BACKGROUND Valve areas derived by the Gorlin formula have been observed to vary with transvalvular volume flow rate. Continuity equation valve areas calculated from Doppler-echo data have become a widely used alternate index of stenosis severity, but it is unclear whether continuity equation valve areas also vary with volume flow rate. This study was designed to investigate the effects of chang...

OBJECTIVES Evaluation of the severity of a coronary artery stenosis is of paramount importance for therapy. A relevant stenosis provokes post-stenotic microvascular dilation with capillary recruitment. This autoregulatory response was investigated in the present study by use of susceptibility-sensitive magnetic resonance imaging (MRI) without contrast agents. BACKGROUND Functional alterations...

this paper explores the flexile flow lines where setup times are sequence- dependent. the optimization criterion is the minimization of total weighted completion time. we propose an iterated greedy algorithm (iga) to tackle the problem. an experimental evaluation is conducted to evaluate the proposed algorithm and, then, the obtained results of iga are compared against those of some other exist...

nowadays, by successful application of on time production concept in other concepts like production management and storage, the need to complete the processing of jobs in their delivery time is considered a key issue in industrial environments. unrelated parallel machines scheduling is a general mood of classic problems of parallel machines. in some of the applications of unrelated parallel mac...

BACKGROUND Coronary thrombosis is a dynamic process dependent on the pathological substrate, the local shear forces, and blood factors. METHODS AND RESULTS We investigated the effect of a severe (80%) eccentric stenosis on fibrin(ogen) interaction with a deeply damaged vessel wall, its relation to platelet deposition in thrombus formation, and the influence of time on thrombus growth. Porcine...

BACKGROUND AND PURPOSE Acute cerebral ischemic events are associated with rupture of vulnerable carotid atheroma and subsequent thrombosis. Factors such as luminal stenosis and fibrous cap thickness have been thought to be important risk factors for plaque rupture. We used a flow-structure interaction model to simulate the interaction between blood flow and atheromatous plaque to evaluate the e...

  Abstract   Background: Iatrogenic airway injury after endotracheal intubation and tracheotomy   remains a serious clinical problem. In this study we reviewed post-intubation and traumatic tracheal stenosis in 47 patients with a special attention to the cause, hense surgical treatment of the stenosis was performed and the results compared with the literatures.   Methods: Since February 1995 th...