367 research outputs found
Edge currents as a probe of the strongly spin-polarized topological noncentrosymmetric superconductors
Recently the influence of antisymmetric spin-orbit coupling has been studied
in novel topological superconductors such as half-Heuslers and artificial
hetero-structures. We investigate the effect of Rashba and/or Dresselhaus
spin-orbit couplings on the band structure and topological properties of a
two-dimensional noncentrosymetric superconductor. For this goal, the
topological helical edge modes are analyzed for different spin-orbit couplings
as well as for several superconducting pairing symmetries. To explore the
transport properties, we examine the response of the spin-polarized edge states
to an exchange field in a superconductor-ferromagnet heterostructure. The
broken chiral symmetry causes the uni-directional currents at opposite edges.Comment: 10 pages, 7 figure
Effects of Kinesiotaping on Postural Control of the Healthy Adults after Lumbar Muscle Fatigue
Introduction: Postural control is necessary to carry out all daily activities. It is the result of corporation between somatosensory, visual, and vestibular systems. Disturbance of each of these systems can lead to impairment of postural control and increased risk of falling and injury. The objectives of the present study were to investigate the effect of lumbar muscle fatigue on postural sway as well as the effect of kinesiotaping on postural sway after lumbar muscle fatigue. Methods and Materials: A total of 15 healthy young men participated in the present cross-over randomized study. Participants’ mean velocity and sway area were assessed using force platform in bilateral standing position with their eyes closed and in three conditions: 1. Baseline, 2. After fatigue without taping (NT), and 3. After fatigue with kinesiotaping (KT). At baseline measurements, no intervention was carried out on the participants. For the non-taping condition, tape was not applied during postural sway measurement. For the taping condition, kinesiotape was applied on lumbar area before fatigue protocol. Lumbar extensor fatigue was produced maintaining 60% of maximum voluntary isometric contraction. Repeated measure ANOVA was used for data analysis. Results: After lumbar extensor fatigue, sway area, and mean velocity were significantly higher than baseline measurements, respectively. Sway area between KT condition and NT condition (0.63±0.19 cm2)was not found to be significantly different (P=0.066), while velocity of sway in KT condition was significantly lower than that in NT condition (P=0.006). Conclusions: Lumbar muscle fatigue impaired postural control. Lumbar muscle kinesiotaping may be useful to reduce the negative effects of fatigue on postural control.Key words: Force Plate, Kinesiotape, Low Back, Muscle Fatigue, Postural Contro
Polar Kerr Effect in Multiband Spin-Orbit Coupled Superconductors
We undertake a theoretical analysis to probe the Kerr spectrum within the
superconducting phase of strontium ruthenate, where the Kerr rotation
experiments demonstrate the existence of a superconducting state with broken
time reversal symmetry. We find that spin-orbit coupling changes the
hybridization along the Fermi surface's diagonal zone mainly affects Hall
transport. We show that the dominant Hall response arises mainly from the
quasi-1D orbitals and , linked to their hybridization, while
other contributions are negligible. This establishes that, the breaking of time
reversal symmetry of quasi-1D orbitals can account for the existence of the
Kerr angle, irrespective of the order symmetry specific to the
orbital. Moreover, the optical Hall conductivity and Kerr angle estimated for
the hypothesised superconducting orders also closely match the experimental
findings, providing important novel insight on the role of the spin-orbit
coupling, hybridization, and emergent order.Comment: 7 pages, 2 figure
Preparation and Characterization of Modified Polyethyleneimine Magnetic Nanoparticles for Cancer Drug Delivery
Magnetic nanoparticles with polymeric coating have great significance in drug delivery purpose. We intended to prepare a modified amphiphilic polymer with targeting susceptibility to reduce side effects to normal cells. In this study polyethyleneimine (PEI) as a polycationic polymer reacted with sebacoyl chloride to make a new amphiphilic polymer and folic acid as a targeting agent to reduce cytotoxicity of polymer and increase specific entrance of nanoparticles to cancerous cells. The obtained polymer (PEI-Sb-FA) was then coated on magnetic nanoparticles (MNPs) to stabilize them. The core-shell nanoparticles were characterized by different methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Curcumin was finally loaded on PEI-Sb-FA-MNPs and the release behavior was studied in different pH. Curcumin loading of 28.2% was obtained and released drug in acidic pH = 4.5 was more than pH = 7.4, showing drug release sensitivity toward pH of media
Developing a Location-Based Recommender System Using Collaborative Filtering Technique in the Tourism Industry
The rapid growth of new information and products in the virtual environment has made it time consuming to acquire relevant information and knowledge amidst a vast amount of information. Therefore, an intelligent system that can offer the most appropriate and desirable among the large amount of information and products by following the conditions and features selected by each user should be essentially efficient. Systems that perform this task are called recommendation systems. Given the volume of social network data, challenges such as short-term processing and increased accuracy of recommendations are discussed in this type of system. Hence, it can perform processes faster with less error and can be effective in improving the performance of social recommending systems in improving the classification and clustering of information with the help of collaboration filtering methods. This study first develops an innovative conceptual model of a social network-based tourism recommendation system using Flicker network data. This model is based on 9 key components. The comparison show that the proposed method has an accuracy of 0.3% and a lower error rate
Comparing the Effect of Voluntary and Electrical Fatigue of Quadriceps on Postural Control
Introduction: Postural control is necessary for conducting all activities and is the result of corporation of somatosensory, visual and vestibular systems. Impairment in each of these systems leads to disturbance of postural control and increases the risk of falling and injury. Fatigue is one of the common conditions that can affect postural control. The aim of this study was to elucidate different effects of Electrical Stimulation (ES) and Voluntary (Vol) quadriceps fatigues on postural control. Methods and Materials: This cross-sectional randomized order of testing study was performed at Biomechanics Laboratory of Iran University of Medical Sciences, Tehran, Iran from December 2014 to May 2015. Sixteen healthy active males (24.5±1.36 yr; height: 155.37±53.79 cm and body weight: 70.93±4.5 kg) participated. All the participants underwent two fatigue protocols: ES and VOL contractions. Each fatigue procedure contains isometric contraction with five seconds holding contraction, two seconds rest between each contraction and intensity of voluntary contraction was 20% of Maximal Voluntary Contraction (MVC). In each fatigue protocols, muscles MVC decreased to 30% in both ES and VOL protocols. MVC and postural control measured by using a digital dynamometer and a force plate that registered the Canter of Pressure (COP). Data collected before and after completion of each fatigue protocol. Monopedal postural control was recorded in eyes closed condition. Results: Results did not show significance effect of fatigue on area and mean velocity while showed significant effect on the anterior-posterior (Y-axis) and on the mediolateral direction (X-axis). Conclusion: Thirty percent loss of MVC in quadriceps muscle did not impair postural control.Keywords: Postural control, Quadriceps muscle fatigue, Voluntary contraction, Electrical stimulatio
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