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Sample records for anomalous skin effect

  1. Influence of External Magnetic Field on Anomalous Skin Effects in Inductively Coupled Plasmas

    Institute of Scientific and Technical Information of China (English)

    MAO Ming; WANG You-Nian

    2004-01-01

    @@ Using a one-dimensional slab model, we study the influence of the external static magnetic field on the anomalous skin effects in the inductively coupled plasma. The rf electromagnetic field in the plasma is determined by solving the linearized Boltzmann equation incorporating with the Maxwell equations. The numerical results show that,due to the existence of the external magnetic field, the anomalous skin effects are greatly enhanced and the number of regions with negative absorption is decreased.

  2. Temperature correction to the Casimir force in cryogenic range and anomalous skin effect

    CERN Document Server

    Svetovoy, V B

    2003-01-01

    Temperature correction to the Casimir force is considered for real metals at low temperatures. With the temperature decrease the mean free path for electrons becomes larger than the field penetration depth. In this condition description of metals with the impedance of anomalous skin effect is shown to be more appropriate than with the permittivity. The effect is crucial for the temperature correction. It is demonstrated that in the zero frequency limit the reflection coefficients should coincide with those of ideal metal if we demand the entropy to be zero at T=0. All the other prescriptions discussed in the literature for the $n=0$ term in the Lifshitz formula give negative entropy. It is shown that the temperature correction in the region of anomalous skin effect is not suppressed as it happens in the plasma model. This correction will be important in the future cryogenic measurements of the Casimir force.

  3. Predicting molecular scale skin-effect in electrochemical impedance due to anomalous subdiffusion mediated adsorption phenomenon

    Science.gov (United States)

    Kushagra, Arindam

    2016-02-01

    Anomalous subdiffusion governs the processes which are not energetically driven, on a molecular scale. This paper proposes a model to predict the response of electrochemical impedance due to such diffusion process. Previous works considered the use of fractional calculus to predict the impedance behaviour in response to the anomalous diffusion. Here, we have developed an expression which predicts the skin-effect, marked by an increase in the impedance with increasing frequency, in this regime. Negative inductances have also been predicted as a consequence of the inertial response of adsorbed species upon application of frequency-mediated perturbations. It might help the researchers in the fields of impedimetric sensors to choose the working frequency and those working in the field of batteries to choose the parameters, likewise. This work would shed some light into the molecular mechanisms governing the impedance when exposed to frequency-based perturbations like electromagnetic waves (microwaves to ionizing radiations) and in charge storage devices like batteries etc.

  4. Predicting molecular scale skin-effect in electrochemical impedance due to anomalous subdiffusion mediated adsorption phenomenon

    Directory of Open Access Journals (Sweden)

    Arindam Kushagra

    2016-02-01

    Full Text Available Anomalous subdiffusion governs the processes which are not energetically driven, on a molecular scale. This paper proposes a model to predict the response of electrochemical impedance due to such diffusion process. Previous works considered the use of fractional calculus to predict the impedance behaviour in response to the anomalous diffusion. Here, we have developed an expression which predicts the skin-effect, marked by an increase in the impedance with increasing frequency, in this regime. Negative inductances have also been predicted as a consequence of the inertial response of adsorbed species upon application of frequency-mediated perturbations. It might help the researchers in the fields of impedimetric sensors to choose the working frequency and those working in the field of batteries to choose the parameters, likewise. This work would shed some light into the molecular mechanisms governing the impedance when exposed to frequency-based perturbations like electromagnetic waves (microwaves to ionizing radiations and in charge storage devices like batteries etc.

  5. Correction to the Casimir force due to the anomalous skin effect

    CERN Document Server

    Esquivel, R

    2004-01-01

    The surface impedance approach is discussed in connection with the precise calculation of the Casimir force between metallic plates. It allows to take into account the nonlocal connection between the current density and electric field inside of metals. In general, a material has to be described by two impedances $Z_{s}(\\omega,q)$ and $Z_{p}(\\omega,q)$ corresponding to two different polarization states. In contrast with the approximate Leontovich impedance they depend not only on frequency $\\omega$ but also on the wave vector along the plate $q$. In this paper only the nonlocal effects happening at frequencies $\\omega<\\omega_{p}$ (plasma frequency) are analyzed. We refer to all of them as the anomalous skin effect. The impedances are calculated for the propagating and evanescent fields in the Boltzmann approximation. It is found that $Z_p$ significantly deviates from the local impedance as a result of the Thomas-Fermi screening. The nonlocal correction to the Casimir force is calculated at zero temperature....

  6. Optical properties of metals: Infrared emissivity in the anomalous skin effect spectral region

    Energy Technology Data Exchange (ETDEWEB)

    Echániz, T. [Departamento de Física de la Materia Condensada, Facultad de Ciencia y Tecnología, UPV/EHU, Sarriena s/n, Leioa 48940 (Spain); Pérez-Sáez, R. B., E-mail: raul.perez@ehu.es; Tello, M. J. [Departamento de Física de la Materia Condensada, Facultad de Ciencia y Tecnología, UPV/EHU, Sarriena s/n, Leioa 48940 (Spain); Instituto de Síntesis y Estudio de Materiales, Universidad del País Vasco, Apdo. 644, Bilbao 48080 (Spain)

    2014-09-07

    When the penetration depth of an electromagnetic wave in a metal is similar to the mean free path of the conduction electrons, the Drude classical theory is no longer satisfied and the skin effect becomes anomalous. Physical parameters of this theory for twelve metals were calculated and analyzed. The theory predicts an emissivity peak ε{sub peak} at room temperature in the mid-infrared for smooth surface metals that moves towards larger wavelengths as temperature decreases. Furthermore, the theory states that ε{sub peak} increases with the emission angle but its position, λ{sub peak}, is constant. Copper directional emissivity measurements as well as emissivity obtained using optical constants data confirm the predictions of the theory. Considering the relationship between the specularity parameter p and the sample roughness, it is concluded that p is not the simple parameter it is usually assumed to be. Quantitative comparison between experimental data and theoretical predictions shows that the specularity parameter can be equal to one for roughness values larger than those predicted. An exhaustive analysis of the experimental optical parameters shows signs of a reflectance broad peak in Cu, Al, Au, and Mo around the wavelength predicted by the theory for p = 1.

  7. Nonlocal Anomalous Hall Effect.

    Science.gov (United States)

    Zhang, Steven S-L; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect-the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt/YIG structures.

  8. Nonlocal Anomalous Hall Effect

    Science.gov (United States)

    Zhang, Steven S.-L.; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect—the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt /YIG structures.

  9. Anomalous Hall effect in polycrystalline Ni films

    KAUST Repository

    Guo, Zaibing

    2012-02-01

    We systematically studied the anomalous Hall effect in a series of polycrystalline Ni films with thickness ranging from 4 to 200 nm. It is found that both the longitudinal and anomalous Hall resistivity increased greatly as film thickness decreased. This enhancement should be related to the surface scattering. In the ultrathin films (46 nm thick), weak localization corrections to anomalous Hall conductivity were studied. The granular model, taking into account the dominated intergranular tunneling, has been employed to explain this phenomenon, which can explain the weak dependence of anomalous Hall resistivity on longitudinal resistivity as well. © 2011 Elsevier Ltd. All rights reserved.

  10. Anomalous Hall Effect for chiral fermions

    CERN Document Server

    Zhang, P -M

    2014-01-01

    Semiclassical chiral fermions manifest the anomalous spin-Hall effect: when put into a pure electric field, they suffer a side jump, analogous to what happens to their massive counterparts in non-commutative mechanics. The transverse shift is consistent with the conservation of the angular momentum. In a pure magnetic field a cork-screw-like, spiraling motion is found.

  11. Towards a Better Understanding of the Anomalous Hall Effect

    Science.gov (United States)

    Yue, Di; Jin, Xiaofeng

    2017-01-01

    Recent experimental efforts to identify the intrinsic and extrinsic contributions in the anomalous Hall effect are reviewed. Benefited from the experimental control of artificial impurity density in single crystalline magnetic thin films, a comprehensive physical picture of the anomalous Hall effect involving multiple competing scattering processes has been established. Some new insights into the microscopic mechanisms of the anomalous Hall effect are discussed.

  12. Anomalous Hall Effect in a Kagome Ferromagnet

    Science.gov (United States)

    Ye, Linda; Wicker, Christina; Suzuki, Takehito; Checkelsky, Joseph; Joseph Checkelsky Team

    The ferromagnetic kagome lattice is theoretically known to possess topological band structures. We have synthesized large single crystals of a kagome ferromagnet Fe3Sn2 which orders ferromagnetically well above room temperature. We have studied the electrical and magnetic properties of these crystals over a broad temperature and magnetic field range. Both the scaling relation of anomalous Hall effect and anisotropic magnetic susceptibility show that the ferromagnetism of Fe3Sn2 is unconventional. We discuss these results in the context of magnetism in kagome systems and relevance to the predicted topological properties in this class of compounds. This research is supported by DMR-1231319.

  13. Anomalous anisotropic magnetoresistance effects in graphene

    Directory of Open Access Journals (Sweden)

    Yiwei Liu

    2014-09-01

    Full Text Available We investigate the effect of external stimulus (temperature, magnetic field, and gases adsorptions on anisotropic magnetoresistance (AMR in multilayer graphene. The graphene sample shows superlinear magnetoresistance when magnetic field is perpendicular to the plane of graphene. A non-saturated AMR with a value of −33% is found at 10 K under a magnetic field of 7 T. It is surprisingly to observe that a two-fold symmetric AMR at high temperature is changed into a one-fold one at low temperature for a sample with an irregular shape. The anomalous AMR behaviors may be understood by considering the anisotropic scattering of carriers from two asymmetric edges and the boundaries of V+(V- electrodes which serve as active adsorption sites for gas molecules at low temperature. Our results indicate that AMR in graphene can be optimized by tuning the adsorptions, sample shape and electrode distribution in the future application.

  14. Quantum anomalous Hall effect in real materials

    Science.gov (United States)

    Zhang, Jiayong; Zhao, Bao; Zhou, Tong; Yang, Zhongqin

    2016-11-01

    Under a strong magnetic field, the quantum Hall (QH) effect can be observed in two-dimensional electronic gas systems. If the quantized Hall conductivity is acquired in a system without the need of an external magnetic field, then it will give rise to a new quantum state, the quantum anomalous Hall (QAH) state. The QAH state is a novel quantum state that is insulating in the bulk but exhibits unique conducting edge states topologically protected from backscattering and holds great potential for applications in low-power-consumption electronics. The realization of the QAH effect in real materials is of great significance. In this paper, we systematically review the theoretical proposals that have been brought forward to realize the QAH effect in various real material systems or structures, including magnetically doped topological insulators, graphene-based systems, silicene-based systems, two-dimensional organometallic frameworks, quantum wells, and functionalized Sb(111) monolayers, etc. Our paper can help our readers to quickly grasp the recent developments in this field. Project supported by the National Basic Research Program of China (Grant No. 2011CB921803), the National Natural Science Foundation of China (Grant No. 11574051), the Natural Science Foundation of Shanghai, China (Grant No. 14ZR1403400), and Fudan High-end Computing Center, China.

  15. In-plane magnetization-induced quantum anomalous Hall effect.

    Science.gov (United States)

    Liu, Xin; Hsu, Hsiu-Chuan; Liu, Chao-Xing

    2013-08-23

    The quantum Hall effect can only be induced by an out-of-plane magnetic field for two-dimensional electron gases, and similarly, the quantum anomalous Hall effect has also usually been considered for systems with only out-of-plane magnetization. In the present work, we predict that the quantum anomalous Hall effect can be induced by in-plane magnetization that is not accompanied by any out-of-plane magnetic field. Two realistic two-dimensional systems, Bi2Te3 thin film with magnetic doping and HgMnTe quantum wells with shear strains, are presented and the general condition for the in-plane magnetization-induced quantum anomalous Hall effect is discussed based on the symmetry analysis. Nonetheless, an experimental setup is proposed to confirm this effect, the observation of which will pave the way to search for the quantum anomalous Hall effect in a wider range of materials.

  16. Anomalous Effects from Dipole-Environment Quantum Entanglement

    CERN Document Server

    Porcelli, Elio B

    2016-01-01

    In this work, we analyze anomalous effects observed in the operation of two different technological devices: a magnetic core and a parallel plate (symmetrical or asymmetrical) capacitor. From experimental measurements on both devices, we detected small raised anomalous forces that cannot be explained by known interactions in the traditional theories. As the variations of device inertia have not been completely understood by means of current theories, we here propose a theoretical framework in which the anomalous effects can consistently be explained by a preexisting state of quantum entanglement between the external environment and either magnetic dipoles of magnetic cores or electric dipoles of capacitors, so that the effects would be manifested by the application of a strong magnetic field on the former or an intense electric field on the latter. The values of the macroscopic observables calculated in such a theoretical framework revealed good agreement with the experimental measurements performed in both c...

  17. Quantum anomalous Hall effect in magnetic insulator heterostructure.

    Science.gov (United States)

    Xu, Gang; Wang, Jing; Felser, Claudia; Qi, Xiao-Liang; Zhang, Shou-Cheng

    2015-03-11

    On the basis of ab initio calculations, we predict that a monolayer of Cr-doped (Bi,Sb)2Te3 and GdI2 heterostructure is a quantum anomalous Hall insulator with a nontrivial band gap up to 38 meV. The principle behind our prediction is that the band inversion between two topologically trivial ferromagnetic insulators can result in a nonzero Chern number, which offers a better way to realize the quantum anomalous Hall state without random magnetic doping. In addition, a simple effective model is presented to describe the basic mechanism of spin polarized band inversion in this system. Moreover, we predict that 3D quantum anomalous Hall insulator could be realized in (Bi2/3Cr1/3)2Te3 /GdI2 superlattice.

  18. Anomalous Hall Effect in a 2D Rashba Ferromagnet.

    Science.gov (United States)

    Ado, I A; Dmitriev, I A; Ostrovsky, P M; Titov, M

    2016-07-22

    Skew scattering on rare impurity configurations is shown to dominate the anomalous Hall effect in a 2D Rashba ferromagnet. The mechanism originates in scattering on rare impurity pairs separated by distances of the order of the Fermi wavelength. The corresponding theoretical description goes beyond the conventional noncrossing approximation. The mechanism provides the only contribution to the anomalous Hall conductivity in the most relevant metallic regime and strongly modifies previously obtained results for lower energies in the leading order with respect to impurity strength.

  19. Skin Exposures & Effects in the Workplace

    Science.gov (United States)

    ... Topics Publications and Products Programs Contact NIOSH NIOSH SKIN EXPOSURES & EFFECTS Recommend on Facebook Tweet Share Compartir ... currently lacking for measuring and assessing skin exposures. Skin Notation (SK) Profiles NIOSH has developed a strategy ...

  20. Z' effects and anomalous gauge couplings at LC with polarization

    CERN Document Server

    Pankov, A A; Verzegnassi, Claudio

    1998-01-01

    We show that the availability of longitudinally polarized electron beams at a $500 GeV$ Linear Collider would allow, from an analysis of the reaction $e^+e^-\\to W^+W^-$, to set stringent bounds on the couplings of a Z' of the most general type. In addition, to some extent it would be possible to disentangle observable effects of the Z' from analogous ones due to competitor models with anomalous trilinear gauge couplings.

  1. Anomalous effective lagrangians and vector resonance models

    NARCIS (Netherlands)

    Pallante, E.; Petronzio, R.

    1993-01-01

    Chiral lagrangians including vector resonances have been shown to saturate the finite part of some of the counterterms needed to regularize ordinary one-loop effective lagrangians of pseudoscalar interactions with external currents. The equivalence between different models has been discussed in the

  2. Quantifying Chiral Magnetic Effect from Anomalous-Viscous Fluid Dynamics

    CERN Document Server

    Jiang, Yin; Yin, Yi; Liao, Jinfeng

    2016-01-01

    Chiral Magnetic Effect (CME) is the macroscopic manifestation of the fundamental chiral anomaly in a many-body system of chiral fermions, and emerges as anomalous transport current in the fluid dynamics framework. Experimental observation of CME is of great interest and has been reported in Dirac and Weyl semimetals. Significant efforts have also been made to search for CME in heavy ion collisions. Encouraging evidence of CME-induced charge separation in those collisions has been reported, albeit with ambiguity due to background contamination. Crucial for addressing such issue, is the need of quantitative predictions for CME signal with sophisticated modelings. In this paper we develop such a tool, the Anomalous Viscous Fluid Dynamics (AVFD) framework, which simulates the evolution of fermion currents in QGP on top of the data-validated VISHNU bulk hydrodynamic flow. With realistic initial conditions and magnetic field lifetime, the AVFD-predicted CME signal could be quantitatively consistent with measured ch...

  3. Anomalous Hall Effect in Geometrically Frustrated Magnets

    Directory of Open Access Journals (Sweden)

    D. Boldrin

    2012-01-01

    space mechanism based on spin chirality that was originally applied to the pyrochlore Nd2Mo2O7 appears unsatisfactory. Recently, an orbital description based on the Aharonov-Bohm effect has been proposed and applied to both the ferromagnetic pyrochlores Nd2Mo2O7 and Pr2Ir2O7; the first of which features long-ranged magnetic order while the latter is a chiral spin liquid. Two further examples of geometrically frustrated conducting magnets are presented in this paper—the kagome-like Fe3Sn2 and the triangular PdCrO2. These possess very different electronic structures to the 3-dimensional heavy-metal pyrochlores and provide new opportunities to explore the different origins of the AHE. This paper summarises the experimental findings in these materials in an attempt to unite the conflicting theoretical arguments.

  4. Effects of surface and interface scattering on anomalous Hall effect in Co/Pd multilayers

    KAUST Repository

    Guo, Z. B.

    2012-09-27

    In this paper, we report the results of surface and interface scattering on anomalous Hall effect in Co/Pd multilayers with perpendicular magnetic anisotropy. The surface scattering effect has been extracted from the total anomalous Hall effect. By scaling surface scattering contribution with ρAHs∼ργss, the exponent γ has been found to decrease with the increase of surface scattering resistivity, which could account for the thickness-dependent anomalous Hall effect. Interface diffusion induced by rapid thermal annealing modifies not only the magnetization and longitudinal resistivity but also the anomalous Hall effect; a large exponent γ ∼ 5.7 has been attributed to interface scattering-dominated anomalous Hall effect.

  5. Quantized Anomalous Hall Effect in Magnetic Topological Insulators

    Institute of Scientific and Technical Information of China (English)

    YU Rui

    2011-01-01

    The Hall effect, the anomalous Hall effect (AHE) and the spin Hall effect are thndamental transport processes in solids arising from the Lorentz force and the spin-orbit coupling respectively. The AHE, in which a voltage transverse to the electric current appears even in the absence of an external magnetic field, was first detected in ferromagnetic (FM) metals in 1881 and later found to arise from the spin-orbit coupling (SOC) between the current and magnetic moments.

  6. Muon anomalous magnetic moment due to the brane stretching effect

    CERN Document Server

    Sawa, K

    2006-01-01

    We investigate the contribution of extra dimensions to muon anomalous magnetic moment using a 6-dimensional model. The approach analyzes the extent to which small brane fluctuations influence the magnetic moment. In particular, we assume that the fluctuations are static in time, which add the new potential terms to the schr{\\"o}dinger equation through the induced vierbein. This paper shows that the fluctuations result in the brane stretching effect due to the negative tension. The effect would be a capable of reproducing the appropriate order for the recent BNL measurements of the muon (g-2) deviation.

  7. Quantized Anomalous Hall Effect in Magnetic Topological Insulators

    Institute of Scientific and Technical Information of China (English)

    YU Rui

    2011-01-01

    @@ The Hall effect, the anomalous Hall effect (AHE) and the spin Hall effect are fundamental transport processes in solids arising from the Lorentz force and the spin-orbit coupling respectively.The AHE, in which a voltage transverse to the electric current appears even in the absence of an external magnetic field, was first detected in ferromagnetic (FM) metals in 1881 and later found to arise from the spin-orbit coupling (SOC) between the current and magnetic moments.Recent progress on the mechanism of AHE has established a link between the AHE and the topological nature of the Hall current by adopting the Berry-phase concepts in close analogy to the intrinsic spin Hall effect.Given the experimental discovery of the quantum Hall and the quantum spin Hall effects, it is natural to ask whether the AHE can also be quantized.In a quantized anomalous Hall (QAH) insulator, spontaneous magnetic moments and spin-orbit coupling combine to give rise to a topologically non-trivial electronic structure, leading to the quantized Hall effect without any external magnetic field.

  8. Quantum anomalous Hall effect in topological insulator memory

    Energy Technology Data Exchange (ETDEWEB)

    Jalil, Mansoor B. A., E-mail: elembaj@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, Singapore 117576 (Singapore); Data Storage Institute, Agency for Science, Technology and Research A*STAR, DSI Building, 5 Engineering Drive 1, Singapore, Singapore 117608 (Singapore); Tan, S. G. [Data Storage Institute, Agency for Science, Technology and Research A*STAR, DSI Building, 5 Engineering Drive 1, Singapore, Singapore 117608 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, Singapore 117576 (Singapore); Siu, Z. B. [Data Storage Institute, Agency for Science, Technology and Research A*STAR, DSI Building, 5 Engineering Drive 1, Singapore, Singapore 117608 (Singapore); NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (Singapore)

    2015-05-07

    We theoretically investigate the quantum anomalous Hall effect (QAHE) in a magnetically coupled three-dimensional-topological insulator (3D-TI) system. We apply the generalized spin-orbit coupling Hamiltonian to obtain the Hall conductivity σ{sup xy} of the system. The underlying topology of the QAHE phenomenon is then analyzed to show the quantization of σ{sup xy} and its relation to the Berry phase of the system. Finally, we analyze the feasibility of utilizing σ{sup xy} as a memory read-out in a 3D-TI based memory at finite temperatures, with comparison to known magnetically doped 3D-TIs.

  9. Large anomalous Hall effect in a half-Heusler antiferromagnet

    Science.gov (United States)

    Suzuki, T.; Chisnell, R.; Devarakonda, A.; Liu, Y.-T.; Feng, W.; Xiao, D.; Lynn, J. W.; Checkelsky, J. G.

    2016-12-01

    The quantum mechanical (Berry) phase of the electronic wavefunction plays a critical role in the anomalous and spin Hall effects, including their quantized limits. While progress has been made in understanding these effects in ferromagnets, less is known in antiferromagnetic systems. Here we present a study of antiferromagnet GdPtBi, whose electronic structure is similar to that of the topologically non-trivial HgTe (refs ,,), and where the Gd ions offer the possibility to tune the Berry phase via control of the spin texture. We show that this system supports an anomalous Hall angle ΘAH > 0.1, comparable to the largest observed in bulk ferromagnets and significantly larger than in other antiferromagnets. Neutron scattering measurements and electronic structure calculations suggest that this effect originates from avoided crossing or Weyl points that develop near the Fermi level due to a breaking of combined time-reversal and lattice symmetries. Berry phase effects associated with such symmetry breaking have recently been explored in kagome networks; our results extend this to half-Heusler systems with non-trivial band topology. The magnetic textures indicated here may also provide pathways towards realizing the topological insulating and semimetallic states predicted in this material class.

  10. A Classical Theory of the Anomalous Zeeman Effect

    Science.gov (United States)

    Espinosa, James; Woodyard, James

    2010-10-01

    Over a hundred years ago, it was discovered that spectral lines were shifted by magnetic fields. Lorentz was able to explain a small set of phenomena that was ironically called the normal Zeeman effect. It took more than twenty years for Lande to arrive at a vector model of the atom to explain the majority of shiftings called the anomalous Zeeman effect. Within a couple of years, Uhlenbeck and Goudsmit introduced the idea of a spinning electron that would give an underlying explanation of the vector model rules. It is generally taught that without the concept of spin there can be no explanation of all the spectral splittings caused by a magnetic field. We will present a purely classical model developed by Woldemar Voigt to describe the most famous anomalous splitting, the sodium D line. In addition, his theory correctly describes the transition from the weak field state to the strong one, called the Paschen-Back effect. We will show how his theory matches well with our classical picture of the atom.

  11. Anomalous Hall effect in Fe/Au multilayers

    KAUST Repository

    Zhang, Q.

    2016-07-22

    To understand the interfacial scattering effect on the anomalous Hall effect (AHE), we prepared multilayers of (Fe(36/n)nm/Au(12/n)nm)n using an e-beam evaporator. This structure design allowed us to investigate the effect of interfacial scattering on the AHE, while keeping the samples\\' thickness and composition unchanged. We measured the (magneto)transport properties of the samples in a wide temperature range (10–310 K) with magnetic fields up to 50 kOe. We found that the scaling between the anomalous Hall resistivity (ρAHE) and longitudinal resistivity (ρxx) can be roughly described by ρAHE∼ργxx with γ=2.65±0.10 and 1.90 ± 0.04 for samples from n=1 to n=4 and samples from n=4 to n=12, respectively. Our quantitative analysis results showed that the interfacial scattering suppresses the contribution of the intrinsic mechanism and gives rise to a side-jump contribution.

  12. Non-collinear antiferromagnets and the anomalous Hall effect

    Science.gov (United States)

    Kübler, J.; Felser, C.

    2014-12-01

    The anomalous Hall effect is investigated theoretically by employing density functional calculations for the non-collinear antiferromagnetic order of the hexagonal compounds Mn3Ge and Mn3Sn using various planar triangular magnetic configurations as well as unexpected non-planar configurations. The former give rise to anomalous Hall conductivities (AHC) that are found to be extremely anisotropic. For the planar cases the AHC is connected with Weyl points in the energy-band structure. If this case were observable in Mn3Ge, a large AHC of about σzx≈ 900 (Ω \\text{cm})-1 should be expected. However, in Mn3Ge it is the non-planar configuration that is energetically favored, in which case it gives rise to an AHC of σxy≈ 100 (Ω \\text{cm})-1 . The non-planar configuration allows a quantitative evaluation of the topological Hall effect that is seen to determine this value of σxy to a large extent. For Mn3Sn it is the planar configurations that are predicted to be observable. In this case the AHC can be as large as σyz≈250 (Ω \\text{cm})-1 .

  13. Anomalous photoelectric effect of a polycrystalline topological insulator film.

    Science.gov (United States)

    Zhang, Hongbin; Yao, Jiandong; Shao, Jianmei; Li, Hai; Li, Shuwei; Bao, Dinghua; Wang, Chengxin; Yang, Guowei

    2014-07-29

    A topological insulator represents a new state of quantum matter that possesses an insulating bulk band gap as well as a spin-momentum-locked Dirac cone on the surface that is protected by time-reversal symmetry. Photon-dressed surface states and light-induced surface photocurrents have been observed in topological insulators. Here, we report experimental observations of an anomalous photoelectric effect in thin films of Bi2Te3, a polycrystalline topological insulator. Under illumination with non-polarised light, transport measurements reveal that the resistance of the topological surface states suddenly increases when the polycrystalline film is illuminated. The resistance variation is positively dependent on the light intensity but has no relation to the applied electric field; this finding can be attributed to the gap opening of the surface Dirac cone. This observation of an anomalous photoelectric effect in polycrystalline topological insulators offers exciting opportunities for the creation of photodetectors with an unusually broad spectral range. Moreover, polycrystalline topological insulator films provide an attractive material platform for exploring the nature and practical application of topological insulators.

  14. Precise quantization of anomalous Hall effect near zero magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Bestwick, A. J. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Fox, E. J. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Kou, Xufeng [Univ. of California, Los Angeles, CA (United States); Pan, Lei [Univ. of California, Los Angeles, CA (United States); Wang, Kang L. [Univ. of California, Los Angeles, CA (United States); Goldhaber-Gordon, D. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-05-04

    In this study, we report a nearly ideal quantum anomalous Hall effect in a three-dimensional topological insulator thin film with ferromagnetic doping. Near zero applied magnetic field we measure exact quantization in the Hall resistance to within a part per 10,000 and a longitudinal resistivity under 1 Ω per square, with chiral edge transport explicitly confirmed by nonlocal measurements. Deviations from this behavior are found to be caused by thermally activated carriers, as indicated by an Arrhenius law temperature dependence. Using the deviations as a thermometer, we demonstrate an unexpected magnetocaloric effect and use it to reach near-perfect quantization by cooling the sample below the dilution refrigerator base temperature in a process approximating adiabatic demagnetization refrigeration.

  15. Influence of disorder on anomalous Hall effect for Heusler compounds

    Science.gov (United States)

    Vilanova Vidal, E.; Schneider, H.; Jakob, G.

    2011-05-01

    The anomalous Hall effect (AHE) is a long known but still not fully understood transport effect. Most theory papers focus on the influence of one particular contribution to the AHE. Actual measured experimental data, however, often are not in accord with idealized assumptions. In this work we discuss the data analysis for materials with low residual resistivity ratios. As prototypical materials we study half metallic Heusler compounds. Here the influence of defects and disorder is apparent in a material with a complex topology of the Fermi surface. Using films of different degree of disorder, we show how different scattering mechanisms can be separated. For Co2FeSi0.6Al0.4 and Co2FeGa0.5Ge0.5 the AHE induced by B2-type disorder and temperature-dependent scattering is positive, while DO3-type disorder and possible intrinsic contributions possess a negative sign.

  16. The quantum anomalous Hall effect in kagome lattices

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhiyong, E-mail: zyzhang@nju.edu.cn [Department of Physics, Nanjing University, Nanjing 210093 (China)

    2011-09-14

    The quantum anomalous Hall (QAH) effect in kagome lattices is investigated in the presence of both Rashba spin-orbit coupling and an exchange field. In addition to the gap at the Dirac points as found in graphene, a new topological energy gap is opened at the {Gamma} point. With the Fermi energy lying in the first gap, the Chern number c = 2 as in graphene, whereas with it lying in the second one, c = 1. The distribution of Berry curvature is obtained to reveal the nontrivial topological properties in momentum space. For stripes with 'armchair' and 'zigzag' edges, the topological characteristics of gapless edge states on the genus g = 2 Riemann surface are studied. The obtained nonzero winding numbers also demonstrate the QAH effect. (paper)

  17. Precise quantization of anomalous Hall effect near zero magnetic field

    Science.gov (United States)

    Bestwick, Andrew; Fox, Eli; Kou, Xufeng; Pan, Lei; Wang, Kang; Goldhaber-Gordon, David

    2015-03-01

    The quantum anomalous Hall effect (QAHE) has recently been of great interest due to its recent experimental realization in thin films of Cr-doped (Bi, Sb)2Te3, a ferromagnetic 3D topological insulator. The presence of ferromagnetic exchange breaks time-reversal symmetry, opening a gap in the surface states, but gives rise to dissipationless chiral conduction at the edge of a magnetized film. Ideally, this leads to vanishing longitudinal resistance and Hall resistance quantized to h /e2 , where h is Planck's constant and e is the electron charge, but perfect quantization has so far proved elusive. Here, we study the QAHE in the limit of zero applied magnetic field, and measure Hall resistance quantized to within one part per 10,000. Deviation from quantization is due primarily to thermally activated carriers, which can be nearly eliminated through adiabatic demagnetization cooling. This result demonstrates an important step toward dissipationless electron transport in technologically relevant conditions.

  18. Detecting topological phases in silicene by anomalous Nernst effect

    Science.gov (United States)

    Xu, Yafang; Zhou, Xingfei; Jin, Guojun

    2016-05-01

    Silicene undergoes various topological phases under the interplay of intrinsic spin-orbit coupling, perpendicular electric field, and off-resonant light. We propose that the abundant topological phases can be distinguished by measuring the Nernst conductivity even at room temperature, and their phase boundaries can be determined by differentiating the charge and spin Nernst conductivities. By modulating the electric and light fields, pure spin polarized, valley polarized, and even spin-valley polarized Nernst currents can be generated. As Nernst conductivity is zero for linear polarized light, silicene can act as an optically controlled spin and valley field-effect transistor. Similar investigations can be extended from silicene to germanene and stanene, and a comparison is made for the anomalous thermomagnetic figure of merits between them. These results will facilitate potential applications in spin and valley caloritronics.

  19. Thickness Dependence of the Quantum Anomalous Hall Effect in Magnetic Topological Insulator Films.

    Science.gov (United States)

    Feng, Xiao; Feng, Yang; Wang, Jing; Ou, Yunbo; Hao, Zhenqi; Liu, Chang; Zhang, Zuocheng; Zhang, Liguo; Lin, Chaojing; Liao, Jian; Li, Yongqing; Wang, Li-Li; Ji, Shuai-Hua; Chen, Xi; Ma, Xucun; Zhang, Shou-Cheng; Wang, Yayu; He, Ke; Xue, Qi-Kun

    2016-08-01

    The evolution of the quantum anomalous Hall effect with the thickness of Cr-doped (Bi,Sb)2 Te3 magnetic topological insulator films is studied, revealing how the effect is caused by the interplay of the surface states, band-bending, and ferromagnetic exchange energy. Homogeneity in ferromagnetism is found to be the key to high-temperature quantum anomalous Hall material.

  20. Quantum anomalous Hall effect in stanene on a nonmagnetic substrate

    Science.gov (United States)

    Zhang, Huisheng; Zhou, Tong; Zhang, Jiayong; Zhao, Bao; Yao, Yugui; Yang, Zhongqin

    2016-12-01

    Since the quantum anomalous Hall (QAH) effect was realized in magnetic topological insulators, research on the effect has become a hot topic. The very harsh realizing requirements of the effect in experiments, however, hinder its practical applications. Based on ab initio methods, we find that nonmagnetic Pb I2 films are ideal substrates for the two-dimensional honeycomb stanene. The QAH effect with a pretty large band gap (up to 90 meV) can be achieved in the functionalized stanene /Pb I2 heterostructure. Despite van der Waals interactions in the heterostructure, band inversions are found to be happening between Sn (s and px ,y ) and Pb (px ,y) orbitals, playing a key role in determining the nontrivial topology and the large band gap of the system. Having no magnetic atoms is imperative to triggering the QAH effect. A very stable rudimentary device having QAH effects is proposed based on the Sn /Pb I2 heterostructure. Our results demonstrate that QAH effects can be easily realized in the Sn /Pb I2 heterostructures in experiments.

  1. Robust quantum anomalous Hall effect in ferromagnetic transition metal halides

    CERN Document Server

    Huang, Chengxi; Wu, Haiping; Deng, Kaiming; Jena, Puru; Kan, Erjun

    2016-01-01

    The quantum anomalous Hall (QAH) effect is a novel topological spintronic phenomenon arising from inherent magnetization and spin-orbit coupling. Various theoretical and experimental efforts have been devoted in search of robust intrinsic QAH insulators. However, up to now, it has only been observed in Cr or V doped (Bi,Sb)2Te3 film in experiments with very low working temperature. Based on the successful synthesis of transition metal halides, we use first-principles calculations to predict that RuI3 monolayer is an intrinsic ferromagnetic QAH insulator with a topologically nontrivial global band gap of 11 meV. This topologically nontrivial band gap at the Fermi level is due to its crystal symmetry, thus the QAH effect is robust. Its Curie temperature, estimated to be ~360 K using Monte-Carlo simulation, is above room temperature and higher than most of two-dimensional ferromagnetic thin films. We also discuss the manipulation of its exchange energy and nontrivial band gap by applying in-plane strain. Our wor...

  2. Quantum anomalous Hall effect in ferromagnetic transition metal halides

    Science.gov (United States)

    Huang, Chengxi; Zhou, Jian; Wu, Haiping; Deng, Kaiming; Jena, Puru; Kan, Erjun

    2017-01-01

    The quantum anomalous Hall (QAH) effect is a novel topological spintronic phenomenon arising from inherent magnetization and spin-orbit coupling. Various theoretical and experimental efforts have been devoted in search of intrinsic QAH insulators. However, up to now, it has only been observed in Cr or V doped (Bi,Sb ) 2T e3 film in experiments with very low working temperature. Based on the successful synthesis of transition metal halides, we use first-principles calculations to predict that the Ru I3 monolayer is an intrinsic ferromagnetic QAH insulator with a topologically nontrivial global band gap of 11 meV. This topologically nontrivial band gap at the Fermi level is due to its crystal symmetry, thus the QAH effect is robust. Its Curie temperature, estimated to be ˜360 K using Monte Carlo simulation, is above room temperature and higher than most two-dimensional ferromagnetic thin films. The inclusion of Hubbard U in the Ru-d electrons does not affect this result. We also discuss the manipulation of its exchange energy and nontrivial band gap by applying in-plane strain. Our work adds an experimentally feasible member to the QAH insulator family, which is expected to have broad applications in nanoelectronics and spintronics.

  3. Gamma Radiation Effects on Peanut Skin Antioxidants

    OpenAIRE

    Adriano Costa de Camargo; Thais Maria Ferreira de Souza Vieira; Marisa Aparecida Bismara Regitano-D’Arce; Maria Antonia Calori-Domingues; Solange Guidolin Canniatti-Brazaca

    2012-01-01

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to...

  4. Concepts of ferrovalley material and anomalous valley Hall effect.

    Science.gov (United States)

    Tong, Wen-Yi; Gong, Shi-Jing; Wan, Xiangang; Duan, Chun-Gang

    2016-12-16

    Valleytronics rooted in the valley degree of freedom is of both theoretical and technological importance as it offers additional opportunities for information storage, as well as electronic, magnetic and optical switches. In analogy to ferroelectric materials with spontaneous charge polarization, or ferromagnetic materials with spontaneous spin polarization, here we introduce a new member of ferroic family, that is, a ferrovalley material with spontaneous valley polarization. Combining a two-band k·p model with first-principles calculations, we show that 2H-VSe2 monolayer, where the spin-orbit coupling coexists with the intrinsic exchange interaction of transition-metal d electrons, is such a room-temperature ferrovalley material. We further predict that such system could demonstrate many distinctive properties, for example, chirality-dependent optical band gap and, more interestingly, anomalous valley Hall effect. On account of the latter, functional devices based on ferrovalley materials, such as valley-based nonvolatile random access memory and valley filter, are contemplated for valleytronic applications.

  5. Concepts of ferrovalley material and anomalous valley Hall effect

    Science.gov (United States)

    Tong, Wen-Yi; Gong, Shi-Jing; Wan, Xiangang; Duan, Chun-Gang

    2016-12-01

    Valleytronics rooted in the valley degree of freedom is of both theoretical and technological importance as it offers additional opportunities for information storage, as well as electronic, magnetic and optical switches. In analogy to ferroelectric materials with spontaneous charge polarization, or ferromagnetic materials with spontaneous spin polarization, here we introduce a new member of ferroic family, that is, a ferrovalley material with spontaneous valley polarization. Combining a two-band k.p model with first-principles calculations, we show that 2H-VSe2 monolayer, where the spin-orbit coupling coexists with the intrinsic exchange interaction of transition-metal d electrons, is such a room-temperature ferrovalley material. We further predict that such system could demonstrate many distinctive properties, for example, chirality-dependent optical band gap and, more interestingly, anomalous valley Hall effect. On account of the latter, functional devices based on ferrovalley materials, such as valley-based nonvolatile random access memory and valley filter, are contemplated for valleytronic applications.

  6. Localization correction to the anomalous Hall effect in amorphous CoFeB thin films

    Institute of Scientific and Technical Information of China (English)

    丁进军; 吴少兵; 杨晓非; 朱涛

    2015-01-01

    An obvious weak localization correction to anomalous Hall conductance (AHC) in very thin CoFeB film is reported. We find that both the weak localization to AHC and the mechanism of anomalous Hall effect are related to the CoFeB thickness. When the film is thicker than 3 nm, the side jump mechanism dominates and the weak localization to AHC vanishes. For very thin CoFeB films, both the side jump and skew scattering mechanisms contribute to the anomalous Hall effect, and the weak localization correction to AHC is observed.

  7. Effect of bicellar systems on skin properties.

    Science.gov (United States)

    Barbosa-Barros, L; Barba, C; Cócera, M; Coderch, L; López-Iglesias, C; de la Maza, A; López, O

    2008-03-20

    Bicelles are discoidal aggregates formed by a flat dimyristoyl-glycero-phosphocholine (DMPC) bilayer, stabilized by a rim of dihexanoyl-glycero-phosphocholine (DHPC) in water. Given the structure, composition and the dimensions of these aggregates around 10-50 nm diameter, their use for topical applications is a promising strategy. This work evaluates the effect of DMPC/DHPC bicelles with molar ratio (2/1) on intact skin. Biophysical properties of the skin, such as transepidermal water loss (TEWL), elasticity, skin capacitance and irritation were measured in healthy skin in vivo. To study the effect of the bicellar systems on the microstructure of the stratum corneum (SC) in vitro, pieces of native tissue were treated with the aforementioned bicellar system and evaluated by freeze substitution applied to transmission electron microscopy (FSTEM). Our results show that bicelles increase the TEWL, the skin elastic parameters and, decrease skin hydration without promoting local signs of irritation and without affecting the SC lipid microstructure. Thus, a permeabilizing effect of bicelles on the skin takes place possibly due to the changes in the phase behaviour of the SC lipids by effect of phospholipids from bicelles.

  8. Magnetic Topological Insulators and Quantum Anomalous Hall Effect

    Science.gov (United States)

    Kou, Xufeng

    The engineering of topological surface states is a key to realize applicable devices based on topological insulators (TIs). Among various proposals, introducing magnetic impurities into TIs has been proven to be an effective way to open a surface gap and integrate additional ferromagnetism with the original topological order. In this Dissertation, we study both the intrinsic electrical and magnetic properties of the magnetic TI thin films grown by molecular beam epitaxy. By doping transition element Cr into the host tetradymite-type V-VI semiconductors, we achieve robust ferromagnetic order with a strong perpendicular magnetic anisotropy. With additional top-gating capability, we realize the electric-field-controlled ferromagnetism in the magnetic TI systems, and demonstrate such magneto-electric effects can be effectively manipulated, depending on the interplays between the band topology, magnetic exchange coupling, and structural engineering. Most significantly, we report the observation of quantum anomalous Hall effect (QAHE) in the Cr-doped (BiSb)2Te3 samples where dissipationless chiral edge conduction is realized in the macroscopic millimeter-size devices without the presence of any external magnetic field, and the stability of the quantized Hall conductance of e2/h is well-maintained as the film thickness varies across the 2D hybridization limit. With additional quantum confinement, we discover the metal-to-insulator switching between two opposite QAHE states, and reveal the universal QAHE phase diagram in the thin magnetic TI samples. In addition to the uniform magnetic TIs, we further investigate the TI/Cr-doped TI bilayer structures prepared by the modulation-doped growth method. By controlling the magnetic interaction profile, we observe the Dirac hole-mediated ferromagnetism and develop an effective way to manipulate its strength. Besides, the giant spin-orbit torque in such magnetic TI-based heterostructures enables us to demonstrate the current

  9. Anomalous $tqZ$ coupling effects in rare B- and K-meson decays

    CERN Document Server

    Li, Xin-Qiang; Yuan, Xing-Bo

    2011-01-01

    As a top-factory, the LHC is performing a direct study of top-quark anomalous FCNC couplings, which are, however, correlated closely with the rare B- and K-meson decays. In this paper, we study the effects of anomalous $tqZ$ (with $q=u,c$) couplings in the rare decays $B_{s,d}\\to \\mu^+\\mu^-$, $B\\to X_s \

  10. Unconventional scaling of the anomalous Hall effect accompanying electron localization correction in the dirty regime

    KAUST Repository

    Lu, Y. M.

    2013-03-05

    Scaling of the anomalous Hall conductivity to longitudinal conductivity σAH∝σ2xx has been observed in the dirty regime of two-dimensional weak and strong localization regions in ultrathin, polycrystalline, chemically disordered, ferromagnetic FePt films. The relationship between electron transport and temperature reveals a quantitatively insignificant Coulomb interaction in these films, while the temperature dependent anomalous Hall conductivity experiences quantum correction from electron localization. At the onset of this correction, the low-temperature anomalous Hall resistivity begins to be saturated when the thickness of the FePt film is reduced, and the corresponding Hall conductivity scaling exponent becomes 2, which is above the recent unified theory of 1.6 (σAH∝σ1.6xx). Our results strongly suggest that the correction of the electron localization modulates the scaling exponent of the anomalous Hall effect.

  11. Large anomalous Hall effect in a non-collinear antiferromagnet at room temperature.

    Science.gov (United States)

    Nakatsuji, Satoru; Kiyohara, Naoki; Higo, Tomoya

    2015-11-12

    In ferromagnetic conductors, an electric current may induce a transverse voltage drop in zero applied magnetic field: this anomalous Hall effect is observed to be proportional to magnetization, and thus is not usually seen in antiferromagnets in zero field. Recent developments in theory and experiment have provided a framework for understanding the anomalous Hall effect using Berry-phase concepts, and this perspective has led to predictions that, under certain conditions, a large anomalous Hall effect may appear in spin liquids and antiferromagnets without net spin magnetization. Although such a spontaneous Hall effect has now been observed in a spin liquid state, a zero-field anomalous Hall effect has hitherto not been reported for antiferromagnets. Here we report empirical evidence for a large anomalous Hall effect in an antiferromagnet that has vanishingly small magnetization. In particular, we find that Mn3Sn, an antiferromagnet that has a non-collinear 120-degree spin order, exhibits a large anomalous Hall conductivity of around 20 per ohm per centimetre at room temperature and more than 100 per ohm per centimetre at low temperatures, reaching the same order of magnitude as in ferromagnetic metals. Notably, the chiral antiferromagnetic state has a very weak and soft ferromagnetic moment of about 0.002 Bohr magnetons per Mn atom (refs 10, 12), allowing us to switch the sign of the Hall effect with a small magnetic field of around a few hundred oersted. This soft response of the large anomalous Hall effect could be useful for various applications including spintronics--for example, to develop a memory device that produces almost no perturbing stray fields.

  12. Chiral Magnetic Effect and Anomalous Hall Effect in Antiferromagnetic Insulators with Spin-Orbit Coupling.

    Science.gov (United States)

    Sekine, Akihiko; Nomura, Kentaro

    2016-03-04

    We search for dynamical magnetoelectric phenomena in three-dimensional correlated systems with spin-orbit coupling. We focus on the antiferromagnetic insulator phases where the dynamical axion field is realized by the fluctuation of the antiferromagnetic order parameter. It is shown that the dynamical chiral magnetic effect, an alternating current generation by magnetic fields, emerges due to such time dependences of the order parameter as antiferromagnetic resonance. It is also shown that the anomalous Hall effect arises due to such spatial variations of the order parameter as antiferromagnetic domain walls. Our study indicates that spin excitations in antiferromagnetic insulators with spin-orbit coupling can result in nontrivial charge responses. Moreover, observing the chiral magnetic effect and anomalous Hall effect in our system is equivalent to detecting the dynamical axion field in condensed matter.

  13. Separation of spin Seebeck effect and anomalous Nernst effect in Co/Cu/YIG

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Dai [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433 (China); Li, Yufan; Qu, D.; Chien, C. L., E-mail: clchien@jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Jin, Xiaofeng [State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433 (China)

    2015-05-25

    The spin Seebeck effect (SSE) and Anomalous Nernst effect (ANE) have been observed in Co/Cu/YIG (yttrium iron garnet) multi-layer structure, where the ferromagnetic insulator YIG acts as the pure spin injector and the ferromagnetic metal Co layer acts as the spin current detector. With the insertion of 5 nm Cu layer, the two ferromagnetic layers are decoupled, thus allowing unambiguous separation of the SSE and ANE contributions under the same experimental conditions in the same sample.

  14. Separation of spin Seebeck effect and anomalous Nernst effect in Co/Cu/YIG

    Science.gov (United States)

    Tian, Dai; Li, Yufan; Qu, D.; Jin, Xiaofeng; Chien, C. L.

    2015-05-01

    The spin Seebeck effect (SSE) and Anomalous Nernst effect (ANE) have been observed in Co/Cu/YIG (yttrium iron garnet) multi-layer structure, where the ferromagnetic insulator YIG acts as the pure spin injector and the ferromagnetic metal Co layer acts as the spin current detector. With the insertion of 5 nm Cu layer, the two ferromagnetic layers are decoupled, thus allowing unambiguous separation of the SSE and ANE contributions under the same experimental conditions in the same sample.

  15. The effect of interfacial intermixing on magnetization and anomalous Hall effect in Co/Pd multilayers

    KAUST Repository

    Guo, Zaibing

    2015-05-01

    The effect of interfacial intermixing on magnetization and anomalous Hall effect (AHE) in Co/Pd multilayers is studied by using rapid thermal annealing to enhance the interfacial diffusion. The dependence of saturation magnetization and coercivity on the temperature of rapid thermal annealing at 5 K is discussed. It is found that AHE is closely related to the relative thickness of the Co and Pd layers. Localized paramagnetism has been observed which destroys AHE, while AHE can be enhanced by annealing.

  16. Gamma Radiation Effects on Peanut Skin Antioxidants

    Directory of Open Access Journals (Sweden)

    Adriano Costa de Camargo

    2012-03-01

    Full Text Available Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ. Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h, measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts’ antioxidative properties when added to soybean oil.

  17. Gamma radiation effects on peanut skin antioxidants.

    Science.gov (United States)

    de Camargo, Adriano Costa; de Souza Vieira, Thais Maria Ferreira; Regitano-D'Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia; Canniatti-Brazaca, Solange Guidolin

    2012-01-01

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD) soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative properties when added to soybean oil.

  18. Anomalous Hall effect in Fe/Gd bilayers

    KAUST Repository

    Xu, W. J.

    2010-04-01

    Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd simultaneously. The temperature and field dependences of longitudinal resistivity, Hall resistivity and magnetization in these films have also been carefully measured. The analysis of these data reveals that these intriguing features are due to the opposite signs of Hall resistivity/or spin polarization and different Curie temperatures of Fe and Gd single-layer films. Copyright (C) EPLA, 2010

  19. Anomalous and planar Righi-Leduc effects in Ni80Fe20 ferromagnets

    Science.gov (United States)

    Madon, B.; Pham, Do Ch.; Wegrowe, J.-E.; Lacour, D.; Hehn, M.; Polewczyk, V.; Anane, A.; Cros, V.

    2016-10-01

    In this paper, we report experimental evidence of anomalous and planar Righi-Leduc effects on NiFe . The Righi-Leduc effect is the thermal analog of the Hall effect, in which the electric current is replaced by the heat current and the electric field by the temperature gradient. When the material is ferromagnetic, it is well known that there are two other contributions to the Hall voltage which depend on the orientation of the magnetization. These two extra contributions are called the anomalous Hall effect when the magnetization is out of the plane of the sample and the planar Hall effect when the magnetization is in the plane of the sample. In the same way, an anomalous and a planar Righi-Leduc effects are shown to appear when a transverse temperature gradient is generated by a heat current.

  20. Anomalous transport effects and possible environmental symmetry 'violation' in heavy-ion collisions

    Indian Academy of Sciences (India)

    Jinfeng Liao

    2015-05-01

    The heavy-ion collision provides a unique many-body environment where local domains of strongly interacting chiral medium may occur and in a sense allow environmental symmetry 'violation' phenomena. For example, certain anomalous transport processes, forbidden in usual medium, become possible in such domains. We briefly review recent progress in both the theoretical understanding and experimental search of various anomalous transport effects (such as the chiral magnetic effect, chiral separation effect, chiral electric separation effect, chiral electric/magnetic waves, etc.) in the hot QCD fluid formed by such collisions.

  1. Gamma radiation effects on peanut skin antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Adriano Costa de [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Canniatti-Brazaca, Solange Guidolin; Vieira, Thais Maria Ferreira de Souza; Regitano-d' Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia, E-mail: sgcbraza@usp.b, E-mail: tvieira@esalq.usp.b, E-mail: mabra@esalq.usp.b, E-mail: macdomin@esalq.usp.b [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao

    2011-07-01

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The viability of using natural sources of antioxidants to replace synthetic antioxidants was assessed. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays at a dose rate of 7.5 kGy/h using a {sup 60}Co source. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached deodorized (RBD) soybean oil that was free from synthetic antioxidants. The oxidative stability of the oil samples was determined using the Rancimat method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. Ethanolic extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Rancimat method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT but lower than THBQ. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative level when added to soybean oil. The induction period of the control soybean oil was 5.7 h, while soybean oil with added ethanolic peanut skin extract had an induction period of 7.2 h, on average. (author)

  2. Sub 100-ps dynamics of the anomalous Hall effect at THz frequencies

    CERN Document Server

    Huisman, T J; Tsukamoto, A; Ma, L; Fan, W J; Zhou, S M; Rasing, Th; Kimel, A V

    2016-01-01

    We report about the anomalous Hall effect in 4f 3d metallic alloys measured using terahertz time-domain spectroscopy. The strength of the observed terahertz spin-dependent transport phenomenon is in good agreement with expectations based on electronic transport measurements. Employing this effect, we succeeded to reveal ultrafast dynamics of the anomalous Hall effect which accompanies the sub-100 picosecond optically induced magnetization reversal in a GdFeCo alloy. The experiments demonstrate the ability to control currents at terahertz frequencies in spintronic devices magnetically and ultrafast.

  3. Quantum anomalous Hall effect in magnetically doped InAs/GaSb quantum wells.

    Science.gov (United States)

    Wang, Qing-Ze; Liu, Xin; Zhang, Hai-Jun; Samarth, Nitin; Zhang, Shou-Cheng; Liu, Chao-Xing

    2014-10-03

    The quantum anomalous Hall effect has recently been observed experimentally in thin films of Cr-doped (Bi,Sb)(2)Te(3) at a low temperature (∼ 30 mK). In this work, we propose realizing the quantum anomalous Hall effect in more conventional diluted magnetic semiconductors with magnetically doped InAs/GaSb type-II quantum wells. Based on a four-band model, we find an enhancement of the Curie temperature of ferromagnetism due to band edge singularities in the inverted regime of InAs/GaSb quantum wells. Below the Curie temperature, the quantum anomalous Hall effect is confirmed by the direct calculation of Hall conductance. The parameter regime for the quantum anomalous Hall phase is identified based on the eight-band Kane model. The high sample quality and strong exchange coupling make magnetically doped InAs/GaSb quantum wells good candidates for realizing the quantum anomalous Hall insulator at a high temperature.

  4. Perpendicular magnetic anisotropy in Co2MnGa and its anomalous Hall effect

    Science.gov (United States)

    Ludbrook, B. M.; Ruck, B. J.; Granville, S.

    2017-02-01

    We report perpendicular magnetic anisotropy in the ferromagnetic Heusler alloy Co2MnGa in a MgO/Co2MnGa/Pd trilayer stack for Co2MnGa thicknesses up to 3.5 nm. There is a thickness- and temperature-dependent spin reorientation transition from perpendicular to in-plane magnetic anisotropy, which we study through the anomalous Hall effect. From the temperature dependence of the anomalous Hall effect, we observe the expected scaling of ρx y A H E with ρxx, suggesting that the intrinsic and side-jump mechanisms are largely responsible for the anomalous Hall effect in this material.

  5. Absence of anomalous Nernst effect in spin Seebeck effect of Pt/YIG

    Science.gov (United States)

    Miao, B. F.; Huang, S. Y.; Qu, D.; Chien, C. L.

    2016-01-01

    The Pt/YIG structure has been widely used to study spin Seebeck effect (SSE), inverse spin Hall effect, and other pure spin current phenomena. However, the magnetic proximity effect in Pt when in contact with YIG, and the potential anomalous Nernst effect (ANE) may compromise the spin current phenomena in Pt/YIG. By inserting a Cu layer of various thicknesses between Pt and YIG, we have separated the signals from the SSE and that of the ANE. It is demonstrated that the thermal voltage in Pt/YIG mainly comes from spin current due to the longitudinal SSE with negligible contribution from the ANE.

  6. Absence of anomalous Nernst effect in spin Seebeck effect of Pt/YIG

    Energy Technology Data Exchange (ETDEWEB)

    Miao, B. F., E-mail: bfmiao@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Huang, S. Y. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Qu, D.; Chien, C. L., E-mail: clchien@jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2016-01-15

    The Pt/YIG structure has been widely used to study spin Seebeck effect (SSE), inverse spin Hall effect, and other pure spin current phenomena. However, the magnetic proximity effect in Pt when in contact with YIG, and the potential anomalous Nernst effect (ANE) may compromise the spin current phenomena in Pt/YIG. By inserting a Cu layer of various thicknesses between Pt and YIG, we have separated the signals from the SSE and that of the ANE. It is demonstrated that the thermal voltage in Pt/YIG mainly comes from spin current due to the longitudinal SSE with negligible contribution from the ANE.

  7. Absence of anomalous Nernst effect in spin Seebeck effect of Pt/YIG

    Directory of Open Access Journals (Sweden)

    B. F. Miao

    2016-01-01

    Full Text Available The Pt/YIG structure has been widely used to study spin Seebeck effect (SSE, inverse spin Hall effect, and other pure spin current phenomena. However, the magnetic proximity effect in Pt when in contact with YIG, and the potential anomalous Nernst effect (ANE may compromise the spin current phenomena in Pt/YIG. By inserting a Cu layer of various thicknesses between Pt and YIG, we have separated the signals from the SSE and that of the ANE. It is demonstrated that the thermal voltage in Pt/YIG mainly comes from spin current due to the longitudinal SSE with negligible contribution from the ANE.

  8. Role of antioxidants in the skin: anti-aging effects.

    Science.gov (United States)

    Masaki, Hitoshi

    2010-05-01

    Intracellular and extracellular oxidative stress initiated by reactive oxygen species (ROS) advance skin aging, which is characterized by wrinkles and atypical pigmentation. Because UV enhances ROS generation in cells, skin aging is usually discussed in relation to UV exposure. The use of antioxidants is an effective approach to prevent symptoms related to photo-induced aging of the skin. In this review, the mechanisms of ROS generation and ROS elimination in the body are summarized. The effects of ROS generated in the skin and the roles of ROS in altering the skin are also discussed. In addition, the effects of representative antioxidants on the skin are summarized with a focus on skin aging.

  9. Transverse spin Seebeck effect versus anomalous and planar Nernst effects in Permalloy thin films.

    Science.gov (United States)

    Schmid, M; Srichandan, S; Meier, D; Kuschel, T; Schmalhorst, J-M; Vogel, M; Reiss, G; Strunk, C; Back, C H

    2013-11-01

    Transverse magnetothermoelectric effects are studied in Permalloy thin films grown on MgO and GaAs substrates and compared to those grown on suspended SiN(x) membranes. The transverse voltage along platinum strips patterned on top of the Permalloy films is measured versus the external magnetic field as a function of the angle and temperature gradients. After the identification of the contribution of the planar and anomalous Nernst effects, we find an upper limit for the transverse spin Seebeck effect, which is several orders of magnitude smaller than previously reported.

  10. Shark skin effect in creeping films

    CERN Document Server

    Scholle, M

    2006-01-01

    If a body in a stream is provided with small ridges aligned in the local flow direction, a remarkable drag reduction can be reached under turbulent flow conditions. This surprising phenomenon is called the 'shark skin effect'. We demonstrate, that a reduction of resistance can also be reached in creeping flows if the ridges are aligned perpendicular to the flow direction. We especially consider in gravity-driven film flows the effect of the bottom topography on the mean transport velocity.

  11. Tunnelling anomalous and planar Hall effects (Conference Presentation)

    Science.gov (United States)

    Matos-Abiague, Alex; Scharf, Benedikt; Han, Jong E.; Hankiewicz, Ewelina M.; Zutic, Igor

    2016-10-01

    We theoretically show how the interplay between spin-orbit coupling (SOC) and magnetism can result in a finite tunneling Hall conductance, transverse to the applied bias. For two-dimensional tunnel junctions with a ferromagnetic lead and magnetization perpendicular to the current flow, the detected anomalous Hall voltage can be used to extract information not only about the spin polarization but also about the strength of the interfacial SOC. In contrast, a tunneling current across a ferromagnetic barrier on the surface of a three-dimensional topological insulator (TI) can induce a planar Hall response even when the magnetization is oriented along the current flow[1]. The tunneling nature of the states contributing to the planar Hall conductance can be switched from the ordinary to the Klein regimes by the electrostatic control of the barrier strength. This allows for an enhancement of the transverse response and a giant Hall angle, with the tunneling planar Hall conductance exceeding the longitudinal component. Despite the simplicity of a single ferromagnetic region, the TI/ferromagnet system exhibits a variety of functionalities. In addition to a spin-valve operation for magnetic sensing and storing information, positive, negative, and negative differential conductances can be tuned by properly adjusting the barrier potential and/or varying the magnetization direction. Such different resistive behaviors in the same system are attractive for potential applications in reconfigurable spintronic devices. [1] B. Scharf, A. Matos-Abiague, J. E. Han, E. M. Hankiewicz, and I. Zutic, arXiv:1601.01009 (2016).

  12. Scaling of anomalous hall effect in amorphous CoFeB Films with accompanying quantum correction

    KAUST Repository

    Zhang, Yan

    2015-05-08

    Scaling of anomalous Hall effect in amorphous CoFeB films with thickness ranging from 2 to 160 nm have been investigated. We have found that the scaling relationship between longitudinal (ρxx) and anomalous Hall (ρAH) resistivity is distinctly different in the Bloch and localization regions. For ultrathin CoFeB films, the sheet resistance (Rxx) and anomalous Hall conductance (GAH) received quantum correction from electron localization showing two different scaling relationships at different temperature regions. In contrast, the thicker films show a metallic conductance, which have only one scaling relationship in the entire temperature range. Furthermore, in the dirty regime of localization regions, an unconventional scaling relationship View the MathML sourceσAH∝σxxα with α=1.99 is found, rather than α=1.60 predicted by the unified theory.

  13. Exploration of Anomalous Gravity Effects by rf-Pumped Magnetized High-T(c) Superconducting Oxides

    Science.gov (United States)

    Robertson, Tony; Litchford, Ron; Peters, Randall; Thompson, Byran; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    A number of anomalous gravitational effects have been reported in the scientific literature during recent years, but there has been no independent confirmation with regard to any of these claims. Therefore, the NASA Marshall Space Flight Center, in response to the propulsion challenges specified by NASA's Breakthrough Propulsion Physics (BPP) program, proposed to explore the possibility of observing anomalous gravitation behavior through the manipulation of Josephson junction effects in magnetized high-Tc superconducting oxides. The technical goal was to critically test this revolutionary physical claim and provide a rigorous, independent, empirical confirmation (or refutation) of anomalous effects related to the manipulation of gravity by radio frequency (rf)-pumped magnetized type-2 superconductors. Because the current empirical evidence for gravity modification is anecdotal, our objective was to design, construct, and meticulously implement a discriminating experiment, which would put these observations on a more firm footing within the scientific community. Our approach is unique in that we advocate the construction of an extremely sensitive torsion balance with which to measure gravity modification effects by rf-pumped type-2 superconductor test masses. This paper reviews the anecdotal evidence for anomalous gravity effects, describes the design and development of a simplified torsion balance experiment for empirically investigating these claims, and presents the results of preliminary experiments.

  14. Effective anomalous Hall coefficient in an ultrathin Co layer sandwiched by Pt layers

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Peng; Wu, Di; Jiang, Zhengsheng; Sang, Hai, E-mail: weiwei.lin@u-psud.fr, E-mail: haisang@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Lin, Weiwei, E-mail: weiwei.lin@u-psud.fr, E-mail: haisang@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Institut d' Electronique Fondamentale, Université Paris-Sud, Orsay 91405 (France)

    2014-02-14

    Anomalous Hall effect in Co/Pt multilayer is important to study the effect of interface with strong spin-orbit coupling. However, the shunting effect of the layers in such system and the circuit in the plane perpendicular to the injected current were overlooked in most works and thus, anomalous Hall coefficient in Co/Pt multilayer has not been determined accurately. Considering the shunting effect and the equivalent circuit, we show that the effective anomalous Hall coefficient of a 0.5 nm thick Co layer sandwiched by Pt layers R{sub S} is 0.29 ± 0.01 μΩ cm/T at the zero temperature limit and increases to about 0.73 μΩ cm/T at the temperature of 300 K. R{sub S} is one order larger than that in bulk Co film, indicating the large contribution of the Co/Pt interface. R{sub S} increases with the resistivity of Co as well as a resistivity independent contribution of −0.23 ± 0.01 μΩ cm/T. The equivalent anomalous Hall current in the Co layer has a maximum of 1.1% of the injected transverse current in the Co layer around the temperature of 80 K.

  15. Effect of interstitial low level laser stimulation in skin density

    Science.gov (United States)

    Jang, Seulki; Ha, Myungjin; Lee, Sangyeob; Yu, Sungkon; Park, Jihoon; Radfar, Edalat; Hwang, Dong Hyun; Lee, Han A.; Kim, Hansung; Jung, Byungjo

    2016-03-01

    As the interest in skin was increased, number of studies on skin care also have been increased. The reduction of skin density is one of the symptoms of skin aging. It reduces elasticity of skin and becomes the reason of wrinkle formation. Low level laser therapy (LLLT) has been suggested as one of the effective therapeutic methods for skin aging as in hasten to change skin density. This study presents the effect of a minimally invasive laser needle system (MILNS) (wavelength: 660nm, power: 20mW) in skin density. Rabbits were divided into three groups. Group 1 didn't receive any laser stimulation as a control group. Group 2 and 3 as test groups were exposed to MILNS with energy of 8J and 6J on rabbits' dorsal side once a week, respectively. Skin density of rabbits was measured every 12 hours by using an ultrasound skin scanner.

  16. Anomalous Triple Gauge Couplings in the Effective Field Theory Approach at the LHC

    CERN Document Server

    Falkowski, Adam; Greljo, Admir; Marzocca, David; Son, Minho

    2016-01-01

    We discuss how to perform consistent extractions of anomalous triple gauge couplings (aTGC) from electroweak boson pair production at the LHC in the Standard Model Effective Field Theory (SMEFT). After recasting recent ATLAS and CMS searches in $pp\\to WZ (WW) \\to \\ell' \

  17. Anomalous Hall effects in pseudo-single-crystal γ'-Fe4N thin films

    Science.gov (United States)

    Kabara, Kazuki; Tsunoda, Masakiyo; Kokado, Satoshi

    2016-05-01

    The anomalous Hall effects (AHE) were investigated at various temperatures for the pseudo-single-crystal Fe4N films, deposited on MgO substrates with changing the degree of order (S) of the nitrogen site. Both the anomalous Hall resistivity and the longitudinal resistivity simply decrease with lowering temperature for all the specimens. The AHE of the Fe4N films is presumed to arise from an intrinsic mechanism because of the relationship between the anomalous Hall resistivity and longitudinal resistivity. The anomalous Hall conductivity, σAH, exhibits a specific behavior at low temperature. In the case of the film with S = 0.93, the σAH drastically drops below 50 K, while it simply increases with lowering temperature in the range of 50-300 K. This low-temperature anomaly decays with decreasing S of the film and nearly vanishes in the films with low S. The threshold temperature and the dependence on S of the low-temperature anomaly of the σAH well correspond to those of the anisotropic magnetoresistance effects in the Fe4N films, reported in the literatures. From these results, it is suggested that the low-temperature anomaly of the σAH originates from the crystal field effect which reflects the structural transformation from a cubic to a tetragonal symmetry below 50 K and provides a modulation of the orbital angular momentum of the 3d orbitals at the Fermi level.

  18. Temperature, pressure, and compositional effects on anomalous or "self" preservation of gas hydrates

    Science.gov (United States)

    Stern, L.A.; Circone, S.; Kirby, S.H.; Durham, W.B.

    2003-01-01

    We previously reported on a thermal regime where pure, polycrystalline methane hydrate is preserved metastably in bulk at up to 75 K above its nominal temperature stability limit of 193 K at 0.1 MPa, following rapid release of the sample pore pressure. Large fractions (>50 vol.%) of methane hydrate can be preserved for 2-3 weeks by this method, reflecting the greatly suppressed rates of dissociation that characterize this "anomalous preservation" regime. This behavior contrasts that exhibited by methane hydrate at both colder (193-240 K) and warmer (272-290 K) isothermal test conditions, where dissociation rates increase monotonically with increasing temperature. Here, we report on recent experiments that further investigate the effects of temperature, pressure, and composition on anomalous preservation behavior. All tests conducted on sI methane hydrate yielded self-consistent results that confirm the highly temperature-sensitive but reproducible nature of anomalous preservation behavior. Temperature-stepping experiments conducted between 250 and 268 K corroborate the relative rates measured previously in isothermal preservation tests, and elevated pore-pressure tests showed that, as expected, dissociation rates are further reduced with increasing pressure. Surprisingly, sII methane-ethane hydrate was found to exhibit no comparable preservation effect when rapidly depressurized at 268 K, even though it is thermodynamically stable at higher temperatures and lower pressures than sI methane hydrate. These results, coupled with SEM imaging of quenched sample material from a variety of dissociation tests, strongly support our earlier arguments that ice-"shielding" effects provided by partial dissociation along hydrate grain surfaces do not serve as the primary mechanism for anomalous preservation. The underlying physical-chemistry mechanism(s) of anomalous preservation remains elusive, but appears to be based more on textural or morphological changes within the hydrate

  19. Higgs mechanism in three-dimensional topological superconductors and anomalous Hall effect in zero magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Flavio; Eremin, Ilya [Theoretische Physik III, Ruhr-Universitaet Bochum (Germany)

    2015-07-01

    We discuss the peculiar nature of Higgs mechanism in an effective field theory for three-dimensional topological superconductors. The effective theory features two order parameters associated to the two chiral fermion species in the system. The resulting electrodynamics of such a topological superconductor exhibits a topological magnetoelectric effect with an axion field given by the phase difference of the order parameters. As consequence, the London regime is highly non-linear and anomalous Hall effect in the absence of an external magnetic field occurs. In this anomalous Hall effect the generated current transverse to an applied electric field changes sign with the temperature. We also discuss the scaling behavior of the penetration depth near the transition temperature, which is also shown to exhibit a scaling exponent that is crucially influenced by the axion term, varying continuously as function of the average phase difference.

  20. Effects of thermal water on skin regeneration.

    Science.gov (United States)

    Faga, Angela; Nicoletti, Giovanni; Gregotti, Cesarina; Finotti, Valentina; Nitto, Agnese; Gioglio, Luciana

    2012-05-01

    An experimental study was carried out in an animal (New Zealand white rabbit) wound model to evaluate any effects of a hypotonic, bicarbonate-calcium-magnesium mineral water (Comano thermal water) on skin regeneration, comparing the healing rate of split-thickness skin graft donor sites treated with the thermal water wet dressing versus a standard petrolatum gauze dressing versus a saline solution wet dressing. The study was performed in two steps; an overall of 22 animals were enrolled in the study. The wound healing progress was evaluated both by the surgeons and by the histologists. Sixty-four punch biopsies were examined in all. The histological samples were examined after staining with haematoxylin and eosin, Masson's and orcein staining and under a transmission electron microscope. The data were statistically analysed. The Comano thermal water proved to improve skin regeneration, not only by increasing keratinocyte proliferation and migration but also favourably modulating the regenerated collagen and elastic fibres in the dermis. We propose that the results of the topical treatment with the thermal water could be due to the favourable combination of a local wet environment with an anti-inflammatory action and that the regenerative properties of Comano thermal water observed in rabbits could also be applied for human use.

  1. Quantum anomalous Hall effect and tunable topological states in 3d transition metals doped silicene.

    Science.gov (United States)

    Zhang, Xiao-Long; Liu, Lan-Feng; Liu, Wu-Ming

    2013-10-09

    Silicene is an intriguing 2D topological material which is closely analogous to graphene but with stronger spin orbit coupling effect and natural compatibility with current silicon-based electronics industry. Here we demonstrate that silicene decorated with certain 3d transition metals (Vanadium) can sustain a stable quantum anomalous Hall effect using both analytical model and first-principles Wannier interpolation. We also predict the quantum valley Hall effect and electrically tunable topological states could be realized in certain transition metal doped silicene where the energy band inversion occurs. Our findings provide new scheme for the realization of quantum anomalous Hall effect and platform for electrically controllable topological states which are highly desirable for future nanoelectronics and spintronics application.

  2. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O.; Valentí, Roser

    2016-05-01

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions.

  3. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators.

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O; Valentí, Roser

    2016-05-17

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions.

  4. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O.; Valentí, Roser

    2016-01-01

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions. PMID:27185665

  5. Anomalous Effects of Driving Field Linewidth on a One-Atom Dressed-State Laser

    Institute of Scientific and Technical Information of China (English)

    YANG Jin-Jin; Hu Xiang-Ming

    2007-01-01

    We examine the effects of driving Geld linewidth on a one-atom dressed state laser. Unexpectedly, the linewidth leads to anomalous effects on the cavity Geld. The mean photon number of the cavity Geld is raised or the normalized variance is reduced to a certain degree as the linewidth increases for an appropriate range of parameters. The responsible mechanism is attributed to the fluctuation-induced modification of the electromagnetic reservoir where the atom stays.

  6. Pharmaceutical effect of contraceptive pills on the skin.

    Science.gov (United States)

    Foldes, E G

    1988-07-01

    Described are the various effects of birth control methods on the skin-mainly those of the contraceptive pill. The equilibrium of healthy skins and mucosa might be affected by these chemicals or pharmaceutical agents, causing different manifestations. The skin and mucosa should be looked upon as integral parts of the human body and its functions even where localized symptoms arise.

  7. Adverse and beneficial effects of plant extracts on skin and skin disorders.

    Science.gov (United States)

    Mantle, D; Gok, M A; Lennard, T W

    2001-06-01

    Plants are of relevance to dermatology for both their adverse and beneficial effects on skin and skin disorders respectively. Virtually all cultures worldwide have relied historically, or continue to rely on medicinal plants for primary health care. Approximately one-third of all traditional medicines are for treatment of wounds or skin disorders, compared to only 1-3% of modern drugs. The use of such medicinal plant extracts for the treatment of skin disorders arguably has been based largely on historical/anecdotal evidence, since there has been relatively little data available in the scientific literature, particularly with regard to the efficacy of plant extracts in controlled clinical trials. In this article therefore, adverse and beneficial aspects of medicinal plants relating to skin and skin disorders have been reviewed, based on recently available information from the peer-reviewed scientific literature. Beneficial aspects of medicinal plants on skin include: healing of wounds and burn injuries (especially Aloe vera); antifungal, antiviral, antibacterial and acaricidal activity against skin infections such as acne, herpes and scabies (especially tea tree (Melaleuca alternifolia) oil); activity against inflammatory/immune disorders affecting skin (e.g. psoriasis); and anti-tumour promoting activity against skin cancer (identified using chemically-induced two-stage carcinogenesis in mice). Adverse effects of plants on skin reviewed include: irritant contact dermatitis caused mechanically (spines, irritant hairs) or by irritant chemicals in plant sap (especially members of the Ranunculaceae, Euphorbiaceae and Compositae plant families); phytophotodermatitis resulting from skin contamination by plants containing furocoumarins, and subsequent exposure to UV light (notably members of the Umbelliferae and Rutaceae plant families); and immediate (type I) or delayed hypersensitivity contact reactions mediated by the immune system in individuals sensitized to plants

  8. Anomalous Quantum Hall Effect of 4D Graphene in Background Fields

    CERN Document Server

    Drissi, L B; Saidi, E H

    2011-01-01

    Bori\\c{c}i-Creutz (BC) model describing the dynamics of light quarks in lattice QCD has been shown to be intimately linked to the four dimensional extension of 2D graphene refereed below to as four dimensional graphene (4D- graphene). Borrowing ideas from the field theory description of the usual 2D graphene, we study in this paper the anomalous quantum Hall effect (AQHE) of the BC fermions in presence of a constant background electromagnetic field strength F_{{\\mu}{\

  9. Semiclassical origin of anomalous shell effect for tetrahedral deformation in radial power-law potential model

    CERN Document Server

    Arita, Ken-ichiro

    2014-01-01

    Shell structures in single-particle energy spectra are investigated against regular tetrahedral type deformation using radial power-law potential model. Employing a natural way of shape parametrization which interpolate sphere and regular tetrahedron, we find prominent shell effects at rather large tetrahedral deformations, which bring about shell energies much larger than the cases of spherical and quadrupole type shapes. We discuss the semiclassical origin of these anomalous shell structures using periodic orbit theory.

  10. Giant Anomalous Hall Effect in the Chiral Antiferromagnet Mn3Ge

    Science.gov (United States)

    Kiyohara, Naoki; Tomita, Takahiro; Nakatsuji, Satoru

    2016-06-01

    The external field control of antiferromagnetism is a significant subject both for basic science and technological applications. As a useful macroscopic response to detect magnetic states, the anomalous Hall effect (AHE) is known for ferromagnets, but it has never been observed in antiferromagnets until the recent discovery in Mn3Sn . Here we report another example of the AHE in a related antiferromagnet, namely, in the hexagonal chiral antiferromagnet Mn3Ge . Our single-crystal study reveals that Mn3Ge exhibits a giant anomalous Hall conductivity |σx z|˜60 Ω-1 cm-1 at room temperature and approximately 380 Ω-1 cm-1 at 5 K in zero field, reaching nearly half of the value expected for the quantum Hall effect per atomic layer with Chern number of unity. Our detailed analyses on the anisotropic Hall conductivity indicate that in comparison with the in-plane-field components |σx z| and |σz y|, which are very large and nearly comparable in size, we find |σy x| obtained in the field along the c axis to be much smaller. The anomalous Hall effect shows a sign reversal with the rotation of a small magnetic field less than 0.1 T. The soft response of the AHE to magnetic field should be useful for applications, for example, to develop switching and memory devices based on antiferromagnets.

  11. Anomalous effective action, Noether current, Virasoro algebra and Horizon entropy

    Energy Technology Data Exchange (ETDEWEB)

    Majhi, Bibhas Ranjan [IUCAA, Ganeshkhind, Pune University Campus, Post Bag 4, Pune (India); Hebrew University of Jerusalem, Racah Institute of Physics, Jerusalem (Israel); Chakraborty, Sumanta [IUCAA, Ganeshkhind, Pune University Campus, Post Bag 4, Pune (India)

    2014-05-15

    Several investigations show that in a very small length scale there exist corrections to the entropy of black hole horizon. Due to fluctuations of the background metric and the external fields the action incorporates corrections. In the low energy regime, the one-loop effective action in four dimensions leads to trace anomaly. We start from the Noether current corresponding to the Einstein-Hilbert plus the one-loop effective action to calculate the charge for the diffeomorphisms which preserve the Killing horizon structure. Then a bracket for the charges is calculated. We show that the Fourier modes of the bracket are exactly similar to the Virasoro algebra. Then using the Cardy formula the entropy is evaluated. Finally, the explicit terms of the entropy expression is calculated for a classical background. It turns out that the usual expression for the entropy; i.e. the Bekenstein-Hawking form, is not modified. (orig.)

  12. Anomalous piezoelectric effects, found in the laboratory and reconstructed by numerical simulation

    Directory of Open Access Journals (Sweden)

    K. P. Teisseyre

    2002-06-01

    Full Text Available Various rocks and minerals, which are not piezoelectric in the common sense, exhibit transient electric polarization in response to sudden changes in stress load. This anomalous piezoelectric effect differs from the regular, static piezoelectric response, in which electric charges appear as a result of crystal lattice deformation. The anomalous piezoelectricity is dynamic decaying in a few seconds or a few tens of seconds. However, in some materials different polarization properties are discovered. To explain certain aspects of the polarization signal increase and decay, some complicated mechanisms of electric charge generation and relaxation need to be assumed in their number ? concurrence of two or three relaxation processes. The hypothetical mechanisms are only mentioned, as the purpose of this work is to construct numerical models, behaving like the rocks investigated. Examples of experimental plots are shown together with the results of the numerical simulation of these experiments.

  13. [Effect of an anomalous broadening of the synchronization band after electric stimulation of heart tissues].

    Science.gov (United States)

    Mazurov, M E

    1987-01-01

    Synchronization effects of the second order induced by a change of the action potential (AP) shape in relation to the frequency of periodic stimulation were studied. Mechanism of anomalous increase of the synchronization band at periodic stimulation of the heart fibers was explained. By means of a modified method of synchronization diagrams the synchronization bands were calculated for possible stimulation regimes taking into account a change in RP shape and dynamic threshold (DT) depending on the frequency of the initiated regimes. Regions of stimulating signals parameters (multiplicity regions or prolonging regions) were discovered, within the range of which the same stimulating signal may induce different synchronization regimes. Physiological meaning of the existence of anomalous synchronization regimes which significantly broaden the adaptation possibilities of the heart is discussed.

  14. Enhancement of perpendicular magnetic anisotropy and anomalous hall effect in Co/Ni multilayers

    Science.gov (United States)

    Liu, Yiwei; Zhang, Jingyan; Jiang, Shaolong; Liu, Qianqian; Li, Xujing; Yu, Guanghua

    2016-12-01

    The perpendicular magnetic anisotropy (PMA) and the anomalous Hall effect (AHE) in Co/Ni multilayer were optimized by manipulating its interface structure (inducing HfO2 capping layer and Pt insertion) and post-annealing treatment. A strong PMA can be obtained in Co/Ni multilayers with HfO2 capping layer even after annealing at 400 °C. The heavy metal Hf may improve the interfacial spin-orbit coupling, which responsible for the enhanced PMA and high annealing stability. Moreover, the multilayer containing HfO2 capping layer also exhibited high saturation anomalous Hall resistivity through post-annealing, which is 0.85 μΩ cm after annealing at 375 °C, 211% larger than in the sample at deposited state which is only 0.27 μΩ cm. The enhancement of AHE is mainly attributed to the interface scattering through post-annealing treatment.

  15. Prediction of near-room-temperature quantum anomalous Hall effect on honeycomb materials.

    Science.gov (United States)

    Wu, Shu-Chun; Shan, Guangcun; Yan, Binghai

    2014-12-19

    Recently, the long-sough quantum anomalous Hall effect was realized in a magnetic topological insulator. However, the requirement of an extremely low temperature (approximately 30 mK) hinders realistic applications. Based on ab initio band structure calculations, we propose a quantum anomalous Hall platform with a large energy gap of 0.34 and 0.06 eV on honeycomb lattices comprised of Sn and Ge, respectively. The ferromagnetic (FM) order forms in one sublattice of the honeycomb structure by controlling the surface functionalization rather than dilute magnetic doping, which is expected to be visualized by spin polarized STM in experiment. Strong coupling between the inherent quantum spin Hall state and ferromagnetism results in considerable exchange splitting and, consequently, an FM insulator with a large energy gap. The estimated mean-field Curie temperature is 243 and 509 K for Sn and Ge lattices, respectively. The large energy gap and high Curie temperature indicate the feasibility of the quantum anomalous Hall effect in the near-room-temperature and even room-temperature regions.

  16. Large anomalous Hall effect driven by a nonvanishing Berry curvature in the noncolinear antiferromagnet Mn3Ge.

    Science.gov (United States)

    Nayak, Ajaya K; Fischer, Julia Erika; Sun, Yan; Yan, Binghai; Karel, Julie; Komarek, Alexander C; Shekhar, Chandra; Kumar, Nitesh; Schnelle, Walter; Kübler, Jürgen; Felser, Claudia; Parkin, Stuart S P

    2016-04-01

    It is well established that the anomalous Hall effect displayed by a ferromagnet scales with its magnetization. Therefore, an antiferromagnet that has no net magnetization should exhibit no anomalous Hall effect. We show that the noncolinear triangular antiferromagnet Mn3Ge exhibits a large anomalous Hall effect comparable to that of ferromagnetic metals; the magnitude of the anomalous conductivity is ~500 (ohm·cm)(-1) at 2 K and ~50 (ohm·cm)(-1) at room temperature. The angular dependence of the anomalous Hall effect measurements confirms that the small residual in-plane magnetic moment has no role in the observed effect except to control the chirality of the spin triangular structure. Our theoretical calculations demonstrate that the large anomalous Hall effect in Mn3Ge originates from a nonvanishing Berry curvature that arises from the chiral spin structure, and that also results in a large spin Hall effect of 1100 (ħ/e) (ohm·cm)(-1), comparable to that of platinum. The present results pave the way toward the realization of room temperature antiferromagnetic spintronics and spin Hall effect-based data storage devices.

  17. Origin of enhanced anomalous Hall effect in ultrathin Pt/permalloy bilayers

    Directory of Open Access Journals (Sweden)

    Y. Q. Zhang

    2016-02-01

    Full Text Available There are two mechanisms which could enhance spin-dependent scattering in a low dimensional Pt/Ferromagnetic metal structure. One is magnetic proximity effect. The other is spin orbit coupling proximity effect which was suggested recently. This work demonstrates that, through a series of experiments on anomalous Hall effect, the spin orbit coupling proximity effect dominates the enhancement in very thin Pt/Permalloy bilayers. It may help to find a way to optimize magnetic transport property of spintronics devices in which the spin orbit coupling is deeply involved.

  18. Anomalous Response in Heteroacene-Based Organic Field Effect Transistors under High Pressure

    Directory of Open Access Journals (Sweden)

    Ken-ichi Sakai

    2014-04-01

    Full Text Available Carrier transport properties of organic field effect transistors in dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene single crystals have been investigated under high pressure. In contrast to the typical pressure effect of monotonic increase in charge transfer rates according to the application of external hydrostatic pressure, it is clarified that the present organic semiconductor devices exhibit nonmonotonic pressure response, such as negative pressure effect. X-ray diffraction analysis under high pressure reveals that on-site molecular orientation and displacement in the heteroacene molecule is assumed to be the origin for the anomalous pressure effects.

  19. Anomalous coupling, top-mass and parton-shower effects in W + W - production

    Science.gov (United States)

    Bellm, J.; Gieseke, S.; Greiner, N.; Heinrich, G.; Plätzer, S.; Reuschle, C.; von Soden-Fraunhofen, J. F.

    2016-05-01

    We calculate the process ppto {W}+{W}-to {e}+{ν}_e{μ}-{overline{ν}}_{μ } at NLO QCD, including also effective field theory (EFT) operators mediating the ggW + W - interaction, which first occur at dimension eight. We further combine the NLO and EFT matrix elements produced by G oS am with the H erwig7/M atchbox framework, which offers the possibility to study the impact of a parton shower. We assess the effects of the anomalous couplings by comparing them to top-mass effects as well as uncertainties related to variations of the renormalisation, factorisation and hard shower scales.

  20. When effective theories predict: the inevitability of Mercury's anomalous perihelion precession

    CERN Document Server

    Wells, James D

    2012-01-01

    If the concepts underlying Effective Theory were appreciated from the earliest days of Newtonian gravity, Le Verrier's announcement in 1845 of the anomalous perihelion precession of Mercury would have been no surprise. Furthermore, the size of the effect could have been anticipated through "naturalness" arguments well before the definitive computation in General Relativity. Thus, we have an illustration of how Effective Theory concepts can guide us in extending our knowledge to "new physics", and not just in how to reduce larger theories to restricted (e.g., lower energy) domains.

  1. Absence of the Thermal Hall Effect in Anomalous Nernst and Spin Seebeck Effects

    Science.gov (United States)

    Chen, Yi-Jia; Huang, Ssu-Yen

    2016-12-01

    The anomalous Nernst effect (ANE) and the spin Seebeck effect (SSE) in spin caloritronics are two of the most important mechanisms to manipulate the spin-polarized current and pure spin current by thermal excitation. While the ANE in ferromagnetic metals and the SSE in magnetic insulators have been extensively studied, a recent theoretical work suggests that the signals from the thermal Hall effect (THE) have field dependences indistinguishable from, and may even overwhelm, those of the ANE and SSE. Therefore, it is vital to investigate the contribution of the THE in the ANE and SSE. In this work, we systematically study the THE in a ferromagnetic metal, Permalloy (Py), and magnetic insulator, an yttrium iron garnet (YIG), by using different Seebeck coefficients between electrodes and contact wires. Our results demonstrate that the contribution of the THE by the thermal couple effect in the Py and YIG is negligibly small if one includes the thickness dependence of the Seebeck coefficient. Thus, the spin-polarized current in the ANE and the pure spin current in the SSE remain indispensable for exploring spin caloritronics phenomena.

  2. Effect of extended confinement on the structure of edge channels in the quantum anomalous Hall effect

    Science.gov (United States)

    Yue, Z.; Raikh, M. E.

    2016-09-01

    The Quantum anomalous Hall (QAH) effect in the films with nontrivial band structure accompanies the ferromagnetic transition in the system of magnetic dopants. Experimentally, the QAH transition manifests itself as a jump in the dependence of longitudinal resistivity on a weak external magnetic field. Microscopically, this jump originates from the emergence of a chiral edge mode on one side of the ferromagnetic transition. We study analytically the effect of an extended confinement on the structure of the edge modes. We employ the simplest model of the extended confinement in the form of a potential step next to the hard wall. It is shown that, unlike the conventional quantum Hall effect, where all edge channels are chiral, in the QAH effect, a complex structure of the boundary leads to nonchiral edge modes which are present on both sides of the ferromagnetic transition. Wave functions of nonchiral modes are different above and below the transition: on the "topological" side, where the chiral edge mode is supported, nonchiral modes are "repelled" from the boundary; i.e., they are much less localized than on the "trivial" side. Thus, the disorder-induced scattering into these modes will boost the extension of the chiral edge mode. The prime experimental manifestation of nonchiral modes is that, by contributing to longitudinal resistance, they smear the QAH transition.

  3. Relation between the structure and catalytic activity for automotive emissions. Use of x-ray anomalous dispersion effect

    CERN Document Server

    Mizuki, J; Tanaka, H

    2003-01-01

    The employment of the X-ray anomalous dispersion effect allows us to detect the change in structure of catalytic converters with the environment exposed. Here we show that palladium atoms in a perovskite crystal move into and out of the crystal by anomalous X-ray diffraction and absorption techniques. This movement of the precious metal plays an important role to keep the catalytic activity long-lived. (author)

  4. Effect of anomalous vertex on decay-lepton distributions in + -→ t\\overline{t}$ and CP-violating asymmetries

    Indian Academy of Sciences (India)

    Saurabh D Rindani

    2000-06-01

    We obtain analytic expressions for the energy and polar-angle double differential distributions of a secondary lepton +(-) arising from the decay of ($\\overline{t}$) in + - → $t\\overline{t}$ with an anomalous decay vertex. We also obtain analytic expressions for the various differential cross-sections with the lepton energy integrat ed over. In this case, we find that the angular distributions of the secondary lepton do not depend on the anomalous coupling in the decay, regardless of possible anomalous couplings occurring in the production amplitude for + - → $t\\overline{t}$. Our study includes the effect of longitudinal - and + beam polarization. We also study the lepton energy and beam polarization dependence of certain CP-violating lepton angular asymmetries arising from an anomalous decay vertex and compare them with the asymmetries arising due to CP-violation in the production process due to the top electric or weak dipole moment.

  5. Stacking order dependence of inverse spin Hall effect and anomalous Hall effect in spin pumping experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Il; Seo, Min-Su; Park, Seung-Young, E-mail: parksy@kbsi.re.kr [Division of Materials Science, Korea Basic Science Institute, Daejeon 305-806 (Korea, Republic of); Kim, Dong-Jun; Park, Byong-Guk [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2015-05-07

    The dependence of the measured DC voltage on the non-magnetic material (NM) in NM/CoFeB and CoFeB/NM bilayers is studied under ferromagnetic resonance conditions in a TE{sub 011} resonant cavity. The directional change of the inverse spin Hall effect (ISHE) voltage V{sub ISHE} for the stacking order of the bilayer can separate the pure V{sub ISHE} and the anomalous Hall effect (AHE) voltage V{sub AHE} utilizing the method of addition and subtraction. The Ta and Ti NMs show a broad deviation of the spin Hall angle θ{sub ISH}, which originates from the AHE in accordance with the high resistivity of NMs. However, the Pt and Pd NMs show that the kinds of NMs with low resistivity are consistent with the previously reported θ{sub ISH} values. Therefore, the characteristics that NM should simultaneously satisfy to obtain a reasonable V{sub ISHE} value in bilayer systems are large θ{sub ISH} and low resistivity.

  6. From magnetically doped topological insulator to the quantum anomalous Hall effect

    Institute of Scientific and Technical Information of China (English)

    He Ke; Ma Xu-Cun; Chen Xi; Lü Li; Wang Ya-Yu; Xue Qi-Kun

    2013-01-01

    Quantum Hall effect (QHE),as a class of quantum phenomena that occur in macroscopic scale,is one of the most important topics in condensed matter physics.It has long been expected that QHE may occur without Landau levels so that neither extemal magnetic field nor high sample mobility is required for its study and application.Such a QHE free of Landau levels,can appear in topological insulators (TIs) with ferromagnetism as the quantized version of the anomalous Hall effect,i.e.,quantum anomalous Hall (QAH) effect.Here we review our recent work on experimental realization of the QAH effect in magnetically doped TIs.With molecular beam epitaxy,we prepare thin films of Cr-doped (Bi,Sb)2Te3 TIs with wellcontrolled chemical potential and long-range ferromagnetic order that can survive the insulating phase.In such thin films,we eventually observed the quantization of the Hall resistance at h/e2 at zero field,accompanied by a considerable drop in the longitudinal resistance.Under a strong magnetic field,the longitudinal resistance vanishes,whereas the Hall resistance remains at the quantized value.The realization of the QAH effect provides a foundation for many other novel quantum phenomena predicted in TIs,and opens a route to practical applications of quantum Hall physics in low-power-consumption electronics.

  7. Comparison of anomalous Doppler resonance effects with molybdenum and graphite limiters on HT-7.

    Science.gov (United States)

    Wang, Y M; Gao, X; Ling, B L; Liu, Y; Zhang, S B; Han, X; Ti, A; Li, E Z

    2012-03-01

    The material of limiter in HT-7 tokamak was changed from graphite to molybdenum in the last experimental campaign. The pitch angle scattering of runaway electrons due to anomalous Doppler resonance effects was observed. The experimental results agree very well with the stable boundary condition expected from the linear resistive theory but only agree with that from the nonlinear evolutionary of runaway-electron distribution theory in low electric field region. The current carried by runaway electrons is the same under different limiter conditions.

  8. Anomalous Hall effect of heavy holes in Ⅲ-Ⅴ semiconductor quantum wells

    Institute of Scientific and Technical Information of China (English)

    Wang Zhi-Gang; Zhang Ping

    2007-01-01

    The anomalous Hall effect of heavy holes in semiconductor quantum wells is studied in the intrinsic transport regime, where the Berry curvature governs the Hall current properties. Based on the first-order perturbation of wave function the expression of the Hall conductivity the same as that from the semiclassical equation of motion of the Bloch particles is derived. The dependence of Hall conductivity on the system parameters is shown. The amplitude of Hall conductivity is found to be balanced by a competition between the Zeeman splitting and the spin-orbit splitting.

  9. Measurement of Nonadiabatic Effects in Ultracold Molecules via Anomalous Linear and Quadratic Zeeman Shifts

    CERN Document Server

    McGuyer, B H; McDonald, M; Reinaudi, G; Skomorowski, W; Moszynski, R; Zelevinsky, T

    2013-01-01

    Anomalously large linear and quadratic Zeeman shifts are measured for weakly bound ultracold $^{88}$Sr$_2$ molecules near the intercombination line asymptote. Nonadiabatic Coriolis coupling and the nature of long-range molecular potentials explain how this effect arises and scales roughly cubically with the size of the molecule. The linear shifts yield nonadiabatic mixing angles of the molecular states. The quadratic shifts are sensitive to fourth-order contributions and to nearby opposite $f$-parity states, and provide a stringent test of a state-of-the-art ab initio model.

  10. Anomalous transport model study of chiral magnetic effects in heavy ion collisions

    CERN Document Server

    Sun, Yifeng; Li, Feng

    2016-01-01

    Using an anomalous transport model for massless quarks, we study the effect of magnetic field on the elliptic flows of quarks and antiquarks in relativistic heavy ion collisions. With initial conditions from a blast wave model and assuming that the strong magnetic field produced in non-central heavy ion collisions can last for a sufficiently long time, we obtain an appreciable electric quadrupole moment in the transverse plane of a heavy ion collision, which subsequently leads to a splitting between the elliptic flows of quarks and antiquarks as expected from the chiral magnetic wave formed in the produced QGP and observed in experiments at the Relativistic Heavy Ion Collider (RHIC).

  11. The giant anomalous Hall effect in the ferromagnet Fe3Sn2--a frustrated kagome metal.

    Science.gov (United States)

    Kida, T; Fenner, L A; Dee, A A; Terasaki, I; Hagiwara, M; Wills, A S

    2011-03-23

    The kagome-bilayer material Fe(3)Sn(2) has recently been shown to be an example of a rare class of magnet-a frustrated ferromagnetic metal. While the magnetism of Fe(3)Sn(2) appears to be relatively simple at high temperature, with localized moments parallel to the c-axis (T(C) = 640 K), upon cooling the competing exchange interactions and spin frustration become apparent as they cause the moments to become non-collinear and to rotate towards the kagome plane, forming firstly a canted ferromagnetic structure and then a re-entrant spin glass (T(f) approximately equal 80 K). In this work we show that Fe(3)Sn(2) possesses an unusual anomalous Hall effect. The saturated Hall resistivity of Fe(3)Sn(2) is 3.2 µΩ cm at 300 K, almost 20 times higher than that of typical itinerant ferromagnets such as Fe and Ni. The anomalous Hall coefficient R(s) is 6.7 × 10(-9) Ω cm G(-1) at 300 K, which is three orders of magnitude larger than that of pure Fe, and obeys an unconventional scaling with the longitudinal resistivity, ρ(xx), of R(s) is proportional to ρ(xx)(3.15). Such a relationship cannot be explained by either the conventional skew or side-jump mechanisms, indicating that the anomalous Hall effect in Fe(3)Sn(2) has an extraordinary origin that is presumed to be related to the underlying frustration of the magnetism. These findings demonstrate that frustrated ferromagnets, whether based on bulk materials or on artificial nanoscale structures, can provide new routes to room temperature spin-dependent electron transport properties suited to application in spintronics.

  12. The framing effect and skin conductance responses

    Directory of Open Access Journals (Sweden)

    Patrick eRing

    2015-08-01

    Full Text Available Individuals often rely on simple heuristics when they face complex choice situations under uncertainty. Traditionally, it has been proposed that cognitive processes are the main driver to evaluate different choice options and finally to reach a decision. Growing evidence, however, highlights a strong interrelation between judgment and decision-making (JDM on the one hand, and emotional processes on the other hand. This also seems to apply to judgmental heuristics, i.e. decision-processes that are typically considered to be fast and intuitive. In this study, participants are exposed to different probabilities of receiving an unpleasant electric shock. Information about electric shock probabilities is either positively or negatively framed. Integrated skin conductance responses (ISCRs while waiting for electric shock realization are used as an indicator for participants' emotional arousal. This measure is compared to objective probabilities. I find evidence for a relation between emotional body reactions measured by ISCRs and the framing effect. Under negative frames, participants show significantly higher ISCRs while waiting for an electric shock to be delivered than under positive frames. This result might contribute to a better understanding of the psychological processes underlying JDM. Further studies are necessary to reveal the causality underlying this finding, i.e. whether emotional processes influence JDM or vice versa.

  13. The framing effect and skin conductance responses.

    Science.gov (United States)

    Ring, Patrick

    2015-01-01

    Individuals often rely on simple heuristics when they face complex choice situations under uncertainty. Traditionally, it has been proposed that cognitive processes are the main driver to evaluate different choice options and to finally reach a decision. Growing evidence, however, highlights a strong interrelation between judgment and decision-making (JDM) on the one hand, and emotional processes on the other hand. This also seems to apply to judgmental heuristics, i.e., decision processes that are typically considered to be fast and intuitive. In this study, participants are exposed to different probabilities of receiving an unpleasant electric shock. Information about electric shock probabilities is either positively or negatively framed. Integrated skin conductance responses (ISCRs) while waiting for electric shock realization are used as an indicator for participants' emotional arousal. This measure is compared to objective probabilities. I find evidence for a relation between emotional body reactions measured by ISCRs and the framing effect. Under negative frames, participants show significantly higher ISCRs while waiting for an electric shock to be delivered than under positive frames. This result might contribute to a better understanding of the psychological processes underlying JDM. Further studies are necessary to reveal the causality underlying this finding, i.e., whether emotional processes influence JDM or vice versa.

  14. Chemically manipulated anomalous Hall effect and perpendicular magnetic anisotropy in Co/Pt multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shao-Long; Chen, Xi; Zhang, Jing-Yan; Yang, Guang; Teng, Jiao; Li, Xu-Jing; Cao, Yi; Zhao, Zhi-Duo; Yang, Kang; Liu, Yang; Yu, Guang-Hua, E-mail: ghyu@mater.ustb.edu.cn

    2014-11-30

    Highlights: • We studied magnetic and electric transport properties of MgO/[Co/Pt]{sub 3}/Mg/MgO films • The chemical states at Co/MgO and Co/Mg interfaces were investigated by XPS. • Interface chemical states have strong influence on AHE and PMA in Co/Pt multilayers. - Abstract: Chemically manipulated anomalous Hall effect (AHE) and perpendicular magnetic anisotropy (PMA) have been studied in MgO/[Co/Pt]{sub 3}/MgO multilayers by introducing a Mg metal layer between the Co layer and the top MgO layer. It is shown that the saturation anomalous Hall resistivity (ρ{sub AH}) and effective magnetic anisotropy (K{sub eff}) are 125% and 26% larger than those in the multilayers without Mg insertion, respectively. The X-ray photoelectron spectroscopy (XPS) analysis shows that the enhancement of AHE and PMA is primarily ascribed to effective control of chemical states at the Co/MgO interface.

  15. Semiclassical wave packet study of anomalous isotope effect in ozone formation.

    Science.gov (United States)

    Vetoshkin, Evgeny; Babikov, Dmitri

    2007-10-21

    We applied the semiclassical initial value representation method to calculate energies, lifetimes, and wave functions of scattering resonances in a two-dimensional potential for O+O2 collision. Such scattering states represent the metastable O3* species and play a central role in the process of ozone formation. Autocorrelation functions for scattering states were computed and then analyzed using the Prony method, which permits one to extract accurate energies and widths of the resonances. We found that the results of the semiclassical wave packet propagation agree well with fully quantum results. The focus was on the 16O16O18O isotopomer and the anomalous isotope effect associated with formation of this molecule, either through the 16O16O+18O or the 16O+16O18O channels. An interesting correlation between the local vibration mode character of the metastable states and their lifetimes was observed and explained. New insight is obtained into the mechanism by which the long-lived resonances in the delta zero-point energy part of spectrum produce the anomalously large isotope effect.

  16. The anomalous exchange bias effect in core-shell Co/CoO nanoparticles

    Science.gov (United States)

    Feygenson, Mikhail; Yuen, Yiu; Kim, Kisub; Aronson, Meigan

    2008-03-01

    We study the anomalous exchange bias effect in Co/CoO nanoparticles by means of neutron and x-ray scattering and magnetic experiments. The Co nanoparticles were prepared in oleic acid by thermal decomposition of Co2(CO)8 and were subsequently oxidized. Co core- CoO shell nanoparticles with differing core and shell dimensions were obtained. The magnetic measurements indicated that there is an optimal ratio of the core and shell dimensions which maximizes the exchange bias field. Anomalous small angle x-ray scattering experiments using core-shell contrast and energy analysis provide high accuracy measurements of the core and shell, and their respective size distributions. Neutron diffraction measurements find that oxidation introduces a new modulation wave vector for the magnetization, leading to the increasing magnetic decompensation of the core-shell interface. It is our proposal that this interface moment enhances the exchange coupling of the core and shell, and leads to the extraordinarily large exchange bias effect.

  17. Anomalous Hall effect in the prospective spintronic material Eu1-x Gd x O integrated with Si.

    Science.gov (United States)

    Parfenov, Oleg E; Averyanov, Dmitry V; Tokmachev, Andrey M; Taldenkov, Alexander N; Storchak, Vyacheslav G

    2016-06-08

    Remarkable properties of EuO make it a versatile spintronic material. Despite numerous experimental and theoretical studies of EuO, little is known about the anomalous Hall effect in this ferromagnet. So far, the effect has not been observed in bulk EuO, though has been detected in EuO films with uncontrolled distribution of defects. In the present work doping is taken under control: epitaxial films of Gd-doped EuO are synthesized integrated with Si using molecular beam epitaxy and characterized with x-ray diffraction and magnetization measurements. Nanoscale transport studies reveal the anomalous Hall effect in the ferromagnetic region for samples with different Gd concentration. The saturated anomalous Hall effect conductivity value of 5.0 S·cm(-1) in Gd-doped EuO is more than an order of magnitude larger than those reported so far for Eu chalcogenides doped with anion vacancies.

  18. Magnetoresistance generated from charge-spin conversion by anomalous Hall effect in metallic ferromagnetic/nonmagnetic bilayers

    Science.gov (United States)

    Taniguchi, Tomohiro

    2016-11-01

    A theoretical formulation of magnetoresistance effect in a metallic ferromagnetic/nonmagnetic bilayer originated from the charge-spin conversion by the anomalous Hall effect is presented. Analytical expressions of the longitudinal and transverse resistivities in both nonmagnet and ferromagnet are obtained by solving the spin diffusion equation. The magnetoresistance generated from charge-spin conversion purely caused by the anomalous Hall effect in the ferromagnet is found to be proportional to the square of the spin polarizations in the ferromagnet and has fixed sign. We also find additional magnetoresistances in both nonmagnet and ferromagnet arising from the mixing of the spin Hall and anomalous Hall effects. The sign of this mixing resistance depends on those of the spin Hall angle in the nonmagnet and the spin polarizations of the ferromagnet.

  19. FALLOUT RADIATION: EFFECTS ON THE SKIN

    Energy Technology Data Exchange (ETDEWEB)

    Conard, R. A.; Cronkite, E. P.; Bond, V. P.

    1963-02-06

    Until recently it has been generally assumed that injury to the skin from ionizing radiation was not a serious hazard associated with the detonation of nuclear dcvices. However, in 1954 the importance of this hazard became apparent when widespread lesions of the skin developed in a large group of people accidentally exposed to fallout radiation in the Marshall Islands following the experimental detonation of a large nuclear device. The accident in the Marshall Islands affords an example of large numbers of lesions of the skin in human beings from the fallout. Studies have been documented and will be referred to frequently in this chapter. The possibility of such accidents must be considered seriously in view of the increasingly widespread use of radioisotopes.

  20. Calendula extract: effects on mechanical parameters of human skin.

    Science.gov (United States)

    Akhtar, Naveed; Zaman, Shahiq Uz; Khan, Barkat Ali; Amir, Muhammad Naeem; Ebrahimzadeh, Muhammad Ali

    2011-01-01

    The aim of this study was to evaluate the effects of newly formulated topical cream of Calendula officinalis extract on the mechanical parameters of the skin by using the cutometer. The Cutometer 580 MPA is a device that is designed to measure the mechanical properties of the skin in response to the application of negative pressure. This non-invasive method can be useful for objective and quantitative investigation of age related changes in skin, skin elasticity, skin fatigue, skin hydration, and evaluation of the effects of cosmetic and antiaging topical products. Two creams (base and formulation) were prepared for the study. Both the creams were applied to the cheeks of 21 healthy human volunteers for a period of eight weeks. Every individual was asked to come on week 1, 2, 3, 4, 5, 6, 7, and 8 and measurements were taken by using Cutometer MPA 580 every week. Different mechanical parameters of the skin measured by the cutometer were; R0, R1, R2, R5, R6, R7, and R8. These were then evaluated statistically to measure the effects produced by these creams. Using ANOVA, and t-test it was found that R0, and R6 were significant (p 0.05). The instrumental measurements produced by formulation reflected significant improvements in hydration and firmness of skin.

  1. CONVECTIVE DRYING OF CHERRY TOMATO: STUDY OF SKIN EFFECT

    Directory of Open Access Journals (Sweden)

    R. KHAMA

    2016-03-01

    Full Text Available A whole single cherry tomato was dried in a forced convective micro-dryer. The experiments were carried out at constant air velocity and humidity and temperatures of 50, 60, 70 °C. In order to study the effect of the skin, two sets of experiments were performed using a tomato with and without skin (easily removed. Shorter drying times were obtained when increasing drying temperatures as well as when removing sample skin. X-ray microtomography, a non-destructive 3D imaging technique was used to follow shrinkage of the samples. This phenomenon was introduced in the modelling part of this study. Analytical solutions of the Fick’law were used to determine the diffusion coefficient at the three temperatures studied, and then the activation energy was obtained through fitting the Arrhenius equation. The skin effect was clearly evidenced by showing that the mass transfer parameter values of an original tomato with skin were largely smaller than the one without skin. Indeed, the moisture effective diffusivity ranged from 2.56×10-11 to 7.67×10-11 m2·s-1 with activation energy of 50430 J·mol-1 for tomato with skin an ranged from 4.59×10-10 m2·s-1 to 6.73×10-10 m2·s-1 with activation energy of 17640 J.mol-1 for tomato without skin.

  2. Anomalous scaling in magnetohydrodynamic turbulence: Effects of anisotropy and compressibility in the kinematic approximation.

    Science.gov (United States)

    Antonov, N V; Kostenko, M M

    2015-11-01

    The field-theoretic renormalization group and the operator product expansion are applied to the model of passive vector (magnetic) field advected by a random turbulent velocity field. The latter is governed by the Navier-Stokes equation for compressible fluid, subject to external random force with the covariance ∝ δ(t-t')k(4-d-y), where d is the dimension of space and y is an arbitrary exponent. From physics viewpoints, the model describes magnetohydrodynamic turbulence in the so-called kinematic approximation, where the effects of the magnetic field on the dynamics of the fluid are neglected. The original stochastic problem is reformulated as a multiplicatively renormalizable field-theoretic model; the corresponding renormalization group equations possess an infrared attractive fixed point. It is shown that various correlation functions of the magnetic field and its powers demonstrate anomalous scaling behavior in the inertial-convective range already for small values of y. The corresponding anomalous exponents, identified with scaling (critical) dimensions of certain composite fields ("operators" in the quantum-field terminology), can be systematically calculated as series in y. The practical calculation is performed in the leading one-loop approximation, including exponents in anisotropic contributions. It should be emphasized that, in contrast to Gaussian ensembles with finite correlation time, the model and the perturbation theory presented here are manifestly Galilean covariant.

  3. Assessing the effects of timing irregularities on radio pulsars anomalous braking indices

    Science.gov (United States)

    Chukwude, A. E.; Chidi Odo, Finbarr

    2016-10-01

    We investigate the statistical effects of non-discrete timing irregularities on observed radio pulsar braking indices using correlations between the second derivative of the measured anomalous frequency (̈νobs) and some parameters that have been widely used to quantify pulsar timing fluctuations (the timing activity parameter (A), the amount of timing fluctuations absorbed by the cubic term (σR23) and a measure of pulsar rotational stability (σz)) in a large sample of 366 Jodrell Bank Observatory radio pulsars. The result demonstrates that anomalous braking indices are largely artifacts produced by aggregations of fluctuations that occur within or outside the pulsar system. For a subsample of 223 normal radio pulsars whose observed timing activity appeared consistent with instabilities in rotation of the underlying neutron stars (or timing noise) over timescales of ˜ 10 - 40 yr, |̈νobs| strongly correlates (with correlation coefficient |r| ˜ 0.80 - 0.90) with the pulsar timing activity parameters and spin-down properties. On the other hand, no meaningful correlations (r < 0.3) were found between ̈νobs and the timing activity diagnostics and spin-down parameters in the remaining 143 objects, whose timing activity appears significantly dominated by white noise fluctuations. The current result can be better understood if the timing noise in isolated pulsars originates from intrinsic spin-down processes of the underlying neutron stars, but white noise fluctuations largely arise from processes external to the pulsar system.

  4. Effects of Anomalous Tensor Couplings in BOs -(B-)Os Mixing

    Institute of Scientific and Technical Information of China (English)

    CHANG Qin; HAN Lin; YANG Ya-Dong

    2012-01-01

    Motivated by the recently observed anomalous large dimuon charge asymmetry in neutral B decays,we study the effects of the anomalous tensor couplings to pursue a possible solution.With the constraints from the observables φJ/(φ)(φ,f0)s,aSsl and ΔMs,the new physics parameter spaces are severely restricted.We find that the contributions induced by the color-singlet or the color-octet tensor operators are helpful to moderate the anomaly in BOs - (B-)Osmixing.Numerically,the observable aSsl could be enhanced by about two orders of magnitude by the contributionsof color-singlet or color-octet tensor operators with their respective nontrivial new weak phase φT1 =41° ± 35° orφs =-47° ± 33° and relevant strength parameters |gT1| =(2.89 ± 1.40) × 10-2 or |gT8| =(0.79 ± 0.34) × 10-2.However,due to the fact that the NP contributions are severely suppressed by the recent LHCb measurement for φJ/φ(φ,f0)s,our theoretical result of aSsl is still much smaller than the central value of the experimental data.

  5. QCD Dirac Spectrum at Finite Chemical Potential: Anomalous Effective Action, Berry Phase and Composite Fermions

    CERN Document Server

    Liu, Yizhuang

    2015-01-01

    We show that the QCD Dirac spectrum at finite chemical potential using a 2-matrix model in the spontaneously broken phase, is amenable to a generic 2-dimensional effective action on a curved eigenvalue manifold. The eigenvalues form a droplet with strong screening and non-linear plasmons. The droplet is threaded by a magnetic vortex which is at the origin of a Berry phase. The adiabatic transport in the droplet maps onto the one in the fractional quantum Hall effect, suggesting that composite fermions at half filling are Dirac particles. We use this observation to argue for two novel anomalous effects in the edge transport of composite fermions, and conversely on a novel contribution to the QCD quark condensate in a rotating frame.

  6. Anomalous photovoltaic effect in organic-inorganic hybrid perovskite solar cells

    Science.gov (United States)

    Yuan, Yongbo; Li, Tao; Wang, Qi; Xing, Jie; Gruverman, Alexei; Huang, Jinsong

    2017-01-01

    Organic-inorganic hybrid perovskites (OIHPs) have been demonstrated to be highly successful photovoltaic materials yielding very-high-efficiency solar cells. We report the room temperature observation of an anomalous photovoltaic (APV) effect in lateral structure OIHP devices manifested by the device’s open-circuit voltage (VOC) that is much larger than the bandgap of OIHPs. The persistent VOC is proportional to the electrode spacing, resembling that of ferroelectric photovoltaic devices. However, the APV effect in OIHP devices is not caused by ferroelectricity. The APV effect can be explained by the formation of tunneling junctions randomly dispersed in the polycrystalline films, which allows the accumulation of photovoltage at a macroscopic level. The formation of internal tunneling junctions as a result of ion migration is visualized with Kelvin probe force microscopy scanning. This observation points out a new avenue for the formation of large and continuously tunable VOC without being limited by the materials’ bandgap. PMID:28345043

  7. Anomalous DIBL Effect in Fully Depleted SOI MOSFETs Using Nanoscale Gate-Recessed Channel Process

    Directory of Open Access Journals (Sweden)

    Avi Karsenty

    2015-01-01

    Full Text Available Nanoscale Gate-Recessed Channel (GRC Fully Depleted- (FD- SOI MOSFET device with a silicon channel thickness (tSi as low as 2.2 nm was first tested at room temperature for functionality check and then tested at low temperature (77 K for I-V characterizations. In spite of its FD-SOI nanoscale thickness and long channel feature, the device has surprisingly exhibited a Drain-Induced Barrier Lowering (DIBL effect at RT. However, this effect was suppressed at 77 K. If the apparition of such anomalous effect can be explained by a parasitic short channel transistor located at the edges of the channel, its suppression is explained by the decrease of the potential barrier between the drain and the channel when lowering the temperature.

  8. Anomalous memory effect in the breakdown of low-pressure argon in a long discharge tube

    Energy Technology Data Exchange (ETDEWEB)

    Meshchanov, A. V.; Korshunov, A. N.; Ionikh, Yu. Z., E-mail: y.ionikh@spbu.ru [St. Petersburg State University (Russian Federation); Dyatko, N. A. [Troitsk Institute for Innovation and Fusion Research (Russian Federation)

    2015-08-15

    The characteristics of breakdown of argon in a long tube (with a gap length of 75 cm and diameter of 2.8 cm) at pressures of 1 and 5 Torr and stationary discharge currents of 5–40 mA were studied experimentally. The breakdown was initiated by paired positive voltage pulses with a rise rate of ∼10{sup 8}–10{sup 9} V/s and duration of ∼1–10 ms. The time interval between pairs was varied in the range of Τ ∼ 0.1–1 s, and that between pulses in a pair was varied from τ = 0.4 ms to ≈Τ/2. The aim of this work was to detect and study the so-called “anomalous memory effect” earlier observed in breakdown in nitrogen. The effect consists in the dynamic breakdown voltage in the second pulse in a pair being higher than in the first pulse (in contrast to the “normal” memory effect, in which the relation between the breakdown voltages is opposite). It is found that this effect is observed when the time interval between pairs of pulses is such that the first pulse in a pair is in the range of the normal memory effect of the preceding pair (under the given conditions, Τ ≈ 0.1–0.4 s). In this case, at τ ∼ 10 ms, the breakdown voltage of the second pulse is higher than the reduced breakdown voltage of the first pulse. Optical observations of the ionization wave preceding breakdown in a long tube show that, in the range of the anomalous memory effect and at smaller values of τ, no ionization wave is detected before breakdown in the second pulse. A qualitative interpretation of the experimental results is given.

  9. The formation of anomalous Hall effect depending on W atoms in ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Can, Musa Mutlu, E-mail: musamutlucan@gmail.com [Faculty of Engineering and Natural Sciences, Nanotechnology Research and Application Center, Sabancı University, Tuzla, 34956 İstanbul (Turkey); CNR-SPIN, Universitá di Napoli “Federico II”, Compl. Univ. di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Shah, S. Ismat [Department of Physics and Astronomy, Department of Material Science and Engineering, University of Delaware, Newark, DE 19716 (United States); Fırat, Tezer [Department of Physics Engineering, Hacettepe University, Beytepe 06800 Ankara (Turkey)

    2014-06-01

    This article investigates the effects of intrinsic point defects and extrinsic W atoms on magneto electrical properties in the ZnO lattice. The analyses were accomplished for ∼0.5% W including ZnO thin films, grown using a radio frequency (RF) magnetron sputtering system. The polarized spin current dependent magnetic formation was investigated by longitudinal and transverse magneto electrical measurements in a temperature range of 5 K to 300 K. The positive magneto resistivity (PMR) ratios reached 28.8%, 12.7%, and 17.6% at 5 K for thin films, having different post-deposition annealing conditions as a consequence of ionic W dependent defects in the lattice. Furthermore, an anomalous Hall effect, originating from polarized spin currents, was understood from the split in Hall resistance versus magnetic field (R{sub xy}(H)) curves for the thin film with high amount of Zn{sup 2+} and W{sup 6+} ionic defects.

  10. Anomalous isotopic effect on electron-directed reactivity by a 3-{\\mu}m midinfrared pulse

    CERN Document Server

    Liu, Kunlong; Lan, Pengfei; Lu, Peixiang

    2012-01-01

    We have theoretically studied the effect of nuclear mass on electron localization in dissociating H_2^+ and its isotopes subjected to a few-cycle 3-{\\mu}m laser pulse. Compared to the isotopic trend in the near-infrared regime, our results reveal an inverse isotopic effect in which the degree of electron-directed reactivity is even higher for heavier isotopes. With the semi-classical analysis, we find, for the first time, the pronounced electron localization is established by the interferences through different channels of one- and, more importantly, higher-order photon coupling. Interestingly, due to the enhanced high-order above-threshold dissociation of heavier isotopes, the interference maxima gradually become in phase with growing mass and ultimately lead to the anomalous isotopic behavior of the electron localization. This indicates that the multi-photon coupling channels will play an important role in controlling the dissociation of larger molecules with midinfrared pulses.

  11. Structure investigation of metal ions clustering in dehydrated gel using x-ray anomalous dispersion effect

    CERN Document Server

    Soejima, Y; Sugiyama, M; Annaka, M; Nakamura, A; Hiramatsu, N; Hara, K

    2003-01-01

    The structure of copper ion clusters in dehydrated N-isopropylacrylamide/sodium acrylate (NIPA/SA) gel has been studied by means of small angle X-ray scattering (SAXS) method. In order to distinguish the intensity scattered by Cu ions, the X-ray anomalous dispersion effect around the Cu K absorption edge has been coupled with SAXS. It is found that the dispersion effect dependent on the incident X-ray energy is remarkable only at the momentum transfer q = 0.031 A sup - sup 1 , where a SAXS peak is observed. The results indicate that copper ions form clusters in the dehydrated gel, and that the mean size of clusters is the same as that of SA clusters produced by microphase separation. It is therefore naturally presumed that copper ions are adsorbed into the SA molecules. On the basis of the presumption, a mechanism is proposed for microphase-separation and clustering of Cu ions.

  12. Precise Quantization of the Anomalous Hall Effect near Zero Magnetic Field

    Science.gov (United States)

    Bestwick, A. J.; Fox, E. J.; Kou, Xufeng; Pan, Lei; Wang, Kang L.; Goldhaber-Gordon, D.

    2015-05-01

    We report a nearly ideal quantum anomalous Hall effect in a three-dimensional topological insulator thin film with ferromagnetic doping. Near zero applied magnetic field we measure exact quantization in the Hall resistance to within a part per 10 000 and a longitudinal resistivity under 1 Ω per square, with chiral edge transport explicitly confirmed by nonlocal measurements. Deviations from this behavior are found to be caused by thermally activated carriers, as indicated by an Arrhenius law temperature dependence. Using the deviations as a thermometer, we demonstrate an unexpected magnetocaloric effect and use it to reach near-perfect quantization by cooling the sample below the dilution refrigerator base temperature in a process approximating adiabatic demagnetization refrigeration.

  13. Scaling of Anomalous Hall Effects in Facing-Target Reactively Sputtered Fe4N Films

    KAUST Repository

    Zhang, Yan

    2015-05-13

    Anomalous Hall effect (AHE) in the reactively sputtered epitaxial and polycrystalline γ′-Fe4N films is investigated systematically. The Hall resistivity is positive in the entire temperature range. The magnetization, carrier density and grain boundaries scattering have a major impact on the AHE scaling law. The scaling exponent γ in the conventional scaling of is larger than 2 in both the epitaxial and polycrystalline γ′-Fe4N films. Although γ>2 has been found in heterogeneous systems due to the effects of the surface and interface scattering on AHE, γ>2 is not expected in homogenous epitaxial systems. We demonstrated that γ>2 results from residual resistivity (ρxx0) in γ′-Fe4N films. Furthermore, the side-jump and intrinsic mechanisms are dominant in both epitaxial and polycrystalline samples according to the proper scaling relation.

  14. Effect of Systemic Antioxidant Allopurinol Therapy on Skin Flap Survival

    Science.gov (United States)

    Rasti Ardakani, Mehdi; Al-Dam, Ahmed; Rashad, Ashkan; Shayesteh Moghadam, Ali

    2017-01-01

    BACKGROUND It has been reported that systemic administration of allopurinol improves cell survival. This study was aimed to evaluate effects of allopurinol on skin flaps in dogs. METHODS Twenty dogs underwent one skin flap surgery with a 2-week interval. The first procedure was performed according to the standard protocols. The second phase was started by a 1-week pretreatment with allopurinol. Length of the necrotic zone was measured and recorded daily. At each phase, flaps were removed and sent for histopathological study after 1 week observation. RESULTS Mean length of the necrotic zone in allopurinol treated skin flaps has been significantly less than normal flaps over all 7 days of observation (p<0.0001). Histopathology study showed less inflammation and more normal tissue structure in the allopurinol treated skin flaps. CONCLUSION It was demonstrated that systemic administration of allopurinol significantly improved skin flap survival. PMID:28289614

  15. Effect of neutron skin thickness on projectile fragmentation

    CERN Document Server

    Dai, Z T; Ma, Y G; Cao, X G; Zhang, G Q; Shen, W Q

    2015-01-01

    The fragment production in collisions of $^{48,50}$Ca+$^{12}$C at 50 MeV/nucleon are simulated via the Isospin-Dependent Quantum Molecular Dynamics (IQMD) model followed by the {GEMINI code}. {By changing the diffuseness parameter of neutron density distribution to obtain different neutron skin size, the effects of neutron skin thickness (${\\delta}_{np}$) on projectile-like fragments (PLF) are investigated. The sensitivity of isoscaling behavior to neutron skin size is studied, from which it is found that the isoscaling parameter $\\alpha$ has a linear dependence on ${\\delta}_{np}$. A linear dependence between ${\\delta}_{np}$ and the mean $N/Z$ [N(Z) is neutron(proton) number] of PLF is obtained as well.} The results show that thicker neutron skin will lead to smaller {isoscaling parameter} $\\alpha$ and N/Z. Therefore, it may be probable to extract information of neutron skin thickness from {isoscaling parameter} $\\alpha$ and N/Z.

  16. Effects of Essential Oils and Polyunsaturated Fatty Acids on Canine Skin Equivalents: Skin Lipid Assessment and Morphological Evaluation

    OpenAIRE

    Cerrato, S.; Ramió-Lluch, L.; Fondevila, D.; Rodes, D.; P. Brazis; Puigdemont, A.

    2013-01-01

    A canine skin equivalent model has been validated for the assessment of a topical formulation effects. Skin equivalents were developed from freshly isolated cutaneous canine fibroblasts and keratinocytes, after enzymatic digestion of skin samples (n = 8) from different breeds. Fibroblasts were embedded into a collagen type I matrix, and keratinocytes were seeded onto its surface at air-liquid interface. Skin equivalents were supplemented with essential oils and polyunsaturated fatty acid form...

  17. Thermally Driven Pure Spin and Valley Currents via the Anomalous Nernst Effect in Monolayer Group-VI Dichalcogenides

    DEFF Research Database (Denmark)

    Yu, Xiao-Qin; Zhu, Zhen-Gang; Su, Gang;

    2015-01-01

    The spin and valley-dependent anomalous Nernst effects are analyzed for monolayer MoS2 and other group-VI dichalcogenides. We find that pure spin and valley currents can be generated perpendicular to the applied thermal gradient in the plane of these two-dimensional materials. This effect provide...

  18. Solid-armature railguns without the velocity-skin effect

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, M.

    1991-12-31

    If the velocity-skin effect could be eliminated, solid-armature railguns might reach high velocity ({ge} 6 km/s) without forcing most of the armature current to pass through an arc. Even then, magnetic diffusion (the ``normal`` skin effect) will limit acceleration. In this paper, the performance limits for railguns which are free from the velocity-skin effect are investigated by deriving the upper limits for a specific kind of power supply. Previous performance estimates made for solid-armature railguns are examined in the light of these results and are found to be relatively very optimistic. A railgun design which limits the velocity-skin effect and which may allow improved performance for solid armatures is described. 6 refs.

  19. Effects of Neutron Skin Thickness in Peripheral Nuclear Reactions

    Institute of Scientific and Technical Information of China (English)

    FANG De-Qing; MA Yu-Gang; CAI Xiang-Zhou; TIAN Wen-Dong; WANG Hong-Wei

    2011-01-01

    Effects of neutron skin thickness in peripheral nuclear collisions are investigated using the statistical abrasion ablation (SAA) model. The reaction cross section, neutron (proton) removal cross section, one-neutron (proton) removal cross section as well as their ratios for nuclei with different neutron skin thickness are studied. It is demonstrated that there are good linear correlations between these observables and the neutron skin thickness for neutron-rich nuclei. The ratio between the (one-)neutron and proton removal cross section is found to be the most sensitive observable of neutron skin thickness. Analysis shows that the relative increase of this ratio could be used to determine the neutron skin size in neutron-rich nuclei.%Effects of neutron skin thickness in peripheral nuclear collisions are investigated using the statistical abrasion ablation (SAA ) model.The reaction cross section,neutron (proton) removal cross section,one-neutron (proton) removal cross section as well as their ratios for nuclei with different neutron skin thickness are studied.It is demonstrated that there are good linear correlations between these observables and the neutron skin thickness for neutron-rich nuclei.The ratio between the (one-)neutron and proton removal cross section is found to be the most sensitive observable of neutron skin thickness.Analysis shows that the relative increase of this ratio could be used to determine the neutron skin size in neutron-rich nuclei.Determining the size and shape of a nucleus is one of the most important subjects since the discovery of atomic nuclei.The rms radii of the neutron (rn) and proton (rp) density distributions are among the most prominent observables for this purpose.Studies for stable nuclei have shown that the nuclear radii are proportional to A1/3,with A being the nuclear mass number.Meanwhile,the density distributions of neutrons and protons in stable nuclei are very similar.

  20. Anomalous Hall effect and magnetoresistance behavior in Co/Pd1−xAgx multilayers

    KAUST Repository

    Guo, Z. B.

    2013-02-13

    In this paper, we report anomalous Hall effect (AHE) correlated with the magnetoresistance behavior in [Co/Pd1-xAg x]n multilayers. For the multilayers with n = 6, the increase in Ag content from x = 0 to 0.52 induces the change in AHE sign from negative surface scattering-dominated AHE to positive interface scattering-dominated AHE, which is accompanied with the transition from anisotropy magnetoresistance (AMR) dominated transport to giant magnetoresistance (GMR) dominated transport. For n = 80, scaling analysis with Rs ∝ρ xx γ yields γ ∼ 3.44 for x = 0.52 which presents GMR-type transport, in contrast to γ ∼ 5.7 for x = 0 which presents AMR-type transport. © 2013 American Institute of Physics.

  1. Tuning anomalous Hall effect in perpendicular multilayers with different oxygen environment by interfacial ionic migration

    Science.gov (United States)

    Zhang, J. Y.; Sun, Q. Y.; Liu, Y. W.; Peng, W. L.; Wang, F. M.; Pan, Y. D.; Ding, L.; Yu, G. H.

    2017-02-01

    Interfacial oxygen migration and its induced anomalous Hall effect are reported in perpendicular multilayers with different interfacial oxygen-coordinated. Saturation Hall resistance RAH for Pt/Co/MgO/Pt and Pt/Co/Al2O3/Pt multilayers is 3.66 Ω and 4.34 Ω in as-deposited state, respectively. After annealing at 400 °C, RAH value reaches 4.82 Ω and 6.67 Ω, which is 32% and 54% larger than that in as-deposited samples, respectively. Especially, the increment value ΔRAH in Pt/Co/Al2O3/Pt multilayers is 101% larger than that in Pt/Co/MgO/Pt film. Interfacial structural analysis shows such differentΔRAH in two samples originates from distinct oxygen migration behavior induced different interfacial oxygen-coordinated.

  2. Chern half metals: a new class of topological materials to realize the quantum anomalous Hall effect.

    Science.gov (United States)

    Hu, Jun; Zhu, Zhenyue; Wu, Ruqian

    2015-03-11

    New topological insulators that demonstrate the quantum anomalous Hall effect (QAHE) are a cutting-edge research topic in condensed matter physics and materials science. So far, the QAHE has been observed only in Cr-doped (Bi,Sb)2Te3 at extremely low temperature. Therefore, it is important to find new materials with large topological band gap and high thermal stability for the realization of the QAHE. On the basis of first-principles and tight-binding model calculations, we discovered a new class of topological phase, Chern half metal, which manifests the QAHE in one spin channel while is metallic in the other spin channel, in Co or Rh deposited graphene. The QAHE is robust in these sytems for the adatom coverage ranging from 2% to 6%. Meanwhile, these systems have large perpendicular magnetic anisotropy energies of 5.3 and 11.5 meV, necessary for the observation of the QAHE at reasonably high temperature.

  3. Theory of Multifarious Quantum Phases and Large Anomalous Hall Effect in Pyrochlore Iridate Thin Films.

    Science.gov (United States)

    Hwang, Kyusung; Kim, Yong Baek

    2016-07-15

    We theoretically investigate emergent quantum phases in the thin film geometries of the pyrochore iridates, where a number of exotic quantum ground states are proposed to occur in bulk materials as a result of the interplay between electron correlation and strong spin-orbit coupling. The fate of these bulk phases as well as novel quantum states that may arise only in the thin film platforms, are studied via a theoretical model that allows layer-dependent magnetic structures. It is found that the magnetic order develop in inhomogeneous fashions in the thin film geometries. This leads to a variety of magnetic metal phases with modulated magnetic ordering patterns across different layers. Both the bulk and boundary electronic states in these phases conspire to promote unusual electronic properties. In particular, such phases are akin to the Weyl semimetal phase in the bulk system and they would exhibit an unusually large anomalous Hall effect.

  4. Anomalous finite-size effects in the Battle of the Sexes

    CERN Document Server

    Cremer, Jonas; Frey, Erwin

    2007-01-01

    The Battle of the Sexes describes asymmetric conflicts in mating behavior of males and females. Males can be philanderer or faithful, while females are either fast or coy, leading to a cyclic dynamics. The adjusted replicator equation predicts stable coexistence of all four strategies. In this situation, we consider the effects of fluctuations stemming from a finite population size. We show that they unavoidably lead to extinction of two strategies in the population. However, the typical time until extinction occurs strongly prolongs with increasing system size. In the meantime, a quasi-stationary probability distribution forms that is anomalously flat in the vicinity of the coexistence state. This behavior originates in a vanishing linear deterministic drift near the fixed point. We provide numerical data as well as an analytical approach to the mean extinction time and the quasi-stationary probability distribution.

  5. Theory for the anomalous electron transport in Hall effect thrusters. II. Kinetic model

    Science.gov (United States)

    Lafleur, T.; Baalrud, S. D.; Chabert, P.

    2016-05-01

    In Paper I [T. Lafleur et al., Phys. Plasmas 23, 053502 (2016)], we demonstrated (using particle-in-cell simulations) the definite correlation between an anomalously high cross-field electron transport in Hall effect thrusters (HETs), and the presence of azimuthal electrostatic instabilities leading to enhanced electron scattering. Here, we present a kinetic theory that predicts the enhanced scattering rate and provides an electron cross-field mobility that is in good agreement with experiment. The large azimuthal electron drift velocity in HETs drives a strong instability that quickly saturates due to a combination of ion-wave trapping and wave-convection, leading to an enhanced mobility many orders of magnitude larger than that expected from classical diffusion theory. In addition to the magnetic field strength, B0, this enhanced mobility is a strong function of the plasma properties (such as the plasma density) and therefore does not, in general, follow simple 1 /B02 or 1 /B0 scaling laws.

  6. Anomalous Hall effect in a ferromagnetic Fe3Sn2 single crystal with a geometrically frustrated Fe bilayer kagome lattice

    Science.gov (United States)

    Wang, Qi; Sun, Shanshan; Zhang, Xiao; Pang, Fei; Lei, Hechang

    2016-08-01

    The anomalous Hall effect (AHE) is investigated for a ferromagnetic Fe3Sn2 single crystal with a geometrically frustrated kagome bilayer of Fe. The scaling behavior between anomalous Hall resistivity ρxy A and longitudinal resistivity ρx x is quadratic and further analysis implies that the AHE in the Fe3Sn2 single crystal should be dominated by the intrinsic Karplus-Luttinger mechanism rather than extrinsic skew-scattering or side-jump mechanisms. Moreover, there is a sudden jump of anomalous Hall conductivity σxy A appearing at about 100 K where the spin-reorientation transition from the c axis to the a b plane is completed. This change of σxy A might be related to the evolution of the Fermi surface induced by the spin-reorientation transition.

  7. Effect of glove occlusion on the skin barrier

    DEFF Research Database (Denmark)

    Tiedemann, Daniel; Clausen, Maja Lisa; John, Swen Malthe

    2016-01-01

    of this study is to review the literature on the effects of glove occlusion on skin barrier function. The PubMed database was searched up to 1 February 2015 for articles on the association between glove occlusion and skin barrier function, including human studies only and in English. Only experimental studies...... including assessment of the skin barrier function were included in the data analysis. Thirteen articles were identified, 8 with focus on occlusion alone, 7 with focus on occlusion in combination with irritant exposure (some overlapping), and 2 field studies. In conclusion, data from the literature showed...... that the negative effect of occlusion in itself is limited, and that only extensive and long-term occlusion will cause barrier impairment. However, studies investigating combined effect of occlusion and exposure to soaps/detergents indicate that occlusion significantly enhances the skin barrier damage caused...

  8. UV doses and skin effects during psoriasis climate therapy

    Science.gov (United States)

    Randeberg, Lise L.; Hernandez-Palacios, Julio; Lilleeng, Mila; Nilsen, Lill Tove; Krogstad, Anne-Lene

    2011-03-01

    Psoriasis is a common autoimmune disease with inflammatory symptoms affecting skin and joints. One way of dealing with psoriasis is by controlled solar UV exposure treatment. However, this treatment should be optimized to get the best possible treatment effect and to limit negative side effects such as erythema and an increased risk of skin cancer. In this study 24 patients at Valle Marina Treatment Center in Gran Canaria were monitored throughout a treatment period of three weeks starting at the beginning of November. The total UV dose to the location was monitored by UV-meters placed on the roof of the treatment centere, and the patients wore individual film dosimeters throughout the treatment period. Skin parameters were accessed by reflection spectroscopy (400-850nm). This paper presents preliminary findings from the skin measurements in the visible part of the spectrum, such as blood oxygenation, erythema and melanin indexes. Reflection spectroscopy was found to be a good tool for such treatment monitoring.

  9. Effects of repeated skin exposure to low nickel concentrations

    DEFF Research Database (Denmark)

    Nielsen, N H; Menné, T; Kristiansen, J

    1999-01-01

    and nickel allergy, either on normal or on SLS-treated forearm skin. The present study strongly suggests that the changes observed were specific to nickel exposure. Standardized methods to assess trace to moderate nickel exposure on the hands, and the associated effects in nickel-sensitized subjects......We studied the effects of repeated daily exposure to low nickel concentrations on the hands of patients with hand eczema and nickel allergy. The concentrations used were chosen to represent the range of trace to moderate occupational nickel exposure. The study was double-blinded and placebo...... with a group of patients who immersed a finger into water. The nickel concentrations used also provoked significant inflammatory skin changes on sodium lauryl sulphate (SLS)-treated forearm skin of the patients, whereas inflammatory skin changes were not observed in healthy volunteers without hand eczema...

  10. Measurement of the nucleation and propagation field in a single Co/Pt multilayer dot by anomalous Hall effect.

    NARCIS (Netherlands)

    Vries, de J.; Delalande, M.Y.; Abelmann, L.; Lodder, J.C.

    2011-01-01

    It has been suggested that the reversal mechanism in highly exchange coupled systems, like Co/Pt multilayers, takes place by nucleation of a reversed domain, followed by domain wall movement. Based on magnetic force microscopy (MFM) and anomalous Hall effect (AHE) measurements, we show that this mod

  11. Measurement of the nucleation and domain depinning field in a single Co/Pt multilayer dot by anomalous Hall effect

    NARCIS (Netherlands)

    Delalande, M.; Vries, de J.; Abelmann, L.; Lodder, J.C.

    2012-01-01

    Co/Pt multilayer dots with perpendicular anisotropy and with diameters of 250 and 350 nm were fabricated on top of a Hall cross configuration. The angular dependence of the magnetic reversal of the individual dot was investigated by Anomalous Hall effect measurements. At near in-plane angles (85° wi

  12. Vacuum effects in magnetic field with with account for fermion anomalous magnetic moment and axial-vector interaction

    Science.gov (United States)

    Bubnov, Andrey; Gubina, Nadezda; Zhukovsky, Vladimir

    2016-05-01

    We study vacuum polarization effects in the model of Dirac fermions with additional interaction of an anomalous magnetic moment with an external magnetic field and fermion interaction with an axial-vector condensate. The proper time method is used to calculate the one-loop vacuum corrections with consideration for different configurations of the characteristic parameters of these interactions.

  13. Two-loop anomalous dimensions of heavy baryon currents in heavy quark effective theory

    CERN Document Server

    Groote, S; Yakovlev, O I

    1996-01-01

    We present results on the two-loop anomalous dimensions of the heavy baryon HQET currents J=(q^TC\\Gamma\\tau q)\\Gamma'Q with arbitrary Dirac matrices \\Gamma and \\Gamma'. From our general result we obtain the two-loop anomalous dimensions for currents with quantum numbers of the ground state heavy baryons \\Lambda_Q, \\Sigma_Q and \\Sigma_Q^*. As a by-product of our calculation and as an additional check we rederive the known two-loop anomalous dimensions of mesonic scalar, pseudoscalar, vector, axial vector and tensor currents (J=\\bar q\\Gamma q) in massless QCD as well as in HQET.

  14. Skin photoprotection by green tea: antioxidant and immunomodulatory effects.

    Science.gov (United States)

    Katiyar, Santosh K

    2003-09-01

    Because of a characteristic aroma and health benefits, green tea is consumed worldwide as a popular beverage. The epicatechin derivatives, commonly called polyphenols, present in green tea possess antioxidant, anti-inflammatory and anti-carcinogenic properties. The major and most highly chemopreventive constituent in green tea responsible for the biochemical or pharmacological effects is (-)-epigallocatechin-3-gallate (EGCG). Epidemiological, clinical and biological studies have implicated that solar ultraviolet (UV) light is a complete carcinogen and repeated exposure can lead to the development of various skin disorders including melanoma and nonmelanoma skin cancers. We and others have shown that topical treatment or oral consumption of green tea polyphenols (GTP) inhibit chemical carcinogen- or UV radiation-induced skin carcinogenesis in different laboratory animal models. Topical treatment of GTP and EGCG or oral consumption of GTP resulted in prevention of UVB-induced inflammatory responses, immunosuppression and oxidative stress, which are the biomarkers of several skin disease states. Topical application of GTP and EGCG prior to exposure of UVB protects against UVB-induced local as well as systemic immune suppression in laboratory animals, which was associated with the inhibition of UVB-induced infiltration of inflammatory leukocytes. Prevention of UVB-induced suppression of immune responses by EGCG was also associated with the reduction in immunosuppressive cytokine interleukin (IL)-10 production at UV irradiated skin and draining lymph nodes, whereas IL-12 production was significantly enhanced in draining lymph nodes. Antioxidant and anti-inflammatory effects of green tea were also observed in human skin. Treatment of EGCG to human skin resulted in the inhibition of UVB-induced erythema, oxidative stress and infiltration of inflammatory leukocytes. We also showed that treatment of GTP to human skin prevents UVB-induced cyclobutane pyrimidine dimers

  15. Effects of TLC-Ag dressings on skin inflammation.

    Science.gov (United States)

    Bisson, Jean-François; Hidalgo-Lucas, Sophie; Bouschbacher, Marielle; Thomassin, Laetitia

    2013-06-01

    The TLC-Ag dressings, a combination of technology lipido-colloid and silver salts, are used to promote healing in wounds with risks or signs of local infection, thanks to the antimicrobial properties of the silver salts. Nanocrystalline silver dressings containing nanocrystalline silver, also used to improve wound healing, present both antimicrobial and anti-inflammatory effects. The aim of this study was to investigate the anti-inflammatory effects of TLC-Ag dressings in a model of chronic skin inflammation induced by repeated application of 12-O-tetradecanoylphorbol-13-acetate to the skin of hairless mice, in comparison with TLC dressing, Silcryst nanocrystalline dressing, desonide cream 0.05%, a corticoid cream used as positive control, and gauze. Daily treatments of the mice began 7 days after the start of induction of chronic skin inflammation and lasted for 7 days. A macroscopic score was performed daily during the treatment period until the mice killing on day 15 and skin samples were taken for histopathological analysis. TLC-Ag reduced significantly the macroscopic score of chronic skin inflammation from day 10 in comparison with gauze and TLC dressing, similarly to Silcryst nanocrystalline dressing and desonide cream, which presented the best anti-inflammatory effects. No significant differences were observed between TLC dressing and gauze. TLC-Ag reduced significantly the microscopic score of chronic skin inflammation in comparison with TLC dressing and gauze, similarly to Silcryst nanocrystalline dressing but significantly less than desonide cream. These results demonstrate that TLC-Ag dressings present significant anti-inflammatory effects on chronic skin inflammation. They can improve wound healing, due to both the antimicrobial and anti-inflammatory properties.

  16. Effects of a skin neuropeptide (substance p on cutaneous microflora.

    Directory of Open Access Journals (Sweden)

    Lily Mijouin

    Full Text Available BACKGROUND: Skin is the largest human neuroendocrine organ and hosts the second most numerous microbial population but the interaction of skin neuropeptides with the microflora has never been investigated. We studied the effect of Substance P (SP, a peptide released by nerve endings in the skin on bacterial virulence. METHODOLOGY/PRINCIPAL FINDINGS: Bacillus cereus, a member of the skin transient microflora, was used as a model. Exposure to SP strongly stimulated the cytotoxicity of B. cereus (+553±3% with SP 10(-6 M and this effect was rapid (<5 min. Infection of keratinocytes with SP treated B. cereus led to a rise in caspase1 and morphological alterations of the actin cytoskeleton. Secretome analysis revealed that SP stimulated the release of collagenase and superoxide dismutase. Moreover, we also noted a shift in the surface polarity of the bacteria linked to a peel-off of the S-layer and the release of S-layer proteins. Meanwhile, the biofilm formation activity of B. cereus was increased. The Thermo unstable ribosomal Elongation factor (Ef-Tu was identified as the SP binding site in B. cereus. Other Gram positive skin bacteria, namely Staphylococcus aureus and Staphylococcus epidermidis also reacted to SP by an increase of virulence. Thermal water from Uriage-les-Bains and an artificial polysaccharide (Teflose® were capable to antagonize the effect of SP on bacterial virulence. CONCLUSIONS/SIGNIFICANCE: SP is released in sweat during stress and is known to be involved in the pathogenesis of numerous skin diseases through neurogenic inflammation. Our study suggests that a direct effect of SP on the skin microbiote should be another mechanism.

  17. Radon exposure of the skin: I. Biological effects

    Energy Technology Data Exchange (ETDEWEB)

    Charles, M W [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2007-09-15

    Radon progeny can plate out on skin and give rise to exposure of the superficial epidermis from alpha emitters Po-218 (7.7 MeV, range {approx}66 {mu}m) and Po-214 (6 MeV, range {approx}44 {mu}m). Dose rates from beta/gamma emitters Pb-214 and Bi-214 are low and only predominate at depths in excess of the alpha range. This paper reviews the evidence for a causal link between exposure from radon and its progeny, and deterministic and stochastic biological effects in human skin. Radiation induced skin effects such as ulceration and dermal atrophy, which require irradiation of the dermis, are ruled out for alpha irradiation from radon progeny because the target cells are considerably deeper than the range of alpha particles. They have not been observed in man or animals. Effects such as erythema and acute epidermal necrosis have been observed in a few cases of very high dose alpha particle exposures in man and after acute high dose exposure in animals from low energy beta radiations with similar depth doses to radon progeny. The required skin surface absorbed doses are in excess of 100 Gy. Such effects would require extremely high levels of radon progeny. They would involve quite exceptional circumstances, way outside the normal range of radon exposures in man. There is no definitive identification of the target cells for skin cancer induction in animals or man. The stem cells in the basal layer which maintain the epidermis are the most plausible contenders for target cells. The majority of these cells are near the end of the range of radon progeny alpha particles, even on the thinnest body sites. The nominal depth of these cells, as recommended by the International Commission on Radiological Protection (ICRP), is 70 {mu}m. There is evidence however that some irradiation of the hair follicles and/or the deeper dermis, as well as the inter-follicular epidermis, is also necessary for skin cancer induction. Alpha irradiation of rodent skin that is restricted to the

  18. Quantum anomalous Hall effect in time-reversal-symmetry breaking topological insulators.

    Science.gov (United States)

    Chang, Cui-Zu; Li, Mingda

    2016-03-31

    The quantum anomalous Hall effect (QAHE), the last member of Hall family, was predicted to exhibit quantized Hall conductivity σ(yx) = e2/h without any external magnetic field. The QAHE shares a similar physical phenomenon with the integer quantum Hall effect (QHE), whereas its physical origin relies on the intrinsic topological inverted band structure and ferromagnetism. Since the QAHE does not require external energy input in the form of magnetic field, it is believed that this effect has unique potential for applications in future electronic devices with low-power consumption. More recently, the QAHE has been experimentally observed in thin films of the time-reversal symmetry breaking ferromagnetic (FM) topological insulators (TI), Cr- and V- doped (Bi,Sb)2Te3. In this topical review, we review the history of TI based QAHE, the route to the experimental observation of the QAHE in the above two systems, the current status of the research of the QAHE, and finally the prospects for future studies.

  19. Anomalous effect of ion velocity on track formation in GeS

    Science.gov (United States)

    Szenes, G.; Pécz, B.

    2016-12-01

    Systematic experiments were performed for studying the effect of the projectile velocity (velocity effect, VE) in GeS which has a highly anisotropic conductivity. The prethinned specimens were irradiated by Bi, Au, W, Xe, Ag, Kr, Ni and Fe ions of about E ≈ 1 MeV/nucleon energy. Track radii were measured by transmission electron microscopy. Compared to previous experiments performed with high velocity projectile, there is a marked VE for Se > 20 keV/nm (Se - electronic stopping power). However, the VE is gradually reduced and finally disappears as Se decreases. This effect is described for the first time. The predictions according to the Analytical Thermal Spike Model are in excellent quantitative agreement with the experiments in the range Se > 20 keV/nm. The anomalous behavior of track evolution at lower values of Se is attributed to the combination of semiconducting and insulating properties. An explanation of the VE is given based on the Coulomb explosion model.

  20. Anomalous Hall effect sensors based on magnetic element doped topological insulator thin films

    Science.gov (United States)

    Ni, Yan; Zhang, Zhen; Nlebedim, Ikenna; Jiles, David

    Anomalous Hall effect (AHE) is recently discovered in magnetic element doped topological insulators (TIs), which promises low power consumption highly efficient spintronics and electronics. This discovery broaden the family of Hall effect (HE) sensors. In this work, both HE and AHE sensor based on Mn and Cr doped Bi2Te3 TI thin films will be systematically studied. The influence of Mn concentration on sensitivity of MnxBi2-xTe3 HE sensors will be discussed. The Hall sensitivity increase 8 times caused by quantum AHE will be reported. AHE senor based on Cr-doped Bi2Te3 TI thin films will also be studied and compared with Mn doped Bi2Te3 AHE sensor. The influence of thickness on sensitivity of CrxBi2-xTe3 AHE sensors will be discussed. Ultrahigh Hall sensitivity is obtained in Cr doped Bi2Te3. The largest Hall sensitivity can reach 2620 Ω/T in sensor which is almost twice higher than that of the normal semiconductor HE sensor. Our work indicates that magnetic element doped topological insulator with AHE are good candidates for ultra-sensitive Hall effect sensors.

  1. The foreign exchange market: return distributions, multifractality, anomalous multifractality and the Epps effect

    Science.gov (United States)

    Drożdż, Stanisław; Kwapień, Jarosław; Oświȩcimka, Paweł; Rak, Rafał

    2010-10-01

    We present a systematic study of various statistical characteristics of high-frequency returns from the foreign exchange market. This study is based on six exchange rates forming two triangles: EUR-GBP-USD and GBP-CHF-JPY. It is shown that the exchange rate return fluctuations for all of the pairs considered are well described by the non-extensive statistics in terms of q-Gaussians. There exist some small quantitative variations in the non-extensivity q-parameter values for different exchange rates (which depend also on the time scales studied), and this can be related to the importance of a given exchange rate in the world's currency trade. Temporal correlations organize the series of returns such that they develop the multifractal characteristics for all of the exchange rates, with a varying degree of symmetry of the singularity spectrum f(α), however. The most symmetric spectrum is identified for the GBP/USD. We also form time series of triangular residual returns and find that the distributions of their fluctuations develop disproportionately heavier tails as compared to small fluctuations, which excludes description in terms of q-Gaussians. The multifractal characteristics of these residual returns reveal such anomalous properties as negative singularity exponents and even negative singularity spectra. Such anomalous multifractal measures have so far been considered in the literature in connection with diffusion-limited aggregation and with turbulence. Studying the cross-correlations among different exchange rates, we found that market inefficiency on short time scales leads to the occurrence of the Epps effect on much longer time scales, but comparable to the ones for the stock market. Although the currency market is much more liquid than the stock markets and has a much greater transaction frequency, the building up of correlations takes up to several hours—a duration that does not differ much from what is observed in the stock markets. This may suggest

  2. Switching of a large anomalous Hall effect between metamagnetic phases of a non-collinear antiferromagnet

    Science.gov (United States)

    Sürgers, Christoph; Wolf, Thomas; Adelmann, Peter; Kittler, Wolfram; Fischer, Gerda; Löhneysen, Hilbert v.

    2017-01-01

    The anomalous Hall effect (AHE), which in long-range ordered ferromagnets appears as a voltage transverse to the current and usually is proportional to the magnetization, often is believed to be of negligible size in antiferromagnets due to their low uniform magnetization. However, recent experiments and theory have demonstrated that certain antiferromagnets with a non-collinear arrangement of magnetic moments exhibit a sizeable spontaneous AHE at zero field due to a non-vanishing Berry curvature arising from the quantum mechanical phase of the electron’s wave functions. Here we show that antiferromagnetic Mn5Si3 single crystals exibit a large AHE which is strongly anisotropic and shows multiple transitions with sign changes at different magnetic fields due to field-induced rearrangements of the magnetic structure despite only tiny variations of the total magnetization. The presence of multiple non-collinear magnetic phases offers the unique possiblity to explore the details of the AHE and the sensitivity of the Hall effect on the details of the magnetic texture. PMID:28218287

  3. Switching of a large anomalous Hall effect between metamagnetic phases of a non-collinear antiferromagnet.

    Science.gov (United States)

    Sürgers, Christoph; Wolf, Thomas; Adelmann, Peter; Kittler, Wolfram; Fischer, Gerda; Löhneysen, Hilbert V

    2017-02-20

    The anomalous Hall effect (AHE), which in long-range ordered ferromagnets appears as a voltage transverse to the current and usually is proportional to the magnetization, often is believed to be of negligible size in antiferromagnets due to their low uniform magnetization. However, recent experiments and theory have demonstrated that certain antiferromagnets with a non-collinear arrangement of magnetic moments exhibit a sizeable spontaneous AHE at zero field due to a non-vanishing Berry curvature arising from the quantum mechanical phase of the electron's wave functions. Here we show that antiferromagnetic Mn5Si3 single crystals exibit a large AHE which is strongly anisotropic and shows multiple transitions with sign changes at different magnetic fields due to field-induced rearrangements of the magnetic structure despite only tiny variations of the total magnetization. The presence of multiple non-collinear magnetic phases offers the unique possiblity to explore the details of the AHE and the sensitivity of the Hall effect on the details of the magnetic texture.

  4. Strong and Anomalous Thermal Expansion Precedes the Thermosalient Effect in Dynamic Molecular Crystals.

    Science.gov (United States)

    Panda, Manas K; Centore, Roberto; Causà, Mauro; Tuzi, Angela; Borbone, Fabio; Naumov, Panče

    2016-07-12

    The ability of thermosalient solids, organic analogues of inorganic martensites, to move by rapid mechanical reconfiguration or ballistic event remains visually appealing and potentially useful, yet mechanistically elusive phenomenon. Here, with a material that undergoes both thermosalient and non-thermosalient phase transitions, we demonstrate that the thermosalient effect is preceded by anomalous thermal expansion of the unit cell. The crystal explosion occurs as sudden release of the latent strain accumulated during the anisotropic, exceedingly strong expansion of the unit cell with αa = 225.9 × 10(-6) K(-1), αb = 238.8 × 10(-6) K(-1) and αc = -290.0 × 10(-6) K(-1), the latter being the largest negative thermal expansivity observed for an organic compound thus far. The results point out to the occurence of the thermosalient effect in phase transitions as means to identify new molecular materials with strong positive and/or negative thermal expansion which prior to this work could only be discovered serendipitously.

  5. Magnetoresistance and anomalous Hall effect of reactive sputtered polycrystalline Ti1 - XCrxN films

    KAUST Repository

    Duan, Xiaofei

    2013-09-01

    The reactive-sputtered polycrystalline Ti1 - xCrxN films with 0.17 ≤ x ≤ 0.51 are ferromagnetic and at x = 0.47 the Curie temperature TC shows a maximum of ~ 120 K. The films are metallic at 0 ≤ x ≤ 0.47, while the films with x = 0.51 and 0.78 are semiconducting-like. The upturn of resistivity below 70 K observed in the films with 0.10 ≤ x ≤ 0.47 is from the effects of the electron-electron interaction and weak localization. The negative magnetoresistance (MR) of the films with 0.10 ≤ x ≤ 0.51 is dominated by the double-exchange interaction, while at x = 0.78, MR is related to the localized magnetic moment scattering at the grain boundaries. The scaling ρxyA/n ∝ ρxx2.19 suggests that the anomalous Hall effect in the polycrystalline Ti1 - xCrxN films is scattering-independent. © 2013 Elsevier B.V. All rights reserved.

  6. Fractional Identification of Rotor Skin Effect in Induction Machines

    Directory of Open Access Journals (Sweden)

    Jean-Claude Trigeassou

    2011-07-01

    Full Text Available Fractional identification of rotor skin effect in induction machines is presented in this paper. Park transformation is used to obtain a system of differential equations which allows to include the skin effect in the rotor bars of asynchronous machines. A transfer function with a fractional derivative order has been selected to represent the admittance of the bar by the help of a non integer integrator which is approximated by a J+1 dimensional modal system. The machine parameters are estimated by an output-error technique using a non linear iterative optimization algorithm. Numerical simulations and experimental results show the performance of the modal approach for modeling and identification.

  7. Anomalous peak-effect in type-II superconductors: A competition between bulk pinning and a surface barrier

    Energy Technology Data Exchange (ETDEWEB)

    Maksimov, I.L. [Department of Theoretical Physics, Nizhny Novgorod University, Gagarin Avenue 23, Nizhny Novgorod 603950 (Russian Federation); Ainbinder, R.M. [Department of Theoretical Physics, Nizhny Novgorod University, Gagarin Avenue 23, Nizhny Novgorod 603950 (Russian Federation)]. E-mail: romain@inbox.ru; Vodolazov, D.Yu. [Institute for Physics of Microstructures, GSP-105, Nizhny Novgorod 603950 (Russian Federation)

    2007-01-15

    In this work, the joint influence of the surface barrier and bulk pinning on the magnetic-field dependence of the critical current I {sub c} for bulk type-II superconductors is investigated. It is shown that in the weak magnetic field H {sub 0}, there is a section in the dependence I {sub c}(H {sub 0}) in which I {sub c} increases with the growth of H {sub 0}; this increase results in a pronounced peak in the dependence I {sub c}(H {sub 0}) - the anomalous peak-effect. This effect is explained by the combined influence of the surface barrier and bulk pinning. Two well-known models - the Bean model and the Kim-Anderson model - of the critical state were analysed in order to describe the anomalous peak-effect quantitatively.

  8. The effect of pregnancy on paternal skin allograft survival

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Elucidation of maternal-fetal tolerance mechanisms clarifies the role of regulatory T cells (Treg) in transplant tolerance. This study aim to investigate the effect of pregnancy on paternal skin allograft survival. Flow cytometry techniques, mixed lymphocytes reaction (MLR), PCR, real-time PCR and skin transplantation were key methods. Treg increased significantly from 4.2% before pregnancy to peak at 6.8% day 8 after pregnancy. Both heme oxygenase-1 (HO-1) and indoleamine 2,3-dioxygenase (IDO) mRNA express high in placenta while low in spleen (P<0.05). Although Treg increased during pregnancy, and splenocytes from the pregnant mice showed lower MLR response toward the paternal stimulator, single time pregnancy showed no significant protective effect on paternal skin allograft survival in the tested condition.

  9. The effect of grape-skin extract on oxidative status

    DEFF Research Database (Denmark)

    Young, J. F.; Dragsted, L. O.; Daneshvar, B.

    2000-01-01

    Epidemiological studies indicate that moderate alcohol consumption, particularly wine, reduce the risk of CHD. The present study was designed to investigate the effect of grape-skin extract on markers of oxidative status. The study was designed as a randomised crossover. A diet with a low content...... of flavonoids was served with strict control of intake in two consecutive 1-week intervention periods to fifteen subjects (nine women, six men) divided randomly into two groups. During one of the weeks the subjects from either group consumed 200 ml grape-skin extract in water (1 mg extract/ml) at each of three...... daily meals (31.3 mg total phenolics, including 9.0 mg catechin). An increased activity of glutathione reductase and a borderline increase of glutathione peroxidase activity in erythrocytes were observed after grape-skin intervention, while the intervention had no significant effect on superoxide...

  10. The effect of pregnancy on paternal skin allograft survival

    Institute of Scientific and Technical Information of China (English)

    SHOU ZhangFei; XU YiFang; XIAO HuaYing; ZHOU Qin; CAI JieRu; YANG Yi; JIANG Hong; ZHANG WenJie; CHEN JiangHua

    2009-01-01

    Elucidation of maternal-fetal tolerance mechanisms clarifies the role of regulatory T cells (Treg)in transplant tolerance.This study aim to investigate the effect of pregnancy on paternal skin allograft survival.Flow cytometry techniques,mixed lymphocytes reaction (MLR),PCR,real-time PCR and skin transplantation were key methods.Treg increased significantly from 4.2% before pregnancy to peak at 6.8% day 8 after pregnancy.Both heme oxygenase-1 (HO-1)and indoleamine 2,3-dioxygenase (IDO)mRNA express high in placenta while low in spleen (P<0.05).Although Treg increased during pregnancy,and splenocytes from the pregnant mice showed lower MLR response toward the paternal stimulator,single time pregnancy showed no significant protective effect on paternal skin allograft survival in the tested condition.

  11. Anomalous Hall effect in L 10-MnAl films with controllable orbital two-channel Kondo effect

    Science.gov (United States)

    Zhu, L. J.; Nie, S. H.; Zhao, J. H.

    2016-05-01

    The anomalous Hall effect (AHE) in strongly disordered magnetic systems has been buried in persistent confusion despite its long history. We report the AHE in perpendicularly magnetized L 10-MnAl epitaxial films with a variable orbital two-channel Kondo (2CK) effect arising from the strong coupling of conduction electrons and the structural disorders of two-level systems. The AHE is observed to excellently scale with ρAH/f =a0ρx x 0+b ρxx 2 at high temperatures where phonon scattering prevails. In contrast, significant deviation occurs at low temperatures where the orbital 2CK effect becomes important, suggesting a negative AHE contribution. The deviation of the scaling agrees with the orbital 2CK effect in the breakdown temperatures and deviation magnitudes.

  12. High-Temperature Quantum Anomalous Hall Effect in n-p Codoped Topological Insulators.

    Science.gov (United States)

    Qi, Shifei; Qiao, Zhenhua; Deng, Xinzhou; Cubuk, Ekin D; Chen, Hua; Zhu, Wenguang; Kaxiras, Efthimios; Zhang, S B; Xu, Xiaohong; Zhang, Zhenyu

    2016-07-29

    The quantum anomalous Hall effect (QAHE) is a fundamental quantum transport phenomenon that manifests as a quantized transverse conductance in response to a longitudinally applied electric field in the absence of an external magnetic field, and it promises to have immense application potential in future dissipationless quantum electronics. Here, we present a novel kinetic pathway to realize the QAHE at high temperatures by n-p codoping of three-dimensional topological insulators. We provide a proof-of-principle numerical demonstration of this approach using vanadium-iodine (V-I) codoped Sb_{2}Te_{3} and demonstrate that, strikingly, even at low concentrations of ∼2%  V and ∼1% I, the system exhibits a quantized Hall conductance, the telltale hallmark of QAHE, at temperatures of at least ∼50  K, which is 3 orders of magnitude higher than the typical temperatures at which it has been realized to date. The underlying physical factor enabling this dramatic improvement is tied to the largely preserved intrinsic band gap of the host system upon compensated n-p codoping. The proposed approach is conceptually general and may shed new light in experimental realization of high-temperature QAHE.

  13. Anomalous transport model study of chiral magnetic effects in heavy ion collisions

    Science.gov (United States)

    Sun, Yifeng; Ko, Che Ming; Li, Feng

    2016-10-01

    Using an anomalous transport model for massless quarks and antiquarks, we study the effect of a magnetic field on the elliptic flows of quarks and antiquarks in relativistic heavy ion collisions. With initial conditions from a blast wave model and assuming that the strong magnetic field produced in noncentral heavy ion collisions can last for a sufficiently long time, we obtain an appreciable electric quadrupole moment in the transverse plane of a heavy ion collision. The electric quadrupole moment subsequently leads to a splitting between the elliptic flows of quarks and antiquarks. The slope of the charge asymmetry dependence of the elliptic flow difference between positively and negatively charged particles is positive, which is expected from the chiral magnetic wave formed in the produced QGP and observed in experiments at the BNL Relativistic Heavy Ion Collider, only if the Lorentz force acting on the charged particles is neglected and the quark-antiquark scattering is assumed to be dominated by the chirality changing channel.

  14. Quantum anomalous Hall effect in magnetically modulated topological insulator/normal insulator heterostructures

    Science.gov (United States)

    Men'shov, V. N.; Tugushev, V. V.; Chulkov, E. V.

    2016-10-01

    We theoretically study how magnetic modulation can be used to manipulate the transport properties of heterostructures formed by a thin film of a three-dimensional topological insulator sandwiched between slabs of a normal insulator. Employing the k • p scheme, in the framework of a continual approach, we argue that electron states of the system are spin-polarized when ultrathin magnetic insertions are incorporated into the film. We demonstrate that (i) the spin-polarization magnitude depends strongly on the magnetic insertion position in the film and (ii) there is the optimal insertion position to realize quantum anomalous Hall effect, which is a function of the material parameters, the film thickness and the topological insulator/normal insulator interface potential. For the heterostructure with a pair of symmetrically placed magnetic insertions, we calculate a phase diagram that shows a series of transitions between distinct quantum regimes of transverse conductivity. We provide consistent interpretation of recent experimental findings in the context of our results.

  15. Anomalous triple gauge couplings in the effective field theory approach at the LHC

    Science.gov (United States)

    Falkowski, Adam; González-Alonso, Martín; Greljo, Admir; Marzocca, David; Son, Minho

    2017-02-01

    We discuss how to perform consistent extractions of anomalous triple gauge couplings (aTGC) from electroweak boson pair production at the LHC in the Standard Model Effective Field Theory (SMEFT). After recasting recent ATLAS and CMS searches in pp → W Z( W W ) → ℓ'νℓ+ℓ-(νℓ) channels, we find that: (a) working consistently at order Λ-2 in the SMEFT expansion the existing aTGC bounds from Higgs and LEP-2 data are not improved, (b) the strong limits quoted by the experimental collaborations are due to the partial Λ-4 corrections (dimension-6 squared contributions). Using helicity selection rule arguments we are able to explain the suppression in some of the interference terms, and discuss conditions on New Physics (NP) models that can benefit from such LHC analyses. Furthermore, standard analyses assume implicitly a quite large NP scale, an assumption that can be relaxed by imposing cuts on the underlying scale of the process ( √{widehat{s}} ). In practice, we find almost no correlation between √{widehat{s}} and the experimentally accessible quantities, which complicates the SMEFT interpretation. Nevertheless, we provide a method to set (conservative) aTGC bounds in this situation, and recast the present searches accordingly. Finally, we introduce a simple NP model for aTGC to compare the bounds obtained directly in the model with those from the SMEFT analysis.

  16. Magnetic modulation doping in topological insulators toward higher-temperature quantum anomalous Hall effect

    Energy Technology Data Exchange (ETDEWEB)

    Mogi, M., E-mail: mogi@cmr.t.u-tokyo.ac.jp; Yoshimi, R.; Yasuda, K.; Kozuka, Y. [Department of Applied Physics and Quantum Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656 (Japan); Tsukazaki, A. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); PRESTO, Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-0075 (Japan); Takahashi, K. S. [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Kawasaki, M.; Tokura, Y. [Department of Applied Physics and Quantum Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656 (Japan); RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan)

    2015-11-02

    Quantum anomalous Hall effect (QAHE), which generates dissipation-less edge current without external magnetic field, is observed in magnetic-ion doped topological insulators (TIs) such as Cr- and V-doped (Bi,Sb){sub 2}Te{sub 3}. The QAHE emerges when the Fermi level is inside the magnetically induced gap around the original Dirac point of the TI surface state. Although the size of gap is reported to be about 50 meV, the observable temperature of QAHE has been limited below 300 mK. We attempt magnetic-Cr modulation doping into topological insulator (Bi,Sb){sub 2}Te{sub 3} films to increase the observable temperature of QAHE. By introducing the rich-Cr-doped thin (1 nm) layers at the vicinity of both the surfaces based on non-Cr-doped (Bi,Sb){sub 2}Te{sub 3} films, we have succeeded in observing the QAHE up to 2 K. The improvement in the observable temperature achieved by this modulation-doping appears to be originating from the suppression of the disorder in the surface state interacting with the rich magnetic moments. Such a superlattice designing of the stabilized QAHE may pave a way to dissipation-less electronics based on the higher-temperature and zero magnetic-field quantum conduction.

  17. Smearing of the quantum anomalous Hall effect due to statistical fluctuations of magnetic dopants

    Science.gov (United States)

    Yue, Z.; Raikh, M. E.

    2016-10-01

    The quantum anomalous Hall effect is induced by substitution of a certain portion x of Bi atoms in a BiTe-based insulating parent compound by magnetic ions (Cr or V). We find the density of in-gap states N (E ) emerging as a result of statistical fluctuations of the composition x in the vicinity of the transition point where the average gap E¯g passes through zero. A local gap follows the fluctuations of x . Using the instanton approach, we show that, near the gap edges, the tails are exponential lnN (E ) ∝-(E¯g-|E |) and the tail states are due to small local gap reduction. Our main finding is that, even when the smearing magnitude exceeds the gap width, there exists a semihard gap around zero energy, where lnN (E ) ∝-E/¯g|E | ln(E/¯g|E | ) . The states responsible for N (E ) originate from local gap reversals within narrow rings. The consequence of the semihard gap is the Arrhenius, rather than variable-range hopping, temperature dependence of the diagonal conductivity at low temperatures.

  18. Theory for the anomalous electron transport in Hall-effect thrusters

    Science.gov (United States)

    Lafleur, Trevor; Baalrud, Scott; Chabert, Pascal

    2016-09-01

    Using insights from particle-in-cell (PIC) simulations, we develop a kinetic theory to explain the anomalous cross-field electron transport in Hall-effect thrusters (HETs). The large axial electric field in the acceleration region of HETs, together with the radially applied magnetic field, causes electrons to drift in the azimuthal direction with a very high velocity. This drives an electron cyclotron instability that produces large amplitude oscillations in the plasma density and azimuthal electric field, and which is convected downstream due to the large axial ion drift velocity. The frequency and wavelength of the instability are of the order of 5 MHz and 1 mm respectively, while the electric field amplitude can be of a similar magnitude to axial electric field itself. The instability leads to enhanced electron scattering many orders of magnitude higher than that from standard electron-neutral or electron-ion Coulomb collisions, and gives electron mobilities in good agreement with experiment. Since the instability is a strong function of almost all plasma properties, the mobility cannot in general be fitted with simple 1/B or 1/B2 scaling laws, and changes to the secondary electron emission coefficient of the HET channel walls are expected to play a role in the evolution of the instability. This work received financial support from a CNES postdoctoral research award.

  19. Ultrasensitive Anomalous Hall Effect in Ta/CoFe/Oxide/Ta Multilayers

    Directory of Open Access Journals (Sweden)

    Guang Yang

    2016-01-01

    Full Text Available Ultrahigh anomalous Hall sensitivity has been demonstrated in Ta/CoFe/Oxide/Ta multilayers. By changing oxides (MgO and HfO2 and annealing temperature, different annealing dependence of sensitivity was found in MgO-sample and HfO2-sample. For the MgO-sample, the anomalous Hall sensitivity reaches 18792 Ω/T in the as-deposited state and significantly reduces as annealing temperature increases. On the contrary, the sensitivity of the as-deposited HfO2-sample is only 765 Ω/T, while it remarkably increases with annealing temperature increasing, finally reaching 14741 Ω/T at 240°C. The opposite variation of anomalous sensitivity in two samples originates from the different change of magnetic anisotropy and anomalous Hall resistance during the annealing process. Our study provides a new perspective that both the choice of oxide material and the optimization of annealing treatment are important to the anomalous Hall sensitivity.

  20. Room-temperature anomalous Hall effect and magnetroresistance in (Ga, Co)-codoped ZnO diluted magnetic semiconductor films

    Institute of Scientific and Technical Information of China (English)

    Liu Xue-Chao; Chen Zhi-Zhan; Shi Er-Wei; Liao Da-Qian; Zhou Ke-Jin

    2011-01-01

    This paper reports that the (Ga, Co)-codoped ZnO thin films have been grown by inductively coupled plasma enhanced physical vapour deposition. Room-temperature ferromagnetism is observed for the as-grown thin films. The x-ray absorption fine structure characterization reveals that Co2+ and Ga3+ ions substitute for Zn2+ ions in the ZnO lattice and exclude the possibility of extrinsic ferromagnetism origin. The ferromagnetic (Ga, Co)-codoped ZnO thin films exhibit carrier concentration dependent anomalous Hall effect and positive magnetoresistance at room temperature. The mechanism of anomalous Hall effect and magneto-transport in ferromagnetic ZnO-based diluted magnetic semiconductors is discussed.

  1. Effect of band filling on anomalous Hall conductivity and magneto-crystalline anisotropy in NiFe epitaxial thin films

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Zhong; Jiang, Hang-Yu; Zhou, Shi-Ming, E-mail: shiming@tongji.edu.cn [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology & Pohl Institute of Solid State Physics, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Hou, Yan-Liang; Ye, Quan-Lin [Department of Physics, Hangzhou Normal University, Hangzhou 310036 (China); Su Si, Ming [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China)

    2016-01-15

    The anomalous Hall effect (AHE) and magneto-crystalline anisotropy (MCA) are investigated in epitaxial Ni{sub x}Fe{sub 1−x} thin films grown on MgO (001) substrates. The scattering independent term b of anomalous Hall conductivity shows obvious correlation with cubic magneto-crystalline anisotropy K{sub 1}. When nickel content x decreasing, both b and K{sub 1} vary continuously from negative to positive, changing sign at about x = 0.85. Ab initio calculations indicate Ni{sub x}Fe{sub 1−x} has more abundant band structures than pure Ni due to the tuning of valence electrons (band fillings), resulting in the increased b and K{sub 1}. This remarkable correlation between b and K{sub 1} can be attributed to the effect of band filling near the Fermi surface.

  2. Intrinsic Quantum Anomalous Hall Effect in the Kagome Lattice Cs2 LiMn3 F12

    Science.gov (United States)

    Xu, Gang; Lian, Biao; Zhang, Shou-Cheng; Zhang's Group Team

    In a kagome lattice, the time reversal symmetry can be broken by a staggered magnetic flux emerging from the ferromagnetic ordering and intrinsic spin-orbit coupling, leading to several well-separated nontrivial Chern bands and intrinsic quantum anomalous Hall effect. Based on this idea and ab initio calculations, we propose the realization of the intrinsic quantum anomalous Hall effect in the single layer Cs2Mn3F12 kagome lattice and on the (001) surface of a Cs2LiMn3F12 single crystal by modifying the carrier coverage on it, where the band gap is around 20 meV. Moreover, a simplified tight binding model based on the inplane dd σ antibonding states is constructed to understand the topological band structures of the system.

  3. Effect of band filling on anomalous Hall conductivity and magneto-crystalline anisotropy in NiFe epitaxial thin films

    Directory of Open Access Journals (Sweden)

    Zhong Shi

    2016-01-01

    Full Text Available The anomalous Hall effect (AHE and magneto-crystalline anisotropy (MCA are investigated in epitaxial NixFe1−x thin films grown on MgO (001 substrates. The scattering independent term b of anomalous Hall conductivity shows obvious correlation with cubic magneto-crystalline anisotropy K1. When nickel content x decreasing, both b and K1 vary continuously from negative to positive, changing sign at about x = 0.85. Ab initio calculations indicate NixFe1−x has more abundant band structures than pure Ni due to the tuning of valence electrons (band fillings, resulting in the increased b and K1. This remarkable correlation between b and K1 can be attributed to the effect of band filling near the Fermi surface.

  4. Intrinsic Quantum Anomalous Hall Effect in the Kagome Lattice Cs_{2}LiMn_{3}F_{12}.

    Science.gov (United States)

    Xu, Gang; Lian, Biao; Zhang, Shou-Cheng

    2015-10-30

    In a kagome lattice, the time reversal symmetry can be broken by a staggered magnetic flux emerging from ferromagnetic ordering and intrinsic spin-orbit coupling, leading to several well-separated nontrivial Chern bands and intrinsic quantum anomalous Hall effect. Based on this idea and ab initio calculations, we propose the realization of the intrinsic quantum anomalous Hall effect in the single layer Cs_{2}Mn_{3}F_{12} kagome lattice and on the (001) surface of a Cs_{2}LiMn_{3}F_{12} single crystal by modifying the carrier coverage on it, where the band gap is around 20 meV. Moreover, a simplified tight binding model based on the in-plane ddσ antibonding states is constructed to understand the topological band structures of the system.

  5. Stability and anomalous compressibility of Bose gases near resonance: The scale-dependent interactions and thermal effects

    Science.gov (United States)

    Jiang, Shao-Jian; Zhou, Fei

    2015-07-01

    The stability of Bose gases near resonance has been a puzzling problem in recent years. In this article, we demonstrate that in addition to generating thermal pressure, thermal atoms enhance the repulsiveness of the scale-dependent interactions between condensed atoms due to a renormalization effect and further stabilize the Bose gases. Consequently, we find that, as a precursor of instability, the compressibility develops an anomalous structure as a function of scattering length and is drastically reduced compared with the mean-field value. Furthermore, the density profile of a Bose gas in a harmonic trap is found to develop a flat top near the center. This is due to the anomalous behavior of compressibility and can be a potential smoking gun for probing such an effect.

  6. Effects of Anomalous Electron Cross-Field Transport in a Low Temperature Magnetized Plasma

    Science.gov (United States)

    Raitses, Yevgeny

    2014-10-01

    The application of the magnetic field in a low pressure plasma can cause a spatial separation of low and high energy electrons. This so-called magnetic filter effect is used for many plasma applications, including ion and neutral beam sources, plasma processing of semiconductors and nanomaterials, and plasma thrusters. In spite of successful practical applications, the magnetic filter effect is not well understood. In this work, we explore this effect by characterizing the electron and ion energy distribution functions in a plasma column with crossed electric and magnetic fields. Experimental results revealed a strong dependence of spatial variations of plasma properties on the gas pressure. For xenon and argon gases, below ~ 1 mtorr, the increase of the magnetic field leads to a more uniform profile of the electron temperature. This surprising result is due to anomalously high electron cross-field transport that causes mixing of hot and cold electrons. High-speed imaging and probe measurements revealed a coherent structure rotating in E cross B direction with frequency of a few kHz. Theory and simulations describing this rotating structure has been developed and points to ionization and electrostatic instabilities as their possible cause. Similar to spoke oscillations reported for Hall thrusters, this rotating structure conducts the large fraction of the cross-field current. The use of segmented electrodes with an electrical feedback control is shown to mitigate these oscillations. Finally, a new feature of the spoke phenomenon that has been discovered, namely a sensitive dependence of the rotating oscillations on the gas pressure, can be important for many applications. This work was supported by DOE Contract DE-AC02-09CH11466.

  7. Effects of microneedle system on the skin permeation of drugs

    OpenAIRE

    呉, 学明

    2007-01-01

    Microneedle systems have been paid attention as having many advantages overtransdermal patches and hypodermic needles. The procedure provides adequate skinpermeation rates without pain or severe infection. to obtain information for designing amicroneedle system, the pretreatment effect of microneedle puncture in the skin barrierstratum corneum on the in vitro skin permeatien of fluorescein isothiocyanate(FITC)一dextrans (4.3, 9.6 and 42.0 kDa) (FD-4, FD-10 and FD-40) was evaluated in hairlessr...

  8. Effective Architectural Design Decisions in Double Skin Facades

    Directory of Open Access Journals (Sweden)

    Tuğba İnan

    2013-06-01

    Full Text Available In architectural discourse, it is possible to notice a rising interest in building skin configurations which promise to help minimizing the loss of energy while maximizing its gain. In parallel, it is possible to see that the use of double-skin glass facades globally pervades. All over the world double-skin facade applications multiply day by day. This technology is still quite new in Turkey and it is not possible to find many applications or researches done on this subject. For this reason, architects and engineers should be focused on the designs solutions providing energy savings. The design of DSF depends on various architectural decisions. In this study, effective design decision parameters on energy performance of DSF systems will be discussed in a comprehensive way in architectural perspective by reviewing previous studies.

  9. Local orbitals approach to the anomalous Hall and Nernst effects in itinerant ferromagnets

    Directory of Open Access Journals (Sweden)

    Středa Pavel

    2014-07-01

    Full Text Available Linear response of the orbital momentum to the gradient of the chemical potential is used to obtain anomalous Hall conductivity. Transition from the ideal Bloch system for which the conductivity is determined by the Berry phase curvatures to the case of strong disorder for which the conductivity becomes dependent on the relaxation time is analysed. Presented tight-binding model reproduces experimentally observed qualitative features of the anomalous Hall conductivity and the transverse Peltier coefficient in the so called bad-metal and scattering-independent regimes.

  10. Anomalous chiral superfluidity

    Energy Technology Data Exchange (ETDEWEB)

    Lublinsky, Michael, E-mail: lublinsky@phys.uconn.ed [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Physics Department, Ben-Gurion University, Beer Sheva 84105 (Israel); Zahed, Ismail [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States)

    2010-02-08

    We discuss both the anomalous Cartan currents and the energy-momentum tensor in a left chiral theory with flavor anomalies as an effective theory for flavored chiral phonons in a chiral superfluid with the gauged Wess-Zumino-Witten term. In the mean-field (leading tadpole) approximation the anomalous Cartan currents and the energy-momentum tensor take the form of constitutive currents in the chiral superfluid state. The pertinence of higher order corrections and the Adler-Bardeen theorem is briefly noted.

  11. Anomalous H/D isotope effect on {sup 35}Cl NQR frequencies in piperidinium p-chlorobenzoate

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Ryo; Honda, Hisashi, E-mail: hhonda@yokohama-cu.ac.jp [Yokohama City University, Graduate School of Integrated Science (Japan); Kimura, Taiki [Yokohama City University, Faculty of Science (Japan); Nakata, Eiichi; Takamizawa, Satoshi; Noro, Sumiko [Yokohama City University, Graduate School of Integrated Science (Japan); Ishimaru, Shin' ichi [Tokyo Denki University, Department of Green and Sustainable Chemistry (Japan)

    2008-01-15

    Anomalous isotope effects were detected in the {sup 35}Cl nuclear quadrupole resonance (NQR) frequency of piperidinium p-chlrobenzoate (C{sub 5}H{sub 10}NH. ClC{sub 6}H{sub 4}COOH) by deuteration of hydrogen atoms. The atoms were determined to form two kinds of N-H...O type H-bonds in the crystal structure. Large frequency shifts of the {sup 35}Cl resonance lines reaching 288 kHz at 77 K and 278 kHz at room temperature were caused upon deuteration, in spite of the fact that the Cl atoms in the molecule do not form hydrogen bonds in the crystal. Results of single crystal X-ray diffraction measurements and density-functional-theorem calculations suggest that a dihedral-angle change of 1.8{sup o} between benzene and the piperidine ring contributes to {sup 35}Cl NQR anomalous frequency shifts.

  12. Anomalous polymer dynamics is non-Markovian: memory effects and the generalized Langevin equation formulation

    NARCIS (Netherlands)

    Panja, D.

    2010-01-01

    Any first course on polymer physics teaches that the dynamics of a tagged monomer of a polymer is anomalously subdiffusive, i.e., the mean-square displacement of a tagged monomer increases as tα for some α < 1 until the terminal relaxation time τ of the polymer. Beyond time τ the motion of the tagge

  13. Beer and beer compounds: physiological effects on skin health.

    Science.gov (United States)

    Chen, W; Becker, T; Qian, F; Ring, J

    2014-02-01

    Beer is one of the earliest human inventions and globally the most consumed alcoholic beverage in terms of volume. In addition to water, the 'German Beer Purity Law', based on the Bavarian Beer Purity Law from 1516, allows only barley, hops, yeasts and water for beer brewing. The extracts of these ingredients, especially the hops, contain an abundance of polyphenols such as kaempferol, quercetin, tyrosol, ferulic acid, xanthohumol/isoxanthohumol/8-prenylnaringenin, α-bitter acids like humulone and β-bitter acids like lupulone. 8-prenylnaringenin is the most potent phytoestrogen known to date. These compounds have been shown to possess various anti-bacterial, anti-inflammatory, anti-oxidative, anti-angiogenic, anti-melanogenic, anti-osteoporotic and anti-carcinogenic effects. Epidemiological studies on the association between beer drinking and skin disease are limited while direct evidence of beer compounds in clinical application is lacking. Potential uses of these substances in dermatology may include treatment of atopic eczema, contact dermatitis, pigmentary disorders, skin infections, skin ageing, skin cancers and photoprotections, which require an optimization of the biostability and topical delivery of these compounds. Further studies are needed to determine the bioavailability of these compounds and their possible beneficial health effects when taken by moderate beer consumption.

  14. Thermal diffusivity effect in opto-thermal skin measurements

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, P; Imhof, R E [Faculty of ESBE, London South Bank University, 103 Borough Road, London SE1 0AA (United Kingdom); Cui, Y [Sunrise Systems Limited, Flint Bridge Business Centre, Ely Road, Waterbeach, Cambridge CB5 9QZ (United Kingdom); Ciortea, L I; Berg, E P, E-mail: xiaop@lsbu.ac.u [Biox Systems Ltd, 103 Borough Road, London SE1 0AA (United Kingdom)

    2010-03-01

    We present our latest study on the thermal diffusivity effect in opto-thermal skin measurements. We discuss how thermal diffusivity affects the shape of opto-thermal signal, and how to measure thermal diffusivity in opto-thermal measurements of arbitrary sample surfaces. We also present a mathematical model for a thermally gradient material, and its corresponding opto-thermal signal. Finally, we show some of our latest experimental results of this thermal diffusivity effect study.

  15. Sensory neuropeptide effects in human skin.

    OpenAIRE

    Fuller, R W; Conradson, T. B.; Dixon, C M; Crossman, D.C.; Barnes, P. J.

    1987-01-01

    1 Neuropeptides released from sensory nerves may account for cutaneous flare and wheal following local trauma. In 28 normal subjects we have studied the effects of four sensory neuropeptides given by intradermal injection on the forearm or back. 2 All peptides caused a flare distant from the site of injection, presumably due to an axon reflex. Substance P (SP) was the most potent (geometric mean dose causing 50% of maximum flare, 4.2 pmol). Neurokinin A (NKA) was the next most potent with neu...

  16. Competing effects of magnetic impurities in the anomalous Hall effect on the surface of a topological insulator

    Science.gov (United States)

    Deng, Ming-Xun; Luo, Wei; Deng, W. Y.; Chen, M. N.; Sheng, L.; Xing, D. Y.

    2016-12-01

    We investigate the anomalous Hall effect (AHE) on the surface of a topological insulator induced by a finite concentration of magnetic impurities, and find topologically nontrivial and trivial mechanisms simultaneously contributing to the Hall conductivity. In the topologically nontrivial mechanism, the impurities gap the surface spectrum and result in a half-integer quantized intrinsic Hall conductivity in units e2/h , while in the topologically trivial mechanism, the half-integer quantized plateau is modified by impurity-induced localized states via a gap-filling process. The nonmagnetic charge potential itself, though participating in the gap-filling process, cannot induce the AHE. In the presence of a finite magnetic potential, the charge potential would destroy the symmetric distribution of the Hall conductivity by redistributing the localized levels. More interestingly, the sign of the Hall conductivity is tunable by changing the strength of the charge potential.

  17. Effect of Age on Tooth Shade, Skin Color and Skin-Tooth Color Interrelationship in Saudi Arabian Subpopulation

    Science.gov (United States)

    Haralur, Satheesh B

    2015-01-01

    Background: Dental restoration or prosthesis in harmony with adjacent natural teeth color is indispensable part for the successful esthetic outcome. The studies indicate is existence of correlation between teeth and skin color. Teeth and skin color are changed over the aging process. The aim of the study was to explore the role of age on the tooth and skin color parameters, and to investigate the effect of ageing on teeth-skin color correlation. Materials and Methods: Total of 225 Saudi Arabian ethnic subjects was divided into three groups of 75 each. The groups were divided according to participant’s age. The participant’s age for Group I, Group II, and Group III was 18-29 years, 30-50 years, and above 50 years, respectively. The tooth color was identified by spectrophotometer in CIE Lab parameters. The skin color was registered with skin surface photography. The data were statistically analyzed with one-way ANOVA and correlation tests with SPSS 18 software. Results: The Group I had the highest ‘L’ value of 80.26, Group III recorded the least value of 76.66. The Group III had highest yellow value ‘b’ at 22.72, while Group I had 19.19. The skin ‘L’ value was highest in the young population; the elder population had the increased red value ‘a’ in comparison to younger subjects. The ‘L’ tooth color parameter had a strong positive linear correlation with skin color in young and adult subjects. While Group III teeth showed the strong positive correlation with ‘b’ parameter at malar region. Conclusion: The elder subjects had darker and yellow teeth in comparison with younger subjects. The reddening of the skin was observed as age-related skin color change. The age had a strong influence on the teeth-skin color correlation. PMID:26464536

  18. Some anomalous effects of sodium ions on the electrophoretic mobility and heteroaggregation of microgel particles.

    Science.gov (United States)

    Routh, Alexander F; Vincent, Brian

    2004-05-15

    a cationic polystyrene latex sample, prepared with the same amidinium-based initiator. These experiments demonstrate the importance of soluble silicates, leached from glass storage vessels, particularly in the presence of sodium ions. Needless to say, the "anomalous" effects disappeared when plastic storage vessels were used in place of the glass ones.

  19. Effects of Essential Oils and Polyunsaturated Fatty Acids on Canine Skin Equivalents: Skin Lipid Assessment and Morphological Evaluation

    Directory of Open Access Journals (Sweden)

    S. Cerrato

    2013-01-01

    Full Text Available A canine skin equivalent model has been validated for the assessment of a topical formulation effects. Skin equivalents were developed from freshly isolated cutaneous canine fibroblasts and keratinocytes, after enzymatic digestion of skin samples (n=8 from different breeds. Fibroblasts were embedded into a collagen type I matrix, and keratinocytes were seeded onto its surface at air-liquid interface. Skin equivalents were supplemented with essential oils and polyunsaturated fatty acid formulation or with vehicle. Skin equivalents were histopathologically and ultrastructurally studied, and the three main lipid groups (free fatty acids, cholesterol, and ceramides were analyzed. Results showed that the culture method developed resulted in significant improvements in cell retrieval and confluence. Treated samples presented a thicker epidermis with increased number of viable cell layers, a denser and compact stratum corneum, and a more continuous basal membrane. Regarding lipid profile, treated skin equivalents showed a significant increase in ceramide content (51.7±1.3 when compared to untreated (41.6 ± 1.4 samples. Ultrastructural study evidenced a compact and well-organized stratum corneum in both treated and control skin equivalents. In conclusion, cell viability and ceramides increase, after lipid supplementation, are especially relevant for the treatment of skin barrier disruptions occurring in canine atopic dermatitis.

  20. Clinical effects of an oral supplement rich in antioxidants on skin radiance in women

    OpenAIRE

    Dumoulin M; Gaudout D; Lemaire B

    2016-01-01

    Marion Dumoulin, David Gaudout, Benoit Lemaire Activ’Inside, Libourne, France Background: Environmental factors impact the skin aging resulting in decrease of skin radiance. Nutrition and particularly antioxidants could help to fight against skin degradation.Objective: The aim of this study was to evaluate the effects of an oral supplement rich in specific antioxidants, SkinAx2TM, on the improvement of the skin radiance in women.Methods: The open-label clinical stu...

  1. Evaluation of skin viability effect on ethosome and liposome-mediated psoralen delivery via cell uptake.

    Science.gov (United States)

    Zhang, Yong-Tai; Shen, Li-Na; Wu, Zhong-Hua; Zhao, Ji-Hui; Feng, Nian-Ping

    2014-10-01

    This study investigated the effect of skin viability on its permeability to psoralen delivered by ethosomes, as compared with liposomes. With decreasing skin viability, the amount of liposome-delivered psoralen that penetrated through the skin increased, whereas skin deposition of psoralen from both ethosomes and liposomes reduced. Psoralen delivery to human-immortalized epidermal cells was more effective using liposomes, whereas delivery to human embryonic skin fibroblast cells was more effective when ethosomes were used. These findings agreed with those of in vivo studies showing that skin psoralen deposition from ethosomes and liposomes first increased and then plateaued overtime, which may indicate gradual saturation of intracellular drug delivery. It also suggested that the reduced deposition of ethosome- or liposome-delivered psoralen in skin with reduced viability may relate to reduced cellular uptake. This work indicated that the effects of skin viability should be taken into account when evaluating nanocarrier-mediated drug skin permeation.

  2. Influence of defects and disorder on anomalous Hall effect and spin Seebeck effect on permalloy and Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Vilanova Vidal, Enrique

    2012-09-19

    In this work Heusler thin films have been prepared and their transport properties have been studied. Of particularly interest is the anomalous Hall effect (AHE). The effect is a long known but still not fully understood transport effect. Most theory papers focus on the influence of one particular contribution to the AHE. Actual measured experimental data, however, often are not in accordance with idealized assumptions. This thesis discusses the data analysis for materials with low residual resistivity ratios. As prototypical materials, half metallic Heusler compounds are studied. Here, the influence of defects and disorder is apparent in a material with a complex topology of the Fermi surface. Using films with different degrees of disorder, the different scattering mechanisms can be separated. For Co{sub 2}FeSi{sub 0.6}Al{sub 0.4} and Co{sub 2}FeGa{sub 0.5}Ge{sub 0.5}, the AHE induced by B2-type disorder and temperature-dependent scattering is positive, while DO{sub 3}-type disorder and possible intrinsic contributions possess a negative sign. For these compounds, magneto-optical Kerr effects (MOKE) are investigated. First order contributions as a function of intrinsic and extrinsic parameters are qualitatively analyzed. The relation between the crystalline ordering and the second order contributions to the MOKE signal is studied. In addition, sets of the Heusler compound Co{sub 2}MnAl thin films were grown on MgO(100) and Si(100) substrates by radio frequency magnetron sputtering. Composition, magnetic and transport properties were studied systematically for samples deposited at different conditions. In particular, the anomalous Hall effect resistivity presents an extraordinarily temperature independent behavior in a moderate magnetic field range from 0 to 0.6 T. The off-diagonal transport at temperatures up to 300 C was analyzed. The data show the suitability of the material for Hall sensors working well above room temperature. Recently, the spin Seebeck effect

  3. Strong anisotropic anomalous Hall effect and spin Hall effect in the chiral antiferromagnetic compounds Mn3X (X =Ge , Sn, Ga, Ir, Rh, and Pt)

    Science.gov (United States)

    Zhang, Yang; Sun, Yan; Yang, Hao; Železný, Jakub; Parkin, Stuart P. P.; Felser, Claudia; Yan, Binghai

    2017-02-01

    We have carried out a comprehensive study of the intrinsic anomalous Hall effect and spin Hall effect of several chiral antiferromagnetic compounds Mn3X (X = Ge, Sn, Ga, Ir, Rh and Pt) by ab initio band structure and Berry phase calculations. These studies reveal large and anisotropic values of both the intrinsic anomalous Hall effect and spin Hall effect. The Mn3X materials exhibit a noncollinear antiferromagnetic order which, to avoid geometrical frustration, forms planes of Mn moments that are arranged in a Kagome-type lattice. With respect to these Kagome planes, we find that both the anomalous Hall conductivity (AHC) and the spin Hall conductivity (SHC) are quite anisotropic for any of these materials. Based on our calculations, we propose how to maximize AHC and SHC for different materials. The band structures and corresponding electron filling, that we show are essential to determine the AHC and SHC, are compared for these different compounds. We point out that Mn3Ga shows a large SHC of about 600 (ℏ /e ) (Ωcm) -1 . Our work provides insights into the realization of strong anomalous Hall effects and spin Hall effects in chiral antiferromagnetic materials.

  4. The effect of various avocado oils on skin collagen metabolism.

    Science.gov (United States)

    Werman, M J; Mokady, S; Nimni, M E; Neeman, I

    1991-01-01

    The effects of various avocado oils on collagen metabolism in skin were studied in growing rats fed diets containing 10% (w/w) of the tested oils. Rats fed the unrefined avocado oil extracted with hexane from the intact fruit, its unsaponifiables or the avocado seed oil, showed significant increases in soluble collagen content in skin, though total collagen content was not affected. The increased soluble collagen content appears to be a consequence of the inhibition of lysyl oxidase activity. The active factor was found to be present in the unrefined avocado oil and probably originated from the avocado seed, since collagen metabolism was affected only by fractions which contained lipids fraction from the seed. In comparison rats fed the refined or unrefined soybean oils showed no effects.

  5. Skin-sparing effects of neutron beam filtering materials.

    Science.gov (United States)

    Otte, V A; Almond, P R; Smathers, J B; Attix, F H

    1987-01-01

    The skin-sparing effects of several filtering materials for fast neutron beams were studied under various conditions. A parallel-plate ionization chamber was used for the measurements. The parameters which were studied included field size, distance from filter to ion chamber, filter material, and filter thickness. On the basis of this work, Teflon (polytetrafluoroethylene) was chosen for fabrication of flattening filters and wedges.

  6. Partial Wave Analysis of Scattering with Nonlocal Aharonov-Bohm Effect and Anomalous Cross Section induced by Quantum Interference

    CERN Document Server

    Lin, D H

    2003-01-01

    Partial wave theory of a three dmensional scattering problem for an arbitray short range potential and a nonlocal Aharonov-Bohm magnetic flux is established. The scattering process of a ``hard shere'' like potential and the magnetic flux is examined. An anomalous total cross section is revealed at the specific quantized magnetic flux at low energy which helps explain the composite fermion and boson model in the fractional quantum Hall effect. Since the nonlocal quantum interference of magnetic flux on the charged particles is universal, the nonlocal effect is expected to appear in quite general potential system and will be useful in understanding some other phenomena in mesoscopic phyiscs.

  7. Anomalous Doppler effect at interaction of electromagnetic waves with electron beams experimental researches and opportunities for application

    CERN Document Server

    Ivanov, B I

    2002-01-01

    The anomalous Doppler effect (ADE) in systems consisting of an electron beam and slow wave structure in longitudinal magnetic field is considered. Resonance condition for amplifiers and generators based on ADE enables resonance maintaining in case of wave phase velocity or beam velocity changing (acceleration of ions at ADE, reception of high efficiency at microwave generation). Essential advantages can be reached at combination of ADE and normal Doppler effect. The review of experimental studies of ADE is presented: amplification and generation of microwaves, energetic relations, excitation of accelerating IH-structures, development of ion acceleration.

  8. Unambiguous separation of the inverse spin Hall and anomalous Nernst effects within a ferromagnetic metal using the spin Seebeck effect

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Stephen M., E-mail: swu@anl.gov; Hoffman, Jason; Pearson, John E.; Bhattacharya, Anand [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2014-09-01

    The longitudinal spin Seebeck effect is measured on the ferromagnetic insulator Fe{sub 3}O{sub 4} with the ferromagnetic metal Co{sub 0.2}Fe{sub 0.6}B{sub 0.2} (CoFeB) as the spin detector. By using a non-magnetic spacer material between the two materials (Ti), it is possible to decouple the two ferromagnetic materials and directly observe pure spin flow from Fe{sub 3}O{sub 4} into CoFeB. It is shown that in a single ferromagnetic metal, the inverse spin Hall effect (ISHE) and anomalous Nernst effect (ANE) can occur simultaneously with opposite polarity. Using this and the large difference in the coercive fields between the two magnets, it is possible to unambiguously separate the contributions of the spin Seebeck effect from the ANE and observe the degree to which each effect contributes to the total response. These experiments show conclusively that the ISHE and ANE in CoFeB are separate phenomena with different origins and can coexist in the same material with opposite response to a thermal gradient.

  9. First Numerical Simulations of Anomalous Hydrodynamics

    CERN Document Server

    Hongo, Masaru; Hirano, Tetsufumi

    2013-01-01

    Anomalous hydrodynamics is a low-energy effective theory that captures effects of quantum anomalies. We develop a numerical code of anomalous hydrodynamics and apply it to dynamics of heavy-ion collisions, where anomalous transports are expected to occur. This is the first attempt to perform fully non-linear numerical simulations of anomalous hydrodynamics. We discuss implications of the simulations for possible experimental observations of anomalous transport effects. From analyses of the charge-dependent elliptic flow parameters ($v_2^\\pm$) as a function of the net charge asymmetry $A_\\pm$, we quantitatively verify that the linear dependence of $\\Delta v_2 \\equiv v_2^- - v_2^+$ on the net charge asymmetry $A_\\pm$ cannot be regarded as a sensitive signal of anomalous transports, contrary to previous studies. We, however, find that the intercept $\\Delta v_2(A_\\pm=0)$ is sensitive to anomalous transport effects.

  10. Chimney Effect Assessment of the Double-skin Facade

    Institute of Scientific and Technical Information of China (English)

    QIU Zhong-zhu; LI Peng; CHOW Tin-tai; REN Jian-xing; WANG Wen-huan

    2009-01-01

    The mathematic model of heat transfer through ventihted double glazing was verified with themeasured data,which were from a test chamber equipped with glass face temperature,solar radiation,ambient temperature,and wind speed measurement facility.Mter the model validation,the double-skin facade assess-ment was carried out through simulation with ESP-r software integrating thermal simulation and air low net work module.The air flow situation in the air gap was analyzed on the basis of the hourly air velocity simulation data within typical winter week,summer week,spring week and autumn week.The differences of chimney ef-fect in different seasons were discussed,and the thermal loads resulted from the ventilated and unventihted dou-ble skin facade were presented.

  11. Co-occurrence of Superparamagnetism and Anomalous Hall Effect in Highly Reduced Cobalt Doped Rutile TiO2 Films

    OpenAIRE

    2004-01-01

    We report a detailed magnetic and structural analysis of highly reduced Co doped rutile TiO2 films displaying an anomalous Hall effect (AHE). The temperature and field dependence of magnetization, and transmission electron microscopy clearly establish the presence of nano-sized superparamagnetic cobalt clusters of 8-10 nm size in the films at the interface. The co-occurrence of superparamagnetism and AHE raises questions regarding the use of the AHE as a test of the intrinsic nature of ferrom...

  12. The giant anomalous Hall effect in the ferromagnet Fe{sub 3}Sn{sub 2}-a frustrated kagome metal

    Energy Technology Data Exchange (ETDEWEB)

    Kida, T; Hagiwara, M [KYOKUGEN, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Fenner, L A; Dee, A A; Wills, A S [Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Terasaki, I, E-mail: a.s.wills@ucl.ac.uk [Department of Applied Physics, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan)

    2011-03-23

    The kagome-bilayer material Fe{sub 3}Sn{sub 2} has recently been shown to be an example of a rare class of magnet-a frustrated ferromagnetic metal. While the magnetism of Fe{sub 3}Sn{sub 2} appears to be relatively simple at high temperature, with localized moments parallel to the c-axis (T{sub C} = 640 K), upon cooling the competing exchange interactions and spin frustration become apparent as they cause the moments to become non-collinear and to rotate towards the kagome plane, forming firstly a canted ferromagnetic structure and then a re-entrant spin glass (T{sub f{approx_equal}}80 K). In this work we show that Fe{sub 3}Sn{sub 2} possesses an unusual anomalous Hall effect. The saturated Hall resistivity of Fe{sub 3}Sn{sub 2} is 3.2 {mu}{Omega} cm at 300 K, almost 20 times higher than that of typical itinerant ferromagnets such as Fe and Ni. The anomalous Hall coefficient R{sub s} is 6.7 x 10{sup -9} {Omega} cm G{sup -1} at 300 K, which is three orders of magnitude larger than that of pure Fe, and obeys an unconventional scaling with the longitudinal resistivity, {rho}{sub xx}, of R{sub s{proportional_to}{rho}xx}{sup 3.15}. Such a relationship cannot be explained by either the conventional skew or side-jump mechanisms, indicating that the anomalous Hall effect in Fe{sub 3}Sn{sub 2} has an extraordinary origin that is presumed to be related to the underlying frustration of the magnetism. These findings demonstrate that frustrated ferromagnets, whether based on bulk materials or on artificial nanoscale structures, can provide new routes to room temperature spin-dependent electron transport properties suited to application in spintronics. (fast track communication)

  13. Effects of cream containing ficus carica L. fruit extract on skin parameters: In vivo evaluation

    Directory of Open Access Journals (Sweden)

    H Khan

    2014-01-01

    Full Text Available This study was aimed to investigate the effects of cream containing Ficus carica L. fruit ([Figure 1] extract on various skin parameters such as skin melanin, erythema, moisture content, trans-epidermal water loss and sebum. For this purpose, formulation with 4% concentrated extract of F. carica fruit and base without extract were developed. Base served as a control. Both base and formulation were applied to the cheeks of human volunteers for 8 weeks to investigate the effects on different skin parameters using non-invasive bioengineering instruments. Formulation decreased the skin melanin, trans-epidermal water loss and skin sebum significantly. Formulation increased the skin hydration significantly and insignificant effects on skin erythema. We concluded that a stable topical cream (w/o emulsion containing F. carica fruit extract have effects on skin melanin, trans-epidermal loss, hydration values and sebum content and possibly could be used against for hyper pigmentation, acne, freckles and wrinkle.

  14. The effect of various dietary fats on skin tumor initiation.

    Science.gov (United States)

    Locniskar, M; Belury, M A; Cumberland, A G; Patrick, K E; Fischer, S M

    1991-01-01

    The type of dietary fat has been shown to modulate the initiation stage of mammary tumorigenesis, with saturated fat fed before and/or during carcinogen treatment resulting in increased tumor incidence. This study was designed to determine whether different types of dietary fat alter the initiation stage of skin carcinogenesis by use of the initiation-promotion mouse skin carcinogenesis model. Sencar mice were divided into three groups and maintained on one of the experimental diets. The AIN-76-based diets consisted of 10% total fat with various types of fat: 8.5% menhaden oil plus 1.5% corn oil, 8.5% coconut oil plus 1.5% corn oil, and 10% corn oil. After three weeks mice were initiated with 10 nmol dimethylbenz[a]anthracene (DMBA). Two weeks later, all mice were switched to a diet containing 5% corn oil. Promotion began four weeks after initiation with twice-weekly application of 1 microgram 12-O-tetradecanoylphorbol-13-acetate and continued for 12 weeks. No statistically significant differences in kilocalories of food consumed or body weights were observed between diet groups during the study. The final papilloma incidence, yield, and size were not significantly different among the diet groups. In a parallel study, [3H]DMBA binding to epidermal DNA showed no dietary differences. Unlike the mammary carcinogenesis model, these data suggest that the type of fat fed during DMBA initiation had minimal effects on this stage of skin carcinogenesis.

  15. Effect on Microbial Growth of a New Skin Protectant Formulation

    Science.gov (United States)

    Stoffel, Joseph; Bernatchez, Stéphanie F.

    2017-01-01

    Objective: Evaluate the effect of a new investigational skin protectant formulation on the growth of various microorganisms in vitro. Approach: An in vitro laboratory assay with various species of gram-positive bacteria, gram-negative bacteria, and yeast grown on agar plates was used to verify that a new investigational product used for the management of incontinence-associated dermatitis (IAD) does not support microbial growth. Results: The investigational product did not support the growth of all organisms tested for 48 h in these assays. The results demonstrate the barrier properties of this investigational formulation against bacteria and yeast that are relevant to incontinent patients. Innovation: IAD accompanied by skin damage is difficult to manage with currently available products. A new skin protectant that can be applied as a liquid and polymerizes into a breathable film in situ even in the presence of exudate (as shown previously) has been developed and tested to ensure that it does not support microbial growth. Conclusion: This work verifies that this new product does not support microbial growth in vitro using organisms relevant for the intended application. PMID:28289552

  16. Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin.

    Science.gov (United States)

    Barel, A; Calomme, M; Timchenko, A; De Paepe, K; Paepe, K De; Demeester, N; Rogiers, V; Clarys, P; Vanden Berghe, D

    2005-10-01

    Chronic exposure of the skin to sunlight causes damage to the underlying connective tissue with a loss of elasticity and firmness. Silicon (Si) was suggested to have an important function in the formation and maintenance of connective tissue. Choline-stabilized orthosilicic acid ("ch-OSA") is a bioavailable form of silicon which was found to increase the hydroxyproline concentration in the dermis of animals. The effect of ch-OSA on skin, nails and hair was investigated in a randomized, double blind, placebo-controlled study. Fifty women with photodamaged facial skin were administered orally during 20 weeks, 10 mg Si/day in the form of ch-OSA pellets (n=25) or a placebo (n=25). Noninvasive methods were used to evaluate skin microrelief (forearm), hydration (forearm) and mechanical anisotropy (forehead). Volunteers evaluated on a virtual analog scale (VAS, "none=0, severe=3") brittleness of hair and nails. The serum Si concentration was significantly higher after a 20-week supplementation in subjects with ch-OSA compared to the placebo group. Skin roughness parameters increased in the placebo group (Rt:+8%; Rm: +11%; Rz: +6%) but decreased in the ch-OSA group (Rt: -16%; Rm: -19%; Rz: -8%). The change in roughness from baseline was significantly different between ch-OSA and placebo groups for Rt and Rm. The difference in longitudinal and lateral shear propagation time increased after 20 weeks in the placebo group but decreased in the ch-OSA group suggesting improvement in isotropy of the skin. VAS scores for nail and hair brittleness were significantly lower after 20 weeks in the ch-OSA group compared to baseline scores. Oral intake of ch-OSA during the 20 weeks results in a significant positive effect on skin surface and skin mechanical properties, and on brittleness of hair and nails.

  17. Effect of microstructure on anomalous strain-rate-dependent behaviour of bacterial cellulose hydrogel.

    Science.gov (United States)

    Gao, Xing; Shi, Zhijun; Lau, Andrew; Liu, Changqin; Yang, Guang; Silberschmidt, Vadim V

    2016-05-01

    This study is focused on anomalous strain-rate-dependent behaviour of bacterial cellulose (BC) hydrogel that can be strain-rate insensitive, hardening, softening, or strain-rate insensitive in various ranges of strain rate. BC hydrogel consists of randomly distributed nanofibres and a large content of free water; thanks to its ideal biocompatibility, it is suitable for biomedical applications. Motivated by its potential applications in complex loading conditions of body environment, its time-dependent behaviour was studied by means of in-aqua uniaxial tension tests at constant temperature of 37 °C at various strain rates ranging from 0.000 1s(-1) to 0.3s(-1). Experimental results reflect anomalous strain-rate-dependent behaviour that was not documented before. Micro-morphological observations allowed identification of deformation mechanisms at low and high strain rates in relation to microstructural changes. Unlike strain-rate softening behaviours in other materials, reorientation of nanofibres and kinematics of free-water flow dominate the softening behaviour of BC hydrogel at high strain rates.

  18. Anomalous compressibility effects and superconductivity of EuFe2As2 under high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Uhoya, Walter [University of Alabama, Birmingham; Tsoi, Georgiy [University of Alabama, Birmingham; Vohra, Y. K. [University of Alabama, Birmingham; McGuire, Michael A [ORNL; Sefat, A. S. [Oak Ridge National Laboratory (ORNL); Sales, Brian C [ORNL; Mandrus, David [ORNL; Weir, S. T. [Lawrence Livermore National Laboratory (LLNL)

    2010-01-01

    The crystal structure and electrical resistance of structurally layered EuFe{sub 2}As{sub 2} have been studied up to 70 GPa and down to a temperature of 10 K, using a synchrotron x-ray source and designer diamond anvils. The room temperature compression of the tetragonal phase of EuFe{sub 2}As{sub 2} (I4/mmm) results in an increase in the a-axis length and a rapid decrease in the c-axis length with increasing pressure. This anomalous compression reaches a maximum at 8 GPa and the tetragonal lattice behaves normally above 10 GPa, with a nearly constant c/a axial ratio. The rapid rise in the superconducting transition temperature (T{sub c}) to 41 K with increasing pressure is correlated with this anomalous compression, and a decrease in T{sub c} is observed above 10 GPa. We present P-V data or the equation of state for EuFe{sub 2}As{sub 2} both in the ambient tetragonal phase and in the high pressure collapsed tetragonal phase up to 70 GPa.

  19. Effects of disinfectants and detergents on skin irritation.

    Science.gov (United States)

    Slotosch, Caroline M; Kampf, Günter; Löffler, Harald

    2007-10-01

    We investigated the biological response of regular human skin to alcohol-based disinfectants and detergents in a repetitive test design. Using non-invasive diagnostic tools such as transepidermal water loss, laser-Doppler flowmetry and corneometry, we quantified the irritative effects of a propanol-based hand disinfectant (Sterillium), its propanol mixture (2-propanol 45% w/w and 1-propanol 30% w/w), sodium lauryl sulfate (SLS) 0.5% and distilled water. The substances were applied in a 2-D patch test in a repetitive occlusive test design to the back. Additionally, we performed a wash test on the forearms that was supposed to mimic the skin affection in the normal daily routine of health care workers. In this controlled half-side test design, we included the single application of the hand rub, SLS 0.5% and water as well as a tandem application of the same substances. Patch test and wash test showed similar results. The alcohol-based test preparations showed minimal irritation rather comparable to the application of water. However, the detergent SLS produced stronger barrier disruption, erythema and dryness than the alcohol-based preparations. There was no additional irritation at the combined use of SLS and disinfectants. By contrary, there was even a decrease in barrier disruption and erythema induced by the tandem application of SLS followed by alcohol-based disinfection compared with the use of SLS alone. These findings show a less irritant effect of alcohol-based disinfectants on the skin than detergents. Our study shows that there is no summation of irritating effects of a common detergent and propanol and that the combination of washing and disinfection has a rather protective aspect compared with washing alone.

  20. Analysis of effect of different construction methods of piles on the end effect on skin friction of piles

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hongbo; CHEN Zhuchang

    2007-01-01

    Based on the comparative analysis of end effect on skin friction of displacement-pile (driven pile),the end effect on skin friction of bored pile is studied.The end effect on skin friction between driven pile and bored pile is different and the end effect on skin friction of bored pile is reduce of skin friction in the soil layer adjacent to the pile end.The degradation degree of skin friction is deduced with the increase of the distance from pile end.The concept of additional mud cake formed by the effect of cushion at the bottom of borehole during pouring concrete is introduced to explain the mechanism of end effect on skin friction of the bored pile.The test results of post-grouting piles indicate that the post-grouting technique is an effective way to improve the end effect on skin friction of bored pile.

  1. Protective effect of gelatin and gelatin hydrolysate from salmon skin on UV irradiation-induced photoaging of mice skin

    Science.gov (United States)

    Chen, Tiejun; Hou, Hu; Lu, Jiaohan; Zhang, Kai; Li, Bafang

    2016-08-01

    The objective of this study was to investigate the effect of gelatin (SG) isolated from salmon skin and its hydrolysate (SGH) on photoaging skin, and the mechanism responsible for anti-photoaging. The average molecular weights of SG and SGH were 65 kDa and 873 Da, respectively. The amino acid compositions of SG and SGH were similar. Both of them were abundant in hydrophobic amino acids. Twenty-five peptides were identified from SGH. SG and SGH could improve UV irradiation-induced pathological changes of macroscopical tissue texture and skin morphology. Hydroxyproline content is an indicator of matrix collagen content, SG and SGH could inhibit the decrease of hydroxyproline content in photoaging skin in a dose dependent manner. In addition, SG and SGH could alleviate UV irradiation-induced oxidative damages to skin by increasing the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), increasing the content of glutathione (GSH) and decreasing the content of malonaldehyde (MDA). Moreover, SG and SGH could enhance immune regulation system by increasing the thymus index. Thus, the anti-photoaging mechanisms of SG and SGH were by inhibiting the depletion of antioxidant defense components, involving in the synthesis of collagen and enhancing the function of immune system. Besides, SGH showed a better result in protecting skin from photoaging than SG.

  2. Dynamic hysteresis modeling including skin effect using diffusion equation model

    Science.gov (United States)

    Hamada, Souad; Louai, Fatima Zohra; Nait-Said, Nasreddine; Benabou, Abdelkader

    2016-07-01

    An improved dynamic hysteresis model is proposed for the prediction of hysteresis loop of electrical steel up to mean frequencies, taking into account the skin effect. In previous works, the analytical solution of the diffusion equation for low frequency (DELF) was coupled with the inverse static Jiles-Atherton (JA) model in order to represent the hysteresis behavior for a lamination. In the present paper, this approach is improved to ensure the reproducibility of measured hysteresis loops at mean frequency. The results of simulation are compared with the experimental ones. The selected results for frequencies 50 Hz, 100 Hz, 200 Hz and 400 Hz are presented and discussed.

  3. Investigation on the effect of developed product and new food for radiation-induced skin damage

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Ho; Kim, Jong Chun; Bae, Chun Sik; Kim, Se Ra; Lee, Hae Jun; Bang, Dae Won; Lee, Jin Hee; Kim, Joong Sun; Ki, Sun Ah; Song, Myung Seop [Chonnam National University, Gwangju (Korea, Republic of)

    2007-07-15

    In vivo evaluation of the developed pilot product on the skin protection against UV irradiation and screening of new candidate materials. Project Results are Establishment of experimental methods for 3 morphological indices of UV-induced skin damages -Establishment of experimental methods for whitening effect evaluation -Evaluation of HemoHIM administration on the skin damage indices -Evaluation of HemoHIM skin application on the skin damage indices -Evaluation of HemoTonic administration on the skin damage indices -Evaluation of HemoTonic skin application on the skin damage indices -Evaluation of HemoHIM on the antiinflamatory effects in the inflammation stage 1 -Evaluation of HemoHIM on the antiinflamatory effects in the inflammation stage 2 -Evaluation of HemoHIM on the antiinflamatory effects in the inflammation stage 3 -Evaluation of HemoHIM on the antiinflamatory effects in the TNBS-induced colitis -Evaluation of HemoHIM on the anti-wrinkle effects in the skin -Evaluation of HemoHIM on the protective effects on the skin tissue (epidermal thickening, dermal cellularity, dermal cyst) -Evaluation of HemoHIM on the protective effects on the skin tumor development

  4. Effects of Dermal Multipotent Cell Transplantation on Skin Wound Healing

    Institute of Scientific and Technical Information of China (English)

    ShiChunmeng; ChengTianmin; SuYongping; RanXinze; MaiYue; QuJifu; LouShufen; XuHui; LuoChengji

    2005-01-01

    There is increasing evidence that dermis contains adult multipotent stem cells. To investigate the effects of dermis-derived multipotent cells on wound healing, we transplanted a clonal population of dermis-derived multipotent cells (termed as DMCs) by topical and systemic application into the skin wound of rats with simple wounds and rats with combined wound and radiation injury. Our results suggest that both topical and systemic transplantation of DMCs accelerate the healing process in rats with a simple wound; the promoting effect by topical transplantation occurs earlier than systemic transplantation. However, systemic transplantation of DMCs promotes the healing process in irradiated rats, while topical transplantation of DMCs fails. Further studies on the mechanisms of DMCs to promote wound healing indicate that the supernatant of DMCs could promote the proliferation of fibroblasts and epidermal cells; DMCs expressed transcripts of a serics of cytokincs and cxtraccllular matrix molecules, including VEGF, PDGF, HGF, TGF-β, ICAM-1, VCAM-1, and Fibronectin, which were closely related to the wound healing by DNA microarray analysis. The implanted DMCs can engraft into recipient skin wounded tissues after transplantation by the FISH analysis with Y-chromosome-specific probe. Systemic transplantation of DMCs also promotes the recovery of peripheral white blood cells in irradiated rats. These results demonstrate the different effects of DMCs on wound healing in nonirradiated and irradiated rats and illustrate the importance of optimizing wound healing via the topical or systemic transplantation of stem cells.

  5. Effects of Intraseasonal Oscillation on the Anomalous East Asian Summer Monsoon During 1999

    Institute of Scientific and Technical Information of China (English)

    SUN Ying; DING Yihui

    2008-01-01

    The 1999 East Asian summer monsoon was very unusual for its weak northward advance and remarkably anomalous climate conditions.The monsoonal southwesterly airflow and related rain belt in East Asia were blocked south of the Yangtze River Valley.The monsoonal airflow and major moisture transport conduct shifted eastward and turned northward to Japan from the tropical western Pacific rather than to East China from the South China Sea(SCS)as in normal years.Severe and prolonged drought occurred over extensive areas of North China and heavy precipitation in South China and Japan.The investigation on the possible intrinsic mechanisms related to such an anomalous monsoon year has shown that the unique behavior of intraseasonal oscillation may play an essential role during this process.During this year,the northward propagation of 30-60-day anomalous low-level cyclone/anticyclone collapsed in the region around 20℃N and did not extend beyond the latitudes of the Yangtze River basin due to the barrier of strong cold air intrusion from the mid-latitudes.The southwesterly moisture flux on the northwestern flank of the anticyclonic moisture transport system in the western North Pacific,which was regulated by the northward shift of 30-60-day cyclonic/anticyclonic moisture transport.also did not reach the region north of 30℃N as well.Under this circumstance,the weak northward advance of the monsoon westerlies and associated northward moisture transport could not arrive in North China and led to the severe droughts there in 1999.The SCS and South China were mostly affected by the alrflow in the southern and northern flanks of the same 30-60-day cyclones or anticyclones.respectively,and thus controlled by the nearly reverse zonal wind and moisture convergent/divergent conditions.The rainfall in the SCS and South China showed out-of-phase oscillation through the transient local Hadley circulation.with the rainfall maximum occurring in the SCS (South China)when the 30-60-day

  6. Emerging magnetism and anomalous Hall effect in iridate-manganite heterostructures

    Science.gov (United States)

    Nichols, John; Gao, Xiang; Lee, Shinbuhm; Meyer, Tricia L.; Freeland, John W.; Lauter, Valeria; Yi, Di; Liu, Jian; Haskel, Daniel; Petrie, Jonathan R.; Guo, Er-Jia; Herklotz, Andreas; Lee, Dongkyu; Ward, Thomas Z.; Eres, Gyula; Fitzsimmons, Michael R.; Lee, Ho Nyung

    2016-09-01

    Strong Coulomb repulsion and spin-orbit coupling are known to give rise to exotic physical phenomena in transition metal oxides. Initial attempts to investigate systems, where both of these fundamental interactions are comparably strong, such as 3d and 5d complex oxide superlattices, have revealed properties that only slightly differ from the bulk ones of the constituent materials. Here we observe that the interfacial coupling between the 3d antiferromagnetic insulator SrMnO3 and the 5d paramagnetic metal SrIrO3 is enormously strong, yielding an anomalous Hall response as the result of charge transfer driven interfacial ferromagnetism. These findings show that low dimensional spin-orbit entangled 3d-5d interfaces provide an avenue to uncover technologically relevant physical phenomena unattainable in bulk materials.

  7. Effect of entropy on anomalous transport in ITG-modes of magneto-plasma

    Science.gov (United States)

    Yaqub Khan, M.; Qaiser Manzoor, M.; Haq, A. ul; Iqbal, J.

    2017-04-01

    The ideal gas equation and S={{c}v}log ≤ft(P/ρ \\right) (where S is entropy, P is pressure and ρ is the mass density) define the interconnection of entropy with the temperature and density of plasma. Therefore, different phenomena relating to plasma and entropy need to be investigated. By employing the Braginskii transport equations for a nonuniform electron–ion magnetoplasma, two new parameters—the entropy distribution function and the entropy gradient drift—are defined, a new dispersion relation is obtained, and the dependence of anomalous transport on entropy is also proved. Some results, like monotonicity, the entropy principle and the second law of thermodynamics, are proved with a new definition of entropy. This work will open new horizons in fusion processes, not only by controlling entropy in tokamak plasmas—particularly in the pedestal regions of the H-mode and space plasmas—but also in engineering sciences.

  8. When Chiral Photons Meet Chiral Fermions: Photoinduced Anomalous Hall Effects in Weyl Semimetals

    Science.gov (United States)

    Chan, Ching-Kit; Lee, Patrick A.; Burch, Kenneth S.; Han, Jung Hoon; Ran, Ying

    2016-01-01

    The Weyl semimetal is characterized by three-dimensional linear band touching points called Weyl nodes. These nodes come in pairs with opposite chiralities. We show that the coupling of circularly polarized photons with these chiral electrons generates a Hall conductivity without any applied magnetic field in the plane orthogonal to the light propagation. This phenomenon comes about because with all three Pauli matrices exhausted to form the three-dimensional linear dispersion, the Weyl nodes cannot be gapped. Rather, the net influence of chiral photons is to shift the positions of the Weyl nodes. Interestingly, the momentum shift is tightly correlated with the chirality of the node to produce a net anomalous Hall signal. Application of our proposal to the recently discovered TaAs family of Weyl semimetals leads to an order-of-magnitude estimate of the photoinduced Hall conductivity which is within the experimentally accessible range.

  9. Effects of Ginsenoside Rb1 on Skin Changes

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Kimura

    2012-01-01

    Full Text Available Ginseng roots (Panax ginseng CA Meyer have been used traditionally for the treatment, especially prevention, of various diseases in China, Korea, and Japan. Both experimental and clinical studies suggest ginseng roots to have pharmacological effects in patients with life-style-related diseases such as non-insulin-dependent diabetic mellitus, atherosclerosis, hyperlipidemia, and hypertension. The topical use of ginseng roots to treat skin complaints including atopic suppurative dermatitis, wounds, and inflammation is also described in ancient Chinese texts; however, there have been relatively few studies in this area. In the present paper, we describe introduce the biological and pharmacological effects of ginsenoside Rb1 isolated from Red ginseng roots on skin damage caused by burn-wounds using male Balb/c mice (in vivo and by ultraviolet B irradiation using male C57BL/6J and albino hairless (HR-1 mice (in vivo. Furthermore, to clarify the mechanisms behind these pharmacological actions, human primary keratinocytes and the human keratinocyte cell line HaCaT were used in experiments in vitro.

  10. Improved treatment of radiation effects on the skin

    Energy Technology Data Exchange (ETDEWEB)

    Wandl, E.O.; Kaercher, K.H.; Wandl-Hainberger, I.

    1985-04-29

    The treatment concept developed by K.H. Kaercher was extended by a therapy using Elasten S cream. In the course of a highvoltage therapy using fast electrons or cobalt-60, interesting aspects in the treatment and progression of the radiation reactions of the skin were established. The dermato-therapeutic principles layed down by K.H. Kaercher with the treatment palette used hitherto, have without doubt invariably proven their value. The exclusive powder treatment, however, may be made more practical by application of the new treatment cream in accordance with the intervals in radiation treatment or as a basic treatment towards the end of therapy. Furthermore it is ideally suited for the care and after-treatment of skin, strained by radiation. It reduces considerably the remaining visible radiation reactions. The treatment with powder and emulsion has for more than 10 years proven effective. After the excellent results of the new cream during radiation treatment, additional positive effects are expected in a long-term trial which will be reported on separately.

  11. The positive effect of skin transpiration in peach fruit growth.

    Science.gov (United States)

    Morandi, Brunella; Manfrini, Luigi; Losciale, Pasquale; Zibordi, Marco; Corelli-Grappadelli, Luca

    2010-09-01

    The effect of fruit transpiration on the mechanisms driving peach (Prunus persica (L.) Batsch) daily growth was investigated. In peach, fruit water losses increase during the season and might play a key role in determining fruit growth. Skin transpiration was reduced during the cell expansion stage by enclosing fruit in plastic bags fitted with holes. In the first year, diameter changes of bagged and control fruit were precisely monitored for 15 days, and percentage dry matter and soluble solids content were determined during the experiment and at harvest. In the second year, midday fruit water potential, daily patterns of fruit growth and of vascular and transpiration flows were monitored. Bagging reduced fruit daily growth on some days, and negatively affected both fruit dry matter percentage and soluble solids content. Fruit transpiration rate was reduced during the midday hours, thus increasing midday fruit water potential and lowering xylem inflows. In accordance with the Münch hypothesis on traslocation, these conditions likely decreased the necessary gradient needed for the transport of phloem sap to sink organs, as in the afternoon, bagged fruit showed lower phloem inflows. These data suggest that skin transpiration in peach has a positive effect on fruit growth, as it enhances fruit phloem import.

  12. Modulation of skin pigmentation by the tetrapeptide PKEK: in vitro and in vivo evidence for skin whitening effects.

    Science.gov (United States)

    Marini, Alessandra; Farwick, Mike; Grether-Beck, Susanne; Brenden, Heidi; Felsner, Ingo; Jaenicke, Thomas; Weber, Monika; Schild, Jennifer; Maczkiewitz, Ursula; Köhler, Tim; Bonfigli, Adriana; Pagani, Valerie; Krutmann, Jean

    2012-02-01

    Uneven skin pigmentation is a significant cosmetic concern, and the identification of topically applicable molecules to address this issue is of general interest. We report that the tetrapeptide PKEK (Pro-Lys-Glu-Lys) can exert skin whitening effects based on one in vitro and four double-blinded vehicle-controlled in vivo studies. (i) Treatment of human keratinocytes with PKEK significantly reduced UVB-stimulated mRNA expression of interleukin (IL)-6, IL-8 and TNF-α and, most importantly, proopiomelanocorticotropin (POMC), i.e. a gene encoding the pigmentation-inducing soluble mediator α- (α-MSH). (ii) PKEK treatment significantly inhibited UVB-induced upregulation of genes encoding for IL-1α, IL-6, IL-8, TNF-α as well as POMC and tyrosinase in 10 healthy volunteers pretreated with PKEK for 4 weeks once daily. (iii) In a study enrolling 39 Caucasian women, facial pigment spots significantly faded after 6 weeks when PKEK was combined with the skin whitener sodium ascorbyl phosphate (SAP), whereas PKEK or SAP alone led to less pronounced fading of the pigment spots. (iv) Addition of PKEK enhanced the skin whitening potency of a SAP-containing preparation if applied for 8 weeks to the back of hands of 19 Caucasians. (v) 27 Japanese women were treated on their faces twice daily with an SAP only or a PKEK+SAP-containing formulation for 8 weeks. Application of PKEK+SAP significantly reduced skin pigmentation by 26% and by 18% according to SCINEXA score. We demonstrate that PKEK has the capacity to reduce UVB-induced skin pigmentation and may be suited to serve as a skin tone-modulating agent in cosmetic products.

  13. Discriminating between Z'-boson effects and effects of anomalous gauge couplings in the double production of W ± bosons at a linear collider

    Science.gov (United States)

    Andreev, Vasili V.; Pankov, A. A.

    2013-06-01

    The potential of the International Linear electron-positron Collider (ILC) for seeking, in the annihilation production of W ±-boson pairs, signals induced by new neutral gauge bosons predicted by models belonging to various classes and featuring an extended gauge sector is studied. Limits that will be obtained at ILC for the parameters and masses of Z' bosons are compared with present-day and future data from the Large Hadron Collider (LHC). The possibility of discriminating between the effects of Z-Z' mixing and signals induced by anomalous gauge couplings (AGC) is demonstrated within theoretically motivated trilinear gauge models involving several free anomalous parameters. It is found that the sensitivity of ILC to the effects of Z-Z' mixing in the process e + e - → W + W - and its ability to discriminate between these two new-physics scenarios, Z' and AGC, become substantially higher upon employing polarized initial ( e + e -) and final ( W ±) states.

  14. Metallic transport and large anomalous Hall effect at room temperature in ferrimagnetic Mn{sub 4}N epitaxial thin film

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Xi; Shigematsu, Kei [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); Chikamatsu, Akira, E-mail: chikamatsu@chem.s.u-tokyo.ac.jp; Fukumura, Tomoteru [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); CREST, Japan Science and Technology Agency (JST), Tokyo 113-0033 (Japan); Hirose, Yasushi; Hasegawa, Tetsuya [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); CREST, Japan Science and Technology Agency (JST), Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan)

    2014-08-18

    We report the electrical transport properties of ferrimagnetic Mn{sub 4}N (001) epitaxial thin films grown by pulsed laser deposition on MgO (001) substrates. The Mn{sub 4}N thin films were tetragonally distorted with a ratio of out-of-plane to in-plane lattice constants of 0.987 and showed perpendicular magnetic anisotropy with an effective magnetic anisotropy constant of 0.16 MJ/m{sup 3}, which is comparable with that of a recently reported molecular-beam-epitaxy-grown film. The thin films exhibited metallic transport with a room temperature resistivity of 125 μΩ cm in addition to a large anomalous Hall effect with a Hall angle tangent of 0.023.

  15. Anomalous Hall effect in ZnxFe3-xO4: Universal scaling law and electron localization below the Verwey transition

    Directory of Open Access Journals (Sweden)

    N. Jedrecy

    2016-08-01

    Full Text Available We show that the well-established universal scaling σxyAHE ∼ σxx1.6 between anomalous Hall and longitudinal conductivities in the low conductivity regime (σxx < 104 Ω−1 cm−1 transforms into the scaling σxyAHE ∼ σxx2 at the onset of strong electron localization. The crossover between the two relations is observed in magnetite-derived ZnxFe3-xO4 thin films where an insulating/hopping regime follows a bad metal/hopping regime below the Verwey transition temperature Tv. Our results demonstrate that electron localization effects come into play in the anomalous Hall effect (AHE modifying significantly the scaling exponent. In addition, the thermal evolution of the anomalous Hall resistivity suggests the existence of spin polarons whose size would decrease below Tv.

  16. IMMUNOMODULATORY EFFECTS OF VITAMIN D ON SKIN INFLAMMATION.

    Science.gov (United States)

    Toniato, E; Spinas, E; Saggini, A; Kritas, S K; Caraffa, A; Antinolfi, P; Saggini, R; Pandolfi, F; Conti, P

    2015-01-01

    Vitamin D has a major role in calcium absorption and maintenance of healthy bones. Vitamin D is also involved in cancer, cardiovascular system, allergic diseases, immune regulation and immune disor¬ders. Irradiation of food as well as animals produces vitamin D and more than 90% of previtamin D3 synthesis in the skin occurs in the epidermis. Vitamin D receptor has been found in many cells including T and B lymphocytes, macrophages, mast cells, NK cells and Tregs, and it selectively binds with high affinity to its ligand. Vitamin D binds its receptor VDR, resulting in transcription of a number of genes playing a role in inhibition of MAPK. Its effect may be also mediated by the direct activation of PKC. Vitamin D has the ability to suppress inflammatory cytokines such as TNF, IL-1, IFN-gamma and IL-2; while it increases the generation of anti-inflammatory cytokines IL-4 and IL-10. In B cells, vitamin D3 have also been shown to suppress IgE antibody class switch partly through the inhibition of NF-kB. Here we discuss the relationship between vitamin D, immunity and skin disorders.

  17. Effects of erythropoietin in skin wound healing are dose related.

    Science.gov (United States)

    Sorg, Heiko; Krueger, Christian; Schulz, Torsten; Menger, Michael D; Schmitz, Frank; Vollmar, Brigitte

    2009-09-01

    The hematopoietic growth factor erythropoietin (EPO) attracts attention due to its all-tissue-protective pleiotropic properties. We studied the effect of EPO on dermal regeneration using intravital microscopy in a model of full dermal thickness wounds in the skin-fold chamber of hairless mice. Animals received repetitive low doses or high doses of EPO (RLD-EPO or RHD-EPO) or a single high dose of EPO (SHD-EPO). SHD-EPO accelerated wound epithelialization, reduced wound cellularity, and induced maturation of newly formed microvascular networks. In contrast, RHD-EPO impaired the healing process, as indicated by delayed epithelialization, high wound cellularity, and lack of maturation of microvascular networks. Also, RHD-EPO caused an excessive erythrocyte mass and rheological malfunction, further deteriorating vessel and tissue maturation. Moreover, RHD-EPO altered fibroblast and keratinocyte migration in vitro, while both cell types exposed to RLD-EPO, and, in particular, to SHD-EPO showed accelerated wound scratch closure. In summary, our data show that a single application of a high dose of EPO accelerates and improves skin wound healing.

  18. The effectiveness of a twice-daily skin-moisturising regimen for reducing the incidence of skin tears.

    Science.gov (United States)

    Carville, Keryln; Leslie, Gavin; Osseiran-Moisson, Rebecca; Newall, Nelly; Lewin, Gill

    2014-08-01

    A cluster randomised controlled trial was conducted to evaluate the effectiveness of a twice-daily moisturising regimen as compared to 'usual' skin care for reducing skin tear incidence. Aged care residents from 14 Western Australian facilities (980 beds) were invited to participate. The facilities were sorted into pairs and matched in terms of bed numbers and whether they provided high or low care. One facility from each matched pair was randomised to the intervention group. Consenting residents in an intervention facility received a twice-daily application of a commercially available, standardised pH neutral, perfume-free moisturiser on their extremities. Residents in the control facilities received ad hoc or no standardised skin-moisturising regimen. Participant numbers were sufficient to detect a 5% difference in incidence rate between the two groups with 80% power and a significance level of P = 0·05, and the inter-cluster correlation coefficient was 0·034. Data were collected over 6 months. A total of 1396 skin tears on 424 residents were recorded during the study. In the intervention group, the average monthly incidence rate was 5·76 per 1000 occupied bed days as compared to 10·57 in the control group. The application of moisturiser twice daily reduced the incidence of skin tears by almost 50% in residents living in aged care facilities.

  19. Evaluating the Effect of Mother – Baby Skin- to- Skin Care on Neonatal Outcomes in Preterm Infants

    Directory of Open Access Journals (Sweden)

    M Kalhor

    2016-08-01

    Full Text Available Introduction: Involving the parents in caring of premature newborns is one of the best and effective manners for preventing the hospitalization of premature newborns. The present study aimed to evaluate the effect of mother – baby skin- to- skin care on neonatal outcomes in preterm infants, in Kosar hospital. Methods: This was a descriptive comparative study conducted on 400 nulliparous women with premature infants admitted to neonatal intensive care unit of Kosar hospital during April 2012 and March 2015. Sampling was performed via convenience sampling. Sample population divided into two groups, one of them 200, the kangaroo care and non- care groups. The data were obtained by a researcher prepared check list, including mother’s demographic characteristics and neonatal outcomes. Both descriptive and statistical analysis methods were applied. For analyzing the data, chi-square test, t-test, and logistic regression tests was applied (P 0.05. In the intervention group, the relationship between maternal variables and neonatal outcome was significant (P <0.05. Conclusion: Mother – baby skin- to- skin care has a positive effect on neonatal outcomes. Thus, supporting and awareness of premature infants’ mothers in order to implement this type of care can reduce the neonatal complications. Moreover, it is effective in decreasing the treatment costs.

  20. Anomalous effect in Schumann resonance phenomena observed in Japan, possibly associated with the Chi-chi earthquake in Taiwan

    Directory of Open Access Journals (Sweden)

    M. Hayakawa

    2005-06-01

    Full Text Available The Schumann resonance phenomenon has been monitored at Nakatsugawa (near Nagoya in Japan since the beginning of 1999, and due to the occurance of a severe earthquake (so-called Chi-chi earthquake on 21 September 1999 in Taiwan we have examined our Schumann resonance data at Nakatsugawa during the entire year of 1999. We have found a very anomalous effect in the Schumann resonance, possibly associated with two large land earthquakes (one is the Chi-chi earthquake and another one on 2 November 1999 (Chia-yi earthquake with a magnitude again greater than 6.0. Conspicuous effects are observed for the larger Chi-chi earthquake, so that we summarize the characteristics for this event. The anomaly is characterized mainly by the unusual increase in amplitude of the fourth Schumann resonance mode and a significant frequency shift of its peak frequency (~1.0Hz from the conventional value on the By magnetic field component which is sensitive to the waves propagating in the NS meridian plane. Anomalous Schumann resonance signals appeared from about one week to a few days before the main shock. Secondly, the goniometric estimation of the arrival angle of the anomalous signal is found to coincide with the Taiwan azimuth (the unresolved dual direction indicates toward South America. Also, the pulsed signals, such as the Q-bursts, were simultaneously observed with the "carrier" frequency around the peak frequency of the fourth Schumann resonance mode. The anomaly for the second event for the Chia-yi earthquake on 2 November had much in common. But, most likely due to a small magnitude, the anomaly appears one day before and lasts until one day after the main shock, with the enhancement at the fourth Schumann resonance mode being smaller in amplitude than the case of the Chi-chi earthquake. Yet, the other characteristics, including the goniometric direction finding result, frequency shift, etc., are nearly the same. Although the emphasis of

  1. Effect of olive and sunflower seed oil on the adult skin barrier: implications for neonatal skin care.

    Science.gov (United States)

    Danby, Simon G; AlEnezi, Tareq; Sultan, Amani; Lavender, Tina; Chittock, John; Brown, Kirsty; Cork, Michael J

    2013-01-01

    Natural oils are advocated and used throughout the world as part of neonatal skin care, but there is an absence of evidence to support this practice. The goal of the current study was to ascertain the effect of olive oil and sunflower seed oil on the biophysical properties of the skin. Nineteen adult volunteers with and without a history of atopic dermatitis were recruited into two randomized forearm-controlled mechanistic studies. The first cohort applied six drops of olive oil to one forearm twice daily for 5 weeks. The second cohort applied six drops of olive oil to one forearm and six drops of sunflower seed oil to the other twice daily for 4 weeks. The effect of the treatments was evaluated by determining stratum corneum integrity and cohesion, intercorneocyte cohesion, moisturization, skin-surface pH, and erythema. Topical application of olive oil for 4 weeks caused a significant reduction in stratum corneum integrity and induced mild erythema in volunteers with and without a history of atopic dermatitis. Sunflower seed oil preserved stratum corneum integrity, did not cause erythema, and improved hydration in the same volunteers. In contrast to sunflower seed oil, topical treatment with olive oil significantly damages the skin barrier, and therefore has the potential to promote the development of, and exacerbate existing, atopic dermatitis. The use of olive oil for the treatment of dry skin and infant massage should therefore be discouraged. These findings challenge the unfounded belief that all natural oils are beneficial for the skin and highlight the need for further research.

  2. Skin tears.

    Science.gov (United States)

    Baranoski, S

    2001-08-01

    Skin tears are a serious, painful problem for older patients. Find out how your staff can recognize patients at risk, what they can do to prevent skin tears, and how to manage them effectively if they occur.

  3. Effects of Father-Neonate Skin-to-Skin Contact on Attachment: A Randomized Controlled Trial

    Science.gov (United States)

    Chen, Er-Mei; Liu, Chieh-Yu

    2017-01-01

    This study examines how skin-to-skin contact between father and newborn affects the attachment relationship. A randomized controlled trial was conducted at a regional teaching hospital and a maternity clinic in northern Taiwan. The study recruited 83 first-time fathers aged 20 years or older. By block randomization, participants were allocated to an experimental (n = 41) or a control (n = 42) group. With the exception of skin-to-skin contact (SSC), participants from each group received the same standard care. Both groups also received an Early Childcare for Fathers nursing pamphlet. During the first three days postpartum, the intervention group members were provided a daily SSC intervention with their respective infants. Each intervention session lasted at least 15 minutes in length. The outcome measure was the Father-Child Attachment Scale (FCAS). After adjusting for demographic data, the changes to the mean FCAS were found to be significantly higher in the intervention group than in the control group. We recommend that nurses and midwives use instructional leaflets and demonstrations during postpartum hospitalization, encouraging new fathers to take an active role in caring for their newborn in order to enhance father-neonate interactions and establish parental confidence. This trial is registered with clinical trial registration number NCT02886767. PMID:28194281

  4. Ferromagnetism, variable range hopping, and the anomalous Hall effect in epitaxial Co:ZnO thin film

    Institute of Scientific and Technical Information of China (English)

    Bai Hong-Liang; Chen Yan-Xue; Mei Liang-Mo; He Shu-Min; Xu Tong-Shuai; Liu Guo-Lei; Yan Shi-Shen; Zhu Da-Peng; Dai Zheng-Kun; Yang Feng-Fan; Dai You-Yong

    2012-01-01

    A series of high quality single crystalline epitaxial Zn0.95Co0.05O thin films is prepared by molecular beam epitaxy.Superparamagnetism and ferromagnetism are observed when the donor density is manipulated in a range of 1018 cm-3- 1020 cm-3 by changing the oxygen partial pressure during film growth.The conduction shows variable range hopping at low temperature and thermal activation conduction at high temperature.The ferromagnetism can be maintained up to room temperature.However,the anomalous Hall effect is observed only at low temperature and disappears above 160 K.This phenomenon can be attributed to the local ferromagnetism and the decreased optimal hopping distance at high temperatures.

  5. Elution time changes due to anomalous DEP effects in microchannels under uniform and non-uniform electric fields

    Directory of Open Access Journals (Sweden)

    Antonino Magliano

    2016-05-01

    Full Text Available Conventional dielectrophoresis (DEP force on cell and particle is altered in the proximity of the electrodes due to the failure of the dipole approximation. In these conditions an anomalous DEP (aDEP force rules the particle manipulation. Anyhow, the role of the aDEP is barely considered in the design of DEP devices. Here we analyze, using a multiscale simulation approach, the aDEP effects in micro-fluidic device coupled with interdigitated channel commonly used in continuous mode field flow fractionation dielectrophoretic (FFF-DEP devices for the separation of circulating tumor cells (MDA and Lymphocytes (LYM. We study the propagation of an injected density of MDA and LYM respectively and evaluate how the aDEP changes the migrations of the cells.

  6. Electron's anomalous magnetic moment effects on electron-hydrogen elastic collisions in the presence of a circularly polarized laser field

    CERN Document Server

    Elhandi, S; attaourti, Y; Manaut, B; Oufni, L

    2010-01-01

    The effect of the electron's anomalous magnetic moment on the relativistic electronic dressing for the process of electron-hydrogen atom elastic collisions is investigated. We consider a laser field with circular polarization and various electric field strengths. The Dirac-Volkov states taking into account this anomaly are used to describe the process in the first order of perturbation theory. The correlation between the terms coming from this anomaly and the electric field strength gives rise to new results, namely the strong dependence of the spinor part of the differential cross section (DCS) with respect to these terms. A detailed study has been devoted to the non relativistic regime as well as the moderate relativistic regime. Some aspects of this dependence as well as the dynamical behavior of the DCS in the relativistic regime have been addressed.

  7. Step-wise switching of anomalous Hall effect in a topological insulator

    Science.gov (United States)

    Zhao, Lukas; Chen, Zhiyi; Korzhovska, Inna; Zhao, Shihua; Krusin-Elbaum, Lia; Konczykowski, Marcin

    Surfaces of three-dimensional (3D) topological insulators (TIs) have emerged as one of the most remarkable states of condensed quantum matter where exotic charge and spin phases of Dirac particles could arise. The main challenge to finding these phases comes from a non-vanishing conductivity of the bulk. Recently we have demonstrated that we can access 2D surface transport and reach the charge neutrality point (CNP) by compensating intrinsically p-type TIs using high energy electron beams, and increase bulk resistivity by orders of magnitude. Here we report a discovery of anomalous Hall signal (AHE) at the CNP in Bi2Te3 of unprecedented appearance; it shows regions of plateaus on sweeping the temperature, where Hall resistivity is flat in temperature, and has sharp (nearly discontinuous) `steps' in-between the plateaus. The height of the steps increases on cooling, consistently following the ratio of 1:3 with each step. We will show by electrostatically tuning gated structures how this macroscopic switching of spins evolves in the vicinity of CNP and discuss the phenomenon of step-wise AHE in the context of charge inhomogeneities (puddles) and correlations between the localized bulk spins and Dirac spins. Supported by NSF-DMR-1420634, NSF-DMR-1312483-MWN, and DOD-W911NF-13-1-0159.

  8. Forearm skin tissue dielectric constant measured at 300 MHz: effect of changes in skin vascular volume and blood flow.

    Science.gov (United States)

    Mayrovitz, Harvey N; Guo, Xiaoran; Salmon, Mark; Uhde, Matt

    2013-01-01

    Skin tissue dielectric constant (TDC) values measured via the open-ended coaxial probe method are useful non-invasive indices of local skin tissue water. However, the effect of skin blood flow (SBF) or skin blood volume (SBV) on TDC values is unknown. To determine the magnitude of such effects, we decreased forearm SBV via vertical arm raising for 5 min (test 1) and increased SBV by bicep cuff compression to 50 mmHg for 5 min (test 2) in 20 healthy supine subjects (10 men). TDC values were measured to a depth of 1·5 mm on anterior forearm, and SBF was measured with laser-Doppler system simultaneously on forearm and finger. Results indicate that decreasing vascular volume (test 1) was associated with a small but statistically significant reduction in TDC (3·0 ± 4·3%, P = 0·003) and increasing vascular volume (test 2) was associated with a slight but statistically significant increase in TDC (3·5 ± 3·0%, PTDC values (3·0-3·5%) over the wide range of induced SBV and SBF changes suggest a minor effect on clinically determined TDC values because of SBV or SBF changes or differences when comparing TDC longitudinally over time or among individuals of different groups in a research setting.

  9. Skin Effect of Reversely Switched Dynistor in Short Pulse Discharge Application

    Institute of Scientific and Technical Information of China (English)

    Lin Liang; Yue-Hui Yu

    2009-01-01

    The skin effect in the reversely switched dynistor (RSD) devices is investigated in this paper. Based on the plasma bipolar drift model of the RSD, the current density distributions on the chip are simulated with considering the skin effect. The results indicate that the current density on the border can be several hundred to a thousand A/cm2 higher than that in the center of the chip. The skin effect becomes more prominent as the voltage increases and the inductance decreases in the main circuit. The phenomenon that most of a certain group of chips break over on the border has proved the existence of the skin effect.

  10. Vascular effects of leukotriene D4 in human skin

    DEFF Research Database (Denmark)

    Bisgaard, H

    1987-01-01

    the increase in blood flow rate, but did not abolish the response to LTD4. Local nerve block inhibited the axon reflex-mediated flare component of the LTD4-induced blood flow rate, leaving a local red reaction. This local red reaction was not affected by H1 and H2 antagonists. These results indicate histamine...... as a mediator of the axon reflex, and show that LTD4 causes a direct vasodilatory effect that is not mediated via histamine or cyclooxygenase products. The laser-Doppler flowmeter was applied for dynamic studies of the vasopressor response in the skin during a Valsalva maneuver, and the relative changes...... in blood flow were confirmed by control estimates of the blood flow rate by a 133xenon washout method. The pressor response to a Valsalva maneuver was reversed by local nerve block, but not affected by LTD4. Therefore LTD4 did not interfere with the sympathetic activity on the cutaneous vessels...

  11. Development and Validation of a Tokamak Skin Effect Transformer model

    CERN Document Server

    Romero, J A; Coda, S; Felici, F; Garrido, I

    2012-01-01

    A control oriented, lumped parameter model for the tokamak transformer including the slow flux penetration in the plasma (skin effect transformer model) is presented. The model does not require detailed or explicit information about plasma profiles or geometry. Instead, this information is lumped in system variables, parameters and inputs. The model has an exact mathematical structure built from energy and flux conservation theorems, predicting the evolution and non linear interaction of the plasma current and internal inductance as functions of the primary coil currents, plasma resistance, non-inductive current drive and the loop voltage at a specific location inside the plasma (equilibrium loop voltage). Loop voltage profile in the plasma is substituted by a three-point discretization, and ordinary differential equations are used to predict the equilibrium loop voltage as function of the boundary and resistive loop voltages. This provides a model for equilibrium loop voltage evolution, which is reminiscent ...

  12. Development and validation of a tokamak skin effect transformer model

    Science.gov (United States)

    Romero, J. A.; Moret, J.-M.; Coda, S.; Felici, F.; Garrido, I.

    2012-02-01

    A lumped parameter, state space model for a tokamak transformer including the slow flux penetration in the plasma (skin effect transformer model) is presented. The model does not require detailed or explicit information about plasma profiles or geometry. Instead, this information is lumped in system variables, parameters and inputs. The model has an exact mathematical structure built from energy and flux conservation theorems, predicting the evolution and non-linear interaction of plasma current and internal inductance as functions of the primary coil currents, plasma resistance, non-inductive current drive and the loop voltage at a specific location inside the plasma (equilibrium loop voltage). Loop voltage profile in the plasma is substituted by a three-point discretization, and ordinary differential equations are used to predict the equilibrium loop voltage as a function of the boundary and resistive loop voltages. This provides a model for equilibrium loop voltage evolution, which is reminiscent of the skin effect. The order and parameters of this differential equation are determined empirically using system identification techniques. Fast plasma current modulation experiments with random binary signals have been conducted in the TCV tokamak to generate the required data for the analysis. Plasma current was modulated under ohmic conditions between 200 and 300 kA with 30 ms rise time, several times faster than its time constant L/R ≈ 200 ms. A second-order linear differential equation for equilibrium loop voltage is sufficient to describe the plasma current and internal inductance modulation with 70% and 38% fit parameters, respectively. The model explains the most salient features of the plasma current transients, such as the inverse correlation between plasma current ramp rates and internal inductance changes, without requiring detailed or explicit information about resistivity profiles. This proves that a lumped parameter modelling approach can be used to

  13. Effect of seasonal and geographical differences on skin and effect of treatment with an osmoprotectant: Sorbitol.

    Science.gov (United States)

    Muizzuddin, Neelam; Ingrassia, Michael; Marenus, Kenneth D; Maes, Daniel H; Mammone, Thomas

    2013-01-01

    Human skin maintains an optimal permeability barrier function in a terrestrial environment that varies considerably in humidity. Cells cultured under hyperosmotic stress accumulate osmolytes including sorbitol. Epidermal keratinocytes experience similar high osmolality under dry environmental conditions because of increased transepidermal water loss (TEWL) and concomitant drying of the skin. This study was designed to determine if epidermal keratinocytes, in vitro, could be protected from high osmotic stress, with the exogenous addition of sorbitol. In addition, we evaluated the effect of a formulation containing topical sorbitol on skin barrier and moisturization of subjects living in arid and humid regions in summer as well as in winter. Results from in vitro experiments showed that 50 mM sorbitol protected epidermal keratinocytes from osmotic toxicity induced by sodium chloride. Clinical studies indicated that skin chronically exposed to hot, dry environment appeared to exhibit stronger skin barrier and a lower baseline TEWL. In addition, skin barrier was stronger in summer than in winter. Sorbitol exhibited significant improvement in both barrier repair and moisturization, especially in individuals subjected to arid environmental conditions.

  14. The effects of surfactants on penetration across the skin*.

    Science.gov (United States)

    Walters, K A; Bialik, W; Brain, K R

    1993-12-01

    Synopsis Many of the properties of surfactants can be related to their ability to concentrate at phase interfaces, leading to a reduction in interracial tension. In biological systems the effects of surfactants are complex, particularly their effect on cell and other membranes, and this can lead to alterations in permeability characteristics. This is of particular relevance when considering the stratum corneum which has long been recognized as the major barrier to skin permeation. The magnitude of skin barrier function alteration is dependent on surfactant structure, both the hydrophobic alkyl chain and the hydropnilic ethylene oxide chain demonstrating some structure-activity behaviour. In many biological systems, including skin, surfactants with a similar hydrophilic group will show maximum membrane activity if they possess a decyl or dodecyl alkyl chain. It is difficult to rationalise this phenomenon, given that such solution properties as partition coefficients and CMCs do not show maxima or minima at these chain lengths. It may be that the physical parameters and molecular dimensions of the decyl/dodecyl chain provide the optimal ability to intercalate with the lipid bilayer structure. There is little doubt that once the surfactant has intercalated with the lipid bilayers in the lamellar liquid crystals of the stratum corneum, fluidity in the hydrophobic regions is increased. Effectively, this leads to a looser, more permeable structure. The significance of data obtained using commercially available surfactants, however, can be questioned on the grounds of purity. The purpose of this review is to describe some of the methods used to evaluate the effects of surfactants on the skin barrier and to discuss recent attempts to predict surfactant action on the skin using various biological and physical techniques. Résumé La plupart des propriétés des surfactants dépend de leur facilitéà se concentrer aux interfaces, menant ainsi à la réduction de la tension

  15. Influence of an anomalous dimension effect on thermal instability in amorphous-InGaZnO thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Kuan-Hsien; Chou, Wu-Ching, E-mail: tcchang3708@gmail.com, E-mail: wuchingchou@mail.nctu.edu.tw [Department of Electrophysics, National Chiao Tung University, Hsin-chu 300, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang3708@gmail.com, E-mail: wuchingchou@mail.nctu.edu.tw [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan (China); Chen, Hua-Mao; Tai, Ya-Hsiang [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsin-chu 300, Taiwan (China); Tsai, Ming-Yen; Hung, Pei-Hua; Chu, Ann-Kuo [Department of Photonics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Wu, Ming-Siou; Hung, Yi-Syuan [Department of Electronics Engineering, National Chiao Tung University, Hsin-Chu 300, Taiwan (China); Hsieh, Tien-Yu [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Yeh, Bo-Liang [Advanced Display Technology Research Center, AU Optronics, No.1, Li-Hsin Rd. 2, Hsinchu Science Park, Hsin-Chu 30078, Taiwan (China)

    2014-10-21

    This paper investigates abnormal dimension-dependent thermal instability in amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors. Device dimension should theoretically have no effects on threshold voltage, except for in short channel devices. Unlike short channel drain-induced source barrier lowering effect, threshold voltage increases with increasing drain voltage. Furthermore, for devices with either a relatively large channel width or a short channel length, the output drain current decreases instead of saturating with an increase in drain voltage. Moreover, the wider the channel and the shorter the channel length, the larger the threshold voltage and output on-state current degradation that is observed. Because of the surrounding oxide and other thermal insulating material and the low thermal conductivity of the IGZO layer, the self-heating effect will be pronounced in wider/shorter channel length devices and those with a larger operating drain bias. To further clarify the physical mechanism, fast I{sub D}-V{sub G} and modulated peak/base pulse time I{sub D}-V{sub D} measurements are utilized to demonstrate the self-heating induced anomalous dimension-dependent threshold voltage variation and on-state current degradation.

  16. In vitro percutaneous absorption of chromium powder and the effect of skin cleanser.

    Science.gov (United States)

    Larese Filon, Francesca; D'Agostin, Flavia; Crosera, Matteo; Adami, Gianpiero; Bovenzi, Massimo; Maina, Giovanni

    2008-09-01

    The present study tried to investigate, using a synthetic sweat at pH 4.5, whether metallic chromium can pass through the skin (in vitro) and the effect of rapid skin decontamination with a common detergent. A suspension of chromium powder in synthetic sweat at pH 4.5 was prepared and shaken with a stirring plate at room temperature for 30 min. Human skin membranes were set up in Franz-diffusion cells and 1 ml of the freshly made suspension was applied to the outer surface of the skin for 24h. The tests were performed without and with decontamination using the cleanser 30 min after the start of exposure. The appearance of metal ions in the aqueous receptor phase was quantified by Electro Thermal Atomic Absorption Spectroscopy (ETAAS) and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Speciation analysis and measurements of chromium skin content were also performed. Chromium skin permeation was demonstrated in in vitro experiments using the Franz cell system, giving a permeation flux of 0.84+/-0.25 ng cm(-2)h(-1) and a lag time of 1.1+/-0.7h. The cleaning procedure stop Cr permeation but its concentration into the skin significantly increased (Mann-Whitney U test P<0.03). The results revealed that chromium applied as powder can pass through the skin and that decontamination, done after 30 min of exposure, prevent Cr skin permeation but increase Cr content into the skin.

  17. [In vitro percutaneous absorption of chromium powder and the effect of skin cleanser].

    Science.gov (United States)

    D'Agostin, F; Crosera, M; Adami, G; Malvestio, A; Rosani, R; Bovenzi, M; Maina, G; Filon, F Larese

    2007-01-01

    Occupational chromium dermatitis occurs frequently among cement and metal workers, workers dealing with leather tanning and employees in the ceramic industry. The present study, using an in-vitro system, evaluated percutaneous absorption of chromium powder and the effect of rapid skin decontamination with a common detergent. Experiments were performed using the Franz diffusion cell method with human skin. Physiological solution was used as receiving phase and a suspension of chromium powder in synthetic sweat was used as donor phase. The tests were performed without or with decontamination using the cleanser 30 minutes after the start of exposure. The amount of chromium permeated through the skin was analysed by Inductively Coupled Plasma Atomic Emission Spectroscopy and Electro Thermal Atomic Absorption Spectroscopy. Speciation analysis and measurements of chromium skin content were also performed. We calculated a permeation flux of 0.843 +/- 0.25 ng cm(-2) h(-1) and a lag time of 1.1 +/- 0.7 h. The cleaning procedure significantly increased chromium skin content, whereas skin passage was not increased. These results showed that chromium powder can pass through the skin and that skin decontamination did not decrease skin absorption. Therefore, it is necessary to prevent skin contamination when using toxic agents.

  18. Effectiveness Evaluation of Skin Covers against Intravascular Brachytherapy Sources Using VARSKIN3 Code

    Directory of Open Access Journals (Sweden)

    Baghani HR

    2013-12-01

    Full Text Available Background and Objective: The most common intravascular brachytherapy sources include 32P, 188Re, 106Rh and 90Sr/90Y. In this research, skin absorbed dose for different covering materials in dealing with these sources were evaluated and the best covering material for skin protection and reduction of absorbed dose by radiation staff was recognized and recommended. Method: Four materials including polyethylene, cotton and two different kinds of plastic were proposed as skin covers and skin absorbed dose at different depths for each kind of the materials was calculated separately using the VARSKIN3 code. Results: The results suggested that for all sources, skin absorbed dose was minimized when using polyethylene. Considering this material as skin cover, maximum and minimum doses at skin surface were related to 90Sr/90Y and 106Rh, respectively. Conclusion: polyethylene was found the most effective cover in reducing skin dose and protecting the skin. Furthermore, proper agreement between the results of VARSKIN3 and other experimental measurements indicated that VRASKIN3 is a powerful tool for skin dose calculations when working with beta emitter sources. Therefore, it can be utilized in dealing with the issue of radiation protection.

  19. Allergic Responses Induced by the Immunomodulatory Effects of Nanomaterials upon Skin Exposure

    Science.gov (United States)

    Yoshioka, Yasuo; Kuroda, Etsushi; Hirai, Toshiro; Tsutsumi, Yasuo; Ishii, Ken J.

    2017-01-01

    Over the past decade, a vast array of nanomaterials has been created through the development of nanotechnology. With the increasing application of these nanomaterials in various fields, such as foods, cosmetics, and medicines, there has been concern about their safety, that is, nanotoxicity. Therefore, there is an urgent need to collect information about the biological effects of nanomaterials so that we can exploit their potential benefits and design safer nanomaterials, while avoiding nanotoxicity as a result of inhalation or skin exposure. In particular, the immunomodulating effect of nanomaterials is one of most interesting aspects of nanotoxicity. However, the immunomodulating effects of nanomaterials through skin exposure have not been adequately discussed compared with the effects of inhalation exposure, because skin penetration by nanomaterials is thought to be extremely low under normal conditions. On the other hand, the immunomodulatory effects of nanomaterials via skin may cause severe problems for people with impaired skin barrier function, because some nanomaterials could penetrate the deep layers of their allergic or damaged skin. In addition, some studies, including ours, have shown that nanomaterials could exhibit significant immunomodulating effects even if they do not penetrate the skin. In this review, we summarize our current knowledge of the allergic responses induced by nanomaterials upon skin exposure. First, we discuss nanomaterial penetration of the intact or impaired skin barrier. Next, we describe the immunomodulating effects of nanomaterials, focusing on the sensitization potential of nanomaterials and the effects of co-exposure of nanomaterials with substances such as chemical sensitizers or allergens, on the onset of allergy, following skin exposure. Finally, we discuss the potential mechanisms underlying the immunomodulating effects of nanomaterials by describing the involvement of the protein corona in the interaction of

  20. Clinical effects of an oral supplement rich in antioxidants on skin radiance in women

    Science.gov (United States)

    Dumoulin, Marion; Gaudout, David; Lemaire, Benoit

    2016-01-01

    Background Environmental factors impact the skin aging resulting in decrease of skin radiance. Nutrition and particularly antioxidants could help to fight against skin degradation. Objective The aim of this study was to evaluate the effects of an oral supplement rich in specific antioxidants, SkinAx2TM, on the improvement of the skin radiance in women. Methods The open-label clinical study enrolled 35 women, aged 40–70, with facial dull complexion. Subjects were supplemented orally with a daily dosage of 150 mg of an antioxidant-rich formulation containing superoxide dismutase-rich melon concentrate, grape seed extract rich in monomers of flavanols, vitamin C, and zinc for 8 weeks. Each subject served as her own control. The C.L.B.T.™ test has been used to evaluate facial skin coloring (C), luminosity (L), brightness (B), and transparency (T) involved in skin radiance. Facial skin imperfections have been assessed by clinical assessment. Firmness has been evaluated by clinical assessment and cutometer measurement. Finally, an auto-questionnaire has been carried out in order to evaluate the satisfaction of the subjects concerning different parameters involved in skin radiance and the global efficacy of the supplement. Results Skin “red pink” and “olive” colors were significantly improved after supplementation (Pskin imperfections were significantly reduced after the antioxidant-rich formulation intake (global reduction: −18.0%; Pskin. Furthermore, 64.7% reported to look better at the end of the supplementation. Conclusion The oral supplement containing the antioxidant-rich formulation was found to improve skin radiance by reducing skin coloring, increasing face luminosity, reducing imperfections, and improving skin firmness in women with dull complexion. PMID:27799805

  1. Proinflammatory Effects of Diesel Exhaust Nanoparticles on Scleroderma Skin Cells

    Directory of Open Access Journals (Sweden)

    A. Mastrofrancesco

    2014-01-01

    Full Text Available Autoimmune diseases are complex disorders of unknown etiology thought to result from interactions between genetic and environmental factors. We aimed to verify whether environmental pollution from diesel engine exhaust nanoparticulate (DEP of actually operating vehicles could play a role in the development of a rare immune-mediated disease, systemic sclerosis (SSc, in which the pathogenetic role of environment has been highlighted. The effects of carbon-based nanoparticulate collected at the exhaust of newer (Euro 5 and older (Euro 4 diesel engines on SSc skin keratinocytes and fibroblasts were evaluated in vitro by assessing the mRNA expression of inflammatory cytokines (IL-1α, IL-6, IL-8, and TNF-α and fibroblast chemical mediators (metalloproteases 2, 3, 7, 9, and 12; collagen types I and III; VEGF. DEP was shown to stimulate cytokine gene expression at a higher extent in SSc keratinocytes versus normal cells. Moreover, the mRNA gene expression of all MMPs, collagen types, and VEGF genes was significantly higher in untreated SSc fibroblasts versus controls. Euro 5 particle exposure increased the mRNA expression of MMP-2, -7, and -9 in SSc fibroblasts in a dose dependent manner and only at the highest concentration in normal cells. We suggest that environmental DEP could trigger the development of SSc acting on genetically hyperreactive cell systems.

  2. Effect of chicken skin on the quality characteristics of semi-dried restructured jerky.

    Science.gov (United States)

    Choi, Yun-Sang; Han, Doo-Jeong; Choi, Ji-Hun; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Hyun-Wook; Kim, Young-Boong; Kim, Cheon-Jei

    2016-05-01

    The objective of this study was to evaluate the effect of skin on the textural properties of semi-dried jerky produced with different acid treatments. Jerky was prepared with no skin (control) or with 1, 3, or 5% chicken skin. After hand mixing (for 3 min) and tumbling (for 30 min) to distribute the curing ingredients, the cured meats were dried for 180 min at 55°C, for 180 min at 65°C, and finally for 60 min at 75°C. The presence of skin was shown to result in a higher fat content, TBA value, and metmyoglobin due to the high fat content of the skin. In contrast, acid treatment decreased the TBA value and metmyoglobin in jerky relative to samples that were not subjected to acid treatment. The presence of skin also improved the moisture contents, processing yields, and mechanical tenderness.

  3. The Effects of Dietary Macronutrient Balance on Skin Structure in Aging Male and Female Mice

    Science.gov (United States)

    McMahon, Aisling C.; Ruohonen, Kari; Raubenheimer, David; Ballard, J. William O.; Le Couteur, David G.; Nicholls, Caroline; Li, Zhe; Maitz, Peter K. M.; Wang, Yiwei; Simpson, Stephen J.

    2016-01-01

    Nutrition influences skin structure; however, a systematic investigation into how energy and macronutrients (protein, carbohydrate and fat) affects the skin has yet to be conducted. We evaluated the associations between macronutrients, energy intake and skin structure in mice fed 25 experimental diets and a control diet for 15 months using the Geometric Framework, a novel method of nutritional analysis. Skin structure was associated with the ratio of dietary macronutrients eaten, not energy intake, and the nature of the effect differed between the sexes. In males, skin structure was primarily associated with protein intake, whereas in females carbohydrate intake was the primary correlate. In both sexes, the dermis and subcutaneous fat thicknesses were inversely proportional. Subcutaneous fat thickness varied positively with fat intake, due to enlarged adipocytes rather than increased adipocyte number. We therefore demonstrated clear interactions between skin structure and macronutrient intakes, with the associations being sex-specific and dependent on dietary macronutrient balance. PMID:27832138

  4. Observation and Modeling of Anomalous CN Polarization Profiles Produced by the Molecular Paschen-Back Effect in Sunspots

    Science.gov (United States)

    Asensio Ramos, A.; Trujillo Bueno, J.; Collados, M.

    2005-04-01

    We report novel spectropolarimetric observations of sunspots carried out with the Tenerife Infrared Polarimeter in a near-IR spectral region around 15410 Å, which is known to contain two groups of prominent OH lines that show circular polarization signals of opposite polarity. Surrounding these well-known OH lines, we have discovered the presence of CN lines of the Δv=1 band that show anomalous polarization profiles. Although the Stokes V signals of the OH lines are antisymmetric and of a sizable amplitude, the CN lines show almost negligible circular polarization. On the contrary, the linear polarization signals turn out to be much stronger in the CN lines than in the OH lines. Interestingly, these CN lines present striking antisymmetric linear polarization profiles, which we are able to explain and model via the Paschen-Back effect theory for diatomic molecules. The presence of such peculiar CN lines in the same spectral region of the OH lines may be useful to improve our empirical knowledge of solar magnetic fields via the simultaneous observation and modeling of the transverse and longitudinal Zeeman effects in two different molecular species.

  5. Quantum spin-quantum anomalous Hall effect with tunable edge states in Sb monolayer-based heterostructures

    Science.gov (United States)

    Zhou, Tong; Zhang, Jiayong; Xue, Yang; Zhao, Bao; Zhang, Huisheng; Jiang, Hua; Yang, Zhongqin

    2016-12-01

    A novel topological insulator with tunable edge states, called a quantum spin-quantum anomalous Hall (QSQAH) insulator, is predicted in a heterostructure of a hydrogenated Sb (S b2H ) monolayer on a LaFe O3 substrate by using ab initio methods. The substrate induces a drastic staggered exchange field in the S b2H film, which plays an important role to generate the QSQAH effect. A topologically nontrivial band gap (up to 35 meV) is opened by Rashba spin-orbit coupling, which can be enlarged by strain and an electric field. To understand the underlying physical mechanism of the QSQAH effect, a tight-binding model based on px and py orbitals is constructed. With the model, the exotic behaviors of the edge states in the heterostructure are investigated. Dissipationless chiral charge edge states related to one valley are found to emerge along both sides of the sample, whereas low-dissipation spin edge states related to the other valley flow only along one side of the sample. These edge states can be tuned flexibly by polarization-sensitive photoluminescence controls and/or chemical edge modifications. Such flexible manipulations of the charge, spin, and valley degrees of freedom provide a promising route towards applications in electronics, spintronics, and valleytronics.

  6. The role of the skin barrier in modulating the effects of common skin microbial species on the inflammation, differentiation and proliferation status of epidermal keratinocytes

    OpenAIRE

    Duckney, Patrick; Wong, Heng Kuan; Serrano, José; Yaradou, Diaraf; Oddos, Thierry; Georgios N. Stamatas

    2013-01-01

    Background Skin resident microbial species are often thought of either as pathogenic or commensal. However, little is known about the role of the skin barrier in modulating their potential for causing disease. To investigate this question we measured the effects of three microbial species commonly found on the skin (Staphylococcus epidermidis, Staphylococcus aureus, and Propionibacterium acnes) on a reconstructed human epidermal model by either applying the bacteria on the model surface (inta...

  7. Anomalous Hall effect suppression in anatase Co:TiO2 by the insertion of an interfacial TiO2 buffer layer

    NARCIS (Netherlands)

    Lee, Y.J.; Jong, de M.P.; Wiel, van der W.G.; Kim, Y.; Brock, J.D.

    2010-01-01

    We present the effect of introducing a TiO2 buffer layer at the SrTiO3/Co:TiO2 interface on the magnetic and structural properties of anatase Co:TiO2 (1.4 at. % Co). Inserting the buffer layer leads to suppression of the room-temperature anomalous Hall effect, accompanied by a reduced density of Co

  8. The effect of skin temperature on performance during a 7.5-km cycling time trial

    NARCIS (Netherlands)

    Levels, K.; Koning, J.J. de; Foster, C.; Daanen, H.A.M.

    2012-01-01

    Aerobic exercise performance is seriously compromised in the heat. Possibly, a high skin temperature causes a rating of perceived exertion (RPE)-mediated decrease in exercise intensity. The purpose of this study was to determine the effect of skin temperature on power output during a 7.5-km cycling

  9. Using a Cell Phone to Investigate the Skin Depth Effect in Salt Water

    Science.gov (United States)

    Rayner, John

    2017-02-01

    This paper describes an experimental investigation of the skin depth effect for electromagnetic waves in salt water using a cell phone that is immersed to a critical depth where it no longer responds when called. We show that this critical depth is directly proportional to the theoretical skin depth for a range of salt concentrations.

  10. dermaOXY skin assay: effect and evidence

    DEFF Research Database (Denmark)

    Menov, Lasse; Klösgen-Buchkremer, Beate Maria

    2015-01-01

    This text is a videnkupon report supported by the Danish Innovation Fonds and conducted by L.M. and B.K. for dermaOXY (by MedicTinedic ApS, Varde, Denmark). It involves two dermaOXY products: dermaOXY HYALURON SERUM and dermaOXY SYN SERUM. These are applied to the facial skin in combination...... with a 90 percent pure oxygen gas stream. Occasionally, the treatment is supported by low-level light exposure, prepared by mechanical microporation of skin or both. The dermaOXY skin improvement approach is used in treatments by clinics spread across 23 countries [1]. This text also includes an assessment...... of the instrument set DermaLab®Combo, which is used for the physical characterization of skin status after treatment. The report consists of four main parts, dedicated to 1. the properties of human skin 2. the anti-aging methods applied by the dermaOXY treatment 3. the analytical methods applied by derma...

  11. Conetronics in 2D metal-organic frameworks: double/half Dirac cones and quantum anomalous Hall effect

    Science.gov (United States)

    Wu, Menghao; Wang, Zhijun; Liu, Junwei; Li, Wenbin; Fu, Huahua; Sun, Lei; Liu, Xin; Pan, Minghu; Weng, Hongming; Dincă, Mircea; Fu, Liang; Li, Ju

    2017-03-01

    Bandstructure with Dirac cones gives rise to massless Dirac fermions with rich physics, and here we predict rich cone properties in M 3C12S12 and M 3C12O12, where M = Zn, Cd, Hg, Be, or Mg based on recently synthesized Ni3C12S12—class 2D metal-organic frameworks (MOFs). For M 3C12S12, their band structures exhibit double Dirac cones with different Fermi velocities that are n (electron) and p (hole) type, respectively, which are switchable by few-percent strain. The crossing of two cones are symmetry-protected to be non-hybridizing, leading to two independent channels at the same k-point akin to spin-channels in spintronics, rendering ‘conetronics’ device possible. For M 3C12O12, together with conjugated metal-tricatecholate polymers M 3(HHTP)2, the spin-polarized slow Dirac cone center is pinned precisely at the Fermi level, making the systems conducting in only one spin/cone channel. Quantum anomalous Hall effect can arise in MOFs with non-negligible spin-orbit coupling like Cu3C12O12. Compounds of M 3C12S12 and M 3C12O12 with different M, can be used to build spin/cone-selecting heterostructure devices tunable by strain or electrostatic gating, suggesting their potential applications in spintroincs/conetronics.

  12. Anomalous magnetostrictive effects in (La1-xTbx)2/3Sr1/3MnO3

    Institute of Scientific and Technical Information of China (English)

    吴坚; 张世远

    2003-01-01

    A series of (La1-xTbx)2/aSr1/3MnOa polycrystalline samples has been studied by means of x-ray diffraction,magnetostriction, and thermal expansion measurements. It has been found that this series undergoes a phase transitionfrom a rhombohedral to an orthorhombic form at the doping level x≈0.20 at room temperature accompanied by ananisotropic magnetostriction up to -50×10-6 under a magnetic field of iT. The linear and volume magnetostrictionsvary with chemical composition, even change sign. At T=80K, the magnetostrictions for the samples of x=0.20 and0.40 exhibit different behaviours. The sample of x=0.20 has positive volume and linear magnetostrictions and a neg-ative anisotropic magnetostriction, while the sample of x=0.40 has an opposite behaviour. The magnitude of volumemagnetostriction for both the samples is essential (~ 10-4) at T=80K under a magnetic field of 4T. We conclude thatthese anomalous effects are due to the charge delocalization and the structural phase transition between orthorhombicand rhombohedral forms induced by the applied magnetic field.

  13. Anomalous magnetostrictive effects in (Lal-xTbx)2/3Sr1/3MnO3

    Institute of Scientific and Technical Information of China (English)

    吴坚; 张世远

    2003-01-01

    A series of (La1-xTbx)2/3Srl/3MnO3 polycrystalline samples has been studied by means of x-ray diffraction,magnetostriction, and thermal expansion measurements. It has been found that this series undergoes a phase transition from a rhombohedral to an orthorhombic form at the doping level x≈0.20 at room temperature accompanied by an anisotropic magnetostriction up to -50×10-6 under a magnetic field of 1T. The linear and volume magnetostrictions vary with chemical composition, even change sign. At T=80K, the magnetostrictions for the samples of x=0.20 and 0.40 exhibit different behaviours. The sample of x=0.20 has positive volume and linear magnetostrictions and a negative anisotropic magnetostriction, while the sample of x=0.40 has an opposite behaviour. The magnitude of volume magnetostriction for both the samples is essential (-10-4) at T=80K under a magnetic field of 4T. We conclude that these anomalous effects are due to the charge delocalization and the structural phase transition between orthorhombic and rhombohedral forms induced by the applied magnetic field.

  14. Observation and modeling of anomalous CN polarization profiles produced by the molecular Paschen-Back effect in sunspots

    CERN Document Server

    Ramos, A A; Collados, M

    2005-01-01

    We report novel spectropolarimetric observations of sunspots carried out with the Tenerife Infrared Polarimeter (TIP) in a near-IR spectral region around 15410 A, which is known to contain two groups of prominent OH lines that show circular polarization signals of opposite polarity. Surrounding these well-known OH lines, we have discovered the presence of CN lines of the $\\Delta v=1$ band which show anomalous polarization profiles. Although the Stokes V signals of the OH lines are antisymmetric and with a sizable amplitude, the CN lines show almost negligible circular polarization. On the contrary, the linear polarization signals turn out to be much stronger in the CN lines than in the OH lines. Interestingly, these CN lines present striking antisymmetric linear polarization profiles, which we are able to explain and model via the Paschen-Back effect theory for diatomic molecules. The presence of such peculiar CN lines in the same spectral region of the OH lines may be useful to improve our empirical knowledg...

  15. Anomalous enhancement and suppression of ionization induced by an effective few-cycle pulse in the frequency domain

    Science.gov (United States)

    Foote, David; Lin, Yingda; Hill, Wendell T., III

    2015-05-01

    In a recent set of coherent control experiments, an anomalous sinusoidal variation of the ionization yield was observed in Xe when ionized by a pairs of phase-locked, many-cycle 800 nm pulses. Compared with the signal of a single transform limited pulse, both enhancement and suppression was possible, which depended on the temporal separation and relative phase of the pulses. In the time domain, the control can be viewed as a temporal Young's double slit experiment - two coherent electron wavepackets interfering. In the frequency domain, the photoelectron spectrum is given by the modulus squared of the Fourier transform of the field, which is a few-cycle squared sinusodial function. In analogy to a few-cycle pulse where the carrier phase dictates the ejection direction of rescattered electrons, enhancement (suppression) occurs when the effective carrier waveform is cos[w-w0]2 (sin[w-w0]2). The contrast decreased with increasing pulse separation and decreasing multiphoton order. Detailed results and a model simulation will be presented.

  16. Theoretical Investigation on Skin Effect Factor of Conductor in Power Cables

    Science.gov (United States)

    Suzuki, Hiroshi; Kanaoka, Mamoru

    This paper describes a newly-derived theoretical equation on the skin effect factor of power cables, and its application to large-size OF and XLPE cables with segmental conductors, including insulated wires. The skin effect factors calculated with the new equation were fit very well to measurements in wide range conductor sizes. In the new equation, the important factor which characterizes the skin effect of segmental conductors is the `equivalent conductivity ratio' ν defined by the ratio of longitudinal conductivity in axial direction of conductor to conductivity of conductor wires. Since the obtained ratio ν in XLPE cable was three times greater than that in OF cable, the larger longitudinal eddy current passing from a wire to another increased the eddy current loss in conductor, which increased the conductor loss of XLPE cable. The new equation enables us to investigate quantitatively the dominant loss component affecting the skin effect factor. Then, the skin effect factors and coefficients for OF and XLPE cables were investigated with the new equation. It was revealed that the best number of separation, in which the skin effect became minimum, existed in OF and XLPE cables with segmental conductors. In addition, it was confirmed that the skin effect coefficients ks1 calculated with the new equation were consistent well with those used in JCS.

  17. Anomalous effective medium approximation breakdown in deeply subwavelength all-dielectric photonic multilayers

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Lavrinenko, Andrei; Zhukovsky, Sergei

    2015-01-01

    We present a comprehensive analysis of the applicability of the effective medium approximation to deeply subwavelength (period ≤λ/50) all-dielectric multilayer structures. We demonstrate that even though the dispersion relations for such multilayers differ from the effective medium prediction onl...

  18. Novel Inhibitory Effect of N-(2-Hydroxycyclohexylvaliolamine on Melanin Production in a Human Skin Model

    Directory of Open Access Journals (Sweden)

    Bum-Ho Bin

    2014-07-01

    Full Text Available Hyper-pigmentation causes skin darkness and medical disorders, such as post-inflammatory melanoderma and melasma. Therefore, the development of anti-melanogenic agents is important for treating these conditions and for cosmetic production. In our previous paper, we demonstrated that the anti-diabetic drug voglibose, a valiolamine derivative, is a potent anti-melanogenic agent. In addition, we proposed an alternative screening strategy to identify valiolamine derivatives with high skin permeability that act as anti-melanogenic agents when applied topically. In this study, we synthesized several valiolamine derivatives with enhanced lipophilicity and examined their inhibitory effects in a human skin model. N-(2-hydroxycyclohexylvaliolamine (HV possesses a stronger inhibitory effect on melanin production than voglibose in a human skin model, suggesting that HV is a more potent anti-melanogenic agent for the skin.

  19. Effects of glycerol on human skin damaged by acute sodium lauryl sulphate treatment.

    Science.gov (United States)

    Atrux-Tallau, Nicolas; Romagny, Céline; Padois, Karine; Denis, Alain; Haftek, Marek; Falson, Françoise; Pirot, Fabrice; Maibach, Howard I

    2010-08-01

    Glycerol, widely used as humectant, is known to protect against irritants and to accelerate recovery of irritated skin. However, most studies were done with topical formulations (i.e. emulsions) containing glycerol in relatively high amounts, preventing drawing conclusions from direct effects. In this study, acute chemical irritations were performed on the forearm with application of a 10% sodium lauryl sulphate (SLS) aqueous solution under occlusion for 3 h. Then, glycerol aqueous solutions from 1 to 10% were applied under occlusion for 3 h. After elimination of moist excess consecutive to occlusive condition, in ambient air for 15 and 30 min, skin barrier function was investigated by dual measurement of skin hydration and transepidermal water loss (TEWL). Treatments with SLS solution under occlusion significantly increased TEWL and decreased skin hydration as assessed by capacitance measurements. The SLS irritant property was raised by the occlusion and the water barrier function as well as water content appeared impaired. Recovery with glycerol at low doses was remarkable through a mechanism that implies its hygroscopic properties and which is saturable. This precocious effect acts through skin rehydration by enhancing water-holding capacity of stratum corneum that would facilitate the late physiological repair of impaired skin barrier. Thus, glycerol appears to substitute for natural moisturizing factors that have been washed out by the detergent action of SLS, enhancing skin hydration but without restoring skin barrier function as depicted by TEWL values that remained high. Thus, irritant contact dermatitis treated with glycerol application compensate for skin dehydration, favouring physiological process to restore water barrier function of the impaired skin. Empirical use of glycerol added topical formulations onto detergent altered skin was substantiated in the present physicochemical approach.

  20. Clinical effects of an oral supplement rich in antioxidants on skin radiance in women

    Directory of Open Access Journals (Sweden)

    Dumoulin M

    2016-10-01

    Full Text Available Marion Dumoulin, David Gaudout, Benoit Lemaire Activ’Inside, Libourne, France Background: Environmental factors impact the skin aging resulting in decrease of skin radiance. Nutrition and particularly antioxidants could help to fight against skin degradation.Objective: The aim of this study was to evaluate the effects of an oral supplement rich in specific antioxidants, SkinAx2TM, on the improvement of the skin radiance in women.Methods: The open-label clinical study enrolled 35 women, aged 40–70, with facial dull complexion. Subjects were supplemented orally with a daily dosage of 150 mg of an antioxidant-rich formulation containing superoxide dismutase-rich melon concentrate, grape seed extract rich in monomers of flavanols, vitamin C, and zinc for 8 weeks. Each subject served as her own control. The C.L.B.T.™ test has been used to evaluate facial skin coloring (C, luminosity (L, brightness (B, and transparency (T involved in skin radiance. Facial skin imperfections have been assessed by clinical assessment. Firmness has been evaluated by clinical assessment and cutometer measurement. Finally, an auto-questionnaire has been carried out in order to evaluate the satisfaction of the subjects concerning different parameters involved in skin radiance and the global efficacy of the supplement.Results: Skin “red pink” and “olive” colors were significantly improved after supplementation (P<0.0001. Luminosity was increased by 25.9% (P<0.0001 whereas brightness and transparency were not affected by the supplementation. Facial skin imperfections were significantly reduced after the antioxidant-rich formulation intake (global reduction: –18.0%; P<0.0001. Indeed, dark circles, redness, and spots significantly diminished after oral treatment. Firmness and elasticity have been shown to be improved. Subjects were globally satisfied by the product (82.4% and have found improvements on their facial skin. Furthermore, 64.7% reported to look

  1. Effect of activation volume on the pressure-induced anomalous resistances in EuFe{sub 2}As{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kwang-Hua, Chu W., E-mail: xajialj@gmail.com [School of Mechanical Engineering, Qinghai University, Xining 810016 (China); Transfer Centre, 3/F, No. 24, Lane 260, Section 1, Mucha Road, Taipei 116, Taiwan, ROC (China)

    2013-03-29

    Highlights: ► Use quantum chemistry to capture the anomalous transition of EuFe{sub 2}As{sub 2}. ► Activation energy and volume are crucial to the critical temperature. ► Pressure effect of EuFe{sub 2}As{sub 2}-resistances can be captured via our approach. - Abstract: We illustrate the effect of activation volume on the pressure-induced anomalous transitional resistances in EuFe{sub 2}As{sub 2} as well as the frictionless transport of many condensed electrons in FeAs based materials by using the verified transition-state approach which is borrowed from the quantum chemistry. Our results suggest that tuning of activation volume could enhance the onset temperature of critical transitional states.

  2. The inverse skin effect in the Z-pinch and plasma focus

    Science.gov (United States)

    Usenko, P. L.; Gaganov, V. V.

    2016-08-01

    The inverse skin effect and its influence on the dynamics of high-current Z-pinch and plasma focus discharges in deuterium are analyzed. It is shown that the second compression responsible for the major fraction of the neutron yield can be interpreted as a result of the inverse skin effect resulting in the axial concentration of the longitudinal current density and the appearance of a reversed current in the outer layers of plasma pinches. Possible conditions leading to the enhancement of the inverse skin effect and accessible for experimental verification by modern diagnostics are formulated.

  3. A Modeling Study of the Effects of Anomalous Snow Cover over the Tibetan Plateau upon the South Asian Summer Monsoon

    Institute of Scientific and Technical Information of China (English)

    刘华强; 孙照渤; 王举; 闵锦忠

    2004-01-01

    The effect of anomalous snow cover over the Tibetan Plateau upon the South Asian summer monsoon is investigated by numerical simulations using the NCAR regional climate model (RegCM2) into which gravity wave drag has been introduced. The simulations adopt relatively realistic snow mass forcings based on Scanning Multi-channel Microwave Radiometer (SMMR) pentad snow depth data. The physical mechanism and spatial structure of the sensitivity of the South Asian early summer monsoon to snow cover anomaly over the Tibetan Plateau are revealed. The main results are summarized as follows. The heavier than normal snow cover over the Plateau can obviously reduce the shortwave radiation absorbed by surface through the albedo effect, which is compensated by weaker upward sensible heat flux associated with colder surface temperature, whereas the effects of snow melting and evaporation are relatively smaller.The anomalies of surface heat fluxes can last until June and become unobvions in July. The decrease of the Plateau surface temperature caused by heavier snow cover reaches its maximum value from late April to early May. The atmospheric cooling in the mid-upper troposphere over the Plateau and its surrounding areas is most obvious in May and can keep a fairly strong intensity in June. In contrast, there is warming to the south of the Plateau in the mid-lower troposphere from April to June with a maximum value in May.The heavier snow cover over the Plateau can reduce the intensity of the South Asian summer monsoon and rainfall to some extent, but this influence is only obvious in early summer and almost disappears in later stages.

  4. Anomalous Hall effect and spin-orbit torques in MnGa/IrMn films: Modification from strong spin Hall effect of the antiferromagnet

    Science.gov (United States)

    Meng, K. K.; Miao, J.; Xu, X. G.; Wu, Y.; Zhao, X. P.; Zhao, J. H.; Jiang, Y.

    2016-12-01

    We report systematic measurements of anomalous Hall effect (AHE) and spin-orbit torques (SOTs) in MnGa/IrMn films, in which a single L 10-MnGa epitaxial layer reveals obvious orbital two-channel Kondo (2CK) effect. As increasing the thickness of the antiferromagnet IrMn, the strong spin Hall effect (SHE) has gradually suppressed the orbital 2CK effect and modified the AHE of MnGa. A scaling involving multiple competing scattering mechanisms has been used to distinguish different contributions to the modified AHE. Finally, the sizeable SOT in the MnGa/IrMn films induced by the strong SHE of IrMn have been investigated. The IrMn layer also supplies an in-plane exchange bias field and enables nearly field-free magnetization reversal.

  5. The moisturizing effects of glycolipid biosurfactants, mannosylerythritol lipids, on human skin.

    Science.gov (United States)

    Yamamoto, Shuhei; Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Yanagidani, Shusaku; Sogabe, Atsushi; Kitamoto, Dai; Kitagawa, Masaru

    2012-01-01

    Glycolipid biosurfactants, such as mannosylerythritol lipids (MELs), are produced by different yeasts belonging to the genus Pseudozyma and have been attracting much attention as new cosmetic ingredients owing to their unique liquid-crystal-forming and moisturizing properties. In this study, the effects of different MEL derivatives on the skin were evaluated in detail using a three-dimensional cultured human skin model and an in vivo human study. The skin cells were cultured and treated with sodium dodecyl sulfate (SDS), and the effects of different lipids on the SDS-damaged cells were evaluated on the basis of cell viability. Most MEL derivatives efficiently recovered the viability of the cells and showed high recovery rates (over 80%) comparable with that of natural ceramide. It is interesting that the recovery rate with MEL-A prepared from olive oil was significantly higher than that of MEL-A prepared from soybean oil. The water retention properties of MEL-B were further investigated on human forearm skin in a preliminary study. Compared with the control, the aqueous solution of MEL-B (5 wt%) was estimated to considerably increase the stratum corneum water content in the skin. Moreover, perspiration on the skin surface was clearly suppressed by treatment with the MEL-B solution. These results suggest that MELs are likely to exhibit a high moisturizing action, by assisting the barrier function of the skin. Accordingly, the yeast glycolipids have a strong potential as a new ingredient for skin care products.

  6. Experimental investigation of system effects in stressed-skin elements

    DEFF Research Database (Denmark)

    Dela Stang, B.; Isaksson, T.; Hansson, M.

    What kind of behaviour can be expected from stressed-skin elements at failure? To answer this question was a primary objective of the experimental investigation presented in this report. Systems of 3 roof units, each made of 5 parallel beams, have been tested for load-carrying capacity...

  7. Skin Cancer, Irradiation, and Sunspots: The Solar Cycle Effect

    Directory of Open Access Journals (Sweden)

    Edward Valachovic

    2014-01-01

    Full Text Available Skin cancer is diagnosed in more than 2 million individuals annually in the United States. It is strongly associated with ultraviolet exposure, with melanoma risk doubling after five or more sunburns. Solar activity, characterized by features such as irradiance and sunspots, undergoes an 11-year solar cycle. This fingerprint frequency accounts for relatively small variation on Earth when compared to other uncorrelated time scales such as daily and seasonal cycles. Kolmogorov-Zurbenko filters, applied to the solar cycle and skin cancer data, separate the components of different time scales to detect weaker long term signals and investigate the relationships between long term trends. Analyses of crosscorrelations reveal epidemiologically consistent latencies between variables which can then be used for regression analysis to calculate a coefficient of influence. This method reveals that strong numerical associations, with correlations >0.5, exist between these small but distinct long term trends in the solar cycle and skin cancer. This improves modeling skin cancer trends on long time scales despite the stronger variation in other time scales and the destructive presence of noise.

  8. Simulation of position sensitivity of the anomalous Hall effect on a single magnetic dot

    NARCIS (Netherlands)

    Vries, de Jeroen; Delalande, Michael; Abelmann, Leon; Alexandrou, Marios; Schedin, Fred; Nutter, Paul; Hill, Ernie; Thomson, Thomas

    2010-01-01

    To overcome the superparamagnetic effect caused by scaling bit and grain sizes in magnetic storage media different approaches are investigated. One alternative is bit patterned magnetic media (BPM) where each bit is represented by a single domain magnetic dot. A key problem with BPM is the large dif

  9. Anomalous dimensions of gauge-invariant amplitudes in massless effective gauge theories of strongly correlated systems

    NARCIS (Netherlands)

    Gusynin, VP; Khveshchenko, DV; Reenders, M

    2003-01-01

    We use the radial gauge to calculate the recently proposed ansatz for the physical electron propagator in such effective models of strongly correlated electron systems as the QED(3) theory of the pseudogap phase of the cuprates. The results of our analysis help to settle the recent dispute about the

  10. Optically Anomalous Crystals

    CERN Document Server

    Shtukenberg, Alexander; Kahr, Bart

    2007-01-01

    Optical anomalies in crystals are puzzles that collectively constituted the greatest unsolved problems in crystallography in the 19th Century. The most common anomaly is a discrepancy between a crystal’s symmetry as determined by its shape or by X-ray analysis, and that determined by monitoring the polarization state of traversing light. These discrepancies were perceived as a great impediment to the development of the sciences of crystals on the basis of Curie’s Symmetry Principle, the grand organizing idea in the physical sciences to emerge in the latter half of the 19th Century. Optically Anomalous Crystals begins with an historical introduction covering the contributions of Brewster, Biot, Mallard, Brauns, Tamman, and many other distinguished crystallographers. From this follows a tutorial in crystal optics. Further chapters discuss the two main mechanisms of optical dissymmetry: 1. the piezo-optic effect, and 2. the kinetic ordering of atoms. The text then tackles complex, inhomogeneous crystals, and...

  11. Effects of the anomalous Higgs couplings on the Higgs boson production at the Large Hadron Collider

    CERN Document Server

    Kanemura, Shinya

    2008-01-01

    We study the impact of dimension-six operators on single- and double-Higgs production via gluon fusion at the Large Hadron Collider (LHC). If the top-Yukawa coupling is modified by some new physics whose scale is of the TeV scale, its effect changes the cross sections of single-Higgs production $gg\\to H$ and double-Higgs production $gg\\to HH$ through the top-loop diagram. In particular, double-Higgs production can receive significant enhancement from the effective top-Yukawa coupling and the new dimension-five coupling $t{\\bar t}HH$ which are induced by the dimension-six operator. Comparing these results to the forthcoming data at the LHC, one can extract information of the dimension-six operators relevant to the top quark and the Higgs boson.

  12. Synergistic effect of low-frequency ultrasound and surfactants on skin permeability.

    Science.gov (United States)

    Tezel, Ahmet; Sens, Ashley; Tuchscherer, Joe; Mitragotri, Samir

    2002-01-01

    Low-frequency ultrasound (20 kHz) and surfactants have been individually shown to enhance transdermal drug transport. In this study, we investigated the synergistic effect of ultrasound and surfactants on transdermal drug delivery. Surfactants with different head group chemistries including anionic, cationic, and nonionic with varying tail lengths (8-16-carbon atoms) were studied. We found that surfactants possessing anionic and cationic head groups were more potent than those possessing nonionic head groups in increasing skin conductivity in the presence of ultrasound. Furthermore, for surfactants possessing the same head group, those with a 14-carbon tail length were found to be most effective in enhancing skin permeability. The data presented in this report show that ultrasound and surfactants synergistically enhance skin permeability. Two mechanisms are shown to play a role in this synergistic effect. First, ultrasound enhances surfactant delivery (enhanced delivery) into the skin and, second, ultrasound disperses surfactant (enhanced dispersion) within the skin. In general, surfactants that are potent enhancers by themselves are potent enhancers in the presence of ultrasound as well. We performed imaging experiments to assess the effect of ultrasound on delivery of a model permeant, sulforhodamine B, into the skin. These experiments show that ultrasound enhances surfactant delivery and dispersion in the skin.

  13. Chiral magnetic effect and anomalous transport from real-time lattice simulations

    CERN Document Server

    Mueller, Niklas; Sharma, Sayantan

    2016-01-01

    We present a first-principle study of anomaly induced transport phenomena by performing real-time lattice simulations with dynamical fermions coupled simultaneously to non-Abelian $SU(N_c)$ and Abelian $U(1)$ gauge fields. Investigating the behavior of vector and axial currents during a sphaleron transition in the presence of an external magnetic field, we demonstrate how the interplay of the Chiral magnetic (CME) and Chiral separation effect (CSE) lead to the formation of a propagating wave. We further analyze the dependence of the magnitude of the induced vector current and the propagation of the wave on the amount of explicit chiral symmetry breaking due to finite quark mass.

  14. Anomalous Hall effect in epitaxial ferrimagnetic anti-perovskite Mn{sub 4−x}Dy{sub x}N films

    Energy Technology Data Exchange (ETDEWEB)

    Meng, M.; Wu, S. X., E-mail: wushx3@mail.sysu.edu.cn; Zhou, W. Q.; Ren, L. Z.; Wang, Y. J.; Wang, G. L.; Li, S. W., E-mail: stslsw@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

    2015-08-07

    Anomalous Hall effect (AHE) has been studied for ferrimagnetic antiperovskite Mn{sub 4−x}Dy{sub x}N films grown by molecular-beam epitaxy. The introduction of Dy changes the AHE dramatically, even changes its sign, while the variations in magnetization are negligible. Two sign reversals of the AHE (negative-positive-negative) are ascribed to the variation of charge carriers as a result of Fermi surface reconstruction. We further demonstrate that the AHE current J{sub AH} is dissipationless (independent of the scattering rate), by confirming that anomalous Hall conductivity, σ{sub AH}, is proportional to the carrier density n at 5 K. Our study may provide a route to further utilize antiperovskite manganese nitrides in spintronics.

  15. Hairy skin exposure to VX in vitro: effectiveness of delayed decontamination.

    Science.gov (United States)

    Rolland, P; Bolzinger, M-A; Cruz, C; Josse, D; Briançon, S

    2013-02-01

    The chemical warfare agents such as VX represent a threat for both military and civilians, which involves an immediate need of effective decontamination systems. Since human scalp is usually unprotected compared to other body regions covered with clothes, it could be a preferential site of exposure in case of terrorist acts. The purpose of this study was to determine if skin decontamination could be efficient when performed more than 1h after exposure. In addition, the impact of hairs in skin contamination was investigated. By using in vitro skin models, we demonstrated that about 75% of the applied quantity of VX was recovered on the skin surface 2h after skin exposition, which means that it is worth decontaminating even if contamination occurred 2h before. The stratum corneum reservoir for VX was quickly established and persistent. In addition, the presence of hairs modified the percutaneous penetration of the nerve agent by binding of VX to hairs. Hair shaft has thus to be taken into account in the decontamination process. Reactive Skin Decontamination Lotion (RSDL) and Fuller's Earth (FE) were active in the skin decontamination 45min post-exposure, but RSDL was more efficient in reducing the amount of VX either in the skin or in the hair.

  16. High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe

    Science.gov (United States)

    Bandurin, Denis A.; Tyurnina, Anastasia V.; Yu, Geliang L.; Mishchenko, Artem; Zólyomi, Viktor; Morozov, Sergey V.; Kumar, Roshan Krishna; Gorbachev, Roman V.; Kudrynskyi, Zakhar R.; Pezzini, Sergio; Kovalyuk, Zakhar D.; Zeitler, Uli; Novoselov, Konstantin S.; Patanè, Amalia; Eaves, Laurence; Grigorieva, Irina V.; Fal'Ko, Vladimir I.; Geim, Andre K.; Cao, Yang

    2016-11-01

    A decade of intense research on two-dimensional (2D) atomic crystals has revealed that their properties can differ greatly from those of the parent compound. These differences are governed by changes in the band structure due to quantum confinement and are most profound if the underlying lattice symmetry changes. Here we report a high-quality 2D electron gas in few-layer InSe encapsulated in hexagonal boron nitride under an inert atmosphere. Carrier mobilities are found to exceed 103 cm2 V‑1 s‑1 and 104 cm2 V‑1 s‑1 at room and liquid-helium temperatures, respectively, allowing the observation of the fully developed quantum Hall effect. The conduction electrons occupy a single 2D subband and have a small effective mass. Photoluminescence spectroscopy reveals that the bandgap increases by more than 0.5 eV with decreasing the thickness from bulk to bilayer InSe. The band-edge optical response vanishes in monolayer InSe, which is attributed to the monolayer's mirror-plane symmetry. Encapsulated 2D InSe expands the family of graphene-like semiconductors and, in terms of quality, is competitive with atomically thin dichalcogenides and black phosphorus.

  17. Anomalous quantum and isotope effects in water clusters: Physical phenomenon, model artifact, or bad approximation?

    CERN Document Server

    Brown, Sandra E

    2014-01-01

    Free energy differences $\\Delta F:=F-F_{\\text{prism}}$ are computed for several isomers of water hexamer relative to the "prism" isomer using the self-consistent phonons method. %$\\Delta F:=F-F({prism})$ We consider the isotope effect defined by the quantity $\\delta F_{D_2O}:=\\Delta F_{\\rm D_2O}-\\Delta F_{\\rm H_2O}$, and the quantum effect, $\\delta F_{\\hbar=0}:=\\Delta F_{\\hbar=0}-\\Delta F_{\\rm H_2O}$, and evaluate them using different flexible water models. While both $\\delta F_{D_2O}$ and $\\delta F_{\\hbar=0}$ are found to be rather small for all of the potentials, they are especially small for two of the empirical models, q-TIP4P/F and TTM3-F, compared to q-SPC/Fw and the two {\\it abinitio}-based models, WHBB and HBB2-pol. This qualitative difference in the properties of different water models cannot be explained by one being "more accurate" than the other. We speculate as to whether the observed anomalies are caused by the special properties of water systems, or are an artifact of either the potential energ...

  18. High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe.

    Science.gov (United States)

    Bandurin, Denis A; Tyurnina, Anastasia V; Yu, Geliang L; Mishchenko, Artem; Zólyomi, Viktor; Morozov, Sergey V; Kumar, Roshan Krishna; Gorbachev, Roman V; Kudrynskyi, Zakhar R; Pezzini, Sergio; Kovalyuk, Zakhar D; Zeitler, Uli; Novoselov, Konstantin S; Patanè, Amalia; Eaves, Laurence; Grigorieva, Irina V; Fal'ko, Vladimir I; Geim, Andre K; Cao, Yang

    2016-11-21

    A decade of intense research on two-dimensional (2D) atomic crystals has revealed that their properties can differ greatly from those of the parent compound. These differences are governed by changes in the band structure due to quantum confinement and are most profound if the underlying lattice symmetry changes. Here we report a high-quality 2D electron gas in few-layer InSe encapsulated in hexagonal boron nitride under an inert atmosphere. Carrier mobilities are found to exceed 10(3) cm(2) V(-1) s(-1) and 10(4) cm(2) V(-1) s(-1) at room and liquid-helium temperatures, respectively, allowing the observation of the fully developed quantum Hall effect. The conduction electrons occupy a single 2D subband and have a small effective mass. Photoluminescence spectroscopy reveals that the bandgap increases by more than 0.5 eV with decreasing the thickness from bulk to bilayer InSe. The band-edge optical response vanishes in monolayer InSe, which is attributed to the monolayer's mirror-plane symmetry. Encapsulated 2D InSe expands the family of graphene-like semiconductors and, in terms of quality, is competitive with atomically thin dichalcogenides and black phosphorus.

  19. On the anomalous Stark effect in a thin disc-shaped quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Oukerroum, A [Laboratoire de Physique de la Matiere Condensee, Faculte des Sciences et Techniques, BP 140, Bd Yassima, 28820 Mohammedia (Morocco); Feddi, E [LaMIPI, ENSET de Rabat, Universite Mohamed V Souissi, BP 6207, Rabat-Institut, 10100 Rabat (Morocco); Bailach, J Bosch; MartInez-Pastor, J [Instituto de Ciencia de los Materiales, Universidad de Valencia, PO Box 2085, E-46071 Valencia (Spain); Dujardin, F [Laboratoire de Physique des Milieux Denses, Universite Paul Verlaine, 1 Bd Arago, F-57078 Metz (France); Assaid, E, E-mail: feddi@univ-metz.f [Laboratoire d' Electronique et Optique des Nanostructures de Semiconducteurs, Faculte des Sciences, BP 20, 24000 El Jadida (Morocco)

    2010-09-22

    The effect of a lateral external electric field F on an exciton ground state in an InAs disc-shaped quantum dot has been studied using a variational method within the effective mass approximation. We consider that the radial dimension of the disc is very large compared to its height. This situation leads to separating the excitonic Hamiltonian into two independent parts: the lateral confinement which corresponds to a two-dimensional harmonic oscillator and an infinite square well in the growth direction. Our calculations show that the complete description of the lateral Stark shift requires both the linear and quadratic terms in F which explains that the exciton possess nonzero lateral dipolar moment and polarizability. The fit of the calculated Stark shift permits us to estimate the lateral permanent dipole moment and the polarizability according to the disc size. Our results are compared to those existing in the literature. In addition the behavior of the optical integral shows that the exciton lifetime is greater than that under zero field which is due to the field-induced polarization.

  20. The effect of dietary and/or cosmetic argan oil on postmenopausal skin elasticity

    Directory of Open Access Journals (Sweden)

    Qiraouani Boucetta K

    2015-01-01

    Full Text Available Kenza Qiraouani Boucetta,1 Zoubida Charrouf,2 Hassan Aguenaou,3 Abdelfattah Derouiche,4 Yahya Bensouda1 1Research Team on Formulation and Biopharmacy, Research Center for Drug, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco; 2Faculty of Sciences, Mohammed V University, Rabat, Morocco; 3Mixed Unit of Research in Nutrition, ITU / CNESTEN, Ibn Tofail University, Kenitra, Morocco; 4Faculty of Sciences, Hassan II University, Casablanca, Morocco Background: During menopause, the decrease of estrogenic secretion induces the disruption of skin functioning, thus causing the decline in skin elasticity characteristic of skin aging. The purpose of this study was to evaluate in postmenopausal women the effect of daily consumption and/or application of argan oil on skin elasticity.Materials and methods: Sixty postmenopausal women consumed butter during the stabilization period and were randomly divided into two groups for the intervention period: the treatment group of 30 participants received dietary argan oil, the control group of 30 participants received olive oil, and both groups applied cosmetic argan oil in the left volar forearm during a 60-day period. Assessments of skin elasticity parameters, ie, the three R-parameters (R2 or gross-elasticity of the skin, R5 or net elasticity of the skin, and R7 or biological elasticity, and the resonance running time (RRT at both volar forearms of the two groups were performed during three visits: before starting oils consumption and application, after 30 days of oils consumption and application, and after 60 days of oils consumption and application.Results: The consumption of argan oil led to a significant increase of gross-elasticity of the skin (R2 (P<0.001, net elasticity of the skin (R5 (P<0.001, biological elasticity (R7 (P<0.001, and a significant decrease of RRT (P=0.002. The application of argan oil led to a significant increase of gross-elasticity of the skin (R2 (P<0.001, net

  1. Effects of a cellulose mask synthesized by a bacterium on facial skin characteristics and user satisfaction

    Directory of Open Access Journals (Sweden)

    Amnuaikit T

    2011-06-01

    Full Text Available Thanaporn Amnuaikit, Toon Chusuit, Panithi Raknam, Prapaporn BoonmeDepartment of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla, ThailandBackground: Cellulose masks obtained from natural sources such as bacteria are of interest as cosmetic devices for the treatment of dry skin because they not only improve hydration of the skin, but have low toxicity and are biodegradable. The aims of this study were to determine the in vivo effects of a cellulose mask obtained from Acetobacter xylinum on skin characteristics and to evaluate user satisfaction with the product.Methods: Thirty healthy Thai volunteers aged 21–40 years participated in the study. The volunteers were randomly separated into a control group and an experimental group. For the control group, volunteers were assigned to apply moist towels to the face for 25 minutes. For the experimental group, the volunteers were assigned to apply the masks, ie, translucent patches which could be fitted onto the face for the same period. The following week, the groups were changed over to the alternative treatment. Skin moisture, sebum, elasticity, texture, dullness, and desquamation levels were assessed using a system used for routine skin counseling before applying the trial product and five minutes after its removal. Degree of satisfaction with use of the cellulose mask was investigated using a five-point rating scale.Results: The cellulose mask increased moisture levels in the skin significantly more than moist towels (P < 0.05 after a single application. No obvious effects on other skin characteristics were found. The cellulose mask product rated around 4/5 on the satisfaction rating scale.Conclusions: A single application of the trial cellulose mask enhanced moisture uptake by facial skin. Users also reported being satisfied with the trial product.Keywords: bacterial cellulose, facial mask, skin characteristics, skin hydration, user

  2. Intrinsic quantum spin Hall and anomalous Hall effects in h-Sb/Bi epitaxial growth on a ferromagnetic MnO2 thin film.

    Science.gov (United States)

    Zhou, Jian; Sun, Qiang; Wang, Qian; Kawazoe, Yoshiyuki; Jena, Puru

    2016-06-07

    Exploring a two-dimensional intrinsic quantum spin Hall state with a large band gap as well as an anomalous Hall state in realizable materials is one of the most fundamental and important goals for future applications in spintronics, valleytronics, and quantum computing. Here, by combining first-principles calculations with a tight-binding model, we predict that Sb or Bi can epitaxially grow on a stable and ferromagnetic MnO2 thin film substrate, forming a flat honeycomb sheet. The flatness of Sb or Bi provides an opportunity for the existence of Dirac points in the Brillouin zone, with its position effectively tuned by surface hydrogenation. The Dirac points in spin up and spin down channels split due to the proximity effects induced by MnO2. In the presence of both intrinsic and Rashba spin-orbit coupling, we find two band gaps exhibiting a large band gap quantum spin Hall state and a nearly quantized anomalous Hall state which can be tuned by adjusting the Fermi level. Our findings provide an efficient way to realize both quantized intrinsic spin Hall conductivity and anomalous Hall conductivity in a single material.

  3. Strong Quantum Size Effects in Pb(111) Thin Films Mediated by Anomalous Friedel Oscillations

    Science.gov (United States)

    Jia, Yu; Wu, Biao; Li, Chong; Einstein, T. L.; Weitering, H. H.; Zhang, Zhenyu

    2010-08-01

    Using first-principles calculations within density functional theory, we study Friedel oscillations (FOs) in the electron density at different metal surfaces and their influence on the lattice relaxation and stability of ultrathin metal films. We show that the FOs at the Pb(111) surface decay as 1/x with the distance x from the surface, different from the conventional 1/x2 power law at other metal surfaces. The underlying physical reason for this striking difference is tied to the strong nesting of the two different Fermi sheets along the Pb(111) direction. The interference of the strong FOs emanating from the two surfaces of a Pb(111) film, in turn, not only results in superoscillatory interlayer relaxations around the center of the film, but also determines its stability in the quantum regime. As a simple and generic picture, the present findings also explain why quantum size effects are exceptionally robust in Pb(111) films.

  4. Effect of pore blockage on adsorption isotherms and dynamics: Anomalous adsorption of iodine on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, S.K.; Liu, F.; Arvind, G.

    2000-04-18

    Isotherm hysteresis and pore-clocking effects of trapped molecules on adsorption dynamics is studied here, using the iodine-carbon system in the 300--343 K temperature range. It is found that a portion of the iodine is strongly adsorbed, and does not desorb, even over very long time scales, while the remainder adsorbs reversibly as a homogeneous monolayer with a Langmuirian isotherm in mesopores. The strongly adsorbed iodine appears to adsorb in micropores and at the mesopore mouths, hindering uptake of the reversible iodine. The uptake data for the adsorption and desorption dynamics of the reversible part is found to be best explained by means of a pore mouth resistance control mechanism. it is concluded that the dynamics of the adsorption and desorption at the pore mouth is important at early stages of the process.

  5. Possible anomalous doppler shift effect in superconductor Sr sub 2 RuO sub 4

    CERN Document Server

    Tanaka, Y; Tanuma, Y; Kashiwaya, S

    2003-01-01

    The effect of Doppler shift is studied in a model for the alpha-beta bands of Sr sub 2 RuO sub 4 consisting of two hybridized one-dimensional (1D) bands. Assuming a superconducting gap with nodes in a diagonal direction, we examine the oscillation of surface density of states and thermal conductivity under a rotating magnetic field. Upon varying the strength of hybridization, the oscillation of these quantities is found to exhibit 2D to 1D crossover. In the crossover regime, which corresponds to the actual Sr sub 2 RuO sub 4 , the thermal conductivity exhibits a two-fold-symmetry oscillation, while a four-fold-symmetry component in the oscillation is barely detectable.

  6. A novel administration route for edaravone: I. Effects of metabolic inhibitors on skin permeability of edaravone.

    Science.gov (United States)

    Sato, Toshiaki; Mizuno, Keizo; Ishii, Fumiyoshi

    2009-05-08

    We examined the effects of metabolic inhibitors on skin permeation of edaravone. SKF-525A, diclofenac sodium (DIC) and indomethacin (IND) were added to supernatant fluid (SF) of hairless rat (HR) skin homogenate. L-Cysteine (L-Cys) and benzotriazole (BTA), as pharmaceutical additives, were added to HR skin homogenate SF, and incubated at 37 degrees C for 30 min. K(m) and V(max) values were calculated. For determination of edaravone skin permeation from edaravone/hydroxypropyl-beta-cyclodextrin (HPbetaCD) complex solution, HR skin was placed in a Franz diffusion cell, and kept at 37 degrees C. Edaravone/HPbetaCD solution that contained L-Cys was put into the donor side. The relative activity in skin homogenate SF after co-treatment with IND and SKF-525A decreased to 40.8% of the control. However, DIC and IND had a weak inhibitory effect. For inhibition of edaravone metabolism, L-Cys and BTA had no effect on K(m) value, but V(max) was significantly decreased compared with controls (*P<0.05, Tukey-Kramer test). The edaravone skin permeation rate and permeability coefficient from edaravone/HPbetaCD complex solution with inhibitor were significantly increased compared with those without inhibitor. We suggest that the metabolism inhibitor was useful for the transdermal delivery of edaravone.

  7. DeoxyArbutin: a novel reversible tyrosinase inhibitor with effective in vivo skin lightening potency.

    Science.gov (United States)

    Boissy, Raymond E; Visscher, Marty; DeLong, Mitchell A

    2005-08-01

    Modulation of melanogenesis in the melanocytes can be achieved using chemicals that share structural homologies with the substrate tyrosine and as thus competitively inhibit the catalytic function of tyrosinase. We have developed a new tyrosinase inhibitor, deoxyArbutin (dA), based on this premise. DeoxyArbutin demonstrates effective inhibition of mushroom tyrosinase in vitro with a Ki that is 10-fold lower that hydroquinone (HQ) and 350-fold lower than arbutin. In a hairless, pigmented guinea pig model, dA demonstrated rapid and sustained skin lightening that was completely reversible within 8 weeks after halt in topical application. In contrast, HQ induced a short but unsustained skin lightening effect whereas kojic acid and arbutin exhibit no skin lightening effect. Results from a panel of safety tests supported the overall establishment of dA as an actionable molecule. In a human clinical trial, topical treatment of dA for 12 weeks resulted in a significant or slight reduction in overall skin lightness and improvement of solar lentigines in a population of light skin or dark skin individuals, respectively. These data demonstrate that dA has potential tyrosinase inhibitory activity that can result in skin lightening and may be used to ameliorate hyperpigmentary lesions.

  8. Parabens inhibit human skin estrogen sulfotransferase activity: possible link to paraben estrogenic effects.

    Science.gov (United States)

    Prusakiewicz, Jeffery J; Harville, Heather M; Zhang, Yanhua; Ackermann, Chrisita; Voorman, Richard L

    2007-04-11

    Parabens (p-hydroxybenzoate esters) are a group of widely used preservatives in topically applied cosmetic and pharmaceutical products. Parabens display weak associations with the estrogen receptors in vitro or in cell based models, but do exhibit estrogenic effects in animal models. It is our hypothesis that parabens exert their estrogenic effects, in part, by elevating levels of estrogens through inhibition of estrogen sulfotransferases (SULTs) in skin. We report here the results of a structure-activity-relationship of parabens as inhibitors of estrogen sulfation in human skin cytosolic fractions and normal human epidermal keratinocytes. Similar to reports of paraben estrogenicity and estrogen receptor affinity, the potency of SULT inhibition increased as the paraben ester chain length increased. Butylparaben was found to be the most potent of the parabens in skin cytosol, yielding an IC(50) value of 37+/-5 microM. Butylparaben blocked the skin cytosol sulfation of estradiol and estrone, but not the androgen dehydroepiandrosterone. The parabens were also tested as inhibitors of SULT activity in a cellular system, with normal human epidermal keratinocytes. The potency of butylparaben increased three-fold in these cells relative to the IC(50) value from skin cytosol. Overall, these results suggest chronic topical application of parabens may lead to prolonged estrogenic effects in skin as a result of inhibition of estrogen sulfotransferase activity. Accordingly, the skin anti-aging benefits of many topical cosmetics and pharmaceuticals could be derived, in part, from the estrogenicity of parabens.

  9. The effect of Kinesiotaping to the skin temperature – Pilot study

    OpenAIRE

    Holma, Teemu

    2014-01-01

    Aim of this study was to research whether kinesiotape has effect to skin temperature. Subjects of this study were 32 asymptomatic students of Satakunta University of Applied Sciences, 20 females and 15 males. The exclusion criteria were: recent back pain or musculoskeletal diseases on back area skin irritations and diseases on taping site. To assess the effect of kinesiotape all the subjects were taped with 30 cm taped from Superios Posterios Iliac Spine(SPIS) upwards to the ribcage. Befo...

  10. Effects of femtosecond laser radiation on the skin

    Science.gov (United States)

    Rogov, P. Yu; Bespalov, V. G.

    2016-08-01

    A mathematical model of linear and nonlinear processes is presented occurring under the influence of femtosecond laser radiation on the skin. There was held an analysis and the numerical solution of an equation system describing the dynamics of the electron and phonon subsystems were received. The results can be used to determine the maximum permissible levels of energy generated by femtosecond laser systems and the establishment of Russian laser safety standards for femtosecond laser systems.

  11. The biodisposition and hypertrichotic effects of bimatoprost in mouse skin.

    Science.gov (United States)

    Woodward, David F; Tang, Elaine S-H; Attar, Mayssa; Wang, Jenny W

    2013-02-01

    Studies on bimatoprost were performed with two objectives: (i) to determine whether bimatoprost possesses hair growth-stimulating properties beyond eyelash hypertrichosis and (ii) to investigate the biodisposition of bimatoprost in skin for the first time. Bimatoprost, at the dose used clinically for eyelash growth (0.03%) and given once daily for 14 days, increased pelage hair growth in C57/black 6 mice. This occurred as a much earlier onset of new hair growth in shaved mice and the time taken to achieve complete hair regrowth, according to photographic documentation and visual assessment. Bimatoprost biodisposition in the skin was determined at three concentrations: 0.01%, 0.03% and 0.06%. Dose-dependent C(max) values were obtained (3.41, 6.74, 12.3 μg/g tissue), and cutaneous bimatoprost was well maintained for 24 h following a single dose. Bimatoprost was recovered from the skin only as the intact molecule, with no detectable levels of metabolites. Thus, bimatoprost produces hypertrichosis as the intact molecule.

  12. Cutaneous effects of topical indomethacin, an inhibitor of prostaglandin synthesis, on uv-damaged skin

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, D.S.

    1975-05-01

    Topical application of a 2.5 percent indomethacin (IM) solution to the sunburned skin of humans and guinea pigs resulted in a marked decrease in ultraviolet light (UVL)-induced erythema. In humans, a decrease in skin temperature and hyperalgesia to near normal levels was also observed. Epidermal responses to UVL injury such as keratinocyte cell death and altered DNA synthesis proceeded unmodified by IM. Repeated applications of IM in the 48-hr period following UVL exposure did not improve upon the results obtained following a single treatment. Guinea-pig skin provides a relevant model system for evaluating the effects of topical nonsteroidal anti-inflammatory agents on sunburn. (auth)

  13. Flavanone silibinin treatment attenuates nitrogen mustard-induced toxic effects in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Anil K.; Tewari-Singh, Neera; Inturi, Swetha; Kumar, Dileep [Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 (United States); Orlicky, David J. [Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 (United States); Agarwal, Chapla [Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 (United States); White, Carl W. [Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045USA (United States); Agarwal, Rajesh, E-mail: Rajesh.Agarwal@UCDenver.edu [Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 (United States)

    2015-05-15

    Currently, there is no effective antidote to prevent skin injuries by sulfur mustard (SM) and nitrogen mustard (NM), which are vesicating agents with potential relevance to chemical warfare, terrorist attacks, or industrial/laboratory accidents. Our earlier report has demonstrated the therapeutic efficacy of silibinin, a natural flavanone, in reversing monofunctional alkylating SM analog 2-chloroethyl ethyl sulfide-induced toxic effects in mouse skin. To translate this effect to a bifunctional alkylating vesicant, herein, efficacy studies were carried out with NM. Topical application of silibinin (1 or 2 mg) 30 min after NM exposure on the dorsal skin of male SKH-1 hairless mice significantly decreased NM-induced toxic lesions at 24, 72 or 120 h post-exposure. Specifically, silibinin treatment resulted in dose-dependent reduction of NM-induced increase in epidermal thickness, dead and denuded epidermis, parakeratosis and microvesication. Higher silibinin dose also caused a 79% and 51%reversal in NM-induced increases in myeloperoxidase activity and COX-2 levels, respectively. Furthermore, silibinin completely prevented NM-induced H2A.X phosphorylation, indicating reversal of DNA damage which could be an oxidative DNA damage as evidenced by high levels of 8-oxodG in NM-exposed mouse skin that was significantly reversed by silibinin. Together, these findings suggest that attenuation of NM-induced skin injury by silibinin is due to its effects on the pathways associated with DNA damage, inflammation, vesication and oxidative stress. In conclusion, results presented here support the optimization of silibinin as an effective treatment of skin injury by vesicants. - Highlights: • Silibinin treatment attenuated nitrogen mustard (NM)-induced skin injury. • Silibinin affects pathways associated with DNA damage, inflammation and vesication. • The efficacy of silibinin could also be associated with oxidative stress. • These results support testing and optimization of

  14. Effect of skin hydration on the dynamics of fingertip gripping contact

    Science.gov (United States)

    André, T.; Lévesque, V.; Hayward, V.; Lefèvre, P.; Thonnard, J.-L.

    2011-01-01

    The dynamics of fingertip contact manifest themselves in the complex skin movements observed during the transition from a stuck state to a fully developed slip. While investigating this transition, we found that it depended on skin hydration. To quantify this dependency, we asked subjects to slide their index fingertip on a glass surface while keeping the normal component of the interaction force constant with the help of visual feedback. Skin deformation inside the contact region was imaged with an optical apparatus that allowed us to quantify the relative sizes of the slipping and sticking regions. The ratio of the stuck skin area to the total contact area decreased linearly from 1 to 0 when the tangential force component increased from 0 to a maximum. The slope of this relationship was inversely correlated to the normal force component. The skin hydration level dramatically affected the dynamics of the contact encapsulated in the course of evolution from sticking to slipping. The specific effect was to reduce the tendency of a contact to slip, regardless of the variations of the coefficient of friction. Since grips were more unstable under dry skin conditions, our results suggest that the nervous system responds to dry skin by exaggerated grip forces that cannot be simply explained by a change in the coefficient of friction. PMID:21490002

  15. Prebiotic effects of almonds and almond skins on intestinal microbiota in healthy adult humans.

    Science.gov (United States)

    Liu, Zhibin; Lin, Xiuchun; Huang, Guangwei; Zhang, Wen; Rao, Pingfan; Ni, Li

    2014-04-01

    Almonds and almond skins are rich in fiber and other components that have potential prebiotic properties. In this study we investigated the prebiotic effects of almond and almond skin intake in healthy humans. A total of 48 healthy adult volunteers consumed a daily dose of roasted almonds (56 g), almond skins (10 g), or commercial fructooligosaccharides (8 g) (as positive control) for 6 weeks. Fecal samples were collected at defined time points and analyzed for microbiota composition and selected indicators of microbial activity. Different strains of intestinal bacteria had varying degrees of growth sensitivity to almonds or almond skins. Significant increases in the populations of Bifidobacterium spp. and Lactobacillus spp. were observed in fecal samples as a consequence of almond or almond skin supplementation. However, the populations of Escherichia coli did not change significantly, while the growth of the pathogen Clostridum perfringens was significantly repressed. Modification of the intestinal microbiota composition induced changes in bacterial enzyme activities, specifically a significant increase in fecal β-galactosidase activity and decreases in fecal β-glucuronidase, nitroreductase and azoreductase activities. Our observations suggest that almond and almond skin ingestion may lead to an improvement in the intestinal microbiota profile and a modification of the intestinal bacterial activities, which would induce the promotion of health beneficial factors and the inhibition of harmful factors. Thus we believe that almonds and almond skins possess potential prebiotic properties.

  16. Effect of microscopic modeling of skin in electrical and thermal analysis of transcranial direct current stimulation

    Science.gov (United States)

    Gomez-Tames, Jose; Sugiyama, Yukiya; Laakso, Ilkka; Tanaka, Satoshi; Koyama, Soichiro; Sadato, Norihiro; Hirata, Akimasa

    2016-12-01

    Transcranial direct current stimulation (tDCS) is a neuromodulation scheme where a small current is delivered to the brain via two electrodes attached to the scalp. The electrode design is an important topic, not only as regards efficacy, but also from a safety perspective, as tDCS may be related to skin lesions that are sometimes observed after stimulation. Previous computational models of tDCS have omitted the effects of microscopic structures in the skin, and the different soak conditions of the electrodes, and model validation has been limited. In this study, multiphysics and multiscale analysis are proposed to demonstrate the importance of microscopic modeling of the skin, in order to clarify the effects of the internal electric field, and to examine temperature elevation around the electrodes. This novel microscopic model of the skin layer took into consideration the effect of saline/water penetration in hair follicles and sweat ducts on the field distribution around the electrodes. The temperature elevation in the skin was then computed by solving the bioheat equation. Also, a multiscale model was introduced to account for macroscopic and microscopic tissues of the head and skin, which was validated by measurement of the head resistance during tDCS. As a result, the electric field in the microscopic model of the skin was less localized when the follicles/ducts were filled with saline instead of hair or tap water. Temperature elevation was also lessened with saline, in comparison with other substances. Saline, which may penetrate the hair follicles and sweat ducts, suppressed the field concentration around the electrodes. For conventional magnitudes of current injection, and a head resistance of less than 10 kΩ, the temperature elevation in the skin when using saline-soaked electrodes was low, less than 0.1 °C, and unlikely to cause adverse thermal effects.

  17. Neutron Skin Thickness of Nuclei and Effective Nucleon-Nucleon Interactions

    Institute of Scientific and Technical Information of China (English)

    LIU Min; WANG Ning; LI Zhu-Xia; WU Xi-Zhen

    2006-01-01

    @@ The Skyrme energy density functional is applied to study the ground state properties of a series of finite nuclei.The charge rms radii, neutron rms radii, and the neutron skin thickness for some nuclei are calculated and compared with the experimental data. The constraint on the effective interactions, especially, the density dependence of the isospin-dependent part of Skyrme interactions is extracted by the data of neutron skin thicknesses of 208 pb and isotopes of Sn.

  18. The role of natural and UV-induced skin pigmentation on low-fluence IPL-induced side effects

    DEFF Research Database (Denmark)

    Thaysen-Petersen, Daniel; Lin, Jennifer Y; Nash, Jf

    2014-01-01

    disproportionately. The aim of this study was to evaluate the influence of constitutive and facultative skin pigmentation on low-fluence intense pulsed light (IPL)-induced adverse skin effects. STUDY DESIGN/MATERIALS AND METHODS: Twenty-one subjects with Fitzpatrick skin type II-IV were enrolled. Two buttock blocks...

  19. ANOMALOUS MAGNETIC FILMS,

    Science.gov (United States)

    Three types of anomalous nickel-iron magnetic films characterized by hysteresigraph and torque-magnetometer measurements; bitter-pattern observations; reprint from ’ Journal of Applied Physics .’

  20. Beneficial effects of pro-/antioxidant-based nutraceuticals in the skin rejuvenation techniques.

    Science.gov (United States)

    de Luca, C; Deeva, I; Mikhal'Chik, E; Korkina, L

    2007-04-15

    Modern technologies of skin rejuvenation include many physical and chemical intervention tools--laser irradiation, oxygen and ozone therapy, chemical peels, plastic surgery operations--affecting by different mechanisms the sensitive physiological free radical/antioxidant balance in the skin. All these interventions induce from mild to severe tissue damage, providing beneficial biochemical stimuli for skin re-epithelization and rejuvenation. Paradoxically, free radical production in the course of tissue inflammation helps to combat free radical damage consequent to the ageing process. We have studied two animal models (experimental burn and trichloracetic peeling), reproducing on the Wistar rat the effects generated by the commonly practiced aesthetic medicine procedures of laser resurfacing and chemical peels, demonstrating that the severe oxidative stress induced both systemically and on skin can be modulated by the oral pre- and post treatment administration of specific nutraceutical formulations. Potent antioxidants (RRR-alpha-tocopherol, coenzyme Q10), enhancing antioxidant defences, coupled with mild pro-oxidants, enhancers of a specific immune defense (soy phospholipids, L-methionine), at the blood and the skin levels, proved in fact to be beneficial in vivo, on the rat, for skin healing, trophism and accelerated re-epithelization. Data obtained allow us to predict the possibility of innovative protocols for dermocosmetology, enabling successful lowering of the risk of permanent adverse effects, and prolonging the duration of the beneficial effects of dermocosmetologic procedures.

  1. Molecular mechanisms of green tea polyphenols with protective effects against skin photoaging.

    Science.gov (United States)

    Roh, Eunmiri; Kim, Jong-Eun; Kwon, Jung Yeon; Park, Jun Seong; Bode, Ann M; Dong, Zigang; Lee, Ki Won

    2017-05-24

    Whereas green tea has historically been consumed in high quantities in Northeast Asia, its popularity is also increasing in many Western countries. Green tea is an abundant source of plant polyphenols exhibiting numerous effects that are potentially beneficial for human health. Accumulating evidence suggests that green tea polyphenols confer protective effects on the skin against ultraviolet (UV) irradiation-induced acceleration of skin aging, involving antimelanogenic, antiwrinkle, antioxidant, and anti-inflammatory effects as well as prevention of immunosuppression. Melanin pigmentation in the skin is a major defense mechanism against UV irradiation, but pigmentation abnormalities such as melasma, freckles, senile lentigines, and other forms of melanin hyperpigmentation can also cause serious health and aesthetic issues. Furthermore, UV irradiation initiates the degradation of fibrillar collagen and elastic fibers, promoting the process of skin aging through deep wrinkle formation and loss of tissue elasticity. UV irradiation-induced formation of free radicals also contributes to accelerated photoaging. Additionally, immunosuppression caused by UV irradiation plays an important role in photoaging and skin carcinogenesis. In this review, we summarize the current literature regarding the antimelanogenic, antiwrinkle, antioxidant, and immunosuppression preventive mechanisms of green tea polyphenols that have been demonstrated to protect against UV irradiation-stimulated skin photoaging, and gauge the quality of evidence supporting the need for clinical studies using green tea polyphenols as anti-photoaging agents in novel cosmeceuticals.

  2. Faraday anomalous dispersion optical filters

    Science.gov (United States)

    Shay, T. M.; Yin, B.; Alvarez, L. S.

    1993-01-01

    The effect of Faraday anomalous dispersion optical filters on infrared and blue transitions of some alkali atoms is calculated. A composite system is designed to further increase the background noise rejection. The measured results of the solar background rejection and image quality through the filter are presented. The results show that the filter may provide high transmission and high background noise rejection with excellent image quality.

  3. The charmonium dissociation in an "anomalous wind"

    CERN Document Server

    Sadofyev, Andrey V

    2016-01-01

    We study the charmonium dissociation in a strongly coupled chiral plasma in the presence of magnetic field and axial charge imbalance. This type of plasma carries ``anomalous flow" induced by the chiral anomaly and exhibits novel transport phenomena such as chiral magnetic effect. We found that the ``anomalous flow" would modify the charmonium color screening length by using the gauge/gravity correspondence. We derive an analytical expression quantifying the ``anomalous flow" experienced by a charmonium for a large class of chiral plasma with a gravity dual. We elaborate on the similarity and {\\it qualitative} difference between anomalous effects on the charmonium color screening length which are {\\it model-dependent} and those on the heavy quark drag force which are fixed by the second law of thermodynamics. We speculate on the possible charmonium dissociation induced by chiral anomaly in heavy ion collisions.

  4. Comparison of skin effects of immediate treatment modalities in experimentally induced hydrofluoric acid skin burns.

    Science.gov (United States)

    Songur, Meltem K; Akdemir, Ovunc; Lineaweaver, William C; Cavusoglu, Turker; Ozsarac, Murat; Aktug, Huseyin; Songur, Ecmel; Tiftikcioglu, Yigit O

    2015-12-01

    Hydrofluoric acid (HF) burns cause immediate damage and painful long-term sequellae. Traditionally, chelating agents have been used as the initial treatment for such burns. We have introduced epidermal growth factor (EGF) into an HF model to compare EGF with Ca(2+) and Mg(2+) treatments; 40 Sprague Dawley rats were divided into five groups. Each rat suffered a 6 × 4 cm(2) burn induced by 40% HF. Group 1 had no treatment, group 2 had saline injected beneath the burn, group 3 received magnesium sulphate injections, group 4 received calcium gluconate and group 5 received EGF. Specimens were evaluated via planimetry and biopsy at intervals of 4, 8, 24 and 72 hours. Fluid losses were significantly less in the Mg(2+) and EGF groups. The EGF group had the smallest burn area, least oedema, least polymorphonuclear granulocyte (PMN) infiltration, most angiogenesis and highest fibroblast proliferation of any group (P < 0·005). EGF limited HF damage morphologically and histologically more effectively than Ca(2+) or Mg(2+). This finding indicates that HF treatment via growth factors may be an improvement over chelation therapy.

  5. Effect of local application of superoxide dismutase on dielectric parameters of cooled skin in rats.

    Science.gov (United States)

    Paramonov, B A; Turkovski, I I; Doroshkevich, O S; Taranova, V N; Pomorski, K P

    2008-11-01

    The effect of on Changes in dielectric parameters of the skin (modulus of complex dielectric permittivity |e| and dielectric loss tangent tgd) were studied on rats with local surface contact cooling followed by treatment with various cream formulations. Addition of antioxidant superoxide dismutase (SOD) to the cream significantly prevented the shifts in these parameters, which attested to less pronounced changes in the water balance in SOD-treated skin. Application of SOD during the early terms after cooling accelerated wound healing. Histological examination performed on posttraumatic day 60 revealed better integrity of the skin structures (hair follicle, sweat and sebaceous gland), which indicates ability of SOD to prevent and ameliorate the degree of cold-induced damage in the skin.

  6. French Maritime Pine Bark Extract (Pycnogenol®) Effects on Human Skin: Clinical and Molecular Evidence.

    Science.gov (United States)

    Grether-Beck, Susanne; Marini, Alessandra; Jaenicke, Thomas; Krutmann, Jean

    2016-01-01

    Nutritional strategies to benefit skin health are of growing importance. Current approaches mainly involve nutritional supplements containing antioxidants which were initially designed to protect human skin against ultraviolet radiation-induced damage. Within recent years, however, a growing number of studies suggests that the beneficial effects of these products clearly extend beyond photoprotection. In this review we take the nutritional supplement Pycnogenol®, which is based on an extract prepared from French marine pine bark extract, as an example to illustrate this development. Accordingly, the existing data provide compelling evidence that Pycnogenol® intake does not only provide photoprotection, but may be used to (i) reduce hyperpigmentation of human skin and (ii) improve skin barrier function and extracellular matrix homeostasis.

  7. Antioxidant effects of an ozonized theobroma oil formulation on damaged-inflammatory rat skin

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Y.; Diaz, M.F.; Hernandez, F.; Gila, D.; Ga, G.

    2011-07-01

    The aim of this study was to determine whether a cosmetic formulation elaborated with ozonized theobroma oil may exert beneficial effects in the restoring of the antioxidant activity on the skin of rats previously irradiated with ultraviolet light. 0.5 g of the formulation was applied on the skin of rats for five days. Superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activity were determined in a homogenate of rat skin. Malondialdehyde (MDA), conjugated dienes (CD) and total hydroperoxide (THP) content were determined as biomarkers of oxidative stress. Using these parameters, antioxidant and oxidant activity, redox index and oxidative stress grade were determined. The total antioxidant activity was significantly increased while the redox index, total oxidant activity and oxidative stress grade decreased significantly in damaged rats treated with the formulation. These results show the antioxidant properties of the cosmetic formulation due to the stimulation of antioxidant enzymes such as SOD and GPx, preventing skin injury induced by ultraviolet irradiation. (Author).

  8. Fermi surface versus Fermi sea contributions to intrinsic anomalous and spin Hall effects of multiorbital metals in the presence of Coulomb interaction and spin-Coulomb drag

    Science.gov (United States)

    Arakawa, Naoya

    2016-06-01

    Anomalous Hall effect (AHE) and spin Hall effect (SHE) are fundamental phenomena, and their potential for application is great. However, we understand the interaction effects unsatisfactorily, and should have clarified issues about the roles of the Fermi sea term and Fermi surface term of the conductivity of the intrinsic AHE or SHE of an interacting multiorbital metal and about the effects of spin-Coulomb drag on the intrinsic SHE. Here, we resolve the first issue and provide the first step about the second issue by developing a general formalism in the linear response theory with appropriate approximations and using analytic arguments. The most striking result is that even without impurities, the Fermi surface term, a non-Berry-curvature term, plays dominant roles at high or slightly low temperatures. In particular, this Fermi surface term causes the temperature dependence of the dc anomalous Hall or spin Hall conductivity due to the interaction-induced quasiparticle damping and the correction of the dc spin Hall conductivity due to the spin-Coulomb drag. Those results revise our understanding of the intrinsic AHE and SHE. We also find that the differences between the dc anomalous Hall and longitudinal conductivities arise from the difference in the dominant multiband excitations. This not only explains why the Fermi sea term such as the Berry-curvature term becomes important in clean and low-temperature case only for interband transports, but also provides the useful principles on treating the electron-electron interaction in an interacting multiorbital metal for general formalism of transport coefficients. Several correspondences between our results and experiments are finally discussed.

  9. Wound tension in rhytidectomy. Effects of skin-flap undermining and superficial musculoaponeurotic system suspension.

    Science.gov (United States)

    Burgess, L P; Casler, J D; Kryzer, T C

    1993-02-01

    This study was conducted to determine the effects of skin-flap undermining and superficial musculoaponeurotic system (SMAS) suspension on wound-closing tension. Nine sides from five fresh-frozen cadavers were used, with closing tension measured at the two main anchor points, anteriorly (A) and posteriorly (P), with and without SMAS plication for minimal (MIN), intermediate (INT), and maximal (MAX) skin-flap undermining. Results indicated that closing tension was significantly decreased with SMAS plication, both A and P, for all three levels of skin undermining. The average decrease in closing tension with SMAS plication was: A-MIN 191 g, A-INT 95 g, A-MAX 83 g, P-MIN 235 g, P-INT 68 g, and P-MAX 70 g (P tension decreased with wider skin-flap undermining, both with and without SMAS plication. The tension-reducing effect of SMAS plication was decreased with wider skin-flap undermining. Regression analysis determined a second-order exponential curve relating closing tension to skin excision.

  10. Anomalous transport due to scale anomaly

    CERN Document Server

    Chernodub, M N

    2016-01-01

    We show that the scale anomaly in field theories leads to new anomalous transport effects that emerge in external electromagnetic field in inhomogeneous gravitational background. In inflating geometry the QED scale anomaly generates electric current which flows in opposite direction with respect to background electric field. In static spatially inhomogeneous gravitational background the dissipationless electric current flows transversely both to the magnetic field axis and to the gradient of the inhomogeneity. The anomalous currents are proportional to the beta function of the theory.

  11. Effects of radioactive hot particles on pig skin

    Energy Technology Data Exchange (ETDEWEB)

    Kaurin, D.G.; Baum, J.W.; Schaefer, C.W. [and others

    1997-06-01

    The purpose of these studies was to determine the incidence and severity of lesions resulting from very localized deposition of dose to skin from small (< 0.5 mm) discrete radioactive particles as produced in the work environments of nuclear reactors. Hanford mini-pigs were exposed, both on a slightly off the skin, to localized replicate doses from 0.31 to 64 Gy (averaged over 1 cm{sup 2} at 70 {mu}m depth unless noted otherwise) using Sc-46, Yb-175, Tm-170, and fissioned UC{sub 2} isotopes having maximum beta-particle energies from about 0.3 to 3 MeV. Erythema and scabs (indicating ulceration) were scored for up to 71 days post-irradiation. The responses followed normal cumulative probability distributions, and therefore, no true threshold could be defined. Hence, 10 and 50% scab incidence rates were deduced using probit analyses. The lowest dose which produced 10% incidence was about 1 Gy for Yb-175 (0.5 MeV maximum energy) beta particle exposures, and about 3 to 9 Gy for other isotopes. The histopathology of lesions was determined at several doses. Single exposures to doses as large as 1,790 Gy were also given, and results were observed for up to 144 days post-exposure. Severity of detriment was estimated by analyzing the results in terms of lesion diameter, persistence, and infection. Over 1,100 sites were exposed. Only two exposed sites became infected after doses near 5000 Gy; the lesions healed quickly on treatment. 105 refs., 145 figs., 47 tabs.

  12. Faraday anomalous dispersion optical tuners

    Science.gov (United States)

    Wanninger, P.; Valdez, E. C.; Shay, T. M.

    1992-01-01

    Common methods for frequency stabilizing diode lasers systems employ gratings, etalons, optical electric double feedback, atomic resonance, and a Faraday cell with low magnetic field. Our method, the Faraday Anomalous Dispersion Optical Transmitter (FADOT) laser locking, is much simpler than other schemes. The FADOT uses commercial laser diodes with no antireflection coatings, an atomic Faraday cell with a single polarizer, and an output coupler to form a compound cavity. This method is vibration insensitive, thermal expansion effects are minimal, and the system has a frequency pull in range of 443.2 GHz (9A). Our technique is based on the Faraday anomalous dispersion optical filter. This method has potential applications in optical communication, remote sensing, and pumping laser excited optical filters. We present the first theoretical model for the FADOT and compare the calculations to our experimental results.

  13. Fabrication and local laser heating of freestanding Ni{sub 80}Fe{sub 20} bridges with Pt contacts displaying anisotropic magnetoresistance and anomalous Nernst effect

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, F.; Grundler, D., E-mail: grundler@ph.tum.de [Lehrstuhl für Physik funktionaler Schichtsysteme, Physik-Department E10, Technische Universität München, James-Franck-Str. 1, D-85748 Garching b. München (Germany)

    2014-04-28

    In spin caloritronics, ferromagnetic samples subject to relatively large in-plane temperature gradients ∇T have turned out to be extremely interesting. We report on a preparation technique that allows us to create freely suspended permalloy/Pt hybrid structures where a scanning laser induces ∇T on the order of a few K/μm. We observe both the anisotropic magnetoresistance at room temperature and the magnetic field dependent anomalous Nernst effect under laser heating. The technique is promising for the realization of device concepts considered in spin caloritronics based on suspended ferromagnetic nanostructures with electrical contacts.

  14. Ductile and Compacted Graphite Iron Casting Skin -- Evaluation, Effect on Fatigue Strength and Elimination

    Science.gov (United States)

    Boonmee, Sarum

    Compacted graphite (CG) iron features a good combination of tensile strength, impact resistance, thermal conductivity and damping capacity. This combination makes CG iron a material of choice for various applications, especially for the automobile industry. The mechanical properties of CG iron listed in the standards (i.e. ASTM) are for machined specimens. However, since most iron castings retain the original casting surface (a.k.a. casting skin), the actual performance of the part could be significantly different from that of the machined specimens. Recent studies have shown the negative effect of the casting skin, but little quantification of its effect on mechanical properties is available. Further, the understanding of its mechanism of formation is at best incomplete. In this research, the effect of the casting skin on mechanical properties in CG and ductile irons (DI) is explored. The differences in tensile and fatigue properties between as-cast and machined samples were quantified and correlated to the casting skin features. It was found that the presence of the casting skin was accountable for 9% reduction of tensile strength and up to 32% reduction of fatigue strength (for CG iron with 40% nodularity). Several mechanisms of the casting skin formation are proposed in this research. The formation of ferritic and pearlitic rims is explained by decarburizing/carburizing reactions at the mold/metal interface. Mg depletion and solidification kinetics effect were identified as the formation mechanisms of the graphite degradation. A 2-D thermal diffusion model was formulated based on Mg depletion theory. The model can be used to predict the casting skin thickness when Mg depletion is the dominant mechanism. Furthermore, using the asymmetric Fe-Gr phase diagram, some instances of casting skin formation were explained based on solidification kinetics theory. The experimental microstructural evidence and the theoretical progress were conducive to the development of

  15. Skin health promotion effects of natural beta-glucan derived from cereals and microorganisms: a review.

    Science.gov (United States)

    Du, Bin; Bian, Zhaoxiang; Xu, Baojun

    2014-02-01

    β-Glucans are natural cell wall polysaccharides found in yeast, fungi (including mushrooms), some bacteria, seaweeds and cereals. Natural β-glucans possess many health promotion effects on human health, such as anti-tumor, anti-diabetes, anti-infection, lowering blood cholesterol and immune-modulating properties. These effects have been reviewed previously. However, skin health promotion of β-glucan derived from cereals and microorganisms has received little attention. This review focuses on antioxidant activity, anti-wrinkle activity, anti-ultraviolet light, wound healing, and moisturizing effect and skin permeation absorption of β-glucan. Furthermore, applications of β-glucan in cosmetics are also discussed.

  16. Evaluation of the effectiveness of wet ice, dry ice, and cryogenic packs in reducing skin temperature.

    Science.gov (United States)

    Belitsky, R B; Odam, S J; Hubley-Kozey, C

    1987-07-01

    The purposes of this study were to evaluate and compare the ability of wet ice (WI), dry ice (DI), and cryogenic packs (CGPs) to reduce and maintain the reduction of skin temperature directly under the cooling agent and to determine whether the cooling effect on skin extended beyond the surface area in contact with the cooling agent. Ten female volunteers participated in the study, and each of the three cold modalities was applied randomly to the skin overlying the right triceps surae muscle. After 15 minutes of cold application, mean skin temperatures recorded under WI, DI, and CGP decreased 12 degrees, 9.9 degrees, and 7.3 degrees C, respectively. The only significant differences in cooling were between WI and DI and between WI and CGP. Fifteen minutes after removal of the cold modalities, no significant differences were found in mean skin temperature between WI, DI, and CGP. The residual mean decrease in skin temperature between the pretreatment rest interval (time 0) and 15 minutes after removal of the cold modality (time 30) was significant for WI only. No cooling was demonstrated 1 cm proximal or distal to any of the cooling agents after 15 minutes of cold application. These findings provide valuable information for the use of cryotherapy in the clinical setting.

  17. Effect of Acupuncture Manipulations at LI4 or LI11 on Blood Flow and Skin Temperature.

    Science.gov (United States)

    Li, Weihui; Ahn, Andrew

    2016-06-01

    Acupuncture induces physiological changes, and patients have reported warm or cool sensations with "Burning Fire" (BF) or "Penetrating Cool" (PC) manipulations. This study aimed to evaluate whether these techniques had distinct effects on skin temperature and blood flow and to examine whether skin temperature correlated with blood flow. The participants were 25 healthy volunteers, each receiving acupuncture manipulations on points LI4 and LI11 bilaterally. Skin temperatures and blood flow were recorded continuously on both arms. The study found that acupuncture significantly increased skin temperature on the needling arm by 0.3514°C on average, but decreased it on the contralateral arm by 0.2201°C on average. Blood flow decreased significantly in both arms during needling (-3.4% and -5.97% for the ipsilateral and the contralateral sides, respectively), but the changes in skin temperature did not correlate with the changes in blood flow. Furthermore, these changes were not significantly different between acupuncture techniques and acupuncture points. In conclusion, acupuncture changes local skin temperature and blood flow independent of the manipulation technique. Moreover, blood flow may not be affected by the increased temperature on the needling arm. These results help to verify traditional Chinese medicine concepts and may help in establishing standards for acupuncture treatments.

  18. Effect of Colorspace Transformation, the Illuminance Component, and Color Modeling on Skin Detection

    Energy Technology Data Exchange (ETDEWEB)

    Jayaram, S; Schmugge, S; Shin, M C; Tsap, L V

    2004-03-22

    Skin detection is an important preliminary process in human motion analysis. It is commonly performed in three steps: transforming the pixel color to a non-RGB colorspace, dropping the illumination component of skin color, and classifying by modeling the skin color distribution. In this paper, we evaluate the effect of these three steps on the skin detection performance. The importance of this study is a new comprehensive colorspace and color modeling testing methodology that would allow for making the best choices for skin detection. Combinations of nine colorspaces, the presence of the absence of the illuminance component, and the two color modeling approaches are compared. The performance is measured by using a receiver operating characteristic (ROC) curve on a large dataset of 805 images with manual ground truth. The results reveal that (1) the absence of the illuminance component decreases performance, (2) skin color modeling has a greater impact than colorspace transformation, and (3) colorspace transformations can improve performance in certain instances. We found that the best performance was obtained by transforming the pixel color to the SCT, HSI, or CIELAB colorspaces, keeping the illuminance component, and modeling the color with the histogram approach.

  19. Effect of surface topographic features on the optical properties of skin: a phantom study

    Science.gov (United States)

    Liu, Guangli; Chen, Jianfeng; Zhao, Zuhua; Zhao, Gang; Dong, Erbao; Chu, Jiaru; Xu, Ronald X.

    2016-10-01

    Tissue-simulating phantoms are used to validate and calibrate optical imaging systems and to understand light transport in biological tissue. Light propagation in a strongly turbid medium such as skin tissue experiences multiple scattering and diffuse reflection from the surface. Surface roughness introduces phase shifts and optical path length differences for light which is scattered within the skin tissue and reflected from the surface. In this paper, we study the effect of mismatched surface roughness on optical measurement and subsequent determination of optical properties of skin tissue. A series of phantoms with controlled surface features and optical properties corresponding to normal human skin are fabricated. The fabrication of polydimethylsiloxane (PDMS) phantoms with known surface roughness follows a standard soft lithography process. Surface roughness of skin-simulating phantoms are measured with Bruker stylus profiler. The diffuse reflectance of the phantom is validated by a UV/VIS spectrophotometer. The results show that surface texture and roughness have considerable influence on the optical characteristics of skin. This study suggests that surface roughness should be considered as an important contributing factor for the determination of tissue optical properties.

  20. Cytotoxic effects of five commonly abused skin toning (bleaching) creams on Allium cepa root tip mitosis.

    Science.gov (United States)

    Udengwu, O S; Chukwujekwu, J C

    2008-09-15

    The Allium test was used to study the cytotoxic effects of five commonly abused skin toning creams--Ikb, Tura, Top gel, Dorot and Mililo. These creams are commonly used by some black skinned people (especially the females) as skin lightening (bleaching) agents. The results showed that all the five bleaching creams were mito-depressive in action. They exhibited both chromatoclassic and mitoclassic effects. Their depressive effects were found to increase with duration of treatment. The induced abnormalities included chromosome contraction, spindle breakages, c-metaphase, star anaphase, chromosome stickiness and sticky bridges, precocious chromosome movement as well as endomitosis. It is suggested that since all eukaryotic cells are basically the same, these observed abnormalities could be similar to the effects these chemicals have on human skin when they are applied. Some of these are known to cause alteration in melanin formation as well as the biosynthesis of the enzyme tyrosinase. Furthermore, since certain points on the chromosomes called fragile sites have been implicated in oncogenesis, the observed abnormalities may be part of (or include) the switching on mechanisms of such genes, which could be responsible for the transformation of normal skin cells to malignant cells in those who abuse these creams.

  1. Large power factor and anomalous Hall effect and their correlation with observed linear magneto resistance in Co-doped Bi2Se3 3D topological insulator.

    Science.gov (United States)

    Singh, Rahul; Shukla, K K; Kumar, A; Okram, G S; Singh, D; Ganeshan, V; Lakhani, Archana; Ghosh, A K; Chatterjee, Sandip

    2016-09-21

    Magnetoresistance (MR), thermo power, magnetization and Hall effect measurements have been performed on Co-doped Bi2Se3 topological insulators. The undoped sample shows that the maximum MR as a destructive interference due to a π-Berry phase leads to a decrease of MR. As the Co is doped, the linearity in MR is increased. The observed MR of Bi2Se3 can be explained with the classical model. The low temperature MR behavior of Co doped samples cannot be explained with the same model, but can be explained with the quantum linear MR model. Magnetization behavior indicates the establishment of ferromagnetic ordering with Co doping. Hall effect data also supports the establishment of ferromagnetic ordering in Co-doped Bi2Se3 samples by showing the anomalous Hall effect. Furthermore, when spectral weight suppression is insignificant, Bi2Se3 behaves as a dilute magnetic semiconductor. Moreover, the maximum power factor is observed when time reversal symmetry (TRS) is maintained. As the TRS is broken the power factor value is decreased, which indicates that with the rise of Dirac cone above the Fermi level the anomalous Hall effect and linearity in MR increase and the power factor decreases.

  2. Large power factor and anomalous Hall effect and their correlation with observed linear magneto resistance in Co-doped Bi2Se3 3D topological insulator

    Science.gov (United States)

    Singh, Rahul; Shukla, K. K.; Kumar, A.; Okram, G. S.; Singh, D.; Ganeshan, V.; Lakhani, Archana; Ghosh, A. K.; Chatterjee, Sandip

    2016-09-01

    Magnetoresistance (MR), thermo power, magnetization and Hall effect measurements have been performed on Co-doped Bi2Se3 topological insulators. The undoped sample shows that the maximum MR as a destructive interference due to a π-Berry phase leads to a decrease of MR. As the Co is doped, the linearity in MR is increased. The observed MR of Bi2Se3 can be explained with the classical model. The low temperature MR behavior of Co doped samples cannot be explained with the same model, but can be explained with the quantum linear MR model. Magnetization behavior indicates the establishment of ferromagnetic ordering with Co doping. Hall effect data also supports the establishment of ferromagnetic ordering in Co-doped Bi2Se3 samples by showing the anomalous Hall effect. Furthermore, when spectral weight suppression is insignificant, Bi2Se3 behaves as a dilute magnetic semiconductor. Moreover, the maximum power factor is observed when time reversal symmetry (TRS) is maintained. As the TRS is broken the power factor value is decreased, which indicates that with the rise of Dirac cone above the Fermi level the anomalous Hall effect and linearity in MR increase and the power factor decreases.

  3. The vasorelaxant effect of adrenomedullin, proadrenomedullin N-terminal 20 peptide and amylin in human skin

    DEFF Research Database (Denmark)

    Hasbak, Philip; Eskesen, Karen; Lind, Peter Henrik

    2006-01-01

    In this study we aimed to assess in vivo, the vasodilator effects of adrenomedullin, proadrenomedullin N-terminal 20 peptide (PAMP) and amylin in human skin vasculature and compare the responses to the effects mediated by the endogenous neuropeptides calcitonin gene-related peptide (CGRP......) and substance P and to examine the mRNA expression of calcitonin receptor-like receptor (CL-R) and receptor-activity modifying proteins, RAMP1, RAMP 2 and RAMP3 in human subcutaneous arteries. Changes in skin blood flow of the forearm were measured using a Laser Doppler Imager after intradermal injection...... of CGRP, adrenomedullin and amylin induces long lasting dilatation of human skin vasculature by activation of CGRP1 receptors. PAMP induces transient vasodilatation. PAMP but not CGRP, adrenomedullin and amylin causes itch sensation and local erythema. The transient effect on vasodilatation as response...

  4. Effects of Cosmetic Formulations Containing Hydroxyacids on Sun-Exposed Skin: Current Applications and Future Developments

    Directory of Open Access Journals (Sweden)

    Andrija Kornhauser

    2012-01-01

    Full Text Available This paper describes recent data on the effects of various skin formulations containing hydroxyacids (HAs and related products on sun-exposed skin. The most frequently used classes of these products, such as α- and β-hydroxyacids, polyhydroxy acids, and bionic acids, are reviewed, and their application in cosmetic formulations is described. Special emphasis is devoted to the safety evaluation of these formulations, particularly on the effects of their prolonged use on sun-exposed skin. We also discuss the important contribution of cosmetic vehicles in these types of studies. Data on the effects of HAs on melanogenesis and tanning are also included. Up-to-date methods and techniques used in those explorations, as well as selected future developments in the cosmetic area, are presented.

  5. Skin effect mitigation in laser processed multi-walled carbon nanotube/copper conductors

    Energy Technology Data Exchange (ETDEWEB)

    Keramatnejad, K.; Zhou, Y. S.; Gao, Y.; Rabiee Golgir, H.; Wang, M.; Lu, Y. F., E-mail: ylu2@unl.edu [Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States); Jiang, L. [School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081 (China); Silvain, J.-F. [Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB-CNRS) 87, Avenue du Docteur Albert Schweitzer F-33608 Pessac Cedex (France)

    2015-10-21

    In this study, laser-processed multi-walled carbon nanotube (MWCNT)/Cu conductors are introduced as potential passive components to mitigate the skin effect of Cu at high frequencies (0–10 MHz). Suppressed skin effect is observed in the MWCNT/Cu conductors compared to primitive Cu. At an AC frequency of 10 MHz, a maximum AC resistance reduction of 94% was observed in a MWCNT/Cu conductor after being irradiated at a laser power density of 189 W/cm{sup 2}. The reduced skin effect in the MWCNT/Cu conductors is ascribed to the presence of MWCNT channels which are insensitive to AC frequencies. The laser irradiation process is observed to play a crucial role in reducing contact resistance at the MWCNT-Cu interfaces, removing impurities in MWCNTs, and densifying MWCNT films.

  6. Skin-whitening and skin-condition-improving effects of topical oxidized glutathione: a double-blind and placebo-controlled clinical trial in healthy women

    Directory of Open Access Journals (Sweden)

    Watanabe F

    2014-10-01

    Full Text Available Fumiko Watanabe,1 Erika Hashizume,1 Gertrude P Chan,2 Ayako Kamimura11Healthcare Products Development Center, KYOWA HAKKO BIO CO., LTD., Tsukuba, Ibaraki, Japan; 2Clinical Trial Management and Testing Associates, Inc., Filinvest Corporate City, Alabang, Muntinlupa City, PhilippinesPurpose: Glutathione is a tripeptide consisting of cysteine, glycine, and glutamate and functions as a major antioxidant. It is synthesized endogenously in humans. Glutathione protects thiol protein groups from oxidation and is involved in cellular detoxification for maintenance of the cell environment. Reduced glutathione (GSH has a skin-whitening effect in humans through its tyrosinase inhibitory activity, but in the case of oxidized glutathione (GSSG this effect is unclear. We examined the skin-whitening and skin-condition effects of topical GSSG in healthy women.Subjects and methods: The subjects were 30 healthy adult women aged 30 to 50 years. The study design was a randomized, double-blind, matched-pair, placebo-controlled clinical trial. Subjects applied GSSG 2% (weight/weight [w/w] lotion to one side of the face and a placebo lotion to the other side twice daily for 10 weeks. We objectively measured changes in melanin index values, moisture content of the stratum corneum, smoothness, wrinkle formation, and elasticity of the skin. The principal investigator and each subject also used subjective scores to investigate skin whitening, wrinkle reduction, and smoothness. Analysis of variance was used to evaluate differences between groups.Results: The skin melanin index was significantly lower with GSSG treatment than with placebo from the early weeks after the start of the trial through to the end of the study period (at 10 weeks, P<0.001. In addition, in the latter half of the study period GSSG-treated sites had significant increases in moisture content of the stratum corneum, suppression of wrinkle formation, and improvement in skin smoothness. There were no

  7. SONOPHORESIS EFFECT ON THE PERMEATION OF METRONIDAZOLE USING 3D SKIN EQUIVALENT

    Directory of Open Access Journals (Sweden)

    Mai Aldwaikat*, Mohammed Alarjah , Jacki Willis and Timothy Mason

    2013-01-01

    Full Text Available Transdermal drug delivery is highly advantageous method for drug administration, yet the compact structure of stratum corneum is an effective barrier which limited the use of this route to very few drug molecules. Ultrasound enhances the permeation through the skin by altering this barrier function in a phenomenon named sonophoresis. This study aimed to evaluate the effect of variable ultrasonic conditions on the permeation of Metronidazole (ML. This involved validating the applicability of utilizing a three dimensional skin equivalent as human skin models for sonophoresis studies. A Franz diffusion cell was used to study the effect of therapeutic ultrasound at 1 MHz and power ultrasound at 20 KHz on the permeation of Metronidazole across the 3D skin equivalent EpiDerm™. HPLC methods were used for the determination of the concentration of Metronidazole in the receiving compartment. Utilizing therapeutic ultrasound at 1 MHz frequency has enhanced the permeation of Metronidazole through the EpiDerm™, as about double the permeation of the ML was obtained with no apparent damage to the membrane. The results indicated significant permeation enhancement with low frequency sonophoresis at 20 KHz frequency treatments through EpiDerm™ skin equivalent. Up to five fold enhancement was measured with the permeation of investigated molecules through EpiDerm™. The mechanism of action observed seemed highly dependent on the ultrasonic conditions.

  8. Effects of Turmeric (Curcuma longa) on Skin Health: A Systematic Review of the Clinical Evidence.

    Science.gov (United States)

    Vaughn, Alexandra R; Branum, Amy; Sivamani, Raja K

    2016-08-01

    Turmeric (Curcuma longa), a commonly used spice throughout the world, has been shown to exhibit antiinflammatory, antimicrobial, antioxidant, and anti-neoplastic properties. Growing evidence shows that an active component of turmeric, curcumin, may be used medically to treat a variety of dermatologic diseases. This systematic review was conducted to examine the evidence for the use of both topical and ingested turmeric/curcumin to modulate skin health and function. The PubMed and Embase databases were systematically searched for clinical studies involving humans that examined the relationship between products containing turmeric, curcumin, and skin health. A total of 234 articles were uncovered, and a total of 18 studies met inclusion criteria. Nine studies evaluated the effects of ingestion, eight studies evaluated the effects of topical, and one study evaluated the effects of both ingested and topical application of turmeric/curcumin. Skin conditions examined include acne, alopecia, atopic dermatitis, facial photoaging, oral lichen planus, pruritus, psoriasis, radiodermatitis, and vitiligo. Ten studies noted statistically significant improvement in skin disease severity in the turmeric/curcumin treatment groups compared with control groups. Overall, there is early evidence that turmeric/curcumin products and supplements, both oral and topical, may provide therapeutic benefits for skin health. However, currently published studies are limited and further studies will be essential to better evaluate efficacy and the mechanisms involved. Copyright © 2016 John Wiley & Sons, Ltd.

  9. The effect of the iBEAM Evo carbon fiber tabletop on skin sparing.

    Science.gov (United States)

    Simpson, John B; Godwin, Guy A

    2011-01-01

    Replicating the attenuation properties of the treatment tabletop are of primary importance for accurate treatment planning; however, the effect of the tabletop on the skin-sparing properties of x-rays can be overlooked. Under some conditions, the reaction of skin to the radiation can be so serious as to be the dose-limiting organ for radiotherapy treatment. Hence, an understanding of the magnitude of the reduction in skin sparing is important. Because of the development of image-guided radiotherapy, modern tabletops have been developed without the use of metal supports that otherwise provided the necessary level of rigidity. Rigidity is instead provided by compressed foam within a carbon-fiber shell, which, although it provides artefact-free imaging and high levels of rigidity, has an adverse affect on the dose in the build-up region. Representative of this type is the iBEAM evo tabletop, whose effect on the skin dose was determined at 6-MV, 10-MV, and 18-MV x-rays. Skin dose was found to increase by 60-70% owing to the tabletop, with the effect increasing with field size and decreasing with energy. By considering an endpoint of erythema, a radiobiological advantage of selecting 10 MV over 6 MV for applicable treatments was demonstrated.

  10. Disentangling the physical contributions to the anomalous Hall effect and domain wall resistance in isoelectronic L10-FePd and L10-FePt alloys

    Science.gov (United States)

    Seemann, Klaus; Garcia-Sanchez, Felipe; Kakay, Attila; Schneider, Claus; Freimuth, Frank; Mokrousov, Yuriy; Bluegel, Stefan; Hertel, Riccardo

    2012-02-01

    We analyze the origin of the electrical resistance arising in domain walls of perpendicularly magnetized materials by considering a superposition of anisotropic magnetoresistance and the resistance implied by the magnetization chirality. The domain wall profiles of L10-FePd and L10-FePt are determined by micromagnetic simulations based on which we perform first principles calculations to quantify electron transport through the core and closure region of the walls. The wall resistance, being twice as high in L10-FePd than in L10-FePt, is found to be clearly dominated in both cases by a high gradient of magnetization rotation, and not by the spin-orbit interaction driven anisotropic magnetoresistance effect. Concerning the anomalous Hall effect on the other hand, we show that difference in spin-orbit interaction strength of Pt and Pd atoms leads to a pronounced cross-over from an extrinsic side jump mechanism in L10-FePd to an intrinsic Berry-phase anomalous Hall effect in L10-FePt.

  11. Functional behavior of the anomalous magnetic relaxation observed in melt-textured YBa2Cu3O7-δ samples showing the paramagnetic Meissner effect

    Science.gov (United States)

    Dias, F. T.; Vieira, V. N.; Garcia, E. L.; Wolff-Fabris, F.; Kampert, E.; Gouvêa, C. P.; Schaf, J.; Obradors, X.; Puig, T.; Roa, J. J.

    2016-10-01

    We have studied the functional behavior of the field-cooled (FC) magnetic relaxation observed in melt-textured YBa2Cu3O7-δ (Y123) samples with 30 wt% of Y2Ba1Cu1O5 (Y211) phase, in order to investigate anomalous paramagnetic moments observed during the experiments. FC magnetic relaxation experiments were performed under controlled conditions, such as cooling rate and temperature. Magnetic fields up to 5T were applied parallel to the ab plane and along the c-axis. Our results are associated with the paramagnetic Meissner effect (PME), characterized by positive moments during FC experiments, and related to the magnetic flux compression into the samples. After different attempts our experimental data could be adequately fitted by an exponential decay function with different relaxation times. We discuss our results suggesting the existence of different and preferential flux dynamics governing the anomalous FC paramagnetic relaxation in different time intervals. This work is one of the first attempts to interpret this controversial effect in a simple analysis of the pinning mechanisms and flux dynamics acting during the time evolution of the magnetic moment. However, the results may be useful to develop models to explain this interesting and still misunderstood feature of the paramagnetic Meissner effect.

  12. Protective effects of black rice bran against chemically-induced inflammation of mouse skin

    Science.gov (United States)

    We investigated the inhibitory effects of black rice (cv. LK1-3-6-12-1-1) bran against 12-O-tetradecanolylphorbol-13-acetate (TPA)-induced skin edema and 2,4-dinitroflurobenzene (DNFB)-induced allergic contact dermatitis (ACD) in inflammatory mouse models. We also determined the effects of the bran...

  13. Effect of local allergen priming on early, late, delayed-phase, and epicutaneous skin reactions

    NARCIS (Netherlands)

    Weller, FR; Weller, MS; Jansen, HM; deMonchy, JGR

    1996-01-01

    Allergic disease is renected in a chronic inflammatory response to an allergen. It is thought that local allergen priming underlies this chronicity. To assess the effect of allergen priming on the amplitude and histologic effect of the allergic reaction, four sequential, intracutaneous skin tests we

  14. Effect of parsley (Petroselinum crispum) on the skin of STZ induced diabetic rats.

    Science.gov (United States)

    Tunali, T; Yarat, A; Yanardağ, R; Ozçelik, F; Ozsoy, O; Ergenekon, G; Emekli, N

    1999-03-01

    Parsley (Petroselinum crispum) is one of the medicinal herbs used by diabetics in Turkey and it has been reported to reduce blood glucose. The purpose of this study therefore was to investigate the effect of feeding parsley on diabetes induced impairments in rat skins. Uncontrolled induced diabetes caused significant increases in nonenzymatic glycosylation of skin proteins, lipid peroxidation and blood glucose. Administration of parsley extract did not inhibit these effects except for the increase in blood glucose. SDS-polyacrylamide gel electrophoresis revealed no significant differences in any protein bands between any of the groups.

  15. Anomalous response of supported few-layer hexagonal boron nitride to DC electric fields: a confined water effect?

    Science.gov (United States)

    Oliveira, Camilla; Matos, Matheus; Mazzoni, Mário; Chacham, Hélio; Neves, Bernardo

    2013-03-01

    Hexagonal boron nitride (h-BN) is a two-dimensional compound from III-V family, with the atoms of boron and nitrogen arranged in a honeycomb lattice, similar to graphene. Unlike graphene though, h-BN is an insulator material, with a gap larger than 5 eV. Here, we use Electric Force Microscopy (EFM) to study the electrical response of mono and few-layers of h-BN to an electric field applied by the EFM tip. Our results show an anomalous behavior in the dielectric response for h-BN for different bias orientation: for a positive bias applied to the tip, h-BN layers respond with a larger dielectric constant than the dielectric constant of the silicon dioxide substrate; while for a negative bias, the h-BN dielectric constant is smaller than the dielectric constant of the substrate. Based on first-principles calculations, we showed that this anomalous response may be interpreted as a macroscopic consequence of confinement of a thin water layer between h-BN and substrate. These results were confirmed by sample annealing and also also by a comparative analysis with h-BN on a non-polar substrate. All the authors acknowledge financial support from CNPq, Fapemig, Rede Nacional de Pesquisa em Nanotubos de Carbono and INCT-Nano-Carbono.

  16. Mechanistic effects of long-term ultraviolet B irradiation induce epidermal and dermal changes in human skin xenografts.

    Science.gov (United States)

    Hachiya, Akira; Sriwiriyanont, Penkanok; Fujimura, Tsutomu; Ohuchi, Atsushi; Kitahara, Takashi; Takema, Yoshinori; Kitzmiller, William J; Visscher, Marty O; Tsuboi, Ryoji; Boissy, Raymond E

    2009-02-01

    UVB irradiation has been reported to induce photoaging and suppress systemic immune function that could lead to photocarcinogenesis. However, because of the paucity of an UVB-induced photodamaged skin model, precise and temporal mechanism(s) underlying the deleterious effects of long-term UVB exposure on human skin have yet to be delineated. In this study, we established a model using human skin xenografted onto severe combined immunodeficient mice, which were subsequently challenged by repeated UVB irradiation for 6 weeks. Three-dimensional optical image analysis of skin replicas and noninvasive biophysical measurements illustrated a significant increase in skin surface roughness, similar to premature photoaging, and a significant loss of skin elasticity after long-term UVB exposure. Resembling authentically aged skin, UVB-exposed samples exhibited significant increases in epithelial keratins (K6, K16, K17), elastins, and matrix metalloproteinases (MMP-1, MMP-9, MMP-12) as well as degradation of collagens (I, IV, VII). The UVB-induced deterioration of fibrous keratin intermediate filaments was also observed in the stratum corneum. Additionally, similarities in gene expression patterns between our model and chronologically aged skin substantiated the plausible relationship between photodamage and chronological age. Furthermore, severe skin photodamage was observed when neutralizing antibodies against TIMP-1, an endogenous inhibitor of MMPs, were administered during the UVB exposure regimen. Taken together, these findings suggest that our skin xenograft model recapitulates premature photoaged skin and provides a comprehensive tool with which to assess the deleterious effects of UVB irradiation.

  17. Flavanone silibinin treatment attenuates nitrogen mustard-induced toxic effects in mouse skin

    Science.gov (United States)

    Jain, Anil K; Tewari-Singh, Neera; Inturi, Swetha; Kumar, Dileep; Orlicky, David J; Agarwal, Chapla; White, Carl W; Agarwal, Rajesh

    2015-01-01

    Currently, there is no effective antidote to prevent skin injuries by sulfur mustard (SM) and nitrogen mustard (NM), which are vesicating agents with potential relevance to chemical warfare, terrorist attacks, or industrial/laboratory accidents. Our earlier report has demonstrated the therapeutic efficacy of silibinin, a natural flavanone, in reversing monofunctional alkylating SM analog 2-chloroethyl ethyl sulfide-induced toxic effects in mouse skin. To translate this effect to a bifunctional alkylating vesicant, herein, efficacy studies were carried out with NM. Topical application of silibinin (1 or 2 mg) 30 min after NM exposure on the dorsal skin of male SKH-1 hairless mice significantly decreased NM-induced toxic lesions at 24, 72 or 120 h post-exposure. Specifically, silibinin treatment resulted in dose-dependent reduction of NM-induced increase in epidermal thickness, dead and denuded epidermis, parakeratosis and microvesication. Higher silibinin dose also caused a 79% and 51% reversal in NM-induced increases in myeloperoxidase activity and COX-2 levels, respectively. Furthermore, silibinin completely prevented NM-induced H2A.X phosphorylation, indicating reversal of DNA damage which could be an oxidative DNA damage as evidenced by high levels of 8-oxodG in NM-exposed mouse skin that was significantly reversed by silibinin. Together, these findings suggest that attenuation of NM-induced skin injury by silibinin is due to its effects on the pathways associated with DNA damage, inflammation, vesication and oxidative stress. In conclusion, results presented here support the optimization of silibinin as an effective treatment of skin injury by vesicants. PMID:25791923

  18. Iatrogenic effects of photoprotection recommendations on skin cancer development, vitamin D levels, and general health.

    Science.gov (United States)

    Reddy, Kavitha K; Gilchrest, Barbara A

    2011-01-01

    Ultraviolet (UV) radiation is an established carcinogen that causes skin cancers and other cutaneous photodamage. Vitamin D is produced in the skin after UV exposure and may also be obtained from dietary and supplemental sources. The effect of recommendations for UV protection, as well as for very large vitamin D supplements, and possible adverse effects of both are explored. Current evidence supports the conclusion that protection from UV radiation reduces the incidence of skin cancers and photodamage, but generally does not compromise vitamin D status or lead to iatrogenic disease. Conversely, risks of maintaining very high vitamin D levels have not been adequately studied. Vitamin D obtained from diet and supplements is functionally identical to that produced after UV exposure, and is a more reliable and quantifiable source of the vitamin.

  19. Transcriptomic analysis of bottlenose dolphin (Tursiops truncatus) skin biopsies to assess the effects of emerging contaminants.

    Science.gov (United States)

    Lunardi, Denise; Abelli, Luigi; Panti, Cristina; Marsili, Letizia; Fossi, Maria Cristina; Mancia, Annalaura

    2016-03-01

    Chemicals discovered in water at levels that may be significantly different than expected are referred to as contaminants of emerging concern (CECs) because the risk to environmental health posed by their occurrence/frequency is still unknown. The worldwide distributed compounds perfluorooctanoic acid (PFOA) and bisphenol A (BPA) may fall into this category due to effects on endocrine receptors. We applied an ex vivo assay using small slices of bioptic skin from the bottlenose dolphin, Tursiops truncatus, cultured and treated for 24 h with different PFOA or BPA concentrations to analyze global gene expression. RNA was labeled and hybridized to a species-specific oligomicroarray. The skin transcriptome held information on the contaminant exposure, potentially predictive about long-term effects on health, being the genes affected involved in immunity modulation, response to stress, lipid homeostasis, and development. The transcriptomic signature of dolphin skin could be therefore relevant as classifier for a specific contaminant.

  20. Synthetic Effect of Vivid Shark Skin and Polymer Additive on Drag Reduction Reinforcement

    Directory of Open Access Journals (Sweden)

    Huawei Chen

    2014-06-01

    Full Text Available Natural shark skin has a well-demonstrated drag reduction function, which is mainly owing to its microscopic structure and mucus on the body surface. In order to improve drag reduction, it is necessary to integrate microscopic drag reduction structure and drag reduction agent. In this study, two hybrid approaches to synthetically combine vivid shark skin and polymer additive, namely, long-chain grafting and controllable polymer diffusion, were proposed and attempted to mimic such hierarchical topography of shark skin without waste of polymer additive. Grafting mechanism and optimization of diffusion port were investigated to improve the efficiency of the polymer additive. Superior drag reduction effects were validated, and the combined effect was also clarified through comparison between drag reduction experiments.

  1. Zinc pyrithione in alcohol-based products for skin antisepsis: persistence of antimicrobial effects.

    Science.gov (United States)

    Guthery, Eugene; Seal, Lawton A; Anderson, Edward L

    2005-02-01

    Alcohol-based products for skin antisepsis have a long history of safety and efficacy in the United States and abroad. However, alcohol alone lacks the required antimicrobial persistence to provide for the sustained periods of skin antisepsis desired in the clinical environment. Therefore, alcohol-based products must have a preservative agent such as iodine/iodophor compounds, chlorhexidine gluconate, or zinc pyrithione, to extend its antimicrobial effects. Iodine, iodophors, and chlorhexidine gluconate are well-characterized antimicrobials and preservatives. The thrust of our effort was to examine the characteristics of the lesser-known zinc pyrithione and to evaluate its utility as a preservative in the formulation of alcohol-based products for skin antisepsis. This work includes a literature review of current zinc pyrithione applications in drugs and cosmetics, a safety and toxicity evaluation, consideration of the proposed mechanisms of antimicrobial action, in vitro and in vivo efficacy data, and a discussion of the mechanisms that confer the desired antimicrobial persistence. In addition, alcohol-based, zinc pyrithione-preserved, commercially available products of skin antisepsis are compared with other commercially available antimicrobials used for skin antisepsis and with additional alcohol-based products with different preservatives. The authors' conclusion is that zinc pyrithione is not only a safe and effective antimicrobial but that its use in certain alcohol-based formulations results in antimicrobial efficacy exceeding that of iodine and chlorhexidine gluconate.

  2. Effect of temperature on the effective mass and the neutron skin of nuclei

    CERN Document Server

    Yüksel, E; Bozkurt, K; Colò, G

    2014-01-01

    We study the finite temperature Hartree-Fock-BCS approximation for selected Sn nuclei with zero-range Skyrme forces. Hartree Fock BCS approximation allows for a straightforward interpretation of the results since it involves $u$ and $v$'s which are not matrices as in HFB. Pairing transitions from superfluid to the normal state are studied with respect to the temperature. The temperature dependence of the nuclear radii and neutron skin are also analyzed. An increase of proton and neutron radii is obtained in neutron rich nuclei especially above the critical temperature. Using different Skyrme energy functionals, a correlation between the effective mass in symmetric nuclear matter and the critical temperature is found. The temperature dependence of the nucleon effective mass is also investigated, showing that proton and neutron effective masses display different behavior below and above the critical temperature.

  3. Anomalous law of cooling

    Science.gov (United States)

    Lapas, Luciano C.; Ferreira, Rogelma M. S.; Rubí, J. Miguel; Oliveira, Fernando A.

    2015-03-01

    We analyze the temperature relaxation phenomena of systems in contact with a thermal reservoir that undergoes a non-Markovian diffusion process. From a generalized Langevin equation, we show that the temperature is governed by a law of cooling of the Newton's law type in which the relaxation time depends on the velocity autocorrelation and is then characterized by the memory function. The analysis of the temperature decay reveals the existence of an anomalous cooling in which the temperature may oscillate. Despite this anomalous behavior, we show that the variation of entropy remains always positive in accordance with the second law of thermodynamics.

  4. Anomalous law of cooling.

    Science.gov (United States)

    Lapas, Luciano C; Ferreira, Rogelma M S; Rubí, J Miguel; Oliveira, Fernando A

    2015-03-14

    We analyze the temperature relaxation phenomena of systems in contact with a thermal reservoir that undergoes a non-Markovian diffusion process. From a generalized Langevin equation, we show that the temperature is governed by a law of cooling of the Newton's law type in which the relaxation time depends on the velocity autocorrelation and is then characterized by the memory function. The analysis of the temperature decay reveals the existence of an anomalous cooling in which the temperature may oscillate. Despite this anomalous behavior, we show that the variation of entropy remains always positive in accordance with the second law of thermodynamics.

  5. Effect of compositions in nanostructured lipid carriers (NLC on skin hydration and occlusion

    Directory of Open Access Journals (Sweden)

    Loo CH

    2012-12-01

    Full Text Available CH Loo,1,2 M Basri,2 R Ismail,1 HLN Lau,1 BA Tejo,2 MS Kanthimathi,3 HA Hassan,1 YM Choo11Malaysian Palm Oil Board, Bandar Baru Bangi, 2Department of Chemistry, Universiti Putra Malaysia, Serdang, 3Department of Molecular Medicine, University of Malaya, Kuala Lumpur, MalaysiaPurpose: To study the effects of varying lipid concentrations, lipid and oil ratio, and the addition of propylene glycol and lecithin on the long-term physical stability of nanostructured lipid nanocarriers (NLC, skin hydration, and transepidermal water loss.Methods: The various NLC formulations (A1–A5 were prepared and their particle size, zeta potential, viscosity, and stability were analyzed. The formulations were applied on the forearms of the 20 female volunteers (one forearm of each volunteer was left untreated as a control. The subjects stayed for 30 minutes in a conditioned room with their forearms uncovered to let the skin adapt to the temperature (22°C ± 2°C and humidity (50% ± 2% of the room. Skin hydration and skin occlusion were recorded at day one (before treatment and day seven (after treatment. Three measurements for skin hydration and skin occlusion were performed in each testing area.Results: NLC formulations with the highest lipid concentration, highest solid lipid concentration, and additional propylene glycol (formulations A1, A2, and A5 showed higher physical stability than other formulations. The addition of propylene glycol into an NLC system helped to reduce the particle size of the NLC and enhanced its long-term physical stability. All the NLC formulations were found to significantly increase skin hydration compared to the untreated controls within 7 days. All NLC formulations exhibited occlusive properties as they reduced the transepidermal water loss within 7 days. This effect was more pronounced with the addition of propylene glycol or lecithin into an NLC formulation, whereby at least 60% reduction in transepidermal water loss was observed

  6. Effects of Locally Applied Glycerol and Xylitol on the Hydration, Barrier Function and Morphological Parameters of the Skin.

    Science.gov (United States)

    Korponyai, Csilla; Szél, Edit; Behány, Zoltán; Varga, Erika; Mohos, Gábor; Dura, Ágnes; Dikstein, Shabtay; Kemény, Lajos; Erős, Gábor

    2017-02-08

    Glycerol and xylitol hydrate the skin and improve its barrier function over a short period. We studied the effects of glycerol and xylitol on the physiological properties and morphology of the skin after longer-term application. Twelve volunteers with dry skin were examined. Three areas on the arms were determined. Area 1 served as untreated control. The vehicle was applied to area 2, while area 3 was treated twice daily with a formulation containing glycerol (5%) and xylitol (5%) for 14 days. Transepidermal water loss (TEWL), hydration and biomechanical properties of the skin were monitored. Biopsies were taken for routine histology and immunohistochemistry for filaggrin and matrix metalloproteinase-1 (MMP-1). The polyols increased the skin hydration and protein quantity of filaggrin, elevated the interdigitation index, decreased the TEWL and improved the biomechanical properties of the skin, but did not change the protein expression of MMP-1. A combination of glycerol and xylitol can be useful additional therapy for dry skin.

  7. The topical use of non-thermal dielectric barrier discharge (DBD): nitric oxide related effects on human skin.

    Science.gov (United States)

    Heuer, Kiara; Hoffmanns, Martin A; Demir, Erhan; Baldus, Sabrina; Volkmar, Christine M; Röhle, Mirco; Fuchs, Paul C; Awakowicz, Peter; Suschek, Christoph V; Opländer, Christian

    2015-01-30

    Dielectric barrier discharge (DBD) devices generate air plasma above the skin containing active and reactive species including nitric oxide (NO). Since NO plays an essential role in skin physiology, a topical application of NO by plasma may be useful in the treatment of skin infections, impaired microcirculation and wound healing. Thus, after safety assessments of plasma treatment using human skin specimen and substitutes, NO-penetration through the epidermis, the loading of skin tissue with NO-derivates in vitro and the effects on human skin in vivo were determined. After the plasma treatment (0-60 min) of skin specimen or reconstructed epidermis no damaging effects were found (TUNEL/MTT). By Franz diffusion cell experiments plasma-induced NO penetration through epidermis and dermal enrichment with NO related species (nitrite 6-fold, nitrate 7-fold, nitrosothiols 30-fold) were observed. Furthermore, skin surface was acidified (~pH 2.7) by plasma treatment (90 s). Plasma application on the forearms of volunteers increased microcirculation fourfold in 1-2 mm and twofold in 6-8 mm depth in the treated skin areas. Regarding the NO-loading effects, skin acidification and increase in dermal microcirculation, plasma devices represent promising tools against chronic/infected wounds. However, efficacy of plasma treatment needs to be quantified in further studies and clinical trials.

  8. Titanium Dioxide Nanoparticle Penetration into the Skin and Effects on HaCaT Cells.

    Science.gov (United States)

    Crosera, Matteo; Prodi, Andrea; Mauro, Marcella; Pelin, Marco; Florio, Chiara; Bellomo, Francesca; Adami, Gianpiero; Apostoli, Pietro; De Palma, Giuseppe; Bovenzi, Massimo; Campanini, Marco; Filon, Francesca Larese

    2015-08-07

    Titanium dioxide nanoparticles (TiO2NPs) suspensions (concentration 1.0 g/L) in synthetic sweat solution were applied on Franz cells for 24 h using intact and needle-abraded human skin. Titanium content into skin and receiving phases was determined. Cytotoxicity (MTT, AlamarBlue(®) and propidium iodide, PI, uptake assays) was evaluated on HaCat keratinocytes after 24 h, 48 h, and seven days of exposure. After 24 h of exposure, no titanium was detectable in receiving solutions for both intact and damaged skin. Titanium was found in the epidermal layer after 24 h of exposure (0.47 ± 0.33 μg/cm(2)) while in the dermal layer, the concentration was below the limit of detection. Damaged skin, in its whole, has shown a similar concentration (0.53 ± 0.26 μg/cm(2)). Cytotoxicity studies on HaCaT cells demonstrated that TiO2NPs induced cytotoxic effects only at very high concentrations, reducing cell viability after seven days of exposure with EC50s of 8.8 × 10(-4) M (MTT assay), 3.8 × 10(-5) M (AlamarBlue(®) assay), and 7.6 × 10(-4) M (PI uptake, index of a necrotic cell death). Our study demonstrated that TiO2NPs cannot permeate intact and damaged skin and can be found only in the stratum corneum and epidermis. Moreover, the low cytotoxic effect observed on human HaCaT keratinocytes suggests that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure.

  9. Titanium Dioxide Nanoparticle Penetration into the Skin and Effects on HaCaT Cells

    Directory of Open Access Journals (Sweden)

    Matteo Crosera

    2015-08-01

    Full Text Available Titanium dioxide nanoparticles (TiO2NPs suspensions (concentration 1.0 g/L in synthetic sweat solution were applied on Franz cells for 24 h using intact and needle-abraded human skin. Titanium content into skin and receiving phases was determined. Cytotoxicity (MTT, AlamarBlue® and propidium iodide, PI, uptake assays was evaluated on HaCat keratinocytes after 24 h, 48 h, and seven days of exposure. After 24 h of exposure, no titanium was detectable in receiving solutions for both intact and damaged skin. Titanium was found in the epidermal layer after 24 h of exposure (0.47 ± 0.33 μg/cm2 while in the dermal layer, the concentration was below the limit of detection. Damaged skin, in its whole, has shown a similar concentration (0.53 ± 0.26 μg/cm2. Cytotoxicity studies on HaCaT cells demonstrated that TiO2NPs induced cytotoxic effects only at very high concentrations, reducing cell viability after seven days of exposure with EC50s of 8.8 × 10−4 M (MTT assay, 3.8 × 10−5 M (AlamarBlue® assay, and 7.6 × 10−4 M (PI uptake, index of a necrotic cell death. Our study demonstrated that TiO2NPs cannot permeate intact and damaged skin and can be found only in the stratum corneum and epidermis. Moreover, the low cytotoxic effect observed on human HaCaT keratinocytes suggests that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure.

  10. Phototoxic and modulatory effects of natural products from the skin of Rhinella jimi (Stevaux, 2002

    Directory of Open Access Journals (Sweden)

    Samuel V. Brito

    2012-02-01

    Full Text Available The skin of amphibians possesses a large diversity of biologically active compounds that are associated with the natural defenses of these animals against pathogens. Five different extracts and fractions were obtained from the skin of Rhinella jimi: methanol extract (ME, methanol fractions (MF, chloroform extract of methanol extract (CF, aqueous alkaloid fraction (AAF and aqueous non-alkaloid fraction (ANAF. All fractions were evaluated with respect to their antibiotic modifying activity in standard bacterial strains and multiresistant clinical isolates. Antagonism was detected with kanamycin and gentamicin when combined with substances obtained from the skin of R. jimi. Phototoxic activity was observed in the methanol and chlorophorm fractions, as well as the aqueous non-alkaloid fraction. The antagonistic action was apparently associated with the protection afforded by the bacterial populations that inhabit the skin of this amphibian, preventing colonization by pathogenic fungi. The phototoxic activity demonstrated by natural products from the skin of R. jimi showed an interruption of the bacterial growth after UV exposure. This could indicate an antibacterial effect activated by the UV light, opening a path for carrying the attack by pathogenic fungi, causing the disease related with the amphibian decline.

  11. Effects of niacin restriction on sirtuin and PARP responses to photodamage in human skin.

    Directory of Open Access Journals (Sweden)

    Claudia A Benavente

    Full Text Available Sirtuins (SIRTs and poly(ADP-ribose polymerases (PARPs, NAD(+-dependent enzymes, link cellular energy status with responses to environmental stresses. Skin is frequently exposed to the DNA damaging effects of UV irradiation, a known etiology in skin cancer. Thus, understanding the defense mechanisms in response to UV, including the role of SIRTs and PARPs, may be important in developing skin cancer prevention strategies. Here, we report expression of the seven SIRT family members in human skin. SIRTs gene expressions are progressively upregulated in A431 epidermoid carcinoma cells (SIRTs1 and 3, actinic keratoses (SIRTs 2, 3, 5, 6, and 7 and squamous cell carcinoma (SIRTs 1-7. Photodamage induces dynamic changes in SIRT expression with upregulation of both SIRT1 and SIRT4 mRNAs. Specific losses of SIRT proteins occur early after photodamage followed by accumulation later, especially for SIRT4. Niacin restriction, which decreases NAD(+, the sirtuin substrate, results in an increase in acetylated proteins, upregulation of SIRTs 2 and 4, increased inherent DNA damage, alterations in SIRT responses to photodamage, abrogation of PARP activation following photodamage, and increased sensitivity to photodamage that is completely reversed by repleting niacin. These data support the hypothesis that SIRTs and PARPs play important roles in resistance to photodamage and identify specific SIRTs that respond to photodamage and may be targets for skin cancer prevention.

  12. Human skin penetration and local effects of topical nano zinc oxide after occlusion and barrier impairment.

    Science.gov (United States)

    Leite-Silva, V R; Sanchez, W Y; Studier, H; Liu, D C; Mohammed, Y H; Holmes, A M; Ryan, E M; Haridass, I N; Chandrasekaran, N C; Becker, W; Grice, J E; Benson, H A E; Roberts, M S

    2016-07-01

    Public health concerns continue to exist over the safety of zinc oxide nanoparticles that are commonly used in sunscreen formulations. In this work, we assessed the effects of two conditions which may be encountered in everyday sunscreen use, occlusion and a compromised skin barrier, on the penetration and local toxicity of two topically applied zinc oxide nanoparticle products. Caprylic/capric triglyceride (CCT) suspensions of commercially used zinc oxide nanoparticles, either uncoated or with a silane coating, were applied to intact and barrier impaired skin of volunteers, without and with occlusion for a period of six hours. The exposure time was chosen to simulate normal in-use conditions. Multiphoton tomography with fluorescence lifetime imaging was used to noninvasively assess zinc oxide penetration and cellular metabolic changes that could be indicative of toxicity. We found that zinc oxide nanoparticles did not penetrate into the viable epidermis of intact or barrier impaired skin of volunteers, without or with occlusion. We also observed no apparent toxicity in the viable epidermis below the application sites. These findings were validated by ex vivo human skin studies in which zinc penetration was assessed by multiphoton tomography with fluorescence lifetime imaging as well as Zinpyr-1 staining and toxicity was assessed by MTS assays in zinc oxide treated skin cryosections. In conclusion, applications of zinc oxide nanoparticles under occlusive in-use conditions to volunteers are not associated with any measurable zinc oxide penetration into, or local toxicity in the viable epidermis below the application site.

  13. Development of effective skin cancer treatment and prevention in xeroderma pigmentosum.

    Science.gov (United States)

    Lambert, W Clark; Lambert, Muriel W

    2015-01-01

    Xeroderma pigmentosum (XP) is a rare, recessively transmitted genetic disease characterized by increasingly marked dyspigmentation and xerosis (dryness) of sun-exposed tissues, especially skin. Skin cancers characteristically develop in sun-exposed sites at very much earlier ages than in the general population; these are often multiple and hundreds or even thousands may develop. Eight complementation groups have been identified. Seven groups, XP-A…G, are associated with defective genes encoding proteins involved in the nucleotide excision DNA repair (NER) pathway that recognizes and excises mutagenic changes induced in DNA by sunlight; the eighth group, XP-V, is associated with defective translesion synthesis (TLS) bypassing such alterations. The dyspigmentation, xerosis and eventually carcinogenesis in XP patients appear to be due to their cells' failure to respond properly to these mutagenic DNA alterations, leading to mutations in skin cells. A subset of cases, especially those in some complementation groups, may develop neurological degeneration, which may be severe. However, in most XP patients, in the past the multiple skin cancers have led to death at an early age due to either metastases or sepsis. Using either topical 5-fluorouracil or imiquimod, we have developed a protocol that effectively prevents most skin cancer development in XP patients.

  14. The pretreatment effect of chemical skin penetration enhancers in transdermal drug delivery using iontophoresis.

    Science.gov (United States)

    Choi, E H; Lee, S H; Ahn, S K; Hwang, S M

    1999-01-01

    The transdermal drug delivery (TDD) system has largely been divided into physical, biochemical and chemical methods. Recently, combinations of these methods were introduced for more effective delivery with less side effects. We performed this study to identify the effectiveness and mechanism of TDD using the physical method, 'iontophoresis', plus the chemical method, 'pretreatment with chemical enhancer'. The action sites of chemical enhancers in the stratum corneum (SC) were observed by electron microscope. We also studied whether this combined method synergistically impaired the skin barrier. To confirm the synergistic effect on skin penetration by this combined method, we measured the blood glucose level after insulin iontophoresis following a chemical enhancer pretreatment in rabbits. The results were that (1) dilatation of the intercellular lipid layers of the SC and lacunae was prominent in pretreatment with chemical enhancers inducing high transepidermal water loss (TEWL); (2) the skin barrier impairment, with repeated treatments showing an increased TEWL and also epidermal proliferation, was increased with the chemical enhancers that showed a high TEWL immediately after treatment; (3) the combination of chemical enhancer pretreatment and iontophoresis showed no synergistic impairment of the skin barrier, and (4) the chemical enhancer pretreatment with greater impairment of the skin barrier could increase the delivery of insulin by iontophoresis. The results showed that a combination of chemical enhancer pretreatment and iontophoresis could deliver drugs more effectively than iontophoresis alone. Our proposed theory is that iontophoretic drug delivery may be easier through the dilated intercellular spaces of the SC which have a lower electrical impedance following the chemical enhancer pretreatment. Because the effect and the side effects in the combination are decided by the chemical enhancer rather than iontophoresis, the development of proper chemical

  15. Skin Diseases: Skin Health and Skin Diseases

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Skin Health and Skin Diseases Past Issues / Fall 2008 Table of Contents ... acne to wrinkles Did you know that your skin is the largest organ of your body? It ...

  16. Anomalous pion decay revisited

    CERN Document Server

    Battistel, O A; Nemes, M C; Hiller, B

    1999-01-01

    An implicit four dimensional regularization is applied to calculate the axial-vector-vector anomalous amplitude. The present technique always complies with results of Dimensional Regularization and can be easily applied to processes involving odd numbers of $\\gamma_5$ matrices. This is illustrated explicitely in the example of this letter.

  17. Partial oxidation of Step-Bound Water Leads to Anomalous pH Effects on Metal Electrode Step-Edges

    CERN Document Server

    Schwarz, Kathleen; Yan, Yushan; Sundararaman, Ravishankar

    2016-01-01

    The design of better heterogeneous catalysts for applications such as fuel cells and electrolyzers requires a mechanistic understanding of electrocatalytic reactions and the dependence of their activity on operating conditions such as pH. A satisfactory explanation for the unexpected pH dependence of electrochemical properties of platinum surfaces has so far remained elusive, with previous explanations resorting to complex co-adsorption of multiple species and resulting in limited predictive power. This knowledge gap suggests that the fundamental properties of these catalysts are not yet understood, limiting systematic improvement. Here, we analyze the change in charge and free energies upon adsorption using density-functional theory (DFT) to establish that water adsorbs on platinum step edges across a wide voltage range, including the double-layer region, with a loss of approximately 0.2 electrons upon adsorption. We show how the change in net surface charge due to this water explains the anomalous pH variat...

  18. Effects of oral administration of glucosylceramide on gene expression changes in hairless mouse skin: comparison of whole skin, epidermis, and dermis.

    Science.gov (United States)

    Takatori, Ryo; Le Vu, Phuong; Iwamoto, Taku; Satsu, Hideo; Totsuka, Mamoru; Chida, Kazuhiro; Shimizu, Makoto

    2013-01-01

    The beneficial effects of dietary glucosylceramide on the barrier function of the skin have been increasingly reported, but the entire mechanism has not been clarified. By DNA microarray, we investigated changes in gene expression in hairless mouse skin when a damage-inducing AD diet and a glucosylceramide diet (GluCer) were imposed. GluCer administration potentially suppressed the upregulation of six genes and the downregulation of four genes in the AD group. Examination of the epidermal and/or dermal expression of Npr3, Cyp17a1, Col1a1, S100a9, Sprr2f, Apol7a, Tppp, and Scd3 revealed responses of various parts of the skin to the diets. In normal hairless mice, GluCer administration induced an increase in the dermal expression of Cyp17a1 and the epidermal expression of Tppp, and a decrease in the epidermal expression of S100a9. Our results provide information on gene expression not only in whole skin but also in the epidermis and dermis that should prove useful in the search for the mechanisms underlying the effects of GluCer on damaged and normal skin.

  19. Effects of palmitoyl-KVK-L-ascorbic acid on skin wrinkles and pigmentation.

    Science.gov (United States)

    Kim, Hyeong Mi; An, Hyo Sun; Bae, Jung-Soo; Kim, Jung Yun; Choi, Chi Ho; Kim, Ju Yeon; Lim, Joo Hyuck; Choi, Joon-Hun; Song, Hyunnam; Moon, Sung Ho; Park, Young Jun; Chang, Shin-Jae; Choi, Sun Young

    2017-03-16

    Wrinkle formation and abnormal pigmentation are major clinical alterations associated with skin aging. As the aim of our study was to investigate the effects of palmitoyl-KVK-L-ascorbic acid on skin aging, the anti-wrinkle and depigmentation effects of palmitoyl-KVK-L-ascorbic acid were evaluated by measuring collagen expression in dermal fibroblast cells and inhibition of melanogenesis in B16F1 cells, respectively. The anti-aging effect of palmitoyl-KVK-L-ascorbic acid cream was also evaluated against a placebo cream in a clinical trial. Our results confirmed that the expression of type Ι collagen in dermal fibroblast cells treated with palmitoyl-KVK-L-ascorbic acid (0.1-4 μg/mL) increased in a dose-dependent manner. In B16F1 cells, treatment with 20 μg/mL palmitoyl-KVK-L-ascorbic acid reduced the melanin content by approximately 20% compared to alpha-melanocyte stimulating hormone treatment. In the clinical trial, application of palmitoyl-KVK-L-ascorbic acid cream led to an improvement in skin roughness and lightness in 12 and 8 weeks, respectively. Our data show that palmitoyl-KVK-L-ascorbic acid is an effective anti-aging agent that reduces wrinkles and abnormal skin pigmentation.

  20. Temperature effect on the static behaviour of adhesively-bonded metal skin to composite stiffener

    NARCIS (Netherlands)

    Teixeira De Freitas, S.; Sinke, J.

    2015-01-01

    The purpose of this research is to study the effect of temperature on the static behavior of an hybrid structure consisting of adhesively bonded Fiber Metal Laminate skin to a composite stiffener. This hybrid structure was tested using stiffener pull-off tests, which is a typical set-up used to simu

  1. Nonspecific vasodilatation during transdermal iontophoresis—the effect of voltage over the skin

    NARCIS (Netherlands)

    Droog, E.J.; Sjöberg, F.

    2003-01-01

    We used laser Doppler perfusion imaging (LDPI) to study nonspecific vasodilatation during iontophoresis. In iontophoresis studies, nonspecific vasodilatation occurs as a result either of galvanic currents or of the applied voltage over the skin. We made dose–response measurements to study the effect

  2. High School Students' Perceptions of How Major Global Environmental Effects Might Cause Skin Cancer.

    Science.gov (United States)

    Boyes, Edward; Stanisstreet, Martin

    1998-01-01

    Quantifies beliefs of high school students about links between skin cancer and global environmental effects. Some students confused the action of heat rays with that of ultraviolet rays and also thought that raised temperatures are culpable. Only one in 10 held the scientifically correct model: that ozone depletion via higher penetration of…

  3. Pulse testing in the presence of wellbore storage and skin effects

    Energy Technology Data Exchange (ETDEWEB)

    Ogbe, D.O.; Brigham, W.E.

    1984-08-01

    A pulse test is conducted by creating a series of short-time pressure transients in an active (pulsing) well and recording the observed pressure response at an observation (responding) well. Using the pressure response and flow rate data, the transmissivity and storativity of the tested formation can be determined. Like any other pressure transient data, the pulse-test response is significantly influenced by wellbore storage and skin effects. The purpose of this research is to examine the influence of wellbore storage and skin effects on interference testing in general and on pulse-testing in particular, and to present the type curves and procedures for designing and analyzing pulse-test data when wellbore storage and skin effects are active at either the responding well or the pulsing well. A mathematical model for interference testing was developed by solving the diffusivity equation for radial flow of a single-phase, slightly compressible fluid in an infinitely large, homogeneous reservoir. When wellbore storage and skin effects are present in a pulse test, the observed response amplitude is attenuated and the time lag is inflated. Consequently, neglecting wellbore storage and skin effects in a pulse test causes the calculated storativity to be over-estimated and the transmissivity to be under-estimated. The error can be as high as 30%. New correlations and procedures are developed for correcting the pulse response amplitude and time lag for wellbore storage effects. Using these correlations, it is possible to correct the wellbore storage-dominated response amplitude and time lag to within 3% of their expected values without wellbore storage, and in turn to calculate the corresponding transmissivity and storativity. Worked examples are presented to illustrate how to use the new correction techniques. 45 references.

  4. Chemical and engineering approaches to enable organic field-effect transistors for electronic skin applications.

    Science.gov (United States)

    Sokolov, Anatoliy N; Tee, Benjamin C-K; Bettinger, Christopher J; Tok, Jeffrey B-H; Bao, Zhenan

    2012-03-20

    Skin is the body's largest organ and is responsible for the transduction of a vast amount of information. This conformable material simultaneously collects signals from external stimuli that translate into information such as pressure, pain, and temperature. The development of an electronic material, inspired by the complexity of this organ is a tremendous, unrealized engineering challenge. However, the advent of carbon-based electronics may offer a potential solution to this long-standing problem. In this Account, we describe the use of an organic field-effect transistor (OFET) architecture to transduce mechanical and chemical stimuli into electrical signals. In developing this mimic of human skin, we thought of the sensory elements of the OFET as analogous to the various layers and constituents of skin. In this fashion, each layer of the OFET can be optimized to carry out a specific recognition function. The separation of multimodal sensing among the components of the OFET may be considered a "divide and conquer" approach, where the electronic skin (e-skin) can take advantage of the optimized chemistry and materials properties of each layer. This design of a novel microstructured gate dielectric has led to unprecedented sensitivity for tactile pressure events. Typically, pressure-sensitive components within electronic configurations have suffered from a lack of sensitivity or long mechanical relaxation times often associated with elastomeric materials. Within our method, these components are directly compatible with OFETs and have achieved the highest reported sensitivity to date. Moreover, the tactile sensors operate on a time scale comparable with human skin, making them ideal candidates for integration as synthetic skin devices. The methodology is compatible with large-scale fabrication and employs simple, commercially available elastomers. The design of materials within the semiconductor layer has led to the incorporation of selectivity and sensitivity within

  5. Effectiveness of three surgical alcohol-based hand rubs on skin flora

    OpenAIRE

    Zandiyeh, Mitra; Roshanaei, Ghodratollah

    2015-01-01

    Background: It is proved that surgical hand disinfectant contains alcohol, and has favorable properties such as strong and rapid antibacterial effect, ease of application, and suitable effect on skin. Therefore, nowadays use of them has been gradually replacing traditional surgical hand scrub with antibacterial soap. Hence, several domestic and imported products are available to the healthcare facilities in Iran. This study was done in order to determine the antibacterial effect of Decosept, ...

  6. The effects of brief cognitive-behaviour therapy for pathological skin picking: A randomized comparison to wait-list control.

    Science.gov (United States)

    Schuck, Kathrin; Keijsers, Ger P J; Rinck, Mike

    2011-01-01

    Thirty-four college students suffering from pathological skin picking were randomly assigned to a four-session cognitive-behavioural treatment (n=17) or a waiting-list condition (n=17). Severity of skin picking, psycho-social impact of skin picking, strength of skin-picking-related dysfunctional cognitions, and severity of skin injury were measured at pre-, post-, and two-months follow-up assessment. Participants in the treatment condition showed a significantly larger reduction on all measured variables in comparison to the waiting-list condition. The obtained effect sizes for the outcome measures were large, ranging from .90 to 1.89. Treatment effects were maintained at follow-up. In conclusion, cognitive-behavioural therapy, even in brief form, constitutes an adequate treatment option for pathological skin-picking behaviour.

  7. Aging skin.

    Science.gov (United States)

    Bolognia, J L

    1995-01-16

    Aging of the skin is a composite of actinic damage, chronologic aging, and hormonal influences. The majority of changes associated with aging, such as wrinkles and solar lentigines ("liver spots"), are due to photoaging and reflect cumulative sun exposure as well as skin pigmentation. Classically, chronologic aging includes those cutaneous changes that occur in non-sun-exposed areas, such as the buttocks, and are observed in both men and women. A clinical example would be soft tissue sagging due to elastic fiber degeneration. In women, investigations into the effect of hormones on aging of the skin have concentrated on estrogens; in men, there have been a limited number of studies on the influence of testosterone. The latter have shown an age-dependent decrease in tissue androgens in pubic skin, but not scrotal or thigh skin. To date, age has not been shown to have an effect on androgen receptor binding, although a decrease in foreskin 5 alpha-reductase activity with increasing age has been described. In fibroblast cultures from foreskins, there have been conflicting results as to whether 5 alpha-reductase activity decreases in an age-dependent manner. Some of the skin changes that have been categorized as secondary to chronologic aging, such as decreased sebaceous gland activity and decreased hair growth, may actually represent a decline in the concentration of tissue androgens with increasing age. The influence of androgens on age-related changes in keratinocyte and fibroblast function remains speculative.

  8. Studies on the protection effects of functional foods for skin immune system from radiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Sung Tae; Shin, Seong Hae; Kim, Do Sun; Heo, Ji Yun; Kang, Hye In [Sunchon National University, Sunchon (Korea, Republic of)

    2007-07-15

    We evaluated the protective effects of pilot products (HemoHIM and HemoTonic) on the UV-induced skin immune damages as the following. centre dot Protective effects of HemoHIM and HemoTonic against UV using contact hypersensitivity model - Protection against depression of contact hypersensitivity by administration and skin application of HemoHIM and HemoTonic - Induction of dendritic cell differentiation and maturation by HemoHIM and HemoTonic treatment - Improvement of antigen-presenting activity of dedritic cells by HemoHIM and HemoTonic treatment centre dot Protective effects of HemoHIM and HemoTonic on skin immune system against UV-irradiation - Protection of antigen-presenting activity of dendritic cells under UV-irradiation - In vivo protection of antigen-presenting activity of Langerhans cells in UV-irradiated mice centre dot Protective effects of HemoHIM on UV-induced apoptosis of dendritic cells - Inhibition of cell membrane change, mitochondrial potential change, SubG1 cell population, nuclear condensation, and DNA fragmentation in UV-irradiated dendritic cells centre dot Anti-allergic effects of HemoHIM and HemoTonic in human adipocyte HMC-1 cells - Inhibition of allergic histamine release from adipocytes - Inhibition of secretion of inflammatory cytokines (IL-6, IL-8, TNF-alpha, GM-CSF) - Inhibition of c-kit, tryptase, FcepsilonRI mRNA expression From these results, the developed functional food products (HemoHIM, HemoTonic) showed the protection and recovery of the immune functions in the UV-irradiated skin. It is suggested that these products may be used as a new functional food or cosmetic material for the protection of skin damage and the promotion of recovery

  9. Skin penetration and antioxidant effect of cosmeto-textiles with gallic acid.

    Science.gov (United States)

    Alonso, C; Martí, M; Barba, C; Lis, M; Rubio, L; Coderch, L

    2016-03-01

    In this work, the antioxidant gallic acid (GA) has been encapsulated in microspheres prepared with poly-ε-caprolactone (PCL) and incorporated into polyamide (PA) obtaining the cosmeto-textile. The topical application of the cosmeto-textile provides a reservoir effect in the skin delivery of GA. The close contact of the cosmeto-textile, containing microsphere-encapsulated GA (ME-GA), with the skin and their corresponding occlusion, may be the main reasons that explain the crossing of active principle (GA) through the skin barrier, located in the stratum corneum, and its penetration into the different compartments of the skin, epidermis and dermis. An ex vivo assessment was performed to evaluate the antioxidant effect of the ME-GA on the stratum corneum (SC) using the thiobarbituric acid-reactive species (TBARS) test. The test is based on a non-invasive ex vivo methodology that evaluates lipid peroxides formed in the outermost layers of the SC from human volunteers after UV radiation to determine the effectiveness of an antioxidant. In this case, a ME-GA cosmeto-textile or ME-GA formulation were applied to the skin in vivo and lipid peroxidation (LPO) in the horny layer were determined after UV irradiation. This methodology may be used as a quality control tool to determine ex vivo the percentage of LPO inhibition on human SC for a variety of antioxidants that are topically applied, in this case GA. Results show that LPO formation was inhibited in human SC when GA was applied directly or embedded in the cosmeto-textile, demonstrating the effectiveness of both applications. The percentage of LPO inhibition obtained after both topical applications was approximately 10% for the cosmeto-textile and 41% for the direct application of microspheres containing GA. This methodology could be used to determine the effectiveness of topically applied antioxidants encapsulated in cosmeto-textiles on human SC.

  10. Contrasting effects of ultraviolet-A and ultraviolet B exposure on induction of contact sensitivity in human skin

    DEFF Research Database (Denmark)

    Skov, Lone; Hansen, Henrik; Barker, J. N.

    1997-01-01

    Ultraviolet-B (UVB), in addition to direct effects on DNA, induces immunological changes in the skin that predispose to the development of skin cancer. Whether ultraviolet-A (UVA) induces similar changes is unknown. This effect can be investigated in humans in vivo using epicutaneous antigens...

  11. Differential cytotoxic effects of graphene and graphene oxide on skin keratinocytes

    Science.gov (United States)

    Pelin, Marco; Fusco, Laura; León, Verónica; Martín, Cristina; Criado, Alejandro; Sosa, Silvio; Vázquez, Ester; Tubaro, Aurelia; Prato, Maurizio

    2017-01-01

    Impressive properties make graphene-based materials (GBMs) promising tools for nanoelectronics and biomedicine. However, safety concerns need to be cleared before mass production of GBMs starts. As skin, together with lungs, displays the highest exposure to GBMs, it is of fundamental importance to understand what happens when GBMs get in contact with skin cells. The present study was carried out on HaCaT keratinocytes, an in vitro model of skin toxicity, on which the effects of four GBMs were evaluated: a few layer graphene, prepared by ball-milling treatment (FLG), and three samples of graphene oxide (GOs, a research-grade GO1, and two commercial GOs, GO2 and GO3). Even though no significant effects were observed after 24 h, after 72 h the less oxidized compound (FLG) was the less cytotoxic, inducing mitochondrial and plasma-membrane damages with EC50s of 62.8 μg/mL (WST-8 assay) and 45.5 μg/mL (propidium iodide uptake), respectively. By contrast, the largest and most oxidized compound, GO3, was the most cytotoxic, inducing mitochondrial and plasma-membrane damages with EC50s of 5.4 and 2.9 μg/mL, respectively. These results suggest that only high concentrations and long exposure times to FLG and GOs could impair mitochondrial activity associated with plasma membrane damage, suggesting low cytotoxic effects at the skin level. PMID:28079192

  12. Effect of chemical peeling on the skin in relation to UV irradiation.

    Science.gov (United States)

    Funasaka, Yoko; Abdel-Daim, Mohamed; Kawana, Seiji; Nishigori, Chikako

    2012-07-01

    Chemical peeling is one of the dermatological treatments available for certain cutaneous diseases and conditions or improvement of cosmetic appearance of photoaged skin. However, it needs to be clarified whether the repetitive procedure of chemical peeling on photodamaged skin is safe and whether the different chemicals used for peeling results in similar outcomes or not. In this article, we reviewed the effect of peeling or peeling agents on the skin in relation to ultraviolet (UV) radiation. The pretreatment of peeling agents usually enhance UV sensitivity by inducing increased sunburn cell formation, lowering minimum erythematous dose and increasing cyclobutane pyrimidine dimers. However, this sensitivity is reversible and recovers to normal after 1-week discontinuation. Using animals, the chronic effect of peeling and peeling agents was shown to prevent photocarcinogenesis. There is also an in vitro study using culture cells to know the detailed mechanisms of peeling agents, especially on cell proliferation and apoptotic changes via activating signalling cascades and oxidative stress. It is important to understand the effect of peeling agents on photoaged skin and to know how to deal with UV irradiation during the application of peeling agents and treatment of chemical peeling in daily life.

  13. Effect of piracetam and nimodipine on full-thickness skin burns in rabbits.

    Science.gov (United States)

    Sari, Elif; Dincel, Gungor C

    2016-08-01

    The potential of several drugs for full-thickness skin burns has been investigated, but the treatment of such burns remains a challenge in plastic surgery. The present study was designed to determine the effect of systemic and topical administration of piracetam and nimodipine on full-thickness skin burn wound healing. A total of 36 New Zealand male rabbits were divided into six groups. Full-thickness skin burns were produced in all the groups, except the control group. Piracetam was administered systemically (piracetam-IV) and topically (piracetam-C) for 14 days, and nimodipine was administered systemically (nimodipine-IV) and topically (nimodipine-C) over the burn wounds for 14 days. The sham group underwent burn injury but was not administered any drug. After 21 days, gross examination and histopathological analysis were performed and the results were compared statistically. Nimodipine-C and nimodipine-IV had no effect on burn wound healing. However, both piracetam-IV and piracetam-C significantly enhanced the healing of the full-thickness skin burn wounds, although the latter was more effective, useful and practical in burn wound healing. The histopathological features of the wounds in the piracetam-C group were closer to those of the control group than those of the other groups. Piracetam-C rather than piracetam-IV may promote full-thickness burn wound healing in rabbits.

  14. Differential cytotoxic effects of graphene and graphene oxide on skin keratinocytes

    Science.gov (United States)

    Pelin, Marco; Fusco, Laura; León, Verónica; Martín, Cristina; Criado, Alejandro; Sosa, Silvio; Vázquez, Ester; Tubaro, Aurelia; Prato, Maurizio

    2017-01-01

    Impressive properties make graphene-based materials (GBMs) promising tools for nanoelectronics and biomedicine. However, safety concerns need to be cleared before mass production of GBMs starts. As skin, together with lungs, displays the highest exposure to GBMs, it is of fundamental importance to understand what happens when GBMs get in contact with skin cells. The present study was carried out on HaCaT keratinocytes, an in vitro model of skin toxicity, on which the effects of four GBMs were evaluated: a few layer graphene, prepared by ball-milling treatment (FLG), and three samples of graphene oxide (GOs, a research-grade GO1, and two commercial GOs, GO2 and GO3). Even though no significant effects were observed after 24 h, after 72 h the less oxidized compound (FLG) was the less cytotoxic, inducing mitochondrial and plasma-membrane damages with EC50s of 62.8 μg/mL (WST-8 assay) and 45.5 μg/mL (propidium iodide uptake), respectively. By contrast, the largest and most oxidized compound, GO3, was the most cytotoxic, inducing mitochondrial and plasma-membrane damages with EC50s of 5.4 and 2.9 μg/mL, respectively. These results suggest that only high concentrations and long exposure times to FLG and GOs could impair mitochondrial activity associated with plasma membrane damage, suggesting low cytotoxic effects at the skin level.

  15. Wall mass transfer and pressure gradient effects on turbulent skin friction

    Science.gov (United States)

    Watson, R. D.; Balasubramanian, R.

    1984-01-01

    The effects of mass injection and pressure gradients on the drag of surfaces were studied theoretically with the aid of boundary-layer and Navier-Stokes codes. The present investigation is concerned with the effects of spatially varying the injection in the case of flat-plate drag. Effects of suction and injection on wavy wall surfaces are also explored. Calculations were performed for 1.2 m long surfaces, one flat and the other sinusoidal with a wavelength of 30.5 cm. Attention is given to the study of the effect of various spatial blowing variations on flat-plate skin friction reduction, local skin friction coefficient calculated by finite difference boundary-layer code and Navier-Stokes code, and the effect of phase-shifting sinusoidal mass transfer on the drag of a sinusoidal surface.

  16. Measuring the effects of topically applied skin optical clearing agents and modeling the effects and consequences for laser therapies

    Science.gov (United States)

    Verkruysse, Wim; Khan, Misbah; Choi, Bernard; Svaasand, Lars O.; Nelson, J. Stuart

    2005-04-01

    Human skin prepared with an optical clearing agent manifests reduced scattering as a result of de-hydration and refractive index matching. This has potentially large effects for laser therapies of several skin lesions such as port wine stain, hair removal and tattoo removal. With most topically applied clearing agents the clearing effect is limited because they penetrate poorly through the intact superficial skin layer (stratum corneum). Agent application modi other than topical are impractical and have limited the success of optical clearing in laser dermatology. In recent reports, however, a mixture of lipofylic and hydrofylic agents was shown to successfully penetrate through the intact stratum corneum layer which has raised new interest in this field. Immediately after application, the optical clearing effect is superficial and, as the agent diffuses through the skin, reduced scattering is manifested in deeper skin layers. For practical purposes as well as to maximize therapeutic success, it is important to quantify the reduced scattering as well as the trans-cutaneous transport dynamics of the agent. We determined the time and tissue depth resolved effects of optically cleared skin by inserting a microscopic reflector array in the skin. Depth dependent light intensity was measured by quantifying the signal of the reflector array with optical coherence tomography. A 1-dimensional mass diffusion model was used to estimate a trans-cutaneous transport diffusion constant for the clearing agent mixture. The results are used in Monte Carlo modeling to determine the optimal time of laser treatment after topical application of the optical clearing agent.

  17. Hydrodynamic function of biomimetic shark skin: effect of denticle pattern and spacing.

    Science.gov (United States)

    Wen, Li; Weaver, James C; Thornycroft, Patrick J M; Lauder, George V

    2015-11-18

    The structure of shark skin has been the subject of numerous studies and recently biomimetic shark skin has been fabricated with rigid denticles (scales) on a flexible substrate. This artificial skin can bend and generate thrust when attached to a mechanical controller. The ability to control the manufacture of biomimetic shark skin facilitates manipulation of surface parameters and understanding the effects of changing denticle patterns on locomotion. In this paper we investigate the effect of changing the spacing and arrangement of denticles on the surface of biomimetic shark skin on both static and dynamic locomotor performance. We designed 3D-printed flexible membranes with different denticle patterns and spacings: (1) staggered-overlapped, (2) linear-overlapped, and (3) linear-non-overlapped, and compared these to a 3D-printed smooth-surfaced control. These 3D printed shark skin models were then tested in a flow tank with a mechanical flapping device that allowed us to either hold the models in a stationary position or move them dynamically. We swam the membranes at a frequency of 1 Hz with different heave amplitudes (from ±1 cm to ±3 cm) while measuring forces, torques, self-propelled swimming speed, and cost of transport (COT). Static tests revealed drag reduction of denticle patterns compared to a smooth control at low speeds, but increased drag at speeds above 25 cm s(-1). However, during dynamic (swimming) tests, the staggered-overlapped pattern produced the fastest swimming speeds with no significant increase in the COT at lower heave values. For instance, at a heave frequency of 1 Hz and amplitude of ±1 cm, swimming speed of the staggered-overlapped pattern increased by 25.2% over the smooth control. At higher heave amplitudes, significantly faster self-propelled swimming speeds were achieved by the staggered-overlapped pattern, but with higher COT. Only the staggered-overlapped pattern provides a significant swimming performance advantage over the

  18. Comparison of disposable diapers with fluff absorbent and fluff plus absorbent polymers: effects on skin hydration, skin pH, and diaper dermatitis.

    Science.gov (United States)

    Davis, J A; Leyden, J J; Grove, G L; Raynor, W J

    1989-06-01

    Diaper dermatitis results from the action of a number of physical and chemical factors on the skin. While its etiology is complex, there is agreement that prolonged contact between wet diapers and the skin leading to excessive hydration of the stratum corneum and reduced barrier function is a primary factor. Recent research also indicates that pH elevation resulting from ammonia production increases the probability of skin damage due to fecal enzyme activity. New diapers containing absorbent polymers blended with cellulose fluff in the absorbent core have been developed. The absorbent polymer binds fluids and controls pH in the diaper environment. To assess the effectiveness of these diapers, a clinical study was conducted with approximately 150 infants over 15 weeks, using fluff diapers and absorbent polymer diapers. The results clearly showed that the diapers with absorbent polymer provide a better skin environment than those with fluff only with respect to lower skin wetness and pH control (instrumental measurements). In addition, the clinicians' grades indicated a directional reduction in diaper rash severity.

  19. Characterization of atopic skin and the effect of a hyperforin-rich cream by laser scanning microscopy

    Science.gov (United States)

    Meinke, Martina C.; Richter, Heike; Kleemann, Anke; Lademann, Juergen; Tscherch, Kathrin; Rohn, Sascha; Schempp, Christoph M.

    2015-05-01

    Atopic dermatitis (AD) is a multifactorial inflammatory skin disease that affects both children and adults in an increasing manner. The treatment of AD often reduces subjective skin parameters, such as itching, dryness, and tension, but the inflammation cannot be cured. Laser scanning microscopy was used to investigate the skin surface, epidermal, and dermal characteristics of dry and atopic skin before and after treatment with an ointment rich in hyperforin, which is known for its anti-inflammatory effects. The results were compared to subjective parameters and transepidermal water loss, stratum corneum moisture, and stratum corneum lipids. Using biophysical methods, in particular laser scanning microscopy, it was found that atopic skin has distinct features compared to healthy skin. Treatment with a hyperforin-rich ointment resulted in an improvement of the stratum corneum moisture, skin surface dryness, skin lipids, and the subjective skin parameters, indicating that the barrier is stabilized and improved by the ointment. But in contrast to the improved skin surface, the inflammation in the deeper epidermis/dermis often continues to exist. This could be clearly shown by the reflectance confocal microscopy (RCM) measurements. Therefore, RCM measurements could be used to investigate the progress in treatment of atopic dermatitis.

  20. Effect of orally administered collagen hydrolysate on gene expression profiles in mouse skin: a DNA microarray analysis.

    Science.gov (United States)

    Oba, Chisato; Ito, Kyoko; Ichikawa, Satomi; Morifuji, Masashi; Nakai, Yuji; Ishijima, Tomoko; Abe, Keiko; Kawahata, Keiko

    2015-08-01

    Dietary collagen hydrolysate has been hypothesized to improve skin barrier function. To investigate the effect of long-term collagen hydrolysate administration on the skin, we evaluated stratum corneum water content and skin elasticity in intrinsically aged mice. Female hairless mice were fed a control diet or a collagen hydrolysate-containing diet for 12 wk. Stratum corneum water content and skin elasticity were gradually decreased in chronologically aged control mice. Intake of collagen hydrolysate significantly suppressed such changes. Moreover, we used DNA microarrays to analyze gene expression in the skin of mice that had been administered collagen hydrolysate. Twelve weeks after the start of collagen intake, no significant differences appeared in the gene expression profile compared with the control group. However, 1 wk after administration, 135 genes were upregulated and 448 genes were downregulated in the collagen group. This suggests that gene changes preceded changes of barrier function and elasticity. We focused on several genes correlated with functional changes in the skin. Gene Ontology terms related to epidermal cell development were significantly enriched in upregulated genes. These skin function-related genes had properties that facilitate epidermal production and differentiation while suppressing dermal degradation. In conclusion, our results suggest that altered gene expression at the early stages after collagen administration affects skin barrier function and mechanical properties. Long-term oral intake of collagen hydrolysate improves skin dysfunction by regulating genes related to production and maintenance of skin tissue.

  1. Modeling the Substrate Skin Effects in Mutual RL Characteristics.,

    Directory of Open Access Journals (Sweden)

    D. de Roest

    2003-12-01

    Full Text Available The goal of this work was to model the influence of the substrateskin effects on the distributed mutual impedance per unit lengthparameters of multiple coupled on-chip interconnects. The proposedanalytic model is based on the frequency-dependent distribution of thecurrent in the silicon substrate and the closed form integrationapproach. It is shown that the calculated frequency-dependentdistributed mutual inductance and the associated mutual resistance arein good agreement with the results obtained from CAD-oriented circuitmodeling technique.

  2. Effect of different pretreatments on functional properties of African catfish (Clarias gariepinus) skin gelatin.

    Science.gov (United States)

    See, S F; Ghassem, M; Mamot, S; Babji, A S

    2015-02-01

    Pretreatments with different types of alkali and acid were compared to determine their effects on gelatin extraction from African catfish (Clarias gariepinus) skin. The study was divided into three parts. In the first part, the skins were only treated with alkaline (Ca(OH)2 or NaOH) solution or pretreated with acetic acid solution. For second part, combination of alkali and acid pretreatment was carried out. For the third part, the skins were first treated with NaOH solution, followed by the treatment with acetic acid, citric acid or sulfuric acid solution. Functional properties including the yield of protein recovery, gel strength, viscosity, pH and viscoelastic properties were determined on gelatins obtained with different pretreatment conditions. Pretreatment with alkali removed noncollagenous proteins effectively, whilst acid pretreatment induced some loss of collagenous proteins. Combination of alkali and acid pretreatment not only removed the noncollagenous proteins and caused a significant amount of swelling, but also provided the proper pH condition for extraction, during which some cross-linkages could be further destroyed but with less breakage of intramolecular peptide chains. Pretreatment of catfish skins with 0.2 N NaOH followed by 0.05 M acetic acid improved yield of protein recovery, gel strength, viscosity, melting temperature and gelling temperature of gelatin extract.

  3. The Effects of Advertising Strategies on Consumer Trust: A Case of Skin Care Products in Taiwan

    Directory of Open Access Journals (Sweden)

    Velly Anatasia

    2016-09-01

    Full Text Available The main aim of this study was to develop advertising strategies in order to increase consumer trust. Four advertising elements, celebrity endorsement, branding, product attribute, and third party certification, were investigated in this study. Data were collected to answer two research questions: (1 To investigate the advertising strategies of skin care products leading to consumer trust, (2 To know the effects of advertising strategies in skin care products on consumer trust. A 5-point Likert scale survey was distributed to the female population in Taipei area. Via online and personal approaches, 266 questionnaires were returned. Targeting on 18-30 years old female skin care product users who stay in Taipei area more than six months, 240 qualified questionnaires were analyzed. The four independent variables are found having a significant relationship with trust in skin care advertising, in which branding has the greatest influence on increasing consumer trust. The control variable which is financial status is not found having statistically significant effect on consumer trust. To conclude, this study is dedicated to the communities in order to optimize their marketing strategies.

  4. Radioprotective effects of dimethyl sulfoxide in the artificial skin reconstructed with cultured human cells

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Young Ha; Choi, Karp Shik [College of Dentistry, Kyungpook National University, Daegu (Korea, Republic of); Song, In Hwan [Department of Anatomy, College of Medicine, Yeungnam University, Daegu (Korea, Republic of)

    2002-03-15

    To evaluate cultured human artificial skin as an experimental model for studying radiation effects in vitro. The skin was constructed by culturing keratinocytes over collagen lattice which made by culturing fibroblasts. Two groups were irradiated to gamma rays at single dose of 25 Gy with or without 3.5% of DMSO. Ultrastructures were investigated by electron microscopy after irradiation. The number of epidermal layers and expression of cytokeratin (CK) 14 and 10 were also seem by light microscopy. At 2 days after irradiation in experimental group without DMSO, necrotic cells were rarely found in the spinosal layer and undercornified cells were visible in the horney layer. Similar findings were also found in experimental group with DMSO but in mild form. The number of epidermal layers in experimental group without DMSO were significantly fewer than other group. CK 14 expressed in all the layer excluding horney layer but CK 10 expressed over 3-4 basal layers. Such patterns of CK expression were similar to all groups. It is suggested that structures of the keratinocytes and epidermal formation could be disturbed by irradiation in artificial skin and that DMSO can protect these damages. Therefore this work could be used as an organotypic experimental model in vitro using human cells for studying radiation effect in skin. Furthermore structural findings provided in this study could be used as useful basic data in further study using this model.

  5. The effects of sodium oxybate on core body and skin temperature regulation in narcolepsy.

    Science.gov (United States)

    van der Heide, Astrid; Donjacour, Claire E H M; Pijl, Hanno; Reijntjes, Robert H A M; Overeem, Sebastiaan; Lammers, Gert J; Van Someren, Eus J W; Fronczek, Rolf

    2015-10-01

    Patients suffering from narcolepsy type 1 show altered skin temperatures, resembling the profile that is related to sleep onset in healthy controls. The aim of the present study is to investigate the effects of sodium oxybate, a widely used drug to treat narcolepsy, on the 24-h profiles of temperature and sleep-wakefulness in patients with narcolepsy and controls. Eight hypocretin-deficient male narcolepsy type 1 patients and eight healthy matched controls underwent temperature measurement of core body and proximal and distal skin twice, and the sleep-wake state for 24 h. After the baseline assessment, 2 × 3 g of sodium oxybate was administered for 5 nights, immediately followed by the second assessment. At baseline, daytime core body temperature and proximal skin temperature were significantly lower in patients with narcolepsy (core: 36.8 ± 0.05 °C versus 37.0 ± 0.05 °C, F = 8.31, P = 0.01; proximal: 33.4 ± 0.26 °C versus 34.3 ± 0.26 °C, F = 5.66, P = 0.03). In patients, sodium oxybate administration increased proximal skin temperature during the day (F = 6.46, P = 0.04) to a level similar as in controls, but did not affect core body temperature, distal temperature or distal-proximal temperature gradient. Sodium oxybate administration normalised the predictive value of distal skin temperature and distal-proximal temperature gradient for the onset of daytime naps (P < 0.01). In conclusion, sodium oxybate administration resulted in a partial normalisation of the skin temperature profile, by increasing daytime proximal skin temperature, and by strengthening the known relationship between skin temperature and daytime sleep propensity. These changes seem to be related to the clinical improvement induced by sodium oxybate treatment. A causal relationship is not proven.

  6. Anomalous transports in a time-delayed system subjected to anomalous diffusion

    Science.gov (United States)

    Chen, Ru-Yin; Tong, Lu-Mei; Nie, Lin-Ru; Wang, Chaojie; Pan, Wanli

    2017-02-01

    We investigate anomalous transports of an inertial Brownian particle in a time-delayed periodic potential subjected to an external time-periodic force, a constant bias force, and the Lévy noise. By means of numerical calculations, effect of the time delay and the Lévy noise on its mean velocity are discussed. The results indicate that: (i) The time delay can induce both multiple current reversals (CRs) and absolute negative mobility (ANM) phenomena in the system; (ii) The CRs and ANM phenomena only take place in the region of superdiffusion, while disappear in the regions of normal diffusion; (iii) The time delay can cause state transition of the system from anomalous →normal →anomalous →normal →anomalous →normal transport in the case of superdiffusion.

  7. Modeling skin effect in large magnetized iron detectors

    CERN Document Server

    Incurvati, M

    2003-01-01

    The experimental problem of the calibration of magnetic field in large iron detectors is discussed. Emphasis is laid on techniques based on ballistic measurements as the ones employed by MINOS or OPERA.In particular, we provide analytical formulas to model the behavior of the apparatus in the transient regime, keeping into account eddy current effects and the finite penetration velocity of the driving fields. These formulas ease substantially the design of the calibration apparatus.Results are compared with experimental data coming from a prototype of the OPERA spectrometer.

  8. Ferromagnetism in reactive sputtered Cu0.96Fe 0.04O1-δ nanocrystalline films evidenced by anomalous Hall effect

    KAUST Repository

    Mi, Wenbo

    2011-03-14

    Cu0.96Fe0.04O1-δ nanocrystalline films were fabricated using reactive sputtering at different oxygen partial pressures (PO2). The electrical transport properties of the films were measured in a broad temperature range (10-300 K) under magnetic fields of up to 5T. Anomalous Hall effect (AHE) of up to 0.4μΩ cm was observed at 10 K and decreased to 0.2μΩ cm at 300 K. The characteristic AHE clearly indicated the existence of ferromagnetism in these materials. The AHE weakened as PO2 increased because the increasing PO2 reduced the fraction of Fe2+ ions, and consequently weakened the double exchange coupling between Fe2+-O2--Cu2+ in the materials. © 2011 The Japan Society of Applied Physics.

  9. Synergistic effects of green tea and ginkgo biloba extracts on the improvement of skin barrier function and elasticity.

    Science.gov (United States)

    Campos, Patricia M B G Maia; Gianeti, Mirela D; Mercurio, Daiane G; Gaspar, Lorena R

    2014-09-01

    This study aimed to evaluate the effects of cosmetic formulations containing green tea (GT) and/or Ginkgo biloba (GB) extracts by preclinical and clinical studies. For the preclinical study, histological analysis was performed after 5 day-period of formulations application on the dorsum of hairless mice. For the clinical study, the formulations were applied on the forearm skin of 48 volunteers, and assessed before and after 3 hours and after a 15 and 30 day-period of application. Histological analysis showed that the formulation with GT (FGT) and the association of GT and GB (FBlend) significantly enhanced viable epidermis thickness and the number of cell layers, suggesting a moisturizing effect in skin deeper layers and increased cell renewal. The clinical efficacy studies showed that the extracts had a moisturizing effect and improved skin microrelief. In addition they synergistically acted on the skin elasticity and skin barrier function. In conclusion, the formulation containing a combination of green tea and Ginkgo biloba extracts effectively improved skin conditions and the effect of formulation FBlend on the improvement of skin elasticity was more pronounced. Finally, the results of the present study revealed other important clinical benefits of Ginkgo biloba and green tea extracts on the skin besides their already known antioxidant action.

  10. Anomalous law of cooling

    OpenAIRE

    Lapas, Luciano C.; Ferreira, Rogelma M. S.; Oliveira, Fernando A.; Rubí, J. Miguel

    2014-01-01

    We analyze the temperature relaxation phenomena of systems in contact with a thermal reservoir that undergo a non-Markovian diffusion process. From a generalized Langevin equation, we show that the temperature is governed by a law of cooling of the Newton's law type in which the relaxation time depends on the velocity autocorrelation and is then characterized by the memory function. The analysis of the temperature decay reveals the existence of an anomalous cooling in which the temperature ma...

  11. Anomalous diffusion of epicentres

    CERN Document Server

    Sotolongo-Costa, Oscar; Posadas, A; Luzon, F

    2007-01-01

    The classification of earthquakes in main shocks and aftershocks by a method recently proposed by M. Baiesi and M. Paczuski allows to the generation of a complex network composed of clusters that group the most correlated events. The spatial distribution of epicentres inside these structures corresponding to the catalogue of earthquakes in the eastern region of Cuba shows anomalous anti-diffusive behaviour evidencing the attractive nature of the main shock and the possible description in terms of fractional kinetics.

  12. Partial oxidation of step-bound water leads to anomalous pH effects on metal electrode step-edges.

    Science.gov (United States)

    Schwarz, Kathleen; Xu, Bingjun; Yan, Yushan; Sundararaman, Ravishankar

    2016-06-28

    The design of better heterogeneous catalysts for applications such as fuel cells and electrolyzers requires a mechanistic understanding of electrocatalytic reactions and the dependence of their activity on operating conditions such as pH. A satisfactory explanation for the unexpected pH dependence of electrochemical properties of platinum surfaces has so far remained elusive, with previous explanations resorting to complex co-adsorption of multiple species and resulting in limited predictive power. This knowledge gap suggests that the fundamental properties of these catalysts are not yet understood, limiting systematic improvement. Here, we analyze the change in charge and free energies upon adsorption using density-functional theory (DFT) to establish that water adsorbs on platinum step edges across a wide voltage range, including the double-layer region, with a loss of approximately 0.2 electrons upon adsorption. We show how this as-yet unreported change in net surface charge due to this water explains the anomalous pH variations of the hydrogen underpotential deposition (Hupd) and the potentials of zero total charge (PZTC) observed in published experimental data. This partial oxidation of water is not limited to platinum metal step edges, and we report the charge of the water on metal step edges of commonly used catalytic metals, including copper, silver, iridium, and palladium, illustrating that this partial oxidation of water broadly influences the reactivity of metal electrodes.

  13. Effects of Nicotinamide on Mouse Skin Tumor Development and lts Mode of Action

    Institute of Scientific and Technical Information of China (English)

    KRISHNA P. GUPTA

    1999-01-01

    Nicotinamide (NA), a naturally occuring vitamin and a protease inhibitor, has been shown to be effective in treating some skin ailments. It inhibits cell proliferation and induces cell differentiation. This report shows the effects of NA on mouse skin tumor development and on the critical events involved in this process. NA reduced tumor growth, inhibited the 12-O-tetradecanoylphorbol- 13-acetate (TPA) induced ornithine decarboxylase activity, but induced the transglutaminase activity which was inhibited by TPA under different experimental conditions.The effects of NA on ornithine decarboxylase (ODC) and transglutaminase (TG) indicated that nicotinamide (NA) probably programmmed the cells for their death in the natural course of time, I.e. Programed cell death. This observation indicates that NA might be a better agent for the detailed study and for the better use in prevention of cancer alone or in combination with other drugs.

  14. ON THE SOURCE OF ASTROMETRIC ANOMALOUS REFRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, M. Suzanne [Department of Natural and Environmental Sciences, Western State Colorado University, 128 Hurst Hall, Gunnison, CO 81230 (United States); McGraw, John T.; Zimmer, Peter C. [Department of Physics and Astronomy, University of New Mexico, MSC07 4220, Albuquerque, NM 87131 (United States); Pier, Jeffrey R., E-mail: mstaylor@western.edu [Division of Astronomical Sciences, NSF 4201 Wilson Blvd, Arlington, VA 22230 (United States)

    2013-03-15

    More than a century ago, astronomers using transit telescopes to determine precise stellar positions were hampered by an unexplained periodic shifting of the stars they were observing. With the advent of CCD transit telescopes in the past three decades, this unexplained motion, termed 'anomalous refraction' by these early astronomers, is again being observed. Anomalous refraction is described as a low-frequency, large angular scale ({approx}2 Degree-Sign ) motion of the entire image plane with respect to the celestial coordinate system as observed and defined by astrometric catalogs. These motions, of typically several tenths of an arcsecond amplitude with timescales on the order of 10 minutes, are ubiquitous to ground-based drift-scan astrometric measurements regardless of location or telescopes used and have been attributed to the effect of tilting of equal-density layers of the atmosphere. The cause of this tilting has often been attributed to atmospheric gravity waves, but this cause has never been confirmed. Although theoretical models of atmospheric refraction show that atmospheric gravity waves are a plausible cause of anomalous refraction, an observational campaign specifically directed at defining this relationship provides clear evidence that anomalous refraction is not consistent with the passage of atmospheric gravity waves. The source of anomalous refraction is found to be meter-scale, slowly evolving quasi-coherent dynamical structures in the boundary layer below 60 m above ground level.

  15. On the Source of Astrometric Anomalous Refraction

    Science.gov (United States)

    Taylor, M. Suzanne; McGraw, John T.; Zimmer, Peter C.; Pier, Jeffrey R.

    2013-03-01

    More than a century ago, astronomers using transit telescopes to determine precise stellar positions were hampered by an unexplained periodic shifting of the stars they were observing. With the advent of CCD transit telescopes in the past three decades, this unexplained motion, termed "anomalous refraction" by these early astronomers, is again being observed. Anomalous refraction is described as a low-frequency, large angular scale (~2°) motion of the entire image plane with respect to the celestial coordinate system as observed and defined by astrometric catalogs. These motions, of typically several tenths of an arcsecond amplitude with timescales on the order of 10 minutes, are ubiquitous to ground-based drift-scan astrometric measurements regardless of location or telescopes used and have been attributed to the effect of tilting of equal-density layers of the atmosphere. The cause of this tilting has often been attributed to atmospheric gravity waves, but this cause has never been confirmed. Although theoretical models of atmospheric refraction show that atmospheric gravity waves are a plausible cause of anomalous refraction, an observational campaign specifically directed at defining this relationship provides clear evidence that anomalous refraction is not consistent with the passage of atmospheric gravity waves. The source of anomalous refraction is found to be meter-scale, slowly evolving quasi-coherent dynamical structures in the boundary layer below 60 m above ground level.

  16. Therapeutic Effects of Erythroid Differentiation Regulator 1 on Imiquimod-Induced Psoriasis-Like Skin Inflammation.

    Science.gov (United States)

    Kim, Kyung Eun; Houh, Younkyung; Park, Hyun Jeong; Cho, Daeho

    2016-02-17

    Psoriasis is a common skin disease accompanied by chronic inflammation. In previous studies, erythroid differentiation regulator 1 (ERDR1) was shown to have a negative correlation with proinflammatory cytokine IL-18. However, the role of ERDR1 in the inflammatory skin disease psoriasis has not been evaluated. In this study, to investigate the role of ERDR1 in psoriasis, recombinant ERDR1 was injected intraperitoneally into a psoriasis mouse model. Recombinant ERDR1 (rERDR1) significantly alleviated the symptoms of psoriasis-like skin inflammation and reduced the mRNA of various psoriasis-related markers, including keratin 14, S100A8, and Th17-related cytokines IL-17 and IL-22, suggesting that rERDR1 exerts therapeutic effects on psoriasis via the regulation of Th17 functions. Additionally, the expression of CCL20, a well-known Th17 attracting chemokine, was determined. CCL20 expression significantly decreased in the rERDR1-injected group compared with the vehicle (PBS)-injected group. CCR6 expression in the psoriatic lesional skin was also decreased by rERDR1 administration, implying the inhibition of CCR6-expressing Th17 cell chemotaxis via the downregulation of CCL20. Taken together, this study provides the first evidence that ERDR1 may be a potential therapeutic target for psoriasis.

  17. Effect of Localized Mechanical Indentation on Skin Water Content Evaluated Using OCT

    Directory of Open Access Journals (Sweden)

    Abhijit A. Gurjarpadhye

    2011-01-01

    Full Text Available The highly disordered refractive index distribution in skin causes multiple scattering of incident light and limits optical imaging and therapeutic depth. We hypothesize that localized mechanical compression reduces scattering by expulsing unbound water from the dermal collagen matrix, increasing protein concentration and decreasing the number of index mismatch interfaces between tissue constituents. A swept-source optical coherence tomography (OCT system was used to assess changes in thickness and group refractive index in ex vivo porcine skin, as well as changes in signal intensity profile when imaging in vivo human skin. Compression of ex vivo porcine skin resulted in an effective strain of −58.5%, an increase in refractive index from 1.39 to 1.50, and a decrease in water volume fraction from 0.66 to 0.20. In vivo OCT signal intensity increased by 1.5 dB at a depth of 1 mm, possibly due to transport of water away from the compressed regions. These finding suggest that local compression could be used to enhance light-based diagnostic and therapeutic techniques.

  18. Effect of Red Clover Isoflavones over Skin, Appendages, and Mucosal Status in Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    Markus Lipovac

    2011-01-01

    Full Text Available Objective. Evaluate in postmenopausal women the effect of red clover extract (RCE isoflavones over subjective status of skin, appendages, and several mucosal sites. Method. Postmenopausal women (n=109 were randomly assigned to receive either two daily capsules of the active compound (80 mg RCE, Group A or placebo of equal appearance (Group B for a 90-day period. After a washout period of 7 days, medication was crossed over and taken for 90 days more. Subjective improvement of skin, appendages, and several mucosal site status was assessed for each studied group at 90 and 187 days using a visual analogue scale (VAS. In addition, libido, tiredness, and urinary, sleep, and mood complaints were also evaluated. Results. Women after RCE intervention (both groups reported better subjective improvement of scalp hair and skin status, libido, mood, sleep, and tiredness. Improvement of urinary complaints, nail, body hair, and mucosa (oral, nasal, and ocular status did not differ between treatment phases (intra- and intergroup. Overall satisfaction with treatment was reported higher after RCE intervention (both groups as compared to placebo. Conclusion. RCE supplementation exerted a subject improvement of scalp hair and skin status as well as libido, mood, sleep, and tiredness in postmenopausal women.

  19. Therapeutic Effects of Erythroid Differentiation Regulator 1 on Imiquimod-Induced Psoriasis-Like Skin Inflammation

    Directory of Open Access Journals (Sweden)

    Kyung Eun Kim

    2016-02-01

    Full Text Available Psoriasis is a common skin disease accompanied by chronic inflammation. In previous studies, erythroid differentiation regulator 1 (ERDR1 was shown to have a negative correlation with proinflammatory cytokine IL-18. However, the role of ERDR1 in the inflammatory skin disease psoriasis has not been evaluated. In this study, to investigate the role of ERDR1 in psoriasis, recombinant ERDR1 was injected intraperitoneally into a psoriasis mouse model. Recombinant ERDR1 (rERDR1 significantly alleviated the symptoms of psoriasis-like skin inflammation and reduced the mRNA of various psoriasis-related markers, including keratin 14, S100A8, and Th17-related cytokines IL-17 and IL-22, suggesting that rERDR1 exerts therapeutic effects on psoriasis via the regulation of Th17 functions. Additionally, the expression of CCL20, a well-known Th17 attracting chemokine, was determined. CCL20 expression significantly decreased in the rERDR1-injected group compared with the vehicle (PBS-injected group. CCR6 expression in the psoriatic lesional skin was also decreased by rERDR1 administration, implying the inhibition of CCR6-expressing Th17 cell chemotaxis via the downregulation of CCL20. Taken together, this study provides the first evidence that ERDR1 may be a potential therapeutic target for psoriasis.

  20. Effects of diltiazem on skinned skeletal muscle fibers of the African clawed toad.

    Science.gov (United States)

    Ishizuka, T; Endo, M

    1983-02-01

    To examine the effects of diltiazem and its l-cis isomer (which possesses only a weak Ca++-antagonistic action) on the contractile system and the sarcoplasmic reticulum of skeletal muscle, we used skinned fibers isolated from iliofibularis muscle of the African clawed toad, Xenopus laevis. Diltiazem showed the following effects: an increase in the Ca++ sensitivity of the contractile system, a decrease in the maximal tension developed in a saturating concentration of Ca++, an inhibition of Ca++ uptake by the sarcoplasmic reticulum, an inhibition of Ca++ release from the sarcoplasmic reticulum by caffeine, and an increase in the Ca++ permeability of the sarcoplasmic reticulum membrane. The effects of the l-cis isomer were similar to those of diltiazem, and the potencies of the two substances were nearly equal, except with respect to the effect on the Ca++ release induced by caffeine: the l-cis isomer potentiated this type of Ca++ release. Diltiazem's effects on amphibian skinned skeletal muscle fibers may not be related qualitatively or quantitatively to the Ca++-antagonistic actions of the drug on mammalian cardiac and smooth muscles. The pharmacological spectrum of diltiazem on skinned skeletal muscle fibers is similar to that of some local anesthetics.

  1. The Glutathione Derivative, GSH Monoethyl Ester, May Effectively Whiten Skin but GSH Does Not

    Directory of Open Access Journals (Sweden)

    Bo Young Chung

    2016-04-01

    Full Text Available Glutathione in its reduced form (GSH is an antioxidant and also is involved in pheomelanin formation. Thus, it has been long believed that GSH has a skin whitening effect. However, its actual or direct effect is unproven. We evaluated the anti-melanogenic effects of GSH and its derivatives in vitro. We examined change of melanogenesis and its related proteins by GSH itself and its derivatives, including GSH monoethyl ester (GSH-MEE, GSH diethyl ester (GSH-DEE and GSH monoisopropyl ester (GSH-MIPE in Melan-A cells, Mel-Ab cells, and B16F10 cells. GSH and GSH-MEE did not display cytotoxic activity, but GSH-MIPE and GSH-DEE did. Intriguingly, GSH itself had no inhibitory effect on melanin production or intracellular tyrosinase activity. Rather, it was GSH-MEE and GSH-MIPE that profoundly reduced the amount of melanin and intracellular tyrosinase activity. Thus, GSH-MEE was selected as a suitable candidate skin-whitening agent and it did not alter melanogenesis-associated proteins such as microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein (TRP-1, and TRP-2, but it did increase the amount of suggested pheomelanin and suggested pheomelanin/eumelanin ratio. GSH-MEE was effective for anti-melanogenesis, whereas GSH itself was not. GSH-MEE could be developed as a safe and efficient agent for the treatment of hyperpigmentation skin disorders.

  2. [Effective and safe pharmacotherapy of acne vulgaris and treatment of sun-damaged skin].

    Science.gov (United States)

    Fendrich, Z; Jandová, E; Finsterlová, M

    2000-03-01

    An inevitable condition for the pharmacist is a basic knowledge of dermatological changes which are prominent in acne and solar impairment of the skin to be able to recommend in a qualified manner an effective and safe treatment to the patient. However, sufferers of the more serious forms of acne should always be referred to their general practitioner, or preferentially a dermatologist. Acne vulgaris is an androgen-induced disorder, but three major mechanisms for the development of the disease have been identified: hypertrophy of the sebaceous gland, hyperkatosis of the follicular epithelium, and proliferation of microbial flora, particularly Propionibacterium acnes. The basis of all lesions is the microcomedone which is developed into the ripe comedone. Inflammatory lesions are thought to be due to proliferation of P. acnes. In the selfmedication of common acne, benzoyl peroxide, which in a 5-10% lotion exerts antimicrobial and keratolytic properties, proved to be useful. Patients appreciate a lot its instant effect which is visible after just one day of treatment. Salicylic acid is another effective drug, which, when used on the long-term basis, has comedolytic properties; it reduces the number of microcomedones and counteracts plugging of the follicles. In addition, in healthy young women who take oral contraception, a triphasic combined oral preparations of contraceptives with newer progestins, notably with norgestimmate, which is practically free of androgenic effects, are recommended with advantage for the treatment of moderate acne vulgaris without any adverse effects. Solar impairment of the skin, the so-called solar ageing, is clinically indistinguishable from biological ageing. Changes connected with solar impairment appear mostly in the dermis, where solar elastosis develops, the skin gets drier and wrinkle formation appears. For the treatment, hydroxy acids are recommended, namely salicylic acid, which is very effective, because in combination with a

  3. Skin photoprotective and antiageing effects of a combination of rosemary (Rosmarinus officinalis and grapefruit (Citrus paradisi polyphenols

    Directory of Open Access Journals (Sweden)

    Vincenzo Nobile

    2016-07-01

    Full Text Available Background: Plant polyphenols have been found to be effective in preventing ultraviolet radiation (UVR-induced skin alterations. A dietary approach based of these compounds could be a safe and effective method to provide a continuous adjunctive photoprotection measure. In a previous study, a combination of rosemary (Rosmarinus officinalis and grapefruit (Citrus paradisi extracts has exhibited potential photoprotective effects both in skin cell model and in a human pilot trial. Objective: We investigated the efficacy of a combination of rosemary (R. officinalis and grapefruit (C. paradisi in decreasing the individual susceptibility to UVR exposure (redness and lipoperoxides and in improving skin wrinkledness and elasticity. Design: A randomised, parallel group study was carried out on 90 subjects. Furthermore, a pilot, randomised, crossover study was carried out on five subjects. Female subjects having skin phototype from I to III and showing mild to moderate chrono- or photoageing clinical signs were enrolled in both studies. Skin redness (a* value of CIELab colour space after UVB exposure to 1 minimal erythemal dose (MED was assessed in the pilot study, while MED, lipoperoxides (malondialdehyde skin content, wrinkle depth (image analysis, and skin elasticity (suction and elongation method were measured in the main study. Results: Treated subjects showed a decrease of the UVB- and UVA-induced skin alterations (decreased skin redness and lipoperoxides and an improvement of skin wrinkledness and elasticity. No differences were found between the 100 and 250 mg extracts doses, indicating a plateau effect starting from 100 mg extracts dose. Some of the positive effects were noted as short as 2 weeks of product consumption. Conclusions: The long-term oral intake of Nutroxsun™ can be considered to be a complementary nutrition strategy to avoid the negative effects of sun exposure. The putative mechanism for these effects is most likely to take place

  4. Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro

    NARCIS (Netherlands)

    Buist, H.E.; Sandt, J.J.M. van de; Burgsteden, J.A. van; Heer, C. de

    2005-01-01

    The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of repeate

  5. The Effect of Skin Pigmentation on the Accuracy of Pulse Oximetry in Infants with Hypoxemia.

    Science.gov (United States)

    Foglia, Elizabeth E; Whyte, Robin K; Chaudhary, Aasma; Mott, Antonio; Chen, Jodi; Propert, Kathleen J; Schmidt, Barbara

    2017-03-01

    To compare pulse oximetry measurement bias between infants with hypoxemia with either dark skin or light skin with Masimo Radical 7 and Nellcor Oximax. There was no significant difference in systematic bias based on skin pigment for either oximeter.

  6. Minimal flavour violation and anomalous top decays

    Energy Technology Data Exchange (ETDEWEB)

    Faller, Sven; Mannel, Thomas [Theoretische Physik 1, Department Physik, Universitaet Siegen, D-57068 Siegen (Germany); Gadatsch, Stefan [Nikhef, National Institute for Subatomatic Physics, P.O. Box 41882, 1009 Amsterdam (Netherlands)

    2013-07-01

    Any experimental evidence of anomalous top-quark couplings will open a window to study physics beyond the standard model (SM). However, all current flavour data indicate that nature is close to ''minimal flavour violation'', i.e. the pattern of flavour violation is given by the CKM matrix, including the hierarchy of parameters. In this talk we present results of the conceptual test of minimal flavour violation for the anomalous charged as well as flavour changing top-quark couplings. Our analysis is embedded in two-Higgs doublet model of type II (2HDM-II). Including renormalization effects, we calculate the top decay rates taking into account anomalous couplings constrained by minimal flavour violation.

  7. Theory of the Muon Anomalous Magnetic Moment

    CERN Document Server

    Melnikov, Kirill

    2006-01-01

    The theory of the muon anomalous magnetic moment is "particle physics in a nutshell" and as such is interesting, exciting and difficult. The current precision of the experimental value for this quantity, improved significantly in the past several years due to experiment E821 at Brookhaven National Laboratory, is so high that a large number of subtle effects not relevant previously, become important for the interpretation of the experimental result. The theory of the muon anomalous magnetic moment is at the cutting edge of current research in particle physics and includes multiloop calculations in both QED and electroweak theory, precision low-energy hadron physics, isospin violations and scattering of light by light. Any deviation between the theoretical prediction and the experimental value might be interpreted as a signal of an as-yet-unknown new physics. This book provides a comprehensive review of the theory of the muon anomalous magnetic moment.

  8. Anomalous magnetohydrodynamics in the extreme relativistic domain

    CERN Document Server

    Giovannini, Massimo

    2016-01-01

    The evolution equations of anomalous magnetohydrodynamics are derived in the extreme relativistic regime and contrasted with the treatment of hydromagnetic nonlinearities pioneered by Lichnerowicz in the absence of anomalous currents. In particular we explore the situation where the conventional vector currents are complemented by the axial-vector currents arising either from the pseudo Nambu-Goldstone bosons of a spontaneously broken symmetry or because of finite fermionic density effects. After expanding the generally covariant equations in inverse powers of the conductivity, the relativistic analog of the magnetic diffusivity equation is derived in the presence of vortical and magnetic currents. While the anomalous contributions are generally suppressed by the diffusivity, they are shown to disappear in the perfectly conducting limit. When the flow is irrotational, boost-invariant and with vanishing four-acceleration the corresponding evolution equations are explicitly integrated so that the various physic...

  9. Electroweak Baryogenesis with Anomalous Higgs Couplings

    CERN Document Server

    Kobakhidze, Archil; Yue, Jason

    2015-01-01

    We investigate feasibility of efficient baryogenesis at the electroweak scale within the effective field theory framework based on a non-linear realisation of the electroweak gauge symmetry. In this framework the LHC Higgs boson is described by a singlet scalar field, which, therefore, admits new interactions. Assuming that Higgs couplings with the eletroweak gauge bosons are as in the Standard Model, we demonstrate that the Higgs cubic coupling and the CP-violating Higgs-top quark anomalous couplings alone may drive the a strongly first-order phase transition. The distinguished feature of this transition is that the anomalous Higgs vacuum expectation value is generally non-zero in both phases. We identify a range of anomalous couplings, consistent with current experimental data, where sphaleron rates are sufficiently fast in the 'symmetric' phase and are suppressed in the 'broken' phase and demonstrate that the desired baryon asymmetry can indeed be generated in this framework. This range of the Higgs anomal...

  10. The amelioration effect of tranexamic acid in wrinkles induced by skin dryness.

    Science.gov (United States)

    Hiramoto, Keiichi; Sugiyama, Daijiro; Takahashi, Yumi; Mafune, Eiichi

    2016-05-01

    Tranexamic acid (trans-4-aminomethylcyclohexanecarboxylic acid) is a medical amino acid widely used as an anti-inflammatory and a whitening agent. This study examined the effect of tranexamic acid administration in wrinkle formation following skin dryness. We administered tranexamic acid (750mg/kg/day) orally for 20 consecutive days to Naruto Research Institute Otsuka Atrichia (NOA) mice, which naturally develop skin dryness. In these NOA mice, deterioration of transepidermal water loss (TEWL), generation of wrinkles, decrease of collagen type I, and increases in mast cell proliferation and tryptase and matrix metalloproteinase (MMP-1) release were observed. However, these symptoms were improved by tranexamic acid treatment. Moreover, the increase in the β-endorphin level in the blood and the expression of μ-opioid receptor on the surface of fibroblasts increased by tranexamic acid treatment. In addition, when the fibroblasts induced by tranexamic acid treatment were removed, the amelioration effect by tranexamic acid treatment was halved. On the other hand, tranexamic acid treated NOA mice and mast cell removal in tranexamic acid treated NOA mice did not result in changes in the wrinkle amelioration effect. Additionally, the amelioration effect of mast cell deficient NOA mice was half that of tranexamic acid treated NOA mice. These results indicate that tranexamic acid decreased the proliferation of mast cells and increases the proliferation of fibroblasts, subsequently improving wrinkles caused by skin dryness.

  11. Isolation of flavonoids from onion skins and their effects on K562 cell viability

    Directory of Open Access Journals (Sweden)

    Guo-Qing Shi

    2016-04-01

    Full Text Available To investigate the anti-proliferative activity of flavonoids from onion skins, extraction by 50% ethanol (v/v, soxhlet polar fractionation, pH gradient separation, thin-layer chromatography, and recrystallization methods were used to isolate and purify flavonoids from dry onion skins. Anti-proliferative activities of some flavonoids obtained on leukemia K562 cell line were deter-mined by MTT assay. Results showed that flavonoids of onion skins were mainly in form of quercetin, kaempferol, isorhamnetin, apigenin-7-O-β-D-glucopyranoside, quercetin-3-O-β-D-glucopyranoside, kaempferol-7-O-β-D-glucopyranoside and rutin. Quercetin and kaempferol decreased K562 cell viability, and quercetin had stronger effect. However, isorhamnetin and rutin exhibited certain proliferation-promoting effects. It suggests that ortho hydroxyl groups on B ring of onion flavonoids might be the key structural elements of their cytotoxic effects on K562 cells, and hydroxyl groups in position 3 or carbonyl groups in position 4 might be one of the structural effect elements.

  12. Effects of skin-derived precursors on wound healing of denervated skin in a nude mouse model.

    Science.gov (United States)

    Shu, Bin; Xie, Ju-Lin; Xu, Ying-Bin; Lai, Wen; Huang, Yong; Mao, Ren-Xiang; Liu, Xu-Sheng; Qi, Shao-Hai

    2015-01-01

    Denervated skin could result in impaired healing of wounds, such as decubitus ulcers and diabetic foot ulcers. Other studies indicated that cutaneous fiber density is reduced after inner nerve transection and that neuropeptide level depletes after denervation, leading to reduced cell proliferation around the wound and thus wound healing problems. Recent studies have revealed that skin-derived precursors (SKPs), which form a neural crest-related stem cell population in the dermis of skin, participate in cutaneous nerve regeneration. We hypothesized that injecting SKPs into denervated wound promotes healing. A bilateral denervation wound model was established followed by SKP transplantation. The wound healing rate was determined at 7, 14, and 21 d after injury. Cell proliferation activity during wound healing was analyzed by proliferating cell nuclear antigen immunohistochemistry (IHC). Nerve fiber density was measured by S-100 IHC. The contents of nerve growth factor, substance P, and calcitonin gene-related peptide were examined by enzyme-linked immunosorbent assay. The rate of epithelization in the SKP-treated group was faster than that in the control group. Wound cell proliferation and nerve fiber density were obviously higher in the SKP-treated group than in the control group. In addition, the content of neuropeptides was higher in the SKP-treated group than in the control group during wound healing. In conclusion, SKPs can promote denervated wound healing through cell proliferation and nerve fiber regeneration, and can facilitate the release of neuropeptides.

  13. Evaluation of the effect of formalin fixation on skin specimens in dogs and cats

    Directory of Open Access Journals (Sweden)

    Jaimie L. Miller

    2014-03-01

    Full Text Available Skin and subcutaneous tissues are the origin of most common neoplasms affecting dogs, accounting for approximately one third of all tumors encountered in the species. Surgical excision is frequently the best chance for a cure; determining factors influencing the success of excision are vital for surgical management of cases. This work examined the shrinkage of skin of various lengths from three sites in formalin for both dogs and cats. Tissues were measured on the animal (initial measurement, at the time of excision (post-removal, and after formalin fixation (post-fixation. While shrinkage after tissue removal was found in samples from the thorax, abdomen, and rear leg in dogs and from the rear leg in cats, no significant shrinkage due to formalin fixation was detected in any sample except for the thoracic samples from the dog. Therefore, when determining where to make incisions to effect a surgical cure, initial measurements should take into account tissue shrinkage effects.

  14. Food Matrix Effects of Polyphenol Bioaccessibility from Almond Skin during Simulated Human Digestion

    Science.gov (United States)

    Mandalari, Giuseppina; Vardakou, Maria; Faulks, Richard; Bisignano, Carlo; Martorana, Maria; Smeriglio, Antonella; Trombetta, Domenico

    2016-01-01

    The goal of the present study was to quantify the rate and extent of polyphenols released in the gastrointestinal tract (GIT) from natural (NS) and blanched (BS) almond skins. A dynamic gastric model of digestion which provides a realistic simulation of the human stomach was used. In order to establish the effect of a food matrix on polyphenols bioaccessibility, NS and BS were either digested in water (WT) or incorporated into home-made biscuits (HB), crisp-bread (CB) and full-fat milk (FM). Phenolic acids were the most bioaccessible class (68.5% release from NS and 64.7% from BS). WT increased the release of flavan-3-ols (p antioxidant status in the digestion medium, indicating that phenolic compounds could bind protein present in the food matrix. The release of bioactives from almond skins could explain the beneficial effects associated with almond consumption. PMID:27649239

  15. Effect of nisin and doxorubicin on DMBA-induced skin carcinogenesis--a possible adjunct therapy.

    Science.gov (United States)

    Preet, Simran; Bharati, Sanjay; Panjeta, Anshul; Tewari, Rupinder; Rishi, Praveen

    2015-11-01

    In view of the emergence of multidrug-resistant cancer cells, there is a need for therapeutic alternatives. Keeping this in mind, the present study was aimed at evaluating the synergism between nisin (an antimicrobial peptide) and doxorubicin (DOX) against DMBA-induced skin carcinogenesis. The possible tumoricidal activity of the combination was evaluated in terms of animal bioassay observations, changes in hisotological architecture of skin tissues, in situ apoptosis assay (TUNEL assay) and in terms of oxidant and antioxidant status of the skin tissues. In vivo additive effect of the combination was evidenced by larger decreases in mean tumour burden and tumour volume in mice treated with the combination than those treated with the drugs alone. Histological observations indicated that nisin-DOX therapy causes chromatin condensation and marginalisation of nuclear material in skin tissues of treated mice which correlated well with the results of TUNEL assay wherein a marked increase in the rate of apoptosis was revealed in tissues treated with the combination. A slightly increased oxidative stress in response to the adjunct therapy as compared to dox-alone-treated group was revealed by levels of lipid peroxidation (LPO) and nitrite generation in skin tissue-treated mice. An almost similar marginal enhancement in superoxide dismutase levels corresponding with a decrease in catalase activity could also be observed in nisin + DOX-treated groups as compared to nisin and dox-alone-treated groups. These results point towards the possible use of nisin as an adjunct to doxorubicin may help in developing alternate strategies to combat currently developing drug resistance in cancer cells.

  16. Your Skin

    Science.gov (United States)

    ... Room? What Happens in the Operating Room? Your Skin KidsHealth > For Kids > Your Skin Print A A ... are really dead skin cells. continue Bye-Bye Skin Cells These old cells are tough and strong, ...

  17. The effect of ginkgo biloba extract on radiosensitivity of mouse skin and jejunal crypt

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Kyung Hwan; Ha, Sung Whan [Seoul National Univ. Medical College, Seoul (Korea, Republic of)

    1998-06-01

    Ginkgo biloba extract(GBE) is known to increase the peripheral blood circulation. This study was designed to evaluate the effect of GBE on the acute normal tissue radiation reaction. C3H mice were divided into two groups, radiation alone and two doses GBE plus radiation, for both acute skin reaction and jejunal crypt assay. GBE was given i.p. one hour before irradiation with priming dose given one day earlier. Thirty to Fifty Gy for acute skin reaction and 11 to 14 Gy for jejunal crypt were irradiated to right hind leg and whole body, respectively. Radiation doses(RD{sub 50}) for peak skin score of 2.0 were 44.2Gy(40.6-48.2Gy) for radiation alone and 44.4Gy(41.6-47.4Gy) for two doses GBE plus radiation, showing no effect of GBE on acute radiation skin damage. The numbers of regenerating jejunal crypts per circumference were also almost the same for each radiation dose level(p=0.57-0.94), and the mean lethal doses(D{sub o}) were 1.80Gy(1.57-2.09Gy) for radiation alone and 1.88Gy(1.65-2.18Gy) for two doses GBE plus radiation, indicating no effect of GBE on jejunal crypt cell survival after radiation. GBE doesn't increase acute normal tissue radiation reaction in this model system. As GBE was verified to enhance radiation effect on tumor, high therapeutic gain is expected when GBE is combined with radiation therapy.

  18. Studies on the Effects of Deltamethrin on Sodium Net Transport Through the in vivo Amphibian Skin

    Institute of Scientific and Technical Information of China (English)

    ALFREDOSALIBIAN; JOSEL.MARAZZO

    1995-01-01

    The action of micromolar concentrations of Deltamethrin on sodium net transport through the in vivo skin of the South American toad Bufo arenarum was studied.The effect or pure ethanolic insecticide solutions and commercial formulations when applied on the mucosal surface was assayed.Deltamethrin provoked a concentration-independent inhibition;the highest inhibition was found at the lowest concentrations.At highest concentrations of the insecticide the Jn Na was not altered.

  19. The impact of skin decontamination on the time window for effective treatment of percutaneous VX exposure.

    Science.gov (United States)

    Joosen, M J A; van den Berg, R M; de Jong, A L; van der Schans, M J; Noort, D; Langenberg, J P

    2017-04-01

    The main goal of the present study was to obtain insight into depot formation and penetration following percutaneous VX poisoning, in order to identify an appropriate decontamination window that can enhance or support medical countermeasures. The study was executed in two phases, using the hairless guinea pig as an animal model. In the first phase the effect of various decontamination regimens on levels of free VX in skin and plasma were studied as well as on blood cholinesterase levels. Animals were exposed to 0.5 mg/kg VX and were not decontaminated (control), decontaminated with RSDL once at 15 or 90 min after exposure or three times at 15, 25 and 35 (10-min interval) or 15, 45 and 75 min after exposure (30-min interval). There was no significant effect of any of the decontamination regimens on the 6-h survival rate of the animals. However, all animals that had been decontaminated 15 min after exposure, showed a survival rate of more than 90%, compared to 50-60% in animals that were not decontaminated or decontaminated at 90 min after exposure. In the second phase of the study, hairless guinea pigs were exposed to 1 mg/kg VX on the shoulder, followed either by decontamination with RSDL (10 min interval), conventional treatment on indication of clinical signs or a combination thereof. It appeared that a thorough, repeated decontamination alone could not save the majority of the animals. A 100% survival rate was observed in the group that received a combination of decontamination and treatment. In conclusion, the effects of VX exposure could be influenced by various RSDL decontamination regimens. The results in freely moving animals showed that skin decontamination, although not fully effective in removing all VX from the skin and skin depot is crucial to support pharmacological intervention.

  20. Transdermal glyceryl trinitrate (nitroglycerin in healthy persons: acute effects on skin temperature and hemodynamic orthostatic response

    Directory of Open Access Journals (Sweden)

    Eva Maria Augusta Boeckh Haebisch

    Full Text Available In order to find an explanation for individual reactions to transdermal glyceryl trinitrate (GTN we studied the skin temperature and hemodynamic reactions in 63 healthy persons. The data were obtained before and after the application of GTN and Glycerin (GL placebo patches, during one hour. The skin temperature was measured on both forearms, the local (left sided and systemic (right sided reaction on GTN was related to the skin fold and the calculated body fat content. The bilateral rise of skin temperature and its duration was higher and longer in obese than in lean persons mainly in obese women. The UV induced thermo and the later photothermoreaction (Erythema was reduced on the left forearm after the application of GTN and GL patches. The observed hemodynamic GTN effect confirmed known postural reactions, such as decreased arterial pressure (ΔmAP = -2.9%, increased heart rate (ΔHR = +7,4% and QTc prolongation (ΔQTc = +4,9% in upright position. An adverse drug effect with increased mean blood pressure (ΔmAP = +12% and increased heart rate (ΔHR = + 10.4% mainly in supine position was observed in 11 % of the participants, but only in men. Such a reaction was already described by Murell, 1879. Individual GTN effects were analyzed and related to habits and family history. In male smokers and in persons with hypertensive and diabetic close relatives, the hypotensive GTN effect was accentuated in supine position. In the upright position the group with hypertensives in the family presented a moderate hypotensive reaction without secondary tachycardia and the smokers presented only a slightly increased heart rate. Our observations suggest that individual reactions to transdermal glyceryl trinitrate (GTN with its active component nitric oxide (NO depends on physiological conditions, related to endogenous vasoactive substances, mainly the interaction with EDRF (the endogenous NO and the activity of the Renin-Angiotensin System.

  1. Influence of the skin effect and current risetime on the fragmentation of wires by pulsed currents

    Science.gov (United States)

    Wall, D. P.; Allen, J. E.; Molokov, S.

    2005-07-01

    This study considers the physical phenomenon whereby wires may fragment in the solid state when subject to a sufficiently high pulsed electric current. A mathematical model is constructed within continuum mechanics which considers both Lorentz force and thermal mechanisms for the creation of stress waves in a wire. Previous studies are extended by including the skin effect, that is allowing for the diffusion of current density across the wire, and also investigating the influence of current risetime. Axisymmetric solutions are sought for rigid-lubricated, clamped, and free wire ends. Analytical solutions are obtained for the case of rigid-lubricated wire ends, while for the other cases the governing equations are solved numerically using an application-specific explicit finite-difference scheme, which is staggered in time and space. The inclusion of the skin effect leads to significant qualitative and quantitative differences in results. For example, in some cases we find tension in the longitudinal (τzz) stress component, which experiments suggest to be responsible for the fragmentation process, while the uniform-current model predicts compression. In most cases, the inclusion of the skin effect leads to higher peak tensile τzz stresses. Some understanding of the present results is gained with reference to analytical quasistatic solutions. Stresses generated by the Lorentz force mechanism are found to be more sensitive than those generated by the thermal mechanism to the current risetime. In both cases axial stresses increase with decreasing current risetime. Despite the differences in the results obtained with the inclusion of the skin effect, our results support the broad conclusions of the uniform-current model results; the largest stresses are found at the clamps for a wire with clamped ends, while the largest stresses in a wire with free ends are generated by the thermal mechanism and are located at the center of the wire.

  2. Protective effect of transparent film dressing on proton therapy induced skin reactions

    Directory of Open Access Journals (Sweden)

    Whaley Jonathan T

    2013-01-01

    Full Text Available Abstract Objective Proton therapy can result in clinically significant radiation dermatitis. In some clinical scenarios, such as lung or breast cancer, the risk of severe radiation dermatitis may limit beam arrangement and prescription doses. Patients undergoing proton therapy for prostate cancer commonly develop mild radiation dermatitis. Herein, we report the outcomes of two prostate cancer patients whose radiation dermatitis appears to have been substantially diminished by transparent film dressings (Beekley stickers. Methods This is a descriptive report of the skin toxicity observed in two patients undergoing proton therapy for prostate cancer at a single institution in 2011. A phantom dosimetric study was performed to evaluate the impact of a transparent film dressing on a beam’s spread out Bragg peak (SOBP. Results Two patients with low risk prostate cancer were treated with proton therapy to a total dose of 79.2Gy (RBE in 1.8 Gy (RBE fractions using two opposed lateral beams daily. Both patients had small circular (2.5 cm diameter transparent adhesive markers placed on their skin to assist with daily alignment. Patient 1 had markers in place bilaterally for the entirety of treatment. Patient 2 had a marker in place for three weeks on one side and six weeks on the other. Over the course of therapy, both men developed typical Grade 1 radiation dermatitis (asymptomatic erythema on their hips; however, in both patients, the erythema was substantially decreased beneath the markers. Patient 2 demonstrated less attenuation and thus greater erythema in the skin covered for three weeks compared to the skin covered for six weeks. The difference in skin changes between the covered and uncovered skin persisted for at least 1 month. A phantom study of double scattered beam SOBP with and without the marker in the beam path showed no gross dosimetric effect. Conclusions Transparent adhesive markers appear to have attenuated radiation dermatitis in

  3. The effect of neutron skin on inclusive prompt photon production in Pb + Pb collisions at Large Hadron Collider energies

    Science.gov (United States)

    De, Somnath

    2017-04-01

    Recent experiments on lead ({{{Pb}}}82208) nuclei have observed the celebrated phenomenon of the neutron skin thickness of low energy nuclear physics. Skin thickness provides a measure of the extension of the spatial distribution of neutrons inside the atomic nucleus than protons. We have studied the effect of neutron skin thickness on inclusive prompt photon production in Pb + Pb collisions at Large Hadron Collider energies. We have calculated the ‘central-to-peripheral ratio’ ({R}{cp}) of prompt photon production with and without accounting for the neutron skin effect. The neutron skin causes a characteristic enhancement of the ratio, in particular at forward rapidity, which is distinguishable in our calculation. However, a very precise direct photon measurement up to large transverse momenta would be necessary to constrain the feature in experiment.

  4. The effect of neutron skin on inclusive prompt photon production in Pb~+~Pb collisions at the LHC

    CERN Document Server

    De, Somnath

    2016-01-01

    Recent experiments on lead (\\textrm{$Pb_{82}^{208}$}) nuclei have observed the celebrated phenomenon of neutron skin-thickness of low energy nuclear physics. The skin-thickness provides a measure of extension of spatial distribution of neutrons inside the atomic nucleus than protons. We have studied the effect of neutron skin-thickness on inclusive prompt photon production in Pb~+~Pb collisions at the Large Hadron Collider energies. We have calculated the \\textquoteleft central-to-peripheral ratio\\textquoteright ($R_\\textrm{cp}$) of prompt photon production with and without accounting for neutron skin effect. The neutron skin causes a characteristic enhancement in the ratio, in particular at forward rapidity, which is distinguishable in our calculation. However a very precise direct photon measurement up to large transverse momenta would be necessary to constrain the feature in experiment.

  5. Antibacterial effects of protruding and recessed shark skin micropatterned surfaces of polyacrylate plate with a shallow groove.

    Science.gov (United States)

    Sakamoto, Akihiko; Terui, Yusuke; Horie, Chihiro; Fukui, Takashi; Masuzawa, Toshiyuki; Sugawara, Shintaro; Shigeta, Kaku; Shigeta, Tatsuo; Igarashi, Kazuei; Kashiwagi, Keiko

    2014-12-01

    Antibacterial effects in terms of biofilm formation and swarming motility were studied using polyacrylate plates having protruding or recessed shark skin micropatterned surfaces with a shallow groove (2 μm pattern width and spacing, 0.4 μm pattern height). It was found that biofilm formation and swarming motility of Pseudomonas aeruginosa were strongly inhibited by the shark skin pattern plates with a shallow (0.4 μm) pattern height. Biofilm formation of Staphylococcus aureus was also strongly inhibited. Live bacteria were located on the pattern rather than in the spacing. When the shape of pattern was a linear ridge instead of shark skin, the antibacterial effects were weaker than seen with the shark skin pattern. The results indicate that the pattern of shark skin is important for decreasing bacterial infection even with a shallow feature height.

  6. Effect of balanced low pressure drying of curcuma longa leaf on skin immune activation activities.

    Science.gov (United States)

    Choi, Wooseok; Lim, Hye Won; Lee, Hyeon Yong

    2014-01-01

    The effect of balanced low pressure drying pretreatment associated with ultrasonication extraction (BU) on the enhancement of skin immune modulatory activities of Curcuma longa leaf was studied by comparing with conventional hot air drying (HE), freeze drying (FE) and balanced low pressure drying (BE) pretreatment processes. In considering skin immune activation activities such as the inhibition of hyaluronidase activity, the BU extract showed ca. 10% higher than those of HE, and even higher than that of the FE extract. Nitric oxide production from macrophage of the BU extract in adding 1.0 mg/mL was increased up to 16.5 μM. When measuring inhibition of IL-6 and TNF-a production from the human T lymphocytes (T cell), the BU extract also showed 53% and 78% of inhibition effect, respectively. It is found that the BU extract could effectively suppress the expression levels of skin inflammation related genes such as Cox-2 and iNOS, down to 80% and 85% compared to the control, respectively. Balanced low pressure drying process was especially active on dehydration of the leaves with minimizing the destruction and making easier elution of the bioactive substances, which resulted in higher extraction yield and better biological activities.

  7. Neutron-skin effect and centrality dependence of high-$p_{\\mathrm{T}}$ observables in nuclear collisions

    CERN Document Server

    Helenius, Ilkka; Eskola, Kari J

    2016-01-01

    We report on our studies of the neutron-skin effects in high-$p_{\\mathrm{T}}$ observables at the LHC. We study the impact of the neutron-skin effect on the centrality dependence of inclusive direct photon, high-$p_{\\mathrm{T}}$ hadron and $W^{\\pm}$ production in nuclear collisions at the LHC. The neutron-skin effect refers to the observation that in spherical heavy nuclei, the tail of the neutron distribution extends farther than the distribution of protons, which can affect observables sensitive to electroweak phenomena in very peripheral collisions. We quantify this effect for direct photons, charged hadrons and W bosons as a function of the collision centrality. In the case of direct photons we find that it will be difficult to resolve the neutron-skin effect, given the uncertainties in the nuclear PDFs and their spatial dependence. With charged hadrons and W's, however, up to 20~\\% unambiguous effects are expected for most peripheral collisions.

  8. Effect of Substance P in Staphylococcus aureus and Staphylococcus epidermidis virulence: Implication for skin homeostasis

    Directory of Open Access Journals (Sweden)

    Awa eNdiaye

    2016-04-01

    Full Text Available Staphylococcus aureus and Staphylococcus epidermidis are two major skin associated bacteria, and Substance P (SP is a major skin neuropeptide. Since bacteria are known to sense and response to many human hormones, we investigated the effects of SP on Staphylococci virulence in reconstructed human epidermis model and HaCaT keratinocytes. We show that SP is stimulating the virulence of Staphylococcus aureus and Staphylococcus epidermidis in a reconstructed human epidermis model. qRT-PCR array analysis of 64 genes expressed by keratinocytes in the response to bacterial infection revealed a potential link between the action of SP on Staphylococci and skin physiopathology. qRT-PCR and direct assay of cathelicidin and human β-defensin 2 secretion also provided that demonstration that the action of SP on bacteria is independent of antimicrobial peptide expression by keratinocytes. Considering an effect of SP on S. aureus and S. epidermidis, we observed that SP increases the adhesion potential of both bacteria on keratinocytes. However, SP modulates the virulence of S. aureus and S. epidermidis through different mechanisms. The response of S. aureus is associated with an increase in Staphylococcal Enterotoxin C2 (SEC2 production and a reduction of exolipase processing whereas in S. epidermidis the effect of SP appears mediated by a rise in biofilm formation activity. The Thermo unstable ribosomal Elongation factor Ef-Tu was identified as the SP-interacting protein in S. aureus and S. epidermidis. SP appears as an inter-kingdom communication factor involved in the regulation of bacterial virulence and essential for skin microflora homeostasis.

  9. A new method to evaluate the effects of shear on the skin.

    Science.gov (United States)

    de Wert, Luuk A; Bader, Dan L; Oomens, Cees W J; Schoonhoven, Lisette; Poeze, Martijn; Bouvy, Nicole D

    2015-01-01

    Currently, pressure ulcer preventive strategies focus mainly on pressure redistribution. Little attention is paid to reduce the harmful effects of shear-force, because little is known about pathophysiological aspects of shear-force. Even today, no method to measure the effects of shear-force on the skin is available. Therefore, the aim of this study was to investigate the response to shear-forces in terms of analyzing a noninvasive biomarker and reactive hyperemic parameter measured at the skin of healthy participants. A physical model was developed to produce a combination of pressure and shear or pressure alone on the skin. Ten healthy male participants were included and pressure (3.9 kPa) and a combined loading of pressure and shear (2.4 kPa + 14.5 N) was applied at the volar aspect of the forearms for 15 and 30 minutes. A Sebutape sample was used to collect IL-1α and total protein (TP) noninvasively. The reactive hyperemic parameter was derived from a laser Doppler flowmeter. The increase in IL-1α/TP-ratio after a combined loading of pressure and shear for 30 minutes of 6.2 ± 2.5 was significantly higher compared with all other test conditions (p < 0.05). The increase in cutaneous blood cell flux was already significantly higher when a combined loading of pressure and shear was applied for 15 minutes compared with pressure alone. These results shows that the IL-1α/TP-ratio and cutaneous blood cell flux can be used as robust measures of the effect of shear-force on skin in humans. Therefore, this model can be used to evaluate materials aimed at the reduction of shear.

  10. Anomalous atomic volume of alpha-Pu

    DEFF Research Database (Denmark)

    Kollar, J.; Vitos, Levente; Skriver, Hans Lomholt

    1997-01-01

    .3%. The comparison between the LDA and GGA results show that the anomalously large atomic volume of alpha-Pu relative to alpha-Np can be ascribed to exchange-correlation effects connected with the presence of low coordinated sites in the structure where the f electrons are close to the onset of localization...

  11. Beta Function and Anomalous Dimensions

    CERN Document Server

    Pica, Claudio

    2010-01-01

    We demonstrate that it is possible to determine the coefficients of an all-order beta function linear in the anomalous dimensions using as data the two-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows to determine the anomalous dimension of the fermion masses at the infrared fixed point, and the resulting values compare well with the lattice determinations.

  12. Anomalous Dimensions of Conformal Baryons

    CERN Document Server

    Pica, Claudio

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small for a wide range of number of flavours. We also find that this is always smaller than the anomalous dimension of the fermion mass operator. These findings challenge the partial compositeness paradigm.

  13. Effects of Ionizing Radiation on Murine Gene Expression in Skin and Bone

    Science.gov (United States)

    Terada, Masahiro; Schreurs, Ann-Sofie; Shirazi-Fard, Yasaman; Alwood, Joshua; Tahimic, Candice; Sowa, Marianne B.; Globus, Ruth K.

    2017-01-01

    Long duration spaceflight causes a negative calcium balance and reduces bone density in astronauts. The potential for exposure to space radiation to contribute to lasting decrements in bone mass is not yet understood. Sustained changes to bone mass have a relatively long latency for development, however skin is a radiation sensitive organ and changes in skin gene expression may serve as an early radiation biomarker of exposures and may correlate with adverse effects on skeletal tissue. Previous studies have shown that FGF18 gene expression levels of hair follicles collected from astronauts on the ISS rose over time. In the hair follicle, FGF18 signaling mediates radioresistance in the telogen by arresting the cell cycle, and FGF18 has the potential to function as a radioprotector. In bone, FGF18 appears to regulate cell proliferation and differentiation positively during osteogenesis and negatively during chondrogenesis. Cellular defense responses to radiation are shared by a variety of organs, hence in this study, we examined whether radiation induced gene expression changes in skin may be predictive of the responses of skeletal tissue to radiation exposure. We have examined oxidative stress and growth arrest pathways in mouse skin and long bones by measuring gene expression levels via quantitative polymerase chain reaction (qPCR) after exposure to total body irradiation (TBI). To investigate the effects of irradiation on gene expression, we used skin and femora (cortical shaft) from the following treatment groups: control (normally loaded, sham-irradiated), and TBI (0.5 Gy Fe-56 600 MeV/n and 0.5 Gy H-1 150 MeV/n). Animals were euthanized one and 11 days post-IR. Statistical analysis was performed via a Student's ttest. In skin samples one day after IR, skin expression of FGF18 was significantly greater (3.8X) than sham-irradiated controls (3.8X), but did not differ 11 days post TBI. Expression levels of other radiation related genes (Nfe2l2, Trp53, Cdkn1a, FoxO3

  14. Effect of Enhancers on in vitro and in vivo Skin Permeation and Deposition of S-Methyl-L-Methionine.

    Science.gov (United States)

    Kim, Ki Taek; Kim, Ji Su; Kim, Min-Hwan; Park, Ju-Hwan; Lee, Jae-Young; Lee, WooIn; Min, Kyung Kuk; Song, Min Gyu; Choi, Choon-Young; Kim, Won-Serk; Oh, Hee Kyung; Kim, Dae-Duk

    2017-03-10

    S-methyl-L-methionine (SMM), also known as vitamin U, is commercially available as skin care cosmetic products for its wound healing and photoprotective effects. However, the low skin permeation expected of SMM due to its hydrophilic nature with a log P value of -3.3, has not been thoroughly addressed. The purpose of this study thus was to evaluate the effect of skin permeation enhancers on the skin permeation/deposition of SMM. Among the enhancers tested for the in vitro skin permeation and deposition of SMM, oleic acid showed the most significant enhancing effect. Moreover, the combination of oleic acid and ethanol further enhanced in vitro permeation and deposition of SMM through hairless mouse skin. Furthermore, the combination of oleic acid and ethanol significantly increased the in vivo deposition of SMM in the epidermis/dermis for 12 hr, which was high enough to exert a therapeutic effect. Therefore, based on the in vitro and in vivo studies, the combination of oleic acid and ethanol was shown to be effective in improving the topical skin delivery of SMM, which may be applied in the cosmetic production process for SMM.

  15. Anomalous radiative transitions

    CERN Document Server

    Ishikawa, Kenzo; Tobita, Yutaka

    2014-01-01

    Anomalous transitions involving photons derived by many-body interaction of the form, $\\partial_{\\mu} G^{\\mu}$, in the standard model are studied. This does not affect the equation of motion in the bulk, but makes wave functions modified, and causes the unusual transition characterized by the time-independent probability. In the transition probability at a time-interval T expressed generally in the form $P=T \\Gamma_0 +P^{(d)}$, now with $\\Gamma_0=0, P^{(d)} \

  16. Effect of uranium on proliferation and mortality of the major constitutive cell types of the skin: influence on skin barrier integrity

    Energy Technology Data Exchange (ETDEWEB)

    Petitot, F.; Spessotto, S.; Paquet, F. [Inst. de Radioprotection et de Surete Nucleaire, Lab. de Radiotoxicologie Experimentale, IRSN/DRPH/SRBE/LRTOX, Site du Tricastin - Pierrelatte (France)

    2005-07-01

    The skin is the initial barrier against mechanical, chemical or biological external stresses. It is a complex, multilayered organ. The upper layer is the epidermis that is mainly constituted by keratinocytes. The fibroblast is the major cell type of the dermis which is underlying the epidermis. In the case of an external contamination, uranium is able to diffuse through the skin [1-3] and can affect skin barrier integrity after chronic topical exposure[1, 3]. Our study tried to elucidate the cellular mechanisms leading to this skin alteration after uranyl nitrate contamination. Proliferation rate and mortality of primary cultures of rat skin fibroblasts and keratinocytes contaminated in vitro with different concentration of depleted-uranyl nitrate or 233-uranyl nitrate were measured. The huge difference between {sup 233}U and depleted-U specific activities, respectively 3.57 x 10{sup 8}Bq.g{sup -1} and 1.45 x 10{sup 4}Bq.g{sup -1}', allowed to distinguish cellular radiotoxicity and chemotoxicity of uranium. Concerning fibroblasts, a significant radiotoxicity of the emitted alpha particles of {sup 233}U was observed with no chemotoxicity for the lowest concentrations, i.e. 2{mu}M and 4{mu}M, of uranyl nitrate. Keratinocytes were more sensitive to both uranium radiotoxicity and chemotoxicity than fibroblasts. This can be explained by the about three times higher ability of keratinocytes to incorporate uranium compared to fibroblasts. This greater capacity of epidermal cells than dermal cells to incorporate uranium was confirmed in vivo for the hairless rat following a uranyl nitrate topical contamination. As a conclusion, the important toxic effect of uranium on keratinocyte demonstrated in our study can explain the previous observations [1, 3] that epidermis was atrophied and so skin permeability increased after an in vivo chronic topical exposure of rat skin to uranyl nitrate. These results are of great importance concerning radiation protection of exposed

  17. Effect of low-power red light laser irradiation on the viability of human skin fibroblast

    Energy Technology Data Exchange (ETDEWEB)

    Bednarska, K.; Rozga, B.; Leyko, W.; Bryszewska, M. [Institute of Biophysics, University of Lodz (Poland); Kolodziejczyk, K.; Szosland, D. [Diabetological Clinic, Medical Academy of Lodz (Poland)

    1998-10-01

    Human skin fibroblast monolayers (S-126 cell line) were exposed to laser radiation (wavelength 670 nm, power density 40 mW/cm{sup 2}). The energy densities were 2 J/cm{sup 2} and 12 J/cm{sup 2}, respectively, and the irradiation was carried out at a temperature of 22 C. For fibroblast viability evaluation, the colorimetric assay (conversion of thiazolyl blue to formazan) was used. The experiments were carried out at 37 C, in the presence of 5% CO{sub 2}, and at different time periods of incubation after irradiation (2, 4, 8 h and 1, 2, 3, 4, 5 days). The results indicated that there was a certain stimulating effect on the long-term proliferation of skin fibroblasts and that the stimulation proceeded in two stages, the first one 2 h and the second one 3 days post-irradiation. (orig.) With 4 figs., 2 tabs., 13 refs.

  18. Computed effects of sweat gland ducts on the propagation of 94 GHz waves in skin

    Science.gov (United States)

    Shafirstein, Gal; Moros, Eduardo G.

    2011-03-01

    The effects of sweat gland ducts (SGD) on specific absorption rate and temperatures during millimeter wave irradiation of skin were investigated with a high resolution finite differences time domain model consisting of a 30 μm stratum corneum (SC), a 350 μm epidermis, 1000 μm dermis and five SGD (60 μm radius, 300 μm height, 370 μm separation). The source was a WR-10 waveguide irradiating at 94 GHz. Without SGD, specific absorption rate (SAR) and temperature maximum were in the dermis near epidermis. With SGD, a higher SAR maximum was inside SGD in the epidermis while temperature maximum moved to the epidermis/stratumcorneum junction. SGD significantly affected how GHz waves were absorbed in the skin. Implications of these finding in nociceptive research will be discussed as well as other potential medical applications.

  19. Preventive effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice

    Science.gov (United States)

    Komatsu, Toshiyuki; Sasaki, Suguru; Manabe, Yuki; Hirata, Takashi

    2017-01-01

    Astaxanthin, a carotenoid found mainly in seafood, has potential clinical applications due to its antioxidant activity. In this study, we evaluated the effect of dietary astaxanthin derived from Haematococcus pluvialis on skin photoaging in UVA-irradiated hairless mice by assessing various parameters of photoaging. After chronic ultraviolet A (UVA) exposure, a significant increase in transepidermal water loss (TEWL) and wrinkle formation in the dorsal skin caused by UVA was observed, and dietary astaxanthin significantly suppressed these photoaging features. We found that the mRNA expression of lympho-epithelial Kazal-type-related inhibitor, steroid sulfatase, and aquaporin 3 in the epidermis was significantly increased by UVA irradiation for 70 days, and dietary astaxanthin significantly suppressed these increases in mRNA expression to be comparable to control levels. In the dermis, the mRNA expression of matrix metalloprotease 13 was increased by UVA irradiation and significantly suppressed by dietary astaxanthin. In addition, HPLC-PDA analysis confirmed that dietary astaxanthin reached not only the dermis but also the epidermis. Our results indicate that dietary astaxanthin accumulates in the skin and appears to prevent the effects of UVA irradiation on filaggrin metabolism and desquamation in the epidermis and the extracellular matrix in the dermis. PMID:28170435

  20. EFFECTIVENESS OF A COGNITIVE SOCIAL PROGRAM TO PREVENT SKIN CANCER IN ADOLESCENT WOMEN

    Directory of Open Access Journals (Sweden)

    PABLO ALFONSO SANABRIA FERRAND

    2006-10-01

    Full Text Available Differential effect of three components of a social cognitive program, e.g., information, self-evaluation of risk andsubjective norms, influencing sun protective practices was established in a group of 57 female teenagers. The componentswere defined as three independent variables consisting of (i Oral information about skin cancer, (ii Self-evaluation ofthe risk of acquiring skin cancer and identification and modification of the barriers, and finally (iii Identification andrestructure of subjective norms that favor exposure and sun tanning behavior. The study design was intrasubject withmeasurements pre- and pos-test and twelve weeks of following-up after finalizing the preventive program. It wasfound that the given information about skin cancer favours negative attitudes towards sun tanning behavior, althoughcontrary to was expected, there was an increase of sunbathing and sun tanning, which just diminished after theimplementation of the preventive program’s second component. The third component was related with the decreasedof the perceived benefits of protection and the increased of severity perception towards foto-ageing. The followed-upand correlations among the psycho-social model ´s variables with protection habits reckon the effectiveness of themodel to increment the sun protection practices

  1. Antioxidative effect of loquat (Eriobotrya japonica Lindl.) fruit skin extract in soybean oil.

    Science.gov (United States)

    Delfanian, Mojtaba; Esmaeilzadeh Kenari, Reza; Sahari, Mohammad Ali

    2015-01-01

    The aim of this study was to compare the effects of solvent and ultrasound-assisted extraction methods with supercritical fluid extraction on antioxidant activity of loquat (Eriobotrya japonica Lindl.) fruit skin extract in stability of soybean oil at 25°C. Oxidative stability alterations of soybean oils containing 400 (SEA) and 1000 ppm (SEB) of ethanol extract, 400 (SSA) and 1000 ppm (SSB) of supercritical CO2 extract, 400 (SUA) and 1000 ppm (SUB) of ultrasound-assisted extract, and 100 ppm of tertiary butylhydroquinone (TBHQ) were monitored by measuring the peroxide value, thiobarbituric acid value, free fatty acids, conjugated dienes and trienes values. Oxidative changes in SEA were lower than that of oils treated with other extracts, but the best protection was observed in soybean oil consisting TBHQ. The solvent extraction method produces the maximum amount of phenolic and tocopherol compounds from loquat fruit skin. Therefore, solvent extraction method had a better effect on antioxidant activity of the loquat fruit skin extract.

  2. Anomalous effective polarity of an air/liquid-mixture interface: a heterodyne-detected electronic and vibrational sum frequency generation study.

    Science.gov (United States)

    Mondal, Sudip Kumar; Inoue, Ken-ichi; Yamaguchi, Shoichi; Tahara, Tahei

    2015-10-07

    We study the effective polarity of an air/liquid-mixture interface by using interface-selective heterodyne-detected electronic sum frequency generation (HD-ESFG) and vibrational sum frequency generation (HD-VSFG) spectroscopies. With water and N,N-dimethylformamide (DMF) chosen as two components of the liquid mixture, the bulk polarity of the mixture is controlled nearly arbitrarily by the mixing ratio. The effective polarity of the air/mixture interface is evaluated by HD-ESFG with a surface-active solvatochromic molecule used as a polarity indicator. Surprisingly, the interfacial effective polarity of the air/mixture interface increases significantly, when the bulk polarity of the mixture decreases (i.e. when the fraction of DMF increases). Judging from the hydrogen-bond structure at the air/mixture interface clarified by HD-VSFG, this anomalous change of the interfacial effective polarity is attributed to the interface-specific solvation structure around the indicator molecule at the air/mixture interface.

  3. Beryllium metal I. experimental results on acute oral toxicity, local skin and eye effects, and genotoxicity.

    Science.gov (United States)

    Strupp, Christian

    2011-01-01

    The toxicity of soluble metal compounds is often different from that of the parent metal. Since no reliable data on acute toxicity, local effects, and mutagenicity of beryllium metal have ever been generated, beryllium metal powder was tested according to the respective Organisation for Economical Co-Operation and Development (OECD) guidelines. Acute oral toxicity of beryllium metal was investigated in rats and local effects on skin and eye in rabbits. Skin-sensitizing properties were investigated in guinea pigs (maximization method). Basic knowledge about systemic bioavailability is important for the design of genotoxicity tests on poorly soluble substances. Therefore, it was necessary to experimentally compare the capacities of beryllium chloride and beryllium metal to form ions under simulated human lung conditions. Solubility of beryllium metal in artificial lung fluid was low, while solubility in artificial lysosomal fluid was moderate. Beryllium chloride dissolution kinetics were largely different, and thus, metal extracts were used in the in vitro genotoxicity tests. Genotoxicity was investigated in vitro in a bacterial reverse mutagenicity assay, a mammalian cell gene mutation assay, a mammalian cell chromosome aberration assay, and an unscheduled DNA synthesis (UDS) assay. In addition, cell transformation was tested in a Syrian hamster embryo cell assay, and potential inhibition of DNA repair was tested by modification of the UDS assay. Beryllium metal was found not to be mutagenic or clastogenic based on the experimental in vitro results. Furthermore, treatment with beryllium metal extracts did not induce DNA repair synthesis, indicative of no DNA-damaging potential of beryllium metal. A cell-transforming potential and a tendency to inhibit DNA repair when the cell is severely damaged by an external stimulus were observed. Beryllium metal was also found not to be a skin or eye irritant, not to be a skin sensitizer, and not to have relevant acute oral

  4. Chemopreventive effect of Lagenaria siceraria in two stages DMBA plus croton oil induced skin papillomagenesis.

    Science.gov (United States)

    Kumar, Navneet; Kale, Raosaheb K; Tiku, Ashu B

    2013-01-01

    Cancer chemoprevention is a dietary or therapeutic strategy to prevent, suppress, or delay carcinogenesis either at initiation or progression level with nontoxic agents. Use of natural dietary compounds has been a major chemopreventive approach to modulate tumorigenic pathways. In the present study, we have evaluated Lagenaria siceraria (bottle gourd), a common vegetable of Indian household for its chemomodulatory potential. The fruit has been used in traditional medicine for a very long time for health benefits and to cure pain, ulcers, fever, cough, asthma, and other bronchial disorders. However, despite its reported beneficial effect the chemo modulatory potential of this plant has not been reported. Therefore chemopreventive effect of bottle gourd juice (BGJ) was studied against 7,12-dimethylbenz(a)anthracene (DMBA) plus croton oil induced skin papillomagenesis in Swiss albino mice. The effect was studied both at antiinitiation and antiinitiation/promotion level followed by histopathological study. A dose of 2.5% and 5% given in drinking water showed significant decrease in papilloma number, papilloma incidence, papilloma multiplicity, papilloma latency, papilloma volume, and papilloma size in different size range. Histopathological study showed chemopreventive effect by minimizing loss of stratification, a decrease in number of epithelial layers, reducing dermal infiltration and protection for various cytoplasmic changes. Higher dose of BGJ was found to be more effective than lower dose and the chemopreventive effect was maximum for antiinitiation/promotion treatment. Altogether, this study reports the chemopreventive effect of Lagenaria siceraria on skin papillomagenesis for the first time and suggests that its consumption may help in suppression of skin cancer.

  5. Effects of Topical Corticosteroid and Tacrolimus on Ceramides and Irritancy to Sodium Lauryl Sulphate in Healthy Skin

    DEFF Research Database (Denmark)

    Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellgren, Lars

    2011-01-01

    The skin barrier, located in the stratum corneum, is influenced mainly by the lipid and protein composition of this layer. In eczematous diseases impairment of the skin barrier is thought to be of prime importance. Topical anti-inflammatory drugs and emollients are the most widely used eczema....... For evaluation of the skin barrier, transepidermal water loss, erythema and electrical capacitance were measured. The ceramide/cholesterol ratio was increased in betamethasone- (p = 0.008) and tacrolimus-treated (p = 0.025) skin compared with emollient-treated skin. No differences in ceramide subgroups were...... treatments. The aim of this study was to examine the effects of topically applied corticosteroid, tacrolimus and emollient on stratum corneum lipids and barrier parameters. Nineteen healthy volunteers participated in the study. Both forearms of the subjects were divided into four areas, which were treated...

  6. Effects of topical corticosteroid and tacrolimus on ceramides and irritancy to sodium lauryl sulphate in healthy skin

    DEFF Research Database (Denmark)

    Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellegren, Lars I

    2011-01-01

    The skin barrier, located in the stratum corneum, is influenced mainly by the lipid and protein composition of this layer. In eczematous diseases impairment of the skin barrier is thought to be of prime importance. Topical anti-inflammatory drugs and emollients are the most widely used eczema....... For evaluation of the skin barrier, transepidermal water loss, erythema and electrical capacitance were measured. The ceramide/cholesterol ratio was increased in betamethasone- (p¿=¿0.008) and tacrolimus-treated (p¿=¿0.025) skin compared with emollient-treated skin. No differences in ceramide subgroups were...... treatments. The aim of this study was to examine the effects of topically applied corticosteroid, tacrolimus and emollient on stratum corneum lipids and barrier parameters. Nineteen healthy volunteers participated in the study. Both forearms of the subjects were divided into four areas, which were treated...

  7. Effect of Diving and Diving Hoods on the Bacterial Flora of the External Ear Canal and Skin

    Science.gov (United States)

    1982-05-01

    NAVAL MEDICAL RESEARCH INSTITUTE BETHESDA, MARYLAND 82-22 EFFECT OF DIVING AND DIVING HOODS ON THE BACTERIAL FLORA OF THE EXTERNAL EAR CANAL AND SKIN...Subtitle) 5. TYPE OF REPeRT & PERIOD COVERED EFFECT OF DIVING AND DIVING HOODS ON THE BACTERIAL - PROGRESS FLORA OF THE EXTERNAL EAR CANAL AND SKIN MEDICAL...bacterial flora of the external ear canals and posterior auricular skin surface was investigated’in a group of 26 divers after 25 dry-suit dives in harbor

  8. Anomalous Microwave Emission

    CERN Document Server

    Kogut, A J

    1999-01-01

    Improved knowledge of diffuse Galactic emission is important to maximize the scientific return from scheduled CMB anisotropy missions. Cross-correlation of microwave maps with maps of the far-IR dust continuum show a ubiquitous microwave emission component whose spatial distribution is traced by far-IR dust emission. The spectral index of this emission, beta_{radio} = -2.2 (+0.5 -0.7) is suggestive of free-free emission but does not preclude other candidates. Comparison of H-alpha and microwave results show that both data sets have positive correlations with the far-IR dust emission. Microwave data, however, are consistently brighter than can be explained solely from free-free emission traced by H-alpha. This ``anomalous'' microwave emission can be explained as electric dipole radiation from small spinning dust grains. The anomalous component at 53 GHz is 2.5 times as bright as the free-free emission traced by H-alpha, providing an approximate normalization for models with significant spinning dust emission.

  9. Fickian dispersion is anomalous

    Science.gov (United States)

    Cushman, John H.; O'Malley, Dan

    2015-12-01

    The thesis put forward here is that the occurrence of Fickian dispersion in geophysical settings is a rare event and consequently should be labeled as anomalous. What people classically call anomalous is really the norm. In a Lagrangian setting, a process with mean square displacement which is proportional to time is generally labeled as Fickian dispersion. With a number of counter examples we show why this definition is fraught with difficulty. In a related discussion, we show an infinite second moment does not necessarily imply the process is super dispersive. By employing a rigorous mathematical definition of Fickian dispersion we illustrate why it is so hard to find a Fickian process. We go on to employ a number of renormalization group approaches to classify non-Fickian dispersive behavior. Scaling laws for the probability density function for a dispersive process, the distribution for the first passage times, the mean first passage time, and the finite-size Lyapunov exponent are presented for fixed points of both deterministic and stochastic renormalization group operators. The fixed points of the renormalization group operators are p-self-similar processes. A generalized renormalization group operator is introduced whose fixed points form a set of generalized self-similar processes. Power-law clocks are introduced to examine multi-scaling behavior. Several examples of these ideas are presented and discussed.

  10. Synergistic effects of iontophoresis and jet injector pretreatment on the in-vitro skin permeation of diclofenac and angiotensin II.

    Science.gov (United States)

    Sugibayashi, K; Kagino, M; Numajiri, S; Inoue, N; Kobayashi, D; Kimura, M; Yamaguchi, M; Morimoto, Y

    2000-10-01

    A non-needle syringe (jet injector) was utilized to increase skin permeation of drugs by iontophoresis. Briefly, physiological saline was initially flushed by the injector to make a pore in the stratum corneum of excised hairless rat skin, and the iontophoretic skin permeation of two model compounds, sodium diclofenac and angiotensin II, was followed using a 2-chamber diffusion cell. Constant voltage and constant current iontophoresis treatments were evaluated. Pretreatment using the jet injector alone resulted in about 13- and 22-fold increases in the steady-state flux of diclofenac and angiotensin II, respectively, through the skin, compared with non-treated controls. Jet injector pretreatment with constant voltage iontophoresis further enhanced skin permeation of diclofenac and angiotensin II, and the enhancement was also greater than that by constant voltage iontophoresis alone. Thus, a synergistic effect was observed. The ratio of enhancement was greater compared with the control. Jet injector pretreatment with constant current iontophoresis, however, did not always yield higher skin permeation of the drugs than injector pretreatment alone, although the lag time was shortened. The difference in the enhancement between the constant voltage- and constant current iontophoresis can be explained by the electric current through the excised skin. Constant current iontophoresis after a short period of constant voltage iontophoresis with multiple jet injector pretreatments may be the best way to increase drug permeability while preventing severe skin damage.

  11. Detecting quark anomalous electroweak couplings at the LHC

    CERN Document Server

    Zhao, Sheng-Zhi

    2015-01-01

    We study the dimension-6 quark anomalous electroweak couplings in the formulation of linearly realized effective Lagrangian. We investigate the constraints on these anomalous couplings from the $pp \\rightarrow W^+W^-$ process in detail at the LHC. With additional kinematic cuts, we find that the 14 TeV LHC can provide a test of anomalous couplings of $O(0.1-1)\\,{\\rm TeV}^{-2}$. The $pp \\rightarrow ZZ/Z\\gamma/\\gamma\\gamma$ processes can provide a good complement as they are sensitive to those anomalous couplings which do not affect the $pp \\rightarrow W^+W^-$ process. Those processes that only contain anomalous triple vertices, like $p p \\to W^* \\to l \

  12. Anomalous Evidence, Confidence Change, and Theory Change.

    Science.gov (United States)

    Hemmerich, Joshua A; Van Voorhis, Kellie; Wiley, Jennifer

    2016-08-01

    A novel experimental paradigm that measured theory change and confidence in participants' theories was used in three experiments to test the effects of anomalous evidence. Experiment 1 varied the amount of anomalous evidence to see if "dose size" made incremental changes in confidence toward theory change. Experiment 2 varied whether anomalous evidence was convergent (of multiple types) or replicating (similar finding repeated). Experiment 3 varied whether participants were provided with an alternative theory that explained the anomalous evidence. All experiments showed that participants' confidence changes were commensurate with the amount of anomalous evidence presented, and that larger decreases in confidence predicted theory changes. Convergent evidence and the presentation of an alternative theory led to larger confidence change. Convergent evidence also caused more theory changes. Even when people do not change theories, factors pertinent to the evidence and alternative theories decrease their confidence in their current theory and move them incrementally closer to theory change.

  13. Fluoroscopically Guided Interventional Procedures: A Review of Radiation Effects on Patients’ Skin and Hair

    Science.gov (United States)

    2010-02-01

    ters below the skin . The build-up of dose below the surface can minimize injury of skin . This is often called skin sparing . Because orthovoltage...radiation ther- apy does not exhibit skin sparing , clini- cal radiation therapy with orthovoltage equipment was prescribed in a manner that... skin reaction in deep therapy as a function of size of the fi eld: a law for radiotherapy [in German] . Fortschr Geb Rontgenstr 1955 ; 82 : 387

  14. Magnetic topological insulator and quantum anomalous Hall effect%磁性拓扑绝缘体与量子反常霍尔效应

    Institute of Scientific and Technical Information of China (English)

    翁红明; 戴希; 方忠

    2014-01-01

    量子反常霍尔绝缘体,有时也被称为陈数绝缘体,是不同于普通绝缘体和拓扑绝缘体的一类新的二维绝缘体,该体系具有可被实验观测的特殊物理性质-量子反常霍尔效应。该体系的物态不能用朗道对称性破缺理论来描写,而要用到拓扑物态的概念。它的发现也经历了从反常霍尔效应的内秉物性阐释,到量子自旋霍尔效应与拓扑绝缘体的发现,再到磁性拓扑绝缘体的理论预测与实现,并最终成功实验观测的漫长过程。由于量子反常霍尔效应的实现不需要外加磁场,而此时样品的边缘态可以被看成一根无能耗的理想导线,因此人们对于其将来可能的应用充满了期待。本文将从理论的角度简单综述该领域的发展历程、基本概念、以及相关的材料系统。%Quantum anomalous Hall insulator, also called as Chern insulator, is a new two-dimensional insulator distinguished from normal insulator and topological insulator by possess-ing a special and experimentally observable physical property-quantum anomalous Hall effect (QAHE). This is a novel quantum state can not be described by the Landau symmetry breaking theory but by the concept of topology of band structure. Its discovery experienced a long his-tory: from the explanation of intrinsic contribution to anomalous Hall effect, to the discovery of quantum spin Hall effect and topological insulator, to the prediction and realization of magnetic topological insulator, and finally to the experimental observation of it. Since QAHE does not require external magnetic field and has dissipationless (without lost of kinetic energy that being transferred to thermal energy) conducting edge states which can be used as an ideal conducting wire, it is expected to have various potential applications in future. This paper gives a review of this field on its history, basic concepts and related materials from the theoretical point of view.

  15. [Preparation and antimicrobial effect of aromatic, natural and bacteriostatic foot wash with skin care].

    Science.gov (United States)

    Gao, Su-Hua; Zhao, Guo-Xiang; Yang, Xiao-Dong; Xu, Ling-Ling

    2013-06-01

    To prepare the aromatic, natural and bacteriostatic foot wash with skin care and research the inhibition effect on the different bacteria and pathogenic fungus which cause dermatophytosis. It was prepared by using Sophoraflavescens and Dictamnus dasycarpus as materials with the addition of Aloe extract, essential oil, surfactant, etc. The antifungal and antibacterial activity was researched by the levitation liquid quantitative method. The foot wash smelled faintly scent. The use of this product can produce a rich foam. The inhibitory rate were all more than 90%. The preparation process of the foot wash was simple. It has obviously bacteriostatic and fungistatic effect.

  16. [Inhibitory effects of natural medicines on the enzymes related to the skin].

    Science.gov (United States)

    Sawabe, Y; Yamasaki, K; Iwagami, S; Kajimura, K; Nakagomi, K

    1998-09-01

    In this paper, we investigated the inhibitory effects of water extracts from sixty-six natural medicines on the enzymes related to the skin, which were tyrosinase, hyaluronidase and collagenase. To clarify the inhibitory components in water extracts, tannin quantity and the inhibitory activity of the water extracts after removal of phenolic compounds using polyclar AT, were measured. Twelve kinds of natural medicines were found to have tyrosinase inhibitory activity. Six of them showed that tannin, which contains sufficient amounts in extracts, might be major inhibitory compounds due to a significant decrease of inhibition by these samples after removal of phenolic compounds. The inhibitory compound of Aurantii fructus immaturus was thought phenolic compounds except tannin. The inhibitory compounds may include Armeniacae semen, Perillae folium and Persicae semen besides a phenolic compound. Twenty-seven species among the natural medicines studied showed inhibitory activity on hyaluronidase. Phenolic compounds in these extracts except Artemisiae argyi folium, could not be candidates for hyaluronidase inhibitors. Seven kinds of the natural medicines have inhibitory activity on collagenase. It was estimated that these inhibitory compounds were phenolic compounds. These results are to be expected for finding novel compounds for skin disease or skin-care cosmetics.

  17. Visible effects of rapamycin (sirolimus) on human skin explants in vitro.

    Science.gov (United States)

    Peramo, Antonio; Marcelo, Cynthia L

    2013-03-01

    In this manuscript, we report observations of the effects of rapamycin in an organotypic culture of human skin explants. The tissues were cultured for 5 days at the air-liquid interface or in submersed conditions with media with and without rapamycin at 2 nM concentration. Histological analysis of tissue sections indicated that rapamycin-treated samples maintained a better epidermal structure in the upper layers of the tissue than untreated samples, mostly evident when skin was cultured in submersed conditions. A significant decrease in the number of positive proliferative cells using the Ki67 antigen was observed when specimens were treated with rapamycin, in both air-liquid and submersed conditions but apoptosis differences between treated and untreated specimens, as seen by cleaved caspase-3 positive cells, were only observed in submersed specimens. Finally, a decrease and variability in the location in the expression of the differentiation marker involucrin and in E-cadherin were also evident in submersed samples. These results suggest that the development of topical applications containing rapamycin, instead of systemic delivery, may be a useful tool in the treatment of skin diseases that require reduction of proliferation and modulation or control of keratinocyte differentiation.

  18. Meta-analysis of the effectiveness of surgical scalpel or diathermy in making abdominal skin incisions.

    LENUS (Irish Health Repository)

    Ahmad, Nasir Zaheer

    2012-02-01

    BACKGROUND: Surgical scalpels are traditionally used to make skin incisions. Diathermy incisions on contrary are less popular among the surgeons. The aim of this meta-analysis was to compare the effectiveness of both techniques and address the common fallacies about diathermy incisions. METHODS: A literature search of MEDLINE and Cochrane databases was done, using the keywords diathermy, cold scalpel, and incisions. Eleven clinical trials comparing both methods of making skin incisions were selected for meta-analysis. The end points compared included postoperative wound infection, pain in first 24 hours after surgery, time taken to complete the incisions, and incision-related blood loss. RESULTS: Postoperative wound infection rate was comparable in both techniques (P = 0.147, odds ratio = 1.257 and 95% CI = 0.923-1.711). Postoperative pain was significantly less with diathermy incisions in first 24 hours (P = 0.031, weighted mean difference = 0.852 and 95% CI = 0.076-1.628). Similarly, the time taken to complete the incision and incision-related blood loss was significantly less with diathermy incisions (95% CI = 0.245-0.502 and 0.548-1.020, respectively). CONCLUSION: Diathermy incisions are equally prone to get wound infection, as do the incisions made with scalpel. Furthermore, lower incidence of early postoperative pain, swiftness of the technique, and a reduced blood loss are the encouraging facts supporting routine use of diathermy for abdominal skin incisions after taking careful precautions.

  19. Phase behavior of skin lipid mixtures: the effect of cholesterol on lipid organization.

    Science.gov (United States)

    Mojumdar, E H; Gooris, G S; Bouwstra, J A

    2015-06-07

    The lipid matrix in the stratum corneum (SC), the upper layer of the skin, plays a critical role in the skin barrier. The matrix consists of ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs). In human SC, these lipids form two coexisting crystalline lamellar phases with periodicities of approximately 6 and 13 nm. In the studies reported here, we investigated the effect of CHOL on lipid organization in each of these lamellar phases separately. For this purpose, we used lipid model mixtures. Our studies revealed that CHOL is imperative for the formation of each of the lamellar phases. At low CHOL levels, the formation of the lamellar phases was dramatically changed: a minimum 0.2 CHOL level in the CER/CHOL/FFA (1 : 0.2 : 1) mixture is required for the formation of each of the lamellar phases. Furthermore, CHOL enhances the formation of the highly dense orthorhombic lateral packing. The gradual increment of CHOL increases the fraction of lipids forming the very dense orthorhombic lateral packing. Therefore, these studies demonstrate that CHOL is an indispensable component of the SC lipid matrix and is of fundamental importance for appropriate dense lipid organization and thus important for the skin barrier function.

  20. Effects of bosentan on collagen type I synthesis on in vitro culture of scleroderma skin fibroblasts

    Directory of Open Access Journals (Sweden)

    S. Soldano

    2011-01-01

    Full Text Available The present study evaluated the effects of a non-selective endothelin (ETA/B receptors antagonist, on collagen type I (COLI synthesis on in vitro culture of scleroderma (SSc skin fibroblasts (Fb. Fb were obtained from skin biopsies of 6 female SSc patients (mean age 64. 1±6 years, after informed consent and Ethical Committee Approval. Cells were treated with endothelin-I [ET-I, 100nM] for 24 and 48 hrs, pre-treated for I hr with ETA/B receptors antagonist [10nM] alone or followed by ET-I for 24 and 48 hrs. Untreated Fb were used as controls. Immunocytochemistry and western blot analysis were performed to evaluate COLI synthesis. ET-I increased COLI synthesis both at 24 and 48 hrs when compared to controls. ETA/B receptor antagonost blocks the increased COLI synthesis ET-I-mediated both at 24 and 48 hrs vs. ET-I. Results showed that ET-I receptors blockage by ETA/B receptors antagonist might prevent the excessive synthesis of COLI, supporting its positive action in the management of skin fibrosis.

  1. Synergistic effects of ethosomes and chemical enhancers on enhancement of naloxone permeation through human skin.

    Science.gov (United States)

    Xu, D H; Zhang, Q; Feng, X; Xu, X; Liang, W Q

    2007-04-01

    The purpose of this study was to investigate the effects of ethosomes, chemical enhancers and their binary combination on the in vitro permeability enhancement of naloxone through human skin. Franz diffusion cells were used for the percutaneous absorption studies. Propylene glycol (PG), N,N-dimethyl formamide (N,N-DMF), N,N-dimethyl acetamide (N,N-DMA), dimethyl sulfoxide (DMSO), Azone and polyethylene glycol 400 (PEG400), were chosen as the chemical enhancers. Naloxone ethosomes showed 11.68 times increase in steady-state flux compared to phosphate buffered solution (PBS). Ethosomes in combination with chemical enhancers synergistically increased (p ethosomal form dramatically enhanced the skin permeation of naloxone in vitro compared with ethosomes (steady-state flux: 96.75 +/- 5.70 microg x cm(-2) x h(-1) vs 20.56 +/- 1.67 microg x cm(-2) x h(-1)). Ethosomal carrier and enhancers accumulated in the skin after 24 h were greater than that of PBS.

  2. Protective Effects of B Vitamins and Antioxidants on the Risk of Arsenic-Related Skin Lesions in Bangladesh

    OpenAIRE

    2008-01-01

    Background An estimated 25–40 million of the 127 million people of Bangladesh have been exposed to high levels of naturally occurring arsenic from drinking groundwater. The mitigating effects of diet on arsenic-related premalignant skin lesions are largely unknown. Objectives The purpose of this study was to clarify the effects of the vitamin B group (thiamin, riboflavin, niacin, pyridoxine, and cobalamin) and antioxidants (vitamins A, C, and E) on arsenic-related skin lesions. Methods We per...

  3. Clinical Evidence of Effects of Lactobacillus plantarum HY7714 on Skin Aging: A Randomized, Double Blind, Placebo-Controlled Study.

    Science.gov (United States)

    Lee, Dong Eun; Huh, Chul-Sung; Ra, Jehyeon; Choi, Il-Dong; Jeong, Ji-Woong; Kim, Sung-Hwan; Ryu, Ja Hyun; Seo, Young Kyoung; Koh, Jae Sook; Lee, Jung-Hee; Sim, Jae-Hun; Ahn, Young-Tae

    2015-12-28

    The beneficial effects of probiotics are now widely reported, although there are only a few studies on their anti-aging effects. We have found that Lactobacillus plantarum HY7714 (HY7714) improves skin hydration and has anti-photoaging effects, and in the present study, we have further evaluated the anti-aging effect of HY7714 via a randomized, double blind, placebo-controlled clinical trial. The trial included 110 volunteers aged 41 and 59 years who have dry skin and wrinkles. Participants took 1 × 10(10) CFU/day of HY7714 (probiotic group) or a placebo (placebo group) for 12 weeks. Skin hydration, wrinkles, skin gloss, and skin elasticity were measured every 4 weeks during the study period. There were significant increases in the skin water content in the face (p < 0.01) and hands (p < 0.05) at week 12 in the probiotic group. Transepidermal water loss decreased significantly in both groups at weeks 4, 8, and 12 (p < 0.001 compared with baseline), and was suppressed to a greater extent in the face and forearm in the probiotic group at week 12. Volunteers in the probiotic group had a significant reduction in wrinkle depth at week 12, and skin gloss was also significantly improved by week 12. Finally, skin elasticity in the probiotic group improved by 13.17% (p < 0.05 vs. controls) after 4 weeks and by 21.73% (p < 0.01 vs. controls) after 12 weeks. These findings are preliminary confirmation of the anti-aging benefit to the skin of L. plantarum HY7714 as a nutricosmetic agent.

  4. Time course and spacial distribution of UV effects on human skin in organ culture.

    Science.gov (United States)

    Mori, Eiichiro; Takahashi, Akihisa; Kitagawa, Kou; Kakei, Saki; Tsujinaka, Daiki; Unno, Megumi; Nishikawa, Shoko; Ohnishi, Ken; Hatoko, Mitsuo; Murata, Norio; Watanabe, Masakatsu; Furusawa, Yoshiya; Ohnishi, Takeo

    2008-05-01

    Apoptosis plays an important role in eliminating cells from populations when cells have been exposed to UV irradiation and damaged. Studies of cells in culture have provided some details of the mechanisms involved when stress response genes act after exposure to UV irradiation and other environmental stresses. However, little is known about the responses of intact sections of human skin growing in organ culture to UV irradiation. In the work reported here, it was found that the response of organ-cultured human skin after exposure to UV irradiation is different than the response of cultured cells. At wavelengths below 300 nm, the action spectrum obtained from organ-cultured skin samples showed a lower sensitivity than that observed at 300 nm, indicating that the overlying stratum corneum and upper epidermal cell layers had probably caused a selective absorption of incident UV radiation at some wavelengths. At 3 hours after UV irradiation, p53 was phosphorylated at Ser 15 and Ser 46, and accumulated in the cell nuclei, notably after exposure to 280-320 nm wavelengths. Accumulations of Bax, active Caspase-3 and cleaved PARP were detected in apoptotic cells at 24 hours post-exposure, along with a reduction of Bcl-2 levels, notably after exposure to 300-365 nm light. This difference in apoptotic responses may result from the characteristics of the different irradiation wavelengths used, and from details in the skin's structure. The data obtained in this study using an organ-culture system utilized direct measurements of the biological effects of different wavelengths of UV lights.

  5. Effects of laser therapy on chronic skin ulcers healing interventions for Sudanese patients

    Directory of Open Access Journals (Sweden)

    Abdelrazig M. Abdelbagi

    2015-12-01

    Results: Utilization of laser dosage (energy density of 40 J/cm2 and 1.6 w/cm2 power density of the wavelength 820 nm and 30 J/cm2 energy density and power density of 0.24 w/cm2 of 780 nm wavelength, in addition to energy density of 8 J/cm2 and power density of 0.24 w/cm2 and 0.40 w/cm2 and energy density of 1.6 J/cm2 for the 675 wavelength was applied. In this study, we used the bio-stimulation effect of LLLT to enhance healing through immune modulation. However, the application of low level diode laser in the treatment of diabetic wounds can be accompanied by low energy density and short wavelength to give better results in a short time and a good diagnostic accuracy for its potentiality in the field. Conclusions: Consequently, the brown skins in Sub-Saharan region for different tissues of Sudanese diabetic patients of chronic skin ulcer can be treated with different wavelengths and energy relative to tissues softening and laser parameters of that optimum values were obtained. The assessment of skin regeneration using laser therapy expose that the quality of growth, the reasonable period of healing and decreases the risk skin infection were achieved. The process of diabetic wounds curing and de-pigmentation, potential resident of decreasing pain and an efficient adjunct to a standard wound management was obtained. [Int J Res Med Sci 2015; 3(12.000: 3720-3725

  6. Anomalous diffraction in hyperbolic materials

    CERN Document Server

    Alberucci, Alessandro; Boardman, Allan D; Assanto, Gaetano

    2016-01-01

    We demonstrate that light is subject to anomalous (i.e., negative) diffraction when propagating in the presence of hyperbolic dispersion. We show that light propagation in hyperbolic media resembles the dynamics of a quantum particle of negative mass moving in a two-dimensional potential. The negative effective mass implies time reversal if the medium is homogeneous. Such property paves the way to diffraction compensation, spatial analogue of dispersion compensating fibers in the temporal domain. At variance with materials exhibiting standard elliptic dispersion, in inhomogeneous hyperbolic materials light waves are pulled towards regions with a lower refractive index. In the presence of a Kerr-like optical response, bright (dark) solitons are supported by a negative (positive) nonlinearity.

  7. Anomalous diffraction in hyperbolic materials

    Science.gov (United States)

    Alberucci, Alessandro; Jisha, Chandroth P.; Boardman, Allan D.; Assanto, Gaetano

    2016-09-01

    We demonstrate that light is subject to anomalous (i.e., negative) diffraction when propagating in the presence of hyperbolic dispersion. We show that light propagation in hyperbolic media resembles the dynamics of a quantum particle of negative mass moving in a two-dimensional potential. The negative effective mass implies time reversal if the medium is homogeneous. Such property paves the way to diffraction compensation, i.e., spatial analog of dispersion compensating fibers in the temporal domain. At variance with materials exhibiting standard elliptic dispersion, in inhomogeneous hyperbolic materials light waves are pulled towards regions with a lower refractive index. In the presence of a Kerr-like optical response, bright (dark) solitons are supported by a negative (positive) nonlinearity.

  8. Anomalous Dimensions of Conformal Baryons

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within...

  9. Anomalous Dimensions of Conformal Baryons

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within the $...

  10. Beta Function and Anomalous Dimensions

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2011-01-01

    We demonstrate that it is possible to determine the coefficients of an all-order beta function linear in the anomalous dimensions using as data the two-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows to determine the anomalou...

  11. Topical treatment with coenzyme Q10-containing formulas improves skin's Q10 level and provides antioxidative effects.

    Science.gov (United States)

    Knott, Anja; Achterberg, Volker; Smuda, Christoph; Mielke, Heiko; Sperling, Gabi; Dunckelmann, Katja; Vogelsang, Alexandra; Krüger, Andrea; Schwengler, Helge; Behtash, Mojgan; Kristof, Sonja; Diekmann, Heike; Eisenberg, Tanya; Berroth, Andreas; Hildebrand, Janosch; Siegner, Ralf; Winnefeld, Marc; Teuber, Frank; Fey, Sven; Möbius, Janne; Retzer, Dana; Burkhardt, Thorsten; Lüttke, Juliane; Blatt, Thomas

    2015-01-01

    Ubiquinone (coenzyme Q10, Q10) represents an endogenously synthesized lipid-soluble antioxidant which is crucial for cellular energy production but is diminished with age and under the influence of external stress factors in human skin. Here, it is shown that topical Q10 treatment is beneficial with regard to effective Q10 replenishment, augmentation of cellular energy metabolism, and antioxidant effects. Application of Q10-containing formulas significantly increased the levels of this quinone on the skin surface. In the deeper layers of the epidermis the ubiquinone level was significantly augmented indicating effective supplementation. Concurrent elevation of ubiquinol levels suggested metabolic transformation of ubiquinone resulting from increased energy metabolism. Incubation of cultured human keratinocytes with Q10 concentrations equivalent to treated skin showed a significant augmentation of energy metabolism. Moreover, the results demonstrated that stressed skin benefits from the topical Q10 treatment by reduction of free radicals and an increase in antioxidant capacity.

  12. Combined effects of treatment with vitamin C, vitamin E and selenium on the skin of diabetic rats.

    Science.gov (United States)

    Sokmen, B B; Basaraner, H; Yanardag, R

    2013-04-01

    The aim of this study was to investigate the effects of vitamin C, vitamin E and selenium (Se) on the skin tissue of streptozotocin-induced diabetic rats. Swiss albino rats were divided into four groups: control, control + antioxidants, diabetic, diabetic + antioxidants groups. Diabetes was induced by intraperitoneal injection of 65 mg/kg streptozotocin. Vitamin C (250 mg/kg), vitamin E (250 mg/kg) and Se (0.2 mg/kg) were given by gavage technique to rats of one diabetic and one control group for 30 days. In the diabetic group, the levels of serum urea and creatinine, skin lipid peroxidation and nonenzymatic glycosylation levels increased, but skin glutathione levels decreased. Treatment with vitamin C, vitamin E and Se reversed these effects. The present study showed that vitamin C, vitamin E and Se exerted antioxidant effects and consequently may prevent skin damage caused by streptozotocin-induced diabetes.

  13. Differential effects of topically applied formalin and aromatic compounds on neurogenic-mediated microvascular leakage in rat skin.

    Science.gov (United States)

    Futamura, Masaki; Goto, Shiho; Kimura, Ryoko; Kimoto, Izumi; Miyake, Mio; Ito, Komei; Sakamoto, Tatsuo

    2009-01-01

    Various volatile organic compounds (VOCs) act as a causative agent of skin inflammation. We investigated the effect of topical application of several VOCs and formalin on microvascular leakage in rat skin. We tested capsaicin, which is a reagent that specifically causes the skin response via endogenously released tachykinins. Evans blue dye extravasation served as an index of the increase in skin vascular permeability. After shaving the abdomen, we applied formalin, m-xylene, toluene, styrene, benzene, ethylbenzene, acetone, diethyl ether, hexane, heptane, cyclohexane and capsaicin to the skin. At 40min after application, skin samples were collected. Among all of the VOCs tested, all of the aromatic compounds significantly produced skin microvascular leakage that was similar to formalin and capsaicin. We also investigated the skin responses seen after the intravenous administration of CP-99,994 (1.5 or 5mg/kg), which is a tachykinin NK1 receptor antagonist, ketotifen (1 or 3mg/kg), which is a histamine H1 receptor antagonist that stabilizes the mast cells, and the topical application of capsazepine (22.5 or 50mM), which is the transient receptor potential vanilloid 1 (TRPV1) antagonist. The response induced by formalin and capsaicin was completely inhibited by CP-99,994. On the other hand, the antagonist partially reduced the response induced by m-xylene, toluene and styrene by 39%, 50% and 46%, respectively. Capsazepine and ketotifen did not alter the response induced by formalin or any of the aromatic compounds. Like capsaicin, formalin and the aromatic compounds at least partially caused skin microvascular leakage, which was due to tachykinin NK1 receptor activation related to the release of tachykinins from the sensory nerve endings. However, it is unlikely that mast cells and TRPV1 play an important role in the skin response.

  14. Anomalous Oscillations due to Aharonov-Bohm and Aharonov-Casher Effects of the One-Dimensional Hubbard Ring in the Strong Coupling Limit

    Science.gov (United States)

    Sano, Kazuhiro; Ōno, Yoshiaki

    2016-12-01

    We investigate anomalous oscillations due to the Aharonov-Bohm (AB) and Aharonov-Casher (AC) effects of the one-dimensional Hubbard ring with flux in the strong coupling limit. By using the exact diagonalization method and the Shiba transformation, we examine the energies of the ground-state and a few excited states in the presence of the flux producing the AB or AC effect, where the transformation not only reverses the sign of the interaction U but also exchanges the role between the AB and AC effects in the model Hamiltonian. We systematically classify the AB and AC oscillations by using the number of minima Nmin of the ground-state energy as a function of a normalized phase shift ϕ for 0 ≤ ϕ effects. For example, it is shown that Nmin is given by NL - Ne (NL - N↑ + N↓) for the AB (AC) effect in the very strong attraction, where NL, Ne, N↑, and N↓ are the system size, the total number of electrons, the number of electrons with up-spin, and the number of electrons with down-spin, respectively, under the condition of NL > Ne > N↓ > N↑. In more special cases, such as for a half-filled band and the spin-balanced case (NL = Ne and N↓ = N↑), we find Nmin to be 0 (2) for the AB (AC) effect in the case of very strong repulsion. These results show us the nature of interesting phenomena originating from the interplay between the strong correlation and the quantum interference effect in a mesoscopic ring.

  15. Effect of residual solvent in polymer adhesive matrix on release and skin permeation of scopolamine.

    Science.gov (United States)

    Anders, Kunst; Lee, Geoffrey

    2015-08-01

    The effects of varying level of residual solvent on the release and permeation of scopolamine from two different polyacrylate matrices through excised mouse skin has been determined. Matrices of the drug-in-adhesive type were prepared having different contents of residual ethyl acetate or heptane adjusted via the drying time at 30°C in a forced-convection oven. The neutral DuroTak 87-4098 showed no effects of residual ethyl acetate on either release or permeation, but was influenced by residual heptane. An increase in release rate from the matrix occurred with an enhancing effect on permeation. The self-curing DuroTak 87-2677 showed effects of residual heptane on both release and permeation. Both solvents were lost from the matrix on contact with an aqueous acceptor medium, although to different extents. Levels of residual ethyl acetate or heptane that fall below the ICH guideline (0.5% w/w) had, however, only a minor, yet measurable, effect on scopolamine release and skin uptake compared with higher solvent levels.

  16. Transient performances analysis of wind turbine system with induction generator including flux saturation and skin effect

    DEFF Research Database (Denmark)

    Li, H.; Zhao, B.; Han, L.

    2010-01-01

    In order to analyze correctly the effect of different models for induction generators on the transient performances of large wind power generation, Wind turbine driven squirrel cage induction generator (SCIG) models taking into account both main and leakage flux saturation and skin effect were pr...... mechancical disturbance and a grid voltage sag, respectively. Simulation results have shown that the effect of the flux saturation is obvious on the transient behavious of the wind power generator system, especially for a grid voltage sag studies.......In order to analyze correctly the effect of different models for induction generators on the transient performances of large wind power generation, Wind turbine driven squirrel cage induction generator (SCIG) models taking into account both main and leakage flux saturation and skin effect were...... proposed. A two-mass lump equivalent model of a wind turbine shaft system was also used to considering shaft flexibility. The transient behaviors of the wind generator system with the different models were investigated and compared with the software platform Matlab/Simulink, under conditions of a large...

  17. Evaporative cooling: effective latent heat of evaporation in relation to evaporation distance from the skin.

    Science.gov (United States)

    Havenith, George; Bröde, Peter; den Hartog, Emiel; Kuklane, Kalev; Holmer, Ingvar; Rossi, Rene M; Richards, Mark; Farnworth, Brian; Wang, Xiaoxin

    2013-03-15

    Calculation of evaporative heat loss is essential to heat balance calculations. Despite recognition that the value for latent heat of evaporation, used in these calculations, may not always reflect the real cooling benefit to the body, only limited quantitative data on this is available, which has found little use in recent literature. In this experiment a thermal manikin, (MTNW, Seattle, WA) was used to determine the effective cooling power of moisture evaporation. The manikin measures both heat loss and mass loss independently, allowing a direct calculation of an effective latent heat of evaporation (λeff). The location of the evaporation was varied: from the skin or from the underwear or from the outerwear. Outerwear of different permeabilities was used, and different numbers of layers were used. Tests took place in 20°C, 0.5 m/s at different humidities and were performed both dry and with a wet layer, allowing the breakdown of heat loss in dry and evaporative components. For evaporation from the skin, λeff is close to the theoretical value (2,430 J/g) but starts to drop when more clothing is worn, e.g., by 11% for underwear and permeable coverall. When evaporation is from the underwear, λeff reduction is 28% wearing a permeable outer. When evaporation is from the outermost layer only, the reduction exceeds 62% (no base layer), increasing toward 80% with more layers between skin and wet outerwear. In semi- and impermeable outerwear, the added effect of condensation in the clothing opposes this effect. A general formula for the calculation of λeff was developed.

  18. Fractal model of anomalous diffusion.

    Science.gov (United States)

    Gmachowski, Lech

    2015-12-01

    An equation of motion is derived from fractal analysis of the Brownian particle trajectory in which the asymptotic fractal dimension of the trajectory has a required value. The formula makes it possible to calculate the time dependence of the mean square displacement for both short and long periods when the molecule diffuses anomalously. The anomalous diffusion which occurs after long periods is characterized by two variables, the transport coefficient and the anomalous diffusion exponent. An explicit formula is derived for the transport coefficient, which is related to the diffusion constant, as dependent on the Brownian step time, and the anomalous diffusion exponent. The model makes it possible to deduce anomalous diffusion properties from experimental data obtained even for short time periods and to estimate the transport coefficient in systems for which the diffusion behavior has been investigated. The results were confirmed for both sub and super-diffusion.

  19. Detection of anomalous events

    Energy Technology Data Exchange (ETDEWEB)

    Ferragut, Erik M.; Laska, Jason A.; Bridges, Robert A.

    2016-06-07

    A system is described for receiving a stream of events and scoring the events based on anomalousness and maliciousness (or other classification). The system can include a plurality of anomaly detectors that together implement an algorithm to identify low-probability events and detect atypical traffic patterns. The anomaly detector provides for comparability of disparate sources of data (e.g., network flow data and firewall logs.) Additionally, the anomaly detector allows for regulatability, meaning that the algorithm can be user configurable to adjust a number of false alerts. The anomaly detector can be used for a variety of probability density functions, including normal Gaussian distributions, irregular distributions, as well as functions associated with continuous or discrete variables.

  20. The Effect of Local Heat and Cold Therapy on the Intraarticular and Skin Surface Temperature of the Knee

    OpenAIRE

    1992-01-01

    Objective. To evaluate the effects of local application of ice chips, ligno-paraffin, short-wave diathermy, and nitrogen-cold air on skin and intraarticular temperature. Methods. Forty-two healthy subjects were divided into 4 treatment groups. A temperature probe was inserted into the knee joint cavity and another placed on the overlying skin, and changes in temperature over 3 hours, by treatment group, were recorded. Results. The mean skin surface temperature dropped from 27.9°C to 11.5°C af...