In this paper, we consider RNA structures with arc-length 4 . First, we represent these structures as matrix models and zero-one linearprogramming problems. Then, we obtain an optimal solution for this problemusing an implicit enumeration method. The optimal solution corresponds toan RNA structure with the maximum number of hydrogen bonds.

background and aim: it is well - known that sex hormones regulate bone metabolism. sex steroids increase osteoblasts activities and affect growth, remodeling and bone homeostasis. the aim of this study was to examine the effects of sex hormones deficiency on craniofacial growth in rats. methods & materials: fifty, thirty–day–old wistar rats comprised the sample in this experimental study. 25 ma...

Shell structures have a rich family of boundary layers including internal layers. Each layer has its own characteristic length scale, which depends on the thickness shell. Some these scales are long, something that is not commonly considered in literature. In this work, three types long-range demonstrated over an extensive set simulations. The observed asymptotic behavior consistent with theore...

There are some artificial and natural materials on foundation of heap leaching structures. Geomembrane liner is the most important artificial isolated layer of these structures. The thickness of this layer is about 1 to 2 mm. Foundation overall settlement of such structures changes the primary length of the geomembrane layer. If the strain of geomembrane is more than allowable one, the layer wi...

Background: Establishing theories for designing arbitrary protein structures is complicated and depends on understanding the principles for protein folding, which is affected by applied features. Computer algorithms can reach high precision and stability in computationally designing enzymes and binders by applying informative features obtained from natural structures. Methods: In this study, a ...

In this research, the influence of structure on the tensile properties of single- walled carbon nanotubes (CNTs) is evaluated using molecular mechanics technique and finite element method. The effects of diameter, length and chiral angle on elastic modulus and Poisson’s ratio of armchair, zigzag and chiral structures are investigated. To simulate the CNTs, a 3D FEM code is developed using the A...

carbon nanotubes (cnts) are specific structures with valuable characteristics. in general, the structure of each nanotube is defined by a unique chiral vector. in this paper, different structures of short single-walled cnts are simulated and their mechanical properties are determined using finite element method. for this aim, a simple algorithm is presented which is able to model the geometry o...

Introduction: In our study, we aimed 200 cases were evaluated for the length, width and angle of hyoid bone and its distance from certain anatomical structures. Methods: This study was perfomed retrospectively in 2010 - 2013 on 200 CT images. 3D volume rendering images of pure hyoid bone were created from the axial CT images in 1 mm slice thickness. In our study, 200 cases (94 female, 106 male...