Rapid and Sensitive Detection of Polycyclic Aromatic Hydrocarbons in Tea Leaves Using Magnetic Approach.

A rapid and efficient method using an alkyl-functionalized magnetic nanoparticles-based extraction technique combined with Ultra-High Performance Liquid Chromatography was developed for the detection of trace amounts of polycyclic aromatic hydrocarbons in tea leaves. As a popular coating for chromatographic column packing materials, C18-alkyl has been demonstrated to be effective in separating polycyclic aromatic hydrocarbons. Additionally, the magnetism of the nanomaterials accelerates the extraction process while their high surface ratio enables desirable dispersity in the sample matrix. Meanwhile, the adsorbents can be washed and reused 30 times without compromising recovery, which greatly reduces the budget. The effects of various parameters were investigated and optimized, and the recoveries for five analytes were in the range of 84.8-105.4%. The RSD of intra-day and inter-day were below 11.9% and 6.8%, respectively. The limits of detection and limits of quantification ranged from 1.69-9.97 ng g-1 and 5.12-30.21 ng g-1, indicating satisfactory sensitivity. Thus, the proposed methodology is rapid, highly efficient, and economical, and it expands the application of magnetic cleanup approaches in complex food matrices.

A novel biomedical meshing algorithm and evaluation based on revised Delaunay and Space Disassembling.

The tetrahedral mesh generation part in Finite Element Method (FEM) of soft tissue simulation is difficult to be realized by traditional mesh algorithms because of the requirements of boundary preservation and quality of all tetrahedra. Aiming to meet the real-time requirement of FEM, we propose a revised Delaunay algorithm with many improved methods, including background grid, random point disarrangement, radial method and visibility check. In this paper, two tetrahedral mesh generation algorithms including Space-Disassembling and the revised Delaunay algorithm, are presented based on different mesh requirements. And a comparison of Space-Disassembling Mesh Algorithm, traditional Delaunay algorithm and the revised Delaunay algorithm is processed based on some pivotal criteria.

Soft tissue deformation simulation in virtual surgery using nonlinear finite element method.

Simulation for soft tissue's realistic deformation is an important part in Virtual Surgery. For large global deformation of soft tissue, linear elastic models are inappropriate, such as Mass-Spring and linear Finite Element Method (FEM). In this paper we present a simulation for 3D soft tissue using nonlinear strain computation. To get a finer mesh for FEM, we consider meshing algorithm based on Improved Delaunay criterion. Besides, we would present Spatial Hashing Collision Detection method and some improvement for real-time computation.