The Phenolics and Antioxidant Properties of Black and Purple versus White Eggplant Cultivars

The total phenolic content, anthocyanins, phenolic acids, antioxidant capacity and α-amylase inhibitory activity of black (Aydin Siyahi), purple (Kadife Kemer) and white (Trabzon Kadife) eggplants grown in Turkey were subjected to a comparative investigation. The black cultivar exhibited the highest total phenolic (17,193 and 6552 mg gallic acid equivalent/kg fw), flavonoid (3019 and 1160 quercetin equivalent/kg fw) and anthocyanin (1686 and 6167 g delphinidin-3-O-glucoside equivalent/kg fw) contents in crude extracts of the peel and pulp. The majority of the caffeic acid was identified in the ester (2830 mg/kg fw) and ester-bound (2594 mg/kg fw) forms in the peel of ‘Kadife Kemer’ and in the glycoside form (611.9 mg/kg fw) in ‘Aydin Siyahi’, as well as in the pulp of these two eggplants. ‘Kadife Kemer’ (purple eggplant) contained the majority of the chlorogenic acid in free form (27.55 mg/kg fw), compared to ‘Aydin Siyahi’ in the ester (7.82 mg/kg fw), glycoside (294.1 mg/kg dw) and ester-bound (2.41 mg/kg fw) forms. The eggplant cultivars (peel and pulp, mg/kg fw) exhibited a relatively high delphinidin-3-O-rutinoside concentration in the peel of ‘Aydin Siyahi’ (avg. 1162), followed by ‘Kadife Kemer’ (avg. 336.6), and ‘Trabzon Kadife’ (avg. 215.1). The crude phenolic extracts of the eggplants exhibited the highest antioxidant capacity values (peel and pulp, µmoL Trolox equivalent/kg fw) of 2,2-diphenyl-1-picrylhydrazyl (DPPH, 8156 and 2335) and oxygen radical absorbance capacity (ORAC, 37,887 and 17,648). The overall results indicate that black and purple eggplants are the cultivars with greater potential benefits in terms of their phenolics and antioxidant values than the white eggplant.     

Behavior of Glassy Carbon Paste Electrode in Flowing Methanolic Solutions

Carbon paste electrodes are often used for electrochemical determinations, but their application in media with high content of organic solvents, particularly in HPLC, is limited by their low stability. The work presented here examines the effect of a moving methanol‐containing solution on a glassy carbon paste electrode by studying its electrochemical behavior in relation to the period of contact and methanol content in the solution. In combination with microscopic observation of the paste surface it can be concluded that the electrode is affected by the methanolic solution and the surface roughness increases, resulting in the stable state compatible with measurements in highly methanolic solutions.     

Isolation of Biogenic Amines Using Paramagnetic Microparticles Off-Line Coupled with Ion Exchange Liquid Chromatography

This study aims at the possibility of single structured paramagnetic microparticles (PMPs), composed of maghemite (γ-Fe₂O₃) core modified with chitosan called MAN8, or tetraethyl orthosilicate covered with Dowex called MAN35, to be helpful for isolation of biogenic amines prior to their further analysis. Primarily, we synthesized and characterized PMPs. To obtain the information about bead morphology, scanning electron microscopy was employed. Furthermore, X-ray fluorescence was employed to carry out the elemental composition analyses. To obtain further insight into interaction between PMP surface and biogenic amines, scanning electron microscope was employed. It was shown that binding of biogenic amines causes increase of relative current response of deprotonated microparticles. We tested the specificity of PMPs to bind biogenic amines on histamine, tyramine, spermine, spermidine, putrescine, and cadaverine. We found that two types of our PMPs were able to selectively bind spermidine, cadaverine, and histamine in the case of MAN35; and histamine, tyramine, and putrescine in the case of MAN8. Finally, we carried out the analyses of real samples obtained from patients suffering from prostate carcinoma, where histamine was determined as the most abundant biogenic amine (10.456–13.654 µg mL^?1). The prepared PMPs were able to isolate the biogenic amines from real samples, and thus they may be helpful in construction of biosensors, or Lab-on-a-Chip platforms, enabling less painful, and more rapid diagnosis of prostate cancer.     

Voltammetric Determination of 8‐Nitroquinoline Using a Silver Solid Electrode and Its Application to Model Samples of Drinking and River Water

This work is focused on the application of a silver solid electrode (AgE) for the development of modern voltammetric methods for the determination of submicromolar concentrations of biologically active compounds present in the environment. 8‐Nitroquinoline (8‐NQ), a well‐known chemical carcinogen, was chosen as a model substance. Differential pulse voltammetry (DPV) was used to study electrochemical behavior of 8‐NQ in different aqueous matrices. The following optimal conditions for determination of 8‐NQ in the concentration ranges from 2 to 100 µmol L^?1 were used: Britton? Robinson (BR) buffer of pH 3.0, the regeneration potentials cycles (E_in=?1000 mV, E_fin=?100 mV) and constant cleaning potential ?2000 mV. Practical applicability of AgE for the determination of micromolar concentrations of 8‐NQ was verified on model samples of drinking and river water.     

Viscoelasticity of a surfactant and its drag-reducing ability

There is considerable interest in the use of viscoelastic cationic surfactant-counterion mixtures in district heating and cooling systems to reduce pressure losses. A recent field test in a secondary system near Prague showed a 30+% reduction in pumping energy requirements.We have studied a number of commercial surfactants and we report here results of rheological, drag reduction and turbulence measurements on Arquad 18–50 (octadecyl trimethyl ammonium chloride (AR 18)) with an excess of sodium salicylate (NA). The concentration studied was 1.6 mM AR 18 and 4.0 mM NA which is about one third the concentration for excellent drag reduction in this surfactant's effective temperature range 30–90°C.Viscosity, , vs. shear rate,D, first normal stress difference,N ₁, vs. shear rate, drag reduction (as pressure drop,i=P/1) vs. average velocity,U _ave, in a 39.4 mm tube for AR 18, and turbulence intensity data for three drag reducing surfactants are reported.Of particular interest are the generally low turbulence intensities in all three directions which correspond to reduced heat, mass and momentum transfer rates compared to water, and the existence of large normal stress differences at 20°C for AR 18, a temperature at which no drag reduction occurs with this surfactant, indicating that normal stress effects do not correlate directly with drag reduction.The effect of time of pumping on increasing drag reduction demonstrates that this factor overwhelms the expected increase in drag reduction as temperature is raised from 18–19°C to 40.5°C.     

Behavioural breaks in the heterogeneous agent model: The impact of herding,overconfidence, and market sentiment

The main aim of this work is to incorporate selected findings from behavioural finance into a Heterogeneous Agent Model using the Brock and Hommes (1998) [34] framework. Behavioural patterns are injected into an asset pricing framework through the so-called ‘Break Point Date’, which allows us to examine their direct impact. In particular, we analyse the dynamics of the model around the behavioural break. Price behaviour of 30 Dow Jones Industrial Average constituents covering five particularly turbulent US stock market periods reveals interesting patterns in this aspect. To replicate it, we apply numerical analysis using the Heterogeneous Agent Model extended with the selected findings from behavioural finance: herding, overconfidence, and market sentiment. We show that these behavioural breaks can be well modelled via the Heterogeneous Agent Model framework and they extend the original model considerably. Various modifications lead to significantly different results and model with behavioural breaks is also able to partially replicate price behaviour found in the data during turbulent stock market periods.     

关于3-正则图的路分解

本文讨论了3-正则图的路分解问题,证明了任意的3-正则图都有{P3,P4}分 解,其中Rk指包含k个顶点的路.