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It would be desirable to establish and standardize methods that can measure the total antioxidant capacity level directly from vegetable extracts containing phenolics. Antioxidant capacity assays may be broadly classified as elect...
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It would be desirable to establish and standardize methods that can measure the total antioxidant capacity level directly from vegetable extracts containing phenolics. Antioxidant capacity assays may be broadly classified as electron transfer (ET)− and hydrogen atom transfer (HAT)−based assays. The majority of HAT assays are kinetics-based, and involve a competitive reaction scheme in which antioxidant and substrate compete for peroxyl radicals thermally generated through the decomposition of azo compounds. ET−based assays measure the capacity of an antioxidant in the reduction of an oxidant, which changes colour when reduced. ET assays include the ABTS/TEAC, CUPRAC, DPPH, Folin-Ciocalteu and FRAP methods, each using different chromogenic redox reagents with different standard potentials. This review intends to offer a critical evaluation of existing antioxidant assays applied to phenolics, and reports the development by our research group of a simple and low-cost antioxidant capacity assay for dietary polyphenols, vitamins C and E, and human serum antioxidants, utilizing the copper(II)-neocuproine reagent as the chromogenic oxidizing agent, which we haved named the CUPRAC (cupric ion reducing antioxidant capacity) method. This method offers distinct advantages over other ET−based assays, namely the selection of working pH at physiological pH (as opposed to the Folin and FRAP methods, which work at alkaline and acidic pHs, respectively), applicability to both hydrophilic and lipophilic antioxidants (unlike Folin and DPPH), completion of the redox reactions for most common flavonoids (unlike FRAP), selective oxidation of antioxidant compounds without affecting sugars and citric acid commonly contained in foodstuffs and the capability to assay –SH bearing antioxidants (unlike FRAP). Other similar ET–based antioxidant assays that we have developed or modified for phenolics are the Fe(III)− and Ce(IV)−reducing capacity methods.
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Cellular Neural Networks (CNNs) have been widely used recently in applications such as edge detection, noise reduction and object detection, which are among the main computer imaging processes. They can also be realized as hardwar...
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Cellular Neural Networks (CNNs) have been widely used recently in applications such as edge detection, noise reduction and object detection, which are among the main computer imaging processes. They can also be realized as hardware based imaging sensors. The fact that hardware CNN models produce robust and effective results has attracted the attention of researchers using these structures within image sensors. Realization of desired CNN behavior such as edge detection can be achieved by correctly setting a cloning template without changing the structure of the CNN. To achieve different behaviors effectively, designing a cloning template is one of the most important research topics in this field. In this study, the edge detecting process that is used as a preliminary process for segmentation, identification and coding applications is conducted by using CNN structures. In order to design the cloning template of goal-oriented CNN architecture, an Artificial Bee Colony (ABC) algorithm which is inspired from the foraging behavior of honeybees is used and the performance analysis of ABC for this application is examined with multiple runs. The CNN template generated by the ABC algorithm is tested by using artificial and real test images. The results are subjectively and quantitatively compared with well-known classical edge detection methods, and other CNN based edge detector cloning templates available in the imaging literature. The results show that the proposed method is more successful than other methods.
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TAA is a harmful, presumptive pollutant in tap waters and waste waters. Several alternatives have been tested as new possibilities for the anodic determination of TAA in aqueous solutions, simulated waste waters and tap water. The...
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TAA is a harmful, presumptive pollutant in tap waters and waste waters. Several alternatives have been tested as new possibilities for the anodic determination of TAA in aqueous solutions, simulated waste waters and tap water. The electrochemical behaviour of thioacetamide (TAA) was investigated at a boron-doped diamond (BDD) electrode both in unbuffered 0.1 M Na2SO4 and buffered solutions as supporting electrolytes. The anodic oxidation of TAA showed well-defined limiting currents or current peaks and a good linearity of the amperometric signal vs. concentration plots. The analytical parameters of sensitivity, RSD and LOD, obtained under various experimental conditions, suggest the suitability of the BDD electrode for electroanalytical purposes. Low fouling effects, good reproducibility and stability, as well as the sharpness of the amperometric signals in both unbuffered/ buffered acidic or neutral media, highly superior to those obtained using a glassy carbon (GC) electrode, recommend the unmodified BDD electrode as a promising potential amperometric sensor for environmental applications, regarding the direct anodic determination of TAA in aqueous media.
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Six novel 3-alkyl(aryl)-4-(p-nitrobenzoylamino)-4,5-dihydro-1H-1,2,4-triazol-5- ones (2a-f) were synthesized by the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H- 1,2,4-triazol-5-ones (1a-f) with p-nitrobenzoyl chloride and ch...
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Six novel 3-alkyl(aryl)-4-(p-nitrobenzoylamino)-4,5-dihydro-1H-1,2,4-triazol-5- ones (2a-f) were synthesized by the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H- 1,2,4-triazol-5-ones (1a-f) with p-nitrobenzoyl chloride and characterized by elemental analyses and IR, 1H-NMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as acetone, isopropyl alcohol, tert-butyl alcohol and N,N-dimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. Thus, the effects of solvents and molecular structure upon acidity were investigated. In addition, isotropic 1H and 13C nuclear magnetic shielding constants of compounds 2 were obtained by the gauge-including-atomic-orbital (GIAO) method at the B3LYP density functional level. The geometry of each compound has been optimized using the 6-311G basis set. Theoretical values were compared to the experimental data. Furthermore, these new compounds and five recently reported 3-alkyl-4-(2-furoylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3a–c,e,f) were screened for their antioxidant activities.
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The likelihood of an ecological system to undergo undesired regime shifts is expected to increase as climate change effects unfold. To understand how regional climate settings can affect resilience; i.e., the ability of an ecosyst...
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The likelihood of an ecological system to undergo undesired regime shifts is expected to increase as climate change effects unfold. To understand how regional climate settings can affect resilience; i.e., the ability of an ecosystem to tolerate disturbances without changing its original structure and processes, we used a synchronized mesocosm experiment (representative of shallow lakes) along a latitudinal gradient. We manipulated nutrient concentrations and water levels in a synchronized mesocosm experiment in different climate zones across Europe involving Sweden, Estonia, Germany, the Czech Republic, Turkey and Greece. We assessed attributes of zooplankton communities that might contribute to resilience under different ecological configurations. We assessed four indicator of relative ecological resilience (cross-scale, within-scale structures, aggregation length and gap size) of zooplankton communities, inferred from discontinuity analysis. Similar resilience attributes were found across experimental treatments and countries, except Greece, which experienced severe drought conditions during the experiment. These conditions apparently led to a lower relative resilience in the Greek mesocosms. Our results indicate that zooplankton community resilience in shallow lakes is marginally affected by water level and the studied nutrient range unless extreme drought occurs. In practice, this means that drought mitigation could be especially challenging in semi-arid countries in the future.
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Data compression at its base is concerned with how information is organized in data. Understanding this organization can lead to efficient ways of representing the information and hence data compression. In this paper we review th...
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Data compression at its base is concerned with how information is organized in data. Understanding this organization can lead to efficient ways of representing the information and hence data compression. In this paper we review the ways in which ideas and approaches fundamental to the theory and practice of data compression have been used in the area of bioinformatics. We look at how basic theoretical ideas from data compression, such as the notions of entropy, mutual information, and complexity have been used for analyzing biological sequences in order to discover hidden patterns, infer phylogenetic relationships between organisms and study viral populations. Finally, we look at how inferred grammars for biological sequences have been used to uncover structure in biological sequences.
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Recently, the increasing number of bio-safety assessments on cadmium-containing quantum dots (QDs) suggested that they could lead to detrimental effects on the central nervous system (CNS) of living organisms, but the underlying a...
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Recently, the increasing number of bio-safety assessments on cadmium-containing quantum dots (QDs) suggested that they could lead to detrimental effects on the central nervous system (CNS) of living organisms, but the underlying action mechanisms are still rarely reported. In this study, whole-transcriptome sequencing was performed to analyze the changes in genome-wide gene expression pattern of rat hippocampus after treatments of cadmium telluride (CdTe) QDs with two sizes to understand better the mechanisms of CdTe QDs causing toxic effects in the CNS. We identified 2095 differentially expressed genes (DEGs). Fifty-five DEGs were between the control and 2.2 nm CdTe QDs, 1180 were between the control and 3.5 nm CdTe QDs and 860 were between the two kinds of CdTe QDs. It seemed that the 3.5 nm CdTe QD exposure might elicit severe effects in the rat hippocampus than 2.2 nm CdTe QDs at the transcriptome level. After bioinformatics analysis, we found that most DEG-enriched Gene Ontology subcategories and Kyoto Encyclopedia of Genes and Genomes pathways were related with the immune system process. For example, the Gene Ontology subcategories included immune response, inflammatory response and T-cell proliferation; Kyoto Encyclopedia of Genes and Genomes pathways included NOD/Toll-like receptor signaling pathway, nuclear factor-κB signaling pathway, tumor necrosis factor signaling pathway, natural killer cell-mediated cytotoxicity and T/B-cell receptor signaling pathway. The traditional toxicological examinations confirmed the systemic immune response and CNS inflammation in rats exposed to CdTe QDs. This transcriptome analysis not only revealed the probably molecular mechanisms of CdTe QDs causing neurotoxicity, but also provided references for the further related studies. Copyright ? 2018 John Wiley & Sons, Ltd.
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The slip at the steel-concrete interface in steel-concrete composite beams was studied analytically and numerically. A theoretical description for steel-concrete composite box beams with partial shear interaction based on the part...
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The slip at the steel-concrete interface in steel-concrete composite beams was studied analytically and numerically. A theoretical description for steel-concrete composite box beams with partial shear interaction based on the partial interaction theory was derived, and equilibrium of the rotation angle w′ was introduced to allow convenient computation of deformation of composite box beams. Numerical simulations of steel-concrete composite box beams subjected to concentrated load and/or uniformly distributed load were conducted. The analytical solutions show excellent agreement with the numerical results. For typical composite box beams used in practice, shear slip in partial composite box beams makes a significant contribution to beam deformation. Even for full composite box beams, slip effects may result in stiffness reduction. However, slip effects are ignored in many design specifications which use transformed section methods; an exception is the American Institute of Steel Construction [1] specifications, which recommend a calculation procedure in the commentary. Finally, the proposed method was extended to analyze the interface slip for shear connectors of different pitch and, to some extent, confirm the accuracy of the predictions.
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Southwestern Turkey is a tectonically active area. To determine kinematics and strain distribution in this region, a GPS network of sixteen stations was established. We have used GPS velocity field data for southwest Anatolia from...
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Southwestern Turkey is a tectonically active area. To determine kinematics and strain distribution in this region, a GPS network of sixteen stations was established. We have used GPS velocity field data for southwest Anatolia from continuous measurements covering the period 2003 to 2006 to estimate current crustal deformation of this tectonically active region. GPS data were processed using GAMIT/GLOBK software and velocity and strain rate fields were estimated in the study area. The measurements showed velocities of 15–30 mm/yr toward the southwest and strain values up to 0.28–8.23×10−8. Results showed that extension has been determined in the Burdur-Isparta region. In this study, all of strain data reveal an extensional neotectonic regime through the northeast edge of the Isparta Angle despite the previously reported compressional neotectonic regime. Meanwhile, results showed some small differences relatively with the 2006 model of Reilinger et al. As a result, active tectonic movements, in agreement with earthquake fault plane solutions showed important activity.
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