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Sample records for 2x devices

  1. Memristor and selector devices fabricated from HfO2-xNx

    Murdoch, B. J.; McCulloch, D. G.; Ganesan, R.; McKenzie, D. R.; Bilek, M. M. M.; Partridge, J. G.

    2016-04-01

    Monoclinic HfO2-xNx has been incorporated into two-terminal devices exhibiting either memristor or selector operation depending on the controlled inclusion/suppression of mobile oxygen vacancies. In HfO2 memristors containing oxygen vacancies, gradual conductance modulation, short-term plasticity, and long-term potentiation were observed using appropriate voltage-spike stimulation, suggesting suitability for artificial neural networks. Passivation of oxygen vacancies, confirmed by X-ray absorption spectroscopy, was achieved in HfO2-xNx films by the addition of nitrogen during growth. Selector devices formed on these films exhibited threshold switching and current controlled negative differential resistance consistent with thermally driven insulator to metal transitions.

  2. MEMS/ECD Method for Making Bi(2-x)Sb(x)Te3 Thermoelectric Devices

    Lim, James; Huang, Chen-Kuo; Ryan, Margaret; Snyder, G. Jeffrey; Herman, Jennifer; Fleurial, Jean-Pierre

    2008-01-01

    A method of fabricating Bi(2-x)Sb(x)Te3-based thermoelectric microdevices involves a combination of (1) techniques used previously in the fabrication of integrated circuits and of microelectromechanical systems (MEMS) and (2) a relatively inexpensive MEMS-oriented electrochemical-deposition (ECD) technique. The present method overcomes the limitations of prior MEMS fabrication techniques and makes it possible to satisfy requirements.

  3. A simple synthesis of Ag{sub 2+x}Se nanoparticles and their thin films for electronic device applications

    Vo, Duc Quy; Dung, Dang Duc; Cho, Sunglae; Kim, Sunwook [School of Chemical Engineering, University of Ulsan, Ulsan (Korea, Republic of)

    2016-01-15

    A simple method to synthesize silver selenide nanoparticles has been proposed. By changing the ratio of Se-oleylamine complex and silver acetate in the reacting mixture at different temperatures, both size and stoichiometry of the silver selenide particles could be successfully controlled. The size of the nanoparticles was adjusted by changing reaction temperatures. The synthesized silver selenide nanoparticles showed size changes from 3 to 10 nm when the corresponding reaction temperatures were 40-100 .deg. C, respectively. In addition to the size change, the stoichiometry of the synthesized nanoparticles (Ag{sub 2+x}Se) could be adjusted by simply varying the ratio of Ag to Se precursors. Through XPS analyses the x value in Ag{sub 2+x}Se was determined, and it changed between 0.54 and −0.03 by varying Ag/Se ratio from 2/0.75 to 2/4. The optical property of the nonstoichiometric Ag{sub 2+x}Se nanoparticles was different from that of stoichiometric Ag{sub 2}Se nanoparticles, but showed the plasmon absorption of Ag-Ag network. The plasmon absorption was decreased with the increased concentration of the Se precursor. Finally, the Ag{sub 2+x}Se thin film in this work showed large magnetoresistance and successfully applied to prepare high-performance Schottky diode. The Ag{sub 2.06}Se film exhibited the magnetoresistance effect up to 0.9% at only 0.8 T at room temperature. The voltage drop and breakdown voltage of the Schottky diode were 0.5 V and 9.3 V, respectively.

  4. P2X receptors.

    North, R Alan

    2016-08-01

    Extracellular adenosine 5'-triphosphate (ATP) activates cell surface P2X and P2Y receptors. P2X receptors are membrane ion channels preferably permeable to sodium, potassium and calcium that open within milliseconds of the binding of ATP. In molecular architecture, they form a unique structural family. The receptor is a trimer, the binding of ATP between subunits causes them to flex together within the ectodomain and separate in the membrane-spanning region so as to open a central channel. P2X receptors have a widespread tissue distribution. On some smooth muscle cells, P2X receptors mediate the fast excitatory junction potential that leads to depolarization and contraction. In the central nervous system, activation of P2X receptors allows calcium to enter neurons and this can evoke slower neuromodulatory responses such as the trafficking of receptors for the neurotransmitter glutamate. In primary afferent nerves, P2X receptors are critical for the initiation of action potentials when they respond to ATP released from sensory cells such as taste buds, chemoreceptors or urothelium. In immune cells, activation of P2X receptors triggers the release of pro-inflammatory cytokines such as interleukin 1β. The development of selective blockers of different P2X receptors has led to clinical trials of their effectiveness in the management of cough, pain, inflammation and certain neurodegenerative diseases.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'. PMID:27377721

  5. P2X receptors in neuroglia

    Verkhratsky, Alexei; Pankratov, Yuri; Lalo, Ulyana; Nedergaard, Maiken

    2012-01-01

    Different types of ionotropic P2X purinoceptors are expressed in all major types of neuroglia, where they mediate a variety of physiological and pathological signaling. Cortical astrocytes express specific P2X1/5 heteromeric receptors that are activated by ongoing synaptic transmission and can trigger fast local signaling through elevation in cytoplasmic Ca2+ and Na+ concentrations. Oligodendrocytes express several types of P2X receptors that may control their development and mediate axonal–g...

  6. Structure, transport and magnetic properties in La2xSr2-2xCo2xRu2-2xO6

    The perovskite solid solutions of the type La2xSr2-2xCo2xRu2-2xO6 with 0.25≤x≤0.75 have been investigated for their structural, magnetic and transport properties. All the compounds crystallize in double perovskite structure. The magnetization measurements indicate a complex magnetic ground state with strong competition between ferromagnetic and antiferromagnetic interactions. Resistivity of the compounds is in confirmation with hopping conduction behaviour though differences are noted especially for x=0.4 and 0.6. Most importantly, low field (50 Oe) magnetization measurements display negative magnetization during the zero field cooled cycle. X-ray photoelectron spectroscopy measurements indicate the presence of Co2+/Co3+ and Ru4+/Ru5+ redox couples in all compositions except x=0.5. Presence of magnetic ions like Ru4+ and Co3+ gives rise to additional ferromagnetic (Ru-rich) and antiferromagnetic sublattices and also explains the observed negative magnetization. - Research Highlights: →In La2xSr2-2xCo2xRu2-2xO6 double perovskite structure is stabilized from x=0.25 to 0.75. →Interplay of FM and AFM exists due to presence of Ru4+/Ru5+ and Co2+/Co3+ redox couples. →Presence of different magnetic sublattices leads to magnetic compensation and negative magnetization.

  7. J-2X Abort System Development

    Santi, Louis M.; Butas, John P.; Aguilar, Robert B.; Sowers, Thomas S.

    2008-01-01

    The J-2X is an expendable liquid hydrogen (LH2)/liquid oxygen (LOX) gas generator cycle rocket engine that is currently being designed as the primary upper stage propulsion element for the new NASA Ares vehicle family. The J-2X engine will contain abort logic that functions as an integral component of the Ares vehicle abort system. This system is responsible for detecting and responding to conditions indicative of impending Loss of Mission (LOM), Loss of Vehicle (LOV), and/or catastrophic Loss of Crew (LOC) failure events. As an earth orbit ascent phase engine, the J-2X is a high power density propulsion element with non-negligible risk of fast propagation rate failures that can quickly lead to LOM, LOV, and/or LOC events. Aggressive reliability requirements for manned Ares missions and the risk of fast propagating J-2X failures dictate the need for on-engine abort condition monitoring and autonomous response capability as well as traditional abort agents such as the vehicle computer, flight crew, and ground control not located on the engine. This paper describes the baseline J-2X abort subsystem concept of operations, as well as the development process for this subsystem. A strategy that leverages heritage system experience and responds to an evolving engine design as well as J-2X specific test data to support abort system development is described. The utilization of performance and failure simulation models to support abort system sensor selection, failure detectability and discrimination studies, decision threshold definition, and abort system performance verification and validation is outlined. The basis for abort false positive and false negative performance constraints is described. Development challenges associated with information shortfalls in the design cycle, abort condition coverage and response assessment, engine-vehicle interface definition, and abort system performance verification and validation are also discussed.

  8. P2X Receptors and Synaptic Plasticity

    Pankratov, Y.; Lalo, U.; Krishtal, A.; Verkhratsky, Alexei

    2009-01-01

    Roč. 158, č. 1 (2009), s. 137-148. ISSN 0306-4522 Institutional research plan: CEZ:AV0Z50390512 Keywords : ATP * P2X receptors * synaptic plasticity Subject RIV: FH - Neurology Impact factor: 3.292, year: 2009

  9. Heteromeric assembly of P2X subunits

    Ralf Hausmann

    2013-12-01

    Full Text Available Transcripts and/or proteins of P2X receptor (P2XR subunits have been found in virtually all mammalian tissues. Generally more than one of the seven known P2X subunits have been identified in a given cell type. Six of the seven cloned P2X subunits can efficiently form functional homotrimeric ion channels in recombinant expression systems. This is in contrast to other ligand-gated ion channel families, such as the Cys-loop or glutamate receptors, where homomeric assemblies seem to represent the exception rather than the rule. P2XR mediated responses recorded from native tissues rarely match exactly the biophysical and pharmacological properties of heterologously expressed homomeric P2XRs. Heterotrimerization of P2X subunits is likely to account for this observed diversity. While the existence of heterotrimeric P2X2/3Rs and their role in physiological processes is well established, the composition of most other P2XR heteromers and/or the interplay between distinct trimeric receptor complexes in native tissues is not clear. After a description of P2XR assembly and the structure of the intersubunit ATP-binding site, this review summarizes the distribution of P2XR subunits in selected mammalian cell types and the biochemically and/or functionally characterized heteromeric P2XRs that have been observed upon heterologous co-expression of P2XR subunits. We further provide examples where the postulated heteromeric P2XRs have been suggested to occur in native tissues and an overview of the currently available pharmacological tools that have been used to discriminate between homo- and heteromeric P2XRs

  10. The P2X7 receptor

    Kvist, Torben Madsen; Schwarz, Peter; Jørgensen, Niklas Rye

    2014-01-01

    Inflammatory diseases are often multiorganic diseases with manifestations not related directly to the primary affected organ. They are often complicated by a generalized bone loss that subsequently leads to osteoporosis and bone fractures. The exact mechanism for the accompanying bone loss is not...... from an increase in bone resorption and the pro-inflammatory cytokines tumor necrosis factor alpha and interleukin 1 beta and has been shown to not only mediate the inflammatory response but also to strongly stimulate bone degradation. The purinergic P2X7 receptor is central in the processing of these...... two cytokines and in the initiation of the inflammatory response, and it is a key molecule in the regulation of both bone formation and bone resorption. The aim of this review is therefore to provide evidence-based novel hypotheses of the role of ATP-mediated purinergic signalling via the P2X7...

  11. Development Status of the J-2X

    Kynard, Mike; Vilja, John

    2008-01-01

    In June 2006, the NASA Marshall Space Flight Center (MSFC) and Pratt & Whitney Rocketdyne began development of an engine for use on the Ares I crew launch vehicle and the Ares V cargo launch vehicle. The development program will be completed in December 2012 at the end of a Design Certification Review and after certification testing of two flight configuration engines. A team of over 600 people within NASA and Pratt & Whitney Rocketdyne are currently working to prepare for the fall 2008 Critical Design Review (CDR), along with supporting an extensive risk mitigation test program. The J-2X will power the Ares I upper stage and the Ares V earth departure stage (EDS). The initial use will be in the Ares I, used to launch the Orion crew exploration vehicle. In this application, it will power the upper stage after being sent aloft on a Space Shuttle-derived. 5-segment solid rocket booster first stage. In this mission. the engine will ignite at altitude and provide the necessary acceleration force to allow the Orion to achieve orbital velocity. The Ares I upper stage, along with the J-2X. will then be expended. On the Ares V. first stage propulsion is provided by five RS-68B engines and two 5-segment boosters similar to the Ares I configuration. In the Ares V mission. the J-2X is first started to power the EDS and its payload. the Altair lunar lander. into earth orbit, then shut-down and get prepared for its next start. The EDS/Altair will remain in a parking orbit, awaiting rendezvous and docking with Orion. Once the two spacecraft are mated, the J-2X will be restarted to achieve earth departure velocity. After powering the Orion and Altair, the EDS will be expended. By using the J-2X Engine in both applications, a significant infrastructure cost savings is realized. Only one engine development is required, and the sustaining engineering and flight support infrastructures can be combined. There is also flexibility for changing, the production and flight manifest because

  12. Isothermal sintering kinetics of UOsub(2+x)

    The isothermal sintering kinetics of UOsub(2+x) were studied by measuring the densification rate in an optical dilatometer developed for this purpose. The sintering was conducted at constant temperature by using thin UOsub(2+x) compacts with a constant nonstoichiometry. The oxygen partial pressure in the sintering atmosphere was continuously measured by a stabilized ZrO2 solid electrolyte cell, particular attention being paid to the starting conditions of the ideal sintering. An empirical densification rate equation that describes the sintering kinetics within a large range was verified: density range 52 - 83% of the theoretical density, temperature range 1000 degC - 1550 degC, nonstoichiometry range Psub(O2)=10sup(-15.3)-10sup(-8.4)Pa, at 1100 degC, sintering time 12 s - 281 h. The effect of temperature on the sintering rate was compatible with the values reported in the literature for the effect of temperature on the uranium self-diffusion, the determined activation energy being 432 +- 13 kJ/mole. It was also noted that the uranium self-diffusion is suitable as the dominating factor in the sintering kinetics of UOsub(2+x). The rise in temperature from 1000 degC to 1550 degC increased the densification rate constant k 40-fold, and the change in oxygen partial pressure from Psub(O2)=10sup(-15.3) to Psub(O2)=10sup(-8.4) Pa at 1100 degC 4-fold. At 800 degC and at composition UOsub(2.1) a sintering rate was measured that corresponds to the sintering rate of a stoichiometric compact at 1320 degC. With the method applied in the present study and the verified empirical equation, the effect of the various factors on the sintering of the uranium dioxide compacts used as fuel elements can be studied accurately. (author)

  13. P2X6 Knockout Mice Exhibit Normal Electrolyte Homeostasis

    Viering, Daan H. H. M.; Bos, Caro; Bindels, René J. M.; Hoenderop, Joost G. J.

    2016-01-01

    ATP-mediated signaling is an important regulator of electrolyte transport in the kidney. The purinergic cation channel P2X6 has been previously localized to the distal convoluted tubule (DCT), a nephron segment important for Mg2+ and Na+ reabsorption, but its role in ion transport remains unknown. In this study, P2x6 knockout (P2x6-/-) mice were generated to investigate the role of P2X6 in renal electrolyte transport. The P2x6-/- animals displayed a normal phenotype and did not differ physiologically from wild type mice. Differences in serum concentration and 24-hrs urine excretion of Na+, K+, Mg2+ and Ca2+ were not detected between P2x6+/+, P2x6+/- and P2x6-/- mice. Quantitative PCR was applied to examine potential compensatory changes in renal expression levels of other P2x subunits and electrolyte transporters, including P2x1-5, P2x7, Trpm6, Ncc, Egf, Cldn16, Scnn1, Slc12a3, Slc41a1, Slc41a3, Cnnm2, Kcnj10 and Fxyd2. Additionally, protein levels of P2X2 and P2X4 were assessed in P2x6+/+ and P2x6-/- mouse kidneys. However, significant changes in expression were not detected. Furthermore, no compensatory changes in gene expression could be demonstrated in heart material isolated from P2x6-/- mice. Except for a significant (P<0.05) upregulation of P2x2 in the heart of P2x6-/- mice compared to the P2x6+/+ mice. Thus, our data suggests that purinergic signaling via P2X6 is not significantly involved in the regulation of renal electrolyte handling under normal physiological conditions. PMID:27254077

  14. Optical and infrared properties of tetramethyltetraselenafulvalene [(TMTSF)2X] and tetramethyltetrathiafulvalene [(TMTTF)2X] compounds

    Jacobsen, Claus Schelde; Tanner, D. B.; Bechgaard, K.

    1983-01-01

    The electronic structure of the organic conductors bis-tetramethyltetraselenafulvalene-X [(TMTSF)2X] and bis-tetramethyltetrathiafulvalene-X [(TMTTF)2X] has been investigated by means of polarized optical and infrared reflectance measurements. Analysis of plasma edges in reflectance is used to...... extract information on transfer integrals. Measurements of infrared reflectance provide information on the energy of charge-transfer processes and on electron-molecular vibration coupling. Far-infrared measurements allow comparison with low-frequency transport properties, and give clues to the transport...

  15. A 2 X 2 achievement goal framework.

    Elliot, A J; McGregor, H A

    2001-03-01

    A 2 x 2 achievement goal framework comprising mastery-approach, mastery-avoidance, performance-approach, and performance-avoidance goals was proposed and tested in 3 studies. Factor analytic results supported the independence of the 4 achievement goal constructs. The goals were examined with respect to several important antecedents (e.g., motive dispositions, implicit theories, socialization histories) and consequences (e.g., anticipatory test anxiety, exam performance, health center visits), with particular attention allocated to the new mastery-avoidance goal construct. The results revealed distinct empirical profiles for each of the achievement goals; the pattern for mastery-avoidance goals was, as anticipated, more negative than that for mastery-approach goals and more positive than that for performance-avoidance goals. Implications of the present work for future theoretical development in the achievement goal literature are discussed. PMID:11300582

  16. Superstrings in AdS2 x S2 x T6

    We consider the type IIB Green-Schwarz superstring theory on AdS2 x S2 x T6 supported by homogeneous Ramond-Ramond 5-form flux and its type IIA T-duals. One motivation is to understand the solution of this theory based on integrability. This background is a limit of a 1/4 supersymmetric supergravity solution describing four intersecting D3-branes and represents a consistent embedding of AdS2 x S2 into critical superstring theory. Its AdS2 x S2 part with corresponding fermions can be described by a classically integrable PSU(1, 1|2)/SO(1, 1) x U(1) supercoset sigma model. We point out that since the RR 5-form field has non-zero components along the 6-torus directions one cannot, in general, factorize the 10D superstring theory into the supercoset part plus six bosons and six additional massless fermions. Still, we demonstrate that the full superstring model (i) is classically integrable, at least to quadratic order in fermions, and (ii) admits a consistent classical truncation to the supercoset part. Following the analogy with other integrable backgrounds and starting with the finite-gap equations of the PSU(1, 1|2)/SO(1, 1) x U(1) supercoset, we propose a set of asymptotic Bethe ansatz equations for a subset of the quantum string states.

  17. Global analysis of general SU(2) x SU(2) x U(1) models with precision data

    Hsieh, Ken; Yu, Jiang-Hao; Yuan, C.P. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Schmitz, Kai [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy

    2010-05-15

    We present the results of a global analysis of a class of models with an extended electroweak gauge group of the form SU(2) x SU(2) x U(1), often denoted as G(221) models, which include as examples the left-right, the lepto-phobic, the hadro-phobic, the fermio-phobic, the un-unified, and the non-universal models. Using an effective Lagrangian approach, we compute the shifts to the coeffcients in the electroweak Lagrangian due to the new heavy gauge bosons, and obtain the lower bounds on the masses of the Z' and W' bosons. The analysis of the electroweak parameter bounds reveals a consistent pattern of several key observables that are especially sensitive to the effects of new physics and thus dominate the overall shape of the respective parameter contours. (orig.)

  18. A stronger entanglement monogamy inequality in a 2x2x3 system

    In this paper, we prove a stronger entanglement monogamy inequality in a 2x2x3 system's pure state |Ψ)ABC. Specifically, we show that the linear entropy of ρA, which is the entanglement between A and BC, is always larger than the sum of the square of concurrence between A and B and the square of concurrence of assistance between A and C. Our proof is based on direct generalizations of the qubit system's results. Our inequality is stronger than the known monogamy inequality of concurrence and shows that the entanglement of assistance always comes from the existing entanglement. However, our inequality also shows that unlike the three-qubit case, in higher dimensional systems the entanglement between A and BC cannot be completely transformed into bipartite entanglement with assistance. Through our proof, we also give some cases when the inequality reduces to an equality.

  19. P2X receptors: New players in cancer pain

    Alessia; Franceschini; Elena; Adinolfi

    2014-01-01

    Pain is unfortunately a quite common symptom for cancer patients. Normally pain starts as an episodic experience at early cancer phases to become chronic in later stages. In order to improve the quality of life of oncological patients, anti-cancer treatments are often accompanied by analgesic therapies. The P2 X receptor are adenosine triphosphate(ATP) gated ion channels expressed by several cells including neurons, cancer and immune cells. Purinergic signaling through P2 X receptors recently emerged as possible common pathway for cancer onset/growth and pain sensitivity. Indeed, tumor microenvironment is rich in extracellular ATP, which has a role in both tumor development and pain sensation. The study of the different mechanisms by which P2 X receptors favor cancer progression and relative pain, represents an interesting challenge to design integrated therapeutic strategies for oncological patients. This review summarizes recent findings linking P2 X receptors and ATP to cancer growth, progression and related pain. Special attention has been paid to the role of P2X2, P2X3, P2X4 and P2X7 in the genesisof cancer pain and to the function of P2X7 in tumor growth and metastasis. Therapeutic implications of the administration of different P2 X receptor blockers to alleviate cancer-associated pain sensations contemporarily reducing tumor progression are also discussed.

  20. Magnetic ground state of UCu 2X 2 (X=Si, Ge) from first principles

    Matar, Samir F.; Siruguri, Vasudeva; Eyert, Volker

    2006-10-01

    The electronic and magnetic structures of UCu 2X 2 germanide and silicide are revisited in view of existing controversy from experimental findings. From self-consistent calculations carried out within the local spin density functional theory using the augmented spherical wave method, the ground state is found to be ferromagnetic within simple and super cell setups. An analysis of the density of states and the chemical bonding shows the dominant role of Cu 2Ge 2-nearly planar like entities within the crystal lattice.

  1. Inequalities detecting quantum entanglement for 2 x d systems

    We present a set of inequalities for detecting quantum entanglement of 2 x d quantum states. For 2 x 2 and 2 x 3 systems, the inequalities give rise to sufficient and necessary separability conditions for both pure and mixed states. For the case of d>3, these inequalities are necessary conditions for separability, which detect all entangled states that are not positive under partial transposition and even some entangled states with positive partial transposition. These inequalities are given by mean values of local observables and present an experimental way of detecting the quantum entanglement of 2 x d quantum states and even multiqubit pure states.

  2. P2X7 Receptors in Neurological and Cardiovascular Disorders

    Stephen D. Skaper

    2009-01-01

    Full Text Available P2X receptors are ATP-gated cation channels that mediate fast excitatory transmission in diverse regions of the brain and spinal cord. Several P2X receptor subtypes, including P2X7, have the unusual property of changing their ion selectivity during prolonged exposure to ATP, which results in a channel pore permeable to molecules as large as 900 daltons. The P2X7 receptor was originally described in cells of hematopoietic origin, and mediates the influx of Ca2+ and Na+ and Ca2+ and Na+ ions as well as the release of proinflammatory cytokines. P2X7 receptors may affect neuronal cell death through their ability to regulate the processing and release of interleukin-1, a key mediator in neurodegeneration, chronic inflammation, and chronic pain. Activation of P2X7, a key mediator in neurodegeneration, chronic inflammation, and chronic pain. Activation of P2X7 receptors provides an inflammatory stimulus, and P2X7 receptor-deficient mice have substantially attenuated inflammatory responses, including models of neuropathic and chronic inflammatory pain. Moreover, P2X7 receptor activity, by regulating the release of proinflammatory cytokines, may be involved in the pathophysiology of depression. Apoptotic cell death occurs in a number of vascular diseases, including atherosclerosis, restenosis, and hypertension, and may be linked to the release of ATP from endothelial cells, P2X7 receptor activation, proinflammatory cytokine production, and endothelial cell apoptosis. In this context, the P2X7 receptor may be viewed as a gateway of communication between the nervous, immune, and cardiovascular systems.

  3. Generalized Measure of Departure from No Three-Factor Interaction Model for 2 x 2 x K Contingency Tables

    Yohei Ban

    2008-12-01

    Full Text Available For 2 x 2 x K contingency tables, Tomizawa considered a Shannon entropy type measure to represent the degree of departure from a log-linear model of no three-factor interaction (the NOTFI model. This paper proposes a generalization of Tomizawa's measure for 2 x 2 x K tables. The measure proposed is expressed by using Patil-Taillie diversity index or Cressie-Read power-divergence. A special case of the proposed measure includes Tomizawa's measure. The proposed measure would be useful for comparing the degrees of departure from the NOTFI model in several tables.

  4. The role of P2X receptors in bone biology

    Jørgensen, N R; Syberg, S; Ellegaard, M

    2015-01-01

    come from studies on murine knockout models and from pharmacologic studies on cells and animals. More recently, the role of P2X receptors in human bone diseases has been documented. Loss-of-functions polymorphisms in the P2X7 receptorare associated with bone loss and increased fracture risk. Very...

  5. P2X4 receptors and neuropathic pain

    Makoto Tsuda

    2013-10-01

    Full Text Available Neuropathic pain, a debilitating pain condition, is a common consequence of damage to the nervous system. Neuropathic pain is often resistant to currently available analgesics. A growing body of evidence indicates that spinal microglia react and undergo a series of changes that directly influence the establishment of neuropathic pain states. After nerve injury, P2X4 receptors (P2X4Rs are upregulated in spinal microglia by several factors at the transcriptional and translational levels. Those include the CC chemokine CCL21 derived from damaged neurons, the extracellular matrix protein fibronectin in the spinal cord, and the transcription factor interferon regulatory factor 8 expressed in microglia. P2X4R expression in microglia is also regulated at the post-translational level by signaling from other cell-surface receptors such as CC chemokine receptor CCR2. Importantly, inhibiting the function or expression of P2X4Rs and P2X4R-regulating molecules suppresses the aberrant excitability of dorsal horn neurons and neuropathic pain. These findings indicate that P2X4R-positive microglia are a central player in mechanisms for neuropathic pain. Thus, microglial P2X4Rs are a potential target for treating the chronic pain state.

  6. The role of P2X receptors in bone biology

    Jørgensen, N R; Syberg, S; Ellegaard, M

    2015-01-01

    receptors regulate bone metabolism and especially for the P2X7 receptor an impressive amount of evidence has now documented its expression in osteoblasts, osteoclasts, and osteocytes as well as important functional roles in proliferation, differentiation, and function of the cells of bone. Key evidence has...... come from studies on murine knockout models and from pharmacologic studies on cells and animals. More recently, the role of P2X receptors in human bone diseases has been documented. Loss-of-functions polymorphisms in the P2X7 receptorare associated with bone loss and increased fracture risk. Very...

  7. Modulation of P2X3 and P2X2/3 Receptors by Monoclonal Antibodies.

    Shcherbatko, Anatoly; Foletti, Davide; Poulsen, Kris; Strop, Pavel; Zhu, Guoyun; Hasa-Moreno, Adela; Melton Witt, Jody; Loo, Carole; Krimm, Stellanie; Pios, Ariel; Yu, Jessica; Brown, Colleen; Lee, John K; Stroud, Robert; Rajpal, Arvind; Shelton, David

    2016-06-01

    Purinergic homomeric P2X3 and heteromeric P2X2/3 receptors are ligand-gated cation channels activated by ATP. Both receptors are predominantly expressed in nociceptive sensory neurons, and an increase in extracellular ATP concentration under pathological conditions, such as tissue damage or visceral distension, induces channel opening, membrane depolarization, and initiation of pain signaling. Hence, these receptors are considered important therapeutic targets for pain management, and development of selective antagonists is currently progressing. To advance the search for novel analgesics, we have generated a panel of monoclonal antibodies directed against human P2X3 (hP2X3). We have found that these antibodies produce distinct functional effects, depending on the homomeric or heteromeric composition of the target, its kinetic state, and the duration of antibody exposure. The most potent antibody, 12D4, showed an estimated IC50 of 16 nm on hP2X3 after short term exposure (up to 18 min), binding to the inactivated state of the channel to inhibit activity. By contrast, with the same short term application, 12D4 potentiated the slow inactivating current mediated by the heteromeric hP2X2/3 channel. Extending the duration of exposure to ∼20 h resulted in a profound inhibition of both homomeric hP2X3 and heteromeric hP2X2/3 receptors, an effect mediated by efficient antibody-induced internalization of the channel from the plasma membrane. The therapeutic potential of mAb12D4 was assessed in the formalin, complete Freund's adjuvant, and visceral pain models. The efficacy of 12D4 in the visceral hypersensitivity model indicates that antibodies against P2X3 may have therapeutic potential in visceral pain indications. PMID:27129281

  8. J-2X Test Articles Using FDM Process

    Anderson, Ted; Ruf, Joe; Steele, Phil

    2010-01-01

    This viewgraph presentation gives a brief history of the J-2X engine, along with detailed description of the material demonstrator and test articles that were created using Fused Deposition Modeling (FDM) process.

  9. Alaska Gravity Data per 2 x 4 min Cell (96)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' gravity density grid for Alaska displays the distribution of about 1.1 million terrestrial and marine gravity data held in the National Geodetic Survey...

  10. Discovery and Identification of W' and Z' in SU(2) x SU(2) x U(1) Models at the LHC

    Cao, Qing-Hong; Li, Zhao; Yu, Jiang-Hao; Yuan, C.-P.

    2012-01-01

    We explore the discovery potential of W' and Z' boson searches for various SU(2) x SU(2) x U(1) models at the Large Hadron Collider (LHC), after taking into account the constraints from low energy precision measurements and direct searches at both the Tevatron (1.96 TeV) and the LHC (7 TeV). In such models, the W' and Z' bosons emerge after the electroweak symmetry is spontaneously broken. Two patterns of the symmetry breaking are considered in this work: one is SU(2)_L x SU(2)_2 x U(1)_X to ...

  11. P2X1 receptors and the endothelium

    LS Harrington

    2005-03-01

    Full Text Available Adenosine triphosphate (ATP is now established as a principle vaso-active mediator in the vasculature. Its actions on arteries are complex, and are mediated by the P2X and P2Y receptor families. It is generally accepted that ATP induces a bi-phasic response in arteries, inducing contraction via the P2X and P2Y receptors on the smooth muscle cells, and vasodilation via the actions of P2Y receptors located on the endothelium. However, a number of recent studies have placed P2X1 receptors on the endothelium of some arteries. The use of a specific P2X1 receptor ligand, a, b methylene ATP has demonstrated that P2X1 receptors also have a bi-functional role. The actions of ATP on P2X1 receptors is therefore dependant on its location, inducing contraction when located on the smooth muscle cells, and dilation when expressed on the endothelium, comparable to that of P2Y receptors.

  12. Electrical Characteristics of TiO(2-x)/TiO2 Resistive Switching Memory Fabricated by Atomic Layer Deposition.

    Heo, Kwan-Jun; Kim, Won-You; Kim, Sung-Jin

    2016-06-01

    The rewritable low-power operated nonvolatile resistive random access memory device composed of Al(top)/TiO(2-x)/TiO2/Al(bottom) are demonstrated. The active component, the TiO2 layer of the device, is fabricated by atomic layer deposition. The oxygen vacancy TiO(2-x)/TiO2 layer annealed at 600 degrees C using rapid thermal annealing and it was proven to be in the rutile phase by X-ray diffraction analysis. The device exhibits nonvolatile memory behavior consistent with resistive switching properties, demonstrates an ON/OFF ratio of approximately 1,000:1, requires range of low voltage less than 0.4 V, and is still operational more than 120 times. PMID:27427707

  13. Electric field effect on superconductivity in $La_{2-x}$$Sr_{x}$$CuO_{4}$

    Dubuis, Guy; Bollinger, A.T.; Pavuna, Davor; Bozovic, I

    2012-01-01

    We demonstrate a method to tune the carrier concentration of a high temperature superconductor over a wide range, using an applied electric field. Thin film devices were made in an electrical double layer transistor configuration utilizing an ionic liquid. In this way, the surface carrier density in La2-xSrxCuO4 films can be varied between 0.01 and 0.14 carriers per Cu atom with a resulting change in critical temperature of 25 K (70% of the maximum critical temperature in this compound). This...

  14. Structure and Stability of Si(114)-(2x1)

    Erwin, S C; Whitman, L J; Erwin, Steven C.; Baski, Alison A.; Whitman, Lloyd J.

    1996-01-01

    We describe a recently discovered stable planar surface of silicon, Si(114). This high-index surface, oriented 19.5 degrees away from (001) toward (111), undergoes a 2x1 reconstruction. We propose a complete model for the reconstructed surface based on scanning tunneling microscopy images and first-principles total-energy calculations. The structure and stability of Si(114)-(2x1) arises from a balance between surface dangling bond reduction and surface stress relief, and provides a key to understanding the morphology of a family of surfaces oriented between (001) and (114).

  15. Adsorption of Ag on Ge(100)-(2 x 1)

    Miller, T.; Rosenwinkel, E.; Chiang, T.C.

    1984-01-01

    The initial stages of interface formation of Ag deposited onto Ge(100)-(2 x 1) were studied with high-energy electron diffraction and high-resolution photoemission. The surface core-level energies for clean Ge(100)-(2 x 1) were not changed with the deposition of about one monolayer of Ag, indicating that there was no chemical reaction or atomic intermixing. The Ag nucleated at a coverage of about 1/3 monolayer and showed three-dimensional growth for higher coverages. 13 references, 3 figures.

  16. P2X7 receptors in satellite glial cells mediate high functional expression of P2X3 receptors in immature dorsal root ganglion neurons

    Chen Yong

    2012-02-01

    Full Text Available Abstract Background The purinergic P2X3 receptor (P2X3R expressed in the dorsal root ganglion (DRG sensory neuron and the P2X7 receptor (P2X7R expressed in the surrounding satellite glial cell (SGC are two major receptors participating in neuron-SGC communication in adult DRGs. Activation of P2X7Rs was found to tonically reduce the expression of P2X3Rs in DRGs, thus inhibiting the abnormal pain behaviors in adult rats. P2X receptors are also actively involved in sensory signaling in developing rodents. However, very little is known about the developmental change of P2X7Rs in DRGs and the interaction between P2X7Rs and P2X3Rs in those animals. We therefore examined the expression of P2X3Rs and P2X7Rs in postnatal rats and determined if P2X7R-P2X3R control exists in developing rats. Findings We immunostained DRGs of immature rats and found that P2X3Rs were expressed only in neurons and P2X7Rs were expressed only in SGCs. Western blot analyses indicated that P2X3R expression decreased while P2X7R expression increased with the age of rats. Electrophysiological studies showed that the number of DRG neurons responding to the stimulation of the P2XR agonist, α,β-meATP, was higher and the amplitudes of α,β-meATP-induced depolarizations were larger in immature DRG neurons. As a result, P2X3R-mediated flinching responses were much more pronounced in immature rats than those found in adult rats. When we reduced P2X7R expression with P2X7R-siRNA in postnatal and adult rats, P2X3R-mediated flinch responses were greatly enhanced in both rat populations. Conclusions These results show that the P2X7R expression increases as rats age. In addition, P2X7Rs in SGCs exert inhibitory control on the P2X3R expression and function in sensory neurons of immature rats, just as observed in adult rats. Regulation of P2X7R expression is likely an effective way to control P2X3R activity and manage pain relief in infants.

  17. P2X receptor channels in endocrine glands

    Stojilkovic, S. S.; Zemková, Hana

    2013-01-01

    Roč. 2, č. 4 (2013), s. 173-180. ISSN 2190-460X R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : ATP * purinergic P2X receptor channels * pituitary * endocrine glands Subject RIV: ED - Physiology

  18. The contribution of valence unstable ytterbium states into kinetic properties of YbNi{sub 2-x}Ge{sub 2+x} and YbCu{sub 2-x}Si{sub 2+x}

    Kuzhel, B.C. [Department of Physics, Ivan Franko National University of Lviv, 50 Dragomanow Str., 79005, Lviv (Ukraine)]. E-mail: kuzhelb@org.lviv.net; Shcherba, I.D. [Department of Physics, Ivan Franko National University of Lviv, 50 Dragomanow Str., 79005, Lviv (Ukraine); Institute of Techniques, Academy of Pedagogy, Podchorozych 2, 30-084, Krakow (Poland); Kravchenko, I.I. [Department of Physics, University of Florida, P.O. Box 118440, Gainesville, FL 32611 (United States)]. E-mail: kravch@phys.ufl.edu

    2006-11-30

    The intermetalic YbNi{sub 2-x}Ge{sub 2+x} (-0.25>=x>=0.25) and YbCu{sub 2-x}Si{sub 2+x} (-0.20>=x>=0.20) alloy systems (CeGa{sub 2}Al{sub 2} -type crystal structure) were studied by measuring X-ray absorption and diffraction at room temperatures as well as electrical resistivity and thermopower in the 4.2-300K temperature range. The temperature dependence of the contribution of valence unstable Yb ions to the total electrical resistance has been analyzed. The qualitative estimation of this contribution has been performed by utilizing the following equation:{delta}{rho}{sub Yb}(T)={rho}{sub exp}(T)-{rho}{sub YbCu{sub 2}Ge{sub 2}}(T)-{delta}{rho}{sub 4.2K},where {delta}{rho}{sub YbCu{sub 2}Ge{sub 2}}(T) is the temperature dependence of YbCu{sub 2}Ge{sub 2} electrical resistance, {delta}{rho}{sub 4.2}={rho}{sub 4.2}(exp)-{rho}{sub 4.2}(YbCu{sub 2}Ge{sub 2})

  19. A solid solution series of atacamite type Ni2xMg2−2xCl(OH)3

    For the first time a complete solid solution series Ni2xMg2−2xCl(OH)3 of an atacamite type alkaline main group metal chloride, Mg2Cl(OH)3, and a transition group metal chloride, Ni2Cl(OH)3, was prepared and characterized by chemical and thermal analysis as well as by Raman and IR spectroscopy, and high resolution laboratory X-ray powder diffraction. All members of the solid solution series crystallize in space group Pnam (62). The main building units of these crystal structures are distorted, edge-linked Ni/MgO4Cl2 and Ni/MgO5Cl octahedra. The distribution of Ni2+- and Mg2+-ions among these two metal-sites within the solid solution series is discussed in detail. The crystallization of the solid solution phases occurs via an intermediate solid solution series, (Ni/Mg)Cl2x(OH)2−2x, with variable Cl: OH ratio up to the 1:3 ratio according to the formula Ni2xMg2−2x Cl(OH)3. For one isolated intermediate solid solution member, Ni0.70Mg0.30Cl0.58(OH)1.42, the formation and crystal structure is presented as well. - Graphical abstract: For the first time a complete solid solution series, Ni2xMg2−2x Cl(OH)3, was synthesized and characterized. Structure solution by revealed that Ni2+ prefers to occupy the Jahn–Teller-like distorted hole, out of two available cation sites. Substitution of Ni2+ by Mg2+ in atacamite type Ni2Cl(OH)3 results in systematic band shifts in Raman and IR spectra as well as in systematic changes in thermal properties. The α-polymorphs M2Cl(OH)3 with M=Mg2+, Ni2+ and other divalent transition metal ions, as described in literature, were identified as separate compounds. - Highlights: • First synthesis of solid solution series between main and transition metal chloride. • Ni2+ prefers to occupy Jahn–Teller-like distorted octahedral holes. • Substitution of Ni2+ by Mg2+ results in systematic Raman and IR band shifts. • α-Polymorphs M2Cl(OH)3 with M=Mg2+, Ni2+, … as described in literature do not exist

  20. Deletion of P2X2 and P2X3 receptor subunits does not alter motility of the mouse colon

    JamesJGalligan

    2010-03-01

    Full Text Available Purinergic P2X receptors contribute to neurotransmission in the gut. P2X receptors are ligand-gated cation channels that mediate synaptic excitation in subsets of enteric neurons. The present study evaluated colonic motility in vitro and in vivo in wild type (WT and P2X2 and P2X3 subunit knockout (KO mice. The muscarinic receptor agonist, bethanechol (0.3-3 micromolar, caused similar contractions of the longitudinal muscle in colon segments from WT, P2X2 and P2X3 subunit KO mice. Nicotine (1-300 micromolar, acting at neuronal nicotinic receptors, caused similar longitudinal muscle relaxations in colonic segments from WT and P2X2 and P2X3 subunit KO mice. Nicotine-induced relaxations were inhibited by nitro-L-arginine (NLA, 100 micromolar and apamin (0.1 micromolar which block inhibitory neuromuscular transmission. ATP (1-1000 micromolar caused contractions only in the presence of NLA and apamin. ATP-induced contractions were similar in colon segments from WT, P2X2 and P2X3 KO mice. The mouse colon generates spontaneous migrating motor complexes (MMCs in vitro. The MMC frequency was higher in P2X2 KO compared to WT tissues; other parameters of the MMC were similar in colon segments from WT, P2X2 and P2X3 KO mice. 5-Hydroxytryptophan-induced fecal output was similar in WT, P2X2 and P2X3 KO mice. These data indicate that nicotinic receptors are located predominately on inhibitory motor neurons supplying the longitudinal muscle in the mouse colon. P2X2 or P2X3 subunit containing receptors are not localized to motorneurons supplying the longitudinal muscle. Synaptic transmission mediated by P2X2 or P2X3 subunit containing receptors is not required for propulsive motility in the mouse colon.

  1. 力竭运动对大鼠大脑P2X2、P2X4和P2X6受体表达的影响%Effect of Exhaustive Exercise on the Expression of Brain P2X2,P2X4,and P2X6 Receptors in Rats

    周未艾; 李硕; 陈海涛

    2012-01-01

    目的:探讨一次和反复力竭游泳运动后大鼠大脑ATP受体P2X之三个亚型P2X2、P2X4和P2X6的时相性变化特点.方法:健康成年雄性SD大鼠68只,分为一次力竭游泳运动组和反复力竭游泳运动组及安静对照组,反复力竭组大鼠每日负重3%体重进行力竭游泳运动,共训练2周.运动组分别于力竭运动后即刻、4小时、12小时和24小时取材,采用实时荧光定量PCR方法测定力竭运动后大鼠P2X2、P2X4和P2X6受体亚型mRNA水平.结果:(1)反复力竭运动后12小时组P2X2相对表达率达到峰值,与反复力竭其它各组及安静对照组、一次力竭12小时组均有显著差异(P<0.01).(2)一次力竭即刻组P2X4相对表达率与安静对照组、4小时组、12小时组比较有显著统计学差异(分别为P< 0.01、P<0.05、P< 0.01).(3)反复力竭运动后12小时组P2X6相对表达率达到峰值.结论:3种受体亚型在一次力竭运动和反复力竭运动后12小时出现峰值或峰值趋势,提示在力竭运动后12小时,这3种P2X受体亚型所参与的中枢神经生理生化活动在此时可能会达到一个活跃期.%Objective The main purpose of this study is to investigate the variation in P2X2,P2X4 and P2X6 receptors in rats brain at different time points after single bout exhaustive exercise and repeated exhaustive exercise. Methods Sixty-eight male SD rats were divided randomly into the single bout exhaustive swimming group (SE), repeated exhausting swimming (RE), and sedentary group (C). The rats in group RE with weight-bearing 3% of body weight swan to exhaustion each day for a total of two weeks. The brain tissue of the rats was removed at 0 hr,4 hr,12 hr and 24 hr after the last exhaustive swimming. The mRNA levels of P2X2,P2X4 and P2X6 receptors in the brain tissue were observed through real-time quantitative PCR method. Results (l)The peak relative expression rate of the P2X2 in the group RE revealed at 12 hr after exhaustive

  2. Thermal expansion of Cr2xFe2-2xMo3O12, Al2xFe2-2xMo3O12 and Al2xCr2-2xMo3O12 solid solutions

    The transition temperature from monoclinic to orthorhombic and the thermal expansion of the orthorhombic phase were investigated for three systems of the family A2M3O12: Cr2xFe2-2xMo3O12, Al2xFe2-2xMo3O12 and Al2xCr2-2xMo3O12. It was possible to obtain a single-phase solid solution in all studied samples (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1). A linear relationship between the transition temperature and the fraction of A3+ cations (x) was observed for each system. In all orthorhombic solid solutions studied here the observed thermal expansion was anisotropic. These anisotropic thermal expansion properties of crystallographic axes a, b and c result in a low positive or near-zero overall linear coefficient of thermal expansion (αl=αV/3). The relationship between the size of A3+ cations in A2M3O12 and the coefficient of thermal expansion is discussed. Near-zero thermal expansion of Cr2Mo3O12 is explained by the behavior of Cr-O and Mo-O bond distances, Cr-Mo non-bond distances and Cr-O-Mo bond angles with increasing temperature, estimated by Rietveld analysis of synchrotron X-ray powder diffraction data. - Graphical abstract: In this figure, all published overall linear coefficients of thermal expansion for orthorhombic A2M3O12 family obtained through diffraction methods as a function of A3+ cation radii size, together with dilatometric results, are plotted. Our results indicate that Cr2Mo3O12 does not exactly follow the established relationship

  3. Structure design of high accuracy 2 x 2 array grating

    A new type high accuracy 2 x 2 array diffraction grating structure is proposed, which has good structure stability in design method of modularization and frame structure. Designed micro-nano adjusting unit consists of differential thread and piezoelectricity driver, that realize micro-nano adjustment request of tiled-grating. Design and manufacture questions about essential parts is discussed. Preliminary test of experiment prototype indicates that the coplanar maximum relative error is 17 μm, minimum adjustment precision of micro-nano adjusting unit is possible to achieve 1.8 nm, and the resolution is 0.9 nm. The optical path experiment indicates that tiling adjusting mechanism may fast and real-time adjust 2 x 2 array diffraction grating to meet requirements, and stable work time is larger than 1 h. (authors)

  4. Structure stability maps for MLn2X4 compounds

    Structure type data for MLn2X4 (Ln=La-Lu, Sc, Y; M=Mg, Ca, Sr, Ba, Mn, Fe, Zn, Cd, Pb; X=S, Se) compounds are systematized. Structure stability maps are designed and analyzed comparatively. Predictions are made concerning structure formation for unstudied sulfides and selenides. Future applications of the structure stability maps and their integration into databases are outlined

  5. Engine Gimbal Requirements for Ground Testing of J-2X

    Kovalcik, Julia; Leahy, Joe

    2009-01-01

    Based on the Apollo-era J-2 that powered the second and third stages of the Saturn V, the current J-2X is the liquid hydrogen and oxygen high-altitude rocket engine in development for both the Ares I Upper Stage and Ares V Earth Departure Stage. During my summer 2009 internship, J-2X was at a stage in its design maturity where verification testing needed to be considered for the benefit of adequate test facility preparation. My task was to focus on gimbal requirements and gimbal related hot-fire test plans. Facility capabilities were also of interest, specifically for hot-fire testing slated to occur at test stands A-1, A-2, and A-3 at Stennis Space Center(SSC) in Bay St. Louis, Mississippi. Gimbal requirements and stage interface conditions were investigated by applying a top-to-bottom systems engineering approach, which involved system level requirements, engine level requirements from both government and engine contractor perspectives, component level requirements, and the J-2X to Upper Stage and Earth Departure Stage interface control documents. Previous hydrogen and oxygen liquid rocket engine gimbal verification methods were researched for a glimpse at lessons learned. Discussion among the J-2X community affected by gimballing was organized to obtain input relative to proper verification of their respective component. Implementing suggestions such as gimbal pattern, angulated dwell time, altitude testing options, power level, and feed line orientation, I was able to match tests to test stands in the A Complex at SSC. Potential test capability gaps and risks were identified and pursued. The culmination of all these efforts was to coordinate with SSC to define additional facility requirements for both the A-3 altitude test stand that is currently under construction and the A-1 sea level test stand which is being renovated

  6. P2X receptor channels in endocrine glands

    Stojilkovic, Stanko S.; Zemkova, Hana

    2013-01-01

    The endocrine system is the system of ductless glands and single cells that synthetize hormones and release them directly into the bloodstream. Regulation of endocrine system is very complex and ATP and its degradable products ADP and adenosine contribute to its regulation acting as extracellular messengers for purinergic receptors. These include P2X receptors, a family of ligand-gated ion channels which expression and roles in endocrine tissues are reviewed here. There are seven mammalian pu...

  7. The trafficking and targeting of P2X receptors

    Ruth Dorothy Murrell-Lagnado

    2013-11-01

    Full Text Available The functional expression of P2X receptors at the plasma membrane is dependent on their trafficking along secretory and endocytic pathways. There are seven P2X receptor subunits, and these differ in their subcellular distributions because they have very different trafficking properties. Some are retained within the endoplasmic reticulum (ER, while others are predominantly at the cell surface or within endosomes and lysosomes. Changes in recruitment of receptors to and from the plasma membrane provides a way of rapidly up- or down-regulating the cellular response to ATP. An additional layer of regulation is the targeting of these receptors within the membranes of each compartment, which affects their stability, function and the nature of the effector proteins with which they form signaling complexes. The trafficking and targeting of P2X receptors is regulated by their interactions with other proteins and with lipids and we can expect this to vary in a cell-type specific manner, giving rise to differences in receptor activity and function.

  8. J-2X Fuel Pump Impeller Seal Simulations

    Schmauch, Preston B.; West, Jeffrey S.

    2011-01-01

    The J-2X engine was originally designed for the upper stage of the previously cancelled Crew Launch Vehicle. Although the Crew Launch Vehicle was cancelled the J-2X engine, which is currently undergoing hot-fire testing, may be used on future programs. The J-2X engine is a direct descendent of the J-2 engine which powered the upper stage during the Apollo program. Many changes including a thrust increase from 230K to 294K lbf have been implemented in this engine. The rotor-dynamic stability of the fuel turbopump is highly dependent on the tangential velocity of the fluid as it enters the the front face impeller seal. Rotor-dynamic analysis predicts that a much lower tangential velocity will be required for stability than was needed for previous engines. The geometry at the seal entrance for this engine is very complex and vastly different than previous engines. In order to better determine the fluid dynamics and tangential velocity in this seal several CFD simulations were performed. The results of these simulations show that for this seal geometry a great reduction in the tangential velocity is to be expected. The simulations also provided insight into methods that could be employed to drive the swirl velocity to near zero. Unsteady and time-averaged results of several simulations will be presented.

  9. Oxygen redistribution in (UCe)Osub(2-x)

    Redistribution of oxygen has been investigated in (Usub(0,7)Cesub(0,3))Osub(2-x) mixed oxide subjected to a temperature gradient in laboratory experiments, in order to apply the results to the nuclear fuel (UPu)Osub(2-x). Cylindrical sintered oxide specimens were exposed to temperature up to 13000C with a longitudinal thermal gradient of about 4000C/cm. The most interesting feature of the experimental set-up is a solid-state electrochemical gauge (ThO2 - Y2O3), placed in the cold part of the sample which allows a continuous measurement of the oxygen activity. The experiments showed a fast oxygen migration down the thermal gradient. The calculations performed with a model based on solid-state thermodiffusion are in good agreement with experimental results. The heat of transport Q measured for bare samples reaches (7.2+-0.5)-kcal/mole. When the sample is coated with a tight fitting metallic cladding, an extra term Qe has to be added to the heat of transport Qe. This was interpreted as an electrotransport phenomena. On the same basis, calculations applied to radial oxygen redistribution in (UPu)Osub(2-x) seem to be adequate at least during the first stage of irradiation, taking Q=(20+-5)kcal/mole

  10. Pt/Ta2 O5 /HfO2- x /Ti resistive switching memory competing with multilevel NAND flash.

    Yoon, Jung Ho; Kim, Kyung Min; Song, Seul Ji; Seok, Jun Yeong; Yoon, Kyung Jean; Kwon, Dae Eun; Park, Tae Hyung; Kwon, Young Jae; Shao, Xinglong; Hwang, Cheol Seong

    2015-07-01

    Pt/Ta2 O5 /HfO2- x /Ti resistive switching memory with a new circuit design is presented as a feasible candidate to succeed multilevel-cell (MLC) NAND flash memory. This device has the following characteristics: 3 bit MLC, electroforming-free, self-rectifying, much higher cell resistance than interconnection wire resistance, low voltage operation, low power consumption, long-term reliability, and only an electronic switching mechanism, without an ionic-motion-related mechanism. PMID:25973913

  11. The Si(100)-Sb 2x1 and Ge(100) 2x1 surfaces: A multi-technique study

    The electronic and geometric structures of the clean and Sb terminated Si(100)2x1 and Ge(100)-2x1 surfaces have been investigated using a multi-technique approach. Low energy electron diffraction (LEED), scanning tunneling microscopy (STM), surface extended X-ray absorption fine structure (SEXAFS) spectroscopy and angle-integrated core-level photoemission electron spectroscopy (PES) were employed to measure the surface symmetry, defect structure, relevant bond lengths, atomic coordination and electronic structure. By employing a multi-technique approach, it is possible to correlate changes in the geometric structure to specific features of the core-level lineshape of the substrate. This allows for the assignment of components of the core-level lineshape to be assigned to specific surface and near-surface atoms

  12. Preparation and characterization of Al2xIn2−2xO3 films deposited on MgO (1 0 0) by MOCVD

    Highlights: • Ternary Al2xIn2−2xO3 alloy films were deposited on MgO (1 0 0) by MOCVD. • The microstructure of the Al2xIn2−2xO3 films were studied upon HRTEM. • Al2xIn2−2xO3 alloy films exhibited great optical transparency in the visible wavelength range. • The band gap of the Al2xIn2−2xO3 films can be modulated by controlling the Al contents in the samples. - Abstract: The ternary Al2xIn2−2xO3 films with different compositions x[Al/(Al + In) atomic ratio] have been fabricated on the MgO (1 0 0) substrates by the metal organic chemical vapor deposition (MOCVD) method. The influence of different Al contents on the structural, optical and electrical properties of Al2xIn2−2xO3 films has been studied. The structural studies reveal a change from single crystalline structure of cubic In2O3 to amorphous as the Al content increases. The average transmittances of all samples in the visible range are over 80%. The optical band gap is observed to increase monotonically from 3.67 to 5.38 eV as the Al content increases from 0.1 to 0.9

  13. The UC2-x - Carbon eutectic: A laser heating study

    Manara, D.; Boboridis, K.; Morel, S.; De Bruycker, F.

    2015-11-01

    The UC2-x - carbon eutectic has been studied by laser heating and fast multi-wavelength pyrometry under inert atmosphere. The study has been carried out on three compositions, two of which close to the phase boundary of the UC2-x - C miscibility gap (with C/U atomic ratios 2 and 2.1), and one, more crucial, with a large excess of carbon (C/U = 2.82). The first two compositions were synthesised by arc-melting. This synthesis method could not be applied to the last composition, which was therefore completed directly by laser irradiation. The U - C - O composition of the samples was checked by using a combustion method in an ELTRA® analyser. The eutectic temperature, established to be 2737 K ± 20 K, was used as a radiance reference together with the cubic - tetragonal (α → β) solid state transition, fixed at 2050 K ± 20 K. The normal spectral emissivity of the carbon-richer compounds increases up to 0.7, whereas the value 0.53 was established for pure hypostoichiometric uranium dicarbide at the limit of the eutectic region. This increase is analysed in the light of the demixing of excess carbon, and used for the determination of the liquidus temperature (3220 K ± 50 K for UC2.82). Due to fast solid state diffusion, also fostered by the cubic - tetragonal transition, no obvious signs of a lamellar eutectic structure could be observed after quenching to room temperature. The eutectic surface C/UC2-x composition could be qualitatively, but consistently, followed during the cooling process with the help of the recorded radiance spectra. Whereas the external liquid surface is almost entirely constituted by uranium dicarbide, it gets rapidly enriched in demixed carbon upon freezing. Demixed carbon seems to quickly migrate towards the inner bulk during further cooling. At the α → β transition, uranium dicarbide covers again the almost entire external surface.

  14. Peculiarities of U2T2X hydrides

    U2Ni2Sn belongs to a large group of U2T2X compounds which are very sensitive to hydrogen absorption. U2Ni2SnH1.8 and U2Ni2SnD1.8 exhibit similar magnetic behaviour-they order antiferromagnetically at T=87K, which is much higher than TN=26K in U2Ni2Sn. Deuterium lattice sites were determined by neutron diffraction. Uranium magnetic moments ∼0.8(3)μB lie in the basal plane of the tetragonal structure

  15. The Exponential Diophantine Equation 2x + by = cz

    Yu, Yahui; Li, Xiaoxue

    2014-01-01

    Let b and c be fixed coprime odd positive integers with min{b, c} > 1. In this paper, a classification of all positive integer solutions (x, y, z) of the equation 2x + by = cz is given. Further, by an elementary approach, we prove that if c = b + 2, then the equation has only the positive integer solution (x, y, z) = (1,1, 1), except for (b, x, y, z) = (89,13,1, 2) and (2r − 1, r + 2,2, 2), where r is a positive integer with r ≥ 2. PMID:24959613

  16. The 2X-HI disks of spiral galaxies

    Koribalski, B S

    2016-01-01

    The outskirts of galaxies - especially the very extended HI disks of galaxies - are strongly affected by their local environment. I highlight the giant 2X-HI disks of nearby galaxies (M 83, NGC 3621, and NGC 1512), studied as part of the Local Volume HI Survey (LVHIS), their kinematics and relation to XUV disks, signatures of tidal interactions and accretion events, the MHI - DHI relation as well as the formation of tidal dwarf galaxies. - Using multi-wavelength data, I create 3D visualisations of the gas and stars in galaxies, with the shape of their warped disks obtained through kinematic modelling of their HI velocity fields.

  17. Evolutionary Markovian Strategies in 2 x 2 Spatial Games

    Fort, H; Fort, Hugo; Sicardi, Estrella

    2006-01-01

    Evolutionary spatial 2 x 2 games between heterogeneous agents are analyzed using different variants of cellular automata (CA). Agents play repeatedly against their nearest neighbors 2 x 2 games specified by a rescaled payoff matrix with two parameteres. Each agent is governed by a binary Markovian strategy (BMS) specified by 4 conditional probabilities [p_R, p_S, p_T, p_P] that take values 0 or 1. The initial configuration consists in a random assignment of "strategists" among the 2^4= 16 possible BMS. The system then evolves within strategy space according to the simple standard rule: each agent copies the strategy of the neighbor who got the highest payoff. Besides on the payoff matrix, the dominant strategy -and the degree of cooperation- depend on i) the type of the neighborhood (von Neumann or Moore); ii) the way the cooperation state is actualized (deterministically or stochastichally); and iii) the amount of noise measured by a parameter epsilon. However a robust winner strategy is [1,0,1,1].

  18. 10 Years of Car-2-X Communication - a Success Story?

    Wischhof, Lars; Ebner, André

    2012-05-01

    For more than ten years, car-2-x communication has been a major topic of research in the scientific community and an important development focus for the automotive industry. First, this article takes a retrospective look at the evolution of car-2-x and the two different communication paradigms: decentralized car-2-car communication and centralized cellular solutions. Afterwards, a comparison of their technical advantages and limitations is presented, respectively. The result shows that in order to implement safety-relevant applications, car-2-car communication has strong advantages compared to cellular technologies but requires high market penetration. However, its introduction solely for safety applications is difficult since the required penetration will not be achieved until several years after initial deployment. Therefore, car-2-car communication must provide a benefit to the customer, even in the phase of market introduction. For this purpose, the article outlines an approach called SODAD (Segment-Oriented Data Abstraction and Dissemination). It offers a possibility to introduce decentralized vehicular applications with early customer benefit, in order to enable safety applications based on car-2-car communication on a long term.

  19. Electric field effect on superconductivity in La2-xSrxCuO4

    Dubuis, G.; Bollinger, A. T.; Pavuna, D.; Božović, I.

    2012-06-01

    We demonstrate a method to tune the carrier concentration of a high temperature superconductor over a wide range, using an applied electric field. Thin film devices were made in an electrical double layer transistor configuration utilizing an ionic liquid. In this way, the surface carrier density in La2-xSrxCuO4 films can be varied between 0.01 and 0.14 carriers per Cu atom with a resulting change in critical temperature of 25 K (˜70% of the maximum critical temperature in this compound). This allows one to study a large segment of the cuprate phase diagram without altering the level of disorder. We used this method [A. T. Bollinger et al., Nature 472, 458-460 (2011)] to study the quantum critical point at the superconductor to insulator phase transition on the underdoped side of superconducting dome, and concluded that this transition is driven by quantum phase fluctuations and Cooper pair delocalization.

  20. Characterization of an 2x2 SCB Optical Switch Integrated with VOA

    Hen-Wei Huang

    2012-06-01

    Full Text Available This work presents the modeling, simulation and characterization of an innovative micromachined 2x2 optical switch monolithically integrated with variable optical attenuators. The device uses bi-stable mechanisms for optical switching, and can be easily realized by a standard micromachining process. The split-cross-bar design (SCB is employed as the optical path configuration. A one-dimensional (1-D heat transfer model is developed for estimating temperature elevation. An analytical solution is also proposed for the thermo-elastic bending and buckling problem of thermal V-beam and curved beam (pre-shaped buckled beam actuators. The resulting governing equations with external y-directed force and thermal strain force are solved analytically. Results of the analytical solutions and the finite element (FEM calculations are compared, with prediction accuracy within 10% of the nonlinear FEM solution, which agrees well with the experimental data.

  1. A tiled CCD detector with 2x2 array and tapered fibre optics for electron microscopy

    Faruqi, A R; Cattermole, D M; Stubbings, S

    2002-01-01

    Charge coupled devices (CCD)-based detectors have made a major impact on data collection in electron microscopy over the past few years. There have been a number of successful applications of CCDs in electron crystallography of two-dimensional protein crystal arrays but high-resolution imaging has been hampered by the relatively poor spatial resolution (and fewer independent pixels) compared to film. A partial solution to this problem, presented in this paper, are to design detectors with larger effective pixel sizes and with more pixels. A CCD detector with a much greater number of 'independent' pixels, achieved by tiling a 2x2 array of CCDs, each of which has 1242x1152 pixels is described here. The sensitive area of the detector, using fibre optics with a demagnification of 2.5 : 1, is 140x130 mm sup 2; the pixel size is 56 mu m square and there is a total of approx 2500x2300 pixels.

  2. Manifestation of long-range ordered state in layered VX2 (X = Cl, Br, I) systems

    We report the first-principles based density functional investigation of correlated magnetic behavior for the layered VX2 (X = Cl, Br, I) system both in bulk and monolayer forms. The bulk system stabilizes in the Néel 120° spin structure with the onset of long-range order at a very low temperature. However, a monolayer of the same system results in a two-dimensional long-range ordered spin-gel configuration in the a–b plane. The occurrence of this two-dimensional non-collinear long-range order for such hexagonal systems with honeycomb topology may provide an additional feature for controlling the use of such materials in magnetic memory devices. (paper)

  3. Magnetic phase diagrams of the spinels AB2xGa2-2xO4 (A = Zn, Co; B = Al, Cr) systems

    The magnetic properties of the spinels CoAl2xGa2-2xO4 and ZnCr2xGa2-2xO4 systems in the range 0 ≤ x ≤ 1 have been studied by mean field theory and high-temperature series expansions. By using the first theory, we have evaluated the nearest neighbour and the next-neighbour super-exchange interaction J1(x) and J2(x), respectively, for the first systems in the range 0 ≤ x ≤ 1 and J1(x = 1), J2(x = 1) for the second system. The intra-planar and the inter-planar interactions are deduced. The corresponding classical exchange energy for magnetic structure is obtained for the first system. The second theory have been applied in the spinels CoAl2xGa2-2xO4 and ZnCr2xGa2-2xO4 systems, combined with the Pade approximants method, we have obtained the magnetic phase diagrams (TN versus dilution x) in the range 0 ≤ x ≤ 1. The obtained theoretical results are in agreement with experimental ones obtained by magnetic measurements and Moessbauer spectroscopy. The threshold percolation in the second system is xp ∼ 0.4. The critical exponents associated with the magnetic susceptibility (γ) and the correlation lengths (ν) are deduced in the range 0 ≤ x ≤ 1

  4. SU(2) x SU(2) x U(1) Interpretation on the 750 GeV Diphoton Excess

    Ren, Jing

    2016-01-01

    We propose that the SU(2) x SU(2) x U(1) (aka G221) models could provide us a 750 GeV scalar resonance that may account for the diphoton excess observed at the LHC while satisfying present collider constraints. The neutral component of the $SU(2)_R$ scalar multiplet can be identified as the 750 GeV scalar. In the lepto-phobic and fermio-phobic G221 models the new charged gauge boson W' could be light, and we find that the diphoton decay width could be dominated by the loop contribution from the $W'$. To initiate gluon fusion production, it is necessary to extend the G221 symmetry to the Pati-Salam and SO(10) symmetry. We investigate the possibilities that the light colored scalars or vectorlike fermions survive in the SO(10) theory and provide large gluon fusion rate for the diphoton signature. It is possible to test the G221 interpretation by direct searches of W' using the multi-gauge boson production channel at the Run 2 LHC.

  5. Statistical association in contingency tables of 2x2

    Fernandes, José António; Mugabe, Delson Alexandre; Correia, Paulo Ferreira

    2012-01-01

    Neste artigo relata-se um estudo sobre a avaliação da associação estatística por estudantes universitários, antes e depois de abordarem essa temática no ensino formal. No estudo participaram 57 estudantes moçambicanos, que frequentavam no ano letivo de 2011/2012 o 2º ano de um curso de formação de professores de matemática do ensino secundário. Os estudantes foram inquiridos sobre a associação estatística de duas variáveis dicotómicas representadas numa tabela de contingência de 2x2. Globalme...

  6. Magnetic structure of NiS2 -xSex

    Yano, S.; Louca, Despina; Yang, J.; Chatterjee, U.; Bugaris, D. E.; Chung, D. Y.; Peng, L.; Grayson, M.; Kanatzidis, Mercouri G.

    2016-01-01

    NiS2 -2 xSex is revisited to determine the magnetic structure using neutron diffraction and magnetic representational analysis. Upon cooling, the insulating parent compound, NiS2, becomes antiferromagnetic with two successive magnetic transitions. The first transition (M 1 ) occurs at TN˜39 K with Γ1ψ1 symmetry and a magnetic propagation vector of k =(000 ) . The second transition (M 2 ) occurs at TN˜30 K with k =(0.5 ,0.5 ,0.5 ) and a Γ1ψ2 symmetry with face-centered translations, giving rise to four possible magnetic domains. With doping, the system becomes metallic. The transition to the M 2 state is suppressed prior to x =0.4 while the M 1 state persists. The M 1 magnetic structure gradually vanishes by x ˜0.8 at a lower concentration than previously reported. The details of the magnetic structures are provided.

  7. New features of the Ge(111) surface with co-existing c(2 x 8) and 2 x 2 reconstructions investigated by scanning tunneling microscopy

    The c(2x8) ground state reconstruction of the Ge(111) surface can be easily disrupted by the 2x2 reconstruction, since both of them are rather close to each other in terms of the surface free energy. Both structures are comprehensively studied in the literature. However, new surface features can be found on the borders between c(2x8) and 2x2 domains of various registries and orientations. We report scanning tunneling microscopy observations and suggest atomic models for the linear chains of 2x2 cells or c(2x4) cells, as well as adatom/restatom group vacancies, including corner holes of a similar geometry, like the case of the Si(111)-7x7 surface

  8. Speciation and unusual reactivity in PuO2+x.

    Conradson, Steven D; Begg, Bruce D; Clark, David L; Den Auwer, Christophe; Espinosa-Faller, Francisco J; Gordon, Pamela L; Hess, Nancy J; Hess, Ryan; Keogh, D Webster; Morales, Luis A; Neu, Mary P; Runde, Wolfgang; Tait, C Drew; Veirs, D Kirk; Villella, Phillip M

    2003-06-16

    Pu L(3) XAFS measurements show that the excess oxygen in single phase PuO(2+)(x)() occurs as oxo groups with Pu-O distances of 1.83-1.91 A. This distance and the energy of the edge (via comparison with a large number of related compounds) are more consistent with a Pu(IV/V) than a Pu(IV/VI) mixture. Analogous to Pu(IV) colloids, although the Pu-Pu pair distribution remains single site even when it shows substantial disorder, the Pu-O distribution can display a number of additional shells at specific distances up to 3.4 A even in high fired materials when no oxo groups are present, implying intrinsic H(+)/OH(-)(/H(2)O). The number of oxo atoms increases when samples are equilibrated with humid air at ambient temperature, indicating that the Pu reactivity in this solid system differs notably from that of isolated complexes and demonstrating the importance of nanoscale cooperative phenomena and total free energy in determining its chemical properties. PMID:12793805

  9. Effects of antidepressants on P2X7 receptors.

    Wang, Wei; Xiang, Zheng-Hua; Jiang, Chun-Lei; Liu, Wei-Zhi; Shang, Zhi-Lei

    2016-08-30

    Antidepressants including paroxetine, fluoxetine and desipramine are commonly used for treating depression. P2×7 receptors are member of the P2X family. Recent studies indicate that these receptors may constitute a novel potential target for the treatment of depression. In the present study, we examined the action of these antidepressants on cloned rat P2×7 receptors that were stably expressed in human embryonic kidney (HEK) 293 cells by using the whole-cell patch-clamp technique, and found that paroxetine at a dose of 10µM could significantly reduce the inward currents evoked by the P2×7 receptors agonist BzATP by pre-incubation for 6-12 but not by acute application (10µM) or pre-incubation for 2-6h at a dose of 1µM, 3µM or 10µM paroxetine. Neither fluoxetine nor desipramine had significant effects on currents evoked by BzATP either applied acutely or by pre-incubation at various concentrations. These results suggest that the sensitivity of rat P2×7 receptors to antidepressants is different, which may represent an unknown mechanism by which these drugs exert their therapeutic effects and side effects. PMID:27318632

  10. X1X1X2X2/X1X2Y sex chromosome systems in the Neotropical Gymnotiformes electric fish of the genus Brachyhypopomus

    Adauto Lima Cardoso

    2015-06-01

    Full Text Available Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The X1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gauderio presented this type of system. Herein we describe the karyotypes of Brachyhypopomus pinnicaudatus and B. n. sp. FLAV, which have an X1X1X2X2/X1X2Y sex chromosome system that evolved via fusion between an autosome and the Y chromosome. The morphology of the chromosomes and the meiotic pairing suggest that the sex chromosomes of B. gauderio and B. pinnicaudatus have a common origin, whereas in B . n. sp. FLAV the sex chromosome system evolved independently. However, we cannot discard the possibility of common origin followed by distinct processes of differentiation. The identification of two new karyotypes with an X1X1X2X2/X1X2Y sex chromosome system in Gymnotiformes makes it the most common among the karyotyped species of the group. Comparisons of these karyotypes and the evolutionary history of the taxa indicate independent origins for their sex chromosomes systems. The recurrent emergence of the X1X1X2X2/X1X2Y system may represent sex chromosomes turnover events in Gymnotiformes.

  11. Higher twist contributions to the structure functions F{sub 2}(x, Q{sup 2}) and g{sub 2}(x, Q{sup 2})

    Bluemlein, Johannes; Boettcher, Helmut

    2012-07-15

    We report on recent results on higher twist contributions to the unpolarized structure functions F{sup p,d}{sub 2}(x,Q{sup 2}) at N{sup 3}LO in the large x region and constraints on the twist-3 contribution to polarized structure function g{sub 2}(x,Q{sup 2}).

  12. Chronic administration of the selective P2X3, P2X2/3 receptor antagonist, A-317491, transiently attenuates cancer-induced bone pain in mice

    Hansen, RR; Nasser, A; Falk, S;

    2012-01-01

    The purinergic P2X3 and P2X2/3 receptors are in the peripheral nervous system almost exclusively confined to afferent sensory neurons, where they are found both at peripheral and central synapses. The P2X3 receptor is implicated in both neuropathic and inflammatory pain. However, the role of the ......X3 receptor in chronic cancer-induced bone pain is less known. Here we investigated the effect of systemic acute and chronic administration of the selective P2X3, P2X2/3 receptor antagonist (5-[[[(3-Phenoxyphenyl)methyl][(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]carbonyl]-1...

  13. Subtype-specific regulation of P2X3 and P2X2/3 receptors by phosphoinositides in peripheral nociceptors

    Logothetis Diomedes

    2009-08-01

    Full Text Available Abstract Background P2X3 and P2X2/3 purinergic receptor-channels, expressed in primary sensory neurons that mediate nociception, have been implicated in neuropathic and inflammatory pain responses. The phospholipids phosphatidylinositol 4,5-bisphosphate (PIP2 and phosphatidylinositol 3,4,5-trisphosphate (PIP3 are involved in functional modulation of several types of ion channels. We report here evidence that these phospholipids are able to modulate the function of homomeric P2X3 and heteromeric P2X2/3 purinoceptors expressed in dorsal root ganglion (DRG nociceptors and in heterologous expression systems. Results In dissociated rat DRG neurons, incubation with the PI3K/PI4K inhibitor wortmannin at 35 μM induced a dramatic decrease in the amplitude of ATP- or α,β-meATP-evoked P2X3 currents, while incubation with 100 nM wortmannin (selective PI3K inhibition produced no significant effect. Intracellular application of PIP2 was able to fully reverse the inhibition of P2X3 currents induced by wortmannin. In Xenopus oocytes and in HEK293 cells expressing recombinant P2X3, 35 μM wortmannin incubation induced a significant decrease in the rate of receptor recovery. Native and recombinant P2X2/3 receptor-mediated currents were inhibited by incubation with wortmannin both at 35 μM and 100 nM. The decrease of P2X2/3 current amplitude induced by wortmannin could be partially reversed by application of PIP2 or PIP3, indicating a sensitivity to both phosphoinositides in DRG neurons and Xenopus oocytes. Using a lipid binding assay, we demonstrate that the C-terminus of the P2X2 subunit binds directly to PIP2, PIP3 and other phosphoinositides. In contrast, no direct binding was detected between the C-terminus of P2X3 subunit and phosphoinositides. Conclusion Our findings indicate a functional regulation of homomeric P2X3 and heteromeric P2X2/3 ATP receptors by phosphoinositides in the plasma membrane of DRG nociceptors, based on subtype-specific mechanisms

  14. Post-translational regulation of P2X receptor channels: modulation by phospholipids

    Louis-Philippe eBernier

    2013-11-01

    Full Text Available P2X receptor channels mediate fast excitatory signaling by ATP and play major roles in sensory transduction, neuro-immune communication and inflammatory response. P2X receptors constitute a gene family of calcium-permeable ATP-gated cation channels therefore the regulation of P2X signaling is critical for both membrane potential and intracellular calcium homeostasis. Phosphoinositides (PIPn are anionic signaling phospholipids that act as functional regulators of many types of ion channels. Direct PIPn binding was demonstrated for several ligand- or voltage-gated ion channels, however no generic motif emerged to accurately predict lipid-protein binding sites. This review presents what is currently known about the modulation of the different P2X subtypes by phospholipids and about critical determinants underlying their sensitivity to PIPn levels in the plasma membrane.All functional mammalian P2X subtypes tested, with the notable exception of P2X5, have been shown to be positively modulated by PIPn, i.e. homomeric P2X1, P2X2, P2X3, P2X4, and P2X7, as well as heteromeric P2X1/5 and P2X2/3 receptors. Based on various results reported on the aforementioned subtypes including mutagenesis of the prototypical PIPn-sensitive P2X4 and PIPn-insensitive P2X5 receptor subtypes, an increasing amount of functional, biochemical and structural evidence converges on the modulatory role of a short polybasic domain located in the proximal C-terminus of P2X subunits. This linear motif, semi-conserved in the P2X family, seems necessary and sufficient for encoding direct modulation of ATP-gated channels by PIPn. Furthermore, the physiological impact of the regulation of ionotropic purinergic responses by phospholipids on pain pathways was recently revealed in the context of native crosstalks between phospholipase C-linked metabotropic receptors and P2X receptor channels in DRG sensory neurons and microglia.

  15. Chemistry of ruthenium in N2P2X2 (X=Cl,Br) coordination sphere: synthesis, characterization and reactivities

    Reaction of 2-(phenylazo)pyridine (pap) with (Ru(PPh3)3X2) (X=Cl,Br) in dichloromethane solution affords (Ru(PPh3)2(pap)X2). These diamagnetic complexes exhibit a weak d-d transition and two intense MLCT transitions in the visible region. In dichloromethane solution they display a one-electron reduction of pap near -0.90 V vs SCE and a reversible ruthenium(II)-ruthenium(III) oxidation near 0.70 V vs SCE. The (RuIII(PPh3)2 (pap)Cl2)+ complex cation, generated by coulometric oxidation of (Ru(PPh3)2(pap)Cl2), shows two intense LMCT transitions in the visible region. It oxidizes N,N-dimethylaniline and (RuII(bpy)2Cl2) (bpy=2,2'bipyridine) to produce N, N, N',N'-tetramethylbenzidine and (RuIII(bpy)2Cl2)+ respectively. Reaction of (Ru(PPh3)2(pap)X2) with Ag+ in ethanol produces (Ru(PPh3)2(pap)(EtOH)2)2+ which upon further reaction with L (L=pap, bpy, acetylacetonate ion(acac-) and oxalate ion (ox2-)) gives complexes of type (Ru(PPh3)2(pap)(L))n+ (n=0,1,2). All these diamagnetic complexes show a weak d-d transition and several intense MLCT transitions in the visible region. The ruthenium(II)-ruthenium(III) oxidation potential decreases in the order (of L): pap>bpy>acac->ox2-. Reductions of the coordinated pap and bpy are also observed. (author). 29 refs., 3 figs., 1 tab

  16. Design and Verification of MIMO 2x2 Reference Antennas

    Szini, Istvan Janos; Pedersen, Gert Frølund; Estrada, J.; Scannavini, A.; Foged, L. J.

    The development and initial discussion of a reference MIMO 2×2 antenna concept has been presented in [1]. The reference antenna concept has been created to eliminate the uncertainties linked to the unknown antenna performance of the few LTE MIMO 2×2 reference devices or golden standards currently...... available for evaluating radiated data throughput measurement methodologies and test facilities. The proposed concept is based on simple antennas with a well-known Figure of Merit (FoM) and controllable performance. In this paper we present the recent developments on the antenna concept and report on the...... first measured performance at uniform incoming power distribution, figures and correlations between different measurement labs....

  17. Atmospheric chemistry of perfluorinated aldehyde hydrates (n-C(x)F(2x+1)CH(OH)2, x = 1, 3, 4)

    Andersen, Mads Peter Sulbæk; Toft, A.; Nielsen, O.J.;

    2006-01-01

    Smog chamber/Fourier transform infrared (FTIR) techniques were used to measure k(Cl+C(x)F(2x+1)CH(OH)(2)) (x = 1, 3, 4) = (5.84 +/- 0.92) x 10(-13) and k(OH+C(x)F(2x+1)CH(OH)(2)) = (1.22 +/- 0.26) x 10(-13) cm(3) molecule(-1) s(-1) in 700 Torr of N(2) or air at 296 +/- 2 K. The Cl initiated...... oxidation of CF(3)CH(OH)(2) in 700 Torr of air gave CF(3)COOH in a molar yield of 101 +/- 6%. IR spectra of C(x)F(2x+1)CH(OH)(2) (x = 1, 3, 4) were recorded and are presented. An upper limit of k(CF(3)CHO+H(2)O) x 10(-23) cm(3) molecule(-1) s(-1) was established for the gas-phase hydration of CF(3)CHO....... Bubbling CF(3)CHO/air mixtures through liquid water led to >80% conversion of CF(3)CHO into the hydrate within the approximately 2 s taken for passage through the bubbler. These results suggest that OH radical initiated oxidation of C(x)F(2x+1)CH(OH)(2) hydrates could be a significant source...

  18. Tsdc and Neutron-Scattering Measurements on Ba1-Xlaxf2+X and Ba1-Xuxf2+2x Solid-Solutions

    Ouwerkerk, M; Veldkamp, F. F.; Andersen, Niels Hessel;

    1985-01-01

    A study was made of the dynamical behaviour of bound interstitial fluoride ions in disordered Ba1−xLaxF2+x and Ba1−xUxF2+2x solid solutions with Thermally Stimulated Depolarisation Current measurements and neutron scattering measurements, and a combination of both techniques. From 10 K to 400 K t...... invariant. In Ba1−xLaxF2+x neutral associates, L-shaped- and (222)- clusters occur. The present study reveals (212)-clusters to be present in Ba1−xUxF2+2x. The relations between ion dynamics and defect structures are discussed.......A study was made of the dynamical behaviour of bound interstitial fluoride ions in disordered Ba1−xLaxF2+x and Ba1−xUxF2+2x solid solutions with Thermally Stimulated Depolarisation Current measurements and neutron scattering measurements, and a combination of both techniques. From 10 K to 400 K...

  19. A new role for P2X4 receptors as modulators of lung surfactant secretion

    Miklavc, Pika; Thompson, Kristin E.; Frick, Manfred

    2013-01-01

    In recent years, P2X receptors have attracted increasing attention as regulators of exocytosis and cellular secretion. In various cell types, P2X receptors have been found to stimulate vesicle exocytosis directly via Ca2+ influx and elevation of the intracellular Ca2+ concentration. Recently, a new role for P2X4 receptors as regulators of secretion emerged. Exocytosis of lamellar bodies (LBs), large storage organelles for lung surfactant, results in a local, fusion-activated Ca2+ entry (FACE)...

  20. Critical evaluation of P2X7 receptor antagonists in selected seizure models

    Fischer, Wolfgang; Franke, Heike; Krügel, Ute; Müller, Heiko; Dinkel, Klaus; Lord, Brian; Letavic, Michael A; Henshall, David C.; Engel, Tobias

    2016-01-01

    The ATP-gated P2X7 receptor (P2X7R) is a non-selective cation channel which senses high extracellular ATP concentrations and has been suggested as a target for the treatment of neuroinflammation and neurodegenerative diseases. The use of P2X7R antagonists may therefore be a viable approach for treating CNS pathologies, including epileptic disorders. Recent studies showed anticonvulsant potential of P2X7R antagonists in certain animal models. To extend this work, we tested three CNS-permeable ...

  1. Loss of P2X7 nucleotide receptor function leads to abnormal fat distribution in mice

    Beaucage, Kim L.; Xiao, Andrew; Pollmann, Steven I.; Grol, Matthew W.; Beach, Ryan J.; Holdsworth, David W.; Sims, Stephen M.; Darling, Mark R.; Dixon, S. Jeffrey

    2013-01-01

    The P2X7 receptor is an ATP-gated cation channel expressed by a number of cell types. We have shown previously that disruption of P2X7 receptor function results in downregulation of osteogenic markers and upregulation of adipogenic markers in calvarial cell cultures. In the present study, we assessed whether loss of P2X7 receptor function results in changes to adipocyte distribution and lipid accumulation in vivo. Male P2X7 loss-of-function (KO) mice exhibited significantly greater body weigh...

  2. Lipopolysaccharide Inhibits the Channel Activity of the P2X7 Receptor

    Elias Leiva-Salcedo

    2011-01-01

    Full Text Available The purinergic P2X7 receptor (P2X7R plays an important role during the immune response, participating in several events such as cytokine release, apoptosis, and necrosis. The bacterial endotoxin lipopolysaccharide (LPS is one of the strongest stimuli of the immune response, and it has been shown that P2X7R activation can modulate LPS-induced responses. Moreover, a C-terminal binding site for LPS has been proposed. In order to evaluate if LPS can directly modulate the activity of the P2X7R, we tested several signaling pathways associated with P2X7R activation in HEK293 cells that do not express the TLR-4 receptor. We found that LPS alone was unable to induce any P2X7R-related activity, suggesting that the P2X7R is not directly activated by the endotoxin. On the other hand, preapplication of LPS inhibited ATP-induced currents, intracellular calcium increase, and ethidium bromide uptake and had no effect on ERK activation in HEK293 cells. In splenocytes-derived T-regulatory cells, in which ATP-induced apoptosis is driven by the P2X7R, LPS inhibited ATP-induced apoptosis. Altogether, these results demonstrate that LPS modulates the activity of the P2X7R and suggest that this effect could be of physiological relevance.

  3. Lipopolysaccharide Inhibits the Channel Activity of the P2X7 Receptor

    Leiva-Salcedo, Elias; Coddou, Claudio; Rodríguez, Felipe E.; Penna, Antonello; Lopez, Ximena; Neira, Tanya; Fernández, Ricardo; Imarai, Mónica; Rios, Miguel; Escobar, Jorge; Montoya, Margarita; Huidobro-Toro, J. Pablo; Escobar, Alejandro; Acuña-Castillo, Claudio

    2011-01-01

    The purinergic P2X7 receptor (P2X7R) plays an important role during the immune response, participating in several events such as cytokine release, apoptosis, and necrosis. The bacterial endotoxin lipopolysaccharide (LPS) is one of the strongest stimuli of the immune response, and it has been shown that P2X7R activation can modulate LPS-induced responses. Moreover, a C-terminal binding site for LPS has been proposed. In order to evaluate if LPS can directly modulate the activity of the P2X7R, we tested several signaling pathways associated with P2X7R activation in HEK293 cells that do not express the TLR-4 receptor. We found that LPS alone was unable to induce any P2X7R-related activity, suggesting that the P2X7R is not directly activated by the endotoxin. On the other hand, preapplication of LPS inhibited ATP-induced currents, intracellular calcium increase, and ethidium bromide uptake and had no effect on ERK activation in HEK293 cells. In splenocytes-derived T-regulatory cells, in which ATP-induced apoptosis is driven by the P2X7R, LPS inhibited ATP-induced apoptosis. Altogether, these results demonstrate that LPS modulates the activity of the P2X7R and suggest that this effect could be of physiological relevance. PMID:21941410

  4. Valence of Ce in T- and T'-La2-xCexCuO4

    We have recently successfully doped the La site in T-La2CuO4 with Ce by a molecular beam epitaxy. The resultant T-La2-xCexCuO4 was insulating up to x = 0.06. This is in sharp contrast to T'-La2-xCexCuO4, which is superconducting with a Tc of about 30 K. In order to clarify the difference between T-La2-xCexCuO4 and T'-La2-xCexCuO4, we estimate the valences of Ce in T-La2-xCexCuO4 and T'-La2-xCexCuO4 by using Vegard's law. The estimated valence of Ce is ≥+3.84 in T-La2-xCexCuO4 and ∼+3.78 in T'-La2-xCexCuO4. The result indicates that electron doping is actually achieved in T-La2-xCexCuO4, but that this compound remains an insulator. This contradicts the general belief that the doping with either electrons or holes conducts or superconducts parent compounds

  5. Comparison of the Giemsa C-banded karyotypes of the three subspecies of Psathyrostachys fragilis, subspp. villosus (2x), secaliformis (2x, 4x), and fragilis (2x) (Poaceae), with notes on chromosome pairing

    Linde-Laursen, I.; Baden, C.

    1994-01-01

    The karyotypes of diploid P. fragilis subsp. villosus (2n = 2x = 14) and tetraploid subsp. secaliformis (2n = 4x = 28) were studied by Giemsa C- and N-banding, and AgNO3 staining and compared with the karyotype of subsp. fragilis (2x). The complements of subsp. villosus and subsp. fragilis were...... metacentrics. Chromocentres were very small and the amount of constitutive heterochromatin was low. N-banding stained chromosomes uniformly. The basic karyotypes of the P. fragilis taxa were similar to those of P. juncea, P. lanuginosa, and P. stoloniformis supporting a close relationship and the presence of a...

  6. Immunocytochemical analysis of P2X2 in rat circumvallate taste buds

    Yang Ruibiao

    2012-05-01

    Full Text Available Abstract Background Our laboratory has shown that classical synapses and synaptic proteins are associated with Type III cells. Yet it is generally accepted that Type II cells transduce bitter, sweet and umami stimuli. No classical synapses, however, have been found associated with Type II cells. Recent studies indicate that the ionotropic purinergic receptors P2X2/P2X3 are present in rodent taste buds. Taste nerve processes express the ionotropic purinergic receptors (P2X2/P2X3. P2X2/P2X3Dbl−/− mice are not responsive to sweet, umami and bitter stimuli, and it has been proposed that ATP acts as a neurotransmitter in taste buds. The goal of the present study is to learn more about the nature of purinergic contacts in rat circumvallate taste buds by examining immunoreactivity to antisera directed against the purinergic receptor P2X2. Results P2X2-like immunoreactivity is present in intragemmal nerve processes in rat circumvallate taste buds. Intense immunoreactivity can also be seen in the subgemmal nerve plexuses located below the basal lamina. The P2X2 immunoreactive nerve processes also display syntaxin-1-LIR. The immunoreactive nerves are in close contact with the IP3R3-LIR Type II cells and syntaxin-1-LIR and/or 5-HT-LIR Type III cells. Taste cell synapses are observed only from Type III taste cells onto P2X2-LIR nerve processes. Unusually large, “atypical” mitochondria in the Type II taste cells are found only at close appositions with P2X2-LIR nerve processes. P2X2 immunogold particles are concentrated at the membranes of nerve processes at close appositions with taste cells. Conclusions Based on our immunofluorescence and immunoelectron microscopical studies we believe that both perigemmal and most all intragemmal nerve processes display P2X2-LIR. Moreover, colloidal gold immunoelectron microscopy indicates that P2X2-LIR in nerve processes is concentrated at sites of close apposition with Type II cells. This supports the hypothesis

  7. Stable electrical performance observed in large-scale monolayer WSe2(1-x)S2x with tunable band gap

    Huang, Jian; Wang, Wenhui; Fu, Qi; Yang, Lei; Zhang, Kun; Zhang, Jingyu; Xiang, Bin

    2016-04-01

    Two-dimensional (2D) semiconductor materials have attracted broad interest due to their unique structures and physical properties. The stability of the 2D-material-based devices plays a key role in their practical applications. Here, we report the promising stable electrical performance in the large-scale monolayer WSe2(1-x)S2x with a tunable band gap. Photoluminescence (PL) spectroscopy was utilized to verify the tunable band gap in the as-grown monolayer with a tuning capability of 120 meV. Gated field effect transistor (FET) performance confirmed the p-type transport behavior in monolayer WSe2(1-x)S2x with a high on/off ratio (>104). Top-gated FET configuration improves the carrier mobility with two orders larger than that in the back-gated FET device. After exposure to air for three months, the device performance manifested excellent stability with no source-drain current drop observed. P-type WSe2(1-x)S2x with a tunable band gap is the ideal complement to n-type tunable monolayers in the application of pn junction-related flexible nanodevices.

  8. P2X7 on mouse T cells: one channel, many functions

    Björn eRissiek

    2015-05-01

    Full Text Available The P2X7 receptor is an adenosine triphosphate (ATP-gated cation channel that is expressed by several cells of the immune system. P2X7 is best known for its proinflammatory role in promoting inflammasome formation and release of mature IL-1β by innate immune cells. Mounting evidence indicates that P2X7 is also an important regulatory receptor of murine and human T cell functions. Murine T cells express a sensitive splice variant of P2X7 that can be activated either by non-covalent binding of ATP or, in the presence of nicotinamide adenine dinucleotide (NAD+, by its covalent ADP-ribosylation catalyzed by the ecto-ADP-ribosyltransferase ARTC2.2. Prolonged activation of P2X7 by either one of these pathways triggers the induction of T cell death. Conversely, lower concentrations of ATP can activate P2X7 to enhance T cell proliferation and production of IL-2. In this review we will highlight the molecular and cellular consequences of P2X7 activation on mouse T cells and its versatile role in T cell homeostasis and activation. Further, we will discuss important differences in the function of P2X7 on human and murine T cells.

  9. Comparative study of the P2X gene family in animals and plants.

    Hou, Zhuoran; Cao, Jun

    2016-06-01

    P2X receptors are ligand-gated ion channels that can bind with the adenosine triphosphate (ATP) and have diverse functional roles in neuropathic pain, inflammation, special sense, and so on. In this study, 180 putative P2X genes, including 176 members in 32 animal species and 4 members in 3 species of lower plants, were identified. These genes were divided into 13 groups, including 7 groups in vertebrates and 6 groups in invertebrates and lower plants, through phylogenetic analysis. Their gene organization and motif composition are conserved in most predicted P2X members, while group-specific features were also found. Moreover, synteny relationships of the putative P2X genes in vertebrates are conserved while simultaneously experiencing a series of gene insertion, inversion, and transposition. Recombination signals were detected in almost all of the vertebrates and invertebrates, suggesting that intragenic recombination may play a significant role in the evolution of P2X genes. Selection analysis also identified some positively selected sites that acted on the evolution of most of the predicted P2X proteins. The phenomenon of alternative splicing occurred commonly in the putative P2X genes of vertebrates. This article explored in depth the evolutional relationship among different subtypes of P2X genes in animal and plants and might serve as a solid foundation for deciphering their functions in further studies. PMID:26874702

  10. Mobility Patterns Informing V2X Research Projects: Eco-Routing and Electrified Roadway Project Examples

    Gonder, Jeff; Brooker, Aaron; Burton, Evan; Wang, Lijuan; Wood, Eric

    2016-05-19

    Presentation given at an 'Expert Workshop on V2X Enabled Electric Vehicles' hosted at NREL on behalf of the International Energy Agency (IEA) Hybrid and Electric Vehicle Implementing Agreement for Task 28: Home Grids and V2X Technologies.

  11. P2X7 receptor antagonist activity of the anti-allergic agent oxatomide.

    Yoshida, Kazuki; Ito, Masaaki; Matsuoka, Isao

    2015-11-15

    Activation of the P2X7 receptor by extracellular ATP is associated with various immune responses including allergic inflammation. Anti-allergic agents, such as H1-antihistamines, are known to inhibit the effects of different chemical mediators such as acetylcholine and platelet-activating factor. Therefore, we hypothesized that some anti-allergic agents might affect P2X7 receptor function. Using N18TG2 and J774 cells, which express functional P2X7 receptors, the effects of several anti-allergic agents on P2X7 receptor function were investigated by monitoring the ATP-induced increase in intracellular Ca(2+) concentrations ([Ca(2+)]i). Among the various agents tested, oxatomide significantly inhibited P2X7 receptor-mediated [Ca(2+)]i elevation in a concentration-dependent manner without affecting the P2Y2 receptor-mediated response in both N18TG2 and J774 cells. Consistently, oxatomide inhibited P2X7 receptor-mediated membrane current and downstream responses such as mitogen-activated protein kinase activation, inflammation-related gene induction, and cell death. In addition, oxatomide inhibited P2X7 receptor-mediated degranulation in mouse bone marrow-derived mast cells. Whole cell patch clamp analyses in HEK293 cells expressing human, mouse, and rat P2X7 receptors revealed that the inhibitory effect of oxatomide on ATP-induced current was most prominent for the human P2X7 receptor and almost non-existent for the rat P2X7 receptor. The potent inhibitory effects of oxatomide on human P2X7 receptor-mediated function were confirmed in RPMI8226 human B cell-like myeloma cells, which endogenously express the P2X7 receptor. Our results demonstrated that the antihistamine oxatomide also acts as a P2X7 receptor antagonist. Future studies should thus evaluate whether P2X7 receptor antagonism contributes to the anti-allergic effects of oxatomide. PMID:26463039

  12. Functional polymorphisms in the P2X7 receptor gene are associated with osteoporosis

    Husted, L B; Harsløf, T; Stenkjær, L; Carstens, M; Jørgensen, N R; Langdahl, Bente Lomholt

    2013-01-01

    UNLABELLED: The P2X(7) receptor is an ATP-gated cation channel. We investigated the effect of both loss-of-function and gain-of-function polymorphisms in the P2X(7) receptor gene on BMD and risk of vertebral fractures and found that five polymorphisms and haplotypes containing three of these...... investigate the effect of these polymorphisms on BMD and risk of vertebral fractures in a case-control study including 798 individuals. METHODS: Genotyping was carried out using TaqMan assays. BMD was measured using dual energy X-ray absorptiometry, and vertebral fractures were assessed by lateral spinal X...... polymorphisms were associated with BMD and fracture risk. INTRODUCTION: The P2X(7) receptor is an ATP-gated cation channel. P2X(7) receptor knockout mice have reduced total bone mineral content, and because several functional polymorphisms have been identified in the human P2X(7) receptor gene, we wanted to...

  13. Oxygen non-stoichiometries in (Th0.7Ce0.3)O2-x

    Oxygen non-stoichiometry in (Th0.7Ce0.3)O2-x oxide solid solutions was investigated from the viewpoint of Ce reduction. The oxygen non-stoichiometry was experimentally determined by means of thermogravimetric analysis as a function of oxygen potential at 1173, 1273 and 1373 K. Features of the isotherms of oxygen non-stoichiometry in (Th0.7Ce0.3)O2-x similar to those in oxygen non-stoichiometric actinide and lanthanide dioxides were observed. The oxygen non-stoichiometry in (Th0.7Ce0.3)O2-x was compared with those of CeO2-x and (U0.7Ce0.3)O2-x. It was concluded that the Ce reduction has some relation to defect forms and their transformations in the solid solutions.

  14. Nb doping effect on TiO2-x films for bolometer applications

    Shin, Young Bong; Kumar Reddy, Y. Ashok; Kang, In-Ku; Lee, Hee Chul

    2016-04-01

    Nb-doped TiO2-x thin films were deposited using a 1 at% niobium doped titanium target by RF reactive magnetron sputtering at various oxygen partial pressures (pO2). The films appeared amorphous in the pO2 range of 4.4-4.7% with resistivity ranging from 0.39 Ω cm to 2.48 Ω cm. Compared to pure TiO2-x films, the resistivity of the Nb-doped TiO2-x films did not change sensitively with the oxygen partial pressure, indicating that the resistivity of the films can be accurately controlled. 1/f noise parameter of Nb-doped TiO2-x films were found to decrease largely while the measured temperature coefficient of resistance (TCR) of the films was still high. The obtained results indicate that Nb-doped TiO2-x films have great potential as an alternative bolometric material.

  15. Self-assembly of [UO2X4]2- (X=Cl, Br) dianions with γ substituted pyridinium cations: Structural systematics and fluorescence properties

    Surbella, Robert G.; Andrews, Michael B.; Cahill, Christopher L.

    2016-04-01

    Room temperature self-assembly of [UO2X4]2- (X=Cl, Br) with γ substituted pyridinium cations has resulted in the formation of twelve compounds that were studied via single crystal X-ray diffraction and fluorescence spectroscopy. Systematic variation of electron donating groups on the pyridinium species is shown to influence the presence and/or strength of various supramolecular synthons, including hydrogen bonding and pi interactions. Combinations of such non-covalent interactions (NCIs) have given rise to a range of supramolecular assemblies, and are shown to influence uranyl emission by way of second sphere coordination to equatorial ligands.

  16. Growth and characterization of Bi2-xSbxTe3 (x=0-0.2) single crystals

    Patel, M. M.; Soni, P. H.; Desai, C. F.

    2015-12-01

    Bismuth telluride is a well known V-VI group intermetallic compound semiconductor. Its narrow band gap, 0.16 eV, makes it suitable for application in thermoelectric devices. Its crystal growth and thin film studies have been well reported. Antimony doping in Bi2Te3 has been studied for its effect on its basic semiconducting, optoelectronic and thermoelectric properties. The authors report here on the crystal growth (zone-melting) and band gap of Bi2-xSbxTe3. The compositions studied are Bi2-xSbxTe3 (x=0-0.2). The freezing interface temperature gradient of 50 °C/cm has been found to yield the best quality crystals obtainable at the growth rate of 0.35 cm/h. The growth features on the free surfaces of crystals have been observed to be of typical character assigned to the crystal symmetry. The crystals have been characterized using XRD technique. FTIR spectra were obtained and used to evaluate the band gap which is found to be of direct type. The paper reports the detailed results.

  17. Saffron reduces ATP-induced retinal cytotoxicity by targeting P2X7 receptors.

    Corso, Lucia; Cavallero, Anna; Baroni, Debora; Garbati, Patrizia; Prestipino, Gianfranco; Bisti, Silvia; Nobile, Mario; Picco, Cristiana

    2016-03-01

    P2X7-type purinergic receptors are distributed throughout the nervous system where they contribute to physiological and pathological functions. In the retina, this receptor is found in both inner and outer cells including microglia modulating signaling and health of retinal cells. It is involved in retinal neurodegenerative disorders such as retinitis pigmentosa and age-related macular degeneration (AMD). Experimental studies demonstrated that saffron protects photoreceptors from light-induced damage preserving both retinal morphology and visual function and improves retinal flicker sensitivity in AMD patients. To evaluate a possible interaction between saffron and P2X7 receptors (P2X7Rs), different cellular models and experimental approaches were used. We found that saffron positively influences the viability of mouse primary retinal cells and photoreceptor-derived 661W cells exposed to ATP, and reduced the ATP-induced intracellular calcium increase in 661W cells. Similar results were obtained on HEK cells transfected with recombinant rat P2X7R but not on cells transfected with rat P2X2R. Finally, patch-clamp experiments showed that saffron inhibited cationic currents in HEK-P2X7R cells. These results point out a novel mechanism through which saffron may exert its protective role in neurodegeneration and support the idea that P2X7-mediated calcium signaling may be a crucial therapeutic target in the treatment of neurodegenerative diseases. PMID:26739703

  18. Building layered NixCo2x(OH)6x nanosheets decorated three-dimensional Ni frameworks for electrochemical applications

    Liu, Zhao-Qing; Chen, Gao-Feng; Zhou, Pei-Lin; Li, Nan; Su, Yu-Zhi

    2016-06-01

    To achieve high electrochemical performance in energy storage and conversion devices, transition metal hydroxides electrode materials need enhancing their intrinsic poor conductivity and fully utilizing their unexploited active sites. Accordingly, a simple and effective strategy is developed to synthesize layered NixCo2x(OH)6x nanosheets using dual three-dimensional Ni as structural and conductive support system. Owing to highly electrical conductivity, rich of interconnected ion/electron transport pathways, and robust structure stability, NixCo2x(OH)6x@Ni electrode exhibits remarkably high specific capacitance, excellent rate capability, and superior cycle stability. Moreover, the asymmetric supercapacitor assembled by NixCo2x(OH)6x@Ni and activated carbon/carbon nanotube achieves a large working voltage window of 1.5 V, a high energy density (≈44.2 Wh kg-1 at a power density of 750 W kg-1) and outstanding long-term cycle ability (remaining 100% of the initial Csp after 5000 cycles). Furthermore, the NixCo2x(OH)6x@Ni as an oxygen evolution reaction electrocatalyst shows small onset overpotential (263 mV), low Tafel slope (78 mV dec-1), large anodic current density of 30 mA cm-2 at a low overpotential of 336 mV and prominent electrochemical durability.

  19. New P2X3 receptor antagonists. Part 1: Discovery and optimization of tricyclic compounds.

    Szántó, Gábor; Makó, Attila; Bata, Imre; Farkas, Bence; Kolok, Sándor; Vastag, Mónika; Cselenyák, Attila

    2016-08-15

    Purinergic P2X3 receptors are trimeric ligand-gated ion channels whose antagonism is an appealing yet challenging and not fully validated drug development idea. With the aim of identification of an orally active, potent human P2X3 receptor antagonist compound that can penetrate the central nervous system, the compound collection of Gedeon Richter was screened. A hit series of tricyclic compounds was subjected to a rapid, two-step optimization process focusing on increasing potency, improving metabolic stability and CNS penetrability. Attempts resulted in compound 65, a potential tool compound for testing P2X3 inhibitory effects in vivo. PMID:27423478

  20. Color-Space-Based Visual-MIMO for V2X Communication

    Jai-Eun Kim; Ji-Won Kim; Youngil Park; Ki-Doo Kim

    2016-01-01

    In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and w...

  1. New insights of P2X7 receptor signaling pathway in alveolar functions

    Mishra, Amarjit

    2013-01-01

    Purinergic P2X7 receptor (P2X7R), an ATP-gated cation channel, is unique among all other family members because of its ability to respond to various stimuli and to modulate pro-inflammatory signaling. The activation of P2X7R in immune cells is absolutely required for mature interleukin -1beta (IL-1beta) and IL-18 production and release. Lung alveoli are lined by the structural alveolar epithelial type I (AEC I) and alveolar epithelial type II cells (AEC II). AEC I plays important roles in alv...

  2. A new role for P2X4 receptors as modulators of lung surfactant secretion

    Manfred Frick

    2013-01-01

    In recent years P2X receptors have attracted increasing attention as regulators of exocytosis and cellular secretion. In various cell types P2X receptors have been found to stimulate vesicle exocytosis directly via Ca2+ influx and elevation of the intracellular Ca2+ concentration. Recently, a new role for P2X4 receptors as regulators of secretion emerged. Exocytosis of lamellar bodies (LBs), large storage organelles for lung surfactant, results in a local, fusion-activated Ca2+ entry (FACE) i...

  3. Lattice instabilities and superconductivity in La2-x(Ba,Sr)xCuO4

    In this paper, the authors present the result of two experiments on the anomalous physical properties of La2-xBaxCuO4 with x = 0.125. The suppression of a low-temperature tetragonal phase by introduction of Sr in the La2-xBaxCuO4 correlates well with the recovery of 30-K superconductivity. Hydrogenation of La2-xBaxCuO4 revealed that the carrier density, rather than the amount of divalent ions, is an essential parameter which governs the anomaly

  4. Kinetics of resistive response of SnO2-x thin films in gas environment

    Data on the gas sensitivity of SnO2-x thin films in oxygen and hydrogen environment are obtained. The films were fabricated by oxidizing metallic tin layers in air at various temperatures. The nonmonotonic kinetics of the resistive response of SnO2-x samples under gas-adsorption conditions is explained by the involvement of 'biographic' electron states (determined by the manufacturing methods and machining of samples), whose density depends on the temperature conditions of manufacturing the SnO2-x film in the adsorbate-semiconductor interaction

  5. Oxygen potential of (Pu, U)O2. 1. Oxygen potential measurement of UO2+X and (Pu0.3U0.7)O2-X

    The ratio of oxygen to metal is one of important fuel specifications on UO2 and MOX fuels, because it effects on irradiation behavior. Oxygen potential of oxide fuels have been measured by various methods on the purpose of optimization of irradiation behavior and fabrication condition. In this report the oxygen potential of UO2+X and (Pu0.3U0.7)O2-X was measured by thermal gravimetry and differential thermal analysis (TG-DTA). Measurements of oxygen potential were carried out at 800degC, 1000degC and 1200degC in Ar/H2/H2O mixture gas flow. Ratio of O/M was obtained from the weight change of the sample according to the partial oxygen pressure that was controlled by H2/H2O ratio in atmosphere. The partial oxygen pressure in atmosphere was measured by stabilized zirconia oxygen sensor. The experimental results agree approximately to the other works. Thermodynamic data, ΔGo-bar2, ΔHo-bar2, ΔSo-bar2, were evaluated from the experimental data. The oxygen potential of UO2+X, (Pu, U)O2±X and PuO2-X was modeled by lattice defect theory using the data of the literature and this work. The resulting equation well reproduce the large amount of oxygen potential-temperature-composition data for the Pu-U oxide system. (author)

  6. Structural Insights into Divalent Cation Modulations of ATP-Gated P2X Receptor Channels.

    Kasuya, Go; Fujiwara, Yuichiro; Takemoto, Mizuki; Dohmae, Naoshi; Nakada-Nakura, Yoshiko; Ishitani, Ryuichiro; Hattori, Motoyuki; Nureki, Osamu

    2016-02-01

    P2X receptors are trimeric ATP-gated cation channels involved in physiological processes ranging widely from neurotransmission to pain and taste signal transduction. The modulation of the channel gating, including that by divalent cations, contributes to these diverse physiological functions of P2X receptors. Here, we report the crystal structure of an invertebrate P2X receptor from the Gulf Coast tick Amblyomma maculatum in the presence of ATP and Zn(2+) ion, together with electrophysiological and computational analyses. The structure revealed two distinct metal binding sites, M1 and M2, in the extracellular region. The M1 site, located at the trimer interface, is responsible for Zn(2+) potentiation by facilitating the structural change of the extracellular domain for pore opening. In contrast, the M2 site, coupled with the ATP binding site, might contribute to regulation by Mg(2+). Overall, our work provides structural insights into the divalent cation modulations of P2X receptors. PMID:26804916

  7. Using Decision Trees to Detect and Isolate Leaks in the J-2X

    National Aeronautics and Space Administration — Full title: Using Decision Trees to Detect and Isolate Simulated Leaks in the J-2X Rocket Engine Mark Schwabacher, NASA Ames Research Center Robert Aguilar, Pratt...

  8. A simple Method To Calculate Transverse Spin Structure Function g2(x,Q^2)

    Tahamtan, Azam; Arash, Firooz

    2012-01-01

    We calculated the spin dependent structure functions g2ww(x,Q^2)in the valon model representation of hadrons. A simple approach is given for the determination of the twist-3 part of g2(x,Q^2) structure function. Thus, enabling to obtain the full transverse struc- ture function, g2(x,Q^2) of proton, neutron and the deuteron.

  9. UV Written 2x8 Optical Power Splitter for FTTH Applications

    Olivero, Massimo; Svalgaard, Mikael

    2006-01-01

    Silica based integrated optical 2x8 power splitters are reported for the first time using UV-writing waveguide fabrication technology. High performance, compactness and low production costs make these components well suited for deployment in FTTH networks.......Silica based integrated optical 2x8 power splitters are reported for the first time using UV-writing waveguide fabrication technology. High performance, compactness and low production costs make these components well suited for deployment in FTTH networks....

  10. DESENSITIZATION PROPERTIES OF P2X3 RECEPTORS SHAPING PAIN SIGNALLING

    Rashid Giniatullin

    2013-12-01

    Full Text Available ATP-gated P2X3 receptors are mostly expressed by nociceptive sensory neurons and participate in transduction of pain signals. P2X3 receptors show a combination of fast desensitization onset and slow recovery. Moreover, even low nanomolar agonist concentrations unable to evoke a response, can induce desensitization via a phenomenon called ‘high affinity desensitization’. We have also observed that recovery from desensitization is agonist-specific and can range from seconds to minutes. The recovery process displays unusually high temperature dependence. Likewise, recycling of P2X3 receptors in peri-membrane regions shows unexpectedly large temperature sensitivity. By applying kinetic modeling, we have previously shown that desensitization characteristics of P2X3 receptor are best explained with a cyclic model of receptor operation involving three agonist molecules binding a single receptor and that desensitization is primarily developing from the open receptor state. Mutagenesis experiments suggested that desensitization depends on a certain conformation of the ATP binding pocket and on the structure of the transmembrane domains forming the ion pore. Further molecular determinants of desensitization have been identified by mutating the intracellular N- and C-termini of P2X3 receptor. Unlike other P2X receptors, the P2X3 subtype is facilitated by extracellular calcium that acts via specific sites in the ectodomain neighboring the ATP binding pocket. Thus, substitution of serine275 in this region (called ‘left flipper’ converts the natural facilitation induced by extracellular calcium to receptor inhibition. Given such their strategic location in nociceptive neurons and unique desensitization properties, P2X3 receptors represent an attractive target for development of new analgesic drugs via promotion of desensitization aimed at suppressing chronic pain.

  11. Critical Evaluation of P2X7 Receptor Antagonists in Selected Seizure Models

    Fischer, Wolfgang; Franke, Heike; Krügel, Ute; Müller, Heiko; Dinkel, Klaus; Lord, Brian; Letavic, Michael A.; Henshall, David C.; Engel, Tobias

    2016-01-01

    The ATP-gated P2X7 receptor (P2X7R) is a non-selective cation channel which senses high extracellular ATP concentrations and has been suggested as a target for the treatment of neuroinflammation and neurodegenerative diseases. The use of P2X7R antagonists may therefore be a viable approach for treating CNS pathologies, including epileptic disorders. Recent studies showed anticonvulsant potential of P2X7R antagonists in certain animal models. To extend this work, we tested three CNS-permeable P2X7R blocker (Brilliant Blue G, AFC-5128, JNJ-47965567) and a natural compound derivative (tanshinone IIA sulfonate) in four well-characterized animal seizure models. In the maximal electroshock seizure threshold test and the pentylenetetrazol (PTZ) seizure threshold test in mice, none of the four compounds demonstrated anticonvulsant effects when given alone. Notably, in combination with carbamazepine, both AFC-5128 and JNJ-47965567 increased the threshold in the maximal electroshock seizure test. In the PTZ-kindling model in rats, useful for testing antiepileptogenic activities, Brilliant Blue G and tanshinone exhibited a moderate retarding effect, whereas the potent P2X7R blocker AFC-5128 and JNJ-47965567 showed a significant and long-lasting delay in kindling development. In fully kindled rats, the investigated compounds revealed modest effects to reduce the mean seizure stage. Furthermore, AFC-5128- and JNJ-47965567-treated animals displayed strongly reduced Iba 1 and GFAP immunoreactivity in the hippocampal CA3 region. In summary, our results show that P2X7R antagonists possess no remarkable anticonvulsant effects in the used acute screening tests, but can attenuate chemically-induced kindling. Further studies would be of interest to support the concept that P2X7R signalling plays a crucial role in the pathogenesis of epileptic disorders. PMID:27281030

  12. P2X7 receptor-mediated analgesia in cancer-induced bone pain

    Falk, Sarah; D. Schwab, Samantha; Frøsig-Jørgensen, Majbrit;

    2015-01-01

    Pain is a common and debilitating complication for cancer patients significantly compromising their quality of life. Cancer-induced bone pain involves a complex interplay of molecular events, including mechanisms observed in inflammatory and neuropathic pain states, but also changes unique for...... cancer-induced bone pain. The P2X7 receptor (P2X7R) is involved in a variety of cellular functions and has been linked to both inflammatory and neuropathic pain. Here we study the analgesic potential of P2X7 receptor antagonism in a rat model of cancer-induced bone pain. In cancer-bearing animals, the P2....... The results suggest that the P2X7R is involved in the mechanisms of cancer-induced bone pain, and that P2X7R antagonism might be a useful analgesic target. No effect was observed in sham or naïve animals, indicating that the P2X7R-mediated effect is state-dependent, and might therefore be an...

  13. P2X7 receptor-deficient mice are susceptible to bone cancer pain

    Hansen, Rikke Rie; Nielsen, Christian K.; Nasser, Arafat;

    2011-01-01

    The purinergic P2X7 receptor is implicated in both neuropathic and inflammatory pain, and has been suggested as a possible target in pain treatment. However, the specific role of the P2X7 receptor in bone cancer pain is unknown. We demonstrated that BALB/cJ P2X7 receptor knockout (P2X7R KO) mice...... were susceptible to bone cancer pain and moreover had an earlier onset of pain-related behaviours compared with cancer-bearing, wild-type mice. Furthermore, acute treatment with the selective P2X7 receptor antagonist, A-438079, failed to alleviate pain-related behaviours in models of bone cancer pain...... with and without astrocyte activation (BALB/cJ or C3H mice inoculated with 4T1 mammary cancer cells or NCTC 2472 osteosarcoma cells, respectively), suggesting that astrocytic P2X7 receptors play a negligible role in bone cancer pain. The results support the hypothesis that bone cancer pain is a...

  14. New insights of P2X7 receptor signaling pathway in alveolar functions.

    Mishra, Amarjit

    2013-01-01

    Purinergic P2X7 receptor (P2X7R), an ATP-gated cation channel, is unique among all other family members because of its ability to respond to various stimuli and to modulate pro-inflammatory signaling. The activation of P2X7R in immune cells is absolutely required for mature interleukin -1beta (IL-1beta) and IL-18 production and release. Lung alveoli are lined by the structural alveolar epithelial type I (AEC I) and alveolar epithelial type II cells (AEC II). AEC I plays important roles in alveolar barrier protection and fluid homeostasis whereas AEC II synthesizes and secrete surfactant and prevents alveoli from collapse. Earlier studies indicated that purinergic P2X7 receptors were specifically expressed in AEC I. However, their implication in alveolar functions has not been explored. This paper reviews two important signaling pathways of P2X7 receptors in surfactant homeostatsis and Acute Lung Injury (ALI). Thus, P2X7R resides at the critical nexus of alveolar pathophysiology. PMID:23634990

  15. A new role for P2X4 receptors as modulators of lung surfactant secretion

    Pika eMiklavc

    2013-10-01

    Full Text Available In recent years P2X receptors have attracted increasing attention as regulators of exocytosis and cellular secretion. In various cell types P2X receptors have been found to stimulate vesicle exocytosis directly via Ca2+ influx and elevation of the intracellular Ca2+ concentration. Recently, a new role for P2X4 receptors as regulators of secretion emerged. Exocytosis of lamellar bodies (LBs, large storage organelles for lung surfactant, results in a local, fusion-activated Ca2+ entry (FACE in alveolar type II epithelial cells. FACE is mediated via P2X4 receptors that are located on the limiting membrane of LBs and inserted into the plasma membrane upon exocytosis of LBs. The localized Ca2+ influx at the site of vesicle fusion promotes fusion pore expansion and facilitates surfactant release. In addition, this inward-rectifying cation current across P2X4 receptors mediates fluid resorption from lung alveoli. It is hypothesized that the concomitant reduction in the alveolar lining fluid facilitates insertion of surfactant into the air-liquid interphase thereby activating it. These findings constitute a novel role for P2X4 receptors in regulating vesicle content secretion as modulators of the secretory output during the exocytic post-fusion phase.

  16. Photovoltaic device

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  17. Photovoltaic device

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  18. Concentration device

    2013-01-01

    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  19. Epitaxial growth of electron doped double perovskites LaxA2-xCrWO6 with A=Sr and Ca

    Ferrimagnetic double perovskites are interesting for tunnel magnetoresistance (TMR) devices due to their high Curie-temperature and their half-metallicity. Because of the preferential formation of LaCrO3, the synthesis of bulk samples of electron-doped LaxSr2-xCrWO6 is difficult. However, due to the non-equilibrium growth conditions during pulsed laser deposition (PLD), the material can be grown as high-quality epitaxial film. We report the growth parameters of the compound LaxSr2-xCrWO6 on SrTiO3 substrates. Using reflection high-energy electron diffraction (RHEED) a layer-by-layer growth over the whole film thickness has been observed. Ca2CrWO6 grown on NdGaO3 has worse crystalline quality and shows paramagnetic behavior

  20. Differential expression of ATP-gated P2X receptors in DRG between chronic neuropathic pain and visceralgia rat models.

    Chen, Lin; Liu, Yu-Wei; Yue, Kai; Ru, Qin; Xiong, Qi; Ma, Bao-Miao; Tian, Xiang; Li, Chao-Ying

    2016-03-01

    There are divergences between neuropathic pain and visceralgia in terms of the duration, location, and character of hyperalgesia. It is generally recognized that nociceptive receptors, including P2X receptors, may play different roles in nociceptive mechanisms. The different roles of P2X1-7 receptors have not been fully understood both in neuropathic pain and visceral hyperalgesia. In order to explore the different expressions of P2X1-7 receptors in these two hyperalgesia models, the lumbosacral dorsal root ganglion (DRG) neurons from rat sciatic nerve chronic constriction injury (CCI) model and neonatal colorectal distention (NCRD) model were studied (both the primary nociceptive neuron afferents of those two models projected to the same segment of spinal cord). Both immunohistochemistry (IHC) technique and real-time fluorescence quantitative polymerase chain reaction (RT-PCR) technology were applied to analyze the protein expression levels and nucleic acid of P2X1-7 receptors. We found that except P2X2 and P2X3, the expression levels of P2X1 and P2X5 receptors increased in neuropathic pain while those expression levels of P2X4, P2X6, and P2X7 receptors increased in visceral pain. Our results also suggested that in addition to P2X2/3 heteromeric, other P2X subunits may also involved in generation heteromeric such as P2X1/5 and/or P2X2/5 in neuropathic pain and P2X4/6 and/or P2X4/7 in visceral pain. PMID:26531254

  1. Microwave dielectric properties and microstructure of Ba2-xSm4+2x/3Ti8+yO24+2y ceramics

    The microstructure and microwave dielectric properties of barium samarium titanium oxide Ba2-xSm4+2x/3Ti8+yO24+2y (x=0.1, y=0∼2) ceramics (BST) were investigated. The optimum compositions of BST ceramics were synthesized and discussed base on the structure formula of the tungsten-bronze-type crystal phase. Differential thermal analysis (DTA) was used to select the suitable sintering temperatures. The relative dielectric constant of the BST compositions saturated in a range from 63 to 85. Qxf values of 8500-13000 (GHz) were obtained for various y values in dense samples. The temperature coefficient of resonant frequency τf was adjusted from a negative -12 ppm per deg. C value to a positive value 17 ppm per deg. C. X-ray diffraction, SEM and EDS analysis were used to investigate the microstructure and correlate its relationship with microwave dielectric properties of BST ceramics

  2. Higher twist contributions to the structure functions Fp2(x,Q2) and Fd2(x,Q2) at large x at higher orders

    The higher twist contributions to the deeply inelastic structure functions Fp2(x,Q2) and Fd2(x,Q2) for larger values of the Bjorken variable x are extracted extrapolating the twist-2 contributions measured in the large W2 region to the region 4 GeV2≤W2 ≤12.5 GeV2 applying target mass corrections. We compare the results for the NLO, NNLO and N3LO analyzes and include also the large x at N4LO to the Wilson coefficients. A gradual lowering of the higher twist contributions going from NLO to N4LO is observed, which stresses the importance of higher order corrections. (orig.)

  3. Statins and ATP regulate nuclear pAkt via the P2X7 purinergic receptor in epithelial cells

    Many studies have documented P2X7 receptor functions in cells of mesenchymal origin. P2X7 is also expressed in epithelial cells and its role in these cells remains largely unknown. Our data indicate that P2X7 regulate nuclear pAkt in epithelial cells. We show that low concentration of atorvastatin, a drug inhibiting HMG-CoA reductase and cholesterol metabolism, or the natural agonist extracellular ATP rapidly decreased the level of insulin-induced phosphorylated Akt in the nucleus. This effect was seen within minutes and was inhibited by P2X7 inhibitors. Experiments employing P2X7 siRNA and HEK293 cells heterologously expressing P2X7 and in vivo experiments further supported an involvement of P2X7. These data indicate that extracellular ATP and statins via the P2X7 receptor modulate insulin-induced Akt signaling in epithelial cells

  4. Light ion irradiation effects on stuffed Lu2(Ti2-xLux)O7-x/2 (x = 0, 0.4 and 0.67) structures

    We have recently synthesized 'stuffed' (i.e., excess Lu) Lu2(Ti2-xLux)O7-x/2 (x = 0, 0.4 and 0.67) compounds using conventional ceramic processing. X-ray diffraction measurements indicate that stuffing more Lu3+ cations into the oxide structure leads eventually to an order-to-disorder (O-D) transition, from an ordered pyrochlore to a disordered fluorite crystal structure. At the maximum deviation in stoichiometry (x = 0.67), the Lu3+ and Ti4+ ions become completely randomized on the cation sublattices, and the oxygen 'vacancies' are randomized on the anion sublattice. Samples were irradiated with 400 keV Ne2+ ions to fluences ranging from 1 x 1015 to 1 x 1016 ions/cm2 at cryogenic temperatures (∼77 K). Ion irradiation effects in these samples were examined by using grazing incident X-ray diffraction. The results show that the ion irradiation tolerance increases with disordering extent in the non-stoichiometric Lu2(Ti2-xLux)O7-x/2.

  5. P2X receptor-mediated ATP purinergic signaling in health and disease

    Jiang LH

    2012-09-01

    Full Text Available Lin-Hua JiangSchool of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United KingdomAbstract: Purinergic P2X receptors are plasma membrane proteins present in a wide range of mammalian cells where they act as a cellular sensor, enabling cells to detect and respond to extracellular adenosine triphosphate (ATP, an important signaling molecule. P2X receptors function as ligand-gated Ca2+-permeable cationic channels that open upon ATP binding to elevate intracellular Ca2+ concentrations and cause membrane depolarization. In response to sustained activation, P2X receptors induce formation of a pore permeable to large molecules. P2X receptors also interact with distinct functional proteins and membrane lipids to form specialized signaling complexes. Studies have provided compelling evidence to show that such P2X receptor-mediated ATP-signaling mechanisms determine and regulate a growing number and diversity of important physiological processes, including neurotransmission, muscle contraction, and cytokine release. There is accumulating evidence to support strong causative relationships of altered receptor expression and function with chronic pain, inflammatory diseases, cancers, and other pathologies or diseases. Numerous high throughput screening drug discovery programs and preclinical studies have thus far demonstrated the proof of concepts that the P2X receptors are druggable targets and selective receptor antagonism is a promising therapeutics approach. This review will discuss the recent progress in understanding the mammalian P2X receptors with respect to the ATP-signaling mechanisms, physiological and pathophysiological roles, and development and preclinical studies of receptor antagonists.Keywords: extracellular ATP, ion channel, large pore, signaling complex, chronic pain, inflammatory diseases

  6. Point mutation in the mouse P2X7 receptor affects intercellular calcium waves in astrocytes

    Sylvia O Suadicani

    2009-04-01

    Full Text Available Purinergic P2 receptors and gap junctions are two groups of proteins involved in the transmission of ICWs (intercellular calcium waves) between astrocytes. The extent to which ICWs spread among these glial cells depends on the amount of ATP released, which can occur through membrane channels, as well as other pathways. Our previous studies have shown that the pore-forming P2X7R (P2X7 receptor) contributes to the amplification of ICW spread by providing sites of ATP release through Panx1 (Pannexin1) channels. To gain insight into the signal transduction events mediating this response we compared the properties of the P2X7R–Panx1 complex in astrocytes from a mouse strain (C57Bl/6) containing a naturally occurring point mutation (P451L) in the C-terminus of the P2X7R to that of non-mutated receptors (Balb/C mice). Electrophysiological, biochemical, pharmacological and fluorescence imaging techniques revealed that the P451L mutation located in the SH3 domain (a Src tyrosine kinase-binding site) of the C-terminus of the P2X7R attenuates Panx1 currents, ATP release and the distance of ICW spread between astrocytes. Similar results were obtained when using the Src tyrosine inhibitor (PP2) and a membrane-permeant peptide spanning the P451L mutation of the P2X7R of the C57Bl6 astrocytes. These results support the participation of a tyrosine kinase of the Src family in the initial steps mediating the opening of Panx1 channels following P2X7R stimulation and in the transmission of calcium signals among astrocytes.

  7. Antidepressants inhibit P2X4 receptor function: a possible involvement in neuropathic pain relief

    Tozaki-Saitoh Hidetoshi

    2009-04-01

    Full Text Available Abstract Background Neuropathic pain is characterized by pain hypersensitivity to innocuous stimuli (tactile allodynia that is nearly always resistant to known treatments such as non-steroidal anti-inflammatory drugs or even opioids. It has been reported that some antidepressants are effective for treating neuropathic pain. However, the underlying molecular mechanisms are not well understood. We have recently demonstrated that blocking P2X4 receptors in the spinal cord reverses tactile allodynia after peripheral nerve injury in rats, implying that P2X4 receptors are a key molecule in neuropathic pain. We investigated a possible role of antidepressants as inhibitors of P2X4 receptors and analysed their analgesic mechanism using an animal model of neuropathic pain. Results Antidepressants strongly inhibited ATP-mediated Ca2+ responses in P2X4 receptor-expressing 1321N1 cells, which are known to have no endogenous ATP receptors. Paroxetine exhibited the most powerful inhibition of calcium influx via rat and human P2X4 receptors, with IC50 values of 2.45 μM and 1.87 μM, respectively. Intrathecal administration of paroxetine produced a striking antiallodynic effect in an animal model of neuropathic pain. Co-administration of WAY100635, ketanserin or ondansetron with paroxetine induced no significant change in the antiallodynic effect of paroxetine. Furthermore, the antiallodynic effect of paroxetine was observed even in rats that had received intrathecal pretreatment with 5,7-dihydroxytryptamine, which dramatically depletes spinal 5-hydroxytryptamine. Conclusion These results suggest that paroxetine acts as a potent analgesic in the spinal cord via a mechanism independent of its inhibitory effect on serotonin transporters. Powerful inhibition on P2X4 receptors may underlie the analgesic effect of paroxetine, and it is possible that some antidepressants clinically used in patients with neuropathic pain show antiallodynic effects, at least in part

  8. Room-temperature associative adsorption and thermal dissociative desorption of trifluorobenzene on Si(100)2x1

    Zhou, Xiaojing; Leung, K. T.

    2004-03-01

    Functionalization of Si(100) has been extensively investigated in ultra-high vacuum and in solutions for its potential applications in molecular devices and chemical sensors. Aromatic molecules are good candidates because of their rich chemical properties, low cost and widespread use in industry. In the present work, trifluorobenzene (TFB) is used to study the effects of halogen substitution on benchmark molecules such as benzene and ethylene. Unlike halogenated ethylenes that exhibit dissociative adsorption at room temperature (RT), TFB is found to adsorb on Si(100) 2x1 associatively at RT and to undergo partial dissociation at a higher substrate temperature. Molecular desorption states at 380 K, 430K and 520K have also been observed in our temperature programmed desorption experiment, which is consistent with the desorption patterns of benzene and toluene. Additional desorption species of C6H6, SiF2 and F2 occurring over the same temperature range indicate a thermally driven dissociation process. Furthermore, ab initio calculation (with full geometry optimization) shows that selective adsorption occurs at the 2,5 position of the ring , which may be used for patterning of molecular devices on Si(100).

  9. Structural, electronic and optical properties of AgXY{sub 2}(X = Al, Ga, In and Y = S, Se, Te)

    Ullah, Saeed; Din, Haleem Ud [Materials Modeling Lab, Department of Physics, Islamia College University, Peshawar (Pakistan); Murtaza, G., E-mail: murtaza@icp.edu.pk [Materials Modeling Lab, Department of Physics, Islamia College University, Peshawar (Pakistan); Ouahrani, T. [Laboratoire de Physique Théorique, B.P. 119, Université de Tlemcen, Tlemcen 13000 (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique et de Modélisation Mathématique, Université de Mascara, Mascara 29000 (Algeria); Naeemullah [Department of Physics, G.D.C. Darra Adam Khel, F.R. Kohat, KPK (Pakistan); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

    2014-12-25

    Highlights: • The compounds are studied by FP-LAPW method within mBJ approximation. • All of the studied materials show isotropic behavior. • All the compounds show direct band gap nature. • Bonding nature is mostly covalent among the studied compounds. • High absorption peaks and reflectivity ensures there utility in optoelectronic devices. - Abstract: The structural, electronic and optical properties of the ternary semiconducting compounds AgXY{sub 2} (X = Al, Ga, In and Y = S, Se, Te) in Heusler and chalcopyrite crystal phases have been investigated using the density functional theory (DFT) based on the full potential linear augmented plane wave (FP-LAPW) method. The calculated lattice constant and band gap values for AgXY{sub 2} in chalcopyrite phase are in good agreement with the available experimental data. Band structure calculations are performed using modified Becke–Johnson (mBJ) method which match closely with experimental data and yield better band gaps rather than those obtained by using generalized gradient approximation (GGA) and Engel–Vosko generalized gradient approximation (EV–GGA). Decrease in band gap is observed by changing cations X and Y from the top to bottom of periodic table. Chemical bonding trends are predicted through charge density plots and quantified by Bader’s analysis. Optical properties reveal that these compounds are suitable candidates for optoelectronic devices in the visible and ultraviolet (UV) regions.

  10. Structural, electronic and optical properties of AgXY2(X = Al, Ga, In and Y = S, Se, Te)

    Highlights: • The compounds are studied by FP-LAPW method within mBJ approximation. • All of the studied materials show isotropic behavior. • All the compounds show direct band gap nature. • Bonding nature is mostly covalent among the studied compounds. • High absorption peaks and reflectivity ensures there utility in optoelectronic devices. - Abstract: The structural, electronic and optical properties of the ternary semiconducting compounds AgXY2 (X = Al, Ga, In and Y = S, Se, Te) in Heusler and chalcopyrite crystal phases have been investigated using the density functional theory (DFT) based on the full potential linear augmented plane wave (FP-LAPW) method. The calculated lattice constant and band gap values for AgXY2 in chalcopyrite phase are in good agreement with the available experimental data. Band structure calculations are performed using modified Becke–Johnson (mBJ) method which match closely with experimental data and yield better band gaps rather than those obtained by using generalized gradient approximation (GGA) and Engel–Vosko generalized gradient approximation (EV–GGA). Decrease in band gap is observed by changing cations X and Y from the top to bottom of periodic table. Chemical bonding trends are predicted through charge density plots and quantified by Bader’s analysis. Optical properties reveal that these compounds are suitable candidates for optoelectronic devices in the visible and ultraviolet (UV) regions

  11. [Effect of P2X7 receptor knock-out on bone cancer pain in mice].

    Zhao, Xin; Liu, Hui-Zhu; Zhang, Yu-Qiu

    2016-06-25

    Cancer pain is one of the most common symptoms in patients with late stage cancer. Lung, breast and prostate carcinoma are the most common causes of pain from osseous metastasis. P2X7 receptor (P2X7R) is one of the subtypes of ATP-gated purinergic ion channel family, predominately distributed in microglia in the spinal cord. Activation of P2X7Rs in the spinal dorsal horn has been associated with release of proinflammatory cytokines from glial cells, causing increased neuronal excitability and exaggerated nociception. Mounting evidence implies a critical role of P2X7R in inflammatory and neuropathic pain. However, whether P2X7R is involved in cancer pain remains controversial. Here we established a bone cancer pain model by injecting the Lewis lung carcinoma cells into the femur bone marrow cavity of C57BL/6J wild-type mice (C57 WT mice) and P2X7R knockout mice (P2rx7(-/-) mice) to explore the role of P2X7R in bone cancer pain. Following intrafemur carcinoma inoculation, robust mechanical allodynia and thermal hyperalgesia in C57 WT mice were developed on day 7 and 14, respectively, and persisted for at least 28 days in the ipsilateral hindpaw of the affected limb. CatWalk gait analysis showed significant decreases in the print area and stand phase, and a significant increase in swing phase in the ipsilateral hindpaw on day 21 and 28 after carcinoma cells inoculation. Histopathological sections (hematoxylin and eosin stain) showed that the bone marrow of the affected femur was largely replaced by invading tumor cells, and the femur displayed medullary bone loss and bone destruction on day 28 after inoculation. Unexpectedly, no significant changes in bone cancer-induced hypersensitivity of pain behaviors were found in P2rx7(-/-) mice, and the changes of pain-related values in CatWalk gait analysis even occurred earlier in P2rx7(-/-) mice, as compared with C57 WT mice. Together with our previous study in rats that blockade of P2X7R significantly alleviated bone cancer

  12. The J-2X Fuel Turbopump - Turbine Nozzle Low Cycle Fatigue Acceptance Rationale

    Hawkins, Lakiesha V.; Duke, Gregory C.; Newman, Wesley R.; Reynolds, David C.

    2011-01-01

    The J-2X Fuel Turbopump (FTP) turbine, which drives the pump that feeds hydrogen to the J-2X engine for main combustion, is based on the J-2S design developed in the early 1970 s. Updated materials and manufacturing processes have been incorporated to meet current requirements. This paper addresses an analytical concern that the J-2X Fuel Turbine Nozzle Low Cycle Fatigue (LCF) analysis did not meet safety factor requirements per program structural assessment criteria. High strains in the nozzle airfoil during engine transients were predicted to be caused by thermally induced stresses between the vane hub, vane shroud, and airfoil. The heritage J-2 nozzle was of a similar design and experienced cracks in the same area where analysis predicted cracks in the J-2X design. Redesign options that did not significantly impact the overall turbine configuration were unsuccessful. An approach using component tests and displacement controlled fracture mechanics analysis to evaluate LCF crack initiation and growth rate was developed. The results of this testing and analysis were used to define the level of inspection on development engine test units. The programmatic impact of developing crack initiation/growth rate/arrest data was significant for the J-2X program. Final Design Certification Review acceptance logic will ultimately be developed utilizing this test and analytical data.

  13. The evolution of P2X7 antagonists with a focus on CNS indications.

    Rech, Jason C; Bhattacharya, Anindya; Letavic, Michael A; Savall, Brad M

    2016-08-15

    The P2X7 receptor is an ATP-gated nonselective cation channel that has been linked to a number of inflammatory diseases. Activation of the P2X7 receptor by elevated levels of ATP results in the release of proinflammatory cytokines and elevated levels of these cytokines has been associated with a variety of disease states. A number of research groups in both industry and academia have explored the identification of P2X7R antagonists as therapeutic agents. Much of this early effort focused on the treatment of diseases related to peripheral inflammation and resulted in several clinical candidates, none of which were advanced to market. The emerging role of the P2X7 receptor in neuroinflammation and related diseases has resulted in a shift in medicinal chemistry efforts toward the development of centrally penetrant antagonists. This review will highlight the biology supporting the role of P2X7 in diseases related to neuroinflammation and review the recent medicinal chemistry efforts to identify centrally penetrant antagonists. PMID:27426304

  14. Podocyte Purinergic P2X4 Channels Are Mechanotransducers That Mediate Cytoskeletal Disorganization.

    Forst, Anna-Lena; Olteanu, Vlad Sorin; Mollet, Géraldine; Wlodkowski, Tanja; Schaefer, Franz; Dietrich, Alexander; Reiser, Jochen; Gudermann, Thomas; Mederos Y Schnitzler, Michael; Storch, Ursula

    2016-03-01

    Podocytes are specialized, highly differentiated epithelial cells in the kidney glomerulus that are exposed to glomerular capillary pressure and possible increases in mechanical load. The proteins sensing mechanical forces in podocytes are unconfirmed, but the classic transient receptor potential channel 6 (TRPC6) interacting with the MEC-2 homolog podocin may form a mechanosensitive ion channel complex in podocytes. Here, we observed that podocytes respond to mechanical stimulation with increased intracellular calcium concentrations and increased inward cation currents. However, TRPC6-deficient podocytes responded in a manner similar to that of control podocytes, and mechanically induced currents were unaffected by genetic inactivation of TRPC1/3/6 or administration of the broad-range TRPC blocker SKF-96365. Instead, mechanically induced currents were significantly decreased by the specific P2X purinoceptor 4 (P2X4) blocker 5-BDBD. Moreover, mechanical P2X4 channel activation depended on cholesterol and podocin and was inhibited by stabilization of the actin cytoskeleton. Because P2X4 channels are not intrinsically mechanosensitive, we investigated whether podocytes release ATP upon mechanical stimulation using a fluorometric approach. Indeed, mechanically induced ATP release from podocytes was observed. Furthermore, 5-BDBD attenuated mechanically induced reorganization of the actin cytoskeleton. Altogether, our findings reveal a TRPC channel-independent role of P2X4 channels as mechanotransducers in podocytes. PMID:26160898

  15. Synthesis and magnetic characterization of Sr-based Ni{sub 2}X-type hexaferrite

    Kamishima, K., E-mail: kamisima@fms.saitama-u.ac.jp; Mashiko, T.; Kakizaki, K.; Sakai, M. [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Saitama 338-8570 (Japan); Watanabe, K. [Biomolecular Characterization Unit, Center of Sustainable Resource Science, RIKEN, 2-1 Wako, Saitama 351-0198 (Japan); Abe, H. [Advanced Electronic Materials Center, National Institute of Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2015-10-15

    We have investigated the synthesis conditions, and the magnetic properties of the Sr{sub 2}Ni{sub 2}X-type hexagonal ferrite, Sr{sub 2}Ni{sub 2}Fe{sub 28}O{sub 46}. The Sr{sub 2}Ni{sub 2}X-type hexaferrite was synthesized at 1240{sup ∘}C. The spontaneous magnetization at 5 K was 44.2 μ{sub B}/f.u., suggesting that most of the Ni{sup 2+} ions are at the up-spin octahedral sites in the spinel-structure blocks within the model of a Néel-type collinear ferrimagnetic structure. The Curie temperature of the Sr{sub 2}Ni{sub 2}X-type hexaferrite was estimated to be T{sub C}[Sr{sub 2}Ni{sub 2}X] = 472{sup ∘}C. This is consistent with the difference of the block stacking structures of SrM-type, Sr{sub 2}Ni{sub 2}X-type, SrNi{sub 2}W-type, and nickel spinel ferrites.

  16. Oxygen potential and lattice parameter measurements in (U,Ce)Osub(2-x)

    Studies have been carried out on (U, Ce)Osub(2-x) to assist the understanding of oxygen behaviour in the fast reactor fuel (U, Pu)Osub(2-x). Oxygen potentials at 1123 K and lattice parameters after rapid cooling to room temperature have been determined as functions of O/M ratio for (Ce/U+Ce) ratios of 0.148 and 0.282. The results show some similarities between the two mixed oxides, but also important differences. The Markin-McIver rule, that oxygen potential at a given temperature is a function only of the supposed plutonium valence, does not apply with cerium. Simple cluster models are basically inconsistent with experimental data and a complex cluster model requires further development before it can account for the oxygen potential behaviour of (U, Ce)Osub(2-x). The ratio of lattice parameter change to O/M ratio change in Usub(1-y)Cesub(y)Osub(2-x) is not strongly dependent on y and averages 0.30 A, slightly greater than the corresponding value for Usub(1-y)Pusub(y)Osub(2-x). A transition to a room-temperature two-phase structure occurs at an O/M ratio of about 1.985 for γ = 0.282. (orig.)

  17. Atmospheric chemistry of n-CxF2x+1CHo (x=1,3,4): Mechanism of the CxF2x+1C(O)O-2+HO2 reaction

    Andersen, Mads Peter Sulbæk; Stenby, C; Nielsen, OJ;

    2004-01-01

    Smog chamber/FTIR techniques were used to study the gas-phase reaction of CxF2x+1C(O)O-2 (x = 1, 3, 4) with HO2 radicals in 700 Torr of air, or O-2, diluent at 296 +/- 2 K. The reactions proceed by three pathways leading to formation of CxF2x+1C(O)OOH and O-2, C2F2x+1C(O)OH and O-3, or CxF2x+1C(O...

  18. Microfluidic Device

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2016-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  19. Preparation of Bi2-xSbxTe3 thermoelectric films by electrodeposition

    2006-01-01

    Bi2-xSbxTe3 thermoelectric films were electrochemically deposited from the solution containing Bi3+, HTeO2+and SbO+.ESEM (environmental scanning electron microscope) investigations indicated that the crystalline state of Bi2-xSbxTe3 films transformed from equiaxed crystal to dendritic crystal with the negative shift of deposition potential. XRD and EDS were used to characterize the structure and composition of the electrodeposited films. The Seebeck coefficient and the temperature dependence of the resistance of Bi2-xSbxTe3 films were measured. The results showed that the composition of the film electrodeposited at -0.5 V is Bi0.5Sb1.5Te3 with the largest Seebeck coefficient of 213 μV·K-1.

  20. Charge ordering in the electron-doped superconductor Nd(2-x)Ce(x)CuO₄.

    da Silva Neto, Eduardo H; Comin, Riccardo; He, Feizhou; Sutarto, Ronny; Jiang, Yeping; Greene, Richard L; Sawatzky, George A; Damascelli, Andrea

    2015-01-16

    In cuprate high-temperature superconductors, an antiferromagnetic Mott insulating state can be destabilized toward unconventional superconductivity by either hole or electron doping. In hole-doped (p-type) cuprates, a charge ordering (CO) instability competes with superconductivity inside the pseudogap state. We report resonant x-ray scattering measurements that demonstrate the presence of charge ordering in the n-type cuprate Nd(2-x)Ce(x)CuO4 near optimal doping. We find that the CO in Nd(2-x)Ce(x)CuO4 occurs with similar periodicity, and along the same direction, as in p-type cuprates. However, in contrast to the latter, the CO onset in Nd(2-x)Ce(x)CuO4 is higher than the pseudogap temperature, and is in the temperature range where antiferromagnetic fluctuations are first detected. Our discovery opens a parallel path to the study of CO and its relationship to antiferromagnetism and superconductivity. PMID:25593186

  1. Design and Fabrication Development of J-2X Engine Metallic Nozzle Extension

    Kopicz, C.; Gradl, P.

    2015-01-01

    Maximized rocket engine performance is in part derived from expanding combustion gasses through the rocket nozzle. For upper stage engines the nozzles can be quite large. On the J-2X engine, an uncooled extension of a regeneratively cooled nozzle is used to expand the combustion gasses to a targeted exit pressure which is defined by an altitude for the desired maximum performance. Creating a J-2X nozzle extension capable of surviving the loads of test and flight environments while meeting engine system performance requirements required development of new processes and facilities. Meeting the challenges of the development resulted in concurrent J-2X nozzle extension design and fabrication. This paper describes how some of the design and fabrication challenges were resolved.

  2. Principles and properties of ion flow in P2X receptors

    Damien Stephen Kenneth Samways

    2014-02-01

    Full Text Available P2X receptors are a family of trimeric ion channels that are gated by extracellular adenosine 5’-triphosphate (ATP. These receptors have long been a subject of intense research interest by virtue of their vital role in mediating the rapid and direct effects of extracellular ATP on membrane potential and intracellular Ca2+ concentration, which in turn underpin the ability of ATP to regulate a diverse range of clinically significant physiological functions, including cardiovascular function, pain, and the immune response. An important aspect of an ion channel’s function is, of course, the means by which it transports ions across the biological membrane. A concerted effort by investigators over the last two decades has culminated in significant advances in our understanding of how P2X receptors conduct the inward flux of Na+ and Ca2+ in response to binding by ATP. However, this work has relied heavily on results from current recordings of P2X receptors altered by site-directed mutagenesis. In the absence of a 3-dimensional channel structure, this prior work provided only a vague and indirect appreciation of the relationship between structure, ion selectivity and flux. The recent publication of the crystal structures for both the closed and open channel conformations of the zebrafish P2X4 receptor has thus proved a significant boon, and has provided an important opportunity to overview the amassed functional data in the context of a working 3-dimensional model of a P2X receptor. In this paper, we will attempt to reconcile the existing functional data regarding ion permeation through P2X receptors with the available crystal structure data, highlighting areas of concordance and discordance as appropriate.

  3. Future NTP Development Synergy Leveraged from Current J-2X Engine Development

    Ballard, Richard O.

    2008-01-01

    This paper is a discussion of how the many long-lead development elements required for the realization of a future nuclear thermal propulsion (NTP) system can be effectively leveraged from the ongoing work being conducted on the J-2X engine program for the Constellation Program. Development studies conducted to date for NTP forward planning have identified a number of technical areas that will require advancement to acceptable technology readiness levels (TRLs) before they can be utilized in NTP system development. These include high-temperature, high-area ratio nozzle extension; long-life, low-NPSP. turbomachinery; and low-boiloff propellant management; and a qualified nuclear fuel element. The current J-2X program is working many of these areas that can be leveraged to support NTP development in a highly compatible and synergistic fashion. In addition to supporting technical development, there are other programmatic issues being worked in the J-2X program that can be leveraged by a future NTP development program. These include compliance with recently-evolved space system requirements such as human-rating, fault tolerance and fracture control. These and other similar mandatory system requirements have been adopted by NASA and can result in a significant technical impact beyond elevation of the root technologies required by NTP. Finally, the exploitation of experience, methodologies, and procedures developed by the J-2X program in the areas of verification, qualification, certification, altitude simulation testing, and facility definition will be especially applicable to a future NTP system. The similarities in system mission (in-space propulsion) and operational environment (vacuum, zero-gee) between J-2X and NTP make this highly synergistic. Thus, it can be $hown that the collective benefit of leveraging experience and technologies developed during the J-2X program can result in significant savings in development cost and schedule for NTP.

  4. Component Testing of the J-2X Augmented Spark Igniter (ASI)

    Osborne, Robin J.; Peters, Warren T.; Gaspar, Kenny C.; Hauger, Katherine; Kwapisz, Mike J.

    2013-01-01

    In support of the development of the J-2X engine, 201 low pressure, liquid oxygen / liquid hydrogen (LOX/LH2) J-2X Augmented Spark Igniter (ASI) subsystem ignition tests were conducted at Marshall Space Flight Center (MSFC). The main objective of these tests was to start the ASI within the anticipated J-2X engine start box, as well as outside of it, to check for ignition margin. The setup for the J-2X ASI component testing simulated, as much as possible, the tank-head start-up configuration of the ASI within the J-2X Engine. The ignition tests were divided into 124 vacuum start tests to simulate altitude start on a flight engine, and 77 sea-level start tests to simulate the first set of ground tests for the J-2X Engine at Stennis Space Center (SSC). Other ignition parameters that were varied included propellant tank pressures, oxidizer temperature entering the ASI oxidizer feedline, oxidizer valve timing, spark igniter condition (new versus damaged), and oxidizer and fuel feedline orifice sizes. Propellant blowdowns using venturis sized to simulate the ASI resistance allowed calculation of transient propellant mass flow rates as well as global mixture ratio for all ignition tests. Global mixture ratio within the ASI at the time of ignition varied from 0.2 to 1.2. Detailed electronics data obtained from an instrumented ignition lead allowed characterization of the breakdown voltage, sustaining voltage and energy contained in each spark as the ASI propellants ignited. Results indicated that ignition always occurred within the first five sparks when both propellants were present in the ASI chamber.

  5. Diluted magnetic Ce1-2xCoxZnxO2-d

    T.S. Santos; Rodrigues, A.N.; M.A. Macêdo

    2012-01-01

    Polvos de Ce1-2xZnxCoxO2-d obtenidos por el proceso sol-gel proteico fueron estudiados por medidas magnéticas. Mediciones de magnetización para indican que el dopaje de Co puede inducir ferromagnetismo a temperatura ambiente, tal vez inducido por vacantes de ox´ıgeno. Del análisis de difracci´on de rayos X ninguna fase secundaria fue observada en Ce1-2xZnxCoxO2-d para x·0.05.

  6. On Some Expansion Theorems Involving Confluent Hypergeometric $_{2}F_{2}(x)$ Polynomial

    Vyas, Yashoverdhan; Fatawat, Kalpana

    2016-01-01

    Recently, Rathie and K{\\i}l{\\i}\\c{c}man (2014) employed Kummer-type transformation for $_{2}F_{2}(a, d+1; b, d; x)$ to develop certain classes of expansions theorems for $_{2}F_{2}(x)$ hypergeometric polynomial. Our aim is to deduce Kummer-type transformation for $_{2}F_{2}(a, d+2; b, d; x)$ and utilize it to develop some new expansion theorems for the confluent hypergeometric $_{2}F_{2}(x)$ polynomial. We also obtain a well-known result given by Kim et al. (Integral Transforms Spec. Funct. 2...

  7. Eugenol Inhibits ATP-induced P2X Currents in Trigeminal Ganglion Neurons

    Li, Hai Ying; Lee, Byung Ky; Kim, Joong Soo; Jung, Sung Jun; Oh, Seog Bae

    2008-01-01

    Eugenol is widely used in dentistry to relieve pain. We have recently demonstrated voltage-gated Na+ and Ca2+ channels as molecular targets for its analgesic effects, and hypothesized that eugenol acts on P2X3, another pain receptor expressed in trigeminal ganglion (TG), and tested the effects of eugenol by whole-cell patch clamp and Ca2+ imaging techniques. In the present study, we investigated whether eugenol would modulate 5'-triphosphate (ATP)-induced currents in rat TG neurons and P2X3-e...

  8. P2X7 receptor-deficient mice are susceptible to bone cancer pain

    Hansen, RR; Nielsen, CK; Nasser, A; Thomsen, SI; Eghorn, LF; Pham, Y; Schulenburg, C; Syberg, S; Ding, Ming; Stojilkovic, SS; Jorgensen, NR; Heegaard, AM

    2011-01-01

    were susceptible to bone cancer pain and moreover had an earlier onset of pain-related behaviours compared with cancer-bearing, wild-type mice. Furthermore, acute treatment with the selective P2X7 receptor antagonist, A-438079, failed to alleviate pain-related behaviours in models of bone cancer pain...... with and without astrocyte activation (BALB/cJ or C3H mice inoculated with 4T1 mammary cancer cells or NCTC 2472 osteosarcoma cells, respectively), suggesting that astrocytic P2X7 receptors play a negligible role in bone cancer pain. The results support the hypothesis that bone cancer pain is a...

  9. Characterisation of ATP analogues to cross-link and label P2X receptors

    Agboh, Kelvin C.; Andrew J. Powell; Evans, Richard J.

    2009-01-01

    P2X receptors are a distinct family of ATP-gated ion channels with a number of physiological roles ranging from smooth muscle contractility to the regulation of blood clotting. In this study we determined whether the UV light-reactive ATP analogues 2-azido ATP, ATP azidoanilide (ATP-AA) and 2′,3′-O-(4-benzoylbenzoyl)-ATP (BzATP) can be used to label the ATP binding site of P2X1 receptors. These analogues were agonists, and in patch clamp studies evoked inward currents from HEK293 cells stably...

  10. LDPC decoder architecture for DVB-S2 and DVB-S2X standards

    Marchand, Cédric; Boutillon, Emmanuel

    2015-01-01

    A particular type of conflict due to multiple-diagonal sub-matrices in the DVB-S2 parity-check matrices is known to complicate the implementation of the layered decoder architecture. The new matrices proposed in DVB-S2X no longer use such sub-matrices. For implementing a decoder compliant both with DVB-S2 and DVB-S2X, we propose an elegant solution which overcomes this conflicts relying on an efficient write disable of the memories, allowing a straightforward implementation of layered LDPC de...

  11. Congestive heart failure induces downregulation of P2X1-receptors in resistance arteries

    Malmsjö, M; Bergdahl, A; Möller, S;

    1999-01-01

    strong contractions in both the mesenteric artery and in the aorta, while ATP and ADP were much less effective. These contractions were not altered by CHF, indicating that vascular contraction mediated by P2Y-receptors are unaffected by CHF. CONCLUSION: CHF induces downregulation of P2X1-receptor...... stimulated contraction in the mesenteric artery depending on decreased mRNA synthesis for the receptor, while the P2Y-receptor activity remains unchanged. Downregulation of P2X1-receptors appears to be specific for peripheral resistance arteries. This may represent a compensatory response to enhanced...

  12. High Internal Gain Axial SiOx-In2-xO3-y/Au Heterostructure Nanocolumnar Array Based Schottky Detector for Broad Band Recognition.

    Singh, Naorem Khelchand; Mondal, Aniruddha

    2015-08-01

    Glancing angle deposition (GLAD) was employed to fabricate the SiOx-In2-xO3-y axial heterostructure nanocolumn. The fabricated heterostructure nanocolumn was annealed at 550 °C for 1 hour at open air condition. The XRD analysis revealed the polycrystalline nature of the annealed SiOx-In2-xO3-y nanocolumn. The emission at 378 nm (~3.3 eV, FWHM 39.101 nm) from Photoluminescence (PL), corresponds to main band gap of In2O3. The In2-xO3-y-SiOx nanocolumn based Schottky detector processed maximum photoresponsivity of 199 A/W at 375 nm, as well as UV-Vis broad band detection. The high internal gain of ~659 at UV region (375 nm) was calculated for the device. The detector exhibited increase in photoresponsivity with decrease in room temperature upto 160 K, which further reduced at low temperature. A very sharp rise time (~1.82 s) and decay time (~1.78 s) was recorded at the applied potential of -2 V and -3 V. PMID:26369205

  13. Study of the spin-glass transition in FeCr{sub 2x}In{sub 2-2x}S{sub 4} thiospinel

    Goya, G.F. E-mail: goya@macbeth.if.usp.br; Rechenberg, H.R.; Sagredo, V

    2001-05-01

    The spin-glass (SG) transition in Fe(In{sub 2-2x}Cr{sub 2x})S{sub 4} thiospinel with x=0.1 and 0.3 has been studied by susceptibility and Moessbauer measurements. It is found that iron in the system is partially inverted, with {approx}80% high-spin Fe{sup 2+} iron at octahedral sites. AC susceptibility data show a spin-glass-like transition at T{sub SG}=10 K that depends on the driving frequency f, following a Vogel-Fulcher law. Below T{sub SG}, the splitting of Zeeman levels yields a complex Moessbauer spectrum, which was fitted using a full {sup 57}Fe-nuclear Hamiltonian with quadrupolar and magnetic interactions. The reduced magnetic hyperfine field b(T)=B(T)/B{sub S} is well described by a Langevin function L(x), with T{sub C}=12.8(3) K and B{sub S}=16.8(3) T.

  14. Structure cristalline du composé Hg3-x Sb x (S+Se)2+x I2-x (x ≃ 0.1).

    Kars, Mohammed; Herrero, Adrian Gómez; Roisnel, Thierry; Rebbah, Allaoua; Otero-Diáz, L Carlos

    2016-03-01

    Single crystals of the mercury chalcohalide Hg3-x Sb x (S+Se)2+x I2-x (x ≃ 0.1) (mercury anti-mony sulfide selenide iodide), were grown by a chemical transport reaction. The structure contains three independent A (Hg/Sb) atoms; each atom is strongly covalently bonded with two X (Se/S) atoms to form approximately linear X-A-X units. The X-A-X units link to form A 4 X 4 rings, which are combined into infinite crankshaft-type bands running along the [100] direction. Four equatorial E (I/X = Se,S) atoms at relatively long distances complete the distorted octa-hedral coordination of A (Hg/Sb). The crystal under investigation was twinned by non-merohedry with a refined twin domain fraction of 0.814 (6):0.186 (6). The structure is isotypic with Hg3Se2I2 [Beck & Hedderich (2000 ▸). J. Solid State Chem. 151, 73-76], but the current determination reveals a coupled substitution, with partial replacement of Hg(+2) by Sb(+3), balanced by the equivalent substitution of I(-1) by S(-2) and Se(-2). Bond-valence calculations are consistent with this relative substitution model. PMID:27006793

  15. Structure cristalline du composé Hg3-xSbx(S+Se2+xI2-x (x ≃ 0.1

    Mohammed Kars

    2016-03-01

    Full Text Available Single crystals of the mercury chalcohalide Hg3-xSbx(S+Se2+xI2-x (x ≃ 0.1 (mercury antimony sulfide selenide iodide, were grown by a chemical transport reaction. The structure contains three independent A (Hg/Sb atoms; each atom is strongly covalently bonded with two X (Se/S atoms to form approximately linear X–A–X units. The X–A–X units link to form A4X4 rings, which are combined into infinite crankshaft-type bands running along the [100] direction. Four equatorial E (I/X = Se,S atoms at relatively long distances complete the distorted octahedral coordination of A (Hg/Sb. The crystal under investigation was twinned by non-merohedry with a refined twin domain fraction of 0.814 (6:0.186 (6. The structure is isotypic with Hg3Se2I2 [Beck & Hedderich (2000. J. Solid State Chem. 151, 73–76], but the current determination reveals a coupled substitution, with partial replacement of Hg+2 by Sb+3, balanced by the equivalent substitution of I−1 by S−2 and Se−2. Bond-valence calculations are consistent with this relative substitution model.

  16. 关于Mordell方程y^2=x^3+k%On the MordeU Equation y^2=x^3+k

    管训贵

    2011-01-01

    Let l,l1 ,l2 ,... ,ls be some integer, and n be a positive integer,and n1 ,n2 ,…… ,ns be some nonnegative integer. In this paper, using some elementary number theory methods, we prove that if k satisfies either k=(4l+2)^3-Пi=1^s(4li+1)^2ni或k=(4l+3)^3-2^2nПi=1^s(4li+1)^2nithen the Mordell y^2=x^3+k equation has no integral solution.%设l,l1,l2,…,ls为任意整数,n为正整数,n1,n2,…,ns为任意非负整数.用初等数论方法证明了:如果k满足k=(4l+2)^3-Пi=1^s(4li+1)^2ni或k=(4l+3)^3-2^2nПi=1^s(4li+1)^2ni,则Mordell方程y^2=x^3+k无整数解.

  17. Dual Gating Mechanism and Function of P2X7 Receptor Channels

    Khadra, A.; Tomic, M.; Yan, Z.; Zemková, Hana; Sherman, A.; Stojilkovic, S. S.

    2013-01-01

    Roč. 104, č. 12 (2013), s. 2612-2621. ISSN 0006-3495 R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : purinergic P2X7 receptors * ATP-gated channels * BzATP * dilation * Markov-state model Subject RIV: ED - Physiology Impact factor: 3.832, year: 2013

  18. Functional expression and circadian rhytmicity of purinergic P2X receptors in suprachiasmatic nuclei of hypothalamus

    Vávra, Vojtěch; Bendová, Zdena; Balík, Aleš; Zemková, Hana

    VIPSI, 2006. s. 15-15. [International Biophysics Workshop on Imaging in Neurosciences and Beyond. 23.09.2006-30.09.2006, Sveti Stefan] R&D Projects: GA AV ČR(CZ) IAA5011408 Institutional research plan: CEZ:AV0Z50110509 Keywords : P2X receptors * SCN Subject RIV: FH - Neurology

  19. Structural Insights into Divalent Cation Modulations of ATP-Gated P2X Receptor Channels

    Go Kasuya

    2016-02-01

    Full Text Available P2X receptors are trimeric ATP-gated cation channels involved in physiological processes ranging widely from neurotransmission to pain and taste signal transduction. The modulation of the channel gating, including that by divalent cations, contributes to these diverse physiological functions of P2X receptors. Here, we report the crystal structure of an invertebrate P2X receptor from the Gulf Coast tick Amblyomma maculatum in the presence of ATP and Zn2+ ion, together with electrophysiological and computational analyses. The structure revealed two distinct metal binding sites, M1 and M2, in the extracellular region. The M1 site, located at the trimer interface, is responsible for Zn2+ potentiation by facilitating the structural change of the extracellular domain for pore opening. In contrast, the M2 site, coupled with the ATP binding site, might contribute to regulation by Mg2+. Overall, our work provides structural insights into the divalent cation modulations of P2X receptors.

  20. Expression and functional role of P2X receptors in neonatal pituitary gonadotrophs

    Balík, Aleš; Mazna, Petr; Zemková, Hana

    Vienna, 2006. [Forum of European Neuroscience /5./. 08.07.2006-12.07.2006, Vienna] R&D Projects: GA AV ČR(CZ) IAA5011408 Institutional research plan: CEZ:AV0Z50110509 Keywords : P2X receptor * neonatal gonadotrophs Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  1. 2x40 Gbit/s Polarization Division Multiplexing With Bit Slot Synchronization

    Jens; C.; Rasmussen; George; Ishikawa; Tamio; Saito

    2003-01-01

    Polarization division multiplexing (PDM) can double the spectral efficiency of an optical transmission system. By means of simulation, the 2x40Gbit/s NRZ PDM system performance under polarization mode dispersion (PMD) and chromatic dispersion has been investigated. To realize the best performance, the bit slots of the two channels should be synchronized.

  2. Testing of the J-2X Augmented Spark Igniter (ASI) and Its Electronics

    Osborne, Robin

    2015-01-01

    Reliable operation of the spark ignition system electronics in the J-2X Augmented Spark Igniter (ASI) is imperative in assuring ASI ignition and subsequent Main Combustion Chamber (MCC) ignition events are reliable in the J-2X Engine. Similar to the man-rated J-2 and RS-25 engines, the J-2X ignition system electronics are equipped with spark monitor outputs intended to indicate that the spark igniters are properly energized and sparking. To better understand anomalous spark monitor data collected on the J-2X development engines at NASA Stennis Space Center (SSC), a comprehensive subsystem study of the engine's low- and high-tension spark ignition system electronics was conducted at NASA Marshall Space Flight Center (MSFC). Spark monitor output data were compared to more detailed spark diagnostics to determine if the spark monitor was an accurate indication of actual sparking events. In addition, ignition system electronics data were closely scrutinized for any indication of an electrical discharge in some location other than the firing tip of the spark igniter - a problem not uncommon in the development of high voltage ignition systems.

  3. The P2X7 Receptor Supports Both Life and Death in Fibrogenic Pancreatic Stellate Cells

    Haanes, Kristian; Schwab, Albrecht; Novak, Ivana

    2012-01-01

    The pancreatic stellate cells (PSCs) have complex roles in pancreas, including tissue repair and fibrosis. PSCs surround ATP releasing exocrine cells, but little is known about purinergic receptors and their function in PSCs. Our aim was to resolve whether PSCs express the multifunctional P2X7...... fibrosis and cancer....

  4. Unbalanced 2 x 2 factorial designs and the interaction effect : A troublesome combination

    Landsheer, Johannes A.; Van Wittenboer, Godfried Den

    2015-01-01

    In this power study, ANOVAs of unbalanced and balanced 2 x 2 datasets are compared (N = 120). Datasets are created under the assumption that H1 of the effects is true. The effects are constructed in two ways, assuming: 1. contributions to the effects solely in the treatment groups; 2. contrasting co

  5. Procrastination and the 2 x 2 Achievement Goal Framework in Malaysian Undergraduate Students

    Ganesan, Rajalakshmi; Mamat, Norul Hidayah Bt; Mellor, David; Rizzuto, Laura; Kolar, Christina

    2014-01-01

    The present study investigated academic procrastination in the context of the 2 x 2 goal achievement theoretical framework within a population of 450 Malaysian undergraduate students, aged 18 to 25 years. Participants completed the Achievement Goal Questionnaire and the Tuckman Procrastination Test. Approach dimensions of both the mastery and…

  6. Lack of a Functioning P2X7 Receptor Leads to Increased Susceptibility to Toxoplasmic Ileitis.

    Catherine M Miller

    Full Text Available Oral infection of C57BL/6J mice with the protozoan parasite Toxoplasma gondii leads to a lethal inflammatory ileitis.Mice lacking the purinergic receptor P2X7R are acutely susceptible to toxoplasmic ileitis, losing significantly more weight than C57BL/6J mice and exhibiting much greater intestinal inflammatory pathology in response to infection with only 10 cysts of T. gondii. This susceptibility is not dependent on the ability of P2X7R-deficient mice to control the parasite, which they accomplish just as efficiently as C57BL/6J mice. Rather, susceptibility is associated with elevated ileal concentrations of pro-inflammatory cytokines, reactive nitrogen intermediates and altered regulation of elements of NFκB activation in P2X7R-deficient mice.Our data support the thesis that P2X7R, a well-documented activator of pro-inflammatory cytokine production, also plays an important role in the regulation of intestinal inflammation.

  7. Color-Space-Based Visual-MIMO for V2X Communication †

    Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

    2016-01-01

    In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance. PMID:27120603

  8. Superconductivity and disorder effect in TlNi2Se2-x S x compounds

    Wang, Hangdong; Mao, Qianhui; Chen, Huimin; Su, Qiping; Dong, Chiheng; Khan, Rajwali; Yang, Jinhu; Chen, Bin; Fang, Minghu

    2015-10-01

    After our first discovery of multi-band superconductivity (SC) in the TlNi2Se2 crystal, we successfully grew a series of TlNi2Se2-x S x (0.0≤slant x≤slant 2.0 ) single crystals. Measurements of resistivity, specific heat, and susceptibility were carried out on these crystals. Superconductivity with {{T}\\text{C}}=2.3 K was first observed in the TlNi2S2 crystal, which also appears to involve heavy electrons with an effective mass m*=13 -25 {{m}\\text{b}} , as inferred from the normal state electronic specific heat and the upper critical field, {{H}\\text{C2}}(T) . It was found that bulk SC and heavy-electron behavior is preserved in all the studied TlNi2Se2-x S x samples. In the mixed state, a novel change of the field dependence of the residual specific heat coefficient, {γ\\text{N}}(H) , occurs in TlNi2Se2-x S x with increasing S content. We also found that the {{T}\\text{C}} value changes with the disorder degree induced by the partial substitution of S for Se, characterized by the residual resistivity ratio (RRR). Thus, the TlNi2Se2-x S x system provides a platform to study the effect of disorder on the multi-band SC.

  9. Superconductivity and disorder effect in TlNi2Se(2-x)S(x) compounds.

    Wang, Hangdong; Mao, Qianhui; Chen, Huimin; Su, Qiping; Dong, Chiheng; Khan, Rajwali; Yang, Jinhu; Chen, Bin; Fang, Minghu

    2015-10-01

    After our first discovery of multi-band superconductivity (SC) in the TlNi2Se2 crystal, we successfully grew a series of TlNi2Se(2-x)S(x) (0.0 ≤ x ≤ 2.0) single crystals. Measurements of resistivity, specific heat, and susceptibility were carried out on these crystals. Superconductivity with T(C) = 2.3 K was first observed in the TlNi2S2 crystal, which also appears to involve heavy electrons with an effective mass m* = 13-25 m(b), as inferred from the normal state electronic specific heat and the upper critical field, H(C2)(T). It was found that bulk SC and heavy-electron behavior is preserved in all the studied TlNi2Se(2-x)S(x) samples. In the mixed state, a novel change of the field dependence of the residual specific heat coefficient, γ(N)(H), occurs in TlNi2Se(2-x)S(x) with increasing S content. We also found that the T(C) value changes with the disorder degree induced by the partial substitution of S for Se, characterized by the residual resistivity ratio (RRR). Thus, the TlNi2Se(2-x)S(x) system provides a platform to study the effect of disorder on the multi-band SC. PMID:26381523

  10. d≥5 static black holes with S2xSd-4 event horizon topology

    We present numerical evidence for the existence of new black hole solutions in d≥6 spacetime dimensions. They approach asymptotically the Minkowski background and have an event horizon topology S2xSd-4. These static solutions share the basic properties of the nonrotating black rings in five dimensions, in particular the presence of a conical singularity.

  11. Ultrasmall Cu2-x S Nanodots for Highly Efficient Photoacoustic Imaging-Guided Photothermal Therapy.

    Mou, Juan; Li, Pei; Liu, Chengbo; Xu, Huixiong; Song, Liang; Wang, Jin; Zhang, Kun; Chen, Yu; Shi, Jianlin; Chen, Hangrong

    2015-05-20

    Monodisperse, ultrasmall (u-Cu(2-x)S NDs) with significantly strong near-infrared absorption and conversion are successfully demonstrated for effective deep-tissue photoacoustic imaging-guided photothermal therapy both in vitro and in vivo. Owing to ultrasmall nanoparticle size and high water dispersibility as well as long stability, such nanodots possess a prolonged circulation in blood and good passive accumulation within tumors through the enhanced permeability and retention effect. These u-Cu(2-x)S NDs have negligible side effects to both blood and normal tissues according to in vivo toxicity evaluations for up to 3 months, showing excellent hemo/histocompatibility. Furthermore, these u-Cu(2-x)S NDs can be thoroughly cleared through feces and urine within 5 days, showing high biosafety for further potential clinical translation. This novel photoacoustic imaging-guided photothermal therapy based on u-Cu(2-x)S NDs composed of a single component shows great prospects as a multifunctional nanoplatform with integration and multifunction for cancer diagnosis and therapy. PMID:25641784

  12. Downregulation of adenosine and P2X receptor-mediated cardiovascular responses in heart failure rats

    Zhao, Xin; Sun, X Y; Erlinge, D;

    2000-01-01

    degradation product adenosine, experiments were performed in a rat model of ischaemic CHF. In this model, ischaemia was induced in rats by ligation of the left coronary artery. Our results demonstrate that there is a selective downregulation of P2X receptor-mediated pressor effects, while the hypotensive...

  13. The therapeutic promise of ATP antagonism at P2X3 receptors in respiratory & urological disorders

    Anthony Ford

    2013-12-01

    Full Text Available A sensory role for ATP was proposed long before general acceptance of its extracellular role. ATP activates & sensitizes signal transmission at multiple sites along the sensory axis, across multiple synapses. P2X & P2Y receptors mediate ATP modulation of sensory pathways & participate in dysregulation, where ATP action directly on primary afferent neurons (PANs, linking receptive field to CNS, has received much attention. Many PANs, especially C-fibers, are activated by ATP, via P2X3-containing trimers. P2X3 knock-out mice & knock-down in rats led to reduced nocifensive activity & visceral reflexes, suggesting that antagonism may offer benefit in sensory disorders. Recently, drug-like P2X3 antagonists, active in a many inflammatory & visceral pain models, have emerged. Significantly, these compounds have no overt CNS action & are inactive versus acute nociception. Selectively targeting ATP sensitization of PANs may lead to therapies that block inappropriate chronic signals at their source, decreasing drivers of peripheral & central wind-up, yet leaving defensive nociceptive and brain functions unperturbed. This article reviews this evidence, focusing on how ATP sensitization of PANs in visceral “hollow” organs primes them to chronic discomfort, irritation & pain (symptoms as well as exacerbated autonomic reflexes (signs, & how the use of isolated organ-nerve preparations has revealed this mechanism. Urinary & airways systems share many features: dependence on continuous afferent traffic to brainstem centers to coordinate efferent autonomic outflow; loss of descending inhibitory influence in functional & sensory disorders; dependence on ATP in mediating sensory responses to diverse mechanical and chemical stimuli; a mechanistically overlapping array of existing medicines for pathological conditions. These similarities may also play out in terms of future treatment of signs & symptoms, in the potential for benefit of P2X3 antagonists.

  14. Co-Expression of Wild-Type P2X7R with Gln460Arg Variant Alters Receptor Function

    Aprile-Garcia, Fernando; Metzger, Michael W.; Paez-Pereda, Marcelo; Stadler, Herbert; Acuña, Matías; Liberman, Ana C.; Senin, Sergio A.; Gerez, Juan; Hoijman, Esteban; Refojo, Damian; Mitkovski, Mišo; Panhuysen, Markus; Stühmer, Walter; Holsboer, Florian; Deussing, Jan M.; Arzt, Eduardo

    2016-01-01

    The P2X7 receptor is a member of the P2X family of ligand-gated ion channels. A single-nucleotide polymorphism leading to a glutamine (Gln) by arginine (Arg) substitution at codon 460 of the purinergic P2X7 receptor (P2X7R) has been associated with mood disorders. No change in function (loss or gain) has been described for this SNP so far. Here we show that although the P2X7R-Gln460Arg variant per se is not compromised in its function, co-expression of wild-type P2X7R with P2X7R-Gln460Arg impairs receptor function with respect to calcium influx, channel currents and intracellular signaling in vitro. Moreover, co-immunoprecipitation and FRET studies show that the P2X7R-Gln460Arg variant physically interacts with P2X7R-WT. Specific silencing of either the normal or polymorphic variant rescues the heterozygous loss of function phenotype and restores normal function. The described loss of function due to co-expression, unique for mutations in the P2RX7 gene so far, explains the mechanism by which the P2X7R-Gln460Arg variant affects the normal function of the channel and may represent a mechanism of action for other mutations. PMID:26986975

  15. Thermonuclear device

    Purpose: To provide a thermonuclear device which causes the thermal expansion of a vacuum vessel to freely escape without refraining and is provided with a vacuum vessel having an excellently large rigidity against an electromagnetic force transiently acting whils retaining a predetermined position. Constitution: The device for supporting the vacuum vessel comprises piston cylinder means in which a pressurized fluid is sealed in cylinder chambers at both sides of a piston and with which these cylinder chambers are liquidly communicated through throttling means, and means for fixing any of the piston and the cylinder of said piston cylinder means to a bed-plate retaining the support device and another to the vacuum vessel. The vacuum vessel is retained through a connecting rod or the like connected to the cylinder of the support device. (Aizawa, K.)

  16. Ferroelectric devices

    Uchino, Kenji

    2009-01-01

    Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat

  17. Preparation and characterization of Al{sub 2x}In{sub 2−2x}O{sub 3} films deposited on MgO (1 0 0) by MOCVD

    Li, Zhao; Ma, Jin, E-mail: jinmasdu@163.com; Zhao, Cansong; Du, Xuejian; Mi, Wei; Luan, Caina; Feng, Xianjin

    2015-07-15

    Highlights: • Ternary Al{sub 2x}In{sub 2−2x}O{sub 3} alloy films were deposited on MgO (1 0 0) by MOCVD. • The microstructure of the Al{sub 2x}In{sub 2−2x}O{sub 3} films were studied upon HRTEM. • Al{sub 2x}In{sub 2−2x}O{sub 3} alloy films exhibited great optical transparency in the visible wavelength range. • The band gap of the Al{sub 2x}In{sub 2−2x}O{sub 3} films can be modulated by controlling the Al contents in the samples. - Abstract: The ternary Al{sub 2x}In{sub 2−2x}O{sub 3} films with different compositions x[Al/(Al + In) atomic ratio] have been fabricated on the MgO (1 0 0) substrates by the metal organic chemical vapor deposition (MOCVD) method. The influence of different Al contents on the structural, optical and electrical properties of Al{sub 2x}In{sub 2−2x}O{sub 3} films has been studied. The structural studies reveal a change from single crystalline structure of cubic In{sub 2}O{sub 3} to amorphous as the Al content increases. The average transmittances of all samples in the visible range are over 80%. The optical band gap is observed to increase monotonically from 3.67 to 5.38 eV as the Al content increases from 0.1 to 0.9.

  18. Effect of P2X(7) receptor knockout on exocrine secretion of pancreas, salivary glands and lacrimal glands

    Novak, Ivana; Jans, Ida M; Wohlfahrt, Louise

    2010-01-01

    The purinergic P2X(7) receptors are expressed in different cell types where they have varied functions, including regulation of cell survival. The P2X(7) receptors are also expressed in exocrine glands, but their integrated role in secretion is unclear. The aim of our study was to determine whether...... release and intracellular Ca(2+) activity using Fura-2. The data showed that pancreatic secretion and salivary secretions were reduced in P2X(7)(-/-) mice, and in contrast, tear secretion was increased in P2X(7)(-/-) mice. The secretory phenotype was also dependent on the sex of the animal, such that...... males were more dependent on the P2X(7) receptor expression. ATP release in all cell preparations could be elicited by carbachol and other agonists, and this was independent of the P2X(7) receptor expression. ATP and carbachol increased intracellular Ca(2+) activity, but responses depended on the gland...

  19. From Paper to Production to Test: An Update on NASA's J-2X Engine for Exploration

    Kynard, Michael

    2011-01-01

    The NASA/industry team responsible for developing the J-2X upper stage engine for the Space Launch System (SLS) Program has made significant progress toward moving beyond the design phase and into production, assembly, and test of development hardware. The J-2X engine exemplifies the SLS Program goal of using proven technology and experience from more than 50 years of United States spaceflight experience combined with modern manufacturing processes and approaches. It will power the second stage of the fully evolved SLS Program launch vehicle that will enable a return to human exploration of space beyond low earth orbit. Pratt & Whitney Rocketdyne (PWR) is under contract to develop and produce the engine, leveraging its flight-proven LH2/LOX, gas generator cycle J-2 and RS-68 engine capabilities, recent experience with the X-33 aerospike XRS-2200 engine, and development knowledge of the J-2S tap-off cycle engine. The J- 2X employs a gas generator operating cycle designed to produce 294,000 pounds of vacuum thrust in primary operating mode with its full nozzle extension. With a truncated nozzle extension suitable to support engine clustering on the stage, the nominal vacuum thrust level in primary mode is 285,000 pounds. It also has a secondary mode, during which it operates at 80 percent thrust by altering its mixture ratio. The J-2X development philosophy is based on proven hardware, an aggressive development schedule, and early risk reduction. NASA Marshall Space Flight Center (MSFC) and PWR began development of the J-2X in June 2006. The government/industry team of more than 600 people within NASA and PWR successfully completed the Critical Design Review (CDR) in November 2008, following extensive risk mitigation testing. Assembly of the first development engine was completed in May 2011 and the first engine test was conducted at the NASA Stennis Space Center (SSC), test stand A2, on 14 July 2011. Testing of the first development engine will continue through the

  20. Optimized effective potential model for the double perovskites Sr2-xYxVMoO6 and Sr2-xYxVTcO6

    In an attempt to explore half-metallic properties of the double perovskites Sr2-xYxVMoO6 and Sr2-xYxVTcO6, we construct an effective low-energy model, which describes the behavior of the t2g states of these compounds. All parameters of such a model are derived rigorously on the basis of first-principles electronic structure calculations. In order to solve this model, we employ the optimized effective potential method and treat the correlation interactions in the random phase approximation. Although correlation interactions considerably reduce the intraatomic exchange splitting in comparison with the Hartree-Fock approach, this splitting still substantially exceeds the typical values obtained in the local-spin-density approximation (LSDA), which alters many predictions based on the LSDA. Our main results are summarized as follows. (i) All ferromagnetic states are expected to be half-metallic. However, their energies are generally higher than those of the ferrimagnetic ordering between V and Mo/Tc sites (except Sr2VMoO6). (ii) All ferrimagnetic states are metallic (except fully insulating Y2VTcO6) and no half-metallic antiferromagnetism has been found. (iii) Moreover, many of the ferrimagnetic structures appear to be unstable with respect to the spin-spiral alignment. Thus, the true magnetic ground state of these systems is expected to be more complex. In addition, we discuss several methodological issues related to nonuniqueness of the effective potential for the half-metallic and magnetic insulating states.

  1. Alteration of P2X3 expression in dorsal root ganglia after sciatic nerve ligation

    Guoxing Zhou; Lesi Xie; Qiben Wang; Qingping Yu; Xiaofu Liu; Qiumei Liu; Wei Peng; Zhicheng Zeng

    2007-01-01

    BACKGROUND: The expressions of P2X3 receptor in dorsal root ganglia (DRG) after different peripheral nerve injuries are diverse. It indicates the different roles of P2X3 in different models-caused neuropathologic pains.OBJECTIVE: To observe the expressions of P2X3 in corresponding DRG after sciatic nerve ligation in rats.DESIGN: Controlled observation experiment.SETTING: Department of Morphology, Hunan Traditional Chinese Medical College; Department of Human Anatomy and Neurobiology, Xiangya Medical College, Central South University.MATERIALS: Thirty-five healthy adult SD rats of clean grade an d either gender, weighing (200±20) g,were involved. According to the random digits table, the involved rats were randomized into 3 groups:normal group (n =5), sham-operated group (n =5) and experimental group (n =25). The experimental group were subdivided into 3, 7, 14, 21, 28 days groups according to different surviving time after operation, 5 rats at each time point. Polyclonal rabbit anti-P2X3 antibody (ABCAM company); biotinylated goat anti-rabbit IgG (Zhongshanjingqiao Biotechnical Co., Ltd., Beijing); Motic fluorescence microscope (Motic, Germany).METHODS: The experiments were carried out in the Department of Human Anatomy and Neurobiology,Xiangya Medical College, Central South University from June to December 2006. ① Rats of experimental group were created into models by ligation of right sciatic nerve according to the method of Seltzer et al. Left sciatic nerve was used as self-control. As for rats in the sham-operated group, ligation of sciatic nerve was omitted, but other procedures were the same as those in the experimental group. Rats of normal group were untouched. ② Rats of the normal group and sham-operated group survived for 14 days separately, and those of experimental group survived for corresponding time. After being deeply anesthetized by intraperitoneal injection of over-dose sodium pentobarbital, the rats of experimental group were transcardially

  2. Effect of P2X4R on airway inflammation and airway remodeling in allergic airway challenge in mice

    CHEN, HONGXIA; Xia, Qingqing; FENG, XIAOQIAN; CAO, FANGYUAN; Yu, Hang; SONG, YINLI; NI, XIUQIN

    2015-01-01

    P2X4 receptor (P2X4R) is the most widely expressed subtype of the P2XRs in the purinergic receptor family. Adenosine triphosphate (ATP), a ligand for this receptor, has been implicated in the pathogenesis of asthma. ATP-P2X4R signaling is involved in pulmonary vascular remodeling, and in the proliferation and differentiation of airway and alveolar epithelial cell lines. However, the role of P2X4R in asthma remains to be elucidated. This aim of the present study was to investigate the effects ...

  3. The S-matrix algebra of the AdS2 X S2 superstring

    Hoare, Ben; Torrielli, Alessandro

    2015-01-01

    In this paper we find the Yangian algebra responsible for the integrability of the AdS2 X S2 X T^6 superstring in the planar limit. We demonstrate the symmetry of the corresponding exact S-matrix in the massive sector, including the presence of the secret symmetry. We give two alternative presentations of the Hopf algebra, along with related discussions on the issue of evaluation representations. We study the classical r-matrix, and re-discover the need for a secret symmetry also in this context. Finally, taking the simplifying zero-coupling limit of the S-matrix as a generating R-matrix for the Algebraic Bethe Ansatz, we obtain an effective model of free fermions on a periodic spin-chain. This limit should provide hints to the one-loop anomalous dimension of the mysterious superconformal quantum mechanics dual to the superstring theory in this geometry.

  4. Synthesis and characterization of Cu/SiO 2- x composite nanowires

    Jin, A. Z.; Wang, Y. G.; Zhang, Z.

    2003-05-01

    Copper/silica-based nanostructures with different morphologies and microstructures have been synthesized on Si wafer by thermal evaporation of CuO and SiO powders in an argon-hybridized hydrogen ambient at high temperatures. Systematically studies by scanning electron microscopy with field emission gun and transmission electron microscopy show that the composite nanowires have a core-shell structure with an average diameter of ˜120 nm and lengths of several hundred nanometers to several ten microns. Electron diffraction pattern and electron energy dispersive X-ray spectroscopy analysis reveal that the core coincides with copper and the shell corresponds to amorphous silicon oxide with chemical composition SiO 2- x (0≦ x≦0.5). Besides the Cu/SiO 2- x nanowires, many other nanostructures such as octpous-, pine-, and chain-like structures have also been found. The growth mechanisms of these products were briefly discussed.

  5. Thermal expansion properties of Lu2-x FexMo3O12

    Wu Mei-Mei; Peng Jie; Zu Yong; Liu Rong-Deng; Hu Zhong-Bo; Liu Yun-Tao; Chen Dong-Feng

    2012-01-01

    The structures and thermal expansion properties of Lu2-xFex Mo3O12 have been investigated by X-ray diffraction (XRD).XRD patterns at room temperature indicate that componnds Lu2 xFexMo3O12 with x ≤ 1.3 exhibit an orthorhombic structure with space group Pnca;compounds with x =1.5 and 1.7 have a monoclinic structure with space group P21/a.Studies on thermal expansion properties show that the linear thermal expansion coefficients of orthorhombic phase vary from negative to positive with increasing Fe content.Attempts to make zero thermal expansion materials indicate that zero thermal expansion can be observed in Lu1.3Feo.7Mo3O12 in the temperature range of 200-400°C.

  6. Status on the Verification of Combustion Stability for the J-2X Engine Thrust Chamber Assembly

    Casiano, Matthew; Hinerman, Tim; Kenny, R. Jeremy; Hulka, Jim; Barnett, Greg; Dodd, Fred; Martin, Tom

    2013-01-01

    Development is underway of the J -2X engine, a liquid oxygen/liquid hydrogen rocket engine for use on the Space Launch System. The Engine E10001 began hot fire testing in June 2011 and testing will continue with subsequent engines. The J -2X engine main combustion chamber contains both acoustic cavities and baffles. These stability aids are intended to dampen the acoustics in the main combustion chamber. Verification of the engine thrust chamber stability is determined primarily by examining experimental data using a dynamic stability rating technique; however, additional requirements were included to guard against any spontaneous instability or rough combustion. Startup and shutdown chug oscillations are also characterized for this engine. This paper details the stability requirements and verification including low and high frequency dynamics, a discussion on sensor selection and sensor port dynamics, and the process developed to assess combustion stability. A status on the stability results is also provided and discussed.

  7. On the number of chiral generations in Z2xZ2 orbifolds

    The data from collider experiments and cosmic observatories indicates the existence of three light matter generations. In some classes of string compactifications the number of generations is related to a topological quantity, the Euler characteristic. However, these do not explain the existence of three generations. In a class of free fermionic string models, related to the Z2xZ2 orbifold compactification, the existence of three generations is correlated with the existence of three twisted sectors in this class of compactifications. However, the three generation models are constructed in the free fermionic formulation and their geometrical correspondence is not readily available. In this paper we classify quotients of the Z2xZ2 orbifold by additional symmetric shifts on the three complex tori. We show that three generation vacua are not obtained in this manner, indicating that the geometrical structures underlying the free fermionic models are more esoteric

  8. Dynamical optical properties of La2-xSrxCuO4 cuprates

    Schneider, M. L.; Rast, S.; Onellion, M.; Ren, Y.; Zhang, X.; Luepke, G.; Perakis, I.; Abrecht, M.; Ariosa, D.; Pavuna, D.; Zeng, X. H.; Weidong, Si; Xi, X. X.

    2001-03-01

    We present pump-probe optical reflectivity measurements on underdoped, optimally doped and overdoped La2-xSrxCuO4 thin films grown on SrTiO3.[1] We find qualitative changes of the reflectivity with temperature, in particular below and above the superconducting transition temperature. We have measured YBa2Cu3O7-x and NdBa2Cu3O7-y thin films for comparison and present these comparative results. The La2-xSrxCuO4 data indicate the existence of two subsystems within the material. The two subsystems are electronic (or optically active), interact, and they transfer energy between them. We discuss our reasoning on these points. 1. M.L. Schneider et.al., submitted

  9. On the Number of Chiral Generations in Z2 X Z2 Orbifolds

    Donagi, R; Donagi, Ron; Faraggi, Alon E.

    2004-01-01

    The data from collider experiments and cosmic observatories indicates the existence of three light matter generations. In some classes of string compactifications the number of generations is related to a topological quantity, the Euler characteristic. However, these do not explain the existence of three generations. In a class of free fermionic string models, related to the Z2 X Z2 orbifold compactification, the existence of three generations is correlated with the existence of three twisted sectors in this class of compactifications. However, the three generation models are constructed in the free fermionic formulation and their geometrical correspondence is not readily available. In this paper we classify quotients of the Z2 X Z2 orbifold by additional symmetric shifts on the three complex tori. We show that three generation vacua are not obtained in this manner, indicating that the geometrical structures underlying the free fermionic models are more esoteric.

  10. Chemisorption of aromatic molecules on Si(100)-2x1. An HREELS study

    Alkunshalie, T

    1998-07-01

    HREELS has been used to investigate the growth of ultra-thin organic film on Si(100)-2x1 by reactive coupling of polyimide precursors. 1,4- phenylenediamine and pyromelltic dianhydride were sequentially dosed on clean Si(100)-2x1 under ultra high vacuum conditions. The interfacial imidisation was initiated by thermal curing at 200 deg C. To simplify the analysis of the vibrational data, model compounds benzoic acid, aniline and phthalic anhydride were characterised first. HREEL spectra show that the model compounds absorb through dissociation of the functional group. The spectra also show that an oligimide chain has been formed which stands upright on the surface. The oligomer chain bonds to the silicon surface via a Si-(NH)-C linkage. (author)

  11. Hydrogen sensitive gas sensor based on porous silicon/TiO{sub 2-x} structure

    Arakelyan, V.M.; Galstyan, V.E.; Martirosyan, Kh.S.; Shahnazaryan, G.E.; Aroutiounian, V.M. [Yerevan State Univ, Dept Phys Semicond and Microelect, Yerevan 0025, (Armenia); Soukiassian, P.G. [CEA, DSM, DRECAM, SPCSI, Lab SIMA, F-91191 Gif Sur Yvette, (France); Soukiassian, P.G. [Univ Paris 11, Dept Phys, F-91405 Orsay, (France)

    2007-07-01

    Porous silicon (PS) layer was formed by electrochemical anodization on a p-type Si surface. Thereafter, n-type TiO{sub 2-x} thin film was deposited onto the PS surface by electron-beam evaporation. Pt catalytic layer and Au electrical contacts for further measurements were deposited onto the PS/TiO{sub 2-x} structure by ion-beam sputtering. Current-voltage characteristic, sensitivity to different concentration of hydrogen and resistance change of obtained structures versus time were examined. Results of measurements have shown that the current-voltage characteristics of structures are similar to that of diode. High sensitivity to hydrogen of obtained structures was also detected. Note that all measurements were carried out at room temperature. (authors)

  12. Hydrogen sensitive gas sensor based on porous silicon/TiO2-x structure

    Porous silicon (PS) layer was formed by electrochemical anodization on a p-type Si surface. Thereafter, n-type TiO2-x thin film was deposited onto the PS surface by electron-beam evaporation. Pt catalytic layer and Au electrical contacts for further measurements were deposited onto the PS/TiO2-x structure by ion-beam sputtering. Current-voltage characteristic, sensitivity to different concentration of hydrogen and resistance change of obtained structures versus time were examined. Results of measurements have shown that the current-voltage characteristics of structures are similar to that of diode. High sensitivity to hydrogen of obtained structures was also detected. Note that all measurements were carried out at room temperature. (authors)

  13. Electronic properties of Hf2X intermetallic compounds (X = Al, Si, Ni, Ga and Ge)

    The electric field gradient (EFG) parameters were calculated for the binary system Hf2X (X = Al, Si, Ni, Ga and Ge), using the full-potential linear augmented plane wave method, applying the generalized gradient approximation. The major contribution to the EFG value in these compounds comes from the p-p contribution next to the probe nucleus. The only other significant contribution is a d-d contribution to the nickel site in Hf2Ni, arises from the broad spatial distribution of the nickel 3d electrons. The similarity in the electronic properties of the Hf2X compounds, with the exception of Hf2Ni, can be attributed to the resemblance of the crystallographic structure and the alike electronic structure of the X-ligand atom, having one or two p-electrons in the external orbital with close shells below.

  14. 77Se-NMR study of quasi-one dimensional organic conductor (TMTSF)2X

    Quasi-one dimensional organic conductor (TMTSF)2X with octahedral anions X = PF6, AsF6, and SbF6 have been studied by NMR measurements at the Se-sites which are substantially responsible for conductivity in this system. Close resemblances in the temperature dependence of the spin-lattice relaxation rate 1/T1 and the evolution of internal field in the SDW state were observed in the three measured compounds. The existence of the sub-phases in the SDW phase of all these compounds, which is evidenced by T1 but not from spectrum measurements, indicates that this is a common feature among (TMTSF)2X system with an incommensurate SDW wave number and is associated with dynamic property rather than static one.

  15. Magnetic penetration depth in superconducting La2-xSrxCuO4 films

    We have measured the magnetic penetration depth λ(T) in a series of superconducting La2-xSrxCuO4 films with Sr concentrations from x=0.135 to 0.175. λ-2(T)-λ-2(0) is quadratic in T for 0.4C, and higher resistivity of films relative to bulk samples, plus the T2 behavior of λ-2(T)-λ-2(0), lead naturally to the conclusion that superconductivity in La2-xSrxCuO4 is d wave. Near TC the real part of the conductivity and λ(T) are analyzed for critical behavior. The data indicate that the critical region is no wider than 1 K. copyright 1999 The American Physical Society

  16. Synthesis of Plasmonic Cu2-x Se@ZnS Core@Shell Nanoparticles.

    Wolf, Andreas; Härtling, Thomas; Hinrichs, Dominik; Dorfs, Dirk

    2016-03-01

    We report the synthesis of plasmonic Cu2-x Se@ZnS core@shell nanoparticles (NPs). We used a shell growth approach, starting from Cu2-x Se NPs that have been shown before to exhibit a localized surface plasmon resonance (LSPR). By careful synthesis planning we avoided cation exchange reactions and received core@shell nanoparticles that, after oxidation under air, exhibit a strong LSPR in the NIR. Interestingly, the crystalline, closed ZnS shell that we grew with variable thickness still allowed a slow oxidation of the core under ambient conditions, while the core was effectively protected from reduction, even in the presence of reducing agents such as borane tert-butyamine complex and diisobutylaluminum hydride, giving rise to a stable particle LSPR, also under strongly reducing conditions. PMID:26604183

  17. Multiple Exhaust Nozzle Effects on J-2X Gas Generator Outlet Impedance

    Kenny, R. Jeremy; Muss, Jeffrey; Hulka, James R.; Casiano, Matthew

    2010-01-01

    The current test setup of the J-2X gas generator system uses a multiple nozzle configuration to exhaust hot gases to drive the propellant supply turbines. Combustion stability assessment of this gas generator design requires knowledge of the impedance effects the multiple nozzle configuration creates on the combustion chamber acoustic modes. Parallel work between NASA and Sierra Engineering is presented, showing two methods used to calculate the effective end impedance resulting from multiple nozzle configurations. The NASA method is a simple estimate of the effective impedance using the long wavelength approximation. Sierra Engineering has developed a more robust numerical integration method implemented in ROCCID to accommodate for multiple nozzles. Analysis using both methods are compared to J-2X gas generator test data collected over the past year.

  18. Superconducting device

    The present invention provides a superconducting device to be used in a thermonuclear device and capable of unifying a current distribution in a parallel superconducting main line without consumption of liquid helium caused by Joule loss. That is, the device has a paired coils comprising a coil comprising one of plurality of superconducting wires and another coil comprising the other of plurality of superconducting wires and having a reverse winding or negative mutual inductance relative to the coil. A circuit comprising a portion of a main line is disposed to the one coil of the paired coils, and a circuit comprising the remainder of the main line is connected to the other coil each in series. The circuit has a parallel constitution. Such a constitution can provide an effect of unifying the current distribution in the main line without consumption of liquid helium due to Joule loss. (I.S.)

  19. Molecular structure of purinergic P2X receptors and their expression in hypothalamus and pituitary

    Zemková, Hana; Balík, Aleš; Jindřichová, Marie; Vávra, Vojtěch

    2008-01-01

    Roč. 57, Suppl.3 (2008), S23-S38. ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA305/07/0681; GA AV ČR(CZ) IAA5011408; GA AV ČR(CZ) IAA500110702; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : purinergic P2X receptors * hypothalamus * pituitary Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 1.653, year: 2008

  20. P2X antagonists inhibit styryl dye entry into hair cells

    Crumling, Mark A.; Tong, Mingjie; Aschenbach, Krista L.; Liu, Li Qian; Pipitone, Christine M.; Duncan, R Keith

    2009-01-01

    The styryl pyridinium dyes, FM1-43 and AM1-43, are fluorescent molecules that can permeate the mechanotransduction channels of hair cells, the sensory receptors of the inner ear. When these dyes are applied to hair cells, they enter the cytoplasm rapidly, resulting in a readily detectable increase in intracellular fluorescence that is often used as a molecular indication of mechanotransduction channel function. However, such dyes can also permeate the ATP receptor, P2X2. Therefore, we explore...

  1. Inelastic neutron scattering in CeSi2-xGax ferromagnetic Kondo lattice compounds

    An inelastic neutron scattering investigation of the ferromagnetic Kondo lattice compounds belonging to the CeSi2-xGax system that have x = 0.7, 1.0, and 1.3 is reported. In these compounds, the ground state is expected to be split by a crystalline electric field. Using the experimental results, we have calculated the crystal-field parameters for all three compounds studied here. (author)

  2. Results in SU(2) x SU(2) super symmetric gauge theories

    We consider N=1 SU(2) x SU(2) supersymmetric gauge theory with n matter fields transforming in the (2,2) representation and one matter field transforming in the (1,3) representation. For n=0, 1, 2 we derive an exact super potential. Various consistency checks are applied on the result. For n=2 we obtain signals that at special values of the light fields additional degrees of freedom become massless. (orig.)

  3. Expression and fuctional role of P2X receptors in neonatal pituitary gonadotrophs

    Zemková, Hana; Bhattacharyya, Sharmistha; Balík, Aleš

    Prague, 2005. s. 33-33. [Conference of the Czech Neuroscience Society /5./, The Annual Meeting of the Network of European Neuroscience Institutes. 19.11.2005-21.11.2005, Prague] R&D Projects: GA AV ČR(CZ) IAA5011408 Institutional research plan: CEZ:AV0Z50110509 Keywords : P2X receptors * neonatal gonadotrophs Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  4. Elastic neutron diffuse scattering in Zr(Ca, Y)O2-x

    Elastic neutron diffuse scattering has been measured in cubic Zr(Ca, Y)O2-x at room temperature. The very high diffuse scattering (up to 70 Laue) is explained mostly by the oxygen displacements along directions, and by Ca displacements along . The weak short-range order contribution strongly suggests that oxygen vacancies tend to place as second rather than at first neighbours of a Ca stabilizing ion

  5. Blow up for a 2x2 strictly hyperbolic system arising from chemical engineering

    Bourdarias, Christian; Junca, Stéphane

    2009-01-01

    We consider a 2x2 hyperbolic system of conservation laws modeling heat less adsorption of a gaseous mixture with two species and infinite exchange kinetics, close to the system of Chromatography. In this model the velocity is not constant because the sorption effect is taken in account. Our aim is to construct a solution with a velocity which blows up at the characteristic boundary. This phenomenon only occurs in particular but physically relevant cases.

  6. AdS2xS2 as an exact heterotic string background

    Orlando, Domenico

    2005-01-01

    An exact heterotic string theory on an AdS2xS2 background supported by an electromagnetic flux is found as a marginal deformation of an SL(2,R)xSU(2) WZW model. Based on a talk given at NATO Advanced Study Institute and EC Summer School on String Theory: from Gauge Interactions to Cosmology, Cargese, Corsica, France, 7 Jun - 19 Jun 2004.

  7. The oxygen defect chemistry of La2-xSrxCuO4-x/2+δ

    This paper reports equilibrium oxygen stoichiometry of La2-xSrxCuO4±y (x = 0, 0.2, 0.4, and 1.0) determined by TGA at temperatures between 800 and 1050 degrees C and oxygen partial pressures between 1 and 10-4 atmospheres. The changes in oxygen content with temperature, oxygen partial pressure, and strontium concentration are evaluated in terms of a defect model

  8. Data transmission from the DRON-2 X-ray diffractometers to a computer

    The circuit of data transmission from DRON-2 X-ray diffractometer to a measurement-computation complex based on UVK SM-3 computer and CAMAC crate is described. The data is transmitted along two-wire TRP 1x2 telephone line of 'current loop type'. Pulses from intensity channel outlet are transmitted as unipolar mark pulses of ∼1 μs duration. The channels are separated by amplitudes

  9. (TMTTF)2Br: first organic superconductor in the (TMTTF)2X family

    Superconductivity in quasi-1-dimensional organic conductors is shown not to be confined to the selenium-containing (TMTSF)2X series (TMTSF=tetramethyltetraselenafulvalene). The title compound is shown to exhibit superconductivity in the 1 K range provided the spin density wave ground state is suppressed by the application of pressure, leading to conclusions about the origin of pairing strength in organic conductors. (orig.)

  10. (TMTTF)[sub 2]Br: first organic superconductor in the (TMTTF)[sub 2]X family

    Balicas, L. (Paris-Sud Univ., 91 - Orsay (France). Lab. de Physique des Solides); Behnia, K. (Paris-Sud Univ., 91 - Orsay (France). Lab. de Physique des Solides); Kang, Woun (Ewha Womans Univ., Seoul (Korea, Republic of). Dept. of Physics); Auban-Senzier, P. (Paris-Sud Univ., 91 - Orsay (France). Lab. de Physique des Solides); Canadell, E. (Paris-11 Univ., 91 - Orsay (France). Lab. de Chimie Theorique); Jerome, D. (Paris-Sud Univ., 91 - Orsay (France). Lab. de Physique des Solides); Ribault, M. (Paris-Sud Univ., 91 - Orsay (France). Lab. de Physique des Solides); Fabre, J.M. (Montpellier-2 Univ., 34 (France). Lab. de Chimie Organique et Structurale)

    1994-10-01

    Superconductivity in quasi-1-dimensional organic conductors is shown not to be confined to the selenium-containing (TMTSF)[sub 2]X series (TMTSF=tetramethyltetraselenafulvalene). The title compound is shown to exhibit superconductivity in the 1 K range provided the spin density wave ground state is suppressed by the application of pressure, leading to conclusions about the origin of pairing strength in organic conductors. (orig.)

  11. Effects of low-energy ion bombardment on RF sputtered MoS2-x films

    Ion bombardment at glancing incidence (670 from substrate normal) with 300 eV argon ions during deposition is shown to have a pronounced densification effect on MoS2-x thin films. Comparison with as-sputtered samples gave a density increase of up to 100%, depending on the ion dose and substrate temperature during deposition. Resputtering of the growing film occurs as a result of the off-normal incidence of the ion beam. (author)

  12. DVB-S2X-enabled precoding for high throughput satellite systems

    Arapoglou, Pantelis-Daniel; Ginesi, Alberto; Cioni, Stefano; Erl, Stefan; Clazzer, Federico; Andrenacci, Stefano; Vanelli-Coralli, Alessandro

    2015-01-01

    Multi-user multiple-input multiple-output (MU-MIMO) has allowed recent releases of terrestrial long-term evolution standards to achieve significant improvements in terms of offered system capacity. The publication of the DVB-S2X standard and particularly of its novel superframe structure is a key enabler for applying similar interference management techniques –such as precoding– to multibeam high throughput satellite (HTS) systems. This paper presents results from the European Space Agency-fu...

  13. DVB-S2x Enabled Precoding for High Throughput Satellite Systems

    Arapoglou, Pantelis-Daniel; Ginesi, Alberto; Cioni, Stefano; Erl, Stefan; Clazzer, Federico; Andrenacci, Stefano; Vanelli-Coralli, Alessandro

    2015-01-01

    Multi-user Multiple-Input Multiple-Output (MU-MIMO) has allowed recent releases of terrestrial LTE standards to achieve significant improvements in terms of offered system capacity. The publications of the DVB-S2x standard and particularly of its novel superframe structure is a key enabler for applying similar interference management techniques -such as precoding- to multibeam High Throughput Satellite (HTS) systems. This paper presents results resulting from European Space Agency (ESA) funde...

  14. A simulation study of rater agreement measures with 2x2 contingency tables

    Ana Benavente; Juan José López; Manuel Ato

    2012-01-01

    Un estudio de simulacion de medidas de acuerdo entre observadores para tablas de contingencia 2x2. Mediante un estudio de simulacion se aborda una comparacion entre seis medidas obtenidas usando tres enfoques diferentes para la evaluacion del acuerdo. Los coeficientes de acuerdo elegidos fueron sigma de Bennet (1954), Pi de Scott (1955), Kappa de Cohen (1960) y gamma de Gwet (2001; 2008) para representar el enfoque clasico descriptivo, el coeficiente alpha de Aickin (1990), para representar e...

  15. Radiative corrections in SU2 x U1 LEP/SLC

    We show the sensitivity of various experimental measurements to one-loop radiative corrections in SU2 x U1. Models considered are the standard GSW model as well as extensions of it which include extra quarks and leptons, SUSY and certain technicolor models. The observation of longitudinal polarization is a great help in seeing these effects in asymmetries in e+e- → μ+μ-, tau+tau- on Z0 resonance. 25 refs., 22 figs., 10 tabs

  16. Synthesis and growth mechanism of dendritic Cu{sub 2-x}Se microstructures

    Filippo, Emanuela, E-mail: emanuela.filippo@unisalento.it [Department of Material Science, University of Salento I, 73100 Lecce (Italy); Manno, Daniela; Serra, Antonio [Department of Material Science, University of Salento I, 73100 Lecce (Italy)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Dendritic crystalline Cu{sub 2-x}Se microstructures were obtained by thermal annealing. Black-Right-Pointing-Pointer CuSe powder was used as starting material and substrate for the growth. Black-Right-Pointing-Pointer Each dendrite is composed of a long central trunk with secondary branches. Black-Right-Pointing-Pointer The lateral branches grow in parallel at about 60 Degree-Sign respect to the central trunk. - Abstract: Dendritic crystalline copper selenides Cu{sub 2-x}Se microstructures with various dimensions have been fabricated in large scale through thermal treatment of CuSe powder in argon flow, without any catalyst. The CuSe powder grains were used as both reagents and substrates for the growth of the Cu{sub 2-x}Se dendrites. The synthesized microstructures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, selected area diffraction pattern and Raman spectroscopy. Each individual dendrite was mainly composed of a long central trunk with secondary lateral branches. The length of the main trunk was in the range 10-30 {mu}m, the width of the secondary branch lay in the range 1-5 {mu}m. The trunk was about 1-2 {mu}m in diameter while the lateral branches were about 0.4-0.8 {mu}m in diameter. The lateral branches grew in parallel and kept about 60 Degree-Sign with respect to the central trunk. A possible growth mechanism has been also proposed to account the growth of these Cu{sub 2-x}Se dendritic microstructures.

  17. Synthesis and Characterization of LiCoxMn2-xO4 Cathode Materials

    YAO Yaochun; DAI Yongnian; YANG Bin; MA Wenhui; Takayuki Watanabe

    2007-01-01

    LiCoxMn2-xO4 cathode materials for lithium ion batteries were synthesized by mechanical activation-solid state reaction at 750℃ for 24 h in air atmosphere, and their crystal structure, morphology, element composition and electrochemical performance were characterized with XRD, SEM, ICP-AES and charge-discharge test. The experimental results show that all samples have a single spinel structure, well formed crystal shape and uniformly particle size distribution. The lattice parameters of LiCoxMa2-xO4 decrease and the average oxidation states of manganese ions increase with an increase in Co content. Compared with pure LiMn2O4, the LiCoxMn2-xO4(x=0.03-0.12) samples show a lower special capacity, but their cycling life are improved. The capacity loss of LiCo0.09Mn1.91O4 and LiCo0.12Mn1.88O4 is only 0.95% ,respectively, after the 20th cycle. The improvement of the cycle performance is attributed to the substitution of Co at the Mn sites in the spinel structure, which suppresses the Jahn-Teller distortion and improves the structural stability.

  18. The Grid Density Dependence of the Unsteady Pressures of the J-2X Turbines

    Schmauch, Preston B.

    2011-01-01

    The J-2X engine was originally designed for the upper stage of the cancelled Crew Launch Vehicle. Although the Crew Launch Vehicle was cancelled the J-2X engine, which is currently undergoing hot-fire testing, may be used on future programs. The J-2X engine is a direct descendent of the J-2 engine which powered the upper stage during the Apollo program. Many changes including a thrust increase from 230K to 294K lbf have been implemented in this engine. As part of the design requirements, the turbine blades must meet minimum high cycle fatigue factors of safety for various vibrational modes that have resonant frequencies in the engine's operating range. The unsteady blade loading is calculated directly from CFD simulations. A grid density study was performed to understand the sensitivity of the spatial loading and the magnitude of the on blade loading due to changes in grid density. Given that the unsteady blade loading has a first order effect on the high cycle fatigue factors of safety, it is important to understand the level of convergence when applying the unsteady loads. The convergence of the unsteady pressures of several grid densities will be presented for various frequencies in the engine's operating range.

  19. Thermodynamic stabilities of MO2+x(s) (M = U, Np, Pu and Am), pourbaix diagrams

    The experimental solubilities of the hydrated amorphous freshly precipitated M(OH)z(am) and MO2(OH)z(am) compounds are often used as an upper limit for the safety assessments of deep waste repositories, since these compounds slowly transform to less soluble ones, as typically M(OH)4(am) to MO2(cr). Solubility (vs. redox potential) at pH=8, and E-pH predominance diagrams are plotted in aqueous solutions at 25degC by using thermodynamic data recently selected by the NEA-TDB review, or estimated by using classical chemical analogies for the non-redox reactions. The solubilities and relative stabilities are also calculated for the MO2+x(s) crystalline compounds of known stabilities: U4O9(s), U3O7(s), U3O8(s) and Np2O5(s) where 2+x = 2.25, 2.33, 2.67 and 2.5 respectively. The stabilities of the other MO2+x(s) compounds are estimated by analogy: M4O9(s) (M=U, Np, Pu), M3O7(s) and M3O8(s) (M=U, Pu), and M2O5(s) (M=Np, Am) are predicted to be more stable (i.e. less soluble), than the amorphous hydroxides. However their precipitation have never been observed at room temperature possibly for kinetic reasons or difficulties in interpreting solubility experiments. (author)

  20. Association between P2X7 Receptor Polymorphisms and Bone Status in Mice

    Syberg, Susanne; Schwarz, Peter; Petersen, Solveig; Steinberg, Thomas H; Jensen, Jens-Erik Beck; Teilmann, Jenni; Jørgensen, Niklas Rye

    2012-01-01

    different bone phenotype. By sequencing the most common strains of inbred mice, we found that only a few strains (BALB, NOD, NZW, and 129) were harboring the wild allelic version of the mutation (P451) in the gene for the purinergic receptor P2X7. The strains were compared by means of dual energy X-ray......Macrophages from mouse strains with the naturally occurring mutation P451L in the purinergic receptor P2X7 have impaired responses to agonists (1). Because P2X7 receptors are expressed in bone cells and are implicated in bone physiology, we asked whether strains with the P451L mutation have a......Bl/6 (B6) and DBA/2J mice. In strains with the 451L allele, pore-formation activity in osteoclasts in vitro was lower after application of ATP. In conclusion, two strains with the 451L allele of the naturally occurring mutation P451L, have weaker bones and lower levels of CTX, suggesting lower...

  1. Oxygen potential of Th1-yUyO2+x

    Oxygen potentials of UO2-ThO2 solid solutions (Th1-yUyO2+x) were retrieved from literature and stored in a database. For each datapoint the oxygen pressure pO2 the nonstoichiometry x, the temperature T and the uranium concentration y was specified. The data were analyzed using a defect model, which includes electronic disorder, point defects and cluster formation. In addition, the thermochemical representation of Lindemer and Besmann for UO2+x was extended for the analysis of the Th1-yUyO2+x data. The solid solution is regarded as an ideal ternary mixture of UO2, ThO2 and a hypothetical compound UaOb. The thermodynamic properties of this compound UaOb were determined in two oxygen pressure ranges of the database. In both the defect model and thermochemical approach ThO2 is treated as an inert compound that does not participate in any of the chemical equilibria describing the oxygen potential. (orig.)

  2. Water adsorption on O(2x2)/Ru(0001) from STM experiments andfirst-principles calculations

    Cabrera-Sanfelix, P.; Sanchez-Portal, D.; Mugarza, A.; Shimizu,T.K.; Salmeron, M.; Arnau, A.

    2007-10-15

    We present a combined theoretical and experimental study of water adsorption on Ru(0001) pre-covered with 0.25 monolayers (ML) of oxygen forming a (2 x 2) structure. Several structures were analyzed by means of Density Functional Theory calculations for which STM simulations were performed and compared with experimental data. Up to 0.25 monolayers the molecules bind to the exposed Ru atoms of the 2 x 2 unit cell via the lone pair orbitals. The molecular plane is almost parallel to the surface with its H atoms pointing towards the chemisorbed O atoms of the 2 x 2 unit cell forming hydrogen bonds. The existence of these additional hydrogen bonds increases the adsorption energy of the water molecule to approximately 616 meV, which is {approx}220 meV more stable than on the clean Ru(0001) surface with a similar configuration. The binding energy shows only a weak dependence on water coverage, with a shallow minimum for a row structure at 0.125 ML. This is consistent with the STM experiments that show a tendency of the molecules to form linear rows at intermediate coverage. Our calculations also suggest the possible formation of water dimers near 0.25 ML.

  3. The Cellular Prion Protein Prevents Copper-Induced Inhibition of P2X4 Receptors

    Ramón A. Lorca

    2011-01-01

    Full Text Available Although the physiological function of the cellular prion protein (PrPC remains unknown, several evidences support the notion of its role in copper homeostasis. PrPC binds Cu2+ through a domain composed by four to five repeats of eight amino acids. Previously, we have shown that the perfusion of this domain prevents and reverses the inhibition by Cu2+ of the adenosine triphosphate (ATP-evoked currents in the P2X4 receptor subtype, highlighting a modulatory role for PrPC in synaptic transmission through regulation of Cu2+ levels. Here, we study the effect of full-length PrPC in Cu2+ inhibition of P2X4 receptor when both are coexpressed. PrPC expression does not significantly change the ATP concentration-response curve in oocytes expressing P2X4 receptors. However, the presence of PrPC reduces the inhibition by Cu2+ of the ATP-elicited currents in these oocytes, confirming our previous observations with the Cu2+ binding domain. Thus, our observations suggest a role for PrPC in modulating synaptic activity through binding of extracellular Cu2+.

  4. Stratification devices

    Andersen, Elsa; Furbo, Simon

    2008-01-01

    results in longer operation periods and improved utilization of the solar collector. Thermal stratification can be achieved, for example by using inlet stratification devices at all inlets to the storage tank. This paper presents how thermal stratification is established and utilized by means of inlet...

  5. PELATIHAN LARI SIRKUIT 2 X 10 MENIT DAN PELATIHAN LARI KONTINYU 2 X 10 MENIT DAPAT MENINGKATKAN VO2 MAX TAEKWONDOIN PUTRA KABUPATEN MANGGARAI - NTT

    Regina Sesilia Noy

    2014-08-01

    Full Text Available VO2 max is very important in everyday life, so as to facilitate any physicalactivity, specially for athletes in order to achieve maximum performance. In aneffort to increase VO2 max training should be carried out regularly, measured andplanned. This study aims to determine the increase in VO2 max through circuittraining run and run continuously. The sample is taekwondoin son Manggarai-NTTwith an average age of 15 years. This study is an experimental study with the studydesign used was Randomized Pre and Post Test Group desigen. With a totalsample of 7 people in each group. Samples were randomly selected. Treatmentgroup 1 (KP1 given training run circuit 2 x 10 minute and Treatment Group 2(KP2 are given continuous training run 2 x 10 minute. Training carried out for 6weeks with a frequency of four times a week starting at 17:00 to 18:00 pm locatedat Frans Sales Lega Airport Manggarai-NTT. The analysis showed an increase inVO2 max was significantly (p <0.05 against both groups fled. In both groups thecircuit run by Pulse Oxymeter and Norma Cooper an increase in VO2 max with p<0.05, as well as a continuous run either by Pulse Oxymeter and Norma Cooperwith an increase in VO2 max value of p <0.05. The results of this analysis meansthat either the training or circuit training run run continuously to improve VO2max. Based on a comparison of test data by an independent test after training inboth groups either by Pulse Oxymeter and Norma Cooper in get p values > 0.05, orthere is no significant difference. Based on these results it can be concluded thatthe run circuit training and continuous training run together can increase VO2 maxand there was no significant difference. The results of this study are expected toincrease the knowledge of coaches, teachers and taekwondoin to perform trainingon a regular basis and are also expected to do similar research that examines VO2max with different training.

  6. The effect of deuteration on the transition into a charge ordered state of (TMTTF)2X salts

    From dielectric permittivity measurements, we show that deuteration yields a large increase of the transition temperature for the charge ordered state of (TMTTF)2X (X = AsF6, SbF6, ReO4) salts. We propose an explanation of this phenomenon, suggesting that deuteration induces a modification of the (TMTTF)2X crystal unit cell. (letter to the editor)

  7. P2X7 receptor-mediated PARP1 activity regulates astroglial death in the rat hippocampus following status epilepticus

    Ji Yang eKim

    2015-09-01

    Full Text Available Poly(ADP-ribose polymerase-1 (PARP1 plays a regulatory role in apoptosis, necrosis, and other cellular processes after injury. Recently, we revealed that PARP1 regulates the differential neuronal/astroglial responses to pilocarpine-induced status epilepticus (SE in the distinct brain regions. In addition, P2X7 receptor (P2X7R, an ATP-gated ion channel, activation accelerates astroglial apoptosis, while it attenuates clasmatodendrosis (lysosome-derived autophagic astroglial death. Therefore, we investigated whether P2X7R regulates regional specific astroglial PARP1 expression/activation in response to SE. In the present study, P2X7R activation exacerbates SE-induced astroglial apoptosis, while P2X7R inhibition attenuates it accompanied by increasing PARP1 activity in the molecular layer of the dentate gyrus following SE. In the CA1 region, however, P2X7R inhibition deteriorates SE-induced clasmatodendrosis via PARP1 activation following SE. Taken together, our findings suggest that P2X7R function may affect SE-induced astroglial death by regulating PARP1 activation/expression in regional-specific manner. Therefore, the selective modulation of P2X7R-mediated PARP1 functions may be a considerable strategy for controls in various types of cell deaths.

  8. Gas phase UV and IR absorption spectra of CxF2x+1CHO (x=1-4)

    Hashikawa, Y; Kawasaki, M; Waterland, RL;

    2004-01-01

    The UV and IR spectra of CxF2x+1 CHO (x = 1-4) were investigated using computational and experimental techniques. CxF2x+1CHO (x = 1-4) have broad UV absorption features centered at 300-310 nm. The maximum absorption cross-section increases significantly and shifts slightly to the red with increas...

  9. Understanding RuO{sub 2}.xH{sub 2}O/carbon nanofibre composites as supercapacitor electrodes

    Pico, F.; Rojas, R.M.; Amarilla, J.M.; Rojo, J.M. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), Cantoblanco, Sor Juana Ines de la Cruz 3, E-28049 Madrid (Spain); Ibanez, J. [Centro Nacional de Investigaciones Metalurgicas, CSIC, Avda Gregorio del Amo 8, E-28040 Madrid (Spain); Lillo-Rodenas, M.A.; Linares-Solano, A. [MCMA, Departamento de Quimica Inorganica, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain)

    2008-01-21

    Composites made from RuO{sub 2}.xH{sub 2}O particles supported on carbon nanofibres (CNF) have been prepared for supercapacitor electrodes. CNF, produced by Grupo Antolin Ing. SA. using a floating catalyst procedure was treated either in HCl or in HNO{sub 3}. Then the composites were obtained by impregnation of CNF with an aqueous RuCl{sub 3}.0.5H{sub 2}O solution followed by filtering and alkali solution treatment. Heat treatment at 150 C for 2 h was done. Specific capacitance of the composites has been measured and discussed on the basis of their RuO{sub 2}.xH{sub 2}O content and RuO{sub 2}.xH{sub 2}O particle size. The composites having RuO{sub 2}.xH{sub 2}O contents below 11 wt% show RuO{sub 2}.xH{sub 2}O particles, which grow from 2 to 4 nm as the RuO{sub 2}.xH{sub 2}O content increases. The specific capacitance of supported RuO{sub 2}.xH{sub 2}O, which can be very high (up to 840 F g{sup -1}), decreases as the RuO{sub 2}.xH{sub 2}O content increases and RuO{sub 2}.xH{sub 2}O particles grow. The composites having RuO{sub 2}.xH{sub 2}O contents above 11 wt% show RuO{sub 2}.xH{sub 2}O particles of nearly constant size (4 nm); the effect of increasing the RuO{sub 2}.xH{sub 2}O content is to increase the amount of particles but not the size of the particles. In these composites the specific capacitance of supported RuO{sub 2}.xH{sub 2}O is nearly constant (440 F g{sup -1}) and close to bare RuO{sub 2}.xH{sub 2}O (460 F g{sup -1}). (author)

  10. Rigidity Transitions in Ternary As_xGe_xSe_1-2x and As_xGe_xS_1-2x Glasses

    Qu, Tao; Boolchand, Punit; Micoulaut, Matthieu

    2003-03-01

    These ternary glasses are of interest for elastic threshold studies because they do not display nanoscale phase separation^1 effects. MDSC measurements on As_xGe_xSe_1-2x glasses have shown^2 T_g(x) to increase monotonically with x, and the non-reversing heat flow, ΔHnr(x), to display a global minimum ˜ 0 in 0.09 < 2.42. The thermally reversing window width in this ternary is large and resides below the Phillips-Thorpe value of rc = 2.4, features that were addressed in ref.1.We have now performed FT-Raman scattering as a function of x, and established compositional trend of corner-sharing mode frequency, ν_cs(x), of Ge(Se_1/2)4 tetrahedra. The results show evidence of a second order elastic threshold near r_c(1) = 2.27(1) and a first order one near r_c(2) = 2.42(1). At the latter, a jump in ν_cs of 0.5(1)cm-1 is observed. The elastic power-law in the intermediate phase yield a value p =0.90(5). Preliminary results on corresponding sulfide glasses have also been obtained. Supported by NSF grant DMR ^_01^_01808 1 P.Boolchand et al. Comptes Rendus ( in press). 2 Y.Wang et al. Europhysics Lett. 52,633(2000).

  11. Correlation between Urothelial Differentiation and Sensory Proteins P2X3, P2X5, TRPV1, and TRPV4 in Normal Urothelium and Papillary Carcinoma of Human Bladder

    Igor Sterle

    2014-01-01

    Full Text Available Terminal differentiation of urothelium is a prerequisite for blood-urine barrier formation and enables normal sensory function of the urinary bladder. In this study, urothelial differentiation of normal human urothelium and of low and high grade papillary urothelial carcinomas was correlated with the expression and localization of purinergic receptors (P2X3, and P2X5 and transient receptor potential vanilloid channels (TRPV1, and TRPV4. Western blotting and immunofluorescence of uroplakins together with scanning electron microscopy of urothelial apical surface demonstrated terminal differentiation of normal urothelium, partial differentiation of low grade carcinoma, and poor differentiation of high grade carcinoma. P2X3 was expressed in normal urothelium as well as in low grade carcinoma and in both cases immunolabeling was stronger in the superficial cells. P2X3 expression decreased in high grade carcinoma. P2X5 expression was detected in normal urothelium and in high grade carcinoma, while in low grade carcinoma its expression was diminished. The expression of TRPV1 decreased in low grade and even more in high grade carcinoma when compared with normal urothelium, while TRPV4 expression was unchanged in all samples. Our results suggest that sensory proteins P2X3 and TRPV1 are in correlation with urothelial differentiation, while P2X5 and TRPV4 have unique expression patterns.

  12. Enhanced photocatalytic and photoelectrochemical activities of reduced TiO2-x/BiOCl heterojunctions

    Fu, Rongrong; Zeng, Xiaoqiao; Ma, Lu; Gao, Shanmin; Wang, Qingyao; Wang, Zeyan; Huang, Baibiao; Dai, Ying; Lu, Jun

    2016-04-01

    A key issue to design highly efficient photoelectrodes for hydrogen production is how to prohibit the rapid carrier recombination. In order to use the visible light and reduce the recombination of electrons and holes, reduced TiO2-x/BiOCl heterojunctions are successfully synthesized and the photoelectrodes are assembled in this work. The effects of various Bi/Ti molar ratios on the structural, morphological, optical, photoelectrochemical and photocatalytic activities of the resultant samples are investigated systematically. The TiO2-x nanoparticles contain Ti3+, Ti2+, and oxygen vacancies (Ov), while the BiOCl nanosheets exposed {001} facet. Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) results indicate that the existence of Ti3+, Ti2+ and Ov expand the light-response range. Linear scan voltammetry and electrochemical impedance spectroscopy results indicate that more efficient electron transportation is presented in the heterojunctions with the appropriate Bi/Ti molar ratio. Consequently, the reduced TiO2-x/BiOCl heterojunction with the most appropriate Bi/Ti molar ratio exhibits a high photocurrent density of 0.755 mA cm-2 with photoconversion efficiency up to 0.634%, 10.5 and 22.6 times larger than that of pure TiO2 and BiOCl. Furthermore, this heterojunction exhibit 48.38 and 12.54 times enhancement for the visible-light decomposition of rhodamine B compared with pure TiO2 and BiOCl.

  13. Heavy metals modulate the activity of the purinergic P2X4 receptor

    To further characterize the nature of the regulatory metal-binding sites of the rat P2X4 receptor, several transition heavy metals were tested to examine their ability to mimic the facilitator action of zinc or the inhibitory action of copper. cDNA coding for the rat P2X4 receptor was injected into Xenopus laevis oocytes; the two-electrode voltage-clamp technique was used to measure and quantify the ATP-evoked currents in the absence or presence of the metals. Cadmium facilitated the ATP-gated currents in a reversible and voltage-independent manner; maximal potentiation occurred within less than 1 min. Cadmium displaced leftward, in a concentration-dependent manner, the ATP concentration-response curve. In contrast, mercury reduced the ATP-gated currents in a reversible, time, and concentration manner. Maximal inhibition occurred after about 5 min of metal application. Cobalt also augmented the ATP-evoked currents, but its action was long lasting and did not reverse even after 45 min of metal washout. Other metals such as lead, nickel, manganese, silver, or gallium did not significantly alter the ATP-gated currents. The co-application of cadmium plus zinc or mercury plus copper caused additive effects. Mutation of H140 by alanine (H140A) augmented both the cadmium-induced facilitation and the mercury-induced inhibition. In contrast, the H241A mutant showed characteristics indistinguishable from the wild type. The H286A mutant showed a normal cadmium-induced potentiation, but an increased mercury inhibition. Out of the metals examined, only cadmium mimicked closely the action of zinc, evidencing commonalities. While mercury mimicked the action of copper, both metals apparently interact at distinct metal-binding sites. The present findings allow us to infer that heavy metals modulate the P2X4 receptor by acting in at least three separate metal-binding sites

  14. Gauge theories in external electromagnetic fields: The standard SU(2) x U(1) model

    Spontaneously broken SU(2) x U(1) electroweak theory in a constant background electromagnetic field is shown to admit a phase transition to a restored symmetry phase for large values of the external field. Allowing for two arbitrary parameters, the Higgs mass and the expectation value of the Higgs field, a lower bound is derived on the critical magnetic field required for restoration. The configuration space heat kernel method adapted to dimensional regularization techniques is used allowing calculations to be performed in arbitrary renormalizable gauges

  15. Electronic specific heat in BaFe$_{2-x}$Ni$_x$As$_2$

    Gong, Dongliang; Xie, Tao; Lu, Xingye; Ren, Cong; Shan, Lei; Zhang, Rui; Dai, Pengcheng; Yang, Yi-Feng; Luo, Huiqian; Li, Shiliang

    2016-01-01

    We have systematically studied the low-temperature specific heat of the BaFe$_{2-x}$Ni$_x$As$_2$ single crystals covering the whole superconducting dome. Using the nonsuperconducting heavily overdoped x = 0.3 sample as a reference for the phonon contribution to the specific heat, we find that the normal-state electronic specific heats in the superconducting samples may have a nonlinear temperature dependence, which challenges previous results in the electron-doped Ba-122 iron-based supercondu...

  16. Structural and magnetic instabilities of La2-xSrxCaCu2O6

    A neutron-scattering study of nonsuperconducting La2-xSrxCaCu2O6 (x=0 and 0.2), a bilayer copper oxide without CuO chains, has revealed an unexpected tetragonal-to-orthorhombic transition with a doping dependent transition temperature. The predominant structural modification below the transition is an in-plane shift of the apical oxygen. In the doped sample, the orthorhombic superstructure is strongly disordered, and a glassy state involving both magnetic and structural degrees of freedom develops at low temperature. The spin correlations are commensurate

  17. Some photoelectrochemical (PEC) measurements on WS/sub x/Se/sub 2-x/ single crystals

    Tungsten sulfo-selenide single crystals have been employed in the present study for the fabrication of photoelectrochemical (PEC) solar cells. These WS/sub x/Se/sub 2-x/(O≤chi≤2) single crystals were grown by direct vapour transport technique. In the solar cells, as grown crystals are used as photocathodes with another electrode of platinum grid. While studying the spectral response, variation in the band gap (E/sub g/) with composition is noticed. Flat band potential measurements have also been carried out to characterize the cell. Usual results are observed in the present investigation

  18. (CuAlTe2)x(2ZnTe)1-x solid solutions

    (CuAlTe2)x(2ZnTe)1-x solid solutions were synthesized by single-temperature method over the all interval of concentrations. As it was established by X-ray diffraction the solid solutions were crystallized at 0.7 2 - 2ZnTe system, as was used for growing large-block crystals of the solid solutions by means of directional crystallization of melt (horizontal variant), was developed on the data of X-ray diffraction and differential thermal assays. It is determined that elementary lattice parameters vary linearly depending on x, microhardness - with maximum, and width of forbidden zone - with minimum for equimolar composition

  19. Superconductivity in layered ZrP2-x Se x with PbFCl-type structure

    Ishida, Shigeyuki; Fujihisa, Hiroshi; Hase, Izumi; Yanagi, Yousuke; Kawashima, Kenji; Oka, Kunihiko; Gotoh, Yoshito; Yoshida, Yoshiyuki; Iyo, Akira; Eisaki, Hiroshi; Kito, Hijiri

    2016-05-01

    We performed a systematic study of the crystal structure, physical properties, and electronic structure of PbFCl-type ZrP2-x Se x (0.3 ≤ x ≤ 0.9). We successfully synthesized single-phase polycrystalline samples for the Se substitution range of 0.4 ≤ x ≤ 0.8. The crystal structure of the compound is characterized by the alternate stacking of a two-dimensional P square net and a Zr-(P1-x Se x ) network. ZrP2-x Se x exhibits a dome-like superconductivity phase diagram and has a maximum superconducting transition temperature (T c) of 6.3 K for x ≈ 0.6. Resistivity and Hall measurements indicated that electron-phonon scattering plays a dominant role and that electron-type carriers dominate charge transport. Specific heat measurements confirmed that ZrP2-x Se x exhibits bulk superconductivity. Further, the value of the specific heat jump at T c (ΔC/γT c ≈ 1.35) is in keeping with the BCS weak-coupling model. These facts suggest a rather conventional pairing mechanism in ZrP2-x Se x . The x dependence of T c can be explained on the basis of the density of states (DOS) for x ≤ 0.7, whereas the decrease in T c with an increase in the DOS for x = 0.8 needs further investigation. One possible reason for the suppression of superconductivity is that the PbFCl-type structure becomes unstable for x ≥ 0.8. The results of electronic structure calculations agree reasonably well with those of the experimental observations, suggesting that the Zrd band plays a primary role in determining the physical properties. Further, the calculations predict a significant change in the Fermi-surface topology for x ≥ 0.8 this is a probable reason for the decrease in T c as well as the instability of the PbFCl-type structure.

  20. Defect and transport properties of nanocrystalline CeO2-x

    It is shown that unique defect thermodynamics and transport properties result for oxides of a few nanometers crystallite size. Fully-dense CeO2-x polycrystals of ∼10 nm grain size were synthesized, and their electrical properties compared with those of samples coarsened from the same material. The nanocrystals showed reduced grain boundary resistance, 104 higher electronic conductivity, and less than one-half the heat of reduction of its coarse-grained counterpart. These properties are attributed to a dominant role of interfacial defect formation. copyright 1996 American Institute of Physics

  1. Magnetic characteristics of ErCo10Mo2-xV x family of compounds

    We have studied the effects of replacing the stabilizing element Mo by V on the magnetic characteristics of the ErCo10Mo2-xV x family of compounds using magnetization measurements. The replacement was carried out progressively from x = 0 to x = 2 in steps of 0.5. X-ray powder diffraction analysis of the prepared samples showed that the expected ThMn12-type structure was obtained overwhelmingly with negligible amounts of secondary phases. The Curie temperatures showed no clear change of the replacement of Mo by V. Spin reorientation temperatures were observed to shift considerably to higher temperatures with increasing V content

  2. Regularity of Cauchy horizons in S{sup 2} x S{sup 1} Gowdy spacetimes

    Hennig, Joerg [Max Planck Institute for Gravitational Physics, Am Muehlenberg 1, D-14476 Golm (Germany); Ansorg, Marcus, E-mail: pjh@aei.mpg.d, E-mail: marcus.ansorg@helmholtz-muenchen.d [Institute of Biomathematics and Biometry, Helmholtz Zentrum Muenchen, Ingolstaedter Landstr. 1, D-85764 Neuherberg (Germany)

    2010-03-21

    We study general S{sup 2} x S{sup 1} Gowdy models with a regular past Cauchy horizon and prove that a second (future) Cauchy horizon exists, provided that a particular conserved quantity J is not zero. We derive an explicit expression for the metric form on the future Cauchy horizon in terms of the initial data on the past horizon and conclude the universal relation A{sub p}A{sub f} = (8piJ){sup 2} where A{sub p} and A{sub f} are the areas of past and future Cauchy horizons respectively.

  3. Blow up at the hyperbolic boundary for a 2x2 system arising from chemical engineering

    Bourdarias, Christian; Gisclon, Marguerite; Junca, Stéphane

    2009-01-01

    We consider an initial boundary value problem for a 2x2 system of conservation laws modeling heatless adsorption of a gaseous mixture with two species and instantaneous exchange kinetics, close to the system of Chromatography. In this model the velocity is not constant because the sorption effect is taken into account. Exchanging the roles of the x, t variables we obtain a strictly hyperbolic system with a zero eigenvalue. Our aim is to construct a solution with a velocity which blows up at t...

  4. Facilitation of Neurotransmitter and Hormone Release by P2X Purinergic Receptors

    Vávra, Vojtěch; Bhattacharya, Anirban; Jindřichová, Marie; Zemková, Hana

    Rijeka : InTech, 2012 - (Contreras, C.), s. 61-82 ISBN 978-953-51-0207-6 R&D Projects: GA AV ČR(CZ) IAA500110910; GA ČR(CZ) GA305/07/0681; GA MŠk(CZ) LC554; GA ČR(CZ) GPP304/12/P371 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : ATP * purinergic P2X receptors * GABA * glutamate * pituitary * supraoptic nucleus * rat brain slices * patch clamp Subject RIV: ED - Physiology

  5. Transverse spin structure function g2(x ,Q2) in the valon model

    Yazdi, Z. Alizadeh; Tahamtan, A.; Taghavi-Shahri, F.; Arash, F.; Zomorrodian, M. E.

    2015-07-01

    The spin dependent structure function, g2w w, is calculated in the valon model. A simple approach is given for the determination of the twist-3 part of g2¯(x ,Q2) in Mellin space, thus enabling us to obtain the full transverse structure function g2(x ,Q2) for the proton, neutron, and deuteron. In light of the new data, we have further calculated the transversely polarized structure function of g23He(x ,Q2) . Our results are checked against the experimental data and nice agreements are observed.

  6. Electronic Origins of Large Thermoelectric Power Factor of LaOBiS2-xSex

    Nishida, Atsuhiro; Nishiate, Hirotaka; Lee, Chul-Ho; Miura, Osuke; Mizuguchi, Yoshikazu

    2016-07-01

    We have examined the electrical transport properties of densified LaOBiS2-xSex, which constitutes a new family of thermoelectric materials. The power factor increases with increasing concentration of Se, i.e., Se substitution leads to an enhanced electrical conductivity, without suppression of the Seebeck coefficient. Hall measurements reveal that the carrier mobility increases with decreasing carrier concentration as Se doping, which is responsible for the low electrical resistivity and large absolute values of the Seebeck coefficient in the system.

  7. Blockade of P2X-purinoceptors by trypan blue in rat vas deferens.

    Bültmann, R.; TRENDELENBURG, M; Starke, K.

    1994-01-01

    1. The possibility of an antagonist effect of trypan blue at P2X-purinoceptors was studied in rat vas deferens. 2. Trypan blue (3.2-320 microM) shifted the concentration-contraction response curve of alpha,beta-methylene ATP (alpha,beta-MeATP) to the right and simultaneously increased the maximum of the curve by up to 40%. The Schild plot had a slope not significantly different from unity and yielded a pA2 value of 5.3 (KB 4.9 microM). 3. Suramin (32 microM) also shifted the concentration-res...

  8. Effective Lagrangian and Dynamical Symmetry Breaking in SU(2)X U(1) NJL Model

    Kruglov, S I

    2003-01-01

    Dynamical symmetry breaking and the formation of scalar condensates in the SU(2) X U(1) Nambu-Jona-Lasinio model with two coupling constants has been studied in the framework of the mean field approximation. The bosonization procedures of the model are performed using the functional integration method. The possibility of the spontaneous CP-symmetry breaking in the model under consideration has been shown. The mass spectrum of the bound states of fermions, as well as the effective Lagrangian of interacting scalar and pseudoscalar mesons are obtained.

  9. Charge and anion ordering phase transitions in (TMTTF){sub 2}X salt conductors

    Nad, F. [Centre de Recherches sur les Tres Basses Temperatures, laboratoire associe a l' Universite Joseph Fourier, CNRS, BP 166, Grenoble (France); Institute of Radioengineering and Electronics, Russian Academy of Sciences, Moscow (Russian Federation); Monceau, P. [Centre de Recherches sur les Tres Basses Temperatures, laboratoire associe a l' Universite Joseph Fourier, CNRS, BP 166, Grenoble (France); Carcel, C.; Fabre, J.M. [Heterochimie et Materiaux Organiques, ENSCM/ESA, Montpellier (France)

    2001-07-23

    We report measurements of the low frequency conductivity and dielectric permittivity of quasi-one-dimensional organic (TMTTF){sub 2}X salts with non-centrosymmetrical anions X=ReO{sub 4} and SCN. We show that the 'structureless transition' at 227.5 K in (TMTTF){sub 2}ReO{sub 4} is due to charge ordering and has a ferroelectric character. The anion ordering transition strongly affects the dielectric response: it suppresses the polarizability in (TMTTF){sub 2}ReO{sub 4} and induces probably an antiferroelectric state in (TMTTF){sub 2}SCN. (author). Letter-to-the-editor.

  10. Disappearance of antiferromagnetic spin excitations in overdoped La2-xSrxCuO4.

    Wakimoto, S; Yamada, K; Tranquada, J M; Frost, C D; Birgeneau, R J; Zhang, H

    2007-06-15

    Magnetic excitations for energies up to approximately 100 meV are studied for overdoped La(2-x)Sr(x)CuO(4) with x=0.25 and 0.30, using time-of-flight neutron spectroscopy. Comparison of spectra integrated over the width of an antiferromagnetic Brillouin zone demonstrates that the magnetic scattering at intermediate energies, 20 magnetism is not related to Fermi surface nesting, but rather is associated with a decreasing volume fraction of (probably fluctuating) antiferromagnetic bubbles. PMID:17677985

  11. Fabrication of submicron La2-xSrxCuO4 intrinsic Josephson junction stacks

    Kubo, Yuimaru; Takahide, Yamaguchi; Tanaka, Takayoshi; Ueda, Shinya; Ishii, Satoshi; Tsuda, Shunsuke; Islam, ATM Nazmul; Tanaka, Isao; Takano, Yoshihiko

    2011-02-01

    Intrinsic Josephson junction (IJJ) stacks of cuprate superconductors have potential to be implemented as intrinsic phase qubits working at relatively high temperatures. We report success in fabricating submicron La2-xSrxCuO4 (LSCO) IJJ stacks carved out of single crystals. We also show a new fabrication method in which argon ion etching is performed after focused ion beam etching. As a result, we obtained an LSCO IJJ stack in which resistive multibranches appeared. It may be possible to control the number of stacked IJJs with an accuracy of a single IJJ by developing this method.

  12. Fabrication of submicron La$_{2-x}$Sr$_{x}$CuO$_{4}$ intrinsic Josephson junction stacks

    Kubo, Yuimaru; Takahide, Yamaguchi; Tanaka, Takayoshi; Ueda, Shinya; Ishii, Satoshi; Tsuda, Shunsuke; Islam, A. T. M. Nazmul; Tanaka, Isao; Takano, Yoshihiko

    2011-01-01

    Intrinsic Josephson junction (IJJ) stacks of cuprate superconductors have potential to be implemented as intrinsic phase qubits working at relatively high temperatures. We report success in fabricating submicron La$_{2-x}$Sr$_{x}$CuO$_{4}$ (LSCO) IJJ stacks carved out of single crystals. We also show a new fabrication method in which argon ion etching is performed after focused ion beam etching. As a result, we obtained an LSCO IJJ stack in which resistive multi-branches appeared. It may be p...

  13. Theory of disordered stripes in hole-doped La2-xSrxCoO4

    The compounds La2-xSrxCoO4 are isostructural to the 214 family of cuprate superconductors, but remain insulating over a wide doping range. Recently, the x=1/3 compound was found to display a peculiar type of magnetism, with short-ranged static antiferromagnetic order and an hour-glass-like excitation spectrum, not unlike some cuprates. We argue that a scenario of disordered charge stripes, formed by Co2+ and Co3+ ions, is consistent with the experimental data. In particular, we calculate the magnetic excitation spectrum in the disordered charge background and discuss possible origins of the stripe disorder.

  14. NMR studies of Ndsub(2-x)CexCuO4

    Copper NMR has been studied as a function of temperature in a number of superconducting Ndsub(2-x)CexCuO4 samples. The electric field gradient is very small and the Knight shift is 2380 ppm at room temperature, both of these implying that the copper is in a Cu+ state. The Knight shift decreases with temperature particularly below Tc. The spin contribution to the Knight shift is estimated to be ∼200 ppm (about a factor ten smaller than in YBa2Cu3O7) indicating that Ns(Ef) at the copper sites is small in this material. (author). 9 refs., 3 figs

  15. Surface core-level shifts for Ge(100)-(2 x 1)

    Miller, T.; Rosenwinkel, E.; Chiang, T.C.

    1983-01-01

    Using surface-sensitive photoemission techniques, Ge 3d core-level binding energies for surface atoms of Ge(100)-(2 x 1) are found to be smaller than the bulk values by 0.41 eV. The surface atoms with shifted core-level binding energies correspond to one full (100) atomic layer. A surface core-exciton resonance is observed in the partial-yield measurements. The empty surface state involved in this excitonic transition, without binding-energy correction, is located at the valence-band maximum. 14 references, 2 figures, 1 table.

  16. Surface core-level shifts for Ge(100)-(2 x 1)

    Miller, T.; Rosenwinkel, E.; Chiang, T.C.

    1983-01-01

    Using surface-sensitive photoemission techniques, Ge 3d core-level binding energies for surface atoms of Ge(100)-(2 x 1) are found to be smaller than the bulk values by 0.41 eV. The surface atoms with shifted core-level binding energies correspond to one full (100) atomic layer. A surface core-exciton resonance is observed in the partial-yield measurements. The empty surface state involved in this excitonic transition, without binding-energy correction, is located at the valence-band maximum.

  17. Fluctuations of the front in a one dimensional model of X+Y-->2X

    Comets, Francis; Quastel, Jeremy; Ramirez, Alejandro

    2006-01-01

    We consider a model of the reaction $X+Y\\to 2X$ on the integer lattice in which $Y$ particles do not move while $X$ particles move as independent continuous time, simple symmetric random walks. $Y$ particles are transformed instantaneously to $X$ particles upon contact. We start with a fixed number $a\\ge 1$ of $Y$ particles at each site to the right of the origin, and define a class of configurations of the $X$ particles to the left of the origin having a finite $l^1$ norm with a specified ex...

  18. Localization and Interaction Effects in Strongly Underdoped La2-xSrxCuO4

    Cieplak, Marta Z.; Malinowski, A.; Guha, S; Berkowski, M.

    2004-01-01

    The in-plane magnetoresistance (MR) in La2-xSrxCuO4 films with 0.03 < x < 0.05 has been studied in the temperature range 1.6 K to 100 K, and in magnetic fields up to 14 T, parallel and perpendicular to the CuO2 planes. The behavior of the MR is consistent with a predominant influence of interaction effects at high temperatures, switching gradually to a regime dominated by spin scattering at low T. Weak localization effects are absent. A positive orbital MR appears close to the boundary betwee...

  19. Existence of ternary hydrogenated phases of BeP/sub 2-x/H/sub y/

    The phosphidation of beryllium in the presence of traces of hydrogen leads to non stoichiometric ternary phases BeP/sub 2-x/H/sub y/. The stoichiometric diphosphide BeP2 cannot be obtained. The hydrogenated phases are black and nonhygroscopic. The structural study with x-ray diffraction, neutrons diffraction, electronic microdiffraction, as well as the crystallographic data from single crystal, provide evidence for a quadratic cell with a = 7.08 A and c = 30.12 A. The stacking is diamond type when considering all the atoms: Be, P and H

  20. Simulation of high temperature, non-congruent phase transitions in UO2+x

    A detailed model of UO2+x undergoing non-congruent melting at very high temperature is being developed to help support the design and analysis of experimental work being conducted as part of nuclear safety research. This work includes the simulation of nuclear fuel under upset conditions where centreline melting may occur. The Phase Field model has been implemented for this purpose using recently published material properties and compares well with experimental data. The versatility and robustness of this modelling technique is demonstrated with a simulation of centreline melting as a consequence of fission heating. (author)

  1. Characterization of P2x-receptors in rabbit isolated ear artery.

    O'Connor, S. E.; Wood, B E; Leff, P.

    1990-01-01

    1. The isolated central ear artery of the rabbit contracts in response to adenosine 5'-triphosphate (ATP) and analogues, effects proposed to be mediated by stimulation of P2x-receptors. We have extended the characterization of the purinoceptor in this tissue by examining the effects of a series of receptor agonists. The study was designed in such a way as to avoid factors which normally limit attempts to classify receptors on the basis of agonist potency orders. 2. D-alpha, beta-methylene ATP...

  2. Stripe order in highly doped La2-xSrxNiO4

    Stripe order in La2-xSrxNiO4 with 0.289h up to x=1/2. We found that the stripe is most stable at nh=1/3 with ε=1/3 from the analyses of the onset temperatures of the charge and spin orderings and the nh dependence of the correlation length of the stripe order. The stability of an ε=1/3 stripe induces a systematic deviation of ε from the ε=nh law for samples with nh≠=1/3. This deviation affects the stripe order on both sides of the hole concentration with nhh>1/3. (orig.)

  3. Competition between triplet, singlet and FFLO states in organic superconductors (TMTSF)2X under magnetic field

    We study the competition between triplet f-wave, singlet d-wave, and the FFLO state in a model for (TMTSF)2X using random phase approximation. The result suggests the possibility of the singlet→FFLO→triplet transition upon increasing the magnetic field. We also show that the triplet component mixing increases in the FFLO state with increasing the magnetic field, and the off-site repulsions increase the mixing rate. The results seem to suggest that the large triplet mixing results in an enhanced tendency toward the FFLO state over the usual pairing state.

  4. Magnetic relaxation behaviour in Gd2-xYxPdSi3 alloys

    The results of time-dependent remanent magnetization (MIRM) behaviour (magnetic relaxation studies) in polycrystalline Gd2-xYxPdSi3 alloys in a magnetically ordered state are reported. We observed that MIRM undergoes slow relaxation with time. We have also measured ac susceptibility as a function of frequency; however, we did not find any upward shift of the peak-temperature with an increase of frequency, which suggests that these alloys are not spin-glasses. Measurements on single-crystalline Gd2PdSi3 show that the magnetic relaxation is an intrinsic property of the materials. (author). Letter-to-the-editor

  5. The role of p2x7 receptor in infectious inflammatory diseases and the influence of ectonucleotidases

    Ana Carolina Morandini

    2014-08-01

    Full Text Available The purinergic receptor P2X ligand-gated ion channel 7 (P2X7 is ubiquitously expressed in almost all tissues and organs of the body with the highest distribution in the immune cells of monocyte-macrophage origin. Classically, P2X7 receptor is involved in apoptotic cell death, and it is well known that extracellular ATP ligation to this purinergic receptor serves as an important secondary stimulus, which is also considered as danger signal for the interleukin (IL-1β cleavage and secretion from pro-inflammatory cells. More recently, however, there has been substantial evidence of additional roles for the P2X7 receptor, both in innate immune response and as an adaptive link, including T-cell activation in a chronic state of inflammation. Also, compelling evidences have revealed an important role for ectonucleotidases as ATP-consuming enzymes in the control and fine-tuning of P2X7 function by regulating the time, concentration, and availability of ATP during infection-driven inflammation. This review focuses on the current evidences for P2X7 receptor involvement in the initial stages of inflammation, as well as for its role in acute and chronic stages of infection. Here, we also highlight the role of ectonucleotidase family in the control of P2X7 function, including the initial and resolution phases of inflammation.

  6. Effect of P2X7 receptor knockout on AQP-5 expression of type I alveolar epithelial cells.

    Georg Ebeling

    Full Text Available P2X7 receptors, ATP-gated cation channels, are specifically expressed in alveolar epithelial cells. The pathophysiological function of this lung cell type, except a recently reported putative involvement in surfactant secretion, is unknown. In addition, P2X7 receptor-deficient mice show reduced inflammation and lung fibrosis after exposure with bleomycin. To elucidate the role of the P2X7 receptor in alveolar epithelial type I cells we characterized the pulmonary phenotype of P2X7 receptor knockout mice by using immunohistochemistry, western blot analysis and real-time RT PCR. No pathomorphological signs of fibrosis were found. Results revealed, however, a remarkable loss of aquaporin-5 protein and mRNA in young knockout animals. Additional in vitro experiments with bleomycin treated precision cut lung slices showed a greater sensitivity of the P2X7 receptor knockout mice in terms of aquaporin-5 reduction as wild type animals. Finally, P2X7 receptor function was examined by using the alveolar epithelial cell lines E10 and MLE-12 for stimulation experiments with bleomycin. The in vitro activation of P2X7 receptor was connected with an increase of aquaporin-5, whereas the inhibition of the receptor with oxidized ATP resulted in down regulation of aquaporin-5. The early loss of aquaporin-5 which can be found in different pulmonary fibrosis models does not implicate a specific pathogenetic role during fibrogenesis.

  7. Neutron Powder Diffraction Studies of Ca2-xSrxCoWO6 Double Perovskites

    Full text: A series of double perovskite compounds of A2-xSrxCoWO6 (A = Ca, Ba) were synthesized and the room- and variable-temperature structural phase transitions have been studied by synchrotron and neutron powder diffraction techniques. These studies demonstrated that the symmetry increases as the average size of the A-site cation increases. These transitions are associated with the gradual reduction and ultimately removal of the octahedral tiles of the BO6 octahedra. Temperature dependent structural studies have been undertaken for selected samples. The transition to cubic is continuous in the three Ca doped samples studied as a function of temperature, Ca2-xSrxCoWO6 x = 1.8, 1.7, 1.6, however in each case analysis of the spontaneous strain shows the transition to be tricritical rather than second order in nature. Where observed the temperature induced P21/n to I4/m transition is first order as required by symmetry. (authors)>>>>

  8. Sodium 'stuffed' Ba2-xSrxFe4O8 ferrites: new cationic conductors

    Sodium insertion in the tetrahedral layer structure of the ferrites Ba2-xSrxFe4O8 was performed by solid state reaction at 1220 K in air. Superstoichiometric oxides with the actual formula (Ba2-xSrx)1-y/4NayFe4O8--y≤0.56; 0.60≤Ba/Sr≤1.67--were characterized by X-ray and neutron powder diffraction. The hexagonal unit-cell volume shows an increasing dependence on the sodium insertion when the Ba/Sr ratio reaches the largest values. The marked expansion of the c parameter is the likely signature of the location of the inserted sodium cations within the interlayer space. One-half of the sodium cations partly sits on the Sr(Ba) sites in octahedral coordination and the other half occupies extra octahedral and tetrahedral sites. ac conductivity measurements point to a cationic conductivity whose thermally activated regime--Ea no. 0.7 eV--evidenced from 570 K, is unsensitive to the sodium content. The bottleneck of the 2D sodium mobility regards the crossing of the oxygen triangular faces shared by the different polyhedra within the interlayer space

  9. Novel TaPO5−xN2x/3 oxynitrides

    Graphical abstract: Tantalum-based nitridophosphate powders TaPO5−xN2x/3 containing 9.1 (yellow) and 12.8 (orange) nitrogen wt.%, respectively. Highlights: ► Synthesis of novel tantalum-based nitridophosphates. ► Amorphous oxide and oxynitride powders. ► Colored oxynitride phases. ► High specific surface area powders. - Abstract: A series of novel nitrided tantalophosphates has been prepared by nitridation of X-ray amorphous TaPO5 precursors under ammonia flow. By varying the nitridation temperature, amorphous TaPO5−xN2x/3 (1.6 2 g−1, (ii) yellow to orange colors depending on nitrogen contents and (iii) formation of a solid solution with variable nitrogen and oxygen contents. The precursors and corresponding oxynitrides have been characterized by several techniques including X-ray diffraction, oxygen/nitrogen elemental analyses, BET analysis, UV–vis spectrophotometry, thermal analysis, SEM, DRIFT and NMR analyses.

  10. Efficient Electrochemical Reduction of Nitrobenzene by Defect-Engineered TiO2-x Single Crystals.

    Liu, Chang; Zhang, Ai-Yong; Pei, Dan-Ni; Yu, Han-Qing

    2016-05-17

    TiO2 is a typical semiconductor and has been extensively used as an effective photocatalyst for environmental pollution control. But it could not be used as an electrochemical reductive catalyst because of its low electric conductivity and electrocatalytic activity. In this work, however, we demonstrate that TiO2 can act as an excellent cathodic electrocatalyst when its crystal shape, exposed facet and oxygen-stoichiometry are finely tailored by the local geometric and electronic structures. The defect-engineered TiO2-x single crystals dominantly exposed by high-energy {001} facets exhibits a high cathodic activity and great stability for electrochemical reduction of nitrobenzene, a typical refractory pollutant with high toxicity in environment. The single crystalline structure, the high-energy {001} facet and the defective oxygen vacancy of the defect-engineered TiO2-x single crystals are found to be mainly responsible for their cathodic superiority. With the findings in this work, a more practical non-Pd cathodic electrocatalyst could be prepared and applied for electrocatalytic reduction of refractory pollutants in water and wastewater, and extend the promising applications of TiO2 in the fields of environmental science. PMID:27128346

  11. Rh3B2-x, new structure type of binary borides with triclinic symmetry

    New binary compound Rh3B2-x, x=0.167 crystallizing with its own structure type has been observed from the as cast alloys. The compound has a limited thermal stability range: it was found to decompose after annealing at 800oC for 20 days. The crystal structure was investigated by X-ray diffraction from two single crystals using different techniques: CAD-4 automatic diffractometer, a=5.470(2), b=6.816(3), c=9.068(4), α=110.74(3), β=94.81(3), γ=90.44(2), 107 refined parameters, R1=0.0418, wR2=0.1087 for 1223 reflections with I>2σ(Io), and BRUKER SMART AXS, a=5.483(4), b=6.818(6), c=9.072 (7), a=110.78(1), b=94.73(1), g=90.46(1), 107 refined parameters, R1=0.0401, wR2=0.0959 for 943 reflections with I>2σ(Io). The Rh3B2-x, structure (space group P1-bar , Pearson symbol aP30-1) is the first representative of structures with triclinic symmetry among binary borides and contains three different types of boron-boron aggregation: isolated boron atoms, B-B pairs and B6 chain fragments

  12. Nonstoichiometry and defect characteristics of La2-xSrxCuO4-∂

    A thermogravimetric analysis has been carried out on La2-xSrxCuO4-∂ (O ≤ x ≤ 1.0) from 923 K to 1,323 K under oxygen partial pressures from 105 to 10 Pa. It was found that the oxygen content of the compounds is corresponding to the nominal stoichiometry of the formula La2-xSrxCuO4-∂ at the temperature of 1,323 K and oxygen partial pressure of about 10 Pa. The oxygen content is always higher than that of this nominal stoichiometric formula at lower temperatures and/or higher oxygen partial pressures. The oxygen partial enthalpies and entropies at different x and ∂ values were deduced from these results. The SrO activity in this compound was measured with a solid electrochemical technique using a fluoride electrolyte. The defect chemistry regarding the existence of Cu3+ and/or O- in the compound will be discussed based on these experimental results

  13. Superconductivity, localization and crystallographic phase transition in La2-xSrxCuO4-y

    We report a resistive investigation of superconductivity in the system La2-xSrxCuO4-y on samples which have been analysed by thermogravimetric techniques for oxygen deficiency determination. A maximum superconductive transition temperature is observed in La2-xSrxCuO4-y near the tetragonal-orthorhombic phase transition, together with a resurgence of high temperature superconductivity in non-substituted La2CuO4-y. Drastic localization effects are observed in the vicinity of x = 0.04 with no sign of superconductivity at low temperature. These observations are coherent with a simple BCS scheme with a band filling dominated by Sr-doping and localization effects dominated by an interplay between 0 vacancies and Sr-doping. This situation leads to half-filling of the band near x = 0.04 with enhanced electron localization via Umklapp scattering through a near nested Fermi surface. Moreover, our data suggest some contribution of antiferromagnetic fluctuations to the superconducting pairing mechanism

  14. Moessbauer studies of GdFe{sub 2-x}Hf{sub x} alloys

    Al-Omari, I. A., E-mail: ialomari@yahoo.com; Gismelseed, A.; Widatallah, H.; Elzain, M.; Al-Rawas, A.; Yousif, A. [Sultan Qaboos University, Department of Physics (Oman)

    2008-11-15

    GdFe{sub 2-x}Hf{sub x} alloys, where x = 0, 0.10, 0.15, 0.20, and 0.30, are produced by arc-melting of pure elements. The samples are investigated by x-ray diffraction and Fe{sup 57} Moessbauer spectroscopy at 78 K and 300 K. We find that the alloy system GdFe{sub 2-x}Hf{sub x} have the single phase cubic Cu{sub 2}Mg type structure in the whole concentration range. Moessbauer spectroscopic results show that all the samples studied are magnetically ordered at 78 K, and at room temperature. The room temperature spectra are fitted with two magnetic components where the direction of magnetization is along the [111] while the spectra at 78 K are fitted with four magnetic subspectra indicating a complex direction of magnetization for all samples under investigation. The average magnetic hyperfine field and the average isomer shift are found to decrease almost linearly with increasing the Hf concentration at 78 K and 300 K due to the replacement of Fe by nonmagnetic Hf.

  15. Mössbauer studies of GdFe2 - x Hf x alloys

    Al-Omari, I. A.; Gismelseed, A.; Widatallah, H.; Elzain, M.; Al-Rawas, A.; Yousif, A.

    2008-11-01

    GdFe2 - x Hf x alloys, where x = 0, 0.10, 0.15, 0.20, and 0.30, are produced by arc-melting of pure elements. The samples are investigated by x-ray diffraction and Fe57 Mössbauer spectroscopy at 78 K and 300 K. We find that the alloy system GdFe2 - x Hf x have the single phase cubic Cu2Mg type structure in the whole concentration range. Mössbauer spectroscopic results show that all the samples studied are magnetically ordered at 78 K, and at room temperature. The room temperature spectra are fitted with two magnetic components where the direction of magnetization is along the [111] while the spectra at 78 K are fitted with four magnetic subspectra indicating a complex direction of magnetization for all samples under investigation. The average magnetic hyperfine field and the average isomer shift are found to decrease almost linearly with increasing the Hf concentration at 78 K and 300 K due to the replacement of Fe by nonmagnetic Hf.

  16. Novel TaPO{sub 5-x}N{sub 2x/3} oxynitrides

    Ray, Erwan [UMR CNRS 6226 ' Sciences Chimiques de Rennes' , equipe ' Verres et Ceramiques' , Universite de Rennes 1, F-35042 Rennes Cedex (France); Tessier, Franck, E-mail: Franck.Tessier@univ-rennes1.fr [UMR CNRS 6226 ' Sciences Chimiques de Rennes' , equipe ' Verres et Ceramiques' , Universite de Rennes 1, F-35042 Rennes Cedex (France); Chevire, Francois; Herbert, Nathalie; Lebullenger, Ronan; Roiland, Claire; Bureau, Bruno [UMR CNRS 6226 ' Sciences Chimiques de Rennes' , equipe ' Verres et Ceramiques' , Universite de Rennes 1, F-35042 Rennes Cedex (France)

    2012-02-05

    Graphical abstract: Tantalum-based nitridophosphate powders TaPO{sub 5-x}N{sub 2x/3} containing 9.1 (yellow) and 12.8 (orange) nitrogen wt.%, respectively. Highlights: Black-Right-Pointing-Pointer Synthesis of novel tantalum-based nitridophosphates. Black-Right-Pointing-Pointer Amorphous oxide and oxynitride powders. Black-Right-Pointing-Pointer Colored oxynitride phases. Black-Right-Pointing-Pointer High specific surface area powders. - Abstract: A series of novel nitrided tantalophosphates has been prepared by nitridation of X-ray amorphous TaPO{sub 5} precursors under ammonia flow. By varying the nitridation temperature, amorphous TaPO{sub 5-x}N{sub 2x/3} (1.6 < x < 4.1) oxynitrides were obtained with different nitrogen contents (N wt.% = 5-15). The most relevant features of this oxynitride series are as follow: (i) specific surface areas higher than 150 m{sup 2} g{sup -1}, (ii) yellow to orange colors depending on nitrogen contents and (iii) formation of a solid solution with variable nitrogen and oxygen contents. The precursors and corresponding oxynitrides have been characterized by several techniques including X-ray diffraction, oxygen/nitrogen elemental analyses, BET analysis, UV-vis spectrophotometry, thermal analysis, SEM, DRIFT and NMR analyses.

  17. Regulation of the P2X7R by microRNA-216b in human breast cancer

    Highlights: • We suggest the expression level of miR-216b and P2X7R in breast cancer tissues and cell lines. • We demonstrated that miR-216b directly targets and inhibits P2X7R. • We suggested miR-216b can attenuate ATP/P2X7R signaling pathways and induced Bcl-2/caspase-3 pathway. - Abstract: Breast cancer is the most common cancer in women around the world. However, the molecular mechanisms underlying breast cancer pathogenesis are only partially understood. Here, in this study, we found that P2X7R was up-regulated and miR-216b was down-regulated in breast cancer cell lines and tissues. Using bioinformatic analysis and 3′UTR luciferase reporter assay, we determined P2X7R can be directly targeted by miR-216b, which can down-regulate endogenous P2X7R mRNA and protein levels. Ectopic expression of miR-216b mimics leads to inhibited cell growth and apoptosis, while blocking expression of the miR-216b results in increased cell proliferation. Furthermore, our findings demonstrate that knockdown of P2X7R promotes apoptosis in breast cancer cells through down-regulating Bcl-2 and increasing the cleavage caspase-3 protein level. Finally, we confirmed that down-regulation of miR-216b in breast cancer is inversely associated with P2X7R expression level. Together, these findings establish miR-216b as a novel regulator of P2X7R and a potential therapeutic target for breast cancer

  18. Atmospheric chemistry of n-C(x)F(2)(x)(+1)CHO (x = 1, 2, 3, 4)

    Hurley, M D; Ball, J C; Wallington, T J;

    2006-01-01

    Smog chamber/FTIR techniques were used to study the atmospheric fate of n-C(x)F(2)(x)(+1)C(O) (x = 1, 2, 3, 4) radicals in 700 Torr O(2)/N(2) diluent at 298 +/- 3 K. A competition is observed between reaction with O(2) to form n-C(x)()F(2)(x)()(+1)C(O)O(2) radicals and decomposition to form n-C(x...... atmospheric chemistry of n-C(x)F(2)(x)(+1)C(O) radicals and their possible role in contributing to the formation of perfluorocarboxylic acids in the environment....

  19. Synthesis, characterization and magnetic properties of lightly doped La2-xSr xCuO4 (x = 0.04) nanoparticles

    Lightly doped La2-xSr xCuO4 (x = 0.04) nanoparticles with different particle sizes have been successfully prepared by a sol-gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared transmission (IR) spectra and superconducting quantum interference device (SQUID) magnetometer. All samples are single phase and have an orthorhombic unit cell. As the particle size reduces, it is found that the IR band at around 685 cm-1 corresponding to the in-plane Cu-O asymmetrical stretching mode shifts to higher frequency and the magnetization exhibits a large enhancement at low temperature. The magnetic susceptibility of all samples follows a modulated Curie law between ∼20 K and ∼100 K and the Curie constant displays a strong dependence on the particle size. It is suggested that as the particle size decreases surface effects should play an important role in the magnetic properties of the nanoparticles

  20. Thermonuclear device

    Purpose: To absorb fabrication errors in radial toroidal coils and a spacer and completely fill the gap between them by the provision of an expansion device between the coils and the supporting spacer by injecting fillers of a predetermined composition. Constitution: An expansion device comprising an expansion plate, packings inserted into grooves formed in the outer circumference of the expansion plate and a recessed pressure receiving plate is inserted between the wall surface of radial toroidal coils and a spacer for maintaining the gap between the toroidal coils. Then, filler comprising polyester resin and glass beads incorporated therein is injected from an injection aperture of the recessed pressure receiving plate having an exhaust aperture at the upper part. The filler is solidified and enables the fabrication error in the coils and the spacer to be absorbed. Since the gap between the coils and the spacer is completely filled, the tumbling force of the coils can surely be transmitted by way of the spacer to upper and lower racks. (Moriyama, K.)

  1. Scalable devices

    Krüger, Jens J.

    2014-01-01

    In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.

  2. Practical microwave electron devices

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  3. Density functional theory study of the adsorption of hydrogen atoms on Cu2X (X = 3d) clusters

    Li, Jiao; Liu, Yanqi; Zhang, Jingjing; Liang, Xiaogang; Duan, Haiming

    2016-05-01

    Density functional theory is carried out to calculate the ground-state structures and electronic properties of Cu2X (X = Sc-Zn) and Cu2X-nH (n = 1-6) clusters. It is found that the dissociation adsorption of H2 molecules of Cu2Ti has obvious advantages over the other mixed clusters. Variations of adsorption energies of Cu2X-nH (n = 1-6) are almost opposite to the energy gaps of Cu2X-(n - 1)H (n = 1-6), which is especially evident in Cu and Zn. Odd-even variations of the distribution of d electrons near the Fermi energy in Cu3-nH and Cu2Zn-nH are opposite, which are strongly correlated to the number of H atoms.

  4. PLASMA DEVICE

    Baker, W.R.

    1961-08-22

    A device is described for establishing and maintaining a high-energy, rotational plasma for use as a fast discharge capacitor. A disc-shaped, current- conducting plasma is formed in an axinl magnetic field and a crossed electric field, thereby creating rotational kinetic enengy in the plasma. Such energy stored in the rotation of the plasma disc is substantial and is convertible tc electrical energy by generator action in an output line electrically coupled to the plasma volume. Means are then provided for discharging the electrical energy into an external circuit coupled to the output line to produce a very large pulse having an extremely rapid rise time in the waveform thereof. (AE C)

  5. P2X7 receptor of rat dorsal root ganglia is involved in the effect of moxibustion on visceral hyperalgesia

    Liu, Shuangmei; Shi, Qingming; Zhu, Qicheng; Zou, Ting; Li, Guilin; Huang, An; Wu, Bing; Peng, Lichao; Song, Miaomiao; Wu, Qin; Xie, Qiuyu; Lin, Weijian; XIE, Wei; Wen, Shiyao; Zhang, Zhedong

    2014-01-01

    Irritable bowel syndrome (IBS) and inflammatory bowel disease often display visceral hypersensitivity. Visceral nociceptors after inflammatory stimulation generate afferent nerve impulses through dorsal root ganglia (DRG) transmitting to the central nervous system. ATP and its activated-purinergic 2X7 (P2X7) receptor play an important role in the transmission of nociceptive signal. Purinergic signaling is involved in the sensory transmission of visceral pain. Moxibustion is a therapy applying...

  6. Endosome-mediated retrograde axonal transport of P2X3 receptor signals in primary sensory neurons

    Xu-Qiao Chen; BinWang; Chengbiao Wu; Jin Pan; Bo Yuan; Yuan-Yuan Su; Xing-Yu Jiang; Xu Zhang; Lan Bao

    2012-01-01

    Neurotrophins and their receptors adopt signaling endosomes to transmit retrograde signals.However,the mechanisms of retrograde signaling for other ligand/receptor systems are poorly understood.Here,we report that the signals of the purinergic (P)2X3 receptor,an ATP-gated ion channel are retrogradely transported in dorsal root ganglion (DRG) neuron axons.We found that Rab5,a small GTPase,controls the early sorting of P2X3 receptors into endosomes,while Rab7 mediates the fast retrograde transport of P2X3 receptors.Intraplantar injection and axonal application into the microfluidic chamber of α,β-methylene-ATP (α,β-MeATP),a P2X selective agonist,enhanced the endocytosis and retrograde transport of P2X3 receptors.The α,β-MeATP-induced Ca2+ influx activated a pathway comprised of protein kinase C,rat sarcoma viral oncogene and extracellular signal-regulated protein kinase (ERK),which associated with endocytic P2X3 receptors to form signaling endosomes.Disruption of the lipid rafts abolished the α,β-MeATP-induced ERK phosphorylation,endocytosis and retrograde transport of P2X3 receptors.Furthermore,treatment of peripheral axons with α,β-MeATP increased the activation level of ERK and cAMP response element-binding protein in the cell bodies of DRG neurons and enhanced neuronal excitability.Impairment of either microtubule-based axonal transport in vivo or dynein function in vitro blocked α,β-MeATP-induced retrograde signals.These results indicate that P2X3 receptor-activated signals are transmitted via retrogradely transported endosomes in primary sensory neurons and provide a novel signaling mechanism for ligand-gated channels.

  7. P2X7 receptor-mediated PARP1 activity regulates astroglial death in the rat hippocampus following status epilepticus

    Ji-Eun Kim

    2015-01-01

    Poly(ADP-ribose) polymerase-1 (PARP1) plays a regulatory role in apoptosis, necrosis, and other cellular processes after injury. Recently, we revealed that PARP1 regulates the differential neuronal/astroglial responses to pilocarpine-induced status epilepticus (SE) in the distinct brain regions. In addition, P2X7 receptor (P2X7R), an ATP-gated ion channel, activation accelerates astroglial apoptosis, while it attenuates clasmatodendrosis (lysosome-derived autophagic astroglial death). Therefo...

  8. The stoichiometry of P2X2/6 receptor heteromers depends on relative subunit expression levels

    Barrera, Nelson P.; Henderson, Robert M.; Murrell-Lagnado, Ruth D.; Edwardson, J Michael

    2007-01-01

    Fast synaptic transmission involves the operation of ionotropic receptors, which are often composed of at least two types of subunit. We have developed a method, based on atomic force microscopy imaging to determine the stoichiometry and subunit arrangement within ionotropic receptors. We showed recently that the P2X(2) receptor for ATP is expressed as a trimer but that the P2X(6) subunit is unable to oligomerize. In this study we addressed the subunit stoichiometry of heteromers containing b...

  9. Effect of structure and phase composition on the properties of BixSb2-xTe3 films

    Investigation into structures and phase composition of BixSb2-xTe-3 films, into dependence of KT tensosensitivity coefficient, resistance temperature coefficient (RTC) on thermodynamic parameters of film production and substrate type, as well as, investigation into effect of doping of BixSb2-xTex film initial batch by acceptor impurities on Rt and RTC represent the aim of the paper

  10. The First CNS-Active Carborane: A Novel P2X7 Receptor Antagonist with Antidepressant Activity

    2014-01-01

    Relative to other polycyclic frameworks (1–3), a carborane cage (4 and Cs·5) exerts a significant biological effect as an inhibitor of the purinergic P2X7 receptor (P2X7R) which allows one to target depression in vivo and thus demonstrate, for the first time, that a carborane has the capacity to modify CNS activity. PMID:24689484

  11. An infinite transfer matrix approach to the product of random 2 x 2 positive matrices

    This paper concerns the efficient and precise determination of the Laypunov exponent (and other statistical properties) of a product of random 2 x 2 matrices. By considering the ensemble average of an infinite series of regular functions and its iteration, we construct a transfer matrix, which is shown to be a trace class operator in a Hilbert space given that the positiveness of the random matrices is assumed. This fact gives a theoretical explanation of the superior convergence of the cycle expansion of the Lyapunov exponent (Bai 2007 J. Phys. A: Math. Theor. 40 8315). A numerical method based on the infinite transfer matrix is applied to a one-dimensional Ising model with a random field and a generalized Fibonacci sequence. It is found that, in the presence of continuous distribution of a disorder or degenerated random matrix, the transfer matrix approach is more efficient than the cycle expansion method

  12. AgGaSe2xTe2(1-x) solid solutions

    Large-block crystals of the ternary compounds AgGaTe2, AgGaSe2 and solid solutions AgGaSe2xTe2(1-x) were grown by the Bridgman method (flat variation). The composition of the prepared crystals was determined by microprobe X-ray spectral analysis, the structure and lattice parameters - by X-ray diffraction. The temperatures of phase transformations were examined by differential thermal analysis, the phase diagram of the AgGaTe2 - AgGaSe2 system was constructed and its thermodynamic analysis was performed. The microhardness (H) of the pointed compounds and solid solutions was measured and its concentration dependence was constructed. It is shown that the curve has maximum

  13. Highly (001)-textured WS2-x films prepared by reactive radio frequency magnetron sputtering

    Highly (001)-oriented WS2-x films were grown onto oxidized silicon substrates by reactive magnetron sputtering from a metallic tungsten target in argon-hydrogen sulfide mixtures. The best films with respect to the van-der-Waals orientation, i.e. with the (001) planes parallel to the substrate surface, were grown by excitation of the plasma with radio frequency of 27.12 MHz. These films exhibit the largest grains and the lowest film strain. It is shown that this effect is not due to the lower deposition rate at this high excitation frequency. Instead it was found that the lower DC voltage at the sputtering target is advantageous for the film growth since the bombardment of the growing film by highly energetic particles is avoided by this type of plasma excitation. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. P2X and P2Y receptor signaling in red blood cells

    Sluyter, Ronald

    2015-01-01

    Purinergic signaling involves the activation of cell surface P1 and P2 receptors by extracellular nucleosides and nucleotides such as adenosine and adenosine triphosphate (ATP), respectively. P2 receptors comprise P2X and P2Y receptors, and have well-established roles in leukocyte and platelet biology. Emerging evidence indicates important roles for these receptors in red blood cells. P2 receptor activation stimulates a number of signaling pathways in progenitor red blood cells resulting in microparticle release, reactive oxygen species formation, and apoptosis. Likewise, activation of P2 receptors in mature red blood cells stimulates signaling pathways mediating volume regulation, eicosanoid release, phosphatidylserine exposure, hemolysis, impaired ATP release, and susceptibility or resistance to infection. This review summarizes the distribution of P2 receptors in red blood cells, and outlines the functions of P2 receptor signaling in these cells and its implications in red blood cell biology. PMID:26579528

  15. Thermoelectric properties and ferromagnetism of diluted magnetic semiconductors Sb2-xCrxTe3

    Thermoelectric properties of single crystals of a new dilute magnetic semiconductor p-Sb2-xCrxTe3 are studied in the temperature interval 7-300 K. The temperature dependences of the thermal conductivity are measured. The Seebeck coefficient S is found to increase upon doping with Cr. At low temperatures, a ferromagnetic phase with Curie temperature TC ∼ 5.8 K exists for a Cr concentration x = 0.0215, its easy magnetization axis being parallel to the crystallographic axis C3. At T = 4.2 K, a negative magnetoresistance and anomalous Hall effect are observed; in strong magnetic fields, the Shubnikov-de Haas effect is manifested

  16. Scalar fields on SL(2, R) and H2 x R geometric spacetimes and linear perturbations

    Using appropriate harmonics, we study the future asymptotic behaviour of massless scalar fields on a class of cosmological vacuum spacetimes. The spatial manifold is assumed to be a circle bundle over a higher genus surface with a locally homogeneous metric. Such a manifold corresponds to the SL-tilde(2, R)-geometry (Bianchi VIII type) or the H2 x R-geometry (Bianchi III type). After a technical preparation including an introduction of suitable harmonics for the circle-fibred Bianchi VIII to separate variables, we derive systems of ordinary differential equations for the scalar field. We present future asymptotic solutions for these equations in a special case, and find that there is a close similarity with those on the circle-fibred Bianchi III spacetime. We discuss the implications of this similarity, especially for (gravitational) linear perturbations. We also point out that this similarity can be explained by the fibre term dominated behaviour of the two models

  17. Ranked solutions of the matric equation A1X1=A2X2

    A. Duane Porter

    1980-01-01

    Full Text Available Let GF(pz denote the finite field of pz elements. Let A1 be s×m of rank r1 and A2 be s×n of rank r2 with elements from GF(pz. In this paper, formulas are given for finding the number of X1,X2 over GF(pz which satisfy the matric equation A1X1=A2X2, where X1 is m×t of rank k1, and X2 is n×t of rank k2. These results are then used to find the number of solutions X1,…,Xn, Y1,…,Ym, m,n>1, of the matric equation A1X1…Xn=A2Y1…Ym.

  18. Ranked solutions of the matric equation A1X1=A2X2

    A. Duane Porter; Nick Mousouris

    1980-01-01

    Let GF(pz) denote the finite field of pz elements. Let A1 be s×m of rank r1 and A2 be s×n of rank r2 with elements from GF(pz). In this paper, formulas are given for finding the number of X1,X2 over GF(pz) which satisfy the matric equation A1X1=A2X2, where X1 is m×t of rank k1, and X2 is n×t of rank k2. These results are then used to find the number of solutions X1,…,Xn, Y1,…,Ym, m,n>1, of the matric equation A1X1…Xn=A2Y1…Ym.

  19. A measurement of the proton structure function F$_{2}$(x,Q$^{2}$)

    Ahmed, T; Andreev, V; Andrieu, B; Appuhn, R D; Arpagaus, M; Aïd, S; Babaev, A; Baranov, P S; Barrelet, E; Bartel, Wulfrin; Barth, Monique; Bassler, U; Beck, H P; Behrend, H J; Belousov, A; Berger, C; Bergstein, H; Bernardi, G; Bernet, R; Bertrand-Coremans, G H; Besançon, M; Beyer, R; Bizot, J C; Blobel, Volker; Borras, K; Botterweck, F; Boudry, V; Braemer, A; Brasse, F W; Braunschweig, W; Brisson, V; Bruncko, Dusan; Brune, C R; Buchholz, R; Buniatian, A Yu; Burke, S; Burton, M; Buschhorn, G W; Bán, J; Bähr, J; Büngener, L; Bürger, J; Büsser, F W; Campbell, A J; Carli, T; Charles, F; Chernyshov, V; Clarke, D; Clegg, A B; Clerbaux, B; Colombo, M G; Contreras, J G; Cormack, C; Coughlan, J A; Courau, A; Coutures, C; Cozzika, G; Criegee, L; Cussans, D G; Cvach, J; Dagoret, S; Dainton, J B; Danilov, M V; Dau, W D; Daum, K; David, M; De Wolf, E A; Deffur, E; Del Buono, L; Delcourt, B; Di Nezza, P; Dollfus, C; Dowell, John D; Dreis, H B; Droutskoi, A; Duboc, J; Duhm, H; Düllmann, D; Dünger, O; Ebert, J; Ebert, T R; Eckerlin, G; Efremenko, V; Egli, S; Eichenberger, S; Eichler, R; Eisele, Franz; Eisenhandler, Eric F; Ellison, R J; Elsen, E E; Erdmann, M; Erdmann, W; Erlichmann, H; Evrard, E; Favart, L; Fedotov, A; Feeken, D; Felst, R; Feltesse, Joel; Ferencei, J; Ferrarotto, F; Flamm, K; Fleischer, M; Flieser, M; Flügge, G; Fomenko, A; Fominykh, B A; Forbush, M; Formánek, J; Foster, J M; Franke, G; Fretwurst, E; Gabathuler, Erwin; Gabathuler, K; Gamerdinger, K; Garvey, J; Gayler, J; Gebauer, M; Gellrich, A; Genzel, H; Gerhards, R; Goerlach, U; Gogitidze, N; Goldberg, M; Goldner, D; González-Pineiro, B; Gorelov, I V; Goritchev, P A; Grab, C; Greenshaw, T J; Grindhammer, G; Gruber, A; Gruber, C; Grässler, Herbert; Grässler, R; Görlich, L; Haack, J; Haidt, Dieter; Hajduk, L; Hamon, O; Hampel, M; Hanlon, E M; Hapke, M; Haynes, W J; Heatherington, J; Heinzelmann, G; Henderson, R C W; Henschel, H; Herynek, I; Hess, M F; Hildesheim, W; Hill, P; Hiller, K H; Hilton, C D; Hladky, J; Hoeger, K C; Horisberger, R P; Hudgson, V L; Huet, Patrick; Hufnagel, H; Höppner, M; Hütte, M; Ibbotson, M; Itterbeck, H; Jabiol, M A; Jacholkowska, A; Jacobsson, C; Jaffré, M; Janoth, J; Jansen, T; Johannsen, K; Johnson, D P; Johnson, L; Jung, H; Jönsson, L B; Kalmus, Peter I P; Kant, D; Kaschowitz, R; Kasselmann, P; Kathage, U; Katzy, J M; Kaufmann, H H; Kazarian, S; Kenyon, Ian Richard; Kermiche, S; Keuker, C; Kiesling, C; Klein, M; Kleinwort, C; Knies, G; Ko, W; Kolanoski, H; Kole, F; Kolya, S D; Korbel, V; Korn, M; Kostka, P; Kotelnikov, S K; Krasny, M W; Krehbiel, H; Krämerkämper, T; Krücker, D; Krüger, U P; Krüner-Marquis, U; Kubenka, J P; Kuhlen, M; Kurca, T; Kurzhöfer, J; Kuznik, B; Köhler, T; Köhne, J H; Küster, H; Lacour, D; Lamarche, F; Lander, R; Landon, M P J; Lange, W; Lanius, P; Laporte, J F; Lebedev, A; Leverenz, C; Levonian, S; Ley, C; Lindner, A; Lindström, G; Linsel, F; Lipinski, J; List, B; Loch, P; Lohmander, H; Lubimov, V; López, G C; Lüke, D; Magnussen, N; Malinovskii, E I; Mani, S; Maracek, R; Marage, P; Marks, J; Marshall, R; Martens, J; Martin, R D; Martyn, H U; Martyniak, J; Masson, S; Mavroidis, A; Maxfield, S J; McMahon, S J; Mehta, A; Meier, K; Mercer, D; Merz, T; Meyer, C A; Meyer, H; Meyer, J; Mikocki, S; Milstead, D; Moreau, F; Morris, J V; Mroczko, E; Murín, P; Müller, G; Müller, K; Nagovitsin, V; Nahnhauer, R; Naroska, Beate; Naumann, T; Newman, P R; Newton, D; Neyret, D; Nguyen, H K; Nicholls, T C; Niebergall, F; Niebuhr, C B; Nisius, R; Nowak, G; Noyes, G W; Nyberg-Werther, M; Oakden, M N; Oberlack, H; Obrock, U; Olsson, J E; Panaro, E; Panitch, A; Pascaud, C; Patel, G D; Peppel, E; Phillips, J P; Pichler, C; Pitzl, D; Pope, G; Prell, S; Prosi, R; Pérez, E; Raupach, F; Reimer, P; Reinshagen, S; Ribarics, P; Rick, Hartmut; Riech, V; Riedlberger, J; Riess, S; Rietz, M; Rizvi, E; Robertson, S M; Robmann, P; Roloff, H E; Roosen, R; Rosenbauer, K; Rostovtsev, A A; Rouse, F; Royon, C; Rusakov, S V; Rybicki, K; Rylko, R; Rädel, G; Rüter, K; Sahlmann, N; Sankey, D P C; Savitsky, M M; Schacht, P; Schiek, S; Schleper, P; Schmidt, C; Schmidt, D; Schmidt, G; Schröder, V; Schuhmann, E; Schwab, B; Schwind, A; Schöning, A; Seehausen, U; Sefkow, F; Seidel, M; Sell, R; Semenov, A A; Shekelian, V I; Shevyakov, I; Shooshtari, H; Shtarkov, L N; Siegmon, G; Siewert, U; Sirois, Y; Skillicorn, Ian O; Smirnov, P; Smith, J R; Soloviev, Yu V; Spiekermann, J; Spitzer, H; Starosta, R; Steenbock, M; Steffen, P; Steinberg, R; Stella, B; Stephens, K; Stier, J; Stiewe, J; Strachota, J; Straumann, U; Struczinski, W; Stösslein, U; Sutton, J P; Sánchez, E; Tapprogge, Stefan; Taylor, R E; Thiebaux, C; Thompson, G; Truöl, P; Turnau, J; Tutas, J; Uelkes, P; Usik, A; Valkár, S; Valkárová, A; Vallée, C; Van Esch, P; Van Mechelen, P; Vartapetian, A H; Vazdik, Ya A; Vecko, M; Verrecchia, P; Villet, G; Wacker, K; Wagener, A; Wagener, M; Walker, I W; Walther, A; Weber, G; Weber, M; Wegener, D; Wegner, A; Wellisch, H P; West, L R; Willard, S; Winde, M; Winter, G G; Wright, A E; Wulff, N; Wünsch, E; Yiou, T P; Zarbock, D; Zhang, Z; Zhokin, A S; Zimmer, M; Zimmermann, W; Zomer, F; Zuber, K; Zácek, J; de Roeck, A; von Schlippe, W; Niebergall, Friedrich

    1995-01-01

    A measurement of the proton structure function F_{\\!2}(x,Q^2) is reported for momentum transfer squared Q^2 between 4.5 GeV^2 and 1600 GeV^2 and for Bjorken x between 1.8\\cdot10^{-4} and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that F_{\\!2} increases significantly with decreasing x, confirming our previous measurement made with one tenth of the data available in this analysis. The Q^2 dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the "diffractive" contribution to F_{\\!2}.

  20. Molecular Structure of Ge_xP_xS_1-2x Bulk Alloy Glasses

    Vempati, U.; Boolchand, P.

    2004-03-01

    Rather complete Raman and MDSC results on the reversibility window and aging effects are now available on ternary Ge_xP_xSe_1-2x glasses. It is therefore of interest to understand in what manner replacing Se by S alters the reversibility window. We have synthesized titled glasses over the 0 MDSC measurements. Unlike the case of Selenide glasses, in S-rich glasses S8 crowns segregate from the backbone altering the constraint counting. But as in the Se-deficient (x > 2/11) glasses, the S-deficient glasses are also found to partially nanoscale phase separate into P_4(S or Se)3 monomers. The reversibility window in the two chalcogenides will be compared and contrasted. *Supported by NSF grant DMR 01-01808

  1. SU(2) x SU(2) structures in two-dimensional critical systems

    A detailed analysis of selection rules for the operator product expansion and of closed operator algebras in unitary and non-unitary critical statistical systems with Virasoro central charge c<1 is presented. The four point correlations constructed by Dotsenko and Fateev are related to those of a SU(2) x SU(2) Wess-Zumino-Witten model. Implementing the constraint of locality on the correlation functions gives rise to equivalent monodromy structures. This implies the existence of a unique correspondence between the selection rules and the operator algebras in both models. Previous results on the SU(2) Wess-Zumino-Witten model allow to determine the rich algebraic structures of the statistical systems. (orig.)

  2. Magnetism in hydrogen-doped U2T2X compounds

    U2T2X compounds (Mo2FeB2 structure type, T-transition metal, X-p-element), exhibiting wide range of magnetic properties from weak paramagnetism to 5f-antiferromagnetism, have been checked for hydrogen absorption properties. Besides U2Co2Sn hydrides, which have been reported already, U2Ni2SnH1.8, U2Ni2InH1.9, and U2Co2InH1.9, have been synthesized. Hydrogenation leads to the enhancement of magnetic interaction for all compounds. U2Ni2SnH1.8 and U2Ni2InH1.9 order antiferromagnetically similar to the initial compounds, and the Neel temperature increases from 26 to 87K and from 15 to 60K, respectively

  3. The solid solution Lu2-xScxSiO5

    The monoclinic silicates Lu2SiO5 and Sc2SiO5 (Y2SiO5 type, space groupC2/c) forma solid solution Lu2-xScxSiO5. Samples with x = 0.5, 0.8, 1.0 were synthesized ceramically from Lu2O3, Sc2O3, and SiO2. The structures of three crystals with x = 0.88, 0.77, and 0.50 were refined on the basis of single-crystal X-ray diffraction data. The rare earth (RE) atoms occupy two crystallographically different 8 f sites with oxygen coordination numbers (CN) of 6 (RE2) and 7 (RE1). Refinements of the occupancy parameters showed Lu/Sc mixing for both sites with a strong preference of the smaller scandium atoms for CN6. (orig.)

  4. Nuclear medium modification of the F{sub 2}(x,Q{sup 2}) structure function

    Sajjad Athar, M., E-mail: sajathar@gmail.co [Department of Physics, Aligarh Muslim University, Aligarh 202 002 (India); Ruiz Simo, I.; Vicente Vacas, M.J. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia - CSIC, 46100 Burjassot (Valencia) (Spain)

    2011-05-01

    We study the nuclear effects in the electromagnetic structure function F{sub 2}(x,Q{sup 2}) in the deep inelastic lepton-nucleus scattering process by taking into account Fermi motion, binding, pion and rho meson cloud contributions. Calculations have been done in a local density approximation using relativistic nuclear spectral functions which include nucleon correlations. The ratios R{sub F}{sub 2}{sup A}(x,Q{sup 2})=(2F{sub 2}{sup A}(x,Q{sup 2}))/(AF{sub 2}{sup D}(x,Q{sup 2})) are obtained and compared with recent JLab results for light nuclei with special attention to the slope of the x distributions. This magnitude shows a non-trivial A dependence and it is insensitive to possible normalization uncertainties. The results have also been compared with some of the older experiments using intermediate mass nuclei.

  5. Magnetic Properties of La2-xSrxCuO4 Nanoparticles in Mesoporous Silica

    We synthesized the La2-xSrxCuO4 (x = 0 and 0.15) nanoparticles with particle size of about 12–13 nm in the pores of mesoporous silica and investigated their size effects through magnetic and ESR measurements. Magnetization curves for the nanoparticle with x = 0 exhibited rapid increase under low magnetic field as in ferromagnetic materials, and the magnetization increased linearly without saturation tendency. In contrast, magnetization for x = 0.15 consistently increased in proportion to magnetic field without diamagnetic behavior. ESR absorption spectra for both x = 0 and 0.15 were reproduced by summation of two absorption lines. Both the magnetic and the ESR measurement results suggested the coexistence of two magnetic components in each nanoparticle.

  6. Low-energy ion bombardment induced anisotropy in sputtered MoS2-x thin films

    Low-energy Ar+ ion bombardments (0.3 keV, 0-10 mA) at glancing angle (67o from substrate normal) on RF magnetron sputtered MoS2-x films give rise to a marked anisotropy in the plane parallel to the substrate. The (002) planes of all the crystallites align along the projected direction of irradiation. The electrical conductivity measurements show that the conductivity in the direction parallel to the projected direction of ion incidence is four times higher than that perpendicular to the projected direction. The strong increase in conductivity in the bombarded films (up to four orders of magnitude) is due to the loss of stoichiometry of the films. The film growth mechanism is finally discussed. (author)

  7. Predicting precompetitive state anxiety: using the 2 x 2 achievement goal framework.

    Li, Chiung-Huang

    2013-10-01

    The goal was to examine the predictiveness of achievement goals for self-confidence, cognitive anxiety, and somatic anxiety using a prospective design. 160 high school athletes completed the 2 x 2 Achievement Goals Questionnaire for Sport after daily practice and the Revised Competitive State Anxiety Inventory-2 before an official competition. Using hierarchical regression analyses, mastery-approach goals were found as positive predictors of self-confidence and negative predictors of cognitive and somatic anxiety. In contrast, performance- and mastery-avoidance goals positively predicted cognitive and somatic anxiety. Also, performance-avoidance goals negatively predicted self-confidence. Generally, athletes who pursued task mastery and improvement of competence were less physically and cognitively anxious and more self-confident. However, athletes felt tense, worried, and had lower confidence when they endorsed avoidance forms of achievement goals. PMID:24611239

  8. The structure of the Pd(110)(2x1)-CO surface

    Kittel, M; Polcik, M; Bradshaw, A M; Toomes, R L; Woodruff, D P; Rotenberg, E

    2002-01-01

    The structure of the Pd(110)(2x1)-CO ordered adsorption phase has been determined by scanned-energy mode photoelectron diffraction. The CO molecules are adsorbed close to short-bridge sites with alternating tilts along the close-packed surface rows. This local geometry is consistent with that found in previous theoretical total energy calculations and an earlier X-ray photoelectron diffraction study, but is in direct contradiction to the results of an earlier quantitative low energy electron diffraction investigation. While the best-fit model structure involves some twist of the CO molecules out of the mirror planes of the surface creating a surface phase of p1g1 symmetry, the more symmetric p2mg falls within the estimated limits of precision of the analysis.

  9. Turbine Design and Analysis for the J-2X Engine Turbopumps

    Marcu, Bogdan; Tran, Ken; Dorney, Daniel J.; Schmauch, Preston

    2008-01-01

    Pratt and Whitney Rocketdyne and NASA Marshall Space Flight Center are developing the advanced upper stage J-2X engine based on the legacy design of the J-2/J-2S family of engines which powered the Apollo missions. The cryogenic propellant turbopumps have been denoted as Mark72-F and Mark72-0 for the fuel and oxidizer side, respectively. Special attention is focused on preserving the essential flight-proven design features while adapting the design to the new turbopump configuration. Advanced 3-D CFD analysis has been employed to verify turbine aero performance at current flow regime boundary conditions and to mitigate risks associated with stresses. A limited amount of redesign and overall configuration modifications allow for a robust design with performance level matching or exceeding requirement.

  10. Nonlinear dynamical behavior of Xenon atoms along dislocation lines in UO2+ x nuclear fuel

    Sui, PengFei; Dai, ZhenHong

    2015-05-01

    Experimental results showed that there are a few Xenon atom bubbles connected by the dislocation line in the UO2+ x nuclear fuel, and the largest radius of bubbles is about 45 nm. This phenomenon is in contrast to traditional bubble formation mechanism. This phenomenon is very important in understanding the properties of nuclear fuel. In this work, we apply a time-dependent microscopic atom transport equation and take into account stress coherent potential in the boundary of the dislocation. Using the equation, we numerically solved the stress coherence effect and studied the transfer properties of Xenon atoms along the dislocation line. Our numerical results show that the transport of the Xenon atoms along the dislocation changes nonlinearly with the external driving energy, and reaches at the saturation values. It explains the growth limit of Xenon atom bubbles that is in agreement with the experiment results.

  11. Measurement-based Evaluation of the Impact of Large Vehicle Shadowing on V2X Communications

    Rodriguez, Ignacio; Portela Lopes de Almeida, Erika; Lauridsen, Mads;

    2016-01-01

    -based evaluation of large vehicle shadowing at 5.8 GHz in V2X scenarios. The receiver antenna height is fixed to average vehicular height (1.5 m), while the transmitter antennas are located at different heights (1.5, 5, and 7 m) in order to investigate both V2V and V2I scenarios. A truck was used to obstruct the...... depend on the transmitter antenna height, reaching maximum values of 21-23 dB. The statistical analysis also shows that the differences in shadow level due to the non-symmetries of the obstacle truck are in the order of approximately 2 dB. A simple 3D ray-tracing simulation is validated against the...

  12. Precursors from S(1)/Z2xZ2' orbifold GUTs

    The possibility of appearance of GUT precursors near the TeV scale (suggested by Dienes-Dudas-Gherghetta) is addressed within 5D GUTs compactified on an S(1)/Z2xZ2' orbifold. For a low compactification scale (large radius), there is a significant non-universal logarithmic contribution in the relative running of gauge couplings. This within 5D SU(5), with the minimal field content, gives wrong prediction for α3(MZ) unless one goes beyond the minimal setting. The realization of the light precursors' idea thus requires some specific extensions. As a scenario alternative to SU(5) we also consider an SU(6) orbifold GUT, whose minimal non-SUSY version gives natural unification. In all the presented unification scenarios with light precursors, various GUT scales are realized. This allows the model to be naturally embedded in either heterotic or Type I string theories

  13. Competition between triplet, singlet, and FFLO states in organic superconductors (TMTSF)2X under magnetic field

    We study the competition between triplet f-wave, singlet d-wave, and the FFLO state in a model for (TMTSF)2X using random phase approximation. The result suggests the possibility of singlet →FFLO→triplet transition upon increasing the magnetic field. The singlet →FFLO→triplet transition can appear in a large parameter regime on the space of the magnetic field and the off-site repulsions which induce the coexistence with 2kF charge and 2kF spin fluctuations, although decreasing the off-site repulsions suppresses the spin triplet f-wave pairing. We also show that the triplet component mixing increases in the FFLO state with increasing the magnetic field, and the off-site repulsions increase the mixing rate. The results seem to suggest that the large triplet mixing results in an enhanced tendency toward the FFLO state over the usual pairing state.

  14. Characterization of U-based thin films: the UFe{sub 2+x} case

    Kim-Ngan, Nhu-T H; Havela, L; Adamska, A M; Danis, S; Pesicka, J; Macl, J [Faculty of Mathematics and Physics, Charles University, 12116 Prague 2 (Czech Republic); Eloirdi, R; Huber, F; Gouder, T [European Commission, Joint Research Centre, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany); Balogh, A G, E-mail: tarnawsk@mag.mff.cuni.cz [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

    2011-07-06

    We have characterized UFe{sub 2+x} films prepared by sputter deposition onto fused silica (SiO{sub 2}) and Si(111) substrates with the film thickness ranging from 75 nm to 900 nm. The X-ray diffraction results showed an amorphous character of the deposited material. Some of the films showed in addition a pattern of highly textured cubic Laves phase. Rutherford Backscattering Spectroscopy with 2 MeV He{sup +} ions has been used to determine the composition, thickness and concentration depth profile of the films. A large ageing affect was observed within 1 month after that the films were exposed to air. Magnetic measurements revealed T{sub C} increasing with relative Fe concentration and reaching approx. 450 K in UFe{sub 3.0}.

  15. Band gap-tunable (CuAg)xIn2xZn2(1−2x)S2 solid solutions synthesized by hydrothermal method with ultrasonic assistance and their photocatalytic H2 production performance

    Highlights: • AgCu)xln2xZn2(1−2x)S2 were successfully prepared by ultrasonic-hydrothermal method. • The band-structure of (AgCu)xln2xZn2(1−2x)S2 can be controlled by changing x value. • A formation mechanism of microsphere was proposed based on characterization results. • The solid solutions were active photocatalysts for H2 production. -- Abstract: A series of (AgCu)xIn2xZn2(1−2x)S2 solid solutions, which were usually obtained at high temperature, were successfully prepared in an environmental-friendly condition via a simple and cost-effective hydrothermal method with ultrasonic assistance. The physical and photophysical properties of these multicomponent semiconductor solid solutions were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible diffuse reflectance spectra (UV–Vis) and N2 adsorption–desorption techniques. XRD patterns of prepared samples shifted to lower angles as the value of x increased, indicating that (AgCu)xIn2xZn2(1−2x)S2 solid solutions had been formed. UV–Vis spectra of the solid solutions shifted monotonically to long wavelength side as M/Zn (M = Cu and Ag) increased, demonstrating that the band gap of the solid solution photocatalysts could be precisely controlled with the variation of the composition. SEM and TEM images showed that the solid solutions were microspheres in morphology. The microspheric morphology, as well as a proper band structure of the solid solutions, influenced its photocatalytic activity. The photocatalytic H2 evolution from an aqueous solution containing Na2S and Na2SO3 under visible-light irradiation over (AgCu)xIn2xZn2(1−2x)S2 solid solutions were evaluated. The Ru (1.5 wt%)-loaded (AgCu)0.1In02Zn1.6S2 had the highest photocatalytic activity for H2 evolution

  16. Nickel deficiency in RENi2-xP2 (RE=La, Ce, Pr). Combined crystallographic and physical property studies

    Bauer, Eric D [Los Alamos National Laboratory; Ronning, Filip [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory; Sarrao, John L [Los Alamos National Laboratory; Bobev, S [U. OF DE; Xia, S [U. OF DE

    2008-01-01

    Large single crystals from RENi{sub 2-x}P{sub 2} (RE = La, Ce, Pr) were synthesized from the pure elements using Sn as a metal flux, and their structures were established by X-ray crystallography. The title compounds were confirmed to crystallize in the body-centered tetragonal ThCr{sub 2}Si{sub 2} structure type (space group I4/mmm (No. 139); Pearson's symbol tI10), but with a significant stoichiometry breadth with respect to the transition metal. Systematic synthetic work, coupled with accurate structure refinements indicated strong correlation between the degree of Ni-deficiency and the reaction conditions. For four different PrNi{sub 2-x}P{sub 2} (x {le} 0.5) samples, temperature dependent dc magnetization measurements indicated typical local moment 4f-magnetism and a stable Pr{sup 3+} ground state. Field-dependent heat capacity data confirmed a ferromagnetic order at low temperature, and the variations of T{sub c} with the concentration of Ni defects are discussed. LaNi{sub 2-x}P{sub 2}, as expected was found to be Pauli-like paramagnetic in the studied temperature regime, while the Ce-analog CeNi{sub 2-x}P{sub 2} (x = 0.28(1)) showed the characteristics of a mixed valent Ce{sup 3+}/Ce{sup 4+} system with a possible Kondo temperature on the order of 230 K.

  17. P2X7 receptor predicts postoperative cancer-specific survival of patients with clear-cell renal cell carcinoma.

    Liu, Zheng; Liu, Yidong; Xu, Le; An, Huimin; Chang, Yuan; Yang, Yuanfeng; Zhang, Weijuan; Xu, Jiejie

    2015-09-01

    The P2X7 receptor, an ATP-gated plasma membrane ion channel, is involved in inflammation, apoptosis and cell proliferation, and thereby plays a crucial role during oncogenic transformation in various malignancies. This study aims to evaluate the impact of P2X7 receptor expression on postoperative cancer-specific survival of patients with clear-cell renal cell carcinoma (ccRCC). A total of 273 patients with ccRCC undergoing nephrectomy at a single institution were retrospectively enrolled in this study, among which 86 patients died of this disease and six patients died of other causes. Clinicopathologic features and cancer-specific survival (CSS) were recorded. P2X7 expression was assessed by immunohistochemistry in clinical specimens. Kaplan-Meier method with log rank test was performed to compare survival curves. Cox regression models were used to evaluate the prognostic values of variables on CSS. Concordance index was calculated to assess prognostic accuracy of prognostic models. Median follow-up period was 90 months (range, 11-120 months). Intratumoral P2X7 expression was significantly lower than peritumoral tissues (P independent prognostic factor for CSS (hazard ratio [HR], 1.693; P = 0.034). The prognostic accuracy of TNM stage, UISS and SSIGN scoring models was improved when intratumoral P2X7 expression was added. Intratumoral P2X7 expression is a potential independent adverse prognostic indicator for postoperative CSS of patients with ccRCC. PMID:26179886

  18. Study on Enhanced Thermal Conductivity of HfO{sub 2}/xGnP Composites

    Kim, In Guk; Lee, Seung Won; Kim, Ji Hyun; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2013-10-15

    It is important parameter for optimum design and safety analysis of a nuclear system. This is because the thermal conductivity of fuels significantly affects the internal energy of the nuclear fuel by heat transfer through the coolant. Therefore, the safety analysis using fuel thermal conductivity is necessary for the prediction of thermalhydraulic behavior. If exfoliated graphene nanoplate (xGnP) is mixed in UO{sub 2} fuel, it is chemically stable and its thermal conductivity will be enhanced. Advantages of xGnP are a high thermal conductivity and a low absorption cross section. In present work, HfO{sub 2} is selected as a substitute of UO{sub 2} due to the similar density of HfO{sub 2} and UO{sub 2}. HfO{sub 2}/xGnP composites were made by adding 10 vol. % of xGnP having a high thermal conductivity and the thermal conductivity of HfO{sub 2}/xGnP composites were measured by LFA 447 NanoFlash. The hafnium oxide (HfO{sub 2}) . 10 vol. % exfoliated graphite nanoplate (xGnP) composite ceramics was produced by hot isostatic pressing (HIP) and oxidative sintering at high temperature. The result of thermal conductivity of HIP sintering was increased by adding xGnP powder. Oxidative sintering was decreased the thermal conductivity because of oxidation between oxygen and carbon in xGnP. But HIP sintering was not effect of oxidation due to vacuum condition in can. In this paper the result of thermal conductivity showed the possibility of enhanced fuel pellet.

  19. Transient heat transfer behavior during reflood phase in a 2x2 ballooned rod bundle

    The coolability of the ballooned region is entirely different with that of the normal ones. Therefore, in this study, the transient heat transfer behavior during the reflood phase of ballooned fuel rods was experimentally investigated in a 2x2 rod bundle test facility. The coolability depends greatly on the blockage characteristics (blockage ratio, blockage length, blockage shape, and blockage configuration) and the system conditions of the test facility (flow, system pressure, and inlet temperature). Among them, the blockage ratio effect on the coolabiltiy is carefully examined varying the reflood rate in the present study, since the blockage ratio plays a significant role on the coolability under the low reflood rate condition (2.5 cm/s). The test results were analyzed with the transient temperature profiles of the fuel rods and the local heat transfer coefficient calculated using a 1-D cylindrical coordinates FVM (Finite-Volume-Method) code. Forced reflood tests with various reflood rates were performed to understand the transient heat transfer behavior and to investigate the influence of the blockage ratio on the coolability in the 2x2 rod bundle test facility. The transient temperature profiles and the local heat transfer coefficients at the upstream and downstream region of the blockage simulator were examined for non-blockage, 90% blockage, and 62% blockage conditions. In the downstream region, the coolability was greatly enhanced except for a low reflood rate (1.0 cm/s). In the upstream region, the cooling performance decreased smoothly with decreasing the reflood rate. When the reflood rate is 1.0 cm/s, the coolabilities at the both upstream and downstream region were significantly reduced regardless of the blockage ratio. As a conclusion, the coolability at the low reflood rate (1.0 cm/s) should be carefully examined with the droplet behavior as a future work

  20. The J-2X Upper Stage Engine: From Design to Hardware

    Byrd, Thomas

    2010-01-01

    NASA is well on its way toward developing a new generation of launch vehicles to support of national space policy to retire the Space Shuttle fleet, complete the International Space Station, and return to the Moon as the first step in resuming this nation s exploration of deep space. The Constellation Program is developing the launch vehicles, spacecraft, surface systems, and ground systems to support those plans. Two launch vehicles will support those ambitious plans the Ares I and Ares V. (Figure 1) The J-2X Upper Stage Engine is a critical element of both of these new launchers. This paper will provide an overview of the J-2X design background, progress to date in design, testing, and manufacturing. The Ares I crew launch vehicle will lift the Orion crew exploration vehicle and up to four astronauts into low Earth orbit (LEO) to rendezvous with the space station or the first leg of mission to the Moon. The Ares V cargo launch vehicle is designed to lift a lunar lander into Earth orbit where it will be docked with the Orion spacecraft, and provide the thrust for the trans-lunar journey. While these vehicles bear some visual resemblance to the 1960s-era Saturn vehicles that carried astronauts to the Moon, the Ares vehicles are designed to carry more crew and more cargo to more places to carry out more ambitious tasks than the vehicles they succeed. The government/industry team designing the Ares rockets is mining a rich history of technology and expertise from the Shuttle, Saturn and other programs and seeking commonality where feasible between the Ares crew and cargo rockets as a way to minimize risk, shorten development times, and live within the budget constraints of its original guidance.

  1. Impaired P2X signalling pathways in renal microvascular myocytes in genetic hypertension

    Gordienko, Dmitri V.

    2014-12-16

    Aims P2X receptors (P2XRs) mediate sympathetic control and autoregulation of renal circulation triggering preglomerular vasoconstriction, which protects glomeruli from elevated pressures. Although previous studies established a casual link between glomerular susceptibility to hypertensive injury and decreased preglomerular vascular reactivity to P2XR activation, the mechanisms of attenuation of the P2XR signalling in hypertension remained unknown. We aimed to analyse molecular mechanisms of the impairment of P2XR signalling in renal vascular smooth muscle cells (RVSMCs) in genetic hypertension. Methods and results We compared the expression of pertinent genes and P2XR-linked Ca2+ entry and Ca2+ release mechanisms in RVSMCs of spontaneously hypertensive rats (SHRs) and their normotensive controls, Wistar Kyoto (WKY) rats. We found that, in SHR RVSMCs, P2XR-linked Ca2+ entry and Ca2+ release from the sarcoplasmic reticulum (SR) are both significantly reduced. The former is due to down-regulation of the P2X1 subunit. The latter is caused by a decrease of the SR Ca2+ load. The SR Ca2+ load reduction is caused by attenuated Ca2+ uptake via down-regulated sarco-/endoplasmic reticulum Ca2+-ATPase 2b and elevated Ca2+ leak from the SR via ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate receptors. Spontaneous activity of these Ca2+-release channels is augmented due to up-regulation of RyR type 2 and elevated IP3 production by up-regulated phospholipase C-β1. Conclusions Our study unravels the cellular and molecular mechanisms of attenuation of P2XR-mediated preglomerular vasoconstriction that elevates glomerular susceptibility to harmful hypertensive pressures. This provides an important impetus towards understanding of the pathology of hypertensive renal injury.

  2. Valence and magnetic transitions in YbMn2Si2-xGex

    Full text: Rare-earth intermetallic compounds containing ytterbium exhibit a wide range of interesting and unusual physical and magnetic properties. This occurs mainly as a result of their mixed valence states (II/III) or changes from one valence state to the other. Nowik et al. have recently investigated the magnetic phase transitions in the YbMn2Si2-xGex series (tetragonal ThCr2Si2-type structure) by magnetisation and Moessbauer effect studies on 57Fe doped samples. A number of transitions were observed in the limiting YbMn2Ge2 and YbMn2Si2 compounds. We have carried out a neutron diffraction investigation of a series of YbMn2Si2-xGex samples (x=0, 0.4, 1.0, 1.4, 2.0) over the temperature range 1.5-600 K to delineate details of the valence and related magnetic transitions. As well as determining the antiferromagnetic structures of YbMn2Ge2 and YbMnSi2, we have also established that the Yb sublattice orders antiferromagnetically below Tn3 ∼ 5 K. Our neutron diffraction measurements are consistent with a trivalent Yb state in YbMn2Si2, whereas analysis of the unit cell volumes leads to a Yb valence of about 2.35 in YbMn2Ge2. The change in valence state occurs around a critical Ge concentration xc ∼1.4

  3. On the System of Diophantine Equations x+1 =3pqu2 and x2-x+1 =3v2%关于Diophantine方程组x+1=3pqu2,x2-x+1=3v2的整数解

    管训贵

    2015-01-01

    设p,q是互异的奇素数,p≡q≡1 (mod 6),主要利用递归序列、Pell方程和四次Diophantine方程解的性质证明了Diophantine方程组x+1=3 pqu2,x2-x+1=3v2除开pq=7×13有非平凡解外,仅有平凡解.

  4. Laser device

    Scott, Jill R.; Tremblay, Paul L.

    2007-07-10

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  5. Laser device

    Scott, Jill R.; Tremblay, Paul L.

    2004-11-23

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  6. P2X7 Receptor Antagonism Attenuates the Intermittent Hypoxia-induced Spatial Deficits in a Murine Model of Sleep Apnea Via Inhibiting Neuroinflammation and Oxidative Stress

    Yan Deng

    2015-01-01

    Conclusions: The P2X7R antagonism attenuates the CIH-induced neuroinflammation, oxidative stress, and spatial deficits, demonstrating that the P2X7R is an important therapeutic target in the cognition deficits accompanied OSAS.

  7. Understanding the role of P2X7 in affective disorders – are glial cells the major players?

    Leanne eStokes

    2015-07-01

    Full Text Available The pathophysiology of several psychiatric disorders has been linked to biomarkers of inflammation generating a theory of major depressive disorder as an inflammatory disease and infection and autoimmunity as major risk factors for schizophrenia. The idea of pro-inflammatory cytokines altering behavior is now well accepted however many questions remain. Microglia can produce a plethora of inflammatory cytokines and these cells appear to be critical in the link between inflammatory changes and depressive disorders. Microglia play a known role in sickness behavior which has many components of depressive-like behavior such as social withdrawal, sleep alterations, and anorexia. Numerous candidate genes have been identified for psychiatric disorders in the last decade. Single nucleotide polymorphisms in the human P2X7 gene have been linked to bipolar disorder, depression, and to the severity of depressive symptoms. P2X7 is a ligand-gated cation channel expressed on microglia with lower levels found on astrocytes and on some neuronal populations. In microglia P2X7 is a major regulator of pro-inflammatory cytokines of the interleukin-1 family. Genetic deletion of P2X7 in mice is protective for depressive behavior in addition to inflammatory responses. P2X7-/- mice have been shown to demonstrate anti-depressive-like behavior in forced swim and tail suspension behavioral tests and stressor-induced behavioral responses were blunted. Both neurochemical (norepinephrine, serotonin, dopamine and inflammatory changes have been observed in the brains of P2X7-/- mice. This review will discuss the recent evidence for involvement of P2X7 in the pathophysiology of depressive disorders and propose mechanisms by which altered signaling through this ion channel may affect the inflammatory state of the brain.

  8. Integrin-mediated transactivation of P2X7R via hemichannel-dependent ATP release stimulates astrocyte migration.

    Alvarez, Alvaro; Lagos-Cabré, Raúl; Kong, Milene; Cárdenas, Areli; Burgos-Bravo, Francesca; Schneider, Pascal; Quest, Andrew F G; Leyton, Lisette

    2016-09-01

    Our previous reports indicate that ligand-induced αVβ3 integrin and Syndecan-4 engagement increases focal adhesion formation and migration of astrocytes. Additionally, ligated integrins trigger ATP release through unknown mechanisms, activating P2X7 receptors (P2X7R), and the uptake of Ca(2+) to promote cell adhesion. However, whether the activation of P2X7R and ATP release are required for astrocyte migration and whether αVβ3 integrin and Syndecan-4 receptors communicate with P2X7R via ATP remains unknown. Here, cells were stimulated with Thy-1, a reported αVβ3 integrin and Syndecan-4 ligand. Results obtained indicate that ATP was released by Thy-1 upon integrin engagement and required the participation of phosphatidylinositol-3-kinase (PI3K), phospholipase-C gamma (PLCγ) and inositol trisphosphate (IP3) receptors (IP3R). IP3R activation leads to increased intracellular Ca(2+), hemichannel (Connexin-43 and Pannexin-1) opening, and ATP release. Moreover, silencing of the P2X7R or addition of hemichannel blockers precluded Thy-1-induced astrocyte migration. Finally, Thy-1 lacking the integrin-binding site did not stimulate ATP release, whereas Thy-1 mutated in the Syndecan-4-binding domain increased ATP release, albeit to a lesser extent and with delayed kinetics compared to wild-type Thy-1. Thus, hemichannels activated downstream of an αVβ3 integrin-PI3K-PLCγ-IP3R pathway are responsible for Thy-1-induced, hemichannel-mediated and Syndecan-4-modulated ATP release that transactivates P2X7Rs to induce Ca(2+) entry. These findings uncover a hitherto unrecognized role for hemichannels in the regulation of astrocyte migration via P2X7R transactivation induced by integrin-mediated ATP release. PMID:27235833

  9. Reassessment of UO2+x melting by combined consideration of experimental and theoretical work

    In the event of upset or very high power conditions, it is possible that the temperature at the centreline of a fuel pellet will exceed the local melting condition. This possibility is enhanced if the fuel element has become defective, in which case the coolant may contact the UO2 and oxidizes it to UO2+x. Hyper-stoichiometric fuel has a reduced thermal conductivity and a lower incipient melting point (solidus), thus reducing the margin of safety to avoid molten fuel. For the sake of safety analysis, it is therefore important to have a good understanding of the U-O binary phase diagram, particularly in the description of UO2+x melting. In this work, a partial re-assessment of the U-O phase diagram is proposed based on recent experimental results, linked to a thermodynamic analysis employing Gibbs energy minimization and Phase- Field theory. The Gibbs energy calculations lead to a better understanding of the implications of the new experimental points on the U-O phase diagram. The effect of high external pressure on the measured phase transition temperatures to reduce the volatilization of uranium oxides is in particular considered. This work demonstrates the synergetic co-development of experimental and theoretical work, and its value in investigating phenomena occurring under extreme, but important, conditions. The binary U-O system is of great interest to both the scientific and technical communities. However, much of the U-O phase diagram is under controversy at temperatures exceeding 2000 K, due to the poor chemical stability of phases with respect to their possible loss of oxygen. Measurements in this domain have been performed in the last few years at ITU Karlsruhe by laser flash heating coupled with fast pyrometry. With this experimental approach, the melting transition of the stoichiometric and hyper-stoichiometric uranium dioxide has been measured up to x = 0.21. Solidus and liquidus points were determined both visually and by observing the corresponding

  10. Integrated System Health Management (ISHM) for Test Stand and J-2X Engine: Core Implementation

    Figueroa, Jorge F.; Schmalzel, John L.; Aguilar, Robert; Shwabacher, Mark; Morris, Jon

    2008-01-01

    ISHM capability enables a system to detect anomalies, determine causes and effects, predict future anomalies, and provides an integrated awareness of the health of the system to users (operators, customers, management, etc.). NASA Stennis Space Center, NASA Ames Research Center, and Pratt & Whitney Rocketdyne have implemented a core ISHM capability that encompasses the A1 Test Stand and the J-2X Engine. The implementation incorporates all aspects of ISHM; from anomaly detection (e.g. leaks) to root-cause-analysis based on failure mode and effects analysis (FMEA), to a user interface for an integrated visualization of the health of the system (Test Stand and Engine). The implementation provides a low functional capability level (FCL) in that it is populated with few algorithms and approaches for anomaly detection, and root-cause trees from a limited FMEA effort. However, it is a demonstration of a credible ISHM capability, and it is inherently designed for continuous and systematic augmentation of the capability. The ISHM capability is grounded on an integrating software environment used to create an ISHM model of the system. The ISHM model follows an object-oriented approach: includes all elements of the system (from schematics) and provides for compartmentalized storage of information associated with each element. For instance, a sensor object contains a transducer electronic data sheet (TEDS) with information that might be used by algorithms and approaches for anomaly detection, diagnostics, etc. Similarly, a component, such as a tank, contains a Component Electronic Data Sheet (CEDS). Each element also includes a Health Electronic Data Sheet (HEDS) that contains health-related information such as anomalies and health state. Some practical aspects of the implementation include: (1) near real-time data flow from the test stand data acquisition system through the ISHM model, for near real-time detection of anomalies and diagnostics, (2) insertion of the J-2X

  11. Preparation and characterization of LiAlxMn2-xO4 for a supercapacitor in aqueous electrolyte

    Yun Xue; Ye Chen; Mi-lin Zhang; Yong-de Yan

    2009-01-01

    LiAlxMn2-xO4 (0≤x≤0.5) was synthesized by high temperature solid-state reaction.The structure and morphology of LiAl/Mn2-xO4 were investigated by X-ray diffraction and scanning electron microscopy (SEM).The results indicate that all samples show spinel phase.The polyhedral particles turn to club-shaped,then change to small spherical,and finally become agglomerates with increasing Al content.The supercapacitive performances of LiAlxMn2-xO4 were studied by means of galvanostatic charge-discharge,cyclic voltammetry,and alternating current (AC) impedance in 2 mol.L-l (NH4)2SO4 aqueous solution.The results show that LiAlxMn2-xO4 represents rectangular shape performance in the potential range of 0-1 V.The capacity and cycle perform-ance can be improved by doping Al.The composition of x=0.1 has the maximum special capacitance of 160 F.g-1,which is 1.37 times that of LiMn2O4 electrode.The capacitance loss of LiAlxMn2-xO4 with x=0.1 is only about 14% after 100 cycles.

  12. Prediction of formation enthalpies for Al2X-type intermetallics using back-propagation neural network

    Research highlights: → An ANN was built to predict the formation enthalpies of Al2X-type intermetallics. → The values predicted by the ANN agree with experiments well to typically within 10%. → The method comparison suggests that our ANN method is superior to Miedema's model. → Some trends of formation enthalpies for Al2X-type intermetallics were observed. - Abstract: A back-propagation artificial neural network (ANN) was established to predict the formation enthalpies of Al2X-type intermetallics as a function of some physical parameters. These physical parameters include the electronegativity difference, the electron density difference, the atomic size difference, and the electron-atom ratio (e/a). The values calculated by the ANN method agree with experiments well to typically within 10%, indicating that the well-trained back-propagation (BP) neural network is feasible, and can precisely predict the formation enthalpies of Al2X-type intermetallics. The method comparison based on the predicted formation enthalpies suggests that our ANN method is superior to Miedema's model. Some trends of formation enthalpies for Al2X-type intermetallics were also observed from the ANN.

  13. Influence of Al content on the properties of ternary Al2xIn2−2xO3 alloy films prepared on YSZ (1 1 1) substrates by MOCVD

    Highlights: • Al2xIn2−2xO3 films were prepared on the Y-stabilized ZrO2 (1 1 1) substrates by MOCVD at 700 °C. • A phase transition from the bixbyite In2O3 structure to the amorphous structure was observed. • The lowest resistivity of 4.7 × 10−3 Ω cm was obtained for the Al0.4In1.6O3 film. • Tunable optical band gap from 3.7 to 4.8 eV was obtained. - Abstract: The ternary Al2xIn2−2xO3 films with different Al contents of x [Al/(Al + In) atomic ratio] have been fabricated on the Y-stabilized ZrO2 (1 1 1) substrates by metal organic chemical vapor deposition at 700 °C. The structural, electrical and optical properties of the films as a result of different Al contents (x = 0.1–0.9) were investigated in detail. With the increase of Al content from 10% to 90%, a phase transition from the bixbyite In2O3 structure with a single orientation along (1 1 1) to the amorphous structure was observed. The minimum resistivity of 4.7 × 10−3 Ω cm, a carrier concentration of 1.4 × 1020 cm−3 and a Hall mobility of 9.8 cm2 v−1 s−1 were obtained for the sample with x = 0.2. The average transmittances for the Al2xIn2−2xO3 films in the visible range were all over 78% and the optical band gap of the films could be tuned from 3.7 to 4.8 eV

  14. Ionothermal Synthesis of High-Voltage Alluaudite Na2+2xFe2-x(SO4)3 Sodium Insertion Compound: Structural, Electronic, and Magnetic Insights.

    Dwibedi, Debasmita; Ling, Chris D; Araujo, Rafael B; Chakraborty, Sudip; Duraisamy, Shanmughasundaram; Munichandraiah, Nookala; Ahuja, Rajeev; Barpanda, Prabeer

    2016-03-23

    Exploring future cathode materials for sodium-ion batteries, alluaudite class of Na2Fe(II)2(SO4)3 has been recently unveiled as a 3.8 V positive insertion candidate (Barpanda et al. Nat. Commun. 2014, 5, 4358). It forms an Fe-based polyanionic compound delivering the highest Fe-redox potential along with excellent rate kinetics and reversibility. However, like all known SO4-based insertion materials, its synthesis is cumbersome that warrants careful processing avoiding any aqueous exposure. Here, an alternate low temperature ionothermal synthesis has been described to produce the alluaudite Na2+2xFe(II)2-x(SO4)3. It marks the first demonstration of solvothermal synthesis of alluaudite Na2+2xM(II)2-x(SO4)3 (M = 3d metals) family of cathodes. Unlike classical solid-state route, this solvothermal route favors sustainable synthesis of homogeneous nanostructured alluaudite products at only 300 °C, the lowest temperature value until date. The current work reports the synthetic aspects of pristine and modified ionothermal synthesis of Na2+2xFe(II)2-x(SO4)3 having tunable size (300 nm ∼5 μm) and morphology. It shows antiferromagnetic ordering below 12 K. A reversible capacity in excess of 80 mAh/g was obtained with good rate kinetics and cycling stability over 50 cycles. Using a synergistic approach combining experimental and ab initio DFT analysis, the structural, magnetic, electronic, and electrochemical properties and the structural limitation to extract full capacity have been described. PMID:26931644

  15. Zr-doped Li[Ni0.5-xMn0.5-xZr2x]O2 (x = 0, 0.025) as cathode material for lithium ion batteries

    Layered Li[Ni0.5-xMn0.5-xZr2x]O2 (x = 0, 0.025) have been prepared by the mixed hydroxide and molten-salt synthesis method. The individual particles of synthesized materials have a sub-microsize range of 200-500 nm, and LiNi0.475Mn0.475Zr0.05O2 has a rougher surface than that of LiNi0.5Mn0.5O2. The Li/Li[Ni0.5-xMn0.5-xZr2x]O2 (x = 0, 0.025) electrodes were cycled between 4.5 and 2.0 V at a current density of 15 mA/g, the discharge capacity of both cells increased during the first ten cycles. The discharge capacity of the Li/LiNi0.475Mn0.475Zr0.05O2 cell increased from 150 to 220 mAh/g, which is 50 mAh/g larger than that of the Li/LiNi0.5Mn0.5O2 cell. We found that the oxidation of oxygen and the Mn3+ ion concerned this phenomenon from the cyclic voltammetry (CV). Thermal stability of the charged Li[Ni0.5-xMn0.5-xZr2x]O2 (x 0, 0.025) cathode was improved by Zr doping

  16. Frustrated spin correlations in diluted spin ice Ho2-xLaxTi2O7

    Ehlers, Georg; Ehlers, G.; Mamontov, E.; Zamponi, M.; Faraone, A.; Qiu, Y.; Cornelius, A.L.; Booth, C.H.; Kam, K.C.; Le Toquin, R.; Cheetham, A.K.; Gardner, J.S.

    2008-04-30

    We have studied the evolution of the structural properties as well as the static and dynamic spin correlations of spin ice Ho2Ti2O7, where Ho was partially replaced by non-magnetic La. The crystal structure of diluted samples Ho2-xLaxTi2O7 was characterized by x-ray and neutron diffraction and by Ho L-III-edge and Ti K-edge extended x-ray absorption fine structure (EXAFS) measurements. It is found that the pyrochlore structure remains intact until about x = 0.3, but a systematic increase in local disorder with increasing La concentration is observed in the EXAFS data, especially from the Ti K edge.Quasi-elastic neutron scattering and ac susceptibility measurements show that, in x<= 0.4 samples at temperatures above macroscopic freezing, the spin -spin correlations are short ranged and dynamic in nature. The main difference with pure spin ice in the dynamics is the appearance of a second, faster, relaxation process.

  17. Structural and electronic properties of XSi{sub 2} (X = Cr, Mo, and W)

    Shugani, Mani, E-mail: shugani.mani@gmail.com [Sadhu Vaswani College, Bairagarh, Department of Physics (India); Aynyas, Mahendra [C. S. A. Govt. P. G. College, Department of Physics (India); Sanyal, S. P. [Barkatullah University, Department of Physics (India)

    2015-07-15

    The structural and electronic properties of metal silicides XSi{sub 2} (X = Cr, Mo, and W), which crystallize in tetragonal structure, are investigated systematically using the first-principle density functional theory. The total energies are computed as a function of volume and fitted to the Birch equation of state. The ground-state properties such as equilibrium lattice constants a{sub 0} and c{sub 0}, bulk modulus B, its pressure derivative B, B′, and the density of states at the Fermi level, N(E{sub F}), are calculated and compared with other experimental and theoretical results, showing good agreement. The calculated band structure indicates that XSi{sub 2} compounds are semimetallic in nature. From the present study, we predict the structural and electronic properties of CrSi{sub 2} in the tetragonal phase and indicate that CrSi{sub 2} is energetically more stable than MoSi{sub 2} and WSi{sub 2}. Analyzing the bonding properties of the three metal silicides, we observe that WSi{sub 2} has a strong covalent bonding due to W 5d electrons.

  18. Spin Start Line Effects on the J2X Gas Generator Chamber Acoustics

    Kenny, R. Jeremy

    2011-01-01

    The J2X Gas Generator engine design has a spin start line connected near to the turbine inlet vanes. This line provides helium during engine startup to begin turbomachinery operation. The spin start line also acts as an acoustic side branch which alters the chamber's acoustic modes. The side branch effectively creates 'split modes' in the chamber longitudinal modes, in particular below the first longitudinal mode and within the frequency range associated with the injection-coupled response of the Gas Generator. Interaction between the spin start-modified chamber acoustics and the injection-driven response can create a higher system response than without the spin start attached to the chamber. This work reviews the acoustic effects of the spin start line as seen throughout the workhorse gas generator test program. A simple impedance model of the spin start line is reviewed. Tests were run with no initial spin start gas existing in the line, as well as being initially filled with nitrogen gas. Tests were also run with varying spin start line lengths from 0" to 40". Acoustic impedance changes due to different spin start gas constituents and line lengths are shown. Collected thermocouple and static pressure data in the spin start line was used to help estimate the fluid properties along the line length. The side branch impedance model was coupled to a chamber impedance model to show the effects on the overall chamber response. Predictions of the spin start acoustic behavior for helium operation are shown and compared against available data.

  19. Blue TiO2-x/SiO2 nanoparticles by laser pyrolysis

    Composite TiSiOC nanoparticles with Ti/Si ratio varying in a very large range were prepared by laser pyrolysis of a gas-spray mixture of silane and titanium tetra-isopropoxide. The as-formed nanoparticle batches exhibit intense blue colours, varying from dark to light blue while the Ti/Si ratio increases. This blue colour is attributed to the formation of sub-stoichiometric TiO2-xcompounds induced by the presence of reducing agents such as silicon-based radicals and carbon atoms in the reaction medium. The blue colour of the powders is stable for several months at room temperature in normal atmospheric conditions. Elemental analysis, specific surface area and pycnometry measurements, as well as Photon Correlation Spectroscopy allow determining the chemical composition and size of the as-synthesized nanoparticles as a function of the Ti/Si ratio. X-ray diffraction, transmission electron microscopy and IR spectroscopy have been used to analyse their chemical organisation, nanostructure and morphology. Mean grain size is found around 20 nm. The nanoparticles exhibit a core-shell structure TiO2-x/SiO2, with a core made of titania, surrounded by an amorphous shell, mainly of silica. Crystallites of anatase are present in the core with size increasing with the Ti/Si ratio. Annealing under air at 800 deg. C induces the removal of carbon and the crystallisation of the powders with light beige to white colours

  20. Physical properties of (GaAs)1-x(Ge2)x: Influence of growth direction

    (GaAs)1-x(Ge2)x metastable alloys were epitaxially grown on (001), (111), (112), and (113) GaAs by rf magnetron sputtering. A different long-range order parameter behavior with Ge concentration is observed for each growth direction. This provides a direct evidence that growth direction affects the long-range order-disorder transition exhibited by these alloys. The epitaxial growth of these alloys was modeled by a Monte Carlo simulation. The good agreement between the experimental and modeled long-range order parameter evidences that atomic ordering in these alloys is ruled mainly by growth direction and the avoidance of the formation of 'wrong' atomic pairs of As-As and Ga-Ga, and not by thermodynamic factors. On the other hand, measurements of the optical gap and Raman scattering, show that the optical properties are governed by near-neighbor correlations and therefore by their short-range order. Hence, the substrate orientation and the long-range order have negligible effect on the optical properties. Fitting the experimental data of the optical gap, we obtained linear expressions that show the fundamental gap behavior with Ge concentration of some of these alloys at room temperature. For 00(x)=1.43-2.99x eV and E0(x)=0.45+0.35x eV, respectively

  1. Growth and band gap determination of the ZrSxSe2-x single crystal series

    Moustafa, Mohamed; Zandt, Thorsten; Janowitz, Christoph; Manzke, Recardo

    2009-07-01

    Single crystals of layered transition-metal dichalcogenide compounds of ZrSxSe2-x with composition 0≤x≤2 were grown by the chemical-vapor-transport technique and characterized with the help of different methods. Indirect gap transitions with remarkably high values of the absorption coefficient α (hν) and the energy-gap values have been extracted from the optical-absorption measurements. An approximate linear dependence of the band gaps on the composition parameter x has been observed, qualifying them to become promising candidates for band gap engineering. The range of the obtained band gaps, which varies from 1.18 eV for ZrSe2 to 1.7 eV for ZrS2 , is suitable for photovoltaic applications in both single- and multiple-junction cells. Additionally, a significant absorption-coefficient tail near the fundamental absorption edge is discussed, which is found to obey the Urbach rule.

  2. Band structure of ZrS{sub x}Se{sub 2-x} by ARPES

    Moustafa, Mohamed; Paulheim, Alexander; Janowitz, Christoph; Manzke, Recardo [Institut fuer Physik, Humboldt-Universitaet Berlin, Berlin (Germany)

    2011-07-01

    The valence band structure of mixed samples of ZrS{sub x} Se{sub 2-x} single crystals, where x varies from 0 to 2, has been studied by means of high-resolution angle-resolved photoelectron spectroscopy (ARPES) using synchrotron radiation. The crystals were found to be extrinsic n-type semiconductors with indirect bandgap. The composition dependence of the band structure is presented and discussed. A characteristic splitting of the chalcogen p-derived valence bands at the symmetric point A is observed. The size of the splitting shows to increases almost linearly as progressing from ZrS{sub 2} to ZrSe{sub 2} reaching 320 meV. Further, the energy gap values are estimated from the valence band maximum to the observed emission close to the conduction band minimum. The gaps are found to vary from 1.78 eV to 1.16 eV for ZrS{sub 2} to ZrSe{sub 2}, respectively, and are compared to our previously reported optical values.

  3. Direct proof of static charge stripe correlations in La2-xBaxCuO4

    Chen, X. M.; Thampy, V.; Mazzoli, C.; Barbour, A.; Gu, G.; Hill, J. P.; Tranquada, J. M.; Dean, M. P. M.; Wilkins, S. B.

    The nature of charge stripe order in the cuprates, and in particular whether the stripes are static or dynamic, is a key issue in understanding the relationship between stripes and superconductivity. In La2-xBaxCuO4 (LBCO) a low temperature structural distortion is widely believed to pin stripes into fixed, static domains, but such an assertion has never been directly verified. We performed resonant soft x-ray photon correlation spectroscopy (XPCS) to probe the charge order Bragg peak of 1/8 doped LBCO. At low temperatures, we observe time-independent x-ray speckle patterns persisting for more than three hours, proving the static nature of the stripes and we go on to discuss how stripe order melts with increasing temperature. Our results demonstrate that the combination of XPCS with diffraction limited light sources such as the National Synchrotron Light Source II can probe the dynamics of even subtle order parameters such as stripes in the cuprates. Work performed at Brookhaven National Laboratory was supported by the US Department of Energy, Division of Materials Science, under Contract No. DE-AC02-98CH10886. Use of the National Synchrotron Light Source II was supported under Contract No. DE-SC0012704.

  4. Study on bubble drag coefficient for bubble flows in 2x1 rods channel simplifying BWR

    In order to get an accurate constitutive equation of the interfacial friction force in two-phase bubble flows, experimental data on drag coefficient and interfacial area concentration have been obtained for air-water flows in 2x1 rods channel simplifying a BWR fuel rod bundle. To know the effects of liquid properties on the data, temperature of the test water was changed from 18 to 50degC. The data are compared with the existing correlations reported in literatures. As a result for an interfacial area concentration, Hibiki and Ishii (2001) semi-theoretical correlation is found to give the best prediction against the present data. As for the drag coefficient, no correlations exist which can predict well the present data. Therefore, we developed a new correlation including three dimensionless numbers, i.e., bubble Capillary number, Morton number and Eoetvoes number. The correlation could predict well Liu et al.'s data (2008) as well as the present data. (author)

  5. 2x250 GeV gamma-gamma collider at TESLA

    This paper presents the conceptual project of a 2x250 GeV photon collider at TESLA. The main idea of the proposal is to use the beam of the linear collider to generate FEL radiation. At an intermediate phase of acceleration (E=10 GeV) the electron beam passes the undulator of the FEL amplifier and amplifies the optical radiation of the master oscillator (λ=1.053 μm, peak power 100 MW). An output radiation of 350 GW peak power is produced at the amplifier exit. After that the electron and optical bunches are separated. The electron bunch is accelerated up to the final energy of 250 GeV and the optical bunch is transported to the conversion point via an open optical waveguide which has the form of a diaphragm focusing line and is placed in parallel with the main accelerator. At the conversion point the optical beam is focused on the electron beam and after the conversion point the gamma quanta follow the initial electron trajectory and meet at the interaction point with the other gamma-beam produced by another part of the collider. The integral luminosity of the colliding γ-beams is Lγγ∼ =1.5x1033 cm-2s-1. The feasibility of the proposal is confirmed by the results of numerical simulations. (orig.)

  6. Anomalous magnetoresistance behavior of superconducting Nd2-xCexCuO4-y single crystal

    Magnetoresistance measurements on a superconducting Nd2-xCexCuO4-y single crystal with Tc∼7 K were made with magnetic fields H applied parallel (H parallel c) and perpendicular (H perpendicular to c) to the tetragonal c-axis. For H parallel c, the resistive superconductive transition curves exhibit a double transition at low temperatures and high magnetic fields. This double resistive transition has a maximum near T∼1.1 K, followed by an extremely sharp transition into the superconducting state. For applied fields of 1 kOe, the resistivity first goes to zero, increases again to a finite value and then goes through a second transition. In this region, the resistivity exhibits non-ohmic behavior for low current densities and ohmic behavior for larger measuring currents. The resistivity for H perpendicular to c does not exhibit any anomalous behavior or a maximum for 0≤H≤60 kOe and 4 K≤T≤7 K. ((orig.))

  7. Structural and electronic properties of silicene on MgX2 (X = Cl, Br, and I)

    Zhu, Jiajie

    2014-07-23

    Silicene is a monolayer of Si atoms in a two-dimensional honeycomb lattice, being expected to be compatible with current Si-based nanoelectronics. The behavior of silicene is strongly influenced by the substrate. In this context, its structural and electronic properties on MgX2 (X = Cl, Br, and I) have been investigated using first-principles calculations. Different locations of the Si atoms are found to be energetically degenerate because of the weak van der Waals interaction with the substrates. The Si buckling height is below 0.55 Å, which is close to the value of free-standing silicene (0.49 Å). Importantly, the Dirac cone of silicene is well preserved on MgX2 (located slightly above the Fermi level), and the band gaps induced by the substrate are less than 0.1 eV. Application of an external electric field and stacking can be used to increase the band gap. © 2014 American Chemical Society.

  8. A Hypergeometric Formula for Hilbert-Schmidt Generic 2 x 2 Generalized Separability Probabilities

    Slater, Paul B

    2012-01-01

    We pursue the research agenda set forth in "Moment-Based Evidence for Simple Rational-Valued Hilbert-Schmidt Generic 2 x 2 Separability Probabilities" (J. Phys. A, 45, 095305 [2012]). But in a more thorough, systematic manner, employing--for probability-distribution reconstruction purposes--a substantially greater number (7,501) of moments of the determinant |rho^{PT}| of the partial transpose rho^{PT} of the corresponding 4 x 4 density matrix rho. The results strengthen the conjectures that the two-rebit (alpha= 1/2) and two-qubit (alpha = 1) separability probabilities are 29/64 and 8/33, respectively. Additionally fortified is the conjecture that the presumptive quaternionic (alpha= 2) analog is 26/323. With high accuracy calculations conducted jointly for the sixty-four values alpha = 1/2, 1, 3/2, 2,...,32, we are able to obtain a certain (hypergeometric-related) function of alpha (with argument z = (3/4)^3 = 27/64) that successfully reproduces the three specific conjectures. Additionally, it yields for th...

  9. The thermally reversing window in ternary GexPxS1-2x glasses

    GexPxS1-2x glasses in the compositional range 0.05 ≤ x ≤ 0.19 have been synthesized and examined in temperature modulated differential scanning calorimetry (MDSC) and Raman scattering experiments. Trends in the non-reversing enthalpy ΔHnr(x) near Tg show the term to almost vanish in the 0.090(5)0.135. In analogy to previous results on chalcogenide glasses, we identify compositions at x0.135 to be stressed rigid. MDSC results also show that the ΔHnr term ages in the stressed-rigid and floppy phases but not in the intermediate phase. The intermediate phase is viewed to be a self-organized phase of a disordered network. It consists of at least four isostatically rigid local structures: corner-sharing GeS4, edge-sharing GeS2, pyramidal P(S1/2)3 and quasi-tetrahedral S = P(S1/2)3 units for which evidence comes from Raman scattering. The latter method also shows the existence of P4S7 and P4S10 molecules in the glasses segregated from the backbone. These aspects of structure contribute to an intermediate phase that is significantly narrower in width than in the corresponding selenide glasses

  10. The thermally reversing window in ternary GexPxS1-2x glasses

    Vempati, U.; Boolchand, P.

    2004-11-01

    GexPxS1-2x glasses in the compositional range 0.05 \\le x \\le 0.19 have been synthesized and examined in temperature modulated differential scanning calorimetry (MDSC) and Raman scattering experiments. Trends in the non-reversing enthalpy ΔHnr(x) near Tg show the term to almost vanish in the 0.090(5)0.135. In analogy to previous results on chalcogenide glasses, we identify compositions at x0.135 to be stressed rigid. MDSC results also show that the ΔHnr term ages in the stressed-rigid and floppy phases but not in the intermediate phase. The intermediate phase is viewed to be a self-organized phase of a disordered network. It consists of at least four isostatically rigid local structures: corner-sharing GeS4, edge-sharing GeS2, pyramidal P(S1/2)3 and quasi-tetrahedral S = P(S1/2)3 units for which evidence comes from Raman scattering. The latter method also shows the existence of P4S7 and P4S10 molecules in the glasses segregated from the backbone. These aspects of structure contribute to an intermediate phase that is significantly narrower in width than in the corresponding selenide glasses.

  11. Implementation of a spike-based Perceptron learning rule using TiO2-x memristors

    Hesham eMostafa

    2015-10-01

    Full Text Available Synaptic plasticity plays a crucial role in allowing neural networks to learn and adapt to various input environments. Neuromorphic systems need to implement plastic synapses to obtain basic 'cognitive' capabilities such as learning. One promising and scalable approach for implementing neuromorphic synapses is to use nano-scale memristors as synaptic elements. In this paper we propose a hybrid CMOS-memristor system comprising CMOS neurons interconnected through TiO$_{2-x}$ memristors, and spike-based learning circuits that modulate the conductance of the memristive synapse elements according to a spike-based Perceptron plasticity rule. We highlight a number of advantages for using this spike-based plasticity rule as compared to other forms of spike timing dependent plasticity (STDP rules. We provide experimental proof-of-concept results with two silicon neurons connected through a memristive synapse that show how the CMOS plasticity circuits can induce stable changes in memristor conductances, giving rise to increased synaptic strength after a potentiation episode and to decreased strength after a depression episode.

  12. Implementation of a spike-based perceptron learning rule using TiO2-x memristors.

    Mostafa, Hesham; Khiat, Ali; Serb, Alexander; Mayr, Christian G; Indiveri, Giacomo; Prodromakis, Themis

    2015-01-01

    Synaptic plasticity plays a crucial role in allowing neural networks to learn and adapt to various input environments. Neuromorphic systems need to implement plastic synapses to obtain basic "cognitive" capabilities such as learning. One promising and scalable approach for implementing neuromorphic synapses is to use nano-scale memristors as synaptic elements. In this paper we propose a hybrid CMOS-memristor system comprising CMOS neurons interconnected through TiO2-x memristors, and spike-based learning circuits that modulate the conductance of the memristive synapse elements according to a spike-based Perceptron plasticity rule. We highlight a number of advantages for using this spike-based plasticity rule as compared to other forms of spike timing dependent plasticity (STDP) rules. We provide experimental proof-of-concept results with two silicon neurons connected through a memristive synapse that show how the CMOS plasticity circuits can induce stable changes in memristor conductances, giving rise to increased synaptic strength after a potentiation episode and to decreased strength after a depression episode. PMID:26483629

  13. Influence of oxygen partial pressure on defect concentrations and on oxygen diffusion in UO2+x

    The hyper-stoichiometric uranium dioxide (UO2+x) is stable over a wide range of temperature and compositions. Such variations of composition and the eventual presence of doping elements or impurities lead to a variation of anionic and electronic defect concentrations. Moreover, many properties of this material are affected by its composition modifications, in particular their atomic transport properties. Firstly we developed a point defect model to evaluate the dependence of the electronic and oxygen defect concentrations upon temperature, equilibrium oxygen partial pressure and impurity content. The physical constants of the model, in particular the equilibrium constants of the defect formation reactions were determined from deviation from stoichiometry and electrical conductivity measurements of literature. This work enabled us to interpret our measures of conductivity, oxygen chemical and self- diffusion coefficients. From a quantitative standpoint, the analysis of our experimental results allows to evaluate the oxygen interstitial diffusion coefficient but also its formation energy. Moreover, an estimate of oxygen di-interstitial formation energy is also provided. Presence of oxygen clusters leads oxygen self- and chemical diffusion to decrease. X-ray Absorption Spectroscopy characterization shows the presence of the same defect in the entire deviation from stoichiometry studied, confirming the approach used to develop the model. (author)

  14. Crystal structure of LuCu4-xSb2 (x = 1.053)

    Crystal structure of new ternary antimonide LuCu4-xSb2 (x = 1.053(8)) was refined by means of powder diffraction method (diffractometer DRON-3M, Cu Kα-radiation, RB = 4.09, χ2 = 1.92). It crystallizes in orthorhombic type of structure ErFe4Ge2 (low-temperature modification): space group Pnnm, Pearson code oP14-2.11, a = 7.01189(14), b = 7.75061(15), c = 4.24323(8) A; Z = 2. Analysing the coordination environments of atoms it was shown, that investigated structure is an inclusion derivative of TiO2 structure type. TiO2, NiAs, MnBi, Ag2HgS2, Ni2In and RCu4-xSb2 (R Tm, Lu) structures belongs to the family of structures built up from the columns of filled octahedra and differ by the filling of space between them by different atoms or groups of atoms

  15. Neutron scattering in Er2-x Yx Ti2 O7

    Gaudet, Jonathan; Hallas, Alannah; Maharaj, Dalini; Kermarrec, Edwin; Butch, Nicholas P.; Dabowska, Hanna; Gaulin, Bruce

    E r2 T i2 O7 (ETO) is a strong candidate for ground state selection via the order by disorder mechanism. A Ψ2 magnetic ground state appears below TN=1.2 K, where Ψ2 and Ψ3 are the two basis states of the irreducible representation Γ5. No sample dependance has been observed in the thermodynamics properties of ETO at low temperature, and in particular on its phase transition to long range magnetic order. ETO's ordered Neel state has been shown to be robust even to a relatively high level of magnetic dilution, as occurs with non-magnetic Y3+ substitution of Er3+ .However, recently two theoretical studies have predicted that ETO's Ψ2 ground state should be unstable to formation of the Ψ3 state, in the presence of such disorder. To explore this possibility,we grew single crystals of Er2 - xYx Ti2O7 (EYTO) with x = 0,0.2 and 0.4 and performed a systematic inelastic neutron scattering studies using the Disk Chopper time-of-flight spectrometer (DCS) at the National Institute of Standards and Technology (NIST). We will show elastic and inelastic neutron scattering at low temperatures and as a a function of applied magnetic field for all three samples and discuss the role of such quenched disorder on the spin dynamics of EYTO.

  16. Exploring the charge-ordering transition in (TMTTF){sub 2}X via thermal expansion measurements

    Souza, Mariano de, E-mail: mariano@physik.uni-frankfurt.d [Physikalisches Institut, Goethe-Universitaet Frankfurt, SFB/TRR 49, D-60438 Frankfurt am Main (Germany); Hofmann, Daniel [Physikalisches Institut, Goethe-Universitaet Frankfurt, SFB/TRR 49, D-60438 Frankfurt am Main (Germany); Foury-Leylekian, Pascale; Moradpour, Alec; Pouget, Jean-Paul [Laboratoire de Physique des Solides, Universite Paris Sud, CNRS UMR 8502, 91405 Orsay (France); Lang, Michael [Physikalisches Institut, Goethe-Universitaet Frankfurt, SFB/TRR 49, D-60438 Frankfurt am Main (Germany)

    2010-06-01

    We report results of high-resolution measurements of the c{sup *}-axis expansivity ({alpha}{sub c}{sup *}) at the charge-ordering (CO) transition for the quasi-1D (TMTTF){sub 2}X compounds with X=SbF{sub 6} and Br and make a comparison with previous results for the X=PF{sub 6} and AsF{sub 6} salts. For X=SbF{sub 6}, due to the screening of the long-range Coulomb forces, a sharp {lambda}-type anomaly is observed at T{sub CO}, which contrasts with the step-like mean-field anomaly at T{sub CO} for PF{sub 6} and AsF{sub 6}, where CO occurs in the Mott-Hubbard charge-localized regime. For the latter two salts, a negative contribution to {alpha}{sub c}{sup *} is observed above T{sub CO}. This feature is assigned to the anions' rigid-unit modes, which become inactive for T

  17. Photoelectric properties of defect chalcogenide HgGa2X4 (x=S, Se, Te)

    Sharma, Ramesh; Dwivedi, Shalini; Sharma, Yamini

    2016-05-01

    We present results of ab initio study of ordered vacancy compounds of mercury. The electronic structure, charge density, optical and transport properties of the semiconductor family HgGa2X4 (X=S, Se, Te) are calculated using the full potential linearized augmented plane wave method which is based on the density functional theory. A direct bandgap is observed in these compounds, which reduces in the order S>Se>Te. From the density of states it is observed that there is strong hybridization of Hg-d, Ga-d and X-p states. The optical properties show a red shift with increasing size and atomic no. of the chalcogenide atoms. We have also reported the transport properties of mercury thiogallates for the first time. The selenide compound exhibits n-type nature whereas HgGa2S4 and HgGa2Te4 show p-type behavior. The power factor and ZT for the HGS increases at low temperatures, the figure of merit is highest for HgGa2Se4 (1.17) at 19 K.

  18. Effects of a 2X gravity environment on the ultrastructure of the gerbil parathyroid gland

    Sannes, P. L.; Hayes, T. G.

    1975-01-01

    A number of studies concerning the effects of hypergravity on bone have shown increases in bone mass or bone dimensions. Correlative studies, which could provide clues to the mechanism for such a response, have been lacking. The purpose of the present study was to evaluate the ultrastructure of parathyroid glands of Mongolian gerbils exposed to a continuous 2 X gravity force for 60 d. It was found that the experimental animals had parathyroid glands which had a greater percentage of chief cells in the active stage of their secretory cycle when compared with control animals. This result was interpreted to indicate an increase in parathyroid gland secretory activity and, hence, an increase in parathyroid hormone release. It was suggested that increased parathyroid secretory activity was necessary to maintain serum calcium levels of hypergravity animals within normal limits. Cellular forms resembling water clear cells and highly compact, degenerating cells were described in experimental animals but not in controls. Areas suggestive of cellular dissolution and disorganization were also reported in experimental parathyroids.

  19. CFD analysis on supercritical pressure water heat transfer in a 2x2 rod bundle

    Heat transfer in supercritical pressure (SCP) water flow through a 2x2 rod bundle is calculated with the SSG, the ω Reynolds stress model (ω-RSM) and the Baseline Reynolds stress model (BSL-RSM). Comparison of the calculation results show that all the models predict similar cross-flow pattern between the adjacent subchannels. However, there is apparent discrepancy in the predicted turbulent mixing. Due to the strong cross-flow, the bulk parameters predicted by the models agree well. Comparison with the experiment data reveals that the SSG which is linked to the scalable wall function underpredicts the rod wall temperature, while the ω-RSM and BSL-RSM which utilize the automatic wall treatment tend to overpredict the wall temperature in the region where the buoyancy effect is dominant in the near-wall region. Such difference can mainly be attributed to the modeling approach near the wall. We may conclude that the resolved wall region is required for SCP heat transfer prediction and that the appropriate modeling of buoyancy effect is the key factor to improve the prediction. In order to assist the correlation evaluation, the CFD calculation results are used to derive the bulk flow parameters which cannot be easily measured in the experiment. The sensitivity study shows that the uncertainty caused by the selection of turbulence models is not vital for the correlation evaluation. (author)

  20. Superconductivity induced by doping Rh in CaFe2-xRhxAs2

    In this paper, we report the synthesis of iron-based superconductors CaFe2-xRhxAs2 using a one-step solid state reaction method that crystallizes in the ThCr2Si2-type structure with a space group I4/mmm. The systematic evolution of the lattice constants demonstrates that the Fe ions are successfully replaced by the Rh. By increasing the doping content of Rh, the spin-density-wave (SDW) transition in the parent compound is suppressed and superconductivity emerges. The maximum superconducting transition temperature is found at 18.5 K with a doping level of x=0.15. The temperature dependence of dc magnetization confirms superconducting transitions at around 15 K. The general phase diagram was obtained and found to be similar to the case of the Rh-doping Sr122 system. Our results explicitly demonstrate the feasibility of inducing superconductivity in Ca122 compounds by higher d-orbital electron doping; however, different Rh-doping effects between FeAs122 compounds and FeAs1111 systems still remains an open question.

  1. Exchange integrals in the helimagnetic phase of ZnCr2xAl2-2xS4 (0.85 ≤ x ≤ 1): A neutron diffraction study

    The spinel solid solutions ZnCr2xAl2-2xS4 have been studied by neutron diffraction experiments. They show a helimagnetic phase in the concentration range: 0.85 ≤ x ≤ 1. The helix angle decreases as x is decreased. In this paper, the three first exchange integrals and their evolution with x are obtained. The disappearance of the long range order is shown to be due to the large decrease of the ferromagnetic in-plane interaction. The results are extended to obtain the fourth exchange integral. (author). 16 refs, 6 figs, 4 tabs

  2. Influence of Quasi-Bi-Stripe Charge Order on the Resistivity and Magnetism in a Bilayer Manganite La$_{2-2x}$Sr$_{1+2x}$Mn$_{2}$O$_{7}$

    Kubota, M.; Oohara, Y.; Yoshizawa, H.; Fujioka, H.; Shimizu, K.; Hirota, K.; Moritomo, Y.; Endoh, Y.

    2000-01-01

    The charge ordering in the bilayer manganite system La$_{2-2x}$Sr$_{1+2x}$Mn$_{2}$O$_{7}$ with $0.30 \\le x \\le 0.50$ has been studied by neutron diffraction. The charge order is characterized by the propagation vector parallel to the [1 0 0] direction (MnO$_2$ direction), but the correlation length is short-ranged and extremely anisotropic, being $\\sim 0.02a^{*}$ and $\\sim 0.2a^{*}$ parallel and perpendicular to the modulation direction, respectively. The observed charge order can be viewed a...

  3. The P2X7 receptor regulates cell survival, migration and invasion of pancreatic ductal adenocarcinoma cells

    Giannuzzo, Andrea; Pedersen, Stine Helene Falsig; Novak, Ivana

    2015-01-01

    BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is presently one of the cancers with the worst survival rates and least effective treatments. Moreover, total deaths due to PDAC are predicted to increase in the next 15 years. Therefore, novel insights into basic mechanism of PDAC development and...... therapies are needed. PDAC is characterized by a complex microenvironment, in which cancer and stromal cells release different molecules, such as ATP. ATP can be transported and/or exocytosed from active cancer cells and released from dying cells in the necrotic core of the cancer. We hypothesized that one...... / propidium iodide assays). RESULTS: We found higher expression of P2X7R protein in PDAC compared to HPDE cells. P2X7R had notable disparate effects on PDAC survival. Firstly, high concentrations of ATP or the specific P2X7R agonist, BzATP, had cytotoxic effects in all cell lines, and cell death was mediated...

  4. Growth mechanisms and origin of localized surface plasmon resonance coupled exciton effects in Cu2_xS thin films

    Savariraj, Dennyson A.; Kim, Hee-Je; Viswanathan, Kodakkal K.; Vijayakumar, M.; Prabakar, Kandasamy

    2016-02-15

    Cu2-xS thin films prepared by template free single step wet chemical method on fluorine doped tin oxide substrate without any surfactant exhibts localized surface plasmon resonance (LSPR) coupled exciton effects. Cu2-xS thin films of unique surface morphology and free carrier density due to copper vacancy is controlled by the growth temperature and time. These selectively grown Cu2-xS thin films possess tunable band gap (2.6 - 1.4 eV) due to quantum size effect. Eventhough, all the samples show satellite peak in the X-ray photoelectron spectra due to Cu vacancies, only the samples with higher oxygen concentration show LSPR in the near infrared region.

  5. The SU(2)xSU(2) sector in the string dual of N=6 superconformal Chern-Simons theory

    We examine the string dual of the recently constructed N=6 superconformal Chern-Simons theory of Aharony, Bergman, Jafferis and Maldacena (ABJM theory). We focus in particular on the SU(2)xSU(2) sector. We find a sigma-model limit in which the resulting sigma-model is two Landau-Lifshitz models added together. We consider a Penrose limit for which we can approach the SU(2)xSU(2) sector. Finally, we find a new Giant Magnon solution in the SU(2)xSU(2) sector corresponding to one magnon in each SU(2). We put these results together to find the full magnon dispersion relation and we compare this to recently found results for ABJM theory at weak coupling

  6. The SU(2)xSU(2) sector in the string dual of N=6 superconformal Chern-Simons theory

    Grignani, Gianluca [Dipartimento di Fisica, Universita di Perugia, I.N.F.N. Sezione di Perugia, Via Pascoli, I-06123 Perugia (Italy)], E-mail: grignani@pg.infn.it; Harmark, Troels [Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen O (Denmark)], E-mail: harmark@nbi.dk; Orselli, Marta [Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen O (Denmark)], E-mail: orselli@nbi.dk

    2009-03-21

    We examine the string dual of the recently constructed N=6 superconformal Chern-Simons theory of Aharony, Bergman, Jafferis and Maldacena (ABJM theory). We focus in particular on the SU(2)xSU(2) sector. We find a sigma-model limit in which the resulting sigma-model is two Landau-Lifshitz models added together. We consider a Penrose limit for which we can approach the SU(2)xSU(2) sector. Finally, we find a new Giant Magnon solution in the SU(2)xSU(2) sector corresponding to one magnon in each SU(2). We put these results together to find the full magnon dispersion relation and we compare this to recently found results for ABJM theory at weak coupling.

  7. Prostaglandin E2 potentiation of P2X3 receptor mediated currents in dorsal root ganglion neurons

    Huang Li-Yen

    2007-08-01

    Full Text Available Abstract Prostaglandin E2 (PGE2 is a well-known inflammatory mediator that enhances the excitability of DRG neurons. Homomeric P2X3 and heteromeric P2X2/3 receptors are abundantly expressed in dorsal root ganglia (DRG neurons and participate in the transmission of nociceptive signals. The interaction between PGE2 and P2X3 receptors has not been well delineated. We studied the actions of PGE2 on ATP-activated currents in dissociated DRG neurons under voltage-clamp conditions. PGE2 had no effects on P2X2/3 receptor-mediated responses, but significantly potentiated fast-inactivating ATP currents mediated by homomeric P2X3 receptors. PGE2 exerted its action by activating EP3 receptors. To study the mechanism underlying the action of PGE2, we found that the adenylyl cyclase activator, forskolin and the membrane-permeable cAMP analogue, 8-Br-cAMP increased ATP currents, mimicking the effect of PGE2. In addition, forskolin occluded the enhancement produced by PGE2. The protein kinase A (PKA inhibitors, H89 and PKA-I blocked the PGE2 effect. In contrast, the PKC inhibitor, bisindolymaleimide (Bis did not change the potentiating action of PGE2. We further showed that PGE2 enhanced α,β-meATP-induced allodynia and hyperalgesia and the enhancement was blocked by H89. These observations suggest that PGE2 binds to EP3 receptors, resulting in the activation of cAMP/PKA signaling pathway and leading to an enhancement of P2X3 homomeric receptor-mediated ATP responses in DRG neurons.

  8. A compact plasmonic MOS-based 2x2 electro-optic switch

    Ye, Chenran; Soref, Richard A; Sorger, Volker J

    2015-01-01

    We report on a three-waveguide electro-optic switch for compact photonic integrated circuits and data routing applications. The device features a plasmonic metal-oxide-semiconductor (MOS) mode for enhanced light-matter-interactions. The switching mechanism originates from a capacitor-like design where the refractive index of the active medium, Indium-Tin-Oxide, is altered via shifting the plasma frequency due to carrier accumulation inside the waveguide-based MOS structure. This light manipulation mechanism controls the transmission direction of transverse magnetic polarized light into either a CROSS or BAR waveguide port. The extinction ratio of 18 dB (7) dB for the CROSS (BAR) state, respectively, is achieved via a gating voltage bias. The ultrafast broadband fJ/bit device allows for seamless integration with Siliconon- Insulator platforms to for low-cost manufacturing.

  9. LTE Radiated Data Throughput Measurements, Adopting MIMO 2x2 Reference Antennas

    Szini, Istvan Janos; Pedersen, Gert Frølund; Barrio, Samantha Caporal Del;

    2012-01-01

    Long Term Evolution (LTE) requires Multiple Input Multiple Output (MIMO) antenna systems. Consequently a new over-the-air (OTA) test methodology need to be created to make proper assessment of LTE devices radiated performance. The antenna specific parameters i.e. total antenna efficiency, gain...... imbalance and correlation coefficient, are essential for a proper MIMO antenna system design. However it can't be use directly to assess the LTE device system performance, since a multiplicity of other factors are involved, e.g. power amplifier load- pull, low noise amplifier source-pull, self interference...... noise, baseband algorithm and other factors. Several standard organizations are working towards a consensus over the proper OTA MIMO test method, however so far results of measurement campaigns have ambiguous results not allowing a desirable progress [1]. Initially presented at one of several MIMO OTA...

  10. Composition and temperature dependence of the thermoelectric power of Ni2+xMn1-xGa alloys

    The thermoelectric power (TEP) measurements have been carried out to investigate the changes in the electronic structure associated with the intermartensitic and martensitic transitions in Ni2+xMn1-xGa (0≤x≤0.19). The samples have been characterized by ac magnetic susceptibility measurements. The correlation between the TEP and the microstructural changes sensitive to the increasing Ni content in Ni2+xMn1-xGa has been investigated. The changes in the density of states as reflected in the temperature variation of the TEP are consistent with the conclusions drawn from the Jahn-Teller mechanism of lattice distortion

  11. P2X7 receptor activation in rat brain cultured astrocytes increases the biosynthetic release of cysteinyl leukotrienes.

    Ballerini, P; Ciccarelli, R; Caciagli, F; Rathbone, M P; Werstiuk, E S; Traversa, U; Buccella, S; Giuliani, P; Jang, S; Nargi, E; Visini, D; Santavenere, C; Di Iorio, P

    2005-01-01

    Astrocytes have been recognized as important elements in controlling inflammatory as well as immune processes in the central nervous system (CNS). Recently, glial cells have been shown to produce cysteinyl leukotrienes (CysLTs) which are known lipid mediators of inflammation and whose extracellular concentrations rise under different pathological conditions in the brain. In the same conditions also extracellular concentrations of ATP dramatically increase reaching levels able to activate P2X7 ionotropic receptors for which an emerging role in neuroinflammation and neurodegeneration has been claimed. RTPCR analysis showed that primary cultures of rat brain astrocytes express P2X7 receptors. Application of the selective P2X7 agonist benzoyl benzoly ATP (BzATP) markedly increased [Ca2+]i which was mediated by a calcium influx from the extracellular milieu. The P2X7 antagonist, oATP, suppressed the BzATP-induced calcium increase. Consistent with the evidence that increased calcium levels activate the leukotriene biosynthetic pathway, challenge of astrocytes with either the calcium ionophore A23187 or BzATP significantly increased CysLT production and the cell pre-treatment with EGTA abolished these effects. Again the P2X7 antagonist prevented the BzATP-mediated CysLT efflux, whereas the astrocyte pretreatment with MK-571, a CysLT1 receptor antagonist, was ineffective. The astrocyte pre-treatment with a cocktail of inhibitors of ATP binding cassette (ABC) proteins reduced the BzATP-mediated CysLT production confirming that ABC transporters are involved in the release of CysLTs. The astrocyte P2X7- evoked rise of CysLT efflux was abolished in the presence of MK-886, an inhibitor of 5-lipoxygenase activating protein (FLAP) whose expression, along with that of 5-lipoxygenase (5-LO) was reported by Northern Blot analysis. The stimulation of P2X7 induced an up-regulation of FLAPmRNA that was reduced by the antagonist oATP. These data suggest that in rat brain cultured

  12. Finite size giant magnons in the SU(2) x SU(2) sector of AdS4 x CP3

    We use the algebraic curve and Luescher's μ-term to calculate the leading order finite size corrections to the dispersion relation of giant magnons in the SU(2) x SU(2) sector of AdS4 x CP3. We consider a single magnon as well as one magnon in each SU(2). In addition the algebraic curve computation is generalized to give the leading order correction for an arbitrary multi-magnon state in the SU(2) x SU(2) sector.

  13. Thermal expansion measurement of (U,Pu)O2-x in oxygen partial pressure-controlled atmosphere

    Kato, Masato; Ikusawa, Yoshihisa; Sunaoshi, Takeo; Nelson, Andrew T.; McClellan, Kenneth J.

    2016-02-01

    Thermal expansion of U0.7Pu0.3O2-x (x = 0, 0.01, 0.02, 0.03) and U0.52Pu0.48O2.00 was investigated by a unique dilatometry which measured in an oxygen partial pressure-controlled atmosphere. The oxygen partial pressure was controlled to hold a constant oxygen-to-metal ratio in the (U,Pu)O2-x during the measurement. Thermal expansion slightly increased with the decrease in oxygen-to-metal ratio. We proposed a relationship to describe thermal expansion as a function of temperature, O/M and Pu content.

  14. Effects of toxic cellular stresses and divalent cations on the human P2X7 cell death receptor

    Dutot, Mélody; Liang, Hong; Pauloin, Thierry; Brignole-Baudouin, Françoise; Baudouin, Christophe; Warnet, Jean-Michel; Rat, Patrice

    2008-01-01

    Purpose The purpose of this study was to investigate responses to toxic cellular stresses in different human ocular epithelia. Methods Reactivity with a specific anti-P2X7 antibody was studied using confocal fluorescence microscopy on conjunctival, corneal, lens, and retinal cell lines as well as using impression cytology on human ocular cells. Activation of the P2X7 receptor by selective agonists (ATP and benzoylbenzoyl-ATP) and inhibition by antagonists (oATP, KN-62, and PPADS) were evaluat...

  15. Evaluation of Start Transient Oscillations with the J-2X Engine Gas Generator Assembly

    Hulka, J. R.; Morgan, C. J.; Casiano, M. J.

    2015-01-01

    During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, distinctive and oftentimes high-amplitude pressure oscillations and hardware vibrations occurred during the start transient of nearly every workhorse gas generator assembly test, as well as during many tests of engine system hardware. These oscillations appeared whether the steady-state conditions exhibited stable behavior or not. They occurred similarly with three different injector types, and with every combustion chamber configuration tested, including chamber lengths ranging over a 5:1 range, several different nozzle types, and with or without a side branch line simulating a turbine spin start gas supply line. Generally, two sets of oscillations occurred, one earlier in the start transient and at higher frequencies, and the other almost immediately following and at lower frequencies. Multiple dynamic pressure measurements in the workhorse combustion chambers indicated that the oscillations were associated with longitudinal acoustic modes of the combustion chambers, with the earlier and higher frequency oscillation usually related to the second longitudinal acoustic mode and the later and lower frequency oscillation usually related to the first longitudinal acoustic mode. Given that several early development gas generator assemblies exhibited unstable behavior at frequencies near the first longitudinal acoustic modes of longer combustion chambers, the start transient oscillations are presumed to provide additional insight into the nature of the combustion instability mechanisms. Aspects of the steadystate oscillations and combustion instabilities from development and engine system test programs have been reported extensively in the three previous JANNAF Liquid Propulsion Subcommittee meetings (see references below). This paper describes the hardware configurations, start transient sequence operations, and transient and dynamic test data during the start

  16. Thermodynamic Properties of κ-(BEDT-TTF2X Salts: Electron Correlations and Superconductivity

    Yasuhiro Nakazawa

    2012-06-01

    Full Text Available Heat capacity measurements of κ-(BEDT-TTF2X (BEDT-TTF: Bis(ethylendithio tetrathiafulvalene, X: counteranions which are classified as two-dimensional (2D dimer-Mott system are reported. At first, we explain structural and electronic features originated from rigid dimerization in donor arrangement in 2D layers. The antiferromagnetic Mott insulating phase located at low-pressure region in the phase diagram shows vanishing γ electronic heat capacity coefficient in the heat capacity, which claims opening of a charge-gap in this insulating state. Then, a systematic change of the γ around the Mott boundary region is reported in relation to the glass freezing of ethylene dynamics. The thermodynamic parameters determined by ∆Cp/γTc of 10 K class superconductors, κ-(BEDT-TTF2Cu(NCS2 and κ-(BEDT-TTF2Cu[N(CN2]Br demonstrate that a rather large gap with a strong coupling character appears around the Fermi-surface. On the other hand, the low temperature heat capacity clearly shows a picture of nodal-gap structure due to an anisotropic pairing. The comparison with lower Tc compounds in the κ-type structure is also performed so as to discuss overall features of the κ-type superconductors. The heat capacity measurements of hole-doped systems containing mercury in the counteranions show an anomalous enhancement of γ, which is consistent with the T1−1 of NMR experiments etc. The results of heat capacity measurements under high pressures are also reported.

  17. Dynamic and kinetic aspects of the adsorption of acrylonitrile on Si(001)-2x1

    Using scanning tunnelling microscopy (STM), photoelectron and photoabsorption spectroscopies, we have examined how acrylonitrile (H2C=CH-C≡N) reacts with the Si(001)-2x1 surface for coverages ranging from ∼1012 molecules/cm2 to ∼1014 molecules/cm2. At 300 K, in the very low coverage regime (below 1013 molecules/cm2), filled- and empty-state STM images show that the molecule bridges, via its β carbon and nitrogen ends, two silicon dangling bonds, across the trench separating two dimer rows. A cumulative-double-bond unit (C=C=N) is formed. The 300 K STM image results from the dynamic flipping of the molecule between two equivalent equilibrium positions, which can be seen when the molecular motion is slowed down at 80 K. For coverages larger than 1013 molecules/cm2, for which STM does not show ordered adsorption any more, the adsorption kinetics were observed in real-time using valence band photoemission and resonant Auger yield, associated with N 1s x-ray absorption spectroscopy (NEXAFS). At 300 K, these techniques point to a situation more complex than the one explored by STM at very low coverage. Three species (cyano-bonded, vinyl-bonded, and cumulative-double-bond species) are detected. Their distribution does not vary with increasing coverage. All dimerization-related surface states are quenched at saturation. The uptake rates versus coverage relationship points to the presence of a mobile precursor. Finally, the paper discusses a possible mechanism leading to the formation of cross-trench C=C=N unit at low coverage, and the reasons why the product branching ratio changes with increasing coverage

  18. Penetration depth in pure and zinc-substituted La2-xSrxCuO4

    In the paper we present measurements of the in-plane λab(T) (H parallel c) and out-of-plane λ perpendicularto (T) (H perpendicular to c) penetration depths in La2-xSrxCu1-yZnyO4 for x = 0.08, 0.1, 0.125, 0.15, and 0.2, and for y = 0, 0.005, 0.01, and 0.02. The penetration depth was obtained from ac susceptibility measurements of powdered samples, immersed in wax and magnetically oriented in a static magnetic field of 10 T. For unsubstituted, underdoped samples (x 0.15) the measured points can be fitted by the exponential function of temperature. Our results support the view that for underdoped samples we are dealing with Bose-Einstein condensation while for overdoped ones the superconductivity is BCS-like. Extrapolated to T = 0, penetration depth values may be described by the quadratic function of strontium concentration similarly as the Tc(x) dependence. For zinc-doped, underdoped La1.85Sr0.15Cu1-yZnyO4 the temperature dependences of penetration depths can be described by power laws, but with exponents n varying linearly with substituent content. These exponents n increase at a rate of about 2.5 per at% of zinc substitution. We found that the penetration-depth anisotropy is dependent on substituent content in La1.85Sr0.15Cu1-yZnyO4, decreasing to a minimum at x≅0.015 and increasing for higher substitutions and can be described by a quadratic function. Our results strongly suggest that both the effective mass and the density of charge carriers must be taken into account in theories describing high-temperature superconductivity. (orig.)

  19. String theory in the Penrose limit of AdS2xS2 spacetime

    The string theory in the Penrose limit of AdS2xS2 is investigated. The specific Penrose limit is the background known as the Nappi-Witten spacetime, which is a plane-wave background with an axion field. The string theory on it is given as the Wess-Zumino-Novikov-Witten (WZNW) model on nonsemi-simple group H4. It is found that, in the past literature, an important type of irreducible representations of the corresponding algebra, h4, were missed. We present these 'new' representations, which have the type of continuous series representations. All three types of representations of the previous literature can be obtained from the new representations by setting the momenta in the theory to special values. Then we realized the affine currents of the WZNW model in terms of four bosonic free fields and constructed the spectrum of the theory by acting the negative frequency modes of free fields on the ground level states in the h4 continuous series representation. The spectrum is shown to be free of ghosts, after the Virasoro constraints are satisfied. In particular we argued that there is no need for constraining one of the longitudinal momenta to have unitarity. The tachyon vertex operator, that correspond to a particular state in the ground level of the string spectrum, is constructed. The operator products of the vertex operator with the currents and the energy-momentum tensor are shown to have the correct forms, with the correct conformal weight of the vertex operator

  20. Adsorption and reaction of acetylene and ethylene on the Si(001)2x1 surface

    The electronic structures and the thermal reaction of chemisorbed C2H2 and C2H4 on the Si(001)2x1 surface have been investigated by carbon K-edge near-edge x-ray absorption fine structure (NEXAFS) and ultraviolet photoemission spectroscopy (UPS) using synchrotron radiation. The bonding and antibonding states due to the interaction of the molecules and the Si surface atoms are identified by detailed polarization-dependent UPS and NEXAFS measurements, respectively. These bonding and antibonding states are shown to originate from the hybridization between the occupied Si dangling bonds and the lowest unoccupied molecular orbitals (πC-C*) of C2H2 and C2H4 double-σ-bonded on the top of the Si dimer. The thermal evolution of mainly C2H2 is investigated in detail for a wide temperature range of 60-1500 K from the condensation to the surface alloy formation. The coexistence of the physisorbatelike and the chemisorbed molecular species is observed at 70-90 K for C2H2 and C2H4, for the coverages greater than ∼0.25 monolayer (ML). The πC-C* resonance of those physisorbatelike C2H4 species in NEXAFS exhibits an unusual polarization dependence indicating adsorption with their molecular planes aligned perpendicular to the surface. The dissociation of C2H2 chemisorbates is shown to occur at 600-700 K as observed by UPS. After the dissociation of molecules, the atomic hydrogen adsorbates are identified by the monohydridelike surface resonance states in the UP spectra at 800-950 K. Most of the Si dangling bonds are passivated by, at least partly, the hydrogen adsorbates at this stage. At ∼1000 K, the desorption of hydrogen occurs, which accompanies the appearance of a broad SiC-like feature in the UP spectra at ∼3 eV below Fermi level

  1. Medical Device Safety

    A medical device is any product used to diagnose, cure, or treat a condition, or to prevent disease. They range ... may need one in a hospital. To use medical devices safely Know how your device works. Keep instructions ...

  2. Infrared criminalistic devices

    Gibin, Igor S.; Savkov, E. V.; Popov, Pavel G.

    1996-12-01

    We are presenting the devices of near-IR spectral range in this report. The devices may be used in criminalistics, in bank business, in restoration works, etc. the action principle of these devices is describing briefly.

  3. Intrauterine devices (IUD)

    ... medlineplus.gov/ency/article/007635.htm Intrauterine devices (IUD) To use the sharing features on this page, please enable JavaScript. An intrauterine device (IUD) is a small plastic T-shaped device used ...

  4. Visible light-sensitive yellow TiO2-x N x and Fe-N co-doped Ti1-y Fe y O2-x N x anatase photocatalysts

    Nitrogen substituted yellow colored anatase TiO2-x N x and Fe-N co-doped Ti1-y Fe y O2-x N x have been easily synthesized by novel hydrazine method. White anatase TiO2-δ and N/Fe-N-doped samples are semiconducting and the presence of ESR signals at g ∼1.994-2.0025 supports the oxygen vacancy and g∼4.3 indicates Fe3+ in the lattice. TiO2-x N x has higher conductivity than TiO2-x and Fe/Fe-N-doped anatase and the UV absorption edge of white TiO2-x extends in the visible region in N, Fe and Fe-N co-doped TiO2, which show, respectively, two band gaps at ∼3.25/2.63, ∼3.31/2.44 and 2.8/2.44 eV. An activation energy of ∼1.8 eV is observed in Arrhenius log resistivity vs. 1/T plots for all samples. All TiO2 and Fe-doped TiO2 show low 2-propanol photodegradation activity but have significant NO photodestruction capability, both in UV and visible regions, while standard Degussa P-25 is incapable in destroying NO in the visible region The mid-gap levels that these N and Fe-N-doped TiO2 consist may cause this discrepancy in their photocatalytic activities. - Graphical abstract: DRS of TiO2, N/Fe-N doped TiO2

  5. P2X4 receptors control the fate and survival of activated microglia%P2X4受体对活化的小胶质细胞的调控作用

    Vázquez-Villoldo N; Domercq M; Martín A; Llop J; Gómez-Vallejo V; Matute C

    2014-01-01

    小胶质细胞是中枢神经系统内的免疫细胞,当脑组织出现损伤时,小胶质细胞被激活,对脑组织起到保护作用。在自身免疫性脑脊髓炎模型大鼠和视神经脊髓炎患者体内,均观察到在脊髓炎性病灶及小胶质细胞内,P2X4受体表达上调。本课题组进行在体和离体实验,用LPS活化小胶质细胞,观察P2X4受体在小胶质细胞炎性反应中的作用。膜片钳检测显示,在LPS激活的小胶质细胞内,P2X4受体活性增加。P2X4受体阻断剂可显著降低小胶质细胞的膜皱缩、TNFα的分泌、细胞形态的改变及LPS导致的小胶质细胞死亡。在体研究显示,LPS髓内注射后会诱发炎性反应,迅速导致小胶质细胞丢失;给予P2X4受体阻断剂可显著减少小胶质细胞的丢失,而P2X4受体激活剂则可显著增加小胶质细胞的丢失。海马齿状回的小胶质细胞特别容易被LPS诱导的炎症反应激活。注射LPS后2 h,位于海马齿状回的小胶质细胞即被激活,大约24 h后死亡,P2X4受体阻断剂可减少LPS诱导的小胶质细胞活化和死亡。上述数据提示,P2X4受体对于小胶质细胞的激活和存活有重要的调控作用。%Microglia, the resident immune cells of the central nervous system, responds to brain disarrange-ments by becoming activated to contend with brain damage. Here we show that the expression of P2X4 receptors is upregulated in inflammatory foci and in activated microglia in the spinal cord of rats with experimental au-toimmune encephalomyelitis (EAE) as well as in the optic nerve of multiple sclerosis patients. To study the role of P2X4 receptors in microgliosis, we activated microglia with LPS in vitro and in vivo. We observed that P2X4 receptor activity in vitro was increased in LPS-activated microglia as assessed by patch-clamp recordings. In ad-dition, P2X4 receptor blockade significantly reduced microglial membrane ruffling, TNF

  6. Implantable electronic medical devices

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  7. Grain boundary tunnel spectroscopy of the electron-doped cuprate superconductor La2-xCexCuO4

    The electron doped superconductor La2-xCexCuO4 (LCCO) has been investigated by electric transport measurements at low temperatures T down to 5 K and high magnetic fields up to 16 T. For this purpose LCCO thin film tunnel junctions have been prepared on bicrystal substrates by molecular beam epitaxy and micro structuring. The samples were characterised by measuring the thin film resistivity and the tunnel conductance of quasi particles across the grain boundary. By these measurements an unconventional symmetry of the order parameter could be revealed for La2-xCexCuO4. Furthermore it was shown, that the tunnel conductance can be used as a probe for the upper critical field Bc2(T). By using this method a value of Bc2∝24 T has been found for La2-xCexCuO4, a value roughly three times bigger than previously known. By this observation it was shown that the superconducting phase covers a larger region in the B-T-phase diagram. In addition it was concluded, that the pseudogap phase in La2-xCexCuO4 is either not existent at all or covers only a small temperature region. Besides quasiparticle tunneling also the tunneling of Cooper pairs in small magnetic fields has been investigated. It was shown that the critical current across the grain boundary depends on the supplier of the bicrystal substrate. (orig.)

  8. Compact Hybrid Subsystem of 16 Channel Optical Demultiplexer, 2x2 Switches, Optical Power Monitors and Control Circuit

    Kenichiro; Takahashi; Toshihiko; Kishimoto; Shintaro; Mouri; Youichi; Hata; Hideaki; Yusa; Mitsuaki; Tamura; Kazuhito; Saito; Hisao; Maki

    2003-01-01

    A compact hybrid subsystem of 16channel optical demultiplexer, 2x2 switches, optical power monitors and control circuit board is developed. The subsystem is able to add or drop arbitrary optical channels and monitor the optical power level by software commands. The size of the subsystem is 170x200x30(mm).

  9. Magnetic and structural properties of the 'brown phase' solid solution Ba(Nd2-xLax)CuO5

    The compounds BaR2CuO5 (R=Y and lanthanides) are well-known impurities that often coexist with the high Tc superconductors, Ba2RCu3O6+x. With R=La and Nd, brown color solid solutions (Ba1+xR2-xCuO5-x) form instead of the 'green phase', BaR2CuO5 (lanthanides with ionic radii smaller than that of Sm). A complete solid solution of Ba(Nd2-xLax)CuO5 exists with the tetragonal space group P4/mbm. Crystallographic studies of selected members (x=0.2, 0.6, 1.2, and 1.6) by X-ray Rietveld refinement technique showed the structure consists of RO8 and BaO10 cages, and square planar CuO4 units. As x increases in Ba(Nd2-xLax)CuO5, the size of these RO8 and BaO10 cages increases. BaLa2CuO5 was confirmed to be ferromagnetic at ∼5 K; despite the isostructural property of BaLa2CuO5 and BaNd5CuO5, the Nd-analog was found to be antiferromagnetic. As x in Ba(Nd2-xLax)CuO5 increases between 0 and 2, the amount of ferromagnetism increases

  10. Atomic scale simulation of fission product trapping and migration in UO2+x and U3O8-z

    The paper discusses simulations, performed at atomic scale of fission product trapping and migration in UO2+x and U3O8-z. The solution and the migration of a range of volatile fission products including iodine, cesium, ruthenium in stoichiometric and nonstoichiometric UO2 and U3O8 are considered

  11. Conductance of P2X4 purinergic receptor is determined by conformational equilibrium in the transmembrane region.

    Minato, Yuichi; Suzuki, Shiho; Hara, Tomoaki; Kofuku, Yutaka; Kasuya, Go; Fujiwara, Yuichiro; Igarashi, Shunsuke; Suzuki, Ei-Ichiro; Nureki, Osamu; Hattori, Motoyuki; Ueda, Takumi; Shimada, Ichio

    2016-04-26

    Ligand-gated ion channels are partially activated by their ligands, resulting in currents lower than the currents evoked by the physiological full agonists. In the case of P2X purinergic receptors, a cation-selective pore in the transmembrane region expands upon ATP binding to the extracellular ATP-binding site, and the currents evoked by α,β-methylene ATP are lower than the currents evoked by ATP. However, the mechanism underlying the partial activation of the P2X receptors is unknown although the crystal structures of zebrafish P2X4 receptor in the apo and ATP-bound states are available. Here, we observed the NMR signals from M339 and M351, which were introduced in the transmembrane region, and the endogenous alanine and methionine residues of the zebrafish P2X4 purinergic receptor in the apo, ATP-bound, and α,β-methylene ATP-bound states. Our NMR analyses revealed that, in the α,β-methylene ATP-bound state, M339, M351, and the residues that connect the ATP-binding site and the transmembrane region, M325 and A330, exist in conformational equilibrium between closed and open conformations, with slower exchange rates than the chemical shift difference (antagonism is due to the closure of ion pathways, except for the pore in the transmembrane region: i.e., the lateral cation access in the extracellular region. PMID:27071117

  12. Theoretical study on photon-phonon coupling at (001)-(2 x 1) surfaces of Ge and {alpha}-Sn

    Perez-Sanchez, F.L. [Escuela de Ciencias, Universidad Autonoma ' ' Benito Juarez' ' de Oaxaca, Av. Universidad S/N, Ex-Hacienda de Cinco Senores, Ciudad Universitaria, Oaxaca de Juarez, Oax., 68120 (Mexico); Perez-Rodriguez, F. [Instituto de Fisica, Benemerita Universidad Autonoma de Puebla, Apdo. Post. J-48, Puebla, Pue. 72570 (Mexico)

    2011-06-15

    We present a study of the far-infrared reflectance anisotropy spectra for (001) surfaces of Ge and {alpha}-Sn in the (2 x 1) asymmetric dimer geometry, which exhibit a resonance structure associated with the excitation of surface phonon modes. We have employed a theoretical formalism, based on the adiabatic bond-charge model (ABCM), for computing the far-infrared reflectance anisotropy spectra. In comparison with previous theoretical results for silicon and diamond surfaces, the resonance structure in the reflectance anisotropy spectrum for Ge(001)-(2 x 1) turns out to be similar to that observed in the spectrum for the Si(001)-(2 x 1) surface, whereas the spectrum for {alpha}-Sn(001)-(2 x 1) surface is noticeably different from the others. We have established a trend of far-infrared reflectance anisotropy spectra for IV(001) surfaces: the weaker dimer strength, the stronger resonances of low-frequency surface phonons. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Electrophysiological evidence of P2X2 receptor expression in the neurons of intracardiac and paratracheal ganglia

    MA Bei; NI Xin; HAN Hong; BURNSTOCK Geoffrey

    2006-01-01

    Objective:To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods: For preparation of intracardiac neurons, hearts were excised, the atria were separated and the medial region containing intracardiac ganglia was isolated and cut into pieces. For preparation of paratracheal neurons, the tracheas were removed and the superficial membranous layer containing paratracheal ganglia was rapidly isolated. Intracardiac and paratracheal ganglion neurons were dissociated after digestion by collagenase and trypsin. Whole-cell patch clamp recording was used to identify the pharmacological properties of P2X receptors in cultured neurons. Results:Neurons from these two ganglia responded to ATP with a rapidly activating, sustained inward current. Αβ-meATP failed to evoke any responses in paratracheal ganglion neurons while a few of intracardiac ganglion neurons responded to αβ-meATP with a tiny sustained inward current. ADP and UTP had no effect on intracardiac neurons. Lowering pH potentiated ATP responses in neurons from these two ganglia whereas increasing pH inhibited ATP responses. Co-application of Zn2+ potentiated ATP responses in intracardiac and paratracheal ganglion neurons. Conclusion: The receptor subtypes involved in intracardiac and paratracheal ganglia appear to be homomeric P2X2, while heteromeric P2X2/3 could not be completely excluded from intracardiac neurons.

  14. Directly-Modulated VCSELs for 2x2 MIMO-OFDM Radio over Fiber in WDM-PON

    Binti Othman, Maisara; Deng, Lei; Pang, Xiaodan; Caminos, Josu; Kozuch, Wojciech Tomasz; Prince, Kamau; Jensen, Jesper Bevensee; Tafur Monroy, Idelfonso

    2011-01-01

    We demonstrate directly- modulated VCSELs supporting 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20-km WDM-PON. Error-free signal demodulation of 64-subcarrier 4-QAM signals modulated at 198.5-Mb/s is achieved after fiber and 2-m indoor wireless transmission....

  15. Directly-Modulated VCSELs for 2x2 MIMO-OFDM Radio over Fiber in WDM-PON

    Binti Othman, Maisara; Deng, Lei; Pang, Xiaodan; Caminos, Josu; Kozuch, Wojciech Tomasz; Prince, Kamau; Jensen, Jesper Bevensee; Tafur Monroy, Idelfonso

    2011-01-01

    We demonstrate directly- modulated VCSELs supporting 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20-km WDM-PON. Error-free signal demodulation of 64-subcarrier 4-QAM signals modulated at 198.5-Mb/s is achieved after fiber and 2-m indoor wireless transmission.

  16. Thermodynamic functions of TiFeX2(X-S, Se, Te) and TICrS2

    The heat capacity of the TiFeX2(X-S, Se, Te) and TICrS2 compounds has been measured in the temperature interval 4.2-300 K. The experimental data on the temperature dependence of the heat capacity are used to calculate the thermodynamic parameters of these compounds : the changes in entropy, enthalpy and Gibbs free energy

  17. Studies on the EPR g factors for the oxygenated and nonoxygenated BaCuO{sub 2+x}

    Cheng, Yong-Kun, E-mail: ykcheng166@126.com; Wu, Shao-Yi; Ding, Chang-Chun; Zhang, Li-Juan

    2015-02-15

    Highlights: • The EPR spectra and local structures are studied for Cu{sup 2+} in BaCuO{sub 2+x} systems. • Cu{sup 2+} suffers axial elongations and planar distance variations of Jahn–Teller nature. • Ligand contributions are important and considered due to obvious covalency. • Lower Δg′ than Cu{sup 2+} in R123 systems may help to distinguish BaCuO{sub 2+x} EPR spectra from hosts. - Abstract: The EPR g factors for the oxygenated and nonoxygenated BaCuO{sub 2+x} are theoretically studied from the perturbation formulas of the g factors for an orthorhombically elongated octahedral 3d{sup 9} complex based on the cluster approach. The relative axial elongation ratios (≈1% and 0.6%) along c axis and the relative planar bond length variations (≈6.9% and 8.9%) are found for the oxygenated and nonoxygenated systems, respectively. The above local orthorhombic distortions of the Jahn–Teller nature around Cu{sup 2+} can suitably account for the axial and perpendicular anisotropies of the observed g factors. The present studies can be useful to understand the influences of this parasitic phase BaCuO{sub 2+x} on the EPR behaviours and superconductivity of the R123 high T{sub c} superconductors.

  18. Hydrogenated CeO2-xSx mesoporous hollow spheres for enhanced solar driven water oxidation.

    Xiao, Yuting; Chen, Yajie; Xie, Ying; Tian, Guohui; Guo, Shien; Han, Taoran; Fu, Honggang

    2016-02-11

    A facile route for the fabrication of hydrogenated sulfur-doped CeO2 (H-CeO2-xSx) mesoporous hollow spheres is reported. The spheres exhibited excellent photocatalytic activity due to the synergistic effect of the higher sulfur doping level and hydrogen post-treatment. PMID:26741276

  19. Ultraefficient Themoelectric Devices Project

    National Aeronautics and Space Administration — Thermoelectric (TE) devices already found a wide range of commercial, military and aerospace applications. However, at present commercially available TE devices...

  20. Preparation of ZnO:CeO2-x thin films by AP-MOCVD: Structural and optical properties

    The growth of columnar CeO2, ZnO and ZnO:CeO2-x films on quartz and AA6066 aluminum alloy substrates by economic atmospheric pressure metal-organic chemical vapor deposition (AP-MOCVD) is reported. A novel and efficient combination of metal acetylacetonate precursors as well as mild operating conditions were used in the deposition process. The correlation among crystallinity, surface morphology and optical properties of the as-prepared films was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and UV-vis spectroscopy. The synthesized films showed different crystallographic orientations depending on the ZnO and CeO2 lattice mismatch, cerium content and growth rate. The CeO2 films synthesized in this work showed plate-like compact structures as a result of the growth process typical of CVD. Both pure and ZnO:CeO2-x films were obtained with a hexagonal structure and highly preferred orientation with the c-axis perpendicular to both substrates under the optimal deposition conditions. The microstructure was modified from dense, short round columns to round structures with cavities ('rose-flower-like' structures) and the typical ZnO morphology by controlling the cerium doping the film and substrate nature. High optical transmittance (>87%) was observed in the pure ZnO films. As for the ZnO:CeO2-x films, the optical transmission was decreased and the UV absorption increased, which subsequently was affected by an increase in cerium content. This paper assesses the feasibility of using ZnO:CeO2-x thin films as UV-absorbers in industrial applications. - Graphical abstract: TEM micrographs and their corresponding SAED pattern obtained for the as-deposited ZnO-CeO2-x thin films for a Zn/Ce metallic ratio 16:9.

  1. RuO{sub 2}.xH{sub 2}O/NiO composites as electrodes for electrochemical capacitors

    Pico, Fernando [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, c/Sor Juana Ines de la Cruz 3, E-28049 Madrid (Spain); Ibanez, Joaquin [Centro Nacional de Investigaciones Metalurgicas, CSIC, Av. Gregorio del Amo 8, E-28040 Madrid (Spain); Centeno, Teresa A. [Instituto Nacional del Carbon, CSIC, c/Francisco Pintado Fe 26, Apartado 73, E-33080 Oviedo (Spain); Pecharroman, Carlos [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, c/Sor Juana Ines de la Cruz 3, E-28049 Madrid (Spain); Rojas, Rosa M. [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, c/Sor Juana Ines de la Cruz 3, E-28049 Madrid (Spain); Amarilla, Jose M. [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, c/Sor Juana Ines de la Cruz 3, E-28049 Madrid (Spain); Rojo, Jose M. [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, c/Sor Juana Ines de la Cruz 3, E-28049 Madrid (Spain)]. E-mail: jmrojo@icmm.csic.es

    2006-06-05

    RuO{sub 2}.xH{sub 2}O/NiO composites having RuO{sub 2} contents in the range 0-100 wt.% have been prepared by a co-precipitation method. Structural, microstructural and textural transformations after heating the as-prepared composites at 200 and 600 deg. C have been followed by X-ray diffraction, scanning electron microscopy (SEM) and nitrogen adsorption/desorption isotherms. At 200 deg. C the composites are made of micrometric particles in which nanometric crystallites of the two oxides are aggregated. The composites show microporosity (0.02-0.10 cm{sup 3}/g), mesoporosity (0.07-0.12 cm{sup 3}/g) and relatively high specific surface area (62-309 m{sup 2}/g). At 600 deg. C the composites are fully dehydrated and RuO{sub 2} has crystallized and segregated. Microporosity and mesoporosity as well as specific surface area are strongly decreased. Specific capacitance and specific surface area of the composites heated at 200 and 600 deg. C have been measured and discussed on the basis of the RuO{sub 2} content. For comparison the specific capacitance and specific surface area of mixtures of NiO and RuO{sub 2}.xH{sub 2}O (or RuO{sub 2}) have been taken as references. The higher specific capacitance of the 200 deg. C-heated composites compared to the 600 deg. C-heated ones is due to the higher specific surface area of the former and the higher pseudocapacitance of RuO{sub 2}.xH{sub 2}O compared to RuO{sub 2}. The discussion reported in this work can be applied to other composites such as RuO{sub 2}.xH{sub 2}O/carbon and RuO{sub 2}.xH{sub 2}O/other oxides.

  2. Upregulated P2X3 Receptor Expression in Patients with Intractable Temporal Lobe Epilepsy and in a Rat Model of Epilepsy.

    Zhou, Xin; Ma, Li-Min; Xiong, Yan; Huang, Hao; Yuan, Jin-Xian; Li, Ruo-Han; Li, Jia-Ni; Chen, Yang-Mei

    2016-06-01

    Purinergic P2X3 receptors (P2X3Rs) play extensive roles in nerve cells in the central nervous system, particularly in hyperexcitability and calcium (Ca(2+)) influx. However, the role of P2X3Rs in epilepsy has not been previously investigated. To determine the relationship between P2X3Rs and epilepsy, the expression and cellular location of P2X3Rs in patients with intractable temporal lobe epilepsy (TLE) and in a lithium chloride-pilocarpine-induced chronic rat model of epilepsy were assessed. Furthermore, the function of P2X3Rs was assessed in vitro. Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were used to evaluate the expression levels of P2X3Rs in brain tissues from TLE patients and an epileptic rat model, whereas immunofluorescence labeling was applied to determine the distribution of target proteins. Whole-cell recording was subsequently performed to identify the influence of P2X3Rs on seizure-like discharges. P2X3Rs were located at the cell bodies and dendrites of neurons with significantly increased expression in the TLE patients and epileptic rat model. In vitro, P2X3R activation accelerated sustained repetitive firing, whereas P2X3R inhibition led to relatively low-frequency discharges. To the best of our knowledge, this is the first study provide evidence that upregulated P2X3R expression exists in both epileptic humans and rats and may aggravate the epileptic state in vitro. Thus, P2X3Rs may represent a novel therapeutic target for antiepileptic drugs. PMID:26738991

  3. Ternary Al{sub 2x}In{sub 2−2x}O{sub 3} films with tunable optical band gap prepared on YSZ (1 0 0) substrates by metal organic chemical vapor deposition

    Feng, Xianjin; Zhao, Cansong; Li, Zhao; Luo, Yi; Ma, Jin, E-mail: jinmasduphy@163.com

    2015-07-15

    Highlights: • Ternary Al{sub 2x}In{sub 2−2x}O{sub 3} films were prepared on the YSZ (1 0 0) substrates by MOCVD at 700 °C. • The lowest resistivity of 4.84 × 10{sup −3} Ω cm was obtained for the sample with x = 0.2. • Excellent optical transparency in the UV and visible wavelength regions was achieved. • Tunable optical band gap from 3.67 to 4.73 eV was obtained. - Abstract: The ternary Al{sub 2x}In{sub 2−2x}O{sub 3} films with different Al contents of x [Al/(Al + In) atomic ratio] have been fabricated on the Y-stabilized ZrO{sub 2} (YSZ) (1 0 0) substrates by the metal organic chemical vapor deposition (MOCVD) method at 700 °C. The influence of various Al contents (x = 0.1–0.9) on the structural, electrical and optical properties of the films have been investigated. Structural analyses revealed a phase transition from the bixbyite In{sub 2}O{sub 3} structure with a single orientation along (1 0 0) to the amorphous structure as the Al content increases from 10% to 90%. The lowest resistivity of 4.84 × 10{sup −3} Ω cm with a carrier concentration of 1.1 × 10{sup 20} cm{sup −3} and a Hall mobility of 11.74 cm{sup 2} V{sup −1} s{sup −1} were obtained for the sample with x = 0.2. The average transmittances for the Al{sub 2x}In{sub 2−2x}O{sub 3} films in the visible range were all over 77% and the optical band gap of the films could be modulated from 3.67 to 4.73 eV.

  4. Influence of Al content on the properties of ternary Al{sub 2x}In{sub 2−2x}O{sub 3} alloy films prepared on YSZ (1 1 1) substrates by MOCVD

    Feng, Xianjin; Zhao, Cansong; Li, Zhao; Luo, Yi; Ma, Jin, E-mail: jinmasduphy@163.com

    2015-10-15

    Highlights: • Al{sub 2x}In{sub 2−2x}O{sub 3} films were prepared on the Y-stabilized ZrO{sub 2} (1 1 1) substrates by MOCVD at 700 °C. • A phase transition from the bixbyite In{sub 2}O{sub 3} structure to the amorphous structure was observed. • The lowest resistivity of 4.7 × 10{sup −3} Ω cm was obtained for the Al{sub 0.4}In{sub 1.6}O{sub 3} film. • Tunable optical band gap from 3.7 to 4.8 eV was obtained. - Abstract: The ternary Al{sub 2x}In{sub 2−2x}O{sub 3} films with different Al contents of x [Al/(Al + In) atomic ratio] have been fabricated on the Y-stabilized ZrO{sub 2} (1 1 1) substrates by metal organic chemical vapor deposition at 700 °C. The structural, electrical and optical properties of the films as a result of different Al contents (x = 0.1–0.9) were investigated in detail. With the increase of Al content from 10% to 90%, a phase transition from the bixbyite In{sub 2}O{sub 3} structure with a single orientation along (1 1 1) to the amorphous structure was observed. The minimum resistivity of 4.7 × 10{sup −3} Ω cm, a carrier concentration of 1.4 × 10{sup 20} cm{sup −3} and a Hall mobility of 9.8 cm{sup 2} v{sup −1} s{sup −1} were obtained for the sample with x = 0.2. The average transmittances for the Al{sub 2x}In{sub 2−2x}O{sub 3} films in the visible range were all over 78% and the optical band gap of the films could be tuned from 3.7 to 4.8 eV.

  5. Preparation and antibacterial properties of nano-TiO2-xNx film%纳米TiO2-xNx薄膜的制备及抗菌性能分析

    李娜; 曹宝成; 王育华; 刘斌

    2012-01-01

    Objective To prepare a nano-TiO2 film and characterize its antibacterial properties for dental application. Methods The TiO2-xNx, antibacterial film was prepared by radio frequency (RF) magnetron sputtering. The crystal structure and surface morphology of the film were characterized by X-ray diffraction, scanning electron microscopy, and EDS, and the antibacterial properties of the film against common dental pathogenic bacteria were evaluated. Results The TiO2-xNx antibacterial film presented with an anatase phase with a mass ratio of nitrogen of 0.13% and compact and smooth surface. Antibacterial assay of the film showed a resistance rate of 97.79% against Streptococcus mutatis, 49.42% against Actinomyces viscosus, and 96.84% against Candida albicans. Conclusion The nano-TiO2-xNx film shows strong antibacterial effects against common dental pathogenic bacteria and can be used as a novel antibacterial dental material.%目的 利用TiO2的抗菌特性,开发一种能够应用于口腔的无机抗菌材料.方法 采用射频磁控溅射法在医用不锈钢表面制备TiO2xNx薄膜,用XRD、SEM、EDS等测试手段表征薄膜的结构、形貌、组成,并通过覆膜法利用口腔常见致病菌考察TiO2-xNx薄膜的抗菌性能.结果 纳米TiO22-xNx抗菌薄膜为锐钛矿相结构,氮元素质量比为0.13%,表面结构均匀致密,对变形链球菌、粘性放线菌及白色念珠菌的抗菌率分别为97.79%、49.42%和96.84%.结论 纳米TiO2-xNx抗菌薄膜对口腔常见致病菌具有较强的抗菌效果,可作为一种新型抗菌剂应用于口腔临床.

  6. Gapped and gapless short-range-ordered magnetic states with (1/2 ,1/2 ,1/2 ) wave vectors in the pyrochlore magnet Tb2 +xTi2 -xO7 +δ

    Kermarrec, E.; Maharaj, D. D.; Gaudet, J.; Fritsch, K.; Pomaranski, D.; Kycia, J. B.; Qiu, Y.; Copley, J. R. D.; Couchman, M. M. P.; Morningstar, A. O. R.; Dabkowska, H. A.; Gaulin, B. D.

    2015-12-01

    Recent low-temperature heat capacity (CP) measurements on polycrystalline samples of the pyrochlore antiferromagnet Tb2 +xTi2 -xO7 +δ have shown a strong sensitivity to the precise Tb concentration x , with a large anomaly exhibited for x ˜0.005 at TC˜0.5 K and no such anomaly and corresponding phase transition for x ≤0 . We have grown single-crystal samples of Tb2 +xTi2 -xO7 +δ , with approximate composition x =-0.001 ,+0.0042 , and +0.0147 , where the x =0.0042 single crystal exhibits a large CP anomaly at TC=0.45 K, but neither the x =-0.001 nor the x =+0.0147 single crystals display any such anomaly. We present new time-of-flight neutron scattering measurements on the x =-0.001 and the x =+0.0147 samples which show strong (1/2 ,1/2 ,1/2 )">1/2 ,1/2 ,1/2 quasi-Bragg peaks at low temperatures characteristic of short-range antiferromagnetic spin ice (AFSI) order at zero magnetic field but only under field-cooled conditions, as was previously observed in our x =0.0042 single crystal. Furthermore, the frozen AFSI state displays a gapped spin excitation spectrum around (1/2 ,1/2 ,1/2 ) quasi-Bragg peaks and gapped AFSI state at low temperatures under field-cooled conditions are robust features of Tb2Ti2O7 , and are not correlated with the presence or absence of the CP anomaly and phase transition at low temperatures. Further, these results show that the ordered state giving rise to the CP anomaly is confined to 0 ≤x ≤0.01 for Tb2 +xTi2 -xO7 +δ , and is not obviously connected with conventional order of magnetic dipole degrees of freedom.

  7. New multiferroics BiFe{sub 1−2x}Al{sub x}Mn{sub x}O{sub 3} nanoparticles: Synthesis and evaluation of various structural, physical, electrical, dielectric and magnetic parameters

    Ahmad, Bashir [Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60800 (Pakistan); Mahmood, Azhar [Department of Chemistry, The Islamia University, Bahawalpur (Pakistan); Ashiq, Muhammad Naeem, E-mail: naeembzu@bzu.edu.pk [Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60800 (Pakistan); Malana, Muhammad Aslam; Najam-Ul-Haq, Muhammad; Ehsan, Muhammad Fahad [Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60800 (Pakistan); Warsi, Muhammad Farooq [Department of Chemistry, The Islamia University, Bahawalpur (Pakistan); Shakir, Imran, E-mail: mshakir@ksu.edu.sa [Deanship of scientific research, College of Engineering, King Saud University, PO Box 800, Riyadh 11421 (Saudi Arabia); BK 21 Physics Research Division, Department of Energy Science, Institute of Basic Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-03-25

    Graphical abstract: Nanostructures multiferroic BiFeO{sub 3} and its derivatives BiFe{sub 1−2x}Al{sub x}Mn{sub x}O{sub 3} in the range of 30–50 nm were fabricated by wet chemical route exhibited very high coercivity values and relatively small values of saturation magnetization and retentivity. -- Highlights: • New nanostructured derivatives of BiFeO{sub 3} were prepared by cheap method. • The rhombohedral structures of BiFe{sub 1−2x}Al{sub x}Mn{sub x}O{sub 3} were established. • The electrical resistivity was increased from 8 × 10{sup 8} to 48 × 10{sup 8} ohm cm. • The magnetic properties of the materials also enhanced by the substituents. -- Abstract: Nanostructures multiferroic BiFeO{sub 3} and its derivatives BiFe{sub 1−2x}Al{sub x}Mn{sub x}O{sub 3} are synthesized by a simple co-precipitation route. FTIR and XRD data confirms the rhombohedral structure and crystallite size is found in the range of 30–50 nm. The surface morphology change from round shaped particles to sheets form. The electrical resistivity is increased while the dielectric parameters decreased with the substituents. The BiFeO{sub 3} shows week ferromagnetic behavior and have high coercivity (Hc = 2590.3 G). The coercivity decreased from 2.59 × 10{sup 3} to 0. 211 × 10{sup 3} G with the increase in Al–Mn contents, while the saturation magnetization is found to increase from 0.030 to 0.056 emu g{sup −1} up to x = 0.3 and then decreased. The measured electrical, dielectric and magnetic parameters suggest that these materials can be utilized for fabricating the nano-devices working at very high frequencies as well as in data storage electronics devices.

  8. Hip supporting device

    2011-01-01

    The present invention relates to a device for limiting movements in one or more anatomical joints, such as a device for limiting movement in the human hip joint after hip replacement surgery. This is provided by a device for limiting movement in the human hip joint, said device comprising: at least...

  9. Implantable CMOS Biomedical Devices

    Toshihiko Noda

    2009-11-01

    Full Text Available The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented.

  10. A Remark on Euler’s Generating Polynomial 2x2+pq%关于Euler生成多项多2x2+pq的一个注记

    殷晓斌; 黄丹丹

    2011-01-01

    Let Ω( n ) be the number of prime factors (counting multiplicity) of the positive integer n. Put EK = max {Ω(2x2 + pq):x ∈ Z ∩ [0,pq- 1]}. In this paper, it is proved that an imaginary quadratic field K = Q(√(- 2pq)), where p,q are different odd positive primes, has class group isomorphic to Z/2Z (○+) Z/2Z if and only if Ek = 2.%假设Ω(n)为正整数n的素因子个数,K=Q(√(- 2pq)),p,q互不相同的奇素数,为虚二次域,记EK=max{Ω(2x2+pq);x∈z ∩[0,pq-1]}.本文证明了Cl(K)≌Z/2Z(○+)Z/2Z当且仅当EK=2.

  11. Barium-deficient celsian, Ba1-xAl2-2xSi2+2xO8 (x = 0.20 or 0.06).

    Skellern, Matthew G; Howie, R Alan; Lachowski, Eric E; Skakle, Janet M S

    2003-02-01

    Barium-deficient forms of celsian (barium aluminium silicate) with the formula Ba(1-x)Al(2-2x)Si(2+2x)O(8) (x = 0.20 and 0.06) have been identified. In contrast with the celsian-orthoclase solid solutions which have been reported previously, these forms, refined in the space group C2/m, with Ba and one O atom in the 4i sites with m site symmetry, and a further O atom in a 4g site with twofold axial symmetry, suggest a slight solid solution with silica. The serendipitous preparation of the compounds represents a possible hazard associated with solid-state synthesis. PMID:12574637

  12. Comparative X ray diffuse scattering studies of some superconducting and non superconducting 1 : 2 salts (TMTSF)2X and (TMTTF)2X; with x = PF6, AsF6, ClO4, NO3

    X-ray diffuse scattering experiments performed on the highly conducting (TMTSF)2X compounds (X = PF6, AsF6, ClO4, NO3) reveal no charge density wave instabilities, whether they display superconducting properties or not. Instead, another type of phase transition, not observed for the superconducting members (PF6, AsF6, ClO4), takes place in the non-superconducting (TMTSF)2NO3, and involves an ordering of the counter ions, which doubles the lattice constant in chain direction. Similar experiments performed on the less conducting (TMTSF)2X compounds (X = ClO4, PF6), which do not present a superconducting state, either reveal the ordering transition of the counter ion (ClO4) or the quasi 1-D 2ksub(F) scattering characteristic of a charge density wave instability (PF6). Consequences on the dimensionality of the Fermi surface and on the superconducting instability are discussed. (orig.)

  13. Higher twist contributions to the structure functions F{sup p}{sub 2}(x,Q{sup 2}) and F{sup d}{sub 2}(x,Q{sup 2}) at large x at higher orders

    Bluemlein, J.; Boettcher, H.

    2008-02-15

    The higher twist contributions to the deeply inelastic structure functions F{sup p}{sub 2}(x,Q{sup 2}) and F{sup d}{sub 2}(x,Q{sup 2}) for larger values of the Bjorken variable x are extracted extrapolating the twist-2 contributions measured in the large W{sup 2} region to the region 4 GeV{sup 2}{<=}W{sup 2} {<=}12.5 GeV{sup 2} applying target mass corrections. We compare the results for the NLO, NNLO and N{sup 3}LO analyzes and include also the large x at N{sup 4}LO to the Wilson coefficients. A gradual lowering of the higher twist contributions going from NLO to N{sup 4}LO is observed, which stresses the importance of higher order corrections. (orig.)

  14. NACA Aircraft on Lakebed - D-558-2, X-1B, and X-1E

    1955-01-01

    Early NACA research aircraft on the lakebed at the High Speed Research Station in 1955: Left to right: X-1E, D-558-2, X-1B There were four versions of the original Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and an altitude of 43,000 feet. The number 2 X-1 was modified and redesignated the X-1E. The modifications included adding a conventional canopy, an ejection seat, a low-pressure fuel system

  15. Sensory–sympathetic coupling in superior cervical ganglia after myocardial ischemic injury facilitates sympathoexcitatory action via P2X7 receptor

    LIU Jun; Li, Guilin; Peng, Haiying; Tu, Guihua; Kong, Fanjun; Liu, Shuangmei; Gao, Yun; Xu, Hong; Qiu, Shuyi; Fan, Bo; Zhu, Qicheng; Yu, Shicheng; Zheng, Chaoran; Wu, Bing; Peng, Lichao

    2013-01-01

    P2X receptors participate in cardiovascular regulation and disease. After myocardial ischemic injury, sensory–sympathetic coupling between rat cervical DRG nerves and superior cervical ganglia (SCG) facilitated sympathoexcitatory action via P2X7 receptor. The results showed that after myocardial ischemic injury, the systolic blood pressure, heart rate, serum cardiac enzymes, IL-6, and TNF-α were increased, while the levels of P2X7 mRNA and protein in SCG were also upregulated. However, these ...

  16. Exchange bias in structure-phase separated K{sub 0.8}Fe{sub 2-x}Ni{sub x}Se{sub 2} (x=0.015) single crystal: Interface evidence

    Li Mingtao; Feng Zhenjie; Yu Huiling; Deng Dongmei; Kang Baojuan; Cao Shixun [Department of Physics, Shanghai University, Shanghai 200444 (China); Zhang Jincang, E-mail: jczhang@staff.shu.edu.cn [Department of Physics, Shanghai University, Shanghai 200444 (China)

    2012-09-15

    Exchange bias behavior is observed in Ni slightly doped K{sub 0.8}Fe{sub 2-x}Ni{sub x}Se{sub 2} (x=0.015) single crystal. Two distinguished phases with epitaxial growth were observed in X-ray diffraction experiments, indicating the structure phase separation in our samples. The magnetic hysteresis loop shifts in both horizontal and vertical directions when the sample was cooled down to 3 K in a magnetic field. The nature of this magnetic anisotropy could be understood as a result of the freezing properties of the local spin disorders in cluster like spin-glass system. Our results suggest that the sample contains short range weak ferromagnetic clusters (phase 2) embedding in the antiferromagnetic backgrounds (phase 1), in which the random distribution of Ni on Fe or Fe-vacancy sites quenched the superconductivity and induced spin disorders. - Highlights: Black-Right-Pointing-Pointer Two distinguished phases are revealed in K{sub 0.8}Fe{sub 2-x}Ni{sub x}Se{sub 2} single crystals. Black-Right-Pointing-Pointer The exchange bias behavior is observed after field cooling for x=0.015 sample. Black-Right-Pointing-Pointer The exchange anisotropy is understood when considering local frozen-spin disorders.

  17. Functional Identification of Close Proximity Amino Acid Side Chains within the Transmembrane-Spanning Helixes of the P2X2 Receptor

    Liang, Xin; Xu, Huijuan; Li, Caiyue; Yin, Shikui; Xu, Tingting; Liu, Jinsong; Li, Zhiyuan

    2013-01-01

    The transition from the closed to open state greatly alters the intra- and inter-subunit interactions of the P2X receptor (P2XR). The interactions that occur in the transmembrane domain of the P2X2R remain unclear. We used substituted cysteine mutagenesis disulfide mapping to identify pairs of residues that are in close proximity within the transmembrane domain of rP2X2R and compared our results to the predicted positions of these amino acids obtained from a rat P2X2R homology model of the av...

  18. The purinergic receptor P2X7 role in control of Dengue virus-2 infection and cytokine/chemokine production in infected human monocytes.

    Corrêa, Gladys; de A Lindenberg, Carolina; Fernandes-Santos, Caroline; Gandini, Mariana; Petitinga Paiva, Fabienne; Coutinho-Silva, Robson; F Kubelka, Claire

    2016-07-01

    Purinergic signaling has a crucial role in intracellular pathogen elimination. The P2X7 purinergic receptor (P2X7R), once activated by ATP, leads to pro-inflammatory responses including reactive oxygen species production. ATP can be released by injured cells, as endogenous danger signals. Dengue fever may evolve to a severe disease, leading to hypovolemic shock and coagulation dysfunctions as a result of a cytokine storm. Our aim was to evaluate the role of P2X7R activation during Dengue virus (DENV) infection. Extracellular ATP inhibited viral load in pretreated monocytes, as measured by NS1 secretion and by decrease in DENV(+) P2X7(+) cell frequencies, suggesting that P2X7R is involved in the antiviral response. Nitric oxide (NO) has anti-DENV properties and is decreased after DENV infection. NO production after ATP stimulation is abrogated by KN62 treatment, a specific P2X7R inhibitor, indicating that P2X7R likely is acting in the virus containment process. Additionally, TNF, CXCL8, CCL2 and CXCL10 factors that are associated with dengue severity were modulated by the P2X7R activation. We conclude that P2X7R is directly involved in the modulation of the antiviral and inflammatory process that occurs during DENV infection in vitro, and may have an important role in patient recovery in a first moment. PMID:26969484

  19. Relation of structure, magnetism, doping and pressure in AFe2-xTxAs2 (T=Co,Rh,Ru)

    We present an overview of our recent investigations on the SrFe2-xTxAs2 (T=Co,Ru,Rh) compounds. In our joint experimental and theoretical study, we report the influence of hydrostatic pressure and substitution at the Fe site on the magneto-structural and superconducting transitions. The magnetism is weakened upon the application of pressure as indicated by resistivity, X-ray data and density functional band structure calculations. Similar to substitution on the Sr site, substitutions on the Fe-site quench the magnetic transition and induce bulk superconductivity with Tc up to 20 K for ambient pressure and up to 27 K for underdoped SrFe2-xCoxAs2 for pressures of 2.6GPa. In our analysis, we attempt to disentangle the interplay of charge doping and structural changes induced by the substitution and by external pressure.

  20. Three-dimensional dispersion induced by extreme tensile strain in La2-xSrxCuO4 films

    Cloetta, D.; Ariosa, D.; Cancellieri, C.; Abrecht, M.; Mitrovic, S.; Pavuna, D.

    2006-07-01

    The electronic band structure probed by angle-resolved photoemission spectroscopy on thin epitaxial La2-xSrxCuO4 films under extreme tensile strain shows anomalous features compatible with c -axis dispersion. This result is in striking contrast with the usual quasi-two-dimensional (2D) dispersion observed up to now in most superconducting cuprates, including relaxed and compressively strained La2-xSrxCuO4 films grown under the same conditions. The data were analyzed using a 3D tight-binding dispersion for a body-centered-tetragonal lattice. We relate the enhancement of the c -axis dispersion to the significant displacement of the apical oxygen induced by epitaxial strain.

  1. Evidence for two coupled subsystems in the superconducting state of La2-xSrxCuO4

    Rast, S.; Schneider, M. L.; Onellion, M.; Zeng, X. H.; Si, Weidong; Xi, X. X.; Abrecht, M.; Ariosa, D.; Pavuna, D.; Ren, Y. H.; Lüpke, G.; Perakis, I.

    2001-12-01

    We used a pump-probe technique to measure the transient change of optical reflectivity of both La2-xSrxCuO4, of various dopings, and slightly underdoped YBa2Cu3O7-x and NdBa2Cu3O7-x thin films. For the La2-xSrxCuO4 films, our data demonstrate the coexistence, in the superconducting state, of two coupled subsystems with different relaxation times and different contributions to the optical reflectivity. One subsystem is associated with the superconducting phase. By contrast, the data from YBa2Cu3O7-x and NdBa2Cu3O7-x shows that the coupling between the two subsystems is weak or absent.

  2. Lattice instabilities, isotope effect, and high-Tc superconductivity in La2-xBaxCuO4

    Unlike La2-xSrxCuO4, La2-xBaxCuO4, x∼xcr=0.12, undergoes a structural change to a low-temperature tetragonal (LTT) phase below 60 K, and this transformation is known to suppress Tc drastically. We present self-consistent local-density-functional calculations for this system that indicate the CuO6 octahedrons are unstable to an X-point tilt in any direction, thereby leading to strongly anharmonic X-point vibrations. The LTT phase is most favored energetically, consistent with experiment. The effect of the LTT distortion on the electronic structure accounts for the suppression of Tc in the LTT phase, and for the enhanced isotope effect at x=xcr

  3. Regular Elements of the Complete Semigroups BX(D of Binary Relations of the Class ∑2(X,8

    Nino Tsinaridze

    2015-03-01

    Full Text Available As we know if D is a complete X-semilattice of unions then semigroup Bx(D possesses a right unit iff D is an XI-semilattice of unions. The investigation of those a-idempotent and regular elements of semigroups Bx(D requires an investigation of XI-subsemilattices of semilattice D for which V(D,a=Q∈∑2(X,8 . Because the semilattice Q of the class ∑2(X,8 are not always XI -semilattices, there is a need of full description for those idempotent and regular elements when V(D,a=Q . For the case where X is a finite set we derive formulas by calculating the numbers of such regular elements and right units for which V(D,a=Q .

  4. Magnetic ordering in electronically phase-separated La2-xSrxCuO4+y: Neutron diffraction experiments

    Udby, Linda; Andersen, Niels Hessel; Chou, F.C.;

    2009-01-01

    We present results of magnetic neutron diffraction experiments on the codoped superoxygenated La2-xSrxCuO4+y (LSCO+O) system with x=0.09. We find that the magnetic phase is long-range ordered incommensurate antiferromagnetic with a Neacuteel temperature T-N coinciding with the superconducting...... ordering temperature T-c=40 K. The incommensurability value is consistent with a hole doping of n(h)approximate to 1>8 but in contrast to nonsuperoxygenated La2-xSrxCuO4 with hole doping close to n(h)approximate to 18 the magnetic-order parameter is not field dependent. We attribute this to the magnetic...

  5. Composition dependence of the band gap of CuInSsub(2x)Sesub(2(1-x))

    The composition dependence of the band gap of CuInSsub(2x)Sesub(2(1-x)) solid solutions is studied by aid of infrared transmission spectra recorded at 77 K and 293 K. In the wavelength-modulated experiments the band gap was determined by the position of the maximum in the dI/dlambda spectrum and was found to change linearly with composition

  6. Design optimization of the characters measurement system of 4 x 2 x 3 multi-slab-amplifier

    Wang Cheng Cheng; Yu Hai Wu; He Shao Bo; Liu Yong; Zhang Xiao Min

    2002-01-01

    The soft aperture slots and multi spatial filters had been used to transmit the same phase of laser beams, the characters measurement system of 4 x 2 x 3 multi-slab-amplifier design has been optimized by a program of Fresnel, where the sizes of pinholes of spatial filters which influence laser propagation have been analyzed here, the design optimization result also discussed, and the methods and results obtained are applicable to the design of high power solid laser amplifier system

  7. A New Chemical Method of Preparing Semiconducting MoX2 (X=S, Se) Thin Films

    Mandal, Krishna Chandra; Savadogo, Oumarou

    1991-12-01

    We report a new chemical method for preparing semiconducting MoX2 (X=S, Se) thin films on glass substrates. For MoS2 deposition, an ammine complex of Mo (VI) ions, thioacetamide and hydrazine hydrate solutions was used, while for MoSe2 films, sodium selenosulphate solution replaced thioacetamide, and other reagents remained unchanged. Structural, optical and electrical properties of the as-deposited and annealed films have been studied.

  8. Structural properties and chemical homogeneity of underdoped La2-xMxCuO4 cuprates (M = Sr, Ba)

    The present work reports a systematic and accurate study on crystal structure and chemical homogeneity of underdoped La2-xMxCuO4 (M = Ba, Sr). Samples' structural characterization performed by Rietveld refinement of XRD powder diffraction profiles provided an accurate working trendline for the dopant concentration determination. Furthermore FT-IR skeletal analysis and SIMS investigations ensured chemical homogeneity even for samples with very low dopant contents

  9. Stratigraphic model deposit Ofi Inf SDZ-2X A1, Jun in block in Orinoco Oil belt

    This work is about the Stratigraphic model deposit O fi I nf SDZ-2X A1, Junin block in Orinoco Oil belt.This model was based on a chrono stratigraphic interpretation and was defined the correlation between the main and secondary surfaces. The wells of the study area pass through the Cambrian, Cretaceous and Miocene sediments. The last is more interesting for the study because of the stratigraphic and sand body surface presence

  10. Vibrational properties of the π-bonded chain model of the Si(111) 2 x 1 surface

    A tight-binding theory is used to study vibrational excitations of the π-bonded chain model of the Si(111)2x1 surface. Some aspects of the surface phonon spectrum are discussed. The authors study the charge fluctuations driven by the vibrational excitations and the surface conductivity associated with the phonons. They find that a longitudinal optical phonon on the surface chains dominates the surface conductivity

  11. Electric conductivity of Ba1-xHoxF2+x solid solution with fluorite-like structure

    The investigations of electric conductivity of Ba1-xHoxF2+x (0.09≤x≤0.20) solid solution with fluorite structure in the 293 - 300K temperature range are performed. It has been found that the crystal conductivity of the BaF2 - HoF3 system is caused practically by temperature independent concentration of F- ions moving in a hopping way

  12. Multiple Roles of the Extracellular Vestibule Amino Acid Residues in the Function of the Rat P2X4 Receptor

    Rokic, Milos Boro; Stojilkovic, S. S.; Vávra, Vojtěch; Kuzyk, Pavlo; Tvrdoňová, Vendula; Zemková, Hana

    2013-01-01

    Roč. 8, č. 3 (2013), e59411. E-ISSN 1932-6203 R&D Projects: GA AV ČR(CZ) IAA500110910; GA ČR(CZ) GBP304/12/G069 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : ATP * purinergic P2X receptor channels * transmembrane domain * extracellular vestibule * gating * ivermectin Subject RIV: ED - Physiology Impact factor: 3.534, year: 2013

  13. Effect of ATP on intracellular pH in pancreatic ducts involves P2X7 receptors

    Henriksen, Katerine L; Novak, Ivana

    2003-01-01

    Pancreatic acini release ATP, which can stimulate HCO3--secreting ducts that express purinergic receptors from both P2X and P2Y families. The aim of this study was to investigate whether extracellular ATP affects HCO3- or H+ transport across the plasma membrane of intralobular ducts, and determine...... unmasked by cellular acidosis. Presumably, ATP alone does not stimulate HCO3- secretion in pancreatic ducts....

  14. Exhaustive swimming differentially inhibits P2X1 receptor- and α1-adrenoceptor-mediated vasoconstriction in isolated rat arteries

    Li, Lu; Wu, Tao; Wei, Cong; Han, Jian-Ke; Jia, Zhen-Hua; Wu, Yi-Ling; Ren, Lei-ming

    2012-01-01

    Aim: To investigate the effects of exhaustive swimming exercise on P2X1 receptor- and α1-adrenoceptor-mediated vasoconstriction of different types of arteries in rats. Methods: Male Wistar rats were divided into 2 groups: the sedentary control group (SCG) and the exhaustive swimming exercise group (ESEG). The rats in the ESEG were subjected to a swim to exhaustion once a day for 2 weeks. Internal carotid, caudal, pulmonary, mesenteric arteries and aorta were dissected out. Isometric vasoconst...

  15. Valence Band Character of NiS2-xSex using 3p-3d Resonant ARPES

    Han, Garam; Kim, Yeongkwan; Koh, Yoonyoung; Kim, Beomyoung; Song, Dongjoon; Seo, Jungjin; Kyung, Wonshik; Lee, Kyungdong; Kim, Changyoung

    2013-03-01

    Understanding the strong correlated system is one of the most challenging tasks in condensed matter physics. Especially, the metal insulator transition (MIT) has been one of the major topics recent few decades. NiS2-xSex is known as one of famous material which has MIT. The cubic pyrite NiS2 is a charge-transfer (CT) insulator. NiS2 attracts particular interest as it easily forms a solid solution with NiSe2 (NiS2-xSex) which, while being isoelectronic and isostructural to NiS2, is nevertheless a good metal. MIT, induced by Se alloying, is observed at low temperature (T) for x =0.45. Perucchi and his collaborators revealed closed relation between MIT and band width through comparison of infrared spectroscopy result and LDA calculation. However, it was only an indirect observation, and is inconsistent with recent proposal that NiS2 is not a CT insulator but an insulator due to the bonding-antibonding splitting in the S - S (Se - Se) dimers. To reveal the true mechanism in the MIT in NiS2-xSex, resonant photoemission experiment is essential. According to competing theories (CT insulator and insulator due to bonding-antibonding splitting), it is expected that the character of the main band that is responsible for the MIT should be different. Therefore, we performed 3p->3d resonant ARPES for various Se dopings (x =0.43; insulator, x =0.5, 0.7, 2.0; metal) and observed a significant change between on- and off-resonances near the MIT. Our experimental result supports that the origin of MIT in NiS2-xSex is the CT theory rather than the dimer theory.

  16. Probing hydrodesulfurization over bimetallic phosphides using monodisperse Ni2-xMxP nanoparticles encapsulated in mesoporous silica

    Danforth, Samuel J.; Liyanage, D. Ruchira; Hitihami-Mudiyanselage, Asha; Ilic, Boris; Brock, Stephanie L.; Bussell, Mark E.

    2016-06-01

    Metal phosphide nanoparticles encapsulated in mesoporous silica provide a well-defined system for probing the fundamental chemistry of the hydrodesulfurization (HDS) reaction over this new class of hydrotreating catalysts. To investigate composition effects in bimetallic phosphides, the HDS of dibenzothiophene (DBT) was carried out over a series of Ni-rich Ni2-xMxP@mSiO2 (M = Co, Fe) nanocatalysts (x ≤ 0.50). The Ni2-xMxP nanoparticles (average diameters: 11-13 nm) were prepared by solution-phase arrested precipitation and encapsulated in mesoporous silica, characterized by a range of techniques (XRD, TEM, IR spectroscopy, BET surface area, CO chemisorption) and tested for DBT HDS activity and selectivity. The highest activity was observed for a Ni1.92Co0.08P@mSiO2 nanocatalyst, but the overall trend was a decrease in HDS activity with increasing Co or Fe content. In contrast, the highest turnover frequency (TOF) was observed for the most Co- and Fe-rich compositions based on sites titrated by CO chemisorption. IR spectral studies of adsorbed CO on the Ni2-xMxP@mSiO2 catalysts indicate that an increase in electron density occurs on Ni sites as the Co or Fe content is increased, which may be responsible for the increased TOFs of the catalytic sites. The Ni2-xMxP@mSiO2 nanocatalysts exhibit a strong preference for the direct desulfurization pathway (DDS) for DBT HDS that changes only slightly with increasing Co or Fe content.

  17. A study of the disorder in heavily doped Ba1-xLaxF2+x by Raman scattering

    The Raman spectra of the Ba1-xLaxF2+x solid solutions (0.005 ≤ x ≤ 0.31) are presented. The low-frequency scattering is studied in some detail. The spectra indicate that no large clusters are present in solid solutions studied. A cross-over which can be interpreted in terms of the fracton model is observed. (author)

  18. Integrated MSM-FET photoreceiver fabricated on MOCVD grown Hg2-xCdxTe

    This paper reports on progress in the monolithic integration of a metal-semiconductor-metal (MSM) detector and transimpedance amplifier and of a photoconductive detector (PCD) with a metal-semiconductor field effect transistor (MESFET) in Hg1-xCdxTe. The layers of CdTe/n-type Hg1-xCdxTe were grown by MOCVD on semi-insulating GaAs substrates (20 misoriented 100). Fabrication of the devices was by an FET planar process; with a standard lift-off used to form Schottky metallization on both the interdigitated electrodes of the MSM detector (2 μm width, 2 μm spacing) and the gate of the MESFETs (5μm length, 100μm width). The MSM photodetectors exhibited breakdown voltages in the range 60 to 80V, a dark current of 10na at 5V bias, and responsivities of >1.0 A/W measured at 40V using CW 1.3 μm illumination

  19. Heat Treatment of Nd1+xBa2-xCu3O7-δ Superconductors

    樊占国; 司平占; 苏大和

    2003-01-01

    Two kinds of Nd1+xBa2-xCu3O7-δ, the sintered samples and zone melted samples, were treated in pure Ar at 950 ℃. The substitution of Nd ions for Ba ions in the Nd1+xBa2-xCu3O7-δ before and after the heat treatment was investigated by XRD. In order to know the effects of heat treatment, the Tc and Jc of samples with and without the heat treatment in Ar were comparatively studied. The results show that the substitution of Nd for Ba decreases, whereas Tc and Jc increase after the treatment. The Nd1+xBa2-xCu3O7-δ samples were oxygenated in pure oxygen at 300 ℃. Based on the XRD spectra it was found that the samples with x<0.4 can transform from tetragonal phase into orthorhombic phase after the oxygenation, whereas in the sample with x>0.4 no phase transition occurs even after a long time oxygenation.

  20. Thermal and spectroscopic properties of the nano-system (ZnO(1-x)SiO2(x))

    El-Kabbany, F.; Taha, S.; Hafez, M.; Yahia, I. S.

    2016-05-01

    Structural and thermal properties of the investigated nano-matrix ZnO(1-x)SiO2(x) samples were characterized by various techniques such as X-ray analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). IR spectroscopic analysis in the frequency range 400-4000 cm-1 is used here to investigate the new nano-system at room temperature. The variation of enthalpy (ΔH) with the concentration of SiO2 nanoparticles for the five systems of the ZnO(1-x)SiO2(x) matrix is determined. Seven different fundamental modes have been investigated. All of the vibrations of the investigated nano-system (ZnO(1-x)SiO2(x)) were found to be 449 cm-1, 469 cm-1, 798 cm-1, 959 cm-1, 1096 cm-1, 1630 cm-1 and 3447 cm-1 correspond to normal vibrations of stretching mode of ZnO, Si - O - Si or O - Si - O bending mode, Si - O - Si symmetric stretching, vibrational mode of Si-O - Zn, Si - O - Si asymmetric stretching, bending vibration mode of adsorbed water and stretching vibration of OH group respectively in which the variations strongly support the variation of ZnO and SiO2 nanoparticles concentration in the studied matrix. Measurements and interpretation of IR spectra as a function of ZnO and SiO2 nanoparticles concentration is reported.

  1. Feasibility of Conducting J-2X Engine Testing at the Glenn Research Center Plum Brook Station B-2 Facility

    Schafer, Charles F.; Cheston, Derrick J.; Worlund, Armis L.; Brown, James R.; Hooper, William G.; Monk, Jan C.; Winstead, Thomas W.

    2008-01-01

    A trade study of the feasibility of conducting J-2X testing in the Glenn Research Center (GRC) Plum Brook Station (PBS) B-2 facility was initiated in May 2006 with results available in October 2006. The Propulsion Test Integration Group (PTIG) led the study with support from Marshall Space Flight Center (MSFC) and Jacobs Sverdrup Engineering. The primary focus of the trade study was on facility design concepts and their capability to satisfy the J-2X altitude simulation test requirements. The propulsion systems tested in the B-2 facility were in the 30,000-pound (30K) thrust class. The J-2X thrust is approximately 10 times larger. Therefore, concepts significantly different from the current configuration are necessary for the diffuser, spray chamber subsystems, and cooling water. Steam exhaust condensation in the spray chamber is judged to be the key risk consideration relative to acceptable spray chamber pressure. Further assessment via computational fluid dynamics (CFD) and other simulation capabilities (e.g. methodology for anchoring predictions with actual test data and subscale testing to support investigation.

  2. Hierarchical self-assembly of designed 2x2-alpha-helix bundle proteins on Au(111) surfaces

    Wackerbarth, Hainer; Tofteng, A.P.; Jensen, K.J.;

    2006-01-01

    Self-assembled monolayers of biomolecules on atomically planar surfaces offer the prospect of complex combinations of controlled properties, e. g., for bioelectronics. We have prepared a novel hemi-4-alpha-helix bundle protein by attaching two alpha-helical peptides to a cyclo-dithiothreitol (cyclo......-DTT) template. The protein was de novo designed to self-assemble in solution to form a 4-alpha-helix bundle, whereas the disulfide moiety enables the formation of a self-assembled monolayer on a Au(111) surface by opening of the disulfide, thus giving rise to a two-step self-assembly process. The 2 x 2-alpha......, respectively. The 2 x 2-alpha-helix bundle protein adlayers were imaged by in situ STM. The images indicated a dense monolayer according with the voltammetric data. No long-range order could be detected, but two clearly distinct STM contrasts were assigned to 2 x 2-alpha-helix bundle protein molecules oriented...

  3. Contribution to the thermodynamic study of the non-stoichiometric oxides UO2+x et FeO1+x

    This thermodynamic study has provided new results concerning the oxide UO2+X and FeO1+x. For the oxides UO2+X correct values have been obtained for μO2M at 900, 1000 and 1100 deg. C using an improved method based on physico-chemical equilibria. For the oxides FeO1+x the use of an E. Calvet high temperature calorimeter has made it possible to measure for the first time the values of hO2M at 800 deg. C over the whole iron monoxide range. The method of oxygen transfer between oxides, usually used to determine the phase limits, has been improved by using a thermo-balance; this has made it possible to draw up simple rules which have to be respected in order to detect the phenomena under study. The theory due to J.S. Anderson has been applied to the oxides UO2+X and a new method is given for improving the representation of non-stoichiometric oxides by models. (author)

  4. Multiple roles of the extracellular vestibule amino acid residues in the function of the rat P2X4 receptor.

    Milos B Rokic

    Full Text Available The binding of ATP to trimeric P2X receptors (P2XR causes an enlargement of the receptor extracellular vestibule, leading to opening of the cation-selective transmembrane pore, but specific roles of vestibule amino acid residues in receptor activation have not been evaluated systematically. In this study, alanine or cysteine scanning mutagenesis of V47-V61 and F324-N338 sequences of rat P2X4R revealed that V49, Y54, Q55, F324, and G325 mutants were poorly responsive to ATP and trafficking was only affected by the V49 mutation. The Y54F and Y54W mutations, but not the Y54L mutation, rescued receptor function, suggesting that an aromatic residue is important at this position. Furthermore, the Y54A and Y54C receptor function was partially rescued by ivermectin, a positive allosteric modulator of P2X4R, suggesting a rightward shift in the potency of ATP to activate P2X4R. The Q55T, Q55N, Q55E, and Q55K mutations resulted in non-responsive receptors and only the Q55E mutant was ivermectin-sensitive. The F324L, F324Y, and F324W mutations also rescued receptor function partially or completely, ivermectin action on channel gating was preserved in all mutants, and changes in ATP responsiveness correlated with the hydrophobicity and side chain volume of the substituent. The G325P mutant had a normal response to ATP, suggesting that G325 is a flexible hinge. A topological analysis revealed that the G325 and F324 residues disrupt a β-sheet upon ATP binding. These results indicate multiple roles of the extracellular vestibule amino acid residues in the P2X4R function: the V49 residue is important for receptor trafficking to plasma membrane, the Y54 and Q55 residues play a critical role in channel gating and the F324 and G325 residues are critical for vestibule widening.

  5. Rhetorical Devices in English Advertisements

    陈芃

    2011-01-01

    In order to achieve persuasive and convincing effects,rhetorical devices are frequently applied in English advertisements.The paper classifies rhetorical devices into four basic categories: phonetic devices,lexical devices,syntactic devices and figures of

  6. Alerts and Notices (Devices)

    ... powered, Hand-held Lasers Used for Pointing or Entertainment 12/16/10 Medical Device Safety Archive The ... About FDA Contact FDA Browse by Product Area Product Areas back Food Drugs Medical Devices Radiation-Emitting ...

  7. Car2x with software defined networks, network functions virtualization and supercomputers technical and scientific preparations for the Amsterdam Arena telecoms fieldlab

    Meijer R.J.; Cushing R.; De Laat C.; Jackson P.; Klous S.; Koning R.; Makkes M.X.; Meerwijk A.

    2015-01-01

    In the invited talk 'Car2x with SDN, NFV and supercomputers' we report about how our past work with SDN [1, 2] allows the design of a smart mobility fieldlab in the huge parking lot the Amsterdam Arena. We explain how we can engineer and test software that handle the complex conditions of the Car2X

  8. The penultimate arginine of the carboxy terminus determines slow desensitisation in a P2X receptor from the cattle tick Boophilus microplus

    P2X ion channels have been functionally characterised from a range of eukaryotes. Whilst these receptors can be broadly classified into fast and slow desensitising, the molecular mechanisms underlying current desensitisation are not fully understood. Here we describe the characterisation of a P2X ch...

  9. SORPTION OF ARSENATE AND ARSENITE ON RUO2 X H2O: ANALYSIS OF SORBED PHASE OXIDATION STATE BY XANES IN ADVANCED PHOTON SOURCE ACTIVITY REPORT 2002

    The sorption reactions of arsenate (As(V)) and arsenite (As(III)) on RuO2 x H2O were examined by X-ray Absorption Near Edge Spectroscopy (XANES) to elucidate the solid state speciation of sorbed As. At all pH values studied (pH 4-8), RuO2 x H

  10. Superlens as matching device

    Veselago, V. G.

    2005-01-01

    The question is considered about possibility of overcoming diffraction limit at device, named superlens. This device is a flat slab, executed from material with index of refraction n,equal n=-1. It is shown, what this device really can focus the radiation to the spot, smaller than wavelength, but herewith superlens works not as optical instrument, based on the laws of geometric optics, but as certain matching device, for which does not exist diffraction limit. This is possible if thickness of...

  11. Development of Medical Devices

    Limaye, Dnyanesh

    2016-01-01

    The medical devices sector helps save lives by providing innovative health care solutions regarding diagnosis, prevention, monitoring, treatment, and alleviation. Medical devices are classified into 1 of 3 categories in the order of increasing risk: Class I, Class II, and Class III.1 Medical devices are distinguished from drugs for regulatory purposes based on mechanism of action. Unlike drugs, medical devices operate via physical or mechanical means and are not dependent on metabolism to acc...

  12. Heterostructures and quantum devices

    Einspruch, Norman G

    1994-01-01

    Heterostructure and quantum-mechanical devices promise significant improvement in the performance of electronic and optoelectronic integrated circuits (ICs). Though these devices are the subject of a vigorous research effort, the current literature is often either highly technical or narrowly focused. This book presents heterostructure and quantum devices to the nonspecialist, especially electrical engineers working with high-performance semiconductor devices. It focuses on a broad base of technical applications using semiconductor physics theory to develop the next generation of electrical en

  13. Photovoltaic device and method

    Cleereman, Robert J; Lesniak, Michael J; Keenihan, James R; Langmaid, Joe A; Gaston, Ryan; Eurich, Gerald K; Boven, Michelle L

    2015-01-27

    The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

  14. Radiation emitting devices act

    This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws

  15. Inspection device in liquid

    The present invention provides an inspection device in PWR reactor core in which inspection operations are made efficient by stabilizing a posture of the device in front-to-back, vertical and left-to-right directions by a simple structure. When the device conducts inspection while running in liquid, the front and the back directions of the device main body are inspected using a visual device while changing the posture by operating a front-to-back direction propulsion device and a right-to-left direction propulsion device, and a vertical direction propulsion device against to rolling, pitching and yawing of the device main body. In this case, a spherical magnet moves freely in the gravitational direction in a vibration-damping fluid in a non-magnetic spherical shell following the change of the posture of the device main body, in which the vibrations due to the movement of the spherical magnet is settled by the vibration-damping fluid thereby stabilizing the posture of the device main body. At a typical inspection posture, the settling effect is enhanced by the attraction force between the spherical magnets in the spherical shell and each of magnetic force-attracted magnetic members disposed to the outer circumference of the shell, and the posture of the device main body can be confirmed in front-to-back, right-to-left and vertical directions by each of the posture confirming magnetic sensors. (N.H.)

  16. 76 FR 8637 - Medical Devices; Medical Device Data Systems

    2011-02-15

    ... Devices; Medical Device Data Systems AGENCY: Food and Drug Administration, HHS. ACTION: Final rule... device are not medical devices. (Response) FDA agrees that the term ``medical device data'' could be... medical devices. (Response) An MDDS is intended to be a communication conduit for medical device data.......

  17. The growth by laser ablation and electronic properties of thin cuprate films: Bi2Sr2-xLaxCuO6 and La2-xSrxCuO4

    Cancellieri, Claudia; Pavuna, Davor; Ariosa Dupont, Daniel

    2008-01-01

    In my thesis work I have concentrated on the growth and the in-depth analysis of high temperature superconducting thin films with the central aim to elucidate their electronic properties, predominantly by in-situ angle resolved photoemission spectroscopy (ARPES). I have used two somewhat complementary approaches and two laser ablation set-ups. The first one, developed previously in Wisconsin, was used mainly for studies of strained La2-xSrxCuO4 (LSCO) with a transfer to the Scienta analyzer v...

  18. Tandem pseudopericyclic reactions: [1,5]-X sigmatropic shift/6pi-electrocyclic ring closure converting N-(2-X-carbonyl)phenyl ketenimines into 2-X-quinolin-4(3H)-ones.

    Alajarín, Mateo; Ortín, María-Mar; Sanchez-Andrada, Pilar; Vidal, Angel

    2006-10-13

    N-(2-X-Carbonyl)phenyl ketenimines undergo, under mild thermal conditions, [1,5]-migration of the X group from the carbonyl carbon to the electron-deficient central carbon atom of the ketenimine fragment, followed by a 6pi-electrocyclic ring closure of the resulting ketene to provide 2-X-substituted quinolin-4(3H)-ones in a sequential one-pot manner. The X groups tested are electron-donor groups, such as alkylthio, arylthio, arylseleno, aryloxy, and amino. When involving alkylthio, arylthio, and arylseleno groups, the complete transformation takes place in refluxing toluene, whereas for aryloxy and amino groups the starting ketenimines must be heated at 230 degrees C in a sealed tube in the absence of solvent. The mechanism for the conversion of these ketenimines into quinolin-4(3H)-ones has been studied by ab initio and DFT calculations, using as model compounds N-(2-X-carbonyl)vinyl ketenimines bearing different X groups (X = F, Cl, OH, SH, NH(2), and PH(2)) converting into 4(3H)-pyridones. This computational study afforded two general reaction pathways for the first step of the sequence, the [1,5]-X shift, depending on the nature of X. When X is F, Cl, OH, or SH, the migration occurs in a concerted mode, whereas when X is NH(2) or PH(2), it involves a two-step sequence. The order of migratory aptitudes of the X substituents at the acyl group is predicted to be PH(2) > Cl > SH > NH(2) > F> OH. The second step of the full transformation, the 6pi-electrocyclic ring closure, is calculated to be concerted and with low energy barriers in all the cases. We have included in the calculations an alternative mode of cyclization of the N-(2-X-carbonyl)vinyl ketenimines, the 6pi-electrocyclic ring closure leading to 1,3-oxazines that involves its 1-oxo-5-aza-1,3,5-hexatrienic system. Additionally, the pseudopericyclic topology of the transition states for some of the [1,5]-X migrations (X = F, Cl, OH, SH), for the 6pi-electrocyclization of the ketene intermediates to the 4

  19. Karyotype description and evidence of multiple sex chromosome system X1X1X2X2/X1X2Y in Potamotrygon aff. motoro and P. falkneri (Chondrichthyes: Potamotrygonidae in the upper Paraná River basin, Brazil

    Vanessa Paes da Cruz

    2011-03-01

    Full Text Available Cytogenetic analysis of Potamotrygon aff. motoro and P. falkneri indicated the occurrence of an X1X1X2X2/X1X2 Y multiple sex chromosome system in both species, with 2n = 66 chromosomes for females and 2n = 65 chromosomes for males. The nucleolus organizer regions (NORs identified using Ag-NOR technique showed that both species have multiple Ag-NORs (5 to 7 chromosomes stained. C-banding technique indicated the presence of heterochromatic blocks in the centromeric regions of almost all chromosomes in both species. Through this study there was evidence of heterogeneity in the karyotypes, which suggests that chromosomal rearrangements such as inversions and/or translocations occurred during the chromosomal evolution in two species of this genus.Análises citogenéticas de Potamotrygon aff. motoro e P. falkneri identificaram a ocorrência de um sistema múltiplo de cromossomos sexuais do tipo X1X1X2X2/X1X2Y, em ambas as espécies, com 2n = 66 cromossomos em fêmeas e 2n = 65 cromossomos nos machos. As regiões organizadoras de nucléolos (RONs identificadas pela reação Ag-RON, evidenciaram marcações múltiplas em ambas as espécies (com variações de 5 a 7 RONs. A técnica de bandamento C, revelou a presença de blocos heterocromáticos localizados nas regiões centromérica em quase todos os cromossomos nas duas espécies em estudo. Através do presente estudo foi evidenciada uma heterogeneidade nos cariótipos, permitindo sugerir que rearranjos cromossômicos, como inversões e/ou translocações, ocorreram durante a evolução cromossômica nas duas espécies desse gênero.

  20. Preparation of nano-Cr2-xAlxO3 (x = 0-1) solid solution powders by using citrate-dispersant method

    A series of nano-Cr2-xAlxO3 (x = 0-1) solid solution powders were prepared by sol-gel-chelating processing with citrate-dispersant method. The crystalline structure and size of the Cr2-xAlxO3 powders were determined by X-ray diffraction and transmission electron microscopy. It was demonstrated that the crystalline size of the Cr2-xAlxO3 powders decreases from 33 nm to 13 nm with an increase in the amount of Al2O3 substitution. The aluminum in the lattice of the Cr2-xAlxO3 can effectively prevent the crystalline growth of the Cr2-xAlxO3 powders during calcining at higher temperature.

  1. Fabrication and photocatalytic property of Pt-intercalated layered perovskite niobates H1-xLaNb2-xMoxO7 (x = 0-0.15)

    H1-xLaNb2-xMoxO7 was prepared by solid-state reaction followed by an ion-exchange reaction. Pt was incorporated in the interlayer of H1-xLaNb2-xMoxO7 by the stepwise intercalation reaction. The H1-xLaNb2-xMoxO7 showed hydrogen production activity and the activities were greatly enhanced by Pt co-incorporating. The x value in H1-xLaNb2-xMoxO7 had an important effect on the photocatalytic activity of the catalyst. When the x = 0.05, the H1-xLaNb2-xMoxO7/Pt showed a photocatalytic activity of 80 cm3 h-1 g-1 hydrogen evolution rate in 10 vol.% methanol solution under irradiation from a 100 W mercury lamp at 333 K.

  2. Expression of the ATP-gated P2X7 Receptor on M Cells and Its Modulating Role in the Mucosal Immune Environment.

    Kim, Sae-Hae; Lee, Ha-Yan; Jang, Yong-Suk

    2015-02-01

    Interactions between microbes and epithelial cells in the gastrointestinal tract are closely associated with regulation of intestinal mucosal immune responses. Recent studies have highlighted the modulation of mucosal immunity by microbe-derived molecules such as ATP and short-chain fatty acids. In this study, we undertook to characterize the expression of the ATP-gated P2X7 receptor (P2X7R) on M cells and its role in gastrointestinal mucosal immune regulation because it was poorly characterized in Peyer's patches, although purinergic signaling via P2X7R and luminal ATP have been considered to play an important role in the gastrointestinal tract. Here, we present the first report on the expression of P2X7R on M cells and characterize the role of P2X7R in immune enhancement by ATP or LL-37. PMID:25713508

  3. Substituted 5,6-(Dihydropyrido[3,4-d]pyrimidin-7(8H)-yl)-methanones as P2X7 Antagonists.

    Ziff, Jeannie; Rudolph, Dale A; Stenne, Brice; Koudriakova, Tatiana; Lord, Brian; Bonaventure, Pascal; Lovenberg, Timothy W; Carruthers, Nicholas I; Bhattacharya, Anindya; Letavic, Michael A; Shireman, Brock T

    2016-04-20

    We describe the synthesis of a novel class of brain penetrating P2X7 antagonists with high potency at both the rat and human P2X7 receptors. Disclosed herein are druglike molecules with demonstrated target engagement of the rat P2X7 receptors after an oral dose. Specifically, compound 20 occupied the P2X7 receptors >80% over the 6 h time course as measured by an ex vivo radioligand binding experiment. In a dose-response assay, this molecule has a plasma EC50 of 8 ng/mL. Overall, 20 has suitable druglike properties and pharmacokinetics in rat and dog. This molecule and others disclosed herein will serve as additional tools to elucidate the role of the P2X7 receptor in neuropsychiatric disorders. PMID:26754558

  4. P2X2 Receptor Terminal Field Demarcates a "Transition Zone" for Gustatory and Mechanosensory Processing in the Mouse Nucleus Tractus Solitarius.

    Breza, Joseph M; Travers, Susan P

    2016-07-01

    Peripheral gustatory neurons express P2X2 purinergic receptors and terminate in the rostral portion of the nucleus tractus solitarius (rNTS), but a relationship between the P2X2 terminal field and taste evoked activity has not been established. Additionally, a portion of somatosensory neurons from the trigeminal nerve, which are devoid of P2X2 expression, also terminate in the lateral rNTS. We hypothesized that P2X2 receptor expression on afferent nerve endings could be used as an anatomical tool for segregating gustatory from mechanosensory responsive regions in the mouse rNTS. C57BL/6 mice were used to record extracellular activity from neurons within the rNTS and the laterally adjacent reticular formation and trigeminal nucleus. Histological reconstruction of electrolytic lesions indicated that gustatory activity coincided with electrode tracks that traversed through P2X2 terminal fields. Gustatory recordings made more rostral in the rNTS had receptive fields located in the anterior oral cavity (AO), whereas gustatory recordings made more caudal in the rNTS had receptive fields located in the posterior oral cavity (PO). Mechanosensory neurons with AO receptive fields were recorded near the lateral border of the P2X2 terminal field and became numerous on electrode tracks made lateral to the P2X2 terminal field. In contrast, mechanosensory responses with PO receptive fields were recorded within the P2X2 terminal field along with gustatory activity and transitioned to mechanosensory only outside the P2X2 terminal field. Collectively, our results indicate that the lateral border of the P2X2 terminal field, demarcates a faithful "transition zone," where AO responses transition from gustatory to mechanosensory. PMID:27131102

  5. Thermography of electronic devices

    Panfilova S. P.

    2007-12-01

    Full Text Available The possibility of application of thermography to diagnose the electronic devices is analyzed in the article. Typical faults of electronic devices which can be found by means of thermography are given. Advantages of noncontact thermal inspection in comparison with the contact one are described. Some features of thermography of electronic devices are considered. Thermography apparatus is viewed and some pieces of advice about choosing it for electronic devices diagnosis are given. An example of the thermographic method for checking the electronic devices is provided. The main features of software used in thermography and its significance are described.

  6. Optical plasma microelectronic devices

    Forati, Ebrahim; Dill, Thyler; Sievenpiper, Dan

    2015-01-01

    The semiconductor channel in conventional microelectronic devices was successfully replaced with an optically triggered gas plasma channel. The combination of DC and laser-induced gas ionizations controls the conductivity of the channel, enabling us to realize different electronic devices such as transistors, switches, modulators, etc. A special micro-scale metasurface was used to enhance the laser-gas interaction, as well as combining it with DC ionization properly. Optical plasma devices benefit form the advantages of plasma/vacuum electronic devices while preserving most of the integrablity of semiconductor based devices.

  7. Diversity of off-shell twisted (4,4) multiplets in SU(2)xSU(2) harmonic superspace

    We elaborate on four different types of twisted N=(4,4) supermultiplets in the SU(2)xSU(2), 2D harmonic superspace. In the conventional N=(4,4), 2D superspace they are described by the superfields qia, qIa, qIA, subjected to proper differential constraints, (i, I, a, A) being the doublet indices of four groups SU(2) which form the full R-symmetry group SO(4)LxSO(4)R of N=(4,4) supersymmetry. We construct the torsionful off-shell sigma-model actions for each type of these multiplets, as well as the corresponding invariant mass terms, in an analytic subspace of the SU(2)xSU(2) harmonic superspace. As an instructive example, N=(4,4) superconformal extension of the SU(2)xU(1) WZNW sigma-model action and its massive deformation are presented for the multiplet qiA. We prove that N=(4,4) supersymmetry requires the general sigma-model action of pair of different multiplets to split into a sum of sigma-model actions of each multiplet. This phenomenon also persists if a larger number of non-equivalent multiplets are simultaneously included. We show that different multiplets may interact with each other only through mixed mass terms which can be set up for multiplets belonging to 'self-dual' pairs (qia, qIA) and (qIa, qiA). The multiplets from different pairs cannot interact at all. For a 'self-dual' pair of the twisted multiplets we give the most general form of the on-shell scalar potential

  8. Dispersion of the second harmonic generation from CdGa2X4 (X = S, Se) defect chalcopyrite: DFT calculations

    Highlights: • Nonlinear optical properties of CdGa2X4 (X = S, Se) were investigated. • The compounds have large uniaxial anisotropy and large negative birefringence. • The second order susceptibility and the first hyperpolarizability were calculated. • CdGa2Se4 posses huge second harmonic generation. - Abstract: All electron full potential linear augmented plane wave method was used for calculating the nonlinear optical susceptibilities of CdGa2X4 (X = S, Se) within the framework of density functional theory. The exchange correlation potential was solved by recently developed modified Becke and Johnson (mBJ) approximation. The crystal structure of CdGa2S4 and CdGa2Se4 reveals a large uniaxial dielectric anisotropy ensuing the birefringence of −0.036 and −0.066 which make it suitable for second harmonic generation. The second order susceptibility |χijk(2)(ω)| and microscopic first hyperpolarizability βijk(ω) were calculated. The calculated |χ123(2)(ω)| and |χ312(2)(ω)| static values for the dominant components found to be 18.36 pm/V and 22.23 pm/V for CdGa2S4 and CdGa2Se4. Both values shifted to be 60.12 pm/V and 108.86 pm/V at λ = 1064 nm. The calculated values of β123(ω) is 6.47 × 10−30 esu at static limit and 12.42 × 10−30 esu at λ = 1064 nm for CdGa2S4, whereas it is 8.82 × 10−30 esu at static limit and 20.51 × 10−30 esu at λ = 1064 nm for CdGa2Se4. The evaluation of second order susceptibilities and first hyperpolarizabilties suggest that CdGa2X4 possess huge second harmonic generation

  9. Exhaustive swimming differentially inhibits P2X1 receptor- and α1-adrenoceptor-mediated vasoconstriction in isolated rat arteries

    Lu LI; Tao WU; Cong WEI; Jian-ke HAN; Zhen-hua JIA; Yi-ling WU; Lei-ming REN

    2012-01-01

    Aim:To investigate the effects of exhaustive swimming exercise on P2X1 receptor- and α1-adrenoceptor-mediated vasoconstriction of different types of arteries in rats.Methods:Male Wistar rats were divided into 2 groups:the sedentary control group (SCG) and the exhaustive swimming exercise group (ESEG).The rats in the ESEG were subjected to a swim to exhaustion once a day for 2 weeks.Internal carotid,caudal,pulmonary,mesenteric arteries and aorta were dissected out.Isometric vasoconstrictive responses of the arteries to α,β-methylene ATP (α,β-MeATP) or noradrenaline (NA) were recorded using a polygraph.Results:The exhaustive swimming exercise did not produce significant change in the EC5o values of α,β-MeATP or NA in vasoconstrictive response of most of the arteries studied.The exhaustive swimming exercise inhibited the vasoconstrictive responses to P2X1 receptor activation in the internal carotid artery,whereas it reduced the maximal vasoconstrictive responses to α1-adrenoceptor stimulation in the caudal,pulmonary,mesenteric arteries and aorta.The rank order of the reduction of the maximal vasoconstriction was as follows:mesenteric,pulmonary,caudal,aorta.Conclusion:Exhaustive swimming exercise differentially affects the P2X1 receptor- and α1-adrenoceptor-regulated vasoconstriction in internal carotid artery and peripheral arteries.The ability to preserve purinergic vasoconstriction in the peripheral arteries would be useful to help in maintenance of the basal vascular tone during exhaustive swimming exercise.

  10. Carbonitride based phosphors and light emitting devices using the same

    Li, Yuanqiang; Tian, Yongchi; Romanelli, Michael Dennis

    2013-08-20

    Disclosed herein is a novel group of carbidonitride phosphors and light emitting devices which utilize these phosphors. In certain embodiments, the present invention is directed to a novel family of carbidonitride-based phosphors expressed as follows: Ca.sub.1-xAl.sub.x-xySi.sub.1-x+xyN.sub.2-x-xyC.sub.xy:A; (1) Ca.sub.1-x-zNa.sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xyC.sub.xy:- A; (2) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x- -xyC.sub.xy:A; (3) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xy-2w/- 3C.sub.xyO.sub.w-v/2H.sub.v:A; and (4) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xy-2w/- 3-v/3C.sub.xyO.sub.wH.sub.v:A, (4a) wherein 0xy+z, and 0

  11. Radiation emitting devices regulations

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  12. Frequency upconversion luminescence in Yb3+-sensitized Er3+- and Pr3+-codoped PbGeO3:PbF2:xF2 (x = Mg, Ba) glass

    Silva, Alexandre O.; Gouveia-Neto, Artur; Bueno, Luciano A.

    2016-01-01

    The optical properties and energy-transfer upconversion luminescence of Er3+- and Pr3+/Yb3+-codoped PbGeO3-PbF2-xF2 (x=Mg, Ba) glass and glass-ceramic under infrared excitation at 975 nm is investigated. In Er3+/Yb3+-codoped samples, green (525 and 550 nm) and red (662 nm) luminescence corresponding to the H2→I4, S4→I4 e F4→I4, respectively, was readily observed. In the Pr3+/Yb3+-codoped system, emission peaks around 485, 530, 610, and 645, which were ascribed to the P03-HJ3 (J=4,5,6) and P03-FJ3 (J=2,3,4) transitions, respectively, were observed. The population of the praseodymium P03 emitting level was accomplished through a combination of ground-state absorption of Yb ions at F2, energy-transfer Yb3+(F2)-Pr3+(H43), and excited-state absorption of Pr ions provoking the G41-P03 transition. The dependence of the upconversion emission on glass composition, pump power, and doping contents was also examined. Glassy and glass-ceramic samples were compared in order to determine the system with better luminescence efficiency.

  13. Effect of synthesis route on structural, morphological properties of Ce0.8Y0.2-xLaxO2 (x = 0, 0.1, 0.2)

    In the present study, the solid solutions with a chemical composition of Ce0.8Y0.2-xLaxO2 (x = 0, 0.1, 0.2) were synthesized via two routes, by hydrothermal method using NaOH as precipitating agent at 230°C for 15 h and by the sol–gel process using citric acid as chelating agent. Compounds have been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA) techniques for appropriate characterization of the distinct thermal events occurring during synthesis. All the compounds crystallize in cubic fluorite structure. The ceria lattice expands depending on the ionic radii of the dopant cations, as indicated by X-ray diffraction study. The sol–gel oxide Ce0.8Y0.1La0.1O2 exhibits a good thermal stability compared with hydrothermal oxide. The microstructure of oxides synthesized by sol–gel showed porosity which increased with the lanthanum La3+ contents and on the other side the hydrothermal method gives single crystal oxides. (author)

  14. Electrochemical performance of mixed valence Na3V2O2x(PO4)2F3-2x/C as cathode for sodium-ion batteries

    Serras, Paula; Palomares, Verónica; Goñi, Aintzane; Kubiak, Pierre; Rojo, Teófilo

    2013-11-01

    A composite made of a mixed-valence sodium-vanadium fluorophosphate and 6.4% wt. carbon, Na3V2O2x(PO4)2F3-2x/C (0 oxidation state of vanadium in the phase. Morphological and texture analyses showed that carbon forms a network surrounding the particles, leading to a mesoporous composite with a high specific area of 67 m2 g-1. Electrochemical characterization conducted in Swagelok cells by cyclic voltammetry and galvanostatic cycling indicated that sodium extraction/insertion proceeds through a complex mechanism in two voltage pseudo-plateaux at 3.6 and 4.1 V vs. Na/Na+. Rate capability of the material ranges from specific capacities of 100 mAh g-1 at C/20 to 75 mAh g-1 at 5C. Cycling stability at 1C showed coulombic efficiency higher than 99% and capacity retention of 95% after 200 cycles.

  15. Moessbauer and magnetic study of Mn2+- and Cr3+ - substituted spinel magnesioferrites of the composition Mg1-xMnxFe2-2xCr2xO4

    Mn2+ - and Cr3+ - substituted spinel magnesioferrites of the composition Mg1-xMnxFe2-2xCr2xO4 (x=0.0, 0.1, 0.2, 0.3, and 0.5) were investigated with X-ray diffraction (XRD), Moessbauer spectroscopy and magnetization measurements. All samples were found to be single-phased and indexed to the Fd3-barm space group. Moessbauer measurements indicate the presence of clustering of magnetic cations and/or superparamagnetism in the sample with x = 0.5. The cation distribution inferred from the XRD and the Moessbauer data suggests that Mn2+ and Cr3+ ions dominantly occupy the A- and B-sites respectively. The gradual decrease of the hyperfine fields and Curie temperatures with increasing x is attributed to the weakening of the AB super- exchange interaction. The temperature variation of saturation magnetization could not be accounted for in terms of the Neel's simple collinear model of ferrimagnetism but were rather explicable in terms of the Yafet-Kittel model of canted magnetism. Such a complexity is attributable to the presence of the three magnetically active Fe3+, Mn2+ and Cr3+ cations in spinel-related structure. (author)

  16. Cu-63 NQR Measurement of Stripe Order Parameter in La(2-x)Sr(x)CuO(4)

    Hunt, A. W.; Singer, P. M.; Thurber, K. R.; Imai, T.

    1999-01-01

    We demonstrate that one can measure the charge-stripe order parameter in the hole-doped CuO(2) planes of La(1.875)Ba(0.125)CuO(4), La(1.48)Nd(0.4)Sr(0.12)CuO(4) and La(1.68)Eu(0.2)Sr(0.12)CuO(4) utilizing the wipeout effects of Cu-63 NQR. Application of the same approach to La(2-x)Sr(x)CuO(4) reveals the presence of similar stripe order for the entire underdoped superconducting regime 1/16 < x < 1/8.

  17. Ectodomain Movements of an ATP-gated Ion Channel (P2X2 Receptor) Probed by Disulfide Locking*

    Stelmashenko, Olga; Compan, Vincent; Browne, Liam E.; North, R Alan

    2014-01-01

    The ectodomain of the P2X receptor is formed mainly from two- or three-stranded β-sheets provided symmetrically by each of the three subunits. These enclose a central cavity that is closed off furthest from the plasma membrane (the turret) and that joins with the transmembrane helices to form the ion permeation pathway. Comparison of closed and open crystal structures indicates that ATP binds in a pocket positioned between strands provided by different subunits and that this flexes the β-shee...

  18. Synthesis and thermophysical properties of solid solutions CuInSe2xTe2(1-x)

    Large-block crystals of CuInSe2, CuInTe2 ternary compounds and CuInSe2xTe2(1-x) solid solutions were prepared by two-temperature method. It is determined that dependence between thermal expansion coefficient and composition of solid solution is linear and dependence of thermal conductivity has minimum. It is demonstrated that Debye temperature decreases while root-mean-square dynamic displacements of atoms increase in crystal lattice with increasing content of tellurium atoms in solid solutions

  19. Nanofabrication of PTCDA molecular chains on rutile TiO2(011)-(2 x 1) surfaces

    The adsorption of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) on a rutile TiO2(011)-(2 x 1) surface is studied using ultra-high vacuum scanning tunneling microscopy. The self-assembly process is dominated by the fine interplay between the lateral intermolecular interactions and the binding to the substrate. By means of temperature-induced change in the adsorption configuration and the activation of diffusion, the molecules are assembled into one-dimensional chains oriented along the (011 bar) crystallographic direction.

  20. Investigation of combined free and forced convection in a 2 x 6 rod bundle during controlled flow transients

    Bates, J.M.; Khan, E.U.

    1980-10-01

    An experimental study was performed to obtain local fluid velocity and temperature measurements in the mixed (combined free and forced) convection regime for specific flow coastdown transients. A brief investigation of steady-state flows for the purely free-convection regime was also completed. The study was performed using an electrically heated 2 x 6 rod bundle contained in a flow housing. In addition a transient data base was obtained for evaluating the COBRA-WC thermal-hydraulic computer program (a modified version of the COBRA-IV code).

  1. Electronic structure of ZrS{sub x}Se{sub 2-x} by density functional theory

    Ghafari, Ailakbar; Moustafa, Mohamed; Janowitz, Christoph; Dwelk, Helmut; Manzke, Recardo [Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstr. 15, D-12489 Berlin (Germany); Bouchani, Arash [Physics Department, Islamic Azad University, Kermanshah Branch (Iran, Islamic Republic of)

    2011-07-01

    The electronic properties of the ZrS{sub x}Se{sub 2-x} (x varies between zero and two) semiconductors have been calculated by density functional theory (using the Wien2K code) employing the full potential Hamiltonian within the Generalized Gradient Approximation (GGA) method. The results obtained for the end members of the series, i.e. ZrS{sub 2} and ZrSe{sub 2} reveal that the valence band maximum and conduction band minimum are located at {gamma} and between {gamma} and K respectively which is in agreement with our photoemission experimental data. Trends in the electronic structure for the whole substitution series are discussed.

  2. Local Atomic Structure of Martensitic Ni$_{2+x}$Mn$_{1-x}$Ga: An EXAFS Study

    Bhobe, P. A.; Priolkar, K. R.; Sarode, P R

    2006-01-01

    The local atomic structure of Ni$_{2+x}$Mn$_{1-x}$Ga with 0 $\\le$ $x$ $\\le$ 0.16 alloys was explored using Mn and Ga K-edge Extended X-ray Absorption Fine Structure (EXAFS) measurement. Inorder to study the atomic re-arrangements that occur upon martensitic transformation, room temperature and low temperature EXAFS were recorded. The changes occurring in the L2$_1$ unit cell and the bond lengths obtained from the analysis enables us to determine the modulation amplitudes over which the consti...

  3. Multiple Bosonic Mode Coupling in Electron Self-Energy of (La_2-xSr_x)CuO_4

    Zhou, X.J.

    2010-06-02

    High resolution angle-resolved photoemission spectroscopy data with significantly improved statistics reveal tne structure in the electron self-energy of the underdoped (La{sub 2-x}Sr{sub x}) CuO{sub 4} (x=0.03, 0.036 and 0.07) samples in the normal state. Four fine structure have been identified near 27, 45, 61 and 75 meV. These features show good correspondence to the structure in the phonon density of states as measured from neutron scattering.

  4. Pentosan polysulfate preserves renal microvascular P2X1 receptor reactivity and autoregulatory behavior in DOCA-salt hypertensive rats.

    Guan, Zhengrong; Singletary, Sean T; Cha, Haword; Van Beusecum, Justin P; Cook, Anthony K; Pollock, Jennifer S; Pollock, David M; Inscho, Edward W

    2016-03-15

    Inflammation contributes to ANG II-associated impairment of renal autoregulation and microvascular P2X1 receptor signaling, but its role in renal autoregulation in mineralocorticoid-induced hypertension is unknown. Autoregulatory behavior was assessed using the blood-perfused juxtamedullary nephron preparation. Hypertension was induced in uninephrectomized control rats (UNx) by subcutaneous implantation of a DOCA pellet plus administration of 1% NaCl in the drinking water (DOCA-salt) for 3 wk. DOCA-salt rats developed hypertension that was unaltered by anti-inflammatory treatment with pentosan polysulfate (DOCA-salt+PPS) but was suppressed with "triple therapy" (hydrochlorothiazide, hydralazine, and reserpine; DOCA-salt+TTx). Baseline arteriolar diameters were similar across all groups. UNx rats exhibited pressure-dependent vasoconstriction with diameters declining to 69 ± 2% of control at 170 mmHg, indicating intact autoregulation. DOCA-salt treatment significantly blunted this pressure-mediated vasoconstriction. Diameters remained between 91 ± 4 and 98 ± 3% of control over 65-170 mmHg, indicating impaired autoregulation. In contrast, pressure-mediated vasoconstriction was preserved in DOCA-salt+PPS and DOCA-salt+TTx rats, reaching 77 ± 7 and 75 ± 3% of control at 170 mmHg, respectively. ATP is required for autoregulation via P2X1 receptor activation. ATP- and β,γ-methylene ATP (P2X1 receptor agonist)-mediated vasoconstriction were markedly attenuated in DOCA-salt rats compared with UNx (P < 0.05), but significantly improved by PPS or TTx (P < 0.05 vs. DOCA-salt) treatment. Arteriolar responses to adenosine and UTP (P2Y2 receptor agonist) were unaffected by DOCA-salt treatment. PPS and TTx significantly reduced MCP-1 and protein excretion in DOCA-salt rats. These results support the hypothesis that hypertension triggers inflammatory cascades but anti-inflammatory treatment preserves renal autoregulation in DOCA-salt rats, most likely by normalizing renal

  5. Primary processes of laser-induced selective dimer-layer removal on Si(001)-(2x1)

    Excitation with nanosecond-laser pulses at fluences well below the melt threshold removes Si dimers on the Si(001)-(2x1) surface and induces atomic-Si desorption through an electronic mechanism. The rate of this photoinduced reaction depends superlinearly on the excitation intensity, and is enhanced resonantly at the photon energy where the optical transition injects holes into the dimer backbond surface-band state. The results reveal the crucial role of surface holes and their nonlinear localization in the bond rupture of Si dimers on this surface

  6. Preparation and characterization of Cu2-xZn1+ySnS4 for thin films solar cells

    D'Angelo Bandres, Renato

    2015-01-01

    CZTS non-stoichiometric thin films [Cu2-xZn1+xSnS4)] for solar cells applications have been successfully deposited on glass substrates using two different types of synthesis and two effective non vacuum deposition methods: as is dip-coating into a sol or drop-wise ink spin-coating. The first synthesis (dip coating) is a two-solution sol-gel, where the first solution is composed of metal salts dissolved in methanol and the second thiourea dissolved in ethylene glycol. As a tin source, tin chlo...

  7. Deformations of constant mean curvature 1/2 surfaces in H2xR with vertical ends at infinity

    Cartier, Sébastien

    2012-01-01

    We study constant mean curvature 1/2 surfaces in H2xR that admit a compactification of the mean curvature operator. We show that a particular family of complete entire graphs over H2 admits a structure of infinite dimensional manifold and deduce a result on the possible behaviors at infinity. Deforming non degenerate constant mean curvature 1/2 annuli, we provide a large class of (non rotational) examples and construct annuli (possibly embedded) without axis, namely with two vertical, asymptotically rotational, non aligned ends.

  8. Macroscopic quantum tunneling and phase diffusion in a La2-xSrxCuO4 intrinsic Josephson junction stack

    Kubo, Yuimaru; Sboychakov, A. O.; Nori, Franco; Takahide, Y.; Ueda, S.; Tanaka, I.; Islam, A. T. M. N.; Takano, Y.

    2012-10-01

    We performed measurements of switching current distribution in a submicrometer La2-xSrxCuO4 (LSCO) intrinsic Josephson junction (IJJ) stack in a wide temperature range. The escape rate saturates below approximately 2 K, indicating that the escape event is dominated by a macroscopic quantum tunneling (MQT) process with a crossover temperature T*≈2K. We applied the theory of MQT for IJJ stacks, taking into account dissipation and the phase retrapping effect in the LSCO IJJ stack. The theory is in good agreement with the experiment both in the MQT and in the thermal activation regimes.

  9. Electrical transport properties of La2-xSrxCuO4-y experimental evidence of a Fermi liquid picture

    The electrical resistivity of the ceramic superconductor La2-xSrxCuO4-y as a function of Sr and O contents from 4 K to 900 K has been measured. It is shown that the dependence of the resistivity with the carrier density as well as the relation between localization and superconductivity can be qualitatively and quantitatively understood within a Fermi liquid picture. The different role played by the Sr and O contents in the conduction process pointing towards a possible breakdown of charge balancing arguments is indicated. (Author)

  10. Terbium (lithium zinc) distannide, TbLi1–x Zn x Sn2 (x = 0.2)

    Andrij Stetskiv; Ivan Tarasiuk; Beata Rozdzynska-Kielbik; Igor Oshchapovsky; Volodymyr Pavlyuk

    2012-01-01

    The new terbium (lithium zinc) distannide, TbLi1–xZnxSn2 (x = 0.2) crystallizes in the orthorhombic CeNiSi2 structure type with space group Cmcm and Pearson symbol oS16. Of the four independent 4c atom positions (m2m site symmetry), three are fully occupied by individual atoms (two by Sn and one by Tb atoms) and the fourth is occupied by Li and Zn atoms with a statistical distribution. The Tb coordination polyhedron is a 21-vertex pseudo-Frank–Kasper polyhedron. One Sn ato...

  11. Static vacancies in antiferromagnetic La2CuO4 and superconducting La2-xSrxCuO4

    The effect of static vacancies that eliminate local Cu2+ spins has been studied in both the antiferromagnetic and superconducting state of La2-xSrxCuO4. Static vacancies induce uncompensated magnetic moments and suppress the three-dimensional Neel state much less effectively than mobile vacancies. Analysis of magnetic susceptibility provides accurately the Cu2+ magnetic moment (∼1μB), which is insensitive to Sr doping, indicating that the d state of Cu2+ remains highly localized upon the introduction of mobile vacancy

  12. Structural transformation in nano-structured CuAlxCrxFe2-2xO4 system

    Polycrystalline spinel ferrite system CuAlxCrxFe2-2xO4 (x=0.2, 0.6) was synthesized by solid-state reaction route. Nanoparticles of the samples have been prepared by using high energy ball milling technique with different milling durations and characterized by X-ray Diffraction and Tunneling Electron Microscope. It is observed that the structural transformation occurred from Cubic to tetragonal and particle size varied between 29 nm -14 nm with increase of milling time

  13. Photoemission spectroscopy study of the hole-doped Haldane chain Y2-xSrxBaNiO5

    In this paper, we present photoemission experiments on the hole-doped Haldane chain compound Y2-xSrxBaNiO5. By using the photon energy dependence of the photoemission cross section, we identified the symmetry of the first ionisation states (d type). Hole doping in this system leads to a significant increase in the spectral weight at the top of the valence band without any change in the vicinity of the Fermi energy. This behavior, never observed in other charge transfer oxides, could result from the Ni3d-O2p hybridization enhancement due to the shortening of the relevant Ni-O distance with doping

  14. Strain enhanced superconductivity of Mo$X_2$ ($X$=S or Se) bilayers with Na intercalation

    Zhang, Jun-Jie; Gao, Bin; Dong, Shuai

    2016-01-01

    Mo$X_2$ ($X$=S or Se) is a semiconductor family with two-dimensional structure. And a recent calculation predicted the superconductivity in electron doped MoS$_2$ monolayer. In this work, the electronic structure and lattice dynamics of Mo$X_2$ bilayers with monolayer Na intercalated, have been calculated. According to the electron-phonon interaction, it is predicted that these bilayers can be transformed from indirect-gap semiconductors to a superconductors by Na intercalation. More interest...

  15. Magnetic field effect on the pairing competition in quasi-one-dimensional organic superconductors (TMTSF)2X

    We microscopically study the effect of the magnetic field (Zeeman splitting) on the superconducting state in a model for quasi-one-dimensional organic conductors (TMTSF)2X. Using random phase approximation, we investigate the competition between spin singlet, spin triplet pairings and the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. We obtain a phase diagram in the T (temperature)-hz (field) space. We show that consecutive transitions from singlet pairing to FFLO and further to Sz=1 triplet pairing can take place upon increasing the magnetic field when 2kF charge fluctuations coexist with 2kF spin fluctuations.

  16. Pairing state competition in quasi-one-dimensional organic superconductors (TMTSF)2X in a magnetic field

    We microscopically study the effect of the magnetic field on the pairing state competition between spin singlet, spin triplet, and the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in a model for quasi-one-dimensional organic conductors (TMTSF)2X. We obtain phase diagram in the temperature-magnetic field space. We show that consecutive pairing transition from singlet pairing to FFLO state and further to Sz=1 triplet pairing can take place upon increasing the magnetic field when 2kF charge fluctuations coexist with 2kF spin fluctuations.

  17. Atomistic Calculations of the Effect of Minor Actinides on Thermodynamic and Kinetic Properties of UO{sub 2{+-}x}

    Deo, Chaitanya; Adnersson, Davis; Battaile, Corbett; uberuaga, Blas

    2012-10-30

    The team will examine how the incorporation of actinide species important for mixed oxide (MOX) and other advanced fuel designs impacts thermodynamic quantities of the host UO{sub 2} nuclear fuel and how Pu, Np, Cm and Am influence oxygen mobility. In many cases, the experimental data is either insufficient or missing. For example, in the case of pure NpO2, there is essentially no experimental data on the hyperstoichiometric form it is not even known if hyperstoichiometry NpO{sub 2{+-}x} is stable. The team will employ atomistic modeling tools to calculate these quantities

  18. Synthesis of rod and lath-shaped CuSe and tremella-shaped Cu{sub 2-x}Se nanostructures at room temperature, and their optical properties

    Hu Pengfei, E-mail: hpf-hqx@shu.edu.cn [Shanghai University, Laboratory for Microstructures (China); Cao Yali [Xinjiang University, Institute of Applied Chemistry (China)

    2012-02-15

    The research for tunable synthesis and characterization techniques is important for the investigation of nanomaterials. Herein we developed old precipitation reaction for the morphology- and phase-tunable synthesis of copper selenides nanostructures at room temperature, avoiding tedious preparation of selenium precursors, such as selenite or selenosulfate. The molar ratio of Cu{sup 2+} and Se sources served the function of a switch for selectively synthesis of stoichiometric CuSe and non-stoichiometric Cu{sub 2-x}Se. Nanorod and lath-like CuSe formed with excess of selenium source, while tremella-shaped Cu{sub 2-x}Se responded to the 1:1 of Cu{sup 2+}/Se or excess of copper source. The structures of nanocrystals, especially the lifelike surface, were characterized in detail by electron microscopy techniques, such as STEM. Novel nanostructures put up the excellent absorption properties in the visible light region, respectively, and could bear potential applications in solar cell devices in the future. This strategy offered a convenient, mild and energy-efficient route for the preparation of other mental chalcogenides nanocrystals with different morphologies or tunable phases.

  19. Persistent deNOx Ability of CaAl2O4:(Eu, Nd/TiO2-xNy Luminescent Photocatalyst

    Li Huihui

    2011-01-01

    Full Text Available Abstract CaAl2O4:(Eu, Nd/TiO2-xNy composite luminescent photocatalyst was successfully synthesized by a simple planetary ball milling process. Improvement of photocatalytic deNOx ability of TiO2-xNy, together with the persistent photocatalytic activity for the decomposition of NO after turning off the light were realized, by coupling TiO2-xNy with long afterglow phosphor, CaAl2O4:(Eu, Nd. The novel persistent photocatalytic behavior was related to the overlap between the absorption wavelength of TiO2-xNy and the emission wavelength of the CaAl2O4:(Eu, Nd. It was found that CaAl2O4:(Eu, Nd/TiO2-xNy composites provided the luminescence to persist photocatalytic reaction for more than 3 h after turning off the light. Graphical Abstract CaAl2O4:(Eu, Nd/TiO2-xNy composite luminescent photocatalyst with persistent deNOx activity after turning off the light was successfully synthesized by a simple planetary ball milling process. The novel persistent photocatalytic behavior was related to the overlap between the absorption wavelength of TiO2-xNy and the emission wavelength of the CaAl2O4:(Eu, Nd. Additional file 1 Click here for file

  20. NMR of electron-doped high-temperature superconductor Pr2-xCexCuO4

    This work deals with the characterization of a relatively little researched subgroup of high-temperature superconducting cuprates (HTSCs) the electron-doped HTSCs, by means of nuclear magnetic resonance (NMR). The investigations include 63Cu and 17O NMR of aligned powder and single crystal samples of Pr2-xCexCuO4 (x = 0, 0.05, 0.10, 0.15, 0.20) as well as Nd2-xCexCuO4 (x = 0, 0.13) in external magnetic fields from 2.35 to 17.6 T and temperatures 8-400 K. Through a variety of experiments, the first unique spectral analysis for both nuclides is performed. It is shown that the indirect, homonuclear coupling, as found at the Hahn echo decay of planar 63,65Cu in hole-doped HTSCs and also in the undoped Pr2CuO4, is largely suppressed by electron doping. An analysis of the quadrupole splitting shows that not only the local distribution of doped electrons and holes in the CuO2 layers can be measured quantitatively, but that there are differences in the 63Cu and 17O splitting of various undoped cuprates due to a variable charge distribution. Thus, a quantitative measurement of the local charge distribution in the CuO2 layer of HTSCs is possible, which results a new more differentiated picture of the different materials.