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https://www.readbyqxmd.com/read/28812366/a-combination-of-experimental-measurement-constitutive-damage-model-and-diffusion-tensor-imaging-to-characterize-the-mechanical-properties-of-the-human-brain
#1
Alireza Karimi, Seyed Mohammadali Rahmati, Reza Razaghi
Understanding the mechanical properties of the human brain is deemed important as it may subject to various types of complex loadings during the Traumatic Brain Injury (TBI). Although many studies so far have been conducted to quantify the mechanical properties of the brain, there is a paucity of knowledge on the mechanical properties of the human brain tissue and the damage of its axon fibers under the various types of complex loadings during the Traumatic Brain Injury (TBI). Although many studies so far have been conducted to quantify the mechanical properties of the brain, there is a paucity of knowledge on the mechanical properties of the human brain tissue and the damage of its axon fibers under the frontal lobe of the human brain...
August 16, 2017: Computer Methods in Biomechanics and Biomedical Engineering
https://www.readbyqxmd.com/read/28812284/new-nanocomposites-of-polystyrene-with-polyaniline-doped-with-lauryl-sulfuric-acid
#2
A A Pud, O A Nikolayeva, L O Vretik, Yu V Noskov, N A Ogurtsov, O S Kruglyak, E A Fedorenko
This work is concentrated on synthesis and investigation of new core-shell nanocomposites of polystyrene (PS) with doped polyaniline (PANI). The latex containing PS nanoparticles with sizes of 15-30 nm was prepared by microemulsion polymerization of styrene in water media. The PS/PANI nanocomposites were synthesized by chemical oxidative polymerization of aniline in the PS latex media in a presence of lauryl sulfuric acid (LSA), which served as both dopant and plasticizer. The real content of PANI in the synthesized nanocomposites was determined by UV-Vis spectroscopy method...
August 15, 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28812230/simulation-of-left-ventricular-dynamics-using-a-low-order-mathematical-model
#3
Michael J Moulton, Brian D Hong, Timothy W Secomb
The eventual goal of this study is to develop methods for estimating dynamic stresses in the left ventricle (LV) that could be used on-line in clinical settings, based on routinely available measurements. Toward this goal, a low-order theoretical model is presented, in which LV shape is represented using a small number of parameters, allowing rapid computational simulations of LV dynamics. The LV is represented as a thick-walled prolate spheroid containing helical muscle fibers with nonlinear passive and time-dependent active contractile properties...
August 15, 2017: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/28812067/nonlinear-imaging-microscopy-for-assessing-structural-and-photochemical-modifications-upon-laser-removal-of-dammar-varnish-on-photosensitive-substrates
#4
M Oujja, S Psilodimitrakopoulos, E Carrasco, M Sanz, A Philippidis, A Selimis, P Pouli, G Filippidis, M Castillejo
The nonlinear optical microscopy (NLM) modalities of Multi-Photon Excited Fluorescence (MPEF) and Third Harmonic Generation (THG) have been combined in this work to characterize as a function of depth with micrometric resolution the type and extent of morphological and photochemical modifications that take place upon ultraviolet (UV) pulsed laser removal of a dammar varnish layer applied on a photosensitive substrate. The latter consists on a layer of the synthetic polymer poly-methyl methacrylate doped with a photosensitizer, the aromatic compound 1,4-di[2-(5-phenyloxazolyl)] benzene, that strongly fluoresces upon UV light illumination...
August 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28811820/modified-mahalanobis-taguchi-system-for-imbalance-data-classification
#5
Mahmoud El-Banna
The Mahalanobis Taguchi System (MTS) is considered one of the most promising binary classification algorithms to handle imbalance data. Unfortunately, MTS lacks a method for determining an efficient threshold for the binary classification. In this paper, a nonlinear optimization model is formulated based on minimizing the distance between MTS Receiver Operating Characteristics (ROC) curve and the theoretical optimal point named Modified Mahalanobis Taguchi System (MMTS). To validate the MMTS classification efficacy, it has been benchmarked with Support Vector Machines (SVMs), Naive Bayes (NB), Probabilistic Mahalanobis Taguchi Systems (PTM), Synthetic Minority Oversampling Technique (SMOTE), Adaptive Conformal Transformation (ACT), Kernel Boundary Alignment (KBA), Hidden Naive Bayes (HNB), and other improved Naive Bayes algorithms...
2017: Computational Intelligence and Neuroscience
https://www.readbyqxmd.com/read/28811516/q-factor-enhancement-of-fano-resonance-in-all-dielectric-metasurfaces-by-modulating-meta-atom-interactions
#6
Guanghou Sun, Lierong Yuan, Yi Zhang, Xuejin Zhang, Yongyuan Zhu
We numerically investigated the effects of meta-atom interactions on the Fano resonance in all-dielectric metasurfaces by introducing alternately flipped asymmetric paired bars (APBs) and split asymmetric paired bars (SAPBs). With alternately flipped configurations, the Q-factor of the Fano resonance is significantly enhanced up to one order of magnitude, and the electric field is strengthened by more than twice. Abnormally, the Q-factor increases with gap size in the alternately flipped SAPBs. These are attributed to the destructive interaction among nearest-neighbor dipole resonators...
August 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28810820/quantitative-label-free-evaluation-of-tissue-engineered-skeletal-muscle-through-multiphoton-microscopy
#7
Brian C Syverud, Mary-Ann Mycek, Lisa Marie Larkin
The lack of tools for assessing engineered tissue viability and function in a non-invasive manner is a major regulatory and translational challenge facing tissue engineers. Label-free, nonlinear optical molecular imaging (OMI) has utilized endogenous nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) fluorescence to indicate metabolic activity. Similarly, second harmonic generation (SHG) signals from myosin and collagen can measure overall muscle structural integrity and function...
August 16, 2017: Tissue Engineering. Part C, Methods
https://www.readbyqxmd.com/read/28810790/nonlinear-interferometer-design-implementation-and-phase-sensitive-sum-frequency-measurement
#8
Jing Wang, Patrick J Bisson, Joam M Marmolejos, Mary Jane Shultz
Sum frequency generation (SFG) spectroscopy is a unique tool for probing the vibrational structure of numerous interfaces. Since SFG is a nonlinear spectroscopy, it has long been recognized that measuring only the intensity-the absolute square of the surface response-limits the potential of SFG for examining interfacial interactions and dynamics. The potential is unlocked by measuring the phase-sensitive or imaginary response. As with any phase, the phase-sensitive SFG response is measured relative to a reference; the spatial relationship between the phase reference and the sample modulates the observed interference intensity and impacts sensitivity and accuracy...
August 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28809980/stimuli-responsive-nlo-properties-of-tetrathiafulvalene-fused-donor-acceptor-chromophores
#9
E Cariati, X Liu, Y Geng, A Forni, E Lucenti, S Righetto, S Decurtins, S-X Liu
The second-order nonlinear optical (NLO) properties of two tetrathiafulvalene (TTF)-fused electron donor-acceptor dyads have been determined using the Electric Field Induced Second Harmonic generation (EFISH) technique and theoretically rationalized. Dyads TTF-dppz (1) and TTF-BTD (2) were obtained by direct fusion of a TTF electron donor unit either with a dipyrido[3,2-a:2',3'-c]phenazine (dppz) or a benzothiadiazole (BTD) electron acceptor moiety. Dyad 1 acts as a reversible acido-triggered NLO switch by protonation/deprotonation at two nitrogen atoms of the dppz acceptor moiety induced by sequential exposure to HCl and ammonia vapors...
August 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28809965/hill-kinetics-as-a-noise-filter-the-role-of-transcription-factor-autoregulation-in-gene-cascades
#10
Anna Ochab-Marcinek, Jakub Jędrak, Marcin Tabaka
An intuition based on deterministic models of chemical kinetics is that population heterogeneity of transcription factor levels in cells is transmitted unchanged downstream to the target genes. We use a stochastic model of a two-gene cascade with a self-regulating upstream gene to show that, counter to the intuition, there is no simple mapping (bimodal to bimodal, unimodal to unimodal) between the shapes of the distributions of transcription factor numbers and target protein numbers in cells. Due to the presence of the two regulations, the system contains two nonlinear transfer functions, defined by the Hill kinetics of transcription factor binding...
August 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28809962/nonlinear-behavior-and-fluctuation-induced-dynamics-in-the-photosensitive-belousov-zhabotinsky-reaction
#11
Valérie Voorsluijs, Ioannis G Kevrekidis, Yannick De Decker
The photosensitive Belousov-Zhabotinsky (pBZ) reaction has been used extensively to study the properties of chemical oscillators. In particular, recent experiments revealed the existence of complex spatiotemporal dynamics for systems consisting of coupled micelles (V < 10(-21) L) or droplets (V ≈ [10(-8)-10(-11)] L) in which the pBZ reaction takes place. These results have been mostly understood in terms of reaction-diffusion models. However, in view of the small size of the droplets and micelles, large fluctuations of concentrations are to be expected...
August 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28809914/beyond-the-perturbative-description-of-the-nonlinear-optical-response-of-low-index-materials
#12
Orad Reshef, Enno Giese, M Zahirul Alam, Israel De Leon, Jeremy Upham, Robert W Boyd
We show that standard approximations in nonlinear optics are violated for situations involving a small value of the linear refractive index. Consequently, the conventional equation for the intensity-dependent refractive index, n(I)=n0+n2I, becomes inapplicable in epsilon-near-zero and low-index media, even in the presence of only third-order effects. For the particular case of indium tin oxide, we find that the χ((3)), χ((5)), and χ((7)) contributions to refraction eclipse the linear term; thus, the nonlinear response can no longer be interpreted as a perturbation in these materials...
August 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28809908/coherent-combining-of-second-harmonic-generators-by-active-phase-control-of-the-fundamental-waves
#13
Alice Odier, Anne Durécu, Jean-Michel Melkonian, Laurent Lombard, Michel Lefebvre, Pierre Bourdon
Coherent beam combining by active phase control could be useful for power scaling fiber-laser-pumped optical frequency converters. However, a fast phase modulator operating at the frequency-converted wavelength, a non-standard component, would be necessary. Fortunately, nonlinear conversion processes rely on a phase-matching condition allowing for indirect phase control using standard phase modulators. In this Letter, coherent combining of second-harmonic generators is demonstrated in both birefringent and quasi-phase-matching schemes in CW regime...
August 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28809887/fano-resonance-based-mode-matching-hybrid-metasurface-for-enhanced-second-harmonic-generation
#14
Zhi Li, Wenwei Liu, Zhancheng Li, Hua Cheng, Shuqi Chen, Jianguo Tian
Plasmonic nanostructures have been considered as potential candidates for enhancing the nonlinear upconversion rate at nanoscale levels due to their strong near-field enhancement. Here, we propose a Fano-resonance-based mode-matching hybrid metasurface that combines the advantages of Fano resonances and mode-matching for boosting second-harmonic conversion. A confined and strong near-field intensity is generated by gold nanoantennas within the volume of polycrystalline zinc sulfide nanoparticles, thus resulting in a larger effective second-harmonic coefficient...
August 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28809882/modulated-vortex-six-wave-mixing
#15
Dan Zhang, Xing Liu, Lingmeng Yang, Xinghua Li, Zhaoyang Zhang, Yanpeng Zhang
We have experimentally generated a vortex six-wave mixing (SWM) signal via a photonic band gap structure in a hot atomic ensemble. The output SWM carrying orbital angular momentum, transferred from a probe beam, has the interaction with the nonlinear effect in the multilevel atomic system. Our results show that a spatial SWM image can be modulated by the detunings and intensities of the related generating fields. Also, the nonreciprocal feature of the SWM signal is demonstrated. Such characteristics can potentially be used in information processing...
August 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28809875/bi-directional-top-hat-d-scan-single-beam-accurate-characterization-of-nonlinear-waveguides
#16
Samuel Serna, Nicolas Dubreuil
The characterization of a third-order nonlinear integrated waveguide is reported for the first time by means of a top-hat dispersive-scan (D-Scan) technique, a temporal analog of the top-hat Z-Scan. With a single laser beam, and by carrying two counterdirectional nonlinear transmissions to assess the input and output coupling efficiencies, a novel procedure is described leading to accurate measurement of the TPA figure of merit, the effective two-photon absorption (TPA), and optical Kerr (including the sign) coefficients...
August 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28809806/a-continuum-damage-mechanics-model-for-the-static-and-cyclic-fatigue-of-cellular-composites
#17
Sergej Diel, Otto Huber
The fatigue behavior of a cellular composite with an epoxy matrix and glass foam granules is analyzed and modeled by means of continuum damage mechanics. The investigated cellular composite is a particular type of composite foam, and is very similar to syntactic foams. In contrast to conventional syntactic foams constituted by hollow spherical particles (balloons), cellular glass, mineral, or metal place holders are combined with the matrix material (metal or polymer) in the case of cellular composites. A microstructural investigation of the damage behavior is performed using scanning electron microscopy...
August 15, 2017: Materials
https://www.readbyqxmd.com/read/28809791/imaging-collagen-in-scar-tissue-developments-in-second-harmonic-generation-microscopy-for-biomedical-applications
#18
REVIEW
Leila Mostaço-Guidolin, Nicole L Rosin, Tillie-Louise Hackett
The ability to respond to injury with tissue repair is a fundamental property of all multicellular organisms. The extracellular matrix (ECM), composed of fibrillar collagens as well as a number of other components is dis-regulated during repair in many organs. In many tissues, scaring results when the balance is lost between ECM synthesis and degradation. Investigating what disrupts this balance and what effect this can have on tissue function remains an active area of research. Recent advances in the imaging of fibrillar collagen using second harmonic generation (SHG) imaging have proven useful in enhancing our understanding of the supramolecular changes that occur during scar formation and disease progression...
August 15, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28809720/aperiodic-robust-model-predictive-control-for-constrained-continuous-time-nonlinear-systems-an-event-triggered-approach
#19
Changxin Liu, Jian Gao, Huiping Li, Demin Xu
The event-triggered control is a promising solution to cyber-physical systems, such as networked control systems, multiagent systems, and large-scale intelligent systems. In this paper, we propose an event-triggered model predictive control (MPC) scheme for constrained continuous-time nonlinear systems with bounded disturbances. First, a time-varying tightened state constraint is computed to achieve robust constraint satisfaction, and an event-triggered scheduling strategy is designed in the framework of dual-mode MPC...
August 14, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28809714/avoiding-congestion-in-cluster-consensus-of-the-second-order-nonlinear-multiagent-systems
#20
Yi Wang, Zhongjun Ma, Guanrong Chen
In order to avoid congestion in the second-order nonlinear leader-following multiagent systems over capacity-limited paths, an approach called cluster lag consensus is proposed, which means that the agents in different clusters will pass through the same positions with the same velocities but lag behind the leader at different times. Lyapunov functionals and matrix theory are applied to analyze such cluster lag consensus. It is shown that when the graphic roots of clusters are influenced by the leader and the intracoupling of cluster agents is larger than a threshold, the cluster lag consensus can be achieved...
August 11, 2017: IEEE Transactions on Neural Networks and Learning Systems
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