Like the biological clock in the body, replication of each cell type (even different cells of the same organism) follows a timing program. Abnormal function of this timer could be an alarm for a disease like cancer. DNA replication starts from a specific point on the chromosome that is called the origin of replication. In contrast to prokaryotes in which DNA replication starts from a single ...

Introduction Posterior urethral valves (PUVs) are a rare malformation in the subcollicular region of the male urethra. They cause varying obstructions of the lower urinary tract. The resulting secondary pathological conditions extend from mild—in part, clinically unmanifested—urinary dysfunctions to severe, bilateral changes in the upper urinary tract and associated renal failure. The literatur...

Transcatheter aortic valve replacement (TAVR) is a novel therapeutic intervention for the replacement of severely stenotic aortic valves in high-risk patients for standard surgical procedures. Since the initial PARTNER trial results, use of TAVR has been on the rise each year. New delivery methods and different valves have been developed and modified in order to promote the minimally invasive p...

Variable intensity and timing of valvular sounds were noted in two patients with permanent pacemakers and prosthetic valves. In the first patient, who had a mitral and a tricuspid prosthesis, valvular opening sounds became widely separated with a change from nodal to ventricular paced rhythm. In a second patient, who had a mitral prosthesis in sinus rhythm with first-degree atrioventricular blo...

the purpose of this study was to examine the effect of self-control feedback on relative and absolute timing through observational and physical practices. participants (n=90) were randomly assigned to physical and observational practice (self-control, yoked, and instructor kr) groups. they practiced a sequential timing task, which required participants to press four keys (2, 6, 8, and 4) respec...

Homogenous Charge Compression Ignition (HCCI) engines hold promise of high fuel efficiency and low emission levels for future green vehicles. But in contrast to gasoline and diesel engines, HCCI engines suffer from lack of having direct means to initiate combustion. A combustion timing controller with robust tracking performance is the key requirement to leverage HCCI application in production ...

Loading conditions and complex geometry have led the cylinder heads to become the most challenging parts of diesel engines. One of the most important durability problems in diesel engines is due to the cracks valves bridge area. The purpose of this study is a thermo-mechanical analysis of cylinder heads of diesel engines using a two-layer viscoplasticity model. The results of the thermo-mechani...

Valves are essential components in non-segmented flow systems, particularly in Flow Injection Analysis (FIA). Although their usual role is associated with sample 'injection' into a carrier stream, this is not by any means their sole use. In hydrodynamic systems, valves must also be regarded as components allowing the manipulation of the flow and affording a high degree of automation of the oper...