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https://www.readbyqxmd.com/read/28636055/effect-of-headless-compression-screw-on-construct-stability-for-centre-of-rotation-and-angulation-based-levelling-osteotomy-biomechanical-testing-in-flexion-and-torsion
#1
Michelle R Meyer, Mireya A Perez, Mohammad S Hossain, Edward B Silverman, Randall B Fitch, Ryan B Wicker
OBJECTIVE: To compare the biomechanical properties of bone and implant constructs when used for the centre of rotation and angulation (CORA) based levelling osteotomy, with and without implantation of a trans-osteotomy headless compression screw tested under three-point flexural and torsional forces; thereby determining the contribution of a trans-osteotomy headless compression screw with regards to stability of the construct. METHODS: Experimental biomechanical study utilizing 12 pairs of cadaveric canine tibias...
June 21, 2017: Veterinary and Comparative Orthopaedics and Traumatology: V.C.O.T
https://www.readbyqxmd.com/read/28634695/assessment-of-early-diastolic-intraventricular-pressure-gradient-in-the-left-ventricle-among-patients-with-repaired-tetralogy-of-fallot
#2
Maki Kobayashi, Ken Takahashi, Mariko Yamada, Kana Yazaki, Kotoko Matsui, Noboru Tanaka, Sachie Shigemitsu, Katsumi Akimoto, Masahiko Kishiro, Keisuke Nakanishi, Shiori Kawasaki, Masaki Nii, Keiichi Itatani, Toshiaki Shimizu
Assessment of left ventricular (LV) dysfunction is vital in patients with repaired tetralogy of Fallot (rTOF). The early diastolic intraventricular pressure gradient (IVPG) in the LV plays an important role in diastolic function. IVPG is calculated as the intraventricular pressure difference divided by the LV length, which allows to account for differences in LV size and therefore calculate IVPG in children. We aimed to investigate the mechanisms of LV diastolic dysfunction by measuring mid-to-apical IVPG as an indicator of the active suction force sucking blood from the left atrium into the LV...
June 20, 2017: Heart and Vessels
https://www.readbyqxmd.com/read/28632144/optimal-pitching-axis-location-of-flapping-wings-for-efficient-hovering-flight
#3
Qi Wang, J Goosen, Fred Van Keulen
Flapping wings can pitch passively about their pitching axes due to their flexibility, inertia, and aerodynamic loads. A shift in the pitching axis location can dynamically alter the aerodynamic loads, which in turn changes the passive pitching motion and the flight efficiency. Therefore, it is of great interest to investigate the optimal pitching axis for flapping wings to maximize the power efficiency during hovering flight. In this study, flapping wings are modeled as rigid plates with non-uniform mass distribution...
June 20, 2017: Bioinspiration & Biomimetics
https://www.readbyqxmd.com/read/28631280/age-and-sex-associated-morphological-variations-of-metatarsal-torsional-patterns-in-humans
#4
Masateru Kitashiro, Naomichi Ogihara, Tetsuro Kokubo, Morio Matsumoto, Masaya Nakamura, Takeo Nagura
It has been demonstrated that the torsional patterns of the metatarsal heads are associated with the presence or absence of the medial longitudinal arch in hominoid feet. The relatively untwisted second metatarsal is unique in humans, but that of the African apes is much more inverted, suggesting that the torsion of the second metatarsal might represent the overall shape and flatness of the foot. Some clinical studies have recently argued that the onset of foot pathologies such as hallux valgus might be related to the torsional pattern of the metatarsals...
June 20, 2017: Clinical Anatomy
https://www.readbyqxmd.com/read/28630736/abnormal-femoral-antetorsion-a-subtrochanteric-deformity
#5
Guy Waisbrod, Florian Schiebel, Martin Beck
Femoral rotational malalignment is associated with pain and functional disability and may be a contributing factor to hip impingement as well as to instability. In general, the deformity can be addressed surgically by rotational osteotomy. However, the anatomic location of the deformity is debated. The goal of the present study was to narrow down the anatomic site of deformity using the lesser trochanter (LT) as an additional landmark. One hundred and eight patients underwent computer tomography (CT)-based rotational analysis of their lower extremities...
July 2017: Journal of Hip Preservation Surgery
https://www.readbyqxmd.com/read/28630019/tunica-vaginalis-pedicle-flap-for-repair-of-ruptured-testis-a-single-center-experience-with-four-patients
#6
R N Damle, J F Lalikos, J T Aidlen, P Ellsworth
Management of testicular rupture with a large tunical defect may not be feasible without excision of viable tissue. This study describes the use of a vascularized tunica vaginalis flap, without debridement of viable tissue, in four adolescents. Postoperative ultrasound showed good blood flow and 80% volume of the contralateral testis in two cases. Postoperative exam revealed normal exam and ultrasonographic appearance in three patients, the fourth was demonstrated to be small and undescended during evaluation of contralateral testicular torsion...
May 24, 2017: Journal of Pediatric Urology
https://www.readbyqxmd.com/read/28628800/increased-internal-femoral-torsion-can-be-regarded-as-a-risk-factor-for-patellar-instability-a-biomechanical-study
#7
Peter Kaiser, Werner Schmoelz, Philip Schoettle, Marit Zwierzina, Christian Heinrichs, Rene Attal
BACKGROUND: Increased internal femoral torsion is regarded as a risk factor for patellar instability. Biomechanical investigations confirming this hypothesis are missing. METHODS: Eight fresh-frozen cadaver knees were tested on a specially designed simulator. Patellar motion and patellofemoral pressure were evaluated for 0°, 10°, and 20° of increased internal and external femoral torsion with native and with transected medial patellofemoral ligaments used to simulate patellar instability...
June 10, 2017: Clinical Biomechanics
https://www.readbyqxmd.com/read/28627890/improved-description-of-sulfur-charge-anisotropy-in-opls-force-fields-model-development-and-parameterization
#8
Xin Cindy Yan, Michael J Robertson, Julian Tirado-Rives, William L Jorgensen
The atomic point-charge model used in most molecular mechanics force fields does not represent well the electronic anisotropy that is featured in many directional non-covalent interactions. Sulfur participates in several types of such interactions with its lone pairs and σ-holes. The current study develops new models, via the addition of off-atom charged sites, for a variety of sulfur compounds in the OPLS-AA and OPLS/CM5 force fields to address the lack of charge anisotropy. Parameter optimization is carried out to reproduce liquid-state properties, torsional and non-covalent energetics from reliable quantum mechanical calculations, and electrostatic potentials...
June 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28626382/a-symptomatic-coffee-bean-acute-sigmoid-volvulus
#9
Michael Scharl, Luc Biedermann
An acute sigmoid volvulus is due to the torsion of the sigmoid colon around its mesenteric axis. It mainly occurs in elderly patients and represents an abdominal emergency requiring urgent treatment. A 53-year-old male patient with severe craniocerebral injury and traumatic subarachnoidal bleeding 3 weeks prior presented on the ward with distended abdomen without abdominal pain, muscular defense, or resistances. He featured large volume diarrhea within the last few hours without signs of bleeding. A plain abdominal X-ray demonstrated a coffee bean sign indicating a sigmoid volvulus...
May 2017: Case Reports in Gastroenterology
https://www.readbyqxmd.com/read/28626327/the-effects-of-dynamic-exercise-using-the-proprioceptive-neuromuscular-facilitation-pattern-on-posture-in-healthy-adults
#10
Misuk Cho, Wontae Gong
[Purpose] The purpose of this study is to examine the effects of dynamic exercise utilizing the proprioceptor neuromuscular facilitation pattern accompanied by abdominal drawing-in exercises on posture in healthy adults. [Subjects and Methods] The total number of subjects were 32; 16 were randomly placed in the training group, and the remaining 16 made up the control group. The subjects in the training group conducted 5 sets of dynamic exercises utilizing the proprioceptor neuromuscular facilitation patterns each day, 3 times a week for 6 weeks...
June 2017: Journal of Physical Therapy Science
https://www.readbyqxmd.com/read/28625046/conformational-switching-of-hoco-radical-selective-vibrational-excitation-and-hydrogen-atom-tunneling
#11
Sergey V Ryazantsev, Vladimir I Feldman, Leonid Khriachtchev
Conformers of carboxyl radical have been studied by IR spectroscopy in argon and nitrogen matrices. In an argon matrix, only the lower-energy conformer trans-HOCO is observed, whereas both cis and trans conformers are found for deuterated carboxyl radical DOCO. In a nitrogen matrix, both conformers of HOCO and DOCO isotopologues can be prepared, indicating strong stabilization of the higher-energy cis conformer by a nitrogen matrix. Selective vibrational excitation promotes the trans-to-cis and cis-to-trans conversions of DOCO in an argon matrix and HOCO and DOCO in a nitrogen matrix, which is the first conformational photoswitching of an open-shell species...
June 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28624013/femoral-torsion-assessment-with-mri-in-children-should-we-use-the-bony-or-cartilaginous-contours
#12
Andrea B Rosskopf, Christoph A Agten, Leonhard E Ramseier, Christian W A Pfirrmann, Florian M Buck
OBJECTIVE: To assess whether the use of cartilaginous contours at the femoral condyles instead of bony contours significantly changes femoral torsion measurements in children. MATERIALS AND METHODS: Femoral torsion was measured in 32 girls (mean age 10.1 years±2.3 standard deviation) and 42 boys (10.9 years±2.5) on axial magnetic resonance (MR) images by two independent readers (R1,R2). The femoral condyle angle was measured using each the cartilaginous and bony contours of the distal femur...
July 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28623782/factors-responsible-for-the-aggregation-behavior-of-hydrophobic-polyelectrolyte-pea-in-aqueous-solution-studied-by-molecular-dynamics-simulations
#13
Praveenkumar Sappidi, Upendra Natarajan
Self-association (i.e. interchain aggregation) behavior of atactic poly(ethacrylic acid) PEA in dilute aqueous solution as function of degree-of-neutralization by Na(+) counter-ions (i.e. charge fraction f) was investigated by molecular dynamics simulations. Aggregation is found to occur in the range 0≤f≤0.7 in agreement with experimental results compared at specified polymer concentration Cp=0.36mol/l in dilute solution. The macromolecular solution was characterized and analysed for radius-of-gyration, torsion angle distribution, inter and intra-molecular hydrogen bonds, radial distribution functions of intermolecular and inter-atomic pairs, inter-chain contacts and solvation enthalpy...
April 27, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28623777/method-for-lateral-force-calibration-in-atomic-force-microscope-using-mems-microforce-sensor
#14
Cezary Dziekoński, Wojciech Dera, Dariusz M Jarząbek
In this paper we present a simple and direct method for the lateral force calibration constant determination. Our procedure does not require any knowledge about material or geometrical parameters of an investigated cantilever. We apply a commercially available microforce sensor with advanced electronics for direct measurement of the friction force applied by the cantilever's tip to a flat surface of the microforce sensor measuring beam. Due to the third law of dynamics, the friction force of the equal value tilts the AFM cantilever...
June 14, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28622901/tridimensional-analysis-of-rotatory-subluxation-and-sagittal-spinopelvic-alignment-in-the-setting-of-adult-spinal-deformity
#15
Emmanuelle Ferrero, Renaud Lafage, Bassel G Diebo, Vincent Challier, Brice Illharreborde, Frank Schwab, Wafa Skalli, Pierre Guigui, Virginie Lafage
STUDY DESIGN: Retrospective single-center. OBJECTIVE: To investigate rotatory subluxation (RS) in adult spinal deformity (ASD) with three-dimensional (3D) stereoradiographic images and analyze relationships between RS, transverse plane parameters, spinopelvic parameters, and clinical outcomes. BACKGROUND: Recent research has demonstrated that sagittal plane malalignment and listhesis correlate with ASD patient-reported outcomes. However, there is still a lack of knowledge regarding the clinical impact of 3D evaluation and rotatory subluxation...
July 2017: Spine Deformity
https://www.readbyqxmd.com/read/28622442/muscular-basis-of-whisker-torsion-in-mice-and-rats
#16
Sebastian Haidarliu, Knarik Bagdasarian, Namrata Shinde, Ehud Ahissar
Whisking mammals move their whiskers in the rostrocaudal and dorsoventral directions with simultaneous rolling about their long axes (torsion). Whereas muscular control of the first two types of whisker movement was already established, the anatomic muscular substrate of the whisker torsion remains unclear. Specifically, it was not clear whether torsion is induced by asymmetrical operation of known muscles or by other largely unknown muscles. Here we report that mystacial pads of newborn and adult rats and mice contain oblique intrinsic muscles (OMs) that connect diagonally adjacent vibrissa follicles...
June 16, 2017: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
https://www.readbyqxmd.com/read/28622314/development-of-a-simple-computerized-torsion-test-to-quantify-subjective-ocular-torsion
#17
Y D Kim, H K Yang, J-M Hwang
PurposeThe double Maddox-rod test (DMRT) and Lancaster red-green test (LRGT) are the most widely used tests worldwide to assess subjective ocular torsion. However, these tests require equipment and the quantified results of ocular torsion are only provided in rough values. Here we developed a novel computerized torsion test (CTT) for individual assessment of subjective ocular torsion and validated the reliability and accuracy of the test compared with those of the DMRT and LRGT.MethodsA total of 30 patients with cyclovertical strabismus and 30 controls were recruited...
June 16, 2017: Eye
https://www.readbyqxmd.com/read/28621780/structure-property-relationship-of-blue-solid-state-emissive-phenanthroimidazole-derivatives
#18
Agne Ivanauskaite, Ramunas Lygaitis, Steponas Raisys, Karolis Kazlauskas, Gediminas Kreiza, Dmytro Volyniuk, Dalius Gudeika, Saulius Jursenas, Juozas V Grazulevicius
Seven new derivatives of phenanthro[9,10-d]imidazole having differenet substituents at the 1st and the 2nd positions of the phenanthroimidazole moiety were synthesized and characterized. The comparative study of their properties was performed employing thermal, optical, electrochemical and photoelectrical measurements. The properties of the newly synthesized compounds were compared with those of earlier reported derivatives of phenanthroimidazole and several interesting new findings were disclosed. Density functional theory calculations accompanied by optical spectroscopy measurements have shown the possibility of tuning the emission properties (excited-stated decay rate, fluorescence quantum yield, etc...
June 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28621398/ab-initio-prediction-of-stable-confomeric-polymorphs-of-benzocaine-molecule-a-local-anaesthatic-molecule
#19
Pallipurath Nidhin, David Stephen, Selvaraj Arun Paul
An ab initio methodology to predict the crystal structures of thermodynamically stable polymorphs of benzocaine within the least energy region of energy landscape by analyzing the local minima from the initial gas phase optimization initiated through the flexible torsion using MP2/6-31G(d,p) method. The global search for the hypothetical dense packing for the structures within the energy penalty region of the local minima have revealed the possible stable conformers under a repulsion alone potential field. The generated hypothetical dense packings from the global search were selected for lattice minimization using the repulsion - dispersion potential field to authenticate the stability...
June 2017: Acta Chimica Slovenica
https://www.readbyqxmd.com/read/28621279/comparative-evaluation-of-stress-developed-on-rotary-retreatment-instruments-during-retrieval-of-gutta-percha
#20
Dhanasekaran Sihivahanan, T Vinay Kumar Reddy, Anchu Rachel Thomas, Natarajan Senthilnathan, Murali Sivakumar, Sushmita Shivanna
AIM: The aim of the study is to compare the maximum stress distribution on the rotary retreatment instruments within the root canal at cervical, middle, and the apical one-third during retreatment of gutta-percha. MATERIALS AND METHODS: A human mandibular premolar was scanned, and three-dimensional geometry of the root was reconstructed using finite element analysis (FEA) software package (ANSYS). The basic model was kept unchanged; tooth models were created using the same dimensions and divided into two groups as follows: Group I: ProTaper Universal retreatment system and group II: Mtwo rotary retreatment system...
June 1, 2017: Journal of Contemporary Dental Practice
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