Molecular Docking Studies and Biological Evaluation of Berberine–Benzothiazole Derivatives as an Anti-Influenza Agent via Blocking of Neuraminidase

In this study, we have introduced newly synthesized substituted benzothiazole based berberine derivatives that have been analyzed for their in vitro and in silico biological properties. The activity towards various kinds of influenza virus strains by employing the cytopathic effect (CPE) and sulforhodamine B (SRB) assay. Several berberine–benzothiazole derivatives (BBDs), such as BBD1, BBD3, BBD4, BBD5, BBD7, and BBD11, demonstrated interesting anti-influenza virus activity on influenza A viruses (A/PR/8/34, A/Vic/3/75) and influenza B viral (B/Lee/40, and B/Maryland/1/59) strain, respectively. Furthermore, by testing neuraminidase activity (NA) with the neuraminidase assay kit, it was identified that BBD7 has potent neuraminidase activity. The molecular docking analysis further suggests that the BBD1–BBD14 compounds’ antiviral activity may be because of interaction with residues of NA, and the same as in oseltamivir.     

A model for predicting the carbonation depth of concrete containing low-calcium fly ash

Low-calcium fly ash (FL) is a general product from the combustion of anthracite and bituminous coals and has been widely used as a mineral admixture to produce high strength and high performance concrete. Carbonation of cement blended with fly ash is much more complex than ordinary Portland cement because of the pozzolanic activity in an aluminosilicate glass phase of fly ash. In this paper, based on multi-component concept, a numerical model that can predict carbonation of low-calcium fly ash contained concrete was built. This numerical model includes two parts: hydration and carbonation models. The hydration model starts with a mix proportion of concrete and considers both Portland cement hydration and pozzolanic activity. By applying a hydration model, the amount of hydration product that is susceptible to carbonate as well as porosity was obtained as a function of curing age. Furthermore, the diffusivity of CO₂ in concrete was determined and the carbonation depth of concrete was also predicted. The prediction results showed good agreement for the results of the experiment performed in this study.     

A multi-phase kinetic model to simulate hydration of slag–cement blends

Ground granulated blast furnace slag, which shows cementitious behavior (latent hydraulic activity) and pozzolanic characteristics (reaction with lime), has been widely used as a mineral admixture in normal and high strength concretes. Hydration of slag–blended cement is much more complex than that of ordinary Portland cement because of the mutual interactions between the cement hydration and the slag reaction. This paper presents a kinetic hydration model for cement–slag blends. The proposed model analyzes the slag reaction separate from cement hydration by considering the production of calcium hydroxide in cement hydration and its consumption in slag reactions. The amount of free water and the amount of calcium hydroxide left in the system were adopted as the control indicators for determining the slag reaction. Using the proposed model, the reaction ratio of slag can be evaluated as a function of curing age, considering the influences of the water to binder ratio, the slag replacement ratio and the curing temperature. Furthermore, the amount of chemically-bound water (self-cementing properties), calcium hydroxide (pozzolanic capabilities), and the heat released from hydration are evaluated by determining the contributions from both the cement hydration and the slag reaction. The evaluated results show good accordance with the experimental results.     

Evaluation of the bond properties between concrete and reinforcement as a function of the degree of reinforcement corrosion

In order to investigate the effect of reinforcement corrosion on the bond properties between concrete and reinforcement, the pullout tests were conducted using reinforcements embedded in concrete specimens, which were corroded by an accelerated electric corrosion method. A finite element method (FEM) analysis was also carried out on the basis of the results of the pullout tests. The maximum bond strength (τ_max) and the bond rigidity (D_s) of specimens decreased in proportion to the increase of corrosion percentage (Δ_w), respectively. Also, the curves of bond stress-free end slip could be analyzed by the FEM, if the τ_max and D_s were determined as a function of corrosion percentage. The equations for calculating the maximum bond strength and the bond rigidity necessary for an FEM analysis of RC members with corroded reinforcements were obtained by the experiments and the FEM analysis of the pullout tests.     

Cytoprotective activity of lotus (Nelumbo nucifera Gaertner) leaf extracts on the mouse embryonic fibroblast cell

This study was conducted to evaluate the cytoprotective activity of lotus (Nelumbo nucifera Gaertner) leaf extract (LLE) on mouse embryonic fibroblast (MEF) cells. The 2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical scavenging activities of LLE increased in a concentration dependent manner. The cells, damaged by oxidative stress, decreased their viability following increasing concentration of H₂O₂, but the co-treatment of n-butanol fraction of LLE and H₂O₂ resulted in an increase in cell growth, by about 25%, compared to the cells treated with H₂O₂. The n-butanol fraction of LLE inhibited the cytotoxicity induced by H₂O₂ in a concentration dependent manner. The oxidative damage to the cells, measured by apoptotic and necrotic cell accumulation, was similar with the addition of the n-butanol fraction of LLE to H₂O₂. Taken together, these results suggest that LLE inhibited the cytotoxicity which is induced by H₂O₂, and has a protective effect on MEF cell against oxidative stress.     

Determination of polycyclic aromatic hydrocarbons in commercial roasted coffee beans

This study was conducted to investigate the presence of 7 polycyclic aromatic hydrocarbons (PAHs) [benzo[a]anthracene (BaA), chrysene (CRY), benzo[b] fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a] pyrene (BaP), dibenzo[a,h]anthracene (DahA), benzo [g,h,i]perylene (BghiP)] in roasted coffee beans from Korean market. In this study, the method for sample preparation involved liquid-liquid extraction after saponification with potassium hydroxide (KOH), followed by solid-phase extraction (SPE). The external standard method was used for measurement, and regression coefficients ranged from 0.9938 to 0.9995. To determine how much of the analyte remained in the samples after sample preparation, 3-methylcholanthrene was spiked into the samples for a recovery study. The limits of detection and quantification of the 7 PAHs ranged from 0.016 to 0.497 and 0.054 to 1.656 μg/kg, respectively. The concentrations of PAHs in the 10 coffee samples ranged from 0.62±0.08 to 53.25±9.38 μg/kg. According to the results, the critically harmful PAH, BaP, was presented at levels harmless to humans.     

Development of a freshness indicator for monitoring the quality of beef during storage

Food Science and Biotechnology - Quality of beef and detect changes in freshness during storage was evaluated using freshness indicator. The freshness indicator can indicate spoilage or freshness...