To reduce the mismatching and non-matching in the protein two-dimension electrophoresis (2-DE) images, we proposed an auto-matching algorithm based on gray hierarchical and geometric blocking in this study. Firstly, protein spots in the gel images were divided into groups by gray level and geometric position, and then a method based on shape context and normalized correlation was used for coarse matching in protein spots. Secondly, matched pairs in coarse matching were set as feature points, and the precise matching in the rest of not matched protein spots was accomplished by the method of geometric correlation and similarity criterion. Finally, local affine transformation was used in the verification of matching results to remove non-matching and mis-matching points. The algorithm was applied to different 2-DE gel images. The results showed that the new matching algorithm could reduce the non-matching and mis-matching spots, and increase the matching accuracy.
ObjectiveTo analyze the reason and prevention of late bioprosthetic heart valve thrombosis (LBVT). MethodsBioprosthetic heart valves were implanted in 580 patients between January 2001 and July 2013 in Changhai Hospital, and only found one case of LBVT (0.2%). Reoperation was performed for a 67-year-old male patient 3 years after bioprosthetic aortic valve replacement due to severe aortic valve stenosis. Retrospectively analyzed the clinical data and reviewed the literature between January 1989 and December 2013 in Pubmed. ResultsNo risk factor for thrombosis was revealed in this patient. Pathology revealed valve thrombosis and collagen and elastic fibers fragmentation and disruption in valve leaflets. In literature review, 20 articles and 47 cases were brought in. The morbidity of LBVT was 0.2%-1.0%. At least 18 patients had high risk factors, and 15 of the 18 patients discontinued anticoagulation after 3 months. However, at least 10 patients had no high risk factors. Forty-four of the 47 patients received stented porcine valve replacement, only one patient received stented bovine pericardial valve replacement. ConclusionsLBVT is a rare but serious complication after bioprosthetic valve replacement, the causes of which include the feature of the patients and the bioprosthetic valves. Bovine pericardial valves could be superior to porcine valves in preventing LBVT. Postoperative long-time aspirin therapy is recommended for patients without high risk factors. Patients with any high risk factors should prolong anticoagulation.