Refine Search

New Search

Advanced search

Results: 18,295,508

(searched for: doi:(10.3816/*) OR doi:(10.1240/*) OR doi:(10.1205/*) OR doi:(10.1197/*) OR doi:(10.1157/*) OR doi:(10.7424/*) OR doi:(10.3921/*) OR doi:(10.1367/*) OR doi:(10.1331/*) OR doi:(10.1383/*) OR doi:(10.2111/*) OR doi:(10.2139/*) OR doi:(10.1006/*) OR doi:(10.1016/*) OR doi:(10.14219/*) OR doi:(10.1067/*) OR doi:(10.1078/*) OR doi:(10.2353/*) OR doi:(10.1054/*) OR doi:(10.1053/*) OR doi:(10.3182/*) OR doi:(10.1602/*) OR doi:(10.7811/*) OR doi:(10.1529/*) OR doi:(10.1533/*) OR doi:(10.1580/*) OR doi:(10.4065/*) OR doi:(10.1378/*) OR doi:(10.3129/*) OR doi:(10.16/*))
Save to Scifeed
Page of 1,829,551
Articles per Page
by
Show export options
  Select all
Sciprofile linkSergey I. Popel, Attia I. Kassem, Yulia N. Izvekova, Sciprofile linkLev M. Zelenyi
Published: 18 September 2020
Physics Letters A, Volume 384; doi:10.1016/j.physleta.2020.126627

Abstract:
The results are presented of the first investigation of linear and nonlinear processes associated with waves which are related to the presence of magnetic fields in dusty plasmas at the Moon. Excitation of lower-hybrid turbulence in dusty plasmas near the lunar surface is studied. It is shown that the lower-hybrid turbulence can be generated wherever the Earth's magnetotail interacts with the near-surface dusty plasmas at the Moon. The electric fields appearing as a consequence of the presence of lower-hybrid turbulence are estimated. They can make a significant contribution to the total electric field above the lunar surface which should be taken into account in the future experimental investigation of electric fields at the Moon.
Junsong Jiang, Sciprofile linkQingtian Zhang, Zhongfei Mu, Sciprofile linkKwok Sum Chan
Published: 18 September 2020
Physics Letters A, Volume 384; doi:10.1016/j.physleta.2020.126641

Abstract:
We investigate the tunnel magnetoresistance (TMR) in an armchair phosphorene nanoribbon modulated by two ferromagnetic stripes. It is shown that large TMR can be achieved by applying a perpendicularly electric field to the phosphorene plane. We find that the TMR can be adjusted by an external gate voltage, and the TMR oscillates periodically from positive to negative by a slight change of the gate voltage. This characteristic can be observed in a wide region of exchange splitting values. Our findings open the way to design phosphorene-based spintronics nanodevices, and it may contribute to the future low power spintronic applications.
Dimitris Angelakis, Nana Liu, Stefano Mancini, Laleh Memarzadeh, Sciprofile linkMatteo G.A. Paris
Published: 18 September 2020
Physics Letters A, Volume 384; doi:10.1016/j.physleta.2020.126665

Published: 18 September 2020
Journal of Biomechanics, Volume 110; doi:10.1016/j.jbiomech.2020.109920

Abstract:
Biomaterial based reconstruction is still the most commonly employed method of small bone defect reconstruction. Bone tissue-engineered techniques are improving, and adjuncts such as vascularization technologies allow re-evaluation of traditional reconstructive methods for healing of critical-sized bone defect. Slow infiltration rate of vasculogenesis after cell-seeded scaffold implantation limits the use of clinically relevant large-sized scaffolds. Hence, in vitro vascularization within the tissue-engineered bone before implantation is required to overcome the serious challenge of low cell survival rate after implantation which affects bone tissue regeneration and osseointegration. Mechanobiological interactions between cells and microvascular mechanics regulate biological processes regarding cell behavior. In addition, load-bearing scaffolds demand mechanical stability properties after vascularization to have adequate strength while implanted. With the advent of bioreactors, vascularization has been greatly improved by biomechanical regulation of stem cell differentiation through fluid-induced shear stress and synergizing osteogenic and angiogenic differentiation in multispecies coculture cells. The benefits of vascularization are clear: avoidance of mass transfer limitation and oxygen deprivation, a significant decrease in cell necrosis, and consequently bone development, regeneration and remodeling. Here, we discuss specific techniques to avoid pitfalls and optimize vascularization results of tissue-engineered bone. Cell source, scaffold modifications and bioreactor design, and technique specifics all play a critical role in this new, and rapidly growing method for bone defect reconstruction. Given the crucial importance of long-term survival of vascular network in physiological function of 3D engineered-bone constructs, greater knowledge of vascularization approaches may lead to the development of new strategies towards stabilization of formed vascular structure.
Sciprofile linkEric Foch, Richard A. Brindle, Clare E. Milner
Published: 18 September 2020
Journal of Biomechanics, Volume 110; doi:10.1016/j.jbiomech.2020.109965

Abstract:
Hip abductor muscle strengthening is often prescribed to reduce the peak hip adduction angle in runners with overuse knee injury. However, no evidence exists associating greater isometric hip abductor muscle strength with smaller peak hip adduction angle during running. Beyond muscle strength, muscle activation patterns may play an important role in controlling joint movement during running. Therefore, the purpose of this investigation was to determine if associations existed among hip adduction angle, hip abductor muscle activity, and isometric hip abductor muscle strength. Twenty-five currently healthy female runners participated. Average gluteus medius muscle activity and tensor fascia lata muscle activity were determined during hip abductor maximal voluntary isometric contractions. Three-dimensional kinematics and hip abductor muscle activity were collected during treadmill running. Dependent variables were analyzed via Pearson product moment correlations. Multi-variable linear regression determined muscle activity’s and strength’s contributions to the peak hip adduction angle. A fair positive correlation was observed between the peak hip adduction angle and average tensor fascia lata muscle activity magnitude. Additionally, there was a moderate negative correlation between isometric hip abductor muscle strength and average gluteus medius muscle activity magnitude. Tensor fascia lata activity magnitude accounted for the most variance of the peak hip adduction angle. This study adds to the literature which indicates a lack of association between isometric hip abductor muscle strength and peak hip adduction angle in healthy runners. Factors other than hip abductor muscle strength and activation may account for more of the variance in peak hip adduction angles among runners.
Alessandra B. Matias, Paolo Caravaggi, Alberto Leardini, Ulisses T. Taddei, Maurizio Ortolani, Sciprofile linkIsabel C.N. Sacco
Published: 18 September 2020
Journal of Biomechanics, Volume 110; doi:10.1016/j.jbiomech.2020.109983

Abstract:
Skin-markers based multi-segment models are growing in popularity to assess foot joint kinematics in different motor tasks. However, scarce is the current knowledge of the effect of high-energy motor tasks, such as running, on the repeatability of these measurements. This study aimed at assessing and comparing the inter-trial, inter-session, and inter-examiner repeatability of skin-markers based foot kinematic measures in walking and running in healthy adults. The repeatability of 24 kinematic measures from an established multi-segment foot model were assessed in two volunteers during multiple barefoot walking and running trials by four examiners in three sessions. Statistical Parametric Mapping (1D-SPM) analysis was performed to assess the degree of shape-similarity between patterns of kinematic measurements. The average inter-trial variability across measurements (deg) was 1.0 ± 0.3 and 0.8 ± 0.3, the inter-session was 3.9 ± 1.4 and 4.4 ± 1.5, and the inter-examiner was 5.4 ± 2.3 and 5.7 ± 2.2, respectively in walking and running. Inter-session variability was generally similar between the two motor tasks, but significantly larger in running for two kinematic measures (p < 0.01). Inter-examiner variability was generally larger than inter-trial and inter-session variability. While no significant differences in frame-by-frame offset variability was detected in foot kinematics between walking and running, 1D-SPM revealed that the shape of kinematic measurements was significantly affected by the motor task, with running being less repeatable than walking. Although confirmation on a larger population and with different kinematic protocols should be sought, attention should be paid in the interpretation of skin-markers based kinematics in running across sessions or involving multiple examiners.
Janusz Wiesław Błaszczyk, Artur Fredyk, Paweł Mikołaj Błaszczyk
Published: 18 September 2020
Journal of Biomechanics, Volume 110; doi:10.1016/j.jbiomech.2020.109982

Abstract:
Kinematic characteristics of the double-leg stance (DLS) to a single-leg stance (SLS) transition were analyzed in a group of young adolescent girls to assess their postural stability control. Twenty volunteers participated in a single experimental session during which their postural stability was assessed based upon the center of pressure (COP) trajectories during the transitions in two typical sensory conditions: with eyes open (EO) and with eyes closed (EC). To quantify the postural control we applied Fitts' model treating the postural sway as the noise at the initial and the target setpoint control. Results showed that in young healthy subjects characteristics of the transition to either left or right single-leg stance were quite symmetrical. The postural sway at the target posture was characterized by the double increase of postural sway when tested with EO and by the almost quadrupled amount of sway in EC trials. The sway at the target resulted in the decline of the COP mean and peak velocity proportionally to the movement index of difficulty (ID). The estimated ID value increased by 74% in EC trials while the probability of instability increased to 70%. The DLS-SLS test can be recommended for clinical and laboratory assessment of postural stability.
Published: 18 September 2020
Tetrahedron, Volume 76; doi:10.1016/s0040-4020(20)30735-3

Published: 18 September 2020
Physics Letters A, Volume 384; doi:10.1016/j.physleta.2020.126636

Abstract:
By introducing the imaginary time, Gor'kov's Ginzburg–Landau equation at zero temperature can be extended to an exact relativistic form without any phenomenological parameter, which is intended to describe the zero-temperature overdoped cuprate. By using such a relativistic equation, we have shown that the two-class scaling observed in the overdoped side of single-crystal La2−xSrxCuO4 (LSCO) films (Božović (2016) [7]) can be derived exactly. In this paper, we further test the validity of the relativistic Ginzburg–Landau equation. By applying the perturbation method into this equation, we theoretically predict that near the superconductor–metal transition point in the overdoped side of LSCO films, the zero-temperature correlation length ξ(0) and the transition temperature Tc should yield a novel scaling ξ(0)∝Tc−σ with a critical exponent σ≈1.31 (up to the two-loop approximation). Here, we propose a diffraction experiment between X-rays and zero-temperature LSCO films to measure the critical exponent σ.
Sciprofile linkRika Yamada, Yutaro Enomoto, Atsushi Nishizawa, Koji Nagano, Sachiko Kuroyanagi, Keiko Kokeyama, Sciprofile linkKentaro Komori, Sciprofile linkYuta Michimura, Takeo Naito, Izumi Watanabe, et al.
Published: 18 September 2020
Physics Letters A, Volume 384; doi:10.1016/j.physleta.2020.126626

Abstract:
The quantum locking technique, which uses additional short low-loss sub-cavities, is effective in reducing quantum noise in space gravitational wave antenna DECIGO. However, the quantum noise of the main interferometer depends on the control systems in the sub-cavities. Here we demonstrate a new method to optimize the quantum noise independently of the feedback gain by completing the square of multiple interferometer outputs in the quantum locking system. We successfully demonstrate in simulations that this method is effective in optimizing the homodyne angle to the best quantum-noise-limited sensitivity.
Page of 1,829,551
Articles per Page
by
Show export options
  Select all
Back to Top Top