression, and are potential anticancer drug targets. The human KRAS proto-oncogene promoter region contains guanine-rich sequences able to fold into G4 structures. Here, by using circular dichroism and differential scanning calorimetry as complementary physicochemical methodologies, we compared the thermodynamic stability of the G4s formed by a shorter and a longer version of the KRAS promoter sequence, namely 5′-AGGGCGGTGTGGGAATAGGGAA-3′ (KRAS 22RT) and 5′-AGGGCGGTGTGGGAAGAGGGAAGAGGGGGAGG-3′ (KRAS 32R). Our results show that the unfolding mechanism of KRAS 32R is more complex than that of KRAS 22RT. The different thermodynamic stability is discussed based on the recently determined NMR structures. The binding properties of TMPyP4 and BRACO-19, two well-known G4-targeting anticancer compounds, to the KRAS G4s were also investigated. The present physicochemical study aims to help in choosing the best G4 target for potential anticancer drugs. 相似文献
Applied Intelligence - Berth allocation is one of the crucial points for efficient management of ports. This problem is complex due to all possible combinations for assigning ships to available... 相似文献
Tart cherries (TCs) contain high levels of anthocyanins that exert potent antioxidant and antiinflammatory effects and potentially benefit individuals with gout.
Methods and results
This study aims to quantitate the major anthocyanins in TC Juice Concentrate (TCJC) and identify the pharmacokinetic (PK) and pharmacodynamic (PD) parameters of the major anthocyanin cyanidin-3-glucosylrutinoside (C3GR). A PK-PD study enrolling human subjects with a history of gout is performed. Subjects are randomized to receive either 60 or 120 mL of TCJC. Anthocyanins are quantitated using liquid chromatography-mass spectroscopy (LCMS). Antioxidant and antiinflammatory mRNA expression is measured using real-time qPCR before and after the administration of TCJC. A population PK model (popPK) is fit to the experimental data, and an indirect PD model (IDR) is constructed in Monolix.
Conclusion
Of the bioavailable anthocyanins, C3GR achieves the highest plasma concentration in a dose-dependent manner. A popPK predicts anthocyanin exposure, and an IDR produces reasonable approximations of PD effects. 相似文献
An improvement of the trajectory matching algorithm is presented, which is based on the use of the derivative of trajectories and of the projection of experimental sinogram lines in the factor space determined by sinogram lines of projections of a model. The algorithm performance is illustrated by use of different phantom structures, to show the effect of symmetry on trajectory matching. A GroEL complex has also been reconstructed from both cryo-negatively stained and unstained frozen-hydrated samples. The refinement of this structure has been carried out by the trajectory matching algorithm as well as by conventional cross-correlation methods. Slight differences among the two results are discussed. The improved trajectory matching algorithm, based on chi2 distances, runs much faster than correlation analysis and looks satisfactory as for the quality of the reconstructed structures. 相似文献