introduction:  in patients who underwent surgery to repair tetralogy of fallot, right ventricular dilation from pulmonary regurgitation may be result in right ventricular failure, arrhythmias and cardiac arrest. hence, pulmonary valve replacement may be necessary to reduce right ventricular volume overload. the aim of present study was to assess the effects of pulmonary valve replacement on rig...

Objective(s): Tissue engineering represents a new approach to solve the current complications of the heart valve replacements by offering viable valve prosthesis with growth and remodeling capability. In this project, electrospinning and dip coating techniques were used to fabricate heart valve constructs from medical grade polyurethane (PU). Methods: Fir...

In this study it has been tried, to compare results and convergence rate of sensitivity analysis and conjugate gradient algorithms to reduce fuel consumption and increasing engine performance by optimizing the timing of opening and closing valves in XU7/L3 engine. In this study, considering the strength and accuracy of simulation GT-POWER software in researches on the internal combustion engine...

The study on the flow behave inside of a ball valve is important for heavy crude oil transportation. Owe to the fast progress of the numerical technique, it becomes an effective way to observe the flows inside a valve and to analyze the flow structure of the oil-water core annular flow. In the present study, the simulation of the oil-water core annular flowing through the valve is conducted...

global myocardial ischemia and ischemia-reperfusion injury are potential adverse events related with cardioplegic arrest. beating heart surgery has avoided such complications and adapted to valve surgery following successful results published on myocardial revascularization. difficulty in weaning from cardiopulmonary bypass may be lessened by using on-pump beating heart surgery for mitral valve...

Background: Heart valve diseases are considered a common disease in human and animals, and valve replacement is an option for treatment of valvular diseases. Objectives: In this study efficacy of a tissue engineered valve in thoracic aorta was evaluated with transthoracic echocardiography. Methods: This study was undertaken on 6 male sheep. Echocardiography was performed on all sheep 24 hours b...

there is a paucity of literature regarding iatrogenic aortic valve perforation after cardiac operation is performed in the vicinity of the aortic valve. this report describes the clinical, echocardiographic, and angiocardiographic recognition of iatrogenic aortic valve perforation in a patient who had previously under gone membranous ventricular septal defect and pulmonary stenosis. five days a...

since knowledge on hydrodynamic torque of a butterfly valve is very important for butterfly valve design, its hydrodynamic torque is investigated in this paper. in reality, the investigation of the loss coefficient and torque from some experiments will take a long time and a lot of money. this paper presents a statistical study of the flow past the butterfly valve in a static analysis using com...

recently, there have been more reports of cardiac valve infections due to the increasing number of intravenous (iv) drug abusers and chronic renal failure patients. among cardiac valves, tricuspid valve is most commonly affected in the course of endocarditis. appropriate management of these patients is a challenging and controversial issue in the field of cardiac surgery. treatment options in s...