Thirty-five consecutive patients with ventricular septal defect (VSD) associated with aortic insufficiency (AI) who underwent corrective surgery are presented. There were seven operative and three late deaths among the patients operated upon before 1968. No death, however, was encountered among the most recent 18 consecutive patients. The VSD was closed directly in 14 patients and with a Teflon...

the existing studies of threshing process of combine harvesters adopt the assumption of constant mass, which is contradictory to the phenomenon of separation of grains and short stalks in actual threshing process. therefore, the characteristics of threshing and separation are not accurately described. aiming at this problem, this study established the tangential-longitudinal threshing and separ...

The precision rotary vector reducer with involute variable tooth thickness (PRVT) is a high-performance transmission device, which very suitable for aerospace, medical machinery, industrial robots, automation equipment, and other fields, its torsional stiffness an important performance index. This paper establishes dynamics model of the whole machine based on Lagrangian method by considering ge...

OBJECTIVE Spasticity is a common complication with neurological diseases and CNS lesions. Instrumented systems to evaluate spasticity often cannot provide an immediate result, thus limiting their clinical usefulness. In this study we investigated the accuracy and reliability of the portable Neurokinetics RA1 Ridgidity Analyzer to measure stiffness of the ankle joint in 46 controls, 14 spinal co...

Cellular responses to chemical cues are at the core of a myriad of fundamental biological processes ranging from embryonic development to cancer metastasis. Most of these biological processes are also influenced by mechanical cues such as the stiffness of the extracellular matrix. How a biological function is influenced by a synergy between chemical concentration and extracellular matrix stiffn...

As it is well known in the field of structural dynamics, by designing a ductile structure and letting the structure yield under strong earthquakes, the forces acting on the structure can be reduced to the level dictated by the yield level. However, the structure undergoes permanent displacement. In this study yielding is emulated in a structural system by adding a " adaptive negative stiffness ...

Children with ventricular septal defect (VSD) often demonstrate failure to thrive (FTT). Such patients usually have reduced systemic cardiac output which has been postulated as a cause for their growth retardation. This study was conducted to ascertain the mechanism of the reduced cardiac output in children with VSD and FTT and also in a porcine model of VSD. Forward stroke volume was reduced i...

Ventricular septal defect (VSD) is the most common form of congenital heart diseases. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases involved in causal cardiac tissue remodeling. We studied the changes of circulating MMP-2 and MMP-9 activities in the patients with VSD severity and closure. There were 96 children with perimembranous VSD enrolled in this study. We ...

Left-to-right (L-R) shunting across a ventricular septal defect (VSD) often involves a direct VSD-pulmonary arterial component (jet) that surges from the VSD immediately into the pulmonary artery. We used the thermodilution technique in dogs with acute experimental VSD to quantify this component. In dogs with supracristal VSD (n = 7), the direct component represented 76 +/- 4% (mean +/- SE) of ...