keyword
MENU ▼
Read by QxMD icon Read
search

eccentric rotation

keyword
https://www.readbyqxmd.com/read/28894230/light-guiding-and-switching-using-eccentric-core-shell-geometries
#1
Ángela I Barreda, Yael Gutiérrez, Juan M Sanz, Francisco González, Fernando Moreno
High Refractive Index (HRI) dielectric nanoparticles have been proposed as an alternative to metallic ones due to their low absorption and magnetodielectric response in the VIS and NIR ranges. For the latter, important scattering directionality effects can be obtained. Also, systems constituted by dimers of HRI dielectric nanoparticles have shown to produce switching effects by playing with the polarization, frequency or intensity of the incident radiation. Here, we show that scattering directionality effects can be achieved with a single eccentric metallo-HRI dielectric core-shell nanoparticle...
September 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28878558/characterization-of-columnar-inertial-modes-in-rapidly-rotating-spheres-and-spheroids
#2
Stefano Maffei, Andrew Jackson, Philip W Livermore
We consider fluid-filled spheres and spheroidal containers of eccentricity ϵ in rapid rotation, as a proxy for the interior dynamics of stars and planets. The fluid motion is assumed to be quasi-geostrophic (QG): horizontal motions are invariant parallel to the rotation axis z, a characteristic which is handled by use of a stream function formulation which additionally enforces mass conservation and non-penetration at the boundary. By linearizing about a quiescent background state, we investigate a variety of methods to study the QG inviscid inertial wave modes which are compared with fully three-dimensional (3D) calculations...
August 2017: Proceedings. Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/28856387/relative-vibrotactile-spatial-acuity-of-the-torso
#3
Ómar I Jóhannesson, Rebekka Hoffmann, Vigdís Vala Valgeirsdóttir, Rúnar Unnþórsson, Alin Moldoveanu, Árni Kristjánsson
While tactile acuity for pressure has been extensively investigated, far less is known about acuity for vibrotactile stimulation. Vibrotactile acuity is important however, as such stimulation is used in many applications, including sensory substitution devices. We tested discrimination of vibrotactile stimulation from eccentric rotating mass motors with in-plane vibration. In 3 experiments, we tested gradually decreasing center-to-center (c/c) distances from 30 mm (experiment 1) to 13 mm (experiment 3). Observers judged whether a second vibrating stimulator ('tactor') was to the left or right or in the same place as a first one that came on 250 ms before the onset of the second (with a 50-ms inter-stimulus interval)...
August 30, 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/28819595/early-intraprosthetic-dislocation-of-a-dual-mobility-acetabular-construct-after-total-hip-arthroplasty
#4
Vineet Tyagi, Oluwaseun Akinbo
INTRODUCTION: The concept of a dual mobility (DM) cup has been in existence for more than 40 years and was initially popularized in Europe. Only recently has it started to garner attention in the United States. Its design, consisting of a small femoral head articulating within a larger polyethylene (PE) insert, which articulates with an outer shell, has found increasing use in patients that are at risk for post-operative dislocations. This case report describes a case of recurrent total hip arthroplasty (THA) dislocation managed with the implantation of a DM cup with an acute intraprosthetic dislocation of the DM construct...
March 2017: Journal of Orthopaedic Case Reports
https://www.readbyqxmd.com/read/28774070/friction-and-wear-reduction-of-eccentric-journal-bearing-made-of-sn-based-babbitt-for-ore-cone-crusher
#5
Auezhan Amanov, Byungmin Ahn, Moon Gu Lee, Yongho Jeon, Young-Sik Pyun
An anti-friction Babbitt alloy-coated bearing made by a casting process is a journal bearing, which is used in an ore cone crusher eccentric. The main purpose of the Babbitt coated eccentric is to provide a low friction to support and guide a rotating shaft. Despite the fact that the Babbitt-coated eccentric offers a low friction coefficient and can be operated without a continuous supply of lubricant, it suffers from mining environments and short service life. In this study, an ultrasonic nanocrystalline surface modification (UNSM) technique was used to further reduce the friction coefficient, to increase the wear resistance, and to extend the service life of the Sn-based Babbitt metal...
November 22, 2016: Materials
https://www.readbyqxmd.com/read/28728169/correlations-between-macular-skin-and-serum-carotenoids
#6
Christopher D Conrady, James P Bell, Brian M Besch, Aruna Gorusupudi, Kelliann Farnsworth, Igor Ermakov, Mohsen Sharifzadeh, Maia Ermakova, Werner Gellermann, Paul S Bernstein
Purpose: Ocular and systemic measurement and imaging of the macular carotenoids lutein and zeaxanthin have been employed extensively as potential biomarkers of AMD risk. In this study, we systematically compare dual wavelength retinal autofluorescence imaging (AFI) of macular pigment with skin resonance Raman spectroscopy (RRS) and serum carotenoid levels in a clinic-based population. Methods: Eighty-eight patients were recruited from retina and general ophthalmology practices from a tertiary referral center and excluded only if they did not have all three modalities tested, had a diagnosis of macular telangiectasia (MacTel) or Stargardt disease, or had poor AFI image quality...
July 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28702502/characteristics-and-clinical-outcomes-in-overhead-sports-athletes-after-rotator-cuff-repair
#7
Tomoyuki Muto, Hiroaki Inui, Hiroki Ninomiya, Hiroshi Tanaka, Katsuya Nobuhara
Rotator cuff tears in young overhead sports athletes are rare. The pathomechanism causing rotator cuff tears in young overhead athletes is different from that in aged patients. The purpose of this study was to investigate rotator cuff tear characteristics in young overhead sports athletes to reveal the pathomechanism causing these injuries. This study included 25 overhead sports athletes less than 30 years old with atraumatic rotator cuff tears necessitating repair. Rotator cuff tear characteristics were evaluated intraoperatively, including rotator cuff tear shape and injured rotator cuff tendon...
2017: Journal of Sports Medicine (Hindawi Publishing Corporation)
https://www.readbyqxmd.com/read/28673118/muscle-recruitment-patterns-of-the-subscapularis-serratus-anterior-and-other-shoulder-girdle-muscles-during-isokinetic-internal-and-external-rotations
#8
Sylvain Gaudet, Jonathan Tremblay, Mickael Begon
The aims of this study were to investigate the differences in peak muscle activity and recruitment patterns during high- and low-velocity, concentric and eccentric, internal and external isokinetic shoulder rotations. Electromyographic activity of the rotator cuff and eight superficial muscles of the shoulder girdle was recorded on 25 healthy adults during isokinetic internal and external shoulder rotation at 60°/s and 240°/s. Peak muscle activity, electromyographic envelopes and peak isokinetic moments were analyzed using three-factor ANOVA and statistical parametric mapping...
July 4, 2017: Journal of Sports Sciences
https://www.readbyqxmd.com/read/28648554/the-isokinetic-rotator-cuff-strength-ratios-in-overhead-athletes-assessment-and-exercise-effect
#9
REVIEW
Kelly Berckmans, Annelies G Maenhout, Lien Matthijs, Louise Pieters, Birgit Castelein, Ann M Cools
OBJECTIVE: Muscle strength imbalance in the shoulder region can be considered as a predisposing factor in the development of movement dysfunctions, possibly leading to overuse injuries. Repetitive overhead throwing, performed in sports, may result in muscle imbalance between the external (ER) and internal (IR) rotators. Muscle strength measured with an isokinetic device, is reported as a concentric (CON) or eccentric (ECC) force. The balance between an agonist and an antagonist is mentioned as a ratio (CON/CON or ECC/CON)...
September 2017: Physical Therapy in Sport
https://www.readbyqxmd.com/read/28637599/isokinetic-clinical-assessment-of-rotator-cuff-strength-in-subacromial-shoulder-impingement
#10
Helen Land, Susan Gordon, Kerrianne Watt
BACKGROUND: Current conservative management of subacromial shoulder impingement (SSI) includes generic strengthening exercises, especially for internal (IR) and external (ER) shoulder rotators. However, there is no evidence that the strength or the ratio of strength between these muscle groups is different between those with SSI (cases) and an asymptomatic population (controls). OBJECTIVE: To identify if isokinetic rotator cuff strength or the ratio of strength is significantly different between cases and controls...
February 2017: Musculoskeletal Science & Practice
https://www.readbyqxmd.com/read/28622581/assessment-of-atherosclerotic-luminal-narrowing-of-coronary-arteries-based-on-morphometrically-generated-visual-guides
#11
Rolf F Barth, David A Kellough, Patricia Allenby, Luke E Blower, Scott H Hammond, Greg M Allenby, L Maximilian Buja
BACKGROUND AND AIMS: Determination of the degree of stenosis of atherosclerotic coronary arteries is an important part of postmortem examination of the heart, but, unfortunately, estimation of the degree of luminal narrowing can be imprecise and tends to be approximations. Visual guides can be useful to assess this, but earlier attempts to develop such guides did not employ digital technology. Using this approach, we have developed two computer-generated morphometric guides to estimate the degree of luminal narrowing of atherosclerotic coronary arteries...
May 30, 2017: Cardiovascular Pathology: the Official Journal of the Society for Cardiovascular Pathology
https://www.readbyqxmd.com/read/28619447/similar-movements-are-associated-with-drastically-different-muscle-contraction-velocities
#12
Daniel A Hagen, Francisco J Valero-Cuevas
We investigated how kinematic redundancy interacts with the neurophysiological control mechanisms required for smooth and accurate, rapid limb movements. Biomechanically speaking, tendon excursions are over-determined because the rotation of few joints determines the lengths and velocities of many muscles. But how different are the muscle velocity profiles induced by various, equally valid hand trajectories? We used an 18-muscle sagittal-plane arm model to calculate 100,000 feasible shoulder, elbow, and wrist joint rotations that produced valid basketball free throws with different hand trajectories, but identical initial and final hand positions and velocities...
July 5, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28601489/is-the-subscapularis-normal-after-the-open-latarjet-procedure-an-isokinetic-and-magnetic-resonance-imaging-evaluation
#13
Alexandre Caubère, Damien Lami, Pascal Boileau, Sébastien Parratte, Matthieu Ollivier, Jean-Noël Argenson
BACKGROUND: The Latarjet procedure is considered to be a violation of the subscapularis muscle. This study evaluated the postoperative status of the subscapularis through isokinetic and magnetic resonance imaging analysis after splitting. We hypothesized that compared with a healthy contralateral shoulder, there would be satisfactory recovery of subscapularis strength at the cost of some fatigability and some mild fatty infiltration. MATERIALS AND METHODS: This was a case-control retrospective study of patients who underwent a Latarjet procedure between January 2013 and January 2015...
June 7, 2017: Journal of Shoulder and Elbow Surgery
https://www.readbyqxmd.com/read/28572997/a-superlinear-iteration-method-for-calculation-of-finite-length-journal-bearing-s-static-equilibrium-position
#14
Wenjie Zhou, Xuesong Wei, Leqin Wang, Guangkuan Wu
Solving the static equilibrium position is one of the most important parts of dynamic coefficients calculation and further coupled calculation of rotor system. The main contribution of this study is testing the superlinear iteration convergence method-twofold secant method, for the determination of the static equilibrium position of journal bearing with finite length. Essentially, the Reynolds equation for stable motion is solved by the finite difference method and the inner pressure is obtained by the successive over-relaxation iterative method reinforced by the compound Simpson quadrature formula...
May 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/28569046/training-improves-vibrotactile-spatial-acuity-and-intensity-discrimination-on-the-lower-back-using-coin-motors
#15
H Christiaan Stronks, Janine Walker, Daniel J Parker, Nick Barnes
Tactile vision substitution devices are assistive technologies for the blind that redirect visual information to the tactile sense. They typically include a tactile display that conveys visual information to the skin. Two important parameters that determine the maximum information bandwidth of tactile displays are the spatial acuity of the skin, and the ability of the user to discriminate between stimulus intensities. These two parameters were investigated by determining the two-point discrimination (TPD) threshold and the just-noticeable intensity difference (JND) using coin motors on the lower back...
June 1, 2017: Artificial Organs
https://www.readbyqxmd.com/read/28560493/three-dimensional-analysis-of-linear-vestibulo-ocular-reflex-in-humans-during-eccentric-rotation-while-facing-downwards
#16
Takao Imai, Yasumitsu Takimoto, Noriaki Takeda, Tomoko Okumura, Hidenori Inohara
When participants undergo eccentric rotation (ER), i.e., they are rotated while displaced from the axis of rotation, they undergo both rotational stimulation and linear acceleration, which induces both the angular vestibulo-ocular reflex (aVOR) and linear VOR (lVOR). During ER, the lVOR induced by tangential linear acceleration enhances the eye movement induced by aVOR. In this study, we attempted to measure aVOR and lVOR separately, while participants underwent ER while facing the ground in a dark room. We analyzed three-dimensional eye movements using a video-oculography system...
August 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/28515976/the-acute-effects-of-concentric-versus-eccentric-muscle-fatigue-on-shoulder-active-repositioning-sense
#17
Guido Spargoli
PURPOSE/BACKGROUND: Shoulder proprioception is essential in the activities of daily living as well as in sports. Acute muscle fatigue is believed to cause a deterioration of proprioception, increasing the risk of injury. The purpose of this study was to evaluate if fatigue of the shoulder external rotators during eccentric versus concentric activity affects shoulder joint proprioception as determined by active reproduction of position. STUDY DESIGN: Quasi-experimental trial...
April 2017: International Journal of Sports Physical Therapy
https://www.readbyqxmd.com/read/28453556/characterization-of-interfragmentary-motion-associated-with-common-osteosynthesis-devices-for-rat-fracture-healing-studies
#18
Nicholaus Meyers, Matthias Sukopp, Rudolf Jäger, Malte Steiner, Romano Matthys, Bernd Lapatki, Anita Ignatius, Lutz Claes
Rat models are widely used in preclinical studies investigating fracture healing. The interfragmentary movement at a fracture site is critical to the course of healing and therefore demands definition in order to aptly interpret the experimental results. Estimation of this movement requires knowledge of the fixation stiffness and loading. The characteristic loading for the rat femur has been estimated, but the stiffness of fixation used in rat studies has yet to be fully described. This study aimed to determine the 6 degree of freedom stiffness of four commonly used implants, two external fixators (RatExFix and UlmExFix), a locking plate, and a locking intramedullary nail, in all degrees of freedom and estimate the interfragmentary movement under specific physiological loads...
2017: PloS One
https://www.readbyqxmd.com/read/28452832/shoulder-dynamic-control-ratio-and-rotation-range-of-motion-in-female-junior-elite-handball-players-and-controls
#19
Robert van Cingel, Bas Habets, Linn Willemsen, Bart Staal
OBJECTIVE: To compare glenohumeral range of motion and shoulder rotator muscle strength in healthy female junior elite handball players and controls. DESIGN: Cross-sectional case-control study. SETTING: Sports medical center. PARTICIPANTS: Forty elite female handball players and 30 controls active in nonoverhead sports participated in this study. MAIN OUTCOME MEASURES: Passive external rotator (ER), internal rotator (IR), and total range of motion (TROM) of the dominant and nondominant arm were examined with a goniometer...
April 27, 2017: Clinical Journal of Sport Medicine: Official Journal of the Canadian Academy of Sport Medicine
https://www.readbyqxmd.com/read/28414265/effectiveness-of-a-home-based-eccentric-exercise-program-on-the-torque-angle-relationship-of-the-shoulder-external-rotators-a-pilot-study
#20
Timothy L Uhl, Thomas Rice, Brianna Papotto, Timothy A Butterfield
CONTEXT: The role of the rotator cuff is to provide dynamic stability to the glenohumeral joint. Human and animal studies have identified sarcomerogenesis as an outcome of eccentric training indicated by more torque generation with the muscle in a lengthened position. OBJECTIVE: The authors hypothesized that a home-based eccentric-exercise program could increase the shoulder external rotators' eccentric strength at terminal internal rotation (IR). DESIGN: Prospective case series...
April 2017: Journal of Sport Rehabilitation
keyword
keyword
99862
1
2
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"