A contact model based on the coefficient of restitution for simulations of bio-prosthetic heart valves.

A new general contact model is proposed for preventing inter-leaflet penetration of bio-prosthetic heart valves (BHV) at the end of the systole, which has the advantage of applying kinematic constraints directly and creating smooth free edges. At the end of each time step, the impenetrability constraints and momentum exchange between the impacting bodies are applied separately based on the coefficient of restitution. The contact method is implemented in a rotation-free, large deformation, and thin shell finite-element (FE) framework based on loop's subdivision surfaces.

The Effect of External Cold and Vibration on Infiltration-Induced Pain in Children: A Randomized Clinical Trial.

Introduction: Children's fear of and anxiety about dental treatments are important problems in maintaining health. The anesthetic injection is the main cause of dental fear. One of the methods to reduce the infiltration-induced pain is to use external cold or vibration using the gate control system.

The Effects of Implantation Orientation of a Bileaflet Mechanical Heart Valve in an Anatomic Left Ventricle-Aorta Configuration.

We have performed three-dimensional high-resolution numerical simulations of a bi-leaflet mechanical heart valve implanted at different orientations in an anatomic left ventricle-aorta obtained from magnetic resonance imaging of a volunteer. The thoroughly validated overset curvilinear-immersed boundary fluid-structure interaction flow solver is used in which the aorta and left ventricle (LV) are discretized with boundary-conforming and nonconforming curvilinear grids, respectively. The motion of the left ventricle wall is prescribed based on a lumped parameter model while the motion of the leaflets is calculated using a strongly coupled fluid-structure interaction algorithm enhanced with Aitken convergence technique.

LncRNA SNHG6 Silencing Could Arrest Progression of High Grade Colorectal Cancers.

Background & Objective: Colorectal cancer (CRC), like other cancers, needs faster and more accurate identifications. A well-timed prognosis of CRC could be an important turning point in the survival of patients. Supplementary signs, such as long non-coding RNAs (lncRNAs), could be helpful for this purpose.

Biological soil crusts determine soil properties and salt dynamics under arid climatic condition in Qara Qir, Iran.

Biological soil crusts are a thin layer within the soil system but strongly determine the infiltration, runoff and water and solute movement. Little is known about the role of biological soil crusts on soil solute dynamics in arid ecosystems and the objective of this paper is to determine in Qara Qir rangeland how biological soil crusts control the water and salt distribution along the soil profile. Rainfall simulation experiments were carried out at five locations, and measurements of the soil at 0-5, 5-10, 10-20, 20-30, 30-50 and 50-80 cm depth were done before, 48 h and 21 days after the rainfall simulations.

A non-dimensional parameter for classification of the flow in intracranial aneurysms. II. Patient-specific geometries.

A simple parameter, called the Aneurysm number () which is defined as the ratio of transport to vortex time scales, has been shown to classify the flow mode in simplified aneurysm geometries. Our objective is to test the hypothesis that can classify the flow in patient-specific intracranial aneurysms (IA). Therefore, the definition of this parameter is extended to anatomic geometries by using hydraulic diameter and the length of expansion area in the approximate direction of the flow.

Current Scenario of the Tehran Municipal Solid Waste Handling Rules towards Green Technology.

This study aims to study the waste management process and recycling of municipal waste in Tehran. Currently, Kahrizak is the defined landfill area which collects the waste generated from 22 districts of Tehran. The organic wastes undergo to the windrow composting method in order to manage the partial of the waste generated in the city.

Association of single nucleotide polymorphisms in WNT genes with the risk of nonsyndromic cleft lip with or without cleft palate.

Nonsyndromic cleft lip with or without cleft palate is a common congenital deformity worldwide with multifaceted etiology. Interaction of genes and environmental factors has been indicated to be related with susceptibility to nonsyndromic cleft lip with or without cleft palate. Some WNT genes which are involved in craniofacial embryogenesis may play a key role in the pathogenesis of nonsyndromic cleft lip with or without cleft palate.

Basic life support knowledge and skills of Iranian general dental practitioners to perform cardiopulmonary resuscitation.

Background: When cardiopulmonary arrest occurs, the dentist's ability to perform cardiopulmonary resuscitation (CPR) is the most important factor to minimize morbidity and mortality. This study assessed the basic life support (BLS) knowledge and performance of general dental practitioners in Hamadan, Iran.

Materials And Methods: The participants in the study were 80 Iranian general dental practitioners who were chosen randomly.