Vascular construction is an important content in tissue engineering domain,in vitro implanting seed cells on absorbable scaffold materials to form multi-layered cellular layer and establish autoblood vessels along the scaffold absorption. The tissue-engineered vessels are characterized by high biocompatibility and plasticity,less foreign body reaction,and no thrombus production and infection; in addition,the vessels may finally become autoblood vessels in the complete significance. In this article,artificial vascular materials,scaffold processing methods,and vascular culture of seed cells were compared to explore an ideal method to make artificial vessels.

To solve the problem of imprecise positioning of feature point and of the feature data redundancy in facial expression recognition by active appearance models (AAM), the automatic adjustment of initial model for AAM fitting is proposed in this paper. The specific aims are to improve the precision of positioning and to more effectively reflect the variation of expressions by acquired features. The problem of feature selection is resolved by adopting quadratic mutual information and reducing the feature dimension. The support vector machine (SVM) classifier is used for expression recognition. The experimental results on CAS-PEAL facial expression database show that the proposed method effectively improves the performance of facial expression recognition, the maximum recognition rate being 83.33%.
Algorithms ; Computer Simulation ; Facial Expression ; Humans ; Image Interpretation, Computer-Assisted ; methods ; Models, Biological ; Pattern Recognition, Automated ; methods ; Signal Processing, Computer-Assisted

Portal hypertension (PHT) is a common complication of liver cirrhosis, which could be measured by the means of portal vein pressure (PVP). However, there is no report about an effective and reliable way to achieve noninvasive assessment of PVP so far. In this study, firstly, we collected ultrasound images and echo signals of different ultrasound contrast agent (UCA) concentrations and different pressure ranges in a low-pressure environment based on an
Contrast Media ; Humans ; Hypertension, Portal/diagnostic imaging* ; Liver Cirrhosis ; Portal Vein/diagnostic imaging* ; Ultrasonography