Two new saponins from the rhizomes of Franch.

The phytochemical investigation on the rhizomes of Franch. resulted in the discovery and characterisation of six compounds, including two new saponins named parisyunnanosides M-N (-), and four known ones (-). The structures of isolated compounds were determined by spectroscopic data analysis and chemical methods.

Two previously undescribed cholestanol saponins from the rhizomes of Paris fargesii var. petiolata.

Two previously undescribed cholestanol saponins, parpetiosides F - G (1-2), and six known analogs (3-8) were isolated from the rhizomes of Paris fargesii var. petiolata. Their structures were elucidated by extensive spectroscopic data analysis and chemical methods.

A new 3D contour extraction method for tooth cavity in a dental CAD/CAM system.

In dental CAD/CAM system, tooth restoration produces customized tooth with a prepared cavity, while the prosthetic tooth fitting is firstly determined by the contour feature of the cavity, the cavity contour extraction of the tooth is one of the important issue. In order to accurately extract the cavity contour, a new Three-Dimension (3D) optimal path searching algorithm based on Intelligent Scissors theory is presented. In this algorithm, the 3D tooth is firstly formulated as a weighted model, by calculating the minimum weigh sum of the local cost from a start point to an end point in the cavity edge, the initial optimal contour can be acquired.

Cloning, expression and mutagenesis of a subunit contact of rabbit muscle-specific (betabeta) enolase.

The cDNA for rabbit muscle-specific (betabeta) enolase was cloned, sequenced and expressed in Escherichia coli. This betabeta-enolase differs at eight positions from that sequenced by Chin (17). Site-directed mutagenesis was used to change residue 414 from glutamate to leucine, thereby abolishing a salt bridge involved in subunit contacts.