Read by QxMD icon Read

Wall deformity

Antoine Léotard, Jessica Taytard, Marion Aouate, Michèle Boule, Veronique Forin, Pauline Lallemant-Dudek
OBJECTIVES: Osteogenesis imperfecta (OI) is the most common genetic skeletal disorder. Extraskeletal findings are common but an association with sleep disordered breathing (SDB) has never been described. The aim of this study was to investigate clinical features of children with OI and suspected SDB. METHODS: A retrospective study of clinical records, signs of SDB and polysomnographic recordings of children with OI was performed. We paid particular attention to symptoms that could be associated with SDB in this population - scoliosis, kyphosis, vertebral arthrodesis, chest wall deformities, basilar impression, autonomy - as well as data already known to be associated with obstructive sleep apnea such as body mass index and upper airway impairment...
February 15, 2018: Annals of Physical and Rehabilitation Medicine
Leigh Conroy, Sarah Quirk, Elizabeth Watt, Gillian Ecclestone, Jessica L Conway, Ivo A Olivotto, Tien Phan, Wendy L Smith
PURPOSE: The purpose of this study was to evaluate the dosimetric effect of breath hold level variability and deformation on breast, chest wall, internal mammary chain (IMC) nodes, and heart. METHODS AND MATERIALS: Left-sided post-lumpectomy (n = 12) and postmastectomy (n = 3) patients underwent deep inspiration breath hold (DIBH) and exhale breath hold (EBH) computed tomography (CT) scans. Forward-planned locoregional breast plans were created on the DIBH scan...
February 13, 2018: Practical Radiation Oncology
Zhijin Lv, Qian Qin, Bei Jiang, Yingcheng Luan, Hengchang Yu
In order to solve the supporting problem in underground engineering with high stress, square steel confined concrete (SQCC) supporting method is adopted to enhance the control on surrounding rocks, and the control effect is remarkable. The commonly used cross section shapes of confined concrete arch are square and circular. At present, designers have no consensus on which kind is more proper. To search for the answer, this paper makes an analysis on the mechanical properties of the two shapes of the cross-sections...
2018: PloS One
Gregory Barshtein, Dan Arbell, Saul Yedgar
The primary goal of red blood cell (RBC) transfusion is to supply oxygen to tissues and organs. However, due to a growing number of studies that have reported negative transfusion outcomes, including reduced blood perfusion, there is rising concern about the risks in blood transfusion. RBC are characterized by unique flow-affecting properties, specifically adherence to blood vessel wall endothelium, cell deformability, and self-aggregability, which define their hemodynamic functionality (HF), namely their potential to affect blood circulation...
2018: Frontiers in Physiology
Gui-Long Liu, Shi-Hong Huang, Che-Si Shi, Bin Zeng, Ke-Shi Zhang, Xian-Ci Zhong
Using copper thin-walled tubular specimens, the subsequent yield surfaces under pre-tension, pre-torsion and pre-combined tension-torsion are measured, where the single-sample and multi-sample methods are applied respectively to determine the yield stresses at specified offset strain. The rule and characteristics of the evolution of the subsequent yield surface are investigated. Under the conditions of different pre-strains, the influence of test point number, test sequence and specified offset strain on the measurement of subsequent yield surface and the concave phenomenon for measured yield surface are studied...
February 10, 2018: Materials
Justyna A Niestrawska, Daniel Ch Haspinger, Gerhard A Holzapfel
Changes in the structural components of aortic tissues have been shown to play a significant role in the pathogenesis of aortic degeneration. Therefore, reliable stress analyses require a suitable and meaningful constitutive model that captures micro-structural changes. As recent data show, in-plane and out-of-plane collagen fiber dispersions vary significantly between healthy and aneurysmatic aortic walls. The aim of this study is to computationally investigate the influence of fiber dispersion on the mechanical response of aortic tissues in health and disease...
February 13, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Malena I Español, Dmitry Golovaty, J Patrick Wilber
In this paper, we derive a continuum variational model for a two-dimensional deformable lattice of atoms interacting with a two-dimensional rigid lattice. The starting point is a discrete atomistic model for the two lattices which are assumed to have slightly different lattice parameters and, possibly, a small relative rotation. This is a prototypical example of a three-dimensional system consisting of a graphene sheet suspended over a substrate. We use a discrete-to-continuum procedure to obtain the continuum model which recovers both qualitatively and quantitatively the behaviour observed in the corresponding discrete model...
January 2018: Proceedings. Mathematical, Physical, and Engineering Sciences
Robert Sinko, Zdeněk P Bažant, Sinan Keten
The Pickett effect describes the excess non-additive strain developed during drying of a nanoporous solid material under creep. One explanation for its origins, developed using micromechanical models, is the progressive relaxation of internally developed microprestress. However, these models have not explicitly considered the effects of this microprestress on nanoscale energy barriers that govern the relative motion and displacement between nanopore walls during deformation. Here, we evaluate the nanoscale effects of transverse microprestresses on the drying creep behaviour of a nanoscale slit pore using coarse-grained molecular dynamics...
January 2018: Proceedings. Mathematical, Physical, and Engineering Sciences
Wiktor Urbanski, Wojciech Jurasz, Michal Wolanczyk, Miroslaw Kulej, Piotr Morasiewicz, Szymon Lukasz Dragan, Rafal Zaluski, Grzegorz Miekisiak, Szymon Feliks Dragan
BACKGROUND: The clinical value of pedicle screws in spinal deformity surgery is well known; however, screw insertion is demanding and sometimes associated with complications. Navigation systems based on intraoperatively obtained three-dimensional (3-D) images were developed to minimize pedicle screw misplacements. However, there is a lack of data confirming superiority of navigation above other techniques. There are also concerns regarding increased radiation used during the procedure...
February 8, 2018: Clinical Orthopaedics and related Research
MennatAllah M Ewais, Shivani Chaparala, Rebecca Uhl, Dawn E Jaroszewski
Pectus excavatum (PEx) is one of the most common congenital chest wall deformities. Depending on the severity, presentation of PEx may range from minor cosmetic issues to disabling cardiopulmonary symptoms. The effect of PEx on adult patients has not been extensively studied. Symptoms may not occur until the patient ages, and they may worsen over the years. More recent publications have implied that PEx may have significant cardiopulmonary implications and repair is of medical benefit. Adults presenting for PEx repair can undergo a successful repair with a minimally invasive "Nuss" approach...
2018: Patient related Outcome Measures
Wanqu Zhu, Byoung Choul Kim, Mingyi Wang, Jessie Huang, Abraham Isak, Natalia M Bexiga, Robert Monticone, Taekjip Ha, Edward G Lakatta, Steven S An
Here we report exquisitely distinct material properties of primary vascular smooth muscle (VSM) cells isolated from the thoracic aorta of adult (8 months) vs. aged (30 months) F344XBN rats. Individual VSM cells derived from the aged animals showed a tense internal network of the actin cytoskeleton (CSK), exhibiting increased stiffness (elastic) and frictional (loss) moduli than those derived from the adult animals over a wide frequency range of the imposed oscillatory deformation. This discrete mechanical response was long-lived in culture and persistent across a physiological range of matrix rigidity...
February 8, 2018: Scientific Reports
Michele Curatolo, Paola Nardinocchi, Luciano Teresi
We study the dynamics of the dehydration process of a hydrogel with a cavity filled with water. We identify two transient phases: the first one dominated by an inflatable-balloon deformation mode, and the second by a suction effect, determining highly not homogeneous deformation modes of the hydrogel walls. This last phase triggers negative pressures into the cavity up to the typical values of water cavitation. An analysis of the factors allowing cavitation pressure to form inside the cavity is proposed, to allow for precise tuning of the key geometrical and material parameters...
February 8, 2018: Soft Matter
Mengyu Xing, Li Zheng, Yizhen Deng, Dandan Xu, Pinggen Xi, Minhui Li, Guanghui Kong, Zide Jiang
Litchi (Litchi chinensis Sonn.) is a commercially important fruit but its production and quality are restricted by litchi downy blight, caused by the oomycete pathogen Peronophythora litchii Chen. Volatile substances produced by a biocontrol antinomycetes Streptomyces fimicarius BWL-H1 could inhibited P. litchii growth and development both in vitro and in detached litchi leaf and fruit infection assay. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) analyses indicated that volatile organic compounds (VOCs) from BWL-H1 resulted in severe damage to the endomembrane system and cell wall of P...
February 8, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Matthew Hughes, Jason Bernard, Matthew Szarko
STUDY DESIGN: An in vitro biomechanical study into the effect of rib deconstruction on the flexibility in ovine ribs, using three-point bending. OBJECTIVE: To examine the feasibility and possible effectiveness of a more conservative costoplasty using an in vitro animal model. SUMMARY OF BACKGROUND DATA: Costoplasty remains useful in the treatment of adolescent idiopathic scoliosis, rib hump, and associated chest wall deformities. However, traditional costoplasty increases morbidity and blood loss...
March 2018: Spine Deformity
Jieyu Cheng, Yimin Chen, Yanyan Yu, Bernard Chiu
Total plaque volume (TPV) measured from 3D carotid ultrasound has been shown to be able to predict cardiovascular events and is sensitive in detecting treatment effects. Manual plaque segmentation was performed in previous studies to quantify TPV, but is tedious, requires long training times and is prone to observer variability. This article introduces the first 3D direct volume-based level-set algorithm to segment plaques from 3D carotid ultrasound images. The plaque surfaces were first initialized based on the lumen and outer wall boundaries generated by a previously described semi-automatic algorithm and then deformed by a direct three-dimensional sparse field level-set algorithm, which enforced the longitudinal continuity of the segmented plaque surfaces...
January 11, 2018: Computers in Biology and Medicine
Badr Kaoui
I propose two-dimensional simulations of drug release from a liposome into the bloodstream. I perform the fluid-structure coupling, between the particles deformation (the liposome and the red blood cells) and the plasma flow, using the immersed boundary method. I compute both the flow and the drug mass transport using the lattice Boltzmann method. The simulations allow computing the instantaneous amount of the released drug, its distribution and its accumulation in the blood vessel wall. These quantities are sensitive to multiple factors and parameters...
February 8, 2018: European Physical Journal. E, Soft Matter
S Krinner, S Schmitt, S Grupp, F F Hennig, A Langenbach, S Schulz-Drost
BACKGROUND: Combinations of sternal and spinal fractures often occur due to high velocity accidents and are associated with a high incidence of concomitant injuries. The anterior thoracic wall is described as the fourth column of torso stability, which is why sternovertebral injuries (SVI) present a high risk of sagittal deformation of the trunk, in particular injuries of the thoracic spine. To date, no studies have been published on the frequency distribution of the involved vertebral bodies in large patient groups...
February 5, 2018: Der Unfallchirurg
Vikas Gupta, Jonas Lantz, Lilian Henriksson, Jan Engvall, Matts Karlsson, Anders Persson, Tino Ebbers
BACKGROUND: Assessment of myocardial deformation from time-resolved cardiac computed tomography (4D CT) would augment the already available functional information from such an examination without incurring any additional costs. A deformable image registration (DIR) based approach is proposed to allow fast and automatic myocardial tracking in clinical 4D CT images. METHODS: Left ventricular myocardial tissue displacement through a cardiac cycle was tracked using a B-spline transformation based DIR...
February 2, 2018: Journal of Cardiovascular Computed Tomography
Alessandra Patera, Stephan Carl, Marco Stampanoni, Dominique Derome, Jan Carmeliet
This paper concerns the problem of wood cellular structure image registration. Given the large variability of wood geometry and the important changes in the cellular organization due to moisture sorption, an affine-based image registration technique is not exhaustive to describe the overall hygro-mechanical behaviour of wood at micrometre scales. Additionally, free tools currently available for non-rigid image registration are not suitable for quantifying the structural deformations of complex hierarchical materials such as wood, leading to errors due to misalignment...
2018: Advanced Structural and Chemical Imaging
Xinlei Wu, Clemens von Birgelen, Zehang Li, Su Zhang, Jiayue Huang, Fuyou Liang, Yingguang Li, William Wijns, Shengxian Tu
Cyclic biomechanical stress at the lumen-intima interface plays a crucial role in the rupture of coronary plaque. We performed a comprehensive assessment of a novel angiography-based method for four-dimensional (4D) dynamic assessment of superficial wall stress (SWS) and deformation with a total of 32 analyses in virtual stenosis models with equal lumen dimensions and 16 analyses in human coronary arteries in vivo. The in silico model analyses demonstrated that the SWS, derived by the proposed global displacement method without knowledge of plaque components or blood pressure, was comparable with the result calculated by traditional finite element method...
February 3, 2018: International Journal of Cardiovascular Imaging
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"