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71.
The increasing prevalence of inflammatory diseases and the adverse effects associated with the long-term use of current anti-inflammatory therapies prompt the identification of alternative approaches to reestablish immune balance. Apigenin, an abundant dietary flavonoid, is emerging as a potential regulator of inflammation. Here, we show that apigenin has immune-regulatory activity in vivo. Apigenin conferred survival to mice treated with a lethal dose of Lipopolysaccharide (LPS) restoring normal cardiac function and heart mitochondrial Complex I activity. Despite the adverse effects associated with high levels of splenocyte apoptosis in septic models, apigenin had no effect on reducing cell death. However, we found that apigenin decreased LPS-induced apoptosis in lungs, infiltration of inflammatory cells and chemotactic factors’ accumulation, re-establishing normal lung architecture. Using NF-κB luciferase transgenic mice, we found that apigenin effectively modulated NF-κB activity in the lungs, suggesting the ability of dietary compounds to exert immune-regulatory activity in an organ-specific manner. Collectively, these findings provide novel insights into the underlying immune-regulatory mechanisms of dietary nutraceuticals in vivo.  相似文献   
72.
Maximum likelihood estimation of models based on continuous latent variables generally requires to solve integrals that are not analytically tractable. Numerical approximations represent a possible solution to this problem. We propose to use the adaptive Gaussian–Hermite (AGH) numerical quadrature approximation for a particular class of continuous latent variable models for time-series and longitudinal data. These dynamic models are based on time-varying latent variables that follow an autoregressive process of order 1, AR(1). Two examples are the stochastic volatility models for the analysis of financial time series and the limited dependent variable models for the analysis of panel data. A comparison between the performance of AGH methods and alternative approximation methods proposed in the literature is carried out by simulation. Empirical examples are also used to illustrate the proposed approach.  相似文献   
73.
Growing evidence suggests that the freely accessible pollen of some plants is chemically protected against pollen-feeding flower visitors. For example, a diet of pollen from buttercup plants (Ranunculus) recently was shown to have a deleterious effect on developing larvae of several bee species not specialized on Ranunculus. Numerous Ranunculus species contain ranunculin, the glucosyl hydrate form of the highly reactive and toxic lactone protoanemonin, that causes the toxicity of these plants. We tested whether the presence of ranunculin is responsible for the lethal effects of R. acris pollen on the larvae of two bee species that are not Ranunculus specialists. To investigate the effect on bee larval development, we added ranunculin to the pollen provisions of the Campanula specialist bee Chelostoma rapunculi and the Asteraceae specialist bee Heriades truncorum, and allowed the larvae to feed on these provisions. We quantified ranunculin in pollen of R. acris and in brood cell provisions collected by the Ranunculus specialist bee Chelostoma florisomne. We demonstrated that although ranunculin was lethal to both tested bee species in high concentrations, the concentration in the pollen of R. acris was at least fourfold lower than that tolerated by the larvae of C. rapunculi and H. truncorum in the feeding experiments. Ranunculin concentration in the brood cells of C. florisomne was on average even twentyfold lower than that in Ranunculus pollen, suggesting that a mechanism different from ranunculin intoxication accounts for the larval mortality reported for bees not specialized on Ranunculus pollen.  相似文献   
74.
The elemental profile of tequila samples from the three main production areas of the State of Jalisco, namely Amatitlan, Guadalajara, and Tequila, was used to carry out their geographical characterization. With this aim, the concentration of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, S, Sr, and Zn was determined by inductively coupled plasma atomic emission spectroscopy. Principal component analysis was addressed to visualize data trends. The number of input variables was reduced by means of backward stepwise linear discriminant analysis and support vector machines were used to construct an adequate classification model. The best classification performance was obtained by a linear support vector machine model with 100% of prediction ability.  相似文献   
75.
The Palearctic planthopper Hyalesthes obsoletus is the natural vector of the grapevine yellow disease Bois noir. Grapevine is an occasional host plant of this polyphagous planthopper. To deepen our knowledge of the role of plant volatile organic compounds for H. obsoletus host plant searching, we carried out behavioral, morphological, and electrophysiological studies. We tested the attraction of H. obsoletus to nettle, field bindweed, hedge bindweed, chaste tree, and grapevine by using a Y-shaped olfactometer. The results showed a significant attraction of male H. obsoletus to chaste tree, and of the females to nettle. Male H. obsoletus were repelled by odor from hedge bindweed. Ultrastructural studies of the antennae showed at least two types of olfactory sensilla at the antennal pedicel: plaque organs and trichoid sensilla. Volatile organic compounds from nettle and chaste tree were collected, and the extracts were analyzed by coupling gas-chromatography to both mass-spectrometry and electroantennography. The volatile organic compounds that elicited electrophysiological responses in male and female antennae were identified. These findings are discussed with respect to behavior of H. obsoletus males and females in the field.  相似文献   
76.
Product flexibility is key to meeting fluctuating chemicals demands in the future. In this contribution, the methanol to hydrocarbons (MTH) reaction was investigated over two Ge-containing H-ITQ-13 samples, one with needle-like (H-ITQ-13(N), with (Si+Ge)/Al) = 42) and another with plate-like (H-ITQ-13(P), with (Si+Ge)/Al > 100) morphology. The samples were characterised using XRD, BET, SEM/EDS and FTIR spectroscopy, and their MTH performance was compared with the performance of H-ZSM-5 and H-ZSM-22. Similar specific surface areas (413 and 455 m2 g?1 for H-ITQ-13(N) and (P), respectively) and similar acid strength (Δν ~ ?327(?310) cm?1) was observed for the two H-ITQ-13 samples. Testing of H-ITQ-13(N) at weight hourly space velocity (WHSV) = 2–8 h?1 at 350–450 °C revealed that C5+ alkenes were the main products (35–45 % selectivity at 400 °C), followed by propene and butene. A low but significant selectivity for aromatic products was observed (6–8 % selectivity at 400 °C). Product selectivity was found to be independent of deactivation. The methanol conversion capacity of H-ITQ-13(N) was 120–150 g methanol g?1 catalyst at 400 °C. Testing H-ITQ-13 at high (30 atm) and ambient pressure, respectively, at 350 °C showed that a high pressure led to enhanced C5+ selectivity, but close to a tenfold decrease in methanol conversion capacity. H-ITQ-13(P) was tested at 400 °C and 2 h?1. It gave lower conversion than H-ITQ-13(N). Furthermore, when compared at the same conversion level, H-ITQ-13(P) gave higher C5+ alkene selectivity, lower aromatics selectivity, and a higher propene to ethene ratio than H-ITQ-13(N). The H-ITQ-13 samples yielded a product spectrum intermediate of H-ZSM-22 and H-ZSM-5. The effluent product cut-off of H-ITQ-13 was similar to that of H-ZSM-5 with tetramethylbenzene as the largest significant product, while H-ZSM-22 produced mainly linear and branched alkenes. The lifetime of H-ITQ-13(N) was clearly enhanced compared to H-ZSM-22, but inferior to H-ZSM-5.  相似文献   
77.
A class of production systems are considered in this paper with the aim of determining closed-loop strategies providing the production effort as functions of the system state. The key feature of the considered class of systems is that the demand and the way it is satisfied are asynchronous sequences of part requests and instantaneous withdrawals, respectively, generated by discrete-event processes, whereas the production process has continuous-time dynamics. The optimization problem, whose objective is to minimize inventory and lateness costs, is restated as an optimal control problem by exploiting some structural properties of the optimal solution. Then, optimal closed-loop strategies are found with dynamic programming techniques.  相似文献   
78.
Perfluoropolyether (PFPE) structures can be functionalized with acrylic groups using appropriate hydrogenated acrylic monomers: the macromers obtained are highly reactive under UV irradiation, and fluorinated polymers can be obtained. In the first part of this work is described the synthesis of new PFPE (meth)acrylic oligomers by extending OH‐terminated fluorinated chains with urethane groups and reactive acrylic functions. The photopolymerization reaction of each product is then reported followed by the characterisation of the main thermal, mechanical and surface properties of UV‐cured coatings. The polymers have good thermal resistance and fair mechanical and chemical resistance. More interestingly they show very low refractive index and low surface tension. For these latter properties the products can be advantageously used in highly demanding applications such as photonic devices and nano‐patterning. Copyright © 2011 Society of Chemical Industry  相似文献   
79.
Trypanosoma rangeli and T. cruzi are both parasitic unicellular species that infect humans. Unlike T. cruzi, the causative agent of Chagas disease, T. rangeli is an infective and non-pathogenic parasite for humans, but pathogenic for vectors from the Rhodnius genus. Because both species can coexist in different hosts and overlap their infective cycles but very little is known about the infection of T. rangeli in mammalian cells, we decided to characterize both the development of this parasite in cell culture and the effect of therapeutic agents with potential trypanocidal action on it. We found that T. rangeli exhibits a cycle of infection in Vero cells similar to that for T. cruzi and that the repurposed drug, 17-AAG, and the natural extract Artemisia sp. essential oil produce a toxic effect on epimastigotes showing a trypanocidal action from the fifth day of culture. Both treatments also affected the infection of trypomastigotes and reduced the capacity of replication of amastigotes of T. rangeli. Since T. cruzi / T. rangeli coinfection cases have been reported, the finding of drugs with potential activity against both species could be significant in the future. Furthermore, studies of susceptibility of both species to drugs could also help to know the different mechanisms of pathogenicity in humans displayed by T. cruzi that are absent in T. rangeli  相似文献   
80.
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