2'-Hydroxycinnamaldehyde (HCA) was isolated from Cinnamomum cassia Blume (Lauraceae) and 2'-benzoyloxycinnamaldehyde (BCA) was prepared by the reaction of HCA and benzoyl chloride. HCA and BCA strongly inhibited in vitro growth of 29 kinds of human cancer cells and in vivo growth of SW-620 human tumor xenograft without the loss of body weight in nude mice. HCA prevented adherence of SW-620 cells to the culture surface but did not inhibit oncogenic K-Ras processing, implying its antitumor mechanisms at the cellular level.

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We present a dental training system through multi-modal interface such as visual, auditory and haptic sensations. The system allows dental students to learn dental procedures and handling dental instruments with realistic feelings and evaluate their performance. To implement this system, it requires stable and fast haptic rendering algorithm, visual model deformation techniques on the virtual tooth being deformed, and sound rendering to simulate contact sound between the virtual tool and tooth. We enhance previous volume-based haptic modeling systems for haptic dental simulation. Collision detection and force computation are implemented on an offset surface rather than the implicit surface to simulate physical interactions between the virtual dental tool and tooth model. To bridge the gap between fast haptic process (1 KHz) and much slower visual update frequency (~30Hz), the system generates intermediate implicit surfaces between two consecutive physical models being deformed resulting in smooth force rendering. The volumetric tooth model is visualized as a geometric model which is adaptively polygonized according to the surface complexity. Volumetric material properties are used to simulate the resistance and texture information depending on anatomical tissues. Finally, we developed a multi-modal workbench to register visual, auditory and haptic sensations so that the user see, hear, and feel the virtual environment in the same space.

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