J.C. Choi

Ethanol extract of Alismatis Rhizoma reduces acute lung inflammation by suppressing NF-κB and activating Nrf2

ETHNOPHARMACOLOGICAL RELEVANCE The tuber of Alisma orientale Juzepzuk, a medicinal herb that has been used for the treatment of various disorders in Korea, has an anti-inflammatory effect. Here, we investigated a possible underlying mechanism and a protective effect on acute lung injury (ALI). MATERIALS AND METHODS Alisma orientale tuber was extracted in 80% ethanol and dried. The powder of the ethanol extract of Alisma orientale tuber (EEAO) was dissolved in PBS. The effect of EEAO on NF-κB and Nrf2 activities was analyzed with RAW 264.7 cells. The effect of EEAO on lung inflammation was determined by histologic and molecular biological analyses of the lung tissue of C57BL/6 mice that were gavaged once a day with 0.3 or 1.2 g/kg of EEAO for 14 days, prior to an intranasal administration of LPS (0.01 g/kg) for inducing ALI. RESULTS EEAO pre-treatment of RAW 264.7 cells suppressed NF-κB activity and the expression of its dependent genes including COX-2, IL-1β and iNOS. Similar treatment enhanced Nrf2 activity and the expression of Nrf2-regulated genes including NQO-1, HO-1 and GCLC. LPS instillation induced acute neutrophilic lung inflammation, which was significantly suppressed by pre-treatment with EEAO. Analysis of the lungs revealed that EEAO pre-treatment induced the expression of Nrf2-regulated genes, with concomitant down-regulation of inflammatory gene expression. CONCLUSIONS EEAO attenuated lung inflammation in LPS-induced ALI mice, which was associated with differential regulation of NF-κB and Nrf2 activities. We suggest that EEAO can be developed as a potential therapeutics for the treatment of ALI.

Prediction of die wear in the wire-drawing process

Abstract In cold-forming processes, failure must be considered before die design, because high working pressure acts on the die surface. One of the main reasons for die failure in industrial application of metal-forming technologies is wear. Die wear affects the tolerances of formed parts, metal flow and costs of processes, etc. The only way to control these failures is to develop methods which allow the prediction of the die wear and which are suited to being used in the design stage in order to optimize the process. In this paper, the wire-drawing process is simulated by the rigid-plastic finite-element method and the results used for predicting the die wear by abrasive-wear theory. The effects of the temperature rise on the wear profiles of the dies are investigated. The simulation results are compared with measured die profiles.

A compact and practical CAD/CAM system for the blanking or piercing of irregular shaped-sheet metal products for progressive working

Abstract This paper describes research work into developing the computer-aided design and manufacturing of stator and rotor parts with blanking or piercing operations. An approach to a CAD/CAM system is based on knowledge-based rules. Knowledge for the CAD/CAM system is formulated from plasticity theories, experimental results and empirical knowledge of field experts. The program for the system has been written in AutoLISP on the AutoCAD for strip- and die-layout and in customer tool kit on the SmartCAM software for modeling and post-processing with a personal computer. It is composed of nine modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, strip-layout, die-layout, data-conversion, modeling, and post-processing modules. Based on knowledge-based rules, the system is designed by considering several factors, such as the material and thickness of product, the complexities of blank geometry and punch profile, the diameter and material of a wire, the working conditions, and the availability of a press. It is capable of generating automatically NC data to match tooling requirements by checking dimensions according to the drawings of the die-layout module. Results obtained using the modules enable the design and manufacturer of stator and rotor parts to be more efficient in this field.

METHODOLOGY OF PREFORM DESIGN CONSIDERING WORKABILITY IN METAL FORMING BY THE ARTIFICIAL NEURAL NETWORK AND TAGUCHI METHOD

Abstract This study describes a new method of preform design in multi-stage metal forming processes considering workability limited by ductile fracture. The finite element simulation combined with ductile fracture criterion has been carried out in order to predict ductile fracture. The artificial neural network (ANN) using Taguchi method has been implemented for minimizing objective functions relevant to the forming process. The combinations of design parameters used in finite element simulation are selected by an orthogonal array in a statistical design of experiments. The orthogonal array and the results of simulation are used as training data of ANN. A cold heading process is taken as an example of designing a preform which does not form any fracture in the finished product. The results of analysis to validate the proposed design method are presented.

Determination of the initial billet geometry for a forged product using neural networks

Abstract In the paper, the authors propose a new technique to determine the initial billet geometry for the forged products using a function approximation in neural networks. A three-layer neural network is used and the back-propagation algorithm is employed to train the network. The billet geometry is determined by applying the ability of the function approximation of neural networks to determine an optimal billet which, satisfies the forming limitations; minimises incomplete filling in the die cavity, load, energy; and also secures a more uniform distribution of effective strain. The neural networks are applied to find the optimal initial billet size for a plane-strain rib-web product in cold forging and for an axisymmetric rib-web product in hot forging. The neural networks may reduce the number of finite-element simulation for the determination of the optimal die geometry of forging products and, further, they can be usefully applied in the physical modeling of the forging design.

Marine algal fucoxanthin inhibits the metastatic potential of cancer cells

Metastasis is major cause of malignant cancer-associated mortality. Fucoxanthin has effect on various pharmacological activities including anti-cancer activity. However, the inhibitory effect of fucoxanthin on cancer metastasis remains unclear. Here, we show that fucoxanthin isolated from brown alga Saccharina japonica has anti-metastatic activity. To check anti-metastatic properties of fucoxanthin, in vitro models including assays for invasion, migration, actin fiber organization and cancer cell-endothelial cell interaction were used. Fucoxanthin inhibited the expression and secretion of MMP-9 which plays a critical role in tumor invasion and migration, and also suppressed invasion of highly metastatic B16-F10 melanoma cells as evidenced by transwell invasion assay. In addition, fucoxanthin diminished the expressions of the cell surface glycoprotein CD44 and CXC chemokine receptor-4 (CXCR4) which play roles in migration, invasion and cancer-endothelial cell adhesion. Fucoxanthin markedly suppressed cell migration in wound healing assay and inhibited actin fiber formation. The adhesion of B16-F10 melanoma cells to the endothelial cells was significantly inhibited by fucoxanthin. Moreover, in experimental lung metastasis in vivo assay, fucoxanthin resulted in significant reduction of tumor nodules. Taken together, we demonstrate, for the first time, that fucoxanthin suppresses metastasis of highly metastatic B16-F10 melanoma cells in vitro and in vivo.

A study of a computer-aided process design system for axisymmetric deep-drawing products

Abstract A computer-aided process design system for axisymmetric deep drawing products has been developed. An approach to the CAD system is based on a knowledge-based system, the knowledge for the CAS system being formulated from plasticity theories, handbooks, experimental results and the empirical knowledge of field experts. The CAD system has been written in AutoLISP on the AutoCAD system with a personal computer. The CAD system is composed of four main modules, which are input, geometrical design, test and rectification and user modification. The input to the system is the drawing of the final sheet-metal object geometry and the output from the system is the drawing of process sequence with intermediate object geometry and the drawing of the process parameters, such as the drawing load, the blank-holding force, the clearance and the cup-drawing coefficients. The developed CAD system will aid designers by providing powerful capabilities for the process design of axisymmetric deep-drawing products.

Dangkwisoo-san, an herbal medicinal formula, ameliorates acute lung inflammation via activation of Nrf2 and suppression of NF-κB.

ETHNOPHARMACOLOGICAL RELEVANCE Dangkwisoo-san (DS), an herbal medicinal formula, has long been used in Korea for the treatment of inflammatory complications caused by physical trauma. Although the therapeutic effect of DS is likely associated with anti-inflammatory activity, the precise underlying mechanisms are largely unknown. Here we sought to elucidate the possible mechanisms of anti-inflammatory activity of DS. MATERIALS AND METHODS The water extract of DS was orally fed to C57BL/6 mice for 14 days prior to LPS intranasal instillation for lung inflammation. The effects of DS on lung inflammation were determined by differential cell counting, lung histology, and semi-quantitative RT-PCR of lung sections. The effects of DS on the activities of Nrf2 and NF-κB were assessed by western blotting, semi-quantitative RT-PCR, and luciferase reporter assays in RAW 264.7, an NF-κB reporter cell line, and HEK 293 transfected with an NF-κB reporter construct. RESULTS Mice that were treated with a water extract of DS showed significant attenuation of lung inflammation induced by intranasal lipopolysaccharide (LPS) compared to control mice treated with vehicle. In vitro experiments show that DS activated Nrf2, an anti-oxidant transcription factor that protects from various inflammatory diseases, and induced Nrf2-regulated genes including GCLC, NQO-1 and HO-1. In addition, DS suppressed NF-κB activity and reduced the production of pro-inflammatory cytokines. Transfection experiment indicates that inhibition of NF-κB likely occurred upstream of IKK complex. Furthermore, DS enhanced the expression of HO-1 and suppressed that of IL-1β and TNF-α in inflamed mouse lungs. CONCLUSIONS These results suggest that the therapeutic effects of DS are related with suppression of inflammation, which is, at least in part, mediated by activation of anti-inflammatory factor Nrf2 and inhibition of pro-inflammatory factor NF-κB.

An integrated design and CAPP system for deep drawing or blanking products

This paper deals with an automated computer-aided process planning system by which designers can determine operation sequences even if they have little experience in the process planning of sheet metal products by press working. The computer- aided process planning program written in AutoLISP for the AutoCAD using a personal computer, for deep drawing or blanking, requires many kinds of technical and empirical skills. The approach to structure of the system is based on knowledge-based rules, and a process knowledge base consisting of design rules is built. Based on the investigation and collection of knowledge about the processes, the methodology adopted to develop this system is described in this paper. An attempt is made to link programs incorporating a number of expert design rules to form a useful package for process planing. This integrated design and CAPP system is composed of two main modules and six submodules. It is designed considering several factors, such as the complexities of blank geometry, punch and die profiles, the availability of a press equipment, and standard parts. Results obtained using the modules enable the designer and manufacturer of deep drawing or blanking dies to be more efficient in this field.

A study on the development of computer-aided process planning system for electric product with bending and piercing operations

Abstract This paper describes a research work of developing computer-aided design of product with bending and piercing operation for progressive working. Approach to the system is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results, and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer. It is composed of four main modules, which are input and shape treatment, flat pattern layout, strip layout, and die layout modules. The system is designed by considering several factors, such as bending sequence by fuzzy set theory, complexities of blank geometry, punch profiles, and the availability of a press equipment and standard parts. The strip layout and die layout drawings automatically generated by formularization and quantification of experimental technology will make minimization of trial and error and reduction of period in developing new products. Results obtained using the modules enable the manufacturer for progressive working of electric products to be more efficient in this field.