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391.
The recent discovery of superconductivity in a metallic aromatic hydrocarbon, alkali-doped p-terphenyl, has attracted considerable interest. The critical temperature T c ranges from few to 123 K, the record for organic superconductors, due to uncontrolled competition of multiple phases and dopants concentrations. In the proposed mechanism of Fano resonance in a superlattice of quantum wires with coexisting polarons and Fermi particles, the lattice properties play a key role. Here, we report a study of the temperature evolution of the parent compound p-terphenyl crystal structure proposed to be made of a self-assembled supramolecular network of nanoscale nanoribbons. Using temperature-dependent synchrotron X-ray diffraction, we report the anisotropic thermal expansion in the ab plane, which supports the presence of a nanoscale network of one-dimensional nanoribbons running in the b-axis direction in the P21/a structure. Below the enantiotropic phase transition at 193 K, the order parameter of the C-1 structure follows a power law behavior with the critical exponent α =?0.34 ± 0.02 and the thermal expansion of the a-axis and b-axis show major changes supporting the formation of a two-dimensional bonds network. The large temperature range of the orientation fluctuations in a double well potential of the central phenyl has been determined.  相似文献   
392.
A new multi-compound method for the analysis of veterinary drugs, namely tiamulin, trimethoprim, tylosin, sulfadiazine and sulfamethazine was developed and validated in medicated feeds. After extraction, the samples were centrifuged, diluted in Milli-Q water, filtered and analysed by high performance liquid chromatography coupled to tandem mass spectrometry. The separation of the analytes was performed on a biphenyl column with a gradient of 0.1% formic acid in acetonitrile and 0.1% formic acid in Milli-Q water. Quantitative validation was done in accordance with the guidelines laid down in European Commission Decision 2002/657/EC. Method performances were evaluated by the following parameters: linearity (R2 < 0.99), precision (repeatability <14% and within-laboratory reproducibility <24%), recovery (73.58–115.21%), sensitivity, limit of detection (LOD), limit of quantification (LOQ), selectivity and expanded measurement uncertainty (k. = 2). The validated method was successfully applied to the 2 medicated feeds obtained from the interlaboratory studies and feed manufactures from Spain in August 2017. In these samples, tiamulin, tylosin and sulfamethazine were detected at the concentration levels declared by the manufacturers. The developed method can therefore be successfully used to routinely control the content and homogeneity of these antibacterial substances in medicated feed.

Abbreviations

AAFCO – Association of American Feed Control Officials; TYL – tylosin; TIAM – tiamulin fumarate; TRIM – trimethoprim; SDZ – sulfadiazine; SMZ – sulfamethazine; UV – ultraviolet detector; FLD – fluorescence detector; HPLC – high performance liquid chromatography; MS/MS – tandem mass spectrometry; LOD – limit of detection; LOQ – limit of quantification; CV – coefficient of variation; SD – standard deviation; U – uncertainty  相似文献   

393.
BACKGROUND: A study was made into how the type of information (picture of real package or card with beverage type and nutritional facts) and consumer attitudes (interest in eating healthily and food neophobia) affect hedonic ratings and purchase intention with respect to milk and soybean vanilla beverages and to what extent the expectations created by information influence the hedonic ratings of these products. RESULTS: A significant effect of the interaction between samples and information type was detected for both expected acceptability and purchase intention when only information about the samples was provided. The effect of this interaction was significant for acceptability ratings when the samples were evaluated together with corresponding information. The acceptability and purchase intention for two soymilk samples were significantly higher for consumers interested in eating healthily. Both types of information generated an assimilation effect for four samples; however, only for milk beverages was this effect complete. CONCLUSION: Information affected purchase intention to a greater extent than it did hedonic ratings. Type of information significantly affected hedonic ratings in most samples, although sensory quality seemed more decisive for two of the soymilk samples. The extent to which information influenced consumer behaviour was also dependent on some consumer attitudes, such as interest in eating healthily. Copyright © 2008 Society of Chemical Industry  相似文献   
394.
Protein synthesis is important for maintaining cellular homeostasis under various stress responses. In this study, we screened an anticancer drug library to select compounds with translational repression functions. AZD8055, an ATP-competitive mechanistic target of rapamycin complex 1/2 (mTORC1/2) inhibitor, was selected as a translational suppressor. AZD8055 inhibited protein synthesis in mouse embryonic fibroblasts and hepatocellular carcinoma HepG2 cells. Extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) were activated during the early phase of mTORC1/2 inhibition by AZD8055 treatment. Combined treatment of AZD8055 with the MAPK kinase1/2 (MEK1/2) inhibitor refametinib or the p38 inhibitor SB203580 markedly decreased translation in HepG2 cells. Thus, the inhibition of ERK1/2 or p38 may enhance the efficacy of AZD8055-mediated inhibition of protein synthesis. In addition, AZD8055 down-regulated the phosphorylation of eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), and AZD8055-induced phosphorylation of ERK1/2 and p38 had no effect on phosphorylation status of 4E-BP1. Interestingly, AZD8055 modulated the 4E-BP1 mRNA pool by up-regulating ERK1/2 and p38 pathways. Together, these results suggest that AZD8055-induced activation of MAPKs interferes with inhibition of protein synthesis at an early stage of mTORC1/2 inhibition, and that it may contribute to the development of resistance to mTORC1/2 inhibitors.  相似文献   
395.
On 11 March 2020, the World Health Organization (WHO) declared a pandemic due to the spread of COVID-19 from Wuhan, China, causing high mortality rates all over the world. The related disease, which mainly affects the lungs, is responsible for the onset of Diffuse Alveolar Damage (DAD) and a hypercoagulability state, frequently leading to Severe Acute Respiratory Syndrome (SARS) and multiorgan failure, particularly in old and severe-critically ill patients. In order to find effective therapeutic strategies, many efforts have been made aiming to shed light on the pathophysiology of COVID-19 disease. Moreover, following the late advent of vaccination campaigns, the need for the comprehension of the pathophysiology of the fatal, although rare, thrombotic adverse events has become mandatory as well. The achievement of such purposes needs a multidisciplinary approach, depending on a correct interpretation of clinical, biochemical, biomolecular, and forensic findings. In this scenario, autopsies have helped in defining, on both gross and histologic examinations, the main changes to which the affected organs undergo and the role in assessing whether a patient is dead “from” or “with” COVID-19, not to mention whether the existence of a causal link exists between vaccination and thrombotic adverse events. In the present work, we explored the role of postmortem immunohistochemistry, and the increasingly used ancillary technique, in helping to understand the mechanism underlying the pathophysiology of both COVID-19 disease and COVID-19 vaccine-related adverse and rare effects.  相似文献   
396.
The objective of this study was to compare the deposition of carotenoids in egg yolk in the presence of different levels of capsaicin in the diet of hens. A yellow corn basal diet was prepared and corresponded to the control treatment; the other five treatments were with red carotenoids as follows: Oleoresin and Biored (commercial unsaponified and saponified extracts of red pepper respectively) and three with red pepper meal (Guajillo) with different levels of capsaicin (0.76, 12.26 and 35.26 mg kg−1 diet). The level of total carotenoids was 20–25 mg kg−1 diet in the five treatments. The total carotenoids in egg yolks (30 ± 0.34 mg kg−1) of red pepper diets with three levels of capsaicin were not statistically different. However, the carotenoid content was lower in egg yolks of commercial preparations (saponified, 26 ± 0.86 mg kg−1; unsaponified, 24 ± 0.85 mg kg−1). The highest level of capsaicin had a significant effect on the deposition of capsanthin and zeaxanthin during the 3 weeks of feeding. For the commercial saponified preparation (Biored) and the unsaponified pepper in the presence of capsaicin the colour obtained was the one preferred by the consumer (9.34 ± 0.05). Oleoresin was a poor pigment. It is concluded that capsaicin had a positive effect on the deposition of carotenoids in egg yolk without affecting the productivity parameters. © 1999 Society of Chemical Industry  相似文献   
397.
Partially biodegradable porous scaffolds incorporating bioactive molecules prepared by clean techniques posses an enormous interest in tissue engineering applications. Poly(methyl methacrylate)-poly(l-lactic acid) (PMMA-PLA) blends were submitted to CO2 supercritical conditions (P = 160-260 bar, T = 60 °C) after certain time and then rapidly depressurized to obtain porous structures that have been related with the supercritical parameters and to the polymer blend composition. In some cases ibuprofen was also incorporated to the formulations previously to the CO2 treatment and studied the appropriate conditions for avoiding its extraction in SCCO2. Scaffolds purity, thermal transitions, swelling and degradation behaviour, and the ibuprofen release were also studied to determine the appropriate scaffolds with a desired porosity for cell seeding. Cell culture was performed on the selected porous scaffolds using human fibroblast examined by scanning electron microscopy (SEM).  相似文献   
398.
Habitat modelling results are extremely sensitive to the habitat suitability criteria (HSC) used in the simulations. HSCs are usually expressed as univariate habitat suitability curves, although such univariate approach has been long questioned, since overlooking interactions between hydraulic variables may misrepresent the complexity of fish behaviour in habitat selection. It could lead to adopt erroneous flow management decisions based on misleading results. Furthermore, the interactive effects of hydraulic variables on habitat selection may be driven by the structural features of the channel, which determine cover availability. Therefore, we compared brown trout habitat selection patterns through multivariate resource selection functions (RSFs) in structurally contrasting rivers to unveil the interactive effects of hydraulics and cover elements and their consequences in univariate HSC results. Microhabitat preferences of young‐of‐the‐year (0+) trout were similar across fast and slow waters, meanwhile juvenile (1+) and adult (>1+) preferences significantly changed. RSFs for young‐of‐the‐year trout were consistent with univariate results and did not differ among water types. However, RSFs for older trout varied among water types and revealed complex interactions among hydraulic variables and between hydraulics and structural elements, which were not described accurately by univariate curves. Therefore, results suggest that interactions between water depth and current velocity have a significant effect on habitat selection patterns in juvenile and adult brown trout, this effect being controlled by cover availability. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
399.
In manufacturing high-technology products using automated manufacturing equipment it is critical to obtain process-operating conditions that simultaneously optimize several output variables of interest. Often these output variables are non-traditional responses such as standard deviations, and there may even be discrete (count or binary) responses. Statistically designed experiments are very useful in optimizing these processes. We illustrate how factorial experiments, statistical models for the responses of interest, and simple optimization techniques can be successfully applied to a bonded leads process.  相似文献   
400.
Abstract

Extra virgin olive oil (EVOO) polyphenols, including the secoiridoids oleocanthal (OLC) and oleacein (OLE), are attracting attention because of their beneficial effects on health. Data on OLC and OLE bioavailability are scarce, as most research on EVOO polyphenols has concentrated on hydroxytyrosol, tyrosol, and oleuropein. Consequently, relevant goals for future research are the elucidation of OLC and OLE bioavailability and finding evidence for their beneficial effects through pre-clinical and clinical studies. The aim of this review is to shed light on OLC and OLE, focusing on their precursors in the olive fruit and the impact of agronomic and processing factors on their presence in EVOO. Also discussed are their bioavailability and absorption, and finally, their bioactivity and health-promoting properties.  相似文献   
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