by Nathaniel T. Hollingsworth Annulus fibrosus damage has been shown to come from combinations of bending, lifting, and twisting. Although the these motions can induce annulus fibrosus damage, the stress-strain state of the annulus during these motions is not known. The objective of this project was to develop more complete constitutive models and to investigate annulus fibrosus damage mechanic...

One of the most important fluid phenomena observed in the left ventricle during diastole is the presence of vortex rings that develop with a strong jet entering through the mitral valve. The present study is focused on the rapid filling phase of diastole, during which the left ventricle expands and receives blood through the fully open mitral valve. The atrioventricular system during the rapid ...

The collagen network of the annulus fibrosus largely controls the functional biomechanics of the lumbar intervertebral discs (IVDs). Quantitative anatomical examinations have shown bundle orientation patterns, possibly coming from regional adaptations of the annulus mechanics. This study aimed to show that the regional differences in annulus mechanical behaviour could be reproduced by consideri...

OBJECTIVES In the present study, the anatomy of the aortic root was assessed noninvasively with multislice computed tomography (MSCT). BACKGROUND Transcatheter aortic valve replacement has been proposed as an alternative to surgery in high-risk patients with severe aortic stenosis. For this procedure, detailed knowledge of aortic annulus diameters and the relation between the annulus and the ...

Measurement of the shape and motion of the mitral valve annulus has proven useful in a number of applications, including pathology diagnosis and mitral valve modeling. Current methods to delineate the annulus from four-dimensional (4D) ultrasound, however, either require extensive overhead or user-interaction, become inaccurate as they accumulate tracking error, or they do not account for annul...

We investigated the influence of the relative phase of a temporally modulated annulus on the perceived flicker strength of a center stimulus having the same temporal modulation. These measurements were performed in two subjects at two temporal frequencies and with different outer diameters of the annulus. The perceived flicker strength was strongly modulated by the phase difference between cent...

In the present work microstructural evolution of A356 Aluminum alloy using an inclined cooling plate casting process for thixoforming feedstock production is investigated. The resultant microstructure was evaluated and compared with those of the same alloy produced by the conventional casting process, i.e. directly cast in the same mold without using an inclined cooling plate. It was found that...

BACKGROUND Surgery for disc herniations can be complicated by two major problems: painful degeneration of the spinal segment and re-herniation. Therefore, we examined an absorbable poly-glycolic acid (PGA) biomaterial, which was lyophilized with hyaluronic acid (HA), for its utility to (a) re-establish spinal stability and to (b) seal annulus fibrosus defects. The biomechanical properties range...

BACKGROUND AND AIM OF THE STUDY Mitral valve dynamic changes during the cardiac cycle have been previously studied in sheep using sonomicrometry. The study aim was to analyze geometric changes of the normal tricuspid annulus in sheep using a similar methodology. This is most likely the first tricuspid valve study using high temporal resolution (200 Hz = 200 data points per second). METHODS Th...

Akın A, Alehan D, Aykan HH, Özkutlu S, Özer S, Karagöz T. Evaluation of Tissue Doppler Echocardiographic Imaging findings in children with pulmonary hypertension. Turk J Pediatr 2017; 59: 244-253. Tissue Doppler Imaging has become an important prognostic marker that can be used in follow-up and determination of the prognosis in pulmonary hypertension patients. We compared the Tissue Doppler ima...