ABSTRACT
Objective In the computational fluid dynamics software FLUENT, the independently developed user defined function (UDF) dynamic mesh program is called to achieve the mobile update of grid note based on the wall shear stress (WSS). Then this method is applied to simulate the development process of atherosclerosis (AS). Methods The UDF program by secondary development could extract WSS results of every note on the wall during the computing process, and if the threshold value criterion condition was met, the node would be adjusted to a new position. The mesh regeneration method combining with the spring smoothing and the local remeshing was adopted to control the update of the grid, so as to ensure the grid quality during deformation. Results The UDF program successfully extracted the WSS and arranged the corresponding deformation for the grid. The morphology of local extension in the proximal part and restenosis in the distal end were resulted from the vortex in the rear of the initial stenosis. Those features were similar to the indication of clinical angiography. Conclusions The independently developed UDF program has reached the expected effects, depicting the topography characteristics of AS influenced by WSS. In future researches, more influential factors should be considered in dynamic mesh deformation control to provide numerical references for clinical prognosis and risk evaluation of AS.
ABSTRACT
According to ObgC gene sequences from Cyathula officinalis genomic data, the specific primers were designed, and a full-length CoObgC cDNA (2 226 bp) was obtained by polymerase chain reaction (PCR) and rapid amplification of cDNA ends (RACE) methord. Sequence alignment showed that CoObgC gene contained a 1 818 bp open reading frame (ORF) encoding 605 amino acids. Sequence analysis predicted that molecular weight of CoObgC protein was about 66.39 kDa, the academic isoelectric point was 5.35, and the protein was stable protein. Then multiple sequence alignment was applied to construct phylogenetic tree. The real-time fluorescence quantification PCR (RT-qPCR) demonstrated that a high expression level in leaf, followed by root and flower, the low transcription was in stem. The recombinant vector pCABIA2300-CoObgC was constructed and introduced into tobacco epidermal cells by agrobacterium-mediated transformation, green fluorescence was tested and targeted to chloroplast under a laser scanning confocal microscope. These findings will be helpful to lay a foundation for studying the structure and function of CoObgC gene, and elucidating C. officinalis molecular biology experiment.
ABSTRACT
In order to explore the dormancy physiological and biochemical mechanism of Paris seeds, the seed embryo growth courses, and the dynamic change of 5 enzymes, include SOD, POD, CAT, MDH, G-6-PDH were measured during variable temperature stratification. The results indicated that Paris seeds embryo grew quickly after 40 d in warm-stratification (18 ± 1) °C, at the meantime the metabolic activity was significantly strengthened. These facts showed that Paris seeds turned into physiological after-ripening process. After 60-80 d, the morphological embryo after-ripping process basically completed, and the following cold-stratification (4 ± 1) °C furthered Paris seed to finish physiological after-ripening. After 40 d, the activity of MDH decreased while G-6-PDH increased significantly. This showed that the main respiratory pathway of seed changed from TCA to PPP, which benifited breaking seed dormancy. In the whole period of stratification process, the activity variation of SOD and CAT was insignificantly and the activity of POD was enhanced significantly after shifting the seed in cold stratification process. This showed that SOD, CAT had no direct effects on breaking Paris seed dormancy but keeping the seed vigor, while the POD might involve in the process of Paris seed dormancy breaking.