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Sample records for random dopant induced

  1. Quantum Mechanical Enhancement of the Random Dopant Induced Threshold Voltage Fluctuations and Lowering in Sub 0.1 Micron MOSFETs

    Science.gov (United States)

    Asenov, Asen; Slavcheva, G.; Brown, A. R.; Davies, J. H.; Saini, Subhash

    1999-01-01

    A detailed study of the influence of quantum effects in the inversion layer on the random dopant induced threshold voltage fluctuations and lowering in sub 0.1 micron MOSFETs has been performed. This has been achieved using a full 3D implementation of the density gradient (DG) formalism incorporated in our previously published 3D 'atomistic' simulation approach. This results in a consistent, fully 3D, quantum mechanical picture which implies not only the vertical inversion layer quantisation but also the lateral confinement effects manifested by current filamentation in the 'valleys' of the random potential fluctuations. We have shown that the net result of including quantum mechanical effects, while considering statistical fluctuations, is an increase in both threshold voltage fluctuations and lowering.

  2. Dual-Material Gate Approach to Suppression of Random-Dopant-Induced Characteristic Fluctuation in 16 nm Metal-Oxide-Semiconductor Field-Effect-Transistor Devices

    Science.gov (United States)

    Li, Yiming; Lee, Kuo-Fu; Yiu, Chun-Yen; Chiu, Yung-Yueh; Chang, Ru-Wei

    2011-04-01

    In this work, we explore for the first time dual-material gate (DMG) and inverse DMG devices for suppressing the random-dopant (RD)-induced characteristic fluctuation in 16 nm metal-oxide-semiconductor field-effect-transistor (MOSFET) devices. The physical mechanism of suppressing the characteristic fluctuation of DMG devices is observed and discussed. The achieved improvement in suppressing the RD-induced threshold voltage, on-state current, and off-state current fluctuations are 28, 12.3, and 59%, respectively. To further suppress the fluctuations, an approach that combines the DMG method and channel-doping-profile engineering is also advanced and explored. The results of our study show that among the suppression techniques, the use of the DMG device with an inverse lateral asymmetric channel-doping-profile has good immunity to fluctuation.

  3. The effect of random dopant fluctuation on threshold voltage and drain current variation in junctionless nanotransistors

    International Nuclear Information System (INIS)

    Rezapour, Arash; Rezapour, Pegah

    2015-01-01

    We investigate the effect of dopant random fluctuation on threshold voltage and drain current variation in a two-gate nanoscale transistor. We used a quantum-corrected technology computer aided design simulation to run the simulation (10000 randomizations). With this simulation, we could study the effects of varying the dimensions (length and width), and thicknesses of oxide and dopant factors of a transistor on the threshold voltage and drain current in subthreshold region (off) and overthreshold (on). It was found that in the subthreshold region the variability of the drain current and threshold voltage is relatively fixed while in the overthreshold region the variability of the threshold voltage and drain current decreases remarkably, despite the slight reduction of gate voltage diffusion (compared with that of the subthreshold). These results have been interpreted by using previously reported models for threshold current variability, load displacement, and simple analytical calculations. Scaling analysis shows that the variability of the characteristics of this semiconductor increases as the effects of the short channel increases. Therefore, with a slight increase of length and a reduction of width, oxide thickness, and dopant factor, we could correct the effect of the short channel. (paper)

  4. Dopant-induced ignition of helium nanoplasmas—a mechanistic study

    Science.gov (United States)

    Heidenreich, Andreas; Schomas, Dominik; Mudrich, Marcel

    2017-12-01

    Helium (He) nanodroplets irradiated by intense near-infrared laser pulses form a nanoplasma by avalanche-like electron impact ionizations (EIIs) even at lower laser intensities where He is not directly field ionized, provided that the droplets contain a few dopant atoms which provide seed electrons for the EII avalanche. In this theoretical paper on calcium and xenon doped He droplets we elucidate the mechanism which induces ionization avalanches, termed ignition. We find that the partial loss of seed electrons from the activated droplets starkly assists ignition, as the Coulomb barrier for ionization of helium is lowered by the electric field of the dopant cations, and this deshielding of the cation charges enhances their electric field. In addition, the dopant ions assist the acceleration of the seed electrons (slingshot effect) by the laser field, supporting EIIs of He and also causing electron loss by catapulting electrons away. The dopants’ ability to lower the Coulomb barriers at He as well as the slingshot effect decrease with the spatial expansion of the dopant, causing a dependence of the dopants’ ignition capability on the dopant mass. Here, we develop criteria (impact count functions) to assess the ignition capability of dopants, based on (i) the spatial overlap of the seed electron cloud with the He atoms and (ii) the overlap of their kinetic energy distribution with the distribution of Coulomb barrier heights at He. The relatively long time delays between the instants of dopant ionization and ignition (incubation times) for calcium doped droplets are determined to a large extent by the time it takes to deshield the dopant ions.

  5. Aggregation in thin-film silver: Induced by chlorine and inhibited by alloying with two dopants

    International Nuclear Information System (INIS)

    Koike, Katsuhiko; Shimada, Koichi; Fukuda, Shin

    2009-01-01

    The Ag aggregation mechanism triggered by chlorine (Cl) is discussed. The frontier orbital theory by K. Fukui is applied in order to determine the growing point in the silver (Ag) cluster. Ag in the thin-film silver would grow to Ag n Cl and stack, triggered by Cl from the outside according to the mechanism described. This would lead to an aggregate with a high Ag density. It is suggested that this would be the generating mechanism of the silver-gray aggregate consisting mostly of Ag, which is generated by exposing it to Cl. Two tactics in order to prevent restrain aggregation induced by Cl according to the mechanism are proposed. Tactic 1 is a restraining of structure change to a plane in the process of Ag 6 Cl + Ag → Ag 7 Cl. Tactic 2 is the trapping of Cl before it generates a bond to Ag. The ability of the two combined dopants with the abilities of tactics 1 and 2, such as in an Ag alloy including palladium and copper (APC), and including neodymium and gold (ANA) is expected to be very high. The aggregation resistance of an Ag alloy including two dopants is evaluated by a salt water immersion test. The APC and ANA demonstrated a very high resistance to Cl, because of the combination of the dopants working with tactic 1 (Pd, Au) and tactic 2 (Cu, Nd). The multilayer sputter coating with an ANA layer demonstrated a very interesting profile where the light transmittance and the electrical sheet resistance are almost the same as the multilayer sputter coating with a pure Ag. The multilayer sputter coating with AIS also demonstrates a very interesting profile, where the light transmittance is higher than the multilayer sputter coating with a pure Ag.

  6. High-performance germanium n+/p junction by nickel-induced dopant activation of implanted phosphorus at low temperature

    International Nuclear Information System (INIS)

    Huang Wei; Lu Chao; Yu Jue; Wei Jiang-Bin; Chen Chao-Wen; Wang Jian-Yuan; Xu Jian-Fang; Li Cheng; Chen Song-Yan; Lai Hong-Kai; Wang Chen; Liu Chun-Li

    2016-01-01

    High-performance Ge n + /p junctions were fabricated at a low formation temperature from 325 °C to 400 °C with a metal(nickel)-induced dopant activation technique. The obtained NiGe electroded Ge n + /p junction has a rectification ratio of 5.6× 10 4 and a forward current of 387 A/cm 2 at −1 V bias. The Ni-based metal-induced dopant activation technique is expected to meet the requirement of the shallow junction of Ge MOSFET. (paper)

  7. Dopant induced variations in microstructure and optical properties of CeO2 nanoparticles

    International Nuclear Information System (INIS)

    Mohanty, Bhaskar Chandra; Lee, Jong Won; Yeon, Deuk-Ho; Jo, Yeon-Hwa; Kim, Jong Hak; Cho, Yong Soo

    2011-01-01

    Research highlights: → Dopant (Zr 4+ , La 3+ , and Ca 2+ ) induced phase stability, and changes in microstructure and optical properties of CeO 2 nanoparticles have been studied. → The nanoparticles were prepared by hydrothermal synthesis of nitrate solutions. → The results show modification of the unit cell parameter by -0.39, +0.83 and +0.16% for doping of 20% Zr 4+ , La 3+ , and Ca 2+ , respectively. → For each batch prepared, nanoparticles with a narrow size distribution of 5-15 nm have been obtained. These particles are single crystals mostly having polygonal two-dimensional projections. → UV-visible spectra of doped particles exhibit shift of the absorption edge and absorption peak with respect to those of the undoped ones and has been attributed to compensation of Ce 3+ and decreasing crystallite size as result of doping. -- Abstract: Nanocrystalline CeO 2 particles doped in the range of 0-20% of Ca 2+ , La 3+ , and Zr 4+ have been prepared from hydrothermal synthesis of nitrate solutions at 200 o C and the influences of the dopants on microstructure and optical properties of the nanoparticles have been investigated. The unit cell parameter is found to be modified by -0.39, +0.83 and +0.16% for doping of 20% Zr 4+ , La 3+ , and Ca 2+ , respectively. For each batch prepared, nanoparticles with a narrow size distribution of 5-15 nm have been obtained. A high-resolution transmission electron microscopy investigation reveals that these particles are single crystals mostly having hexagonal, square or circular two-dimensional projections. UV-visible spectra of doped powders exhibit shift of the absorption edge and absorption peak with respect to those of the undoped CeO 2 particles and has been attributed to compensation of Ce 3+ and decreasing crystallite size as result of doping.

  8. The effect of dopant-induced electron traps on spectrum evolution of doped organic light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Y.Q. [Surface Physics Laboratory (National Key Laboratory), Lab of Advanced Materials, Fudan University, Shanghai 200433 (China)]. E-mail: yqzhan@fudan.edu.cn; Zhou, J. [Surface Physics Laboratory (National Key Laboratory), Lab of Advanced Materials, Fudan University, Shanghai 200433 (China); Zhou, Y.C. [Surface Physics Laboratory (National Key Laboratory), Lab of Advanced Materials, Fudan University, Shanghai 200433 (China); Wu, Y. [Surface Physics Laboratory (National Key Laboratory), Lab of Advanced Materials, Fudan University, Shanghai 200433 (China); Yang, H. [Surface Physics Laboratory (National Key Laboratory), Lab of Advanced Materials, Fudan University, Shanghai 200433 (China); Li, F.Y. [Surface Physics Laboratory (National Key Laboratory), Lab of Advanced Materials, Fudan University, Shanghai 200433 (China); Ding, X.M. [Surface Physics Laboratory (National Key Laboratory), Lab of Advanced Materials, Fudan University, Shanghai 200433 (China); Hou, X.Y. [Surface Physics Laboratory (National Key Laboratory), Lab of Advanced Materials, Fudan University, Shanghai 200433 (China)]. E-mail: xyhou@fudan.edu.cn

    2007-05-07

    A prototype of light emitting device with two symmetrically located Al/LiF electrodes is fabricated to study the voltage dependence of emission spectra. 4-(dicyanomethylene)-2-methyl-6- (pdimethylaminostyryl)-4H-pyran doped tris-(8-hydroxy-quinolinato) aluminum thin film is the emitting layer of the device. Experiments show that with increasing applied voltage the emission intensity of the device decreases, of which the dopant emission intensity decreases more steeply than that of the host. Based on the theory of space-charge-limited current in insulator with a single shallow trap level it is deduced that the photoluminescence intensity of the dopant emission decreases linearly with applied voltage, in good agreement with experimental measurements. The evolution of the emission spectra can be well explained by the suggested mechanism that the electrons are trapped in the dopant molecules, which blocks the energy transfer from the host, and leads to more excitons in the host to emit light.

  9. The effect of dopant-induced electron traps on spectrum evolution of doped organic light-emitting devices

    International Nuclear Information System (INIS)

    Zhan, Y.Q.; Zhou, J.; Zhou, Y.C.; Wu, Y.; Yang, H.; Li, F.Y.; Ding, X.M.; Hou, X.Y.

    2007-01-01

    A prototype of light emitting device with two symmetrically located Al/LiF electrodes is fabricated to study the voltage dependence of emission spectra. 4-(dicyanomethylene)-2-methyl-6- (pdimethylaminostyryl)-4H-pyran doped tris-(8-hydroxy-quinolinato) aluminum thin film is the emitting layer of the device. Experiments show that with increasing applied voltage the emission intensity of the device decreases, of which the dopant emission intensity decreases more steeply than that of the host. Based on the theory of space-charge-limited current in insulator with a single shallow trap level it is deduced that the photoluminescence intensity of the dopant emission decreases linearly with applied voltage, in good agreement with experimental measurements. The evolution of the emission spectra can be well explained by the suggested mechanism that the electrons are trapped in the dopant molecules, which blocks the energy transfer from the host, and leads to more excitons in the host to emit light

  10. Dopant atoms as quantum components in silicon nanoscale devices

    Science.gov (United States)

    Zhao, Xiaosong; Han, Weihua; Wang, Hao; Ma, Liuhong; Li, Xiaoming; Zhang, Wang; Yan, Wei; Yang, Fuhua

    2018-06-01

    Recent progress in nanoscale fabrication allows many fundamental studies of the few dopant atoms in various semiconductor nanostructures. Since the size of nanoscale devices has touched the limit of the nature, a single dopant atom may dominate the performance of the device. Besides, the quantum computing considered as a future choice beyond Moore's law also utilizes dopant atoms as functional units. Therefore, the dopant atoms will play a significant role in the future novel nanoscale devices. This review focuses on the study of few dopant atoms as quantum components in silicon nanoscale device. The control of the number of dopant atoms and unique quantum transport characteristics induced by dopant atoms are presented. It can be predicted that the development of nanoelectronics based on dopant atoms will pave the way for new possibilities in quantum electronics. Project supported by National Key R&D Program of China (No. 2016YFA0200503).

  11. Oxygen-induced high diffusion rate of magnesium dopants in GaN/AlGaN based UV LED heterostructures.

    Science.gov (United States)

    Michałowski, Paweł Piotr; Złotnik, Sebastian; Sitek, Jakub; Rosiński, Krzysztof; Rudziński, Mariusz

    2018-05-23

    Further development of GaN/AlGaN based optoelectronic devices requires optimization of the p-type material growth process. In particular, uncontrolled diffusion of Mg dopants may decrease the performance of a device. Thus it is meaningful to study the behavior of Mg and the origins of its diffusion in detail. In this work we have employed secondary ion mass spectrometry to study the diffusion of magnesium in GaN/AlGaN structures. We show that magnesium has a strong tendency to form Mg-H complexes which immobilize Mg atoms and restrain their diffusion. However, these complexes are not present in samples post-growth annealed in an oxygen atmosphere or Al-rich AlGaN structures which naturally have a high oxygen concentration. In these samples, more Mg atoms are free to diffuse and thus the average diffusion length is considerably larger than for a sample annealed in an inert atmosphere.

  12. Enhanced photocatalytic activity induced by sp 3 to sp 2 transition of carbon dopants in BiOCl crystals

    KAUST Repository

    Sun, Jianguo

    2017-09-19

    The insufficient light absorption and low quantum efficiency limit the photocatalytic performance of wide bandgap semiconductors. Here, we report a facile strategy to engineer the surface disordered defects of BiOCl nanosheets via carbon doping. The surface defects boost the light absorption and also the quantum yields, as the doped carbon atoms exhibit a transition from sp3 to sp2 hybridization at elevated temperature, corresponding to a change of assembly state from 3D cluster to 2D graphite-like structure. This transition results in an effective charge separation and thus one order of enhancement in photocatalytic activity toward phenol degradation under visible light. The current study opens an avenue to introduce sp3 to sp2 transition of carbon dopants for simultaneous increment of light absorption and quantum efficiency for application in photocatalysis and energy conversion.

  13. Dopant induced single electron tunneling within the sub-bands of single silicon NW tri-gate junctionless n-MOSFET

    Science.gov (United States)

    Uddin, Wasi; Georgiev, Yordan M.; Maity, Sarmistha; Das, Samaresh

    2017-09-01

    We report 1D electron transport of silicon junctionless tri-gate n-type transistor at 4.2 K. The step like curve observed in the current voltage characteristic suggests 1D transport. Besides the current steps for 1D transport, we found multiple spikes within individual steps, which we relate to inter-band single electron tunneling, mediated by the charged dopants available in the channel region. Clear Coulomb diamonds were observed in the stability diagram of the device. It is shown that a uniformly doped silicon nanowire can provide us the window for the single electron tunnelling. Back-gate versus front-gate color plot, where current is in a color scale, shows a crossover of the increased conduction region. This is a clear indication of the dopant-dopant interaction. It has been shown that back-gate biasing can be used to tune the coupling strength between the dopants.

  14. Amnestically Induced Persistence in Random Walks

    Science.gov (United States)

    Cressoni, J. C.; da Silva, Marco Antonio Alves; Viswanathan, G. M.

    2007-02-01

    We study how the Hurst exponent α depends on the fraction f of the total time t remembered by non-Markovian random walkers that recall only the distant past. We find that otherwise nonpersistent random walkers switch to persistent behavior when inflicted with significant memory loss. Such memory losses induce the probability density function of the walker’s position to undergo a transition from Gaussian to non-Gaussian. We interpret these findings of persistence in terms of a breakdown of self-regulation mechanisms and discuss their possible relevance to some of the burdensome behavioral and psychological symptoms of Alzheimer’s disease and other dementias.

  15. Quantitative Characterization of the Nanoscale Local Lattice Strain Induced by Sr Dopants in La1.92Sr0.08CuO4

    Science.gov (United States)

    Lin, J. Q.; Liu, X.; Blackburn, E.; Wakimoto, S.; Ding, H.; Islam, Z.; Sinha, S. K.

    2018-05-01

    The nanometer scale lattice deformation brought about by the dopants in the high temperature superconducting cuprate La2 -xSrx CuO4 (x =0.08 ) was investigated by measuring the associated x-ray diffuse scattering around multiple Bragg peaks. A characteristic diffuse scattering pattern was observed, which can be well described by continuum elastic theory. With the fitted dipole force parameters, the acoustic-type lattice deformation pattern was reconstructed and found to be of similar size to lattice thermal vibration at 7 K. Our results address the long-term concern of dopant introduced local lattice inhomogeneity, and show that the associated nanometer scale lattice deformation is marginal and cannot, alone, be responsible for the patched variation in the spectral gaps observed with scanning tunneling microscopy in the cuprates.

  16. Model of dopant action in oxide cathodes

    International Nuclear Information System (INIS)

    Engelsen, Daniel den; Gaertner, Georg

    2005-01-01

    The paper describes an electrochemical model, which largely explains the formation of Ba in the oxide cathode at activation and normal operation. In a non-doped oxide cathode electrolysis of BaO is, besides the exchange reaction from the activators in the cathode nickel, an important source of Ba. By doping with rare earth oxides the conductivity of the oxide layer increases, which implies that the potential difference during current drawing over the oxide layer becomes lower and electrolysis of BaO is suppressed. This implies that the part of the electronic conductivity of the (Ba,Sr)O layer induced by the dopants also controls the sensitivity for poisoning: the higher the dopant level, the larger the sensitivity for poisoning. Furthermore, the suppression of electrolysis during normal operation largely explains why doped oxide cathodes have a better life performance than non-doped cathodes. Finally a hypothesis on the enhancement of sintering upon doping is presented

  17. Thermoluminescence glow curve for UV induced ZrO2:Ti phosphor with variable concentration of dopant and various heating rate

    Directory of Open Access Journals (Sweden)

    Neha Tiwari

    2014-10-01

    Full Text Available The present paper reports the synthesis and characterization of Ti doped ZrO2 nanophosphors. The effects of variable concentration of titanium on thermoluminescence (TL behaviour are studied. The samples were prepared by combustion a synthesis technique which is suitable for less time taking techniques also for large scale production for nano phosphors. The starting material used for sample preparation are Zr(NO33 and Ti(NO33 and urea used as a fuel. The prepared sample was characterized by X-ray diffraction technique (XRD with variable concentration of Ti (0.05–0.5 mol% there is no any phase change found with increase the concentration of Ti. Sample shows cubic structure and the particle size calculated by Scherer's formula. The surface morphology of prepared phosphor was determined by field emission gun scanning electron microscopy (FEGSEM technique for optimized concentration of dopant. The good connectivity with grains and the semi-sphere like structure was found by FEGSEM. The functional group analysis was determined by Fourier transform infrared (FTIR spectroscopic techniques. The prepared phosphor examined by thermoluminescence technique. For recording TL glow curve every time 2 mg phosphor was irradiated by UV 254 nm source and fixed the heating rate at 5 °C s−1. Sample shows well resolved peak at 167 °C with a shoulder peak at 376 °C. The higher temperature peak shows the well stability and less fading in prepared phosphor. Also the effect of Ti concentration at fixed UV exposure time was studied. The effect of UV exposure time and dose versus intensity plot was studied. Sample shows linear response with dose and broaden peak with high temperature shows the more stability and less fading in TL glow curve. The linear dose response, high stability and less fading phenomenon shows the sample may be useful for thermoluminescence dosimetry application. Trapping parameters are calculated for every recorded glow curve. The

  18. Dopant profile engineering of advanced Si MOSFET's using ion implantation

    International Nuclear Information System (INIS)

    Stolk, P.A.; Ponomarev, Y.V.; Schmitz, J.; Brandenburg, A.C.M.C. van; Roes, R.; Montree, A.H.; Woerlee, P.H.

    1999-01-01

    Ion implantation has been used to realize non-uniform, steep retrograde (SR) dopant profiles in the active channel region of advanced Si MOSFET's. After defining the transistor configuration, SR profiles were formed by dopant implantation through the polycrystalline Si gate and the gate oxide (through-the-gate, TG, implantation). The steep nature of the as-implanted profile was retained by applying rapid thermal annealing for dopant activation and implantation damage removal. For NMOS transistors, TG implantation of B yields improved transistor performance through increased carrier mobility, reduced junction capacitances, and reduced susceptibility to short-channel effects. Electrical measurements show that the gate oxide quality is not deteriorated by the ion-induced damage, demonstrating that transistor reliability is preserved. For PMOS transistors, TG implantation of P or As leads to unacceptable source/drain junction broadening as a result of transient enhanced dopant diffusion during thermal activation

  19. Invalidity of the Fermi liquid theory and magnetic phase transition in quasi-1D dopant-induced armchair-edged graphene nanoribbons

    Science.gov (United States)

    Hoi, Bui Dinh; Davoudiniya, Masoumeh; Yarmohammadi, Mohsen

    2018-04-01

    Based on theoretically tight-binding calculations considering nearest neighbors and Green's function technique, we show that the magnetic phase transition in both semiconducting and metallic armchair graphene nanoribbons with width ranging from 9.83 Å to 69.3 Å would be observed in the presence of injecting electrons by doping. This transition is explained by the temperature-dependent static charge susceptibility through calculation of the correlation function of charge density operators. This work showed that charge concentration of dopants in such system plays a crucial role in determining the magnetic phase. A variety of multicritical points such as transition temperatures and maximum susceptibility are compared in undoped and doped cases. Our findings show that there exist two different transition temperatures and maximum susceptibility depending on the ribbon width in doped structures. Another remarkable point refers to the invalidity (validity) of the Fermi liquid theory in nanoribbons-based systems at weak (strong) concentration of dopants. The obtained interesting results of magnetic phase transition in such system create a new potential for magnetic graphene nanoribbon-based devices.

  20. Electron-beam-induced reactivation of Si dopants in hydrogenated two-dimensional AlGaAs heterostructures: a possible new route for III-V nanostructure fabrication

    International Nuclear Information System (INIS)

    Kurowski, Ludovic; Bernard, Dorothee; Constant, Eugene; Decoster, Didier

    2004-01-01

    Hydrogen incorporation in n-type Si-doped GaAs epilayers is a well-known process which leads to the neutralization of the active Si impurities with the formation of SiH complexes. Recently, we have shown that SiH complex dissociation and, consequently, Si-dopant reactivation could occur when the epilayers are exposed to an electron beam. Two epilayers have been studied: the first is a 0.35 μm thick hydrogenated Si-doped GaAs epilayer and the second is Si planar-doped AlGaAs/GaAs/InGaAs heterostructures. Firstly, Hall effect measurements have been carried out on the epilayers exposed, after RF hydrogen plasma exposition, to increasing electron doses with different injection energies. For the 2D heterostructures, we have observed that the free carrier density N s does not vary significantly for weak electron densities. This reactivation presents a threshold value, contrary to the 0.35 μm epilayer in which N s varies quite linearly. It will be shown that such phenomena might be attributed to the filling of surface states as the dopants are progressively reactivated. Then, using a high spatial resolution electron beam lithography system, nanometric conductive patterns have been fabricated starting from hydrogenated epilayers. Electric measurements have been performed and the results obtained show that about 15 nm spatial resolution could be expected. In conclusion, taking into account this spatial resolution, the high spatial contrast of conductivity which could be expected due to the existence of an electron dose threshold, and the high mobility of the AlGaAs/GaAs/InGaAs heterostructure, the effects described in this paper could open a new way for the fabrication of III-V 1D or 2D mesoscopic structures for electronic or optoelectronic applications

  1. Ferromagnetic clusters induced by a nonmagnetic random disorder in diluted magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bui, Dinh-Hoi [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Physics Department, Hue University’s College of Education, 34 Le Loi, Hue (Viet Nam); Phan, Van-Nham, E-mail: phanvannham@dtu.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam)

    2016-12-15

    In this work, we analyze the nonmagnetic random disorder leading to a formation of ferromagnetic clusters in diluted magnetic semiconductors. The nonmagnetic random disorder arises from randomness in the host lattice. Including the disorder to the Kondo lattice model with random distribution of magnetic dopants, the ferromagnetic–paramagnetic transition in the system is investigated in the framework of dynamical mean-field theory. At a certain low temperature one finds a fraction of ferromagnetic sites transiting to the paramagnetic state. Enlarging the nonmagnetic random disorder strength, the paramagnetic regimes expand resulting in the formation of the ferromagnetic clusters.

  2. The Synergistic Effect of Nitrogen Dopant and Calcination Temperature on the Visible-Light-Induced Photoactivity of N-Doped TiO2

    Directory of Open Access Journals (Sweden)

    Yao-Tung Lin

    2013-01-01

    Full Text Available The synergistic effect of nitrogen content and calcinations temperature on the N-doped TiO2 catalysts prepared by sol-gel method was investigated. The phase and structure, chemical state, optical properties, and surface area/pore distribution of N-doped TiO2 were characterized using X-ray diffraction spectrometer, high-resolution transmission electron microscope, X-ray photoelectron spectroscopy, UV-vis diffusion reflectance spectroscopy, and Brunauer-Emmett-Teller specific surface area. Finding showed that the photocatalytic activity of N-doped TiO2 was greatly enhanced compared to pure TiO2 under visible irradiation. N dopants could retard the transformation from anatase to rutile phase. Namely, N-doping effect is attributed to the anatase phase stabilization. The results showed nitrogen atoms were incorporated into the interstitial positions of the TiO2 lattice. Ethylene was used to evaluate the photocatalytic activity of samples under visible-light illumination. The results suggested good anatase crystallization, smaller particle size, and larger surface are beneficial for photocatalytic activity of N-doped TiO2. The N-doped TiO2 catalyst prepared with ammonia to titanium isopropoxide molar ratio of 2.0 and calcinated at 400°C showed the best photocatalytic ability.

  3. Photo-dissociation of hydrogen passivated dopants in gallium arsenide

    International Nuclear Information System (INIS)

    Tong, L.; Larsson, J.A.; Nolan, M.; Murtagh, M.; Greer, J.C.; Barbe, M.; Bailly, F.; Chevallier, J.; Silvestre, F.S.; Loridant-Bernard, D.; Constant, E.; Constant, F.M.

    2002-01-01

    A theoretical and experimental study of the photo-dissociation mechanisms of hydrogen passivated n- and p-type dopants in gallium arsenide is presented. The photo-induced dissociation of the Si Ga -H complex has been observed for relatively low photon energies (3.48 eV), whereas the photo-dissociation of C As -H is not observed for photon energies up to 5.58 eV. This fundamental difference in the photo-dissociation behavior between the two dopants is explained in terms of the localized excitation energies about the Si-H and C-H bonds

  4. Influence of Dopants in ZnO Films on Defects

    Science.gov (United States)

    Peng, Cheng-Xiao; Weng, Hui-Min; Zhang, Yang; Ma, Xing-Ping; Ye, Bang-Jiao

    2008-12-01

    The influence of dopants in ZnO films on defects is investigated by slow positron annihilation technique. The results show S that parameters meet SAl > Sun > SAg for Al-doped ZnO films, undoped and Ag-doped ZnO films. Zinc vacancies are found in all ZnO films with different dopants. According to S parameter and the same defect type, it can be induced that the zinc vacancy concentration is the highest in the Al-doped ZnO film, and it is the least in the Ag-doped ZnO film. When Al atoms are doped in the ZnO films grown on silicon substrates, Zn vacancies increase as compared to the undoped and Ag-doped ZnO films. The dopant concentration could determine the position of Fermi level in materials, while defect formation energy of zinc vacancy strongly depends on the position of Fermi level, so its concentration varies with dopant element and dopant concentration.

  5. Using Dopants to Tune Oxygen Vacancy Formation in Transition Metal Oxide Resistive Memory.

    Science.gov (United States)

    Jiang, Hao; Stewart, Derek A

    2017-05-17

    Introducing dopants is an important way to tailor and improve electronic properties of transition metal oxides used as high-k dielectric thin films and resistance switching layers in leading memory technologies, such as dynamic and resistive random access memory (ReRAM). Ta 2 O 5 has recently received increasing interest because Ta 2 O 5 -based ReRAM demonstrates high switching speed, long endurance, and low operating voltage. However, advances in optimizing device characteristics with dopants have been hindered by limited and contradictory experiments in this field. We report on a systematic study on how various metal dopants affect oxygen vacancy formation in crystalline and amorphous Ta 2 O 5 from first principles. We find that isoelectronic dopants and weak n-type dopants have little impact on neutral vacancy formation energy and that p-type dopants can lower the formation energy significantly by introducing holes into the system. In contrast, n-type dopants have a deleterious effect and actually increase the formation energy for charged oxygen vacancies. Given the similar doping trend reported for other binary transition metal oxides, this doping trend should be universally valid for typical binary transition metal oxides. Based on this guideline, we propose that p-type dopants (Al, Hf, Zr, and Ti) can lower the forming/set voltage and improve retention properties of Ta 2 O 5 ReRAM.

  6. Charge separation technique for metal-oxide-silicon capacitors in the presence of hydrogen deactivated dopants

    International Nuclear Information System (INIS)

    Witczak, Steven C.; Winokur, Peter S.; Lacoe, Ronald C.; Mayer, Donald C.

    2000-01-01

    An improved charge separation technique for metal-oxide-silicon (MOS) capacitors is presented which accounts for the deactivation of substrate dopants by hydrogen at elevated irradiation temperatures or small irradiation biases. Using high-frequency capacitance-voltage (C-V) measurements, radiation-induced inversion voltage shifts are separated into components due to oxide trapped charge, interface traps and deactivated dopants, where the latter is computed from a reduction in Si capacitance. In the limit of no radiation-induced dopant deactivation, this approach reduces to the standard midgap charge separation technique used widely for the analysis of room-temperature irradiations. The technique is demonstrated on a p-type MOS capacitor irradiated with 60 Co γ-rays at 100 C and zero bias, where the dopant deactivation is significant

  7. Microwave modulation characteristics of twisted liquid crystals with chiral dopant

    Directory of Open Access Journals (Sweden)

    Rui Yuan

    2017-01-01

    Full Text Available Adding a chiral dopant in twisted nematic (TN liquid crystal cell can stabilize the orientation of liquid crystal molecules, particularly in high TN (HTN or super TN (STN liquid crystal cells. The difference in pitches in liquid crystal is induced by the chiral dopant, and these different pitches affect the orientation of liquid crystal director under an external applied voltage and influence the characteristics of microwave modulation. To illustrate this point, the microwave phase shift per unit length (MPSL versus voltage is calculated on the basis of the elastic theory of liquid crystal and the finite-difference iterative method. Enhancing the pitch induced by the chiral dopant in liquid crystal increases the MPSLs, but the stability of the twisted structures is decreased. Thus, appropriate pitches of 100d, 4d, and 2d can be applied in TN, HTN, and STN cells with cell gap d to enhance the characteristics of microwave modulation and stabilize the structures in twisted cell. This method can improve the characteristics of liquid crystal microwave modulators such that the operating voltage and the size of such phase shifters can be decreased.

  8. On the pertinence to Physics of random walks induced by random dynamical systems: a survey

    International Nuclear Information System (INIS)

    Petritis, Dimitri

    2016-01-01

    Let be an abstract space and a denumerable (finite or infinite) alphabet. Suppose that is a family of functions such that for all we have and a family of transformations . The pair (( S_a)_a , ( p_a)_a ) is termed an iterated function system with place dependent probabilities. Such systems can be thought as generalisations of random dynamical systems. As a matter of fact, suppose we start from a given ; we pick then randomly, with probability p_a (x) , the transformation S_a and evolve to S_a (x) . We are interested in the behaviour of the system when the iteration continues indefinitely. Random walks of the above type are omnipresent in both classical and quantum Physics. To give a small sample of occurrences we mention: random walks on the affine group, random walks on Penrose lattices, random walks on partially directed lattices, evolution of density matrices induced by repeated quantum measurements, quantum channels, quantum random walks, etc. In this article, we review some basic properties of such systems and provide with a pathfinder in the extensive bibliography (both on mathematical and physical sides) where the main results have been originally published. (paper)

  9. Prospects for photosensitive dopants in liquid argon

    International Nuclear Information System (INIS)

    Anderson, D.F.

    1990-12-01

    Evidence is presented that the addition of a few ppM of a photosensitive dopant to a U/liquid argon or Pb/liquid argon calorimeter will make a substantial reduction in the e/π ratio. Previous results indicating high voltage problems and no change in the e/π ratio in tests of photosensitive dopants with the Fermilab D0 experiment's U/liquid argon tests calorimeter are also explained. 13 refs., 3 figs

  10. Two-dimensional dopant profiling for shallow junctions by TEM and AFM

    International Nuclear Information System (INIS)

    Yoo, K.

    2000-01-01

    respectively. For the Etch/AFM method, to overcome the artefact induced by tip size, for the first time a detailed investigation was made of the convolution occurring for the etched MOSFET structures and a double deconvolution method was developed. The resulting 2-D dopant profiles for n + /p 80nm deep junction sample showed reasonable agreement with Etch/TEM method demonstrating the advantage of the developed deconvolution method. For the first time, the present work successfully achieved quantitative 2-D dopant profiles for sub-100nm deep junctions. The developed dopant profiling methods are expected to contribute to the research and development for next generation devices. (author)

  11. Synthesis and characterization of the polyaniline dopant Schiff base

    Directory of Open Access Journals (Sweden)

    Mirian Y. Matsumoto

    2012-06-01

    Full Text Available The Schiff base, N-salicilidenoanilina was used as dopant to induce polymerization of aniline and thus preparing polyaniline (PAni. The different conditions of preparation, including Schiff base structure, and the dosage of acidity reaction medium, were investigated to discuss the influence of these conditions relative conductivity of the resulting samples. The products were also characterized by Fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis, electrochemical impedance spectroscopy (EIE. The results showed the synthesis conditions play an important in the formation and the final properties of the polyaniline

  12. Defect evolution and dopant activation in laser annealed Si and Ge

    DEFF Research Database (Denmark)

    Cristiano, F.; Shayesteh, M.; Duffy, R.

    2016-01-01

    Defect evolution and dopant activation are intimately related to the use of ion implantation and annealing, traditionally used to dope semiconductors during device fabrication. Ultra-fast laser thermal annealing (LTA) is one of the most promising solutions for the achievement of abrupt and highly...... doped junctions. In this paper, we report some recent investigations focused on this annealing method, with particular emphasis on the investigation of the formation and evolution of implant/anneal induced defects and their impact on dopant activation. In the case of laser annealed Silicon, we show...

  13. Magnetic properties of ZnO nanowires with Li dopants and Zn vacancies

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Xinhong; Cai, Ningning [Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications), Ministry of Education, P.O. Box 72, Beijing 100876 (China); Yang, Chuanghua [School of Physics and Telecommunication Engineering, Shanxi University of Technology (SNUT), Hanzhong 723001, Shanxi (China); Chen, Jun [Beijing Applied Physics and Computational Mathematics, Beijing 100088 (China); Lu, Pengfei, E-mail: photon.bupt@gmail.com [Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications), Ministry of Education, P.O. Box 72, Beijing 100876 (China)

    2016-04-30

    The electronic and magnetic properties of ZnO nanowire with Li dopants and vacancies have been investigated using first-principles density functional theory. It is found that the Zn vacancy can induce magnetism while increasing the formation energy of the system. However, the calculated results indicate that the introduction of Li-dopants will reduce the formation energy of system. We also have studied the magnetic couplings with vacancies as well as their corresponding configurations with Li-dopants for four configurations of ZnO nanowires. The results show that ferromagnetic properties can be improved/reversed after the introduction of Li-dopants. Ferromagnetic mechanism is originated from the fierce p–p hybridization of O near the Fermi level. We find that ferromagnetism of Li-doped ZnO nanowires with Zn vacancies can be realized at room temperature and they are promising spintronic materials. - Highlights: • Li-dopants will reduce the formation energy of ZnO nanowires with Zn vacancy. • The fierce p–p hybridization of O near Fermi level is responsible for FM properties. • Li-doped ZnO–V{sub Zn} nanowire is a promising FM semiconductor material.

  14. Carrier illumination measurement of dopant lateral diffusion

    International Nuclear Information System (INIS)

    Budiarto, E.; Segovia, M.; Borden, P.; Felch, S.

    2005-01-01

    This paper describes the application of the carrier illumination technique to non-destructively measure the lateral diffusion of implanted dopants after annealing. Experiments to validate the feasibility of this method employed test structures with a constant line width of 300 nm and varying undoped spaces of 100-5000 nm. The test patterns were implanted with a p-type dopant and annealed in a 3 x 3 matrix. For each implant condition, the measured lateral diffusion was found to increase with annealing temperature, as expected. More interestingly, the lateral diffusion was not observed to relate to the vertical diffusion by a fixed proportionality factor, as is usually assumed. The ratio of lateral to vertical diffusion varies with annealing temperature, with a trend that depends on the implant condition

  15. Profiling N-Type Dopants in Silicon

    Czech Academy of Sciences Publication Activity Database

    Hovorka, Miloš; Mika, Filip; Mikulík, P.; Frank, Luděk

    2010-01-01

    Roč. 51, č. 2 (2010), s. 237-242 ISSN 1345-9678 R&D Projects: GA ČR GP102/09/P543; GA AV ČR IAA100650803 Institutional research plan: CEZ:AV0Z20650511 Keywords : silicon * dopant contrast * photoemission electron microscopy * scanning electron microscopy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.779, year: 2010 http://www.jim.or.jp/journal/e/51/02/237.html

  16. Application of real space Kerker method in simulating gate-all-around nanowire transistors with realistic discrete dopants*

    International Nuclear Information System (INIS)

    Li Chang-Sheng; Ma Lei; Guo Jie-Rong

    2017-01-01

    We adopt a self-consistent real space Kerker method to prevent the divergence from charge sloshing in the simulating transistors with realistic discrete dopants in the source and drain regions. The method achieves efficient convergence by avoiding unrealistic long range charge sloshing but keeping effects from short range charge sloshing. Numerical results show that discrete dopants in the source and drain regions could have a bigger influence on the electrical variability than the usual continuous doping without considering charge sloshing. Few discrete dopants and the narrow geometry create a situation with short range Coulomb screening and oscillations of charge density in real space. The dopants induced quasi-localized defect modes in the source region experience short range oscillations in order to reach the drain end of the device. The charging of the defect modes and the oscillations of the charge density are identified by the simulation of the electron density. (paper)

  17. induced by cadmium using random amplified polymorphic DNA

    African Journals Online (AJOL)

    darya

    2013-04-17

    Apr 17, 2013 ... metallurgy, painting, plastic production, etc., and is being released into the biosphere, and ...... aquatic macrophytes: Random amplified polymorphic DNA analysis and identification of ... ecotoxicology. Toxicol. Ecotoxicol.

  18. Transport in Silicon Nanowires: Role of Radial Dopant Profile

    DEFF Research Database (Denmark)

    Markussen, Troels; Rurali, Riccardo; Jauho, Antti-Pekka

    2008-01-01

    distributions of P dopant impurities. We find that the radial distribution of the dopants influences the conductance properties significantly: surface doped wires have longer mean-free paths and smaller sample-to-sample fluctuations in the cross-over from ballistic to diffusive transport. These findings can...

  19. Effect of different carbon fillers and dopant acids on electrical ...

    Indian Academy of Sciences (India)

    The nature of both the carbon filler and the dopant acid can significantly influence the conductivity of these nanocomposites. This paper describes the effects of carbon fillers like carbon black (CB), graphite (GR) and muti-walled carbon nanotubes (MWCNT) and of dopant acids like methane sulfonic acid (MSA), camphor ...

  20. Effect of phosphorus dopant concentration on the carrier mobility in ...

    African Journals Online (AJOL)

    This study investigated the effect of phosphorus dopant concentration on mobility of crystalline silicon (c-Si). It considers different temperature ranges, from 100 K to 500 K, and dopant concentration from 1012 cm-3 to 1020 cm-3 in relation to its effect on the mobility of the crystalline silicon. This study indicates that the ...

  1. Subquantum nonlocal correlations induced by the background random field

    Energy Technology Data Exchange (ETDEWEB)

    Khrennikov, Andrei, E-mail: Andrei.Khrennikov@lnu.s [International Center for Mathematical Modelling in Physics and Cognitive Sciences, Linnaeus University, Vaexjoe (Sweden); Institute of Information Security, Russian State University for Humanities, Moscow (Russian Federation)

    2011-10-15

    We developed a purely field model of microphenomena-prequantum classical statistical field theory (PCSFT). This model not only reproduces important probabilistic predictions of quantum mechanics (QM) including correlations for entangled systems, but also gives a possibility to go beyond QM, i.e. to make predictions of phenomena that could be observed at the subquantum level. In this paper, we discuss one such prediction-the existence of nonlocal correlations between prequantum random fields corresponding to all quantum systems. (And by PCSFT, quantum systems are represented by classical Gaussian random fields and quantum observables by quadratic forms of these fields.) The source of these correlations is the common background field. Thus all prequantum random fields are 'entangled', but in the sense of classical signal theory. On the one hand, PCSFT demystifies quantum nonlocality by reducing it to nonlocal classical correlations based on the common random background. On the other hand, it demonstrates total generality of such correlations. They exist even for distinguishable quantum systems in factorizable states (by PCSFT terminology-for Gaussian random fields with covariance operators corresponding to factorizable quantum states).

  2. Subquantum nonlocal correlations induced by the background random field

    International Nuclear Information System (INIS)

    Khrennikov, Andrei

    2011-01-01

    We developed a purely field model of microphenomena-prequantum classical statistical field theory (PCSFT). This model not only reproduces important probabilistic predictions of quantum mechanics (QM) including correlations for entangled systems, but also gives a possibility to go beyond QM, i.e. to make predictions of phenomena that could be observed at the subquantum level. In this paper, we discuss one such prediction-the existence of nonlocal correlations between prequantum random fields corresponding to all quantum systems. (And by PCSFT, quantum systems are represented by classical Gaussian random fields and quantum observables by quadratic forms of these fields.) The source of these correlations is the common background field. Thus all prequantum random fields are 'entangled', but in the sense of classical signal theory. On the one hand, PCSFT demystifies quantum nonlocality by reducing it to nonlocal classical correlations based on the common random background. On the other hand, it demonstrates total generality of such correlations. They exist even for distinguishable quantum systems in factorizable states (by PCSFT terminology-for Gaussian random fields with covariance operators corresponding to factorizable quantum states).

  3. Dopant ink composition and method of fabricating a solar cell there from

    Energy Technology Data Exchange (ETDEWEB)

    Loscutoff, Paul; Wu, Kahn; Molesa, Steven Edward

    2017-10-25

    Dopant ink compositions and methods of fabricating solar cells there from are described. A dopant ink composition may include a cross-linkable matrix precursor, a bound dopant species, and a solvent. A method of fabricating a solar cell may include delivering a dopant ink composition to a region above a substrate. The dopant ink composition includes a cross-linkable matrix precursor, a bound dopant species, and a solvent. The method also includes baking the dopant ink composition to remove a substantial portion of the solvent of the dopant ink composition, curing the baked dopant ink composition to cross-link a substantial portion of the cross-linkable matrix precursor of the dopant ink composition, and driving dopants from the cured dopant ink composition toward the substrate.

  4. Dopant ink composition and method of fabricating a solar cell there from

    Science.gov (United States)

    Loscutoff, Paul; Wu, Kahn; Molesa, Steven Edward

    2015-03-31

    Dopant ink compositions and methods of fabricating solar cells there from are described. A dopant ink composition may include a cross-linkable matrix precursor, a bound dopant species, and a solvent. A method of fabricating a solar cell may include delivering a dopant ink composition to a region above a substrate. The dopant ink composition includes a cross-linkable matrix precursor, a bound dopant species, and a solvent. The method also includes baking the dopant ink composition to remove a substantial portion of the solvent of the dopant ink composition, curing the baked dopant ink composition to cross-link a substantial portion of the cross-linkable matrix precursor of the dopant ink composition, and driving dopants from the cured dopant ink composition toward the substrate.

  5. About influence of buffer porous layers between epitaxial layers of heterostructure on distributions of concentrations of dopants in heterobipolar transistors

    Directory of Open Access Journals (Sweden)

    E Pankratov

    2016-10-01

    Full Text Available In this paper we introduce an approach to manufacture a heterobipolar transistors. Framework this approach we consider doping by diffusion or by ion implantation of required parts of a heterostructure with special configuration and optimization of annealing of dopant and/or radiation defects. In this case one have possibility to manufacture bipolar transistors, which include into itself p-n-junctions with higher sharpness and smaller dimensions. We also consider influence of presents of buffer porous layers between epitaxial layers of heterostructure on distributions of concentrations of dopants in the considered transistors. An approach to decrease value of mismatch-induced stress has been considered.

  6. Correlated random walks induced by dynamical wavefunction collapse

    Science.gov (United States)

    Bedingham, Daniel

    2015-03-01

    Wavefunction collapse models modify Schrödinger's equation so that it describes the collapse of a superposition of macroscopically distinguishable states as a genuine physical process [PRA 42, 78 (1990)]. This provides a basis for the resolution of the quantum measurement problem. An additional generic consequence of the collapse mechanism is that it causes particles to exhibit a tiny random diffusive motion. Furthermore, the diffusions of two sufficiently nearby particles are positively correlated -- it is more likely that the particles diffuse in the same direction than would happen if they behaved independently [PRA 89, 032713 (2014)]. The use of this effect is proposed as an experimental test of wave function collapse models in which pairs of nanoparticles are simultaneously released from nearby traps and allowed a brief period of free fall. The random displacements of the particles are then measured. The experiment must be carried out at sufficiently low temperature and pressure for the collapse effects to dominate over the ambient environmental noise. It is argued that these constraints can be satisfied by current technologies for a large class of viable wavefunction collapse models. Work supported by the Templeton World Charity Foundation.

  7. Mechanism of dopant-vacancy association in α-quartz GeO2

    KAUST Repository

    Wang, Hao; Chroneos, Alexander; Schwingenschlö gl, Udo

    2013-01-01

    Improving the electron mobility of devices such as Ge metal oxide semiconductor field effect transistors requires good Ge/dielectric interfaces. GeO2 thus is reconsidered as a passivation layer for Ge. However, O-vacancies need to be controlled as they have a deleterious impact on the properties. We employ electronic structure calculations to investigate the introduction of trivalent ions (Al, Y, and La) in α-quartz GeO2. The binding energies of the dopant-vacancy pairs reveal that dopants can be used to control the O-vacancies and reduce the induced dangling bonds. It is proposed that the introduction of Al will limit the concentration of O-vacancies at low Fermi energy.

  8. Mechanism of dopant-vacancy association in α-quartz GeO2

    KAUST Repository

    Wang, Hao

    2013-02-28

    Improving the electron mobility of devices such as Ge metal oxide semiconductor field effect transistors requires good Ge/dielectric interfaces. GeO2 thus is reconsidered as a passivation layer for Ge. However, O-vacancies need to be controlled as they have a deleterious impact on the properties. We employ electronic structure calculations to investigate the introduction of trivalent ions (Al, Y, and La) in α-quartz GeO2. The binding energies of the dopant-vacancy pairs reveal that dopants can be used to control the O-vacancies and reduce the induced dangling bonds. It is proposed that the introduction of Al will limit the concentration of O-vacancies at low Fermi energy.

  9. Metal oxalate complexes as novel inorganic dopants: Studies on ...

    Indian Academy of Sciences (India)

    Unknown

    UV-visible and IR spectral features not only confirmed the polyaniline doping by complex anions but also substantiated ... MoS3 dopant. Although inorganic metal complexes bear- ... distilled water and then with methanol and acetone until.

  10. Extended OLED operational lifetime through phosphorescent dopant profile management

    Science.gov (United States)

    Forrest, Stephen R.; Zhang, Yifan

    2017-05-30

    This disclosure relates, at least in part, an organic light emitting device, which in some embodiments comprises an anode; a cathode; a first emissive layer disposed between the anode and the cathode, the first emissive layer comprising an electron transporting compound and a phosphorescent emissive dopant compound; and wherein the phosphorescent emissive dopant compound has a concentration gradient, in the emissive layer, which varies from the cathode side of the first emissive layer to the anode side of the emissive layer.

  11. Magnetoresistance and charge transport in graphene governed by nitrogen dopants.

    Science.gov (United States)

    Rein, Markus; Richter, Nils; Parvez, Khaled; Feng, Xinliang; Sachdev, Hermann; Kläui, Mathias; Müllen, Klaus

    2015-02-24

    We identify the influence of nitrogen-doping on charge- and magnetotransport of single layer graphene by comparing doped and undoped samples. Both sample types are grown by chemical vapor deposition (CVD) and transferred in an identical process onto Si/SiO2 wafers. We characterize the samples by Raman spectroscopy as well as by variable temperature magnetotransport measurements. Over the entire temperature range, the charge transport properties of all undoped samples are in line with literature values. The nitrogen doping instead leads to a 6-fold increase in the charge carrier concentration up to 4 × 10(13) cm(-2) at room temperature, indicating highly effective doping. Additionally it results in the opening of a charge transport gap as revealed by the temperature dependence of the resistance. The magnetotransport exhibits a conspicuous sign change from positive Lorentz magnetoresistance (MR) in undoped to large negative MR that we can attribute to the doping induced disorder. At low magnetic fields, we use quantum transport signals to quantify the transport properties. Analyses based on weak localization models allow us to determine an orders of magnitude decrease in the phase coherence and scattering times for doped samples, since the dopants act as effective scattering centers.

  12. Dopant Adsorption and Incorporation at Irradiated GaN Surfaces

    Science.gov (United States)

    Sun, Qiang; Selloni, Annabella; Myers, Thomas; Doolittle, W. Alan

    2006-03-01

    Mg and O are two of the common dopants in GaN, but, in spite of extensive investigation, the atomic scale understanding of their adsorption and incorporation is still incomplete. In particular, high-energy electron irradiation, such as occurring during RHEED, has been reported to have an important effect on the incorporation of these impurities, but no study has addressed the detailed mechanisms of this effect yet. Here we use DFT calculations to study the adsorption and incorporation of Mg and O at the Ga- and N-polar GaN surfaces under various Ga, Mg and O coverage conditions as well as in presence of light or electron beam-induced electronic excitation. We find that the adsorption and incorporation of the two impurities have opposite surface polarity dependence: substitutional Mg prefers to incorporate at the GaN(0001) surface, while O prefers to adsorb and incorporate at the N-polar surface. In addition, our results indicate that in presence of light irradiation the tendency of Mg to surface-segregate is reduced. The O adsorption energy on the N-polar surface is also significantly reduced, consistent with the experimental observation of a much smaller concentration of oxygen in the irradiated samples.

  13. Directed Atom-by-Atom Assembly of Dopants in Silicon.

    Science.gov (United States)

    Hudak, Bethany M; Song, Jiaming; Sims, Hunter; Troparevsky, M Claudia; Humble, Travis S; Pantelides, Sokrates T; Snijders, Paul C; Lupini, Andrew R

    2018-05-17

    The ability to controllably position single atoms inside materials is key for the ultimate fabrication of devices with functionalities governed by atomic-scale properties. Single bismuth dopant atoms in silicon provide an ideal case study in view of proposals for single-dopant quantum bits. However, bismuth is the least soluble pnictogen in silicon, meaning that the dopant atoms tend to migrate out of position during sample growth. Here, we demonstrate epitaxial growth of thin silicon films doped with bismuth. We use atomic-resolution aberration-corrected imaging to view the as-grown dopant distribution and then to controllably position single dopants inside the film. Atomic-scale quantum-mechanical calculations corroborate the experimental findings. These results indicate that the scanning transmission electron microscope is of particular interest for assembling functional materials atom-by-atom because it offers both real-time monitoring and atom manipulation. We envision electron-beam manipulation of atoms inside materials as an achievable route to controllable assembly of structures of individual dopants.

  14. Small-world effect induced by weight randomization on regular networks

    International Nuclear Information System (INIS)

    Li, Menghui; Fan, Ying; Wang, Dahui; Li, Daqing; Wu, Jinshan; Di, Zengru

    2007-01-01

    The concept of edge weight provides additional depth for describing and adjusting the properties of networks. Redistribution of edge weight can effectively change the properties of networks even though the corresponding binary topology remains unchanged. Based on regular networks with initially homogeneous dissimilarity weights, random redistribution of edge weight can be enough to induce small world phenomena. The effects of random weight redistribution on both static properties and dynamical models of networks are investigated. The results reveal that randomization of weight can enhance the ability of synchronization of chaotic systems dramatically

  15. Random small interfering RNA library screen identifies siRNAs that induce human erythroleukemia cell differentiation.

    Science.gov (United States)

    Fan, Cuiqing; Xiong, Yuan; Zhu, Ning; Lu, Yabin; Zhang, Jiewen; Wang, Song; Liang, Zicai; Shen, Yan; Chen, Meihong

    2011-03-01

    Cancers are characterized by poor differentiation. Differentiation therapy is a strategy to alleviate malignant phenotypes by inducing cancer cell differentiation. Here we carried out a combinatorial high-throughput screen with a random siRNA library on human erythroleukemia K-562 cell differentiation. Two siRNAs screened from the library were validated to be able to induce erythroid differentiation to varying degrees, determined by CD235 and globin up-regulation, GATA-2 down-regulation, and cell growth inhibition. The screen we performed here is the first trial of screening cancer differentiation-inducing agents from a random siRNA library, demonstrating that a random siRNA library can be considered as a new resource in efforts to seek new therapeutic agents for cancers. As a random siRNA library has a broad coverage for the entire genome, including known/unknown genes and protein coding/non-coding sequences, screening using a random siRNA library can be expected to greatly augment the repertoire of therapeutic siRNAs for cancers.

  16. Study of Liquid Argon Dopants for LHC Hadron Calorimetry

    CERN Multimedia

    2002-01-01

    Hadron calorimetry based on the Liquid Argon Ionisation Chamber technique is one of the choice techniques for LHC-experimentation. A systematic study of the effect of selected dopants on Liquid Argon (LAr) will be carried out with the aim to achieve an improvement on: \\item (i)~``Fast Liquid Argon'' search and study of dopants to increase the drift velocity. It has been already shown that CH&sub4. added at a fraction of one percent increases the drift velocity by a factor of two or more. \\item (ii)~``Compensated Liquid Argon'' search and study of dopants to increase the response to densely ionising particles, resulting in improved compensation, such as photosensitive dopants. \\end{enumerate}\\\\ \\\\ Monitoring of the parameters involved in understanding the response of a calorimeter is essential. In case of doped LAr, the charge yield, the non-saturated drift velocity and the electron lifetime in the liquid should be precisely and simultaneously monitored as they all vary with the level of dopant concentrati...

  17. Instability in time-delayed switched systems induced by fast and random switching

    Science.gov (United States)

    Guo, Yao; Lin, Wei; Chen, Yuming; Wu, Jianhong

    2017-07-01

    In this paper, we consider a switched system comprising finitely or infinitely many subsystems described by linear time-delayed differential equations and a rule that orchestrates the system switching randomly among these subsystems, where the switching times are also randomly chosen. We first construct a counterintuitive example where even though all the time-delayed subsystems are exponentially stable, the behaviors of the randomly switched system change from stable dynamics to unstable dynamics with a decrease of the dwell time. Then by using the theories of stochastic processes and delay differential equations, we present a general result on when this fast and random switching induced instability should occur and we extend this to the case of nonlinear time-delayed switched systems as well.

  18. Ab initio calculation of chromium oxide containing Ti dopant

    International Nuclear Information System (INIS)

    Maldonado, Frank; Novillo, Corina; Stashans, Arvids

    2012-01-01

    Highlights: ► Microstructure changes in chromium oxide due to the Ti doping. ► Discovery of magnetism in Ti-doped α-Cr 2 O 3 crystal. ► Explanation of the origin of n-type electrical conductivity. ► Detailed analysis of electronic properties and density of states. ► As to authors’ knowledge, Ti-doped crystal is studied for the first time by the DFT. - Abstract: First-principles computations based on the density functional theory within the generalised gradient approximation and introduced intra-atomic interaction term for strongly correlated electrons (DFT + U method) has been used in this work. Ti impurity doping in the α-Cr 2 O 3 crystal has been carried out considering single defect model within the periodic crystalline structure. Atomic displacements, Bader charges on atoms have been computed showing that Ti dopant converts the chemical bonding in its neighbourhood into more ionic one. The defect-local microstructure is such as there exist general tendency of atomic rearrangements away with respect to the Ti imperfection. It is found that defect incorporation produces some local changes upon the band structure of the material and also induces a metallic state. That implies n-type electrical conductivity in the Ti-doped α-Cr 2 O 3 crystals and relates our work directly to a number of experimental studies in this area. Our results provide evidence over change in magnetic moments in the vicinity of defect, which means that the chromium oxide doped with Ti impurity might not act as an antiferromagnetic substance.

  19. Ab initio calculation of chromium oxide containing Ti dopant

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, Frank [Grupo de Fisicoquimica de Materiales, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Novillo, Corina [Escuela de Ingenieria Quimica, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Stashans, Arvids, E-mail: arvids@utpl.edu.ec [Grupo de Fisicoquimica de Materiales, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador)

    2012-01-17

    Highlights: Black-Right-Pointing-Pointer Microstructure changes in chromium oxide due to the Ti doping. Black-Right-Pointing-Pointer Discovery of magnetism in Ti-doped {alpha}-Cr{sub 2}O{sub 3} crystal. Black-Right-Pointing-Pointer Explanation of the origin of n-type electrical conductivity. Black-Right-Pointing-Pointer Detailed analysis of electronic properties and density of states. Black-Right-Pointing-Pointer As to authors' knowledge, Ti-doped crystal is studied for the first time by the DFT. - Abstract: First-principles computations based on the density functional theory within the generalised gradient approximation and introduced intra-atomic interaction term for strongly correlated electrons (DFT + U method) has been used in this work. Ti impurity doping in the {alpha}-Cr{sub 2}O{sub 3} crystal has been carried out considering single defect model within the periodic crystalline structure. Atomic displacements, Bader charges on atoms have been computed showing that Ti dopant converts the chemical bonding in its neighbourhood into more ionic one. The defect-local microstructure is such as there exist general tendency of atomic rearrangements away with respect to the Ti imperfection. It is found that defect incorporation produces some local changes upon the band structure of the material and also induces a metallic state. That implies n-type electrical conductivity in the Ti-doped {alpha}-Cr{sub 2}O{sub 3} crystals and relates our work directly to a number of experimental studies in this area. Our results provide evidence over change in magnetic moments in the vicinity of defect, which means that the chromium oxide doped with Ti impurity might not act as an antiferromagnetic substance.

  20. Substitutional Co dopant on the GaAs(110) surface: A first principles study

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhou; Yi, Zhijun, E-mail: zhijunyi@cumt.edu.cn

    2016-12-01

    Using the first principles ground state method, the electronic properties of single Co dopant replacing one Ga atom on the GaAs(110) surface are studied. Our calculated local density of states (LDOS) at Co site presents several distinct peaks above the valence band maximum (VBM), and this agrees with recent experiments. Moreover, the calculated STM images at bias voltages of 2 eV and −2 eV also agree with experiments. We discussed the origin of Co impurity induced distinct peaks, which can be characterized with the hybridization between Co d orbitals and p-like orbitals of surface As and Ga atoms.

  1. Thermally induced high frequency random amplitude fatigue damage at sharp notches

    International Nuclear Information System (INIS)

    Lewis, M.W.J.

    1992-01-01

    Experiments have been performed using the SUPERSOMITE facility to investigate the initiation and growth of fatigue cracks at the tips of sharp surface notches subjected to random thermally-induced stress. The experimental situation is complex involving plasticity, random amplitude loading and heat transfer medium/surface coupling. Crack initiation and growth prediction have been considered using the Creager and Neuber methods to compute the strain ranges in the vicinity of the notch root. Good agreement has been obtained between the experimental results and theoretical predictions. The paper reports the results of the analysis of the notch behavior

  2. Direct observation of dopant distribution in GaAs compound semiconductors using phase-shifting electron holography and Lorentz microscopy.

    Science.gov (United States)

    Sasaki, Hirokazu; Otomo, Shinya; Minato, Ryuichiro; Yamamoto, Kazuo; Hirayama, Tsukasa

    2014-06-01

    Phase-shifting electron holography and Lorentz microscopy were used to map dopant distributions in GaAs compound semiconductors with step-like dopant concentration. Transmission electron microscope specimens were prepared using a triple beam focused ion beam (FIB) system, which combines a Ga ion beam, a scanning electron microscope, and an Ar ion beam to remove the FIB damaged layers. The p-n junctions were clearly observed in both under-focused and over-focused Lorentz microscopy images. A phase image was obtained by using a phase-shifting reconstruction method to simultaneously achieve high sensitivity and high spatial resolution. Differences in dopant concentrations between 1 × 10(19) cm(-3) and 1 × 10(18) cm(-3) regions were clearly observed by using phase-shifting electron holography. We also interpreted phase profiles quantitatively by considering inactive layers induced by ion implantation during the FIB process. The thickness of an inactive layer at different dopant concentration area can be measured from the phase image. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Dopant density from maximum-minimum capacitance ratio of implanted MOS structures

    International Nuclear Information System (INIS)

    Brews, J.R.

    1982-01-01

    For uniformly doped structures, the ratio of the maximum to the minimum high frequency capacitance determines the dopant ion density per unit volume. Here it is shown that for implanted structures this 'max-min' dopant density estimate depends upon the dose and depth of the implant through the first moment of the depleted portion of the implant. A a result, the 'max-min' estimate of dopant ion density reflects neither the surface dopant density nor the average of the dopant density over the depletion layer. In particular, it is not clear how this dopant ion density estimate is related to the flatband capacitance. (author)

  4. Effect of substrate type, dopant and thermal treatment on ...

    Indian Academy of Sciences (India)

    Effect of substrate type, dopant and thermal treatment on physicochemical properties of TiO2–SnO2 sol–gel films. I STAMBOLOVA. ∗. , V BLASKOV, S VASSILEV†, M SHIPOCHKA and A LOUKANOV‡. Institute of General and Inorganic Chemistry, †Institute of Electrochemistry and Energy Systems, BAS,. Acad. G. Bonchev ...

  5. A helical naphthopyran dopant for photoresponsive cholesteric liquid crystals

    OpenAIRE

    Kim, Yuna; Frigoli, Michel; Vanthuyne, Nicolas; Tamaoki, Nobuyuki

    2017-01-01

    The first photoresponsive cholesteric liquid crystal comprising a photoisomerizable helical naphthopyran derivative dopant and a nematic liquid crystal is reported. An unprecedented helical twisting power switching ratio of over 90% allowed us to demonstrate multi-cycle rotational motion of micro-objects by UV light irradiation.

  6. Effect of Vitamin E on Oxaliplatin-induced Peripheral Neuropathy Prevention: A Randomized Controlled Trial.

    Science.gov (United States)

    Salehi, Zeinab; Roayaei, Mahnaz

    2015-01-01

    Peripheral neuropathy is one of the most important limitations of oxaliplatin base regimen, which is the standard for the treatment of colorectal cancer. Evidence has shown that Vitamin E may be protective in chemotherapy-induced peripheral neuropathy. The aim of this study is to evaluate the effect of Vitamin E administration on prevention of oxaliplatin-induced peripheral neuropathy in patients with colorectal cancer. This was a prospective randomized, controlled clinical trial. Patients with colorectal cancer and scheduled to receive oxaliplatin-based regimens were enrolled in this study. Enrolled patients were randomized into two groups. The first group received Vitamin E at a dose of 400 mg daily and the second group observed, until after the sixth course of the oxaliplatin regimen. For oxaliplatin-induced peripheral neuropathy assessment, we used the symptom experience diary questionnaire that completed at baseline and after the sixth course of chemotherapy. Only patients with a score of zero at baseline were eligible for this study. Thirty-two patients were randomized to the Vitamin E group and 33 to the control group. There was no difference in the mean peripheral neuropathy score changes (after - before) between two groups, after sixth course of the oxaliplatin base regimen (mean difference [after - before] of Vitamin E group = 6.37 ± 2.85, control group = 6.57 ± 2.94; P = 0.78). Peripheral neuropathy scores were significantly increased after intervention compared with a base line in each group (P peripheral neuropathy.

  7. Low-energy neutron-induced single-event upsets in static random access memory

    International Nuclear Information System (INIS)

    Guo Xiaoqiang; Guo Hongxia; Wang Guizhen; Ling Dongsheng; Chen Wei; Bai Xiaoyan; Yang Shanchao; Liu Yan

    2009-01-01

    The visual analysis method of data process was provided for neutron-induced single-event upset(SEU) in static random access memory(SRAM). The SEU effects of six CMOS SRAMs with different feature size(from 0.13 μm to 1.50 μm) were studied. The SEU experiments were performed using the neutron radiation environment at Xi'an pulsed reactor. And the dependence of low-energy neutron-induced SEU cross section on SRAM's feature size was given. The results indicate that the decreased critical charge is the dominant factor for the increase of single event effect sensitivity of SRAM devices with decreased feature size. Small-sized SRAM devices are more sensitive than large-sized ones to single event effect induced by low-energy neutrons. (authors)

  8. Molecular Electrical Doping of Organic Semiconductors: Fundamental Mechanisms and Emerging Dopant Design Rules.

    Science.gov (United States)

    Salzmann, Ingo; Heimel, Georg; Oehzelt, Martin; Winkler, Stefanie; Koch, Norbert

    2016-03-15

    Today's information society depends on our ability to controllably dope inorganic semiconductors, such as silicon, thereby tuning their electrical properties to application-specific demands. For optoelectronic devices, organic semiconductors, that is, conjugated polymers and molecules, have emerged as superior alternative owing to the ease of tuning their optical gap through chemical variability and their potential for low-cost, large-area processing on flexible substrates. There, the potential of molecular electrical doping for improving the performance of, for example, organic light-emitting devices or organic solar cells has only recently been established. The doping efficiency, however, remains conspicuously low, highlighting the fact that the underlying mechanisms of molecular doping in organic semiconductors are only little understood compared with their inorganic counterparts. Here, we review the broad range of phenomena observed upon molecularly doping organic semiconductors and identify two distinctly different scenarios: the pairwise formation of both organic semiconductor and dopant ions on one hand and the emergence of ground state charge transfer complexes between organic semiconductor and dopant through supramolecular hybridization of their respective frontier molecular orbitals on the other hand. Evidence for the occurrence of these two scenarios is subsequently discussed on the basis of the characteristic and strikingly different signatures of the individual species involved in the respective doping processes in a variety of spectroscopic techniques. The critical importance of a statistical view of doping, rather than a bimolecular picture, is then highlighted by employing numerical simulations, which reveal one of the main differences between inorganic and organic semiconductors to be their respective density of electronic states and the doping induced changes thereof. Engineering the density of states of doped organic semiconductors, the Fermi

  9. On substrate dopant engineering for ET-SOI MOSFETs with UT-BOX

    International Nuclear Information System (INIS)

    Wu Hao; Xu Miao; Wan Guangxing; Zhu Huilong; Zhao Lichuan; Tong Xiaodong; Zhao Chao; Chen Dapeng; Ye Tianchun

    2014-01-01

    The importance of substrate doping engineering for extremely thin SOI MOSFETs with ultra-thin buried oxide (ES-UB-MOSFETs) is demonstrated by simulation. A new substrate/backgate doping engineering, lateral non-uniform dopant distributions (LNDD) is investigated in ES-UB-MOSFETs. The effects of LNDD on device performance, V t -roll-off, channel mobility and random dopant fluctuation (RDF) are studied and optimized. Fixing the long channel threshold voltage (V t ) at 0.3 V, ES-UB-MOSFETs with lateral uniform doping in the substrate and forward back bias can scale only to 35 nm, meanwhile LNDD enables ES-UB-MOSFETs to scale to a 20 nm gate length, which is 43% smaller. The LNDD degradation is 10% of the carrier mobility both for nMOS and pMOS, but it is canceled out by a good short channel effect controlled by the LNDD. Fixing V t at 0.3 V, in long channel devices, due to more channel doping concentration for the LNDD technique, the RDF in LNDD controlled ES-UB-MOSFETs is worse than in back-bias controlled ES-UB-MOSFETs, but in the short channel, the RDF for LNDD controlled ES-UB-MOSFET is better due to its self-adaption of substrate doping engineering by using a fixed thickness inner-spacer. A novel process flow to form LNDD is proposed and simulated. (semiconductor devices)

  10. Computational Study of Nb-Doped-SnO2/Pt Interfaces: Dopant Segregation, Electronic Transport, and Catalytic Properties

    DEFF Research Database (Denmark)

    Fu, Qiang; Halck, Niels Bendtsen; Hansen, Heine Anton

    2017-01-01

    functional theory and non equilibrium Green's function study, we investigate the Nb segregation at Pt/NTO interfaces under operational electrochemical conditions, and reveal the resulting effects on the electronic transport, as well as the catalytic properties. We find that the Nb dopants tend to aggregate......Carbon black, a state-of-the-art cathode material for proton exchange membrane fuel cells (PEMFCs), suffers from severe corrosion in practical applications. Niobium-doped tin dioxide (NTO) is a promising alternative to support the Pt catalysts at the cathodes. Here, through a combined density....... The electronic conductivities of the Pt/NTO systems are not particularly sensitive to the distance of the Nb dopants relative to the interface, but depend explicitly on the Nb concentration and configuration. Through a dopant induced ligand effect, the NTO substrates can improve the catalytic activity of the Pt...

  11. Two opposite hysteresis curves in semiconductors with mobile dopants

    OpenAIRE

    Lee, Jae Sung; Lee, Shin Buhm; Kahng, Byungnam; Noh, Tae Won

    2012-01-01

    Recent experimental researches on semiconductors with mobile dopants (SMD) have reported unconventional hysteretic current-voltage (I-V) curves, which form dynamically in either one of the two opposite directions, the counter-figure-eight and figure-eight ways. However the fundamental theory for the formation of the two directions is still absent, and this poses a major barrier for researches oriented to applications. Here, we introduce a theoretical model to explain the origin of the two dir...

  12. Controlling energy transfer between multiple dopants within a single nanoparticle

    Science.gov (United States)

    DiMaio, Jeffrey R.; Sabatier, Clément; Kokuoz, Baris; Ballato, John

    2008-01-01

    Complex core-shell architectures are implemented within LaF3 nanoparticles to allow for a tailored degree of energy transfer (ET) between different rare earth dopants. By constraining specific dopants to individual shells, their relative distance to one another can be carefully controlled. Core-shell LaF3 nanoparticles doped with Tb3+ and Eu3+ and consisting of up to four layers were synthesized with an outer diameter of ≈10 nm. It is found that by varying the thicknesses of an undoped layer between a Tb3+-doped layer and a Eu3+-doped layer, the degree of ET can be engineered to allow for zero, partial, or total ET from a donor ion to an acceptor ion. More specifically, the ratio of the intensities of the 541-nm Tb3+ and 590 nm Eu3+ peaks was tailored from core-shell configuration that restricts ET is used. Beyond simply controlling ET, which can be limiting when designing materials for optical applications, this approach can be used to obtain truly engineered spectral features from nanoparticles and composites made from them. Further, it allows for a single excitation source to yield multiple discrete emissions from numerous lanthanide dopants that heretofore would have been quenched in a more conventional active optical material. PMID:18250307

  13. Radiation-induced segregation behavior in random and ordered face-centered cubic materials

    International Nuclear Information System (INIS)

    Bui, T.X.; Robertson, I.M.; Klatt, J.L.; Averback, R.S.; Kirk, M.A.

    1993-01-01

    Radiation-induced segregation has been studied in random solid solution alloys Ni-10%Al and Ni-6%Si, and in the ordered (L1 2 structure) intermetallics Ni 3 Si and Ni 3 Al. These materials were irradiated with 2 MeV He + ions at a temperature between 0.45 and 0.55T m and at an ion dose rate of approximately 1x10 -4 dpa per second. Subsequent Auger Electron Spectroscopy analysis showed that silicon segregated to the surface in the Ni-6% Si and Ni 3 Si alloys, and aluminum segregated away from the near surface region in the Ni-10% Al alloy. The Ni 3 Al samples exhibited no detectable segregation with respect to depth from the sample surface. The mechanisms that may give rise to this resistance to radiation induced segregation will be examined in terms of the mobility of the alloying constituents, ordering energies and atomic sizes. (orig.)

  14. Non-random intrachromosomal distribution of radiation-induced chromatid aberrations in Vicia faba. [Aberration clustering

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, I; Rieger, R [Akademie der Wissenschaften der DDR, Gatersleben. Zentralinst. fuer Genetik und Kulturpflanzenforschung

    1976-04-01

    A reconstructed karyotype of Vicia faba, with all chromosomes individually distinguishable, was treated with X-rays, fast neutrons, (/sup 3/H) uridine (/sup 3/HU). The distribution within metaphase chromosomes of induced chromatid aberrations was non-random for all agents used. Aberration clustering, in part agent specific, occurred in chromosome segments containing heterochromatin as defined by the presence of G bands. The pattern of aberration clustering found after treatment with /sup 3/HU did not allow the recognition of chromosome regions active in transcription during treatment. Furthermore, it was impossible to obtain unambiguous indications of the presence of AT- and GC-base clusters from the patterns of /sup 3/HT- and /sup 3/HC-induced chromatid aberrations, respectively. Possible reasons underlying these observations are discussed.

  15. A molecular dynamics study on the oxygen diffusion in doped fluorites: the effect of the dopant distribution

    Energy Technology Data Exchange (ETDEWEB)

    Tarancon, A. [M2E/XaRMAE/IREC, Department of Advanced Materials for Energy Applications, Catalonia Institute for Energy Research (IREC), Josep Pla 2, Torre 2, B2, 08019 Barcelona (Spain); Morata, A.; Peiro, F. [MIND/XaRMAE/IN2UB, Department of Electronics, University of Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Dezanneau, G. [Laboratoire Structures, Proprietes et Modelisation des Solides, Grande Voie des Vignes, Ecole Centrale Paris, F-92295 Chatenay-Malabry Cedex (France)

    2011-02-15

    The effect of the dopant distribution on the oxygen diffusion in doped fluorites typically used for solid oxide fuel cells electrolyte applications has been analysed by using molecular dynamics simulations. The oxygen mass transport in both yttria-stabilized zirconia (YSZ) and gadolinia-doped ceria has been studied and compared in the range of temperatures between 1,159 and 1,959 K. A new methodology based on the analysis of local environments is used to describe the diffusion process at an atomic scale. Preferred vacancy migration pathways, most suitable conduction models, energy landscapes and jump efficiency have been detailed for each material. Finally, a particular case of non-random distribution of dopants in YSZ is presented in order to quantitatively evaluate the effect of the dopant pattern on the mass transport properties and the potential of the methodology developed here for understanding and foreseeing real configurations at the nanoscale. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Atom-probe for FinFET dopant characterization

    Energy Technology Data Exchange (ETDEWEB)

    Kambham, A.K., E-mail: kambham@imec.be [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W. [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)

    2011-05-15

    With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10{sup o} and 45{sup o}) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: {yields} This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). {yields} Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. {yields} The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions

  17. Atom-probe for FinFET dopant characterization

    International Nuclear Information System (INIS)

    Kambham, A.K.; Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W.

    2011-01-01

    With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10 o and 45 o ) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: → This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). → Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. → The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions. → In this publication we

  18. Reflexology in the management of chemotherapy induced peripheral neuropathy: A pilot randomized controlled trial.

    Science.gov (United States)

    Kurt, Seda; Can, Gulbeyaz

    2018-02-01

    The current experimental study aimed to evaluate the effectiveness of reflexology on the management of symptoms and functions of chemotherapy-induced peripheral neuropathy (CIPN) in cancer patients. This study was conducted as a randomized controlled trial in 60 patients (30 experimental and 30 control patients) who had chemotherapy-induced Grade II-IV peripheral neuropathy complaints from July 2013 to November 2015. Data were collected using the patient identification form, European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Chemotherapy-Induced Peripheral Neuropathy (EORTC-CIPN-20) form, and BPI (used for related chemotherapy-induced peripheral neuropathy symptoms). The majority of the patients were being treated for gastrointestinal or breast cancer and were primarily receiving Eloxatine- or taxane-based treatment. It was found that reflexology applications did not lead to differences in either group in terms of peripheral neuropathy severity and incidence (p > 0.05) and only led to improvement in sensory functions in the experimental group (p Peripheral neuropathy, reflexology, chemotherapy, EORTC QLQ-CIPN-20, BPI. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. An inverse method for identification of a distributed random excitation acting on a vibrating structure flow-induced vibration application

    International Nuclear Information System (INIS)

    Perotin, L.; Granger, S.

    1997-01-01

    In order to improve the prediction of wear problems due to flow-induced vibration in PWR components, an inverse method for identifying a distributed random excitation acting on a dynamical system has been developed at EDF. This method, whose applications go far beyond the flow-induced vibration field, has been implemented into the MEIDEE software. This method is presented. (author)

  20. Metformin for treatment of antipsychotic-induced weight gain: a randomized, placebo-controlled study.

    Science.gov (United States)

    Wang, Man; Tong, Jian-hua; Zhu, Gang; Liang, Guang-ming; Yan, Hong-fei; Wang, Xiu-zhen

    2012-06-01

    To evaluate the efficacy of metformin for treatment of antipsychotic-induced weight gain. Seventy-two patients with first-episode schizophrenia who gained more than 7% of their predrug weight were randomly assigned to receive 1000 mg/d of metformin or placebo in addition to their ongoing treatment for 12 weeks using a double-blind study design. The primary outcome was change in body weight. The secondary outcomes included changes in body mass index, fasting glucose and insulin, and insulin resistance index. Of the 72 patients who were randomly assigned, 66 (91.6%) completed treatments. The body weight, body mass index, fasting insulin and insulin resistance index decreased significantly in the metformin group, but increased in the placebo group during the 12-week follow-up period. Significantly more patients in the metformin group lost their baseline weight by more than 7%, which was the cutoff for clinically meaningful weight loss. Metformin was tolerated well by majority patients. Metformin was effective and safe in attenuating antipsychotic-induced weight gain and insulin resistance in first-episode schizophrenia patients. Patients displayed good adherence to metformin. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Stochastic resonance induced by novel random transitions of motion of FitzHugh-Nagumo neuron model

    International Nuclear Information System (INIS)

    Zhang Guangjun; Xu Jianxue

    2005-01-01

    In contrast to the previous studies which have dealt with stochastic resonance induced by random transitions of system motion between two coexisting limit cycle attractors in the FitzHugh-Nagumo (FHN) neuron model after Hopf bifurcation and which have dealt with the phenomenon of stochastic resonance induced by external noise when the model with periodic input has only one attractor before Hopf bifurcation, in this paper we have focused our attention on stochastic resonance (SR) induced by a novel transition behavior, the transitions of motion of the model among one attractor on the left side of bifurcation point and two attractors on the right side of bifurcation point under the perturbation of noise. The results of research show: since one bifurcation of transition from one to two limit cycle attractors and the other bifurcation of transition from two to one limit cycle attractors occur in turn besides Hopf bifurcation, the novel transitions of motion of the model occur when bifurcation parameter is perturbed by weak internal noise; the bifurcation point of the model may stochastically slightly shift to the left or right when FHN neuron model is perturbed by external Gaussian distributed white noise, and then the novel transitions of system motion also occur under the perturbation of external noise; the novel transitions could induce SR alone, and when the novel transitions of motion of the model and the traditional transitions between two coexisting limit cycle attractors after bifurcation occur in the same process the SR also may occur with complicated behaviors types; the mechanism of SR induced by external noise when FHN neuron model with periodic input has only one attractor before Hopf bifurcation is related to this kind of novel transition mentioned above

  2. Effect of antioxidant supplementation on exercise-induced cardiac troponin release in cyclists: a randomized trial.

    Science.gov (United States)

    Klinkenberg, Lieke J J; Res, Peter T; Haenen, Guido R; Bast, Aalt; van Loon, Luc J C; van Dieijen-Visser, Marja P; Meex, Steven J R

    2013-01-01

    Cardiac troponin is the biochemical gold standard to diagnose acute myocardial infarction. Interestingly however, elevated cardiac troponin concentrations are also frequently observed during and after endurance-type exercise. Oxidative stress associated with prolonged exercise has been proposed to contribute to cardiac troponin release. Therefore, the aim of this study was to assess the effect of 4 week astaxanthin supplementation (a potent cartenoid antioxidant) on antioxidant capacity and exercise-induced cardiac troponin release in cyclists. Thirty-two well-trained male cyclists (age 25±5, weight 73±7 kg, maximum O2 uptake 60±5 mL·kg(-1)·min(-1), Wmax 5.4±0.5 W·kg(-1); mean ± SD) were repeatedly subjected to a laboratory based standardized exercise protocol before and after 4 weeks of astaxanthin (20 mg/day), or placebo supplementation in a double-blind randomized manner. Blood samples were obtained at baseline, at 60 min of cycling and immediately post-exercise (≈ 120 min). The pre-supplementation cycling trial induced a significant rise of median cardiac troponin T concentrations from 3.2 (IQR 3.0-4.2) to 4.7 ng/L (IQR 3.7-6.7), immediately post-exercise (pexercise-induced cardiac troponin T release (p = 0.24), as measured by the incremental area under the curve. Furthermore, the elevation in basal plasma astaxanthin concentrations was not reflected in changes in antioxidant capacity markers (trolox equivalent antioxidant capacity, uric acid, and malondialdehyde). Markers of inflammation (high-sensitivity C-reactive protein) and exercise-induced skeletal muscle damage (creatine kinase) were equally unaffected by astaxanthin supplementation. Despite substantial increases in plasma astaxanthin concentrations, astaxanthin supplementation did not improve antioxidant capacity in well-trained cyclists. Accordingly, exercise-induced cardiac troponin T concentrations were not affected by astaxanthin supplementation. ClinicalTrials.gov NCT01241877.

  3. A reliable method for the counting and control of single ions for single-dopant controlled devices

    International Nuclear Information System (INIS)

    Shinada, T; Kurosawa, T; Nakayama, H; Zhu, Y; Hori, M; Ohdomari, I

    2008-01-01

    By 2016, transistor device size will be just 10 nm. However, a transistor that is doped at a typical concentration of 10 18 atoms cm -3 has only one dopant atom in the active channel region. Therefore, it can be predicted that conventional doping methods such as ion implantation and thermal diffusion will not be available ten years from now. We have been developing a single-ion implantation (SII) method that enables us to implant dopant ions one-by-one into semiconductors until the desired number is reached. Here we report a simple but reliable method to control the number of single-dopant atoms by detecting the change in drain current induced by single-ion implantation. The drain current decreases in a stepwise fashion as a result of the clusters of displaced Si atoms created by every single-ion incidence. This result indicates that the single-ion detection method we have developed is capable of detecting single-ion incidence with 100% efficiency. Our method potentially could pave the way to future single-atom devices, including a solid-state quantum computer

  4. EFFECT OF FLAXSEED OIL IN PLAQUE INDUCED GINGIVITIS- A RANDOMIZED CONTROLLED DOUBLE-BLIND STUDY

    Directory of Open Access Journals (Sweden)

    Alluru Deepika

    2018-02-01

    Full Text Available BACKGROUND Oil pulling has been used extensively as a traditional remedy for many years. It is supposed to cure oral and systemic diseases, but the evidence is minimal. Intraorally it is supposed to cause strengthening of teeth, gums, and the jaw and to prevent decay, oral malodour, bleeding gums, dryness of the throat and cracked lips. The aim of this study was to evaluate the effect of oil pulling with flaxseed oil on plaque induced gingivitis and to compare its efficacy with chlorhexidine mouthwash. MATERIALS AND METHODS A total of 20 teenaged individuals attending the Out Patient - Department of Dentistry with plaque-induced gingivitis were selected for this study. They were divided randomly into the study or oil pulling group (Group I and the control or chlorhexidine group (Group II with 10 subjects in each group. Plaque index and modified gingival index scores were recorded for the selected individuals of both the groups. The study group was subjected to oil pulling with flaxseed oil every day in the morning before brushing whereas the control group used chlorhexidine mouth rinse. Reassessment of the index scores was done after 30 days in both the groups. RESULTS There was a statistically significant reduction of the pre- and post-values of the plaque and modified gingival index scores in both the study and control groups (P <0.001. CONCLUSION The oil pulling therapy with flaxseed oil is thus an effective adjuvant in reducing plaque-induced gingivitis.

  5. Moxibustion for the treatment of chemotherapy-induced leukopenia: a systematic review of randomized clinical trials.

    Science.gov (United States)

    Choi, Tae-Young; Lee, Myeong Soo; Ernst, Edzard

    2015-06-01

    The purpose of this study is to assess the efficacy of moxibustion as a treatment of chemotherapy-induced leukopenia. Twelve databases were searched from their inception through June 2014, without a language restriction. Randomized clinical trials (RCTs) were included if moxibustion was used as the sole treatment or as a part of a combination therapy with conventional drugs for leukopenia induced by chemotherapy. Cochrane criteria were used to assess the risk of bias. Six RCTs with a total of 681 patients met our inclusion criteria. All of the included RCTs were associated with a high risk of bias. The trials included patients with various types of cancer receiving ongoing chemotherapy or after chemotherapy. The results of two RCTs suggested the effectiveness of moxibustion combined with chemotherapy vs. chemotherapy alone. In four RCTs, moxibustion was more effective than conventional drug therapy. Six RCTs showed that moxibustion was more effective than various types of control interventions in increasing white blood cell counts. There is low level of evidence based on these six trials that demonstrates the superiority of moxibustion over drug therapies in the treatment of chemotherapy-induced leukopenia. However, the number of trials, the total sample size, and the methodological quality are too low to draw firm conclusions. Future RCTs appear to be warranted.

  6. Selectivity improvement of positive photoionization ion mobility spectrometry for rapid detection of organophosphorus pesticides by switching dopant concentration.

    Science.gov (United States)

    Zhou, Qinghua; Li, Jia; Wang, Bin; Wang, Shuang; Li, Haiyang; Chen, Jinyuan

    2018-01-01

    Ion mobility spectrometry (IMS) opened a potential avenue for the rapid detection of organophosphorus pesticides (OPPs), though an improved selectivity of stand-alone IMS was still in high demand. In this study, a stand-alone positive photoionization ion mobility spectrometry (PP-IMS) apparatus was constructed for the rapid detection of OPPs with acetone as dopant. The photoionization of acetone molecules was induced by the ultraviolet irradiation to produce the reactant ions (Ac) 2 H + , which were employed to ionize the OPPs including fenthion, imidan, phosphamidon, dursban, dimethoate and isocarbophos via the proton transfer reaction. Due to the difference in proton affinity, the tested OPPs exhibited the different dopant-dependent manners. Based on this observation, the switching of dopant concentration was implemented to improve the selectivity of PP-IMS for OPPs detection. For instance, a mixture of fenthion, dursban and dimethoate was tested. By switching the concentration of doped acetone from 0.07 to 2.33 to 19.94mgL -1 , the ion peaks of fenthion and dursban were inhibited in succession, achieving the selective detection of dimethoate at last. In addition, another mixture of imidan and phosphamidon was initially detected by PP-IMS with a dose of 0.07mgL -1 acetone, indicating that their ion peaks were severely overlapped; when the concentration of doped acetone was switched to 19.94mgL -1 , the inhibition of imidan signals promised the accurate identification of phosphamidon in mixture. Finally, the PP-IMS in combination of switching dopant concentration was applied to detect the mixed fenthion, dursban and dimethoate in Chinese cabbage, demonstrating the applicability of proposed method to real samples. Copyright © 2017. Published by Elsevier B.V.

  7. Dynamics of δ-dopant redistribution during heterostructure growth

    Science.gov (United States)

    Pankratov, E. L.

    2007-06-01

    It has recently been shown that growth of a multilayer structure with one or more delta-layers at high temperature leads to spreading and asymmetrization of the dopant distribution [see, for example, E.F.J. Schubert, Vac. Sci. Technol. A. 8, 2980 (1990), A.M. Nazmul, S. Sugahara, M. Tanaka, J. Crystal Growth 251, 303 (2003); R.C. Newman, M.J. Ashwin, M.R. Fahy, L. Hart, S.N. Holmes, C. Roberts, X. Zhang, Phys. Rev. B 54, 8769 (1996); E.F. Schubert, J.M. Kuo, R.F. Kopf, H.S. Luftman, L.C. Hopkins, N.J. Sauer, J. Appl. Phys. 67, 1969 (1990); P.M. Zagwijn, J.F. van der Veen, E. Vlieg, A.H. Reader, D.J. Gravesteijn, J. Appl. Phys. 78, 4933 (1995); W.S. Hobson, S.J. Pearton, E.F. Schubert, G. Cabaniss, Appl. Phys. Lett. 55, 1546 (1989); Delta Doping of Semiconductors, edited by E.F. Schubert (Cambridge University Press, Cambridge, 1996); Yu.N. Drozdov, N.B. Baidus', B.N. Zvonkov, M.N. Drozdov, O.I. Khrykin, V.I. Shashkin, Semiconductors 37, 194 (2003); E. Skuras, A.R. Long, B. Vogele, M.C. Holland, C.R. Stanley, E.A. Johnson, M. van der Burgt, H. Yaguchi, J. Singleton, Phys. Rev. B 59, 10712 (1999); G. Li, C. Jagadish, Solid-State Electronics 41, 1207 (1997)]. In this work analytical and numerical analysis of dopant dynamics in a delta-doped area of a multilayer structure has been accomplished using Fick's second law. Some reasons for asymmetrization of a delta-dopant distribution are illustrated. The spreading of a delta-layer has been estimated using example materials of a multilayer structure, a delta-layer and an overlayer.

  8. Products of random matrices from fixed trace and induced Ginibre ensembles

    Science.gov (United States)

    Akemann, Gernot; Cikovic, Milan

    2018-05-01

    We investigate the microcanonical version of the complex induced Ginibre ensemble, by introducing a fixed trace constraint for its second moment. Like for the canonical Ginibre ensemble, its complex eigenvalues can be interpreted as a two-dimensional Coulomb gas, which are now subject to a constraint and a modified, collective confining potential. Despite the lack of determinantal structure in this fixed trace ensemble, we compute all its density correlation functions at finite matrix size and compare to a fixed trace ensemble of normal matrices, representing a different Coulomb gas. Our main tool of investigation is the Laplace transform, that maps back the fixed trace to the induced Ginibre ensemble. Products of random matrices have been used to study the Lyapunov and stability exponents for chaotic dynamical systems, where the latter are based on the complex eigenvalues of the product matrix. Because little is known about the universality of the eigenvalue distribution of such product matrices, we then study the product of m induced Ginibre matrices with a fixed trace constraint—which are clearly non-Gaussian—and M  ‑  m such Ginibre matrices without constraint. Using an m-fold inverse Laplace transform, we obtain a concise result for the spectral density of such a mixed product matrix at finite matrix size, for arbitrary fixed m and M. Very recently local and global universality was proven by the authors and their coworker for a more general, single elliptic fixed trace ensemble in the bulk of the spectrum. Here, we argue that the spectral density of mixed products is in the same universality class as the product of M independent induced Ginibre ensembles.

  9. Valence and atomic size dependent exchange barriers in vacancy-mediated dopant diffusion

    International Nuclear Information System (INIS)

    Nelson, J.S.; Schultz, P.A.; Wright, A.F.

    1998-01-01

    First-principles pseudopotential calculations of dopant-vacancy exchange barriers indicate a strong dependency on dopant valence and atomic size, in contrast to current models of vacancy-mediated dopant diffusion. First-row elements (B, C, N) are found to have exchange barriers which are an order of magnitude larger than the assumed value of 0.3 eV (the Si vacancy migration energy). copyright 1998 American Institute of Physics

  10. A Randomized Clinical Trial of Schinus terebinthifolius Mouthwash to Treat Biofilm-Induced Gingivitis

    Science.gov (United States)

    Freires, Irlan de Almeida; Alves, Livia Araújo; Ferreira, Gabriela Lacet Silva; Jovito, Vanessa de Carvalho; de Castro, Ricardo Dias; Cavalcanti, Alessandro Leite

    2013-01-01

    Objectives. This study aimed to investigate the efficacy of a Schinus terebinthifolius (ST) mouthwash in reducing gingival inflammation levels (GI) and biofilm accumulation (BA) in children with gingivitis. Methods. This was a randomized, controlled, triple blind, and phase II clinical trial, with children aged 9–13 years (n = 27) presenting with biofilm-induced gingivitis. The sample was randomized into experimental (0.3125% ST, n = 14) and control (0.12% chlorhexidine/CHX, n = 13) groups. Products were masked as regards color, flavor and aroma. Intervention protocol consisted in supervised rinsing of 10 mL/day for 01 minute for 10 days. Gingival bleeding and simplified oral hygiene indexes were used to assess the efficacy variables, measured at baseline and after intervention by calibrated examiners. Data were statistically treated with paired t-test, unpaired t-test, and Wilcoxon and Mann-Whitney tests (α = .05). Results. It was found that both ST and CHX were able to significantly reduce GI levels after 10 days (P 0.05). CHX was the only product able to significantly reduce BA after 10 days when compared to baseline (P < 0.05). Conclusion. ST mouthwash showed significant anti-inflammatory activity (equivalent to CHX), but it was not able to reduce biofilm accumulation. PMID:23843886

  11. Tuning Nanocrystal Surface Depletion by Controlling Dopant Distribution as a Route Toward Enhanced Film Conductivity

    Science.gov (United States)

    Staller, Corey M.; Robinson, Zachary L.; Agrawal, Ankit; Gibbs, Stephen L.; Greenberg, Benjamin L.; Lounis, Sebastien D.; Kortshagen, Uwe R.; Milliron, Delia J.

    2018-05-01

    Electron conduction through bare metal oxide nanocrystal (NC) films is hindered by surface depletion regions resulting from the presence of surface states. We control the radial dopant distribution in tin-doped indium oxide (ITO) NCs as a means to manipulate the NC depletion width. We find in films of ITO NCs of equal overall dopant concentration that those with dopant-enriched surfaces show decreased depletion width and increased conductivity. Variable temperature conductivity data shows electron localization length increases and associated depletion width decreases monotonically with increased density of dopants near the NC surface. We calculate band profiles for NCs of differing radial dopant distributions and, in agreement with variable temperature conductivity fits, find NCs with dopant-enriched surfaces have narrower depletion widths and longer localization lengths than those with dopant-enriched cores. Following amelioration of NC surface depletion by atomic layer deposition of alumina, all films of equal overall dopant concentration have similar conductivity. Variable temperature conductivity measurements on alumina-capped films indicate all films behave as granular metals. Herein, we conclude that dopant-enriched surfaces decrease the near-surface depletion region, which directly increases the electron localization length and conductivity of NC films.

  12. Understanding and controlling transient enhanced dopant diffusion in silicon

    International Nuclear Information System (INIS)

    Stolk, P.A.; Gossmann, H.J.; Eaglesham, D.J.; Jacobson, D.C.; Poate, J.M.; Luftman, H.S.

    1995-01-01

    Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during initial annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, the authors have used B doping marker layers in Si to probe the injection of interstitials from near-surface, non-amorphizing Si implants during annealing. The in-diffusion of interstitials is limited by trapping at impurities and has an activation energy of ∼3.5 eV. Substitutional C is the dominant trapping center with a binding energy of 2--2.5 eV. The high interstitial supersaturation adjacent to the implant damage drives substitutional B into metastable clusters at concentrations below the B solid solubility limit. Transmission electron microscopy shows that the interstitials driving TED are emitted from {311} defect clusters in the damage region at a rate which also exhibits an activation energy of 3.6 eV. The population of excess interstitials is strongly reduced by incorporating substitutional C in Si to levels of ∼10 19 /cm 3 prior to ion implantation. This provides a promising method for suppressing TED, thus enabling shallow junction formation in future Si devices through dopant implantation

  13. Protective effect of selenium on cisplatin induced nephrotoxicity: A double-blind controlled randomized clinical trial.

    Science.gov (United States)

    Ghorbani, Ali; Omidvar, Bita; Parsi, Abazar

    2013-04-01

    Renal injury is common following cisplatin infusion. Some agents have been used to attenuate cisplatin nephrotoxicity. However, except hydration, none of them has been proved to be effective. In this study selenium as an antioxidant supplement was tested on cisplatin induced renal injury. 122 cancerous patients (85 male and 37 female; age range of 14 to 82 years old) were enrolled to receive chemotherapy regimens consisting cisplatin. They were allocated into two groups using a random number list . Investigators, patients and analyzers all, were blinded in allocation by using sealed opaque envelopes. Intervention group received a single 400 mcg selenium tablet and patients in control group took a placebo tablet which was similar with selenium preparation in color, weight, shape and taste. Primary end points were an increase in plasma creatinine above 1.5 mg/dl in men and 1.4mg/dl in women, or increase of plasma creatinine more than 50% from baseline or urine flow rate less than 0.5 ml/kg/h. Creatinine level was measured initially and on the 5th day after cisplatin therapy. There was no difference in cumulative dose of cisplatin between the groups (p=0.54). There were not evidences of acute renal failure (ARF) in cases. While, among placebo group, 7 patients had criteria of acute kidney injury. Conclusions :selenium could probably prevent cisplatin-induced acute kidney injury, when it is added to hydration therapy in cancerous patients.

  14. Effect of antioxidant supplementation on exercise-induced cardiac troponin release in cyclists: a randomized trial.

    Directory of Open Access Journals (Sweden)

    Lieke J J Klinkenberg

    Full Text Available Cardiac troponin is the biochemical gold standard to diagnose acute myocardial infarction. Interestingly however, elevated cardiac troponin concentrations are also frequently observed during and after endurance-type exercise. Oxidative stress associated with prolonged exercise has been proposed to contribute to cardiac troponin release. Therefore, the aim of this study was to assess the effect of 4 week astaxanthin supplementation (a potent cartenoid antioxidant on antioxidant capacity and exercise-induced cardiac troponin release in cyclists.Thirty-two well-trained male cyclists (age 25±5, weight 73±7 kg, maximum O2 uptake 60±5 mL·kg(-1·min(-1, Wmax 5.4±0.5 W·kg(-1; mean ± SD were repeatedly subjected to a laboratory based standardized exercise protocol before and after 4 weeks of astaxanthin (20 mg/day, or placebo supplementation in a double-blind randomized manner. Blood samples were obtained at baseline, at 60 min of cycling and immediately post-exercise (≈ 120 min.The pre-supplementation cycling trial induced a significant rise of median cardiac troponin T concentrations from 3.2 (IQR 3.0-4.2 to 4.7 ng/L (IQR 3.7-6.7, immediately post-exercise (p<0.001. Four weeks of astaxanthin supplementation significantly increased mean basal plasma astaxanthin concentrations from non-detectable values to 175±86 µg·kg(-1. However, daily astaxanthin supplementation had no effect on exercise-induced cardiac troponin T release (p = 0.24, as measured by the incremental area under the curve. Furthermore, the elevation in basal plasma astaxanthin concentrations was not reflected in changes in antioxidant capacity markers (trolox equivalent antioxidant capacity, uric acid, and malondialdehyde. Markers of inflammation (high-sensitivity C-reactive protein and exercise-induced skeletal muscle damage (creatine kinase were equally unaffected by astaxanthin supplementation.Despite substantial increases in plasma astaxanthin concentrations

  15. A theoretical study of dopant atom detection and probe behavior in STEM

    Science.gov (United States)

    Mittal, Anudha

    Very detailed information about the atomic and electronic structure of materials can be obtained via atomic-scale resolution scanning transmission electron microscopy (STEM). These experiments reach the limits of current microscopes, which means that optimal experimental design is a key ingredient in success. The step following experiment, extraction of information from experimental data is also complex. Comprehension of experimental data depends on comparison with simulated data and on fundamental understanding of aspects of scattering behavior. The research projects discussed in this thesis are formulated within three large concepts. 1. Usage of simulation to suggest experimental technique for observation of a particular structural feature.. Two specific structural features are explored. One is the characterization of a substitutional dopant atom in a crystal. Annular dark field scanning transmission electron microscope (ADF-STEM) images allow detection of individual dopant atoms in a crystal based on contrast between intensities of doped and non-doped column in the image. The magnitude of the said contrast is heavily influenced by specimen and microscope parameters. Analysis of multislice-based simulations of ADF-STEM images of crystals doped with one substitutional dopant atom for a wide range of crystal thicknesses, types and locations of dopant atom inside the crystal, and crystals with different atoms revealed trends and non-intuitive behaviors in visibility of the dopant atom. The results provide practical guidelines for the optimal experimental setup regarding both the microscope and specimen conditions in order to characterize the presence and location of a dopant atom. Furthermore, the simulations help in recognizing the cases where detecting a single dopant atom via ADF-STEM imaging is not possible. The second is a more specific case of detecting intrinsic twist in MoS2 nanotubes. Objective molecular dynamics simulations coupled with a density

  16. Towards chiral distributions of dopants in microporous frameworks: helicoidal supramolecular arrangement of (1R,2S)-ephedrine and transfer of chirality.

    Science.gov (United States)

    Gómez-Hortigüela, Luis; Álvaro-Muñoz, Teresa; Bernardo-Maestro, Beatriz; Pérez-Pariente, Joaquín

    2015-01-07

    A molecular-mechanics computational study is performed in order to analyze the arrangement of (1R,2S)-(-)-ephedrine molecules within the 12-MR channels of the AFI aluminophosphate microporous framework and the influence on the spatial distribution of dopants embedded in the tetrahedral network. Results showed that ephedrine molecules arrange exclusively as dimers by π-π stacking of the aromatic rings within the AFI channels. Interestingly, the asymmetric nature of ephedrine and the presence of H-bond-forming groups (NH2 and OH) involve a preferential orientation where consecutive dimers within the channels are rotated by an angle of +30°; this is driven by the establishment of inter-dimer H-bonds. This preferential orientation leads to the development of a supramolecular enantiomerically-pure helicoidal (chiral) arrangement of ephedrine dimers. In addition, the computational results demonstrate that the particular molecular structure of ephedrine imparts a strong trend to attract negative charges to the vicinity of the NH2(+) positively-charged groups. Hence divalent dopants such as Mg, whose replacement by trivalent Al in the aluminophosphate network involves the generation of a negative charge, will tend to locate close to the NH2(+) molecular groups, suggesting that an imprinting of the organic arrangement to the spatial distribution of dopants would be feasible. Combined with the trend of ephedrine to arrange in a helicoidal fashion, an enantiomerically-pure helicoidal distribution of dopants would be expected, thus inducing a new type of chirality in microporous materials.

  17. Three-dimensional analysis of Eu dopant atoms in Ca-α-SiAlON via through-focus HAADF-STEM imaging

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Genki, E-mail: genki@eng.hokudai.ac.jp; Yamaki, Fuuta; Kunisada, Yuji; Sakaguchi, Norihito; Akiyama, Tomohiro

    2017-04-15

    Highlights: • Through-focus HAADF-STEM imaging was studied. • Spatial distribution of Eu atoms in Ca-α-SiAlON was analyzed. • A large convergence semi-angle increased the depth resolution. • The radial distribution function of Eu dopants was analyzed. - Abstract: Three-dimensional (3D) distributional analysis of individual dopant atoms in materials is important to development of optical, electronic, and magnetic materials. In this study, we adopted through-focus high-angle annular dark-field (HAADF) imaging for 3D distributional analysis of Eu dopant atoms in Ca-α-SiAlON phosphors. In this context, the effects of convergence semi-angle and Eu z-position on the HAADF image contrast were investigated. Multi-slice image simulation revealed that the contrast of the dopant site was sensitive to change of the defocus level. When the defocus level matched the depth position of a Eu atom, the contrast intensity was significantly increased. The large convergence semi-angle greatly increased the depth resolution because the electron beam tends spread instead of channeling along the atomic columns. Through-focus HAADF-STEM imaging was used to analyze the Eu atom distribution surrounding 10 nm cubes with defocus steps of 0.68 nm each. The contrast depth profile recorded with a narrow step width clearly analyzed the possible depth positions of Eu atoms. The radial distribution function obtained for the Eu dopants was analyzed using an atomic distribution model that was based on the assumption of random distribution. The result suggested that the Ca concentration did not affect the Eu distribution. The decreased fraction of neighboring Eu atoms along z-direction might be caused by the enhanced short-range Coulomb-like repulsive forces along the z-direction.

  18. A β-cyclodextrin based binary dopant for polyaniline: Structural, thermal, electrical, and sensing performance

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Tanushree; Mishra, Satyendra [University Institute of Chemical Technology, North Maharashtra University, Jalgaon 425001, Maharashtra (India); Shimpi, Navinchandra G., E-mail: navin_shimpi@rediffmail.com [Department of Chemistry, University of Mumbai, Kalina, Mumbai 400098, Maharashtra (India)

    2017-06-15

    Highlights: • A binary dopant based on β-cyclodextrin has been proposed for PANI. • The binary dopant provided long term stability to electrically conducting PANI. • The β-cyclodextrin based binary dopant rendered PANI sensitive towards CO at RT. - Abstract: The effect of hydrochloric acid/β-cyclodextrin (HCl/β-CD) binary dopant on the morphological, thermal, electrical, and sensing properties of PANI was investigated and compared with those of the conventionally doped PANI. The PANI samples were characterized using FTIR, UV–Vis, {sup 1}H NMR, and FESEM. Significant changes were observed in the structural, thermal, and electrical character of PANI doped with the HCl/β-CD binary dopant. A higher doping level was obtained for the PANI-binary dopant system, as observed from its {sup 1}H NMR spectra. Moreover, the binary dopant imparted long-term stability to the sensor in its conductive form. In addition, the PANI-binary dopant system exhibited a significantly high gas response towards carbon monoxide gas at room temperature.

  19. Manipulation and analysis of a single dopant atom in GaAs

    NARCIS (Netherlands)

    Wijnheijmer, A.P.

    2011-01-01

    This thesis focuses on the manipulation and analysis of single dopant atoms in GaAs by scanning tunneling microscopy (STM) and spectroscopy (STS) at low temperatures. The observation of ionization rings is one of the key results, showing that we can control the charge state of a single dopant atom

  20. Thermodynamic modelling of fast dopant diffusion in Si

    Science.gov (United States)

    Saltas, V.; Chroneos, A.; Vallianatos, F.

    2018-04-01

    In the present study, nickel and copper fast diffusion in silicon is investigated in the framework of the cBΩ thermodynamic model, which connects point defect parameters with the bulk elastic and expansion properties. All the calculated point defect thermodynamic properties (activation Gibbs free energy, activation enthalpy, activation entropy, and activation volume) exhibit temperature dependence due to the non-linear anharmonic behavior of the isothermal bulk modulus of Si. Calculated activation enthalpies (0.15-0.16 eV for Ni and 0.17-0.19 eV for Cu) are in agreement with the reported experimental results. Small values of calculated activation volumes for both dopants (˜4% of the mean atomic volume) are consistent with the interstitial diffusion of Ni and Cu in Si.

  1. The effect of dopants on laser imprint mitigation

    Science.gov (United States)

    Phillips, Lee; Gardner, John H.; Bodner, Stephen E.; Colombant, Denis; Dahlburg, Jill

    1999-11-01

    An intact implosion of a pellet for direct-drive ICF requires that the perturbations imprinted by the laser be kept below some threshold. We report on simulations of targets that incorporate very small concentrations of a high-Z dopant in the ablator, to increase the electron density in the ablating plasma, causing the laser to be absorbed far enough from the solid ablator to achieve a substantial degree of thermal smoothing. These calculations were performed using NRL's FAST radiation hydrodynamics code(J.H. Gardner, A.J. Schmitt, et al., Phys. Plasmas) 5, 1935 (1998), incorporating the flux-corrected transport algorithm and opacities generated by an STA code, with non-LTE radiation transport based on the Busquet method.

  2. Defect and dopant kinetics in laser anneals of Si

    International Nuclear Information System (INIS)

    La Magna, A.; Fisicaro, G.; Mannino, G.; Privitera, V.; Piccitto, G.; Svensson, B.G.; Vines, L.

    2008-01-01

    In this work a modeling approach is applied to investigate the kinetics of the defect-dopant system in the extremely far-from-the equilibrium conditions caused by the laser irradiation in Si. A rigorous derivation of the master equations for the evolution of the defect-impurity system is obtained starting from the Boltzmann's formalism. The model derived is not limited by the stringent hypothesis of instantaneous equilibration of the local system energy to the lattice thermal field. This fact allows: (a) the formalization of a reliable theoretical formalism for the study of evolving defect-impurity systems in a non-uniform fast varying thermal field and (b) the generalization of the kinetic parameters (e.g. diffusivity, clustering rate constants, etc.). Early comparisons between simulations and experimental analysis of the processes are discussed. These results indicate the reliability of the energetic calibration for the self-interstitial clusters derived using conventional thermal processes

  3. Forecasting Space Weather-Induced GPS Performance Degradation Using Random Forest

    Science.gov (United States)

    Filjar, R.; Filic, M.; Milinkovic, F.

    2017-12-01

    Space weather and ionospheric dynamics have a profound effect on positioning performance of the Global Satellite Navigation System (GNSS). However, the quantification of that effect is still the subject of scientific activities around the world. In the latest contribution to the understanding of the space weather and ionospheric effects on satellite-based positioning performance, we conducted a study of several candidates for forecasting method for space weather-induced GPS positioning performance deterioration. First, a 5-days set of experimentally collected data was established, encompassing the space weather and ionospheric activity indices (including: the readings of the Sudden Ionospheric Disturbance (SID) monitors, components of geomagnetic field strength, global Kp index, Dst index, GPS-derived Total Electron Content (TEC) samples, standard deviation of TEC samples, and sunspot number) and observations of GPS positioning error components (northing, easting, and height positioning error) derived from the Adriatic Sea IGS reference stations' RINEX raw pseudorange files in quiet space weather periods. This data set was split into the training and test sub-sets. Then, a selected set of supervised machine learning methods based on Random Forest was applied to the experimentally collected data set in order to establish the appropriate regional (the Adriatic Sea) forecasting models for space weather-induced GPS positioning performance deterioration. The forecasting models were developed in the R/rattle statistical programming environment. The forecasting quality of the regional forecasting models developed was assessed, and the conclusions drawn on the advantages and shortcomings of the regional forecasting models for space weather-caused GNSS positioning performance deterioration.

  4. Transient enhanced diffusion of dopants in preamorphized Si layers

    International Nuclear Information System (INIS)

    Claverie, A.; Bonafos, C.; Omri, M.; Mauduit, B. de; Ben Assayag, G.; Martinez, A.; Alquier, D.; Mathiot, D.

    1997-01-01

    Transient Enhanced Diffusion (TED) of dopants in Si is the consequence of the evolution, upon annealing, of a large supersaturation of Si self-interstitial atoms left after ion bombardment. In the case of amorphizing implants, this supersaturation is located just beneath the c/a interface and evolves through the nucleation and growth of End-Of-Range (EOR) defects. For this reason, the authors discuss here the relation between TED and EOR defects. Modelling of the behavior of these defects upon annealing allows one to understand why and how they affect dopant diffusion. This is possible through the development of the Ostwald ripening theory applied to extrinsic dislocation loops. This theory is shown to be readily able to quantitatively describe the evolution of the defect population (density, size) upon annealing and gives access to the variations of the mean supersaturation of Si self-interstitial atoms between the loops and responsible for TED. This initial supersaturation is, before annealing, at least 5 decades larger than the equilibrium value and exponentially decays with time upon annealing with activation energies that are the same than the ones observed for TED. It is shown that this time decay is precisely at the origin of the transient enhancement of boron diffusivity through the interstitial component of boron diffusion. Side experiments shed light on the effect of the proximity of a free surface on the thermal behavior of EOR defects and allow us to quantitatively describe the space and time evolutions of boron diffusivity upon annealing of preamorphized Si layers

  5. Randomized test of an implementation intention-based tool to reduce stress-induced eating.

    Science.gov (United States)

    O'Connor, Daryl B; Armitage, Christopher J; Ferguson, Eamonn

    2015-06-01

    Stress may indirectly contribute to disease (e.g. cardiovascular disease, cancer) by producing deleterious changes to diet. The purpose of this study was to test the effectiveness of a stress management support (SMS) tool to reduce stress-related unhealthy snacking and to promote stress-related healthy snacking. Participants were randomized to complete a SMS tool with instruction to link stressful situations with healthy snack alternatives (experimental) or a SMS tool without a linking instruction (control). On-line daily reports of stressors and snacking were completed for 7 days. Daily stressors were associated with unhealthy snack consumption in the control condition but not in the experimental condition. Participants highly motivated towards healthy eating consumed a greater number of healthy snacks in the experimental condition on stressful days compared to participants in the experimental condition with low and mean levels of motivation. This tool is an effective, theory driven, intervention that helps to protect against stress-induced high-calorie snack consumption.

  6. On the Shaker Simulation of Wind-Induced Non-Gaussian Random Vibration

    Directory of Open Access Journals (Sweden)

    Fei Xu

    2016-01-01

    Full Text Available Gaussian signal is produced by ordinary random vibration controllers to test the products in the laboratory, while the field data is usually non-Gaussian. Two methodologies are presented in this paper for shaker simulation of wind-induced non-Gaussian vibration. The first methodology synthesizes the non-Gaussian signal offline and replicates it on the shaker in the Time Waveform Replication (TWR mode. A new synthesis method is used to model the non-Gaussian signal as a Gaussian signal multiplied by an amplitude modulation function (AMF. A case study is presented to show that the synthesized non-Gaussian signal has the same power spectral density (PSD, probability density function (PDF, and loading cycle distribution (LCD as the field data. The second methodology derives a damage equivalent Gaussian signal from the non-Gaussian signal based on the fatigue damage spectrum (FDS and the extreme response spectrum (ERS and reproduces it on the shaker in the closed-loop frequency domain control mode. The PSD level and the duration time of the derived Gaussian signal can be manipulated for accelerated testing purpose. A case study is presented to show that the derived PSD matches the damage potential of the non-Gaussian environment for both fatigue and peak response.

  7. Effectiveness of triclosan in the management of radiation-induced oral mucositis: A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Satheeshkumar P

    2010-01-01

    Full Text Available Introduction: Oral care in cancer patients is an important aspect in the quality of life of patients undergoing cancer therpay. Mucositis, trismus, salivary gland dysfunction are the main complications of the cancer therapy, which lead to long-term comlications such as radiation caries, poor oral hygiene and osteoradionecrosis. A timely oral evaluation and intervention in these patients can reduce the severity of the potential complications. Triclosan is an antibacterial agent widely used in periodontal therapy, the effectiveness of triclosan in the management of radiation induced oral mucositis is evaluated here. Aims: 1 To determine the effectiveness of triclosan in the management of radiation-induced oral mucositis. 2 To compare the effectiveness of triclosan mouth rinse with conventional sodium bicarbonate mouth rinse. Materials and Methods: Twenty-four patients who underwent radiation therapy for oral cancer and subsequently developed oral mucositis were included in the study. They were randomly allocated into two groups on noticing grade I mucositis (erythema. The study group was advised to use triclosan mouthwash containing triclosan 0.03% W/V and sodium bicarbonate 2 mg mouth wash for the control group. A weekly follow-up evaluation of body weight, food intake, pain and grading of mucositis were made during the radiation treatment period and post radiation treatment period. Results: Both the groups were statistically identical. All the 24 patients in both the groups passed through grade 3 mucositis on the last day of radiotherapy. However, 10 patients in the control group and only one patient in the study group entered to grade 4 mucositis. A definite change was noticed in the severity of the mucositis, food intake and weight loss. The control group took more than 45 days to resolve while the study group took only less than 28 days. Discussion: The results of the study were evaluated and tried to formulate a hypothesis so as to explain

  8. Curcumin and Piperine Supplementation and Recovery Following Exercise Induced Muscle Damage: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Barthélémy Delecroix, Abd Elbasset Abaïdia, Cédric Leduc, Brian Dawson, Grégory Dupont

    2017-03-01

    Full Text Available The aim of this study was to analyze the effects of oral consumption of curcumin and piperine in combination on the recovery kinetics after exercise-induced muscle damage. Forty-eight hours before and following exercise-induced muscle damage, ten elite rugby players consumed curcumin and piperine (experimental condition or placebo. A randomized cross-over design was performed. Concentric and isometric peak torque for the knee extensors, one leg 6 seconds sprint performance on a non-motorized treadmill, counter movement jump performance, blood creatine kinase concentration and muscle soreness were assessed immediately after exercise, then at 24h, 48h and 72h post-exercise. There were moderate to large effects of the exercise on the concentric peak torque for the knee extensors (Effect size (ES = -1.12; Confidence interval at 90% (CI90%: -2.17 to -0.06, the one leg 6 seconds sprint performance (ES=-1.65; CI90% = -2.51to -0.80 and the counter movement jump performance (ES = -0.56; CI90% = -0.81 to -0.32 in the 48h following the exercise. There was also a large effect of the exercise on the creatine kinase level 72h after the exercise in the control group (ES = 3.61; CI90%: 0.24 to 6.98. This decrease in muscle function and this elevation in creatine kinase indicate that the exercise implemented was efficient to induce muscle damage. Twenty four hours post-exercise, the reduction (from baseline in sprint mean power output was moderately lower in the experimental condition (-1.77 ± 7.25%; 1277 ± 153W in comparison with the placebo condition (-13.6 ± 13.0%; 1130 ± 241W (Effect Size = -1.12; Confidence Interval 90%=-1.86 to -0.86. However, no other effect was found between the two conditions. Curcumin and piperine supplementation before and after exercise can attenuate some, but not all, aspects of muscle damage.

  9. Effectiveness of artichoke extract in preventing alcohol-induced hangovers: a randomized controlled trial

    Science.gov (United States)

    Pittler, Max H.; White, Adrian R.; Stevinson, Clare; Ernst, Edzard

    2003-01-01

    Background Extract of globe artichoke (Cynara scolymus) is promoted as a possible preventive or cure for alcohol-induced hangover symptoms. However, few rigorous clinical trials have assessed the effects of artichoke extract, and none has examined the effects in relation to hangovers. We undertook this study to test whether artichoke extract is effective in preventing the signs and symptoms of alcohol-induced hangover. Methods We recruited healthy adult volunteers between 18 and 65 years of age to participate in a randomized double-blind crossover trial. Participants received either 3 capsules of commercially available standardized artichoke extract or indistinguishable, inert placebo capsules immediately before and after alcohol exposure. After a 1-week washout period the volunteers received the opposite treatment. Participants predefined the type and amount of alcoholic beverage that would give them a hangover and ate the same meal before commencing alcohol consumption on the 2 study days. The primary outcome measure was the difference in hangover severity scores between the artichoke extract and placebo interventions. Secondary outcome measures were differences between the interventions in scores using a mood profile questionnaire and cognitive performance tests administered 1 hour before and 10 hours after alcohol exposure. Results Fifteen volunteers participated in the study. The mean number (and standard deviation) of alcohol units (each unit being 7.9 g, or 10 mL, of ethanol) consumed during treatment with artichoke extract and placebo was 10.7 (3.1) and 10.5 (2.4) respectively, equivalent to 1.2 (0.3) and 1.2 (0.2) g of alcohol per kilogram body weight. The volume of nonalcoholic drink consumed and the duration of sleep were similar during the artichoke extract and placebo interventions. None of the outcome measures differed significantly between interventions. Adverse events were rare and were mild and transient. Interpretation Our results suggest that

  10. Random function representation of stationary stochastic vector processes for probability density evolution analysis of wind-induced structures

    Science.gov (United States)

    Liu, Zhangjun; Liu, Zenghui

    2018-06-01

    This paper develops a hybrid approach of spectral representation and random function for simulating stationary stochastic vector processes. In the proposed approach, the high-dimensional random variables, included in the original spectral representation (OSR) formula, could be effectively reduced to only two elementary random variables by introducing the random functions that serve as random constraints. Based on this, a satisfactory simulation accuracy can be guaranteed by selecting a small representative point set of the elementary random variables. The probability information of the stochastic excitations can be fully emerged through just several hundred of sample functions generated by the proposed approach. Therefore, combined with the probability density evolution method (PDEM), it could be able to implement dynamic response analysis and reliability assessment of engineering structures. For illustrative purposes, a stochastic turbulence wind velocity field acting on a frame-shear-wall structure is simulated by constructing three types of random functions to demonstrate the accuracy and efficiency of the proposed approach. Careful and in-depth studies concerning the probability density evolution analysis of the wind-induced structure have been conducted so as to better illustrate the application prospects of the proposed approach. Numerical examples also show that the proposed approach possesses a good robustness.

  11. Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

    KAUST Repository

    Sioud, Salim; Amad, Maan H.; Al-Talla, Zeyad

    2012-01-01

    with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs

  12. Radiation-induced mucositis: a randomized clinical trial of micronized sucralfate versus salt & soda mouthwashes.

    Science.gov (United States)

    Dodd, Marylin J; Miaskowski, Christine; Greenspan, Deborah; MacPhail, Laurie; Shih, Ai-Shan; Shiba, Gayle; Facione, Noreen; Paul, Steven M

    2003-01-01

    Oral mucositis is one of the major toxicities caused by radiation therapy (RT) treatments to the head and neck. The clinical efficacy of sucralfate (Carafate R) mouthwash for head and neck cancer patients (HNC) is not consistent across studies. In this study, it was hypothesized that if the particles in the original sucralfate suspension were micronized (i.e., < or = 25 microns) then the coating action of the mouthwash in the oral cavity would be enhanced. The purpose of this pilot study was to compare the efficacy of micronized sucralfate (Carafate R) mouthwash and salt & soda mouthwash in terms of the severity of the mucositis, the severity of mucositis-related pain, and the time required to heal RT-induced mucositis in patients with HNC. Severe mucositis and related pain can interfere with the ingestion of food and fluids, so patients' body weights were measured as well. All patients in this randomized clinical trial carried out a systematic oral hygiene protocol called the PRO-SELF: Mouth Aware (PSMA) Program. Patients who developed RT-induced mucositis anytime during their course of RT were randomized to one of the two mouthwashes and followed to the completion of RT and at one month following RT. Two referral sites were used for the study. Repeated measures occurred with the following instruments/variables: MacDibbs Mouth Assessment and weight. Demographic, disease, and cancer treatment information was also obtained. Thirty patients successfully completed the study. The typical participant was male (70%), married/partnered (70%), White (63%), not working or retired (73%), and had an average of 14.5 years of education (SD = 3.7). T-tests and Chi-square analyses with an alpha set at 0.05 were used to compare differences between the two mouthwashes. No significant differences were found in the number of days to onset of mucositis (i.e., 16 +/- 8.4 days). When patients had their worst MacDibbs score, (i.e., the most severe mucositis), there were no significant

  13. A network meta-analysis on randomized trials focusing on the preventive effect of statins on contrast-induced nephropathy

    DEFF Research Database (Denmark)

    Peruzzi, Mariangela; De Luca, Leonardo; Thomsen, Henrik S

    2014-01-01

    -analysis. Randomized trials focusing on statins were searched and pooled with random-effect odds ratios. A total of 14 trials (6,160 patients) were included, focusing on atorvastatin (high/low dose), rosuvastatin (high dose), simvastatin (high/low dose), and placebo or no statin therapy before contrast administration....... The risk of contrast-induced nephropathy was reduced by atorvastatin high dose and rosuvastatin high dose, with no difference between these two agents. Results for atorvastatin low dose and simvastatin (high/low dose) in comparison to placebo were inconclusive. Atorvastatin and rosuvastatin administered...

  14. Dopant-free twinning superlattice formation in InSb and InP nanowires

    International Nuclear Information System (INIS)

    Yuan, Xiaoming; Guo, Yanan; Caroff, Philippe; Tan, Hark Hoe; Jagadish, Chennupati; He, Jun

    2017-01-01

    Periodic arrangement of twin planes creates a controllable polytype that can affect both the electronic and optical properties of nanowires. The approach that is most used for inducing twinning superlattice (TSL) formation in III-V nanowires is introducing impurity dopants during growth. Here, we demonstrate that controlling the growth parameters is sufficient to produce regular twinning planes in Au-catalysed InSb and InP nanowires. Our results show that TSL formation in InSb nanowires only exists in a very narrow growth window. We suggest that growth conditions induce a high concentration of In (or Sb) in the Au droplet, which plays a similar role to that of surfactant impurities such as Zn, and increases the droplet wetting angle to yield a geometry that is favorable for TSL formation. The demonstration of TSL structure in InSb and InP nanowires by controlling the input of In (or Sb) further enhances fundamental understanding of TSL formation in III-V nanowires and allows us to tune the properties of these nanowires by crystal phase engineering. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Dopant-free twinning superlattice formation in InSb and InP nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Xiaoming [School of Physics and Electronics, Hunan Key Laboratory for Supermicrostructure and Ultrafast Process, Central South University, Changsha, Hunan (China); Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT (Australia); Guo, Yanan; Caroff, Philippe; Tan, Hark Hoe; Jagadish, Chennupati [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT (Australia); He, Jun [School of Physics and Electronics, Hunan Key Laboratory for Supermicrostructure and Ultrafast Process, Central South University, Changsha, Hunan (China)

    2017-11-15

    Periodic arrangement of twin planes creates a controllable polytype that can affect both the electronic and optical properties of nanowires. The approach that is most used for inducing twinning superlattice (TSL) formation in III-V nanowires is introducing impurity dopants during growth. Here, we demonstrate that controlling the growth parameters is sufficient to produce regular twinning planes in Au-catalysed InSb and InP nanowires. Our results show that TSL formation in InSb nanowires only exists in a very narrow growth window. We suggest that growth conditions induce a high concentration of In (or Sb) in the Au droplet, which plays a similar role to that of surfactant impurities such as Zn, and increases the droplet wetting angle to yield a geometry that is favorable for TSL formation. The demonstration of TSL structure in InSb and InP nanowires by controlling the input of In (or Sb) further enhances fundamental understanding of TSL formation in III-V nanowires and allows us to tune the properties of these nanowires by crystal phase engineering. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Boron, arsenic and phosphorus dopant incorporation during low temperature low pressure silicon epitaxial growth

    International Nuclear Information System (INIS)

    Borland, J.O.; Thompson, T.; Tagle, V.; Benzing, W.

    1987-01-01

    Submicron silicon epitaxial structures with very abrupt epi/substrate transition widths have been realized through the use of low temperature silicon epitaxial growth techniques. At these low temperature and low pressure epitaxial growth conditions there is minimal, if any, dopant diffusion from the substrate into the epilayer during deposition. The reincorporation of autodoped dopant as well as the incorporation of intentional dopant can be a trade-off at low temperatures and low pressures. For advanced CMOS and Bi-CMOS technologies, five to six orders of magnitude change in concentration levels are desirable. In this investigation, all of the epitaxial depositions were carried out in an AMC-7810 epi-reactor with standard jets for a turbulent mixing system, and using a modified center inject configuration to achieve a single pass laminar flow system. To simulate the reincorporation of various autodoped dopant, the authors ran a controlled dopant flow of 100 sccm for each of the three dopants (boron, phosphorus and arsenic) to achieve the controlled background dopant level in the reactor gas stream

  17. Improvement of efficiency roll-off in blue phosphorescence OLED using double dopants emissive layer

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seung Il; Yoon, Ju An; Kim, Nam Ho; Kim, Jin Wook; Kang, Jin Sung; Moon, Chang-Bum [Department of Green Energy & Semiconductor Engineering, Hoseo University, Asan (Korea, Republic of); Kim, Woo Young, E-mail: wykim@hoseo.edu [Department of Green Energy & Semiconductor Engineering, Hoseo University, Asan (Korea, Republic of); Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4L7 (Canada)

    2015-04-15

    Blue phosphorescent organic light-emitting diodes (PHOLEDs) were fabricated using double dopants FIrpic and FIr6 in emissive layer (EML) with structure of ITO/NPB (700 Å)/mCP:FIrpic-8%:FIr6-x% (300 Å)/TPBi (300 Å)/Liq (20 Å)/Al (1200 Å). We optimized concentration of the second dopant FIr6 in the presence of a fixed FIrpic to observe its effect on electrical performance of PHOLED device. 24.8 cd/A of luminous efficiency was achieved by the device with dopant ratio of 8%FIrpic:4%FIr6 in EML. Efficiency roll-off was also improved 20% compared to the PHOLED device singly dopped with FIrpic or FIr6 only. Second doping proved its effect in stabilizing charge balance in EML and enhancing energy transfer of triplet excitons between two dopants. - Highlights: • We fabricated blue PHOLED with double blue phosphorescent dopants in single EML. • Efficiency roll-off was improved by using double dopant in single EML. • The host–dopant transfer is discussed by analyzing the photo-absorption and photoluminescence. • The spectroscopic analysis using multi-peak fits with a Gaussian function.

  18. Influence of the dopant during the one step mechano-chemical synthesis of sodium alanate

    International Nuclear Information System (INIS)

    Rongeat, C; Geipel, C; Llamas-Jansa, I; Schultz, L; Gutfleisch, O

    2009-01-01

    High-pressure reactive milling under hydrogen atmosphere is used for the one-step synthesis of doped sodium alanate. In-situ monitoring of the pressure and the temperature inside the vial gives a direct feedback about the reactions occurring during the milling. This information is used to study the influence of the dopant during synthesis, e.g. the amount of dopant added. The study of the pressure variations during milling is a reliable tool for screening the efficiency of different dopants.

  19. Evaluation of Co-Q10 anti-gingivitis effect on plaque induced gingivitis: A randomized controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Anirban Chatterjee

    2012-01-01

    Full Text Available Background: Deficiency of Co-Q10 has been found to be responsible for periodontal destruction; therefore, this study was undertaken to evaluate the anti-gingivitis effect of Co-Q10 on plaque induced gingivitis. Materials and Methods: Thirty subjects with plaque induced gingivitis were enrolled in a split mouth randomized controlled trial. For each subject, scaling was randomly performed for any two quadrants, followed by the topical application of Co-Q10 randomly in a previously scaled and as an unscaled quadrant for a period of 28 days. Four treatment options were planned: option A: scaling only; option B: Co-Q10 along with scaling; option C: Co-Q10. Results: Marked reduction in gingival, bleeding, and plaque scores were recorded at the sites where C0-Q10 was applied. Mean±S.D of aforementioned periodontal parameters at 28th day showed significant reduction for option A, B, and C when compared with baseline. Conclusion: Promising results were obtained after the solitary application of Co-Q10 as well as when it was used as an adjunct to scaling and root planing for treatment of plaque induced gingivitis.

  20. Improving solid-state hydriding and dehydriding properties of the LiBH{sub 4} plus MgH{sub 2} system with the addition of Mn and V dopants

    Energy Technology Data Exchange (ETDEWEB)

    Crosby, Kyle; Wan, Xuefei; Shaw, Leon L. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 97 North Eagleville Road, U-3136, Storrs, CT 06269 (United States)

    2010-11-01

    The hydriding process of the 2LiH + MgB{sub 2} mixture is controlled by outward diffusion of Mg and inward diffusion of Li and H within MgB{sub 2} crystals to form LiBH{sub 4}. This study explores the feasibility of using transition metal dopants, such as Mn and V, to enhance the diffusion rate and thus the hydriding kinetics. It is found that Mn can indeed enhance the hydriding kinetics of the 2LiH + MgB{sub 2} mixture, while V does not. The major factor in enhancing the diffusion rate and thus the hydriding kinetics is related to the dopant's ability to induce the lattice distortion of MgB{sub 2} crystals. This study demonstrates that the kinetics of the diffusion controlled solid-state hydriding process can be improved by doping if the dopant is properly selected. (author)

  1. Inducing Behavioral Change in Seekers of Pro-Anorexia Content Using Internet Advertisements: Randomized Controlled Trial.

    Science.gov (United States)

    Yom-Tov, Elad; Brunstein-Klomek, Anat; Mandel, Or; Hadas, Arie; Fennig, Silvana

    2018-02-22

    The influence of pro-anorexia (pro-ana) websites is debated, with studies indicating both negative and positive effects, as well as significant variation in the effects of different websites for those suffering from eating disorders (EDs) and the general population. Online advertising, known to induce behavioral change both online and in the physical world, has not been used so far to modify the search behavior of people seeking pro-ana content. The objective of this randomized controlled trial (RCT) was to examine if online advertisements (ads) can change online search behaviors of users who are looking for online pro-ana content. Using the Bing Ads system, we conducted an RCT to randomly expose the searchers for pro-ana content to 10 different ads referring people to one of the three websites: the National Eating Disorders Association, the National Institutes of Mental Health, and MyProAna. MyProAna is a pro-ana website that was found in a previous study to be associated with less pathological online behaviors than other pro-ana websites. We followed participants exposed and unexposed to the ads to explore their past and future online searches. The ads were shown 25,554 times and clicked on 217 times. Exposure to the ads was associated with a decrease in searches for pro-ana and self-harm content. Reductions were greatest among those referred to MyProAna (reduction of 34.0% [73/215] and 37.2% [80/215] for pro-ana and self-harm, respectively) compared with users who were referred elsewhere (reduction of 15.47% [410/2650] and 3.21% [85/2650], respectively), and with users who were not shown the ads, who increased their behaviors (increase of 57.12% [6462/11,314] and 4.07% [461/11,314], respectively). In addition, those referred to MyProAna increased their search for treatment, as did control users, who did so to a lesser extent. However, users referred elsewhere decreased their searches for this content. We found that referring users interested in ED

  2. Solvent effects on dopant-free pH-falling polymerization of aniline

    Czech Academy of Sciences Publication Activity Database

    Rakić, A. A.; Vukomanović, M.; Trifunovic, S.; Travas-Sejdic, J.; Chaudhary, O. J.; Horský, Jiří; Ciric-Marjanovic, G.

    2015-01-01

    Roč. 209, November (2015), s. 279-296 ISSN 0379-6779 Institutional support: RVO:61389013 Keywords : dopant-free template -free method * nanostructures * polyaniline Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.299, year: 2015

  3. Chromium 51 em K2CrO4: reactions of dopant atoms in solid state

    International Nuclear Information System (INIS)

    Valim, J.B.; Nascimento, R.L.G. do; Collins, C.H.; Collins, K.E.

    1986-01-01

    The study of the chemistry of 'dopant' 51 Cr(III) atoms in crystalline Cr(VI) compounds began as a sub-field of Hot Atom Chemistry. We shall review the attempts to use 'dopant' chromium-51 atoms as surrogate chromium recoil atoms with the special property of having a low-energy, recoil-dam-age-free history. These dopant atoms have shown behaviors very similar to those of high energy recoil 51 Gr atoms, thus offering little hope of learning about special damage site structures and reactions by behavioral differences. Recent work has shown that at least some of the 'dopant' 51 Cr(III) is present as a second, non-chromate solid phase in 'doped crystal' experiments. Monodisperse 51 Cr(OH) 3 particles mixed with pure K 2 CrO 4 are very reactive. (Author) [pt

  4. Sc and Nb Dopants in SrCoO3 Modulate Electronic and Vacancy Structures for Improved Water Splitting and SOFC Cathodes

    KAUST Repository

    Tahini, Hassan A.

    2017-01-12

    SrCoO3 is a promising material in the field of electrocatalysis. Difficulties in synthesising the material in its cubic phase have been overcome by doping it with Sc and Nb ions [Mater. Horiz.2015, 2, 495–501]. Using ab initio calculations and special quasi random structures we undertake a systematic study of these dopants in order to elucidate the effect of doping on electronic structure of the SrCoO3 host and the formation of oxygen vacancies. We find that while the overall electronic structure of SrCoO3 is preserved, increasing the Sc fraction leads to a decrease of electrical conductivity, in agreement with earlier experimental work. For low Sc and Nb doping fractions we find that the oxygen vacancy formation increases relative to undoped SrCoO3. However, as the dopants concentration is increased the vacancy formation energy drops significantly, indicating a strong tendency to accommodate high concentration of oxygen vacancies and hence non-stoichiometry. This is explained based on the electronic instabilities caused by the presence of Sc ions which weakens the B-O interactions as well as the increased degree of electron delocalization on the oxygen sublattice. Sc dopants also shift the p-band centre closer to the Fermi level, which can be associated with experimentally reported improvements in oxygen evolution reactions. These findings provide crucial baseline information for the design of better electrocatalysts for oxygen evolution reactions as well as fuel-cell cathode materials.

  5. Sc and Nb Dopants in SrCoO3 Modulate Electronic and Vacancy Structures for Improved Water Splitting and SOFC Cathodes

    KAUST Repository

    Tahini, Hassan A.; Tan, Xin; Zhou, Wei; Zhu, Zhonghua; Schwingenschlö gl, Udo; Smith, Sean C.

    2017-01-01

    SrCoO3 is a promising material in the field of electrocatalysis. Difficulties in synthesising the material in its cubic phase have been overcome by doping it with Sc and Nb ions [Mater. Horiz.2015, 2, 495–501]. Using ab initio calculations and special quasi random structures we undertake a systematic study of these dopants in order to elucidate the effect of doping on electronic structure of the SrCoO3 host and the formation of oxygen vacancies. We find that while the overall electronic structure of SrCoO3 is preserved, increasing the Sc fraction leads to a decrease of electrical conductivity, in agreement with earlier experimental work. For low Sc and Nb doping fractions we find that the oxygen vacancy formation increases relative to undoped SrCoO3. However, as the dopants concentration is increased the vacancy formation energy drops significantly, indicating a strong tendency to accommodate high concentration of oxygen vacancies and hence non-stoichiometry. This is explained based on the electronic instabilities caused by the presence of Sc ions which weakens the B-O interactions as well as the increased degree of electron delocalization on the oxygen sublattice. Sc dopants also shift the p-band centre closer to the Fermi level, which can be associated with experimentally reported improvements in oxygen evolution reactions. These findings provide crucial baseline information for the design of better electrocatalysts for oxygen evolution reactions as well as fuel-cell cathode materials.

  6. Materials properties of hafnium and zirconium silicates: Metal interdiffusion and dopant penetration studies

    Science.gov (United States)

    Quevedo Lopez, Manuel Angel

    Hafnium and Zirconium based gate dielectrics are considered potential candidates to replace SiO2 or SiON as the gate dielectric in CMOS processing. Furthermore, the addition of nitrogen into this pseudo-binary alloy has been shown to improve their thermal stability, electrical properties, and reduce dopant penetration. Because CMOS processing requires high temperature anneals (up to 1050°C), it is important to understand the diffusion properties of any metal associated with the gate dielectric in silicon at these temperatures. In addition, dopant penetration from the doped polysilicon gate into the Si channel at these temperatures must also be studied. Impurity outdiffusion (Hf, Zr) from the dielectric, or dopant (B, As, P) penetration through the dielectric into the channel region would likely result in deleterious effects upon the carrier mobility. In this dissertation extensive thermal stability studies of alternate gate dielectric candidates ZrSixOy and HfSixO y are presented. Dopant penetration studies from doped-polysilicon through HfSixOy and HfSixOyNz are also presented. Rutherford Backscattering Spectroscopy (RBS), Heavy Ion RBS (HI-RBS), X-ray Photoelectron Spectroscopy (XPS), High Resolution Transmission Electron Microscopy (HR-TEM), and Time of Flight and Dynamic Secondary Ion Mass Spectroscopy (ToF-SIMS, D-SIMS) methods were used to characterize these materials. The dopant diffusivity is calculated by modeling of the dopant profiles in the Si substrate. In this disseration is reported that Hf silicate films are more stable than Zr silicate films, from the metal interdiffusion point of view. On the other hand, dopant (B, As, and P) penetration is observed for HfSixO y films. However, the addition of nitrogen to the Hf - Si - O systems improves the dopant penetration properties of the resulting HfSi xOyNz films.

  7. Improving gas sensing properties of graphene by introducing dopants and defects: a first-principles study

    International Nuclear Information System (INIS)

    Zhang Yonghui; Chen Yabin; Zhou Kaige; Liu Caihong; Zeng Jing; Zhang Haoli; Peng Yong

    2009-01-01

    The interactions between four different graphenes (including pristine, B- or N-doped and defective graphenes) and small gas molecules (CO, NO, NO 2 and NH 3 ) were investigated by using density functional computations to exploit their potential applications as gas sensors. The structural and electronic properties of the graphene-molecule adsorption adducts are strongly dependent on the graphene structure and the molecular adsorption configuration. All four gas molecules show much stronger adsorption on the doped or defective graphenes than that on the pristine graphene. The defective graphene shows the highest adsorption energy with CO, NO and NO 2 molecules, while the B-doped graphene gives the tightest binding with NH 3 . Meanwhile, the strong interactions between the adsorbed molecules and the modified graphenes induce dramatic changes to graphene's electronic properties. The transport behavior of a gas sensor using B-doped graphene shows a sensitivity two orders of magnitude higher than that of pristine graphene. This work reveals that the sensitivity of graphene-based chemical gas sensors could be drastically improved by introducing the appropriate dopant or defect.

  8. Bobath Concept versus constraint-induced movement therapy to improve arm functional recovery in stroke patients: a randomized controlled trial.

    Science.gov (United States)

    Huseyinsinoglu, Burcu Ersoz; Ozdincler, Arzu Razak; Krespi, Yakup

    2012-08-01

    To compare the effects of the Bobath Concept and constraint-induced movement therapy on arm functional recovery among stroke patients with a high level of function on the affected side. A single-blinded, randomized controlled trial. Outpatient physiotherapy department of a stroke unit. A total of 24 patients were randomized to constraint-induced movement therapy or Bobath Concept group. The Bobath Concept group was treated for 1 hour whereas the constraint-induced movement therapy group received training for 3 hours per day during 10 consecutive weekdays. Main measures were the Motor Activity Log-28, the Wolf Motor Function Test, the Motor Evaluation Scale for Arm in Stroke Patients and the Functional Independence Measure. The two groups were found to be homogeneous based on demographic variables and baseline measurements. Significant improvements were seen after treatment only in the 'Amount of use' and 'Quality of movement' subscales of the Motor Activity Log-28 in the constraint-induced movement therapy group over the the Bobath Concept group (P = 0.003; P = 0.01 respectively). There were no significant differences in Wolf Motor Function Test 'Functional ability' (P = 0.137) and 'Performance time' (P = 0.922), Motor Evaluation Scale for Arm in Stroke Patients (P = 0.947) and Functional Independence Measure scores (P = 0.259) between the two intervention groups. Constraint-induced movement therapy and the Bobath Concept have similar efficiencies in improving functional ability, speed and quality of movement in the paretic arm among stroke patients with a high level of function. Constraint-induced movement therapy seems to be slightly more efficient than the Bobath Concept in improving the amount and quality of affected arm use.

  9. Dopant profiling based on scanning electron and helium ion microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chee, Augustus K.W., E-mail: kwac2@cam.ac.uk [Centre for Advanced Photonics and Electronics, Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Boden, Stuart A. [University of Southampton, Electronics and Computer Science, Highfield, Southampton SO17 1BJ (United Kingdom)

    2016-02-15

    In this paper, we evaluate and compare doping contrast generated inside the scanning electron microscope (SEM) and scanning helium ion microscope (SHIM). Specialised energy-filtering techniques are often required to produce strong doping contrast to map donor distributions using the secondary electron (SE) signal in the SEM. However, strong doping contrast can be obtained from n-type regions in the SHIM, even without energy-filtering. This SHIM technique is more sensitive than the SEM to donor density changes above its sensitivity threshold, i.e. of the order of 10{sup 16} or 10{sup 17} donors cm{sup −3} respectively on specimens with or without a p–n junction; its sensitivity limit is well above 2×10{sup 17} acceptors cm{sup −3} on specimens with or without a p–n junction. Good correlation is found between the widths and slopes of experimentally measured doping contrast profiles of thin p-layers and the calculated widths and slopes of the potential energy distributions across these layers, at a depth of 1 to 3 nm and 5 to 10 nm below the surface in the SHIM and the SEM respectively. This is consistent with the mean escape depth of SEs in silicon being about 1.8 nm and 7 nm in the SHIM and SEM respectively, and we conclude that short escape depth, low energy SE signals are most suitable for donor profiling. - Highlights: • Strong doping contrast from n-type regions in the SHIM without energy-filtering. • Sensitivity limits are established of the SHIM and SEM techniques. • We discuss the impact of SHIM imaging conditions on quantitative dopant profiling. • Doping contrast stems from different surface layer thicknesses in the SHIM and SEM.

  10. A lattice Boltzmann simulation of coalescence-induced droplet jumping on superhydrophobic surfaces with randomly distributed structures

    Science.gov (United States)

    Zhang, Li-Zhi; Yuan, Wu-Zhi

    2018-04-01

    The motion of coalescence-induced condensate droplets on superhydrophobic surface (SHS) has attracted increasing attention in energy-related applications. Previous researches were focused on regularly rough surfaces. Here a new approach, a mesoscale lattice Boltzmann method (LBM), is proposed and used to model the dynamic behavior of coalescence-induced droplet jumping on SHS with randomly distributed rough structures. A Fast Fourier Transformation (FFT) method is used to generate non-Gaussian randomly distributed rough surfaces with the skewness (Sk), kurtosis (K) and root mean square (Rq) obtained from real surfaces. Three typical spreading states of coalesced droplets are observed through LBM modeling on various rough surfaces, which are found to significantly influence the jumping ability of coalesced droplet. The coalesced droplets spreading in Cassie state or in composite state will jump off the rough surfaces, while the ones spreading in Wenzel state would eventually remain on the rough surfaces. It is demonstrated that the rough surfaces with smaller Sks, larger Rqs and a K at 3.0 are beneficial to coalescence-induced droplet jumping. The new approach gives more detailed insights into the design of SHS.

  11. Sucralfate gel as a radioprotector against radiation induced dermatitis in a hypo-fractionated schedule: a non-randomized study.

    Science.gov (United States)

    Kouloulias, V; Asimakopoulos, C; Tolia, M; Filippou, G; Platoni, K; Dilvoi, M; Beli, I; Georgakopoulos, J; Patatoukas, G; Kelekis, N

    2013-04-01

    External beam radiotherapy with high doses provokes many acute skin reactions, such as erythema and moist desquamation. Many topical preparations are used in radiation oncology departments in the skin care. Sucralfate humid gel, a colloidal physical form of the anti-ulcer drug sucralfate, promotes epithelial regeneration and activates cell proliferation. Based on this knowledge, we performed a non-randomized clinical trial to evaluate the efficacy of topical sucralfate gel in 30 breast cancer patients receiving postoperative accelerated hypofractionated photon beam therapy. The comparison was performed with 30 patients as historical controls. The acute reaction of the skin was significantly lower in the group receiving the sucralfate gel (p<0.05, Mann Whitney test), while 90% of the patients had no evidence of radiation induced skin toxicity. There was no sucralfate gel related toxicity reported by any patient in this study. More patients in a randomized way are needed for more definite results.

  12. A phononic crystal strip based on silicon for support tether applications in silicon-based MEMS resonators and effects of temperature and dopant on its band gap characteristics

    Directory of Open Access Journals (Sweden)

    Thi Dep Ha

    2016-04-01

    Full Text Available Phononic crystals (PnCs and n-type doped silicon technique have been widely employed in silicon-based MEMS resonators to obtain high quality factor (Q as well as temperature-induced frequency stability. For the PnCs, their band gaps play an important role in the acoustic wave propagation. Also, the temperature and dopant doped into silicon can cause the change in its material properties such as elastic constants, Young’s modulus. Therefore, in order to design the simultaneous high Q and frequency stability silicon-based MEMS resonators by two these techniques, a careful design should study effects of temperature and dopant on the band gap characteristics to examine the acoustic wave propagation in the PnC. Based on these, this paper presents (1 a proposed silicon-based PnC strip structure for support tether applications in low frequency silicon-based MEMS resonators, (2 influences of temperature and dopant on band gap characteristics of the PnC strips. The simulation results show that the largest band gap can achieve up to 33.56 at 57.59 MHz and increase 1280.13 % (also increase 131.89 % for ratio of the widest gaps compared with the counterpart without hole. The band gap properties of the PnC strips is insignificantly effected by temperature and electron doping concentration. Also, the quality factor of two designed length extensional mode MEMS resonators with proposed PnC strip based support tethers is up to 1084.59% and 43846.36% over the same resonators with PnC strip without hole and circled corners, respectively. This theoretical study uses the finite element analysis in COMSOL Multiphysics and MATLAB softwares as simulation tools. This findings provides a background in combination of PnC and dopant techniques for high performance silicon-based MEMS resonators as well as PnC-based MEMS devices.

  13. A phononic crystal strip based on silicon for support tether applications in silicon-based MEMS resonators and effects of temperature and dopant on its band gap characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Thi Dep, E-mail: hathidep@yahoo.com [School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731 (China); Faculty of Electronic Technology, Industrial University of Ho Chi Minh City, Hochiminh City (Viet Nam); Bao, JingFu, E-mail: baojingfu@uestc.edu.cn [School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731 (China)

    2016-04-15

    Phononic crystals (PnCs) and n-type doped silicon technique have been widely employed in silicon-based MEMS resonators to obtain high quality factor (Q) as well as temperature-induced frequency stability. For the PnCs, their band gaps play an important role in the acoustic wave propagation. Also, the temperature and dopant doped into silicon can cause the change in its material properties such as elastic constants, Young’s modulus. Therefore, in order to design the simultaneous high Q and frequency stability silicon-based MEMS resonators by two these techniques, a careful design should study effects of temperature and dopant on the band gap characteristics to examine the acoustic wave propagation in the PnC. Based on these, this paper presents (1) a proposed silicon-based PnC strip structure for support tether applications in low frequency silicon-based MEMS resonators, (2) influences of temperature and dopant on band gap characteristics of the PnC strips. The simulation results show that the largest band gap can achieve up to 33.56 at 57.59 MHz and increase 1280.13 % (also increase 131.89 % for ratio of the widest gaps) compared with the counterpart without hole. The band gap properties of the PnC strips is insignificantly effected by temperature and electron doping concentration. Also, the quality factor of two designed length extensional mode MEMS resonators with proposed PnC strip based support tethers is up to 1084.59% and 43846.36% over the same resonators with PnC strip without hole and circled corners, respectively. This theoretical study uses the finite element analysis in COMSOL Multiphysics and MATLAB softwares as simulation tools. This findings provides a background in combination of PnC and dopant techniques for high performance silicon-based MEMS resonators as well as PnC-based MEMS devices.

  14. The effect of pheniramine on fentanyl-induced cough: a randomized, double blinded, placebo controlled clinical study

    Directory of Open Access Journals (Sweden)

    Zakir Arslan

    Full Text Available Abstract Background and objectives: There are many studies conducted on reducing the frequency and severity of fentayl-induced cough during anesthesia induction. We propose that pheniramine maleate, an antihistaminic, may suppress this cough. We aim to observe the effect of pheniramine on fentanyl-induced cough during anesthesia induction. Methods: This is a double-blinded, prospective, three-arm parallel, randomized clinical trial of 120 patients with ASA (American Society of Anesthesiologists physical status III and IV who aged ≥18 and scheduled for elective open heart surgery during general anesthesia. Patients were randomly assigned to three groups of 40 patients, using computer-generated random numbers: placebo group, pheniramine group, and lidocaine group. Results: Cough incidence differed significantly between groups. In the placebo group, 37.5% of patients had cough, whereas the frequency was significantly decreased in pheniramine group (5% and lidocaine group (15% (Fischer exact test, p = 0.0007 and p = 0.0188, respectively. There was no significant change in cough incidence between pheniramine group (5% and lidocaine group (15% (Fischer exact test, p = 0.4325. Cough severity did also change between groups. Post Hoc tests with Bonferroni showed that mean cough severity in placebo differed significantly than that of pheniramine group and lidocaine group (p < 0.0001 and p = 0.009, respectively. There was no significant change in cough severity between pheniramine group and lidocaine group (p = 0.856. Conclusion: Intravenous pheniramine is as effective as lidocaine in preventing fentayl-induced cough. Our results emphasize that pheniramine is a convenient drug to decrease this cough.

  15. Milrinone therapy for enterovirus 71-induced pulmonary edema and/or neurogenic shock in children: a randomized controlled trial.

    Science.gov (United States)

    Chi, Chia-Yu; Khanh, Truong Huu; Thoa, Le Phan Kim; Tseng, Fan-Chen; Wang, Shih-Min; Thinh, Le Quoc; Lin, Chia-Chun; Wu, Han-Chieh; Wang, Jen-Ren; Hung, Nguyen Thanh; Thuong, Tang Chi; Chang, Chung-Ming; Su, Ih-Jen; Liu, Ching-Chuan

    2013-07-01

    Enterovirus 71-induced brainstem encephalitis with pulmonary edema and/or neurogenic shock (stage 3B) is associated with rapid mortality in children. In a small pilot study, we found that milrinone reduced early mortality compared with historical controls. This prospective, randomized control trial was designed to provide more definitive evidence of the ability of milrinone to reduce the 1-week mortality of stage 3B enterovirus 71 infections. Prospective, unicenter, open-label, randomized, controlled study. Inpatient ward of a large tertiary teaching hospital in Ho Chi Minh City, Vietnam. Children (≤ 18 yr old) admitted with proven enterovirus 71-induced pulmonary edema and/or neurogenic shock. Patients were randomly assigned to receive intravenous milrinone (0.5 μg/kg/min) (n = 22) or conventional management (n = 19). Both groups received dopamine or dobutamine and intravenous immunoglobulin. The primary endpoint was 1-week mortality. The secondary endpoints included length of ventilator dependence and hospital stay and adverse events. The median age was 2 years with a predominance of boys in both groups. The 1-week mortality was significantly lower, 18.2% (4/22) in the milrinone compared with 57.9% (11/19) in the conventional management group (relative risk = 0.314 [95% CI, 0.12-0.83], p = 0.01). The median duration of ventilator-free days was longer in the milrinone treatment group (p = 0.01). There was no apparent neurologic sequela in the survivors in either group, and no drug-related adverse events were documented. Milrinone significantly reduced the 1-week mortality of enterovirus 71-induced pulmonary edema and/or neurogenic shock without adverse effects. Further studies are needed to determine whether milrinone might be useful to prevent progression of earlier stages of brainstem encephalitis.

  16. The effect of pheniramine on fentanyl-induced cough: a randomized, double blinded, placebo controlled clinical study.

    Science.gov (United States)

    Arslan, Zakir; Çalık, Eyup Serhat; Kaplan, Bekir; Ahiskalioglu, Elif Oral

    2016-01-01

    There are many studies conducted on reducing the frequency and severity of fentayl-induced cough during anesthesia induction. We propose that pheniramine maleate, an antihistaminic, may suppress this cough. We aim to observe the effect of pheniramine on fentanyl-induced cough during anesthesia induction. This is a double-blinded, prospective, three-arm parallel, randomized clinical trial of 120 patients with ASA (American Society of Anesthesiologists) physical status III and IV who aged ≥18 and scheduled for elective open heart surgery during general anesthesia. Patients were randomly assigned to three groups of 40 patients, using computer-generated random numbers: placebo group, pheniramine group, and lidocaine group. Cough incidence differed significantly between groups. In the placebo group, 37.5% of patients had cough, whereas the frequency was significantly decreased in pheniramine group (5%) and lidocaine group (15%) (Fischer exact test, p=0.0007 and p=0.0188, respectively). There was no significant change in cough incidence between pheniramine group (5%) and lidocaine group (15%) (Fischer exact test, p=0.4325). Cough severity did also change between groups. Post Hoc tests with Bonferroni showed that mean cough severity in placebo differed significantly than that of pheniramine group and lidocaine group (ppheniramine group and lidocaine group (p=0.856). Intravenous pheniramine is as effective as lidocaine in preventing fentayl-induced cough. Our results emphasize that pheniramine is a convenient drug to decrease this cough. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  17. [The effect of pheniramine on fentanyl-induced cough: a randomized, double blinded, placebo controlled clinical study].

    Science.gov (United States)

    Arslan, Zakir; Çalık, Eyup Serhat; Kaplan, Bekir; Ahiskalioglu, Elif Oral

    2016-01-01

    There are many studies conducted on reducing the frequency and severity of fentayl-induced cough during anesthesia induction. We propose that pheniramine maleate, an antihistaminic, may suppress this cough. We aim to observe the effect of pheniramine on fentanyl-induced cough during anesthesia induction. This is a double-blinded, prospective, three-arm parallel, randomized clinical trial of 120 patients with ASA (American Society of Anesthesiologists) physical status III and IV who aged ≥18 and scheduled for elective open heart surgery during general anesthesia. Patients were randomly assigned to three groups of 40 patients, using computer-generated random numbers: placebo group, pheniramine group, and lidocaine group. Cough incidence differed significantly between groups. In the placebo group, 37.5% of patients had cough, whereas the frequency was significantly decreased in pheniramine group (5%) and lidocaine group (15%) (Fischer exact test, p=0.0007 and p=0.0188, respectively). There was no significant change in cough incidence between pheniramine group (5%) and lidocaine group (15%) (Fischer exact test, p=0.4325). Cough severity did also change between groups. Post Hoc tests with Bonferroni showed that mean cough severity in placebo differed significantly than that of pheniramine group and lidocaine group (ppheniramine group and lidocaine group (p=0.856). Intravenous pheniramine is as effective as lidocaine in preventing fentayl-induced cough. Our results emphasize that pheniramine is a convenient drug to decrease this cough. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  18. Shallow dopants in nanostructered and in isotopically engineered silicon

    Energy Technology Data Exchange (ETDEWEB)

    Stegner, Andre Rainer

    2011-01-15

    This work addressed two major topics. The first part was dedicated to the investigation of the doping properties of Si nanostructures. There, we have reported our results on Si nanoparticles with particular focus on questions concerning the atomic incorporation efficiency of dopants, their compensation by surface defects, and the change of their localization due to confinement effects. In the second part of this thesis, we have addressed several open questions concerning the spin properties of shallow acceptor states in bulk Si crystals with different isotope compositions. As far as the first part is concerned, ESR and SIMS have been used to quantitatively investigate the P doping efficiency and the interrelationship of Si-db states and P doping in freestanding Si-NCs over a wide range of diameters. Two types of Si-db defect states, the P{sub b} center and the D center, were identified, where the P{sub b} centers are found at concentrations comparable to bulk Si/SiO{sub 2} interfaces. Moreover, the incorporation of P donors and B acceptors in amorphous Si nanoparticles was demonstrated via ESR. Employing EDMR, we investigated the spin-dependent transport through Si-NC networks. The selectivity and the high sensitivity of EDMR enabled the observation of isolated neutral donor states, which exhibit a characteristic hyperfine splitting in samples with very small diameters. This opened up a possibility for the direct study of the properties of the donor wave function in Si-NCs. To this end, we have used the hyperfine splitting as a spectroscopic measure to monitor the localization of donor wave functions when going from the bulk to the nanoscale. As far as the spin properties of shallow acceptors in Si are concerned, we have addressed a number of fundamental questions concerning the line shape, the magnitude of the residual broadening and the substructure of the boron resonances observed in low-temperature EPR experiments. Performing EPR measurements on different

  19. Deprotonation effect of tetrahydrofuran-2-carbonitrile buffer gas dopant in ion mobility spectrometry.

    Science.gov (United States)

    Fernandez-Maestre, Roberto; Meza-Morelos, Dairo; Wu, Ching

    2016-06-15

    When dopants are introduced into the buffer gas of an ion mobility spectrometer, spectra are simplified due to charge competition. We used electrospray ionization to inject tetrahydrofuran-2-carbonitrile (F, 2-furonitrile or 2-furancarbonitrile) as a buffer gas dopant into an ion mobility spectrometer coupled to a quadrupole mass spectrometer. Density functional theory was used for theoretical calculations of dopant-ion interaction energies and proton affinities, using the hybrid functional X3LYP/6-311++(d,p) with the Gaussian 09 program that accounts for the basis set superposition error; analytes structures and theoretical calculations with Gaussian were used to explain the behavior of the analytes upon interaction with F. When F was used as a dopant at concentrations below 1.5 mmol m(-3) in the buffer gas, ions were not observed for α-amino acids due to charge competition with the dopant; this deprotonation capability arises from the production of a dimer with a high formation energy that stabilized the positive charge and created steric hindrance that deterred the equilibrium with analyte ions. F could not completely strip other compounds of their charge because they either showed steric hindrance at the charge site that deterred the approach of the dopant (2,4-lutidine, and DTBP), formed intramolecular bonds that stabilized the positive charge (atenolol), had high proton affinity (2,4-lutidine, DTBP, valinol and atenolol), or were inherently ionic (tetraalkylammonium ions). This selective deprotonation suggests the use of F to simplify spectra of complex mixtures in ion mobility and mass spectrometry in metabolomics, proteomics and other studies that generate complex spectra with thousands of peaks. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  20. First-in-man mesenchymal stem cells for radiation-induced xerostomia (MESRIX): study protocol for a randomized controlled trial

    DEFF Research Database (Denmark)

    Grønhøj, Christian; Jensen, David H; Glovinski, Peter V

    2017-01-01

    and quantitative measurements of saliva, as well as submandibular gland size, vascularization, fibrosis, and secretory tissue evaluation based on contrast-induced magnetic resonance imaging (MRI) and core-needle samples. The assessments are performed at baseline (1 month prior to treatment) and 1 and 4 months....... A total of 30 patients are randomized in a 1:1 ratio to receive ultrasound-guided, administered ASC or placebo to the submandibular glands. The primary outcome is change in unstimulated whole salivary flow rate. The secondary outcomes are safety, efficacy, change in quality of life, qualitative...

  1. The effectiveness of foot reflexology in inducing ovulation: a sham-controlled randomized trial.

    Science.gov (United States)

    Holt, Jane; Lord, Jonathan; Acharya, Umesh; White, Adrian; O'Neill, Nyree; Shaw, Steve; Barton, Andy

    2009-06-01

    To determine whether foot reflexology, a complementary therapy, has an effect greater than sham reflexology on induction of ovulation. Sham-controlled randomized trial with patients and statistician blinded. Infertility clinic in Plymouth, United Kingdom. Forty-eight women attending the clinic with anovulation. Women were randomized to receive eight sessions of either genuine foot reflexology or sham reflexology with gentle massage over 10 weeks. The primary outcome was ovulation detected by serum progesterone level of >30 nmol/L during the study period. Twenty-six patients were randomized to genuine reflexology and 22 to sham (one randomized patient was withdrawn). Patients remained blinded throughout the trial. The rate of ovulation during true reflexology was 11 out of 26 (42%), and during sham reflexology it was 10 out of 22 (46%). Pregnancy rates were 4 out of 26 in the true group and 2 out of 22 in the control group. Because of recruitment difficulties, the required sample size of 104 women was not achieved. Patient blinding of reflexology studies is feasible. Although this study was too small to reach a definitive conclusion on the specific effect of foot reflexology, the results suggest that any effect on ovulation would not be clinically relevant. Sham reflexology may have a beneficial general effect, which this study was not designed to detect.

  2. PIXE channeling for concentration and location measurements of Zn- and Cd-dopants in InP single crystals

    International Nuclear Information System (INIS)

    Vogt, J.; Krause, H.; Flagmeyer, R.; Otto, G.; Lux, M.

    1993-01-01

    We present results of the determination of Cd- and Zn-dopants in InP single crystals using the PIXE and RBS spectrometry at our 2 MeV Van de Graaff accelerator. The (100) oriented crystals were doped by thermodiffusion of Cd and Zn atoms. For concentration and localization measurements we used the ion-channeling technique and energy dispersive spectrometry of proton induced X-ray emission (PIXE). Angular scans of the K-lines of In, Cd and Zn were obtained. The strong In X-rays were attenuated by a rhodium foil in front of the low energy Ge detector. The PIXE-channeling results were compared with SIMS and Hall-effect measurements. (orig.)

  3. The effect of milrinone on induced hypotension in elderly patients during spinal surgery: a randomized controlled trial.

    Science.gov (United States)

    Hwang, Wonjung; Kim, Eunsung

    2014-08-01

    Induced hypotension is widely used intraoperatively to reduce blood loss and to improve the surgical field during spinal surgery. To determine the effect of milrinone on induced hypotension during spinal surgery in elderly patients. Prospective randomized clinical trial. Forty patients, 60 to 70 years old, ASA I-II, who underwent elective lumbar fusion surgery. Intraoperative hemodynamics, blood loss, hourly urine output, and grade of surgical field. All patients were randomized to group M or N. The study drug was infused after perivertebral muscle retraction until complete interbody fusion. In group M, 50 μg/kg/min of milrinone was infused over 10 minutes as a loading dose followed by 0.6 μg/kg/min of milrinone as a continuous dose. In group N, an identical volume of normal saline was infused in the same fashion. This study was not funded by commercial or other sponsorship and the authors confirm no conflicts of interest, financial or otherwise. During infusion of the study drug, the systolic and mean blood pressures were maintained within adequate limits of induced hypotension in group M. Intraoperative blood loss was 445.0±226.5 mL in group M and 765.0±339.2 mL in group N (p=.001). Hourly urine output was 1.4±0.6 mL in group M and 0.8±0.2 mL in group N (pmilrinone is useful for induced hypotension in elderly patients during spinal surgery. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Effects of small-angle mistilts on dopant visibility in ADF-STEM imaging of nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Held, Jacob T.; Duncan, Samuel; Mkhoyan, K. Andre, E-mail: mkhoyan@umn.edu

    2017-06-15

    Highlights: • ADF-STEM is powerful technique for 3D location of substitutionally doped atoms. • The effects of specimen mistilt on ADF-STEM imaging of doped atoms are evaluated. • Visibility changes over 0–30 mrad mistilts are large enough to preclude 3D dopant location. • Dopant visibility is a strong function of specimen mistilt and cannot be ignored. - Abstract: Quantitative ADF-STEM imaging paired with image simulations has proven to be a powerful technique for determining the three dimensional location of substitutionally doped atoms in thin films. Expansion of this technique to lightly-doped nanocrystals requires an understanding of the influence of specimen mistilt on dopant visibility due to the difficulty of accurate orientation determination in such systems as well as crystal movement under the beam. In this study, the effects of specimen mistilt on ADF-STEM imaging are evaluated using germanium-doped silicon nanocrystals as model systems. It is shown that dopant visibility is a strong function of specimen mistilt, and the accuracy of specimen orientation is an important factor in the analysis of three-dimensional dopant location, but the sensitivity to mistilt can be weakened by increasing the STEM probe convergence angle and optimizing ADF detector inner angle.

  5. Titanium dioxide nanotube membranes for solar energy conversion: effect of deep and shallow dopants.

    Science.gov (United States)

    Ding, Yuchen; Nagpal, Prashant

    2017-04-12

    Nanostructured titanium dioxide (TiO 2 ) has been intensively investigated as a material of choice for solar energy conversion in photocatalytic, photoelectrochemical, photovoltaic, and other photosensitized devices for converting light into chemical feedstocks or electricity. Towards management of light absorption in TiO 2 , while the nanotubular structure improves light absorption and simultaneous charge transfer to mitigate problems due to the indirect bandgap of the semiconductor, typically dopants are used to improve light absorption of incident solar irradiation in the wide bandgap of TiO 2 . While these dopants can be critical to the success of these solar energy conversion devices, their effect on photophysical and photoelectrochemical properties and detailed photokinetics are relatively under-studied. Here, we show the effect of deep and shallow metal dopants on the kinetics of photogenerated charged carriers in TiO 2 and the resulting effect on photocatalytic and photoelectrochemical processes using these nanotube membranes. We performed a detailed optical, electronic, voltammetry and electrochemical impedance study to understand the effect of shallow and deep metal dopants (using undoped and niobium- and copper-doped TiO 2 nanotubes) on light absorption, charge transport and charge transfer processes. Using wireless photocatalytic methylene blue degradation and carbon dioxide reduction, and wired photoelectrochemical device measurements, we elucidate the effect of different dopants on solar-to-fuel conversion efficiency and simultaneously describe the photokinetics using a model, to help design better energy conversion devices.

  6. Effects on Implosion Characteristics of High-Z Dopant Profiles in ICF Ignition Capsule Ablators

    Science.gov (United States)

    Li, Yongsheng; Wang, Min; Gu, Jianfa; Zou, Shiyang; Kang, Dongguo; Ye, Wenhua; Zhang, Weiyan

    2012-10-01

    For ignition target design (ITD) of indirect drive ICF [J. Lindl, PoP 2, 3933(1995)], high-Z dopants in capsule ablators were used to prevent preheat of DTadjacentablators by Au M-band flux in laser-driven gold Hohlraums, therefore to restrain the growth of high-mode hydro-instabilities and to improve the targetrobustness.Based on NIC's Rev. 5 ITD[S. W. Haan et al., PoP 18, 051001(2011)], we investigated the effect of thickness and dopant concentration of doped layers on implosion characteristics, including the Atwood number (AWN) of fuel-ablator interface, the density gradient scale length (DGSL) of ablation front and the implosion velocity (VIM); all three variables decrease with increment of dopant dosage, and increase with dopant concentration while keeping dosage constant. Since a smaller AWN, a larger DGSL, and a faster VIM always characterize a more robust ITD, one should make tradeoff among them by adjusting the dopant profiles in ablators.A Gaussian spectrum (GS) was used to imitate the Au M-band flux [Y. S. Li et al., PoP 18, 022701(2011)], and the impact of GScenter on implosion characteristics of Rev. 5 ITD was studied while moving the GScenter towards higher energy, the ablatorpreheat got severe, AWN got larger, DGSL got larger, and VIM got faster.

  7. Non-metallic dopant modulation of conductivity in substoichiometric tantalum pentoxide: A first-principles study

    Science.gov (United States)

    Bondi, Robert J.; Fox, Brian P.; Marinella, Matthew J.

    2017-06-01

    We apply density-functional theory calculations to predict dopant modulation of electrical conductivity (σo) for seven dopants (C, Si, Ge, H, F, N, and B) sampled at 18 quantum molecular dynamics configurations of five independent insertion sites into two (high/low) baseline references of σo in amorphous Ta2O5, where each reference contains a single, neutral O vacancy center (VO0). From this statistical population (n = 1260), we analyze defect levels, physical structure, and valence charge distributions to characterize nanoscale modification of the atomistic structure in local dopant neighborhoods. C is the most effective dopant at lowering Ta2Ox σo, while also exhibiting an amphoteric doping behavior by either donating or accepting charge depending on the host oxide matrix. Both B and F robustly increase Ta2Ox σo, although F does so through elimination of Ta high charge outliers, while B insertion conversely creates high charge O outliers through favorable BO3 group formation, especially in the low σo reference. While N applications to dope and passivate oxides are prevalent, we found that N exacerbates the stochasticity of σo we sought to mitigate; sensitivity to the N insertion site and some propensity to form N-O bond chemistries appear responsible. We use direct first-principles predictions of σo to explore feasible Ta2O5 dopants to engineer improved oxides with lower variance and greater repeatability to advance the manufacturability of resistive memory technologies.

  8. Prediction of the spatial occurrence of fire induced spalling in concrete slabs using random fields

    Directory of Open Access Journals (Sweden)

    Van Coile R.

    2013-09-01

    Full Text Available As the loss of concrete cover can significantly influence the reliability of concrete elements during fire, spalling should be taken into account when performing reliability calculations. However, the occurrence and spatial variation of spalling are highly uncertain. A first step towards a probabilistic analysis of spalling is made by combining existing deterministic models with a stochastic representation of the concrete tensile strength and by using random fields to model the tensile strength spatial variation.

  9. Melatonin for Atypical Antipsychotic-Induced Metabolic Adverse Effects: A Meta-Analysis of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Ashwin Kamath

    2018-01-01

    Full Text Available The objective of our study was to determine the effect of melatonin administration on atypical antipsychotic-induced metabolic adverse effects in patients with psychiatric disorders. A systematic search was performed in PUBMED, Cochrane Library, Scopus, Web of Science, and EBSCOhost electronic databases. Randomized controlled trials studying the effect of melatonin on antipsychotic-induced metabolic adverse effects were identified and subjected to meta-analysis. Four studies were included in the meta-analysis, including 57 patients on melatonin and 61 patients on placebo. Melatonin produced a significant decrease in the diastolic blood pressure compared with placebo (mean difference = −4.44 [95% CI, −7.00 to −1.88]; p=0.0007; I2 = 13%, but not the systolic blood pressure (mean difference = −4.23 [95% CI, −8.11 to −0.36]; p=0.03; I2 = 0%. Although a decrease in the body mass index was seen in the melatonin group, the difference was not significant in the random-effects analysis model. To conclude, in patients on atypical antipsychotics, melatonin at a dose of up to 5 mg/day for a treatment duration of up to 12 weeks attenuated the rise in diastolic blood pressure compared with placebo but had no significant effects on other metabolic parameters.

  10. Melatonin for Atypical Antipsychotic-Induced Metabolic Adverse Effects: A Meta-Analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Kamath, Ashwin; Rather, Zahoor Ahmad

    2018-01-01

    The objective of our study was to determine the effect of melatonin administration on atypical antipsychotic-induced metabolic adverse effects in patients with psychiatric disorders. A systematic search was performed in PUBMED, Cochrane Library, Scopus, Web of Science, and EBSCOhost electronic databases. Randomized controlled trials studying the effect of melatonin on antipsychotic-induced metabolic adverse effects were identified and subjected to meta-analysis. Four studies were included in the meta-analysis, including 57 patients on melatonin and 61 patients on placebo. Melatonin produced a significant decrease in the diastolic blood pressure compared with placebo (mean difference = -4.44 [95% CI, -7.00 to -1.88]; p = 0.0007; I 2 = 13%), but not the systolic blood pressure (mean difference = -4.23 [95% CI, -8.11 to -0.36]; p = 0.03; I 2 = 0%). Although a decrease in the body mass index was seen in the melatonin group, the difference was not significant in the random-effects analysis model. To conclude, in patients on atypical antipsychotics, melatonin at a dose of up to 5 mg/day for a treatment duration of up to 12 weeks attenuated the rise in diastolic blood pressure compared with placebo but had no significant effects on other metabolic parameters.

  11. Sucralfate mouthwash for prevention and treatment of 5-fluorouracil-induced mucositis: a randomized, placebo-controlled trial.

    Science.gov (United States)

    Nottage, Michelle; McLachlan, Sue-Anne; Brittain, Mary-Anne; Oza, Amit; Hedley, David; Feld, Ronald; Siu, Lillian L; Pond, Gregory; Moore, Malcolm J

    2003-01-01

    A randomized, double-blind, placebo-controlled trial was conducted to evaluate the effectiveness of a sucralfate mouthwash in preventing and alleviating oral mucositis induced by 5-fluorouracil (5FU). A total of 81 patients with colorectal cancer were enrolled. Patients were studied during their first cycle of chemotherapy with 5FU and leucovorin (LV) daily for 5 days every 4 weeks (Mayo Clinic schedule). Patients were randomly allocated to receive either a sucralfate suspension or a placebo suspension that was identical in appearance. Patients were instructed to use the suspension as a mouthwash four times daily from the beginning of the chemotherapy cycle. All patients received oral cryotherapy. Patients graded the severity of their own symptoms on a daily basis, and this was the primary outcome measure. There was no difference in the frequency or severity of oral mucositis between the sucralfate- and the placebo-treated group. Some mucositis was reported by 79% of the patient group. Assessment of mucositis by trial staff underestimated the incidence of this problem. Results of this trial do not support the hypothesis that a sucralfate mouthwash can prevent or alleviate oral mucositis induced by 5FU. Patient reporting of mucositis is a more sensitive instrument for assessment of mucositis than review by medical staff.

  12. Randomized Phase III and Extension Studies of Naldemedine in Patients With Opioid-Induced Constipation and Cancer.

    Science.gov (United States)

    Katakami, Nobuyuki; Harada, Toshiyuki; Murata, Toru; Shinozaki, Katsunori; Tsutsumi, Masakazu; Yokota, Takaaki; Arai, Masatsugu; Tada, Yukio; Narabayashi, Masaru; Boku, Narikazu

    2017-12-01

    Purpose Opioid-induced constipation (OIC) is a frequent and debilitating adverse effect (AE) of opioids-common analgesics for cancer pain. We investigated the efficacy and safety of a peripherally acting μ-opioid receptor antagonist, naldemedine (S-297995), for OIC, specifically in patients with cancer. Patients and Methods This phase III trial consisted of a 2-week, randomized, double-blind, placebo-controlled study (COMPOSE-4) and an open-label, 12-week extension study (COMPOSE-5). In COMPOSE-4, eligible adults with OIC and cancer were randomly assigned on a 1:1 basis to receive once-daily oral naldemedine 0.2 mg or placebo. The primary end point was the proportion of spontaneous bowel movement (SBM) responders (≥ 3 SBMs/week and an increase of ≥ 1 SBM/week from baseline). The primary end point of COMPOSE-5 was safety. Results In COMPOSE-4, 193 eligible patients were randomly assigned to naldemedine (n = 97) or placebo (n = 96). The proportion of SBM responders in COMPOSE-4 was significantly greater with naldemedine than with placebo (71.1% [69 of 97 patients] v 34.4% [33 of 96 patients]; P opioid withdrawal and had no notable impact on opioid-mediated analgesia. Conclusion Once-daily oral naldemedine 0.2 mg effectively treated OIC and was generally well tolerated in patients with OIC and cancer.

  13. Remote Ischemic Preconditioning To Reduce Contrast-Induced Nephropathy: A Randomized Controlled Trial

    NARCIS (Netherlands)

    Menting, T.P.; Sterenborg, T.B.; Waal, Y.R. de; Donders, R.; Wever, K.E.; Lemson, M.S.; Vliet, J.A. van der; Wetzels, J.F.M.; Schultze Kool, L.J.; Warle, M.C.

    2015-01-01

    BACKGROUND: Despite the increasing use of pre- and post-hydration protocols and low osmolar instead of high osmolar iodine containing contrast media, the incidence of contrast induced nephropathy (CIN) is still significant. There is evidence that contrast media cause ischemia reperfusion injury of

  14. Probing dopants in wide semiconductor quantum point contacts

    International Nuclear Information System (INIS)

    Yakimenko, I I; Berggren, K-F

    2016-01-01

    Effects of randomly distributed impurities on conductance, spin polarization and electron localization in realistic gated semiconductor quantum point contacts (QPCs) have been simulated numerically. To this end density functional theory in the local spin-density approximation has been used. In the case when the donor layer is embedded far from the two-dimensional electron gas (2DEG) the electrostatic confinement potential exhibits the conventional parabolic form, and thus the usual ballistic transport phenomena take place both in the devices with split gates alone and with an additional metallic gate on the top. In the opposite case, i.e. when the randomly distributed donors are placed not far away from the 2DEG layer, there are drastic changes like the localization of electrons in the vicinity of confinement potential minima which give rise to fluctuations in conductance and resonances. The conductance as a function of the voltage applied to the top gate for asymmetrically charged split gates has been calculated. In this case resonances in conductance caused by randomly distributed donors are shifted and decrease in amplitude while the anomalies caused by interaction effects remain unmodified. It has been also shown that for a wide QPC the polarization can appear in the form of stripes. The importance of partial ionization of the random donors and the possibility of short range order among the ionized donors are emphasized. The motivation for this work is to critically evaluate the nature of impurities and how to guide the design of high-mobility devices. (paper)

  15. Hydrogen Storage Properties of Lithium Aluminohydride Modified by Dopants and Mechanochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, Keita [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Alkali metal aluminohydrides have high potential as solid hydrogen storage materials. They have been known for their irreversible dehydrogenation process below 100 atm until Bogdanovic et al [1, 2] succeeded in the re-hydrogenation of NaAlH4 below 70 atm. They achieved 4 wt.% H2 reversible capacity by doping NaAlH4 with Ti and/or Fe organo-metalic compounds as catalysts. This suggests that other alkali and, possibly alkaline earth metal aluminohydrides can be used for reversible hydrogen storage when modified by proper dopants. In this research, Zr27Ti9Ni38V5Mn16Cr5, LaNi4.85Sn0.15, Al3Ti, and PdCl2 were combined , LaNi4.85Sn0.15, Al3Ti, and PdCl2 were combined with LiAlH4 by ball-milling to study whether or not LiAlH4 is capable to both absorb and desorb hydrogen near ambient conditions. X-ray powder diffraction, differential thermal analysis, and scanning electron microscopy were employed for sample characterizations. All four compounds worked as catalysts in the dehydrogenation reactions of both LiAlH4 and Li3AlH6 by inducing the decomposition at lower temperature. However, none of them was applicable as catalyst in the reverse hydrogenation reaction at low to moderate hydrogen pressure.

  16. Hydrogen Storage Properties of Lithium Aluminohydride modified by dopants and mechanochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, Keita [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Alkali metal aluminohydrides have high potential as solid hydrogen storage materials. They have been known for their irreversible dehydrogenation process below 100 atm until Bogdanovic et al [1, 2] succeeded in the re-hydrogenation of NaAlH4 below 70 atm. They achieved 4 wt.% H2 reversible capacity by doping NaAlH4 with Ti and/or Fe organo-metalic compounds as catalysts. This suggests that other alkali and, possibly alkaline earth metal aluminohydrides can be used for reversible hydrogen storage when modified by proper dopants. In this research, Zr27Ti9Ni38V5Mn16Cr5, LaNi4.85Sn0.15, Al3Ti, and PdCl2 were combined with LiAlH4 by ball-milling to study whether or not LiAlH4 is capable to both absorb and desorb hydrogen near ambient conditions. X-ray powder diffraction, differential thermal analysis, and scanning electron microscopy were employed for sample characterizations. All four compounds worked as catalysts in the dehydrogenation reactions of both LiAlH4 and Li3AlH6 by inducing the decomposition at lower temperature. However, none of them was applicable as catalyst in the reverse hydrogenation reaction at low to moderate hydrogen pressure.

  17. Hydrogen Storage Properties of Lithium Aluminohydride Modified by Dopants and Mechanochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, Ketia [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Alkali metal aluminohydrides have high potential as solid hydrogen storage materials. They have been known for their irreversible dehydrogenation process below 100 atm until Bogdanovic et al succeeded in the re-hydrogenation of NaAlH4 below 70 atm. They achieved 4 wt.% H2 reversible capacity by doping NaAlH4 with Ti and/or Fe organo-metallic compounds as catalysts. This suggests that other alkali and, possibly alkaline earth metal aluminohydrides can be used for reversible hydrogen storage when modified by proper dopants. In this research, Zr27Ti9Ni38V5Mn16Cr5, LaNi 4.85Sn0.15, Al3Ti, and PdCl2 were combined with LiAlH4 by ball-milling to study whether or not LiAlH4 is capable to both absorb and desorb hydrogen near ambient conditions. X-ray powder diffraction, differential thermal analysis, and scanning electron microscopy were employed for sample characterizations. All four compounds worked as catalysts in the dehydrogenation reactions of both LiAlH4 and Li3AlH6 by inducing the decomposition at lower temperature. However, none of them was applicable as catalyst in the reverse hydrogenation reaction at low to moderate hydrogen pressure.

  18. Effect of Cu-Dopant on the Structural, Magnetic and Electrical Properties of ZnO

    Science.gov (United States)

    Aryanto, D.; Kurniawan, C.; Subhan, A.; Sudiro, T.; Sebayang, P.; Ginting, M.; Siregar, S. M. K.; Nasruddin, M. N.

    2017-05-01

    Zn1- x Cu x O (x = 0, 2, 3, and 4 at.%) was synthesized by using solid-state reaction technique. The ZnO and CuO powders were mixed and then milled by using high-speed shaker mill. The influence of Cu dopants on the structure, magnetic, and electrical properties was investigated by using XRD, VSM, and I-V and C-V measurements. The XRD analysis showed that the Zn1- x Cu x O had hexagonal wurtzite polycrystalline. The diffraction intensity decreased and the peak position shifted directly to a higher 2θ angle with increasing the dopant concentration. Furthermore, the lattice parameters decreased when the ZnO was doped with x = 0.04, which indicated that the crystal structure changed. The increase of Cu dopants was believed to affect the magnetic and electrical properties of ZnO.

  19. Two-dimensional dopant profiling by electrostatic force microscopy using carbon nanotube modified cantilevers

    International Nuclear Information System (INIS)

    Chin, S.-C.; Chang, Y.-C.; Chang, C.-S.; Tsong, T T; Hsu, Chen-Chih; Wu, Chih-I; Lin, W-H; Woon, W-Y; Lin, L-T; Tao, H-J

    2008-01-01

    A two-dimensional (2D) dopant profiling technique is demonstrated in this work. We apply a unique cantilever probe in electrostatic force microscopy (EFM) modified by the attachment of a multiwalled carbon nanotube (MWNT). Furthermore, the tip apex of the MWNT was trimmed to the sharpness of a single-walled carbon nanotube (SWNT). This ultra-sharp MWNT tip helps us to resolve dopant features to within 10 nm in air, which approaches the resolution achieved by ultra-high vacuum scanning tunnelling microscopy (UHV STM). In this study, the CNT-probed EFM is used to profile 2D buried dopant distribution under a nano-scale device structure and shows the feasibility of device characterization for sub-45 nm complementary metal-oxide-semiconductor (CMOS) field-effect transistors

  20. Theory of space charge limited currents in films and nanowires with dopants

    Science.gov (United States)

    Zhang, Xiaoguang; Pantelides, Sokrates

    2015-03-01

    We show that proper description of the space charge limited currents (SCLC) in a homogeneous bulk material must account fully for the effect of the dopants and the interplay between dopants and traps. The sharp rise in the current at the trap-filled-limit (TFL) is partially mitigated by the dopant energy levels and the Frenkel effect, namely the lowering of the ionization energy by the electric field, which is screened by the free carriers. In nanowires, lack of effective screening causes the trap occupation at small biases to reach a high level comparable to the TFL in bulk. This explains the high current density in SCLCs observed in nanowires. This work is supported by the LDRD program at ORNL. Portion of this research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.

  1. Randomized controlled trial of fish oil and montelukast and their combination on airway inflammation and hyperpnea-induced bronchoconstriction.

    Directory of Open Access Journals (Sweden)

    Sandra Tecklenburg-Lund

    2010-10-01

    Full Text Available Both fish oil and montelukast have been shown to reduce the severity of exercise-induced bronchoconstriction (EIB. The purpose of this study was to compare the effects of fish oil and montelukast, alone and in combination, on airway inflammation and bronchoconstriction induced by eucapnic voluntary hyperpnea (EVH in asthmatics.In this model of EIB, twenty asthmatic subjects with documented hyperpnea-induced bronchoconstriction (HIB entered a randomized double-blind trial. All subjects entered on their usual diet (pre-treatment, n = 20 and then were randomly assigned to receive either one active 10 mg montelukast tablet and 10 placebo fish oil capsules (n = 10 or one placebo montelukast tablet and 10 active fish oil capsules totaling 3.2 g EPA and 2.0 g DHA (n = 10 taken daily for 3-wk. Thereafter, all subjects (combination treatment; n = 20 underwent another 3-wk treatment period consisting of a 10 mg active montelukast tablet or 10 active fish oil capsules taken daily.While HIB was significantly inhibited (p0.017 between treatment groups; percent fall in forced expiratory volume in 1-sec was -18.4 ± 2.1%, -9.3±2.8%, -11.6 ± 2.8% and -10.8 ± 1.7% on usual diet (pre-treatment, fish oil, montelukast and combination treatment respectively. All three treatments were associated with a significant reduction (p0.017 in these biomarkers between treatments.While fish oil and montelukast are both effective in attenuating airway inflammation and HIB, combining fish oil with montelukast did not confer a greater protective effect than either intervention alone. Fish oil supplementation should be considered as an alternative treatment for EIB.ClinicalTrials.gov NCT00676468.

  2. First-in-man mesenchymal stem cells for radiation-induced xerostomia (MESRIX): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Grønhøj, Christian; Jensen, David H; Glovinski, Peter V; Jensen, Siri Beier; Bardow, Allan; Oliveri, Roberto S; Specht, Lena; Thomsen, Carsten; Darkner, Sune; Kiss, Katalin; Fischer-Nielsen, Anne; von Buchwald, Christian

    2017-03-07

    Salivary gland hypofunction and xerostomia are major complications following radiotherapy for head and neck cancer and may lead to debilitating oral disorders and impaired quality of life. Currently, only symptomatic treatment is available. However, mesenchymal stem cell (MSC) therapy has shown promising results in preclinical studies. Objectives are to assess safety and efficacy in a first-in-man trial on adipose-derived MSC therapy (ASC) for radiation-induced xerostomia. This is a single-center, phase I/II, randomized, placebo-controlled, double-blinded clinical trial. A total of 30 patients are randomized in a 1:1 ratio to receive ultrasound-guided, administered ASC or placebo to the submandibular glands. The primary outcome is change in unstimulated whole salivary flow rate. The secondary outcomes are safety, efficacy, change in quality of life, qualitative and quantitative measurements of saliva, as well as submandibular gland size, vascularization, fibrosis, and secretory tissue evaluation based on contrast-induced magnetic resonance imaging (MRI) and core-needle samples. The assessments are performed at baseline (1 month prior to treatment) and 1 and 4 months following investigational intervention. The trial is the first attempt to evaluate the safety and efficacy of adipose-derived MSCs (ASCs) in patients with radiation-induced xerostomia. The results may provide evidence for the effectiveness of ASC in patients with salivary gland hypofunction and xerostomia and deliver valuable information for the design of subsequent trials. EudraCT, Identifier: 2014-004349-29. Registered on 1 April 2015. ClinicalTrials.gov, Identifier: NCT02513238 . First received on 2 July 2015. The trial is prospectively registered.

  3. An extended five-stream model for diffusion of ion-implanted dopants in monocrystalline silicon

    International Nuclear Information System (INIS)

    Khina, B.B.

    2007-01-01

    Low-energy high-dose ion implantation of different dopants (P, Sb, As, B and others) into monocrystalline silicon with subsequent thermal annealing is used for the formation of ultra-shallow p-n junctions in modern VLSI circuit technology. During annealing, dopant activation and diffusion in silicon takes place. The experimentally observed phenomenon of transient enhanced diffusion (TED), which is typically ascribed to the interaction of diffusing species with non-equilibrium point defects accumulated in silicon due to ion damage, and formation of small clusters and extended defects, hinders further down scaling of p-n junctions in VLSI circuits. TED is currently a subject of extensive experimental and theoretical investigation in many binary and multicomponent systems. However, the state-of-the-art mathematical models of dopant diffusion, which are based on the so-called 'five-stream' approach, and modern TCAD software packages such as SUPREM-4 (by Silvaco Data Systems, Ltd.) that implement these models encounter severe difficulties in describing TED. Solving the intricate problem of TED suppression and development of novel regimes of ion implantation and rapid thermal annealing is impossible without elaboration of new mathematical models and computer simulation of this complex phenomenon. In this work, an extended five-stream model for diffusion in silicon is developed which takes into account all possible charge states of point defects (vacancies and silicon self-interstitials) and diffusing pairs 'dopant atom-vacancy' and 'dopant atom-silicon self-interstitial'. The model includes the drift terms for differently charged point defects and pairs in the internal electric field and the kinetics of interaction between unlike 'species' (generation and annihilation of pairs and annihilation of point defects). Expressions for diffusion coefficients and numerous sink/source terms that appear in the non-linear, non-steady-state reaction-diffusion equations are derived

  4. Randomized Comparison of Dry Dressings Versus Hydrogel in Management of Radiation-Induced Moist Desquamation

    International Nuclear Information System (INIS)

    Macmillan, Maureen S.; Wells, Mary; MacBride, Sheila; Raab, Gillian M.; Munro, Alastair; MacDougall, Hugh

    2007-01-01

    Purpose: We present the results of a randomized controlled clinical trial that evaluated the effect of a hydrogel or dry dressing on the time to healing of moist desquamation after radiotherapy to the head-and-neck, breast, or anorectal areas. Methods and Materials: A total of 357 patients were randomized before radiotherapy to receive simple dry dressings (Tricotex) or a hydrogel (Intrasite), with Tricotex as a secondary dressing. Patients were instructed to use their dressings from the onset of moist desquamation, if it occurred. Results: Of the 357 patients, 100 (28%) developed moist desquamation. The time to healing was significantly prolonged (hazard ratio, 0.64; 95% confidence interval, 0.42-0.99), in patients assigned to gel dressings. No evidence was found that gel dressings had a significant impact on subjectively reported skin symptoms. Conclusion: The results of this study have not supported the routine use of hydrogels in the care of patients with moist desquamation and suggests that the healing times are prolonged, without any improvement in patient comfort

  5. Random lasing of microporous surface of Cr2+:ZnSe crystal induced by femtosecond laser

    International Nuclear Information System (INIS)

    Yang, Xianheng; Feng, Guoying; Yao, Ke; Yi, Jiayu; Zhang, Hong; Zhou, Shouhuan

    2015-01-01

    We demonstrate a random lasing emission based on microporous surface of Cr 2+ :ZnSe crystal prepared by femtosecond pulsed laser ablation in high vacuum (below 5 × 10 −4 Pa). The scanning electron microscope results show that there are a mass of micropores with an average size of ∼13 μm and smaller ones with ∼1.2 μm on the surface of Cr 2+ :ZnSe crystal. The adjacent micropore spacing of the smaller micropores ranges from 1 μm to 5 μm. Under 1750 nm excitation of Nd:YAG (355 nm) pumped optical parametric oscillator, a random lasing emission with center wavelength of 2350 nm and laser-like threshold of 0.3 mJ/pulse is observed. The emission lifetime of 2350 nm laser reduces from 800 ns to 30 ns as the pump energy increases above threshold. The emission spectra and decay time of smooth surface, groove and microporous surface of Cr 2+ :ZnSe crystal are contrasted. The optional pump wavelength range is from 1500 nm to 1950 nm, which in accordance with the optical absorption property of Cr 2+ :ZnSe crystal. The peak position of excitation spectra is almost identical to the strongest absorption wavelength

  6. Transcranial Random Noise Stimulation-induced plasticity is NMDA-receptor independent but sodium-channel blocker and benzodiazepines sensitive

    Directory of Open Access Journals (Sweden)

    Leila eChaieb

    2015-04-01

    Full Text Available Background: Application of transcranial random noise stimulation (tRNS between 0.1 and 640 Hz of the primary motor cortex (M1 for 10 minutes induces a persistent excitability increase lasting for at least 60 minutes. However, the mechanism of tRNS-induced cortical excitability alterations is not yet fully understood. Objective: The main aim of this study was to get first efficacy data with regard to the possible neuronal effect of tRNS. Methods: Single-pulse transcranial magnetic stimulation (TMS was used to measure levels of cortical excitability before and after combined application of tRNS at an intensity of 1mA for 10mins stimulation duration and a pharmacological agent (or sham on 8 healthy male participants. Results: The sodium channel blocker carbamazepine showed a tendency towards inhibiting MEPs 5-60 mins poststimulation. The GABAA agonist lorazepam suppressed tRNS-induced cortical excitability increases at 0-20 and 60 min time points. The partial NMDA receptor agonist D-cycloserine, the NMDA receptor antagonist dextromethorphan and the D2/D3 receptor agonist ropinirole had no significant effects on the excitability increases seen with tRNS.Conclusions: In contrast to transcranial direct current stimulation (tDCS, aftereffects of tRNS are seem to be not NMDA receptor dependent and can be suppressed by benzodiazepines suggesting that tDCS and tRNS depend upon different mechanisms.

  7. Effect of rare earth dopants on structural and mechanical properties of nanoceria synthesized by combustion method

    International Nuclear Information System (INIS)

    Akbari-Fakhrabadi, A.; Meruane, V.; Jamshidijam, M.; Gracia-Pinilla, M.A.; Mangalaraja, R.V.

    2016-01-01

    Structural characteristics of combustion synthesized, calcined and densified pure and doped nanoceria with tri-valent cations of Er, Y, Gd, Sm and Nd were analyzed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The results showed that the as-synthesized and calcined nanopowders were mesoporous and calculated lattice parameters were close to theoretical ion-packing model. The effect of dopants on elastic modulus, microhardness and fracture toughness of sintered pure and doped ceria were investigated. It was observed that tri-valent cation dopants increased the hardness of the ceria, whereas the fracture toughness and elastic modulus were decreased.

  8. Dopant distributions in n-MOSFET structure observed by atom probe tomography

    International Nuclear Information System (INIS)

    Inoue, K.; Yano, F.; Nishida, A.; Takamizawa, H.; Tsunomura, T.; Nagai, Y.; Hasegawa, M.

    2009-01-01

    The dopant distributions in an n-type metal-oxide-semiconductor field effect transistor (MOSFET) structure were analyzed by atom probe tomography. The dopant distributions of As, P, and B atoms in a MOSFET structure (gate, gate oxide, channel, source/drain extension, and halo) were obtained. P atoms were segregated at the interface between the poly-Si gate and the gate oxide, and on the grain boundaries of the poly-Si gate, which had an elongated grain structure along the gate height direction. The concentration of B atoms was enriched near the edge of the source/drain extension where the As atoms were implanted.

  9. Addition of photosensitive dopants to the D0 liquid argon calorimeter

    International Nuclear Information System (INIS)

    Amos, N.A.; Anderson, D.F.

    1992-10-01

    The addition of photosensitive dopants to liquid argon greatly enhances the signal from heavily ionizing particles. Since binding energy losses we correlated with the heavily ionizing component in hadronic showers, the addition of photosensitive dopants has been suggested as a mechanism to tune the e/π ratio in liquid argon calorimeters. A measurement was performed at the FNAL test beam, adding 4 ppM tetramethylgermanium to the Dφ uranium-liquid argon calorimeter. An increase in response for electromagnetic and hadronic showers was observed, with no net change in the e/π ratio

  10. Dopant distributions in n-MOSFET structure observed by atom probe tomography.

    Science.gov (United States)

    Inoue, K; Yano, F; Nishida, A; Takamizawa, H; Tsunomura, T; Nagai, Y; Hasegawa, M

    2009-11-01

    The dopant distributions in an n-type metal-oxide-semiconductor field effect transistor (MOSFET) structure were analyzed by atom probe tomography. The dopant distributions of As, P, and B atoms in a MOSFET structure (gate, gate oxide, channel, source/drain extension, and halo) were obtained. P atoms were segregated at the interface between the poly-Si gate and the gate oxide, and on the grain boundaries of the poly-Si gate, which had an elongated grain structure along the gate height direction. The concentration of B atoms was enriched near the edge of the source/drain extension where the As atoms were implanted.

  11. Optimized Laser Thermal Annealing on Germanium for High Dopant Activation and Low Leakage Current

    DEFF Research Database (Denmark)

    Shayesteh, Maryam; O' Connell, Dan; Gity, Farzan

    2014-01-01

    In this paper, state-of-the-art laser thermal annealing is used to fabricate Ge diodes. We compared the effect of laser thermal annealing (LTA) and rapid thermal annealing (RTA) on dopant activation and electrical properties of phosphorus and Arsenic-doped n +/p junctions. Using LTA, high carrier...... implant conditions. On the other hand, RTA revealed very high I on/I off ratio ∼ 107 and n ∼ 1, at the cost of high dopant diffusion and lower carrier concentrations which would degrade scalability and access resistance....

  12. The ionization mechanisms in direct and dopant-assisted atmospheric pressure photoionization and atmospheric pressure laser ionization.

    Science.gov (United States)

    Kauppila, Tiina J; Kersten, Hendrik; Benter, Thorsten

    2014-11-01

    A novel, gas-tight API interface for gas chromatography-mass spectrometry was used to study the ionization mechanism in direct and dopant-assisted atmospheric pressure photoionization (APPI) and atmospheric pressure laser ionization (APLI). Eight analytes (ethylbenzene, bromobenzene, naphthalene, anthracene, benzaldehyde, pyridine, quinolone, and acridine) with varying ionization energies (IEs) and proton affinities (PAs), and four common APPI dopants (toluene, acetone, anisole, and chlorobenzene) were chosen. All the studied compounds were ionized by direct APPI, forming mainly molecular ions. Addition of dopants suppressed the signal of the analytes with IEs above the IE of the dopant. For compounds with suitable IEs or Pas, the dopants increased the ionization efficiency as the analytes could be ionized through dopant-mediated gas-phase reactions, such as charge exchange, proton transfer, and other rather unexpected reactions, such as formation of [M + 77](+) in the presence of chlorobenzene. Experiments with deuterated toluene as the dopant verified that in case of proton transfer, the proton originated from the dopant instead of proton-bound solvent clusters, as in conventional open or non-tight APPI sources. In direct APLI using a 266 nm laser, a narrower range of compounds was ionized than in direct APPI, because of exceedingly high IEs or unfavorable two-photon absorption cross-sections. Introduction of dopants in the APLI system changed the ionization mechanism to similar dopant-mediated gas-phase reactions with the dopant as in APPI, which produced mainly ions of the same form as in APPI, and ionized a wider range of analytes than direct APLI.

  13. The role of natural and UV-induced skin pigmentation on low-fluence IPL-induced side effects: a randomized controlled trial.

    Science.gov (United States)

    Thaysen-Petersen, Daniel; Lin, Jennifer Y; Nash, Jf; Beerwerth, Frank; Wulf, Hans C; Philipsen, Peter A; Haedersdal, Merete

    2014-02-01

    The risk of adverse skin effects following light-based hair removal is greater in pigmented skin based on the theory of selective photothermolysis. Thus sunlight-induced pigment i.e., facultative pigmentation, increases the risk of adverse skin effects, perhaps 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. Twenty-one subjects with Fitzpatrick skin type II-IV were enrolled. Two buttock blocks were randomized to receive 0 or 8 solar simulated ultraviolet radiation (UVR) exposures of consecutively increasing Standard Erythema Doses (2-4 SED). Each block was subdivided into four sites, randomized to receive IPL of 0, 7, 8, or 10 J/cm(2) , once a week for 3 weeks. Biopsies were taken 16-24 hours after the first IPL exposure and subjects were seen 1 and 4 weeks after the last IPL exposure. Outcome measures were: (i) skin reactions, (ii) pain, (iii) mRNA expression of pigment-markers microphthalmia-associated transcription factor (MITF) and pro-opiomelanocortin (POMC), and (iv) clinical appearance of biopsy wounds. Skin pigmentation increased after UVR (baseline median 13.8%, after UVR 28.1%, P = 0.0001) in all skin types. Subjects reported low pain intensities (median 1.5, scale 0-10) and experienced transient erythema immediately after IPL exposure. No persistent erythema, blisters, crusting, textual, or pigment changes were observed. The risk of erythema and pain intensities increased with IPL dose and skin pigmentation (P skin reactions in skin with similar degree of natural and facultative pigmentation (P ≥ 0.104). Expression of cellular pigment-markers was not influenced by IPL exposure, neither in constitutive nor in facultative pigmented skin. Clinical appearance of biopsy wounds was unaffected by IPL exposure. The prevalence and intensity of low-fluence IPL-induced adverse skin effects depended on IPL

  14. Turbulence production in an APG-boundary-layer transition induced by randomized perturbations

    Science.gov (United States)

    Borodulin, V. I.; Kachanov, Y. S.; Roschektayev, A. P.

    This paper is devoted to an experimental investigation of formation and development of coherent vortical structures at late stages of a laminar-turbulent transition initiated by a harmonic, almost two-dimensional Tollmien-Schlichting (TS) wave perturbed by weak (initially) broadband disturbances. The initial base flow represented a self-similar boundary layer with an adverse pressure gradient (APG) with Hartree parameter ßH = -0.115. Experiments were performed at controlled disturbance conditions with the help of the ‘deterministic noise’ method and a universal disturbance source of instability waves. The main measurements were carried out by means of a hot-wire anemometer in a broad spatial region of the flow starting with stages of quasi-sinusoidal small-amplitude instability wave and ending with final stages of transition characterized by formation of concentrated localized vortical structures. The excited perturbations were partly random (within 20 TS-wave fundamental periods) but periodical at very large time scales during which the flow passes the model several times. The detailed measurements and the experimental data processing gave us the possibility to obtain instantaneous velocity and vorticity fields in the (x, y, z, t)-space and to perform computer-aided ‘visualization’ of the instantaneous flow structure. Specific features of the turbulence production mechanism occurring at late stages of transition are studied and compared with previously reported data obtained at sinusoidal excitation. A qualitative similarity is found between essentially nonlinear stages of transition observed in the present (randomized) case and those studied previously in cases of transition initiated by a harmonic TS wave or by a TS wave packet. It is found that interaction of primary wave with a broadband ‘noise’ of 3D TS waves leads at late stages of transition to formation of ?-vortices, intensive ? -shaped high-shear (HS) layers, O -shaped vortices, ring

  15. Pattern imprinting in deep sub-micron static random access memories induced by total dose irradiation

    International Nuclear Information System (INIS)

    Zheng Qi-Wen; Yu Xue-Feng; Cui Jiang-Wei; Guo Qi; Ren Di-Yuan; Cong Zhong-Chao; Zhou Hang

    2014-01-01

    Pattern imprinting in deep sub-micron static random access memories (SRAMs) during total dose irradiation is investigated in detail. As the dose accumulates, the data pattern of memory cells loading during irradiation is gradually imprinted on their background data pattern. We build a relationship between the memory cell's static noise margin (SNM) and the background data, and study the influence of irradiation on the probability density function of ΔSNM, which is the difference between two data sides' SNMs, to discuss the reason for pattern imprinting. Finally, we demonstrate that, for micron and deep sub-micron devices, the mechanism of pattern imprinting is the bias-dependent threshold shift of the transistor, but for a deep sub-micron device the shift results from charge trapping in the shallow trench isolation (STI) oxide rather than from the gate oxide of the micron-device. (condensed matter: structural, mechanical, and thermal properties)

  16. Voltage induced magnetostrictive switching of nanomagnets: Strain assisted strain transfer torque random access memory

    Science.gov (United States)

    Khan, Asif; Nikonov, Dmitri E.; Manipatruni, Sasikanth; Ghani, Tahir; Young, Ian A.

    2014-06-01

    A spintronic device, called the "strain assisted spin transfer torque (STT) random access memory (RAM)," is proposed by combining the magnetostriction effect and the spin transfer torque effect which can result in a dramatic improvement in the energy dissipation relative to a conventional STT-RAM. Magnetization switching in the device which is a piezoelectric-ferromagnetic heterostructure via the combined magnetostriction and STT effect is simulated by solving the Landau-Lifshitz-Gilbert equation incorporating the influence of thermal noise. The simulations show that, in such a device, each of these two mechanisms (magnetostriction and spin transfer torque) provides in a 90° rotation of the magnetization leading a deterministic 180° switching with a critical current significantly smaller than that required for spin torque alone. Such a scheme is an attractive option for writing magnetic RAM cells.

  17. Voltage induced magnetostrictive switching of nanomagnets: Strain assisted strain transfer torque random access memory

    International Nuclear Information System (INIS)

    Khan, Asif; Nikonov, Dmitri E.; Manipatruni, Sasikanth; Ghani, Tahir; Young, Ian A.

    2014-01-01

    A spintronic device, called the “strain assisted spin transfer torque (STT) random access memory (RAM),” is proposed by combining the magnetostriction effect and the spin transfer torque effect which can result in a dramatic improvement in the energy dissipation relative to a conventional STT-RAM. Magnetization switching in the device which is a piezoelectric-ferromagnetic heterostructure via the combined magnetostriction and STT effect is simulated by solving the Landau-Lifshitz-Gilbert equation incorporating the influence of thermal noise. The simulations show that, in such a device, each of these two mechanisms (magnetostriction and spin transfer torque) provides in a 90° rotation of the magnetization leading a deterministic 180° switching with a critical current significantly smaller than that required for spin torque alone. Such a scheme is an attractive option for writing magnetic RAM cells.

  18. Disorder Induced Dynamic Equilibrium Localization and Random Phase Steps of Bose—Einstein Condensates

    International Nuclear Information System (INIS)

    Duan Ya-Fan; Xu Zhen; Qian Jun; Sun Jian-Fang; Jiang Bo-Nan; Hong Tao

    2011-01-01

    We numerically analyze the dynamic behavior of Bose—Einstein condensate (BEC) in a one-dimensional disordered potential before it completely loses spatial quantum coherence. We find that both the disorder statistics and the atom interactions produce remarkable effects on localization. We also find that the single phase of the initial condensate is broken into many small pieces while the system approaches localization, showing a counter-intuitive step-wise phase but not a thoroughly randomized phase. Although the condensates as a whole show less flow and expansion, the currents between adjacent phase steps retain strong time dependence. Thus we show explicitly that the localization of a finite size Bose—Einstein condensate is a dynamic equilibrium state. (general)

  19. Pattern imprinting in deep sub-micron static random access memories induced by total dose irradiation

    Science.gov (United States)

    Zheng, Qi-Wen; Yu, Xue-Feng; Cui, Jiang-Wei; Guo, Qi; Ren, Di-Yuan; Cong, Zhong-Chao; Zhou, Hang

    2014-10-01

    Pattern imprinting in deep sub-micron static random access memories (SRAMs) during total dose irradiation is investigated in detail. As the dose accumulates, the data pattern of memory cells loading during irradiation is gradually imprinted on their background data pattern. We build a relationship between the memory cell's static noise margin (SNM) and the background data, and study the influence of irradiation on the probability density function of ΔSNM, which is the difference between two data sides' SNMs, to discuss the reason for pattern imprinting. Finally, we demonstrate that, for micron and deep sub-micron devices, the mechanism of pattern imprinting is the bias-dependent threshold shift of the transistor, but for a deep sub-micron device the shift results from charge trapping in the shallow trench isolation (STI) oxide rather than from the gate oxide of the micron-device.

  20. Effectiveness of Positioning Stents in Radiation-Induced Xerostomia in Patients with Tongue Carcinoma: A Randomized Controlled Trial.

    Science.gov (United States)

    Mall, Priyanka; Chand, Pooran; Singh, Balendra Pratap; Rao, Jitendra; Siddarth, Ramashanker; Srivastava, Kirti

    2016-01-01

    The aim of this study was to perform an objective and subjective evaluation of the efficacy of positioning stents in radiation-induced xerostomia in patients with tongue carcinoma. A total of 30 patients with tongue carcinoma and undergoing conventional radiotherapy were randomly assigned to control (n = 15) and study (n = 15) groups, without and with a positioning stent, respectively. Assessment of salivary output reduction was done before and after radiotherapy, at 3- and 6-month intervals, by measurement of unstimulated and stimulated salivary flow rates (objective evaluation). Xerostomia (subjective evaluation) was noted using six items from the Quality of Life Head and Neck Module (QLQ-H&N35) as proposed by the European Organization for Research and Treatment of Cancer. The significance level was set at .05. Mean unstimulated and stimulated salivary flow rates at 3- and 6-month intervals revealed significantly (P xerostomia and its symptoms.

  1. Formulas for Rational-Valued Separability Probabilities of Random Induced Generalized Two-Qubit States

    Directory of Open Access Journals (Sweden)

    Paul B. Slater

    2015-01-01

    Full Text Available Previously, a formula, incorporating a 5F4 hypergeometric function, for the Hilbert-Schmidt-averaged determinantal moments ρPTnρk/ρk of 4×4 density-matrices (ρ and their partial transposes (|ρPT|, was applied with k=0 to the generalized two-qubit separability probability question. The formula can, furthermore, be viewed, as we note here, as an averaging over “induced measures in the space of mixed quantum states.” The associated induced-measure separability probabilities (k=1,2,… are found—via a high-precision density approximation procedure—to assume interesting, relatively simple rational values in the two-re[al]bit (α=1/2, (standard two-qubit (α=1, and two-quater[nionic]bit (α=2 cases. We deduce rather simple companion (rebit, qubit, quaterbit, … formulas that successfully reproduce the rational values assumed for general  k. These formulas are observed to share certain features, possibly allowing them to be incorporated into a single master formula.

  2. Randomized trial of opioids versus tricyclic antidepressants for radiation-induced mucositis pain in head and neck cancer

    International Nuclear Information System (INIS)

    Ehrnrooth, E.; Grau, C.; Zachariae, R.; Andersen, Joern

    2001-01-01

    Patients who receive radiotherapy for head and neck cancer are likely to develop painful mucositis. The pain is characterized by a burning or stinging sensation similar to neuropathic pain sensations. The purpose of the present study was to compare the analgesic effect of a tricyclic antidepressant (TC), commonly used in the treatment of neuropathic pain, with the effect of opioids on radiation-induced mucositis pain. Forty-three patients receiving 66-68 Gy external radiation according to the DAHANCA guidelines (the Danish Head and Neck Cancer Study Group) were randomized to either morphine or TC when mucositis pain was insufficiently managed with weak analgesics. Patients with insufficient pain control in either treatment arm received supplementary medication from the opposite treatment arm. Pain was evaluated weekly using a VAS scale and the McGill Pain Questionnaire. The degree of mucositis and the degree of depression were measured at the same time intervals. Twenty-two patients entered the opioid arm and 21 the TC arm. Two patients in each arm were non-evaluable. VAS pain scores were significantly reduced in the opioid treatment arm one week after randomization (p=0.01). Eight patients in the TC arm were managed with TC alone, but for 11 patients it was necessary to add morphine. The 20 evaluable patients in the morphine arm required no additional treatment. There were no significant differences in side effects between the two groups. Higher pain scores in the TC arm, but not in the opioid arm, were significantly correlated with higher BDI scores. Some head and neck cancer patients with radiation-induced nucositis pain may have sufficient pain control on TC alone. This might be useful in patients with relative counter-indications to opioid treatment

  3. Randomized trial of opioids versus tricyclic antidepressants for radiation-induced mucositis pain in head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ehrnrooth, E.; Grau, C.; Zachariae, R.; Andersen, Joern [Aarhus Univ. Hospital (Denmark). Dept. of Oncology

    2001-11-01

    Patients who receive radiotherapy for head and neck cancer are likely to develop painful mucositis. The pain is characterized by a burning or stinging sensation similar to neuropathic pain sensations. The purpose of the present study was to compare the analgesic effect of a tricyclic antidepressant (TC), commonly used in the treatment of neuropathic pain, with the effect of opioids on radiation-induced mucositis pain. Forty-three patients receiving 66-68 Gy external radiation according to the DAHANCA guidelines (the Danish Head and Neck Cancer Study Group) were randomized to either morphine or TC when mucositis pain was insufficiently managed with weak analgesics. Patients with insufficient pain control in either treatment arm received supplementary medication from the opposite treatment arm. Pain was evaluated weekly using a VAS scale and the McGill Pain Questionnaire. The degree of mucositis and the degree of depression were measured at the same time intervals. Twenty-two patients entered the opioid arm and 21 the TC arm. Two patients in each arm were non-evaluable. VAS pain scores were significantly reduced in the opioid treatment arm one week after randomization (p=0.01). Eight patients in the TC arm were managed with TC alone, but for 11 patients it was necessary to add morphine. The 20 evaluable patients in the morphine arm required no additional treatment. There were no significant differences in side effects between the two groups. Higher pain scores in the TC arm, but not in the opioid arm, were significantly correlated with higher BDI scores. Some head and neck cancer patients with radiation-induced nucositis pain may have sufficient pain control on TC alone. This might be useful in patients with relative counter-indications to opioid treatment.

  4. Surgically induced astigmatism after phacoemulsification with and without correction for posture-related ocular cyclotorsion: randomized controlled study.

    LENUS (Irish Health Repository)

    Dooley, Ian

    2012-02-01

    PURPOSE: To report the impact of posture-related ocular cyclotorsion on one surgeon\\'s surgically induced astigmatism (SIA) results and the variance in SIA. SETTING: Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland. METHODS: This prospective randomized controlled study included eyes that had phacoemulsification with intraocular lens implantation. Eyes were randomly assigned to have (intervention group) or not have (control group) correction for posture-related ocular cyclotorsion. In the intervention group, the clear corneal incision was placed precisely at the 120-degree meridian with instruments designed to correct posture-related ocular cyclotorsion. In the control group, the surgeon endeavored to place the incision at the 120-degree meridian, but without markings. RESULTS: The intervention group comprised 41 eyes and the control group, 61 eyes. The mean absolute SIA was 0.74 diopters (D) in the intervention group and 0.78 D in the control group; the difference between groups was not statistically significant (P>.5, unpaired 2-tailed Student t test). The variance in SIA was 0.29 D(2) and 0.31 D(2), respectively; the difference between groups was not statistically significant (P>.5, unpaired F test). CONCLUSIONS: Attempts to correct for posture-related ocular cyclotorsion did not influence SIA or its variance in a single-surgeon series. These results should be interpreted with full appreciation of the limitations of currently available techniques to correct for posture-related ocular cyclotorsion in the clinical setting.

  5. Sage tea-thyme-peppermint hydrosol oral rinse reduces chemotherapy-induced oral mucositis: A randomized controlled pilot study.

    Science.gov (United States)

    Mutluay Yayla, Ezgi; Izgu, Nur; Ozdemir, Leyla; Aslan Erdem, Sinem; Kartal, Murat

    2016-08-01

    This pilot study aimed to investigate the preventive effect of sage tea-thyme-peppermint hydrosol oral rinse used in conjunction with basic oral care on chemotherapy-induced oral mucositis. An open-label randomized controlled study. Two oncology hospitals in Ankara, Turkey. Patients receiving 5-fluorouracil-based chemotherapy regimens were divided into the intervention group (N=30) and control group (N=30). Basic oral care was prescribed to the control group, while the intervention group was prescribed sage tea-thyme-peppermint hydrosol in addition to basic oral care. All patients were called to assess their compliance with the study instructions on day 5 and 14. Oral mucositis was evaluated using an inspection method or by assessing oral cavity photos based on the World Health Organization oral toxicity scale on day 5 and 14. Most of the patients in the intervention group did not develop oral mucositis on day 5. In addition, the incidence of grade 1 oral mucositis was statistically lower in the intervention group (10%) than the control group (53.3%) on day 5. By day 14, the majority of patients in both the groups had grade 0 oral mucositis. Sage tea-thyme-peppermint hydrosol oral rinse has promising results in alleviating oral mucositis. This hydrosol can be recommended for clinical use as it is well tolerated and cost-effective. However, further randomized controlled trials are needed to support the study. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Non-random alkylation of DNA sequences induced in vivo by chemical mutagens

    Energy Technology Data Exchange (ETDEWEB)

    Durante, M.; Geri, C.; Bonatti, S.; Parenti, R. (Universita di Pisa (Italy))

    1989-08-01

    Previous studies of the interaction of alkylating agents on the eukaryotic genome support the idea that induction of DNA adducts is at specific genomic sites. Here we show molecular and cytological evidence that alkylation is rather specific. Mammalian cell cultures were exposed to different doses of mutagens and the DNA was analyzed by density gradient ultracentrifugation, hydroxylapatite fractionation, and by restriction enzyme analysis. Studies with the labelled mutagens N-ethyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine show that there is a non-random distribution of the adducts. The adducts are found more frequently in A-T, G-C rich satellite DNA and highly repetitive sequences. Analysis with restriction enzymes shows that both methyl and ethyl groups influence the restriction patterns of the enzymes HpaII and MspI that recognize specific endogenous DNA methylation. These data suggest, as a subsequent mechanism, a modification in the pattern of the normal endogenous methylation of 5-methylcytosine.

  7. Adaptive force produced by stress-induced regulation of random variation intensity.

    Science.gov (United States)

    Shimansky, Yury P

    2010-08-01

    The Darwinian theory of life evolution is capable of explaining the majority of related phenomena. At the same time, the mechanisms of optimizing traits beneficial to a population as a whole but not directly to an individual remain largely unclear. There are also significant problems with explaining the phenomenon of punctuated equilibrium. From another perspective, multiple mechanisms for the regulation of the rate of genetic mutations according to the environmental stress have been discovered, but their precise functional role is not well understood yet. Here a novel mathematical paradigm called a Kinetic-Force Principle (KFP), which can serve as a general basis for biologically plausible optimization methods, is introduced and its rigorous derivation is provided. Based on this principle, it is shown that, if the rate of random changes in a biological system is proportional, even only roughly, to the amount of environmental stress, a virtual force is created, acting in the direction of stress relief. It is demonstrated that KFP can provide important insights into solving the above problems. Evidence is presented in support of a hypothesis that the nature employs KFP for accelerating adaptation in biological systems. A detailed comparison between KFP and the principle of variation and natural selection is presented and their complementarity is revealed. It is concluded that KFP is not a competing alternative, but a powerful addition to the principle of variation and natural selection. It is also shown KFP can be used in multiple ways for adaptation of individual biological organisms.

  8. Impact of dopant profiles on the end of range defects for low energy germanium preamorphized silicon

    International Nuclear Information System (INIS)

    Camillo-Castillo, R.A.; Law, M.E.; Jones, K.S.

    2004-01-01

    As the industry continues to aggressively scale CMOS technology, the shift to lower energy ion implantation becomes essential. The consequent shallower amorphous layers result in dopant profiles that are in closer proximity to the end of range (EOR) damage and therefore a better understanding of the interaction between the dopant atoms and the EOR is required. A study is conducted on the influence of dopant profiles on the behavior of the EOR defects. Czochralski-grown silicon wafers are preamorphized with 1 x 10 15 cm -2 , 10 keV Ge + ions and subsequently implanted with 1 x 10 15 cm -2 , 1 keV B + ions. A sequence of rapid thermal and furnace anneals are performed at 750 deg. C under a nitrogen ambient for periods of 1 s up to 6 h. Plan view transmission electron microscopy (PTEM) reveals a significant difference in the defect evolution for samples with and without boron, suggesting that the boron influences the evolution of the EOR defects. The extended defects observed for samples which contain boron appear as dot-like defects which are unstable and dissolve after very short anneal times. The defect evolution however, in samples without boron follows an Oswald ripening behavior and form {3 1 1}-type defects and dislocation loops. Hall effect measurements denote a high initial activation and subsequent deactivation of the dopant atoms which is characteristic of the formation of boron interstitial clusters. Diffusion analyses via secondary ion mass spectroscopy (SIMS) support this theory

  9. Functionally Graded Thermoelectric Material though One Step Band Gap and Dopant Engineering

    DEFF Research Database (Denmark)

    Jensen, Ellen Marie; Borup, Kasper Andersen; Cederkrantz, Daniel

    , and dopant concentration. Parameters relevant to the thermoelectric properties have been determined along the pulling direction. All of these properties exhibit the wanted gradient. It has thereby been shown that engineering of the electrical contributions to the thermoelectric properties of a material...

  10. Origin of electrolyte-dopant dependent sulfur poisoning of SOFC anodes

    DEFF Research Database (Denmark)

    Zeng, Zhenhua; Björketun, Mårten E; Ebbesen, Sune

    2013-01-01

    The mechanisms governing the sulfur poisoning of the triple phase boundary (TPB) of Ni-XSZ (X2O3 stabilized zirconia) anodes have been investigated using density functional theory. The calculated sulfur adsorption energies reveal a clear correlation between the size of the cation dopant X3...

  11. Effect of Dopant Activation on Device Characteristics of InGaN-based Light Emitting Diodes

    Science.gov (United States)

    Lacroce, Nicholas; Liu, Guangyu; Tan, Chee-Keong; Arif, Ronald A.; Lee, Soo Min; Tansu, Nelson

    2015-03-01

    Achieving high uniformity in growths and device characteristics of InGaN-based light-emitting diodes (LEDs) is important for large scale manufacturing. Dopant activation and maintaining control of variables affecting dopant activation are critical steps in the InGaN-based light emitting diodes (LEDs) fabrication process. In the epitaxy of large scale production LEDs, in-situ post-growth annealing is used for activating the Mg acceptor dopant in the p-AlGaN and p-GaN of the LEDs. However, the annealing temperature varies with respect to position in the reactor chamber, leading to severe uniform dopant activation issue across the devices. Thus, it is important to understand how the temperature gradient and the resulting variance in Mg acceptor activation will alter the device properties. In this work, we examine the effect of varying p-type doping levels in the p-GaN layers and AlGaN electron blocking layer of the GaN LEDs on the optoelectronic properties including the band profile, carrier concentration, current density, output power and quantum efficiency. By understanding the variations and its effect, the identification of the most critical p-type doping layer strategies to address this variation will be clarified.

  12. (Invited) Pure Dopant Deposition of B and Ga for Ultrashallow Junctions in Si-based Devices

    NARCIS (Netherlands)

    Nanver, L.K.; Sammak, A.; Mohammadi, V.; Mok, K.R.C.; Qi, L.; Sakic, A.; Golshani, N.; Darakhshandeh, J.; Scholtes, T.M.L.; De Boer, W.B.

    2012-01-01

    Envisioning wide future relevance, work is reviewed here on the pure dopant deposition of boron (PureB), gallium (PureGa) and the combination of the two (PureGaB), as used in the fabrication of nanometer shallow p+n Si and/or Ge diodes. Focus is placed on the special properties that have put these

  13. Bistable Si dopants in the GaAs (1 1 0) surface

    International Nuclear Information System (INIS)

    Smakman, E P; Koenraad, P M

    2015-01-01

    In this review, recent work is discussed on bistable Si dopants in the GaAs (1 1 0) surface, studied by scanning tunneling microscopy (STM). The bistability arises because the dopant atom can switch between a positive and a negative charge state, which are associated with two different lattice configurations. Manipulation of the Si atom charge configuration is achieved by tuning the local band bending with the STM tip. Furthermore, illuminating the sample with a laser also influences the charge state, allowing the operation of the dopant atom as an optical switch. The switching dynamics without illumination is investigated in detail as a function of temperature, lateral tip position, and applied tunneling conditions. A physical model is presented that independently describes the thermal and quantum tunneling contributions to the switching frequency and charge state occupation of a single Si atom. The basic functionality of a memory cell is demonstrated employing a single bistable Si dopant as the active element, using the STM tip as a gate to write and read the information. (topical review)

  14. Determination of the dopant weight fraction in polyaniline films using a quartz-crystal microbalance

    Czech Academy of Sciences Publication Activity Database

    Ayad, M. M.; Zaki, E. A.; Stejskal, Jaroslav

    2007-01-01

    Roč. 515, č. 23 (2007), s. 8381-8385 ISSN 0040-6090 R&D Projects: GA AV ČR IAA4050313 Institutional research plan: CEZ:AV0Z40500505 Keywords : dopant weight fraction * polyaniline * polyaniline film Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.693, year: 2007

  15. Optical acetone vapor sensors based on chiral nematic liquid crystals and reactive chiral dopants

    NARCIS (Netherlands)

    Cachelin, P.; Green, J.P.; Peijs, T.; Heeney, M.; Bastiaansen, C.W.M.

    2016-01-01

    Accurate monitoring of exposure to organic vapors, such as acetone, is an important part of maintaining a safe working environment and adhering to long- and short-term exposure limits. Here, a novel acetone vapor detection system is described based on the use of a reactive chiral dopant in a nematic

  16. Finite element simulations of electrostatic dopant potentials in thin semiconductor specimens for electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Somodi, P.K.; Twitchett-Harrison, A.C.; Midgley, P.A. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Kardynał, B.E. [Peter Grünberg Institute 9, Forschungszentrum Jülich, D-52425 Jülich (Germany); Barnes, C.H.W. [Department of Physics, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Dunin-Borkowski, R.E., E-mail: rafaldb@gmail.com [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute 5, Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2013-11-15

    Two-dimensional finite element simulations of electrostatic dopant potentials in parallel-sided semiconductor specimens that contain p–n junctions are used to assess the effect of the electrical state of the surface of a thin specimen on projected potentials measured using off-axis electron holography in the transmission electron microscope. For a specimen that is constrained to have an equipotential surface, the simulations show that the step in the projected potential across a p–n junction is always lower than would be predicted from the properties of the bulk device, but is relatively insensitive to the value of the surface state energy, especially for thicker specimens and higher dopant concentrations. The depletion width measured from the projected potential, however, has a complicated dependence on specimen thickness. The results of the simulations are of broader interest for understanding the influence of surfaces and interfaces on electrostatic potentials in nanoscale semiconductor devices. - Highlights: • Finite element simulations are performed to calculate electrostatic dopant potentials in TEM specimens that contain p–n junctions. • The effect of the electrical state of the specimen surface on the projected potential is assessed for equipotential specimen surfaces. • The step in projected potential is always found to be lower than the step in potential in the bulk device. • The step in projected potential is least sensitive to surface state energy for thicker specimens and higher dopant concentrations. • The depletion width measured from the projected potential has a complicated dependence on specimen thickness.

  17. Finite element simulations of electrostatic dopant potentials in thin semiconductor specimens for electron holography

    International Nuclear Information System (INIS)

    Somodi, P.K.; Twitchett-Harrison, A.C.; Midgley, P.A.; Kardynał, B.E.; Barnes, C.H.W.; Dunin-Borkowski, R.E.

    2013-01-01

    Two-dimensional finite element simulations of electrostatic dopant potentials in parallel-sided semiconductor specimens that contain p–n junctions are used to assess the effect of the electrical state of the surface of a thin specimen on projected potentials measured using off-axis electron holography in the transmission electron microscope. For a specimen that is constrained to have an equipotential surface, the simulations show that the step in the projected potential across a p–n junction is always lower than would be predicted from the properties of the bulk device, but is relatively insensitive to the value of the surface state energy, especially for thicker specimens and higher dopant concentrations. The depletion width measured from the projected potential, however, has a complicated dependence on specimen thickness. The results of the simulations are of broader interest for understanding the influence of surfaces and interfaces on electrostatic potentials in nanoscale semiconductor devices. - Highlights: • Finite element simulations are performed to calculate electrostatic dopant potentials in TEM specimens that contain p–n junctions. • The effect of the electrical state of the specimen surface on the projected potential is assessed for equipotential specimen surfaces. • The step in projected potential is always found to be lower than the step in potential in the bulk device. • The step in projected potential is least sensitive to surface state energy for thicker specimens and higher dopant concentrations. • The depletion width measured from the projected potential has a complicated dependence on specimen thickness

  18. The Impact of Dopant Segregation on the Maximum Carrier Density in Si:P Multilayers.

    Science.gov (United States)

    Keizer, Joris G; McKibbin, Sarah R; Simmons, Michelle Y

    2015-07-28

    Abrupt dopant profiles and low resistivity are highly sought after qualities in the silicon microelectronics industry and, more recently, in the development of an all epitaxial Si:P based quantum computer. If we increase the active carrier density in silicon to the point where the material becomes superconducting, while maintaining a low thermal budget, it will be possible to fabricate nanoscale superconducting devices using the highly successful technique of depassivation lithography. In this work, we investigate the dopant profile and activation in multiple high density Si:P δ-layers fabricated by stacking individual layers with intervening silicon growth. We determine that dopant activation is ultimately limited by the formation of P-P dimers due to the segregation of dopants between multilayers. By increasing the encapsulation thickness between subsequent layers, thereby minimizing the formation of these deactivating defects, we are able to achieve an active carrier density of ns = 4.5 ×10(14) cm(-2) for a triple layer. The results of electrical characterization are combined with those of secondary ion mass spectroscopy to construct a model that accurately describes the impact of P segregation on the final active carrier density in Si:P multilayers. Our model predicts that a 3D active carrier density of 8.5 × 10(20) cm(-3) (1.7 atom %) can be achieved.

  19. Ternary logic implemented on a single dopant atom field effect silicon transistor

    NARCIS (Netherlands)

    Klein, M.; Mol, J.A.; Verduijn, J.; Lansbergen, G.P.; Rogge, S.; Levine, R.D.; Remacle, F.

    2010-01-01

    We provide an experimental proof of principle for a ternary multiplier realized in terms of the charge state of a single dopant atom embedded in a fin field effect transistor (Fin-FET). Robust reading of the logic output is made possible by using two channels to measure the current flowing through

  20. Laser thermal annealing of Ge, optimized for highly activated dopants and diode ION/IOFF ratios

    DEFF Research Database (Denmark)

    Shayesteh, M.; O'Connell, D.; Gity, F.

    2014-01-01

    The authors compared the influence of laser thermal annealing (LTA) and rapid thermal annealing (RTA) on dopant activation and electrical performance of phosphorus and arsenic doped n+/p junction. High carrier concentration above 1020 cm-3 as well as an ION/IOFF ratio of approximately 105 and ide...

  1. Charge Exchange Reaction in Dopant-Assisted Atmospheric Pressure Chemical Ionization and Atmospheric Pressure Photoionization.

    Science.gov (United States)

    Vaikkinen, Anu; Kauppila, Tiina J; Kostiainen, Risto

    2016-08-01

    The efficiencies of charge exchange reaction in dopant-assisted atmospheric pressure chemical ionization (DA-APCI) and dopant-assisted atmospheric pressure photoionization (DA-APPI) mass spectrometry (MS) were compared by flow injection analysis. Fourteen individual compounds and a commercial mixture of 16 polycyclic aromatic hydrocarbons were chosen as model analytes to cover a wide range of polarities, gas-phase ionization energies, and proton affinities. Chlorobenzene was used as the dopant, and methanol/water (80/20) as the solvent. In both techniques, analytes formed the same ions (radical cations, protonated molecules, and/or fragments). However, in DA-APCI, the relative efficiency of charge exchange versus proton transfer was lower than in DA-APPI. This is suggested to be because in DA-APCI both dopant and solvent clusters can be ionized, and the formed reagent ions can react with the analytes via competing charge exchange and proton transfer reactions. In DA-APPI, on the other hand, the main reagents are dopant-derived radical cations, which favor ionization of analytes via charge exchange. The efficiency of charge exchange in both DA-APPI and DA-APCI was shown to depend heavily on the solvent flow rate, with best efficiency seen at lowest flow rates studied (0.05 and 0.1 mL/min). Both DA-APCI and DA-APPI showed the radical cation of chlorobenzene at 0.05-0.1 mL/min flow rate, but at increasing flow rate, the abundance of chlorobenzene M(+.) decreased and reagent ion populations deriving from different gas-phase chemistry were recorded. The formation of these reagent ions explains the decreasing ionization efficiency and the differences in charge exchange between the techniques. Graphical Abstract ᅟ.

  2. Nucleophilic Aromatic Substitution Between Halogenated Benzene Dopants and Nucleophiles in Atmospheric Pressure Photoionization.

    Science.gov (United States)

    Kauppila, Tiina J; Haack, Alexander; Kroll, Kai; Kersten, Hendrik; Benter, Thorsten

    2016-03-01

    In a preceding work with dopant assisted-atmospheric pressure photoionization (DA-APPI), an abundant ion at [M + 77](+) was observed in the spectra of pyridine and quinoline with chlorobenzene dopant. This contribution aims to reveal the identity and route of formation of this species, and to systematically investigate structurally related analytes and dopants. Compounds containing N-, O-, and S-lone pairs were investigated with APPI in the presence of fluoro-, chloro-, bromo-, and iodobenzene dopants. Computational calculations on a density functional theory (DFT) level were carried out to study the reaction mechanism for pyridine and the different halobenzenes. The experimental and computational results indicated that the [M + 77](+) ion was formed by nucleophilic aromatic ipso-substitution between the halobenzene radical cation and nucleophilic analytes. The reaction was most efficient for N-heteroaromatic compounds, and it was weakened by sterical effects and enhanced by resonance stabilization. The reaction was most efficient with chloro-, bromo-, and iodobenzenes, whereas with fluorobenzene the reaction was scarcely observed. The calculated Gibbs free energies for the reaction between pyridine and the halobenzenes were shown to increase in the order I < Br < Cl < F. The reaction was found endergonic for fluorobenzene due to the strong C-F bonding, and exergonic for the other halobenzenes. For fluoro- and chlorobenzenes the reaction was shown to proceed through an intermediate state corresponding to [M + dopant](+), which was highly stable for fluorobenzene. For the bulkier bromine and iodine, this intermediate did not exist, but the halogens were shown to detach already during the approach by the nucleophile.

  3. Dopant structural distortions in high-temperature superconductors: an active or a passive role?

    International Nuclear Information System (INIS)

    Haskel, D.; Stern, E.A.; Dogan, F.; Moodenbaugh, A.R.

    2001-01-01

    The parent compounds of high-temperature superconductors, such as YBa 2 Cu 3 O 6 and La 2 CuO 4 , are strongly interacting electron systems, rendering them insulators with Mott-Hubbard gaps of a few electron volts. Charge carriers (holes) are introduced by chemical doping, causing an insulator-metal (IM) transition and, at low temperatures, superconductivity. The role of dopants is widely seen as limited to the introduction of holes into the CuO 2 planes (i.e. occupying electronic states derived from Cu 3d x2-y2 and O 2p x,y atomic orbitals). Most theories of high-T c superconductivity deal with pairing interactions between these planar holes. Local distortions around dopants are poorly understood, because of the experimental difficulty in obtaining such information, particularly at low doping. This has resulted in the neglect, in most theories, of the effect of such distortions on the chemical and electronic structure of high-T c superconductors. Angular-resolved X-ray absorption fine structure (XAFS) spectroscopy on oriented samples is an ideal technique to elucidate the dopant distortions. Element specificity, together with a large orientation dependence of the XAFS signal in these layered structures, allows the local structure around dopants to be resolved. Results are presented here on (Sr, Ba) and Ni dopants, which substitute at the La and Cu sites, respectively, of insulating La 2 CuO 4 . The relevance of the measured local distortions for a complete understanding of the normal and superconducting properties of cuprates is discussed. (au)

  4. The effect of Vaccinium uliginosum extract on tablet computer-induced asthenopia: randomized placebo-controlled study.

    Science.gov (United States)

    Park, Choul Yong; Gu, Namyi; Lim, Chi-Yeon; Oh, Jong-Hyun; Chang, Minwook; Kim, Martha; Rhee, Moo-Yong

    2016-08-18

    To investigate the alleviation effect of Vaccinium uliginosum extract (DA9301) on tablet computer-induced asthenopia. This was a randomized, placebo-controlled, double-blind and parallel study (Trial registration number: 2013-95). A total 60 volunteers were randomized into DA9301 (n = 30) and control (n = 30) groups. The DA9301 group received DA9301 oral pill (1000 mg/day) for 4 weeks and the control group received placebo. Asthenopia was evaluated by administering a questionnaire containing 10 questions (responses were scored on a scales of 0-6; total score: 60) regarding ocular symptoms before (baseline) and 4 weeks after receiving pills (DA9301 or placebo). The participants completed the questionnaire before and after tablet computer (iPad Air, Apple Inc.) watching at each visit. The change in total asthenopia score (TAS) was calculated and compared between the groups TAS increased significantly after tablet computer watching at baseline in DA9301 group. (from 20.35 to 23.88; p = 0.031) However, after receiving DA9301 for 4 weeks, TAS remained stable after tablet computer watching. In the control group, TAS changes induced by tablet computer watching were not significant both at baseline and at 4 weeks after receiving placebo. Further analysis revealed the scores for "tired eyes" (p = 0.001), "sore/aching eyes" (p = 0.038), "irritated eyes" (p = 0.010), "watery eyes" (p = 0.005), "dry eyes" (p = 0.003), "eye strain" (p = 0.006), "blurred vision" (p = 0.034), and "visual discomfort" (p = 0.018) significantly improved in the DA9301 group. We found that oral intake of DA9301 (1000 mg/day for 4 weeks) was effective in alleviating asthenopia symptoms induced by tablet computer watching. The study is registered at www.clinicaltrials.gov (registration number: NCT02641470, date of registration December 30, 2015).

  5. Effects of coenzyme Q10 on statin-induced myopathy: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Banach, Maciej; Serban, Corina; Sahebkar, Amirhossein; Ursoniu, Sorin; Rysz, Jacek; Muntner, Paul; Toth, Peter P; Jones, Steven R; Rizzo, Manfredi; Glasser, Stephen P; Lip, Gregory Y H; Dragan, Simona; Mikhailidis, Dimitri P

    2015-01-01

    To evaluate the efficacy of coenzyme Q10 (CoQ10) supplementation on statin-induced myopathy. We searched the MEDLINE, Cochrane Library, Scopus, and EMBASE databases (November 1, 1987, to May 1, 2014) to identify randomized controlled trials investigating the impact of CoQ10 on muscle pain and plasma creatine kinase (CK) activity as 2 measures of statin-induced myalgia. Two independent reviewers extracted data on study characteristics, methods, and outcomes. We included 6 studies with 302 patients receiving statin therapy: 5 studies with 226 participants evaluated the effect of CoQ10 supplementation on plasma CK activity, and 5 studies (4 used in the CK analysis and 1 other study) with 253 participants were included to assess the effect of CoQ10 supplementation on muscle pain. Compared with the control group, plasma CK activity was increased after CoQ10 supplementation, but this change was not significant (mean difference, 11.69 U/L [to convert to μkat/L, multiply by 0.0167]; 95% CI, -14.25 to 37.63 U/L; P=.38). Likewise, CoQ10 supplementation had no significant effect on muscle pain despite a trend toward a decrease (standardized mean difference, -0.53; 95% CI, -1.33 to 0.28; P=.20). No dose-effect association between changes in plasma CK activity (slope, -0.001; 95% CI, -0.004 to 0.001; P=.33) or in the indices of muscle pain (slope, 0.002; 95% CI, -0.005 to 0.010; P=.67) and administered doses of CoQ10 were observed. The results of this meta-analysis of available randomized controlled trials do not suggest any significant benefit of CoQ10 supplementation in improving statin-induced myopathy. Larger, well-designed trials are necessary to confirm the findings from this meta-analysis. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  6. Effect of edaravone on radiation-induced brain necrosis in patients with nasopharyngeal carcinoma after radiotherapy: a randomized controlled trial.

    Science.gov (United States)

    Tang, Yamei; Rong, Xiaoming; Hu, Weihan; Li, Guoqian; Yang, Xiaoxia; Yang, Jianhua; Xu, Pengfei; Luo, Jinjun

    2014-11-01

    Excessive generation of free radicals plays a critical role in the pathogenesis of radiation-induced brain injury. This study was designed to evaluate the protective effect of edaravone, a free radical scavenger, on radiation-induced brain necrosis in patients with nasopharyngeal carcinoma. Eligible patients were randomized 1:1 to the control group and the edaravone group (intravenous 30 mg twice per day for 2 weeks). Both groups received intravenous conventional steroid therapy and were monitored by brain MRI and LENT/SOMA scales prior to the entry of the trial and at 3-months after completing the trial. The primary end point was a 3-month response rate of the proportional changes determined by MRI. The trial is registered at Clinicaltrials.gov Identifier: NCT01865201. Between 2009 and 2012, we enrolled 154 patients. Of whom 137 were eligible for analysis. The volumes of necrosis estimated on T(2)-weighted image showed that 55.6 % edaravone-treated patients (40 out of 72) showed edema decreases ≥25 %, which was significantly higher than that in the control group (35.4 %, 23 out of 65, p = 0.025). Forty-four patients treated with edaravone (61.1 %) reported improvement in neurologic symptoms and signs evaluated by LENT/SOMA scales, while the rate was 38.5 % in the control group (p = 0.006). MRI of the edaravone group showed a significant decrease in area of T(1)-weighted contrast enhancement (1.67 ± 4.69 cm(2), p = 0.004) and the T(2)-weighted edema (5.08 ± 10.32 cm(2), p = 0.000). Moreover, compared with those in control group, patients with edaravone exhibited significantly better radiological improvement measured by T(2)-weighted image (p = 0.042). Administration of edaravone, in adjunct to steroid regimen, might provide a better outcome in patients with radiation-induced brain necrosis.

  7. An inducible tool for random mutagenesis in Aspergillus niger based on the transposon Vader.

    Science.gov (United States)

    Paun, Linda; Nitsche, Benjamin; Homan, Tim; Ram, Arthur F; Kempken, Frank

    2016-07-01

    The ascomycete Aspergillus niger is widely used in the biotechnology, for instance in producing most of the world's citric acid. It is also known as a major food and feed contaminant. While generation of gene knockouts for functional genomics has become feasible in ku70 mutants, analyzing gene functions or metabolic pathways remains a laborious task. An unbiased transposon-based mutagenesis approach may aid this process of analyzing gene functions by providing mutant libraries in a short time. The Vader transposon is a non-autonomous DNA-transposon, which is activated by the homologous tan1-transposase. However, in the most commonly used lab strain of A. niger (N400 strain and derivatives), we found that the transposase, encoded by the tan1 gene, is mutated and inactive. To establish a Vader transposon-based mutagenesis system in the N400 background, we expressed the functional transposase of A. niger strain CBS 513.88 under the control of an inducible promoter based on the Tet-on system, which is activated in the presence of the antibiotic doxycycline (DOX). Increasing amounts of doxycycline lead to higher Vader excision frequencies, whereas little to none activity of Vader was observed without addition of doxycycline. Hence, this system appears to be suitable for producing stable mutants in the A. niger N400 background.

  8. Temperature induced complementary switching in titanium oxide resistive random access memory

    Energy Technology Data Exchange (ETDEWEB)

    Panda, D., E-mail: dpanda@nist.edu [Department of Electronics Engineering, National Institute of Science and Technology, Berhampur, Odisha 761008 (India); Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Simanjuntak, F. M.; Tseng, T.-Y. [Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu 30010, Taiwan (China)

    2016-07-15

    On the way towards high memory density and computer performance, a considerable development in energy efficiency represents the foremost aspiration in future information technology. Complementary resistive switch consists of two antiserial resistive switching memory (RRAM) elements and allows for the construction of large passive crossbar arrays by solving the sneak path problem in combination with a drastic reduction of the power consumption. Here we present a titanium oxide based complementary RRAM (CRRAM) device with Pt top and TiN bottom electrode. A subsequent post metal annealing at 400°C induces CRRAM. Forming voltage of 4.3 V is required for this device to initiate switching process. The same device also exhibiting bipolar switching at lower compliance current, Ic <50 μA. The CRRAM device have high reliabilities. Formation of intermediate titanium oxi-nitride layer is confirmed from the cross-sectional HRTEM analysis. The origin of complementary switching mechanism have been discussed with AES, HRTEM analysis and schematic diagram. This paper provides valuable data along with analysis on the origin of CRRAM for the application in nanoscale devices.

  9. Constraint-Induced Aphasia Therapy for Treatment of Chronic Post-Stroke Aphasia: A Randomized, Blinded, Controlled Pilot Trial.

    Science.gov (United States)

    Szaflarski, Jerzy P; Ball, Angel L; Vannest, Jennifer; Dietz, Aimee R; Allendorfer, Jane B; Martin, Amber N; Hart, Kimberly; Lindsell, Christopher J

    2015-09-24

    To provide a preliminary estimate of efficacy of constraint-induced aphasia therapy (CIAT) when compared to no-intervention in patients with chronic (>1 year) post-stroke aphasia in order to plan an appropriately powered randomized controlled trial (RCT). We conducted a pilot single-blinded RCT. 24 patients were randomized: 14 to CIAT and 10 to no-intervention. CIAT groups received up to 4 hours/day of intervention for 10 consecutive business days (40 hours or therapy). Outcomes were assessed within 1 week of intervention and at 1 and 12 weeks after intervention and included several linguistic measures and a measure of overall subjective communication abilities (mini-Communicative Abilities Log (mini-CAL)). Clinicians treating patients (CIAT group) did not communicate with other team members to maintain blinding and the testing team members were blinded to treatment group assignment. Overall, the results of this pilot RCT support the results of previous observational studies that CIAT may lead to improvements in linguistic abilities. At 12 weeks, the treatment group reported better subjective communication abilities (mini-CAL) than the no-intervention group (p=0.019). Other measures trended towards better performance in the CIAT group. In this pilot RCT intensive language therapy led to an improvement in subjective language abilities. The effects demonstrated allow the design of a definitive trial of CIAT in patients with a variety of post-stroke aphasia types. In addition, our experiences have identified important considerations for designing subsequent trial(s) of CIAT or other interventions for post-stroke aphasia.

  10. Sugammadex antagonism of rocuronium-induced neuromuscular blockade in patients with liver cirrhosis undergoing liver resection: a randomized controlled study.

    Science.gov (United States)

    Abdulatif, Mohamed; Lotfy, Maha; Mousa, Mahmoud; Afifi, Mohamed H; Yassen, Khaled

    2018-02-05

    This randomized controlled study compared the recovery times of sugammadex and neostigmine as antagonists of moderate rocuroniuminduced neuromuscular block in patients with liver cirrhosis and controls undergoing liver resection. The study enrolled 27 adult patients with Child class "A" liver cirrhosis and 28 patients with normal liver functions. Normal patients and patients with liver cirrhosis were randomized according to the type of antagonist (sugammadex 2mg/kg or neostigmine 50μg/kg). The primary outcome was the time from antagonist administration to a trainoffour (TOF) ratio of 0.9 using mechanosensor neuromuscular transmission module. The durations of the intubating and topup doses of rocuronium, the length of stay in the postanesthesia care unit (PACU), and the incidence of postoperative re curarization were recorded. The durations of the intubating and topup doses of rocuronium were prolonged in patients with liver cirrhosis than controls. The times to a TOF ratio of 0.9 were 3.1 (1.0) and 2.6 (1.0) min after sugammadex administration in patients with liver cirrhosis and controls, respectively, p=1.00. The corresponding times after neostigmine administration were longer than sugammadex 14.5 (3.6) and 15.7 (3.6) min, respectively, psugammadex compared to neostigmine. We did not encounter postoperative recurarization after sugammadex or neostigmine. Sugammadex rapidly antagonize moderate residual rocuronium induced neuromuscular block in patients with Child class "A" liver cirrhosis undergoing liver resection. Sugammadex antagonism is associated with 80% reduction in the time to adequate neuromuscular recovery compared to neostigmine.

  11. Omega-3 fatty acids are protective against paclitaxel-induced peripheral neuropathy: A randomized double-blind placebo controlled trial

    Directory of Open Access Journals (Sweden)

    Ghoreishi Zohreh

    2012-08-01

    Full Text Available Abstract Background Axonal sensory peripheral neuropathy is the major dose-limiting side effect of paclitaxel.Omega-3 fatty acids have beneficial effects on neurological disorders from their effects on neurons cells and inhibition of the formation of proinflammatory cytokines involved in peripheral neuropathy. Methods This study was a randomized double blind placebo controlled trial to investigate the efficacy of omega-3 fatty acids in reducing incidence and severity of paclitaxel-induced peripheral neuropathy (PIPN. Eligible patients with breast cancer randomly assigned to take omega-3 fatty acid pearls, 640 mg t.i.d during chemotherapy with paclitaxel and one month after the end of the treatment or placebo. Clinical and electrophysiological studies were performed before the onset of chemotherapy and one month after cessation of therapy to evaluate PIPN based on "reduced Total Neuropathy Score". Results Twenty one patients (70% of the group taking omega-3 fatty acid supplement (n = 30 did not develop PN while it was 40.7%( 11 patients in the placebo group(n = 27. A significant difference was seen in PN incidence (OR = 0.3, .95% CI = (0.10-0.88, p = 0.029. There was a non-significant trend for differences of PIPN severity between the two study groups but the frequencies of PN in all scoring categories were higher in the placebo group (0.95% CI = (−2.06 -0.02, p = 0.054. Conclusions Omega-3 fatty acids may be an efficient neuroprotective agent for prophylaxis against PIPN. Patients with breast cancer have a longer disease free survival rate with the aid of therapeutical agents. Finding a way to solve the disabling effects of PIPN would significantly improve the patients’ quality of life. Trial registration This trial was registered at ClinicalTrials.gov (NCT01049295

  12. Influence of Photobiomodulation Therapy on Gingivitis Induced by Multi-Bracket Appliances: A Split-Mouth Randomized Controlled Trial.

    Science.gov (United States)

    Stein, Steffen; Schauseil, Michael; Hellak, Andreas; Korbmacher-Steiner, Heike; Braun, Andreas

    2018-05-18

    The objective of this split-mouth trial was to investigate the influence of photobiomodulation therapy (PBMT) on adjuvant treatment of gingivitis induced by multi-bracket appliances, after bracket debonding and professional tooth cleaning. Thirteen patients (mean age 16.15 years; standard deviation ±2.12 years) who had completed active orthodontic treatment with fixed orthodontic appliances in an orthodontic clinic were included on a randomized basis. At time point T0, after bracket debonding and professional tooth cleaning, the papilla bleeding index (PBI) and bleeding on probing (BOP) were assessed in the upper jaw by the blinded investigator (M.S.), who was not aware at any time of which quadrant received PBMT. The study was based on a patient-blinded split-mouth design. In each patient, PBMT was administered by a practitioner (S.S.) in one upper quadrant (wavelength: 660 nm; Power: 100 mW; Power density: 100 mW/cm 2 ; Energy density per application point = 2 J/cm 2 ; Energy per application point = 2 J; Total dose = 52 J/cm 2 ; Total energy = 52 J; Irradiation time: 26 × 20 sec), while the other upper quadrant received a simulated laser application with the laser system turned off. Randomized equal allocation of the sides was accomplished. The second PBI and BOP assessment followed 4-6 days after laser irradiation (T1) by M.S. No statistical differences were observed between the sides with regard to PBI and BOP values at T0 (p > 0.05). The PBI and BOP values decreased significantly between T0 and T1 on both sides (p appliances.

  13. The effect of magnesium on maternal blood pressure in pregnancy-induced hypertension. A randomized double-blind placebo-controlled trial

    DEFF Research Database (Denmark)

    Rudnicki, M; Frölich, A; Rasmussen, W F

    1991-01-01

    The effects of magnesium were compared with those of placebo in a randomized double-blind controlled study of 58 patients with pregnancy-induced hypertension, of whom 27 received magnesium and 31 placebo. Twenty patients in each group were nulliparas. The treatment comprised 48 h of either intrav...

  14. Recovery from prolonged deep rocuronium-induced neuromuscular blockade: A randomized comparison of sugammadex reversal with spontaneous recovery.

    Science.gov (United States)

    Rahe-Meyer, N; Berger, C; Wittmann, M; Solomon, C; Abels, E A M; Rietbergen, H; Reuter, D A

    2015-07-01

    Deep neuromuscular blockade (NMB) may not always be maintained to the end of surgery and the depth of block may be allowed to gradually diminish over time, particularly if reversal of NMB is not routinely performed. The current study aimed to assess recovery from deep rocuronium-induced NMB with sugammadex compared with placebo, provide data regarding the extent of residual blockade after deep rocuronium-induced NMB (placebo group), and to determine whether complete and reliable recovery could be provided by sugammadex (sugammadex group). This was a randomized, placebo-controlled, safety-assessor-blinded study in adult patients of American Society of Anesthesiologists Class I to III. Patients with clinically relevant kidney or liver insufficiency were excluded. Anesthesia was administered as routinely practiced at each study site. Rocuronium 0.6 mg/kg was administered for intubation, with maintenance doses of 0.1-0.2 mg/kg as needed. After the last rocuronium dose, at deep NMB (target depth 1-2 post-tetanic counts), patients received a single dose of sugammadex 4.0 mg/kg or placebo as randomized. The primary endpoint was time from sugammadex or placebo administration to recovery of the train-of-four (TOF) ratio to 0.9. Safety was assessed through monitoring of adverse events, vital signs and physical examination. Patients were also assessed for evidence of residual or recurrence of NMB. With this design, the study will provide data regarding the extent of residual blockade under these conditions (placebo group), and determine whether complete and reliable recovery could be provided by sugammadex (sugammadex group). Recovery to a TOF ratio of ≥ 0.9 with sugammadex was significantly faster (~ 40 times) than spontaneous recovery: geometric mean (95 % confidence interval) times were 2.2 (1.9-2.5) and 89.8 (80.1-100.7) min, respectively (p sugammadex, with median time to recovery > 1.5 h in the placebo group and one patient taking 4.8 h to achieve a

  15. The efficacy of octreotide in the therapy of acute radiation-induced diarrhea: a randomized controlled study

    International Nuclear Information System (INIS)

    Yavuz, Melek N.; Yavuz, A. Aydin; Aydin, Fazil; Can, Gamze; Kavgaci, Halil

    2002-01-01

    Purpose: Although the somatostatin analog octreotide is currently used in the treatment of chemotherapy-induced diarrhea and secretory diarrhea associated with various disorders, its role in the management of radiation enteritis is not well defined. We performed a randomized study that compared octreotide acetate with diphenoxylate hydrochloride plus atropine sulfate, the drug commonly used as therapy for acute radiation-induced diarrhea (ARID). Methods and Materials: Sixty-one patients with Grade 2 (four to six stools per day) or Grade 3 (≥ seven stools per day, National Cancer Institute Common Toxicity Criteria) diarrhea associated with pelvic radiotherapy were assigned randomly to receive octreotide s.c., 100 μg three times daily (n=33) or diphenoxylate and atropine orally, 2.5 mg four times daily (n = 28). Radiotherapy was delivered to all patients in a conventional manner, with high-energy photons in a total dose ≥45 Gy, which exceeds the tolerance of intestine. Overall, there was no significant difference in patient characteristics or radiotherapy applied between the two arms. Patients were evaluated daily for the primary study end point, resolution of diarrhea, as well as for interruption of pelvic radiotherapy. Results: Within 3 days, ARID completely resolved in 20 patients in the octreotide arm (2 within the first day, 11 within the second day, and 7 within the third day) vs. only 4 (all within the second day of therapy) in the diphenoxylate arm (p=0.002). On the diphenoxylate arm, 15/28 patients were required to discontinue pelvic radiotherapy; on the octreotide arm, 6/33 patients were required to discontinue pelvic radiotherapy for an average of 1.89±0.5 and 0.45±0.2 days, respectively (p=0.003). No side effects were observed in either arm. Three patients on the diphenoxylate arm and only 1 on the octreotide arm required further treatment for parenteral replenishment of fluids and electrolytes or other antidiarrheal treatments. Conclusion

  16. Effects of Transcranial Direct Current Stimulation Block Remifentanil-Induced Hyperalgesia: A Randomized, Double-Blind Clinical Trial

    Directory of Open Access Journals (Sweden)

    Gilberto Braulio

    2018-02-01

    Full Text Available Background: Remifentanil-induced hyperalgesia (r-IH involves an imbalance in the inhibitory and excitatory systems. As the transcranial Direct Current Stimulation (tDCS modulates the thalamocortical synapses in a top-down manner, we hypothesized that the active (a-t-DCS would be more effective than sham(s-tDCS to prevent r-IH. We used an experimental paradigm to induce temporal summation of pain utilizing a repetitive cold test (rCOLDT assessed by the Numerical Pain Score (NPS 0-10 and we evaluated the function of the descending pain modulatory system (DPMS by the change on the NPS (0–10 during the conditioned pain modulation (CPM-task (primary outcomes. We tested whether a-tDCS would be more effective than s-tDCS to improve pain perception assessed by the heat pain threshold (HPT and the reaction time during the ice-water pain test (IPT (secondary outcomes.Methods: This double-blinded, factorial randomized trial included 48 healthy males, ages ranging 19–40 years. They were randomized into four equal groups: a-tDCS/saline, s-tDCS/saline, a-tDCS/remifentanil and s-tDCS/remifentanil. tDCS was applied over the primary motor cortex, during 20 min at 2 mA, which was introduced 10 min after starting remifentanil infusion at 0.06 μg⋅kg-1⋅min-1 or saline.Results: An ANCOVA mixed model revealed that during the rCOLDT, there was a significant main effect on the NPS scores (F = 3.81; P = 0.01. The s-tDCS/remifentanil group presented larger pain scores during rCOLDT, [mean (SD 5.49 (1.04] and a-tDCS/remifentanil group had relative lower pain scores [4.15 (1.62]; showing its blocking effect on r-IH. a-tDCS/saline and s-tDCS/saline groups showed lowest pain scores during rCOLDT, [3.11 (1.2] and [3.15 (1.62], respectively. The effect of sedation induced by remifentanil during the rCOLDT was not significant (F = 0.76; P = 0.38. Remifentanil groups showed positive scores in the NPS (0–10 during the CPM-task, that is, it produced a disengagement of

  17. A double-blind, randomized clinical study to determine the efficacy of benzocaine 10% on histamine-induced pruritus and UVB-light induced slight sunburn pain.

    Science.gov (United States)

    Bauer, Martin; Schwameis, Richard; Scherzer, Thomas; Lang-Zwosta, Isabelle; Nishino, Kanako; Zeitlinger, Markus

    2015-01-01

    This study aims to explore the efficacy of the topical application of 10% benzocaine for treating pruritus and pain as compared to vehicle ointment. Twenty male subjects were treated in a randomized double-blind fashion with the investigational medicinal product (IMPD) and vehicle. Immediately after the injection of 100 µg histamine on both arms, subjects received topical treatment and pruritus was subsequently assessed with visual analogue scale (VASpruritus) and Eppendorfer questionnaire. Ultraviolet B radiation (UVB) was administered on the back to induce slight sunburn. Twelve hours after UVB application again the IMPD was applied on the right or left upper back and vehicle on the other side and pain related to sunburn was measured with VASpain and pressure algometry. A trend towards better reduction of pruritus was shown for benzocaine in VASpruritus. For the VASpain significant differences in group comparison (p = 0.02) were observed. Algometer measurements showed onset of pain reduction in the verum group after 20 min whereas in the vehicle-treated area pain relief occurred only after 60 min after application. The topically administered ointment containing 10% benzocaine was found superior over vehicle for treating pain, but not pruritus.

  18. Smoking cessation induced by deep repetitive transcranial magnetic stimulation of the prefrontal and insular cortices: a prospective, randomized controlled trial.

    Science.gov (United States)

    Dinur-Klein, Limor; Dannon, Pinhas; Hadar, Aviad; Rosenberg, Oded; Roth, Yiftach; Kotler, Moshe; Zangen, Abraham

    2014-11-01

    Tobacco smoking is the leading cause of preventable death in developed countries. Our previous studies in animal models and humans suggest that repeated activation of cue-induced craving networks followed by electromagnetic stimulation of the dorsal prefrontal cortex (PFC) can cause lasting reductions in drug craving and consumption. We hypothesized that disruption of these circuitries by deep transcranial magnetic stimulation (TMS) of the PFC and insula bilaterally can induce smoking cessation. Adults (N = 115) who smoke at least 20 cigarettes/day and failed previous treatments were recruited from the general population. Participants were randomized to receive 13 daily sessions of high-frequency, low-frequency or sham stimulation following, or without, presentation of smoking cues. Deep TMS was administered using an H-coil version targeting the lateral PFC and insula bilaterally. Cigarette consumption was evaluated during the treatment by measuring cotinine levels in urine samples and recording participants' self-reports as a primary outcome variable. Dependence and craving were assessed using standardized questionnaires. High (but not low) frequency deep TMS treatment significantly reduced cigarette consumption and nicotine dependence. The combination of this treatment with exposure to smoking cues enhanced reduction in cigarette consumption leading to an abstinence rate of 44% at the end of the treatment and an estimated 33% 6 months following the treatment. This study further implicates the lateral PFC and insula in nicotine addiction and suggests the use of deep high-frequency TMS of these regions following presentation of smoking cues as a promising treatment strategy. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  19. A combined theoretical and experimental investigation about the influence of the dopant in the anodic electropolymerization of α-tetrathiophene

    International Nuclear Information System (INIS)

    Aleman, Carlos; Oliver, Ramon; Brillas, Enric; Casanovas, Jordi; Estrany, Francesc

    2006-01-01

    This work presents an experimental and theoretical investigation about the influence of the dopant in the electropolymerization of α-tetrathiophene. The results derived from anodic polymerization of α-tetrathiophene using SCN - , Cl - , Br - , NO 3 - ClO 3 - andClO 4 - as dopant agents are compared with theoretical results provided by quantum mechanical calculations on 1:1 charge-transfer complexes formed by α-tetrathiophene and X=SCN, Cl, Br, NO 3 , ClO 3 and ClO 4 . The consistency between experimental and theoretical results allows explain and rationalize the influence of the dopant in the electropolymerization of α-tetrathiophene

  20. Random Telegraph Signal Amplitudes in Sub 100 nm (Decanano) MOSFETs: A 3D 'Atomistic' Simulation Study

    Science.gov (United States)

    Asenov, Asen; Balasubramaniam, R.; Brown, A. R.; Davies, J. H.; Saini, Subhash

    2000-01-01

    In this paper we use 3D simulations to study the amplitudes of random telegraph signals (RTS) associated with the trapping of a single carrier in interface states in the channel of sub 100 nm (decanano) MOSFETs. Both simulations using continuous doping charge and random discrete dopants in the active region of the MOSFETs are presented. We have studied the dependence of the RTS amplitudes on the position of the trapped charge in the channel and on the device design parameters. We have observed a significant increase in the maximum RTS amplitude when discrete random dopants are employed in the simulations.

  1. Stochastic resonance induced by the novel random transitions of two-dimensional weak damping bistable duffing oscillator and bifurcation of moment equation

    International Nuclear Information System (INIS)

    Zhang Guangjun; Xu Jianxue; Wang Jue; Yue Zhifeng; Zou Hailin

    2009-01-01

    In this paper stochastic resonance induced by the novel random transitions of two-dimensional weak damping bistable Duffing oscillator is analyzed by moment method. This kind of novel transition refers to the one among three potential well on two sides of bifurcation point of original system at the presence of internal noise. Several conclusions are drawn. First, the semi-analytical result of stochastic resonance induced by the novel random transitions of two-dimensional weak damping bistable Duffing oscillator can be obtained, and the semi-analytical result is qualitatively compatible with the one of Monte Carlo simulation. Second, a bifurcation of double-branch fixed point curves occurs in the moment equations with noise intensity as their bifurcation parameter. Third, the bifurcation of moment equations corresponds to stochastic resonance of original system. Finally, the mechanism of stochastic resonance is presented from another viewpoint through analyzing the energy transfer induced by the bifurcation of moment equation.

  2. Neuroimaging Correlates of Post-Stroke Aphasia Rehabilitation in a Pilot Randomized Trial of Constraint-Induced Aphasia Therapy.

    Science.gov (United States)

    Nenert, Rodolphe; Allendorfer, Jane B; Martin, Amber M; Banks, Christi; Ball, Angel; Vannest, Jennifer; Dietz, Aimee R; Szaflarski, Jerzy P

    2017-07-18

    BACKGROUND Recovery from post-stroke aphasia is a long and complex process with an uncertain outcome. Various interventions have been proposed to augment the recovery, including constraint-induced aphasia therapy (CIAT). CIAT has been applied to patients suffering from post-stroke aphasia in several unblinded studies to show mild-to-moderate linguistic gains. The aim of the present study was to evaluate the neuroimaging correlates of CIAT in patients with chronic aphasia related to left middle cerebral artery stroke. MATERIAL AND METHODS Out of 24 patients recruited in a pilot randomized blinded trial of CIAT, 19 patients received fMRI of language. Eleven of them received CIAT (trained) and eight served as a control group (untrained). Each patient participated in three fMRI sessions (before training, after training, and 3 months later) that included semantic decision and verb generation fMRI tasks, and a battery of language tests. Matching healthy control participants were also included (N=38; matching based on age, handedness, and sex). RESULTS Language testing showed significantly improved performance on Boston Naming Test (BNT; paphasia with no specific effect from CIAT training.

  3. [Effects of granisetron/lidocaine combination on propofol injection-induced pain: a double-blind randomized clinical trial].

    Science.gov (United States)

    Ma, Yu-shan; Lin, Xue-mei; Zhou, Jun

    2009-05-01

    To investigate the alleviation effect of vein pretreatment and granisetron/lidocaine combination on propofol injection-induced pain. Two hundreds patients scheduled for gynaecological laparoscopic operations were randomly divided into four groups: control group (group I), lidocaine group (group II), granisetron group (group III) and granisetron/lidocaine combination group (group IV), with 50 patients in each group. The patients in the above four groups received placebo (saline), lidocaine 20 mg, granisetron 2 mg and granisetron 2 mg plus lidocaine intravenously respectively. The patients were injected with one-forth of scheduled propofol via a dorsal hand vein after one minute of venous occlusion. The pain during the injection of propofol was evaluated. Pain occurred in 84% of patients in the control group, 46% in the lidocaine group, 52% in the granisetron group and 24% in the granisetron/lidocaine combination group. There was a significant reduction in pain incidence in the three experimental groups compared with the control group (Pgranisetron/lidocaine combination group than in the control group (Pgranisetron/lidocaine may be effective not only in attenuating pains during i.v. injection of propofol, but also in preventing postoperative nausea, vomiting and shivering.

  4. Vitamin B6 versus mianserin and placebo in acute neuroleptic-induced akathisia: a randomized, double-blind, controlled study.

    Science.gov (United States)

    Miodownik, Chanoch; Lerner, Vladimir; Statsenko, Nikolay; Dwolatzky, Tzvi; Nemets, Boris; Berzak, Elina; Bergman, Joseph

    2006-01-01

    Treatment strategies against acute neuroleptic-induced akathisia (NIA) include anticholinergic (antimuscarinic) agents, dopamine agonists, GABAergic agents, beta-blockers, benzodiazepines, and serotonin antagonists. However, many patients who have acute akathisia fail to respond. In previous studies, mianserin and vitamin B6 were found to be effective in the treatment of acute akathisia. The purpose of this study was to compare the efficacy of B(6), mianserin and placebo in the treatment of acute NIA. Sixty schizophrenia and schizoaffective inpatients who have NIA were randomly divided to receive vitamin B(6) 1,200 mg/d, mianserin 15 mg/d, or placebo for 5 days, in a double-blind design. The Barnes Akathisia Rating Scale, Brief Psychiatric Rating Scale, and Clinical Global Impression were used to assess the severity of NIA and psychotic symptoms. The assessment was made at baseline and daily for the duration of the study. Compared with the placebo group, the vitamin B(6)-treated and mianserin-treated patients showed a significant improvement in the subjective (P vitamin B(6) group (13/23, 56%) as well as in the mianserin groups (13/20, 65%), and in only one patient in the placebo group (1/17, 6%; P vitamin B(6) and mianserin suggests that the pathophysiology of acute NIA is heterogeneous with the various subtypes of acute NIA responding differently to the various pharmacological approaches.

  5. Radiation-induced proctosigmoiditis. Prospective, randomized, double-blind controlled trial of oral sulfasalazine plus rectal steroids versus rectal sucralfate

    Energy Technology Data Exchange (ETDEWEB)

    Kochhar, R.; Patel, F.; Dhar, A.; Sharma, S.C.; Ayyagari, S.; Aggarwal, R.; Goenka, M.K.; Gupta, B.D.; Mehta, S.K. (Postgraduate Institute of Medical Education and Research, Chandigarh (India))

    1991-01-01

    In a prospective study, 37 consecutive patients with radiation-induced proctosigmoiditis were randomized to receive a four-week course of either 3.0 g oral sulfasalazine plus 20 mg twice daily rectal prednisolone enemas (group I, N = 18) or 2.0 g twice daily rectal sucralfate enemas plus oral placebo (group II, N = 19). The two groups were comparable with respect to demographic features, duration of symptoms, and clinical and endoscopic staging of the disease. Fifteen patients in group I and 17 in group II completed the trial. At four weeks, both groups showed significant clinical improvement (P less than 0.01 for group I and P less than 0.001 for group II) and endoscopic healing (P less than 0.01 for group I and P less than 0.001 for group II). When the two groups were compared, sucralfate enemas showed a significantly better response as assessed clinically (P less than 0.05), although endoscopically the response was not statistically different (P greater than 0.05). We conclude that both treatment regimens are effective in the management of radiation proctitis. Sucralfate enemas give a better clinical response, are tolerated better, and because of the lower cost should be the preferred mode of short-term treatment.

  6. Radiation-induced proctosigmoiditis. Prospective, randomized, double-blind controlled trial of oral sulfasalazine plus rectal steroids versus rectal sucralfate

    International Nuclear Information System (INIS)

    Kochhar, R.; Patel, F.; Dhar, A.; Sharma, S.C.; Ayyagari, S.; Aggarwal, R.; Goenka, M.K.; Gupta, B.D.; Mehta, S.K.

    1991-01-01

    In a prospective study, 37 consecutive patients with radiation-induced proctosigmoiditis were randomized to receive a four-week course of either 3.0 g oral sulfasalazine plus 20 mg twice daily rectal prednisolone enemas (group I, N = 18) or 2.0 g twice daily rectal sucralfate enemas plus oral placebo (group II, N = 19). The two groups were comparable with respect to demographic features, duration of symptoms, and clinical and endoscopic staging of the disease. Fifteen patients in group I and 17 in group II completed the trial. At four weeks, both groups showed significant clinical improvement (P less than 0.01 for group I and P less than 0.001 for group II) and endoscopic healing (P less than 0.01 for group I and P less than 0.001 for group II). When the two groups were compared, sucralfate enemas showed a significantly better response as assessed clinically (P less than 0.05), although endoscopically the response was not statistically different (P greater than 0.05). We conclude that both treatment regimens are effective in the management of radiation proctitis. Sucralfate enemas give a better clinical response, are tolerated better, and because of the lower cost should be the preferred mode of short-term treatment

  7. A randomized placebo controlled trial to evaluate the effects of butamirate and dextromethorphan on capsaicin induced cough in healthy volunteers.

    Science.gov (United States)

    Faruqi, Shoaib; Wright, Caroline; Thompson, Rachel; Morice, Alyn H

    2014-12-01

    The examination of cough reflex sensitivity through inhalational challenge can be utilized to demonstrate pharmacological end points. Here we compare the effect of butamirate, dextromethorphan and placebo on capsaicin-induced cough in healthy volunteers. In this randomized, placebo-controlled, six way crossover study the effect of dextromethrophan 30 mg, four doses of butamirate and placebo was evaluated on incremental capsaicin challenges performed at baseline and 2, 4, 6, 8, 12 and 24 h following dosing. The primary end point was the area under the curve (AUC(0,12h)) of log10 C5 from pre-dose to 12 h after dosing. Plasma butamirate metabolites were analyzed to evaluate pharmacokinetic and pharmacodynamic relationships. Thirty-four subjects (13 males, median age 25 years) completed the study. Cough sensitivity decreased from baseline in all arms of the study. Dextromethorphan was superior to placebo (P = 0.01) but butamirate failed to show significant activity with maximum attenuation at the 45 mg dose. There was no apparent relationship between pharmacokinetic and pharmacodynamic parameters for butamirate. We have demonstrated for the first time that dextromethorphan attenuates capsaicin challenge confirming its broad activity on the cough reflex. The lack of efficacy of butamirate could be due to formulation issues at higher doses. © 2014 The British Pharmacological Society.

  8. The utility of bispectral index monitoring for prevention of rocuronium-induced withdrawal movement in children: A randomized controlled trial.

    Science.gov (United States)

    Lim, Byung Gun; Lee, Il Ok; Kim, Young Sung; Won, Young Ju; Kim, Heezoo; Kong, Myoung Hoon

    2017-01-01

    This study was designed to determine whether a deep hypnotic state with a bispectral index (BIS) value less than 40 could alleviate withdrawal movement (WM) upon rocuronium injection during anesthesia induction in children. Finally, 135 healthy children (3-12 years) scheduled for minor elective surgery were studied. Without premedication, anesthesia was induced with thiopental sodium 5 mg/kg. Patients were randomized into 2 groups (control vs experimental) and then by virtue of rocuronium injection time, patients in the experimental group were allocated into 2 groups, as follows: in the control group (group C; n = 45), rocuronium 0.6 mg/kg was administered at the loss of eyelash reflex; in the 1st experimental group, rocuronium 0.6 mg/kg was administered when BIS fell to less than 40 (group T; n = 45); however, if BIS did not fall below 40 after thiopental sodium administration, manual ventilation was provided with oxygen 6 L/minute using sevoflurane 8% and then rocuronium was administered when BIS fell below 40 (the 2nd experimental group, group S; n = 45). Rocuronium-induced WM was evaluated using a 4-point scale (no movement; movement/withdrawal involving the arm only; generalized response, with movement/withdrawal of more than 1 extremity, but no requirement for restraint of the body; and generalized response which required restraint of the body and caused coughing or breath-holding). No significant differences were found among the groups for patient characteristics including age, sex, height, and location of venous cannula. However, body weight, height, and body mass index in group S were all smaller than those in group T. The incidence of WM caused by rocuronium was 100% in group C, 95.6% in group T, and 80% in group S, and was significantly lower in group S than in group C. The grade of WM was 3.7 ± 0.6 in group C, 3.2 ± 0.9 in group T, and 2.6 ± 1.0 in group S. It was significantly lower in group T than in group C and

  9. A blinded, randomized, controlled trial of three doses of high-dose insulin in poison-induced cardiogenic shock.

    Science.gov (United States)

    Cole, J B; Stellpflug, S J; Ellsworth, H; Anderson, C P; Adams, A B; Engebretsen, K M; Holger, J S

    2013-05-01

    High dose insulin (HDI) has proven superior to glucagon and catecholamines in the treatment of poison-induced cardiogenic shock (PICS) in previous animal studies. Standard recommendations for dosing of insulin vary and the optimal dose of HDI in PICS has not been established. Our hypothesis was a dose of 10 U/kg/hr of HDI would be superior to 1 U/kg/hr with cardiac output (CO) as our primary outcome measure in pigs with propranolol-induced PICS. This was a blinded, prospective, randomized trial with 4 arms consisting of 4 pigs in each arm. The arms were as follows: placebo (P), 1 U/kg/hr (HDI-1), 5 U/kg/hr (HDI-5), and 10 U/kg/hr (HDI-10). Cardiogenic shock was induced with a bolus of 0.5 mg/kg of propranolol followed by an infusion of 0.25 mg/kg/min until the point of toxicity, defined as 0.75 x (HR x MAP) was reached. At this point the propranolol infusion was decreased to 0.125 mg/kg/min and a 20 mL/kg bolus of normal saline (NS) was administered. The protocol was continued for 6 hours or until the animals died. 2 pigs died in the P arm, 1 pig died each in the HDI-1 and HDI-5 arms, and all pigs lived in the HDI-10 arm. There was a statistically significant difference in dose by time interaction on CO of 1.13 L/min over the 6 hr study period (p = < 0.001). There was also a statistically significant difference in dose by time interaction on MAP, HR, and systemic vascular resistance (SVR). No statistically significant difference was found between any of the arms regarding glucose utilization. HDI was statistically and clinically significantly superior to placebo in this propranolol model of PICS. Furthermore a dose response over time was found where CO increased corresponding to increases in doses of HDI.

  10. Phosphorus doped and defects engineered graphene for improved electrochemical sensing: synergistic effect of dopants and defects

    International Nuclear Information System (INIS)

    Chu, Ke; Wang, Fan; Tian, Ye; Wei, Zhen

    2017-01-01

    Heteroatom-doped graphene materials emerged as promising metal-free catalysts have recently attracted a growing interest in electrochemical sensing applications. However, their catalytic activity and sensing performances still need to be further improved. Herein, we reported the development of unique phosphorus (P)-doped and plasma-etched graphene (denoted as PG-E) as an efficient metal-free electrocatalyst for dopamine (DA) sensing. It was demonstrated that introducing both P-dopants and plasma-engineered defects in graphene could synergistically improve the activity toward electrocatalytic oxidation of DA by increasing the accessible active sites and promoting the electron transport capability. The resulting PG-E modified electrode showed exceptional DA sensing performances with low detection limit, high selectivity and good stability. These results suggested that the synergistic effect of dopants and defects might be an important factor for developing the advanced graphene-based metal-free catalysts for electrochemical sensing.

  11. Lattice site location of electrical dopant impurities in group-III nitrides

    CERN Document Server

    Amorim, Lígia; Temst, Kristiaan; Wahl, Ulrich

    Dopants are impurities introduced in semiconductors in small quantities to tailor the material characteristics, the effects of which depend on the exact site the dopant occupies in the crystal lattice. The lattice location of impurities is, thus, crucial for the overall understanding of the semiconductor characteristics. In general, several techniques can be used to investigate the lattice site of an impurity, the most accurate and dedicated being emission channeling. However, a characteristic of this technique is that it requires the implantation of radioactive probes, usually created and accelerated in a radioactive ion beam facility. In some cases, emission channeling might however be the only technique capable to investigate the lattice sites occupied by the impurity atoms, provided an appropriate isotope for this technique can be used. For instance, the use of other methods such as Rutherford backscattering spectrometry, perturbed angular correlations, Mössbauer spectroscopy and extended X-ray absorptio...

  12. Application of dopant-free hole transport materials for perovskite solar cells

    International Nuclear Information System (INIS)

    Franckevincius, M.; Gulbinas, V.; Gratzel, M.; Zakeeruddin, S.; Pauerle, P.; Mishra, A.; Steck, C.

    2015-01-01

    In this work we present the synthesis, characterization and application of a series of additive and dopant free hole transport materials (HTM) for solid-state perovskite-based solar cells. Newly synthesized HTMs showed strong absorption in the visible spectral range and suitable HOMO-LUMO energy levels for the application for methylammonium lead(II) iodide (CH_3NH_3PbI_3) perovskite. Dopant-free perovskite solar cells have been fabricated using CH_3NH_3PbI_3 perovskite and the newly synthesized HTMs following sequential deposition method, which allows us to reach power conversion efficiencies as high as 11.4 %. The easy of synthesis, low cost and relatively high performance of newly synthesized HTMs has great prospects for commercial applications in the near-future. (authors)

  13. Two-dimensional dopant profiling of gallium nitride p-n junctions by scanning capacitance microscopy

    Science.gov (United States)

    Lamhamdi, M.; Cayrel, F.; Frayssinet, E.; Bazin, A. E.; Yvon, A.; Collard, E.; Cordier, Y.; Alquier, D.

    2016-04-01

    Two-dimensional imaging of dopant profiles for n and p-type regions are relevant for the development of new power semiconductors, especially for gallium nitride (GaN) for which classical profiling techniques are not adapted. This is a challenging task since it needs a technique with simultaneously good sensitivity, high spatial resolution and high dopant gradient resolution. To face these challenges, scanning capacitance microscopy combined with Atomic Force Microscopy is a good candidate, presenting reproducible results, as demonstrated in literature. In this work, we attempt to distinguish reliably and qualitatively the various doping concentrations and type at p-n and unipolar junctions. For both p-n and unipolar junctions three kinds of samples were prepared and measured separately. The space-charge region of the p-n metallurgical junction, giving rise to different contrasts under SCM imaging, is clearly observed, enlightening the interest of the SCM technique.

  14. Dopant-Modulating Mechanism of Lithium Adsorption and Diffusion at the Graphene /Li2S Interface

    Science.gov (United States)

    Guo, Lichao; Li, Jiajun; Wang, Huayu; Zhao, Naiqin; Shi, Chunsheng; Ma, Liying; He, Chunnian; He, Fang; Liu, Enzuo

    2018-02-01

    Graphene modification is one of the most effective routes to enhance the electrochemical properties of the transition-metal sulfide anode for Li-ion batteries and the Li2S cathode for Li-S batteries. Boron, nitrogen, oxygen, phosphorus, and sulfur doping greatly affect the electrochemical properties of Li2S /graphene . Here, we investigate the interfacial binding energy, lithium adsorption energy, interface diffusion barrier, and electronic structure by first-principles calculations to unveil the diverse effects of different dopants during interfacial lithiation reactions. The interfacial lithium storage follows the pseudocapacitylike mechanism with intercalation character. Two different mechanisms are revealed to enhance the interfacial lithium adsorption and diffusion, which are the electron-deficiency host doping and the vacancylike structure evolutions with bond breaking. The synergistic effect between different dopants with diverse doping effects is also proposed. The results give a theoretical basis for the materials design with doped graphene as advanced materials modification for energy storage.

  15. High-resolution three-dimensional mapping of semiconductor dopant potentials

    DEFF Research Database (Denmark)

    Twitchett, AC; Yates, TJV; Newcomb, SB

    2007-01-01

    Semiconductor device structures are becoming increasingly three-dimensional at the nanometer scale. A key issue that must be addressed to enable future device development is the three-dimensional mapping of dopant distributions, ideally under "working conditions". Here we demonstrate how a combin......Semiconductor device structures are becoming increasingly three-dimensional at the nanometer scale. A key issue that must be addressed to enable future device development is the three-dimensional mapping of dopant distributions, ideally under "working conditions". Here we demonstrate how...... a combination of electron holography and electron tomography can be used to determine quantitatively the three-dimensional electrostatic potential in an electrically biased semiconductor device with nanometer spatial resolution....

  16. Two-dimensional dopant profiling of gallium nitride p–n junctions by scanning capacitance microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lamhamdi, M. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France); Ecole national des sciences appliquées khouribga, Université Hassan 1er, 26000 Settat (Morocco); Cayrel, F. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France); Frayssinet, E. [CRHEA-CNRS, Rue Bernard Grégory, Sophia Antipolis, 06560 Valbonne (France); Bazin, A.E.; Yvon, A.; Collard, E. [STMicroelectronics, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours (France); Cordier, Y. [CRHEA-CNRS, Rue Bernard Grégory, Sophia Antipolis, 06560 Valbonne (France); Alquier, D. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France)

    2016-04-01

    Two-dimensional imaging of dopant profiles for n and p-type regions are relevant for the development of new power semiconductors, especially for gallium nitride (GaN) for which classical profiling techniques are not adapted. This is a challenging task since it needs a technique with simultaneously good sensitivity, high spatial resolution and high dopant gradient resolution. To face these challenges, scanning capacitance microscopy combined with Atomic Force Microscopy is a good candidate, presenting reproducible results, as demonstrated in literature. In this work, we attempt to distinguish reliably and qualitatively the various doping concentrations and type at p–n and unipolar junctions. For both p–n and unipolar junctions three kinds of samples were prepared and measured separately. The space-charge region of the p–n metallurgical junction, giving rise to different contrasts under SCM imaging, is clearly observed, enlightening the interest of the SCM technique.

  17. MOS Capacitance—Voltage Characteristics II. Sensitivity of Electronic Trapping at Dopant Impurity from Parameter Variations

    International Nuclear Information System (INIS)

    Jie Binbin; Sah Chihtang

    2011-01-01

    Low-frequency and high-frequency Capacitance—Voltage (C—V) curves of Metal—Oxide—Semiconductor Capacitors (MOSC), including electron and hole trapping at the dopant donor and acceptor impurities, are presented to illustrate giant trapping capacitances, from > 0.01C OX to > 10C OX . Five device and materials parameters are varied for fundamental trapping parameter characterization, and electrical and optical signal processing applications. Parameters include spatially constant concentration of the dopant-donor-impurity electron trap, N DD , the ground state electron trapping energy level depth measured from the conduction band edge, E C –E D , the degeneracy of the trapped electron at the ground state, g D , the device temperature, T, and the gate oxide thickness, x OX . (invited papers)

  18. Damage accumulation and dopant migration during shallow As and Sb implantation into Si

    Energy Technology Data Exchange (ETDEWEB)

    Werner, M.; Berg, J.A. van den E-mail: j.a.vandenberg@salford.ac.uk; Armour, D.G.; Vandervorst, W.; Collart, E.H.J.; Goldberg, R.D.; Bailey, P.; Noakes, T.C.Q

    2004-02-01

    The damage evolution and concomitant dopant redistribution as a function of ion fluence during ultra shallow, heavy ion implants into Si have been investigated using medium energy ion scattering (MEIS) and secondary ion mass spectrometry (SIMS). These studies involved As and Sb ions implanted at room temperature, at energies of 2.5 and 2 keV to doses from 3 x 10{sup 13} to 5 x 10{sup 15} cm{sup -2}. MEIS is capable of detecting both the displaced atom and implant profiles with sub-nanometre depth resolution. These studies show that for doses up to 1 x 10{sup 14} cm{sup -2} (at which an amorphous layer is formed) the damage build up does not follow the energy deposition function. Instead it proceeds through the initial formation of a {approx}4 nm wide amorphous layer immediately under the oxide, that grows inwards into the bulk with increasing dose. This behaviour is explained in terms of the migration of some of the interstitials produced along the length of the collision cascade to the oxide or amorphous/crystal Si interface, where their trapping nucleates the growth of a shallow amorphous layer and the subsequent planar growth inwards of the damage layer. Although for doses {>=}4 x 10{sup 14} cm{sup -2} the As depth profiles agreed well with TRIM calculations, for lower doses As was observed to have a shallower profile, {approx}2 nm nearer to the surface. This behaviour is related the growth of the amorphous layer and ascribed to the movement of As into the near-surface amorphous layer (probably mediated by point defect migration) in which the larger dopant is accommodated more easily. SIMS studies have confirmed this dopant segregation effect. Shallow Sb implants also exhibit this novel dopant movement effect for low doses in combination with a damage evolution similar to As.

  19. Damage accumulation and dopant migration during shallow As and Sb implantation into Si

    International Nuclear Information System (INIS)

    Werner, M.; Berg, J.A. van den; Armour, D.G.; Vandervorst, W.; Collart, E.H.J.; Goldberg, R.D.; Bailey, P.; Noakes, T.C.Q.

    2004-01-01

    The damage evolution and concomitant dopant redistribution as a function of ion fluence during ultra shallow, heavy ion implants into Si have been investigated using medium energy ion scattering (MEIS) and secondary ion mass spectrometry (SIMS). These studies involved As and Sb ions implanted at room temperature, at energies of 2.5 and 2 keV to doses from 3 x 10 13 to 5 x 10 15 cm -2 . MEIS is capable of detecting both the displaced atom and implant profiles with sub-nanometre depth resolution. These studies show that for doses up to 1 x 10 14 cm -2 (at which an amorphous layer is formed) the damage build up does not follow the energy deposition function. Instead it proceeds through the initial formation of a ∼4 nm wide amorphous layer immediately under the oxide, that grows inwards into the bulk with increasing dose. This behaviour is explained in terms of the migration of some of the interstitials produced along the length of the collision cascade to the oxide or amorphous/crystal Si interface, where their trapping nucleates the growth of a shallow amorphous layer and the subsequent planar growth inwards of the damage layer. Although for doses ≥4 x 10 14 cm -2 the As depth profiles agreed well with TRIM calculations, for lower doses As was observed to have a shallower profile, ∼2 nm nearer to the surface. This behaviour is related the growth of the amorphous layer and ascribed to the movement of As into the near-surface amorphous layer (probably mediated by point defect migration) in which the larger dopant is accommodated more easily. SIMS studies have confirmed this dopant segregation effect. Shallow Sb implants also exhibit this novel dopant movement effect for low doses in combination with a damage evolution similar to As

  20. Three dimensional mapping of Fe dopants in ceria nanocrystals using direct spectroscopic electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Goris, Bart; Meledina, Maria; Turner, Stuart [EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Zhong, Zhichao [Centrum Wiskunde & Informatica, P.O. Box 94079, 1090 GB Amsterdam (Netherlands); Batenburg, K. Joost [Centrum Wiskunde & Informatica, P.O. Box 94079, 1090 GB Amsterdam (Netherlands); Mathematical Institute, Leiden University, Niels Bohrweg 1, 2333CA Leiden (Netherlands); Bals, Sara [EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2016-12-15

    Electron tomography is a powerful technique for the 3D characterization of the morphology of nanostructures. Nevertheless, resolving the chemical composition of complex nanostructures in 3D remains challenging and the number of studies in which electron energy loss spectroscopy (EELS) is combined with tomography is limited. During the last decade, dedicated reconstruction algorithms have been developed for HAADF-STEM tomography using prior knowledge about the investigated sample. Here, we will use the prior knowledge that the experimental spectrum of each reconstructed voxel is a linear combination of a well-known set of references spectra in a so-called direct spectroscopic tomography technique. Based on a simulation experiment, it is shown that this technique provides superior results in comparison to conventional reconstruction methods for spectroscopic data, especially for spectrum images containing a relatively low signal to noise ratio. Next, this technique is used to investigate the spatial distribution of Fe dopants in Fe:Ceria nanoparticles in 3D. It is shown that the presence of the Fe{sup 2+} dopants is correlated with a reduction of the Ce atoms from Ce{sup 4+} towards Ce{sup 3+}. In addition, it is demonstrated that most of the Fe dopants are located near the voids inside the nanoparticle. - Highlights: • A direct tomographic reconstruction technique is proposed for spectroscopic data. • Spectrum fitting is combined with a tomography reconstruction in a single step. • The technique yields superior results for data with a low signal to noise ratio. • The technique is applied to map Fe dopants in ceria nanoparticles.

  1. One- and two-dimensional dopant/carrier profiling for ULSI

    Science.gov (United States)

    Vandervorst, W.; Clarysse, T.; De Wolf, P.; Trenkler, T.; Hantschel, T.; Stephenson, R.; Janssens, T.

    1998-11-01

    Dopant/carrier profiles constitute the basis of the operation of a semiconductor device and thus play a decisive role in the performance of a transistor and are subjected to the same scaling laws as the other constituents of a modern semiconductor device and continuously evolve towards shallower and more complex configurations. This evolution has increased the demands on the profiling techniques in particular in terms of resolution and quantification such that a constant reevaluation and improvement of the tools is required. As no single technique provides all the necessary information (dopant distribution, electrical activation,..) with the requested spatial and depth resolution, the present paper attempts to provide an assessment of those tools which can be considered as the main metrology technologies for ULSI-applications. For 1D-dopant profiling secondary ion mass spectrometry (SIMS) has progressed towards a generally accepted tool meeting the requirements. For 1D-carrier profiling spreading resistance profiling and microwave surface impedance profiling are envisaged as the best choices but extra developments are required to promote them to routinely applicable methods. As no main metrology tool exist for 2D-dopant profiling, main emphasis is on 2D-carrier profiling tools based on scanning probe microscopy. Scanning spreading resistance (SSRM) and scanning capacitance microscopy (SCM) are the preferred methods although neither of them already meets all the requirements. Complementary information can be extracted from Nanopotentiometry which samples the device operation in more detail. Concurrent use of carrier profiling tools, Nanopotentiometry, analysis of device characteristics and simulations is required to provide a complete characterization of deep submicron devices.

  2. Synthesis of Some Green Dopants for OLEDs Based on Arylamine 2,3-disubstituted Bithiophene Derivatives

    Directory of Open Access Journals (Sweden)

    Mi-Seon Song

    2013-11-01

    Full Text Available A series of green dopants based on 2,2-diphenylvinyl end-capped bithiophene and three different arylamine moieties (9-phenylcarbazole, triphenylamine, and N,N’-di-(p-tolylbenzeneamine were successfully synthesized by the Suzuki and Wittig coupling reactions. The photophysical properties of these compounds are reported. The strongest PL emitting compound with the 9-phenylcarbazole moiety has been used for fabricating an OLED device with good overall performance.

  3. Direct imaging of dopant distribution in polycrystalline ZnO films

    Czech Academy of Sciences Publication Activity Database

    Lorenzo, F.; Aebersold, A.B.; Morales-Masis, M.; Ledinský, Martin; Escrig, S.; Vetushka, Aliaksi; Alexander, D.T.L.; Hessler-Wyser, A.; Fejfar, Antonín; Hébert, C.; Nicolay, S.; Ballif, C.

    2017-01-01

    Roč. 9, č. 8 (2017), s. 7241-7248 ISSN 1944-8244 R&D Projects: GA ČR GC16-10429J Institutional support: RVO:68378271 Keywords : dopant distribution * film polarity * grain boundaries * NanoSIMS * polycrystalline film * zinc oxide Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 7.504, year: 2016

  4. Influence of photochemical transformations upon optic-spectral characteristics of iodine cadmium crystals with copper dopant

    International Nuclear Information System (INIS)

    Novosad, S.S.

    2000-01-01

    The influence of photochemical transformations upon absorption. X-ray, photo- and thermostimulated luminescence of crystals CdI 2 :CuI, CdI 2 :CuI and CdI 2 :CuO grown by Stockbarger - Czochralski method has been studied. The photochemical reactions in crystals of iodine cadmium with the dopant of copper leads to reducing the intensity of X-ray, photo- and thermostimulated luminescence, the appearance of new luminescent centers is not observed

  5. Imaging of dopant distribution in optical fibers with an orthogonal TOF SIMS

    Czech Academy of Sciences Publication Activity Database

    Lorinčík, Jan; Kašík, Ivan; Vaniš, Jan; Sedláček, L.; Dluhoš, J.

    2014-01-01

    Roč. 46, č. 1 (2014), s. 238-240 ISSN 0142-2421. [19th International Conference on Secondary Ion Mass Spectrometry ( SIMS ). Jeju, 29.09.2013-04.10.2013] Grant - others:GA AV ČR(CZ) M100761202 Institutional support: RVO:67985882 Keywords : TOF SIMS * Optical fibers * Dopant Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.245, year: 2014

  6. Effect of metallic dopants on the microstructure and mechanical properties of TiB2

    Czech Academy of Sciences Publication Activity Database

    Chlup, Zdeněk; Bača, L.; Halasová, Martina; Neubauer, E.; Hadraba, Hynek; Stelzer, N.; Roupcová, Pavla

    2015-01-01

    Roč. 35, č. 10 (2015), s. 2745-2754 ISSN 0955-2219 R&D Projects: GA ČR(CZ) GAP108/11/1644; GA MŠk(CZ) ED1.1.00/02.0068 Grant - others:The Austrian Research Promotion Agency (FFG)(AT) 834287 Institutional support: RVO:68081723 Keywords : Titanium diboride * Metallic dopants * Microstructure * Mechanical properties * Fracture behaviour1 Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.933, year: 2015

  7. Dynamics of Defects and Dopants in Complex Systems: Si and Oxide Surfaces and Interfaces

    Science.gov (United States)

    Kirichenko, Taras; Yu, Decai; Banarjee, Sanjay; Hwang, Gyeong

    2004-10-01

    Fabrication of forthcoming nanometer scale electronic devices faces many difficulties including formation of extremely shallow and highly doped junctions. At present, ultra-low-energy ion implantation followed by high-temperature thermal annealing is most widely used to fabricate such ultra-shallow junctions. In the process, a great challenge lies in achieving precise control of redistribution and electrical activation of dopant impurities. Native defects (such as vacancies and interstitials) generated during implantation are known to be mainly responsible for the TED and also influence significantly the electrical activation/deactivation. Defect-dopant dynamics is rather well understood in crystalline Si and SiO2. However, little is known about their diffusion and annihilation (or precipitation) at the surfaces and interfaces, despite its growing importance in determining junction profiles as device dimensions get smaller. In this talk, we will present our density functional theory calculation results on the atomic and electronic structure and dynamical behavior of native defects and dopant-defect complexes in disordered/strained Si and oxide systems, such as i) clean and absorbent-modified Si(100) surface and subsurface layers, ii) amorphous-crystalline Si interfaces and iii) amorphous SiO2/Si interfaces. The fundamental understanding and data is essential in developing a comprehensive kinetic model for junction formation, which would contribute greatly in improving current process technologies.

  8. Influence of pentavalent dopant addition to polarization and bioactivity of hydroxyapatite

    International Nuclear Information System (INIS)

    Dhal, Jharana; Bose, Susmita; Bandyopadhyay, Amit

    2013-01-01

    Influence of pentavalent tantalum doping in bulk hydroxyapatite (HAp) ceramics has been investigated for polarizability and bioactivity. Phase analysis from X-ray diffraction measurement indicates that increasing dopant concentration decreased the amount of HAp phase and increased β-TCP and/or α-TCP phases during sintering at 1250 °C in a muffle furnace. Results from thermally stimulated depolarization current (TSDC) measurements showed that doping hindered charge storage ability in HAp ceramics, and doped samples stored fewer charge compared to pure HAp. However, doping enhanced wettability of HAp samples, which was improved further due to polarization. In vitro human osteoblast cell–material interaction study revealed an increase in bioactivity due to dopant addition and polarization compared to pure HAp. This increase in bioactivity was attributed to the increase in wettability due to surface charge and dopant addition. - Highlights: • Tantalum doping makes HAp unstable during sintering at 1250 °C and forms TCP. • Tantalum doping reduces charge storage ability of HAp ceramics. • Even with lower charge storage ability tantalum doping improves wettability. • Tantalum doping enhances bioactivity of calcium phosphate based sintered compacts

  9. Dopant effects on charge transport to enhance performance of phosphorescent white organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liping; Chen, Jiangshan; Ma, Dongge, E-mail: mdg1014@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Changchun 130022 (China)

    2015-11-07

    We compared the performance of phosphorescent white organic light emitting diodes (WOLEDs) with red-blue-green and green-blue-red sequent emissive layers. It was found that the influence of red and green dopants on electron and hole transport in emissive layers leads to the large difference in the efficiency of fabricated WOLEDs. This improvement mechanism is well investigated by the current density-voltage characteristics of single-carrier devices based on dopant doped emissive layers and the comparison of electroluminescent and photoluminescence spectra, and attributed to the different change of charge carrier transport by the dopants. The optimized device achieves a maximum power efficiency, current efficiency, and external quantum efficiency of 37.0 lm/W, 38.7 cd/A, and 17.7%, respectively, which are only reduced to 32.8 lm/W, 38.5 cd/A, and 17.3% at 1000 cd/m{sup 2} luminance. The critical current density is as high as 210 mA/cm{sup 2}. It can be seen that the efficiency roll-off in phosphorescent WOLEDs can be well improved by effectively designing the structure of emissive layers.

  10. n-Dopants Based on Dimers of Benzimidazoline Radicals: Structures and Mechanism of Redox Reactions.

    Science.gov (United States)

    Zhang, Siyuan; Naab, Benjamin D; Jucov, Evgheni V; Parkin, Sean; Evans, Eric G B; Millhauser, Glenn L; Timofeeva, Tatiana V; Risko, Chad; Brédas, Jean-Luc; Bao, Zhenan; Barlow, Stephen; Marder, Seth R

    2015-07-20

    Dimers of 2-substituted N,N'-dimethylbenzimidazoline radicals, (2-Y-DMBI)2 (Y=cyclohexyl (Cyc), ferrocenyl (Fc), ruthenocenyl (Rc)), have recently been reported as n-dopants for organic semiconductors. Here their structural and energetic characteristics are reported, along with the mechanisms by which they react with acceptors, A (PCBM, TIPS-pentacene), in solution. X-ray data and DFT calculations both indicate a longer C-C bond for (2-Cyc-DMBI)2 than (2-Fc-DMBI)2 , yet DFT and ESR data show that the latter dissociates more readily due to stabilization of the radical by Fc. Depending on the energetics of dimer (D2 ) dissociation and of D2 -to-A electron transfer, D2 reacts with A to form D(+) and A(-) by either of two mechanisms, differing in whether the first step is endergonic dissociation or endergonic electron transfer. However, the D(+) /0.5 D2 redox potentials-the effective reducing strengths of the dimers-vary little within the series (ca. -1.9 V vs. FeCp2 (+/0) ) (Cp=cyclopentadienyl) due to cancelation of trends in the D(+/0) potential and D2 dissociation energy. The implications of these findings for use of these dimers as n-dopants, and for future dopant design, are discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Dopant-Free and Carrier-Selective Heterocontacts for Silicon Solar Cells: Recent Advances and Perspectives.

    Science.gov (United States)

    Gao, Pingqi; Yang, Zhenhai; He, Jian; Yu, Jing; Liu, Peipei; Zhu, Juye; Ge, Ziyi; Ye, Jichun

    2018-03-01

    By combining the most successful heterojunctions (HJ) with interdigitated back contacts, crystalline silicon (c-Si) solar cells (SCs) have recently demonstrated a record efficiency of 26.6%. However, such SCs still introduce optical/electrical losses and technological issues due to parasitic absorption/Auger recombination inherent to the doped films and the complex process of integrating discrete p + - and n + -HJ contacts. These issues have motivated the search for alternative new functional materials and simplified deposition technologies, whereby carrier-selective contacts (CSCs) can be formed directly with c-Si substrates, and thereafter form IBC cells, via a dopant-free method. Screening and modifying CSC materials in a wider context is beneficial for building dopant-free HJ contacts with better performance, shedding new light on the relatively mature Si photovoltaic field. In this review, a significant number of achievements in two representative dopant-free hole-selective CSCs, i.e . , poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/Si and transition metal oxides/Si, have been systemically presented and surveyed. The focus herein is on the latest advances in hole-selective materials modification, interfacial passivation, contact resistivity, light-trapping structure and device architecture design, etc. By analyzing the structure-property relationships of hole-selective materials and assessing their electrical transport properties, promising functional materials as well as important design concepts for such CSCs toward high-performance SCs have been highlighted.

  12. Two dimensional dopant diffusion study by scanning capacitance microscopy and TSUPREM IV process simulation

    International Nuclear Information System (INIS)

    Kim, J.; McMurray, J. S.; Williams, C. C.; Slinkman, J.

    1998-01-01

    We report the results of a 2-step two-dimensional (2D) diffusion study by Scanning Capacitance Microscopy (SCM) and 2D TSUPREM IV process simulation. A quantitative 2D dopant profile of gate-like structures consisting heavily implanted n+ regions separated by a lighter doped n-type region underneath 0.56 μm gates is measured with the SCM. The SCM is operated in the constant-change-in-capacitance mode. The 2-D SCM data is converted to dopant density through a physical model of the SCM/silicon interaction. This profile has been directly compared with 2D TSUPREM IV process simulation and used to calibrate the simulation parameters. The sample is then further subjected to an additional diffusion in a furnace for 80 minutes at 1000C. The SCM measurement is repeated on the diffused sample. This final 2D dopant profile is compared with a TSUPREM IV process simulation tuned to fit the earlier profile with no change in the parameters except the temperature and time for the additional diffusion. Our results indicate that there is still a significant disagreement between the two profiles in the lateral direction. TSUPREM IV simulation considerably underestimates the diffusion under the gate region

  13. Predicting Low Energy Dopant Implant Profiles in Semiconductors using Molecular Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Beardmore, K.M.; Gronbech-Jensen, N.

    1999-05-02

    The authors present a highly efficient molecular dynamics scheme for calculating dopant density profiles in group-IV alloy, and III-V zinc blende structure materials. Their scheme incorporates several necessary methods for reducing computational overhead, plus a rare event algorithm to give statistical accuracy over several orders of magnitude change in the dopant concentration. The code uses a molecular dynamics (MD) model to describe ion-target interactions. Atomic interactions are described by a combination of 'many-body' and pair specific screened Coulomb potentials. Accumulative damage is accounted for using a Kinchin-Pease type model, inelastic energy loss is represented by a Firsov expression, and electronic stopping is described by a modified Brandt-Kitagawa model which contains a single adjustable ion-target dependent parameter. Thus, the program is easily extensible beyond a given validation range, and is therefore truly predictive over a wide range of implant energies and angles. The scheme is especially suited for calculating profiles due to low energy and to situations where a predictive capability is required with the minimum of experimental validation. They give examples of using the code to calculate concentration profiles and 2D 'point response' profiles of dopants in crystalline silicon and gallium-arsenide. Here they can predict the experimental profile over five orders of magnitude for <100> and <110> channeling and for non-channeling implants at energies up to hundreds of keV.

  14. Color optimization of single emissive white OLEDs via energy transfer between RGB fluorescent dopants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nam Ho; Kim, You-Hyun; Yoon, Ju-An; Lee, Sang Youn [Department of Green Energy and Semiconductor Engineering, Hoseo University, Asan (Korea, Republic of); Ryu, Dae Hyun [Department of Information Technology, Hansei University, Gunpo (Korea, Republic of); Wood, Richard [Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada L8S 4L7 (Canada); Moon, C.-B. [Department of Green Energy and Semiconductor Engineering, Hoseo University, Asan (Korea, Republic of); Kim, Woo Young, E-mail: wykim@hoseo.edu [Department of Green Energy and Semiconductor Engineering, Hoseo University, Asan (Korea, Republic of); Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada L8S 4L7 (Canada)

    2013-11-15

    The electroluminescent characteristics of white organic light-emitting diodes (WOLEDs) were investigated including single emitting layer (SEL) with an ADN host and dopants; BCzVBi, C545T, and DCJTB for blue, green and red emission, respectively. The structure of the high efficiency WOLED device was; ITO/NPB(700 Å)/ADN: BCzVBi-7%:C545T-0.05%:DCJTB-0.1%(300 Å)/Bphen(300 Å)/Liq(20 Å)/Al(1200 Å) for mixing three primary colors. Luminous efficiency was 9.08 cd/A at 3.5 V and Commission Intenationale de L’eclairage (CIE{sub x,y}) coordinates of white emission was measured as (0.320, 0.338) at 8 V while simulated CIE{sub x,y} coordinates were (0.336, 0.324) via estimation from each dopant's PL spectrum. -- Highlights: • This paper observes single-emissive-layered white OLED using fluorescent dopants. • Electrical and optical properties are analyzed. • Color stability of white OLED is confirmed for new planar light source.

  15. New cyclometalated iridium(III) complex as a phosphorescent dopant in organic light emitting devices

    Science.gov (United States)

    Ivanov, P.; Tomova, R.; Petrova, P.; Stanimirov, S.; Petkov, I.

    2014-05-01

    A new cyclometalated iridium (III) bis[2-(4-chlorophenyl)benzothiazolato-N,C2]-acetylacetonate, (Cl-bt)2Ir(acac), was synthesized and identified by 1H NMR and elemental analysis. The application was studied of the new compound as a dopant in the hole transporting layer (HTL) of the following organic light emitting diode (OLED) structure: HTL/EL/ETL, where HTL was 4,4'-bis(9H-carbazol-9-yl)biphenyl (CBP) or N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD), incorporated in a poly(N-vinylcarbazole) (PVK) matrix; EL was an electroluminescent layer of bis(8-hydroxy-2-methylquinoline)-(4-phenylpheno-xy) aluminum (BAlq); and ETL was an electron-transporting layer of bis[2-(2-benzothiazoly) phenolato]zinc(II) (Zn(btz)2). We established that the electroluminescence spectra of the OLEDs at different dopant concentrations were basically the sum of the greenish-blue emission of BAlq and the yellowish-green emission of the Ir complex. It was also found that increasing the dopant concentration resulted in an increase in the relative electroluminescent intensity of the Ir complex emission, while that of BAlq decreased, thus a fine tuning of the OLED color was observed.

  16. n-Dopants Based on Dimers of Benzimidazoline Radicals: Structures and Mechanism of Redox Reactions

    KAUST Repository

    Zhang, Siyuan

    2015-06-18

    Dimers of 2-substituted N,N\\'-dimethylbenzimidazoline radicals, (2-Y-DMBI)2 (Y=cyclohexyl (Cyc), ferrocenyl (Fc), ruthenocenyl (Rc)), have recently been reported as n-dopants for organic semiconductors. Here their structural and energetic characteristics are reported, along with the mechanisms by which they react with acceptors, A (PCBM, TIPS-pentacene), in solution. X-ray data and DFT calculations both indicate a longer C-C bond for (2-Cyc-DMBI)2 than (2-Fc-DMBI)2, yet DFT and ESR data show that the latter dissociates more readily due to stabilization of the radical by Fc. Depending on the energetics of dimer (D2) dissociation and of D2-to-A electron transfer, D2 reacts with A to form D+ and A- by either of two mechanisms, differing in whether the first step is endergonic dissociation or endergonic electron transfer. However, the D+/0.5D2 redox potentials-the effective reducing strengths of the dimers-vary little within the series (ca. -1.9V vs. FeCp2+/0) (Cp=cyclopentadienyl) due to cancelation of trends in the D+/0 potential and D2 dissociation energy. The implications of these findings for use of these dimers as n-dopants, and for future dopant design, are discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Spectroscopic diagnostics of NIF ICF implosions using line ratios of Kr dopant in the ignition capsule

    Science.gov (United States)

    Dasgupta, Arati; Ouart, Nicholas; Giuiani, John; Clark, Robert; Schneider, Marilyn; Scott, Howard; Chen, Hui; Ma, Tammy

    2017-10-01

    X ray spectroscopy is used on the NIF to diagnose the plasma conditions in the ignition target in indirect drive ICF implosions. A platform is being developed at NIF where small traces of krypton are used as a dopant to the fuel gas for spectroscopic diagnostics using krypton line emissions. The fraction of krypton dopant was varied in the experiments and was selected so as not to perturb the implosion. Our goal is to use X-ray spectroscopy of dopant line ratios produced by the hot core that can provide a precise measurement of electron temperature. Simulations of the krypton spectra using a 1 in 104 atomic fraction of krypton in direct-drive exploding pusher with a range of electron temperatures and densities show discrepancies when different atomic models are used. We use our non-LTE atomic model with a detailed fine-structure level atomic structure and collisional-radiative rates to investigate the krypton spectra at the same conditions. Synthetic spectra are generated with a detailed multi-frequency radiation transport scheme from the emission regions of interest to analyze the experimental data with 0.02% Kr concentration and compare and contrast with the existing simulations at LLNL. Work supported by DOE/NNSA; Part of this work was also done under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  18. Electroluminescence of organic light-emitting diodes with an ultra-thin layer of dopant

    Energy Technology Data Exchange (ETDEWEB)

    Li Weizhi [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China); Yu Junsheng [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)], E-mail: jsyu@uestc.edu.cn; Wang, Tao [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China); Jiang, Yadong [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)], E-mail: jiangyd@uestc.edu.cn; Wei, Bangxiong [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)

    2008-03-15

    Conventional fluorescent dyes, i.e., 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), 5,12-dihydro-5,12-dimethylquino [2,3-b]acridine-7,14-dione (DMQA) and 5,6,11,12-tetraphenylnaphthacene (Rubrene), were used to investigate the performance of organic light-emitting diodes (OLEDs) based on indium tin oxide (ITO)/N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB)/tris-(8-hydroxyquinolate)-aluminum (Alq{sub 3})/MgAg. The dyes were either inserted into devices as an ultra-thin film at the NPB/Alq{sub 3} interface by sequential evaporation, or doped into the Alq{sub 3} emission layer by co-evaporation with the doping ratio about 2%. Electroluminescence (EL) spectra of devices indicated that concentration quenching effect (CQE) of the dye-dopant was slightly bigger in the former than in the latter, while the degrees of CQE for three dopants are in the order of DMQA > DCJTB > Rubrene suggested by the difference in EL spectra and performances of devices. In addition, EL process of device with an ultra-thin layer of dopant is dominated by direct carrier trapping (DCT) process due to almost no holes recombine with electrons in Alq{sub 3}-host layer.

  19. Nanoarchitectonics for Controlling the Number of Dopant Atoms in Solid Electrolyte Nanodots.

    Science.gov (United States)

    Nayak, Alpana; Unayama, Satomi; Tai, Seishiro; Tsuruoka, Tohru; Waser, Rainer; Aono, Masakazu; Valov, Ilia; Hasegawa, Tsuyoshi

    2018-02-01

    Controlling movements of electrons and holes is the key task in developing today's highly sophisticated information society. As transistors reach their physical limits, the semiconductor industry is seeking the next alternative to sustain its economy and to unfold a new era of human civilization. In this context, a completely new information token, i.e., ions instead of electrons, is promising. The current trend in solid-state nanoionics for applications in energy storage, sensing, and brain-type information processing, requires the ability to control the properties of matter at the ultimate atomic scale. Here, a conceptually novel nanoarchitectonic strategy is proposed for controlling the number of dopant atoms in a solid electrolyte to obtain discrete electrical properties. Using α-Ag 2+ δ S nanodots with a finite number of nonstoichiometry excess dopants as a model system, a theory matched with experiments is presented that reveals the role of physical parameters, namely, the separation between electrochemical energy levels and the cohesive energy, underlying atomic-scale manipulation of dopants in nanodots. This strategy can be applied to different nanoscale materials as their properties strongly depend on the number of doping atoms/ions, and has the potential to create a new paradigm based on controlled single atom/ion transfer. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Color optimization of single emissive white OLEDs via energy transfer between RGB fluorescent dopants

    International Nuclear Information System (INIS)

    Kim, Nam Ho; Kim, You-Hyun; Yoon, Ju-An; Lee, Sang Youn; Ryu, Dae Hyun; Wood, Richard; Moon, C.-B.; Kim, Woo Young

    2013-01-01

    The electroluminescent characteristics of white organic light-emitting diodes (WOLEDs) were investigated including single emitting layer (SEL) with an ADN host and dopants; BCzVBi, C545T, and DCJTB for blue, green and red emission, respectively. The structure of the high efficiency WOLED device was; ITO/NPB(700 Å)/ADN: BCzVBi-7%:C545T-0.05%:DCJTB-0.1%(300 Å)/Bphen(300 Å)/Liq(20 Å)/Al(1200 Å) for mixing three primary colors. Luminous efficiency was 9.08 cd/A at 3.5 V and Commission Intenationale de L’eclairage (CIE x,y ) coordinates of white emission was measured as (0.320, 0.338) at 8 V while simulated CIE x,y coordinates were (0.336, 0.324) via estimation from each dopant's PL spectrum. -- Highlights: • This paper observes single-emissive-layered white OLED using fluorescent dopants. • Electrical and optical properties are analyzed. • Color stability of white OLED is confirmed for new planar light source

  1. n-Dopants Based on Dimers of Benzimidazoline Radicals: Structures and Mechanism of Redox Reactions

    KAUST Repository

    Zhang, Siyuan; Naab, Benjamin D.; Jucov, Evgheni V.; Parkin, Sean; Evans, Eric G B; Millhauser, Glenn L.; Timofeeva, Tatiana V.; Risko, Chad; Bredas, Jean-Luc; Bao, Zhenan; Barlow, Stephen; Marder, Seth R.

    2015-01-01

    Dimers of 2-substituted N,N'-dimethylbenzimidazoline radicals, (2-Y-DMBI)2 (Y=cyclohexyl (Cyc), ferrocenyl (Fc), ruthenocenyl (Rc)), have recently been reported as n-dopants for organic semiconductors. Here their structural and energetic characteristics are reported, along with the mechanisms by which they react with acceptors, A (PCBM, TIPS-pentacene), in solution. X-ray data and DFT calculations both indicate a longer C-C bond for (2-Cyc-DMBI)2 than (2-Fc-DMBI)2, yet DFT and ESR data show that the latter dissociates more readily due to stabilization of the radical by Fc. Depending on the energetics of dimer (D2) dissociation and of D2-to-A electron transfer, D2 reacts with A to form D+ and A- by either of two mechanisms, differing in whether the first step is endergonic dissociation or endergonic electron transfer. However, the D+/0.5D2 redox potentials-the effective reducing strengths of the dimers-vary little within the series (ca. -1.9V vs. FeCp2+/0) (Cp=cyclopentadienyl) due to cancelation of trends in the D+/0 potential and D2 dissociation energy. The implications of these findings for use of these dimers as n-dopants, and for future dopant design, are discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Coupling of erbium dopants to yttrium orthosilicate photonic crystal cavities for on-chip optical quantum memories

    Energy Technology Data Exchange (ETDEWEB)

    Miyazono, Evan; Zhong, Tian; Craiciu, Ioana; Kindem, Jonathan M.; Faraon, Andrei, E-mail: faraon@caltech.edu [T. J. Watson Laboratory of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, California 91125 (United States)

    2016-01-04

    Erbium dopants in crystals exhibit highly coherent optical transitions well suited for solid-state optical quantum memories operating in the telecom band. Here, we demonstrate coupling of erbium dopant ions in yttrium orthosilicate to a photonic crystal cavity fabricated directly in the host crystal using focused ion beam milling. The coupling leads to reduction of the photoluminescence lifetime and enhancement of the optical depth in microns-long devices, which will enable on-chip quantum memories.

  3. Direct atomic fabrication and dopant positioning in Si using electron beams with active real-time image-based feedback

    Science.gov (United States)

    Jesse, Stephen; Hudak, Bethany M.; Zarkadoula, Eva; Song, Jiaming; Maksov, Artem; Fuentes-Cabrera, Miguel; Ganesh, Panchapakesan; Kravchenko, Ivan; Snijders, Panchapakesan C.; Lupini, Andrew R.; Borisevich, Albina Y.; Kalinin, Sergei V.

    2018-06-01

    Semiconductor fabrication is a mainstay of modern civilization, enabling the myriad applications and technologies that underpin everyday life. However, while sub-10 nanometer devices are already entering the mainstream, the end of the Moore’s law roadmap still lacks tools capable of bulk semiconductor fabrication on sub-nanometer and atomic levels, with probe-based manipulation being explored as the only known pathway. Here we demonstrate that the atomic-sized focused beam of a scanning transmission electron microscope can be used to manipulate semiconductors such as Si on the atomic level, inducing growth of crystalline Si from the amorphous phase, reentrant amorphization, milling, and dopant front motion. These phenomena are visualized in real-time with atomic resolution. We further implement active feedback control based on real-time image analytics to automatically control the e-beam motion, enabling shape control and providing a pathway for atom-by-atom correction of fabricated structures in the near future. These observations open a new epoch for atom-by-atom manufacturing in bulk, the long-held dream of nanotechnology.

  4. Direct atomic fabrication and dopant positioning in Si using electron beams with active real-time image-based feedback.

    Science.gov (United States)

    Jesse, Stephen; Hudak, Bethany M; Zarkadoula, Eva; Song, Jiaming; Maksov, Artem; Fuentes-Cabrera, Miguel; Ganesh, Panchapakesan; Kravchenko, Ivan; Snijders, Panchapakesan C; Lupini, Andrew R; Borisevich, Albina Y; Kalinin, Sergei V

    2018-06-22

    Semiconductor fabrication is a mainstay of modern civilization, enabling the myriad applications and technologies that underpin everyday life. However, while sub-10 nanometer devices are already entering the mainstream, the end of the Moore's law roadmap still lacks tools capable of bulk semiconductor fabrication on sub-nanometer and atomic levels, with probe-based manipulation being explored as the only known pathway. Here we demonstrate that the atomic-sized focused beam of a scanning transmission electron microscope can be used to manipulate semiconductors such as Si on the atomic level, inducing growth of crystalline Si from the amorphous phase, reentrant amorphization, milling, and dopant front motion. These phenomena are visualized in real-time with atomic resolution. We further implement active feedback control based on real-time image analytics to automatically control the e-beam motion, enabling shape control and providing a pathway for atom-by-atom correction of fabricated structures in the near future. These observations open a new epoch for atom-by-atom manufacturing in bulk, the long-held dream of nanotechnology.

  5. Self-assembling nano-diameter needlelike pinning centers in YBCO, utilizing a foreign element dopant

    Energy Technology Data Exchange (ETDEWEB)

    Sawh, Ravi-Persad [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States); Weinstein, Roy [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States); Obot, Victor [Department of Mathematics, Texas Southern University, 3100 Cleburne St, Houston Texas 77004-4597 (United States); Parks, Drew [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States); Gandini, Alberto [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States); Skorpenske, Harley [Texas Center for Superconductivity and Physics Department, University of Houston, 632 Science and Research Bldg 1, Houston Texas 77204-5005 (United States)

    2006-06-01

    Although pinning centers created by irradiation presently produce the highest J{sub c}, it is probable that ultimately these will be emulated by chemical pinning centers. The best pinning centers produced by irradiation nevertheless provide guidelines for desirable morphology of chemical pinning structures. The highest J{sub c} produced earlier in textured HTS was obtained using isotropic high-energy ions produced by fission of {sup 235}U. This so-called U/n process produces pinning centers of diameter {<=} 4.5 nm, with an effective length of {approx}2.7 {mu}m. Maximum J{sub c} occurs for pinning center density of {approx}10{sup 10} cm{sup -3}. We use this as a model for desired chemical pinning centers. Our approach to introducing chemical pinning centers has been to produce precipitates within the HTS containing elements not native to the HTS, and to seek needlelike (columnar) deposits of small diameter. We report here on the formation of needlelike or columnar deposits in textured Y123 containing a dopant foreign to Y123. It serves as a demonstration that self-assembling nanometer diameter columns utilizing a dopant foreign to the HTS system are a feasible goal. These deposits, however, do not fully meet the ultimate requirements of pinning centers because the desired deposits should be smaller. The self-assembling columns formed contain titanium, are {approx}500 nm in diameter, and up to 10 {mu}m long. The size and morphology of the deposits vary with the mass of admixed Ti dopant. J{sub c} is decreased for small dopant mass. At larger dopant masses needlelike precipitates form, and J{sub c} increases again. A small range of mass of admixed Ti exists in which J{sub c} is enhanced by pinning. In the range of admixed Ti mass studied in these experiments there is a negligible effect on T{sub c}. Magnetization studies of J{sub c} are also reported.

  6. Improved optical properties and detectivity of an uncooled silicon carbide mid-wave infrared optical detector with increased dopant concentration

    International Nuclear Information System (INIS)

    Lim, Geunsik; Kar, Aravinda; Manzur, Tariq

    2012-01-01

    An n-type 4H-SiC substrate is doped with gallium using a laser doping technique and its optical response is investigated at the mid-wave infrared (MWIR) wavelength 4.21 μm as a function of the dopant concentration. The dopant creates a p-type energy level of 0.3 eV, which is the energy of a photon corresponding to the MWIR wavelength 4.21 μm. Therefore, Ga-doped SiC can be used as an uncooled MWIR detector because an optical signal was obtained at this wavelength when the sample was at room temperature. The energy level of the Ga dopant in the substrate was confirmed by optical absorption spectroscopy. Secondary ion mass spectroscopy (SIMS) of the doped samples revealed an enhancement in the solid solubility of Ga in the substrate when doping is carried out by increasing the number of laser scans. A higher dopant concentration increases the number of holes in the dopant energy level, enabling photoexcitation of more electrons from the valence band by the incident MWIR photons. The detector performance improves as the dopant concentration increases from 1.15 × 10 19 to 6.25 × 10 20 cm −3 . The detectivity of the optical photodetector is found to be 1.07 × 10 10 cm Hz 1/2 W −1 for the case of doping with four laser passes. (paper)

  7. Topical Mannitol Reduces Capsaicin-Induced Pain: Results of a Pilot-Level, Double-Blind, Randomized Controlled Trial.

    Science.gov (United States)

    Bertrand, Helene; Kyriazis, Marylene; Reeves, K Dean; Lyftogt, John; Rabago, David

    2015-11-01

    Capsaicin specifically activates, and then gradually exhausts, the transient receptor potential vanilloid type 1 (TRPV1) receptor, a key receptor in neuropathic pain. Activation of the TRPV-1 receptor is accompanied by burning pain. A natural substance or medication that can reduce the burning pain resulting from capsaicin application may have therapeutic potential in neuropathic pain. To assess the pain-relieving effects of a mannitol-containing cream in a capsaicin-based pain model. Randomized, placebo-controlled, double-blind clinical trial. Outpatient pain clinic. Twenty-five adults with pain-free lips. Capsaicin .075% cream was applied to both halves of each participant's upper lip, inducing pain via stimulation of the transient receptor potential vanilloid 1 (TRPV1, capsaicin) receptor, then removed after 5 minutes or when participants reported a burning pain of 8/10, whichever came first. A cream containing mannitol and the same cream without mannitol (control) were then immediately applied, 1 on each side of the lip, in an allocation-masked manner. Participants self-recorded a numeric rating scale (NRS, 0-10) pain score for each side of the lip per minute for 10 minutes. A t-test was performed to evaluate the pain score change from baseline between each side of the lip at each recording. Area under the curve (AUC) analysis was used to determine the overall difference between groups. Participants reached a capsaicin-induced pain level of 7.8 ± 1.0 points in 3.3 ± 1.6 minutes that was equal on both sides of the lip. Both groups reported progressive diminution of pain over the 10-minute study period. However, participants reported significantly reduced pain scores on the mannitol cream half-lip compared to control at 3 through 10 minutes (P < .05) and in AUC analysis (P < .001). Mannitol cream reduced self-reported pain scores in a capsaicin pain model more rapidly than a control cream, potentially via a TRPV1 receptor effect. Copyright © 2015 American

  8. Can ginger ameliorate chemotherapy-induced nausea? Protocol of a randomized double blind, placebo-controlled trial.

    Science.gov (United States)

    Marx, Wolfgang; McCarthy, Alexandra L; Ried, Karin; Vitetta, Luis; McKavanagh, Daniel; Thomson, Damien; Sali, Avni; Isenring, Liz

    2014-04-09

    Preliminary research shows ginger may be an effective adjuvant treatment for chemotherapy-induced nausea and vomiting but significant limitations need to be addressed before recommendations for clinical practice can be made. In a double-blinded randomised-controlled trial, chemotherapy-naïve patients will be randomly allocated to receive either 1.2 g of a standardised ginger extract or placebo per day. The study medication will be administrated as an adjuvant treatment to standard anti-emetic therapy and will be divided into four capsules per day, to be consumed approximately every 4 hours (300 mg per capsule administered q.i.d) for five days during the first three cycles of chemotherapy. Acute, delayed, and anticipatory symptoms of nausea and vomiting will be assessed over this time frame using a valid and reliable questionnaire, with nausea symptoms being the primary outcome. Quality of life, nutritional status, adverse effects, patient adherence, cancer-related fatigue, and CINV-specific prognostic factors will also be assessed. Previous trials in this area have noted limitations. These include the inconsistent use of standardized ginger formulations and valid questionnaires, lack of control for anticipatory nausea and prognostic factors that may influence individual CINV response, and the use of suboptimal dosing regimens. This trial is the first to address these issues by incorporating multiple unique additions to the study design including controlling for CINV-specific prognostic factors by recruiting only chemotherapy-naïve patients, implementing a dosing schedule consistent with the pharmacokinetics of oral ginger supplements, and independently analysing ginger supplements before and after recruitment to ensure potency. Our trial will also be the first to assess the effect of ginger supplementation on cancer-related fatigue and nutritional status. Chemotherapy-induced nausea and vomiting are distressing symptoms experienced by oncology patients; this

  9. Prevention of contrast-induced nephropathy with single bolus erythropoietin in patients with diabetic kidney disease: A randomized controlled trial.

    Science.gov (United States)

    Shema-Didi, Lilach; Kristal, Batya; Eizenberg, Sarit; Marzuq, Nabil; Sussan, Majdy; Feldman-Idov, Yulie; Ofir, Pnina; Atar, Shaul

    2016-04-01

    Contrast-induced-nephropathy (CIN) is associated with poor outcomes, thus prevention of CIN may be of clinical value. Erythropoietin (EPO) has been shown to elicit tissue-protective effects in experimental models and in clinical studies of acute kidney injury. We therefore evaluated its effectiveness for prevention of CIN after coronary angiography (CA) ± percutaneous coronary intervention (PCI) in diabetic patients with chronic kidney disease. A prospective, randomized, controlled trial was carried out in 138 diabetic patients with eGFR <60 mL/min who underwent non-urgent CA ± PCI. Patients received normal saline and n-acetyl cysteine before CA, with or without 50,000 U of EPO administered 30 min prior to CA. CIN was defined as an increase in serum creatinine of at least 0.5 mg/dL during the first 2 days after exposure to contrast media. Primary outcome was the incidence of CIN. Secondary outcomes were the sensitivity and positive predictive value (PPV) of Cystatin C (CC) and Neutrophil-gelatinase-associated-lipocalin (NGAL) for diagnosis of CIN. The observed incidence of CIN was 8.7%, significantly lower than the expected for such high-risk population. The administration of EPO prior to CA did not reduce the incidence of CIN (9.7% vs. 7.6%, P = 0.65). CC and NGAL demonstrated a low sensitivity (16.6%) and low PPV (6.7 and 33.3%, respectively) for detecting CIN. The administration of EPO prior to CA did not reduce the incidence of CIN. Additional prospective research with a larger sample size and in other patient categories is essential to further define the potential protective effect of EPO on prevention of CIN. © 2015 Asian Pacific Society of Nephrology.

  10. Pre- and postoperative dexamethasone does not reduce bleaching-induced tooth sensitivity: A randomized, triple-masked clinical trial.

    Science.gov (United States)

    Rezende, Márcia; Bonafé, Elize; Vochikovski, Laína; Farago, Paulo Vitor; Loguercio, Alessandro Dourado; Reis, Alessandra; Kossatz, Stella

    2016-01-01

    Tooth sensitivity (TS) is the most common side effect of dental bleaching therapies. Dexamethasone has been used with tooth bleaching to reduce TS. The efficacy of dexamethasone for this purpose has not been well studied. The authors conducted a triple-masked, randomized, clinical trial with a parallel design involving 63 healthy participants who received either a placebo or dexamethasone. The placebo or dexamethasone (8 milligrams) was administered 1 hour before the in-office bleaching (35% hydrogen peroxide) and extra doses of 4 mg were administered every 6 hours for a total of 48 hours. TS was recorded on 2 scales: visual analog scale (0-10) and numeric rating scale (0-4) in different periods. The color evaluations were performed before and 1 month after dental bleaching with visual shade guides VITA Classical (VITA Zahnfabrik) and VITA Bleachedguide 3D-MASTER (VITA Zahnfabrik), and for a shade guide evaluation, the authors used a digital spectrophotometer, VITA Easyshade (VITA Zahnfabrik). The absolute risk of TS was evaluated by a Fisher exact test. Data of TS intensity using the NRS scale for the 2 groups were compared with Mann-Whitney and Friedman tests, whereas data from the visual analog scale were evaluated by 2-way repeated measures analysis of variance. The color changes between groups were compared using a t test (α = .05). In both groups, the authors detected a high risk of TS, which was approximately 90%. No significant difference was observed in terms of TS intensity. A whitening of approximately 3 shade guide units of the VITA Classical was detected in both groups, which were statistically similar. The use of dexamethasone before bleaching did not reduce the risk and intensity of bleaching-induced TS. The use of the steroidal anti-inflammatory agent dexamethasone was not capable of preventing TS arising from in-office dental bleaching. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  11. A randomized prospective study of rehabilitation therapy in the treatment of radiation-induced dysphagia and trismus

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Y.; Shen, Q.; Lu, K.; Peng, Y. [Sun Yat-sen Univ., Guangzhou (China). Dept. of Neurology; Wang, Y. [Sun Yat-sen Univ., Guangzhou (China). Dept. of Internal Medicine; Wang, Y. [Sun Yat-sen Univ., Guangzhou (China). Dept. of Neurosurgery

    2011-01-15

    Purpose: To evaluate the therapeutic effect of rehabilitation therapy on radiation-induced dysphagia and trismus in nasopharyngeal carcinoma (NPC) patients after radiotherapy. Patients and Methods: 43 NPC patients after radiotherapy were included. Patients were randomly assigned to either the rehabilitation group or a control group. Both groups were subjected to routine treatment, while the rehabilitation group also received rehabilitation therapy for 3 months. The severity of dysphagia was assessed using the water swallow test, while trismus was evaluated with the LENT/SOMA score and the interincisor distance (IID). The water swallow test, the LENT/SOMA score, as well as IID for both groups before and after treatment were analyzed and compared. Results: After treatment, the rehabilitation group displayed a significant improvement in swallowing function, while the control group did not. The efficacy rate (percentage of patients with excellent or effective results) of rehabilitation group was higher than that of control group (77% vs. 43%), and the difference was statistically significant ({chi}{sup 2} = 5.32, p = 0.02). IID pretreatment and posttreatment did not show much difference in the rehabilitation group, while in the control group IID significantly decreased posttreatment (1.1 {+-} 0.36 cm vs.1.8 {+-} 0.56 cm, p = 0.001). Although the mean IID in patients of both groups decreased after the 3 month follow-up, the decrease in the rehabilitation group was less than that of the control group (0.19 {+-} 0.5 cm vs. 0.69 {+-} 0.56 cm, p = 0.004). The efficacy rate of trismus in the rehabilitation group was significantly higher than that of the control group (64% vs. 28%, {chi}{sup 2} = 5.31, p = 0.02). Conclusions: Rehabilitation training can improve swallow function and slow down the progress of trismus in NPC patients following radiotherapy. (orig.)

  12. A randomized prospective study of rehabilitation therapy in the treatment of radiation-induced dysphagia and trismus

    International Nuclear Information System (INIS)

    Tang, Y.; Shen, Q.; Lu, K.; Peng, Y.; Wang, Y.; Wang, Y.

    2011-01-01

    Purpose: To evaluate the therapeutic effect of rehabilitation therapy on radiation-induced dysphagia and trismus in nasopharyngeal carcinoma (NPC) patients after radiotherapy. Patients and Methods: 43 NPC patients after radiotherapy were included. Patients were randomly assigned to either the rehabilitation group or a control group. Both groups were subjected to routine treatment, while the rehabilitation group also received rehabilitation therapy for 3 months. The severity of dysphagia was assessed using the water swallow test, while trismus was evaluated with the LENT/SOMA score and the interincisor distance (IID). The water swallow test, the LENT/SOMA score, as well as IID for both groups before and after treatment were analyzed and compared. Results: After treatment, the rehabilitation group displayed a significant improvement in swallowing function, while the control group did not. The efficacy rate (percentage of patients with excellent or effective results) of rehabilitation group was higher than that of control group (77% vs. 43%), and the difference was statistically significant (χ 2 = 5.32, p = 0.02). IID pretreatment and posttreatment did not show much difference in the rehabilitation group, while in the control group IID significantly decreased posttreatment (1.1 ± 0.36 cm vs.1.8 ± 0.56 cm, p = 0.001). Although the mean IID in patients of both groups decreased after the 3 month follow-up, the decrease in the rehabilitation group was less than that of the control group (0.19 ± 0.5 cm vs. 0.69 ± 0.56 cm, p = 0.004). The efficacy rate of trismus in the rehabilitation group was significantly higher than that of the control group (64% vs. 28%, χ 2 = 5.31, p = 0.02). Conclusions: Rehabilitation training can improve swallow function and slow down the progress of trismus in NPC patients following radiotherapy. (orig.)

  13. Sensory trigeminal ULF-TENS stimulation reduces HRV response to experimentally induced arithmetic stress: A randomized clinical trial.

    Science.gov (United States)

    Monaco, Annalisa; Cattaneo, Ruggero; Ortu, Eleonora; Constantinescu, Marian Vladimir; Pietropaoli, Davide

    2017-05-01

    Ultra Low Frequency Transcutaneous Electric Nervous Stimulation (ULF-TENS) is extensively used for pain relief and for the diagnosis and treatment of temporomandibular disorders (TMD). In addition to its local effects, ULF-TENS acts on the autonomic nervous system (ANS), with particular reference to the periaqueductal gray (PAG), promoting the release of endogenous opioids and modulating descending pain systems. It has been suggested that the PAG participates in the coupling between the emotional stimulus and the appropriate behavioral autonomic response. This function is successfully investigated by HRV. Therefore, our goal is to investigate the effects of trigeminal ULF-TENS stimulation on autonomic behavior in terms of HRV and respiratory parameters during an experimentally-induced arithmetic stress test in healthy subjects. Thirty healthy women between 25 and 35years of age were enrolled and randomly assigned to either the control (TENS stimulation off) or test group (TENS stimulation on). Heart (HR, LF, HF, LF/HF ratio, DET, RMSSD, PNN50, RR) and respiratory (BR) rate were evaluated under basal, T1 (TENS off/on), and stress (mathematical task) conditions. Results showed that HRV parameters and BR significantly changed during the arithmetic stress paradigm (pTENS and control group could be discriminated only by non-linear HRV data, namely RR and DET (p=0.038 and p=0.027, respectively). During the arithmetic task, LF/HF ratio was the most sensitive parameter to discriminate between groups (p=0.019). Our data suggest that trigeminal sensory ULF-TENS reduces the autonomic response in terms of HRV and BR during acute mental stress in healthy subjects. Future directions of our work aim at applying the HRV and BR analysis, with and without TENS stimulation, to individuals with dysfunctional ANS among those with TMD. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Study to assess the effectiveness of modified constraint-induced movement therapy in stroke subjects: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Priyanka Singh

    2013-01-01

    Full Text Available Background and Purpose: The purpose of this study was to assess the effectiveness of modified constraint induced movement therapy (m-CIMT in stroke subjects. Materials and Methods: A total of forty sub-acute stroke subjects were randomly assigned to either a m-CIMT (n = 20 or in a control group (n = 20. The m-CIMT group (14 men, 6 women; mean age = 55.2 years consisted of structured 2 h therapy sessions emphasizing affected arm use, occurring 5 times/week for 2 weeks. A mitt was used to restrain the unaffected arm for 10 h/day for 2 week. The control group (11 men, 9 women; mean age = 56.4 years consisted of conventional rehabilitation for time-matched exercise program. The outcome measures were evaluated at pre- and post-intervention by using the Wolf Motor Function Test (WMFT and Fugl-Meyer assessment (FMA of motor recovery after stroke. Results: After intervention significant effects were observed in m-CIMT group on WMFT (pre-test and post-test score was 28.04 ± 6.58, 13.59 ± 2.86; P =0.003. Similarly on FMA (pre- and post-test score was 31.15 ± 6.37, 55.7 ± 6.4; P = 0.00. Conclusion: There is a significant improvem ent in upper extremity function so it indicates that m-CIMT is effective in improving the motor function of the affected arm in stroke subjects. However, its long-term effect has not proved since there was no follow-up after intervention.

  15. Randomized control trial of benzydamine HCl versus sodium bicarbonate for prophylaxis of concurrent chemoradiation-induced oral mucositis.

    Science.gov (United States)

    Chitapanarux, Imjai; Tungkasamit, Tharatorn; Petsuksiri, Janjira; Kannarunimit, Danita; Katanyoo, Kanyarat; Chakkabat, Chakkapong; Setakornnukul, Jiraporn; Wongsrita, Somying; Jirawatwarakul, Naruemon; Lertbusayanukul, Chawalit; Sripan, Patumrat; Traisathit, Patrinee

    2018-03-01

    The purpose of the study is to compare the efficacy of benzydamine HCl with sodium bicarbonate in the prevention of concurrent chemoradiation-induced oral mucositis in head and neck cancer patients. Sixty locally advanced head and neck cancer patients treated with high-dose radiotherapy concurrently with platinum-based chemotherapy were randomly assigned to receive either benzydamine HCl or sodium bicarbonate from the first day of treatment to 2 weeks after the completion of treatment. The total score for mucositis, based on the Oral Mucositis Assessment Scale (OMAS), was used for the assessment, conducted weekly during the treatment period and at the fourth week of the follow-up. Pain score, all prescribed medications, and tube feeding needs were also recorded and compared. The median of total OMAS score was statistically significant lower in patients who received benzydamine HCl during concurrent chemo-radiotherapy (CCRT) than in those who received sodium bicarbonate, (p value < 0.001). There was no difference in median pain score, (p value = 0.52). Nineteen percent of patients in sodium bicarbonate arm needed oral antifungal agents whereas none in the benzydamine HCl arm required such medications, (p value = 0.06). Tube feeding needs and the compliance of CCRT were not different between the two study arms. For patients undergoing high-dose radiotherapy concurrently with platinum-based chemotherapy, using benzydamine HCl mouthwash as a preventive approach was superior to basic oral care using sodium bicarbonate mouthwash in terms of reducing the severity of oral mucositis and encouraging trend for the less need of oral antifungal drugs.

  16. Study of the chlorine as dopant in synthesized polymers by plasma; Estudio del cloro como dopante en polimeros sintetizados por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.; Cruz, G.; Olayo, M.G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Timoshina, T. [ESIQIE, IPN, 07738 Mexico D.F. (Mexico); Morales, J.; Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    In the search of new and better dopants for semiconductor polymers, in this work the synthesis by plasma and the characterization of two doped polymers with chlorine, Pyrrole (PPy) and Thiophene (PTh) is presented. The characterization of the polymers it was carried out by FT-lR, it shows the C-Cl vibration that it is confirmed with the X-ray photoelectron spectroscopy technique (XPS). The elementary analysis shows a greater quantity of Cl in the PTh-CI compared with PPy-CI. However, this effect is not reflected in the electric conductivity since the PTh-Cl presents a lightly greater conductivity than the PPy-CI. SEM shows a formed structure of small agglomerated spheres of different size. (Author)

  17. Muscle Recruitment and Coordination following Constraint-Induced Movement Therapy with Electrical Stimulation on Children with Hemiplegic Cerebral Palsy: A Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Kaishou Xu

    Full Text Available To investigate changes of muscle recruitment and coordination following constraint-induced movement therapy, constraint-induced movement therapy plus electrical stimulation, and traditional occupational therapy in treating hand dysfunction.In a randomized, single-blind, controlled trial, children with hemiplegic cerebral palsy were randomly assigned to receive constraint-induced movement therapy (n = 22, constraint-induced movement therapy plus electrical stimulation (n = 23, or traditional occupational therapy (n = 23. Three groups received a 2-week hospital-based intervention and a 6-month home-based exercise program following hospital-based intervention. Constraint-induced movement therapy involved intensive functional training of the involved hand during which the uninvolved hand was constrained. Electrical stimulation was applied on wrist extensors of the involved hand. Traditional occupational therapy involved functional unimanual and bimanual training. All children underwent clinical assessments and surface electromyography (EMG at baseline, 2 weeks, 3 and 6 months after treatment. Surface myoelectric signals were integrated EMG, root mean square and cocontraction ratio. Clinical measures were grip strength and upper extremity functional test.Constraint-induced movement therapy plus electrical stimulation group showed both a greater rate of improvement in integrated EMG of the involved wrist extensors and cocontraction ratio compared to the other two groups at 3 and 6 months, as well as improving in root mean square of the involved wrist extensors than traditional occupational therapy group (p<0.05. Positive correlations were found between both upper extremity functional test scores and integrated EMG of the involved wrist as well as grip strength and integrated EMG of the involved wrist extensors (p<0.05.Constraint-induced movement therapy plus electrical stimulation is likely to produce the best outcome in improving muscle recruitment

  18. Rationale and design of a randomized double-blind clinical trial in breast cancer: dextromethorphan in chemotherapy-induced peripheral neuropathy.

    Science.gov (United States)

    Martin, Elodie; Morel, Véronique; Joly, Dominique; Villatte, Christine; Delage, Noémie; Dubray, Claude; Pereira, Bruno; Pickering, Gisèle

    2015-03-01

    Anti-cancer chemotherapy often induces peripheral neuropathy and consequent cognitive and quality of life impairment. Guidelines recommend antiepileptics or antidepressants but their efficacy is limited.Dextromethorphan, a N-methyl-D-aspartate receptor antagonist, has shown its efficacy in painful diabetic neuropathy and in post-operative pain but has not been studied in chemotherapy-induced peripheral neuropathy. This clinical trial evaluates the effect of dextromethorphan on pain, cognition and quality of life in patients who suffer from neuropathic pain induced by chemotherapy for breast cancer. It also assesses the impact of dextromethorphan genetic polymorphism on analgesia. This trial is a randomized, placebo-controlled, double-blind clinical study in two parallel groups (NCT02271893). It includes 40 breast cancer patients suffering from chemotherapy-induced peripheral neuropathy. They are randomly allocated to dextromethorphan (maximal dose 90 mg/day) or placebo for 4 weeks. The primary endpoint is pain intensity measured after 4 weeks of treatment on a (0-10) Numeric Pain Rating Scale. Secondary outcomes include assessment of neuropathic pain, cognitive function, anxiety/depression, sleep and quality of life. Data analysis is performed using mixed models and the tests are two-sided, with a type I error set at α=0.05. Considering the poor efficacy of available drugs in chemotherapy-induced neuropathic pain, dextromethorphan may be a valuable therapeutic option. Pharmacogenetics may provide predictive factors of dextromethorphan response in patients suffering from breast cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. The Effects of the Bali Yoga Program for Breast Cancer Patients on Chemotherapy-Induced Nausea and Vomiting: Results of a Partially Randomized and Blinded Controlled Trial.

    Science.gov (United States)

    Anestin, Annélie S; Dupuis, Gilles; Lanctôt, Dominique; Bali, Madan

    2017-10-01

    Complementary and alternative medicine has been shown to be beneficial in reducing chemotherapy-induced nausea and vomiting. However, conclusive results are lacking in order to confirm its usefulness. The purpose of this study was to determine whether a standardized yoga intervention could reduce these adverse symptoms. This was a partially randomized and blinded controlled trial comparing a standardized yoga intervention with standard care. Eligible patients were adults diagnosed with stages I to III breast cancer receiving chemotherapy. Patients randomized to the experimental group participated in an 8-week yoga program. There was no significant difference between the experimental and control groups on chemotherapy-induced nausea and vomiting after 8 weeks. Results suggest the yoga program is not beneficial in managing these adverse symptoms. However, considering preliminary evidence suggesting yoga's beneficial impact in cancer symptom management, methodological limitations should be explored and additional studies should be conducted.

  20. Modulation of the acidity of niobic acid by ion-doping: Effects of nature and amount of the dopant ions

    Energy Technology Data Exchange (ETDEWEB)

    Carniti, Paolo [Dipartimento di Chimica, Università degli Studi di Milano (UNIMI), Milano (Italy); Gervasini, Antonella, E-mail: antonella.gervasini@unimi.it [Dipartimento di Chimica, Università degli Studi di Milano (UNIMI), Milano (Italy); Marzo, Matteo [Dipartimento di Chimica, Università degli Studi di Milano (UNIMI), Milano (Italy); Auroux, Aline [Université Lyon 1, CNRS, UMR 5256, (IRCELYON), Villeurbanne (France)

    2013-09-10

    Highlights: ► Mitigation of the surface acidity of niobic acid was pursued by K-, Ba-, and Nd-doping. ► Thermal techniques of study were effective for the acidity study. ► The nature of the dopant influences the effectiveness of the acidity tuning of niobic acid. ► The acidity of the doped surfaces decreased with increasing the dopant species added to niobic acid. ► The samples showed different acidity when measured in gas–solid phase (intrinsic acidity) and water (effective acidity). - Abstract: The acidity of niobic acid (NBO) has been successfully mitigated and tuned by addition of K{sup +}, Ba{sup 2+} and Nd{sup 3+} dopant species in amounts from 1 to 15 atom nm{sup −2}. The characterization of the intrinsic acid properties of the samples was performed by adsorption of NH{sub 3} in a volumetric–microcalorimetric coupled line and by temperature programmed desorption (TPD) of 2-phenylethylamine in a thermogravimetric apparatus. The K-dopant was more effective in decreasing the acidity of niobic acid than the Ba- and Nd-dopants. Complementary measurements of the effective acidity of the samples in water by base titrations with 2-phenylethylamine completed the study and revealed a different picture of the effect of the three dopants on the NBO acidity in water. All the results indicated that the K-dopant targeted more selectively the Brønsted acid sites, acting as an ion-exchanger, while Ba- and Nd-species predominantly acted on the Lewis acid sites of the NBO surface.

  1. Comparative study of effects of Mo and W dopants on the ferroelectric property of Pb(Zr0.3Ti0.7) thin films

    International Nuclear Information System (INIS)

    Zhang Zhen; Wang Shijie; Lu Li; Shu Chang; Song Wendong; Wu Ping

    2008-01-01

    Pb(Zr 0.3 Ti 0.7 )O 3 thin films, respectively, doped with 1 mol% W and 1 mol% Mo have been deposited on the LaNiO 3 bottom electrodes using pulse laser deposition. The x-ray diffraction analyses revealed that both dopants induced (1 1 0) orientation of the perovskite structures. Compared with the undoped PZT films, the doped PZT films showed smoother and denser surfaces. The XPS measurements indicated that W possessed a valence state of +6 in the PZTW films, but Mo showed mixed valence states of +4 and +6. The hysteresis loops and fatigue results of the undoped, the W-doped (PZTW) and the Mo-doped PZT (PZTM) films were obtained. While both the two doped films revealed better fatigue behaviour than undoped PZT, the PZTW film had a slow fatigue rate in comparison with the PZTM film, which is consistent with our previous theoretical predictions

  2. Exciton-dopant and exciton-charge interactions in electronically doped OLEDs

    International Nuclear Information System (INIS)

    Williams, Christopher; Lee, Sergey; Ferraris, John; Zakhidov, A. Anvar

    2004-01-01

    The electronic dopants, like tetrafluorocyanoquinodimethane (F 4 -TCNQ) molecules, used for p-doping of hole transport layers in organic light-emitting diodes (OLEDs) are found to quench the electroluminescence (EL) if they diffuse into the emissive layer. We observed EL quenching in OLED with F 4 -TCNQ doped N,N'-diphenyl-N'N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine hole transport layer at large dopant concentrations, >5%. To separate the effects of exciton-dopant quenching, from exciton-polaron quenching we have intentionally doped the emissive layer of (8-tris-hydroxyquinoline) with three acceptors (A) of different electron affinities: F 4 -TCNQ, TCNQ, and C 60 , and found that C 60 is the strongest EL-quencher, while F 4 -TCNQ is the weakest, contrary to intuitive expectations. The new effects of charge transfer and usually considered energy transfer from exciton to neutral (A) and charged acceptors (A - ) are compared as channels for non-radiative Ex-A decay. At high current loads the EL quenching is observed, which is due to decay of Ex on free charge carriers, hole polarons P + . We consider contributions to Ex-P + interaction by short-range charge transfer and describe the structure of microscopic charge transfer (CT)-processes responsible for it. The formation of metastable states of 'charged excitons' (predicted and studied by Agranovich et al. Chem. Phys. 272 (2001) 159) by electron transfer from a P to an Ex is pointed out, and ways to suppress non-radiative Ex-P decay are suggested

  3. Prospective randomized trial of enoxaparin, pentoxifylline and ursodeoxycholic acid for prevention of radiation-induced liver toxicity.

    Directory of Open Access Journals (Sweden)

    Max Seidensticker

    Full Text Available Targeted radiotherapy of liver malignancies has found to be effective in selected patients. A key limiting factor of these therapies is the relatively low tolerance of the liver parenchyma to radiation. We sought to assess the preventive effects of a combined regimen of pentoxifylline (PTX, ursodeoxycholic acid (UDCA and low-dose low molecular weight heparin (LMWH on focal radiation-induced liver injury (fRILI.Patients with liver metastases from colorectal carcinoma who were scheduled for local ablation by radiotherapy (image-guided high-dose-rate interstitial brachytherapy were prospectively randomized to receive PTX, UDCA and LMWH for 8 weeks (treatment or no medication (control. Focal RILI at follow-up was assessed using functional hepatobiliary magnetic resonance imaging (MRI. A minimal threshold dose, i.e. the dose to which the outer rim of the fRILI was formerly exposed to, was quantified by merging MRI and dosimetry data.Results from an intended interim-analysis made a premature termination necessary. Twenty-two patients were included in the per-protocol analysis. Minimal mean hepatic threshold dose 6 weeks after radiotherapy (primary endpoint was significantly higher in the study treatment-group compared with the control (19.1 Gy versus 14.6 Gy, p = 0.011. Qualitative evidence of fRILI by MRI at 6 weeks was observed in 45.5% of patients in the treatment versus 90.9% of the control group. No significant differences between the groups were observed at the 12-week follow-up.The post-therapeutic application of PTX, UDCA and low-dose LMWH significantly reduced the extent and incidence fRILI at 6 weeks after radiotherapy. The development of subsequent fRILI at 12 weeks (4 weeks after cessation of PTX, UDCA and LMWH during weeks 1-8 in the treatment group was comparable to the control group thus supporting the observation that the agents mitigated fRILI.EU clinical trials register 2008-002985-70 ClinicalTrials.gov NCT01149304.

  4. Interactive Sensor-Based Balance Training in Older Cancer Patients with Chemotherapy-Induced Peripheral Neuropathy: A Randomized Controlled Trial.

    Science.gov (United States)

    Schwenk, Michael; Grewal, Gurtej S; Holloway, Dustin; Muchna, Amy; Garland, Linda; Najafi, Bijan

    2016-01-01

    Cancer patients with chemotherapy-induced peripheral neuropathy (CIPN) have deficits in sensory and motor skills leading to inappropriate proprioceptive feedback, impaired postural control, and fall risk. Balance training programs specifically developed for CIPN patients are lacking. This pilot study investigated the effect of an interactive motor adaptation balance training program based on wearable sensors for improving balance in older cancer patients with CIPN. Twenty-two patients (age: 70.3 ± 8.7 years) with objectively confirmed CIPN [vibration perception threshold (VPT) >25 V] were randomized to either an intervention (IG) or a control (CG) group. The IG received interactive game-based balance training including repetitive weight shifting and virtual obstacle crossing tasks. Wearable sensors provided real-time visual/auditory feedback from the lower limb trajectory and allowed the perception of motor errors during each motor action. The CG received no exercise intervention and continued their normal activity. Outcome measures were changes in sway of ankle, hip, and center of mass (CoM) in both mediolateral and anteroposterior (AP) directions during 30-second balance tests with increasing task difficulty [i.e. standing in feet-closed position with eyes open (EO) and eyes closed (EC), and in semi-tandem position with EO] at baseline and after the intervention. Additionally, gait performance (speed, variability) and fear of falling [Falls Efficacy Scale-International (FES-I)] were measured. Training was safe despite the participants' impaired health status, great severity of CIPN (VPT 49.6 ± 26.7 V), and great fear of falling (FES-I score 31.37 ± 11.20). After the intervention, sway of hip, ankle, and CoM was significantly reduced in the IG compared to the CG while standing in feet-closed position with EO (p = 0.010-0.022, except AP CoM sway) and in semi-tandem position (p = 0.008-0.035, except ankle sway). No significant effects were found for balance with

  5. Trivalent dopants on ZnO semiconductor obtained by mechanical milling

    Energy Technology Data Exchange (ETDEWEB)

    Damonte, L.C., E-mail: damonte@fisica.unlp.edu.a [Dto. De Fisica, UNLP, IFLP-CONICET, C.C.67 (1900) La Plata (Argentina); Dto. De Fisica Aplicada, Universidad Politecnica de Valencia, Valencia (Spain); Donderis, V. [Dto. De Ingenieria Electrica, Universidad Politecnica de Valencia, Cami de Vera s/n, 46071 Valencia (Spain); Hernandez-Fenollosa, M.A. [Dto. De Fisica Aplicada, Universidad Politecnica de Valencia, Valencia (Spain)

    2009-08-26

    Al-doped ZnO powders were obtained by mechanical milling. This n-type oxide material is of interest for application in electronic devices as solar cells. The incorporation of the metal dopant into the ZnO wurtzite structure has been verified by X-ray diffraction, positron annihilation spectroscopy and optical analysis. The optical reflection measurements were strongly affected by the Al incorporation. The positron annihilation spectroscopy constituted an adequate probe to sense the cation substitution in the doped semiconductor.

  6. Trivalent dopants on ZnO semiconductor obtained by mechanical milling

    International Nuclear Information System (INIS)

    Damonte, L.C.; Donderis, V.; Hernandez-Fenollosa, M.A.

    2009-01-01

    Al-doped ZnO powders were obtained by mechanical milling. This n-type oxide material is of interest for application in electronic devices as solar cells. The incorporation of the metal dopant into the ZnO wurtzite structure has been verified by X-ray diffraction, positron annihilation spectroscopy and optical analysis. The optical reflection measurements were strongly affected by the Al incorporation. The positron annihilation spectroscopy constituted an adequate probe to sense the cation substitution in the doped semiconductor.

  7. Redistribution of dopant and impurity concentrations during the formation of uniform WSi2 films by RTP

    International Nuclear Information System (INIS)

    Siegal, M.P.; Santiago, J.J.

    1988-01-01

    Secondary ion mass spectroscopy has been used to study the effects of rapid thermal processing on the formation of tetragonal tungsten disilicide thin films on Si(100), p-type 5 Ω . cm wafers. The substrates were chemically etched, followed by an RF sputter deposition of 710A W metal. The samples were then fast radiatively processed in an RTP system for time intervals ranging from 15 to 45 seconds at high temperature (--1100 0 C) under high vacuum. The redistribution of the boron dopant concentration profile is described in this paper

  8. Phosphorus {delta}-doped silicon: mixed-atom pseudopotentials and dopant disorder effects

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Damien J; Marks, Nigel A [Nanochemistry Research Institute, Curtin University, PO Box U1987, Perth WA 6845 (Australia); Warschkow, Oliver; McKenzie, David R, E-mail: d.carter@curtin.edu.au [Centre for Quantum Computer Technology, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)

    2011-02-11

    Within a full density functional theory framework we calculate the band structure and doping potential for phosphorus {delta}-doped silicon. We compare two different representations of the dopant plane; pseudo-atoms in which the nuclear charge is fractional between silicon and phosphorus, and explicit arrangements employing distinct silicon and phosphorus atoms. While the pseudo-atom approach offers several computational advantages, the explicit model calculations differ in a number of key points, including the valley splitting, the Fermi level and the width of the doping potential. These findings have implications for parameters used in device modelling.

  9. High Thermoelectric Figure of Merit by Resonant Dopant in Half-Heusler Alloys

    OpenAIRE

    Chen, Long; Liu, Yamei; He, Jian; Tritt, Terry M.; Poon, S. Joseph

    2017-01-01

    Half-Heusler alloys have been one of the benchmark high temperature thermoelectric materials owing to their thermal stability and promising figure of merit ZT. Simonson et al. early showed that small amounts of vanadium doped in Hf0.75Zr0.25NiSn enhanced the Seebeck coefficient and correlated the change with the increased density of states near the Fermi level. We herein report a systematic study on the role of vanadium (V), niobium (Nb), and tantalum (Ta) as prospective resonant dopants in e...

  10. The effect of different dopant concentration of tailor-made silica fibers in radiotherapy dosimetry

    Science.gov (United States)

    Begum, Mahfuza; Mizanur Rahman, A. K. M.; Zubair, H. T.; Abdul-Rashid, H. A.; Yusoff, Z.; Begum, Mahbuba; Alkhorayef, M.; Alzimami, K.; Bradley, D. A.

    2017-12-01

    In thermoluminescence (TL) material dopant concentration has an important effect on their characteristics as a ;radiation-sensor;. The study investigates dosimetric properties of four different concentration (4 mol%, 5 mol%, 7 mol% and 25 mol%) tailor-made Ge-doped silica fibers. The intention is to seek development of alternative TL materials that offer exceptional advantages over existing passive systems of dosimetry, including improved spatial resolution, a water impervious nature and low cost. Photon beams (6 MV and 10 MV) from a clinical linear accelerator were used for irradiation of the fiber samples over radiation therapy doses, ranging from 0.5 Gy to 8 Gy. SEM-EDX analysis was also performed to investigate the homogeneity of distribution of Ge dopant concentration from the fiber samples. The results of measurement were also compared with two of the more commonly used standard TLDs, TLD-100 (LiF: Mg,Ti-7.5% 6LiF) and TLD-700 ((7LiF: Mg,Ti-99.9%7LiF) chips respectively. The TL intensity of the fiber samples was found to strongly depend on Ge dopant concentration, with samples showing enhanced TL yields with decreasing Ge dopant concentration. 4 mol% Ge-doped silica fiber provided the greatest response whereas the 25 mol% samples showed the least, indicative of the well-known concentration quenching effects All fiber TLDs provided linear dose response over the delivered radiotherapy dose-range, the fibers also showing a weak dependence on photon beam energies in comparing the TL yields at 6 and 10 MV. The fading behavior of the different concentration Ge doped TLD-materials were also measured over a period of thirty (30) days subsequent to irradiation. The relative sensitivity of the samples with respect to standard TLD-100 were found to be 0.37, 0.26, 0.13 and 0.02 in respect of the 4, 5, 7 and 25 mol% fibers. The primary dosimetry peak, which was by far the most prominent of any other feature covered by the glow curve, was found to be around 244 °C using

  11. Photosensitive self-assembling materials as functional dopants for organic photovoltaic cells

    Czech Academy of Sciences Publication Activity Database

    Bubnov, Alexej; Iwan, A.; Cigl, Martin; Boharewicz, B.; Tazbir, I.; Wójcik, K.; Sikora, A.; Hamplová, Věra

    2016-01-01

    Roč. 6, č. 14 (2016), s. 11577-11590 ISSN 2046-2069 R&D Projects: GA MŠk 7AMB13PL041; GA MŠk(CZ) LD14007; GA ČR GA15-02843S Grant - others:EU - ICT(XE) COST Action IC1208 Institutional support: RVO:68378271 Keywords : self-assembling materials * functional dopants * organic photovoltaic cells * azo group * liquid crystal Subject RIV: JI - Composite Materials Impact factor: 3.108, year: 2016

  12. Constraint-induced movement therapy in treatment of acute and sub-acute stroke: a meta-analysis of 16 randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Xi-hua Liu

    2017-01-01

    Results: A total of 16 prospective randomized controlled trials (379 patients in the constraint-induced movement-therapy group and 359 in the control group met inclusion criteria. Analysis showed significant mean differences in favor of constraint-induced movement therapy for the Fugl–Meyer motor assessment of the arm (weighted mean difference (WMD = 10.822; 95% confidence intervals (95% CI: 7.419–14.226, the action research-arm test (WMD = 10.718; 95% CI: 5.704–15.733, the motor activity log for amount of use and quality of movement (WMD = 0.812; 95% CI: 0.331–1.293 and the modified Barthel index (WMD = 10.706; 95% CI: 4.417–16.966. Conclusion: Constraint-induced movement therapy may be more beneficial than traditional rehabilitation therapy for improving upper limb function after acute or sub-acute stroke.

  13. Influence of dopants on the glow curve structure and energy dependence of LiF:Mg,Cu,Si detectors

    International Nuclear Information System (INIS)

    Knezevic, Z.; Ranogajec-Komor, M.; Miljanic, S.; Lee, J.I.; Kim, J.L.; Music, S.

    2011-01-01

    LiF thermoluminescent material doped with Mg, Cu and Si recently developed by the Korea Atomic Energy Research Institute (KAERI) has shown very good dosimetric properties. Since the thermoluminescence in LiF was found to be dependent on the proper combination of dopants, the investigation of the concentration and type of dopants is very important in developing and characterisation of new TL materials. The aim of this work was to determine the influence of type and concentration of activators on the glow curve structure, sensitivity, reproducibility and on the photon energy response of LiF:Mg,Cu,Si detectors. The energy response was studied in air and on the ISO water phantom in the range of mean photon energies between 33 keV and 164 keV. The morphology and local chemical composition of LiF:Mg,Cu,Si detectors were examined using high resolution scanning electron microscopy (FE-SEM). The results show that type and concentration of activators influence the glow curve and sensitivity. Different dopant concentrations did not show influence on the photon energy response. The sensitivity of LiF:Mg,Cu,Si detector with dopant concentration of Mg = 0.35 mol%, Cu = 0.025 mol% and Si = 0.9 mol% was very high (up to 65 times higher than that of TLD-100). The photon energy response of LiF:Mg,Cu,Si detectors containing all three dopants in various concentrations is in accordance with the IAEA recommendations for individual monitoring.

  14. Influence of dopants on the glow curve structure and energy dependence of LiF:Mg,Cu,Si detectors

    Energy Technology Data Exchange (ETDEWEB)

    Knezevic, Z., E-mail: zknez@irb.h [Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Ranogajec-Komor, M.; Miljanic, S. [Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Lee, J.I.; Kim, J.L. [Korea Atomic Energy Research Institute, P.O. Box 105 Yuseong, Daejon 305-600 (Korea, Republic of); Music, S. [Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia)

    2011-03-15

    LiF thermoluminescent material doped with Mg, Cu and Si recently developed by the Korea Atomic Energy Research Institute (KAERI) has shown very good dosimetric properties. Since the thermoluminescence in LiF was found to be dependent on the proper combination of dopants, the investigation of the concentration and type of dopants is very important in developing and characterisation of new TL materials. The aim of this work was to determine the influence of type and concentration of activators on the glow curve structure, sensitivity, reproducibility and on the photon energy response of LiF:Mg,Cu,Si detectors. The energy response was studied in air and on the ISO water phantom in the range of mean photon energies between 33 keV and 164 keV. The morphology and local chemical composition of LiF:Mg,Cu,Si detectors were examined using high resolution scanning electron microscopy (FE-SEM). The results show that type and concentration of activators influence the glow curve and sensitivity. Different dopant concentrations did not show influence on the photon energy response. The sensitivity of LiF:Mg,Cu,Si detector with dopant concentration of Mg = 0.35 mol%, Cu = 0.025 mol% and Si = 0.9 mol% was very high (up to 65 times higher than that of TLD-100). The photon energy response of LiF:Mg,Cu,Si detectors containing all three dopants in various concentrations is in accordance with the IAEA recommendations for individual monitoring.

  15. Heterovalent Dopant Incorporation for Bandgap and Type Engineering of Perovskite Crystals

    KAUST Repository

    Abdelhady, Ahmed L.

    2016-01-02

    Controllable doping of semiconductors is a fundamental technological requirement for electronic and optoelectronic devices. As intrinsic semiconductors, hybrid perovskites have so far been a phenomenal success in photovoltaics. The inability to dope these materials heterovalently (or aliovalently) has greatly limited their wider utilizations in electronics. Here we show an efficient in situ chemical route that achieves the controlled incorporation of trivalent cations (Bi3+, Au3+, or In3+) by exploiting the retrograde solubility behavior of perovskites. We term the new method dopant incorporation in the retrograde regime. We achieve Bi3+ incorporation that leads to bandgap tuning (∼300 meV), 104 fold enhancement in electrical conductivity, and a change in the sign of majority charge carriers from positive to negative. This work demonstrates the successful incorporation of dopants into perovskite crystals while preserving the host lattice structure, opening new avenues to tailor the electronic and optoelectronic properties of this rapidly emerging class of solution-processed semiconductors. © 2016 American Chemical Society.

  16. Preparation and characterization of electrodeposited SnS:In thin films: Effect of In dopant

    Science.gov (United States)

    Kafashan, Hosein; Balak, Zohre

    2017-09-01

    SnS:In thin films were grown on fluorine doped tin oxide (FTO) substrate by cathodic electrodeposition technique. The solution was containing 2 mM SnCl2 and 16 mM Na2S2O3 and different amounts of 1 mM InCl3 as In-dopant. The pH, bath temperature, deposition time, and deposition potential (E) were fixed at 2.1, 60 °C, 30 min, and - 1 V, respectively. The XRD results showed that the synthesized films were polycrystalline orthorhombic SnS. The XPS results demonstrated that the films were composed of Sn, S and In. According to the FESEM images, an increase in In-dopant concentration leads to a change in morphology from grain-like to sheet-like having a nanoscale thickness of 20-80 nm and fiber-like. The PL spectra of undoped SnS exhibited four emission peaks including a UV peak, two blue emission peaks, and an IR emission peak. According to the UV-Vis spectra, the direct band gap of SnS:In thin films was estimated to be 1.40-1.66 eV.

  17. High thermoelectric figure of merit by resonant dopant in half-Heusler alloys

    Science.gov (United States)

    Chen, Long; Liu, Yamei; He, Jian; Tritt, Terry M.; Poon, S. Joseph

    2017-06-01

    Half-Heusler alloys have been one of the benchmark high temperature thermoelectric materials owing to their thermal stability and promising figure of merit ZT. Simonson et al. early showed that small amounts of vanadium doped in Hf0.75Zr0.25NiSn enhanced the Seebeck coefficient and correlated the change with the increased density of states near the Fermi level. We herein report a systematic study on the role of vanadium (V), niobium (Nb), and tantalum (Ta) as prospective resonant dopants in enhancing the ZT of n-type half-Heusler alloys based on Hf0.6Zr0.4NiSn0.995Sb0.005. The V doping was found to increase the Seebeck coefficient in the temperature range 300-1000 K, consistent with a resonant doping scheme. In contrast, Nb and Ta act as normal n-type dopants, as evident by the systematic decrease in electrical resistivity and Seebeck coefficient. The combination of enhanced Seebeck coefficient due to the presence of V resonant states and the reduced thermal conductivity has led to a state-of-the-art ZT of 1.3 near 850 K in n-type (Hf0.6Zr0.4)0.99V0.01NiSn0.995Sb0.005 alloys.

  18. Quantitative dopant profiling in semiconductors. A new approach to Kelvin probe force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Baumgart, Christine

    2012-07-01

    Failure analysis and optimization of semiconducting devices request knowledge of their electrical properties. To meet the demands of today's semiconductor industry, an electrical nanometrology technique is required which provides quantitative information about the doping profile and which enables scans with a lateral resolution in the sub-10 nm range. In the presented work it is shown that Kelvin probe force microscopy (KPFM) is a very promising electrical nanometrology technique to face this challenge. The technical and physical aspects of KPFM measurements on semiconductors required for the correct interpretation of the detected KPFM bias are discussed. A new KPFM model is developed which enables the quantitative correlation between the probed KPFM bias and the dopant concentration in the investigated semiconducting sample. Quantitative dopant profiling by means of the new KPFM model is demonstrated by the example of differently structured, n- and p-type doped silicon. Additionally, the transport of charge carriers during KPFM measurements, in particular in the presence of intrinsic electric fields due to vertical and horizontal pn junctions as well as due to surface space charge regions, is discussed. Detailed investigations show that transport of charge carriers in the semiconducting sample is a crucial aspect and has to be taken into account when aiming for a quantitative evaluation of the probed KPFM bias.

  19. Effects of Lithium Dopant on Size and Morphology of Magnesium Oxide Nano powders

    International Nuclear Information System (INIS)

    Mohd Sufri Mastuli; Siti Nur Hazlinda Hasbu; Noraziahwati Ibrahim; Mohd Azizi Nawawi; Mohd Sufri Mastuli

    2014-01-01

    Lithium doped of magnesium oxide powders have been synthesized using the sol-gel method with magnesium acetate tetrahydrate, oxalic acid dihydrate and lithium acetate dihydrate used as the starting materials. The dried sol-gel products were calcined at 950 degree Celsius for 36 h to form the Li doped-MgO samples. The calcined samples were characterized using X-Ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The present work is investigated the effect of lithium ion on the band gap energy of studied samples. The band gap energies were obtained from a Tauc plot that drawn based on absorption edge of each sample that measured using a UV-Vis spectrophotometer. It is found that the doped and undoped MgO samples showed a slightly different in their band gap energies. The lithium ion that present in the MgO as a dopant affects the crystallite size and morphology of the final products. Our study shows that the lithium dopant can modified optical properties of the metal oxide which to be beneficial in some industrial applications. (author)

  20. Electrical properties of tin-doped zinc oxide nanostructures doped at different dopant concentrations

    International Nuclear Information System (INIS)

    Nasir, M. F.; Zainol, M. N.; Hannas, M.; Mamat, M. H.; Rusop, Mohamad; Rahman, S. A.

    2016-01-01

    This project has been focused on the electrical and optical properties respectively on the effect of Tin doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different Sn dopant concentrations at 1 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 °C. Sn doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (Perkin Elmer Lambda 750) for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% Sn doping concentration with the value 3.08 × 10"3 Ωcm"−"1. The absorption coefficient spectrum obtained shows all films exhibit very low absorption in the visible (400-800 nm) and near infrared (NIR) (>800 nm) range but exhibit high absorption in the UV range.

  1. Industrially feasible, dopant-free, carrier-selective contacts for high-efficiency silicon solar cells

    KAUST Repository

    Yang, Xinbo

    2017-05-31

    Dopant-free, carrier-selective contacts (CSCs) on high efficiency silicon solar cells combine ease of deposition with potential optical benefits. Electron-selective titanium dioxide (TiO) contacts, one of the most promising dopant-free CSC technologies, have been successfully implemented into silicon solar cells with an efficiency over 21%. Here, we report further progress of TiO contacts for silicon solar cells and present an assessment of their industrial feasibility. With improved TiO contact quality and cell processing, a remarkable efficiency of 22.1% has been achieved using an n-type silicon solar cell featuring a full-area TiO contact. Next, we demonstrate the compatibility of TiO contacts with an industrial contact-firing process, its low performance sensitivity to the wafer resistivity, its applicability to ultrathin substrates as well as its long-term stability. Our findings underscore the great appeal of TiO contacts for industrial implementation with their combination of high efficiency with robust fabrication at low cost.

  2. Photoreflection investigations of the dopant activation in InP doped with beryllium ions

    International Nuclear Information System (INIS)

    Avakyants, L.P.; Bokov, P.Yu.; Chervyakov, A.V.

    2005-01-01

    The processes of the dopant activation in the InP crystals implanted with Be + ions (energy 100 keV, dose 10 13 cm -2 and subsequent thermal annealing during 10 s) have been studied by means of photoreflection spectroscopy. Spectral lines of the crystal InP were absent in the photoreflection spectra of the samples annealed at temperatures less then 400 Deg C. This fact is connected with the disordering of the crystal structure due to the ion implantation. In the temperature range 400-700 Deg C the lines from InP band gap (1.34 eV) and conductance band-spin-orbit splitting valence subband (1.44 eV) have been observed due to the recovery of the crystal structure. In the photoreflectance spectra of a 800 Deg C annealed sample the Franz-Keldysh oscillations have been observed, which can be an evidence in favour of the dopant activation. Carrier concentration calculated from the period of Franz-Keldysh oscillations was equal to 2.2 x 10 16 cm -3 [ru

  3. Germania and Alumina Dopant Diffusion and Viscous Flow Effects at Preparation of Doped Optical Fibers

    Directory of Open Access Journals (Sweden)

    Jens Kobelke

    2017-01-01

    Full Text Available We report on germania and alumina dopant profile shift effects at preparation of compact optical fibers using packaging methods (Stack-and-Draw method, Rod-in-Tube (RiT technique. The sintering of package hollow volume by viscous flow results in a shift of the core-pitch ratio in all-solid microstructured fibers. The ratio is increased by about 5% in the case of a hexagonal package. The shift by diffusion effects of both dopants is simulated for typical slow speed drawing parameters. Thermodynamic approximations of surface dissociation of germania doped silica suggest the need of an adequate undoped silica barrier layer to prevent an undesired bubble formation at fiber drawing. In contrast, alumina doping does not estimate critical dissociation effects with vaporous aluminium oxide components. We report guide values of diffusion length of germania and alumina for the drawing process by kinetic approximation. The germania diffusion involves a small core enlargement, typically in the sub-micrometer scale. Though, the alumina diffusion enlarges it by a few micrometers. A drawn pure alumina preform core rod transforms to an amorphous aluminosilicate core with a molar alumina concentration of only about 50% and a non-gaussian concentration profile.

  4. Hard-Wired Dopant Networks and the Prediction of High Transition Temperatures in Ceramic Superconductors

    International Nuclear Information System (INIS)

    Phillips, J.C.

    2010-01-01

    The review multiple successes of the discrete hard-wired dopant network model ZZIP, and comment on the equally numerous failures of continuum models, in describing and predicting the properties of ceramic superconductors. The prediction of transition temperatures can be regarded in several ways, either as an exacting test of theory, or as a tool for identifying theoretical rules for defining new homology models. Popular first principle methods for predicting transition temperatures in conventional crystalline superconductors have failed for cuprate HTSC, as have parameterized models based on CuO2 planes (with or without apical oxygen). Following a path suggested by Bayesian probability, it was found that the glassy, self-organized dopant network percolative model is so successful that it defines a new homology class appropriate to ceramic superconductors. The reasons for this success in an exponentially complex (non-polynomial complete, NPC) problem are discussed, and a critical comparison is made with previous polynomial (PC) theories. The predictions are successful for the superfamily of all ceramics, including new non-cuprates based on FeAs in place of CuO2.

  5. The Role of Dopant Ions on Charge Injection and Transport in Electrochemically Doped Quantum Dot Films.

    Science.gov (United States)

    Gudjonsdottir, Solrun; van der Stam, Ward; Kirkwood, Nicholas; Evers, Wiel H; Houtepen, Arjan J

    2018-05-16

    Control over the charge density is very important for implementation of colloidal semiconductor nanocrystals into various optoelectronic applications. A promising approach to dope nanocrystal assemblies is charge injection by electrochemistry, in which the charge compensating electrolyte ions can be regarded as external dopant ions. To gain insight into the doping mechanism and the role of the external dopant ions, we investigate charge injection in ZnO nanocrystal assemblies for a large series of charge compensating electrolyte ions with spectroelectrochemical and electrochemical transistor measurements. We show that charge injection is limited by the diffusion of cations in the nanocrystal films as their diffusion coefficient are found to be ∼7 orders of magnitude lower than those of electrons. We further show that the rate of charge injection depends strongly on the cation size and cation concentration. Strikingly, the onset of electron injection varies up to 0.4 V, depending on the size of the electrolyte cation. For the small ions Li + and Na + the onset is at significantly less negative potentials. For larger ions (K + , quaternary ammonium ions) the onset is always at the same, more negative potential, suggesting that intercalation may take place for Li + and Na + . Finally, we show that the nature of the charge compensating cation does not affect the source-drain electronic conductivity and mobility, indicating that shallow donor levels from intercalating ions fully hybridize with the quantum confined energy levels and that the reorganization energy due to intercalating ions does not strongly affect electron transport in these nanocrystal assemblies.

  6. Characteristics of titanium oxide memristor with coexistence of dopant drift and a tunnel barrier

    International Nuclear Information System (INIS)

    Tian Xiao-Bo; Xu Hui

    2014-01-01

    The recent published experimental data of titanium oxide memristor devices which are tested under the same experimental conditions exhibit the strange instability and complexity of these devices. Such undesired characteristics preclude the understanding of the device conductive processes and the memristor-based practical applications. The possibility of the coexistence of dopant drift and tunnel barrier conduction in a memristor provides preliminary explanations for the undesired characteristics. However, current research lacks detailed discussion about the coexistence case. In this paper, dopant drift and tunnel barrier-based theories are first analyzed for studying the relations between parameters and physical variables which affect characteristics of memristors, and then the influences of each parameter change on the conductive behaviors in the single and coexistence cases of the two mechanisms are simulated and discussed respectively. The simulation results provide further explanations of the complex device conduction. Theoretical methods of eliminating or reducing the coexistence of the two mechanisms are proposed, in order to increase the stability of the device conduction. This work also provides the support for optimizing the fabrications of memristor devices with excellent performance

  7. Finite element simulations of electrostatic dopant potentials in thin semiconductor specimens for electron holography.

    Science.gov (United States)

    Somodi, P K; Twitchett-Harrison, A C; Midgley, P A; Kardynał, B E; Barnes, C H W; Dunin-Borkowski, R E

    2013-11-01

    Two-dimensional finite element simulations of electrostatic dopant potentials in parallel-sided semiconductor specimens that contain p-n junctions are used to assess the effect of the electrical state of the surface of a thin specimen on projected potentials measured using off-axis electron holography in the transmission electron microscope. For a specimen that is constrained to have an equipotential surface, the simulations show that the step in the projected potential across a p-n junction is always lower than would be predicted from the properties of the bulk device, but is relatively insensitive to the value of the surface state energy, especially for thicker specimens and higher dopant concentrations. The depletion width measured from the projected potential, however, has a complicated dependence on specimen thickness. The results of the simulations are of broader interest for understanding the influence of surfaces and interfaces on electrostatic potentials in nanoscale semiconductor devices. © 2013 Elsevier B.V. All rights reserved.

  8. Origin of electrolyte-dopant dependent sulfur poisoning of SOFC anodes.

    Science.gov (United States)

    Zeng, ZhenHua; Björketun, Mårten E; Ebbesen, Sune; Mogensen, Mogens B; Rossmeisl, Jan

    2013-05-14

    The mechanisms governing the sulfur poisoning of the triple phase boundary (TPB) of Ni-XSZ (X2O3 stabilized zirconia) anodes have been investigated using density functional theory. The calculated sulfur adsorption energies reveal a clear correlation between the size of the cation dopant X(3+) and the sulfur tolerance of the Ni-XSZ anode; the smaller the ionic radius, the higher the sulfur tolerance. The mechanistic study shows that the size of X(3+) strongly influences XSZ's surface energy, which in turn determines the adhesion of Ni to XSZ. The Ni-XSZ interaction has a direct impact on the Ni-S interaction and on the relative stability of reconstructed and pristine Ni(100) facets at the TPB. Together, these two effects control the sulfur adsorption on the Ni atoms at the TPB. The established relationships explain experimentally observed dopant-dependent anode performances and provide a blueprint for the future search for and preparation of highly sulfur tolerant anodes.

  9. Electrical properties of tin-doped zinc oxide nanostructures doped at different dopant concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, M. F., E-mail: babaibaik2002@yahoo.com; Zainol, M. N., E-mail: nizarzainol@yahoo.com; Hannas, M., E-mail: mhannas@gmail.com [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Mamat, M. H., E-mail: mhmamat@salam.uitm.edu.my; Rusop, Mohamad, E-mail: rusop@salam.uitm.edu.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia); Rahman, S. A., E-mail: saadah@um.edu.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Low Dimensional Materials Research Centre, Physics Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-07-06

    This project has been focused on the electrical and optical properties respectively on the effect of Tin doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different Sn dopant concentrations at 1 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 °C. Sn doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (Perkin Elmer Lambda 750) for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% Sn doping concentration with the value 3.08 × 10{sup 3} Ωcm{sup −1}. The absorption coefficient spectrum obtained shows all films exhibit very low absorption in the visible (400-800 nm) and near infrared (NIR) (>800 nm) range but exhibit high absorption in the UV range.

  10. Excitonic pathway to photoinduced magnetism in colloidal nanocrystals with nonmagnetic dopants.

    Science.gov (United States)

    Pinchetti, Valerio; Di, Qiumei; Lorenzon, Monica; Camellini, Andrea; Fasoli, Mauro; Zavelani-Rossi, Margherita; Meinardi, Francesco; Zhang, Jiatao; Crooker, Scott A; Brovelli, Sergio

    2018-02-01

    Electronic doping of colloidal semiconductor nanostructures holds promise for future device concepts in optoelectronic and spin-based technologies. Ag + is an emerging electronic dopant in III-V and II-VI nanostructures, introducing intragap electronic states optically coupled to the host conduction band. With its full 4d shell Ag + is nonmagnetic, and the dopant-related luminescence is ascribed to decay of the conduction-band electron following transfer of the photoexcited hole to Ag + . This optical activation process and the associated modification of the electronic configuration of Ag + remain unclear. Here, we trace a comprehensive picture of the excitonic process in Ag-doped CdSe nanocrystals and demonstrate that, in contrast to expectations, capture of the photohole leads to conversion of Ag + to paramagnetic Ag 2+ . The process of exciton recombination is thus inextricably tied to photoinduced magnetism. Accordingly, we observe strong optically activated magnetism and diluted magnetic semiconductor behaviour, demonstrating that optically switchable magnetic nanomaterials can be obtained by exploiting excitonic processes involving nonmagnetic impurities.

  11. Influence of dopant concentration on spectroscopic properties of Sr2CeO4:Yb nanocrystals

    Science.gov (United States)

    Stefanski, M.; Kędziorski, A.; Hreniak, D.; Strek, W.

    2017-12-01

    Optical properties of Sr2CeO4:Yb nanocrystals synthesized via Pechini's method are reported. The samples were characterized by X-ray diffraction data measurements. The unit cell parameters were determined using Rietveld refinement. It was found that they decreased with increasing amount of Yb ions. The absorption, excitation, emission spectra and luminescence decay profiles of the Sr2CeO4:Yb nanocrystals were investigated. It was observed that optical properties were strongly dependent on Yb concentration. It was found that Yb3+-O2- charge transfer transitions have great influence on the absorption spectra. It can be seen in the emission spectra that in addition to standard bands/lines corresponding to Ce-O metal-to-ligand charge transfer of Sr2CeO4 and f-f transitions of Yb3+, there is emission band centered at 744 nm. Its intensity depends on the concentration of the dopant. Recorded decay times become shorter with increasing dopant concentration due to the Yb3+ concentration quenching. Excitation spectra indicate the energy transfer from Ce-O charge transfer states to Yb3+2F5/2 state. The issue of appearance of down-conversion process in Sr2CeO4:Yb nanocrystals is considered.

  12. Heterovalent Dopant Incorporation for Bandgap and Type Engineering of Perovskite Crystals

    KAUST Repository

    Abdelhady, Ahmed L.; Saidaminov, Makhsud I.; Banavoth, Murali; Adinolfi, Valerio; Voznyy, Oleksandr; Katsiev, Khabiboulakh; Alarousu, Erkki; Comin, Riccardo; Dursun, Ibrahim; Sinatra, Lutfan; Sargent, Edward H.; Mohammed, Omar F.; Bakr, Osman

    2016-01-01

    Controllable doping of semiconductors is a fundamental technological requirement for electronic and optoelectronic devices. As intrinsic semiconductors, hybrid perovskites have so far been a phenomenal success in photovoltaics. The inability to dope these materials heterovalently (or aliovalently) has greatly limited their wider utilizations in electronics. Here we show an efficient in situ chemical route that achieves the controlled incorporation of trivalent cations (Bi3+, Au3+, or In3+) by exploiting the retrograde solubility behavior of perovskites. We term the new method dopant incorporation in the retrograde regime. We achieve Bi3+ incorporation that leads to bandgap tuning (∼300 meV), 104 fold enhancement in electrical conductivity, and a change in the sign of majority charge carriers from positive to negative. This work demonstrates the successful incorporation of dopants into perovskite crystals while preserving the host lattice structure, opening new avenues to tailor the electronic and optoelectronic properties of this rapidly emerging class of solution-processed semiconductors. © 2016 American Chemical Society.

  13. Double-blind, placebo-controlled, randomized study of chlorhexidine prophylaxis for 5-fluorouracil-based chemotherapy-induced oral mucositis with nonblinded randomized comparison to oral cooling (cryotherapy) in gastrointestinal malignancies.

    Science.gov (United States)

    Sorensen, Jens Benn; Skovsgaard, Torben; Bork, Ellen; Damstrup, Lars; Ingeberg, Sten

    2008-04-01

    The purpose was to evaluate prevention of oral mucositis (OM) using chlorhexidine compared with placebo and with oral cooling (cryotherapy) during fluorouracil (5-FU)-based chemotherapy in gastrointestinal (GI) cancer. Patients with previously untreated GI cancer receiving bolus 5-FU/leucovorin chemotherapy were randomized to chlorhexidine mouthrinse 3 times a day for 3 weeks (Arm A), double-blind placebo (normal saline) with the same dose and frequency (Arm B), or cryotherapy with crushed ice 45 minutes during chemotherapy (Arm C). Patients self-reported on severity (CTC-grading) and duration of OM. Among 225 patients randomized, 206 answered the questionnaire (70, 64, and 63 patients in Arms A, B, and C, respectively) and were well balanced with respect to diagnoses, stage, age, sex, smoking habits, and performance status. Mucositis grade 3-4 occurred more frequently in Arm B (33%) than in A (13%, Pcryotherapy. The latter is easy and inexpensive but has limited use, as it is drug- and schedule-dependent. The current study is the first double-blind randomized evaluation of prophylactic chlorhexidine in a large adult patient population with solid tumors receiving highly OM-inducing chemotherapy. A role for chlorhexidine in the prevention of OM is suggested, which should be evaluated further.

  14. Effects of co-dopants on the magnetic properties of Ni–Zn ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Sea-Fue, E-mail: sfwang@ntut.edu.tw; Hsu, Yung-Fu; Chou, Kai-Mou; Tsai, Jeng-Ting

    2015-01-15

    In this study, substitution of co-dopants into the Ni{sub 0.4}Zn{sub 0.6}Fe{sub 2}O{sub 4} ceramic was performed. Al{sup 3+}, Sn{sup 4+} and Ti{sup 4+} ions were added to the Ni{sub 0.4}Zn{sub 0.4}Li{sub 0.10}Fe{sub 2.10}O{sub 4} ceramic to improve magnetic properties. After sintering, all samples were indexed on a spinel structure and no detectable second phase was observed. When the concentration of dopants increased, the grain size of the Ni–Zn ferrites increased from 1.40 to 6.05 μm and the saturation magnetization declined from 428.8 emu/cm{sup 3} to 374.0 emu/cm{sup 3}. Amongst the systems investigated, the Ni{sub 0.4}Zn{sub 0.4}Li{sub 0.10}Al{sub 0.050}Fe{sub 2.050}O{sub 4}, Ni{sub 0.4}Zn{sub 0.425}Li{sub 0.10}Ti{sub 0.025}Fe{sub 2.050}O{sub 4}, and Ni{sub 0.4}Zn{sub 0.450}Li{sub 0.10}Ti{sub 0.050}Fe{sub 2.000}O{sub 4} ceramics revealed promising magnetic properties for applications. The measured initial permeability and quality factor were respectively 291.9 and 45.1 for the Ni{sub 0.4}Zn{sub 0.4}Li{sub 0.10}Al{sub 0.050}Fe{sub 2.050}O{sub 4} ceramic, 316.9 and 42.5 for the Ni{sub 0.4}Zn{sub 0.425}Li{sub 0.10}Ti{sub 0.025}Fe{sub 2.050}O{sub 4} ceramic, 429.4 and 34.8 for the Ni{sub 0.4}Zn{sub 0.450}Li{sub 0.10}Ti{sub 0.050}Fe{sub 2.000}O{sub 4} ceramic. The high initial permeability and quality factor values associated with good electrical resistivity (>10{sup 6} Ω-cm) qualify the ceramics for high frequency applications. - Highlights: • Co-dopants Al{sup 3+}–Li{sup +}, Sn{sup 4+}–Li{sup +}, and Ti{sup 4}–Li{sup +} were substituted into Ni–Zn lattices. • Grain size of Ni–Zn ferrites grew from 1.40 to 6.05 μm with rising dopants content. • Saturation magnetization declined from 428.8 to 374.0 emu/cm{sup 3} with adding dopants. • Ni{sub 0.4}Zn{sub 0.4}Li{sub 0.10}Al{sub 0.050}Fe{sub 2.050}O{sub 4} ceramic showed an μ{sub i} of 291.9 and a Q{sub f} of 45.1.

  15. A novel δ-doped partially insulated dopant-segregated Schottky barrier SOI MOSFET for analog/RF applications

    International Nuclear Information System (INIS)

    Patil, Ganesh C; Qureshi, S

    2011-01-01

    In this paper, a comparative analysis of single-gate dopant-segregated Schottky barrier (DSSB) SOI MOSFET and raised source/drain ultrathin-body SOI MOSFET (RSD UTB) has been carried out to explore the thermal efficiency, scalability and analog/RF performance of these devices. A novel p-type δ-doped partially insulated DSSB SOI MOSFET (DSSB Pi-OX-δ) has been proposed to reduce the self-heating effect and to improve the high-frequency performance of DSSB SOI MOSFET over RSD UTB. The improved analog/RF figures of merit such as transconductance, transconductance generation factor, unity-gain frequency, maximum oscillation frequency, short-circuit current gain and unilateral power gain in DSSB Pi-OX-δ MOSFET show the suitability of this device for analog/RF applications. The reduced drain-induced barrier lowering, subthreshold swing and parasitic capacitances also make this device highly scalable. By using mixed-mode simulation capability of MEDICI simulator a cascode amplifier has been implemented using all the structures (RSD UTB, DSSB SOI and DSSB Pi-OX-δ MOSFETs). The results of this implementation show that the gain-bandwidth product in the case of DSSB Pi-OX-δ MOSFET has improved by 50% as compared to RSD UTB and by 20% as compared to DSSB SOI MOSFET. The detailed fabrication flow of DSSB Pi-OX-δ MOSFET has been proposed which shows that with the bare minimum of steps the performance of DSSB SOI MOSFET can be improved significantly in comparison to RSD UTB

  16. Chemical and Electrochemical Synthesis of Polypyrrole Using Carrageenan as a Dopant: Polypyrrole/Multi-Walled Carbon Nanotube Nanocomposites

    Directory of Open Access Journals (Sweden)

    Mostafizur Rahaman

    2018-06-01

    Full Text Available In this article, iota-carrageenan (IC and kappa-carrageenan (KC are used as dopants for the chemical and electrochemical synthesis of polypyrrole (PPy. The composites of chemically synthesized PPy with multi-walled carbon nanotubes (MWNTs were prepared using an in situ technique. Both the dialyzed and non-dialyzed IC and KC were used as dopants for electrochemical polymerization of pyrrole. Chemically synthesized PPy and PPy/MWNTs composites were studied by ultraviolet visible (UV-vis absorption spectra to investigate the effect of the concentration and the incorporation of MWNTs. In addition, the electrical, thermal, mechanical, and microscopic characterizations of these films were performed to examine the effect of the dopants and MWNTs on these properties, along with their surface morphology. The films of electrochemically polymerized PPy were characterized using UV-vis absorption spectra, scanning electron microscopy, and cyclic voltammetry (CV. The results were then compared with the chemical polymerized PPy.

  17. Perspective analysis of tri gate germanium tunneling field-effect transistor with dopant segregation region at source/drain

    Science.gov (United States)

    Liu, Liang-kui; Shi, Cheng; Zhang, Yi-bo; Sun, Lei

    2017-04-01

    A tri gate Ge-based tunneling field-effect transistor (TFET) has been numerically studied with technology computer aided design (TCAD) tools. Dopant segregated Schottky source/drain is applied to the device structure design (DS-TFET). The characteristics of the DS-TFET are compared and analyzed comprehensively. It is found that the performance of n-channel tri gate DS-TFET with a positive bias is insensitive to the dopant concentration and barrier height at n-type drain, and that the dopant concentration and barrier height at a p-type source considerably affect the device performance. The domination of electron current in the entire BTBT current of this device accounts for this phenomenon and the tri-gate DS-TFET is proved to have a higher performance than its dual-gate counterpart.

  18. A combined theoretical and experimental investigation about the influence of the dopant in the anodic electropolymerization of {alpha}-tetrathiophene

    Energy Technology Data Exchange (ETDEWEB)

    Aleman, Carlos [Departament d' Enginyeria Quimica, E.T.S. d' Enginyeria Industrial de Barcelona, Universitat Politecnica de Catalunya, Diagonal 647, Barcelona E-08028 (Spain)], E-mail: carlos.aleman@upc.edu; Oliver, Ramon [Unitat de Quimica Industrial, E.U.E. Tecnica Industrial de Barcelona, Universitat Politecnica de Catalunya, Comte d' Urgell 187, Barcelona E-08036 (Spain); Brillas, Enric [Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1, Barcelona E-08028 (Spain); Casanovas, Jordi [Departament de Quimica, Escola Politecnica Superior, Universitat de Lleida, c/Jaume II No. 69, Lleida E-25001 (Spain); Estrany, Francesc [Unitat de Quimica Industrial, E.U.E. Tecnica Industrial de Barcelona, Universitat Politecnica de Catalunya, Comte d' Urgell 187, Barcelona E-08036 (Spain)], E-mail: francesc.estrany@upc.edu

    2006-04-21

    This work presents an experimental and theoretical investigation about the influence of the dopant in the electropolymerization of {alpha}-tetrathiophene. The results derived from anodic polymerization of {alpha}-tetrathiophene using SCN{sup -}, Cl{sup -}, Br{sup -}, NO{sub 3}{sup -}ClO{sub 3}{sup -}andClO{sub 4}{sup -} as dopant agents are compared with theoretical results provided by quantum mechanical calculations on 1:1 charge-transfer complexes formed by {alpha}-tetrathiophene and X=SCN, Cl, Br, NO{sub 3}, ClO{sub 3} and ClO{sub 4}. The consistency between experimental and theoretical results allows explain and rationalize the influence of the dopant in the electropolymerization of {alpha}-tetrathiophene.

  19. The interplay between dopants and oxygen vacancies in the magnetism of V-doped TiO2

    KAUST Repository

    Grau-Crespo, Ricardo

    2011-08-03

    Density functional theory calculations indicate that the incorporation of V into Ti lattice positions of rutile TiO2 leads to magnetic V 4 + species, but the extension and sign of the coupling between dopant moments confirm that ferromagnetic order cannot be reached via low-concentration doping in the non-defective oxide. Oxygen vacancies can introduce additional magnetic centres, and we show here that one of the effects of vanadium doping is to reduce the formation energies of these defects. In the presence of both V dopants and O vacancies all the spins tend to align with the same orientation. We conclude that V doping favours the ferromagnetic behaviour of TiO2 not only by introducing spins associated with the dopant centres but also by increasing the concentration of oxygen vacancies with respect to the pure oxide. © 2001 IOP Publishing Ltd.

  20. Site-selective dopant profiling of p-n junction specimens in the dual-beam FIB/SEM system

    International Nuclear Information System (INIS)

    Chee, K W A; Beanland, R; Midgley, P A; Humphreys, C J

    2010-01-01

    Results from site-specific dopant profiling in a dual-beam FIB/SEM system are reported. Si specimens containing p-n junctions were milled using Ga + ion beam energies ranging from 30 keV to 2 keV, and analysed in situin the vacuum chamber. We compare the dopant contrast observed when milling a cleaved surface to that obtained from a side-wall of a trench cut using 30 kV Ga + ions, and using successively lower ion beam energies. The latter technique is suitable for site-specific dopant profiling. We find that lower energy ion beam milling significantly improves contrast, but only achieves 50 % of that observed on a freshly-cleaved surface. Furthermore, the contrast on a side-wall previously milled using high energy Ga + ions is less than that of a cleaved surface subjected to the same ion beam energy.

  1. The interplay between dopants and oxygen vacancies in the magnetism of V-doped TiO2

    KAUST Repository

    Grau-Crespo, Ricardo; Schwingenschlö gl, Udo

    2011-01-01

    Density functional theory calculations indicate that the incorporation of V into Ti lattice positions of rutile TiO2 leads to magnetic V 4 + species, but the extension and sign of the coupling between dopant moments confirm that ferromagnetic order cannot be reached via low-concentration doping in the non-defective oxide. Oxygen vacancies can introduce additional magnetic centres, and we show here that one of the effects of vanadium doping is to reduce the formation energies of these defects. In the presence of both V dopants and O vacancies all the spins tend to align with the same orientation. We conclude that V doping favours the ferromagnetic behaviour of TiO2 not only by introducing spins associated with the dopant centres but also by increasing the concentration of oxygen vacancies with respect to the pure oxide. © 2001 IOP Publishing Ltd.

  2. Effects of modified constraint-induced movement therapy on reach-to-grasp movements and functional performance after chronic stroke: a randomized controlled study.

    Science.gov (United States)

    Lin, K-C; Wu, C-Y; Wei, T-H; Lee, C-Y; Liu, J-S

    2007-12-01

    To evaluate changes in (1) motor control characteristics of the hemiparetic hand during the performance of a functional reach-to-grasp task and (2) functional performance of daily activities in patients with stroke treated with modified constraint-induced movement therapy. Two-group randomized controlled trial with pretreatment and posttreatment measures. Rehabilitation clinics. Thirty-two chronic stroke patients (21 men, 11 women; mean age=57.9 years, range=43-81 years) 13-26 months (mean 16.3 months) after onset of a first-ever cerebrovascular accident. Thirty-two patients were randomized to receive modified constraint-induced movement therapy (restraint of the unaffected limb combined with intensive training of the affected limb) or traditional rehabilitation for three weeks. Kinematic analysis was used to assess motor control characteristics as patients reached to grasp a beverage can. Functional outcomes were evaluated using the Motor Activity Log and Functional Independence Measure. There were moderate and significant effects of modified constraint-induced movement therapy on some aspects of motor control of reach-to-grasp and on functional ability. The modified constraint-induced movement therapy group preplanned reaching and grasping (P=0.018) more efficiently and depended more on the feedforward control of reaching (P=0.046) than did the traditional rehabilitation group. The modified constraint-induced movement therapy group also showed significantly improved functional performance on the Motor Activity Log (Pcontrol strategy during goal-directed reaching, a possible mechanism for the improved movement performance of stroke patients undergoing this therapy.

  3. Prophylactic use of pregabalin for prevention of succinylcholine-induced fasciculation and myalgia: a randomized, double-blinded, placebo-controlled study

    Directory of Open Access Journals (Sweden)

    Vinit K. Srivastava

    2016-04-01

    Full Text Available ABSTRACT BACKGROUND: Succinylcholine is commonly used to achieve profound neuromuscular blockade of rapid onset and short duration. OBJECTIVE: The present study compared the efficacy of pregabalin for prevention of succinylcholine-induced fasciculation and myalgia. DESIGN: Prospective, randomized, placebo controlled, double blinded study. MATERIALS AND METHODS: Patients of both genders undergoing elective spine surgery were randomly assigned to two groups. Patients in Group P (pregabalin group received 150 mg of pregabalin orally 1 h prior to induction of anesthesia with sips of water and patients in Group C (control group received placebo. Anesthesia was induced with fentanyl 1.5 mcg/kg, propofol 1.5-2.0 mg/kg followed by succinylcholine 1.5 mg/kg. The intensity of fasciculations was assessed by an observer blinded to the group allotment of the patient on a 4-point scale. A blinded observer recorded postoperative myalgia grade after 24 h of surgery. Patients were provided patient-controlled analgesia with fentanyl for postoperative pain relief. RESULTS: Demographic data of both groups were comparable (p > 0.05. The incidence of muscle fasciculation's was not significant between two groups (p = 0.707, while more patients in group C had moderate to severe fasciculation's compared to group P (p = 0.028. The incidence and severity of myalgia were significantly lower in group P (p < 0.05. CONCLUSION: Pregabalin 150 mg prevents succinylcholine-induced fasciculations and myalgia and also decreases the fentanyl consumption in elective sine surgery.

  4. Reaction of N,N’-dimethylformamide and divalent viologen molecule to generate an organic dopant for molybdenum disulfide

    Directory of Open Access Journals (Sweden)

    A. Fukui

    2018-05-01

    Full Text Available Tuning the carrier concentration is essential for semiconducting materials to apply optoelectronic devices. Molybdenum disulfide (MoS2 is a semiconducting material composed of atomically thin (∼0.7 nm thickness layers. To dope thin MoS2, instead of using conventional atom/ion injection processes, a surface charge transfer method was successfully applied. In this study, we report a simple preparation method of a molecular dopant applicable to the doping process. The method follows a previous report for producing a molecular dopant, benzyl viologen (BV which shows electron doping to MoS2. To prepare dopant BV molecules, a reduction process with a commercially available divalent BV by sodium borohydride (NaBH4 is required; however, the reaction requires a large consumption of NaBH4. NaBH4 drastically reacts with the solvent water itself. We found a reaction process of BV in an organic solvent, N,N’-dimethylformamide (DMF, by adding a small amount of water dissolving the divalent BV. The reaction is mild (at room temperature and is autonomous once DMF comes into contact with the divalent BV aqueous solution. The reaction can be monitored with a UV-Vis spectrometer, and kinetic analysis indicates two reaction steps between divalent/monovalent/neutral viologen isomers. The product was soluble in toluene and did not dissolve in water, indicating it is similar to the reported dopant BV. The synthesized molecule was found to act as a dopant for MoS2 by applying a metal-oxide-semiconductor field-effect-transistor (MOSFET structure. The process is a general method and applicable to other viologen-related dopants to tune the electronic structure of 2D materials to facilitate generating atomically thin devices.

  5. Reaction of N,N'-dimethylformamide and divalent viologen molecule to generate an organic dopant for molybdenum disulfide

    Science.gov (United States)

    Fukui, A.; Miura, K.; Ichimiya, H.; Tsurusaki, A.; Kariya, K.; Yoshimura, T.; Ashida, A.; Fujimura, N.; Kiriya, D.

    2018-05-01

    Tuning the carrier concentration is essential for semiconducting materials to apply optoelectronic devices. Molybdenum disulfide (MoS2) is a semiconducting material composed of atomically thin (˜0.7 nm thickness) layers. To dope thin MoS2, instead of using conventional atom/ion injection processes, a surface charge transfer method was successfully applied. In this study, we report a simple preparation method of a molecular dopant applicable to the doping process. The method follows a previous report for producing a molecular dopant, benzyl viologen (BV) which shows electron doping to MoS2. To prepare dopant BV molecules, a reduction process with a commercially available divalent BV by sodium borohydride (NaBH4) is required; however, the reaction requires a large consumption of NaBH4. NaBH4 drastically reacts with the solvent water itself. We found a reaction process of BV in an organic solvent, N,N'-dimethylformamide (DMF), by adding a small amount of water dissolving the divalent BV. The reaction is mild (at room temperature) and is autonomous once DMF comes into contact with the divalent BV aqueous solution. The reaction can be monitored with a UV-Vis spectrometer, and kinetic analysis indicates two reaction steps between divalent/monovalent/neutral viologen isomers. The product was soluble in toluene and did not dissolve in water, indicating it is similar to the reported dopant BV. The synthesized molecule was found to act as a dopant for MoS2 by applying a metal-oxide-semiconductor field-effect-transistor (MOSFET) structure. The process is a general method and applicable to other viologen-related dopants to tune the electronic structure of 2D materials to facilitate generating atomically thin devices.

  6. Coincident resection at both ends of random, γ-induced double-strand breaks requires MRX (MRN, Sae2 (Ctp1, and Mre11-nuclease.

    Directory of Open Access Journals (Sweden)

    James W Westmoreland

    2013-03-01

    Full Text Available Resection is an early step in homology-directed recombinational repair (HDRR of DNA double-strand breaks (DSBs. Resection enables strand invasion as well as reannealing following DNA synthesis across a DSB to assure efficient HDRR. While resection of only one end could result in genome instability, it has not been feasible to address events at both ends of a DSB, or to distinguish 1- versus 2-end resections at random, radiation-induced "dirty" DSBs or even enzyme-induced "clean" DSBs. Previously, we quantitatively addressed resection and the role of Mre11/Rad50/Xrs2 complex (MRX at random DSBs in circular chromosomes within budding yeast based on reduced pulsed-field gel electrophoretic mobility ("PFGE-shift". Here, we extend PFGE analysis to a second dimension and demonstrate unique patterns associated with 0-, 1-, and 2-end resections at DSBs, providing opportunities to examine coincidence of resection. In G2-arrested WT, Δrad51 and Δrad52 cells deficient in late stages of HDRR, resection occurs at both ends of γ-DSBs. However, for radiation-induced and I-SceI-induced DSBs, 1-end resections predominate in MRX (MRN null mutants with or without Ku70. Surprisingly, Sae2 (Ctp1/CtIP and Mre11 nuclease-deficient mutants have similar responses, although there is less impact on repair. Thus, we provide direct molecular characterization of coincident resection at random, radiation-induced DSBs and show that rapid and coincident initiation of resection at γ-DSBs requires MRX, Sae2 protein, and Mre11 nuclease. Structural features of MRX complex are consistent with coincident resection being due to an ability to interact with both DSB ends to directly coordinate resection. Interestingly, coincident resection at clean I-SceI-induced breaks is much less dependent on Mre11 nuclease or Sae2, contrary to a strong dependence on MRX complex, suggesting different roles for these functions at "dirty" and clean DSB ends. These approaches apply to resection at

  7. Long-term treadmill exercise-induced neuroplasticity and associated memory recovery of streptozotocin-induced diabetic rats: an experimenter blind, randomized controlled study.

    Science.gov (United States)

    You, Joshua Sung H; Kim, Chung-Ju; Kim, Mee Young; Byun, Yong Gwon; Ha, So Young; Han, Bong Suk; Yoon, Bum Chul

    2009-01-01

    We investigated a long-term exercise-induced neuroplasticity and spatial memory recovery in 15 rats in a treadmill as follows: normal control rats (NC), streptozotocin (STZ)-induced diabetic control rats (DC), and STZ-induced diabetic rats exercising in a treadmill (DE). As per the DE group, the running exercise in a treadmill was administered for 30 minutes a day for 6 weeks. Neuronal immediate-early gene (IEG) expression (c-Fos) in the hippocampus and radial arm maze (RAM) tests were measured and revealed that the c-Fos levels in DE were significantly higher than those in NC and DC (p memory performance scores, obtained from the RAM test, were significantly different among the three groups (p memory scores of NC and DE were higher than those of DC (p memory. This is the first experimental evidence in literature that supports the efficacy of exercise-induced neuroplasticity and spatial motor memory in diabetes care.

  8. Improving stability of photoluminescence of ZnSe thin films grown by molecular beam epitaxy by incorporating Cl dopant

    International Nuclear Information System (INIS)

    Wang, J. S.; Shen, J. L.; Chen, W. J.; Tsai, Y. H.; Wang, H. H.; Yang, C. S.; Chen, R. H.; Tsai, C. D.

    2011-01-01

    This investigation studies the effect of chlorine (Cl) dopant in ZnSe thin films that were grown by molecular beam epitaxy on their photoluminescence (PL) and the stability thereof. Free excitonic emission was observed at room-temperature in the Cl-doped sample. Photon irradiation with a wavelength of 404 nm and a power density of 9.1 W/cm 2 has a much stronger effect on PL degradation than does thermal heating to a temperature of 150 deg. C. Additionally, this study shows that the generation of nonradiative centers by both photon irradiation and thermal heating can be greatly inhibited by incorporating Cl dopant.

  9. Variation of thermophysical parameters of PCM CaCl2.6H2O with dopant from T-history data analysis

    Science.gov (United States)

    Sutjahja, I. M.; Silalahi, Alfriska O.; Sukmawati, Nissa; Kurnia, D.; Wonorahardjo, S.

    2018-03-01

    T-history is a powerful method for deriving the thermophysical parameters of a phase change material (PCM), which consists of solid and liquid specific heats as well as latent heat enthalpy. The performance of a PCM for thermal energy storage could be altered by chemical dopants added directly to the PCM in order to form a stable suspension. We described in this paper the role of chemical dopants in the variation of thermophysical parameters for CaCl2 · 6H2O inorganic PCM with 1 wt% and 2 wt% dopant concentration and BaSO4 (1 wt%) as a nucleator using the T-history method. The dopant consists graphite and CuO nanoparticles. The data analysis follows the original method proposed by (Zhang et al 1999 Meas. Sci. Technol. 10 201–205) and its modification by (Hong et al 2004 Int. J. Refrig. 27 360–366). In addition, the enthalpy-temperature curve is obtained by adopting a method proposed by (Marín et al 2003 Meas. Sci. Technol. 14 184–189). We found that the solid specific heat tends to increase non-linearly with increased dopant concentration for all dopants. The increased liquid specific heat, however, indicates the optimum value for 1 wt% graphite dopant. In contrast, the CuO dopant shows a smaller increase in dopant concentration. The specific heat data are analyzed based on the interacting mesolayer model for a nanofluid. The heat of fusion show strong variation with dopant type, in agreement with other experimental data for various PCMs and dopant particles.

  10. Intradermally Administered Yellow Fever Vaccine at Reduced Dose Induces a Protective Immune Response: A Randomized Controlled Non-Inferiority Trial

    NARCIS (Netherlands)

    M.G. Roukens (Guy); A.C.Th.M. Vossen (Ann); P.J. Bredenbeek (Peter); J.T. van Dissel (Jaap); L.G. Visser (Leo)

    2008-01-01

    textabstractBackground:Implementation of yellow fever vaccination is currently hampered by limited supply of vaccine. An alternative route of administration with reduced amounts of vaccine but without loss of vaccine efficacy would boost vaccination programmes.Methods and Findings:A randomized,

  11. Native whey induces higher and faster leucinemia than other whey protein supplements and milk: A randomized controlled trial

    Science.gov (United States)

    Resistance exercise and protein intake are both strong stimuli for muscle protein synthesis. The potential for a protein to acutely increase muscle protein synthesis seems partly dependent on absorption kinetics and the amino acid composition. The aim of this double-blinded randomized cross-over stu...

  12. Early reversal of profound rocuronium-induced neuromuscular blockade by sugammadex in a randomized multicenter study - Efficacy, safety, and pharmacokinetics

    NARCIS (Netherlands)

    Sparr, Harald J.; Vermeyen, Karel M.; Beaufort, Anton M.; Rietbergen, Henk; Proost, Johannes H.; Saldien, Vera; Velik-Salchner, Corinna; Wierda, J. Mark K. H.

    Background: Sugammadex reverses the neuromuscular blocking effects of rocuronium by chemical encapsulation. The efficacy, safety, and pharmacokinetics of sugammadex for reversal of profound rocuronium-induced neuromuscular blockade were evaluated. Methods: Ninety-eight male adult patients were

  13. Ginger for Prevention of Antituberculosis-induced Gastrointestinal Adverse Reactions Including Hepatotoxicity: A Randomized Pilot Clinical Trial.

    Science.gov (United States)

    Emrani, Zahra; Shojaei, Esphandiar; Khalili, Hossein

    2016-06-01

    In this study, the potential benefits of ginger in preventing antituberculosis drug-induced gastrointestinal adverse reactions including hepatotoxicity have been evaluated in patients with tuberculosis. Patients in the ginger and placebo groups (30 patients in each group) received either 500 mg ginger (Zintoma)(®) or placebo one-half hour before each daily dose of antituberculosis drugs for 4 weeks. Patients' gastrointestinal complaints (nausea, vomiting, dyspepsia, and abdominal pain) and antituberculosis drug-induced hepatotoxicity were recorded during the study period. In this cohort, nausea was the most common antituberculosis drug-induced gastrointestinal adverse reactions. Forty eight (80%) patients experienced nausea. Nausea was more common in the placebo than the ginger group [27 (90%) vs 21 (70%), respectively, p = 0.05]. During the study period, 16 (26.7%) patients experienced antituberculosis drug-induced hepatotoxicity. Patients in the ginger group experienced less, but not statistically significant, antituberculosis drug-induced hepatotoxicity than the placebo group (16.7% vs 36.7%, respectively, p = 0.07). In conclusion, ginger may be a potential option for prevention of antituberculosis drug-induced gastrointestinal adverse reactions including hepatotoxicity. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Efficacy of Sucralfate Mouth Wash in Prevention of 5-fluorouracil Induced Oral Mucositis: A Prospective, Randomized, Double-Blind, Controlled Trial.

    Science.gov (United States)

    Ala, Shahram; Saeedi, Majid; Janbabai, Ghasem; Ganji, Reza; Azhdari, Elham; Shiva, Afshin

    2016-01-01

    Sucralfate has been used for the prevention and treatment of radiotherapy- and chemotherapy-induced stomatitis and mucositis in a number of studies, but the results are contradictory. To answer such discrepancies, the present study was designed to evaluate the efficacy of sucralfate mouthwash in prevention of 5-fluorouracil (5-FU)-induced oral mucositis in patients with gastrointestinal malignancies. Patients with gastrointestinal cancers receiving 5-FU-based chemotherapy regimens were included in this randomized, blinded, controlled trial and were randomly allocated to either sucralfate mouthwash (every 6 h) or placebo. The patients were visited at fifth and tenth day of trial; the presence and severity of oral mucositis and the intensity of pain were assessed. The patients receiving sucralfate experienced lower frequency and severity of mucositis (76% vs. 38.5%, P = 0.005 and 84 vs. 38.5%, P < 0.001, respectively) and less intense pain (2.5 ± 2.2 vs. 5.08 ± 3.82, P = 0.004 and 1.33 ± 0.86 vs. 4.12 ± 3.5, P = 0.001, respectively) compared with the placebo group both at day 5 and day 10. Within the sucralfate group, a decrease in frequency and severity of mucositis was observed throughout the trial period, while in the placebo group no such effect was observed. Sucralfate mouthwash reduced the frequency and severity of 5-FU-induced oral mucositis in patients with gastrointestinal malignancies compared with placebo, indicating its efficacy in the prevention of chemotherapy-induced mucositis.

  15. Electroacupuncture prevents endothelial dysfunction induced by ischemia-reperfusion injury via a cyclooxygenase-2-dependent mechanism: A randomized controlled crossover trial.

    Directory of Open Access Journals (Sweden)

    Seung Min Kathy Lee

    Full Text Available Exploring clinically effective methods to reduce ischemia-reperfusion (IR injury in humans is critical. Several drugs have shown protective effects, but studies using other interventions have been rare. Electroacupuncture (EA has induced similar protection in several animal studies but no study has investigated how the effects could be translated and reproduced in humans. This study aimed to explore the potential effect and mechanisms of EA in IR-induced endothelial dysfunction in humans.This is a prospective, randomized, crossover, sham-controlled trial consisting of two protocols. Protocol 1 was a crossover study to investigate the effect of EA on IR-induced endothelial dysfunction. Twenty healthy volunteers were randomly assigned to EA or sham EA (sham. Flow mediated dilation (FMD of the brachial artery (BA, nitroglycerin-mediated endothelial independent dilation, blood pressure before and after IR were measured. In protocol 2, seven volunteers were administered COX-2 inhibitor celecoxib (200 mg orally twice daily for five days. After consumption, volunteers underwent FMD before and after IR identical to protocol 1.In protocol 1, baseline BA diameter, Pre-IR BA diameter and FMD were similar between the two groups (p = NS. After IR, sham group showed significantly blunted FMD (Pre-IR: 11.41 ± 3.10%, Post-IR: 4.49 ± 2.04%, p < 0.001. However, EA protected this blunted FMD (Pre-IR: 10.96 ± 5.30%, Post-IR: 9.47 ± 5.23%, p = NS, p < 0.05 compared with sham EA after IR. In protocol 2, this protective effect was completely abolished by pre-treatment with celecoxib (Pre-IR: 11.05 ± 3.27%; Post-IR: 4.20 ± 1.68%, p = 0.001.EA may prevent IR-induced endothelial dysfunction via a COX-2 dependent mechanism.

  16. Electroacupuncture prevents endothelial dysfunction induced by ischemia-reperfusion injury via a cyclooxygenase-2-dependent mechanism: A randomized controlled crossover trial

    Science.gov (United States)

    Park, Jimin; Woo, Jong Shin; Leem, Jungtae; Park, Jun Hyeong; Lee, Sanghoon; Chung, Hyemoon; Lee, Jung Myung; Kim, Jin-Bae; Kim, Woo-Shik; Kim, Kwon Sam; Kim, Weon

    2017-01-01

    Objective Exploring clinically effective methods to reduce ischemia-reperfusion (IR) injury in humans is critical. Several drugs have shown protective effects, but studies using other interventions have been rare. Electroacupuncture (EA) has induced similar protection in several animal studies but no study has investigated how the effects could be translated and reproduced in humans. This study aimed to explore the potential effect and mechanisms of EA in IR-induced endothelial dysfunction in humans. Methods This is a prospective, randomized, crossover, sham-controlled trial consisting of two protocols. Protocol 1 was a crossover study to investigate the effect of EA on IR-induced endothelial dysfunction. Twenty healthy volunteers were randomly assigned to EA or sham EA (sham). Flow mediated dilation (FMD) of the brachial artery (BA), nitroglycerin-mediated endothelial independent dilation, blood pressure before and after IR were measured. In protocol 2, seven volunteers were administered COX-2 inhibitor celecoxib (200 mg orally twice daily) for five days. After consumption, volunteers underwent FMD before and after IR identical to protocol 1. Results In protocol 1, baseline BA diameter, Pre-IR BA diameter and FMD were similar between the two groups (p = NS). After IR, sham group showed significantly blunted FMD (Pre-IR: 11.41 ± 3.10%, Post-IR: 4.49 ± 2.04%, p < 0.001). However, EA protected this blunted FMD (Pre-IR: 10.96 ± 5.30%, Post-IR: 9.47 ± 5.23%, p = NS, p < 0.05 compared with sham EA after IR). In protocol 2, this protective effect was completely abolished by pre-treatment with celecoxib (Pre-IR: 11.05 ± 3.27%; Post-IR: 4.20 ± 1.68%, p = 0.001). Conclusion EA may prevent IR-induced endothelial dysfunction via a COX-2 dependent mechanism. PMID:28591155

  17. Constraint-Induced Movement Therapy Combined with Transcranial Direct Current Stimulation over Premotor Cortex Improves Motor Function in Severe Stroke: A Pilot Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Suellen M. Andrade

    2017-01-01

    Full Text Available Objective. We compared the effects of transcranial direct current stimulation at different cortical sites (premotor and motor primary cortex combined with constraint-induced movement therapy for treatment of stroke patients. Design. Sixty patients were randomly distributed into 3 groups: Group A, anodal stimulation on premotor cortex and constraint-induced movement therapy; Group B, anodal stimulation on primary motor cortex and constraint-induced movement therapy; Group C, sham stimulation and constraint-induced movement therapy. Evaluations involved analysis of functional independence, motor recovery, spasticity, gross motor function, and muscle strength. Results. A significant improvement in primary outcome (functional independence after treatment in the premotor group followed by primary motor group and sham group was observed. The same pattern of improvement was highlighted among all secondary outcome measures regarding the superior performance of the premotor group over primary motor and sham groups. Conclusions. Premotor cortex can contribute to motor function in patients with severe functional disabilities in early stages of stroke. This study was registered in ClinicalTrials.gov database (NCT 02628561.

  18. A new method to characterize dopant profiles in NMOSFETs using conventional transmission electron microscopy

    International Nuclear Information System (INIS)

    Kawamura, Kazuo; Ikeda, Kazuto; Terauchi, Masami

    2004-01-01

    We have developed a new method using conventional transmission electron microscopy (TEM) to obtain two dimensional dopant profiles in silicon and applied it to 40 nm-gate-length N + /p metal oxide semiconductor field effect transistors (MOSFETs). The results are consistent with those of selective-chemically etched samples observed by TEM. This method, using focused ion beam (FIB) sample preparation and conventional TEM, has the great advantage of simple sample preparation and high spatial resolution compared to other characterization methods, such as atomic capacitance microscopy, spreading resistance microscopy, and TEM combined with selective chemical etching. This indicates that this method can be applicable to the analysis of FETs at the 65 nm or smaller node

  19. Effect of indium dopant on surface and mechanical characteristics of ZnO : In nanostructured films

    Energy Technology Data Exchange (ETDEWEB)

    Fang, T.-H.; Kang, S.-H. [Institute of Mechanical and Electromechanical Engineering, National Formosa University, No 64, Wenhua Rd., Huwei, Yunlin 632, Taiwan (China)], E-mail: fang.tehua@msa.hinet.net

    2008-12-21

    Epitaxial ZnO : In nanorod films were grown on SiO{sub 2} substrates using a chemical solution method with a pre-coated ZnO sputtered seed layer. Structural and surface characterizations of the ZnO : In nanostructured films were achieved by means of x-ray diffraction, a scanning electron microscope, an atomic force microscope and contact angle measurements. The hardness and Young's modulus of the nanostructured films were investigated by nanoindentation measurements. The results showed that when the indium dopant was increased, the hardness and Young's modulus of the films also rose. The films exhibited hydrophobic behaviour with contact angles of about 128-138 deg., and a decrease in the hardness and Young's modulus with decreasing loads or indentation depths. Buckling behaviour took place during the indentation process, and the fracture strength of the films was also discussed.

  20. Metalorganic chemical vapor deposition of ZnO:N using NO as dopant

    International Nuclear Information System (INIS)

    Dangbegnon, J.K.; Talla, K.; Roro, K.T.; Botha, J.R.

    2009-01-01

    Highly c-axis orientated ZnO was grown by metal organic chemical vapor deposition (MOCVD) using NO as both oxidant and nitrogen dopant source. The properties of the deposited material are investigated by X-ray diffraction to study the crystalline quality of the thin films. Photoluminescence measurements are used to determine the optical properties of the material as a function of VI/II ratio and post growth-annealing temperature. Two transitions appear at 3.228 and 3.156 eV and are interpreted as involving active nitrogen acceptors. An increase in the NO flow increases the concentration of nitrogen in the films, which are activated by subsequent annealing at 600 deg. C in an oxygen ambient.

  1. Metalorganic chemical vapor deposition of ZnO:N using NO as dopant

    Energy Technology Data Exchange (ETDEWEB)

    Dangbegnon, J.K., E-mail: JulienKouadio.Dangbegnon@nmmu.ac.z [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Talla, K.; Roro, K.T.; Botha, J.R. [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2009-12-01

    Highly c-axis orientated ZnO was grown by metal organic chemical vapor deposition (MOCVD) using NO as both oxidant and nitrogen dopant source. The properties of the deposited material are investigated by X-ray diffraction to study the crystalline quality of the thin films. Photoluminescence measurements are used to determine the optical properties of the material as a function of VI/II ratio and post growth-annealing temperature. Two transitions appear at 3.228 and 3.156 eV and are interpreted as involving active nitrogen acceptors. An increase in the NO flow increases the concentration of nitrogen in the films, which are activated by subsequent annealing at 600 deg. C in an oxygen ambient.

  2. Role of dopant in annealing of chemical radiation damage in potassium nitrate

    International Nuclear Information System (INIS)

    Mohapatra, B.M.; Bhatta, D.

    1984-01-01

    The role of cationic vacancy in th annealing of gamma-irradiated potassium nitrate has been investigated using Ba 2+ as a dopant. Isothermal annealing data show that the pure potassium nitrate is immune to annealing above and below the temperature of crystal transition 127degC (Rhombic↔tTrigonal), while the doped crystals undergo recovery by a combination of one first order and one second order process above the phase change and by a second order process below this temperature. The recovery process above 127degC is initially fast (upto 1 hr) but subsequently it slows down to a pseudo-plateau. The proportion of damage which recombines by first and second order processes is 40.6 and 59.4 respectively. (author)

  3. Contributed Review: A review of the investigation of rare-earth dopant profiles in optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Sidiroglou, F.; Baxter, G. [Optical Technology Research Laboratory, College of Engineering and Science, Victoria University, P.O. Box 14428, Melbourne, VIC 8001 (Australia); Roberts, A. [School of Physics, The University of Melbourne, Melbourne, VIC 3010 (Australia)

    2016-04-15

    Rare-earth doped optical fibers have captivated the interest of many researchers around the world across the past three decades. The growth of this research field has been stimulated primarily through their application in optical communications as fiber lasers and amplifiers, although rare-earth doped optical fiber based devices are now finding important uses in many other scientific and industrial areas (for example, medicine, sensing, the military, and material processing). Such wide commercial interest has provided a strong incentive for innovative fiber designs, alternative glass compositions, and novel fabrication processes. A prerequisite for the ongoing progress of this research field is developing the capacity to provide high resolution information about the rare-earth dopant distribution profiles within the optical fibers. This paper constitutes a comprehensive review of the imaging techniques that have been utilized in the analysis of the distribution of the rare-earth ion erbium within the core of optical fibers.

  4. Operation and scalability of dopant-segregated Schottky barrier MOSFETs with recessed channels

    International Nuclear Information System (INIS)

    Shih, Chun-Hsing; Hsia, Jui-Kai

    2013-01-01

    Recessed channels were used in scaled dopant-segregated Schottky barrier MOSFETs (DS-SBMOS) to control the severe short-channel effect. The physical operation and device scalability of the DS-SBMOS resulting from the presence of recessed channels and associated gate-corners are elucidated. The coupling of Schottky and gate-corner barriers has a key function in determining the on–off switching and drain current. The gate-corner barriers divide the channel into three regions for protection from the drain penetration field. To prevent resistive degradations in the drive current, an alternative asymmetric recessed channel (ARC) without a source-side gate-corner is proposed to simultaneously optimize both the short-channel effect and drive current in the scaled DS-SBMOS. By employing the proposed ARC architecture, the DS-SBMOS devices can be successfully scaled down, making them promising candidates for next-generation CMOS devices. (paper)

  5. Study of the chlorine as dopant in synthesized polymers by plasma

    International Nuclear Information System (INIS)

    Vasquez, M.; Cruz, G.; Olayo, M.G.; Timoshina, T.; Morales, J.; Olayo, R.

    2003-01-01

    In the search of new and better dopants for semiconductor polymers, in this work the synthesis by plasma and the characterization of two doped polymers with chlorine, Pyrrole (PPy) and Thiophene (PTh) is presented. The characterization of the polymers it was carried out by FT-lR, it shows the C-Cl vibration that it is confirmed with the X-ray photoelectron spectroscopy technique (XPS). The elementary analysis shows a greater quantity of Cl in the PTh-CI compared with PPy-CI. However, this effect is not reflected in the electric conductivity since the PTh-Cl presents a lightly greater conductivity than the PPy-CI. SEM shows a formed structure of small agglomerated spheres of different size. (Author)

  6. A survey of acceptor dopants for β-Ga2O3

    Science.gov (United States)

    Lyons, John L.

    2018-05-01

    With a wide band gap, high critical breakdown voltage and commercially available substrates, Ga2O3 is a promising material for next-generation power electronics. Like most wide-band-gap semiconductors, obtaining better control over its electrical conductivity is critically important, but has proven difficult to achieve. Although efficient p-type doping in Ga2O3 is not expected, since theory and experiment indicate the self-trapping of holes, the full development of this material will require a better understanding of acceptor dopants. Here the properties of group 2, group 5 and group 12 acceptor impurities in β-Ga2O3 are explored using hybrid density functional calculations. All impurities are found to exhibit acceptor transition levels above 1.3 eV. After examining formation energies as a function of chemical potential, Mg (followed closely by Be) is determined to be the most stable acceptor species.

  7. Restoring the lattice of Si-based atom probe reconstructions for enhanced information on dopant positioning.

    Science.gov (United States)

    Breen, Andrew J; Moody, Michael P; Ceguerra, Anna V; Gault, Baptiste; Araullo-Peters, Vicente J; Ringer, Simon P

    2015-12-01

    The following manuscript presents a novel approach for creating lattice based models of Sb-doped Si directly from atom probe reconstructions for the purposes of improving information on dopant positioning and directly informing quantum mechanics based materials modeling approaches. Sophisticated crystallographic analysis techniques are used to detect latent crystal structure within the atom probe reconstructions with unprecedented accuracy. A distortion correction algorithm is then developed to precisely calibrate the detected crystal structure to the theoretically known diamond cubic lattice. The reconstructed atoms are then positioned on their most likely lattice positions. Simulations are then used to determine the accuracy of such an approach and show that improvements to short-range order measurements are possible for noise levels and detector efficiencies comparable with experimentally collected atom probe data. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Simple structured hybrid WOLEDs based on incomplete energy transfer mechanism: from blue exciplex to orange dopant

    Science.gov (United States)

    Zhang, Tianyou; Zhao, Bo; Chu, Bei; Li, Wenlian; Su, Zisheng; Yan, Xingwu; Liu, Chengyuan; Wu, Hairuo; Gao, Yuan; Jin, Fangming; Hou, Fuhua

    2015-05-01

    Exciplex is well known as a charge transfer state formed between electron-donating and electron-accepting molecules. However, exciplex based organic light emitting diodes (OLED) often performed low efficiencies relative to pure phosphorescent OLED and could hardly be used to construct white OLED (WOLED). In this work, a new mechanism is developed to realize efficient WOLED with extremely simple structure by redistributing the energy of triplet exciplex to both singlet exciplex and the orange dopant. The micro process of energy transfer could be directly examined by detailed photoluminescence decay measurement and time resolved photoluminescence analysis. This strategy overcomes the low reverse intersystem crossing efficiency of blue exciplex and complicated device structure of traditional WOLED, enables us to achieve efficient hybrid WOLEDs. Based on this mechanism, we have successfully constructed both exciplex-fluorescence and exciplex-phosphorescence hybrid WOLEDs with remarkable efficiencies.

  9. Current status of models for transient phenomena in dopant diffusion and activation

    International Nuclear Information System (INIS)

    Pichler, P.; Stiebel, D.

    2002-01-01

    Transient phenomena caused by ion-implantation processes have been studied for more than 25 years now with a continuously increasing number of research articles published in this field per year. One driving force of this research is the ongoing miniaturization of ULSI MOS and bipolar technology which uses extensively the capabilities of technology-computer-aided-design (TCAD). The other driving force which attracts also academic institutions and research institutes is the high complexity of the phenomena, involving the interaction of dopants, intrinsic point defects, extended defects and impurities like carbon as well as the interactions of mobile defects with surfaces and interfaces and their redistribution in multilayer structures. This paper outlines some recent advances towards a quantitative description of such phenomena

  10. Off-axis electron holography for the measurement of active dopants in silicon semiconductor devices

    International Nuclear Information System (INIS)

    Cooper, David

    2016-01-01

    There is a need in the semiconductor industry for a dopant profiling technique with nm-scale resolution. Here we demonstrate that off-axis electron holography can be used to provide maps of the electrostatic potential in semiconductor devices with nm-scale resolution. In this paper we will discuss issues regarding the spatial resolution and precision of the technique. Then we will discuss problems with specimen preparation and how this affects the accuracy of the measurements of the potentials. Finally we show results from experimental off-axis electron holography applied to nMOS and pMOS CMOS devices grown on bulk silicon and silicon- on-insulator type devices and present solutions to common problems that are encountered when examining these types of devices. (paper)

  11. Scintillation characteristic of In, Ga-doped ZnO thin films with different dopant concentrations

    International Nuclear Information System (INIS)

    Fujimoto, Yutaka; Yanagida, Takayuki; Yokota, Yuui; Chani, Valery; Yoshikawa, Akira; Sekiwa, Hideyuki

    2011-01-01

    The present study describes the first detailed evaluation of the rise and the decay time of scintillation phenomenon in In 3+ - and Ga 3+ -doped ZnO thin films with different dopant concentrations. In 3+ -(25, 55, and 141 ppm) and Ga 3+ -(33, 67, 333, and 1374 ppm) doped ZnO films were grown by the Liquid Phase Epitaxy (LPE) method. The characterization was performed using the pulse X-ray equipped streak camera system. Both the rise and the decay times were shortened considerably with increasing content of In 3+ and Ga 3+ in the films. However, the scintillation light yield under 241 Am α-ray excitation reduced when concentration of In 3+ and Ga 3+ in the ZnO films was high. (author)

  12. Low-cost copper complexes as p-dopants in solution processable hole transport layers

    Energy Technology Data Exchange (ETDEWEB)

    Kellermann, Renate [Department for Materials Science and Engineering, Chair for Materials for Electronics and Energy Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91058 (Germany); Siemens AG – Corporate Technology, Guenther-Scharowsky-Str. 1, Erlangen 91058 (Germany); Taroata, Dan; Maltenberger, Anna; Hartmann, David; Schmid, Guenter [Siemens AG – Corporate Technology, Guenther-Scharowsky-Str. 1, Erlangen 91058 (Germany); Brabec, Christoph J. [Department for Materials Science and Engineering, Chair for Materials for Electronics and Energy Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91058 (Germany)

    2015-09-07

    We demonstrate the usage of the Lewis-acidic copper(II)hexafluoroacetylacetonate (Cu(hfac){sub 2}) and copper(II)trifluoroacetylacetonate (Cu(tfac){sub 2}) as low-cost p-dopants for conductivity enhancement of solution processable hole transport layers based on small molecules in organic light emitting diodes (OLEDs). The materials were clearly soluble in mixtures of environmentally friendly anisole and xylene and spin-coated under ambient atmosphere. Enhancements of two and four orders of magnitude, reaching 4.0 × 10{sup −11} S/cm with a dopant concentration of only 2 mol% Cu(hfac){sub 2} and 1.5 × 10{sup −9} S/cm with 5 mol% Cu(tfac){sub 2} in 2,2′,7,7′-tetra(N,N-ditolyl)amino-9,9-spiro-bifluorene (spiro-TTB), respectively, were achieved. Red light emitting diodes were fabricated with reduced driving voltages and enhanced current and power efficiencies (8.6 lm/W with Cu(hfac){sub 2} and 5.6 lm/W with Cu(tfac){sub 2}) compared to the OLED with undoped spiro-TTB (3.9 lm/W). The OLED with Cu(hfac){sub 2} doped spiro-TTB showed an over 8 times improved LT{sub 50} lifetime of 70 h at a starting luminance of 5000 cd/m{sup 2}. The LT{sub 50} lifetime of the reference OLED with PEDOT:PSS was only 8 h. Both non-optimized OLEDs were operated at similar driving voltage and power efficiency.

  13. Local structure investigation of Ga and Yb dopants in Co4Sb12 skutterudites

    Science.gov (United States)

    Hu, Yanyun; Chen, Ning; Clancy, J. P.; Salvador, James R.; Kim, Chang-Yong; Shi, Xiaoya; Li, Qiang; Kim, Young-June

    2017-12-01

    We report comprehensive x-ray absorption spectroscopy studies at both the Ga K edge and Yb L2 edge to elucidate the local structure of Ga and Yb dopants in YbxGayCo4Sb12 . Our extended x-ray absorption fine structure (EXAFS) data confirm that Ga atoms occupy two crystallographic sites: one is the 24 g site replacing Sb, and the other is the 2 a site in the off-center void position. We find that the occupancy ratio of these two sites varies significantly as a function of the filling fraction of additional Yb, which exclusively occupies the 2 a on-center site. At low concentrations of Yb, Ga24 g and Ga2 a dopants coexist and they form a charge-compensated compound defect proposed by Qiu et al. [Adv. Funct. Mater. 23, 3194 (2013), 10.1002/adfm.201202571]. The Ga24 g occupancy increases gradually with increasing Yb concentration, and almost all Ga occupies the 24 g site for the highest Yb concentration studied (x =0.4 ). In addition to the local structural evidence provided by our EXAFS data, we also present x-ray absorption near-edge structure (XANES) spectra, which show a small Ga K -edge energy shift as a function of Yb concentration consistent with the change from predominantly Ga2 a to Ga24 g states. Our result suggests that the increased solubility of Yb in Yb-Ga co-doped Co4Sb12 skutterudites is due to the increased Ga24 g electron acceptor, and thus provides an important strategy to optimize the carrier concentration in partially filled skutterudites.

  14. Sintering of nickel catalysts. Effects of time, atmosphere, temperature, nickel-carrier interactions, and dopants

    Energy Technology Data Exchange (ETDEWEB)

    Sehested, Jens; Gelten, Johannes A.P.; Helveg, Stig [Haldor Topsoee A/S, Nymoellevej 55, DK-2800 Kgs. Lyngby (Denmark)

    2006-08-01

    Supported nickel catalysts are widely used in the steam-reforming process for industrial scale production of hydrogen and synthesis gas. This paper provides a study of sintering in nickel-based catalysts (Ni/Al{sub 2}O{sub 3} and Ni/MgAl{sub 2}O{sub 4}). Specifically the influence of time, temperature, atmosphere, nickel-carrier interactions and dopants on the rate of sintering is considered. To probe the sintering kinetics, all catalysts were analyzed by sulfur chemisorption to determine the Ni surface area. Furthermore selected samples were further analyzed using X-ray diffraction (XRD), mercury porosimetry, BET area measurements, and electron microscopy (EM). The observed sintering rates as a function of time, temperature, and P{sub H{sub 2}O}/P{sub H{sub 2}} ratio were consistent with recent model predictions [J. Sehested, J.A.P. Gelten, I.N. Remediakis, H. Bengaard, J.K. Norskov, J. Catal. 223 (2004) 432] over a broad range of environmental conditions. However, exposing the catalysts to severe sintering conditions the loss of nickel surface area is faster than model predictions and the deviation is attributed to a change in the sintering mechanism and nickel removal by nickel-carrier interactions. Surprisingly, alumina-supported Ni particles grow to sizes larger than the particle size of the carrier indicating that the pore diameter does not represent an upper limit for Ni particle growth. The effects of potassium promotion and sulfur poisoning on the rates of sintering were also investigated. No significant effects of the dopants were observed after ageing at ambient pressure. However, at high pressures of steam and hydrogen (31bar and H{sub 2}O:H{sub 2}=10:1) potassium promotion increased the sintering rate relative to that of the unpromoted catalyst. Sulfur also enhances the rate of sintering at high pressures, but the effect of sulfur is less than for potassium. (author)

  15. Effects of Chromium Dopant on Ultraviolet Photoresponsivity of ZnO Nanorods

    Science.gov (United States)

    Mokhtari, S.; Safa, S.; Khayatian, A.; Azimirad, R.

    2017-07-01

    Structural and optical properties of bare ZnO nanorods, ZnO-encapsulated ZnO nanorods, and Cr-doped ZnO-encapsulated ZnO nanorods have been investigated. Encapsulated ZnO nanorods were grown using a simple two-stage method in which ZnO nanorods were first grown on a glass substrate directly from a hydrothermal bath, then encapsulated with a thin layer of Cr-doped ZnO by dip coating. Comparative study of x-ray diffraction patterns showed that Cr was successfully incorporated into the shell layer of ZnO nanorods. Moreover, energy-dispersive x-ray spectroscopy confirmed presence of Cr in this sample. It was observed that the thickness of the shell layer around the core of the ZnO nanorods was at least about 20 nm. Transmission electron microscopy of bare ZnO nanorods revealed single-crystalline structure. Based on optical results, both the encapsulation process and addition of Cr dopant decreased the optical bandgap of the samples. Indeed, the optical bandgap values of Cr-doped ZnO-encapsulated ZnO nanorods, ZnO-encapsulated ZnO nanorods, and bare ZnO nanorods were 2.89 eV, 3.15 eV, and 3.34 eV, respectively. The ultraviolet (UV) parameters demonstrated that incorporation of Cr dopant into the shell layer of ZnO nanorods considerably facilitated formation and transportation of photogenerated carriers, optimizing their performance as a practical UV detector. As a result, the photocurrent of the Cr-doped ZnO-encapsulated ZnO nanorods was the highest (0.6 mA), compared with ZnO-encapsulated ZnO nanorods and bare ZnO nanorods (0.21 mA and 0.06 mA, respectively).

  16. The Role of Dopant Ions on Charge Injection and Transport in Electrochemically Doped Quantum Dot Films

    Science.gov (United States)

    2018-01-01

    Control over the charge density is very important for implementation of colloidal semiconductor nanocrystals into various optoelectronic applications. A promising approach to dope nanocrystal assemblies is charge injection by electrochemistry, in which the charge compensating electrolyte ions can be regarded as external dopant ions. To gain insight into the doping mechanism and the role of the external dopant ions, we investigate charge injection in ZnO nanocrystal assemblies for a large series of charge compensating electrolyte ions with spectroelectrochemical and electrochemical transistor measurements. We show that charge injection is limited by the diffusion of cations in the nanocrystal films as their diffusion coefficient are found to be ∼7 orders of magnitude lower than those of electrons. We further show that the rate of charge injection depends strongly on the cation size and cation concentration. Strikingly, the onset of electron injection varies up to 0.4 V, depending on the size of the electrolyte cation. For the small ions Li+ and Na+ the onset is at significantly less negative potentials. For larger ions (K+, quaternary ammonium ions) the onset is always at the same, more negative potential, suggesting that intercalation may take place for Li+ and Na+. Finally, we show that the nature of the charge compensating cation does not affect the source-drain electronic conductivity and mobility, indicating that shallow donor levels from intercalating ions fully hybridize with the quantum confined energy levels and that the reorganization energy due to intercalating ions does not strongly affect electron transport in these nanocrystal assemblies. PMID:29718666

  17. Theoretical characterization of a class of orange dopants for white-light-emitting single polymers

    International Nuclear Information System (INIS)

    Hu, Bo; Yao, Chan; Wang, Qingwei; Zhang, Hao; Yu, Jiankang

    2012-01-01

    New single-polymer white electroluminescent systems containing two individual emission species − polyfluorene as a blue host and 2,1,3-benzothiadiazole(BTD) derivative as an orange dopant − have been designed and investigated on the basis of the quantum chemical calculations. Calculations show that the change of chemical composition along the backbone in BTD-based derivative yields modifications to the electronic and optical properties. Furthermore, by introducing electron-donating groups [−CH 3 , –OCH 3 , and –NH 2 ] on terminal N,N-disubstituted amino groups, desirable orange emission can be obtained and may be further combined with polyfluorene to form white light. Also, we estimate the reorganization energies upon cation or anion formation as one of the important parameters of mobility with the charge hopping model to determine whether the molecular structural changes may improve the hole/electron transport. The electrostatic surface potentials are finally taken into account to evaluate stability. -- Graphical abstract: New single-polymer white electroluminescent systems containing two individual emission species − polyfluorene as a blue host and 2,1,3-benzothiadiazole(BTD) derivative as an orange dopant − have been designed and investigated on the basis of the quantum chemical calculations. Highlights: ► The change of chemical composition along the backbone yields modifications to the electronic and optical properties. ► Introducing [–CH 3 , –OCH 3 , and –NH 2 ] on terminal N,N-disubstituted amino groups, desirable orange emission can be obtained. ► Desirable orange emission may be further combined with polyfluorene to form white light. ► Designed BTD-based derivatives can function as good hole or ambipolar transport materials in the OLEDs. ► According to the calculated electrostatic surface potentials, OMC-PZ has better stability than that of OMC-PZT.

  18. The Preliminary Effects of Massage and Inhalation Aromatherapy on Chemotherapy-Induced Acute Nausea and Vomiting: A Quasi-Randomized Controlled Pilot Trial.

    Science.gov (United States)

    Zorba, Pinar; Ozdemir, Leyla

    2017-04-20

    Despite pharmacological treatment, chemotherapy-induced nausea and vomiting (CINV) are observed in patients. This quasi-randomized controlled pilot study evaluated the feasibility and preliminary effects of massage and inhalation aromatherapies on chemotherapy-induced acute nausea/vomiting. Seventy-five patients with breast cancer were randomly grouped into 1 of 3 groups: massage (n = 25), inhalation (n = 25), and control (n = 25). The patients in the massage group received 20-minute aromatherapy foot massage, whereas those in the inhalation group received 3-minute inhalation aromatherapy before their second, third, and fourth chemotherapy cycles. The control group underwent only the routine treatment. A nausea, vomiting, and retching patient follow-up form was used to evaluate nausea severity by visual analog scale and frequency of vomiting and retching. The incidence of nausea and retching was significantly higher in the control group than in the other groups in the third and fourth chemotherapy cycles (P aromatherapy groups than in the control group. Nausea and retching incidence was reduced in the aromatherapy groups compared with that in the control group. Nonpharmacological approaches are recommended for managing CINV. Massage and inhalation aromatherapy seems promising regarding the management of CINV.

  19. Effect of Kangfuxin Solution on Chemo/Radiotherapy-Induced Mucositis in Nasopharyngeal Carcinoma Patients: A Multicenter, Prospective Randomized Phase III Clinical Study

    Directory of Open Access Journals (Sweden)

    Yangkun Luo

    2016-01-01

    Full Text Available Objective. To evaluate the efficacy and safety of Kangfuxin Solution, a pure Chinese herbal medicine, on mucositis induced by chemoradiotherapy in nasopharyngeal carcinoma patients. Methods. A randomized, parallel-group, multicenter clinical study was performed. A total of 240 patients were randomized to receive either Kangfuxin Solution (test group or compound borax gargle (control group during chemoradiotherapy. Oral mucositis, upper gastrointestinal mucositis, and oral pain were evaluated by Common Terminology Criteria for Adverse Events (CTCAE v3.0 and the Verbal Rating Scale (VRS. Results. Of 240 patients enrolled, 215 were eligible for efficacy analysis. Compared with the control group, the incidence and severity of oral mucositis in the test group were significantly reduced (P=0.01. The time to different grade of oral mucositis occurrence (grade 1, 2, or 3 was longer in test group (P<0.01, and the accumulated radiation dose was also higher in test group comparing to the control group (P<0.05. The test group showed lower incidence of oral pain and gastrointestinal mucositis than the control group (P<0.01. No significant adverse events were observed. Conclusion. Kangfuxin Solution demonstrated its superiority to compound borax gargle on mucositis induced by chemoradiotherapy. Its safety is acceptable for clinical application.

  20. Improvement of stance control and muscle performance induced by focal muscle vibration in young-elderly women: a randomized controlled trial.

    Science.gov (United States)

    Filippi, Guido M; Brunetti, Orazio; Botti, Fabio M; Panichi, Roberto; Roscini, Mauro; Camerota, Filippo; Cesari, Matteo; Pettorossi, Vito E

    2009-12-01

    Filippi GM, Brunetti O, Botti FM, Panichi R, Roscini M, Camerota F, Cesari M, Pettorossi VE. Improvement of stance control and muscle performance induced by focal muscle vibration in young-elderly women: a randomized controlled trial. To determine the effect of a particular protocol of mechanical vibration, applied focally and repeatedly (repeated muscle vibration [rMV]) on the quadriceps muscles, on stance and lower-extremity muscle power of young-elderly women. Double-blind randomized controlled trial; 3-month follow-up after intervention. Human Physiology Laboratories, University of Perugia, Italy. Sedentary women volunteers (N=60), randomized in 3 groups (mean age +/- SD, 65.3+/-4.2y; range, 60-72). rMV (100Hz, 300-500microm, in three 10-minute sessions a day for 3 consecutive days) was applied to voluntary contracted quadriceps (vibrated and contracted group) and relaxed quadriceps (vibrated and relaxed group). A third group received placebo stimulation (nonvibrated group). Area of sway of the center of pressure, vertical jump height, and leg power. Twenty-four hours after the end of the complete series of applications, the area of sway of the center of pressure decreased significantly by approximately 20%, vertical jump increased by approximately 55%, and leg power increased by approximately 35%. These effects were maintained for at least 90 days after treatment. rMV is a short-lasting and noninvasive protocol that can significantly and persistently improve muscle performance in sedentary young-elderly women.

  1. Anomalous radial and angular strain relaxation around dilute p-, isoelectronic-, and n-type dopants in Si crystal

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Mingshu [School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui Province 230026 (China); Dong, Juncai, E-mail: dongjc@ihep.ac.cn [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, Dongliang [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2017-02-01

    Doping is widely applied in yielding desirable properties and functions in silicon technology; thus, fully understanding the relaxation mechanism for lattice-mismatch strain is of fundamental importance. Here we systematically study the local lattice distortion near dilute IIIA-, IVA-, and VA-group substitutional dopants in Si crystal using density functional theory, and anomalous radial and angular strain relaxation modes are first revealed. Both the nearest-neighbor (NN) bond-distances and the tetrahedral bond-angles are found to exhibit completely opposite dependence on the electronic configurations for the low Z (Z<26) and high Z (Z>26) dopants. More surprisingly, negative and positive angular shifts for the second NN twelve Si2 atoms are unveiled surrounding the p- and n-type dopants, respectively. While electron localization function shows that the doped hole and electron are highly localized near the dopants, hence being responsible for the abnormal angular shifts, a universal radial strain relaxation mechanism dominated by a competition of the Coulomb interactions among the ion-core, bond-charge, and the localized hole or electron is also proposed. These findings may prove to be instrumental in precise design of silicon-based solotronics.

  2. P2 Asymmetry of Au's M-band Flux and its smoothing effect due to high-Z ablator dopants

    Science.gov (United States)

    Li, Yongsheng; Zhai, Chuanlei; Ren, Guoli; Gu, Jianfa; Huo, Wenyi; Meng, Xujun; Ye, Wenhua; Lan, Ke; Zhang, Weiyan

    2017-10-01

    X-ray drive asymmetry is one of the main seeds of low-mode implosion asymmetry that blocks further improvement of the nuclear performance of ``high-foot'' experiments on the National Ignition Facility. More particularly, the P2 asymmetry of Au's M-band flux can also severely influence the implosion performance. Here we study the smoothing effect of mid- and/or high-Z dopants in ablator on M-band flux asymmetries, by modeling and comparing the implosion processes of a Ge-doped and a Si-doped ignition capsule driven by x-ray sources with asymmetric M-band flux. As the results, (1) mid- or high-Z dopants absorb M-band flux and re-emit isotropically, helping to smooth M-band flux arriving at the ablation front, therefore reducing the P2 asymmetries of the imploding shell and hot spot; (2) the smoothing effect of Ge-dopant is more remarkable than Si-dopant due to its higher opacity than the latter in Au's M-band; and (3) placing the doped layer at a larger radius in ablator is more efficient. Applying this effect may not be a main measure to reduce the low-mode implosion asymmetry, but might be of significance in some critical situations such as Inertial Confinement Fusion (ICF) experiments very near the performance cliffs of asymmetric x-ray drives.

  3. On the roles of the dopants in LiF: Mg,Cu,Na,Si thermoluminescent material

    International Nuclear Information System (INIS)

    Lee, J. I.; Kim, J. L.; Chang, S. Y.; Chung, K. S.; Choe, H. S.

    2005-01-01

    In this paper, some results of the study on the roles of the dopants in the LiF:Mg,Cu,Na,Si thermoluminescent (TL) material that was developed at the Korea Atomic Energy Research Inst. for radiation protection are presented. Although there have been many studies to investigate the roles of the dopants in LiF:Mg,Cu,P TL material in the TL process, there are some discrepancies in the understanding of the roles of Cu and P between various researchers. In case of LiF:Mg,Cu,Na,Si TL material, there are a few studies on the roles of the dopants. Three kinds of samples in each of which one dopant is excluded, and the optimised sample, were prepared for this study. The measurements and analysis of the three-dimensional TL spectra, based on the temperature, wavelength and intensity, and the glow curves for those samples are used in this study. The results show that Mg plays a role in the trapping of the charge carriers and Cu plays a role in the luminescence recombination process; however, the effect of Na and Si on the glow curve structure and the TL emission spectra is much less than that of Mg and Cu. It is considered that Na and Si each plays a role in the improvement of the luminescence efficiency. (authors)

  4. Analysis of the dopant distribution in Co-deposited organic thin films by scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    Paredes, Yolanda A.; Campos, Andrea P.C.; Achete, Carlos A.; Cremona, Marco

    2015-01-01

    Organic light-emitting diodes using phosphorescent dyes (PHOLEDs) have excellent performance, with internal quantum efficiencies approaching 100%. To maximize their performance, PHOLED devices use a conductive organic host material with a sufficiently dispersed phosphorescent guest to avoid concentration quenching. Fac-tris(2-phenylpyridine) iridium, [Ir(ppy)_3] is one of the most widely used green phosphorescent organic compounds. In this work, we used scanning transmission electron microscopy (STEM) equipped with HAADF (high-angle annular dark-field) and EDS (energy dispersive X-ray spectroscopy) detectors to analyze the distribution of the [Ir(ppy)_3] concentration in the host material. This analysis technique, employed for the first time in co-deposited organic thin films, can simultaneously obtain an image and its respective chemical information, allowing for definitive characterization of the distribution and morphology of [Ir(ppy)_3]. The technique was also used to analyze the effect of the vibration of the substrate during thermal co-deposition of the [Ir(ppy)_3] molecules into an organic matrix. - Highlights: • We present a methodology to analyze the dopant distribution in organic thin films. • The method combines HAADF-STEM imaging and EDS X-ray spectroscopy. • Ir(ppy)_3 dopant was co-deposited into Spiro2-CBP organic matrix. • The dopant was co-deposited with and without substrate vibration. • Images and chemical information of the dopant were simultaneously obtained.

  5. Analysis of the dopant distribution in Co-deposited organic thin films by scanning transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Paredes, Yolanda A. [Center of Nanotechnology and Nanoscience, Universidad de las Fuerzas Armadas ESPE, Sangolqui 171-5-31B (Ecuador); Campos, Andrea P.C.; Achete, Carlos A. [DIMAT—INMETRO, Xerém, Duque de Caxias, RJ 25250-020 (Brazil); Cremona, Marco [DIMAT—INMETRO, Xerém, Duque de Caxias, RJ 25250-020 (Brazil); Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, PUC-Rio, Rio de Janeiro, RJ 22453-970 (Brazil)

    2015-12-01

    Organic light-emitting diodes using phosphorescent dyes (PHOLEDs) have excellent performance, with internal quantum efficiencies approaching 100%. To maximize their performance, PHOLED devices use a conductive organic host material with a sufficiently dispersed phosphorescent guest to avoid concentration quenching. Fac-tris(2-phenylpyridine) iridium, [Ir(ppy){sub 3}] is one of the most widely used green phosphorescent organic compounds. In this work, we used scanning transmission electron microscopy (STEM) equipped with HAADF (high-angle annular dark-field) and EDS (energy dispersive X-ray spectroscopy) detectors to analyze the distribution of the [Ir(ppy){sub 3}] concentration in the host material. This analysis technique, employed for the first time in co-deposited organic thin films, can simultaneously obtain an image and its respective chemical information, allowing for definitive characterization of the distribution and morphology of [Ir(ppy){sub 3}]. The technique was also used to analyze the effect of the vibration of the substrate during thermal co-deposition of the [Ir(ppy){sub 3}] molecules into an organic matrix. - Highlights: • We present a methodology to analyze the dopant distribution in organic thin films. • The method combines HAADF-STEM imaging and EDS X-ray spectroscopy. • Ir(ppy){sub 3} dopant was co-deposited into Spiro2-CBP organic matrix. • The dopant was co-deposited with and without substrate vibration. • Images and chemical information of the dopant were simultaneously obtained.

  6. Crystal structure, chemical bond and enhanced performance of β-Zn4Sb3 compounds with interstitial indium dopant

    International Nuclear Information System (INIS)

    Tang, Dingguo; Zhao, Wenyu; Yu, Jian; Wei, Ping; Zhou, Hongyu; Zhu, Wanting; Zhang, Qingjie

    2014-01-01

    Highlights: • The interstitial In dopant leads to the local structural perturbations in β-Zn 4 Sb 3 . • The simultaneous increases in α and σ are observed in the In-doped Zn 4 Sb 3 compounds. • The In dopant plays different doping behaviors by the dopant contents in the samples. • A maximum ZT of 1.41 at 700 K is achieved for the In-doped Zn 4 Sb 3 compounds. - Abstract: In-doped β-Zn 4 Sb 3 compounds (Zn 4−x In x Sb 3 , 0 ⩽ x ⩽ 0.24) were prepared by melt-quenching and spark plasma sintering technology in the work. The resultant samples were systematically investigated by X-ray diffraction, X-ray photoelectron spectroscopy, differential scanning calorimetry and thermoelectric property measurements. The In dopant was identified to preferentially occupy the interstitial site in β-Zn 4 Sb 3 and led to the local structural perturbations near the 12c Sb2 and 36f Zn1 sites. The Auger parameters of Zn and Sb indicated that the increase in the valence of Zn was attributed to the charge transfer from Zn to In atoms. The binding energies of In 3d 5/2 core level showed that the interstitial In dopant was n-type dopant (In 3+ ) in slightly In-doped Zn 4−x In x Sb 3 , but acted as acceptor and was p-type dopant (In + ) in heavily In-doped ones. The discovery provides a reasonable explanation for the puzzled relation between σ and x for Zn 4−x In x Sb 3 . Simultaneously increasing the electrical conductivity and Seebeck coefficient of Zn 4−x In x Sb 3 can be realized through the local structural perturbations. The significantly enhanced power factor and the intrinsic low thermal conductivity resulted in a remarkable increase in the dimensionless figure of merit (ZT). The highest ZT reached 1.41 at 700 K for Zn 3.82 In 0.18 Sb 3 and increased by 68% compared with that of the undoped β-Zn 4 Sb 3

  7. Effect of YH0618 soup on chemotherapy-induced toxicity in patients with cancer who have completed chemotherapy: study protocol for a randomized controlled trial.

    Science.gov (United States)

    You, Jie-Shu; Chen, Jian-Ping; Chan, Jessie S M; Lee, Ho-Fun; Wong, Mei-Kuen; Yeung, Wing-Fai; Lao, Li-Xing

    2016-07-26

    The incidence of cancer has been staying at a high level worldwide in recent years. With advances in cancer diagnosis and therapy strategy, the survival rate of patients with cancer has been increasing, but the side effects of these treatments, especially chemotherapy, are obvious even when the chemotherapy ceases. YH0618, a prescription, has showed efficacy in reducing chemotherapy-induced toxicity through long clinical practice. However, there is no scientific research exploring the effects of YH0618 in patients with cancer. Therefore, using a randomized controlled trial, this study will explore the efficacy of YH0618 on ameliorating chemotherapy-induced toxicity including dermatologic toxicity, myelosuppression, hepatotoxicity and nephrotoxicity and improving fatigue in cancer patients who have completed chemotherapy. This is a prospective assessor-blinded, parallel, randomized controlled trial. Patients with cancer at any stage who have completed chemotherapy within two weeks will be randomly divided into group A (YH0618) and group B (wait-list) using a 1:1 allocation ratio. The chemotherapeutic agents include taxanes or anthracyclines. Subjects assigned to group A will receive YH0618 soup 6 days a week for 6 weeks and uncontrolled follow-up for 6 weeks, while group B are required to wait for 6 weeks before receiving YH0618 intervention. The primary outcome of this study is the incidence of protocol-specified grade ≥2 dermatologic toxicities graded by NCI CTCAE Chinese version 4.0 and changes of fingernail color, face skin color and tongue color evaluated by the L*a*b system within 6 weeks. There are some secondary outcomes associated with dermatologic toxicity including fatigue and clinical objective examination. There are few scientific and safe methods in ameliorating chemotherapy-induced toxicity. The proposed study may provide direct and convincing evidence to support YH0618 as an adjuvant treatment for reducing chemotherapy-induced toxicity, which

  8. Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

    KAUST Repository

    Sioud, Salim

    2012-05-04

    RATIONALE To enhance the ionization efficiencies in atmospheric pressure photoionization mass spectrometry a dopant with favorable ionization energy such as chlorobenzene is typically used. These dopants are typically toxic and difficult to mix with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs) was developed and optimized using ultra high performance liquid chromatography (UPLC) coupled to atmospheric pressure photoionization high-resolution mass spectrometry. Various single and multicomponent mixed dopants consisting of ethanol, chlorobenzene, bromobenzene, anisole and toluene were evaluated. RESULTS Fourteen out of eighteen PAHs were successfully separated and detected at low pg/μL levels within 5 min with high mass accuracy ≤4 ppm. The optimal mixed multicomponent dopant consisted of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v %) and it improved the limit of detection (LOD) by 2- to 10-fold for the tested PAHs compared to those obtained with pure chlorobenzene. CONCLUSIONS A novel multicomponent dopant that contains 99% ethanol and 1% mixture of chlorobenzene, bromobenzene and anisole was found to be an effective dopant mixture to ionize PAHs. The developed UPLC multicomponent dopant assisted atmospheric pressure photoionization high-resolution mass spectrometry offered a rapid non targeted screening method for detecting the PAHs at low pg/;μL levels within a 5 min run time with high mass accuracy a;circ4 ppm. Copyright © 2012 John Wiley & Sons, Ltd.

  9. The use of isoprene as a novel dopant in negative ion atmospheric pressure photoionization mass spectrometry coupled to high-performance liquid chromatography.

    Science.gov (United States)

    Dousty, Faezeh; O'Brien, Rob

    2015-06-15

    As in the case with positive ion atmospheric pressure photoionization (PI-APPI), the addition of dopants significantly improves the sensitivity of negative ion APPI (NI-APPI). However, the research on dopant-assisted-NI-APPI has been quite limited compared to the studies on dopant-assisted PI-APPI. This work presents the potential of isoprene as a novel dopant for NI-APPI. Thirteen compounds, possessing suitable gas-phase ion energetic properties in order to make stable negative ions, were selected. Dopants were continuously introduced into a tee junction prior to the ion source through a fused-silica capillary, while analytes were directly injected into the same tee. Then both were mixed with the continuous solvent from high-performance liquid chromatography (HPLC), nebulized, and entered the source. The nebulized stream was analyzed by APPI tandem quadrupole mass spectrometry in the negative ion mode. The results obtained using isoprene were compared with those obtained by using toluene as a dopant and dopant-free NI-APPI. Isoprene enhanced the ionization intensities of the studied compounds, which were found to be comparable and, in some cases, more effective than toluene. The mechanisms leading to the observed set of negative analyte ions were also discussed. Because in NI-APPI, thermal electrons, which are produced during the photoionization of a dopant, are considered the main reagent ions, both isoprene and toluene promoted the ionization of analytes through the same mechanisms, as expected. Isoprene was shown to perform well as a novel dopant for NI-APPI. Isoprene has a high photoabsorption cross section in the VUV region; therefore, its photoionization leads to a highly effective production of thermal electrons, which further promotes the ionization of analytes. In addition, isoprene is environmentally benign and less toxic compared to currently used dopants. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Defect-induced mix experiment for NIF

    Directory of Open Access Journals (Sweden)

    Schmitt M.J.

    2013-11-01

    Full Text Available The Defect Induced Mix Experiment (DIME-II will measure the implosion and mix characteristics of CH capsules filled with 5 atmospheres of DT by incorporating mid-Z dopant layers of Ge and Ga. This polar direct drive (PDD experiment also will demonstrate the filling of a CH capsule at target chamber center using a fill tube. Diagnostics for these experiments include areal x-ray backlighting to obtain early time images of the implosion trajectory and a multiple-monochromatic imager (MMI to collect spectrally-resolved images of the capsule dopant line emission near bangtime. The inclusion of two (or more thin dopant layers at separate depths within the capsule shell facilitates spatial correlation of mix between the layers and the hot gas core on a single shot. The dopant layers are typically 2 μm thick and contain dopant concentrations of 1.5%. Three dimensional Hydra simulations have been performed to assess the effects of PDD asymmetry on capsule performance.

  11. Ionization of EPA contaminants in direct and dopant-assisted atmospheric pressure photoionization and atmospheric pressure laser ionization.

    Science.gov (United States)

    Kauppila, Tiina J; Kersten, Hendrik; Benter, Thorsten

    2015-06-01

    Seventy-seven EPA priority environmental pollutants were analyzed using gas chromatography-mass spectrometry (GC-MS) equipped with an optimized atmospheric pressure photoionization (APPI) and an atmospheric pressure laser ionization (APLI) interface with and without dopants. The analyzed compounds included e.g., polycyclic aromatic hydrocarbons (PAHs), nitro compounds, halogenated compounds, aromatic compounds with phenolic, acidic, alcohol, and amino groups, phthalate and adipatic esters, and aliphatic ethers. Toluene, anisole, chlorobenzene, and acetone were tested as dopants. The widest range of analytes was ionized using direct APPI (66/77 compounds). The introduction of dopants decreased the amount of compounds ionized in APPI (e.g., 54/77 with toluene), but in many cases the ionization efficiency increased. While in direct APPI the formation of molecular ions via photoionization was the main ionization reaction, dopant-assisted (DA) APPI promoted ionization reactions, such as charge exchange and proton transfer. Direct APLI ionized a much smaller amount of compounds than APPI (41/77 compounds), showing selectivity towards compounds with low ionization energies (IEs) and long-lived resonantly excited intermediate states. DA-APLI, however, was able to ionize a higher amount of compounds (e.g. 51/77 with toluene), as the ionization took place entirely through dopant-assisted ion/molecule reactions similar to those in DA-APPI. Best ionization efficiency in APPI and APLI (both direct and DA) was obtained for PAHs and aromatics with O- and N-functionalities, whereas nitro compounds and aliphatic ethers were the most difficult to ionize. Halogenated aromatics and esters were (mainly) ionized in APPI, but not in APLI.

  12. A review of the treatment options for skin rash induced by EGFR-targeted therapies: Evidence from randomized clinical trials and a meta-analysis

    International Nuclear Information System (INIS)

    Ocvirk, Janja; Heeger, Steffen; McCloud, Philip; Hofheinz, Ralf-Dieter

    2013-01-01

    Agents targeting the epidermal growth factor receptor (EGFR) are amongst the most extensively used of the targeted agents in the therapy of some of the most common solid tumors. Although they avoid many of the classic side effects associated with cytotoxic chemotherapy, they are associated with unpleasant cutaneous toxicities which can affect treatment compliance and impinge on patient quality of life. To date, despite a plethora of consensus recommendations, expert opinions and reviews, there is a paucity of evidence-based guidance for the management of the skin rash that occurs in the treatment of patients receiving EGFR-targeted therapies. A literature search was conducted as a first step towards investigating not only an evidence-based approach to the management of skin rash, but also with a view to designing future randomized trials. The literature search identified seven randomized trials and a meta-analysis was conducted using the data from four of these trials involving oral antibiotics. The meta-analysis of the data from these four trials suggests that prophylactic antibiotics might reduce the relative risk of severe rash associated with EGFR-targeted agents by 42–77%. Vitamin K cream was also identified as having a potential role in the management EGFR-targeted agent induced rash. This review and meta-analysis clearly identify the need for further randomized studies of the role of oral antibiotics in this setting. The results of the ongoing randomized trials of the topical application of vitamin K cream plus or minus doxycycline and employing prophylactic versus reactive strategies are eagerly awaited

  13. Effects of creatine monohydrate supplementation on exercise-induced apoptosis in athletes: A randomized, double-blind, and placebo-controlled study

    Directory of Open Access Journals (Sweden)

    Rahman Rahimi

    2015-01-01

    Full Text Available Background: Creatine monohydrate (CrM has been shown to be beneficial to health due to its antioxidant potential. Strenuous exercise is associated with oxidative stress, which could lead to apoptosis. We investigated the ability of CrM in amelioration of apoptosis induced by incremental aerobic exercise (AE to exhaustion in young athletes. Materials and Methods: In a placebo-controlled, double-blind, randomized, parallel study, 31 young athletes (age 19.52 ± 2.75 years, body mass 79.24 ± 16.13 kg, height 1.73 ± 6.49 m, body fat 16.37% ± 5.92% were randomly assigned to CrM (4 × 5 g/day, n = 15 or placebo (PL: 4 × 5 g/day of maltodextrine powder; n = 16 to investigate the effect of 7 days CrM on serum p53 and insulin-like growth factor-1 (IGF-1 concentration after acute incremental AE test to exhaustion. Subjects performed AE before (test 1 and after 7 days of supplementation (test 2. Results: Before supplementation, AE to exhaustion induced a significant increase in serum p53 and IGF-1 concentrations at both CrM and PL groups (P 0.05. Conclusion: Our results suggest that supplementation with CrM prevents apoptosis, as measured by decreases in p53 concentration, induced by AE to exhaustion in young athletes. However, CrM had no effect on IGF-1 concentration after AE to exhaustion in young athletes.

  14. Non-invasive high-intensity focused ultrasound for UV-induced hyperpigmentation in Fitzpatrick skin types III and IV: a prospective, randomized, controlled, evaluator-blinded trial.

    Science.gov (United States)

    Vachiramon, Vasanop; Jurairattanaporn, Natthachat; Harnchoowong, Sarawin; Chayavichitsilp, Pamela

    2018-02-01

    Skin hyperpigmentation is a frequently encountered problem, particularly in darker skin types. Unfortunately, standard treatments for this condition have shown disappointing results. High-intensity focused ultrasound (HIFU) is commonly indicated for skin laxity, but recently was used to treat UV-induced hyperpigmentation in animal models. This study is aimed to evaluate the efficacy and safety of high-intensity focused ultrasound for UVB-induced hyperpigmentation in human subjects. A randomized, evaluator-blinded pilot study was conducted on 20 subjects. Each subject was induced three hyperpigmentary spots by local broadband UVB. After 2 weeks, each spot was randomly allocated to control, low-energy, and high-energy HIFU. Subjects were instructed to follow up weekly for a duration of 1 month. Lightness index measurements, mean improvement scores, subjects' satisfaction, pain scores, and side effects were evaluated. All 20 subjects completed the study. Fourteen subjects had Fitzpatrick (FPT) skin type III and six subjects had FPT skin type IV. Twelve subjects showed greater improvement at control sites while eight subjects showed greater improvement at HIFU-treated sites. In FPT skin type III, HIFU appeared to be inferior to control in both lightness index and mean improvement scores, but in FPT skin type IV, HIFU had greater lightness index improvement and higher improvement scores than control. Side effects were more frequent in high-energy-treated areas. Focused ultrasound may be offered in some patients with hyperpigmentary conditions. More research is needed to determine proper energy settings for optimal outcome.

  15. Microscopic Mechanism of Doping-Induced Kinetically Constrained Crystallization in Phase-Change Materials.

    Science.gov (United States)

    Lee, Tae Hoon; Loke, Desmond; Elliott, Stephen R

    2015-10-07

    A comprehensive microscopic mechanism of doping-induced kinetically constrained crystallization in phase-change materials is provided by investigating structural and dynamical dopant characteristics via ab initio molecular dynamics simulations. The information gained from this study may provide a basis for a fast screening of dopant species for electronic memory devices, or for understanding the general physics involved in the crystallization of doped glasses. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Provision of intrauterine contraception in association with first trimester induced abortion reduces the need of repeat abortion: first-year results of a randomized controlled trial.

    Science.gov (United States)

    Pohjoranta, Elina; Mentula, Maarit; Gissler, Mika; Suhonen, Satu; Heikinheimo, Oskari

    2015-11-01

    Can the need of subsequent abortion be reduced by providing intrauterine contraception as a part of the abortion service? Provision of intrauterine devices (IUDs) in association with first trimester abortion more than halved the incidence of repeat abortion during the first year of follow-up. Following abortion, the incidence of subsequent abortion is high, up to 30-40%. In cohort studies, intrauterine contraception has reduced the need of repeat abortion by 60-70%. A randomized controlled trial. The main outcome measure was the incidence of subsequent induced abortions during the follow-up. Altogether 751 women seeking first trimester induced abortion were recruited and randomized into two groups. Randomization was accomplished by computer-assisted permuted-block randomization with random block sizes of four to six. The investigators did not participate in randomization, which was done before commencing the study. The participants were recruited between 18 October 2010 and 21 January 2013. The inclusion criteria were age ≥18 years, duration of pregnancy ≤12 weeks, accepting intrauterine contraception, residence in Helsinki and signing the informed consent form. Women with contraindications to intrauterine contraception, such as uterine anomaly, acute genital infection or pap-smear change requiring surgical treatment were ineligible to participate.This study was conducted in collaboration between the Department of Obstetrics and Gynaecology, University of Helsinki and Helsinki University Hospital, and Centralized family planning of the City of Helsinki.The intervention group (n = 375) was provided with intrauterine contraception (either the levonorgestrel-releasing intrauterine system or copper-releasing intrauterine device) immediately following surgical abortion (18.1%) or at a follow-up 2-4 weeks after medical abortion (81.9%). Women in the control group were prescribed oral contraceptives and advised to contact their primary healthcare unit for a follow

  17. Random lasing of microporous surface of Cr{sup 2+}:ZnSe crystal induced by femtosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xianheng; Feng, Guoying, E-mail: guoing-feng@scu.edu.cn, E-mail: zhoush@scu.edu.cn; Yao, Ke; Yi, Jiayu; Zhang, Hong [College of Electronics and Information Engineering, Sichuan University, Chengdu 610065 (China); Zhou, Shouhuan, E-mail: guoing-feng@scu.edu.cn, E-mail: zhoush@scu.edu.cn [College of Electronics and Information Engineering, Sichuan University, Chengdu 610065 (China); North China Research Institute of Electro-Optics, Beijing 100015 (China)

    2015-06-15

    We demonstrate a random lasing emission based on microporous surface of Cr{sup 2+}:ZnSe crystal prepared by femtosecond pulsed laser ablation in high vacuum (below 5 × 10{sup −4} Pa). The scanning electron microscope results show that there are a mass of micropores with an average size of ∼13 μm and smaller ones with ∼1.2 μm on the surface of Cr{sup 2+}:ZnSe crystal. The adjacent micropore spacing of the smaller micropores ranges from 1 μm to 5 μm. Under 1750 nm excitation of Nd:YAG (355 nm) pumped optical parametric oscillator, a random lasing emission with center wavelength of 2350 nm and laser-like threshold of 0.3 mJ/pulse is observed. The emission lifetime of 2350 nm laser reduces from 800 ns to 30 ns as the pump energy increases above threshold. The emission spectra and decay time of smooth surface, groove and microporous surface of Cr{sup 2+}:ZnSe crystal are contrasted. The optional pump wavelength range is from 1500 nm to 1950 nm, which in accordance with the optical absorption property of Cr{sup 2+}:ZnSe crystal. The peak position of excitation spectra is almost identical to the strongest absorption wavelength.

  18. Sham-controlled, randomized, feasibility trial of acupuncture for prevention of radiation-induced xerostomia among patients with nasopharyngeal carcinoma

    Science.gov (United States)

    Meng, Zhiqiang; Garcia, M. Kay; Hu, Chaosu; Chiang, Joseph; Chambers, Mark; Rosenthal, David I.; Peng, Huiting; Wu, Caijun; Zhao, Qi; Zhao, Genming; Liu, Luming; Spelman, Amy; Palmer, J. Lynn; Wei, Qi; Cohen, Lorenzo

    2013-01-01

    Background Xerostomia (dry mouth) after head/neck radiation is a common problem among cancer patients. Quality of life (QOL) is impaired, and available treatments are of little benefit. This trial determined the feasibility of conducting a sham-controlled trial of acupuncture and whether acupuncture could prevent xerostomia among head/neck patients undergoing radiotherapy. Methods A sham controlled, feasibility trial was conducted at Fudan University Shanghai Cancer Center, Shanghai, China among patients with nasopharyngeal carcinoma undergoing radiotherapy. To determine feasibility of a sham procedure, 23 patients were randomized to real acupuncture (N = 11) or to sham acupuncture (N = 12). Patients were treated 3 times/week during their course of radiotherapy. Subjective measures were the Xerostomia Questionnaire (XQ) and MD Anderson Symptom Inventory for Head and Neck Cancer (MDASI-HN). Objective measures were unstimulated whole salivary flow rates (UWSFR) and stimulated salivary flow rates (SSFR). Patients were followed for 1 month after radiotherapy. Results XQ scores for acupuncture were significantly lower than sham controls starting in week 3 and lasted through the 1-month follow-up (all P’s xerostomia symptoms and improved QOL when compared with sham acupuncture. Large-scale, multi-center, randomized, placebo-controlled trials are now needed. PMID:22285177

  19. Randomized controlled trial of acupuncture for prevention of radiation-induced xerostomia among patients with nasopharyngeal carcinoma

    Science.gov (United States)

    Meng, Zhiqiang; Garcia, M. Kay; Hu, Chaosu; Chiang, Joseph; Chambers, Mark; Rosenthal, David I.; Peng, Huiting; Zhang, Ying; Zhao, Qi; Zhao, Genming; Liu, Luming; Spelman, Amy; Palmer, J. Lynn; Wei, Qi; Cohen, Lorenzo

    2011-01-01

    Background Xerostomia (dry mouth) after head/neck radiation is a common problem among cancer patients and available treatments are of little benefit. The objective of this trial was to determine if acupuncture can prevent xerostomia among head/neck patients undergoing radiotherapy. Methods A randomized, controlled trial among patients with nasopharyngeal carcinoma was conducted comparing acupuncture to standard care. Participants were treated at Fudan University Shanghai Cancer Center, Shanghai, China. Forty patients were randomized to acupuncture treatment and 46 to standard care. Patients were treated 3 times/week on the same days they received radiotherapy. Subjective measures included the Xerostomia Questionnaire (XQ) and MD Anderson Symptom Inventory for Head/Neck (MDASI-HN). Objective measures were unstimulated and stimulated whole salivary flow rates (UWSFR; SSFR). Patients were followed for 6 months after the end of radiotherapy. Results XQ scores for acupuncture were statistically significantly lower than controls starting in week 3 through the 6-months(P=0.003 at week3, all other P’s xerostomia and improved QOL. PMID:22072272

  20. A double-blind, randomized, pilot dose-finding study of maca root (L. meyenii) for the management of SSRI-induced sexual dysfunction.

    Science.gov (United States)

    Dording, Christina M; Fisher, Lauren; Papakostas, George; Farabaugh, Amy; Sonawalla, Shamsah; Fava, Maurizio; Mischoulon, David

    2008-01-01

    We sought to determine whether maca, a Peruvian plant, is effective for selective-serotonin reuptake inhibitor (SSRI)-induced sexual dysfunction. We conducted a double-blind, randomized, parallel group dose-finding pilot study comparing a low-dose (1.5 g/day) to a high-dose (3.0 g/day) maca regimen in 20 remitted depressed outpatients (mean age 36+/-13 years; 17 women) with SSRI-induced sexual dysfunction. The Arizona Sexual Experience Scale (ASEX) and the Massachusetts General Hospital Sexual Function Questionnaire (MGH-SFQ) were used to measure sexual dysfunction. Ten subjects completed the study, and 16 subjects (9 on 3.0 g/day; 7 on 1.5 g/day) were eligible for intent-to-treat (ITT) analyses on the basis of having had at least one postbaseline visit. ITT subjects on 3.0 g/day maca had a significant improvement in ASEX (from 22.8+/-3.8 to 16.9+/-6.2; z=-2.20, P=0.028) and in MGH-SFQ scores (from 24.1+/-1.9 to 17.0+/-5.7; z=-2.39, P=0.017), but subjects on 1.5 g/day maca did not. Libido improved significantly (PMaca was well tolerated. Maca root may alleviate SSRI-induced sexual dysfunction, and there may be a dose-related effect. Maca may also have a beneficial effect on libido.

  1. Effect of acupuncture for radioactive-iodine-induced anorexia in thyroid cancer patients: a randomized, double-blinded, sham-controlled pilot study.

    Science.gov (United States)

    Jeon, Ju-Hyun; Yoon, Jeungwon; Cho, Chong-Kwan; Jung, In-Chul; Kim, Sungchul; Lee, Suk-Hoon; Yoo, Hwa-Seung

    2015-05-01

    The aim of this study is to evaluate the efficacy and safety of acupuncture for radioactive iodine (RAI)-induced anorexia in thyroid cancer patients. Fourteen thyroid cancer patients with RAI-induced anorexia were randomized to a true acupuncture or sham acupuncture group. Both groups were given 6 true or sham acupuncture treatments in 2 weeks. Outcome measures included the change of the Functional Assessment of Anorexia and Cachexia Treatment (FAACT; Anorexia/Cachexia Subscale [ACS], Functional Assessment of Cancer Therapy-General [FACT-G]), Visual Analogue Scale (VAS), weight, body mass index (BMI), ACTH, and cortisol levels. The mean FAACT ACS scores of the true and sham acupuncture groups increased from baseline to exit in intention-to-treat (ITT) and per protocol (PP) analyses; the true acupuncture group showed higher increase but with no statistical significance. Between groups, from baseline to the last treatment, statistically significant differences were found in ITT analysis of the Table of Index (TOI) score (P = .034) and in PP analysis of the TOI (P = .016), FACT-G (P = .045), FAACT (P = .037) scores. There was no significant difference in VAS, weight, BMI, ACTH, and cortisol level changes between groups. Although the current study is based on a small sample of participants, our findings support the safety and potential use of acupuncture for RAI-induced anorexia and quality of life in thyroid cancer patients. © The Author(s) 2015.

  2. Effect of Paracetamol Pretreatment on Rocuronium-Induced Injection Pain: A Randomized, Double-Blind, Placebo-Controlled Comparison with Lidocaine

    Directory of Open Access Journals (Sweden)

    Gulnaz Ates

    2013-10-01

    Full Text Available Aim: To compare the effect of intravenous paracetamol on rocuronium-induced injection pain with that of lidocaine. Material and Method: One hundred and eighty patients scheduled for elective surgery under general anesthesia were recruited to this prospective, randomized, double-blinded, placebo-controlled study. A 20-gauge cannula was inserted into a vein on the dorsum of the patient%u2019s left hand and lactated Ringer%u2019s solution was infused at 100 ml/h. After 5 minutes, infusion was stopped and the left arm of the patient%u2019s was elevated for 15 seconds for gravity of venous blood. While venous occlusion was applied to the left upper arm using a pneumatic tourniquet, one of the pretreatment solutions (normal saline 5 mL, lidocaine 40 mg, paracetamol 50 mg was injected over a period of 10 seconds. The intensity of the pain patients experienced was assessed using a 4-point verbal rating scale in Group C (normal saline 5 mL, n=60, Group L (lidocaine 40 mg, n=60 and Group P (paracetamol 50 mg, n=60. After 2 minutes, the venous occlusion was released and the patients received 0.06 mg/kg rocuronim bromide over 10 seconds and the rocuronim-induced pain was assessed. Results: The overall incidence of rocuronium-induced injection pain was significantly more in Group C than the other groups (p

  3. Design of a randomized controlled trial of Internet-based cognitive behavioral therapy for treatment-induced menopausal symptoms in breast cancer survivors.

    Science.gov (United States)

    Atema, Vera; van Leeuwen, Marieke; Oldenburg, Hester S A; Retèl, Valesca; van Beurden, Marc; Hunter, Myra S; Aaronson, Neil K

    2016-11-25

    Menopausal symptoms are common and may be particularly severe in younger women who undergo treatment-induced menopause. Medications to reduce menopausal symptoms are either contra-indicated or have bothersome side effects. Previous studies have demonstrated that face-to-face cognitive behavioral therapy (CBT) is effective in alleviating menopausal symptoms in women with breast cancer. However, compliance with face-to-face CBT programs can be problematic. A promising approach is to use the Internet to make this form of CBT more accessible and feasible for patients. This study is evaluating the efficacy and cost-effectiveness of an Internet-based CBT program, with or without therapist guidance, in alleviating or reducing the severity of menopausal symptoms. In a multicenter, randomized controlled trial we are evaluating the efficacy of two Internet-based CBT programs in alleviating or reducing the impact of menopausal symptoms, and particularly hot flushes and night sweats, in breast cancer survivors who have experienced a treatment-induced menopause. Secondary outcomes include sexual functioning, sleep quality, hot flush frequency, psychological distress, health-related quality of life and cost-effectiveness. We will recruit 248 women who will be randomized to either a therapist guided or a self-management version of the 6-week Internet-based CBT program, or to a usual care, waiting list control group. Self-administered questionnaires are completed at baseline (T0), and at 10 weeks (T1) and 24 weeks (T2) post-randomization. Internet-based CBT is a potentially useful treatment for reducing menopausal symptoms in breast cancer survivors. This study will provide evidence on the efficacy and cost-effectiveness of such an Internet-based CBT program, with or without therapist support. If demonstrated to be efficacious and cost-effective, the availability of such structured supportive intervention programs will be a welcome addition to standard medical treatment offered

  4. Experimental study on reactor neutron induced effect of deep sub-micron CMOS static random access memory

    International Nuclear Information System (INIS)

    Yang Shanchao; Guo Xiaoqiang; Lin Dongsheng; Chen Wei; Li Ruibin; Bai Xiaoyan; Wang Guizhen

    2010-01-01

    This paper investigates neutron irradiation effects of two kinds of commercial CMOS SRAM (static random access memory), of which one is 4M memory with the feature size of 0.25 μm and the other is 16M memory with the feature size of 0.13 μm. We designed a memory testing system of irradiation effects and performed the neutron irradiation experiment using the Xi'an Pulse Reactor. The upset of two kinds of memory cells did not present a threshold versus the increase of neutron fluence. The results showed that deep sub-micron SRAM behaved single-event upset (SEU) effect in neutron irradiation environment. The SEU effect of SRAM with smaller size and higher integrated level tends to upset is considered to be related to the reduction of the device feature size, and fewer charges for upsets of the memory cell also lead to the SEU effect. (authors)

  5. Music Therapy Reduces Radiotherapy-Induced Fatigue in Patients With Breast or Gynecological Cancer: A Randomized Trial.

    Science.gov (United States)

    Alcântara-Silva, Tereza Raquel; de Freitas-Junior, Ruffo; Freitas, Nilceana Maya Aires; de Paula Junior, Wanderley; da Silva, Delson José; Machado, Graziela Dias Pinheiro; Ribeiro, Mayara Kelly Alves; Carneiro, Jonathas Paiva; Soares, Leonardo Ribeiro

    2018-04-01

    To investigate the influence of music therapy on the reduction of fatigue in women with breast or gynecological malignant neoplasia during radiotherapy, since it is one of the most frequent side effects of this type of treatment, and may interfere with self-esteem, social activities, and quality of life. Randomized controlled trial (control group [CG] and music therapy group [MTG]) to assess fatigue, quality of life, and symptoms of depression in women undergoing radiotherapy using the Functional Assessment of Cancer Therapy: Fatigue (FACT-F) version 4, Functional Assessment of Cancer Therapy-General (FACT-G) version 4, and Beck Depression Inventory in 3 separate times, namely, during the first week of radiotherapy, on the week of the intermediary phase, and during the last week of radiotherapy. Individual 30- to 40-minute sessions of music therapy with the presence of a trained music therapist were offered to participants. In this study, 164 women were randomized and 116 (63 CG and 53 MTG) were included in the analyses, with mean age of 52.90 years (CG) and 51.85 years (MTG). Participants in the MTG had an average of 10 music therapy sessions, totaling 509 sessions throughout the study. FACT-F results were significant regarding Trial Outcome Index ( P = .011), FACT-G ( P = .005), and FACT-F ( P = .001) for the MTG compared with the CG. Individual music therapy sessions may be effective to reduce fatigue related to cancer and symptoms of depression, as well as to improve quality of life for women with breast or gynecological cancer undergoing radiotherapy. Further well-designed research studies are needed to adequately determine the effects of music therapy on fatigue.

  6. Technical report Development of a piezoelectric inkjet dopant delivery device for an atmospheric pressure photoionization source with liquid chromatography/mass spectrometry

    KAUST Repository

    Amad, Maan H.

    2013-01-01

    This paper describes a simple robust and integrated piezoelectric actuated printhead as a dopant delivery system for atmospheric pressure photoionization with liquid chromatography/mass spectrometry The newly designed dopant delivery system avoids problems associated with traditional liquid delivery systems such as solvent immiscibility backpressure and increased post-column dead volume issues The performance of the new device was tested and evaluated using chlorobenzene as a dopant with a test mixture consisting of 18 different polycyclic aromatic hydrocarbons (PAHs) The results show that the new system works robustly at low dopant consumption level (16 uL min-1) consuming only approximately 5% of the amount used by conventional sources The low dopant consumption has resulted in up to a 20-fold reduction in signal intensity of tested PAH molecules but has led to less presence of background cluster ions and dopant trace contaminant background ions in the source area Consequently all tested PAHs were detected with excellent signal-to-noise ratio with at least two-to ten-fold improvements in the limit of detection and quantification compared to those obtained with traditional dopant assistance using a post-column addition method © IM Publications LLP 2013.

  7. Influence of Ni-dopant on the properties of synthetic goethite

    International Nuclear Information System (INIS)

    Krehula, Stjepko; Music, Svetozar; Popovic, Stanko

    2005-01-01

    The influence of Ni-dopant on the properties of α-FeOOH was investigated by XRD, FT-IR, 57 Fe Moessbauer spectroscopy and transmission electron microscopy. α-FeOOH was synthesized at a highly alkaline pH by precipitation from the FeCl 3 solution with the addition of tetramethylammonium hydroxide and autoclaving at 160 o C. The samples doped with Ni 2+ ions were precipitated in the same way, but in the presence of varying concentrations of NiCl 2 . Solid solutions, having the structure of α-FeOOH, were observed in samples with the Ni/Fe ratio up to 0.05. Upon increasing the amount of Ni-dopant the XRD lines were gradually broadened. The sample with the ratio Ni/Fe=0.10 showed NiFe 2 O 4 , besides the dominant phase having the structure type of α-FeOOH. Shifts of IR bands at 892 and 796cm -1 were not observed in all samples doped with Ni. For the ratio Ni/Fe=0.10, the IR bands centered at 631 and 404cm -1 were significantly broadened. RT Moessbauer spectrum of undoped α-FeOOH and Ni-doped α-FeOOH showed distributions of hyperfine magnetic fields. B hf decreased from 35.1T for an undoped α-FeOOH to 32.1T for α-FeOOH containing Ni 2+ ions (Ni/Fe=0.05). The saturation of the α-FeOOH structure with Ni 2+ ions in amounts higher than ∼5mol% was also observed by Moessbauer spectroscopy. The particle size (length) of acicular α-FeOOH particles with a maximum in the interval 180-220nm was slightly decreased with Ni-doping, but the distribution of the length/width ratio showed no change, having a maximum at 4-5. TEM photographs additionally showed small populations of cubic-shaped or pseudocubic particles of ∼10nm in size for the ratio Ni/Fe=0.05 and about 10-20nm in size for the ratio Ni/Fe=0.10. These particles were assigned to NiFe 2 O 4

  8. Physical properties of high-Tc superconducting oxides. Modification of tc using organic dopants. Final report. Proprietes physiques d'oxydes supraconducteurs a haute Tc. Modification de tc sous l'effet de dopants organiques

    Energy Technology Data Exchange (ETDEWEB)

    Brau, A

    1993-01-01

    An attempt was made to significantly modify the Tc transition temperature of certain copper-based superconducting oxides by introducing organic or mineral dopants, and to study the mobility of 300K-carriers in crystallized tallium-base superconducting oxides. Since the critical transition temperature of superconducting oxides is highly influenced by the density of the free carriers they contain, the authors tried making superconducting powders react with either an organic electron acceptor or a mineral compound. The goal was to increase the density of the holes by altering the copper's degree of oxidation. Their preparatory work showed a direct charge-transfer reaction between the electron-donor copper and the acceptor TCNQ and studied the degree to which the electron acceptor can alter the copper's oxidation. Initial results also showed that dopants can affect superconducting Tc and the course of R(T) curves.

  9. The efficacy of the Kampo medicine rikkunshito for chemotherapy-induced anorexia (RICH trial): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Inoue, Takuya; Takagi, Hironori; Owada, Yuki; Watanabe, Yuzuru; Yamaura, Takumi; Fukuhara, Mitsuro; Muto, Satoshi; Okabe, Naoyuki; Matsumura, Yuki; Hasegawa, Takeo; Osugi, Jun; Hoshino, Mika; Higuchi, Mitsunori; Shio, Yutaka; Yokouchi, Hiroshi; Kanazawa, Kenya; Ohbuchi, Katsuya; Fukushima, Takahisa; Munakata, Mitsuru; Suzuki, Hiroyuki

    2017-10-18

    Cisplatin is a key drug in lung cancer therapy. However, cisplatin is also well known to induce gastrointestinal disorders, such as chemotherapy-induced nausea and vomiting, anorexia, and weight loss. These symptoms sometimes affect patients' quality of life and make continuation of chemotherapy difficult. Anorexia is a cause of concern for patients with cancer because a persistent loss of appetite progresses to cancer cachexia. Although evidence-based management for chemotherapy has recently been established, there is room for improvement. This placebo-controlled, double-blind, randomized trial will aim to determine the efficacy of the traditional Japanese Kampo medicine rikkunshito (TJ-43) for preventing anorexia caused by cisplatin-including chemotherapy in patients with lung cancer. Patients with lung cancer who plan to receive cisplatin-including chemotherapy will be recruited. Patients who provide written consent will be randomly allocated to receive either TJ-43 (arm A) or placebo (arm B) for one course of chemotherapy (21 or 28 consecutive days). Investigators and patients will be masked to the treatment assignment throughout the trial. The primary endpoint will be evaluated as the change in dietary intake from day 0 (the day before the start of chemotherapy) to day 7 of cisplatin-including chemotherapy. The two arms of the trial will comprise 30 patients each. From November 2014, a total of 60 patients will be recruited, and recruitment for the study is planned to be complete by October 2017. This trial is designed to examine the efficacy of rikkunshito (TJ-43) for reducing anorexia and maintaining food intake caused by cisplatin-including chemotherapy in patients with lung cancer. Japan Pharmaceutical Information Center Clinical Trials Information (JAPIC CTI), trial registration: JAPIC CTI-142747 . Registered on 15 December 2014; the RICH trial.

  10. Low-level laser in the treatment of patients with hypothyroidism induced by chronic autoimmune thyroiditis: a randomized, placebo-controlled clinical trial.

    Science.gov (United States)

    Höfling, Danilo B; Chavantes, Maria Cristina; Juliano, Adriana G; Cerri, Giovanni G; Knobel, Meyer; Yoshimura, Elisabeth M; Chammas, Maria Cristina

    2013-05-01

    Chronic autoimmune thyroiditis (CAT) is the most common cause of acquired hypothyroidism, which requires lifelong levothyroxine replacement therapy. Currently, no effective therapy is available for CAT. Thus, the objective of this study was to evaluate the efficacy of low-level laser therapy (LLLT) in patients with CAT-induced hypothyroidism by testing thyroid function, thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb), and ultrasonographic echogenicity. A randomized, placebo-controlled trial with a 9-month follow-up was conducted from 2006 to 2009. Forty-three patients with a history of levothyroxine therapy for CAT-induced hypothyroidism were randomly assigned to receive either 10 sessions of LLLT (830 nm, output power of 50 mW, and fluence of 707 J/cm(2); L group, n=23) or 10 sessions of a placebo treatment (P group, n=20). The levothyroxine was suspended 30 days after the LLLT or placebo procedures. Thyroid function was estimated by the levothyroxine dose required to achieve normal concentrations of T3, T4, free-T4 (fT4), and thyrotropin after 9 months of postlevothyroxine withdrawal. Autoimmunity was assessed by measuring the TPOAb and TgAb levels. A quantitative computerized echogenicity analysis was performed pre- and 30 days postintervention. The results showed a significant difference in the mean levothyroxine dose required to treat the hypothyroidism between the L group (38.59 ± 20.22 μg/day) and the P group (106.88 ± 22.90 μg/day, Phypothyroidism.

  11. A phase II randomized study of topical intrarectal administration of amifostine for the prevention of acute radiation-induced rectal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Kouloulias, V.E. [Dept. of Radiation Oncology, Aretaieion Univ. Hospital, Univ. of Athens Medical School, Athens (Greece); Dept. of Electrical and Computer Engineering, National Technical Univ. of Athens, Athens (Greece); Center of Radiation Oncology, YGEIA Diagnostic and Therapeutic Center of Athens, Athens (Greece); Kouvaris, J.R.; Kokakis, J.D.; Antypas, C.; Mallas, E.; Vosdoganis, S.P.; Vlahos, L.J. [Dept. of Radiation Oncology, Aretaieion Univ. Hospital, Univ. of Athens Medical School, Athens (Greece); Pissakas, G. [Radiotherapy Dept., Agios Savvas Anticancer Hospital, Athens (Greece); Matsopoulos, G. [Dept. of Electrical and Computer Engineering, National Technical Univ. of Athens, Athens (Greece); Michopoulos, S. [Gastroenterology Unit, Alexandra General Hospital, Athens (Greece); Kostakopoulos, A. [Urology Dept., Sismanoglio Hospital, Univ. of Athens Medical School, Athens (Greece)

    2004-09-01

    Purpose: to investigate the cytoprotective effect of intrarectal amifostine administration on acute radiation-induced rectal toxicity. Patients and methods: 67 patients with T1b-2 NO MO prostate cancer were randomized to receive amifostine intrarectally (group A, n - 33) or not (group B, n = 34) before irradiation. Therapy was delivered using a four-field technique with three-dimensional conformal planning. In group A, 1,500 mg amifostine was administered intrarectally as an aqueous solution in a 40-ml enema. Two different toxicity scales were used: EORTC/RTOG rectal and urologic toxicity criteria along with a Subjective-RectoSigmoid (S-RS) scale based on the endoscopic terminology of the World Organization for Digestive Endoscopy. Objective measurements with rectosigmoidoscopy were performed at baseline and 1-2 days after the completion of radiotherapy. The area under curve for the time course of mucositis (RTOG criteria) during irradiation represented the mucositis index (MI). Results: intrarectal amifostine was feasible and well tolerated without any systemic or local side effects. According to the RTOG toxicity scale, five out of 33 patients showed grade 1 mucositis in group A versus 15 out of 34 patients with grade 1/2 in group B (p = 0.026). Mean rectal MI was 0.3 {+-} 0.1 in group A versus 2.2 {+-} 0.4 in group B (p < 0.001), while S-RS score was 3.9 {+-} 0.5 in group A versus 6.3 {+-} 0.7 in group B (p < 0.001). The incidence of urinary toxicity was the same in both groups. Conclusion: intrarectal administration of amifostine seems to have a cytoprotective efficacy in acute radiation-induced rectal mucositis. Further randomized studies are needed for definitive therapeutic decisions. (orig.)

  12. Quantitative assessment of salivary gland function by radioisotopic scanning in a randomized trial of pilocarpine for prevention of radiation Induced Xerostomia

    International Nuclear Information System (INIS)

    Fard-Esfahani, A.; Modarress-Mosalla, M.; Haddad, P.; Eftekhari, M.; Saghari, M.

    2001-01-01

    Radioisotope scanning is the best method for objective assessment of salivary gland function. Thus, it was used in a randomized trial of concomitant pilocarpine for assessment of radiation-induced xerostomia, in addition to subjective evaluation by an approved questionnaire and objective standard xerostomia grading. Patients randomized in a placebo-controlled trial of pilocarpine concurrent with irradiation for prevention of radiation-induced xerostomia were evaluated by salivary gland scintigraphy immediately before and 6 months after the end of head and neck radiotherapy. Salivary gland function was measured by ejection fraction (E F) of Technetium-99 m pertechnetate. The mean values for pre-and post-radiotherapy scans were calculated and compared. Also post-radiotherapy scan findings in the two groups of pilocarpine and placebo were compared using the Student's t-test. In addition, comparison was made between the scan results and the subjective findings and objective grading s.Twenty patients underwent the pre-radiotherapy salivary scintigraphy, and also 20 post-radiotherapy scans were performed . Mean parotid E F was 60.85% in the pre-radiotherapy and 9.08% in the post-radiotherapy scans (p<0.01). The means for submandibular glands in the pre-and post-radiotherapy scans were 41% and 11.2%, respectively (p<0.01). Also the mean E F was 14.5% in the pilocarpine group and 3.65 in the placebo group for parotid glands (p=0.07) and 18.3% and 4.1% respectively for submandibular glands (p<0.05). The salivary scans confirmed the subjective and objective xerostomia findings. Salivary gland scintigraphy is a valuable method for evaluation of xerostomia after head and neck radiotherapy, quantitatively demonstrating the protective effect of pilocarpine compared to placebo on salivary glands

  13. Randomized sham-controlled pilot trial of weekly electro-acupuncture for the prevention of taxane-induced peripheral neuropathy in women with early stage breast cancer.

    Science.gov (United States)

    Greenlee, Heather; Crew, Katherine D; Capodice, Jillian; Awad, Danielle; Buono, Donna; Shi, Zaixing; Jeffres, Anne; Wyse, Sharon; Whitman, Wendy; Trivedi, Meghna S; Kalinsky, Kevin; Hershman, Dawn L

    2016-04-01

    To investigate the effect of electro-acupuncture (EA) as a non-pharmacological intervention to prevent or reduce chemotherapy-induced peripheral neuropathy (CIPN) in breast cancer patients undergoing chemotherapy of taxane. Women with stage I-III breast cancer scheduled to receive taxane therapy were randomized to receive a standardized protocol of 12 true or sham EA (SEA) weekly treatments concurrent with taxane treatment. Subjects completed the Brief Pain Inventory-Short Form (BPI-SF), Functional Assessment of Cancer Therapy-Taxane neurotoxicity subscale (FACT-NTX), and other assessments at baseline and weeks 6, 12, and 16. A total of 180 subjects were screened, 63 enrolled and 48 completed week 16 assessments. Mean age was 50 with 25 % white, 25 % black, and 43 % Hispanic; 52 % had no prior chemotherapy. At week 12, both groups reported an increase in mean BPI-SF worst pain score, but no mean differences were found between groups (SEA 2.8 vs. EA 2.6, P = .86). By week 16, the SEA group returned to baseline, while the EA group continued to worsen (SEA 1.7 vs. EA 3.4, P = .03). The increase in BPI-SF worst pain score was 1.62 points higher in the EA group than in the SEA group at week 16 (P = .04). In a randomized, sham-controlled trial of EA for prevention of taxane-induced CIPN, there were no differences in pain or neuropathy between groups at week 12. Of concern, subjects on EA had a slower recovery than SEA subjects. Future studies should focus on EA for treatment as opposed to prevention of CIPN.

  14. Radiation Therapy Did Not Induce Long-Term Changes in Rectal Mucosa: Results From the Randomized Scandinavian Prostate Cancer Group 7 Trial

    Energy Technology Data Exchange (ETDEWEB)

    Slagsvold, Jens Erik, E-mail: Jens.Erik.Slagsvold@stolav.no [Cancer Clinic, St. Olavs Hospital, Trondheim University Hospital, Trondheim (Norway); Viset, Trond [Department of Pathology, St. Olavs Hospital, Trondheim University Hospital, Trondheim (Norway); Wibe, Arne [Institute of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim (Norway); Department of Surgery, St. Olavs Hospital, Trondheim University Hospital, Trondheim (Norway); Kaasa, Stein [Cancer Clinic, St. Olavs Hospital, Trondheim University Hospital, Trondheim (Norway); European Palliative Care Research Center, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim (Norway); Widmark, Anders [Department of Radiation Sciences, Cancercentrum, Umeå (Sweden); Lund, Jo-Åsmund [Cancer Clinic, St. Olavs Hospital, Trondheim University Hospital, Trondheim (Norway); European Palliative Care Research Center, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim (Norway)

    2016-07-15

    Purpose: To investigate long-term changes in the rectal mucosa after curative external beam radiation therapy in the treatment of prostate cancer. Methods and Materials: In the Scandinavian Prostate Cancer Group 7 trial, 880 men with locally advanced prostate cancer were randomized to hormonal therapy alone versus hormonal therapy plus radiation therapy to 70 Gy. A subcohort from this trial being randomized at our center (n=178) was invited to a study on late anorectal side effects during 2003-2005, approximately 5 years after treatment, including measuring health-reported quality of life and physician-assessed toxicity score by the Late Effects Normal Tissue Task Force/Subjective, Objective, Management, Analytic (LENT/SOMA) and European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group score. Sixty-seven patients had a rectal mucosa biopsy. Sixty-four biopsies were included in the final analysis, of which 33 patients were randomized to hormonal treatment and 31 to hormonal treatment plus radiation therapy. The presence of fibrosis, number of capillaries, and lymphocyte infiltration was then evaluated by light microscopy. Results: The group receiving radiation therapy had significantly higher LENT/SOMA and function/bother scale scores than the group that only received hormonal treatment, but there was no significant difference in the presence of fibrosis, ectasia, number of capillaries in the lamina propria, or lymphocyte infiltration between the groups. Conclusion: Radiation therapy to 70 Gy to the prostate does not induce long-term microscopic mucosal changes in the rectum 5 years after treatment. This is in contrast to the general assumption that structural changes, including fibrosis, seen after radiation therapy include the mucosa. We speculate that the main late effects of radiation therapy on the structure of the rectum are located in the deeper layers of the rectal wall than the mucosa.

  15. Safety of primed repetitive transcranial magnetic stimulation and modified constraint-induced movement therapy in a randomized controlled trial in pediatric hemiparesis.

    Science.gov (United States)

    Gillick, Bernadette T; Krach, Linda E; Feyma, Tim; Rich, Tonya L; Moberg, Kelli; Menk, Jeremiah; Cassidy, Jessica; Kimberley, Teresa; Carey, James R

    2015-04-01

    To investigate the safety of combining a 6-Hz primed low-frequency repetitive transcranial magnetic stimulation (rTMS) intervention in the contralesional hemisphere with a modified constraint-induced movement therapy (mCIMT) program in children with congenital hemiparesis. Phase 1 randomized, double-blinded, placebo-controlled pretest/posttest trial. University academic facility and pediatric specialty hospital. Subjects (N = 19; age range, 8-17 y) with congenital hemiparesis caused by ischemic stroke or periventricular leukomalacia. No subject withdrew because of adverse events. All subjects included completed the study. Subjects were randomized to 1 of 2 groups: either real rTMS plus mCIMT (n = 10) or sham rTMS plus mCIMT (n = 9). Adverse events, physician assessment, ipsilateral hand function, stereognosis, cognitive function, subject report of symptoms assessment, and subject questionnaire. No major adverse events occurred. Minor adverse events were found in both groups. The most common events were headaches (real: 50%, sham: 89%; P = .14) and cast irritation (real: 30%, sham: 44%; P = .65). No differences between groups in secondary cognitive and unaffected hand motor measures were found. Primed rTMS can be used safely with mCIMT in congenital hemiparesis. We provide new information on the use of rTMS in combination with mCIMT in children. These findings could be useful in research and future clinical applications in advancing function in congenital hemiparesis. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  16. EFFECTS OF MODIFIED CONSTRAINT-INDUCED MOVEMENT THERAPY FOR LOWER LIMB ON MOTOR FUNCTION IN STROKE PATIENTS: A RANDOMIZED CONTROLLED STUDY

    Directory of Open Access Journals (Sweden)

    Sevim ACAROZ CANDAN

    2017-10-01

    Full Text Available Background: Few studies have examined the effectiveness of modified constraint-induced movement therapy (mCIMT for the paretic lower limb following stroke. This study aimed to investigate the effects of mCIMT on motor function of the lower limb in stroke patients. Methods: A randomized, controlled study of 30 participants, who were randomized to 2 groups, was conducted. The study group received mCIMT, and the control group received neurodevelopmental therapy (NDT for two weeks. All were evaluated for motor function through the Functional Ambulation Classification (FAC, Berg Balance Scale (BBS,10-Meter Walk Test, gait parameters (cadence and step length ratio and postural symmetry ratio at pretreatment and post-treatment, like two times. Results: The improvements in BBS score, postural symmetry ratio, step length ratio, cadence and walking velocity had greater in the study group than the control group (P < 0.05. The improvement of FAC score was more pronounced in the study group (P = 0.005. Conclusion: mCIMT for paretic lower limb had superior effect against the NDT to enhance the motor function (gait parameters, balance, ambulation, and symmetry in patients with stroke. mCIMT may be used as a new alternative treatment for lower limb rehabilitation.

  17. Efficacy and safety of electroacupuncture with different acupoints for chemotherapy-induced nausea and vomiting: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Chen, Bo; Hu, Shu-xiang; Liu, Bao-hu; Zhao, Tian-yi; Li, Bo; Liu, Yan; Li, Ming-yue; Pan, Xing-fang; Guo, Yong-ming; Chen, Ze-lin; Guo, Yi

    2015-05-12

    Many patients experience nausea and vomiting during chemotherapy treatment. Evidence demonstrates that electroacupuncture is beneficial for controlling chemotherapy-induced nausea and vomiting (CINV). However, the acupoint or matching acupoint with the best efficacy for controlling CINV still remains unidentified. This study consists of a randomized controlled trial (RCT) with four parallel arms: a control group and three electroacupuncture groups (one with Neiguan (PC6), one with Zhongwan (CV12), and one with both PC6 and CV12). The control group received standard antiemetic only, while the other three groups received electroacupuncture stimulation with different acupoints besides the standard antiemetic. The intervention is done once daily from the first day (day 1) to the fourth day (day 4) during chemotherapy treatment. The primary outcome measures include frequency of nausea, vomiting and retching. The secondary outcome measures are the grade of constipation and diarrhea, electrogastrogram, assessment of quality of life, assessment of anxiety and depression, and other adverse effects during the chemotherapy. Assessments are scheduled from one day pre-chemotherapy (day 0) to the fifth day of chemotherapy (day 5). Follow-ups are done from day 6 to day 21. The aim of this study is to evaluate the efficacy and safety of electro-acupuncture with different acupoints in the management of CINV. The register number of randomized controlled trial is NCT02195908 . The date of registration was 21 July 2014.

  18. Current Evidence on Auricular Therapy for Chemotherapy-Induced Nausea and Vomiting in Cancer Patients: A Systematic Review of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Jing-Yu Tan

    2014-01-01

    Full Text Available Auricular therapy (AT has been historically viewed as a convenient approach adjunct to pharmacological therapy for cancer patients with chemotherapy-induced nausea and vomiting (CINV. The aim of this study was to assess the evidence of the therapeutic effect of AT for CINV management in cancer patients. Relevant randomized controlled trials were retrieved from 12 electronic databases without language restrictions. Meanwhile, manual search was conducted for Chinese journals on complementary medicine published within the last five years, and the reference lists of included studies were also checked to identify any possible eligible studies. Twenty-one studies with 1713 participants were included. The effect rate of AT for managing acute CINV ranged from 44.44% to 93.33% in the intervention groups and 15% to 91.67% in the control groups. For delayed CINV, it was 62.96% to 100% and 25% to 100%, respectively. AT seems to be a promising approach in managing CINV. However, the level of evidence was low and the definite effect cannot be concluded as there were significant methodological flaws identified in the analyzed studies. The implications drawn from the 21 studies put some clues for future practice in this area including the need to conduct more rigorously designed randomized controlled trials.

  19. Current Evidence on Auricular Therapy for Chemotherapy-Induced Nausea and Vomiting in Cancer Patients: A Systematic Review of Randomized Controlled Trials

    Science.gov (United States)

    Molassiotis, Alexander; Wang, Tao; Suen, Lorna K. P.

    2014-01-01

    Auricular therapy (AT) has been historically viewed as a convenient approach adjunct to pharmacological therapy for cancer patients with chemotherapy-induced nausea and vomiting (CINV). The aim of this study was to assess the evidence of the therapeutic effect of AT for CINV management in cancer patients. Relevant randomized controlled trials were retrieved from 12 electronic databases without language restrictions. Meanwhile, manual search was conducted for Chinese journals on complementary medicine published within the last five years, and the reference lists of included studies were also checked to identify any possible eligible studies. Twenty-one studies with 1713 participants were included. The effect rate of AT for managing acute CINV ranged from 44.44% to 93.33% in the intervention groups and 15% to 91.67% in the control groups. For delayed CINV, it was 62.96% to 100% and 25% to 100%, respectively. AT seems to be a promising approach in managing CINV. However, the level of evidence was low and the definite effect cannot be concluded as there were significant methodological flaws identified in the analyzed studies. The implications drawn from the 21 studies put some clues for future practice in this area including the need to conduct more rigorously designed randomized controlled trials. PMID:25525445

  20. An experimental study of solid source diffusion by spin on dopants and its application for minimal silicon-on-insulator CMOS fabrication

    Science.gov (United States)

    Liu, Yongxun; Koga, Kazuhiro; Khumpuang, Sommawan; Nagao, Masayoshi; Matsukawa, Takashi; Hara, Shiro

    2017-06-01

    Solid source diffusions of phosphorus (P) and boron (B) into the half-inch (12.5 mm) minimal silicon (Si) wafers by spin on dopants (SOD) have been systematically investigated and the physical-vapor-deposited (PVD) titanium nitride (TiN) metal gate minimal silicon-on-insulator (SOI) complementary metal-oxide-semiconductor (CMOS) field-effect transistors (FETs) have successfully been fabricated using the developed SOD thermal diffusion technique. It was experimentally confirmed that a low temperature oxidation (LTO) process which depresses a boron silicide layer formation is effective way to remove boron-glass in a diluted hydrofluoric acid (DHF) solution. It was also found that top Si layer thickness of SOI wafers is reduced in the SOD thermal diffusion process because of its consumption by thermal oxidation owing to the oxygen atoms included in SOD films, which should be carefully considered in the ultrathin SOI device fabrication. Moreover, normal operations of the fabricated minimal PVD-TiN metal gate SOI-CMOS inverters, static random access memory (SRAM) cells and ring oscillators have been demonstrated. These circuit level results indicate that no remarkable particles and interface traps were introduced onto the minimal wafers during the device fabrication, and the developed solid source diffusion by SOD is useful for the fabrication of functional logic gate minimal SOI-CMOS integrated circuits.

  1. EFFECT OF INTRACUFF MEDIA-ALKALINISED LIGNOCAINE, SALINE, AND AIR ON ENDOTRACHEAL TUBE INDUCED EMERGENCE PHENOMENA: A RANDOMIZED CONTROLLED STUDY

    Directory of Open Access Journals (Sweden)

    Indu S

    2016-07-01

    Full Text Available CONTEXT Emergence from general anaesthesia is associated with post extubation cough, hoarseness, sore throat, and dysphagia, which may affect the smoothness of extubation. Prophylactic interventions have been studied to reduce these tracheal morbidities with varying results. AIMS To compare the efficacy of air, alkalinised lignocaine and saline in maintaining intracuff pressure and reducing postoperative cough (PEC and sore throat (POST. SETTINGS AND DESIGN A randomised controlled study conducted in a teaching hospital. METHODS AND MATERIALS 105 patients scheduled for elective surgeries were randomly allocated into groups of 35 each. The endotracheal tube (ETT cuffs were inflated with air, alkalinised lignocaine, or saline. The intracuff pressure (ICP was initially set to 25-30 cm of H2O; measured every 30 minutes and before extubation; the minimum volume for occlusion (MOV noted. The incidence PEC and POST were monitored. STATISTICAL ANALYSIS Data analysed using Chi-square test, Fisher’s exact test; Bonferroni method allowed multiple comparisons. A p value <0.05 was considered significant. RESULTS Pre-lubricated ETT cuff inflation with liquid media maintained an acceptable ICP. Saline and alkalinised lignocaine were effective in reducing PEC and POST. Alkalinised lignocaine provided smoother extubation and fared better in the early postoperative period. CONCLUSIONS Pre-lubricated ETT cuffs with liquid media reduced PEC and POST. Alkalinised lignocaine showed better profile than saline. Optimum ICP reduces tracheal morbidity.

  2. Oral misoprostol with mifepristone versus misoprostol alone for inducing labor in intrauterine fetal death: A randomized placebo-controlled trial

    Directory of Open Access Journals (Sweden)

    Yazhini Arjunan

    2017-01-01

    Full Text Available Context: Intrauterine fetal death (IUFD causes emotional distress and could result in intrauterine infection. In view of these complications, medical induction is recommended, if it is safe. Aim: The aim of this study was to compare the efficacy and safety of a combination of mifepristone and misoprostol with oral misoprostol alone for induction of labor in IUFD. Settings and Design: This is a randomized placebo-controlled trial conducted at a tertiary care teaching hospital in southern India. Patients and Methods: We recruited 72 women with IUFD in a singleton pregnancy after 28 weeks with intact membranes. Thirty-six women received oral placebo followed by misoprostol. In other group, 36 women received 200 mg oral mifepristone followed by misoprostol (both groups received 50 μg orally 4th hourly up to 5 doses. The interval between mifepristone/placebo and the first dose of misoprostol was 24 h. Results: Successful delivery occurred within 72 h in 31 of 36 (86% women who received mifepristone before misoprostol and in 28 of 36 (78% women who received only misoprostol (P = 0.541. Median (interquartile range induction to delivery interval was 3.5 (2–5 and 4 (3–5 h in the combination group and misoprostol group, respectively (P = 0.465. Conclusions: Addition of mifepristone to misoprostol appears to be marginally more effective than misoprostol alone for induction of labor in intermediate and late IUFD, although the differences were not statistically significant.

  3. Schottky Barrier Height Tuning via the Dopant Segregation Technique through Low-Temperature Microwave Annealing.

    Science.gov (United States)

    Fu, Chaochao; Zhou, Xiangbiao; Wang, Yan; Xu, Peng; Xu, Ming; Wu, Dongping; Luo, Jun; Zhao, Chao; Zhang, Shi-Li

    2016-04-27

    The Schottky junction source/drain structure has great potential to replace the traditional p/n junction source/drain structure of the future ultra-scaled metal-oxide-semiconductor field effect transistors (MOSFETs), as it can form ultimately shallow junctions. However, the effective Schottky barrier height (SBH) of the Schottky junction needs to be tuned to be lower than 100 meV in order to obtain a high driving current. In this paper, microwave annealing is employed to modify the effective SBH of NiSi on Si via boron or arsenic dopant segregation. The barrier height decreased from 0.4-0.7 eV to 0.2-0.1 eV for both conduction polarities by annealing below 400 °C. Compared with the required temperature in traditional rapid thermal annealing, the temperature demanded in microwave annealing is ~60 °C lower, and the mechanisms of this observation are briefly discussed. Microwave annealing is hence of high interest to future semiconductor processing owing to its unique capability of forming the metal/semiconductor contact at a remarkably lower temperature.

  4. Polycrystalline silicon carbide dopant profiles obtained through a scanning nano-Schottky contact

    Energy Technology Data Exchange (ETDEWEB)

    Golt, M. C.; Strawhecker, K. E.; Bratcher, M. S. [U.S. Army Research Laboratory, WMRD, Aberdeen Proving Ground, Maryland 21005 (United States); Shanholtz, E. R. [ORISE, Belcamp, Maryland 21017 (United States)

    2016-07-14

    The unique thermo-electro-mechanical properties of polycrystalline silicon carbide (poly-SiC) make it a desirable candidate for structural and electronic materials for operation in extreme environments. Necessitated by the need to understand how processing additives influence poly-SiC structure and electrical properties, the distribution of lattice defects and impurities across a specimen of hot-pressed 6H poly-SiC processed with p-type additives was visualized with high spatial resolution using a conductive atomic force microscopy approach in which a contact forming a nano-Schottky interface is scanned across the sample. The results reveal very intricate structures within poly-SiC, with each grain having a complex core-rim structure. This complexity results from the influence the additives have on the evolution of the microstructure during processing. It was found that the highest conductivities localized at rims as well as at the interface between the rim and the core. The conductivity of the cores is less than the conductivity of the rims due to a lower concentration of dopant. Analysis of the observed conductivities and current-voltage curves is presented in the context of nano-Schottky contact regimes where the conventional understanding of charge transport to diode operation is no longer valid.

  5. Transition Metal Dopants Essential for Producing Ferromagnetism in Metal Oxide Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Lydia; Thurber, Aaron P.; Anghel, Josh; Sabetian, Maryam; Engelhard, Mark H.; Tenne, D.; Hanna, Charles; Punnoose, Alex

    2010-08-13

    Recent claims that ferromagnetism can be produced in nanoparticles of metal oxides without the presence of transition metal dopants has been refuted in this work by investigating 62 high quality well-characterized nanoparticle samples of both undoped and Fe doped (0-10% Fe) ZnO. The undoped ZnO nanoparticles showed zero or negligible magnetization, without any dependence on the nanoparticle size. However, chemically synthesized Zn₁₋xFexO nanoparticles showed clear ferromagnetism, varying systematically with Fe concentration. Furthermore, the magnetic properties of Zn₁₋xFexO nanoparticles showed strong dependence on the reaction media used to prepare the samples. The zeta potentials of the Zn₁₋xFexO nanoparticles prepared using different reaction media were significantly different, indicating strong differences in the surface structure. Electron paramagnetic resonance studies clearly showed that the difference in the ferromagnetic properties of Zn₁₋xFexO nanoparticles with different surface structures originate from differences in the fraction of the doped Fe³⁺ ions that are coupled ferromagnetically.

  6. Polycrystalline silicon carbide dopant profiles obtained through a scanning nano-Schottky contact

    International Nuclear Information System (INIS)

    Golt, M. C.; Strawhecker, K. E.; Bratcher, M. S.; Shanholtz, E. R.

    2016-01-01

    The unique thermo-electro-mechanical properties of polycrystalline silicon carbide (poly-SiC) make it a desirable candidate for structural and electronic materials for operation in extreme environments. Necessitated by the need to understand how processing additives influence poly-SiC structure and electrical properties, the distribution of lattice defects and impurities across a specimen of hot-pressed 6H poly-SiC processed with p-type additives was visualized with high spatial resolution using a conductive atomic force microscopy approach in which a contact forming a nano-Schottky interface is scanned across the sample. The results reveal very intricate structures within poly-SiC, with each grain having a complex core-rim structure. This complexity results from the influence the additives have on the evolution of the microstructure during processing. It was found that the highest conductivities localized at rims as well as at the interface between the rim and the core. The conductivity of the cores is less than the conductivity of the rims due to a lower concentration of dopant. Analysis of the observed conductivities and current-voltage curves is presented in the context of nano-Schottky contact regimes where the conventional understanding of charge transport to diode operation is no longer valid.

  7. Dopant site location in dual-implanted GaP using (111) planar channeling

    International Nuclear Information System (INIS)

    Parikh, N.R.; Kao, C.T.; Lee, D.R.; Muse, J.; Swanson, M.L.; Venkatasubramanian, R.; Timmons, M.

    1990-01-01

    Previous studies have indicated that dual implantation can efficiently introduce group IV dopant onto selected sub-lattice sites in III--V compound semiconductors, thus enhancing electrical activation. The authors have studied this phenomenon in GaP using Rutherford Backscattering Spectroscopy (RBS) to determine the lattice location of Sn atoms. The authors used single crystals of GaP (100) which had been implanted at 400 degrees C with 120 Sn + following previously implanted 69 Ga + or 31 P + . Energies were selected for equivalent projected ranges, and all species were implanted with doses of 1 x 10 15 atoms/cm 2 . Asymmetry in the angular scan of the {111} planar channel was then used to determine the sub-lattice location of the implanted Sn. RBS results indicated that for all implants Sn atoms were substituting Ga and P sites equally. However, Hall effect measurements gave p type conduction for GaP implanted with Sn alone, while those with prior implants of Ga or P resulted in n-type conduction. RBS and Hall effect results are explained by a vacancy complex model

  8. Diagnosing the Stagnation Conditions of MagLIF Implosions Using Co and Kr dopants

    Science.gov (United States)

    Harding, E. C.; Hansen, S. B.; Harvey-Thompson, A. J.; Weis, M. R.; Hahn, K. D.; Gomez, M. R.; Knapp, P. F.; Slutz, S. A.; Geissel, M.; Ampleford, D. J.; Jennings, C. A.; Peterson, K.; Rochau, G. A.; Doron, R.; Stambulchik, E.; Nedostup, O.; Maron, Y.; Golovkin, I.

    2017-10-01

    Recent experiments on the Z-machine tested several new diagnostic techniques for investigating the stagnation conditions and the origins of the mix present in a Magnetized Liner Inertial Fusion (MagLIF) target. For the first time we have collected K-shell spectra from a low-concentration, Kr dopant placed in the gaseous D2 fuel. In addition, thin Co coatings were strategically applied to three different internal surfaces of the target in order to assess which surfaces actively contribute to the contamination of the fuel. Both imaging spectroscopy and narrow-band crystal imaging were used to identify the location of He-like Co ions. The Te and ne of the Co is inferred by fitting the He-alpha lines and the near-by Li-like satellites. The experimental measurements and the challenges associated with the analysis will be discussed. Sandia Natl Lab is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE NNSA under contract DE-NA-0003525.

  9. Defect- and dopant-controlled carbon nanotubes fabricated by self-assembly of graphene nanoribbons

    Institute of Scientific and Technical Information of China (English)

    Cun Zhang and Shaohua Chen

    2015-01-01

    Molecular dynamics simulations showed that a basal carbon nanotube can activate and guide the fabrication of single-walled carbon nanotubes (CNTs) on its internal surface by self-assembly of edge-unpassivated graphene nanoribbons with defects. Furthermore, the distribution of defects on self-assembled CNTs is controllable. The system temperature and defect fraction are two main factors that influence the success of self-assembly. Due to possible joint flaws formed at the boundaries under a relatively high constant temperature, a technique based on increasing the temperature is adopted. Self-assembly is always successful for graphene nanoribbons with relatively small defect fractions, while it will fail in cases with relatively large ones. Similar to the self-assembly of graphene nanoribbons with defects, graphene nanoribbons with different types of dopants can also be self-assembled into carbon nanotubes. The finding provides a possible fabrication technique not only for carbon nanotubes with metallic or semi-con- ductive properties but also for carbon nanotubes with electromagnetic induction characteristics.

  10. Size limit on the phosphorous doped silicon nanocrystals for dopant activation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, P., E-mail: pengyuan.yang@surrey.ac.uk [Surrey Ion Beam Centre, Advanced Technology Institute, University of Surrey, Guildford GU2 5XH (United Kingdom); Gwilliam, R.M. [Surrey Ion Beam Centre, Advanced Technology Institute, University of Surrey, Guildford GU2 5XH (United Kingdom); Crowe, I.F.; Papachristodoulou, N.; Halsall, M.P. [Photon Science Institute, School of Electrical and Electronic Engineering, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Hylton, N.P. [Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); Hulko, O.; Knights, A.P. [Department of Engineering Physics and the Centre for Emerging Device Technologies, McMaster University, 1280 Main Street West, Hamilton L8S 4L7, Ontario (Canada); Shah, M.; Kenyon, A.J. [Department of Electronic and Electrical Engineering, University College London, London WC1E 7JE (United Kingdom)

    2013-07-15

    We studied the photoluminescence spectra of silicon nanocrystals doped with and without phosphorus as a function of isothermal annealing time. Silicon nanocrystals were prepared by the implantation of 80 keV Si{sup +} into a 500 nm SiO{sub 2} film to an areal density of 8 × 10{sup 16} at/cm{sup 2}. Half of the samples were co-implanted with P{sup +} at 80 keV to 5 × 10{sup 15} at/cm{sup 2}. The photoluminescence of the annealed samples were photo-excited at wavelength of 405 nm. For short anneal times, when the nanocrystal size distribution has a relatively small mean diameter, formation in the presence of phosphorus yields an increase in the luminescence intensity and a blue shift in the emission peak compared with intrinsic nanocrystals. As the mean size increases with annealing time, this enhancement rapidly diminishes and the peak energy shifts to the red. Our results indicate the donor electron generation depends strongly on the nanocrystal size. We also found a critical limit above which it allows dopant activation.

  11. Effect of Metal Dopant on Ninhydrin—Organic Nonlinear Optical Single Crystals

    Directory of Open Access Journals (Sweden)

    R. S. Sreenivasan

    2013-01-01

    Full Text Available In the present work, metal (Cu2+-substituted ninhydrin single crystals were grown by slow evaporation method. The grown crystals have been subjected to single crystal XRD, powder X-ray diffraction, FTIR, dielectric and SHG studies. Single crystal X-ray diffraction analysis reveals that the compound crystallizes in monoclinic system with noncentrosymmetric space group P21 with lattice parameters a=11.28 Å, b=5.98 Å, c=5.71 Å, α=90∘, β=98.57, γ=90∘, and V=381 (Å3, which agrees very well with the reported value. The sharp and strong peaks in the powder X-ray diffraction pattern confirm the good crystallinity of the grown crystals. The presence of dopants marginally altered the lattice parameters without affecting the basic structure of the crystal. The UV-Vis transmittance spectrum shows that the crystal has a good optical transmittance in the entire visible region with lower cutoff wavelength 314 nm. The vibrational frequencies of various functional groups in the crystals have been derived from FT-IR analysis. Based on the shifts in the vibrations, the presence of copper in the lattice of the grown crystal is clearly established from the pure ninhydrin crystals. Both dielectric constant and dielectric loss decrease with the increase in frequency. The second harmonic generation efficiency was measured by employing powder Kurtz method.

  12. The effects of dopants on the electrical resistivity in lead magnesium niobate multilayer ceramic capacitors

    International Nuclear Information System (INIS)

    Chang, D.D.; Ling, H.C.

    1989-01-01

    Electrical resistivity studies were performed on multilayer ceramic capacitors (MLC) based on lead magnesium niobate and containing dopants of lead titanate, lead zinc niobate, and lead cobalt niobate. The results showed that lead titanate and/or lead zinc niobate had no effect on the electrical resistivity while lead cobalt niobate decreased the resistivity. In samples without lead cobalt niobate, we observed a conduction mechanism with an activation energy of --1 eV, which is commonly observed in barium titanate based dielectrics. This is attributed to ionic conduction via the motion of oxygen vacancies. The increase in conductivity (or decrease in resistivity) resulting from the addition of lead cobalt niobate was rationalized as due to electronic conduction through charge hopping among the cations. This conduction mechanism was characterized by an activation energy of --0.5 eV. Since the activation energy associated with the long-term failure was previously determined by a matrix of temperature and voltage accelerated life tests to be -- 1 eV, they conclude that conduction through charge hopping is not affecting the long-term reliability of these devices

  13. Role of metformin in oxaliplatin-induced peripheral neuropathy in patients with stage III colorectal cancer: randomized, controlled study.

    Science.gov (United States)

    El-Fatatry, Basma Mahrous; Ibrahim, Osama Mohamed; Hussien, Fatma Zakaria; Mostafa, Tarek Mohamed

    2018-06-21

    Peripheral sensory neuropathy is the most prominently reported adverse effect of oxaliplatin. The purpose of this study was to evaluate metformin role in oxaliplatin-induced neuropathy. From November 2014 to May 2016, 40 patients with stage III colorectal cancer completed 12 cycles of FOLFOX-4 regimen. Twenty patients in the control arm received FOLFOX-4 regimen only, and 20 patients in the metformin arm, received the same regimen along with metformin 500 mg three times daily. The metformin efficacy was evaluated using National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE version 4.0), a12-item neurotoxicity questionnaire (Ntx-12) from the validated Functional Assessment of Cancer Therapy/Gynecologic Oncology Group and, the brief pain inventory short form "worst pain" item. In addition to neurotensin, malondialdehyde and interleukin-6 serum levels assessment. At the end of the 12th cycle, there were less patients with grade 2 and 3 neuropathy in metformin arm as compared to control arm. (60 versus 95%, P = 0.009) In addition, metformin arm showed significantly higher total scores of Ntx-12 questionnaire than control arm (24.0 versus 19.2, P < 0.001). Furthermore, the mean pain score in metformin arm was significantly lower than those of control arm, (6.7 versus 7.3, P = 0.005). Mean serum levels of malondialdehyde and neurotensin were significantly lower in metformin arm after the 6th and the 12th cycles. Metformin may be a promising drug in protecting colorectal cancer patients against oxaliplatin-induced chronic peripheral sensory neuropathy.

  14. Prophylaxis of Radiation-Induced Nausea and Vomiting Using 5-Hydroxytryptamine-3 Serotonin Receptor Antagonists: A Systematic Review of Randomized Trials

    Energy Technology Data Exchange (ETDEWEB)

    Salvo, Nadia; Doble, Brett [Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario (Canada); Khan, Luluel [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Amirthevasar, Gayathri [Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario (Canada); Dennis, Kristopher [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Pasetka, Mark; DeAngelis, Carlo [Department of Oncology Pharmacy, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Tsao, May [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Chow, Edward, E-mail: Edward.Chow@sunnybrook.ca [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada)

    2012-01-01

    Purpose: To systematically review the effectiveness and safety of 5-hydroxytryptamine-3 receptor antagonists (5-HT3 RAs) compared with other antiemetic medication or placebo for prophylaxis of radiation-induced nausea and vomiting. Methods and Materials: We searched the following electronic databases: MEDLINE, Embase, the Cochrane Central Register of Controlled Clinical Trials, and Web of Science. We also hand-searched reference lists of included studies. Randomized, controlled trials that compared a 5-HT3 RA with another antiemetic medication or placebo for preventing radiation-induced nausea and vomiting were included. We excluded studies recruiting patients receiving concomitant chemotherapy. When appropriate, meta-analysis was conducted using Review Manager (v5) software. Relative risks were calculated using inverse variance as the statistical method under a random-effects model. We assessed the quality of evidence by outcome using the Grading of Recommendations Assessment, Development, and Evaluation approach. Results: Eligibility screening of 47 articles resulted in 9 included in the review. The overall methodologic quality was moderate. Meta-analysis of 5-HT3 RAs vs. placebo showed significant benefit for 5-HT3 RAs (relative risk [RR] 0.70; 95% confidence interval [CI] 0.57-0.86 for emesis; RR 0.84, 95% CI 0.73-0.96 for nausea). Meta-analysis comparing 5-HT3 RAs vs. metoclopramide showed a significant benefit of the 5-HT3 RAs for emetic control (RR 0.27, 95% CI 0.15-0.47). Conclusion: 5-Hydroxytryptamine-3 RAs are superior to placebo and other antiemetics for prevention of emesis, but little benefit was identified for nausea prevention. 5-Hydroxytryptamine-3 RAs are suggested for prevention of emesis. Limited evidence was found regarding delayed emesis, adverse events, quality of life, or need for rescue medication. Future randomized, controlled trials should evaluate different 5-HT3 antiemetics and new agents with novel mechanisms of action such at the NK

  15. Prophylaxis of Radiation-Induced Nausea and Vomiting Using 5-Hydroxytryptamine-3 Serotonin Receptor Antagonists: A Systematic Review of Randomized Trials

    International Nuclear Information System (INIS)

    Salvo, Nadia; Doble, Brett; Khan, Luluel; Amirthevasar, Gayathri; Dennis, Kristopher; Pasetka, Mark; DeAngelis, Carlo; Tsao, May; Chow, Edward

    2012-01-01

    Purpose: To systematically review the effectiveness and safety of 5-hydroxytryptamine-3 receptor antagonists (5-HT3 RAs) compared with other antiemetic medication or placebo for prophylaxis of radiation-induced nausea and vomiting. Methods and Materials: We searched the following electronic databases: MEDLINE, Embase, the Cochrane Central Register of Controlled Clinical Trials, and Web of Science. We also hand-searched reference lists of included studies. Randomized, controlled trials that compared a 5-HT3 RA with another antiemetic medication or placebo for preventing radiation-induced nausea and vomiting were included. We excluded studies recruiting patients receiving concomitant chemotherapy. When appropriate, meta-analysis was conducted using Review Manager (v5) software. Relative risks were calculated using inverse variance as the statistical method under a random-effects model. We assessed the quality of evidence by outcome using the Grading of Recommendations Assessment, Development, and Evaluation approach. Results: Eligibility screening of 47 articles resulted in 9 included in the review. The overall methodologic quality was moderate. Meta-analysis of 5-HT3 RAs vs. placebo showed significant benefit for 5-HT3 RAs (relative risk [RR] 0.70; 95% confidence interval [CI] 0.57–0.86 for emesis; RR 0.84, 95% CI 0.73–0.96 for nausea). Meta-analysis comparing 5-HT3 RAs vs. metoclopramide showed a significant benefit of the 5-HT3 RAs for emetic control (RR 0.27, 95% CI 0.15–0.47). Conclusion: 5-Hydroxytryptamine-3 RAs are superior to placebo and other antiemetics for prevention of emesis, but little benefit was identified for nausea prevention. 5-Hydroxytryptamine-3 RAs are suggested for prevention of emesis. Limited evidence was found regarding delayed emesis, adverse events, quality of life, or need for rescue medication. Future randomized, controlled trials should evaluate different 5-HT3 antiemetics and new agents with novel mechanisms of action such at

  16. Efficacy of Traditional Chinese Medicine in Treatment and Prophylaxis of Radiation-Induced Oral Mucositis in Patients Receiving Radiotherapy: A Randomized Controlled Trial.

    Science.gov (United States)

    Wang, Cong; Wang, Peiguo; Ouyang, Huaqiang; Wang, Jing; Sun, Lining; Li, Yanwei; Liu, Dongying; Jiang, Zhansheng; Wang, Bin; Pan, Zhanyu

    2018-06-01

    To estimate the efficacy of traditional Chinese medicine (Chining decoction, CHIN) for radiation-induced oral mucositis in patients with head and neck cancer. From May 2014 to December 2015, 70 consecutive patients were randomly assigned to receive CHIN (treatment group) or recombinant human epidermal growth factor (rhEGF) spray (control group) at a 1:1 ratio. CHIN was administered to treatment group from the first day of radiotherapy until the completion of radiotherapy. Simultaneously, the rhEGF spray was administered to control group on the oral mucosa of irradiated area. The clinical benefit was determined by gradation of mucositis (Common Terminology Criteria for Adverse Events v4.0), oral pain, and xerostomia (visual analysis scale) for each week during radiotherapy. Body mass index was evaluated before and after radiotherapy. Patients in the treatment group had prominent remission of oral pain and grade of mucositis on each observing point compared with those in control group ( P .05). CHIN presented an obvious advantage in preventing radiation-induced oral mucositis compared with rhEGF spray.

  17. Gluten-free vegan diet induces decreased LDL and oxidized LDL levels and raised atheroprotective natural antibodies against phosphorylcholine in patients with rheumatoid arthritis: a randomized study.

    Science.gov (United States)

    Elkan, Ann-Charlotte; Sjöberg, Beatrice; Kolsrud, Björn; Ringertz, Bo; Hafström, Ingiäld; Frostegård, Johan

    2008-01-01

    The purpose of this study was to investigate the effects of vegan diet in patients with rheumatoid arthritis (RA) on blood lipids oxidized low-density lipoprotein (oxLDL) and natural atheroprotective antibodies against phosphorylcholine (anti-PCs). Sixty-six patients with active RA were randomly assigned to either a vegan diet free of gluten (38 patients) or a well-balanced non-vegan diet (28 patients) for 1 year. Thirty patients in the vegan group completed more than 3 months on the diet regimen. Blood lipids were analyzed by routine methods, and oxLDL and anti-PCs were analyzed by enzyme-linked immunosorbent assay. Data and serum samples were obtained at baseline and after 3 and 12 months. Mean ages were 50.0 years for the vegan group and 50.8 years for controls. Gluten-free vegan diet induced lower body mass index (BMI) and low-density lipoprotein (LDL) and higher anti-PC IgM than control diet (p vegan group, BMI, LDL, and cholesterol decreased after both 3 and 12 months (p vegan patients into clinical responders and non-responders at 12 months, the effects on oxLDL and anti-PC IgA were seen only in responders (p vegan diet in RA induces changes that are potentially atheroprotective and anti-inflammatory, including decreased LDL and oxLDL levels and raised anti-PC IgM and IgA levels.

  18. Effect of eicosapentaenoic and docosahexaenoic acid on resting and exercise-induced inflammatory and oxidative stress biomarkers: a randomized, placebo controlled, cross-over study

    Directory of Open Access Journals (Sweden)

    Galpin Andrew J

    2009-08-01

    Full Text Available Abstract Background The purpose of the present investigation was to determine the effects of EPA/DHA supplementation on resting and exercise-induced inflammation and oxidative stress in exercise-trained men. Fourteen men supplemented with 2224 mg EPA+2208 mg DHA and a placebo for 6 weeks in a random order, double blind cross-over design (with an 8 week washout prior to performing a 60 minute treadmill climb using a weighted pack. Blood was collected pre and post exercise and analyzed for a variety of oxidative stress and inflammatory biomarkers. Blood lactate, muscle soreness, and creatine kinase activity were also measured. Results Treatment with EPA/DHA resulted in a significant increase in blood levels of both EPA (18 ± 2 μmol·L-1 vs. 143 ± 23 μmol·L-1; p -1 vs. 157 ± 13 μmol·L-1; p 0.05. There was a mild increase in oxidative stress in response to exercise (XO and H2O2 (p Conclusion EPA/DHA supplementation increases blood levels of these fatty acids and results in decreased resting levels of inflammatory biomarkers in exercise-trained men, but does not appear necessary for exercise-induced attenuation in either inflammation or oxidative stress. This may be due to the finding that trained men exhibit a minimal increase in both inflammation and oxidative stress in response to moderate duration (60 minute aerobic exercise.

  19. Total knee replacement induces peripheral blood lymphocytes apoptosis and it is not prevented by regional anesthesia - a randomized study.

    Science.gov (United States)

    Kosel, Juliusz; Rusak, Małgorzata; Gołembiewski, Łukasz; Dąbrowska, Milena; Siemiątkowski, Andrzej

    2016-01-01

    Among the many changes caused by a surgical insult one of the least studied is postoperative immunosuppression. This phenomenon is an important cause of infectious complications of surgery such as surgical site infection or hospital acquired pneumonia. One of the mechanisms leading to postoperative immunosuppression is the apoptosis of immunological cells. Anesthesia during surgery is intended to minimize harmful changes and maintain perioperative homeostasis. The aim of the study was evaluation of the effect of the anesthetic technique used for total knee replacement on postoperative peripheral blood lymphocyte apoptosis. 34 patients undergoing primary total knee replacement were randomly assigned to two regional anesthetic protocols: spinal anesthesia and combined spinal-epidural anesthesia. 11 patients undergoing total knee replacement under general anesthesia served as control group. Before surgery, immediately after surgery, during first postoperative day and seven days after the surgery venous blood samples were taken and the immunological status of the patient was assessed with the use of flow cytometry, along with lymphocyte apoptosis using fluorescent microscopy. Peripheral blood lymphocyte apoptosis was seen immediately in the postoperative period and was accompanied by a decrease of the number of T cells and B cells. There were no significant differences in the number of apoptotic lymphocytes according to the anesthetic protocol. Changes in the number of T CD3/8 cells and the number of apoptotic lymphocytes were seen on the seventh day after surgery. Peripheral blood lymphocyte apoptosis is an early event in the postoperative period that lasts up to seven days and is not affected by the choice of the anesthetic technique. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  20. Total knee replacement induces peripheral blood lymphocytes apoptosis and it is not prevented by regional anesthesia - a randomized study

    Directory of Open Access Journals (Sweden)

    Juliusz Kosel

    2016-04-01

    Full Text Available ABSTRACT BACKGROUND: Among the many changes caused by a surgical insult one of the least studied is postoperative immunosuppression. This phenomenon is an important cause of infectious complications of surgery such as surgical site infection or hospital acquired pneumonia. One of the mechanisms leading to postoperative immunosuppression is the apoptosis of immunological cells. Anesthesia during surgery is intended to minimize harmful changes and maintain perioperative homeostasis. The aim of the study was evaluation of the effect of the anesthetic technique used for total knee replacement on postoperative peripheral blood lymphocyte apoptosis. METHODS: 34 patients undergoing primary total knee replacement were randomly assigned to two regional anesthetic protocols: spinal anesthesia and combined spinal-epidural anesthesia. 11 patients undergoing total knee replacement under general anesthesia served as control group. Before surgery, immediately after surgery, during first postoperative day and seven days after the surgery venous blood samples were taken and the immunological status of the patient was assessed with the use of flow cytometry, along with lymphocyte apoptosis using fluorescent microscopy. RESULTS: Peripheral blood lymphocyte apoptosis was seen immediately in the postoperative period and was accompanied by a decrease of the number of T cells and B cells. There were no significant differences in the number of apoptotic lymphocytes according to the anesthetic protocol. Changes in the number of T CD3/8 cells and the number of apoptotic lymphocytes were seen on the seventh day after surgery. CONCLUSION: Peripheral blood lymphocyte apoptosis is an early event in the postoperative period that lasts up to seven days and is not affected by the choice of the anesthetic technique.

  1. A Randomized, Double-Blind Pilot Study of Dose Comparison of Ramosetron to Prevent Chemotherapy-Induced Nausea and Vomiting

    Directory of Open Access Journals (Sweden)

    Ka-Rham Kim

    2015-01-01

    Full Text Available Purpose. This study was conducted to determine the optimal dose titration of ramosetron to prevent the Rhodes Index of Nausea, Vomiting, and Retching (RINVR. Methods. Patients treated with folic acid, 5-fluorouracil, and oxaliplatin were randomized into three groups (0.3 mg, 0.45 mg, and 0.6 mg ramosetron before chemotherapy. The pharmacokinetics and pharmacodynamics using RINVR were evaluated. Results. Seventeen, 15, and 18 patients received ramosetron at doses of 0.3 mg, 0.45 mg, and 0.6 mg, respectively. Tmax (h, Cmax (ng/mL, and AUClast (ng·h/mL were associated with dose escalation significantly, showing a reverse correlation with the RINVR during chemotherapy. Acute CINV was observed in four patients (22.2%, two patients (14.3%, and one (5.6% patient and a delayed CINV on day 7 was found in eight (47%, three (21.4%, and five (27.8% patients in each group. The complete response rate was increased with dose escalation (35.3%, 50.0%, and 72.2% in each group and also showed the tendency for decreasing moderate-to-severe CINV. Conclusions. This study shows a trend regarding the dose-response relationship for ramosetron to prevent CINV, including delayed emesis. It suggested that dose escalation should be considered in patients with CINV in a subsequent cycle of chemotherapy, and an individual approach using RINVR could be useful to monitor CINV.

  2. P2 asymmetry of Au's M-band flux and its smoothing effect due to high-Z ablator dopants

    Directory of Open Access Journals (Sweden)

    Yongsheng Li

    2017-03-01

    Full Text Available X-ray drive asymmetry is one of the main seeds of low-mode implosion asymmetry that blocks further improvement of the nuclear performance of “high-foot” experiments on the National Ignition Facility [Miller et al., Nucl. Fusion 44, S228 (2004]. More particularly, the P2 asymmetry of Au's M-band flux can also severely influence the implosion performance of ignition capsules [Li et al., Phys. Plasmas 23, 072705 (2016]. Here we study the smoothing effect of mid- and/or high-Z dopants in ablator on Au's M-band flux asymmetries, by modeling and comparing the implosion processes of a Ge-doped ignition capsule and a Si-doped one driven by X-ray sources with P2 M-band flux asymmetry. As the results, (1 mid- or high-Z dopants absorb hard X-rays (M-band flux and re-emit isotropically, which helps to smooth the asymmetric M-band flux arriving at the ablation front, therefore reducing the P2 asymmetries of the imploding shell and hot spot; (2 the smoothing effect of Ge-dopant is more remarkable than Si-dopant because its opacity in Au's M-band is higher than the latter's; and (3 placing the doped layer at a larger radius in ablator is more efficient. Applying this effect may not be a main measure to reduce the low-mode implosion asymmetry, but might be of significance in some critical situations such as inertial confinement fusion (ICF experiments very near the performance cliffs of asymmetric X-ray drives.

  3. Incubation and nanostructure formation on n- and p-type Si(1 0 0) and Si(1 1 1) at various doping levels induced by sub-nanojoule femto- and picosecond near-infrared laser pulses

    International Nuclear Information System (INIS)

    Schüle, M.; Afshar, M.; Feili, D.; Seidel, H.; König, K.; Straub, M.

    2014-01-01

    Highlights: • Nanorifts, ripples of period 130 nm and randomly nanoporous surface structures were generated. • Such nanostructures emerged on heavily and lightly n- and p-doped Si(1 0 0) and Si(1 1 1) surfaces. • Strong incubation occurred irrespective of dopant type and concentration or surface orientation. • Incubation is attributed to photoexcitation from laser-induced defect states in the bandgap. • Aggregation of defects results in nanocracks, which turn into nanorift and nanoripple patterns. • Ablation involved predominantly single-photon processes but also multiphoton absorption. - Abstract: N- and p-doped Si(1 0 0) and Si(1 1 1) surfaces with dopant concentrations of 2 × 10 14 –1 × 10 19 cm −3 were irradiated by tightly focused 85-MHz repetition rate Ti:sapphire laser light (central wavelength 800 nm, bandwidth 120 nm) at pulse durations of 12 fs to 1.6 ps. Dependent on pulse peak intensity and exposure time nanorifts, ripples of period 130 nm as well as sponge-like randomly nanoporous surface structures were generated with water immersion and, thereafter, laid bare by etching off aggregated oxide nanoparticles. The same structure types emerged in air or water with transform-limited 100-fs pulses. At a pulse length of 12 fs pronounced incubation occurred with incubation coefficients S = 0.66–0.85, whereas incubation was diminished for picosecond pulses (S > 0.95). The ablation threshold strongly rose with dopant concentration. At similar doping level it was higher for n-type than for p-type samples and for Si(1 0 0) compared to Si(1 1 1) surfaces. These observations are attributed to laser-induced defect states in the bandgap which participate in photoexcitation, deactivation of dopants by complex formation, and different densities of interface states at the boundary with the ultrathin native silicon dioxide surface layer. The threshold increase with pulse length revealed predominant single-photon excitation as well as multiphoton

  4. Metformin for treatment of antipsychotic-induced amenorrhea and weight gain in women with first-episode schizophrenia: a double-blind, randomized, placebo-controlled study.

    Science.gov (United States)

    Wu, Ren-Rong; Jin, Hua; Gao, Keming; Twamley, Elizabeth W; Ou, Jian-Jun; Shao, Ping; Wang, Juan; Guo, Xiao-Feng; Davis, John M; Chan, Philip K; Zhao, Jing-Ping

    2012-08-01

    Data on the treatment of antipsychotic-induced amenorrhea, particularly when occurring with weight gain, are limited. The authors investigated the efficacy and safety of metformin in the treatment of antipsychotic-induced amenorrhea and weight gain in women with first-episode schizophrenia. Eighty-four women (ages 18-40 years) with first-episode schizophrenia who suffered from amenorrhea during antipsychotic treatment were randomly assigned, in a double-blind study design, to receive 1000 mg/day of metformin or placebo in addition to their antipsychotic treatment for 6 months. The primary outcome measures were restoration of menstruation and change in body weight and body mass index (BMI). Secondary outcome measures were changes in levels of prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and testosterone; in fasting levels of insulin and glucose; in LH/FSH ratio; and in insulin resistance index. Repeated mixed models with repeated-measures regression analyses and binary logistic regression were used in the analysis. A total of 76 patients completed the 6-month trial. Significantly more patients in the metformin group (N=28, 66.7%) than in placebo group (N=2, 4.8%) resumed their menstruation. Among patients treated with metformin, BMI decreased by a mean of 0.93 and the insulin resistance index by 2.04. In contrast, patients who received placebo had a mean increase in BMI of 0.85. The prolactin, LH, and testosterone levels and LH/FSH ratio decreased significantly in the metformin group at months 2, 4, and 6, but these levels did not change in the placebo group. Metformin was effective in reversing antipsychotic-induced adverse events, including restoration of menstruation, promotion of weight loss, and improvement in insulin resistance in female patients with schizophrenia.

  5. Comparison of the efficacy of 4- and 8-week lansoprazole treatment for ESD-induced gastric ulcers: a randomized, prospective, controlled study.

    Science.gov (United States)

    Park, Ji Hoon; Baek, Eun Kyung; Choi, Chang Hwan; Lee, Kyung Hun; Kim, Beom Jin; Kim, Jeong Wook; Kim, Jae Gyu; Chang, Sae Kyung

    2014-01-01

    Although endoscopic submucosal dissection (ESD) is widely used to treat gastric neoplasms, there is no consensus for the optimal treatment for ESD-induced ulcers. We compared efficacy between 4 and 8 weeks of lansoprazole treatment for iatrogenic gastric ulcers that developed after ESD. Eighty-four patients who were diagnosed with gastric adenoma or early gastric cancer were enrolled and randomly assigned to treatment with lansoprazole (30 mg/day) for 4 or 8 weeks. Eight weeks after ESD, we conducted follow-up endoscopy to compare ulcer stage and ulcer reduction ratio (dividing the ulcer dimension at 8 weeks by the initial ulcer dimension) between the two groups. From the 84 patients, 69 patients were included in the final analysis, with 34 in the 4-week group and 35 in the 8-week group. Eight weeks after ESD, there were no significant difference observed between the two groups in terms of the ulcer stage (68 % in the scar stage in the 4-week group vs. 69 % in the 8-week group, P = 0.93) or the ulcer reduction ratio (0.0081 ± 0.015 in the 4-week group vs. 0.0037 ± 0.008 in the 8-week group, P = 0.15). Also, in the subgroup analysis among the patients with large ulcers (>30 mm), those parameters were not different. For ESD-induced gastric ulcers, treatment with lansoprazole for 4 weeks was as effective as treatment for 8 weeks. Considering cost-effectiveness, proton pump inhibitor therapy for 4 weeks may be sufficient for ESD-induced gastric ulcers.

  6. The Origin of Improved Electrical Double-Layer Capacitance by Inclusion of Topological Defects and Dopants in Graphene for Supercapacitors.

    Science.gov (United States)

    Chen, Jiafeng; Han, Yulei; Kong, Xianghua; Deng, Xinzhou; Park, Hyo Ju; Guo, Yali; Jin, Song; Qi, Zhikai; Lee, Zonghoon; Qiao, Zhenhua; Ruoff, Rodney S; Ji, Hengxing

    2016-10-24

    Low-energy density has long been the major limitation to the application of supercapacitors. Introducing topological defects and dopants in carbon-based electrodes in a supercapacitor improves the performance by maximizing the gravimetric capacitance per mass of the electrode. However, the main mechanisms governing this capacitance improvement are still unclear. We fabricated planar electrodes from CVD-derived single-layer graphene with deliberately introduced topological defects and nitrogen dopants in controlled concentrations and of known configurations, to estimate the influence of these defects on the electrical double-layer (EDL) capacitance. Our experimental study and theoretical calculations show that the increase in EDL capacitance due to either the topological defects or the nitrogen dopants has the same origin, yet these two factors improve the EDL capacitance in different ways. Our work provides a better understanding of the correlation between the atomic-scale structure and the EDL capacitance and presents a new strategy for the development of experimental and theoretical models for understanding the EDL capacitance of carbon electrodes. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Dopant-site-dependent scattering by dislocations in epitaxial films of perovskite semiconductor BaSnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Useong; Park, Chulkwon; Kim, Rokyeon; Mun, Hyo Sik; Kim, Hoon Min; Kim, Namwook; Yu, Jaejun; Char, Kookrin, E-mail: kchar@phya.snu.ac.kr [Center for Strongly Correlated Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Ha, Taewoo; Kim, Jae Hoon [Department of Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Hyung Joon; Kim, Tai Hoon; Kim, Kee Hoon [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-05-01

    We studied the conduction mechanism in Sb-doped BaSnO{sub 3} epitaxial films, and compared its behavior with that of the mechanism of its counterpart, La-doped BaSnO{sub 3}. We found that the electron mobility in BaSnO{sub 3} films was reduced by almost 7 times when the dopant was changed from La to Sb, despite little change in the effective mass of the carriers. This indicates that the scattering rate of conduction electrons in the BaSnO{sub 3} system is strongly affected by the site at which the dopants are located. More importantly, we found that electron scattering by threading dislocations also depends critically on the dopant site. We propose that the large enhancement of scattering by the threading dislocations in Sb-doped BaSnO{sub 3} films is caused by the combination effect of the change in the distribution of Sb impurities in the films, the formation of the Sb impurity clusters near the threading dislocations, and the conduction electron clustering near the Sb impurities.

  8. Dopant-site-dependent scattering by dislocations in epitaxial films of perovskite semiconductor BaSnO3

    Directory of Open Access Journals (Sweden)

    Useong Kim

    2014-05-01

    Full Text Available We studied the conduction mechanism in Sb-doped BaSnO3 epitaxial films, and compared its behavior with that of the mechanism of its counterpart, La-doped BaSnO3. We found that the electron mobility in BaSnO3 films was reduced by almost 7 times when the dopant was changed from La to Sb, despite little change in the effective mass of the carriers. This indicates that the scattering rate of conduction electrons in the BaSnO3 system is strongly affected by the site at which the dopants are located. More importantly, we found that electron scattering by threading dislocations also depends critically on the dopant site. We propose that the large enhancement of scattering by the threading dislocations in Sb-doped BaSnO3 films is caused by the combination effect of the change in the distribution of Sb impurities in the films, the formation of the Sb impurity clusters near the threading dislocations, and the conduction electron clustering near the Sb impurities.

  9. New cyclometalated Iridium(III) beta-dicetone complex as phosphorescent dopant in Organic light emitting devices

    Science.gov (United States)

    Ivanov, P.; Petrova, P.; Stanimirov, S.; Tomova, R.

    2017-01-01

    A new Bis[4-(benzothiazolato-N,C2‧-2-yl)-N,N-dimethylaniline]Iridium(III) acetylacetonate (Me2N-bt) 2Ir(acac) was synthesized and identified by 1H NMR and elemental analysis. The application of the new compound as a dopant in the hole transporting layer (HTL) of Organic light emitting diode (OLED) structure: HTL/EL/ETL, where HTL was N,N’-bis(3-methylphenyl)-N,N’-diphenylbenzidine (TPD), incorporated in Poly(N-vinylcarbazole) (PVK) matrix, EL - electroluminescent layer of Bis(8-hydroxy-2-methylquinoline)-(4-phenylpheno-xy)aluminum (BAlq) and ETL - electron-transporting layer of Tris-(8-hydroxyquinoline) aluminum (Alq3) or Bis[2-(2-benzothiazoly) phenolato]zinc (Zn(btz)2). We established that the electroluminescent spectra of OLEDs at different concentrations of the dopant were basically the sum of the greenish-blue emission of BAlq and yellowish-green emission of Ir complex. It was found that with increasing of the dopant concentration the relative electroluminescent intensity of Iridium complex emission increased and this of BAlq decreased and as a result the fine tuning of OLED color was observed.

  10. On exceeding the solubility limit of Cr+3 dopants in SnO2 nanoparticles based dilute magnetic semiconductors

    Science.gov (United States)

    URS, Kusuma; Bhat, S. V.; Kamble, Vinayak

    2018-04-01

    The paper investigates the magnetic behavior of chromium doped SnO2 Dilute Magnetic Semiconductor (DMS) nanoparticles, through structural, spectroscopic, and magnetic studies. A non-equilibrium solution combustion method is adopted to synthesize 0-5 at. % Cr doped SnO2 nanoparticles. The detailed spectroscopic studies on the system using micro-Raman spectroscopy, x-ray photoelectron spectroscopy, and electron paramagnetic resonance spectroscopy along with the structural analysis confirm the presence of Cr in 3+ oxidation state, which substitutes at Sn4+ site in SnO6 octahedra of the rutile structure. This doping is found to enhance the defects in the system, i.e., oxygen vacancies. All the synthesized SnO2 nanoparticles (with or without dopants) are found to exhibit Room Temperature Ferromagnetism (RTFM). This occurrence of RTFM is attributed to the magnetic exchange interaction through F-centers of oxygen vacancies as well as dopant magnetic impurities and explained through the Bound Magnetic Polaron (BMP) model of DMS systems. Nonetheless, as the doping of Cr is further increased beyond 2%, the solubility limit is achieved. This antiferromagnetic exchange interaction from interstitial Cr dopants dominates over the BMP mechanism and, hence, leads to the decrease in the net magnetic moment drastically.

  11. Theoretical study of nitrogen-doped graphene nanoflakes: Stability and spectroscopy depending on dopant types and flake sizes.

    Science.gov (United States)

    Lin, Chih-Kai

    2018-03-05

    As nitrogen-doped graphene has been widely applied in optoelectronic devices and catalytic reactions, in this work we have investigated where the nitrogen atoms tend to reside in the material and how they affect the electron density and spectroscopic properties from a theoretical point of view. DFT calculations on N-doped hexagonal and rectangular graphene nanoflakes (GNFs) showed that nitrogen atoms locating on zigzag edges are obviously more stable than those on armchair edges or inside flakes, and interestingly, the N-hydrogenated pyridine moiety could be preferable to pure pyridine moiety in large models. The UV-vis absorption spectra of these nitrogen-doped GNFs display strong dependence on flake sizes, where the larger flakes have their major peaks in lower energy ranges. Moreover, the spectra exhibit different connections to various dopant types and positions: the graphitic-type dopant species present large variety in absorption profiles, while the pyridinic-type ones show extraordinary uniform stability and spectra independent of dopant positions/numbers and hence are hardly distinguishable from each other. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  12. Dopant redistribution and electrical activation in silicon following ultra-low energy boron implantation and excimer laser annealing

    International Nuclear Information System (INIS)

    Whelan, S.; La Magna, A.; Privitera, V.; Mannino, G.; Italia, M.; Bongiorno, C.; Fortunato, G.; Mariucci, L.

    2003-01-01

    Excimer laser annealing (ELA) of ultra-low-energy (ULE) B-ion implanted Si has been performed. High-resolution transmission electron microscopy has been used to assess the as-implanted damage and the crystal recovery following ELA. The electrical activation and redistribution of B in Si during ELA has been investigated as a function of the laser energy density (melted depth), the implant dose, and the number of laser pulses (melt time). The activated and retained dose has been evaluated with spreading resistance profiling and secondary ion mass spectrometry. A significant amount of the implanted dopant was lost from the sample during ELA. However, the dopant that was retained in crystal material was fully activated following rapid resolidification. At an atomic concentration below the thermodynamic limit, the activation efficiency (dose activated/dose implanted into Si material) was a constant for a fixed melt depth, irrespective of the dose implanted and hence the total activated dose was raised as the implant dose was increased. The electrical activation was increased for high laser energy density annealing when the dopant was redistributed over a deeper range

  13. A randomized study to assess the efficacy of herbal product to prevent cisplatin-induced nephrotoxicity in a rat model.

    Science.gov (United States)

    Kucuk, Eyup Veli; Bindayi, Ahmet; Mese, Meral; Gulcu Bulmus, Funda; Parmaksiz, Ergun; Cetinel, Ali Cihangir; Bicik Bahcebasi, Zerrin; Sarica, Kemal

    2017-10-03

    This study aimed to investigate the protective effect and antioxidant activity of an herbal product that made from multiple plants in a rat model of kidney dysfunction induced by intraperitoneal cisplatin. Twenty-four rats were divided into four different groups namely: Group 1 - control healthy animals without any specific medication, Group 2 - Herbal product only 5 mg/kg, Group 3 - cisplatin only and Group 4 - Herbal product 5 mg/kg + cisplatin. Evaluation of our findings demonstrated a significant (p = 0.017) reduction in Catalase activities and a significant increase (p = 0.001) in renal tissue Malondialdehyde levels in cisplatin- treated rats when compared with the control group. Also, Glutathion and Glutathione peroxidase content revealed significant (p = 0.031) reduction in renal tissues of cisplatintreated rats compared with the control group. Pre-treatment of rats with the herbal product ameliorated these cisplatininduced changes of the antioxidant enzymes. No statistically significant changes were demonstrated in Superoxide dismutase activities in the tissue specimens of any group. This potent antioxidant herbal medicine was found to have potential antioxidant activity, which may in turn to be effective in the protection of kidney tissue resulting from cisplatin application. Therefore, much attention should be given to the possible role of natural dietary antioxidants for protecting the kidney.

  14. A randomized study to assess the efficacy of herbal product to prevent cisplatin-induced nephrotoxicity in a rat model

    Directory of Open Access Journals (Sweden)

    Eyup Veli Kucuk

    2017-10-01

    Full Text Available Objectives: This study aimed to investigate the protective effect and antioxidant activity of an herbal product that made from multiple plants in a rat model of kidney dysfunction induced by intraperitoneal cisplatin. Materials and methods: Twenty-four rats were divided into four different groups namely: Group 1 - control healthy animals without any specific medication, Group 2 - Herbal product only 5 mg/kg, Group 3 - cisplatin only and Group 4 - Herbal product 5 mg/kg + cisplatin. Results: Evaluation of our findings demonstrated a significant (p = 0.017 reduction in Catalase activities and a significant increase (p = 0.001 in renal tissue Malondialdehyde levels in cisplatin- treated rats when compared with the control group. Also, Glutathion and Glutathione peroxidase content revealed significant (p = 0.031 reduction in renal tissues of cisplatintreated rats compared with the control group. Pre-treatment of rats with the herbal product ameliorated these cisplatininduced changes of the antioxidant enzymes. No statistically significant changes were demonstrated in Superoxide dismutase activities in the tissue specimens of any group. Conclusions: This potent antioxidant herbal medicine was found to have potential antioxidant activity, which may in turn to be effective in the protection of kidney tissue resulting from cisplatin application. Therefore, much attention should be given to the possible role of natural dietary antioxidants for protecting the kidney.

  15. Ti-dopant-enhanced photocatalytic activity of a CaFe{sub 2}O{sub 4}/MgFe{sub 2}O{sub 4} bulk heterojunction under visible-light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Borse, Pramod H. [International Advanced Research Center for Powder Metallurgy and New Materials, Hyderabad (India); Kim, Jae Y.; Lee, Jae S. [Pohang University of Science and Technology, Pohang (Korea, Republic of); Lim, Kwon T. [Pukyong National University, Busan (Korea, Republic of); Jeong, Euh D.; Bae, Jong S.; Yoon, Jang H.; Yu, Seong M.; Kim, Hyun G. [Korea Basic Science Institute, Busan (Korea, Republic of)

    2012-07-15

    The effect substitution of Ti{sup 4+} at the Fe{sup 3+} site in a CaFe{sub 2}O{sub 4{sup -}}MgFe{sub 2}O{sub 4} bulk hetero-junction (BH) lattice photocatalyst was explored and the Ti ion concentration was optimized to fabricate an efficient photocatalyst. A BH consisting of an optimum dopant concentration (Ti{sup +4}) level of x = 0.03 exhibited an increased band gap and generated a 1.5 times higher photocurrent. The newly fabricated Ti ion doped photocatalyst showed an enhanced quantum yield (up to ∼13.3%) for photodecomposition of a H{sub 2}O-CH{sub 3}OH mixture, as compared to its undoped BH counterpart under visible light (λ ≥ 420 nm). In contrast, the material doped with a very high Ti-dopant concentration displayed deteriorated photochemical properties. An efficient charge-separation induced by Ti-ion doping seems to be responsible for the higher photocatalytic activity in a doped bulk BH.

  16. Regulation of Lipolysis and Adipose Tissue Signaling during Acute Endotoxin-Induced Inflammation: A Human Randomized Crossover Trial.

    Directory of Open Access Journals (Sweden)

    Nikolaj Rittig

    Full Text Available Lipolysis is accelerated during the acute phase of inflammation, a process being regulated by pro-inflammatory cytokines (e.g. TNF-α, stress-hormones, and insulin. The intracellular mechanisms remain elusive and we therefore measured pro- and anti-lipolytic signaling pathways in adipocytes after in vivo endotoxin exposure.Eight healthy, lean, male subjects were investigated using a randomized cross over trial with two interventions: i bolus injection of saline (Placebo and ii bolus injection of lipopolysaccharide endotoxin (LPS. A 3H-palmitate tracer was used to measure palmitate rate of appearance (Rapalmitate and indirect calorimetry was performed to measure energy expenditures and lipid oxidation rates. A subcutaneous abdominal fat biopsy was obtained during both interventions and subjected to western blotting and qPCR quantifications.LPS caused a mean increase in serum free fatty acids (FFA concentrations of 90% (CI-95%: 37-142, p = 0.005, a median increase in Rapalmitate of 117% (CI-95%: 77-166, p<0.001, a mean increase in lipid oxidation of 49% (CI-95%: 1-96, p = 0.047, and a median increase in energy expenditure of 28% (CI-95%: 16-42, p = 0.001 compared with Placebo. These effects were associated with increased phosphorylation of hormone sensitive lipase (pHSL at ser650 in adipose tissue (p = 0.03, a trend towards elevated pHSL at ser552 (p = 0.09 and cAMP-dependent protein kinase A (PKA phosphorylation of perilipin 1 (PLIN1 (p = 0.09. Phosphatase and tensin homolog (PTEN also tended to increase (p = 0.08 while phosphorylation of Akt at Thr308 tended to decrease (p = 0.09 during LPS compared with Placebo. There was no difference between protein or mRNA expression of ATGL, G0S2, and CGI-58.LPS stimulated lipolysis in adipose tissue and is associated with increased pHSL and signs of increased PLIN1 phosphorylation combined with a trend toward decreased insulin signaling. The combination of these mechanisms appear to be the driving forces

  17. Predictive Toxicology: Modeling Chemical Induced Toxicological Response Combining Circular Fingerprints with Random Forest and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Alexios eKoutsoukas

    2016-03-01

    Full Text Available Modern drug discovery and toxicological research are under pressure, as the cost of developing and testing new chemicals for potential toxicological risk is rising. Extensive evaluation of chemical products for potential adverse effects is a challenging task, due to the large number of chemicals and the possible hazardous effects on human health. Safety regulatory agencies around the world are dealing with two major challenges. First, the growth of chemicals introduced every year in household products and medicines that need to be tested, and second the need to protect public welfare. Hence, alternative and more efficient toxicological risk assessment methods are in high demand. The Toxicology in the 21st Century (Tox21 consortium a collaborative effort was formed to develop and investigate alternative assessment methods. A collection of 10,000 compounds composed of environmental chemicals and approved drugs were screened for interference in biochemical pathways and released for crowdsourcing data analysis. The physicochemical space covered by Tox21 library was explored, measured by Molecular Weight (MW and the octanol/water partition coefficient (cLogP. It was found that on average chemical structures had MW of 272.6 Daltons. In case of cLogP the average value was 2.476. Next relationships between assays were examined based on compounds activity profiles across the assays utilizing the Pearson correlation coefficient r. A cluster was observed between the Androgen and Estrogen Receptors and their ligand bind domains accordingly indicating presence of cross talks among the receptors. The highest correlations observed were between NR.AR and NR.AR_LBD, where it was r=0.66 and between NR.ER and NR.ER_LBD, where it was r=0.5.Our approach to model the Tox21 data consisted of utilizing circular molecular fingerprints combined with Random Forest and Support Vector Machine by modeling each assay independently. In all of the 12 sub-challenges our modeling

  18. Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: longitudinal relaxation dispersion for spin I = 1.

    Science.gov (United States)

    Nilsson, Tomas; Halle, Bertil

    2012-08-07

    The frequency dependence of the longitudinal relaxation rate, known as the magnetic relaxation dispersion (MRD), can provide a frequency-resolved characterization of molecular motions in complex biological and colloidal systems on time scales ranging from 1 ns to 100 μs. The conformational dynamics of immobilized proteins and other biopolymers can thus be probed in vitro or in vivo by exploiting internal water molecules or labile hydrogens that exchange with a dominant bulk water pool. Numerous water (1)H and (2)H MRD studies of such systems have been reported, but the widely different theoretical models currently used to analyze the MRD data have resulted in divergent views of the underlying molecular motions. We have argued that the essential mechanism responsible for the main dispersion is the exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings when internal water molecules or labile hydrogens escape from orientationally confining macromolecular sites. In the EMOR model, the exchange process is thus not just a means of mixing spin populations but it is also the direct cause of spin relaxation. Although the EMOR theory has been used in several studies to analyze water (2)H MRD data from immobilized biopolymers, the fully developed theory has not been described. Here, we present a comprehensive account of a generalized version of the EMOR theory for spin I = 1 nuclides like (2)H. As compared to a previously described version of the EMOR theory, the present version incorporates three generalizations that are all essential in applications to experimental data: (i) a biaxial (residual) electric field gradient tensor, (ii) direct and indirect effects of internal motions, and (iii) multiple sites with different exchange rates. In addition, we describe and assess different approximations to the exact EMOR theory that are useful in various regimes. In particular, we consider the experimentally

  19. Thermal equilibrium concentration of intrinsic point defects in heavily doped silicon crystals - Theoretical study of formation energy and formation entropy in area of influence of dopant atoms-

    Science.gov (United States)

    Kobayashi, K.; Yamaoka, S.; Sueoka, K.; Vanhellemont, J.

    2017-09-01

    It is well known that p-type, neutral and n-type dopants affect the intrinsic point defect (vacancy V and self-interstitial I) behavior in single crystal Si. By the interaction with V and/or I, (1) growing Si crystals become more V- or I-rich, (2) oxygen precipitation is enhanced or retarded, and (3) dopant diffusion is enhanced or retarded, depending on the type and concentration of dopant atoms. Since these interactions affect a wide range of Si properties ranging from as-grown crystal quality to LSI performance, numerical simulations are used to predict and to control the behavior of both dopant atoms and intrinsic point defects. In most cases, the thermal equilibrium concentrations of dopant-point defect pairs are evaluated using the mass action law by taking only the binding energy of closest pair to each other into account. The impacts of dopant atoms on the formation of V and I more distant than 1st neighbor and on the change of formation entropy are usually neglected. In this study, we have evaluated the thermal equilibrium concentrations of intrinsic point defects in heavily doped Si crystals. Density functional theory (DFT) calculations were performed to obtain the formation energy (Ef) of the uncharged V and I at all sites in a 64-atom supercell around a substitutional p-type (B, Ga, In, and Tl), neutral (C, Ge, and Sn) and n-type (P, As, and Sb) dopant atom. The formation (vibration) entropies (Sf) of free I, V and I, V at 1st neighboring site from B, C, Sn, P and As atoms were also calculated with the linear response method. The dependences of the thermal equilibrium concentrations of trapped and total intrinsic point defects (sum of free I or V and I or V trapped with dopant atoms) on the concentrations of B, C, Sn, P and As in Si were obtained. Furthermore, the present evaluations well explain the experimental results of the so-called ;Voronkov criterion; in B and C doped Si, and also the observed dopant dependent void sizes in P and As doped Si

  20. Atomic ordering of the fluorine dopant in the $HgBa_{2}CuO_{4+\\delta}high-T_{c}$ superconductor

    CERN Document Server

    Correia, João Guilherme; Araújo, João Pedro; Bordet, P; Haas, Heinz; Le Floc'h, S; Lopes, A M L; Rita, E; Carvalho-Soares, João

    2005-01-01

    Lattice sites and collective ordering of fluorine atoms in oxygen- reduced samples of HgBa/sub 2/CuO/sub 4/ were investigated with the perturbed angular correlation technique by measuring the electric field gradients induced at /sup 199m/Hg nuclei. The experimental data were interpreted with the help of ab initio calculations of charge distributions for different fluorine configurations in Hg/sub m/Ba /sub 2m/Cu/sub m/O/sub 4m/F/sub n/, supercells. Internal parameters were allowed to relax, to cancel residual atomic forces due to the dopant. The experimental results show clearly that fluorine occupies only the center of the mercury mesh. For a fluorine content delta F>~0.35 the best agreement with theoretical data is obtained under the assumption that fluorine shows a tendency toward ordering along interstitial rows parallel to a, b. In conformity with experimental data from diffraction techniques the calculations show elongations of the O(2)-Hg-O(2) dumbbell and barium shifts towards the fluorine atoms as ef...

  1. Oral pilocarpine for radiation-induced xerostomia: integrated efficacy and safety results from two prospective randomized clinical trials

    International Nuclear Information System (INIS)

    Rieke, John W.; Hafermann, Mark D.; Johnson, Jonas T.; LeVeque, Francis G.; Iwamoto, Ryan; Steiger, Barry W.; Muscoplat, Charles; Gallagher, Susan C.

    1995-01-01

    Purpose: Pilocarpine hydrochloride administered in either a fixed-dose or in a dose-titration protocol three times a day for 12 weeks was evaluated for its ability to relieve symptoms of postradiation xerostomia and to improve saliva production. The studies were randomized, double-blind, placebo-controlled, multicenter clinical trials. A total of 369 patients who had received at least 40 Gy of radiation to the head and neck with clinically significant xerostomia were enrolled in the two studies. In the dose-titration study, 162 patients were enrolled and they received a thrice daily regimen of 2.5 mg tablets for first 4 weeks, 5.0 mg tablets for the second 4 weeks, and 10.0 mg tablets for last 4 weeks of a 12-week study. Patients in the titration study were allowed to down titrate following at least one dose escalation to alleviate bothersome side effects, if any. In the fixed dose study, 207 patients received either placebo, 5.0 mg, or 10.0 mg tablets t.i.d. for 12 weeks. Methods and Materials: Patients were evaluated for symptomatic relief by responding to questionnaires using visual analog scales and categorical questions; and, for saliva production by sialometry. Questionnaires measured relief of intraoral dryness, improvement in overall condition (global response), oral discomfort, difficulty in speaking, chewing and swallowing, denture wearing, and usage of artificial saliva. Evaluations were conducted at baseline, and weeks 4, 8, and 12. Results: There were statistically significant improvements in salivary flow in pilocarpine treatment groups vs. placebo. There was a significant improvement in the overall 'global' condition of xerostomia associated with the use of pilocarpine in both studies. In the fixed-dose study, there were significant improvements in oral dryness, mouth comfort, ability to speak, and reduction in the use of oral comfort agents. The dose-titration study showed improvements in dryness that approached significance (p = 0.057) and a

  2. Randomization tests

    CERN Document Server

    Edgington, Eugene

    2007-01-01

    Statistical Tests That Do Not Require Random Sampling Randomization Tests Numerical Examples Randomization Tests and Nonrandom Samples The Prevalence of Nonrandom Samples in Experiments The Irrelevance of Random Samples for the Typical Experiment Generalizing from Nonrandom Samples Intelligibility Respect for the Validity of Randomization Tests Versatility Practicality Precursors of Randomization Tests Other Applications of Permutation Tests Questions and Exercises Notes References Randomized Experiments Unique Benefits of Experiments Experimentation without Mani

  3. Dopant concentration dependent magnetism of Cu-doped TiO{sub 2} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Anitha, B.; Khadar, M. Abdul, E-mail: mabdulkhadar@rediffmail.com [University of Kerala, Centre for Nanoscience and Nanotechnology (India)

    2016-06-15

    Undoped and Cu-doped nanocrystals of TiO{sub 2} having the size range of 8–11 nm were synthesized by peroxide gel method. XRD analysis using Rietveld refinement confirmed anatase phase with a small percentage of rutile content for undoped TiO{sub 2} nanocrystals while a pure anatase phase with preferential growth along [004] direction was observed for nanocrystals of Cu-doped TiO{sub 2}. Variation in the intensity ratios of the XRD peaks of the doped samples compared to that of the undoped sample offered an evidence for the substitutional incorporation of Cu ions in the TiO{sub 2} lattice. The preferential growth of the nanocrystals along the [004] direction was verified using HRTEM analysis. Cu doping extended the optical absorption edge of TiO{sub 2} nanocrystals to the visible spectral region and caused a blue shift and broadening of the E{sub g} (1) Raman active mode of anatase TiO{sub 2}. Undoped TiO{sub 2} sample showed a weak ferromagnetism superimposed on a diamagnetic background while Cu-doped TiO{sub 2} samples exhibited a weak ferromagnetism in the low-field region with a paramagnetic component in the high-field region. The magnetic moment exhibited by the doped samples is interpreted as the resultant of a weak ferromagnetic moment in the low-field region arising from the presence of defects near the surface of TiO{sub 2} nanoparticles or from the interaction of the substituted Cu ions with the oxygen vacancies, and the paramagnetic contribution from the increased Cu dopant concentration near the surface of the particles arising from self-purification mechanism.

  4. Carrier transport assisted by dopants in doped poly(N-vinylcarbozole) light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xiaohong [Institute of Optoelectronic Technology, Bejing Jiaotong University, Beijing 100044 (China); Liu Ming [Institute of Optoelectronic Technology, Bejing Jiaotong University, Beijing 100044 (China); Xu Zheng [Institute of Optoelectronic Technology, Bejing Jiaotong University, Beijing 100044 (China); Hou Yanbing [Institute of Optoelectronic Technology, Bejing Jiaotong University, Beijing 100044 (China); Teng Feng [Institute of Optoelectronic Technology, Bejing Jiaotong University, Beijing 100044 (China); Xu Xurong [Institute of Optoelectronic Technology, Bejing Jiaotong University, Beijing 100044 (China)

    2004-04-07

    We have investigated the transient electroluminescence (EL) onset of the double-layer light-emitting devices made from poly(N-vinylcarbozole) (PVK) doped with 4-(dicyanomethylene)-2-t-butyl-6(1, 1, 7, 7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) and tris(8-hydroxy-quinoline) aluminium (Alq{sub 3}). For the double-layered device in which PVK was doped with 0.1 wt% DCJTB, the EL onset of PVK lags that of DCJTB and Alq{sub 3}, while the EL onset of DCJTB and Alq{sub 3} is simultaneous. However, the EL emission of the double-layered device of PVK/Alq{sub 3} originates only from Alq{sub 3}. The results show that DCJTB dopants can not only help to tunnel electrons from Alq{sub 3} zone to PVK but can also assist electrons transfer in PVK under high electric field by hopping between DCJTB molecules or from DCJTB to PVK sites at a low doping concentration of 0.1 wt%. When the DCJTB doping concentration is 4.0 wt%, the EL onset of Alq{sub 3} lags that of DCJTB. The difference in the EL onsets of DCJTB, Alq{sub 3} and PVK is attributed to the slow build-up of the internal space charge in the vicinity of the interface between PVK and Alq{sub 3}. The electron potential difference of the interface between Alq{sub 3} and PVK doped by DCJTB can be adjusted by changing the DCJTB doping concentration in double-layer devices.

  5. Reversal of SSRI-induced female sexual dysfunction by adjunctive bupropion in menstruating women: a double-blind, placebo-controlled and randomized study.

    Science.gov (United States)

    Safarinejad, Mohammad R

    2011-03-01

    A significant number of patients undergoing treatment with selective serotonin reuptake inhibitors (SSRIs) report sexual dysfunction. SSRI-induced sexual dysfunction adversely affects quality of life and patient adherence to and compliance with treatment regimens. This trial examined the efficacy and safety of adjunctive bupropion in the treatment of SSRI-induced female sexual dysfunction. Sexual function was assessed by using the sexual function domains of the Female Sexual Function Index (primary efficacy outcome measure) and the Clinical Global Impression Scale adapted for sexual function (secondary efficacy outcome measure). End point treatment satisfaction was assessed using a Visual Analog Scale. A total of 218 women (25-45 years old) with SSRI-induced sexual dysfunction were randomized to receive 12 weeks of double-blind fixed dosed treatment with bupropion sustained release 150 mg b.i.d. (n = 109) or placebo (n = 109). The mean (SD) for Female Sexual Function Index total score was higher in the bupropion sustained release group (25.9 (5.12), 95% confidence interval (CI) 22.2-29.4) than in the placebo group (17.2 (4.9), 95% CI 15.8-20.1) (p = 0.001). Mean (SD) Clinical Global Impression Scale score for the bupropion group (2.4 (0.6), 95% CI 2.0-3.6) was significantly lower than that for the placebo group (4.2 (0.8), 95% CI 3.4-5.4) (p = 0.001). At the end of the trial the mean (SD) scores for desire (4.1 (0.7), 95% CI 3.5-4.8) (p = 0.001), arousal (4.4 (0.6), 95% CI 3.7-4.8) (p = 0.01), lubrication (4.4 (0.4), 95% CI 3.3-4.8) (p = 0.001), orgasm (4.4 (0.5), 95% CI 3.7-4.7) (p = 0.001), and satisfaction (4.2 (0.7), 95% CI 3.4-4.8) (p = 0.001) were significantly higher in the bupropion group. The highest improvement was observed in sexual desire, followed by lubrication. Compared with baseline, desire and lubrication domains increased by 86.4% (95% CI 64.9-102.2%, p = 0.001) and 69.2% (95% CI 44.7-82.6%, p = 0.001) in the bupropion group. Adjunctive treatment

  6. Nevasic audio program for the prevention of chemotherapy induced nausea and vomiting: A feasibility study using a randomized controlled trial design.

    Science.gov (United States)

    Moradian, Saeed; Walshe, Catherine; Shahidsales, Soodabeh; Ghavam Nasiri, Mohammad Reza; Pilling, Mark; Molassiotis, Alexander

    2015-06-01

    Pharmacological therapy is only partially effective in preventing or treating chemotherapy induced nausea and vomiting (CINV). Therefore, exploring the complementary role of non-pharmacological approaches used in addition to pharmacological agents is important. Nevasic uses specially constructed audio signals hypothesized to generate an antiemetic reaction. The aim of this study was to examine the feasibility of conducting a randomized controlled trial (RCT) to evaluate the effectiveness of Nevasic to control CINV. A mixed methods design incorporating an RCT and focus group interviews. For the RCT, female breast cancer patients were randomized to receive either Nevasic plus usual care, music plus usual care, or usual care only. Data were analysed using descriptive statistics and linear mixed-effects models. Five focus group interviews were conducted to obtain participants' views regarding the acceptability of the interventions in the trial. 99 participants were recruited to the RCT and 15 participated in focus group interviews. Recruitment targets were achieved. Issues of Nevasic acceptability were highlighted as weaknesses of the program. This study did not detect any evidence for the effectiveness of Nevasic; however, the results showed statistically significant less use of anti-emetics (p = 0.003) and borderline non-significant improvement in quality of life (p = 0.06). Conducting a non-pharmacological intervention using such an audio program is feasible, although difficulties and limitations exist with its use. Further studies are required to investigate the effectiveness of Nevasic from perspectives such as anti-emetic use, as well as its overall effect on the levels of nausea and vomiting. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Randomized, double-blind, crossover study of palonosetron compared with granisetron for the prevention of chemotherapy-induced nausea and vomiting in a Chinese population.

    Science.gov (United States)

    Tian, Weihua; Wang, Zhiqiang; Zhou, Juntian; Zhang, Shucai; Wang, Jinghui; Chen, Qiang; Huang, Cheng; Pan, Liangxi; Zhang, Lili; Huang, Jianjin; Shen, Hong; Lin, Tongyu

    2011-03-01

    The objective of this study was to compare the efficacy and tolerability of palonosetron and granisetron in a Chinese population receiving highly emetogenic cisplatin-based chemotherapy or moderately emetogenic chemotherapy. Patients were stratified by chemotherapy with cisplatin (yes/no) and then randomly assigned to receive either palonosetron (0.25 mg i.v.) in the first cycle followed by granisetron (3 mg i.v.) in the second cycle or vice versa. The primary efficacy endpoint was the proportion of patients with complete response 0-24 h post-chemotherapy administration. The proportions of patients with complete response 24-120 and 0-120 h following chemotherapy were also compared. Of the 144 patients randomized, 36 (25%) received 60-80 mg/m(2) cisplatin; 66 of 72 patients in the palonosetron to granisetron group and 56 of 72 patients in the granisetron to palonosetron group completed treatment with both antiemetics. The efficacy and safety analyses included 128 palonosetron treatments and 138 granisetron treatments. Palonosetron consistently produced numerically higher complete response rates than granisetron in the acute phase (0-24 h, 71.09 vs. 65.22%), the delayed phase (24-120 h, 60.16 vs. 55.80%), and overall (0-120 h, 53.13 vs. 50.00%) though the differences were not significant. Both palonosetron and granisetron were well tolerated. Palonosetron was well tolerated and effective in preventing acute and delayed chemotherapy-induced nausea and vomiting in a Chinese population. When used as monotherapy, 0.25-mg palonosetron was not inferior to 3-mg granisetron for preventing vomiting following highly or moderately emetogenic chemotherapy.

  8. [Contrast-induced nephropathy in patients at risk of renal failure undergoing computed tomography: systematic review and meta-analysis of randomized controlled trials].

    Science.gov (United States)

    Arana, Estanislao; Catalá-López, Ferrán

    2010-09-11

    We evaluated and quantified by meta-analysis techniques the incidence of contrast-induced nephropathy (CIN) in patients at risk undergoing computed tomography (CT). We conducted a systematic review of randomized controlled clinical trials designated to evaluate the nephrotoxicity related to iso-osmolar contrast media (IOCM) compared to low-osmolar contrast media (LOCM). Main electronic databases searched included PubMed/MEDLINE, EMBASE, ISI Web of Knowledge and Virtual Health Library (BVS-BIREME), as well as abstracts presented at related scientific societies meetings. Prior to data extraction, definitions of nephrotoxicity and risk population were established. Besides meta-analysis, the global agreement between CIN definitions was evaluated with Mantel-Haenszel stratified test. Five studies were included with 716 randomized patients. When CIN was defined as increased serum creatinine (SCr)>or=25%, the relative risk (RR) was 0.71 (CI95%: 0.40-1.26)-in favor of IOCM-and when it was defined as SCr>or=0.5mg/dL it showed a RR 1.48 (CI95%: 0.37-5.87)-favoring LOCM-in the four studies used this criterion. Mantel-Haenszel stratified test was chi2=2.51 (p=0.8). In patients with renal failure undergoing CT there is a similar risk of CIN with the administration of any contrast media studied. CIN incidence depends on the chosen criteria and is lower with the definition of SCr>or=0.5mg/dL at 24-72h. No agreement was found between CIN definitions were adopted. Copyright © 2009 Elsevier España, S.L. All rights reserved.

  9. [A multicenter, randomized, controlled, phase Ⅳ clinical study of PEG-rhG-CSF for preventing chemotherapy induced neutropenia in patients with breast cancer].

    Science.gov (United States)

    Jiang, Z F; Xu, F R; Fan, J; Li, B J; Gao, J N; Hu, J W; Wang, X J; Zhang, Y Q; Wang, J H; Li, F; Liu, Q; Liu, Y H; Wang, S; Wang, Y S; Ouyang, Q C; Hu, B; Sun, G P; Zhang, Y; Zang, A M; Fan, P Z; Wu, C P; Liu, J; Zhang, H W; Wang, W; Hu, X C; Tang, L L; Zhang, J; Bao, Y Y; Geng, C Z; Sun, Q; Zhang, F; Yin, Y M; Jiang, H C; An, Y H

    2018-04-24

    Objective: To explore the efficacy and safety of polyethylene glycal recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in preventing chemotherapy-induced neutropenia in patiens with breast cancer. Methods: There were two parts in the present phase Ⅳ clinical study. One was a randomized, controlled clinical study. Patients in this study received PEG-rhG-CSF or rhG-CSF in the first cycle and followed with both PEG-rhG-CSF in the rest of 3 cycles. The other one was a single arm study. Patients who developed Ⅲ/Ⅳ grade neutropenia in the screening cycle received PEG-rhG-CSF in the rest of 3 cycles chemotherapy. Results: In the first cycle of randomized, controlled study, the incidence of Ⅳ grade neutropenia are 31.48% and 35.58% respectively in PEG-rhG-CSF and rhG-CSF group, with no statistically significant differences ( P =0.527 6). The duration of Ⅳ grade neutropenia respectively are 2.22±1.58 and 3.00±1.59 days, with a statistically significant difference ( P =0.016 6). In the single arm study, the incidence of Ⅳ grade neutropenia was 57.76% in screening cycle. And the incidence decreased to 16.35%, 10%, and 8.57% in the followed 3 cycle after the use of PEG-rhG-CSF. The incidence of adverse effects was 5.06%, and the major adverse effect was bone pain which with an incidence of 2.8%. Conclusion: The fixed 6mg dose of PEG-rhG-CSF can effectively prevent neutropenia in patients with breast cancer in multicycle chemotherapy and it has a low incidence of adverse events and mild adverse reaction.

  10. Rikkunshito for Preventing Chemotherapy-Induced Nausea and Vomiting in Lung Cancer Patients: Results from 2 Prospective, Randomized Phase 2 Trials

    Directory of Open Access Journals (Sweden)

    Toshiyuki Harada

    2018-01-01

    Full Text Available The herbal medicine rikkunshito has the potential to improve chemotherapy-induced nausea and vomiting (CINV by stimulating ghrelin secretion. We aimed to evaluate the efficacy and safety of rikkunshito in preventing CINV for patients with lung cancer. Two separate prospective, randomized, phase II parallel design studies were conducted in patients with lung cancer. Fifty-eight and sixty-two patients scheduled to receive highly emetogenic chemotherapy (HEC and moderately emetogenic chemotherapy (MEC, respectively, were randomized 1:1 to receive either standard antiemetic therapy in accordance with international guidelines (S group or standard antiemetic therapy plus oral rikkunshito (R group. The primary endpoint was overall complete response (CR—that is, no emesis and rescue medication in the first 120 h post-chemotherapy. Secondary endpoints included CR in the acute (0–24 h and delayed (>24–120 h phases and safety. Fifty-seven patients (S group, 28; R group, 29 receiving HEC and sixty-two patients (S group, 30; R group, 32 receiving MEC with comparable characteristics were evaluated. The CR rates were similar across the S and R groups for the HEC study in the overall (67.9% vs. 62.1%, acute (96.4% vs. 89.6%, and delayed (67.9% vs. 62.1% phases, respectively, and for the MEC study in the overall (83.3% vs. 84.4%, acute (100% vs. 100%, and delayed (83.3% vs. 84.4% phases, respectively. No severe adverse events were observed. Although rikkunshito was well tolerated, it did not demonstrate an additional preventative effect against CINV in lung cancer patients receiving HEC or MEC.Clinical Trial Registry Information: This study is registered with the University Hospital Medical Information Network (UMIN Clinical Trial Registry1, identification numbers UMIN 000014239 and UMIN 000014240.

  11. Effects of Number of Repetitions and Number of Hours of Shaping Practice during Constraint-Induced Movement Therapy: A Randomized Controlled Trial

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    Auwal Abdullahi

    2018-01-01

    Full Text Available Background. Constraint-induced movement therapy (CIMT is effective in improving motor outcomes after stroke. However, its existing protocols are resource-intensive and difficult to implement. The aim of this study is to design an easier CIMT protocol using number of repetitions of shaping practice. Method. The study design was randomized controlled trial. Participants within 4 weeks after stroke were recruited at Murtala Muhammad Specialist Hospital. They were randomly assigned to groups A, B, C, and D. Group A received 3 hours of traditional therapy. Groups B, C, and D received modified CIMT consisting of 3 hours of shaping practice per session, 300 repetitions of shaping practice in 3 sessions, and 600 repetitions of shaping practice in 3 sessions per day, respectively, and constraint for 90% of the waking hours. All treatment protocols were administered 5 times per week for 4 weeks. The primary outcome was measured using upper limb Fugl-Meyer assessment, while the secondary outcome was measured using motor activity log, Wolf Motor Function Test, and upper limb self-efficacy test at baseline, 2 weeks, and 4 weeks after intervention. Result. There were 48 participants 4 weeks after intervention. The result showed that there was no significant difference between groups at baseline (p>0.05. Within-group improvements attained minimal clinically important difference (MCID in modified CIMT and 300 repetitions and 600 repetitions groups. Conclusion. Number of repetitions of shaping practice significantly improved motor function, real-world arm use, and upper limb self-efficacy after stroke. Therefore, it seems to be a simple alternative for the use of number of hours. Trial Registration. This trial is registered with Pan African Clinical Trial Registry (registration number: PACTR201610001828172 (date of registration: 21/10/2016.

  12. A randomized, double-blind, multicentre study comparing daily 2 and 5 mg of tropisetron for the control of nausea and vomiting induced by low-dose cisplatin- or non-cisplatin-containing chemotherapy

    NARCIS (Netherlands)

    Wymenga, ANM; vanderGraaf, WTA; Wils, JA; vanHeukelom, LS; vanderLinden, GHM; DullemondWestland, AC; Nooy, M; vanderHeul, C; deBruijn, KM; deVries, EGE

    Background: This study compares efficacy safety and tolerability of 2 and 5 mg tropisetron in prevention of nausea and vomiting induced by low-dose cisplatin- or non-cisplatin-containing chemotherapy. Patients and methods: 152 chemotherapy-naive cancer patients were randomized in a double-blind

  13. Nutrient Intake During Diet-Induced Weight Loss and Exercise Interventions in a Randomized Trial in Older Overweight and Obese Adults.

    Science.gov (United States)

    Miller, G D; Beavers, D P; Hamm, D; Mihalko, S L; Messier, S P

    2017-01-01

    Dietary restriction in obese older adults undergoing weight loss may exacerbate nutrient deficiencies common in this group; the nutritional health of older adults is a factor in their quality of life, disability, and mortality. This study examined the effect of an 18-month weight loss program based in social cognitive theory incorporating partial meal replacements, on nutrient intake in older overweight and obese adults. The following analysis is from the Intensive Diet and Exercise for Arthritis (IDEA) trial, a single-blind, randomized controlled trial. Individuals were randomized into one of three 18-month interventions: exercise (E); intensive diet-induced weight loss (D); or intensive diet-induced weight loss plus exercise (D+E). The study setting was at a university research facility. Overweight and obese older adults (n=388; BMI=33.7±3.8 kg/m2; 65.8±6.1 years) were recruited. The D and D+E interventions (group mean goal of ≥10% loss by 18-months) utilized partial meal replacements (2 meal replacement shakes/day for 6-months). Exercise training for E and D+E was 3 days/week, 60 minutes/day. Three day food records were collected at baseline, 6-months, and 18-months and analyzed for total energy and macro- and micronutrient intake. Comparisons of dietary intake among treatment groups were performed at 6 and 18 months using mixed linear models. Weight loss at 18-months was 11.3±8.3% (D), 10.3±6.8% (D+E), and 1.2±4.2% (E). Meal replacements were used by more than 60% (6-months) and 50% (18-months) of D and D+E participants, compared to ≤15% for E. Both D and D+E consumed less energy and fat, and more carbohydrates and selected micronutrients than E during follow-up. More than 50% of all participants consumed less than the recommended intake of particular vitamins and minerals. The diet intervention improved intakes of several nutrients. However, inadequate intake of several vitamins and minerals of concern for older adults suggests they need further

  14. Reversal of Vecuronium-induced Neuromuscular Blockade with Low-dose Sugammadex at Train-of-four Count of Four: A Randomized Controlled Trial.

    Science.gov (United States)

    Asztalos, László; Szabó-Maák, Zoltán; Gajdos, András; Nemes, Réka; Pongrácz, Adrienn; Lengyel, Szabolcs; Fülesdi, Béla; Tassonyi, Edömér

    2017-09-01

    Rocuronium-induced neuromuscular block that spontaneously recovered to a train-of-four count of four can be reversed with sugammadex 0.5 or 1.0 mg/kg. We investigated whether these doses of sugammadex can also reverse vecuronium at a similar level of block. Sixty-five patients were randomly assigned, and 64 were analyzed in this controlled, superiority study. Participants received general anesthesia with propofol, sevoflurane, fentanyl, and vecuronium. Measurement of neuromuscular function was performed with acceleromyography (TOF-Watch-SX, Organon Teknika B.V., The Netherlands ). Once the block recovered spontaneously to four twitches in response to train-of-four stimulation, patients were randomly assigned to receive sugammadex 0.5, 1.0, or 2.0 mg/kg; neostigmine 0.05 mg/kg; or placebo. Time from study drug injection to normalized train-of-four ratio 0.9 and the incidence of incomplete reversal within 30 min were the primary outcome variables. Secondary outcome was the incidence of reparalysis (normalized train-of-four ratio less than 0.9). Sugammadex, in doses of 1.0 and 2.0 mg/kg, reversed a threshold train-of-four count of four to normalized train-of-four ratio of 0.9 or higher in all patients in 4.4 ± 2.3 min (mean ± SD) and 2.6 ± 1.6 min, respectively. Sugammadex 0.5 mg/kg reversed the block in 6.8 ± 4.1 min in 70% of patients (P 0.05 vs. sugammadex 0.5 mg/kg). The overall frequency of reparalysis was 18.7%, but this incidence varied from group to group. Sugammadex 1.0 mg/kg, unlike 0.5 mg/kg, properly reversed a threshold train-of-four count of four vecuronium-induced block but did not prevent reparalysis.

  15. Intranasal administration of a therapeutic HIV vaccine (Vacc-4x induces dose-dependent systemic and mucosal immune responses in a randomized controlled trial.

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    Kristin Brekke

    Full Text Available Vacc-4x, a Gag p24-based therapeutic HIV vaccine, has been shown to reduce viral load set-points after intradermal administration. In this randomized controlled pilot study we investigate intranasal administration of Vacc-4x with Endocine as adjuvant.Safety and immunogenicity were tested in patients on effective ART. They were randomized to low, medium or high dose Vacc-4x or adjuvant alone, administered four times at weekly intervals with no booster. Vacc-4x-specific T cell responses were measured in vitro by proliferation and in vivo by a single DTH skin test at the end of study. Nasal and rectal mucosal secretions were analyzed for Vacc-4x-specific antibodies by ELISA. Immune regulation induced by Vacc-4x was assessed by functional blockade of the regulatory cytokines IL-10 and TGF-β.Vacc-4x proliferative T cell responses increased only among the vaccinated (p ≤ 0.031. The low dose group showed the greatest increase in Vacc-4x CD8+T cell responses (p = 0.037 and developed larger DTH (p = 0.005 than the adjuvant group. Rectal (distal Vacc-4x IgA and IgG antibodies also increased (p = 0.043 in this group. In contrast, the high dose generated higher nasal (local Vacc-4x IgA (p = 0.028 and serum IgG (p = 0.030 antibodies than the adjuvant. Irrespective of dose, increased Vacc-4x CD4+T cell responses were associated with low proliferation (r = -0.82, p < 0.001 and high regulation (r = 0.61, p = 0.010 at baseline.Intranasal administration of Vacc-4x with Endocine was safe and induced dose-dependent vaccine-specific T cell responses and both mucosal and systemic humoral responses. The clinical significance of dose, immune regulation and mucosal immunity warrants further investigation.ClinicalTrials.gov NCT01473810.

  16. The effects of the adjunctive bupropion on male sexual dysfunction induced by a selective serotonin reuptake inhibitor: a double-blind placebo-controlled and randomized study.

    Science.gov (United States)

    Safarinejad, Mohammad Reza

    2010-09-01

    To determine the safety and efficacy of adjunctive bupropion sustained-release (SR) on male sexual dysfunction (SD) induced by a selective serotonin reuptake inhibitor (SSRI), as SD is a common side-effect of SSRIs and the most effective treatments have yet to be determined. The randomized sample consisted of 234 euthymic men who were receiving some type of SSRI. The men were randomly assigned to bupropion SR (150 mg twice daily, 117) or placebo (twice daily, 117) for 12 weeks. Efficacy was evaluated using the Clinical Global Impression-Sexual Function (CGI-SF; the primary outcome measure), the International Index of Erectile Function (IIEF), Arizona Sexual Experience Scale (ASEX), and Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) (secondary outcome measures). Participants were followed biweekly during study period. After 12 weeks of treatment, the mean (sd) scores for CGI-SF were significantly lower, i.e. better, in patients on bupropion SR, at 2.4 (1.2), than in the placebo group, at 3.9 (1.1) (P= 0.01). Men who received bupropion had a significant increase in the total IIEF score (54.4% vs 1.2%; P= 0.003), and in the five different domains of the IIEF. Total ASEX scores were significantly lower, i.e. better, among men who received bupropion than placebo, at 15.5 (4.3) vs 21.5 (4.7) (P= 0.002). The EDITS scores were 67.4 (10.2) for the bupropion and 36.3 (11.7) for the placebo group (P= 0.001). The ASEX score and CGI-SF score were correlated (P= 0.003). In linear regression analyses the CGI-SF score was not affected significantly by the duration of SD, type of SSRI used and age. Bupropion is an effective treatment for male SD induced by SSRIs. These results provide empirical support for conducting a further study of bupropion.

  17. Efficacy of short-term high-dose statin in preventing contrast-induced nephropathy: a meta-analysis of seven randomized controlled trials.

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    Yongchuan Li

    Full Text Available A few studies focused on statin therapy as specific prophylactic measures of contrast-induced nephropathy have been published with conflicting results. In this meta-analysis of randomized controlled trials, we aimed to assess the effectiveness of short-term high-dose statin treatment for the prevention of CIN and clinical outcomes and re-evaluate of the potential benefits of statin therapy.We searched PubMed, OVID, EMBASE, Web of science and the Cochrane Central Register of Controlled Trials databases for randomized controlled trials comparing short-term high-dose statin treatment versus low-dose statin treatment or placebo for preventing CIN. Our outcome measures were the risk of CIN within 2-5 days after contrast administration and need for dialysis.Seven randomized controlled trials with a total of 1,399 patients were identified and analyzed. The overall results based on fixed-effect model showed that the use of short-term high-dose statin treatment was associated with a significant reduction in risk of CIN (RR =0.51, 95% CI 0.34-0.76, p =0.001; I(2 = 0%. The incidence of acute renal failure requiring dialysis was not significant different after the use of statin (RR = 0.33, 95% CI 0.05-2.10, p = 0.24; I(2 = 0%. The use of statin was not associated with a significant decrease in the plasma C-reactive protein level (SMD -0.64, 95% CI: -1.57 to 0.29, P = 0.18, I(2 = 97%.Although this meta-analysis supports the use of statin to reduce the incidence of CIN, it must be considered in the context of variable patient demographics. Only a limited recommendation can be made in favour of the use of statin based on current data. Considering the limitations of included studies, a large, well designed trial that incorporates the evaluation of clinically relevant outcomes in participants with different underlying risks of CIN is required to more adequately assess the role for statin in CIN prevention.

  18. Low level laser therapy for concurrent chemoradiotherapy induced oral mucositis in head and neck cancer patients – A triple blinded randomized controlled trial

    International Nuclear Information System (INIS)

    Gautam, Ajay Prashad; Fernandes, Donald J.; Vidyasagar, Mamidipudi S.; Maiya, Arun G.; Vadhiraja, Bejadi M.

    2012-01-01

    Background and purpose: Oral mucositis (OM) is most cumbersome acute side effect of concurrent chemoradiotherapy (CCRT) for head and neck cancer (HNC). OM associated pain affects oral functions and nutrition of the patient that may result in discontinuity of treatment. Several modalities have been tried to prevent and treat OM, but none proved completely successful until date. We used prophylactic low level laser therapy (LLLT) for the prevention and treatment of CCRT induced OM. Materials and methods: In this triple blinded study, 221 HNC patients scheduled to undergo CCRT (Cisplatin (1, 22, 43 day) + RT = 66 Grays (2 Gy/fraction), 33 fractions, 5 fractions/week, for 45 days) were block randomized into laser (n = 111) and placebo (n = 110) group. Laser group received LLLT (HeNe, λ = 632.8 nm, power-density = 24 mW, dosage = 3.0 J/point, total dosage/session = 36–40 J, spot-size = 1 cm 2 , 5 sessions/week) while placebo received sham treatment daily prior to radiation. OM (RTOG/EORTC Scale), oral pain (VAS), dysphagia (FIS), weight loss and CCRT break were assessed. Data were analyzed using frequencies and percentage, generalized estimating equations (GEE) and odds ratio. Results: There was significant reduction in incidence of severe OM (F = 16.64, df = 8876, p < 0.0001) and its associated pain (F = 25.06, df = 8876, p < 0.0001), dysphagia (F = 20.17, df = 8876, p < 0.0001) and opioid analgesics use (p < 0.0001) in laser than placebo group patients. Conclusions: LLLT decreased the incidence of CCRT induced severe OM and its associated pain, dysphagia and opioid analgesics use.

  19. Randomized Trial of Vitamin C/E Complex for Prevention of Radiation-Induced Xerostomia in Patients with Head and Neck Cancer.

    Science.gov (United States)

    Chung, Man Ki; Kim, Do Hun; Ahn, Yong Chan; Choi, Joon Young; Kim, Eun Hye; Son, Young-Ik

    2016-09-01

    The present study was conducted to determine the preventive efficacy of vitamin C/E complex supplementation for radiotherapy (RT)-induced xerostomia in patients with head and neck cancer. Prospective, double-blinded, randomized, placebo-controlled study. A single tertiary referral institution. The trial group (n = 25) received antioxidant supplements (100 IU of vitamin E + 500 mg of vitamin C) twice per day during RT, while the control group (n = 20) received an identical placebo. Pre-RT and 1 and 6 months post-RT, patient-reported xerostomia questionnaires, observer-rated xerostomia score, and salivary scintigraphy were serially obtained to compare xerostomia severity between the 2 groups. The trial group showed greater improvements in xerostomia questionnaire and score at 6 months post-RT when compared with those at 1 month post-RT (P = .007 and .008, respectively). In contrast, the control group showed no changes between 1 and 6 months post-RT. By salivary scintigraphy, there was no difference in maximal accumulation or ejection fraction between the 2 groups. However, the trial group maintained significantly better oral indices at the prestimulatory (P = .01) and poststimulatory (P = .009) stages at 1 month post-RT, compared with the control group. At the final follow-up, there was no difference in overall survival and disease-free survival between the 2 groups. Our data suggest that short-term supplementation with an antioxidant vitamin E/C complex exerts a protective effect against RT-induced xerostomia. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  20. Antioxidant Capacity of Calendula Officinalis Flowers Extract and Prevention of Radiation Induced Oropharyngeal Mucositis in Patients with Head and Neck Cancers: A Randomized Controlled Clinical Study

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Kazemi

    2013-03-01

    Full Text Available This study was designed to determine the effect of Calendula officinalis flowers extract mouthwash as oral gel on radiation-induced oropharyngeal mucositis (OM in patients with head-and-neck cancer. Forty patients with neck and head cancers under radiotherapy or concurrent chemoradiotherapy protocols were randomly assigned to receive either 2% calendula extract mouthwash or placebo (20 patients in each group. Patients were treated with telecobalt radiotherapy at conventional fractionation (200 cGy/fraction, five fractions weekly, 30–35 fractions within 4–7 weeks. The oropharyngeal mucositis was evaluated by two clinical investigators (a radiation oncologist and a dentist, using the oral mucositis assessment scale (OMAS. Trying to find out the possible mechanism of action of the treatment, total antioxidant, polyphenol and flavonoid contents, and quercetin concentration of the mouth wash were measured. Calendula mouthwash significantly decreased the intensity of OM compared to placebo at week 2 (score: 5.5 vs. 6.8, p = 0.019, week 3 (score: 8.25 vs. 10.95, p < 0.0001 and week 6 (score: 11.4 vs. 13.35, p = 0.031. Total antioxidant, polyphenol and flavonoid contents and quercetin concentration of the 2% extract were 2353.4 ± 56.5 μM, 313.40 ± 6.52 mg/g, 76.66 ± 23.24 mg/g, and 19.41 ± 4.34 mg/l, respectively. Calendula extract gel could be effective on decreasing the intensity of radiotherapy- induced OM during the treatment and antioxidant capacity may be partly responsible for the effect.

  1. Antioxidant capacity of calendula officinalis flowers extract and prevention of radiation induced oropharyngeal mucositis in patients with head and neck cancers: a randomized controlled clinical study.

    Science.gov (United States)

    Babaee, Neda; Moslemi, Dariush; Khalilpour, Mohammad; Vejdani, Fatemeh; Moghadamnia, Yasaman; Bijani, Ali; Baradaran, Mahmoud; Kazemi, Mohammad Taghi; Khalilpour, Asieh; Pouramir, Mahdi; Moghadamnia, Ali Akbar

    2013-03-07

    This study was designed to determine the effect of Calendula officinalis flowers extract mouthwash as oral gel on radiation-induced oropharyngeal mucositis (OM) in patients with head-and-neck cancer. Forty patients with neck and head cancers under radiotherapy or concurrent chemoradiotherapy protocols were randomly assigned to receive either 2% calendula extract mouthwash or placebo (20 patients in each group). Patients were treated with telecobalt radiotherapy at conventional fractionation (200 cGy/fraction, five fractions weekly, 30-35 fractions within 4-7 weeks). The oropharyngeal mucositis was evaluated by two clinical investigators (a radiation oncologist and a dentist), using the oral mucositis assessment scale (OMAS). Trying to find out the possible mechanism of action of the treatment, total antioxidant, polyphenol and flavonoid contents, and quercetin concentration of the mouth wash were measured. Calendula mouthwash significantly decreased the intensity of OM compared to placebo at week 2 (score: 5.5 vs. 6.8, p = 0.019), week 3 (score: 8.25 vs. 10.95, p antioxidant, polyphenol and flavonoid contents and quercetin concentration of the 2% extract were 2353.4 ± 56.5 μM, 313.40 ± 6.52 mg/g, 76.66 ± 23.24 mg/g, and 19.41 ± 4.34 mg/l, respectively. Calendula extract gel could be effective on decreasing the intensity of radiotherapy- induced OM during the treatment and antioxidant capacity may be partly responsible for the effect.

  2. Granulocyte macrophage-colony stimulating factor (GM-CSF) and sucralfate in prevention of radiation-induced mucositis: a prospective randomized study

    International Nuclear Information System (INIS)

    Makkonen, Tuula A.; Minn, Heikki; Jekunen, Antti; Vilja, Pekka; Tuominen, Juhani; Joensuu, Heikki

    2000-01-01

    Purpose: To compare subcutaneously given molgramostim (GM-CSF) and sucralfate mouth washings to sucralfate mouth washings in prevention of radiation-induced mucositis. Methods and Materials: Forty head and neck cancer patients were randomly assigned to use either GM-CSF and sucralfate (n = 20) or sucralfate alone (n = 20) during radiotherapy. Sucralfate was used as 1.0 g mouth washing 6 times daily after the first 10 Gy of radiotherapy, and 150-300 μg GM-CSF was given subcutaneously. The grade of radiation mucositis and blood cell counts were monitored weekly. Salivary lactoferrin was measured as a surrogate marker for oral mucositis. Results: We found no significant difference between the molgramostim and the control groups in the oral mucositis grade, oral pain, use of analgesic drugs, weight loss, or survival. The median maximum neutrophil counts (median, 9.2 x 10 9 /L vs. 5.9 x 10 9 /L, p = 0.0005), eosinophil counts (median, 1.3 x 10 9 /L vs. 0.2 x 10 9 /L, p = 0.0004), and salivary lactoferrin concentrations were higher in patients who received GM-CSF. The most common toxicities in the GM-CSF plus sucralfate group were skin reactions at the GM-CSF injection site (65%), fever (30%), bone pain (25%), and nausea (15%), whereas the toxicity of sucralfate given alone was minimal. Conclusion: We found no evidence indicating that subcutaneously given GM-CSF reduces the severity of radiation-induced mucositis

  3. Effects on muscle performance of NSAID treatment with piroxicam versus placebo in geriatric patients with acute infection-induced inflammation. A double blind randomized controlled trial.

    Science.gov (United States)

    Beyer, Ingo; Bautmans, Ivan; Njemini, Rose; Demanet, Christian; Bergmann, Pierre; Mets, Tony

    2011-12-30

    Inflammation is the main cause of disease-associated muscle wasting. In a previous single blind study we have demonstrated improved recovery of muscle endurance following celecoxib treatment in hospitalized geriatric patients with acute infection. Here we further evaluate NSAID treatment with piroxicam in a double blind RCT and investigate the role of cytokines and heat shock proteins (Hsp) with respect to muscle performance. We hypothesized that NSAID treatment would preserve muscle performance better than antibiotic treatment alone, by reducing infection-associated inflammation and by increasing expression of cytoprotective Hsp. Consecutive admissions to the geriatric ward were screened. 30 Caucasian patients, median age 84.5 years, with acute infection-induced inflammation and serum levels of CRP > 10 mg/L were included and randomized to active treatment with 10 mg piroxicam daily or placebo. Assessment comprised general clinical and biochemical parameters, 25 cytokines in serum, intra-and extracellular Hsp27 and Hsp70, Elderly Mobility Scale (EMS) scores, grip strength (GS), fatigue resistance (FR) and lean body mass (LBM). Patients were evaluated until discharge with a maximum of 3 weeks after treatment allocation. EMS scores, FR and grip work (GW), a measure taking into account GS and FR, significantly improved with piroxicam, but not with placebo. Early decreases in IL-6 serum levels with piroxicam correlated with better muscle performance at week 2. Basal expression of Hsp27 in monocytes without heat challenge (WHC) was positively correlated with FR at baseline and significantly increased by treatment with piroxicam compared to placebo. Profound modifications in the relationships between cytokines or Hsp and changes in muscle parameters were observed in the piroxicam group. Piroxicam improves clinically relevant measures of muscle performance and mobility in geriatric patients hospitalized with acute infection-induced inflammation. Underlying mechanisms may

  4. Effects of Probiotic Lactobacillus Casei DN-114 001 in Prevention of Radiation-Induced Diarrhea: Results From Multicenter, Randomized, Placebo-Controlled Nutritional Trial

    International Nuclear Information System (INIS)

    Giralt, Jordi; Regadera, Jose Perez; Verges, Ramona; Romero, Jesus; Fuente, Isabel de la; Biete, Albert; Villoria, Jesus; Cobo, Jose Maria; Guarner, Francisco

    2008-01-01

    Purpose: To determine whether a probiotic drink containing Lactobacillus casei DN-114 001 reduces the incidence of radiation-induced diarrhea in patients with gynecologic cancer. Methods and Materials: Patients who were undergoing pelvic radiotherapy (45-50 Gy, conventional fractionation) for either cervical carcinoma (radiotherapy and weekly cisplatin) or endometrial adenocarcinoma (postoperative radiotherapy) were randomly assigned to a probiotic drink or placebo, in a double-blind fashion. The probiotic drink consisted of liquid yogurt containing L. casei DN-114 001 at 10 8 CFU/g. The patients recorded the daily the number of bowel movements and scored the stool consistency using the Bristol scale. Diarrhea was graded weekly according the Common Toxicity Criteria system. The primary endpoint was to reduce the incidence of diarrhea, defined by a Common Toxicity Criteria Grade of 2 or greater or the need for loperamide. Results: A total of 85 patients were enrolled. Grade 2 or greater diarrhea and/or the use of loperamide was observed in 24 of 41 patients in the placebo group and 30 of 44 in the probiotic group (p = 0.568). No differences were found in the median time to the presentation of the primary endpoint. Probiotic intervention had a significant effect on stool consistency (p = 0.04). The median time for patients to present with Bristol scale stools of Type 6 or greater was 14 days for patients receiving the probiotic drink vs. 10 days for those receiving placebo. Conclusion: Nutritional intervention with the probiotic drink containing L. casei DN-114 001 does not reduce the incidence of radiation-induced diarrhea as defined by a Common Toxicity Criteria Grade 2 or greater. However, it had a significant effect on stool consistency as measured by the Bristol scale

  5. Gluten-free vegan diet induces decreased LDL and oxidized LDL levels and raised atheroprotective natural antibodies against phosphorylcholine in patients with rheumatoid arthritis: a randomized study

    Science.gov (United States)

    Elkan, Ann-Charlotte; Sjöberg, Beatrice; Kolsrud, Björn; Ringertz, Bo; Hafström, Ingiäld; Frostegård, Johan

    2008-01-01

    Introduction The purpose of this study was to investigate the effects of vegan diet in patients with rheumatoid arthritis (RA) on blood lipids oxidized low-density lipoprotein (oxLDL) and natural atheroprotective antibodies against phosphorylcholine (anti-PCs). Methods Sixty-six patients with active RA were randomly assigned to either a vegan diet free of gluten (38 patients) or a well-balanced non-vegan diet (28 patients) for 1 year. Thirty patients in the vegan group completed more than 3 months on the diet regimen. Blood lipids were analyzed by routine methods, and oxLDL and anti-PCs were analyzed by enzyme-linked immunosorbent assay. Data and serum samples were obtained at baseline and after 3 and 12 months. Results Mean ages were 50.0 years for the vegan group and 50.8 years for controls. Gluten-free vegan diet induced lower body mass index (BMI) and low-density lipoprotein (LDL) and higher anti-PC IgM than control diet (p vegan group, BMI, LDL, and cholesterol decreased after both 3 and 12 months (p vegan patients into clinical responders and non-responders at 12 months, the effects on oxLDL and anti-PC IgA were seen only in responders (p vegan diet in RA induces changes that are potentially atheroprotective and anti-inflammatory, including decreased LDL and oxLDL levels and raised anti-PC IgM and IgA levels. PMID:18348715

  6. Effects of a self-management program on antiemetic-induced constipation during chemotherapy among breast cancer patients: a randomized controlled clinical trial.

    Science.gov (United States)

    Hanai, Akiko; Ishiguro, Hiroshi; Sozu, Takashi; Tsuda, Moe; Arai, Hidenori; Mitani, Akira; Tsuboyama, Tadao

    2016-01-01

    Research on patient-reported outcomes indicates that constipation is a common adverse effect of chemotherapy, and the use of 5-hydroxytryptamine (serotonin; 5HT3) receptor antagonists aggravates this condition. As cancer patients take multiple drugs as a part of their clinical management, a non-pharmacological self-management (SM) of constipation would be recommended. We aimed to evaluate the effectiveness of a SM program on antiemetic-induced constipation in cancer patients. Thirty patients with breast cancer, receiving 5HT3 receptor antagonists to prevent emesis during chemotherapy were randomly assigned to the intervention or control group. The SM program consisted of abdominal massage, abdominal muscle stretching, and education on proper defecation position. The intervention group started the program before the first chemotherapy cycle, whereas patients in the wait-list control group received the program on the day before their second chemotherapy cycle. The primary outcome was constipation severity, assessed by the constipation assessment scale (CAS, sum of eight components). The secondary outcome included each CAS component (0-2 points) and mood states. A self-reported assessment of satisfaction with the program was performed. The program produced a statistically and clinically significant alleviation of constipation severity (mean difference in CAS, -3.00; P = 0.02), decrease in the likelihood of a small volume of stool (P = 0.03), and decrease in depression and dejection (P = 0.02). With regards to program satisfaction, 43.6 and 26.4 % patients rated the program as excellent and good, respectively. Our SM program is effective for mitigating the symptoms of antiemetic-induced constipation during chemotherapy.

  7. Detection of genetic variability in Basmati and non-Basmati rice varieties and their radiation induced mutants through random amplified polymorphic DNA (RAPD)

    Energy Technology Data Exchange (ETDEWEB)

    Farooq, S; Iqbal, N; Arif, M [Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad (Pakistan)

    1998-03-01

    Random Amplified Polymorphic DNA (RAPDs) markers were utilized to detect polymorphism between pure lines and commercially available Basmati rice varieties to assess variation which may be helpful in quality control and varietal identification (Basmati-370 and derived radiation induced mutants), differentiation of mutants and parents, and identification of RAPD markers co-segregating with important agronomic traits including plant height, days to flower and grain quality. Basmati varieties were distinguished from non-Basmati varieties with the help of five diagnostic markers which will be useful for detecting mixing of non-Basmati and Basmati rices, currently a serious marketing problem. Different Basmati cultivars were identified with the help of diagnostic RAPD markers which can be used in quality control as well as for ``fingerprinting`` of cultivars. Different radiation induced mutants were also successfully distinguished from the parents on the basis of variety specific and mutant specific markers which will be useful for varietal identification. In addition to this, other markers were also identified which can differentiate mutants from each other and are being, used for the fingerprinting of different mutants, particularly the dwarf mutants having similar appearance but different parentage. For identification of RAPD markers co-segregating with plant height and days to flower, 50 F{sub 2} plants and four F{sub 3} families were studied from a reciprocal cross made between Kashmir Basmati (tall and early) and Basmati-198 (dwarf and late). Segregating bands were observed within these populations, and indicating the possible use of RAPD markers for tagging gene(s) of agronomic importance in rice. (author). 38 refs, 6 figs, 3 tabs.

  8. Detection of genetic variability in Basmati and non-Basmati rice varieties and their radiation induced mutants through random amplified polymorphic DNA (RAPD)

    International Nuclear Information System (INIS)

    Farooq, S.; Iqbal, N.; Arif, M.

    1998-01-01

    Random Amplified Polymorphic DNA (RAPDs) markers were utilized to detect polymorphism between pure lines and commercially available Basmati rice varieties to assess variation which may be helpful in quality control and varietal identification (Basmati-370 and derived radiation induced mutants), differentiation of mutants and parents, and identification of RAPD markers co-segregating with important agronomic traits including plant height, days to flower and grain quality. Basmati varieties were distinguished from non-Basmati varieties with the help of five diagnostic markers which will be useful for detecting mixing of non-Basmati and Basmati rices, currently a serious marketing problem. Different Basmati cultivars were identified with the help of diagnostic RAPD markers which can be used in quality control as well as for ''fingerprinting'' of cultivars. Different radiation induced mutants were also successfully distinguished from the parents on the basis of variety specific and mutant specific markers which will be useful for varietal identification. In addition to this, other markers were also identified which can differentiate mutants from each other and are being, used for the fingerprinting of different mutants, particularly the dwarf mutants having similar appearance but different parentage. For identification of RAPD markers co-segregating with plant height and days to flower, 50 F 2 plants and four F 3 families were studied from a reciprocal cross made between Kashmir Basmati (tall and early) and Basmati-198 (dwarf and late). Segregating bands were observed within these populations, and indicating the possible use of RAPD markers for tagging gene(s) of agronomic importance in rice. (author)

  9. Effect of Alternate Nostril Breathing Exercise on Experimentally Induced Anxiety in Healthy Volunteers Using the Simulated Public Speaking Model: A Randomized Controlled Pilot Study.

    Science.gov (United States)

    Kamath, Ashwin; Urval, Rathnakar P; Shenoy, Ashok K

    2017-01-01

    A randomized controlled pilot study was carried out to determine the effect of a 15-minute practice of ANB exercise on experimentally induced anxiety using the simulated public speaking model in yoga-naïve healthy young adults. Thirty consenting medical students were equally divided into test and control groups. The test group performed alternate nostril breathing exercise for 15 minutes, while the control group sat in a quiet room before participating in the simulated public speaking test (SPST). Visual Analog Mood Scale and Self-Statements during Public Speaking scale were used to measure the mood state at different phases of the SPST. The psychometric scores of both groups were comparable at baseline. Repeated-measures ANOVA showed a significant effect of phase ( p < 0.05), but group and gender did not have statistically significant influence on the mean anxiety scores. However, the test group showed a trend towards lower mean scores for the anxiety factor when compared with the control group. Considering the limitations of this pilot study and the trend seen towards lower anxiety in the test group, alternate nostril breathing may have potential anxiolytic effect in acute stressful situations. A study with larger sample size is therefore warranted. This trial is registered with CTRI/2014/03/004460.

  10. [A Randomized Controlled Clinical Trial of Treatment of Lumbar Disc Herniation-induced Sciatica by Acupuncture Stimulation of Sciatic Nerve Trunk].

    Science.gov (United States)

    Qiu, Ling; Hu, Xiao-Li; Zhao, Xue-Yu; Zheng, Xu; Zhang, Ji; Zhang, Min; He, Liu

    2016-10-25

    To observe the efficacy of acupuncture stimulation of the sciatic nerve trunk in the treatment of patients suffering from sciatica induced by lumbar disc herniation (LDH). A total of 60 LDH sciatica patients met the inclusion criteria were randomly divided into treatment group and control group, with 30 cases in each. Patients of the treatment group were treated by directly needling the sciatic nerve and routine acupuncture of Ashi -points, Lumbar Jiaji (EX-B 2), Dachangshu (BL 28), etc., and those of the control group treated by simple routine acupuncture. The treatment was conducted once a day, 5 times a week, 4 weeks altogether. The clinical effect was evaluated according to the "Standards for Diagnosis and Therapeutic Effect Evaluation of Syndromes of Chinese Medicine" and the pain intensity was assessed by using simplified Short-Form McGill Pain Questionnaire (SF-MPQ) containing pain rating index (PRI), visual analogue scale (VAS) and present pain intensity (PPI). After the treatment, of the two 30 cases of LDH sciatica patients in the control and treatment groups, 11 and 18 were cured, 7 and 7 experienced marked improvement, 10 and 4 were effective, 2 and 1 was invalid, with the effective rate being 93.3% and 96.7%, respectively. The cured+markedly effective rate of the treatment group was significantly higher than that of the control group ( P sciatica in LDH patients, and is superior to simple routine acupuncture in the clinical efficacy.

  11. Four Weeks of Supplementation With Isolated Soy Protein Attenuates Exercise-Induced Muscle Damage and Enhances Muscle Recovery in Well Trained Athletes: A Randomized Trial.

    Science.gov (United States)

    Shenoy, Shweta; Dhawan, Mrinal; Singh Sandhu, Jaspal

    2016-09-01

    The effects of consumption of isolated soy protein (ISP) for a chronic period (4 weeks) on exercise induced muscle damage (EIMD) in athletic population have never been explored. To examine the effects of ISP on muscle damage indices elicited via a bout of damaging exercise. Forty males (20 boxers, 20 cyclists) aged 18 - 28 years were randomly assigned to two groups (ISP and Placebo) (n = 20). All participants who engaged themselves in specific, regular training of 30 hours a week during the competitive season were included in the study. Participants consumed the supplement and the placebo for 4 weeks. The damaging exercise consisted of 100 consecutive drop-jumps. Pre and post supplementation readings of the criterion variables, highly sensitive C reactive protein (hs-cRP), creatine Kinase (CK), myeloperoxidase (MPO), isometric muscle strength, maximum aerobic capacity (VO 2 max), heart rate (HR) and muscle soreness were obtained at baseline (Day 1), at 24 hours (Day 2) and at 48 hours (Day 3) following EIMD. Differences were observed in pre and post supplementation values (P athletic population.

  12. A single serving of blueberry (V. corymbosum) modulates peripheral arterial dysfunction induced by acute cigarette smoking in young volunteers: a randomized-controlled trial.

    Science.gov (United States)

    Del Bo', Cristian; Porrini, Marisa; Fracassetti, Daniela; Campolo, Jonica; Klimis-Zacas, Dorothy; Riso, Patrizia

    2014-12-01

    Cigarette smoking causes oxidative stress, hypertension and endothelial dysfunction. Polyphenol-rich foods may prevent these conditions. We investigated the effect of a single serving of fresh-frozen blueberry intake on peripheral arterial function and arterial stiffness in young smokers. Sixteen male smokers were recruited for a 3-armed randomized-controlled study with the following experimental conditions: smoking treatment (one cigarette); blueberry treatment (300 g of blueberry) + smoking; control treatment (300 mL of water with sugar) + smoking. Each treatment was separated by one week of wash-out period. The blood pressure, heart rate, peripheral arterial function (reactive hyperemia and Framingham reactive hyperemia), and arterial stiffness (digital augmentation index, digital augmentation index normalized for a heart rate of 75 bpm) were measured before and 20 min after smoking with Endo-PAT2000. Smoking impaired the blood pressure, heart rate and peripheral arterial function, but did not affect the arterial stiffness. Blueberry consumption counteracted the impairment of the reactive hyperemia index induced by smoking (-4.4 ± 0.8% blueberry treatment vs. -22.0 ± 1.1% smoking treatment, p blueberry treatment vs. -42.8 ± 20.0% smoking treatment, p blueberry treatment vs. +13.1 ± 0.02% smoking treatment, mmHg, p blueberry on reactive hyperemia, Framingham reactive hyperemia, and systolic blood pressure in subjects exposed to smoke of one cigarette. Future studies are necessary to elucidate the mechanisms involved.

  13. Proton induced single event upset cross section prediction for 0.15 μm six-transistor (6T) silicon-on-insulator static random access memories

    International Nuclear Information System (INIS)

    Li Lei; Zhou Wanting; Liu Huihua

    2012-01-01

    In this paper, an efficient physics-based method to estimate the saturated proton upset cross section for six-transistor (6T) silicon-on-insulator (SOI) static random access memory (SRAM) cells using layout and technology parameters is proposed. This method calculates the effects of radiation based on device physics. The simple method handles the problem with ease by SPICE simulations, which can be divided into two stages. At first, it uses a standard SPICE program to predict the cross section for recoiling heavy ions with linear energy transfer (LET) of 14 MeV-cm 2 /mg. Then, the predicted cross section for recoiling heavy ions with LET of 14 MeV-cm 2 /mg is used to estimate the saturated proton upset cross section for 6T SOI SRAM cells with a simple model. The calculated proton induced upset cross section based on this method is in good agreement with the test results of 6T SOI SRAM cells processed using 0.15 μm technology. (author)

  14. A pilot randomized controlled trial of D-cycloserine and distributed practice as adjuvants to constraint-induced movement therapy after stroke.

    Science.