Antigenotoxic effects of water extract from Korean fermented soybean paste (doen-jang)

Aflatoxin B1 is a major metabolite of the toxigenic molds Aspergillus flavus and Aspergillus parasiticus. In this study, a bacterial reverse mutation assay with Salmonella Typhimurium strains TA1535, TA1537, TA98, TA100, and TA102 and an in vitro chromosome aberration test with Chinese hamster lung (CHL) cells were used to investigate the genotoxicity of water extract from Korean soybean paste (doen-jang [dwen-jahng]) and its antigenotoxic activity against aflatoxin B1. The water extract itself did not exhibit cytotoxicity or mutagenicity. The extract significantly reduced the numbers of revertants when it was added to the assay system with Salmonella Typhimurium TA100 (P < 0.05). The extract also exhibited significant inhibitory effects on chromosome aberration in CHL cells (P < 0.05). Dose-response relationships were observed between the concentration of the water extract and both its antimutagenic effect and its suppression of chromosome aberration. The results of this work indicate that water extract from Korean soybean paste could have potential as an antigenotoxic substance.     

Applicability of self-consistent global model for characterization of inductively coupled Cl2 plasma

Investigations of the influence of gas pressure and input power on the Cl₂ plasma parameters in the inductively coupled plasma system were carried out. The investigations combined plasma diagnostics by Langmuir probe with plasma modeling represented by the self-consistent global model with Maxwellian approximation for the electron energy distribution function. From the experiments, it was found that the increase of gas pressure in the range of 0.27-3.33 Pa for 400-700 W of input power results in a decrease in both electron temperature (3.3-2.0 eV) and density (6.5×10¹⁶−3.0×10¹⁶ m⁻³ for 400 W and 1.2×10¹⁷-6.7×10¹⁶ m⁻³ for 700 W). For the given range of experimental conditions, the model showed an outstanding agreement with the experiments and provided the data on kinetics of plasma active species, their densities and fluxes.     

Self-consistent global model for inductively coupled Cl2 plasma: Comparison with experimental data and application for the etch process analysis

The investigations of the influence of gas pressure and input power on the Cl₂ plasma parameters in the inductively coupled plasma system were carried out. The investigations combined plasma diagnostics by Langmuir probe and plasma modeling using the self-consistent global model with Maxwellian approximation for electron energy distribution function. From the experiments, it was found that an increase of gas pressure in the range of 0.27-3.33 Pa at 400-700 W input power results in decreasing both electron temperature (3.3-2.0 eV) and density (6.6 × 10¹⁰ − 3.0 × 10¹⁰ cm^− 3 for 400 W and 1.2 × 10¹¹ − 6.4 × 10¹⁰ cm^− 3 for 700 W). The model showed an outstanding agreement with the experiments and provided the data on densities and fluxes of active species. These data combined with the model of etch kinetics demonstrated the possibility of different etch rate behaviors depending on the input process parameters as well as on the properties of the etched surface.     

Development of verification and conformance testing tools for a railway signaling communication protocol

Verification and conformance testing for protocol specification, the key part of the protocol development process, are complementary technologies employed to increase confidence that a system will function as stated in its specifications. In this paper, we verify the safety and liveness of the protocol specified for the Labeled Transition System (LTS) by using a model-checking method and implementing the testing tool, which experimentally demonstrates the presence of deadlock and reachability from the initial state to a random state. Implementing the testing tool can use modal mu-calculus to assess whether protocol model properties, presented by modal logic, meet protocol specifications. In addition, we propose a conformance testing tool to check correct implementation of sequences that have been derived by the UIO method from the specification of the protocol being verified. This generating tool uses the C++ language in the Microsoft Windows NT environment.     

Reduction of aflatoxins by Korean soybean paste and its effect on cytotoxicity and reproductive toxicity--part 2. Antigenotoxic effects of the methanol extract of Korean soybean paste (doen-jang) on aflatoxin B1-induced bacterial reverse mutation and chromosome aberration

A bacterial reverse-mutation assay with Salmonella Typhimurium TA1535, TA1537, TA98, TA100, and TA102 and an in vitro chromosome aberration assay with Chinese hamster lung (CHL) cells were used to investigate the genotoxicity of the methanol extract of Korean soybean paste (doen-jang [dwen-jahng]) and its antigenotoxic activity against aflatoxin B1. The methanol extract revealed nonmutagenic potential for all of the bacterial strains tested. The extract significantly reduced the numbers of revertants per plate when it was added to the assay system with Salmonella Typhimurium TA100 (P < 0.05). The extract also exhibited significant inhibitory effects on chromosome aberration in CHL cells (P < 0.05). The findings of this work indicate that the methanol extract of Korean soybean paste could have strong potential as an antigenotoxic material.     

A RWA Algorithm for Differentiated Services with QoS Guarantees in the Next Generation Internet based on DWDM Networks

A major challenge in next generation Internet (NGI) backbone networks based on dense-wavelength division multiplexing (DWDM) is the provision of guaranteed quality-of-service (QoS) for a wide variety of multimedia applications. This paper proposes a new routing algorithm called multi-wavelength minimum interference path routing (MW-MIPR) to provide more reliable QoS guarantees by consideration of the potential future network's congestion status. This improves wavelength utilization by choosing a route that does not interfere too much with potential future connection requests. Moreover, we introduce a differentiated routing and wavelength assignment (RWA) mechanism combined with recovery strategy and the proposed MW-MIPR algorithm based on the differentiated service model in the NGI. Simulation results show that the proposed MW-MIPR algorithm achieves a smaller blocking probability than dynamic routing (DR) that yields the best performance among previous RWA algorithms. And we prove that a differentiated RWA combined with a recovery capability together with the proposed routing scheme provides satisfied QoS assurance for each service class in terms of signal quality and survivability.     

Etch damage evaluation on (Bi4−xLax)Ti3O12 thin films during the etch process using inductively coupled plasma sources

The etching mechanism of (Bi_4−xLa_x)Ti₃O₁₂ (BLT) thin films in Ar/Cl₂ inductively coupled plasma (ICP) and plasma-induced damages at the etched surfaces were investigated as a function of gas-mixing ratios. The maximum etch rate of BLT thin films was 50.8 nm/min of 80% Ar/20% Cl₂. From various experimental data, amorphous phases on the etched surface existed on both chemically and physically etched films, but the amorphous phase was thicker after the 80% Ar/20% Cl₂ process. Moreover, crystalline “breaking” appeared during the etching in Cl₂-containing plasma. Also the remnant polarization and fatigue resistances decreased more for the 80% Ar/20% Cl₂ etch than for pure Ar plasma etch.     

Indirect current control of active filter for harmonic elimination with novel observer-based noise reduction scheme

Active power filters have been developed recently to solve the harmonics disturbance problems on power system networks. The direct current control scheme is generally used to control the harmonic compensating current directly for current source active power filters. To improve the characteristics of harmonic elimination, the voltage regulation scheme is proposed which regulates the filter capacitor voltage at the input side. Hence the voltage regulation scheme is an indirect current control technique for making sinusoidal line current. To implement this proposed scheme, the electronic differentiator should be used. By using the conventional differentiator, high frequency noise is generated in the controller. This deteriorates both the accuracy and reliability of the controller. To reduce this noise, a novel observer-based noise reduction scheme is proposed for our active filter system. The observer-based algorithm and characteristics of indirect current-controlled active filters are investigated through simulations and experiments.