Considering the survival rate of small animals and the continuity of the experiments, high-dose X-ray shooting process is not suitable for the small animals in computed tomography (CT) experiments. But the low-dose process results with images might be polluted by noises which are not conducive for the experiments. In order to solve this problem, we in this paper introduce a global dictionary learning based denoising method to apply the promotion of the low dose CT image. We at first adopted the K-means singular value decomposition (K-SVD) algorithm to train a global dictionary based on the high dose CT image. Then, the noise image could be decomposed into sparse component which was free from noise through the orthogonal matching pursuit (OMP) algorithm. Finally, the noise-free image could be achieved by reconstructing the image only with its sparse components. The experiments results showed that the method we proposed here could decrease the noise efficiently and remain the details, and it would help promote the low dose image quality and increase the survival rate of the small animals.
ObjectiveTo summary the safety and efficiency of the minimally invasive direct cardiac surgery (MIDCS) approach in elderly patients with heart disease. MethodsWe retrospectively analyzed the clinical data of 60 patients underwent MIDCS in Beijng Anzhen Hospital between April 2010 and January 2013. There were 34 males and 26 females with mean age of 66.4±4.8 years and mean weight of 66.1±10.6 kg. ResultsMean cardiopulmonary bypass time and aortic cross-clamp time was 141.2±57.2 minutes and 99.8±37.6 minutes respectively. A total of 37 patients (90.2%) recovered to beat automatically after heart ceased operation. Median mechanical ventilation time was 17.1±9.1 hours. Mean intensive care unit stay was 22.1±12.2 hours. Mean post operative hospital stay was 7.0±2.5 days. Mean incision length was 5.3±0.9 cm. Mean pericardial draining volume was 466.6±412.1 ml in the first day after operation. No transfusion occurred in 27 (45.0%) patients. Early postoperative mortality was 3.3% (2/60). There were 2 patients of reexplorations for bleeding, 1 patient of the twice tracheal intubation, 1 patient of cardiac arrest after operation, 2 patients of poor healing of skin incision, and 1 patient of injury of right phrenic nerve. When leaving hospital, 47 patients were in heart functional class Ⅰ, 8 patients in class Ⅱ, and 3 patients in class Ⅲ. ConclusionMIDCS is associated with good operative effect in the near future with superior safety and broad application range in elderly patients with heart disease.
Objective Through analyzing BKCa channel expression in atrial fibroblasts in patients with sinus rhythm and atrial fibrillation (AF), to explore the mechanism of myocardial fibrosis and provide new therapeutic strategies for the treatment and reversal of AF structure reconstruction. Methods We selected 10 patients of rheumatic heart valvular disease who underwent valve replacement surgery. They were 5 patients with sinus rhythm (a sinus rhythm group, 2 males and 3 females with an average age of 49.1±8.3 years) and 5 with AF (an AF group, 3 males and 2 females with an average age of 50.3±5.8 years). About 100 mg tissue was obtained from the right auricula dextra, and the atrial fibroblasts were cultured by tissue block adherence method, and the expression of BKCa channel genes and proteins in cultured fibroblasts was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting methods. Results (1) The general data of 10 patients between the AF group and the sinus rhythm group were compared. There was no significant difference between the two groups in age (t=1.21, P=0.67) and sex (t=2.56, P=0.75). There was statistical difference in the left atrial diameter and the right atrium diameter between the two groups (t=19.45, P=0.01; t=23.52, P=0.06); (2) the mRNA expression of BKCa subunit was detected by qRT-PCR method, and there was no significant difference in the mRNA expression of BKCa α and BKCa β1 between the two groups (t=3.14, P=0.79; t=2.88, P=0.69); (3) the expression of BKCa protein was detected by western blotting method, and there was no significant difference in the protein expression of BKCa α and BKCa β1 between the two groups (t=0.55, P=0.31; t=0.73, P=0.46). Conclusion BKCa pathway may not be involved in the pathogenesis and maintenance of AF, but it may play an important role in the process of myocardial fibrosis.
This article presented the clinical diagnosis and management of a patient with severe aortic regurgitation and moderate aortic stenosis who underwent transcatheter aortic valve replacement complicated with coronary obstruction and retroperitoneal hematoma. The hemodynamics collapsed during the procedure, and transcatheter aortic valve replacement was performed under support of extracorporeal membrane oxygenation and coronary protection. After a negative coronary angiography, the wire was extracted, but a repeated angiography showed left coronary obstruction, so a coronary stent was implanted to the ostium of left coronary artery through the grid of the valve stent. Abdominal CT showed a giant retroperitoneal hematoma 2 weeks after transcatheter aortic valve replacement, and the emergent angiography indicated contrast leakage from left external iliac artery, so a balloon compression was performed followed by a covered stent implantation. This article also provided the clinical characteristics, risk factors and management of coronary obstruction and vascular complication for clinical reference.