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Sample records for lewis bumpy-torus plasma

  1. Preliminary scaling laws for plasma current, ion kinetic temperature, and plasma number density in the NASA Lewis bumpy torus plasma

    Science.gov (United States)

    Roth, J. R.

    1976-01-01

    Parametric variation of independent variables which may affect the characteristics of bumpy torus plasma have identified those which have a significant effect on the plasma current, ion kinetic temperature, and plasma number density, and those which do not. Empirical power law correlations of the plasma current, and the ion kinetic temperature and number density were obtained as functions of potential applied to the midplane electrode rings, the background neutral gas pressure, and the magnetic field strength. Additional parameters studied included the type of gas, the polarity of the midplane electrode rings, the mode of plasma operation, and the method of measuring the plasma number density. No significant departures from the scaling laws appear to occur at the highest ion kinetic temperatures or number densities obtained to date.

  2. Development of concentric equipotential surfaces in bumpy torus plasma

    International Nuclear Information System (INIS)

    Takasugi, Keiichi; Iguchi, Harukazu; Fujiwara, Masami; Ikegami, Hideo

    1983-01-01

    Radial profiles of the plasma space potential are measured in Nagoya Bumpy Torus (NBT-1) by the use of a heavy ion beam probe. Asymmetric potential profiles owing to toroidal drift are observed in high pressure operation (C-mode). As the pressure is decreased, toroidal plasma is effectively heated (T-mode), poloidal precessional frequency overcomes the electron collision frequency and the equipotential surfaces becomes concentric inside the hot electron ring. (author)

  3. The Bumpy Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Cobble, James Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-09

    This document summarizes the Bumpy Torus Experiment as a viable fusion reactor concept. Conclusions reached include the following: In 30 years, order-of-magnitude technological advances have occurred in multiple areas of plasma heating and confinement. The ORNL bumpy torus of the 1970s was technology limited. Now that ITER is technology limited, an alternate concept is needed. A device built on such a concept should be current free, CW, modular, have a gentle shutdown, and demonstrable stability. The bumpy torus meets or has the potential to meet all of these criteria. Earlier, stability was not possible due to power limits; it has not been fully tested. It is time to revisit the bumpy-torus concept with a modest new machine.

  4. The Bumpy Torus Experiment

    International Nuclear Information System (INIS)

    Cobble, James Allen

    2016-01-01

    This document summarizes the Bumpy Torus Experiment as a viable fusion reactor concept. Conclusions reached include the following: In 30 years, order-of-magnitude technological advances have occurred in multiple areas of plasma heating and confinement. The ORNL bumpy torus of the 1970s was technology limited. Now that ITER is technology limited, an alternate concept is needed. A device built on such a concept should be current free, CW, modular, have a gentle shutdown, and demonstrable stability. The bumpy torus meets or has the potential to meet all of these criteria. Earlier, stability was not possible due to power limits; it has not been fully tested. It is time to revisit the bumpy-torus concept with a modest new machine.

  5. Equilibrium and stability of high-beta plasma in Modified Bumpy Torus (MBT)

    International Nuclear Information System (INIS)

    Todoroki, J.; Shiina, S.; Saito, K.; Osanai, Y.; Nogi, Y.; Gesso, H.; Yagi, I.; Yokoyama, K.; Yoshimura, H.; Nihon Univ., Tokyo. Atomic Energy Research Inst.)

    1977-01-01

    The equilibrium and stability properties of the plasma in Modified Bumpy Torus, which is an asymmetric system with closed magnetic lines of force, is reported. For small beta value, the growth rate of m=1 mode instability in MBT can be smaller than that of Scyllac configuration. The results of 1/4 toroidal sector experiment are reported. (author)

  6. A 12 coil superconducting bumpy torus magnet facility for plasma research

    Science.gov (United States)

    Roth, J. R.; Holmes, A. D.; Keller, T. A.; Krawczonek, W. M.

    1972-01-01

    A summary is presented of the performance of the two-coil superconducting pilot rig which preceded the NASA Lewis bumpy torus. This pilot rig was operated for 550 experimental runs over a period of 7 years. The NASA Lewis bumpy torus facility consists of 12 superconducting coils, each with a 19 cm in diameter and capable of producing magnetic field strengths of 3.0 teslas on their axes. The magnets are equally spaced around a major circumference 1.52 m in diameter, and are mounted with the major axis of the torus vertical in a single vacuum tank 2.59 m in diameter. The design value of maximum magnetic field on the magnetic axis (3.0 teslas) was reached and exceeded. A maximum magnetic field of 3.23 teslas was held for a period of 60 minutes, and the coils did not go to normal. When the coils were charged to a maximum magnetic field of 3.35 teslas, the coil system was driven normal without damage to the facility.

  7. Influence of globalmagnetic perturbations on plasma behavior in Elmo Bumpy Torus

    International Nuclear Information System (INIS)

    Quon, B.H.; Dandl, R.A.; Colestock, P.L.; Bieniosek, F.M.; Ikegami, H.

    1979-02-01

    The sensitivity of plasma confinement to magnetic field error effects has been tested experimentally using externally introduced global field errors on the ELMO Bumpy Torus (EBT). Below a critical error field (deltaB/sub r//B)/sub cr/ of approx. = to 0.6-1 x 10 -3 the plasma was observed to be essentially free from convective cells, toroidal currents, and instabilities. This observed critical value is comparable to a neoclassical critical field error (deltaB/sub r//B)/sub cr/ approx. = rho/R, the ratio of the ion Larmor radius to the major radius of the torus

  8. Characteristics and performance of a superconducting bumpy-torus magnet facility for plasma research

    Science.gov (United States)

    Roth, J. R.; Holmes, A. D.; Keller, T. A.; Krawczonek, W. M.

    1973-01-01

    The NASA Lewis bumpy-torus facility consists of 12 superconducting coils, each 19 cm i.d. and capable of 3.0 T on its axis. The coils are equally spaced around a toroidal array with a major diameter of 1.52 m; they are mounted with the major axis of the torus vertical in a single vacuum tank 2.6 m in diameter. Tests of the facility mapped out its magnetic, cryogenic, vacuum, mechanical, and electrical performance. The design value of the maximum magnetic field on the magnetic axis, 3.0 T, was reached and exceeded. A maximum magnetic field of 3.23 T was held for a period of 60 minutes. When the coils were charged to a maximum magnetic field of 3.35 T, the coil system went normal without apparent damage or degradation of performance.

  9. Study of plasma confinement in ELMO Bumpy Torus with a heavy-ion beam probe

    Energy Technology Data Exchange (ETDEWEB)

    Bieniosek, F. M.

    1981-01-01

    Plasma confinement in ELMO Bumpy Torus (EBT) is generally strongly dependent on an ambipolar electric field. Spatially resolved measurements of the resulting electric space potential phi/sub sp/ have been made in a single plasma cross section by the heavy-ion beam probe. This diagnostic injects a 4-60-keV beam of (usually) Cs/sup +/ ions into the plasma. Measurement of the energy of Cs/sup 2 +/ secondary ions leaving the plasma gives a continuous monitor of the local space potential. In addition, the total detected Cs/sup 2 +/ ion current is proportional to the product of the local electron density and the ionization rate, which, in turn, is a function of the electron temperature. This signal, nf(T/sub e/), is sensitive to all three electron distributions found in EBT - those of the cold surface plasma, the warm core plasma, and the hot electron ring.

  10. Study of plasma confinement in ELMO Bumpy Torus with a heavy-ion beam probe

    International Nuclear Information System (INIS)

    Bieniosek, F.M.

    1981-01-01

    Plasma confinement in ELMO Bumpy Torus (EBT) is generally strongly dependent on an ambipolar electric field. Spatially resolved measurements of the resulting electric space potential phi/sub sp/ have been made in a single plasma cross section by the heavy-ion beam probe. This diagnostic injects a 4-60-keV beam of (usually) Cs + ions into the plasma. Measurement of the energy of Cs 2+ secondary ions leaving the plasma gives a continuous monitor of the local space potential. In addition, the total detected Cs 2+ ion current is proportional to the product of the local electron density and the ionization rate, which, in turn, is a function of the electron temperature. This signal, nf(T/sub e/), is sensitive to all three electron distributions found in EBT - those of the cold surface plasma, the warm core plasma, and the hot electron ring

  11. Effects of applied dc radial electric fields on particle transport in a bumpy torus plasma

    Science.gov (United States)

    Roth, J. R.

    1978-01-01

    The influence of applied dc radial electric fields on particle transport in a bumpy torus plasma is studied. The plasma, magnetic field, and ion heating mechanism are operated in steady state. Ion kinetic temperature is more than a factor of ten higher than electron temperature. The electric fields raise the ions to energies on the order of kilovolts and then point radially inward or outward. Plasma number density profiles are flat or triangular across the plasma diameter. It is suggested that the radial transport processes are nondiffusional and dominated by strong radial electric fields. These characteristics are caused by the absence of a second derivative in the density profile and the flat electron temperature profiles. If the electric field acting on the minor radius of the toroidal plasma points inward, plasma number density and confinement time are increased.

  12. Heavy ion beam study of potential formation in bumpy torus plasma

    International Nuclear Information System (INIS)

    Takasugi, Keiichi.

    1985-01-01

    A heavy ion beam probe is constructed for the study of plasma confinement in Nagoya Bumpy Torus (NBT-1/1M). The measurement of the local plasma potential as well as the electron density profile is possible with good spatial (1 -- 2 cm) and temporal (-- 1 msec) resolutions. The feedback controlled detection technique and the time resolved fast detection technique are coupled to use, which enables us to measure local potential reliably even in the pulsed experiments. The process of the devlopment of concentric equipotential surface is observed. The cold and collisional plasma in bumpy torus is not in the equilibrium (C-mode), and the vertically polarized potential profile is produced by the toroidal drift. With the growth of warm collisionless electron component, the polarization is poloidally short-circuited, and the concentric equipotential surface is developed. The concentric negative potential well and its positive rim are observed in the standard operation. The position of the potential boundary (rim) moves with the second harmonic ECRH zone at the midplane of each mirror section, where the hot electron ring exists. The rim potential is formed by the direct loss of warm electrons. It is confirmed that the core electron heating is essential for the negative potential formation. The potential depth is much larger than the ion temperature Tsub(i), and cannot be explained by the existing neoclassical theory. A stable positive potential is observed near T-M transition. The positive potential is also observed in the ion heated plasma. Relating to the growth of the high energy component, the potential formation due to direct loss process is discussed. (author)

  13. Performance analyses of Elmo Bumpy Torus plasmas and plasma support systems

    International Nuclear Information System (INIS)

    Fenstermacher, M.E.

    1979-01-01

    The development and applcation of the OASIS Code (Operational Analysis of ELMO Bumpy Torus Support and Ignition Systems) for the study of EBT device and plasma performance are presented. The code performs a time-independent, zero-dimensional self-consistent calculation of plasma and plasmasupport systems parameters for the physics and engineering of EBT devices. The features of OASIS modeling for the EBT plasma include: (1) particle balance of the bulk toroidal and electron ring plasma components for experimental (H-H, D-D, He-He etc.) as well as reactor (D-T) devices; (2) energy balance in the bulk and ring plasmas for externally heated or ignition devices; (3) alpha particle effects for reactor devices; (4) auxiliary heating effects, including microwave (ECRH), RF heating (e.g., ICRH), and neutral beam methods; and (5) ignition conditions, including fusion power, alpha power and neutron wall loading. The performance studies using OASIS focussed on variation in plasma and device size and on microwave input power and frequency. An additional study was performed to determine the characteristics of an EBT reactor proof-of-principle device operated with a deuterium-tritium plasma. Sensitivity studies were performed for variation in the input microwave power sharing fractions and the dependence of the bulk n tau scaling law on bulk electron temperature

  14. Bumpy torus annulus startup

    International Nuclear Information System (INIS)

    Sperling, J.L.; Hamasaki, S.; Krall, N.A.

    1982-01-01

    In order that a stable bumpy torus plasma configuration can be attained, it is first necessary to irradiate the plasma with sufficient external power to cause annulus formation. To estimate the power required to initiate annuli, it is assumed that quasilinear electron-cyclotron heating by microwaves is the dominant electron heating mechanism. A scaling law for required microwave power is derived which shows that annulus formation is assisted by smaller cross-section areas, lower density, lower microwave frequency, and higher C-mode temperature. The scaling law is quantitatively evaluated for NBT, EBT-1, EBT-S, EBT-P, and EBT-R parameters. The resulting power estimates are consistent with the available microwave power in previous and present experiments. In larger projected bumpy tori, like EBT-P and EBT-R, it may be necessary to initiate annulus formation at densities which are lower than in the stable T-mode so that the necessary microwave power can be reduced to reasonably modest levels. It is suggested that instabilities as well as rf heating can aid the formation of bumpy torus electron annuli. Rf experiments on NBT and EBT-S would be beneficial in determining the capability of rf power to assist annulus startup

  15. Research program for plasma confinement and heating in ELMO bumpy torus devices

    International Nuclear Information System (INIS)

    Dandl, R.A.; Dory, R.A.; Eason, H.O.

    1975-06-01

    A sequence of experimental devices and related research activities which leads progressively toward an attractive full-scale reactor is described. The implementation of the steps in this sequence hinges on the development of microwave power sources, with high specific power levels, at millimeter wavelengths. Two proposed steps in this sequence are described. The first step proposed here, denoted EBT-S, requires increasing the EBT magnetic field to permit microwave heating at 18 and 28 GHz, as compared to the present 10.6 and 18-GHz configuration. A three-fold increase in plasma density, some increase in the temperatures, and an opportunity to test the validity of the transport models presently used to predict the plasma parameters are anticipated. This step will provide important operating experience with the 28-GHz power supplies, which are prototype tubes for millimeter sources at 120 GHz In the second step a new superconducting bumpy torus, EBT-II, would be fabricated to permit microwave heating at 90 and 120 GHz. This device would be designed to produce plasma densities and temperatures comparable to those of present-day tokamaks. This report reviews the experimental and theoretical research on EBT that has been carried out to date or formulated for the near future, and provides a status report as well as a research program plan. (U.S.)

  16. ELMO Bumpy Torus

    International Nuclear Information System (INIS)

    Berry, L.A.; Hedrick, C.L.; Uckan, N.A.

    1979-03-01

    The ELMO Bumpy Torus (EBT) program of experiment, theory, and reactor studies has been a remarkably successful one. In the five years since EBT-I began operating, work has progressed from a demonstration of macrostability to an increasingly detailed understanding of transport properties. Collisionless scaling (tau/sub E/ increases with temperature) has been observed, and the magnitude of the energy confinement time is consistent with neoclassical theory. Experiments on EBT-S (for scale) are now being conducted at the increased magnetic field levels and higher microwave power and frequency made possible by a 28-GHz gyrotron development program. A review of the program is given

  17. Elmo Bumpy Torus Reactor

    International Nuclear Information System (INIS)

    McAlees, D.G.; Uckan, N.A.; Lidsky, L.M.

    1976-01-01

    In the Elmo Bumpy Torus Reactor (EBTR) study the feasibility of achieving a fusion power plant based on the EBT confinement concept was evaluated. If the present understanding of the physics can be extrapolated to reactor scale devices the reactor could operate at high beta, high power density, and at steady state. The high aspect ratio of the device eases the accessibility, structural design and remote maintenance problems which are common to low aspect ratio machines. A version of the EBTR reference design described here could be constructed with only minor extrapolations in available technology

  18. ELMO Bumpy Torus

    International Nuclear Information System (INIS)

    1978-01-01

    The ELMO Bumpy Torus (EBT) program of experiment, theory, and reactor studies has been a remarkably successful one. In the five years since EBT-I began operating, work has progressed from demonstrating macrostability to an increasingly detailed understanding of transport properties. Collisionless scaling (tau/sub E/ increases with temperature) has been observed and the magnitude of the energy confinement time is consistent with neoclassical theory. Experiments on EBT-S are now being conducted at the increased magnetic field levels and higher microwave power and frequency made possible by a 28-GHz gyrotron development program. Initial results confirm our assumptions of neoclassical scaling. In conjunction with the experimental advances, EBT theory now has a well-developed transport theory which models the physics which we now think to be important: for example, it yields negative ambipolar electric fields which are consistent with those measured. Stability calculations continue to predict stable equilibrium with β/sub ring/ approx. β/sub core/ approx. 20 to 40%

  19. The ELMO Bumpy Torus: present and future

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1978-01-01

    The ELMO Bumpy Torus (EBT) experiment at ORNL was designed to circumvent the MHD stability problem encountered in standard bumpy tori by using the ''minimum-B'' properties of annular high-beta, hot-electron plasmas formed by microwave heating. The EBT combines the attractive features of both mirrors and tokamaks. The feasibility of this combined system has been demonstrated successfully in the EBT-I experiment and discussed at greater length elsewhere. The present status of the EBT research activities at ORNL is described briefly

  20. An experimental determination of the hot electron ring geometry in a Bumpy Torus and its implications for Bumpy Torus stability

    International Nuclear Information System (INIS)

    Hillis, D.L.; Wilgen, J.B.; Bigelow, T.S.; Jaeger, E.F.; Swain, D.W.; Hankins, O.E.; Juhala, R.E.

    1986-10-01

    The hot electron rings of the ELMO Bumpy Torus (EBT) [Plasma Physics and Controlled Nuclear Fusion (IAEA, Vienna, 1975), Vol. II, p. 141] are formed by electron cyclotron resonance heating (ECRH) and have an electron temperature of 350 to 500 keV. The original intention of these hot electron rings was to provide a local minimum in the magnetic field and, thereby, stabilize the simple interchange and flute modes, which are inherent in a closed field line bumpy torus. To evaluate the electron energy density of the EBT rings and determine if enough stored energy is present to provide a local minimum in the magnetic field, a detailed understanding of the spatial distribution of the rings is imperative. The purpose of this report is to measure the ring thickness and investigate its implications for bumpy torus stability. The spatial location and radial profile of the hot electron ring are measured with a unique metal ball pellet injector, which injects small metallic balls into the EBT ring plasma. From these measurements the radial extent (or ring thickness) is about 5 to 7 cm full width at half maximum for typical EBT operation, which is much larger than previously expected. These measurements and recent modeling of the EBT plasma indicate that the hot electron ring's stored energy may not be sufficient to produce a local minimum in the magnetic field

  1. Thomson scattering on ELMO Bumpy Torus

    International Nuclear Information System (INIS)

    Cobble, J.A.

    1985-04-01

    Below 10 12 cm -3 density, a Thomson scattering experiment is an exacting task. Aside from the low signal level, the core plasma in this instance is bathed in high-energy x rays, surrounded by a glowing molecular surface plasma, and heated steady state by microwaves. This means that the noise level from radiation is high and the environment is extremely harsh-so harsh that much effort is required to overcome system damage. In spite of this, the ELMO Bumpy Torus (EBT) system has proven itself capable of providing reliable n/sub e/ and T/sub e/ measurements at densities as low as 2 x 10 11 cm -3 . Radial scans across 20 cm of the plasma diameter have been obtained on a routine basis, and the resulting information has been a great help in understanding confinement in the EBT plasma. The bulk electron properties are revealed as flat profiles of n/sub e/ and T/sub e/, with density ranging from 0.5 to 2.0 x 10 12 cm -3 and temperature decreasing from 100 to 20 eV as pressure in the discharge is increased at constant power. Evidence is presented for a suprathermal tail, which amounts to about 10% of the electron distribution at low pressures. The validity of this conclusion is supported by two independent sensitivity calibrations

  2. Monte Carlo neutral density calculations for ELMO Bumpy Torus

    International Nuclear Information System (INIS)

    Davis, W.A.; Colchin, R.J.

    1986-11-01

    The steady-state nature of the ELMO Bumpy Torus (EBT) plasma implies that the neutral density at any point inside the plasma volume will determine the local particle confinement time. This paper describes a Monte Carlo calculation of three-dimensional atomic and molecular neutral density profiles in EBT. The calculation has been done using various models for neutral source points, for launching schemes, for plasma profiles, and for plasma densities and temperatures. Calculated results are compared with experimental observations - principally spectroscopic measurements - both for guidance in normalization and for overall consistency checks. Implications of the predicted neutral profiles for the fast-ion-decay measurement of neutral densities are also addressed

  3. Research support for plasma diagnostics on Elmo Bumpy Torus: investigation of diamagnetic diagnostics for the electron rings

    International Nuclear Information System (INIS)

    Carpenter, K.H.

    1981-02-01

    Diamagnetic diagnostics for the EBT electron rings are fundamental to the experiment. The diamagnetic flux pickup loops on each cavity output signals proportional to ring perpendicular energy. A data analysis technique is described, which in its simplest form is subtracting 1/4 the signal from each neighboring cavity pickup loop from the central one's, which provides a signal proportional to the energy in a single ring. The calibration factor relating absolute perpendicular energy to diamagnetic signal depends weakly on the geometrical model for the ring. Calculations with a bumpy cylinder MHD equilibrium code give calibration factors in reasonable agreement (20%) to the values obtained using a simple, concentric cylindrical current sheet model. The cylindrical current sheet model is used to show that diamagnetic field components measured external to the plasma require high precision or correlation with other diagnostics in order to fix model parameters. A computer simulation shows an assumption of constant ring thickness and energy density with increasing length (and energy) is compatible to diamagnetic field observations on NBT

  4. A program to develop advanced EBT [ELMO Bumpy Torus] concepts and international collaboration on the Bumpy Torus concept: Final report

    International Nuclear Information System (INIS)

    1987-01-01

    This project was undertaken to develop innovative concepts for improving the performance of ELMO Bumpy Torus devices in those aspects of plasma confinement that are particularly relevant to an eventual EBT reactor concept. These include effective magnetic utilization using Andreoletti coils, enhanced confinement using positive ambipolar potentials, and attractive divertor concepts that are compatible with formation and maintenance of ELMO rings. Each of the three major objectives was achieved and, except for the divertor studies, documented for publication and presentation at major scientific meetings. This report provides a brief recapitulation of the major results achieved in the form of a collection of those publications, together with this Introduction

  5. Reactor assessments of advanced bumpy torus configurations

    International Nuclear Information System (INIS)

    Uckan, N.A.; Owen, L.W.; Spong, D.A.; Miller, R.L.; Ard, W.B.; Pipkins, J.F.; Schmitt, R.J.

    1984-02-01

    Recently, several innovative approaches were introduced for enhancing the performance of the basic ELMO Bumpy Torus (EBT) concept and for improving its reactor potential. These include planar racetrack and square geometries, Andreoletti coil systems, and bumpy torus-stellarator hybrids (which include twisted racetrack and helical axis stellarator - snakey torus). Preliminary evaluations of reactor implications of each approach have been carried out based on magnetics (vacuum) calculations, transport and scaling relationships, and stability properties deduced from provisional configurations that implement the approach but are not necessarily optimized. Further optimization is needed in all cases to evaluate the full potential of each approach. Results of these studies indicate favorable reactor projections with a significant reduction in reactor physical size as compared to conventional EBT reactor designs carried out in the past

  6. Space potential profiles in ELMO Bumpy Torus (EBT) experiment

    International Nuclear Information System (INIS)

    Bieniosek, F.M.; Connor, K.A.

    1983-01-01

    Spatially resolved measurements of the electric space potential in the ELMO Bumpy Torus (EBT) have been made by a heavy ion beam probe. The EBT-I device is characterized by positive potentials in the surface plasma the order of 100 V and by a nearly symmetric potential well in the core plasma of up to 300 V with respect to the surface potential. The EBT-S device has a similar potential structure with well depth and peak potential similar to or greater than that of EBT-I. Peak potential and well depth increase as the edge gas pressure is lowered and as the microwave power is increased. The potential structure is strongly linked to the specific heating geometry. The ambipolar electric field is large enough generally to dominate the core electron neoclassical diffusion. The potential profile is approximately parabolic in the core, which is shown to be a natural consequence of the spatially uniform plasma source function

  7. Numerical model for radial transport in the ELMO Bumpy Torus

    International Nuclear Information System (INIS)

    Jaeger, E.F.; Hedrick, C.L.

    1977-11-01

    Neutral and charged particle densities and temperatures are calculated as functions of radius for the toroidal plasma in the ELMO Bumpy Torus (EBT) experiment. Energy dependent ionization and charge-exchange rates, ambipolar diffusion, and self-consistent radial electric field profiles are included. Variation in magnetic field due to finite plasma pressure, effects of energetic electron rings, and transport due to drift waves and magnetic field errors are neglected. Diffusion is assumed to be neoclassical with enhanced losses at low collisionalities. The model reproduces many of the observed features of EBT operation in the quiescent toroidal (T) mode. The self-consistently calculated electric field is everywhere positive (not as in experiments) unless enhanced electron collisionality is included. Solutions for advanced EBT's are obtained and confinement parameters predicted

  8. Electron energy confinement in ELMO Bumpy Torus (EBT)

    International Nuclear Information System (INIS)

    Hiroe, S.; Haste, G.R.; Dandl, R.A.

    1979-06-01

    Using a calibrated, solid-state, soft x-ray detector, the electron temperature and density have been measured over a wide range of operating conditions of ELMO Bumpy Torus (EBT). The empirical relations of the temperature or the density to the microwave power and the ambient pressure have been determined. The toroidally stored energy has been observed to increase as the stored energy of the hot electron annulus increases. The energy confinement time has been obtained for various plasma parameters and has been found to agree with the neoclassical theory. The advantages of EBT collisionless scaling for fusion plasma confinement have been noted, i.e., n/sub e/tau/sub E/ increases as T/sub e/ 1 5 in the collisionless regime

  9. Kinetic transport model for the ELMO Bumpy Torus

    International Nuclear Information System (INIS)

    Jaeger, E.F.; Hedrick, C.L.; Tolliver, J.S.

    1978-05-01

    A bounce-averaged drift kinetic equation is solved for the toroidal plasma in the ELMO Bumpy Torus (EBT). The distribution function is assumed isotropic in pitch angle and calculated as a function of radius and speed using finite differences on a two-dimensional grid. A Fokker-Planck representation of the collision operator includes Coulomb, microwave, ionizing, and charge-exchange collisions. Ion and electron fluxes, computed as integrals of the distribution function, are of comparable magnitude for ambipolar potentials which are approximately self-consistent. Initial results assume an unperturbed distribution function which is Maxwellian; however, this is not a necessary assumption in the model. Careful accounting of loss regions where electric and magnetic poloidal drifts cancel (super banana particle orbits) leads to ion loss rates which are in some cases two orders of magnitude greater than electron rates. In these cases, radially inward pointing self-consistent electric fields occur with potentials on the order of a few times the ion temperature. These negative field results are in approximate agreement with experiment and appear to be stable to the electric field runaway encountered in positive field cases

  10. ELMO Bumpy Torus fusion-reactor design study

    International Nuclear Information System (INIS)

    Bathke, C.G.; Krakowski, R.A.

    1981-01-01

    A complete power plant design of a 1200-MWe ELMO Bumpy Torus Reactor (EBTR) is described that emphasizes those features that are unique to the EBT confinement concept, with subsystems and balance-of-plant items that are generic to magnetic fusion being adopted from past, more extensive tokamak reactor designs

  11. Neoclassical transport associated with collisionless detrapping in a bumpy torus

    International Nuclear Information System (INIS)

    Hastings, D.E.

    1983-10-01

    In the two collisionality nonresonant regime in a bumpy torus the transitional particles can make a large contribution to neoclassical transport. This contribution can be moderated by the toroidally induced radial drift which causes transitional particles to detrap and retrap in the mirror sectors. This effect leads to diffusion coefficients which are linear in the collision frequency and scale with the inverse aspect ratio instead of the more usual square of the inverse aspect ratio. (author)

  12. The classical theory of the bumpy torus relativistic annulus

    International Nuclear Information System (INIS)

    Hamasaki, S.; Krall, N.A.; Sperling, J.L.

    1983-01-01

    The relativistic electron annulus is a critical component of the bumpy torus magnetic fusion concept. An analysis of the annulus is presented in which the ring steady state is determined by the explicit balance of quasi-linear heating and classical losses, i.e. collisions and synchrotron radiation. Both anisotropy and loss-cone effects are included in the formalism. It is demonstrated that a large number of electron cyclotron harmonics, not just the first and second, contribute in an appreciable way to annulus steady state and power balance. Without a loss cone, the analysis reproduces the relativistic passing electron population observed in bumpy tori on confined drift surfaces near the centre of the bumpy torus cross-section. Loss-cone effects permit an annulus population with large perpendicular pressure to exist. It is shown that the balance between quasi-linear heating and the classical losses cannot account for the experimental scaling of bumpy torus annulus temperature; therefore, processes not included in the classical ring power balance model must contribute in a non-trivial way to observed annulus properties. (author)

  13. Transient waveform acquisition system for the ELMO Bumpy Torus

    International Nuclear Information System (INIS)

    Young, K.G.; Burris, R.D.; Hillis, D.H.; Overbey, D.R.

    1984-10-01

    The transient waveform system described in this report is designed to acquire analog waveforms from the ELMO Bumpy Torus (EBT) diagnostic experiments. Pressure, density, synchrotron radiation, etc., are acquired and digitized with a Kinetic Systems TR812 transient recorder and associated modules located in a CAMAC crate. The system can simultaneously acquire, display, and transmit sets of data consisting of identification parameters and up to 1024 data points for 1 to 64 input signals (frequency range = 0.01 pulse/s to 100 kHz) of data every one or more minutes; thus, it can run continuously without operator intervention. The data are taken on a VAX 11/780 and transmitted to a data base on a DECSystem-10. To aid the programmer in making future modifications to the system, detailed documentation using the Yourdon structural methods has been given

  14. ELMO Bumpy Torus Reactor and power plant: conceptual design study

    International Nuclear Information System (INIS)

    Bathke, C.G.; Dudziak, D.J.; Krakowski, R.A.

    1981-08-01

    A complete power plant design of a 1200-MWe ELMO Bumpy Torus Reactor (EBTR) is presented. An emphasis is placed on those features that are unique to the EBT confinement concept, with subsystems and balance-of-plant items that are more generic to magnetic fusion being adapted from past, more extensive tokamak reactor designs. Similar to the latter tokamak studies, this conceptual EBTR design also emphasizes the use of conventional or near state-of-the-art engineering technology and materials. An emphasis is also placed on system accessibility, reliability, and maintainability, as these crucial and desirable characteristics relate to the unique high-aspect-ratio configuration of EBTs. Equal and strong emphasis is given to physics, engineering/technology, and costing/economics components of this design effort. Parametric optimizations and sensitivity studies, using cost-of-electricity as an object function, are reported. Based on these results, the direction for future improvement on an already attractive reactor design is identified

  15. Effect of electric fields and fluctuations on confinement in a bumpy torus

    International Nuclear Information System (INIS)

    Hiroe, S.; Glowienka, J.C.; Hillis, D.L.

    1986-06-01

    In order to understand the relationships between confinement and space potential (electric field) and between confinement and density fluctuations, plasma parameters in the ELMO Bumpy Torus Scale (EBT-S) have been measured systematically for a wide range of operating conditions. Present EBT plasma parameters do not show a strong dependence on the potential profile, but rather exhibit a correlation with the fluctuations. The plasma pressure profile is found to be consistent with the profile anticipated on the basis of the flute stability criterion for a marginally stable plasma. For a heating power of 100 kW, the stored energy density is found to be restricted to the range between 4.5 x 10 13 eV-cm -3 and 7 x 10 13 eV-cm -3 . The lower limit remains constant regardless of heating power and pertains to plasmas lacking an equilibrium and/or stability. The upper limit increases with heating power and is found to result from the onset of instabilities. In between the two limits is a plasma that is in an equilibrium state and is marginally stable. Operational trajectories exist that take the EBT plasma from one limit to the other

  16. Radial transport in the Elmo Bumpy Torus in collisionless electron regimes

    International Nuclear Information System (INIS)

    Jaeger, E.F.; Hedrick, C.L.; Spong, D.A.

    1979-01-01

    One important area of disagreement between radial transport theory and the ELMO Bumpy Torus (EBT) experiment has been the degree of collisionality of the toroidal plasma electrons. Experiment shows relatively warm electrons (kTsub(e) approximately 300-600eV) and collisionless scaling, i.e. energy confinement increasing with temperature. But results of early one-dimensional (1-D), neoclassical transport models with radially inward pointing electric fields are limited to relatively cool electrons (kTsub(e) approximately 100-200eV) and collisional scaling. In this paper these early results are extended to include lowest-order effects of ion diffusion in regions where poloidal drift frequencies are small. The effects of direct, or non-diffusive, losses in such regions are neglected along with the effects of finite radial electric fields on electron transport coefficients and of self-consistent poloidal electric fields on ion transport coefficients. Results show that solutions in the collisionless electron regime do exist. Furthermore, when the effects of finite electron ring beta on magnetic fields near the plasma edge are included, these solutions occur at power levels consistent with experiment. (author)

  17. Kinetic transport properties of a bumpy torus with finite radial ambipolar field

    International Nuclear Information System (INIS)

    Spong, D.A.; Harris, E.G.; Hedrick, C.L.

    1978-04-01

    Bumpy torus neoclassical transport coefficients have been calculted including finite values of the radial ambipolar field. These are obtained by solving a bounce-averaged drift kinetic equation in a local approximation for perturbations in the distribution function (away from a stationary Maxwellian) caused by toroidicity and radial gradients in plasma density, temperature, and potential. Particle and energy fluxes along with the associated transport coefficients are then calculated by taking appropriate moments of the distribution function. Particle orbits are treated by breaking them up into a vertical drift component (due to toroidicity) and a theta precessional drift (as a result of Vector E x Vector B and drifts due to the bumpy toroidal field). The kinetic equation has been solved using both a functional expansion method and finite difference techniques [Alternating-Direction-Implicit (ADI)]. The resulting transport coefficients exhibit a strong dependence on the ambipolar electric field and plasma collisionality. In the large electric field limit, our results are in close agreement with the earlier work of Kovrizhnykh

  18. Application of catastrophe theory to a point model for bumpy torus with neoclassical non-resonant electrons

    Energy Technology Data Exchange (ETDEWEB)

    Punjabi, A; Vahala, G [College of William and Mary, Williamsburg, VA (USA). Dept. of Physics

    1983-12-01

    The point model for the toroidal core plasma in the ELMO Bumpy Torus (with neoclassical non-resonant electrons) is examined in the light of catastrophe theory. Even though the point model equations do not constitute a gradient dynamic system, the equilibrium surfaces are similar to those of the canonical cusp catastrophe. The point model is then extended to incorporate ion cyclotron resonance heating. A detailed parametric study of the equilibria is presented. Further, the nonlinear time evolution of these equilibria is studied, and it is observed that the point model obeys the delay convention (and hence hysteresis) and shows catastrophes at the fold edges of the equilibrium surfaces. Tentative applications are made to experimental results.

  19. Electron confinement studies on the EBT-S Bumpy Torus Experiment using soft x-ray techniques

    International Nuclear Information System (INIS)

    Hillis, D.L.; Haste, G.R.; Berry, L.A.

    1983-01-01

    Soft x-ray bremsstrahlung measurements have been performed on the ELMO Bumpy Torus (EBT-S) plasma to determine the electron temperature T/sub e/ and electron density density n/sub e/ using a calibrated Si(Li) detector over a wide range of operating conditions. The purpose of this paper is to outline the necessary assumptions and essential x-ray techniques that are inherent in soft x-ray measurements in order to investigate the electron heating and confinement properties of EBT-S. In addition, by utilizing the electron density as determined by the soft x-ray measurements, the previous EBT-S confinement analyses have been extended. The steady-state plasma of EBT-S is heated by microwaves using a continuous wave (cw) gyrotron that can operate up to power levels of 200 kW. From the soft x-ray measurements, both the electron temperature and density are found to increase at higher microwave power levels. For operation at microwave power levels of 200 kW, T/sub e/ approaches 1 keV while n/sub e/ approaches 1.2 x 10 12 cm - 3 . In general, confinement properties are found to improve with increased microwave power. The data are compared with neoclassical transport scaling and the electron transport is found to be collisionless (#betta#/Ω<1) as well as neoclassical

  20. Power balance in ELMO Bumpy Torus: bulk electrons and ions in a 37 kW discharge

    International Nuclear Information System (INIS)

    McNeill, D.H.

    1985-10-01

    The power balance of the bulk electrons and ions in discharges with 37 kW of applied microwave power in the ELMO Bumpy Torus (EBT) is examined in a zero-dimensional model using data on the intensity and linewidth of the molecular and atomic hydrogen emission. At least 60% of the applied power is ultimately dissipated by processes involving the neutral particles, including dissociation of molecules, ionization of and radiation from atoms, and heating of cold electrons produced during atomic ionization. The molecular influx rate and the density of atoms are used independently to determine the bulk electron particle confinement time, and an upper bound estimate is made of the diffusional power loss from the bulk plasma electrons. Parameters derived from the basic spectroscopic data presented in this paper include the neutral atom density 2 - 5x10 10 cm -3 , incident molecular flux 3 - 5x10 15 cm -2 s -1 , bulk ion temperature approx. =3 eV, and particle confinement time <1.1 ms. The bulk electron energy confinement time is 0.7 ms or less in the standard operating regime. Published data on the nonthermal electron and ion populations in the plasma are used to evaluate approximately the overall energy flow in the discharge. 54 refs

  1. Theoretical studies of Elmo Bumpy Torus. Annual report

    International Nuclear Information System (INIS)

    1984-01-01

    The work was divided into four basic areas. Studies of the effect of waves on stability and transport considered the possibility of using radio frequency waves to stabilize interchange modes, as well as the general problem of influencing plasma transport by wave absorption. Studies related to wave heating of plasmas considered nonlinear effects such as mode conversion and parametric absorption, along with studies of the structure of ion cyclotron waves in a strongly bumpy geometry. Ring physics studies added nonadiabaticity and whistler instabilities to the model, producing a fairly realistic picture of energy balance, power requirements, and scaling for hot electron rings. Finally, studies analyzing EBT transport data were performed, with emphasis on testing various hypotheses for apparent anomalies in the EBT

  2. Curvature-driven instabilities in the Elmo Bumpy Torus (EBT)

    International Nuclear Information System (INIS)

    Abe, H.; Spong, D.A.; Antonsen, T.M. Jr.; Tsang, K.T.; Nguyen, K.T.

    1982-01-01

    Curvature-driven instabilities are analyzed for an EBT configuration which consists of plasma interacting with a hot electron ring whose drift frequencies are larger than the growth rates predicted from conventional magnetohydrodynamic (MHD) theory. Stability criteria are obtained for five possible modes: the conventional hot electron interchange, a high-frequency hot electron interchange (at frequencies greater than the ion-cyclotron frequency), a compressional instability, a background plasma interchange, and an interacting pressure-driven interchange. A wide parameter regime for stable operation is found, which, however, severely deteriorates for a band of intermediate mode numbers. Finite Larmor radius effects can eliminate this deterioration; moreover, all short-wavelength curvature-driven modes are stabilized if the hot electron Larmor radius rho/sub h/ satisfies (kappa/sub perpendicular/rho/sub h/) 2 > 2Δ/[Rβ/sub h/(1 + P'/sub parallel//P'/sub perpendicular/)], where kappa/sub perpendicular/ is the transverse wavenumber, Δ is the ring half-width, R is the mid-plane radius of curvature, β/sub h/ is the hot electron beta value, and P' is the pressure gradient. Resonant wave-particle instabilities predicted by a new low frequency variational principle show that a variety of remnant instabilities may still persist

  3. Nuclear performance calculations for the ELMO Bumpy Torus Reactor (EBTR) reference design

    International Nuclear Information System (INIS)

    Santoro, R.T.; Barnes, J.M.

    1977-12-01

    The nuclear performance of the ELMO Bumpy Torus Reactor reference design has been calculated using the one-dimensional discrete ordinates code ANISN and the latest available ENDF/B-IV transport cross-section data and nuclear response functions. The calculated results include estimates of the spatial and integral heating rate with emphasis on the recovery of fusion neutron energy in the blanket assembly and minimization of the energy deposition rates in the cryogenic magnet coil assemblies. The tritium breeding ratio in the natural lithium-laden blanket was calculated to be 1.29 tritium nuclei per incident neutron. The radiation damage in the reactor structural material and in the magnet assembly is also given

  4. The NASA-Lewis program on fusion energy for space power and propulsion, 1958-1978

    International Nuclear Information System (INIS)

    Schulze, N.R.; Roth, J.R.

    1990-01-01

    An historical synopsis is provided of the NASA-Lewis research program on fusion energy for space power and propulsion systems. It was initiated to explore the potential applications of fusion energy to space power and propulsion systems. Some fusion related accomplishments and program areas covered include: basic research on the Electric Field Bumpy Torus (EFBT) magnetoelectric fusion containment concept, including identification of its radial transport mechanism and confinement time scaling; operation of the Pilot Rig mirror machine, the first superconducting magnet facility to be used in plasma physics or fusion research; operation of the Superconducting Bumpy Torus magnet facility, first used to generate a toroidal magnetic field; steady state production of neutrons from DD reactions; studies of the direct conversion of plasma enthalpy to thrust by a direct fusion rocket via propellant addition and magnetic nozzles; power and propulsion system studies, including D(3)He power balance, neutron shielding, and refrigeration requirements; and development of large volume, high field superconducting and cryogenic magnet technology

  5. Engineering challenges encountered in the design of the ELMO BUMPY TORUS proof-of-principle fusion device

    International Nuclear Information System (INIS)

    Dillow, C.F.; Imster, H.F.

    1982-01-01

    This paper first provides a summary of the history and current status of the Elmo Bumpy Torus (EBT) fusion concept. A brief description of the EBT-P is then provided in which the many unique features of this fusion device are highlighted. This description will provide the technical background for the following discussions of some of the more challenging mechanical engineering problems encountered to date in the evolution of the EBT-P design. The problems discussed are: optimization of the device primary structure design, optimization of the superconducting magnet x-ray shield design, design of the liquid helium supply and distribution system, and selection of high vacuum seals and pumps and their protection from the high power microwave environment. The common challenge in each of these design issues was to assure adequate performance at minimum cost

  6. Use of advanced programmable logic controllers to monitor and control the Elmo Bumpy Torus-proof-of-principle device

    International Nuclear Information System (INIS)

    Boyd, B.A.

    1983-01-01

    The Elmo Bumpy Torus - Proof-of-Principle (EBT-P) device is designed with an instrumentation and control system based upon the use of an advanced Programmable Logic Controller (PLC). The modern PLC incorporates many advanced programming features not available in earlier PLC's intended for application to conventional relay logic replacement. The additional power and flexibility of these modern PLC's is especially applicable to an experimental device such as EBT-P which is made up of several complex interrelated subsystems whose operational characteristics will be evolving throughout the lifetime of the device. The rationale for the selection of advanced PLC's for EBT-P and the approach taken to design of the software developed to control EBT-P are the topics addressed in this paper

  7. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume II. Toroidal vessel

    International Nuclear Information System (INIS)

    1982-01-01

    The Toroidal Vessel provides the vacuum enclosure for containing the high temperature steady state plasma. In addition, the Toroidal Vessel must provide several viewing ports for plasma diagnostics, vacuum pumping ports for both high vacuum and roughing vacuum, feed-through ports for ECRH waveguides, limiter feed throughs for cooling and supporting the limiters, and ports for ion gages. The vessel must operate in an intense environment comprised of x-rays, microwaves, magnetic fields and plasma heat loads as well as the atmosphere pressure and gravity loads and the internal thermal stress loads due to heating and cooling of the torus. A key issue addressed was the choice of vacuum vessel seal and wall materials. In addition, during the course of the study, ORNL requested that horsecollar diagnostic ports be incorporated in the design. A comprehensive trade study was performed considering the vessel material issues in concert with the impact of the horsecollar port design. A change in baseline from an aluminum vessel with elastomer seals and circular diagnostic ports to austenitic stainless steel vessel with metal seals and horsecollar ports was agreed upon by both MDAC and ORNL towards the end of Title I

  8. Birth of new folds and competing attractors in Elmo Bumpy Torus

    Energy Technology Data Exchange (ETDEWEB)

    Punjabi, A; Vahala, G

    1984-04-09

    The topology of equilibrium surfaces for the point model equations with neoclassical nonresonant ions in EBT is a complicated nongradient-dynamic version of the canonical cusp catastrophe. New folds emerge from degenerate equilibrium surfaces as the control vector (filling pressure, microwave power, ambipolar potential) is changed. Strong sensitivity to small changes in initial conditions of the state variables (electron/ion temperatures, plasma density) is found that can drastically alter the final equilibrium state when competing point attractors are present. 5 references, 3 figures.

  9. The compressional Alfven instability in ECRH plasmas

    International Nuclear Information System (INIS)

    El Nadi, A.

    1982-01-01

    It is shown that the hot electron component present in an electron cyclotron resonance heated plasma can destabilize the compressional Alfven wave if β of the background plasma exceeds a certain limit. The relevance of the result to the Elmo Bumpy Torus experiment is discussed. (author)

  10. Equilibrium and stability of high-beta plasma in a finite l=+-1 toroidal system

    International Nuclear Information System (INIS)

    Shiina, S.; Saito, K.; Todoroki, J.; Hamada, S.; Gesso, H.; Nogi, Y.; Osanai, Y.; Yoshimura, H.

    1983-01-01

    The equilibrium and stability are theoretically and experimentally investigated of high-beta plasma in the Modified Bumpy Torus, which is an asymmetric closed-line system with fairly large l=0 and l=+-1 field components. The finiteness of the l=+-1 component induces significant stabilizing effects due both to self formation of a magnetic well and to the conducting wall. (author)

  11. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume IV. Microwave system. Preliminary design report

    International Nuclear Information System (INIS)

    Adams, R.N.

    1982-01-01

    The EBT-P Microwave System provides microwaves for electron cyclotron resonance heating (ECRH) to both stabilize and heat the EBT-P plasma. A 28 gigahertz (GHz) system is required to form the hot electron annulus plasma that provides MHD stabilization to the core plasma. A 60 GHz system is required to heat the core plasma and will provide some second harmonic heating of the hot electron annulus. The principal microwave system elements and their design characteristics are summarized. The microwave system includes 200 kilowatt (kW) gyrotrons at 60 GHz for core heating and 200 kW gyrotrons at 28 GHz for annulus heating. The basic operating complement will be six (6) 60 GHz tubes and two (2) 28 GHz tubes. PACE (Plant and Capital Equipment) procurement will include four (4) 60 GHz gyrotrons with two (2) GHz tubes procured under operations and the two (2) 28 GHz tubes will be provided, with mounts, from the EBT-S program. Each tube is rigidly mounted on an oil filled tank assembly which provides electrical isolation and cooling. All tubes and mounts will be located in the lower level of the torus enclosure. An extensive demineralized water flow system is required to provide gyrotron cooling

  12. Plasma Theory Division

    International Nuclear Information System (INIS)

    Callen, J.D.; Dory, R.A.; Aghevli, R.

    1977-01-01

    The progress during the past year is organized by group efforts and divided into five major areas. The basic tokamak areas and the sections in which their work is summarized are: magnetohydrodynamic (MHD) theory, kinetic theory, and transport simulation. The ELMO Bumpy Torus (EBT) theory work has its own research projects on MHD theory, kinetic theory, and transport simulation. In the plasma engineering area, relevant research work is further developed and synthesized into models that are used in the design of advanced fusion systems--The Next Step (TNS), demonstration fusion reactor (Demo), EBT ignition test, etc. Specific plasma engineering projects on providing the TNS physics basis and the development of the EBT reactor study are discussed. The computing support activities during the past year are summarized

  13. Annual review of the Institute of Plasma Physics, Nagoya University, for fiscal 1978

    International Nuclear Information System (INIS)

    1979-01-01

    Activities of Institute of Plasma Physics, Nagoya University, from April 1978 to March 1979, are described in individual short summaries. As a main project, the JIPP T-II program aims at confinement and heating of hot plasmas in a tokamak/stellarator hybrid system. The STP-3 system for high beta pinch plasma has now almost been completed. Installation of the RFC-XX is now complete with the delivery of two rf oscillators for point cusp plugs. In high energy beam experiment, toroidal magnetic configurations maintained by intense relativistic currents were demonstrated. The Nagoya Bumpy Torus is a race track convertible to a circular torus. In parallel with the above research projects, there continued experiments on basic plasma physics, laser-produced plasma, the atomic processes and the surface physics related to the plasma-wall interaction. Theoretical and computational divisions worked in close collaboration with the above. (J.P.N.)

  14. Inward transport of a toroidally confined plasma subject to strong radial electric fields

    Science.gov (United States)

    Roth, J. R.; Krawczonek, W. M.; Powers, E. J.; Hong, J.; Kim, Y.

    1977-01-01

    The paper aims at showing that the density and confinement time of a toroidal plasma can be enhanced by radial electric fields far stronger than the ambipolar values, and that, if such electric fields point into the plasma, radially inward transport can result. The investigation deals with low-frequency fluctuation-induced transport using digitally implemented spectral analysis techniques and with the role of strong applied radial electric fields and weak vertical magnetic fields on plasma density and particle confinement times in a Bumpy Torus geometry. Results indicate that application of sufficiently strong radially inward electric fields results in radially inward fluctuation-induced transport into the toroidal electrostatic potential well; this inward transport gives rise to higher average electron densities and longer particle confinement times in the toroidal plasma.

  15. Equilibrium of high beta plasma in closed magnetic line system (MBT)

    International Nuclear Information System (INIS)

    Gesso, H.; Shiina, S.; Saito, K.; Nogi, Y.; Osaniai, Y.; Yoshimura, H.; Todoroki, J.; Hamada, S.; Nihon Univ., Tokyo. Atomic Energy Research Inst.)

    1985-01-01

    The beta effects on the plasma equilibrium in Modified Bumpy Torus (MBT) sector, which is an asymmetric closed line system with l = 0 and fairly large l = +- 1 field distortions, are studied. For this purpose, the equilibrium of high beta plasma produced by theta-pinch is compared with that of betaless plasma numerically calculated from the measured magnetic field profiles in device. The equilibrium condition depends weakly on beta value, but the plasma cross-section is vertically elongated as the beta value increases. The m = 1 long wavelength MHD instability is not observed during the observation time of approx. 15 μs. These experimental results are compared with MHD theory based on the new ordering taking the finiteness of l = +- 1 field distortion (deltasub(+-1) > or approx. 1) into account, which suggests significant stabilizing effects due to self formation of magnetic well and also due to the conducting wall. (author)

  16. Wall effects on the absorption of electron cyclotron waves in an EBT plasma

    International Nuclear Information System (INIS)

    Uckan, T.

    1979-03-01

    The absorption of electron cyclotron waves propagating along an externally applied magnetic field in a uniform plasma surrounded by a cylindrical metallic cavity wall is studied. In the model, the cavity wall, the vacuum-plasma interface, and the effects of finite electron temperature are considered, and the dispersion relation for the wave propagation is derived. The results are then applied to the ELMO Bumpy Torus (EBT-I) plasma, and the propagation characteristics are computed. The wave absorption in the ordinary mode is found to be a result of the wall effects, which cannot be predicted with the infinite plasma theory. The loaded quality factor, Q/sub L/, is also estimated from the model to be about 12, which is in good agreement with the experimentally observed value

  17. Optimization of confinement in a toroidal plasma subject to strong radial electric fields

    International Nuclear Information System (INIS)

    Roth, J.R.

    1977-01-01

    A preliminary report on the identification and optimization of independent variables which affect the ion density and confinement time in a bumpy torus plasma is presented. The independent variables include the polarity, position, and number of the midplane electrode rings, the method of gas injection, and the polarity and strength of a weak vertical magnetic field. Some characteristic data taken under condition when most of the independent variables were optimized are presented. The highest value of the electron number density on the plasma axis is 3.2 x 10 to the 12th power/cc, the highest ion heating efficiency is 47 percent, and the longest particle containment time is 2.0 milliseconds

  18. Extreme ultraviolet and soft x-ray diagnostics of high-temperature plasmas. Annual progress report, June 1, 1977--May 31, 1978

    International Nuclear Information System (INIS)

    Moos, H.W.; Armstrong, L. Jr.; Fastie, W.G.

    1978-01-01

    Spatial scans of Alcator Tokamak have led to a more direct determination of the oxygen and nitrogen concentrations. These scans have also shown that grad B and curvature drifts are significant transport mechanisms in this device. Spatial scans of Elmo Bumpy Torus from both the top and the side have produced two dimensional plots of the impurity concentrations. Preliminary results from 2XIIB show that oxygen is the dominant impurity; nitrogen, carbon, and titanium are also present. The Spatial Imaging Detector System is discussed; construction is complete and it is being prepared for installation on a plasma machine. EUV photometric calibration techiques at this laboratory are described. The accuracy and stability of this calibration is discussed. Theoretical calculations of relativistic transition rates and energies have continued, and studies of electron-impact ionization and excitation cross sections have begun

  19. Microwave interaction with hot electron plasmas

    International Nuclear Information System (INIS)

    Tanaka, M.; Fujiwara, M.; Ikegami, H.

    1980-01-01

    A numerical calculation is presented of ray trajectories and cyclotron damping for toroidal plasmas using geometrical optics. In the absorption region, group velocity does not always coincide with the velocity of energy flow, therefore it should be careful to apply the geometrical optics to finite temperature plasmas. In these calculations, attention is paid mainly to the finite temperature effect on ray tracing. Some numerical results for ordinary waves are presented. Second, new cutoff and resonance appear in the plasmas with anisotropic electron temperature. This resonance frequency is shifted from the usual cyclotron resonance by an amount proportional to T 11 /mc 2 , so that one can determine T 11 when this resonance frequency is measured. A simple discussion is given. The results are presented of recent density measurement on Nagoya Bumpy Torus obtained by interferometer system with different frequencies, 35 GHz and 55 GHz. The results are different than each other in T-mode. The possible reasons for these differences are enumerated in this section

  20. Annual review of the Institute of Plasma Physics, Nagoya University, for fiscal 1983

    International Nuclear Information System (INIS)

    1984-01-01

    As to the reacting plasma project, the design team performed the extensive analysis of highly elongated, high β plasma configuration in fiscal 1983. As physical issues, the experiments on lower hybrid wave current start-up and ion Bernstein wave heating were successfully carried out in the JIPP-T-2U tokamak device. For the research and development related to reacting plasma, a 1/4 module of a 120 keV neutral beam system was completed. The construction of a tritium handling facility, the development of fast pulsed superconduction and the development of new aluminum alloys were accomplished as the results of 3-year preparatory program ending in 1983. The Institute also tried to pursue the alternative concept on fusion plasma research by organizing the program based on a low β toroidal system, radio frequency containment, high energy beam experiment, Nagoya bumpy torus and high β pinch plasma. The scientific activities of the Institute related to reacting plasma physics, various preparatory experiments, various basic studies and plasma theory and computation are reported. Also the services of the Computer Center, the Research Information Center and other facilities are described. (Kako, I.)

  1. Radial structure of curvature-driven instabilities in a hot-electron plasma

    International Nuclear Information System (INIS)

    Spong, D.A.; Berk, H.L.; Van Dam, J.W.

    1984-01-01

    A nonlocal analysis of curvature-driven instabilities for a hot-electron ring interacting with a warm background plasma has been made. Four different instability modes characteristic of hot-electron plasmas have been examined: the high-frequency hot-electron interchange (at frequencies larger than the ion-cyclotron frequency), the compressional Alfven instability, the interacting background pressure-driven interchange, and the conventional hot-electron interchange (at frequencies below the ion-cyclotron frequency). The decoupling condition between core and hot-electron plasmas has also been examined, and its influence on the background and hot-electron interchange stability boundaries has been studied. The assumed equilibrium plasma profiles and resulting radial mode structure differ somewhat from those used in previous local analytic estimates; however, when the analysis is calibrated to the appropriate effective radial wavelength of the nonlocal calculation, reasonable agreement is obtained. Comparison with recent experimental measurements indicates that certain of these modes may play a role in establishing operating boundaries for the ELMO Bumpy Torus-Scale (EBT-S) experiment. The calculations given here indicate the necessity of having core plasma outside the ring to prevent the destabilizing wave resonance of the precessional mode with a cold plasma

  2. Elmo Bumpy Torus proof of principle. Phase II - title 1 report. Volume I. Device summary

    International Nuclear Information System (INIS)

    Haas, D.W.

    1982-02-01

    This document presents a summary of the EBT-P Preliminary Design (Title I) effort. The work was performed, under the direction of ORNL, for the Department of Energy by MDAC-St. Louis. Major subcontractors assisting MDAC included General Dynamics for the magnet system, Gilbert Associates for the device utilities and facility architecture and engineering, and Lockheed - Oak Ridge for engineering support services. The Title I period of performance was from 1 October 1980 to 1 March 1982

  3. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume VII. Cryogenic system

    International Nuclear Information System (INIS)

    Poteat, T.J.

    1982-01-01

    This document, Volume VII EBT-P Cryogenic System Title I Design Report, describes the system that resulted from the Title I Preliminary Design effort. It is a self-contained document that can be read apart from the other Volumes comprising the EBT-P Title I Report. This document is a contract deliverable item and provides the detail necessary to support the Cryogenic System design contained in the EBT-P Baseline Design Data Book

  4. Quality-assurance approach for the Elmo Bumpy Torus Proof-of-Principal experiment

    International Nuclear Information System (INIS)

    Sticksel, F.M.

    1981-01-01

    Components, subsystems and systems will be subjected to inspection and test as necessary to ensure compliance to applicable specifications, Acceptance Test Procedures and/or customer requirements. Quality Assurance will inspect each component, subsystem and system for selected mechanical and electrical defects. In addition, Quality Assurance will either perform, or verify performance of, and analyze, or verify analysis of, all required field and laboratory tests. If hardware is modified, repaired or replaced after final testing, necessary re-inspection and retest must be performed. Insofar as possible the component, subsystem or system will be released as acceptable upon completion of these activities. When nonconformances are detected during the course of site surveillance activities, MDAC or Gilbert/Commonwealth will initiate a Nonconformance Record for review by MDAC Quality Assurance and Project Engineering personnel. These nonconformances will be identified and dispositioned per MDAC Standard Practices with the advice and concurrence of Gilbert/Commonwealth personnel, if deemed appropriate. MDAC Quality Assurance personnel will witness the pre-operational testing and review the test data

  5. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume VIII. Device utilities

    International Nuclear Information System (INIS)

    Erickson, D.T.

    1982-01-01

    This report describes the activities conducted during the Preliminary Design Period for the Device Utilities Systems. All GAI preliminary specifications, drawings, and reports (listed in Section 4.0) have been transmitted to ORNL for review and approval. Device Utility Systems Descriptions are also presented in Section 4.0. The GAI Device Enclosure Gamma Radiation Analysis is presented in Appendix B. Pending design criteria revisions are described in Section 6.0. A type B Change Notice Request (CNR) has been transmitted to GAI. The Type B CNR authorizes cost and schedule assessment for each revision identified. Formal Proposed Design Changes (PDC's) will be provided to ORNL when this data is available

  6. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume IX. Support structure

    International Nuclear Information System (INIS)

    Conlee, J.L.

    1982-01-01

    The EBT-P support structure provides structural support for the 36 mirror coil magnets, magnet protection system, the toroidal vessel, and much of the device ancillary equipment. The structure is comprised of a primary support and a superstructure. The primary support is a reinforced concrete ring located directly inboard of the torus and is supported by nine columns. The toroidal vessel and the mirror coil magnets are cantilevered from the ring with the centerline of the torus located eight feet above the floor. The superstructure is an aluminum truss structure that rests on the concrete ring. The superstructure provides support for the device ancillary equipment. Engineering drawings of the support structure are given

  7. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume VIII. Device utilities

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, D.T.

    1982-02-26

    This report describes the activities conducted during the Preliminary Design Period for the Device Utilities Systems. All GAI preliminary specifications, drawings, and reports (listed in Section 4.0) have been transmitted to ORNL for review and approval. Device Utility Systems Descriptions are also presented in Section 4.0. The GAI Device Enclosure Gamma Radiation Analysis is presented in Appendix B. Pending design criteria revisions are described in Section 6.0. A type B Change Notice Request (CNR) has been transmitted to GAI. The Type B CNR authorizes cost and schedule assessment for each revision identified. Formal Proposed Design Changes (PDC's) will be provided to ORNL when this data is available.

  8. EBT-S 28-GHz, 200-kW, CW, mixed-mode, quasi-optical plasma heating system

    International Nuclear Information System (INIS)

    White, T.L.; Kimrey, H.D.; Bigelow, T.S.; Bates, D.D.; Eason, H.O.

    1984-07-01

    The ELMO Bumpy Torus-Scale (EBT-S) 28-GHz, 200-kW, cw, plasma heating system consists of a gyrotron oscillator, an oversized waveguide two-bend transmission system, and a quasi-optical mixed-mode microwave distribution manifold that feeds microwave power to the 24 plasma loads of the EBT-S fusion experiment. Balancing power to the 24 loads of the EBT-S fusion experiment. Balancing power to the 24 loads was achieved by adjusting the areas at 24 coupling irises. System performance is easily measured using system calorimetry. The distribution manifold mixed-mode power transmission, reflection, and loss coefficients are 89%, 6%, and 5%, respectively. The overall system efficiency (plasma power/gyrotron power) is 80%, but with some modifications to the distribution manifold we believe the ultimate efficiency can approach 90%. The system reliability is outstanding with a world's record 1 x 10 5 kW h of 28-GHz energy delivered to the EBT-S device with well over 1 x 10 3 operating hours

  9. Wyndham Lewis

    OpenAIRE

    Maes-Jelinek, Hena

    2013-01-01

    Ours is a clownish age. If so the manYou be to understand it then you canScarcely be other than a man in an Iron MaskOr choose but choose a most invidious task. –Henceforth the voice you hear is the deep growl –The mask, if any, the notorious scowl –Of Enemy Number One. Wyndham Lewis was so prolific a writer that one sometimes tends to forget he was a painter in the first place, though his method owes much to the painter’s approach to his subject. His basic motive as a writer was to defend We...

  10. Lewy Body Dementia

    Science.gov (United States)

    Lewy body dementia Overview Lewy body dementia, also known as dementia with Lewy bodies, is the second most common type of progressive dementia after Alzheimer's disease dementia. Protein deposits, ...

  11. Lewy Body Dementia Association

    Science.gov (United States)

    ... Now events There are no upcoming events. Lewy Body Digest September 2017 Lewy Digest Caregiving as a ... and research, we support those affected by Lewy body dementias, their families and caregivers. We are dedicated ...

  12. Extreme ultraviolet and soft x-ray diagnostics of high-temperature plasmas. Annual progress report, June 1, 1976--May 31, 1977

    International Nuclear Information System (INIS)

    Moos, H.W.; Armstrong, L. Jr.; Fastie, W.G.

    1977-01-01

    The results of the research program at this laboratory from mid February 1976 until January 31, 1977, are described. The four major research areas of the program: diagnostic studies of magnetically confined high temperature plasmas, supporting laboratory studies, theoretical studies of highly ionized atoms, and instrument development are discussed. Spatially resolved ultraviolet measurements on Elmo Bumpy Torus have determined impurity confinement times. The measured oxygen densities and fluxes are being determined at Alcator; the spectroscopic studies show that hydrogen discharges in this tokamak have an effective Z close to one. A laboratory study of the Penning discharge between 100 and 300 A shows that it is a bright source for evaluation of EUV diagnostic instrumentation. Design of a multispatial element spectrometer system is complete and construction has begun. A spectrophotometer compatible with both types of facilities is available for absolute intensity calibration transfer from the NBS SURF II facility to ERDA plasma facilities. Computer programs needed for relativistic calculation of transition probabilities and wavelengths have been completed and applied to calculations in the Li, Be, Ar, and K isoelectronic sequences

  13. Lewy Body Dementia Research

    Science.gov (United States)

    ... notices changes in at least one area of cognition, such as memory or language. Daytime Sleepiness is ... the field of Lewy body dementias. Memantine Improves Attention and Episodic Memory in Mild to Moderate Lewy ...

  14. Lewy Body Dementia Diagnosis

    Science.gov (United States)

    ... provide an experienced diagnostic team skilled in Lewy body dementia. A thorough dementia diagnostic evaluation includes physical ... a good way to benefit others with Lewy body dementia. Medications Medications are one of the most ...

  15. Lewy body dementias

    DEFF Research Database (Denmark)

    Løkkegaard, Annemette; Korbo, Lise

    2017-01-01

    Dementia with Lewy bodies and Parkinson disease dementia share the same pathophysiology. Together they are called Lewy body dementias and are the second most common type of dementia. Lewy body dementias receive little attention, and patients are often misdiagnosed, leading to less than ideal...

  16. Bernard Lewis: An Appreciation.

    Science.gov (United States)

    Humphreys, R. Stephen

    1990-01-01

    Discusses the career and publications of Bernard Lewis, a noted scholar in the field of Middle-Eastern studies and Islamic history. Traces the history of Western-based Islamic historiography. Examines Lewis' interpretation of Islamic history, outlining his political and social views. (RW)

  17. Lewis Acidic Ionic Liquids.

    Science.gov (United States)

    Brown, Lucy C; Hogg, James M; Swadźba-Kwaśny, Małgorzata

    2017-08-21

    Until very recently, the term Lewis acidic ionic liquids (ILs) was nearly synonymous with halometallate ILs, with a strong focus on chloroaluminate(III) systems. The first part of this review covers the historical context in which these were developed, speciation of a range of halometallate ionic liquids, attempts to quantify their Lewis acidity, and selected recent applications: in industrial alkylation processes, in supported systems (SILPs/SCILLs) and in inorganic synthesis. In the last decade, interesting alternatives to halometallate ILs have emerged, which can be divided into two sub-sections: (1) liquid coordination complexes (LCCs), still based on halometallate species, but less expensive and more diverse than halometallate ionic liquids, and (2) ILs with main-group Lewis acidic cations. The two following sections cover these new liquid Lewis acids, also highlighting speciation studies, Lewis acidity measurements, and applications.

  18. Evaluation of performance of select fusion experiments and projected reactors. Final report

    International Nuclear Information System (INIS)

    Miley, G.H.

    1978-10-01

    The performance of NASA Lewis fusion experiments (SUMMA and Bumpy Torus) is compared with other experiments and that necessary for a power reactor. Key parameters cited are gain (fusion power/input power) and the time average fusion power, both of which may be more significant for real fusion reactors than the commonly used Lawson parameter. The NASA devices are over 10 orders of magnitude below the required powerplant values in both gain and time average power. The best experiments elsewhere are also as much as 4 to 5 orders of magnitude low. However, the NASA experiments compare favorably with other alternate approaches that have received less funding than the mainline experiments. The steady-state character and efficiency of plasma heating are strong advantages of the NASA approach. The problem, though, is to move ahead to experiments of sufficient size to advance in gain and average power parameters

  19. Lewy body dementias

    DEFF Research Database (Denmark)

    Løkkegaard, Annemette; Korbo, Lise

    2017-01-01

    Dementia with Lewy bodies and Parkinson disease dementia share the same pathophysiology. Together they are called Lewy body dementias and are the second most common type of dementia. Lewy body dementias receive little attention, and patients are often misdiagnosed, leading to less than ideal...... management. In this article, diagnostic criteria combined with imaging and other biomarkers as well as current treatment recommendations are summarized, and some of the challenges for the future are outlined. Refinement of diagnosis and clarification of the pathogenesis are required in search for disease...

  20. Office of Fusion Energy recommendations on the Elmo Bumpy Torus proof-of-principle experiment site selection

    International Nuclear Information System (INIS)

    1980-01-01

    This report provies background information and rationale for the procedures used and decisions made up to this point. A brief history and technical description of the EBT concept are given. The OFE recommendations as to siting are included

  1. Elmo Bumpy Torus proof of principle. Phase II. Title 1 report. Volume III. Magnet system. Preliminary design report

    International Nuclear Information System (INIS)

    Ackerman, S.

    1982-01-01

    During Title I, General Dynamics' principal role as a subcontractor to the McDonnell Douglas Astronautics Company (MDAC) is to assist in the further development of a low-cost superconducting magnet mirror coil system for the EBT-P program consistent with long life and dependable operation. The activity can best be defined as an extension of ORNL's previous development program with further joint ORNL/MDAC/GDC refining of the mirror coil components. MDAC/GDC participation for the entire program can be subdivided into four distinct elements as follows: (1) design, development, and fabrication of two dewar subassemblies to enclose the ORNL developed and fabricated cold mass assemblies; (2) design, development, and fabrication of a production prototype magnet system including conductor (procurement), cold mass components, dewar and x-ray shield. This prototype would form the basis for the production of 36 magnets for the torus and three spares. (3) design, development, and fabrication of an electrical/electronic system including quench protection, instrumentation and control, and power supply to power and protect the mirror coil system during its operation in the torus; (4) fabrication of the 39 production magnets

  2. Bottoms up design of the Elmo Bumpy Torus - proof of principal (EBT-P) fusion research facility

    International Nuclear Information System (INIS)

    Erickson, D.T.

    1981-01-01

    The McDonnell Douglas Astronautics Company, under subcontract to the Union Carbide Corporation Nuclear Division at the DOE Oak Ridge National Laboratory has committed to furnish the EBT-P research facility. Gilbert Associates, Inc. of Reading, Pennysylvania, as the Architect and Engineering subcontractor has been selected for design and construction of this facility. The bottoms up effort to provide the EBT-P facility is now alive and well, with the property purchased, dedication ceremonies conducted, the Preliminary Design effort completed and detail design currently active

  3. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume V. Vacuum-pumping system. Preliminary design report

    International Nuclear Information System (INIS)

    1982-01-01

    This report summarizes Title I Preliminary Design of the EBT-P Vacuum Pumping System. The Vacuum Pumping System has been designed by the McDonnell Douglas Astronautics Co. - St. Louis (MDAC). It includes the necessary vacuum pumps and vacuum valves to evacuate the torus, the Mirror Coil Dewars (MC Dewars), and the Gyrotron Magnet Dewars. The pumping ducts, manifolds, and microwave protection system are also included. A summary of the function of each subsystem and a description of its principle components is provided below. The analyses performed during the system design are also identified

  4. Lewy Body Disease

    Science.gov (United States)

    ... range of symptoms, including Changes in alertness and attention Hallucinations Problems with movement and posture Muscle stiffness Confusion Loss of memory Lewy body disease can be hard to diagnose, ...

  5. Rejoinder to Lewis

    Directory of Open Access Journals (Sweden)

    Ashton Anderson

    2015-01-01

    Full Text Available In a response to our article “Political Ideology and Racial Preferences in Online Dating,” Kevin Lewis (2015 has raised concerns about various aspects of our analysis of user behavior on a national online dating site. The core of Lewis’ critique is that we do not report specifics of the sample, the website, and the analysis. Lewis also details numerous smaller points with respect to details of the analysis. The goal of this response is not to reply to every point that Lewis makes. As with any research project, our design decisions require tradeoffs, and readers should evaluate the evidence on their own. Rather, we use this space to make broader points about the general value for sociology of research using online data and how such research should be practiced.

  6. Ferrocene-based Lewis acids and Lewis pairs: Synthesis and ...

    Indian Academy of Sciences (India)

    The design and synthesis of molecules containing non-interacting Lewis base and Lewis acid groups. [Frustrated Lewis pairs (FLP's)] have received intense attention due to their potential applications in the area of molecular catalysis.1–3. For example,. Stephen's and co-workers have demonstrated that the unquenched ...

  7. Symptoms of Lewy Body Dementia

    Science.gov (United States)

    ... the fight against LBD! Donate Symptoms Lewy body dementia (LBD) has variable presentations that include cognitive difficulties ... wake cycle alterations. Cognitive impairment in Lewy body dementia (LBD) is often misdiagnosed as Alzheimer’s disease (AD). ...

  8. Lewis, Prof. Gilbert Newton

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1935 Honorary. Lewis, Prof. Gilbert Newton. Date of birth: 25 October 1875. Date of death: 24 March 1946. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held ...

  9. Frustrated Lewis Pairs

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 11. Frustrated Lewis Pairs : Enabling via inability. Sanjoy Mukherjee ... Author Affiliations. Sanjoy Mukherjee Pakkirisamy Thilagar1. Department of Inorgainic and Physical Chemistry Indian Institute of Science Bangalore 560 012, India.

  10. RAYS: a geometrical optics code for EBT

    International Nuclear Information System (INIS)

    Batchelor, D.B.; Goldfinger, R.C.

    1982-04-01

    The theory, structure, and operation of the code are described. Mathematical details of equilibrium subroutiones for slab, bumpy torus, and tokamak plasma geometry are presented. Wave dispersion and absorption subroutines are presented for frequencies ranging from ion cyclotron frequency to electron cyclotron frequency. Graphics postprocessors for RAYS output data are also described

  11. Minimum-B mirrors plus EBT principles

    International Nuclear Information System (INIS)

    Yoshikawa, S.

    1983-01-01

    Electrons are heated at the minimum B location(s) created by the multipole field and the toroidal field. Resulting hot electrons can assist plasma confinement by (1) providing mirror, (2) creating azimuthally symmetric toroidal confinement, or (3) creating modified bumpy torus

  12. Radial mode structure of curvature-driven instabilities in EBT

    International Nuclear Information System (INIS)

    Spong, D.A.

    1983-01-01

    Viewgraphs describe the theoretical treatment of the radial mode structure of plasma instabilities in the Elmo Bumpy Torus. The calculation retains nonlocal structure of the modes, connects inner and outer ring regions together, uses a self-consistent finite β, includes the relativistic effects for the hot electron ring, and examines a wide range of parameters

  13. Lewy Body Digest eNewsletter

    Science.gov (United States)

    ... resources Join the fight against LBD! Donate Lewy Digest Click here to subscribe today to receive regular ... research in Lewy body dementia. April 2018 Lewy Digest Month of Compassion Caregiver Spotlight Research Centers of ...

  14. On the axisymmetric Lewis metric

    International Nuclear Information System (INIS)

    Gariel, J.; Marcilhacy, G.

    2001-03-01

    We obtain the general solution of the axisymmetric stationary vacuum spacetime of Lewis. After precising the fundamental hypothesis of Lewis, we demonstrate that the solution is related to an arbitrary harmonic function. Formally, these solutions are the same as for the corresponding cylindrically symmetric case, and can be classified in a similar way. Furthermore, the interpretation, in the cylindrically symmetric system, of the field equations as decribing the motion of a classical particle in a central force field is still valid. (author)

  15. Lewis and Clark as Naturalists.

    Science.gov (United States)

    Smithsonian Institution, Washington, DC. National Museum of Natural History.

    Intended for use in elementary and high school education, this Web site includes a teacher's guide and three lesson plans. The site contains images of museum specimens, scientific drawings, and field photos of the plant and animal species observed by Meriwether Lewis and William Clark, along with journal excerpts, historical notes, and references…

  16. Electron transport in EBT in the low collision frequency limit

    International Nuclear Information System (INIS)

    Hastings, D.E.

    1983-01-01

    A variational principle formulation is used to calculate the electron neoclassical transport coefficients in a bumpy torus for the low collisionality regime. The electron radial drift is calculated as a function of the plasma position and the poloidal electric field which is determined self-consistently. A bounce-averaged differential collision operator is used and the results are compared to previous treatments using a BGK operator

  17. Unruly Woman: An Interview with Helen Lewis.

    Science.gov (United States)

    Briscoe, Lori; Collins, Erica S.; Deal, Amanda; Hancock, Ron; McGraw, Kristyn; Lewis, Helen

    2000-01-01

    Overviews the career of Helen Lewis as sociologist, social activist, teacher, writer, researcher, and mentor. Helen Lewis discusses growing up in segregated Georgia, her unorthodox approach to education, her fight for social and economic equality, her instrumental role in the development of Appalachian Studies programs, and how social activism…

  18. Frustrated Lewis pairs: Design and reactivity

    Indian Academy of Sciences (India)

    for FLP systems and their unique reactivity are discussed here. Keywords. Lewis .... we will concentrate on the design principles of such. FLPs and the ... Designs of frustrated Lewis pairs ..... 64 and neutral titanium (III) complex [Cp2TiOC6.

  19. Quantification of Lewis acid induced Brønsted acidity of protogenic Lewis bases.

    Science.gov (United States)

    Lathem, A Paige; Heiden, Zachariah M

    2017-05-09

    Proton transfer promoted by the coordination of protogenic Lewis bases to a Lewis acid is a critical step in catalytic transformations. Although the acidification of water upon coordination to a Lewis acid has been known for decades, no attempts have been made to correlate the Brønsted acidity of the coordinated water molecule with Lewis acid strength. To probe this effect, the pK a 's (estimated error of 1.3 pK a units) in acetonitrile of ten protogenic Lewis bases coordinated to seven Lewis acids containing Lewis acidities varying 70 kcal mol -1 , were computed. To quantify Lewis acid strength, the ability to transfer a hydride (hydride donor ability) from the respective main group hydride was used. Coordination of a Lewis acid to water increased the acidity of the bound water molecule between 20 and 50 pK a units. A linear correlation exhibiting a 2.6 pK a unit change of the Lewis acid-water adduct per ten kcal mol -1 change in hydride donor ability of the respective main group hydride was obtained. For the ten protogenic Lewis bases studied, the coordinated protogenic Lewis bases were acidified between 10 and 50 pK a units. On average, a ten kcal mol -1 change in hydride donor ability of the respective main group hydride resulted in about a 2.8 pK a unit change in the Brønsted acidity of the Lewis acid-Lewis base adducts. Since attempts to computationally investigate the pK a of main group dihydrogen complexes were unsuccessful, experimental determination of the first reported pK a of a main group dihydrogen complex is described. The pK a of H 2 -B(C 6 F 5 ) 3 was determined to be 5.8 ± 0.2 in acetonitrile.

  20. Nitrile ylides: diastereoselective cycloadditions using chiral oxazolidinones without Lewis acid.

    Science.gov (United States)

    Sibi, Mukund P; Soeta, Takahiro; Jasperse, Craig P

    2009-12-03

    Lewis acid complexation is generally required for chiral-auxiliary-controlled stereoselectivity, and chiral Lewis acid catalysis is frequently optimal for introducing asymmetry. In this work, we show that nitrile ylide cycloadditions to electron-poor acceptors attached to chiral auxiliaries proceed in high yield and stereoselectivity in the absence of Lewis acids. In contrast, chiral Lewis acids are inferior in these cycloadditions.

  1. SSTI- Lewis Spacecraft Nickel-Hydrogen Battery

    Science.gov (United States)

    Tobias, R. F.

    1997-01-01

    Topics considered include: NASA-Small Spacecraft Technology Initiative (SSTI) objectives, SSTI-Lewis overview, battery requirement, two cells Common Pressure Vessel (CPV) design summary, CPV electric performance, battery design summary, battery functional description, battery performance.

  2. Edward B Lewis (1918–2004)

    Indian Academy of Sciences (India)

    Administrator

    Ed Lewis spent his life working on the genetics of Dro- sophila with ... bithorax mutations, in which organs that control balance ... His pioneering work on homeotic genes induced ... a close and cooperative family within the larger scientific.

  3. Slovene critics on Sinclair Lewis's novels

    Directory of Open Access Journals (Sweden)

    Vanja Avsenak

    2010-12-01

    Full Text Available The purpose of this article is to present the reception of Sinclair Lewis's novels by Slovene critics. Initially, the article focuses on the life and workof Sinclair Lewis, giving special emphasis to social influences that made the author a representative figure in the literary and social world. Thus his works are nowadays to be understood primarily as fiction, but on the other hand also as sociological documents of a social and political situation of the period between the two world wars. Generally, the effect they produce is one of a critical discussion of the nation of the United States. When speaking of the social relevance that Lewis's novels have, it is obvious that his works are the portrayals of Americans and their deficiencies. At the time of their publication Lewis's novels received unfavourable criticism on accountof his overly open pro-European attitude and Slovene critics of the period before World War II emphasise this in much detail. It was precisely this anti-American propaganda in the novels themselves and sincerity on the part of the novelist that won the European critics as well as the readers whenit came to appreciating his works. However, Lewis's view of the Americans, as presented throughout his works, only enhanced his literary credibility as a modern writer. That is why the articles by Slovene critics that appeared after the Second World War, and even more significantly after Lewis's death, almost minutely reflect a more favourable attitude to Sinclair Lewis, which was also the case with foreign literary criticism of the post-war period. Critics still discuss the qualities and flaws of Lewis's novels, but being more lenient they no longer profess that the novels lack in artistic value. They remain, however, primarily relevant as social documents of the pre- and post-war era, which fully presented the American middle-class mentality in America and elsewhere. For this reason, the Nobel Prize for Literature awarded to

  4. Complexation of Nitrous Oxide by Frustrated Lewis Pairs

    NARCIS (Netherlands)

    Otten, Edwin; Neu, Rebecca C.; Stephan, Douglas W.

    2009-01-01

    Frustrated Lewis pairs comprised of a basic yet sterically encumbered phosphine with boron Lewis acids bind nitrous oxide to give intact PNNOB linkages. The synthesis, structure, and bonding of these species are described.

  5. Lewis x is highly expressed in normal tissues: a comparative immunohistochemical study and literature revision.

    Science.gov (United States)

    Croce, María V; Isla-Larrain, Marina; Rabassa, Martín E; Demichelis, Sandra; Colussi, Andrea G; Crespo, Marina; Lacunza, Ezequiel; Segal-Eiras, Amada

    2007-01-01

    An immunohistochemical analysis was employed to determine the expression of carbohydrate antigens associated to mucins in normal epithelia. Tissue samples were obtained as biopsies from normal breast (18), colon (35) and oral cavity mucosa (8). The following carbohydrate epitopes were studied: sialyl-Lewis x, Lewis x, Lewis y, Tn hapten, sialyl-Tn and Thomsen-Friedenreich antigen. Mucins were also studied employing antibodies against MUC1, MUC2, MUC4, MUC5AC, MUC6 and also normal colonic glycolipid. Statistical analysis was performed and Kendall correlations were obtained. Lewis x showed an apical pattern mainly at plasma membrane, although cytoplasmic staining was also found in most samples. TF, Tn and sTn haptens were detected in few specimens, while sLewis x was found in oral mucosa and breast tissue. Also, normal breast expressed MUC1 at a high percentage, whereas MUC4 was observed in a small number of samples. Colon specimens mainly expressed MUC2 and MUC1, while most oral mucosa samples expressed MUC4 and MUC1. A positive correlation between MUC1VNTR and TF epitope (r=0.396) was found in breast samples, while in colon specimens MUC2 and colonic glycolipid versus Lewis x were statistically significantly correlated (r=0.28 and r=0.29, respectively). As a conclusion, a defined carbohydrate epitope expression is not exclusive of normal tissue or a determined localization, and it is possible to assume that different glycoproteins and glycolipids may be carriers of carbohydrate antigens depending on the tissue localization considered.

  6. One hundred years of Lewis Chemical Bond!

    Indian Academy of Sciences (India)

    2016-09-20

    Sep 20, 2016 ... was a conceptual quantum jump, coming more than a decade ahead of ... did use a 'cubic model of atoms' with eight electrons in their corners, he realized that ... started referring to these advances as Lewis-Langmuir theory.

  7. Playing around in Lewis Carroll's "Alice" Books

    Science.gov (United States)

    Susina, Jan

    2010-01-01

    Mathematician Charles Dodgson's love of play and his need for rules came together in his use of popular games as part of the structure of the two famous children's books, "Alice in Wonderland" and "Through the Looking-Glass," he wrote under the pseudonym Lewis Carroll. The author of this article looks at the interplay between…

  8. The Critical Reception of Lewis Nordan

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2010-01-01

    The essay covers the critical reception of Mississippi-writer Lewis Nordan from his debut in 1983 to the boost in scholarly attention in the new millennium. The essay covers newspaper reviews but pays particular attention to the many academic essays that have placed Nordan as a writer...

  9. Lewis acid controlled regioselectivity in styrene hydrocyanation

    NARCIS (Netherlands)

    Bini, L.; Pidko, E.A.; Müller, C.; Santen, van R.A.; Vogt, D.

    2009-01-01

    According to present knowledge, the Ni-catalyzed hydrocyanation of styrene leads predominantly to the branched product 2-phenylpropionitrile (98%). We observed a dramatic inversion of the regioselectivity upon addition of a Lewis acid. Up to 83 % of the linear product 3-phenylpropionitrile was

  10. Frustrated Lewis pairs-assisted tritium labeling

    Czech Academy of Sciences Publication Activity Database

    Marek, Aleš; Široká, Sabina; Elbert, Tomáš

    2016-01-01

    Roč. 14, č. 5 (2016), s. 219 ISSN 2336-7202. [Sjezd českých a slovenských chemických společností /68./. 04.09.2016-07.09.2016, Praha] Institutional support: RVO:61388963 Keywords : frustrated Lewis pairs * one-pot synthesis * tritium -labeling Subject RIV: CC - Organic Chemistry

  11. Teaching Beginning Chemistry Students Simple Lewis Dot Structures

    Science.gov (United States)

    Nassiff, Peter; Czerwinski, Wendy A.

    2015-01-01

    Students beginning their initial study of chemistry often have a difficult time mastering simple Lewis dot structures. Textbooks show students how to manipulate Lewis structures by moving valence electron dots around the chemical structure so each atom has an octet or duet. However, an easier method of teaching Lewis structures for simple…

  12. A Biography of Distinguished Scientist Gilbert Newton Lewis (by Edward S. Lewis)

    Science.gov (United States)

    Harris, Reviewed By Harold H.

    1999-11-01

    The Edward Mellen Press: Lewiston, NY, 1998. 114 pp + index. ISBN 0-7734-8284-9. $69.95. There may not be a surname better known to students of chemistry than Lewis, from the Lewis electron-dot diagrams and the Lewis theory of acids and bases. More advanced students may know of the groundbreaking textbook Thermodynamics, by Lewis and Randall. Yet few Americans know much about this remarkable U.S.-born scholar, whose contributions equal those of the greatest scientists. He is a chemist-educator of whom we should be as proud and as well informed as we are of Linus Pauling, who was part of the westward movement of science in this country that G. N. Lewis began, or of the recently deceased Glenn Seaborg, who was one of the many students of Lewis who achieved renown. Gilbert N. Lewis was born in Weymouth, Massachusetts, in 1875, but his family moved to near Lincoln, Nebraska, in 1884. He spent two years at the University of Nebraska, but then moved to Harvard when his father became an executive at Merchants Trust Company in Boston. Young Lewis (then only 17) was also said to have been disappointed with the quality of education in Nebraska, and this may have been part of the impetus for the family's move east. After earning his baccalaureate at Harvard, he taught for a year at Phillips Andover Academy before returning to Harvard to study for his doctorate, which he completed 100 years ago, in 1899, under T. W. Richards. Lewis's doctoral work was on the thermodynamics of zinc and cadmium amalgams. At that time, physical chemistry was only beginning to achieve recognition as a branch of science, and its boundaries were ill defined. Edward Lewis quotes his father as often saying, "Physical chemistry is anything interesting." Like many chemists of his time, Lewis went to Europe to complete his preparation for a career; he was in the laboratories of Ostwald in Leipzig and Nernst in Göttingen in 1900-1901. On his return to the United States, he was an instructor at Harvard

  13. C. S. Lewis: The Romantic Rationalist

    Directory of Open Access Journals (Sweden)

    Vasiliu Daniela

    2014-12-01

    Full Text Available The paper “C. S. Lewis: The Romantic Rationalist” presents the way C. S. Lewis gives an account in his first fictional (allegorical book, The Pilgrim’s Regress, of how he discovered Christianity on the converging paths of romanticism and rationalism. The outstanding scholar and author whose intellectual and spiritual development has turned him into one of the most influential Christian writers of the twentieth century became an atheist in his teens and after a long journey through different philosophical convictions he converted to Christianity in his early thirties, a change that affected his entire work. His love of literature was essential in discovering both the rational and the imaginative appeal of Christianity, which led him into a vision of the reality of the world and of life that satisfied the longing of his heart and the hunger of his imagination.

  14. Capgras' syndrome in dementia with Lewy bodies.

    Science.gov (United States)

    Marantz, Andrew G; Verghese, Joe

    2002-01-01

    We report the occurrence of Capgras' syndrome, or the delusion of doubles, in a patient with dementia with Lewy bodies. The patient believed that several similar-looking impostors had replaced his wife of over 50 years. Uncharacteristically, he adopted a friendly attitude with these impostors. This unusual convivial reaction to the impostors may result from differential involvement of the dual visual pathways processing facial recognition and emotional responses to faces. The delusion resolved spontaneously, coincident with worsening of the dementia. In a retrospective chart review of 18 autopsy-confirmed cases of dementia with Lewy bodies, delusions were reported in 5 subjects (27.8%), of whom 1 had misidentification delusions much like Capgras' syndrome.

  15. Rendezvous, un juego de Lewis Carroll

    Directory of Open Access Journals (Sweden)

    José Manuel Sánchez Muñoz

    2011-10-01

    Full Text Available Todos en mayor o menor medida asociamos el nombre de Lewis Carrolla la literatura, sobre todo a la de temática infantil, con títulos a sus espaldas como Alicia en el País de las Maravillas, Alicia a través del espejo, o La Caza del Snark. Pero además de literato, Lewis Carrol fue un hombre con bastantes inquietudes en torno a la matemática, la lógica y el pensamiento filosófico. Pero no todo el mundo es conocedor de su faceta como creativo en el campo de los juegos. Rendezvous es una de sus más sorprendentes invenciones,un juego de inteligencia para todos los públicos, cuyas directrices hacen de él un entretenimiento bastante original.

  16. Ermakov–Lewis invariants and Reid systems

    Energy Technology Data Exchange (ETDEWEB)

    Mancas, Stefan C., E-mail: stefan.mancas@erau.edu [Department of Mathematics, Embry-Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICyT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San José 2055, Col. Lomas 4a Sección, 78216 San Luis Potosí, S.L.P. (Mexico)

    2014-06-13

    Reid's mth-order generalized Ermakov systems of nonlinear coupling constant α are equivalent to an integrable Emden–Fowler equation. The standard Ermakov–Lewis invariant is discussed from this perspective, and a closed formula for the invariant is obtained for the higher-order Reid systems (m≥3). We also discuss the parametric solutions of these systems of equations through the integration of the Emden–Fowler equation and present an example of a dynamical system for which the invariant is equivalent to the total energy. - Highlights: • Reid systems of order m are connected to Emden–Fowler equations. • General expressions for the Ermakov–Lewis invariants both for m=2 and m≥3 are obtained. • Parametric solutions of the Emden–Fowler equations related to Reid systems are obtained.

  17. Lewis Information Network (LINK): Background and overview

    Science.gov (United States)

    Schulte, Roger R.

    1987-01-01

    The NASA Lewis Research Center supports many research facilities with many isolated buildings, including wind tunnels, test cells, and research laboratories. These facilities are all located on a 350 acre campus adjacent to the Cleveland Hopkins Airport. The function of NASA-Lewis is to do basic and applied research in all areas of aeronautics, fluid mechanics, materials and structures, space propulsion, and energy systems. These functions require a great variety of remote high speed, high volume data communications for computing and interactive graphic capabilities. In addition, new requirements for local distribution of intercenter video teleconferencing and data communications via satellite have developed. To address these and future communications requirements for the next 15 yrs, a project team was organized to design and implement a new high speed communication system that would handle both data and video information in a common lab-wide Local Area Network. The project team selected cable television broadband coaxial cable technology as the communications medium and first installation of in-ground cable began in the summer of 1980. The Lewis Information Network (LINK) became operational in August 1982 and has become the backbone of all data communications and video.

  18. Lewis' Educational and Research Collaborative Internship Program

    Science.gov (United States)

    Heyward, Ann; Gott, Susan (Technical Monitor)

    2004-01-01

    The Lewis Educational and Research Collaborative Internship Program (LERCIP) is a collaborative undertaking by the Office of Educational Programs at NASA Glenn Research Center at Lewis Field (formerly NASA Lewis Research Center) and the Ohio Aerospace Institute. This program provides 10-week internships in addition to summer and winter extensions if funding is available and/or is requested by mentor (no less than 1 week no more than 4 weeks) for undergraduate/graduate students and secondary school teachers. Students who meet the travel reimbursement criteria receive up to $500 for travel expenses. Approximately 178 interns are selected to participate in this program each year and begin arriving the fourth week in May. The internships provide students with introductory professional experiences to complement their academic programs. The interns are given assignments on research and development projects under the personal guidance of NASA professional staff members. Each intern is assigned a NASA mentor who facilitates a research assignment. In addition to the research assignment, the summer program includes a strong educational component that enhances the professional stature of the participants. The educational activities include a research symposium and a variety of workshops, and lectures. An important aspect of the program is that it includes students with diverse social, cultural and economic backgrounds. The purpose of this report is to document the program accomplishments for 2004.

  19. Ablative Material Testing at Lewis Rocket Lab

    Science.gov (United States)

    1997-01-01

    The increasing demand for a low-cost, reliable way to launch commercial payloads to low- Earth orbit has led to the need for inexpensive, expendable propulsion systems for new launch vehicles. This, in turn, has renewed interest in less complex, uncooled rocket engines that have combustion chambers and exhaust nozzles fabricated from ablative materials. A number of aerospace propulsion system manufacturers have utilized NASA Lewis Research Center's test facilities with a high degree of success to evaluate candidate materials for application to new propulsion devices.

  20. Interview with Smithsonian NASM Spacesuit Curator Dr. Cathleen Lewis

    Science.gov (United States)

    Lewis, Cathleen; Wright, Rebecca

    2012-01-01

    Dr. Cathleen Lewis was interviewed by Rebecca Wright during the presentation of an "Interview with Smithsonian NASM Spacesuit Curator Dr. Cathleen Lewis" on May 14, 2012. Topics included the care, size, and history of the spacesuit collection at the Smithsonian and the recent move to the state-of-the-art permanent storage facility at the Udvar-Hazy facility in Virginia.

  1. LEWIS BINFORD AND HIS MORAL MAJORITY (Lewis Binford y su mayoría moral

    Directory of Open Access Journals (Sweden)

    Alice Beck Kehoe

    2011-06-01

    Full Text Available This essay looks at the late Lewis Binford’s career from the standpoint of sociology of science. His thinking and manner reflect his socialization in Virginia Baptist subculture. As convinced of his authority on science as Jerry Falwell was of his authority on Biblical morality, Lewis Binford and his third wife Sally Rosen Binford excited a group of 1960s students to follow Lewis in an outmoded version of science (hypothetico-deductive and in trusting statistics. The “frames of reference” he laboriously constructed are naïve on environmental interpretation and, because he expressed contempt for “political” aspects of archaeology, fail to take into account effects of colonialism. His work is often scientistic, in the “modern” mode that historian Dorothy Ross describes as characteristic of twentieth-century American social sciences. ESPAÑOL: En este ensayo se analiza la etapa final de la carrera de Lewis Binford desde el punto de vista de la sociología de la ciencia. Su pensamiento refleja su socialización en el seno de la subcultura de la Virginia baptista. Tan convencido de su autoridad en la ciencia como Jerry Falwell lo fuera sobre la moralidad bíblica, Lewis Binford y su tercera esposa Sally Rosen Binford animaron a un grupo estudiantes de los sesenta a seguir a Lewis a través de una versión anticuada de la ciencia (hipotético-deductiva y a confiar en la estadística. Los “marcos de referencia” que laboriosamente construyó son ingenuos en la interpretación del medio ambiente y, como expresó el desprecio por los aspectos “políticos” de la arqueología, no tienen en cuenta los efectos del colonialismo. Su trabajo es a menudo cientificista, en el sentido “moderno” que la historiadora Dorothy Ross describe como una característica de las ciencias sociales norteamericanas del siglo XX.

  2. Nuclear pursuits: The scientific biography of Wilfrid Bennett Lewis

    International Nuclear Information System (INIS)

    Fawcett, R.

    1994-01-01

    The scientific life of Wilfrid Bennett Lewis. The biography covers Lewis's role in the development of radar, his tenure as the Chief Superintendent of the Telecommunications Research Establishment at Malvern through his heading of the then fledgling Canadian nuclear research facility in Chalk River, Ontario. Lewis's drive, intelligence, and remarkable organizational skills placed him at the forefront of Canada's nuclear program. His influence lead to a collaboration between Atomic Energy of Canada Limited and Ontario Hydro that ultimately resulted in the development of the CANDU reactor. His influence was also profound in the near by town of Deep River with one prime legacy being the W.B. Lewis Library. Lewis's bibliography is included in the biography

  3. Data processing system for NBT experiments

    International Nuclear Information System (INIS)

    Takahashi, C.; Hosokawa, M.; Shoji, T.; Fujiwara, M.

    1981-07-01

    Data processing system for Nagoya Bumpy Torus (NBT) has been developed. Since plasmas are produced and heated in steady state by use of high power microwaves, sampling and processing data prevails in long time scale on the order of one minute. The system, which consists of NOVA 3/12 minicomputer and many data acquisition devices, is designed to sample and process large amount of data before the next discharge starts. Several features of such long time scale data processing system are described in detail. (author)

  4. S3C: EBT Steady-State Shooting code description and user's guide

    International Nuclear Information System (INIS)

    Downum, W.B.

    1983-09-01

    The Oak Ridge National Laboratory (ORNL) one-dimensional (1-D) Steady-State Shooting code (S3C) for ELMO Bumpy Torus (EBT) plasmas is described. Benchmark calculations finding the steady-state density and electron and ion temperature profiles for a known neutral density profile and known external energy sources are carried out. Good agreement is obtained with results from the ORNL Radially Resolved Time Dependent 1-D Transport code for an EBT-Q type reactor. The program logic is described, along with the physics models in each code block and the variable names used. Sample input and output files are listed, along with the main code

  5. [Clinical Neuropsychology of Dementia with Lewy Bodies].

    Science.gov (United States)

    Nagahama, Yasuhiro

    2016-02-01

    Dementia with Lewy bodies (DLB) shows lesser memory impairment and more severe visuospatial disability than Alzheimer disease (AD). Although deficits in both consolidation and retrieval underlie the memory impairment, retrieval deficit is predominant in DLB. Visuospatial dysfunctions in DLB are related to the impairments in both ventral and dorsal streams of higher visual information processing, and lower visual processing in V1/V2 may also be impaired. Attention and executive functions are more widely disturbed in DLB than in AD. Imitation of finger gestures is impaired more frequently in DLB than in other mild dementia, and provides additional information for diagnosis of mild dementia, especially for DLB. Pareidolia, which lies between hallucination and visual misperception, is found frequently in DLB, but its mechanism is still under investigation.

  6. Superconducting microwave electronics at Lewis Research Center

    Science.gov (United States)

    Warner, Joseph D.; Bhasin, Kul B.; Leonard, Regis F.

    Over the last three years, NASA Lewis Research Center has investigated the application of newly discovered high temperature superconductors to microwave electronics. Using thin films of YBa2Cu3O7-delta and Tl2Ca2Ba2Cu3Ox deposited on a variety of substrates, including strontium titanate, lanthanum gallate, lanthanum aluminate and magnesium oxide, a number of microwave circuits have been fabricated and evaluated. These include a cavity resonator at 60 GHz, microstrip resonators at 35 GHz, a superconducting antenna array at 35 GHz, a dielectric resonator at 9 GHz, and a microstrip filter at 5 GHz. Performance of some of these circuits as well as suggestions for other applications are reported.

  7. Superconducting Microwave Electronics at Lewis Research Center

    Science.gov (United States)

    Warner, Joseph D.; Bhasin, Kul B.; Leonard, Regis F.

    1991-01-01

    Over the last three years, NASA Lewis Research Center has investigated the application of newly discovered high temperature superconductors to microwave electronics. Using thin films of YBa2Cu3O7-delta and Tl2Ca2Ba2Cu3Ox deposited on a variety of substrates, including strontium titanate, lanthanum gallate, lanthanum aluminate and magnesium oxide, a number of microwave circuits have been fabricated and evaluated. These include a cavity resonator at 60 GHz, microstrip resonators at 35 GHz, a superconducting antenna array at 35 GHz, a dielectric resonator at 9 GHz, and a microstrip filter at 5 GHz. Performance of some of these circuits as well as suggestions for other applications are reported.

  8. Lewis-Sumner syndrome and Tangier disease.

    Science.gov (United States)

    Théaudin, Marie; Couvert, Philippe; Fournier, Emmanuel; Bouige, Daniel; Bruckert, Eric; Perrotte, Paul; Vaschalde, Yvan; Maisonobe, Thierry; Bonnefont-Rousselot, Dominique; Carrié, Alain; Le Forestier, Nadine

    2008-07-01

    To report unusual electrophysiologic data in a patient with Tangier disease in an effort to better understand the pathophysiologic features of the peripheral nerve lesions in this disease. Case report. A 15-year-old girl had subacute onset of asymmetric neuropathy with persistent conduction block, resembling Lewis-Sumner syndrome. Electrophysiologic data in Tangier disease. After initially unsuccessful treatment with intravenously administered immunoglobulins, the finding of an abnormal lipid profile led to the diagnosis of Tangier disease due to the R587W mutation in the adenotriphosphate-binding cassette transporter-1 gene (ABCA1) (OMIM 9q22-q31). Conduction block, which is the electrophysiologic hallmark of focal demyelination, can be present in Tangier disease. It could be induced by focal nerve ischemia or by preferential lipid deposition in the paranodal regions of myelinated Schwann cells. The presence of a conduction block in Tangier disease may lead to a misdiagnosis of dysimmune neuropathy.

  9. C. S. Lewis, Reluctant Convert and (not so Ordinary Anglican

    Directory of Open Access Journals (Sweden)

    Mănăstireanu Dănuţ

    2014-12-01

    Full Text Available After some passing considerations on the reception of Lewis in Romania, the present paper discusses the role played by Anglicanism in the late personal commitment of C.S. Lewis to the Christian faith, after years of atheism, scepticism, and agnosticism. It argues that in fact Anglicanism contributed very little to Lewis’s (reconversion to Christianity. Furthermore, the paper agrees with the generally accepted idea that the particular calling that Lewis felt he had, that of being a Christian apologist, made him wary of being associated with the defence of any specific Christian tradition. In virtue of this special calling, Lewis also reacted quite strongly against certain aspects of Anglicanism, like, for instance, the ordination of women to priesthood, which he perceived as an obstacle to ecumenism and, implicitly, to an effective defence of the Christian faith in the public arena. In spite of all this, there is little doubt that Lewis has fully and unreservedly adopted Anglicanism as his preferred version of Christianity. From this particular stance, the life and ministry of C.S. Lewis made a huge public impact in the twentieth century and beyond. In light of the undeniable influence he had on the intellectual and religious scene in the last hundred years, one may ask not so much how Anglican was Lewis, but, rather, ‘why isn’t Anglicanism more like Lewis’.

  10. Increase in the Hydrophilicity and Lewis Acid-Base Properties of Solid Surfaces Achieved by Electric Gliding Discharge in Humid Air: Effects on Bacterial Adherence

    International Nuclear Information System (INIS)

    Kamgang, J. O.; Brisset, J.-L.; Naitali, M.; Herry, J.-M.; Bellon-Fontaine, M.-N.; Briandet, R.

    2009-01-01

    This study addressed the effects of treatment with gliding discharge plasma on the surface properties of solid materials, as well as the consequences concerning adherence of a model bacterium. As evaluated by contact angles with selected liquids, plasma treatment caused an increase in surface hydrophilicity and in the Lewis acid-base components of the surface energy of all materials tested. These modifications were more marked for low density polyethylene and stainless steel than for polytetrafluoroethylene. After treatment, the hydrophilicity of the materials remained relatively stable for at least 20 days. Moreover, analysis of the topography of the materials by atomic force microscopy revealed that the roughness of both polymers was reduced by glidarc plasma treatment. As a result of all these modifications, solid substrates were activated towards micro-organisms and the adherence of S. epidermidis, a negatively charged Lewis-base and mildly hydrophilic strain selected as the model, was increased in almost all the cases tested. (plasma technology)

  11. NASA Lewis Research Center's materials and structures division

    International Nuclear Information System (INIS)

    Weymueller, C.R.

    1976-01-01

    Research activities at the NASA Lewis Research Center on materials and structures are discussed. Programs are noted on powder metallurgy superalloys, eutectic alloys, dispersion strengthened alloys and composite materials. Discussions are included on materials applications, coatings, fracture mechanics, and fatigue

  12. Is It Lewy Body Dementia or Something Else?

    Science.gov (United States)

    ... Options Join the fight against LBD! Donate Is It LBD or Something Else? Early and accurate diagnosis ... dementia with Lewy bodies’ (DLB). Symptoms that differentiate it from Alzheimer’s include unpredictable levels of cognitive ability, ...

  13. Distance Learning With NASA Lewis Research Center's Learning Technologies Project

    Science.gov (United States)

    Petersen, Ruth

    1998-01-01

    The NASA Lewis Research Center's Learning Technologies Project (LTP) has responded to requests from local school district technology coordinators to provide content for videoconferencing workshops. Over the past year we have offered three teacher professional development workshops that showcase NASA Lewis-developed educational products and NASA educational Internet sites. In order to determine the direction of our involvement with distance learning, the LTP staff conducted a survey of 500 U.S. schools. We received responses from 72 schools that either currently use distance learning or will be using distance learning in 98-99 school year. The results of the survey are summarized in the article. In addition, the article provides information on distance learners, distance learning technologies, and the NASA Lewis LTP videoconferencing workshops. The LTP staff will continue to offer teacher development workshops through videoconferencing during the 98-99 school year. We hope to add workshops on new educational products as they are developed at NASA Lewis.

  14. I-Metaiodobenzylguanidine Myocardial Scintigraphy in Lewy Body-Related Disorders: A Literature Review

    Directory of Open Access Journals (Sweden)

    Eun Joo Chung

    2015-05-01

    Full Text Available Lewy body-related disorders are characterized by the presence of Lewy bodies and Lewy neurites, which have abnormal aggregations of α-synuclein in the nigral and extranigral areas, including in the heart. 123I-metaiodobenzylguanidine (MIBG scintigraphy is a well-known tool to evaluate cardiac sympathetic denervation in the Lewy body-related disorders. MIBG scintigraphy showed low uptake of MIBG in the Lewy body-related disorders, including Parkinson’s disease, dementia with Lewy bodies, pure autonomic failure and rapid eye movement sleep behavior disorder. This review summarizes previous results on the diagnostic applications of MIBG scintigraphy in Lewy body-related disorders.

  15. Lewis Research Center space station electric power system test facilities

    Science.gov (United States)

    Birchenough, Arthur G.; Martin, Donald F.

    1988-01-01

    NASA Lewis Research Center facilities were developed to support testing of the Space Station Electric Power System. The capabilities and plans for these facilities are described. The three facilities which are required in the Phase C/D testing, the Power Systems Facility, the Space Power Facility, and the EPS Simulation Lab, are described in detail. The responsibilities of NASA Lewis and outside groups in conducting tests are also discussed.

  16. Chiral lewis Acid catalysis in nitrile oxide cycloadditions.

    Science.gov (United States)

    Sibi, Mukund P; Itoh, Kennosuke; Jasperse, Craig P

    2004-05-05

    We describe examples of highly regio- and enantioselective nitrile oxide cycloadditions to unsaturated alkenes using substoichiometric amounts of a chiral Lewis acid. Pyrazolidinones proved to be effective achiral templates in the cycloadditions providing C-adducts typically in >30:1 selectivity and 80-99% ee. To avoid potential problems involving coordination of the Lewis acid by amine bases, we have devised a novel method for the generation of unstable nitrile oxides from hydroximinoyl chlorides using Amberlyst 21 as the base.

  17. Tribute to Erwin Felix Lewy-Bertaut

    International Nuclear Information System (INIS)

    2006-01-01

    Erwin Lewy (alias Felix Bertaut) was born in 1913 in Germany, he emigrated to France where he undertook graduate studies in chemistry. Then, he joined the powder central laboratory where he learnt how to use international tables for structure determination. His thesis work was the X-ray study of the statistical distribution of the size of iron grains. The method Bertaut developed is still a reference in powder granulometry. Bertaut was also interested in the nascent neutron diffraction method and he flew to the United-States to improve his knowledge on this topic. Felix Bertaut created the neutron diffraction laboratory in the atomic research center in Grenoble and later he headed the CNRS' crystallography laboratory till 1982. Felix Bertaut and his laboratories became internationally renowned in crystallography, neutron diffraction and magnetism. He favored the scientific cooperation between France and Germany that led to the creation of the Laue-Langevin Institute (ILL). The ILL became European and was a key partner for building the European Synchrotron Facility (ESRF) in Grenoble. Bertaut was elected as a full member of the French Academy of Sciences in 1979, he died in 2003. (A.C.)

  18. Lewis Research Center R and D Facilities

    Science.gov (United States)

    1991-01-01

    The NASA Lewis Research Center (LeRC) defines and develops advanced technology for high priority national needs. The work of the Center is directed toward new propulsion, power, and communications technologies for application to aeronautics and space, so that U.S. leadership in these areas is ensured. The end product is knowledge, usually in a report, that is made fully available to potential users--the aircraft engine industry, the energy industry, the automotive industry, the space industry, and other NASA centers. In addition to offices and laboratories for almost every kind of physical research in such fields as fluid mechanics, physics, materials, fuels, combustion, thermodynamics, lubrication, heat transfer, and electronics, LeRC has a variety of engineering test cells for experiments with components such as compressors, pumps, conductors, turbines, nozzles, and controls. A number of large facilities can simulate the operating environment for a complete system: altitude chambers for aircraft engines; large supersonic wind tunnels for advanced airframes and propulsion systems; space simulation chambers for electric rockets or spacecraft; and a 420-foot-deep zero-gravity facility for microgravity experiments. Some problems are amenable to detection and solution only in the complete system and at essentially full scale. By combining basic research in pertinent disciplines and generic technologies with applied research on components and complete systems, LeRC has become one of the most productive centers in its field in the world. This brochure describes a number of the facilities that provide LeRC with its exceptional capabilities.

  19. Lewy body dementia--clinical, pathological and neurochemical interconnections.

    Science.gov (United States)

    Perry, R; McKeith, I; Perry, E

    1997-01-01

    Senile dementia of Lewy body type or Lewy body dementia (SDLT or LBD) is defined as a Lewy body associated disease presenting in the elderly primarily with dementia with variable extrapyramidal disorder. Characteristic clinical symptoms include fluctuating cognitive impairment, psychotic features such as hallucinations and a particular sensitivity to neuroleptic medication. Although apolipoprotein e4 allele is increased 2-3 fold in SDLT (as in Alzheimer's disease) and beta-amyloidosis occurs in most cases, the most robust neurobiological correlate of the dementia so far identified appears to be extensive cholinergic deficits in the neocortex. This is consistent with previously reported correlations between cortical cholinergic activity and dementia in Parkinson's disease (PD) and Alzheimer's disease. There is also a significant interaction between the density of limbic cortical Lewy bodies and dementia in both SDLT and PD, although the cortical neuronal population affected remains to be identified. Cortical Lewy body density is positively correlated with the age of disease onset in PD and SDLT. This may account for the increased incidence of psychiatric syndromes, as opposed to extrapyramidal disorder in Lewy body disease with advancing age as may age-related loss of cholinergic activity in cortical areas such as the hippocampus.

  20. Capgras syndrome in Dementia with Lewy Bodies.

    Science.gov (United States)

    Thaipisuttikul, Papan; Lobach, Iryna; Zweig, Yael; Gurnani, Ashita; Galvin, James E

    2013-05-01

    Capgras syndrome is characterized by the recurrent, transient belief that a person has been replaced by an identical imposter. We reviewed clinical characteristics of Dementia with Lewy Bodies (DLB) patients with Capgras syndrome compared to those without Capgras. We identified 55 consecutive DLB patients (11 cases with Capgras syndrome (DLB-C) and 44 cases without evidence of Capgras (DLB). Semi-structured interviews with the patient and an informant, neurological exams, and neuropsychological testing were performed. Caregivers were assessed for caregiver burden and depression. Primary comparisons were made between DLB-C and DLB. Exploratory analyses using stepwise logistic regression and bootstrap analyses were performed to determine clinical features associated with Capgras. DLB-C patients experienced more visual hallucinations and self-reported anxiety, had higher scores on the Neuropsychiatric Inventory, and were less likely to be treated with cholinesterase inhibitors at time of initial evaluation. Extrapyramidal symptoms and depression were not associated with Capgras. Caregivers of DLB-C patients had higher caregiver burden. DLB-C was associated with self-reported anxiety (OR = 10.9; 95% CI = 2.6-47.6). In a bootstrap analysis, clinical findings that were predictors of Capgras included visual hallucinations (log(OR) = 18.3; 95% CI = 17.9-19.3) and anxiety (log(OR) = 2.9; 95% CI = 0.31-20.2). Our study suggests that Capgras syndrome is common in DLB and usually occurs in the presence of anxiety and visual hallucinations, suggesting related etiopathogenesis. Early appreciation of Capgras syndrome may afford the opportunity to alleviate caregiver burden and improve patient and caregiver outcomes.

  1. Pareidolias: complex visual illusions in dementia with Lewy bodies.

    Science.gov (United States)

    Uchiyama, Makoto; Nishio, Yoshiyuki; Yokoi, Kayoko; Hirayama, Kazumi; Imamura, Toru; Shimomura, Tatsuo; Mori, Etsuro

    2012-08-01

    Patients rarely experience visual hallucinations while being observed by clinicians. Therefore, instruments to detect visual hallucinations directly from patients are needed. Pareidolias, which are complex visual illusions involving ambiguous forms that are perceived as meaningful objects, are analogous to visual hallucinations and have the potential to be a surrogate indicator of visual hallucinations. In this study, we explored the clinical utility of a newly developed instrument for evoking pareidolic illusions, the Pareidolia test, in patients with dementia with Lewy bodies-one of the most common causes of visual hallucinations in the elderly. Thirty-four patients with dementia with Lewy bodies, 34 patients with Alzheimer's disease and 26 healthy controls were given the Pareidolia test. Patients with dementia with Lewy bodies produced a much greater number of pareidolic illusions compared with those with Alzheimer's disease or controls. A receiver operating characteristic analysis demonstrated that the number of pareidolias differentiated dementia with Lewy bodies from Alzheimer's disease with a sensitivity of 100% and a specificity of 88%. Full-length figures and faces of people and animals accounted for >80% of the contents of pareidolias. Pareidolias were observed in patients with dementia with Lewy bodies who had visual hallucinations as well as those who did not have visual hallucinations, suggesting that pareidolias do not reflect visual hallucinations themselves but may reflect susceptibility to visual hallucinations. A sub-analysis of patients with dementia with Lewy bodies who were or were not treated with donepzil demonstrated that the numbers of pareidolias were correlated with visuoperceptual abilities in the former and with indices of hallucinations and delusional misidentifications in the latter. Arousal and attentional deficits mediated by abnormal cholinergic mechanisms and visuoperceptual dysfunctions are likely to contribute to the development

  2. Intralaminar nuclei of the thalamus in Lewy body diseases.

    Science.gov (United States)

    Brooks, Daniel; Halliday, Glenda M

    2009-02-16

    Although the intralaminar thalamus is a target of alpha-synuclein pathology in Parkinson's disease, the degree of neuronal loss in Lewy body diseases has not been assessed. We have used unbiased stereological techniques to quantify neuronal loss in intralaminar thalamic nuclei concentrating alpha-synuclein pathology (the anterodorsal, cucullar, parataenial, paraventricular, central medial, central lateral and centre-median/parafascicular complex) in different clinical forms of Lewy body disease (Parkinson's disease with and without dementia, and dementia with Lewy bodies, N=21) compared with controls (N=5). Associations were performed in the Lewy body cases between intralaminar cell loss and the main diagnostic clinical (parkinsonism, dementia, fluctuation in consciousness, and visual hallucinations) and pathological (Braak stage of Parkinson's disease) features of these diseases, as well as between cell loss and the scaled severity of the alpha-synuclein deposition within the intralaminar thalamus. As expected, significant alpha-synuclein accumulation occurred in the intralaminar thalamus in the cases with Lewy body disease. Pathology concentrated anteriorly and in the central lateral and paraventricular nuclei was related to the Braak stage of Parkinson's disease, ageing, and the presence of dementia. Across all types of Lewy body cases there was substantial atrophy and neuronal loss in the central lateral, cucullar and parataenial nuclei, and neuronal loss without atrophy in the centre-median/parafascicular complex. Cases with visual hallucinations showed a greater degree of atrophy of the cucullar nucleus, possibly due to amygdala denervation. The significant degeneration demonstrated in the intralaminar thalamus is likely to contribute to the movement and cognitive dysfunction observed in Lewy body disorders.

  3. Lewy and his inclusion bodies: Discovery and rejection

    Directory of Open Access Journals (Sweden)

    Eliasz Engelhardt

    Full Text Available ABSTRACT Fritz Jacob Heinrich Lewy described the pathology of Paralysis agitans [Parkinson disease] and was the first to identify eosinophilic inclusion bodies in neurons of certain brain nuclei, later known as Lewy bodies, the pathological signature of the Lewy body diseases. In 1912, he published his seminal study, followed soon after by an update paper, and 10 years later, in 1923, by his voluminous book, where he exhaustively described the subject. The publication provided extensive information on the pathology of Paralysis agitans, and the entirely novel finding of eosinophilic inclusion bodies, which would become widely recognized and debated in the future. His discovery was acknowledged by important researchers who even named the structure after him. However, after his last publication on the issue, inexplicably, he never mentioned his histopathological discovery again. Despite several hypotheses, the reasons that led him to neglect (reject the structure which he so preeminently described have remained elusive.

  4. Sudden Death: An Uncommon Occurrence in Dementia with Lewy Bodies.

    Science.gov (United States)

    Molenaar, Joery P; Wilbers, Joyce; Aerts, Marjolein B; Leijten, Quinten H; van Dijk, Jan G; Esselink, Rianne A; Bloem, Bastiaan R

    2016-01-01

    We present a 75-year-old woman with dementia and parkinsonism who developed severe orthostatic hypotension and eventually died. Autopsy revealed extensive Lewy body formation in the midbrain, limbic system, intermediate spinal cord, and medulla oblongata. Furthermore, a vast amount of Lewy bodies was seen in the paravertebral sympathetic ganglia which likely explained the severe autonomic failure. We speculate that this autonomic failure caused sudden death through dysregulation of respiration or heart rhythm, reminiscent of sudden death in multiple system atrophy (MSA). Clinicians should be aware of this complication in patients presenting with parkinsonism and autonomic dysfunction, and that sudden death may occur in dementia with Lewy bodies (DLB) as it does in MSA.

  5. Fugle og andre observationer på Lewis og Harris

    DEFF Research Database (Denmark)

    Provencal, Philippe

    2017-01-01

    En beskrivelse af observationer af især fugle men også nogle få pattedyr på øen Lewis and Harris i de Ydre Hebrider. Observationerne fandt sted fra den 19. til den 23- april 2017.......En beskrivelse af observationer af især fugle men også nogle få pattedyr på øen Lewis and Harris i de Ydre Hebrider. Observationerne fandt sted fra den 19. til den 23- april 2017....

  6. Lewis acid enhanced switching of the 1,1-dicyanodihydroazulene/vinylheptafulvene photo/thermoswitch

    DEFF Research Database (Denmark)

    Parker, Christian Richard; Tortzen, Christian Gregers; Broman, Søren Lindbæk

    2011-01-01

    Mild Lewis acids enhance the rate of the thermal conversion of vinylheptafulvene (VHF) to dihydroazulene (DHA). In the absence of light, stronger Lewis acids promote the otherwise photoinduced DHA to VHF conversion.......Mild Lewis acids enhance the rate of the thermal conversion of vinylheptafulvene (VHF) to dihydroazulene (DHA). In the absence of light, stronger Lewis acids promote the otherwise photoinduced DHA to VHF conversion....

  7. preparation of bicyclic lactones using lewis acids catalyzed ene

    African Journals Online (AJOL)

    Administrator

    The synthesis of the cis-fused bicyclic lactones relies extensively on the Lewis acid ... having an allylic hydrogen (an"ene") and a compound containing an electron .... observed that the lithium enolate obtained from 3-methyl-2(5H)- furanone ...

  8. Frustrated Lewis pairs-assisted reduction of carbonyl compounds

    Czech Academy of Sciences Publication Activity Database

    Marek, Aleš; Pedersen, M. H. F.

    2015-01-01

    Roč. 71, č. 6 (2015), s. 917-921 ISSN 0040-4020 Institutional support: RVO:61388963 Keywords : frustrated Lewis pairs * hydrogen activation * benzyl alcohol * tritium labeling * labeled compounds Subject RIV: CC - Organic Chemistry Impact factor: 2.645, year: 2015

  9. Q & A with Ed Tech Leaders: Interview with Brian Lewis

    Science.gov (United States)

    Shaughnessy, Michael F.; Fulgham, Susan M.

    2013-01-01

    Brian Lewis, International Society for Technology in Education (ISTE) chief executive officer, is an education advocate and leader specializing in management and governance, policy, corporate communications, branding, and marketing. He provides leadership to ISTE's Washington, DC, and Eugene, Oregon, offices and directs organizational…

  10. Daniel Day-Lewis - veri peab voolama / Kristiina Davidjants

    Index Scriptorium Estoniae

    Davidjants, Kristiina, 1974-

    2008-01-01

    Iiri-juudi näitleja Daniel Day-Lewis, kes võitis oma rolliga P.T. Andersoni filmis "Veri hakkab voolama" parima meespeaosatäitja Oscari. Tema põhjalikust tööst rollidega läbi tema filmiloomingu

  11. Who Needs Lewis Structures to Get VSEPR Geometries?

    Science.gov (United States)

    Lindmark, Alan F.

    2010-01-01

    Teaching the VSEPR (valence shell electron-pair repulsion) model can be a tedious process. Traditionally, Lewis structures are drawn and the number of "electron clouds" (groups) around the central atom are counted and related to the standard VSEPR table of possible geometries. A simpler method to deduce the VSEPR structure without first drawing…

  12. Bibliography of Lewis Research Center Technical Publications announced in 1991

    Science.gov (United States)

    1992-01-01

    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific engineering work performed and managed by the Lewis Research Center in 1991. All the publications were announced in the 1991 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses.

  13. Frustrated Lewis pairs-assisted reduction of carbonyl compounds

    DEFF Research Database (Denmark)

    Marek, Ales; Pedersen, Martin Holst Friborg

    2015-01-01

    An alternative and robust method for the reduction of carbonyl groups by frustrated Lewis pairs (FLPs) is reported in this paper. With its very mild reaction conditions, good to excellent yields, absolute regioselectivity and the non-metallic character of the reagent, it provides an excellent too...

  14. Reduced CSF CART in dementia with Lewy bodies

    DEFF Research Database (Denmark)

    Schultz, Kristofer; Wiehager, Sara; Nilsson, Karin

    2009-01-01

    Dementia with Lewy bodies (DLB) is the second most common form of neurodegenerative dementia after Alzheimer's disease (AD). The underlying neurobiological mechanism of DLB is not fully understood and no generally accepted biomarkers are yet available for the diagnosis of DLB. In a recent MRI study...

  15. Modified NASA-Lewis chemical equilibrium code for MHD applications

    Science.gov (United States)

    Sacks, R. A.; Geyer, H. K.; Grammel, S. J.; Doss, E. D.

    1979-01-01

    A substantially modified version of the NASA-Lewis Chemical Equilibrium Code was recently developed. The modifications were designed to extend the power and convenience of the Code as a tool for performing combustor analysis for MHD systems studies. The effect of the programming details is described from a user point of view.

  16. Fullerene–Carbene Lewis Acid–Base Adducts

    KAUST Repository

    Li, Huaping; Risko, Chad; Seo, Jung Hwa; Campbell, Casey; Wu, Guang; Brédas, Jean-Luc; Bazan, Guillermo C.

    2011-01-01

    The reaction between a bulky N-heterocylic carbene (NHC) and C60 leads to the formation of a thermally stable zwitterionic Lewis acid-base adduct that is connected via a C-C single bond. Low-energy absorption bands with weak oscillator strengths

  17. File list: DNS.Lng.10.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Lng.10.AllAg.Carcinoma,_Lewis_Lung mm9 DNase-seq Lung Carcinoma, Lewis Lung htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Lng.10.AllAg.Carcinoma,_Lewis_Lung.bed ...

  18. File list: DNS.Lng.50.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Lng.50.AllAg.Carcinoma,_Lewis_Lung mm9 DNase-seq Lung Carcinoma, Lewis Lung htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Lng.50.AllAg.Carcinoma,_Lewis_Lung.bed ...

  19. File list: Unc.Lng.20.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Lng.20.AllAg.Carcinoma,_Lewis_Lung mm9 Unclassified Lung Carcinoma, Lewis Lung ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Lng.20.AllAg.Carcinoma,_Lewis_Lung.bed ...

  20. File list: Oth.Lng.05.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Lng.05.AllAg.Carcinoma,_Lewis_Lung mm9 TFs and others Lung Carcinoma, Lewis Lun...g http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Lng.05.AllAg.Carcinoma,_Lewis_Lung.bed ...

  1. File list: His.Lng.05.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Lng.05.AllAg.Carcinoma,_Lewis_Lung mm9 Histone Lung Carcinoma, Lewis Lung SRX10...91778,SRX1091782,SRX1091783,SRX1091781,SRX1091784,SRX1091779,SRX1091785,SRX1091780 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Lng.05.AllAg.Carcinoma,_Lewis_Lung.bed ...

  2. File list: Pol.Lng.50.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Lng.50.AllAg.Carcinoma,_Lewis_Lung mm9 RNA polymerase Lung Carcinoma, Lewis Lun...g http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Lng.50.AllAg.Carcinoma,_Lewis_Lung.bed ...

  3. File list: Pol.Lng.05.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Lng.05.AllAg.Carcinoma,_Lewis_Lung mm9 RNA polymerase Lung Carcinoma, Lewis Lun...g http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Lng.05.AllAg.Carcinoma,_Lewis_Lung.bed ...

  4. File list: Pol.Lng.10.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Lng.10.AllAg.Carcinoma,_Lewis_Lung mm9 RNA polymerase Lung Carcinoma, Lewis Lun...g http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Lng.10.AllAg.Carcinoma,_Lewis_Lung.bed ...

  5. File list: DNS.Lng.20.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Lng.20.AllAg.Carcinoma,_Lewis_Lung mm9 DNase-seq Lung Carcinoma, Lewis Lung htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Lng.20.AllAg.Carcinoma,_Lewis_Lung.bed ...

  6. Monocyte chemotactic protein-1 deficiency attenuates and high-fat diet exacerbates bone loss in mice with Lewis lung carcinoma.

    Science.gov (United States)

    Yan, Lin; Nielsen, Forrest H; Sundaram, Sneha; Cao, Jay

    2017-04-04

    Bone loss occurs in obesity and cancer-associated complications including wasting. This study determined whether a high-fat diet and a deficiency in monocyte chemotactic protein-1 (MCP-1) altered bone structural defects in male C57BL/6 mice with Lewis lung carcinoma (LLC) metastases in lungs. Compared to non-tumor-bearing mice, LLC reduced bone volume fraction, connectivity density, trabecular number, trabecular thickness and bone mineral density and increased trabecular separation in femurs. Similar changes occurred in vertebrae. The high-fat diet compared to the AIN93G diet exacerbated LLC-induced detrimental structural changes; the exacerbation was greater in femurs than in vertebrae. Mice deficient in MCP-1 compared to wild-type mice exhibited increases in bone volume fraction, connectivity density, trabecular number and decreases in trabecular separation in both femurs and vertebrae, and increases in trabecular thickness and bone mineral density and a decrease in structure model index in vertebrae. Lewis lung carcinoma significantly decreased osteocalcin but increased tartrate-resistant acid phosphatase 5b (TRAP 5b) in plasma. In LLC-bearing mice, the high-fat diet increased and MCP-1 deficiency decreased plasma TRAP 5b; neither the high-fat diet nor MCP-1 deficiency resulted in significant changes in plasma concentration of osteocalcin. In conclusion, pulmonary metastasis of LLC is accompanied by detrimental bone structural changes; MCP-1 deficiency attenuates and high-fat diet exacerbates the metastasis-associated bone wasting.

  7. Tribute to Erwin Felix Lewy-Bertaut; Hommage a Erwin Felix Lewy-Bertaut

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Erwin Lewy (alias Felix Bertaut) was born in 1913 in Germany, he emigrated to France where he undertook graduate studies in chemistry. Then, he joined the powder central laboratory where he learnt how to use international tables for structure determination. His thesis work was the X-ray study of the statistical distribution of the size of iron grains. The method Bertaut developed is still a reference in powder granulometry. Bertaut was also interested in the nascent neutron diffraction method and he flew to the United-States to improve his knowledge on this topic. Felix Bertaut created the neutron diffraction laboratory in the atomic research center in Grenoble and later he headed the CNRS' crystallography laboratory till 1982. Felix Bertaut and his laboratories became internationally renowned in crystallography, neutron diffraction and magnetism. He favored the scientific cooperation between France and Germany that led to the creation of the Laue-Langevin Institute (ILL). The ILL became European and was a key partner for building the European Synchrotron Facility (ESRF) in Grenoble. Bertaut was elected as a full member of the French Academy of Sciences in 1979, he died in 2003. (A.C.)

  8. Lewis basicity of relevant monoanions in a non-protogenic organic solvent using a zinc(ii) Schiff-base complex as a reference Lewis acid.

    Science.gov (United States)

    Oliveri, Ivan Pietro; Di Bella, Santo

    2017-09-12

    Anions are ubiquitous species playing a primary role in chemistry, whose reactivity is essentially dominated by their Lewis basicity. However, no Lewis basicity data, in terms of Gibbs energy, are reported in the literature. We report here the first Lewis basicity of relevant monoanions through the determination of binding constants for the formation of stable 1 : 1 adducts, using a Zn II Schiff-base complex, 1, as a reference Lewis acid. Binding constants for equilibrium reactions were achieved through a nonlinear regression analysis of the binding isotherms from spectrophotometric titration data. The Lewis acidic complex 1 is a proper reference species because it forms stable adducts with both neutral and charged Lewis bases, thus allowing ranking their Lewis basicity. Binding constants indicate generally a strong Lewis basicity for all involved anions, rivalling or exceeding that of the stronger neutral bases, such as primary amines or pyridine. The cyanide anion results to be the strongest Lewis base, while the nitrate is the weaker base within the present anion series. Moreover, even the weaker base anions behave as stronger bases than the most common non-protogenic coordinating solvents.

  9. Incorporating spectroscopic on-line monitoring as a method of detection for a Lewis cell setup

    Energy Technology Data Exchange (ETDEWEB)

    Heller, Forrest D.; Casella, Amanda J.; Lumetta, Gregg J.; Nash, Kenneth L.; Sinkov, Sergey I.; Bryan, Samuel A.

    2017-01-01

    A Lewis cell was designed and constructed for investigating solvent extraction systems by spectrophotometrically monitoring both the organic and aqueous phases in real time. This new Lewis cell was tested and shown to perform well compared to other previously reported Lewis cell designs. The advantage of the new design is that the spectroscopic measurement allows determination of not only metal ion concentrations, but also information regarding chemical speciation—information not available with previous Lewis cell designs. For convenience, the new Lewis cell design was dubbed COSMOFLEX (COntinuous Spectroscopic MOnitoring of Forrest’s Liquid-liquid EXtraction cell).

  10. Effect of unequal fuel and oxidizer Lewis numbers on flame dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Shamim, Tariq [Department of Mechanical Engineering, The University of Michigan-Dearborn, Dearborn, MI 48128-1491 (United States)

    2006-12-15

    The interaction of non-unity Lewis number (due to preferential diffusion and/or unequal rates of heat and mass transfer) with the coupled effect of radiation, chemistry and unsteadiness alters several characteristics of a flame. The present study numerically investigates this interaction with a particular emphasis on the effect of unequal and non-unity fuel and oxidizer Lewis numbers in a transient diffusion flame. The unsteadiness is simulated by considering the flame subjected to modulations in reactant concentration. Flames with different Lewis numbers (ranging from 0.5 to 2) and subjected to different modulating frequencies are considered. The results show that the coupled effect of Lewis number and unsteadiness strongly influences the flame dynamics. The impact is stronger at high modulating frequencies and strain rates, particularly for large values of Lewis numbers. Compared to the oxidizer side Lewis number, the fuel side Lewis number has greater influence on flame dynamics. (author)

  11. The Organization of Narrative Discourse in Lewy Body Spectrum Disorder

    Science.gov (United States)

    Ash, Sharon; McMillan, Corey; Gross, Rachel G.; Cook, Philip; Morgan, Brianna; Boller, Ashley; Dreyfuss, Michael; Siderowf, Andrew; Grossman, Murray

    2011-01-01

    Narrative discourse is an essential component of day-to-day communication, but little is known about narrative in Lewy Body spectrum disorder (LBSD), including Parkinson's disease (PD), Parkinson's disease with dementia (PDD), and dementia with Lewy bodies (DLB). We performed a detailed analysis of a semi-structured speech sample in 32 non-aphasic patients with LBSD, and we related their narrative impairments to gray matter (GM) atrophy using voxel-based morphometry. We found that patients with PDD and DLB have significant difficulty organizing their narrative speech. This was correlated with deficits on measures of executive functioning and speech fluency. Regression analyses associated this deficit with reduced cortical volume in inferior frontal and anterior cingulate regions. These findings are consistent with a model of narrative discourse that includes executive as well as language components and with an impairment of the organizational component of narrative discourse in patients with PDD and DLB. PMID:21689852

  12. Operational criteria for senile dementia of Lewy body type (SDLT).

    Science.gov (United States)

    McKeith, I G; Perry, R H; Fairbairn, A F; Jabeen, S; Perry, E K

    1992-11-01

    Recent reports have suggested that brain stem and cortical Lewy body formation may identify a neurodegenerative disorder in elderly demented individuals which accounts for up to 20% of cases of senile dementia coming to autopsy. Retrospective analysis of case notes of 21 autopsy patients with neuropathologically proven senile dementia of Lewy body type (SDLT) and 37 cases with neuropathologically proven Alzheimer's disease (AD) identified a characteristic clinical syndrome in SDLT. Fluctuating cognitive impairment; psychotic features including visual and auditory hallucinations, and paranoid delusions; depressive symptoms; falling and unexplained losses of consciousness were all seen significantly more often than in AD. Over half of the SDLT patients in this series who were given neuroleptics in standard dose showed acute and often irreversible adverse reactions indicative of a neuroleptic sensitivity syndrome. The survival time of drug treated patients was reduced by 50%. Operational criteria to aid in the clinical distinction between SDLT and AD patients are proposed and hypotheses regarding possible aetiology and treatment discussed.

  13. Imidazolinium and amidinium salts as Lewis acid organocatalysts

    Directory of Open Access Journals (Sweden)

    Oksana Sereda

    2012-10-01

    Full Text Available The application of imidazolinium and amidinium salts as soft Lewis acid organocatalysts is described. These salts were suitable catalysts for the activation of unsaturated thioesters in a Diels–Alder reaction and in the ring opening of thiiranes and epoxides. The products were isolated in good yields. The mild catalysts did not cause desulfurization of the products containing a thiol or thiocarbonyl group.

  14. Improved Lignin Polyurethane Properties with Lewis Acid Treatment

    OpenAIRE

    Chung, Hoyong; Washburn, Newell R.

    2012-01-01

    Chemical modification strategies to improve the mechanical properties of lignin-based polyurethanes are presented. We hypothesized that treatment of lignin with Lewis acids would increase the concentration of hydroxyl groups available to react with diisocyanate monomers. Under the conditions used, hydrogen bromide-catalyzed modification resulted in a 28% increase in hydroxyl group content. Associated increases in hydrophilicity of solvent-cast thin films were also recorded as evidenced by ...

  15. Bibliography of Lewis Research Center technical publications announced in 1990

    Science.gov (United States)

    1991-01-01

    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1990. All the publications were announced in the 1990 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses.

  16. Bibliography of Lewis Research Center technical publications announced in 1992

    Science.gov (United States)

    1993-01-01

    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1992. All the publications were announced in the 1992 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses.

  17. Bibliography of Lewis Research Center technical publications announced in 1993

    Science.gov (United States)

    1994-01-01

    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1993. All the publications were announced in the 1993 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses.

  18. Bibliography of Lewis Research Center technical publications announced in 1989

    Science.gov (United States)

    1990-01-01

    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1989. All the publications were announced in the 1989 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses.

  19. Lewis' Educational and Research Collaborative Intership Program Grant Closeout Report

    Science.gov (United States)

    2003-01-01

    The Lewis' Educational and Research Collaborative Internship Program (LERCIP) is a collaborative undertaking by the Office of Educational Programs at NASA Glenn Research Center at Lewis Field (formerly NASA Lewis Research Center) and the Ohio Aerospace Institute. This program provides 10-week internships and 10 or 12-week fellowships for undergraduate/graduate students and secondary school teachers. Approximately 130 interns are selected to participate in this program each year and begin arriving the second week in May. The internships provide students with introductory professional experiences to complement their academic programs. The interns are given assignments on research and development projects under the personal guidance of NASA professional staff members. Each intern is assigned a NASA mentor who facilitates a research assignment. In addition to the research assignment, the summer program includes a strong educational component that enhances the professional stature of the participants. The educational activities include a research symposium and a variety of workshops, lectures and short courses. An important aspect of the program is that it includes students with diverse social, cultural and economic backgrounds.

  20. Developing an approach for teaching and learning about Lewis structures

    Science.gov (United States)

    Kaufmann, Ilana; Hamza, Karim M.; Rundgren, Carl-Johan; Eriksson, Lars

    2017-08-01

    This study explores first-year university students' reasoning as they learn to draw Lewis structures. We also present a theoretical account of the formal procedure commonly taught for drawing these structures. Students' discussions during problem-solving activities were video recorded and detailed analyses of the discussions were made through the use of practical epistemology analysis (PEA). Our results show that the formal procedure was central for drawing Lewis structures, but its use varied depending on situational aspects. Commonly, the use of individual steps of the formal procedure was contingent on experiences of chemical structures, and other information such as the characteristics of the problem given. The analysis revealed a number of patterns in how students constructed, checked and modified the structure in relation to the formal procedure and the situational aspects. We suggest that explicitly teaching the formal procedure as a process of constructing, checking and modifying might be helpful for students learning to draw Lewis structures. By doing so, the students may learn to check the accuracy of the generated structure not only in relation to the octet rule and formal charge, but also to other experiences that are not explicitly included in the formal procedure.

  1. Development of Fluorous Lewis Acid-Catalyzed Reactions

    Directory of Open Access Journals (Sweden)

    Joji Nishikido

    2006-08-01

    Full Text Available Organic synthetic methodology in the 21st century aims to conform to the principles of green sustainable chemistry (GSC and we may expect that in the future, the realization of GSC will be an important objective for chemical industries. An important aim of synthetic organic chemistry is to implement waste-free and environmentally-benign industrial processes using Lewis acids as versatile as aluminum choride. A key technological objective of our work in this area has been to achieve a “catalyst recycling system that utilizes the high activity and structural features of fluorous Lewis acid catalysts”. Thus, we have developed a series of novel fluorous Lewis acid catalysts, namely the ytterbium(III, scandium(III, tin(IV or hafnium(IV bis(perfluoroalkanesulfonylamides or tris(perfluoro- alkanesulfonylmethides. Our catalysts are recyclable and effective for acylations of alcohols and aromatics, Baeyer-Villiger reactions, direct esterifications and transesterifications in a fluorous biphasic system (FBS, in supercritical carbon dioxide and on fluorous silica gel supports.

  2. Fullerene–Carbene Lewis Acid–Base Adducts

    KAUST Repository

    Li, Huaping

    2011-08-17

    The reaction between a bulky N-heterocylic carbene (NHC) and C60 leads to the formation of a thermally stable zwitterionic Lewis acid-base adduct that is connected via a C-C single bond. Low-energy absorption bands with weak oscillator strengths similar to those of n-doped fullerenes were observed for the product, consistent with a net transfer of electron density to the C60 core. Corroborating information was obtained using UV photoelectron spectroscopy, which revealed that the adduct has an ionization potential ∼1.5 eV lower than that of C60. Density functional theory calculations showed that the C-C bond is polarized, with a total charge of +0.84e located on the NHC framework and -0.84e delocalized on the C 60 cage. The combination of reactivity, characterization, and theoretical studies demonstrates that fullerenes can behave as Lewis acids that react with C-based Lewis bases and that the overall process describes n-doping via C-C bond formation. © 2011 American Chemical Society.

  3. Lewis acid catalyzed transformations of Z-ligustilide

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Maria Yolanda [Universidad Autonoma del Estado de Morelos, Cuernavaca, Morelos (Mexico); Delgado, Guillermo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    1999-08-01

    Some Lewis acid mediated reactions of Z-ligustilide (1), a bioactive constituent of the medicinal species Ligusticum porteri, were investigated. These reactions provided varying mixtures of Z-butylidenephthalide (7), E-butylidenephthalide (8), n-butyphthalide (13), and novel linear dimeric phthalides (9-12) as the main products. The formation of the dimers occurred in low yields and with regio and situ-selectivity. Initial competitive O- and C- complexation of the Lewis acid with Z-ligustilide promoted the formation of the dimers occurred in low yields and with regio and situ- selectivity. Initial competitive O- and C- complexation of the Lewis acid with Z-ligustilide promoted the formation of carbocations at C(8), C(6) and C(7), which were stabilized by the addition of the C(6')-C(7') olefin of a second unit of the starting material, to provide cations at C(6') and C(7'). Subsequent isomerizations and elimination of the catalyst afforded the dimeric products 9-12. The yields and structure of the products are quite dependent on variations of the reaction conditions and the catalyst employed. [Spanish] Se investigaron algunas reacciones de Z-ligustilidas (1), un constituyente bioactivo de la planta medicinal Ligusticum porteri, catalizadas por acidos de Lewis. Estas reacciones produjeron mezclas variables de Z-butilidenftalida (7), E-butilidenftalida (8), n-butilftalida (13), y ftalidos dimetricos lineales novedosos (9-12) como productos principales. La formacion de los dimeros procedio en rendimientos bajos y con regio- y situ-selectividad. La O- y C- complejacion competitiva inicial del acido de Lewis con Z-lingustilida promueve la formacion de cationes en C(8), C(6) y C(7), los cuales son estabilizados por la adicion de la olefina C(6')-C(7') de una segunda unidad de la materia prima para generar los cationes en C(6')-C(7'). Isomerizaciones subsecuentes y la eliminacion del catalizador conducen a los productos dimericos 9

  4. The NASA-Lewis program on fusion energy for space power and propulsion, 1958-1978

    International Nuclear Information System (INIS)

    Schulze, N.R.; Roth, J.R.

    1991-01-01

    This paper presents a retrospective summary and bibliography of the National Aeronautics and Space Administration research program on fusion energy for space power and propulsion systems conducted at the Lewis Research Center. This effort extended over a 20-yr period ending in 1978, involved several hundred person-years of effort, and included theory, experiment, technology development, and mission analysis. This program was initiated in 1958 and was carried out within the Electromagnetic Propulsion Division. Within this division, mission analysis and basic research on high-temperature plasma physics were carried out in the Advanced Concepts Branch. Three pioneering high-field superconducting magnetic confinement facilities were developed with the support of the Magnetics and Cryophysics Branch. The results of this program serve as a basis for subsequent discussions of the space applications of fusion energy, contribute to the understanding of high-temperature plasmas and how to produce them, and advance the state of the art of superconducting magnet technology used in fusion research

  5. Gilbert Newton Lewis: his influence on physical-organic chemists at Berkeley

    International Nuclear Information System (INIS)

    Calvin, M.

    1982-03-01

    A review is presented of the historical contributions of Gilbert N. Lewis to science and a discussion of the influence of Lewis on the research of the members of the physical-organic staff at Berkeley, including Melvin Calvin, during the twenties, thirties and forties. Some specific examples are discussed. Also, the effect of Lewis, his science and administrative concepts in the creation of excellence in a department of chemistry are reviewed

  6. Gilbert Newton Lewis: his influence on physical-organic chemists at Berkeley

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, M.

    1982-03-01

    A review is presented of the historical contributions of Gilbert N. Lewis to science and a discussion of the influence of Lewis on the research of the members of the physical-organic staff at Berkeley, including Melvin Calvin, during the twenties, thirties and forties. Some specific examples are discussed. Also, the effect of Lewis, his science and administrative concepts in the creation of excellence in a department of chemistry are reviewed.

  7. NASA Lewis and Ohio Company Hit Hole in One

    Science.gov (United States)

    1998-01-01

    Ben Hogan Company's Golf Ball Division, which is based in Elyria, Ohio, had developed concepts and prototypes for new golf balls but was unable to determine exact performance characteristics. Specifically, the company's R&D department wanted to measure the spin rates of experimental golf balls. After the Golf Ball Division requested assistance, researchers and technicians from the NASA Lewis Research Center went to Elyria and conducted several days worth of tests. Ben Hogan is using the test results to improve the spin characteristics of a new ball it plans to introduce to the market.

  8. Feminine Hypostases in Epic Fantasy: Tolkien, Lewis, Rowling

    Directory of Open Access Journals (Sweden)

    Măcineanu Laura

    2015-12-01

    Full Text Available The paper identifies the types of female figures present in the works of three well-known fantasy writers, J.R.R. Tolkien, C.S. Lewis and J.K. Rowling, discussing the ways in which these characters are presented, their relationship with other characters, and their role in the economy of the novel, which is more important than may appear from a first reading. It also tries to explain the reasons that prompted the above-mentioned authors to choose these female hypostases.

  9. Telecommuting (Work-At-Home) at NASA Lewis Research Center

    Science.gov (United States)

    Srinidhi, Saragur M.

    1994-01-01

    This report presents a study in evaluating the viability of providing a work-at-home (telecommuting) program for Lewis Research Center's corporate employees using Integrated Services Digital Network (ISDN). Case studies have been presented for a range of applications from casual data access to interactive access. The network performance of telemedia applications were studied against future requirements for such level of remote connectivity. Many of the popular ISDN devices were characterized for network and service functionality. A set of recommendations to develop a telecommuting policy have been proposed.

  10. NASA Lewis advanced IPV nickel-hydrogen technology

    Science.gov (United States)

    Smithrick, John J.; Britton, Doris L.

    1993-01-01

    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts. Some of the advancements are as follows: to use 26 percent potassium hydroxide electrolyte to improve cycle life and performance, to modify the state of the art cell design to eliminate identified failure modes and further improve cycle life, and to develop a lightweight nickel electrode to reduce battery mass, hence reduce launch and/or increase satellite payload. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen battery cells was reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 accelerated LEO cycles at 80 percent DOD compared to 3,500 cycles for cells containing 31 percent KOH. Results of the boiler plate cell tests have been validated at NWSC, Crane, Indiana. Forty-eight ampere-hour flight cells containing 26 and 31 percent KOH have undergone real time LEO cycle life testing at an 80 percent DOD, 10 C. The three cells containing 26 percent KOH failed on the average at cycle 19,500. The three cells containing 31 percent KOH failed on the average at cycle 6,400. Validation testing of NASA Lewis 125 Ah advanced design IPV nickel-hydrogen flight cells is also being conducted at NWSC, Crane, Indiana under a NASA Lewis contract. This consists of characterization, storage, and cycle life testing. There was no capacity degradation after 52 days of storage with the cells in the discharged state, on open circuit, 0 C, and a hydrogen pressure of 14.5 psia. The catalyzed wall wick cells have been cycled for over 22,694 cycles with no cell failures in the continuing test. All three of the non-catalyzed wall wick cells failed (cycles 9,588; 13,900; and 20,575). Cycle life test results of the Fibrex nickel electrode has demonstrated the feasibility of an improved nickel electrode giving a higher specific energy nickel-hydrogen cell. A nickel-hydrogen boiler plate cell using an 80

  11. Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes.

    Science.gov (United States)

    Denmark, Scott E; Chung, Won-Jin

    2008-06-20

    A catalytic system involving silicon tetrachloride and a chiral, Lewis basic bisphosphoramide catalyst is effective for the addition of glycolate-derived silyl ketene acetals to aldehydes. It was found that the sense of diastereoselectivity could be modulated by changing the size of the substituents on the silyl ketene acetals. In general, the trimethylsilyl ketene acetals derived from methyl glycolates with a large protecting group on the alpha-oxygen provide enantiomerically enriched alpha,beta-dihydroxy esters with high syn-diastereoselectivity, whereas the tert-butyldimethylsilyl ketene acetals derived from bulky esters of alpha-methoxyacetic acid provide enantiomerically enriched alpha,beta-dihydroxy esters with high anti-diastereoselecitvity.

  12. Molecular Imaging and Updated Diagnostic Criteria in Lewy Body Dementias.

    Science.gov (United States)

    Bohnen, Nicolaas I; Müller, Martijn L T M; Frey, Kirk A

    2017-08-14

    The aims of the study were to review recent advances in molecular imaging in the Lewy body dementias (LBD) and determine if these may support the clinical but contested temporal profile distinction between Parkinson disease (PD) with dementia (PDD) versus dementia with Lewy bodies (DLB). There do not appear to be major regional cerebral metabolic or neurotransmitter distinctions between PDD and DLB. However, recent studies highlight the relative discriminating roles of Alzheimer proteinopathies. PDD patients have lower cortical β-amyloid deposition than DLB. Preliminary tau PET studies suggest a gradient of increasing tau binding from cognitively normal PD (absent to lowest) to cognitively impaired PD (low) to DLB (intermediate) to Alzheimer disease (AD; highest). However, tau binding in DLB, including the medial temporal lobe, is substantially lower than in AD. Alzheimer-type proteinopathies appear to be more common in DLB compared to PDD with relative but no absolute differences. Given the spectrum of overlapping pathologies, future α-synuclein ligands are expected to have the best potential to distinguish the LBD from pure AD.

  13. Lewis Acid Assisted Nitrate Reduction with Biomimetic Molybdenum Oxotransferase Complex.

    Science.gov (United States)

    Elrod, Lee Taylor; Kim, Eunsuk

    2018-03-05

    The reduction of nitrate (NO 3 - ) to nitrite (NO 2 - ) is of significant biological and environmental importance. While Mo IV (O) and Mo VI (O) 2 complexes that mimic the active site structure of nitrate reducing enzymes are prevalent, few of these model complexes can reduce nitrate to nitrite through oxygen atom transfer (OAT) chemistry. We present a novel strategy to induce nitrate reduction chemistry of a previously known catalyst Mo IV (O)(SN) 2 (2), where SN = bis(4- tert-butylphenyl)-2-pyridylmethanethiolate, that is otherwise incapable of achieving OAT with nitrate. Addition of nitrate with the Lewis acid Sc(OTf) 3 (OTf = trifluoromethanesulfonate) to 2 results in an immediate and clean conversion of 2 to Mo VI (O) 2 (SN) 2 (1). The Lewis acid additive further reacts with the OAT product, nitrite, to form N 2 O and O 2 . This work highlights the ability of Sc 3+ additives to expand the reactivity scope of an existing Mo IV (O) complex together with which Sc 3+ can convert nitrate to stable gaseous molecules.

  14. Impairments of speech fluency in Lewy body spectrum disorder.

    Science.gov (United States)

    Ash, Sharon; McMillan, Corey; Gross, Rachel G; Cook, Philip; Gunawardena, Delani; Morgan, Brianna; Boller, Ashley; Siderowf, Andrew; Grossman, Murray

    2012-03-01

    Few studies have examined connected speech in demented and non-demented patients with Parkinson's disease (PD). We assessed the speech production of 35 patients with Lewy body spectrum disorder (LBSD), including non-demented PD patients, patients with PD dementia (PDD), and patients with dementia with Lewy bodies (DLB), in a semi-structured narrative speech sample in order to characterize impairments of speech fluency and to determine the factors contributing to reduced speech fluency in these patients. Both demented and non-demented PD patients exhibited reduced speech fluency, characterized by reduced overall speech rate and long pauses between sentences. Reduced speech rate in LBSD correlated with measures of between-utterance pauses, executive functioning, and grammatical comprehension. Regression analyses related non-fluent speech, grammatical difficulty, and executive difficulty to atrophy in frontal brain regions. These findings indicate that multiple factors contribute to slowed speech in LBSD, and this is mediated in part by disease in frontal brain regions. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Specific acid catalysis and Lewis acid catalysis of Diels–Alder reactions in aqueous media

    NARCIS (Netherlands)

    Mubofu, Egid B.; Engberts, Jan B.F.N.

    2004-01-01

    A comparative study of specific acid catalysis and Lewis acid catalysis of Diels–Alder reactions between dienophiles (1, 4 and 6) and cyclopentadiene (2) in water and mixed aqueous media is reported. The reactions were performed in water with copper(II) nitrate as the Lewis acid catalyst whereas

  16. An Integrated Perspective of Humanism and Supernaturalism for Education: C. S. Lewis's Version of Education

    Science.gov (United States)

    Lee, Seung Chun

    2013-01-01

    This paper explores some theoretical reflections on the connection between C. S. Lewis's thoughts on the purpose and process of education and his understanding of supernatural human nature which has been relatively little explored. An introduction about Lewis's career as a college teacher blends into the background of this paper. It is followed by…

  17. Nest-site selection and nest survival of Lewis's woodpecker in aspen riparian woodlands

    Science.gov (United States)

    Karen R. Newlon; Victoria A. Saab

    2011-01-01

    Riparian woodlands of aspen (Populus tremuloides) provide valuable breeding habitat for several cavity-nesting birds. Although anecdotal information for this habitat is available for Lewis's Woodpecker (Melanerpes lewis), no study has previously examined the importance of aspen woodlands to this species' breeding biology. From 2002 to 2004, we monitored 76...

  18. LewiSpace: An Exploratory Study with a Machine Learning Model in an Educational Game

    Science.gov (United States)

    Ghali, Ramla; Ouellet, Sébastien; Frasson, Claude

    2016-01-01

    The use of educational games as a tool for providing learners with a playful and educational aspect is widespread. In this paper, we present an educational game that we developed to teach a chemistry lesson, namely drawing a Lewis diagram. Our game is a 3D environment known as LewiSpace and aims at balancing between playful and educational…

  19. Catalytic Conversion of Glucose into 5-Hydroxymethylfurfural by Hf(OTf4 Lewis Acid in Water

    Directory of Open Access Journals (Sweden)

    Junjie Li

    2015-12-01

    Full Text Available A series of Lewis acidic metal salts were used for glucose dehydration to 5-hydroymethylfurfural (HMF in water. Effect of valence state, ionic radii of Lewis acidic cation, and the type of anions on the catalytic performance have been studied systematically. The experimental results showed that the valence state played an important role in determining catalytic activity and selectivity. It was found that a higher glucose conversion rate and HMF selectivity could be obtained over high valent Lewis acid salts, where the ionic radii of these Lewis acidic metal salts are usually relatively small. Analysis on the effect of the anions of Lewis acid salts on the catalytic activity and the selectivity suggested that a higher glucose conversion and HMF selectivity could be readily obtained with Cl−. Furthermore, the recyclability of high valence state Lewis acid salt was also studied, however, inferior catalytic performance was observed. The deactivation mechanism was speculated to be the fact that high valence state Lewis acid salt was comparatively easier to undergo hydrolysis to yield complicated metal aqua ions with less catalytic activity. The Lewis acidic activity could be recovered by introducing a stoichiometric amount of hydrochloric acid (HCl to the catalytic before the reaction.

  20. Lewis acid catalysis of a Diels-Alder reaction in water

    NARCIS (Netherlands)

    Otto, S; Bertoncin, F; Engberts, JBFN

    1996-01-01

    Here we report the first detailed study of a Diels-Alder (DA) reaction that is catalyzed by Lewis acids in water. The effect of Co2+, Ni2+, Cu2+ and Zn2+ ions as Lewis acid catalysts on the rate and endo-exo selectivity of the DA reaction between the bidentate dienophiles

  1. Lewis acid-catalyzed depolymerization of soda lignin in supercritical ethanol/water mixtures

    NARCIS (Netherlands)

    Güvenatam, Burcu; Heeres, Erik H.J.; Pidko, Evgeny A.; Hensen, Emiel J M

    2016-01-01

    The depolymerization of lignin model compounds and soda lignin by super Lewis acidic metal triflates has been investigated in a mixture of ethanol and water at 400 °C. The strong Lewis acids convert representative model compounds for the structure-forming linkages in lignin, namely α-O-4, 5-O-4

  2. Specific acid catalysis and Lewis acid catalysis of Diels-Alder reactions in aqueous media

    NARCIS (Netherlands)

    Mubofu, E.B.; Engberts, J.B.F.N.

    A comparative study of specific acid catalysis and Lewis acid catalysis of Diells-Alder reactions between dienophiles (1, 4 and 6) and cyclopentadiene (2) in water and mixed aqueous media is reported. The reactions were performed in water with copper(II) nitrate as the Lewis acid catalyst whereas

  3. Oral Interpretation of C.S. Lewis'"Narnia Tales": A Refracting of "Pictures."

    Science.gov (United States)

    Keefe, Carolyn

    "The Chronicles of Narnia" are a series of seven fairy tales written by C.S. Lewis that have become popular with both children and adults. Lewis points to five aspects of the fairy tale form that made the form suitable for expressing the images he saw. The aspects are: (1) no love interest; (2) no close psychology; (3) severe restraints…

  4. Reduced frequency of blood group Lewis a-b- in female Type 1 diabetes patients

    DEFF Research Database (Denmark)

    Kharagjitsingh, A.V.; Prinsen, K.; Lemkes, H.H.

    2008-01-01

    AIMS: To examine a disputed association between the Lewis(a(-)b(-)) phenotype and Type 1 diabetes (T1D). METHODS: Lewis red blood cell phenotyping was performed for 97 T1D White patients and 100 control subjects using monoclonal antibodies. Two historical cohorts were also included as a control...

  5. Streptococcal cell wall-induced arthritis and adjuvant arthritis in F344----Lewis and in Lewis----F344 bone marrow chimeras

    International Nuclear Information System (INIS)

    van Bruggen, M.C.; van den Broek, M.F.; van den Berg, W.B.

    1991-01-01

    Streptococcal cell wall (SCW)-induced arthritis and adjuvant arthritis (AA) are rat models for chronic, erosive polyarthritis. Both models can be induced in susceptible Lewis rats, whereas F344 rats are resistant. In AA as well as in SCW arthritis, antigen-specific T lymphocytes have been demonstrated to be crucial for chronic disease. In this communication the authors describe their studies to probe the cellular mechanism responsible for the difference in susceptibility of Lewis and F344, using bone marrow chimeras. By transplanting bone marrow cells from F344 into lethally irradiated Lewis recipients, Lewis rats were rendered resistant to SCW arthritis induction. F344 rats reconstituted with Lewis bone marrow, i.e., Lewis----F344 chimeras, develop an arthritis upon SCW injection. For AA comparable results were obtained. These data suggest that both resistance and susceptibility to bacterium-induced chronic arthritis are mediated by hemopoietic/immune cells and that the recipiental environment does not influence the susceptibility to chronic joint inflammation

  6. Elucidating the Key Role of a Lewis Base Solvent in the Formation of Perovskite Films Fabricated from the Lewis Adduct Approach.

    Science.gov (United States)

    Cao, Xiaobing; Zhi, Lili; Li, Yahui; Fang, Fei; Cui, Xian; Yao, Youwei; Ci, Lijie; Ding, Kongxian; Wei, Jinquan

    2017-09-27

    High-quality perovskite films can be fabricated from Lewis acid-base adducts through molecule exchange. Substantial work is needed to fully understand the formation mechanism of the perovskite films, which helps to further improve their quality. Here, we study the formation of CH 3 NH 3 PbI 3 perovskite films by introducing some dimethylacetamide into the PbI 2 /N,N-dimethylformamide solution. We reveal that there are three key processes during the formation of perovskite films through the Lewis acid-base adduct approach: molecule intercalation of solvent into the PbI 2 lattice, molecule exchange between the solvent and CH 3 NH 3 I, and dissolution-recrystallization of the perovskite grains during annealing. The Lewis base solvents play multiple functions in the above processes. The properties of the solvent, including Lewis basicity and boiling point, play key roles in forming smooth perovskite films with large grains. We also provide some rules for choosing Lewis base additives to prepare high-quality perovskite films through the Lewis adduct approach.

  7. Magnetics transport aspects of EBTR reactors

    International Nuclear Information System (INIS)

    Bathke, C.G.

    1981-01-01

    The magnetic model developed for the ELMO Bumpy Torus Reactor (EBTR) study is described. A multiple-loop current simulation of toroidal-field (TF) and aspect-ratio-enhancement (ARE) coils is used to calculate the vacuum magnetic field. The bounce-averaged vertical drift velocity, v/sub y/, and poloidal drift frequency, Ω, are determined from the field topology. Upon performing the appropriate averages of v/sub y/ and Ω, the point-plasma toroidal curvature, R/sub T/, and magnetic curvature, R/sub c/, are obtained for use in modeling EBT transport. In addition, the fraction, f/sub α/, of alpha particles completing their first orbit within the plasma is calculated

  8. Effect of beta limits on reactor performance in EBT

    International Nuclear Information System (INIS)

    Uckan, N.A.; Spong, D.A.; Nelson, D.B.

    1981-01-01

    Because of uncertainties in extrapolating results of simplified models to a reactor plasma, the parameters that influence the beta limits cannot be determined accurately at the present time. Also, the reasonable changes within the models and/or assumptions are seen to affect the core beta limits by almost an order of magnitde. Hence, at the present, these limits cannot be used as a rigid (and reliable) requirement for ELMO Bumpy Torus (EBT) reactor engineering considerations. However, sensitivity studies can be carried out to determine the boundaries of the operating regime and to demonstrate the effects of various modes, assumptions, and models on reactor performance (Q value). First, the modes believed to limit the core β and ring plasma performance are discussed, and the simplifications and/or assumptions involved in deriving these limits are highlighted. Then, the implications of these limits for a reactor are given

  9. Resonant ion transport in EBT

    International Nuclear Information System (INIS)

    Hastings, D.E.; Jaeger, E.F.; Hedrick, C.L.; Tolliver, J.S.

    1983-05-01

    We use a model for the ELMO Bumpy Torus as a bumpy cylinder with a toroidally induced vertical drift imposed on the plasma. With this model we obtain the neoclassical plasma-transport coefficients for ions in both the banana and plateau resonant regimes. The problem of solving the linearized bounce-averaged drift kinetic equation is formulated as a variational principle, which is shown to be valid for both the banana and plateau regimes. We use limiting forms of this principle to obtain a continuous collisionality approximation to the energy-dependent flux. We then use this approximation to obtain analytic formulae for the particle- and energy-diffusion coefficients. These are shown to give excellent agreement with numerical results

  10. Instabilities due to anisotropic velocity distributions. Progress report, June 1, 1974--June 1, 1975

    International Nuclear Information System (INIS)

    Harris, E.G.

    1975-01-01

    A continuing theoretical study of plasma instabilities and related phenomena including nonlinear effects, particle and energy transport and heating schemes is presented. In the past year, a study of linear resistive instabilities with applications to Tokamaks was almost completed and is being prepared for publication. A sigma stability analysis is being worked on at the present time. Some thought was given to a nonlinear resistive instability analysis but not much progress has been made. A study of equilibrium and stability of elliptical cross section Tokamaks was completed. Considerable work was completed on plasma heating by rf waves at the lower hybrid frequency and by Alfven waves. This work is continuing. A study of instabilities excited by runaway beams of electrons in Tokamaks was largly completed. Some work was done on trapped particle instabilities in Tokamaks and their relation to other instabilities driven by gradients of density or temperature. Work is underway on diffusion and thermal conduction in the bumpy torus. (U.S.)

  11. EBTR design-point selection

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Bathke, C.G.

    1981-01-01

    The procedure used to select the design point for the ELMO Bumpy Torus Reactor (EBTR) study is described. The models used in each phase of the selection process are described, with an emphasis placed on the parametric design curves produced by each model. The tradeoffs related to burn physics, stability/equilibrium, electron-ring physics, and magnetics design are discussed. The resulting design point indicates a plasma with a 35-m major radius and a 1-m minor radium operating at an average core-plasma beta of 0.17, which at approx. 30 keV produces an average neutron wall loading of 1.4 MW/m 2 while maintaining key magnet (< 10 T) and total power (less than or equal to 4000 MWt) constraints

  12. Exercise for Individuals with Lewy Body Dementia: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Michael Inskip

    Full Text Available Individuals with Lewy body Dementia (LBD, which encompasses both Parkinson disease dementia (PDD and Dementia with Lewy Bodies (DLB experience functional decline through Parkinsonism and sedentariness exacerbated by motor, psychiatric and cognitive symptoms. Exercise may improve functional outcomes in Parkinson's disease (PD, and Alzheimer's disease (AD. However, the multi-domain nature of the LBD cluster of symptoms (physical, cognitive, psychiatric, autonomic results in vulnerable individuals often being excluded from exercise studies evaluating physical function in PD or cognitive function in dementia to avoid confounding results. This review evaluated existing literature reporting the effects of exercise interventions or physical activity (PA exposure on cluster symptoms in LBD.A high-sensitivity search was executed across 19 databases. Full-length articles of any language and quality, published or unpublished, that analysed effects of isolated exercise/physical activity on indicative Dementia with Lewy Bodies or PD-dementia cohorts were evaluated for outcomes inclusive of physical, cognitive, psychiatric, physiological and quality of life measures. The protocol for this review (Reg. #: CRD42015019002 is accessible at http://www.crd.york.ac.uk/PROSPERO/.111,485 articles were initially retrieved; 288 full articles were reviewed and 89.6% subsequently deemed ineligible due to exclusion of participants with co-existence of dementia and Parkinsonism. Five studies (1 uncontrolled trial, 1 randomized controlled trial and 3 case reports evaluating 16 participants were included. Interventions were diverse and outcome homogeneity was low. Habitual gait speed outcomes were measured in 13 participants and increased (0.18m/s, 95% CI -0.02, 0.38m/s, exceeding moderate important change (0.14m/s for PD cohorts. Other outcomes appeared to improve modestly in most participants.Scarce research investigating exercise in LBD exists. This review confirms

  13. Ransom, Religion, and Red Giants: C.S. Lewis and Fred Hoyle

    Science.gov (United States)

    Larsen, Kristine

    2010-01-01

    Famed fantasy writer C.S. Lewis (1898-1963) was known to friends as a well-read astronomy aficionado. However, this medieval scholar and Christian apologist embraced a pre-Copernican universe (with its astrological overtones) in his Chronicles of Narnia series and defended the beauty and relevance of the geocentric model in his final academic work, "The Discarded Image". In the "Ransom Trilogy” ("Out of the Silent Planet", "Perelandra", and "That Hideous Strength") philologist Ransom (loosely based on Lewis's close friend J.R.R. Tolkien) travels to Lewis's visions of Mars and Venus, where he interacts with intelligent extraterrestrials, battles with evil scientists, and aids in the continuation of extraterrestrial Christian values. In the final book, Ransom is joined by a handful of colleagues in open warfare against the satanic N.I.C.E. (National Institute for Coordinated Experiments). Geneticist and evolutionary biologist J.B.S. Haldane criticized Lewis for his scientifically inaccurate descriptions of the planets, and his disdain for the scientific establishment. Lewis responded to the criticism in essays of his own. Another of Lewis's favorite scientific targets was atheist Fred Hoyle, whom he openly criticized for anti-Christian statements in Hoyle's BBC radio series. Writer and Lewis friend Dorothy L. Sayers voiced her own criticism of Hoyle. In a letter, Lewis dismissed Hoyle as "not a great philosopher (and none of my scientific colleagues think much of him as a scientist.” Given Lewis's lack of respect for Hoyle, and use of creative license in describing the planets, and the flat-earth, "geocentric” Narnia, it is surprising that Lewis very carefully includes an astronomically correct description of red giants in two novels in the Narnia series ("The Magician's Nephew" and "The Last Battle"). This inclusion is even more curious given that Fred Hoyle is well-known as one of the pioneers in the field of stellar death and the properties of red giants.

  14. File list: NoD.Lng.05.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Lng.05.AllAg.Carcinoma,_Lewis_Lung mm9 No description Lung Carcinoma, Lewis Lun...g http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Lng.05.AllAg.Carcinoma,_Lewis_Lung.bed ...

  15. File list: InP.Lng.50.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Lng.50.AllAg.Carcinoma,_Lewis_Lung mm9 Input control Lung Carcinoma, Lewis Lung... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Lng.50.AllAg.Carcinoma,_Lewis_Lung.bed ...

  16. File list: NoD.Lng.10.AllAg.Carcinoma,_Lewis_Lung [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Lng.10.AllAg.Carcinoma,_Lewis_Lung mm9 No description Lung Carcinoma, Lewis Lun...g http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Lng.10.AllAg.Carcinoma,_Lewis_Lung.bed ...

  17. DOE/NASA Lewis large-wind-turbine program

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R.L.

    1982-01-01

    There are several ongoing large wind system development project; ots directed toward meeting the technology requirements for utility applications. First generation tehcnology machines (Mod-0A and Mod-1) and second generation machines (Mod-2) are in opoeration at selected utility sites. Third generation technology machines (Mod-5) are in the design phase and are scheduled for initial operation in 1984 if project funding is continued. An overview of the large wind turbine activities managed by NASA Lewis is provided. These activities include results from the first and second generation field machines (Mod-0A, 01, and -2), the status of the Department of Interior WTS-4 machine for which NASA is responsible for technical management, and the design phase of the third generation wind turbines (Mod-5).

  18. Renal Failure in Dementia with Lewy Bodies Presenting as Catatonia

    Science.gov (United States)

    Fekete, Robert

    2013-01-01

    Catatonia, originally described by Karl Kahlbaum in 1874, may be regarded as a set of clinical features found in a subtype of schizophrenia, but the syndrome may also stem from organic causes including vascular parkinsonism, brain masses, globus pallidus lesions, metabolic derangements, and pharmacologic agents, especially first generation antipsychotics. Catatonia may include paratonia, waxy flexibility (cerea flexibilitas), stupor, mutism, echolalia, and catalepsy (abnormal posturing). A case of catatonia as a result of acute renal failure in a patient with dementia with Lewy bodies is described. This patient recovered after intravenous fluid administration and reinstitution of the atypical dopamine receptor blocking agent quetiapine, but benzodiazepines and amantadine are additional possible treatments. Recognition of organic causes of catatonia leads to timely treatment and resolution of the syndrome. PMID:23466522

  19. Renal Failure in Dementia with Lewy Bodies Presenting as Catatonia

    Directory of Open Access Journals (Sweden)

    Robert Fekete

    2013-01-01

    Full Text Available Catatonia, originally described by Karl Kahlbaum in 1874, may be regarded as a set of clinical features found in a subtype of schizophrenia, but the syndrome may also stem from organic causes including vascular parkinsonism, brain masses, globus pallidus lesions, metabolic derangements, and pharmacologic agents, especially first generation antipsychotics. Catatonia may include paratonia, waxy flexibility (cerea flexibilitas, stupor, mutism, echolalia, and catalepsy (abnormal posturing. A case of catatonia as a result of acute renal failure in a patient with dementia with Lewy bodies is described. This patient recovered after intravenous fluid administration and reinstitution of the atypical dopamine receptor blocking agent quetiapine, but benzodiazepines and amantadine are additional possible treatments. Recognition of organic causes of catatonia leads to timely treatment and resolution of the syndrome.

  20. Survey on Cosmogenic 26Al in Lewis Cliff Meteorites

    Science.gov (United States)

    Welten, K. C.; Alderliesten, C.; Lindner, L.

    1992-07-01

    INTRODUCTION: We have embarked upon a ^26Al gamma-ray survey of meteorites selected from about 2000 samples recently recovered from the Lewis Cliff Ice Fields (84 degrees 18'S/161 degrees 20'E). Due to its 705-ka half-life ^26Al can be used for estimating terrestrial ages and thus contribute to further characterization of Antarctic meteorites in addition to their classification and thermoluminescence (TL) properties. The ^26Al survey is also useful for identifying meteorites with unusual exposure histories, which merit additional measurements of cosmogenic radionuclides (by AMS) and noble gases. In addition, it provides clues on possible pairings. METHOD: Low-level gamma-ray spectroscopy is well suited for ^26Al survey work, since bulk meteorite samples can be measured routinely and nondestructively without any previous sample preparation. The required size of the samples (30-500 g) makes the method relatively independent of depth effects and compositional inhomogeneities. The use of a high-resolution GeLi detector also allows the determination of the natural ^40K activity and thus the K content of the samples, which can be used as an additional pairing criterion for ordinary chondrites. Also ^137Cs, a fall-out surface contamination [1], is simultaneously measured; low values may be characteristic for meteorites recently fallen or released from the ablating ice. For the detector an efficiency calibration curve has been made that adequately accounts for differences in size and shape of the meteorite samples. RESULTS and DISCUSSION: TERRESTRIAL AGES: So far, we have measured over 30 Lewis Cliff equilibrated H and L chondrites, collected from widely differing locations. Normalized to L-chondrite composition, the ^26Al contents range from 27 to 110 dpm/kg with peaks around 43 and 53 dpm/kg. This bimodal ^26Al distribution is reminiscent of that observed for Allan Hills ordinary chondrites [2]. Tentative terrestrial ages, calculated on the basis of ^26Al saturation

  1. Transport Coefficients for the NASA Lewis Chemical Equilibrium Program

    Science.gov (United States)

    Svehla, Roger A.

    1995-01-01

    The new transport property data that will be used in the NASA Lewis Research Center's Chemical Equilibrium and Applications Program (CEA) is presented. It complements a previous publication that documented the thermodynamic and transport property data then in use. Sources of the data and a brief description of the method by which the data were obtained are given. Coefficients to calculate the viscosity, thermal conductivity, and binary interactions are given for either one, or usually, two temperature intervals, typically 300 to 1000 K and 1000 to 5000 K. The form of the transport equation is the same as used previously. The number of species was reduced from the previous database. Many species for which the data were estimated were eliminated from the database. Some ionneutral interactions were added.

  2. A comparison of two instructional methods for drawing Lewis Structures

    Science.gov (United States)

    Terhune, Kari

    Two instructional methods for teaching Lewis structures were compared -- the Direct Octet Rule Method (DORM) and the Commonly Accepted Method (CAM). The DORM gives the number of bonds and the number of nonbonding electrons immediately, while the CAM involves moving electron pairs from nonbonding to bonding electrons, if necessary. The research question was as follows: Will high school chemistry students draw more accurate Lewis structures using the DORM or the CAM? Students in Regular Chemistry 1 (N = 23), Honors Chemistry 1 (N = 51) and Chemistry 2 (N = 15) at an urban high school were the study participants. An identical pretest and posttest was given before and after instruction. Students were given instruction with either the DORM (N = 45), the treatment method, or the CAM (N = 44), the control for two days. After the posttest, 15 students were interviewed, using a semistructured interview process. The pretest/posttest consisted of 23 numerical response questions and 2 to 6 free response questions that were graded using a rubric. A two-way ANOVA showed a significant interaction effect between the groups and the methods, F (1, 70) = 10.960, p = 0.001. Post hoc comparisons using the Bonferroni pairwise comparison showed that Reg Chem 1 students demonstrated larger gain scores when they had been taught the CAM (Mean difference = 3.275, SE = 1.324, p Chemistry 1 students performed better with the DORM, perhaps due to better math skills, enhanced working memory, and better metacognitive skills. Regular Chemistry 1 students performed better with the CAM, perhaps because it is more visual. Teachers may want to use the CAM or a direct-pairing method to introduce the topic and use the DORM in advanced classes when a correct structure is needed quickly.

  3. Lewis pair polymerization by classical and frustrated Lewis pairs: Acid, base and monomer scope and polymerization mechanism

    KAUST Repository

    Zhang, Yuetao

    2012-01-01

    Classical and frustrated Lewis pairs (LPs) of the strong Lewis acid (LA) Al(C 6F 5) 3 with several Lewis base (LB) classes have been found to exhibit exceptional activity in the Lewis pair polymerization (LPP) of conjugated polar alkenes such as methyl methacrylate (MMA) as well as renewable α-methylene-γ-butyrolactone (MBL) and γ-methyl- α-methylene-γ-butyrolactone (γ-MMBL), leading to high molecular weight polymers, often with narrow molecular weight distributions. This study has investigated a large number of LPs, consisting of 11 LAs as well as 10 achiral and 4 chiral LBs, for LPP of 12 monomers of several different types. Although some more common LAs can also be utilized for LPP, Al(C 6F 5) 3-based LPs are far more active and effective than other LA-based LPs. On the other hand, several classes of LBs, when paired with Al(C 6F 5) 3, can render highly active and effective LPP of MMA and γ-MMBL; such LBs include phosphines (e.g., P tBu 3), chiral chelating diphosphines, N-heterocyclic carbenes (NHCs), and phosphazene superbases (e.g., P 4- tBu). The P 4- tBu/Al(C 6F 5) 3 pair exhibits the highest activity of the LP series, with a remarkably high turn-over frequency of 9.6 × 10 4 h -1 (0.125 mol% catalyst, 100% MMA conversion in 30 s, M n = 2.12 × 10 5 g mol -1, PDI = 1.34). The polymers produced by LPs at RT are typically atactic (P γMMBL with ∼47% mr) or syndio-rich (PMMA with ∼70-75% rr), but highly syndiotactic PMMA with rr ∼91% can be produced by chiral or achiral LPs at -78 °C. Mechanistic studies have identified and structurally characterized zwitterionic phosphonium and imidazolium enolaluminates as the active species of the current LPP system, which are formed by the reaction of the monomer·Al(C 6F 5) 3 adduct with P tBu 3 and NHC bases, respectively. Kinetic studies have revealed that the MMA polymerization by the tBu 3P/ Al(C 6F 5) 3 pair is zero-order in monomer concentration after an initial induction period, and the polymerization

  4. High power electron cyclotron heating in ISX and ORMAK Upgrade at ORNL

    International Nuclear Information System (INIS)

    England, A.C.; Eldridge, O.C.; Marcus, F.B.; Sprott, J.C.; Namkung, W.; Wilgen, J.B.

    1976-05-01

    A phased program of plasma heating at the electron cyclotron frequency is proposed for the Oak Ridge tokamaks ISX and ORMAK Upgrade. The past history of the program of electron cyclotron heating (ECH) at ORNL on mirrors and in the ELMO Bumpy Torus has been successful. Future technological developments in the production of high power high frequency microwave tubes look promising at this time. The physics of wave propagation and particle heating are fairly well understood and indicate the viability of this technique. Studies on breakdown and on runaway electron reduction will provide useful information for larger machines. Recent experiments in the USSR on small tokamaks have shown that ECH is a viable heating technique. Providing that the microwave tubes become available, the engineering considerations suggest that the technique is practical and workable, based on present day technology

  5. National RF Test Facility as a multipurpose development tool

    International Nuclear Information System (INIS)

    McManamy, T.J.; Becraft, W.R.; Berry, L.A.

    1983-01-01

    Additions and modifications to the National RF Test Facility design have been made that (1) focus its use for technology development for future large systems in the ion cyclotron range of frequencies (ICRF), (2) expand its applicability to technology development in the electron cyclotron range of frequencies (ECRF) at 60 GHz, (3) provide a facility for ELMO Bumpy Torus (EBT) 60-GHz ring physics studies, and (4) permit engineering studies of steady-state plasma systems, including superconducting magnet performance, vacuum vessel heat flux removal, and microwave protection. The facility will continue to function as a test bed for generic technology developments for ICRF and the lower hybrid range of frequencies (LHRF). The upgraded facility is also suitable for mirror halo physics experiments

  6. Comparative measurement of the neutral density and particle confinement time in EBT

    International Nuclear Information System (INIS)

    Glowienka, J.C.; Richards, R.K.

    1985-11-01

    The neutral density and particle confinement time in the ELMO Bumpy Torus-Scale Experiment (EBT-S) have been determined by two different techniques. These involve a spectroscopic measurement of molecular and atomic hydrogen emissions and a time-decay measurement of a fast-ion population using a diagnostic neutral beam. The results from both diagnostics exhibit identical trends for either estimate, although the absolute values differ by a factor of 2 to 3. The observed variations with fill gas pressure and microwave power from either technique are consistent with measurements of electron density and temperature. In this paper, the measurement techniques are discussed, and the results are compared in the context of consistency with independently observed plasma behavior. 6 refs., 7 figs

  7. Kinetic stability analyses in a bumpy cylinder

    International Nuclear Information System (INIS)

    Dominguez, R.R.; Berk, H.L.

    1981-01-01

    Recent interest in the ELMO Bumpy Torus (EBT) has prompted a number of stability analyses of both the hot electron rings and the toroidal plasma. Typically these works employ the local approximation, neglecting radial eigenmode structure and ballooning effects to perform the stability analysis. In the present work we develop a fully kinetic formalism for performing nonlocal stability analyses in a bumpy cylinder. We show that the Vlasov-Maxwell integral equations (with one ignorable coordinate) are self-adjoint and hence amenable to analysis using numerical techniques developed for self-adjoint systems of equations. The representation we obtain for the kernel of the Vlasov-Maxwell equations is a differential operator of arbitrarily high order. This form leads to a manifestly self-adjoint system of differential equations for long wavelength modes

  8. From Conventional Lewis Acids to Heterogeneous Montmorillonite K10: Eco-Friendly Plant-Based Catalysts Used as Green Lewis Acids.

    Science.gov (United States)

    Hechelski, Marie; Ghinet, Alina; Louvel, Brice; Dufrénoy, Pierrick; Rigo, Benoît; Daïch, Adam; Waterlot, Christophe

    2018-04-25

    The concept of green chemistry began in the USA in the 1990s. Since the publication of the 12 principles of this concept, many reactions in organic chemistry have been developed, and chemical products have been synthesized under environmentally friendly conditions. Lewis acid mediated synthetic transformations are by far the most numerous and best studied. However, the use of certain Lewis acids may cause risks to environmental and human health. This Review discusses the evolution of Lewis acid catalyzed reactions from a homogeneous liquid phase to the solid phase to yield the expected organic molecules under green, safe conditions. In particular, recent developments and applications of biosourced catalysts from plants are highlighted. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Lewis Research Center studies of multiple large wind turbine generators on a utility network

    Science.gov (United States)

    Gilbert, L. J.; Triezenberg, D. M.

    1979-01-01

    A NASA-Lewis program to study the anticipated performance of a wind turbine generator farm on an electric utility network is surveyed. The paper describes the approach of the Lewis Wind Energy Project Office to developing analysis capabilities in the area of wind turbine generator-utility network computer simulations. Attention is given to areas such as, the Lewis Purdue hybrid simulation, an independent stability study, DOE multiunit plant study, and the WEST simulator. Also covered are the Lewis mod-2 simulation including analog simulation of a two wind turbine system and comparison with Boeing simulation results, and gust response of a two machine model. Finally future work to be done is noted and it is concluded that the study shows little interaction between the generators and between the generators and the bus.

  10. Barack Obama, John Lewis, and the Legacy of the Civil Rights Struggle

    Directory of Open Access Journals (Sweden)

    Glenn T. Eskew

    2012-01-01

    Full Text Available The watershed election in 2008 of Barack Obama as the first President of the United States to have African ancestry resulted from the life work of such civil rights activists as U.S. Congressman John Lewis. Born on a sharecropper’s farm in 1940, the African American Lewis grew up in segregated Alabama. As a college student in Nashville, he joined the sit-in protests and volunteered for the original Freedom Ride in 1961. He was elected chairman of the Student Nonviolent Coordinating Committee, becoming the youngest speaker at the March on Washington in 1963. The radical shift to Black ultimately forced Lewis out of SNCC. Consequently Lewis capitalized on the Voting Rights Act of 1965, turned his attentions to voter registration campaigns, and continued working within the system. In 1986 he won election to the U.S. House of Representatives to represent Atlanta’s Fifth Congressional District, a seat he continues to hold today.

  11. 2009 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Lewis County, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data for the Lewis County survey area for the Puget Sound LiDAR Consortium. This data...

  12. 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Lewis County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint collected Light Detection and Ranging (LiDAR) data for the Lewis County project of 2005. The project site covered approximately 223 square miles, divided...

  13. Functional connectivity in cortical regions in dementia with Lewy bodies and Alzheimer's disease.

    Science.gov (United States)

    Kenny, Eva R; Blamire, Andrew M; Firbank, Michael J; O'Brien, John T

    2012-02-01

    Using resting-state functional magnetic resonance imaging, spontaneous low-frequency fluctuations in the blood oxygenation level-dependent signal were measured to investigate connectivity between key brain regions hypothesized to be differentially affected in dementia with Lewy bodies compared with Alzheimer's disease and healthy controls. These included connections of the hippocampus, because of its role in learning, and parietal and occipital areas involved in memory, attention and visual processing. Connectivity was investigated in 47 subjects aged 60 years and over: 15 subjects with dementia with Lewy bodies, 16 subjects with Alzheimer's disease and 16 control subjects. Subjects were scanned using a 3 Tesla magnetic resonance imaging system. The mean blood oxygenation level-dependent signal time series was extracted from seed regions in the hippocampus, posterior cingulate cortex, precuneus and primary visual cortex and correlated with all other brain voxels to determine functional connectivity. Both subjects with dementia with Lewy bodies and Alzheimer's disease showed greater connectivity than control subjects. Compared with controls, the dementia with Lewy bodies group had greater connectivity between the right posterior cingulate cortex and other brain areas. In dementia with Lewy bodies, there were no significant differences in hippocampal connectivity compared with controls, but in Alzheimer's disease left hippocampal connectivity was greater compared with controls. There were no significant differences between groups for precuneus or primary visual cortex connectivity. No seed regions showed significantly less connectivity in subjects with dementia with Lewy bodies or Alzheimer's disease compared with controls. We found greater connectivity with the posterior cingulate in dementia with Lewy bodies and with the hippocampus in Alzheimer's disease. Consistent with the known relative preservation of memory in dementia with Lewy bodies compared with Alzheimer

  14. Hard x-ray measurements of the hot-electron rings in EBT-S

    International Nuclear Information System (INIS)

    Hillis, D.L.

    1982-06-01

    A thorough understanding of the hot electron rings in ELMO Bumpy Torus-Scale (EBT-S) is essential to the bumpy torus concept of plasma production, since the rings provide bulk plasma stability. The hot electrons are produced via electron cyclotron resonant heating using a 28-GHz cw gyrotron, which has operated up to power levels of 200 kW. The parameters of the energetic electron rings are studied via hard x-ray measurement techniques and with diamagnetic pickup coils. The hard x-ray measurements have used collimated NaI(Tl) detectors to determine the electron temperature T/sub e/ and electron density n/sub e/ for the hot electron annulus. Typical values of T/sub e/ are 400 to 500 keV and of n/sub e/ 2 to 5 x 10 11 cm -3 . The total stored energy of a single energetic electron ring as measured by diamagnetic pickup loops approaches approx. 40 J and is in good agreement with that deduced from hard x-ray measurements. By combining the experimental measurements from hard x-rays and the diamagnetic loops, an estimate can be obtained for the volume of a single hot electron ring. The ring volume is determined to be approx. 2.2 litres, and this volume remains approximately constant over the T-mode operating regime. Finally, the power in the electrons scattered out of the ring is measured indirectly by measuring the x-ray radiation produced when those electrons strike the chamber walls. The variation of this radiation with increasing microwave power levels is found to be consistent with classical scattering estimates

  15. Clinical and imaging correlates of amyloid deposition in dementia with Lewy bodies.

    Science.gov (United States)

    Donaghy, Paul C; Firbank, Michael J; Thomas, Alan J; Lloyd, Jim; Petrides, George; Barnett, Nicola; Olsen, Kirsty; O'Brien, John T

    2018-04-19

    Amyloid deposition is common in dementia with Lewy bodies, but its pathophysiological significance is unclear. The objective of this study was to investigate the relationship between amyloid deposition and clinical profile, gray matter volume, and brain perfusion in dementia with Lewy bodies. Dementia with Lewy bodies (n = 37), Alzheimer's disease (n = 20), and controls (n = 20) underwent a thorough clinical assessment, 3T MRI, and early- and late-phase 18 F-Florbetapir PET-CT to assess cortical perfusion and amyloid deposition, respectively. Amyloid scans were visually categorized as positive or negative. Image analysis was carried out using statistical parametric mapping (SPM) 8. There were no significant differences between amyloid-positive and amyloid-negative dementia with Lewy bodies cases in age (P = .78), overall cognitive impairment (P = .83), level of functional impairment (P = .80), or any other clinical or cognitive scale. There were also no significant differences in hippocampal or gray matter volumes. However, amyloid-positive dementia with Lewy bodies cases had lower medial temporal lobe perfusion (P = .03) than amyloid-negative cases, although a combination of medial temporal lobe perfusion, hippocampal volume, and cognitive measures was unable to accurately predict amyloid status in dementia with Lewy bodies. Amyloid deposition was not associated with differences in clinical or neuropsychological profiles in dementia with Lewy bodies, but was associated with imaging evidence of medial temporal lobe dysfunction. The presence of amyloid in dementia with Lewy bodies cannot be identified on the basis of clinical and other imaging features and will require direct assessment via PET imaging or CSF. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf

  16. Visual Hallucinations in PD and Lewy Body Dementias: Old and New Hypotheses

    Directory of Open Access Journals (Sweden)

    M. Onofrj

    2013-01-01

    Full Text Available Visual Hallucinations (VH are a common non-motor symptom of Parkinson’s Disease (PD and the Lewy body dementias (LBD of Parkinson's disease with dementia (PDD and Dementia with Lewy Bodies (DLB. The origin of VH in PD and LBD is debated: earlier studies considered a number of different possible mechanisms underlying VH including visual disorders, Rapid Eye Movement (REM Sleep Intrusions, dysfunctions of top down or bottom up visual pathways, and neurotransmitter imbalance.

  17. A dual Lewis base activation strategy for enantioselective carbene-catalyzed annulations.

    Science.gov (United States)

    Izquierdo, Javier; Orue, Ane; Scheidt, Karl A

    2013-07-24

    A dual activation strategy integrating N-heterocyclic carbene (NHC) catalysis and a second Lewis base has been developed. NHC-bound homoenolate equivalents derived from α,β-unsaturated aldehydes combine with transient reactive o-quinone methides in an enantioselective formal [4 + 3] fashion to access 2-benzoxopinones. The overall approach provides a general blueprint for the integration of carbene catalysis with additional Lewis base activation modes.

  18. Lewis antigen mediated adhesion of freshly removed human bladder tumors to E-selectin

    DEFF Research Database (Denmark)

    Skorsteensgaard, Karna; Vestergaard, Else Marie; Langkilde, Niels

    1999-01-01

    PURPOSE: Twenty fresh surgical specimens of human bladder tumors were tested for their ability to adhere to recombinant P and E-selectin. The adhesion was correlated to immunological detection of carbohydrate structures. MATERIALS AND METHODS: A static titertray assay with immobilized selectins.......003), whereas no correlation was found to secretor and Lewis genotypes. CONCLUSIONS: These data on clinical specimens indicate that Lewis antigen mediated E-selectin adhesion may play a role in the human bladder cancer disease....

  19. Fate of TCE in heated Fort Lewis soil.

    Science.gov (United States)

    Costanza, Jed; Fletcher, Kelly E; Löffler, Frank E; Pennell, Kurt D

    2009-02-01

    This study explores the transformation of trichloroethene (TCE) caused by heating contaminated soil and groundwater samples obtained from the East Gate Disposal Yard (EGDY) located in Fort Lewis, WA. After field samples transferring into glass ampules and introducing 1.5 micromol of TCE, the sealed ampules were incubated at temperatures of 25, 50, and 95 degrees C for periods of up to 95.5 days. Although TCE was completely transformed into cis-1,2-dichloroethene (cis-DCE) after 42 days at 25 degrees C by microbial activity, this transformation was not observed at 50 or 95 degrees C. Chloride levels increased after 42 days at 25 degrees C corresponding to the mass of TCE transformed to cis-DCE, were constant at 50 degrees C, and increased at 95 degrees C yielding a TCE degradation half-life of 1.6-1.9 years. These findings indicate that indigenous microbes contribute to the partial dechlorination of TCE to cis-DCE at temperatures of less than 50 degrees C, whereas interphase mass transfer and physical recovery of TCE will predominate over in situ degradation processes at temperatures of greater than 50 degrees C during thermal treatment at the EGDY site.

  20. NASA Lewis steady-state heat pipe code users manual

    International Nuclear Information System (INIS)

    Tower, L.K.

    1992-06-01

    The NASA Lewis heat pipe code has been developed to predict the performance of heat pipes in the steady state. The code can be used as a design tool on a personal computer or, with a suitable calling routine, as a subroutine for a mainframe radiator code. A variety of wick structures, including a user input option, can be used. Heat pipes with multiple evaporators, condensers, and adiabatic sections in series and with wick structures that differ among sections can be modeled. Several working fluids can be chosen, including potassium, sodium, and lithium, for which the monomer-dimer equilibrium is considered. The code incorporates a vapor flow algorithm that treats compressibility and axially varying heat input. This code facilitates the determination of heat pipe operating temperatures and heat pipe limits that may be encountered at the specified heat input and environment temperature. Data are input to the computer through a user-interactive input subroutine. Output, such as liquid and vapor pressures and temperatures, is printed at equally spaced axial positions along the pipe as determined by the user

  1. Lewis Swift celebrated comet hunter and the people's astronomer

    CERN Document Server

    Kronk, Gary W

    2017-01-01

    This biography covers the life of Lewis Swift (1820-1913), who discovered 13 comets and nearly 1,200 other deep sky objects. All 13 comets found by Swift now bear his name, including three periodic comets with periods of 6 years (11P/Tempel-Swift-LINEAR), 9 years (64P/Swift-Gehrels), and 133 years (109P/Swift-Tuttle). Swift's enthusiasm and success as an amateur astronomer helped make him famous in the United States. With the help of others, Swift was able to buy a 16-inch refractor, the third largest telescope in the United States at the time. Hulbert Harrington Warner built "Warner Observatory" to house this telescope. As a prolific writer and lecturer, Swift's stories appeared in newspapers and magazines, while his lectures showed that he was able to explain anything in a way that everyone could understand.  When Warner went broke during the "Panic of 1893," Swift was forced to leave his home. Almost two dozen invitations arrived from around the United States asking him to bring his telescope to their ci...

  2. Clinical and neuroimage findings of dementia with lewy bodies

    International Nuclear Information System (INIS)

    Kang, Do Young; Park, Kyung Won; Kim, Jae Woo

    2002-01-01

    Dementia with lewy bodies (DLB) is the second common degenerative dementia and has several characteristics including fluctuating cognition, visual hallucination and Parkinsonism. We investigated clinical manifestations and neuroimaging findings in DLB patients. Ten probable DLB patients were included in this study. Brain MRI, Tc-99m HMPAO brain perfusion SPECT and I-123 IPT SPECT were performed. All patients were men and mean age of onset was 64.2 years (range from 54 to 80). All had fluctuating cognition and Parkinsonism, and 8 had visual hallucination. Dementia preceded Parkinsonism in 3 patients. Fluctuation of K-MMSE ranges from 3 to 8 points. Rest tremor was seen in 5 patients. Brain MRI showed cortical atrophy in all patients. Tc-99m brain perfusion SPECT showed hypoperfusion in occipital area as well as fronto-temporo-parietal areas. I-123 IPT SPECT revealed reduced uptake comparable to Parkinson's disease in the striatum. DLB should be first considered as one of possible diagnosis in patients showing dementia in the early stage of Parkinsonism. Hypoperfusion in the occipital area was thought to be a characteristic finding in DLB and to be helpful in differentiating DLB from other degenerative dementias

  3. Microfluidic Separation of Ethylene and Ethane Using Frustrated Lewis Pairs.

    Science.gov (United States)

    Voicu, Dan; Stephan, Douglas W; Kumacheva, Eugenia

    2015-12-21

    Separation of gaseous olefins and paraffins is one of the most important separation processes in the industry. Development of new cost-effective technologies aims at reducing the high energy consumption during the separation process. Here, we took advantage of the reaction of frustrated Lewis pairs (FLPs) with ethylene to achieve reactive extraction of ethylene from ethylene-ethane mixtures. The extraction was studied using a microfluidic platform, which enabled a rapid, high-throughput assessment of reaction conditions to optimize gas separation efficiency. A separation factor of 7.3 was achieved for ethylene from a 1:1 volume ratio mixture of ethylene and ethane, which corresponded to an extracted ethylene purity of 88 %. The results obtained in the microfluidic studies were validated using infrared spectroscopy. This work paves the way for further development of the FLPs and optimization of reaction conditions, thereby maximizing the separation efficiency of olefins from their mixtures with paraffins. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Streamline segment statistics of premixed flames with nonunity Lewis numbers

    Science.gov (United States)

    Chakraborty, Nilanjan; Wang, Lipo; Klein, Markus

    2014-03-01

    The interaction of flame and surrounding fluid motion is of central importance in the fundamental understanding of turbulent combustion. It is demonstrated here that this interaction can be represented using streamline segment analysis, which was previously applied in nonreactive turbulence. The present work focuses on the effects of the global Lewis number (Le) on streamline segment statistics in premixed flames in the thin-reaction-zones regime. A direct numerical simulation database of freely propagating thin-reaction-zones regime flames with Le ranging from 0.34 to 1.2 is used to demonstrate that Le has significant influences on the characteristic features of the streamline segment, such as the curve length, the difference in the velocity magnitude at two extremal points, and their correlations with the local flame curvature. The strengthenings of the dilatation rate, flame normal acceleration, and flame-generated turbulence with decreasing Le are principally responsible for these observed effects. An expression for the probability density function (pdf) of the streamline segment length, originally developed for nonreacting turbulent flows, captures the qualitative behavior for turbulent premixed flames in the thin-reaction-zones regime for a wide range of Le values. The joint pdfs between the streamline length and the difference in the velocity magnitude at two extremal points for both unweighted and density-weighted velocity vectors are analyzed and compared. Detailed explanations are provided for the observed differences in the topological behaviors of the streamline segment in response to the global Le.

  5. Liquid-Phase Catalytic Transfer Hydrogenation of Furfural over Homogeneous Lewis Acid-Ru/C Catalysts.

    Science.gov (United States)

    Panagiotopoulou, Paraskevi; Martin, Nickolas; Vlachos, Dionisios G

    2015-06-22

    The catalytic performance of homogeneous Lewis acid catalysts and their interaction with Ru/C catalyst are studied in the catalytic transfer hydrogenation of furfural by using 2-propanol as a solvent and hydrogen donor. We find that Lewis acid catalysts hydrogenate the furfural to furfuryl alcohol, which is then etherified with 2-propanol. The catalytic activity is correlated with an empirical scale of Lewis acid strength and exhibits a volcano behavior. Lanthanides are the most active, with DyCl3 giving complete furfural conversion and a 97 % yield of furfuryl alcohol at 180 °C after 3 h. The combination of Lewis acid and Ru/C catalysts results in synergy for the stronger Lewis acid catalysts, with a significant increase in the furfural conversion and methyl furan yield. Optimum results are obtained by using Ru/C combined with VCl3 , AlCl3 , SnCl4 , YbCl3 , and RuCl3 . Our results indicate that the combination of Lewis acid/metal catalysts is a general strategy for performing tandem reactions in the upgrade of furans. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Lewis Carroll, a educação e o ensino de geometria na Inglaterra vitoriana - Lewis Carroll, education and the teaching of geometry in victorian England

    Directory of Open Access Journals (Sweden)

    Rafael Montoito

    2015-04-01

    Full Text Available Parte da pesquisa motivada pela tradução para o português do livro Euclides e seus rivais modernos, publicado por Lewis Carroll em 1879, este artigo se inscreve numa série de estudos que visam a um exame hermenêutico dessa obra. São discutidos temas relacionados com a educação, a educação matemática e o ensino de geometria na Inglaterra vitoriana.Palavras-chave: Lewis Carroll, Euclides e seus rivais modernos, história da educação, educação matemática, geometria. LEWIS CARROLL, EDUCATION AND THE TEACHING OF GEOMETRY IN VICTORIAN ENGLANDAbstractResearch partly motivated by Lewis Carrroll's Euclid and his modern rivals (1879 portuguese translation, this paper presents some hermeneutical remarks taken as necessary to understand the context in which such book was produced. The paper focuses particularly on education, in general, and on the teaching of mathematics and geometry in victorian England.Key-words: Lewis Carroll, Euclid and his modern rivals, history of education, mathematics education, geometry. LEWIS CARROLL, LA EDUCACIÓN Y EL ENSINO DE GEOMETRÍA EN LA INGLATERRA VICTORIANAResumenParte de la investigación motivada por la traducción al portugués del libro Euclides y sus enemigos modernos, publicado por Lewis Carroll en 1879, este artículo se inscribe en una serie de estudios que tienen por objetivo hacer un examen hermenéutico de la obra. Son aquí discutidos temas relacionados como la educación, la educación matemática y la enseñanza de geometría en la Inglaterra victoriana.Palabras-clave: Lewis Carroll, Euclides y sus enemigos modernos, historia de la educación, educación matemática, geometría. LEWIS CARROLL, L’ÉDUCATION ET L’ENSEIGMENT DE GÉOMÉTRIE EN L’ANGLETERRE VICTORIENNERésuméFaisant partie de la recherche motivée par la traduction en portugais du livre Euclide et ses rivaux modernes, publié par Lewis Carrol en 1879 , cet article s’inscrit dans une série d’études dont le but

  7. Comparative Proteomic Analysis of Two Uveitis Models in Lewis Rats.

    Science.gov (United States)

    Pepple, Kathryn L; Rotkis, Lauren; Wilson, Leslie; Sandt, Angela; Van Gelder, Russell N

    2015-12-01

    Inflammation generates changes in the protein constituents of the aqueous humor. Proteins that change in multiple models of uveitis may be good biomarkers of disease or targets for therapeutic intervention. The present study was conducted to identify differentially-expressed proteins in the inflamed aqueous humor. Two models of uveitis were induced in Lewis rats: experimental autoimmune uveitis (EAU) and primed mycobacterial uveitis (PMU). Differential gel electrophoresis was used to compare naïve and inflamed aqueous humor. Differentially-expressed proteins were separated by using 2-D gel electrophoresis and excised for identification with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF). Expression of select proteins was verified by Western blot analysis in both the aqueous and vitreous. The inflamed aqueous from both models demonstrated an increase in total protein concentration when compared to naïve aqueous. Calprotectin, a heterodimer of S100A8 and S100A9, was increased in the aqueous in both PMU and EAU. In the vitreous, S100A8 and S100A9 were preferentially elevated in PMU. Apolipoprotein E was elevated in the aqueous of both uveitis models but was preferentially elevated in EAU. Beta-B2-crystallin levels decreased in the aqueous and vitreous of EAU but not PMU. The proinflammatory molecules S100A8 and S100A9 were elevated in both models of uveitis but may play a more significant role in PMU than EAU. The neuroprotective protein β-B2-crystallin was found to decline in EAU. Therapies to modulate these proteins in vivo may be good targets in the treatment of ocular inflammation.

  8. Improved lignin polyurethane properties with Lewis acid treatment.

    Science.gov (United States)

    Chung, Hoyong; Washburn, Newell R

    2012-06-27

    Chemical modification strategies to improve the mechanical properties of lignin-based polyurethanes are presented. We hypothesized that treatment of lignin with Lewis acids would increase the concentration of hydroxyl groups available to react with diisocyanate monomers. Under the conditions used, hydrogen bromide-catalyzed modification resulted in a 28% increase in hydroxyl group content. Associated increases in hydrophilicity of solvent-cast thin films were also recorded as evidenced by decreases in water contact angle. Polyurethanes were then prepared by first preparing a prepolymer based on mixtures of toluene-2,4-diisocyanate (TDI) and unmodified or modified lignin, then polymerization was completed through addition of polyethylene glycol (PEG), resulting in mass ratios of TDI:lignin:PEG of 43:17:40 in the compositions investigated here. The mixture of TDI and unmodified lignin resulted in a lignin powder at the bottom of the liquid, suggesting it did not react directly with TDI. However, a homogeneous solution resulted when TDI and the hydrogen bromide-treated lignin were mixed, suggesting demethylation indeed increased reactivity and resulted in better integration of lignin into the urethane network. Significant improvements in mechanical properties of modified lignin polyurethanes were observed, with a 6.5-fold increase in modulus, which were attributed to better integration of the modified lignin into the covalent polymer network due to the higher concentration of hydroxyl groups. This research indicates that chemical modification strategies can lead to significant improvements in the properties of lignin-based polymeric materials using a higher fraction of an inexpensive lignin monomer from renewable resources and a lower fraction an expensive, petroleum-derived isocyanate monomer to achieve the required material properties.

  9. Expression of hPNAS-4 Radiosensitizes Lewis Lung Cancer

    International Nuclear Information System (INIS)

    Zeng Hui; Yuan Zhu; Zhu Hong; Li Lei; Shi Huashan; Wang Zi; Fan Yu; Deng Qian; Zeng Jianshuang; He Yinbo; Xiao Jianghong; Li Zhiping

    2012-01-01

    Purpose: This study aimed to transfer the hPNAS-4 gene, a novel apoptosis-related human gene, into Lewis lung cancer (LL2) and observe its radiosensitive effect on radiation therapy in vitro and in vivo. Methods and Materials: The hPNAS-4 gene was transfected into LL2 cells, and its expression was detected via western blot. Colony formation assay and flow cytometry were used to detect the growth and apoptosis of cells treated with irradiation/PNAS-4 in vitro. The hPNAS-4 gene was transferred into LL2-bearing mice through tail vein injection of the liposome/gene complex. The tumor volumes were recorded after radiation therapy. Proliferating cell nuclear antigen (PCNA) immunohistochemistry staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were performed to detect the tumor cell growth and apoptosis in vivo. Results: The hPNAS-4 gene was successfully transferred into LL2 cells and tumor tissue, and its overexpressions were confirmed via western blot analysis. Compared with the control, empty plasmid, hPNAS-4, radiation, and empty plasmid plus radiation groups, the hPNAS-4 plus radiation group more significantly inhibited growth and enhanced apoptosis of LL2 cells in vitro and in vivo (P<.05). Conclusions: The hPNAS-4 gene was successfully transferred into LL2 cells and tumor tissue and was expressed in both LL2 cell and tumor tissue. The hPNAS-4 gene therapy significantly enhanced growth inhibition and apoptosis of LL2 tumor cells by radiation therapy in vitro and in vivo. Therefore, it may be a potential radiosensitive treatment of radiation therapy for lung cancer.

  10. Lewis M. Rutherfurd and the First Photograph of Solar Granulation

    Science.gov (United States)

    Harvey, J. W.; Briggs, John W.; Prosser, Sian

    2017-08-01

    A major astronomical controversy of the mid-19th century was discordant descriptions of the small scale structure of the solar surface. Visual observers contradicted each other by describing the surface as consisting of “corrugations”, “willow leaves”, “rice grains”, “cumuli”, “thatch”, “granules”, etc. Early photographs of the solar surface were not good enough to settle the controversy. The French astronomer Jules Janssen is credited with the first 1876 photographs that clearly showed what we now call solar granulation (1876, CRAS 82, 1363). Upon seeing these images, New Yorker Lewis M. Rutherfurd (1878, MNRAS 38, 410) praised the high quality of Janssen’s images but asserted that he had also photographed granulation as early as 1871 using collodion wet plates. He sent copies of his best photograph to the Royal Astronomical Society to support his assertion. Curious about his claim, Briggs and Harvey set up Rutherfurd’s 13-inch achromatic refractor on Kitt Peak and found that it easily showed well-resolved solar granulation, so his claim might well have been justified. But without his plates we could not confirm the claim. For 140 years the copies of Rutherfurd’s best solar photograph remained in the archives of the Royal Astronomical Society and were recently discovered by Prosser (RAS Photographs A3/001B and A3/002). By coincidence a few days later, Briggs found the original August 11, 1871 plate. Despite poor condition these photographs show solar granulation. There are at least two other possible early claimants (Reade; Vogel) but their plates are almost certainly lost. Rutherfurd was a master of astronomical instrumentation and photography. He was reticent about his work, letting results speak for themselves, so it is satisfying to find that he was justified in making his claim of priority.

  11. Manipulating the Lewis antigen specificity of the cholesterol-dependent cytolysin lectinolysin

    Directory of Open Access Journals (Sweden)

    Sara eLawrence

    2012-11-01

    Full Text Available The cholesterol-dependent cytolysins (CDCs attack cells by punching large holes in their membranes. Lectinolysin from Streptococcus mitis is unique among CDCs due to the presence of an N-terminal lectin domain that enhances the pore-forming activity of the toxin. We recently determined the crystal structures of the lectin domain in complex with various glycans. These structures revealed the molecular basis for the Lewis antigen specificity of the toxin. Based on this information we have used in silico molecular modelling to design a mutant toxin, which we predicted would increase its specificity for Lewis y, an antigen found on the surface of cancer cells. Surprisingly, we found by surface plasmon resonance binding experiments that the resultant mutant lectin domain exhibited higher specificity for Lewis b antigens instead. We then undertook comparative crystallographic and molecular dynamics simulation studies of the wild-type and mutant lectin domains to understand the molecular basis for the disparity between the theoretical and experimental results. The crystallographic results revealed that the net number of interactions between Lewis y and wild-type versus mutant was unchanged whereas there was a loss of a hydrogen bond between mutant and Lewis b compared to wild-type. In contrast, the molecular dynamics studies revealed that the Lewis b antigen spent more time in the binding pocket of the mutant compared to wild-type and the reverse was true for Lewis y. The results of these simulation studies are consistent with the conclusions drawn from the surface plasmon resonance studies. This work is part of a program to engineer lectinolysin so that it will target and kill specific cells in human diseases.

  12. Historical perspectives - The role of the NASA Lewis Research Center in the national space nuclear power programs

    Science.gov (United States)

    Bloomfield, H. S.; Sovie, R. J.

    1991-01-01

    The history of the NASA Lewis Research Center's role in space nuclear power programs is reviewed. Lewis has provided leadership in research, development, and the advancement of space power and propulsion systems. Lewis' pioneering efforts in nuclear reactor technology, shielding, high temperature materials, fluid dynamics, heat transfer, mechanical and direct energy conversion, high-energy propellants, electric propulsion and high performance rocket fuels and nozzles have led to significant technical and management roles in many natural space nuclear power and propulsion programs.

  13. Historical perspectives: The role of the NASA Lewis Research Center in the national space nuclear power programs

    Science.gov (United States)

    Bloomfield, H. S.; Sovie, R. J.

    1991-01-01

    The history of the NASA Lewis Research Center's role in space nuclear power programs is reviewed. Lewis has provided leadership in research, development, and the advancement of space power and propulsion systems. Lewis' pioneering efforts in nuclear reactor technology, shielding, high temperature materials, fluid dynamics, heat transfer, mechanical and direct energy conversion, high-energy propellants, electric propulsion and high performance rocket fuels and nozzles have led to significant technical and management roles in many national space nuclear power and propulsion programs.

  14. Stochastic Modeling of Rainfall in Peninsular Malaysia Using Bartlett Lewis Rectangular Pulses Models

    Directory of Open Access Journals (Sweden)

    Ibrahim Suliman Hanaish

    2011-01-01

    Full Text Available Three versions of Bartlett Lewis rectangular pulse rainfall models, namely, the Original Bartlett Lewis (OBL, Modified Bartlett Lewis (MBL, and 2N-cell-type Bartlett Lewis model (BL2n, are considered. These models are fitted to the hourly rainfall data from 1970 to 2008 obtained from Petaling Jaya rain gauge station, located in Peninsular Malaysia. The generalized method of moments is used to estimate the model parameters. Under this method, minimization of two different objective functions which involve different weight functions, one weight is inversely proportional to the variance and another one is inversely proportional to the mean squared, is carried out using Nelder-Mead optimization technique. For the purpose of comparison of the performance of the three different models, the results found for the months of July and November are used for illustration. This performance is assessed based on the goodness of fit of the models. In addition, the sensitivity of the parameter estimates to the choice of the objective function is also investigated. It is found that BL2n slightly outperforms OBL. However, the best model is the Modified Bartlett Lewis MBL, particularly when the objective function considered involves weight which is inversely proportional to the variance.

  15. Lewis-Acid/Base Effects on Gallium Volatility in Molten Chlorides

    International Nuclear Information System (INIS)

    Williams, D.F.

    2001-01-01

    It has been proposed that GaCl 3 can be removed by direct volatilization from a Pu-Ga alloy that is dissolved in a molten chloride salt. Although pure GaCl 3 is quite volatile (boiling point, 201 C), the behavior of GaCl 3 dissolved in chloride salts is different due to solution effects and is critically dependent on the composition of the solvent salt (i.e., its Lewis-acid/base character). In this report, the behavior of gallium in prototypical Lewis-acid and Lewis-base salts is compared. It was found that gallium volatility is suppressed in basic melts and enhanced in acidic melts. The implications of these results on the potential for simple gallium removal in molten salt systems are significant

  16. Composition, texture and methane potential of cellulosic residues from Lewis acids organosolv pulping of wheat straw.

    Science.gov (United States)

    Constant, Sandra; Barakat, Abdellatif; Robitzer, Mike; Di Renzo, Francesco; Dumas, Claire; Quignard, Françoise

    2016-09-01

    Cellulosic pulps have been successfully isolated from wheat straw through a Lewis acids organosolv treatment. The use of Lewis acids with different hardness produced pulps with different delignification degrees. The cellulosic residue was characterised by chemical composition, X-ray diffraction, FT-IR spectroscopy, N2 physisorption, scanning electron microscopy and potential for anaerobic digestibility. Surface area and pore volume increased with the hardness of the Lewis acid, in correspondence with the decrease of the amount of lignin and hemicellulose in the pulp. The non linearity of the correlation between porosity and composition suggests that an agglomeration of cellulose fibrils occurs in the early stages of pulping. All organosolv pulps presented a significantly higher methane potential than the parent straw. A methane evolution of 295Ncm(3)/g OM was reached by a moderate improvement of the accessibility of the native straw. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. A chromatographic study of the Lewis acid-base chemistry of zirconia surfaces

    International Nuclear Information System (INIS)

    Blackwell, J.A.; Carr, P.W.

    1991-01-01

    This paper reports on the chromatographic properties of porous microparticulate zirconium oxide surfaces in aqueous media which are highly dependent upon the chemical composition of the eluent. In particular, retention is controlled by the type and concentration of hard Ligand exchange is the dominant mechanism for the retention of solutes which are Lewis bases. consequently, the capacity factor and plate height depend on both the thermodynamic and kinetic properties of whatever competing Lewis bases may be present in the eluent. These Lewis base eluent components act to control retention in two ways. They modify the net ligand exchange contribution to retention, and they serve as sites for secondary interactions, such as hydrogen bonding and hydrophobic interactions between solutes and the dynamic stationary phase

  18. On the behaviour of biradicaloid [P(μ-NTer)]2 towards Lewis acids and bases.

    Science.gov (United States)

    Hinz, Alexander; Schulz, Axel; Villinger, Alexander

    2016-05-07

    The well-known diphosphadiazane-1,3-diyl [P(μ-NTer)]2 (Ter = 2,6-bis(2,4,6-trimethyl-phenyl)-phenyl) was treated with Lewis bases such as N-heterocyclic carbenes and Lewis acids e.g. gold(i) chloride complexes. In the reaction with the Lewis base, fragmentation of the P2N2 framework was observed, yielding a salt of the type [(NHC)2P](+)[(TerN)2P](-) in a clean reaction. The reaction of [P(μ-NTer)]2 with gold(i) chloride afforded 1 : 1 and 1 : 2 complexes. The dinuclear complex [(ClAu)2P(μ-NTer)2P] displays a bridging P atom between both gold centers, as has been observed for P based zwitterions.

  19. Technical accomplishments of the NASA Lewis Research Center, 1989

    Science.gov (United States)

    1990-01-01

    Topics addressed include: high-temperature composite materials; structural mechanics; fatigue life prediction for composite materials; internal computational fluid mechanics; instrumentation and controls; electronics; stirling engines; aeropropulsion and space propulsion programs, including a study of slush hydrogen; space power for use in the space station, in the Mars rover, and other applications; thermal management; plasma and radiation; cryogenic fluid management in space; microgravity physics; combustion in reduced gravity; test facilities and resources.

  20. Lewis Base Activation of Silyl Acetals: Iridium-Catalyzed Reductive Horner-Wadsworth-Emmons Olefination.

    Science.gov (United States)

    Dakarapu, Udaya Sree; Bokka, Apparao; Asgari, Parham; Trog, Gabriela; Hua, Yuanda; Nguyen, Hiep H; Rahman, Nawal; Jeon, Junha

    2015-12-04

    A Lewis base promoted deprotonative pronucleophile addition to silyl acetals has been developed and applied to the iridium-catalyzed reductive Horner-Wadsworth-Emmons (HWE) olefination of esters and the chemoselective reduction of the resulting enoates. Lewis base activation of silyl acetals generates putative pentacoordinate silicate acetals, which fragment into aldehydes, silanes, and alkoxides in situ. Subsequent deprotonative metalation of phosphonate esters followed by HWE with aldehydes furnishes enoates. This operationally convenient, mechanistically unique protocol converts the traditionally challenging aryl, alkenyl, and alkynyl esters to homologated enoates at room temperature within a single vessel.

  1. Anatomy of an organizational change effort at the Lewis Research Center

    Science.gov (United States)

    Hawker, James R.; Dali, Richard S.

    1988-01-01

    By 1979, after a long decline following the end of the Apollo program, the Lewis Research Center found its very existence endangered because it was not doing the kind of research that could attract funding at the time. New management under Andrew J. Stofan applied a program of strategic planning, participative management, and consensus decision making. A corporate-cultural change was effected which enabled Lewis to commit itself to four fundable research and development projects. Morale-building and training programs which were essential to this change are described.

  2. NASA Lewis Launch Collision Probability Model Developed and Analyzed

    Science.gov (United States)

    Bollenbacher, Gary; Guptill, James D

    1999-01-01

    There are nearly 10,000 tracked objects orbiting the earth. These objects encompass manned objects, active and decommissioned satellites, spent rocket bodies, and debris. They range from a few centimeters across to the size of the MIR space station. Anytime a new satellite is launched, the launch vehicle with its payload attached passes through an area of space in which these objects orbit. Although the population density of these objects is low, there always is a small but finite probability of collision between the launch vehicle and one or more of these space objects. Even though the probability of collision is very low, for some payloads even this small risk is unacceptable. To mitigate the small risk of collision associated with launching at an arbitrary time within the daily launch window, NASA performs a prelaunch mission assurance Collision Avoidance Analysis (or COLA). For the COLA of the Cassini spacecraft, the NASA Lewis Research Center conducted an in-house development and analysis of a model for launch collision probability. The model allows a minimum clearance criteria to be used with the COLA analysis to ensure an acceptably low probability of collision. If, for any given liftoff time, the nominal launch vehicle trajectory would pass a space object with less than the minimum required clearance, launch would not be attempted at that time. The model assumes that the nominal positions of the orbiting objects and of the launch vehicle can be predicted as a function of time, and therefore, that any tracked object that comes within close proximity of the launch vehicle can be identified. For any such pair, these nominal positions can be used to calculate a nominal miss distance. The actual miss distances may differ substantially from the nominal miss distance, due, in part, to the statistical uncertainty of the knowledge of the objects positions. The model further assumes that these position uncertainties can be described with position covariance matrices

  3. Symposium: new trends in unconventional approaches to magnetic fusion

    International Nuclear Information System (INIS)

    Post, R.F.

    1983-01-01

    An extensive review of the meeting is given. The concepts discussed included reverse-field pinches, compact tori, advanced stellarators, multipoles, surface magnetic confinement systems, the bumpy torus, and a collection of mirror-based approaches

  4. Direct reading fast microwave interferometer for EBT

    International Nuclear Information System (INIS)

    Uckan, T.

    1984-10-01

    A simple and inexpensive 4-mm direct reading fast (rise time approx. 100 μs) microwave interferometer is described. The system is particularly useful for density measurements on the ELMO Bumpy Torus (EBT) during pulsed operation

  5. A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini

    Directory of Open Access Journals (Sweden)

    Michael Caterino

    2013-10-01

    Full Text Available Here we present a complete revision of the species of Baconia. Up until now there have been 27 species assigned to the genus (Mazur, 2011, in two subgenera (Binhister Cooman and Baconia s. str., with species in the Neotropical, Nearctic, Palaearctic, and Oriental regions. We recognize all these species as valid and correctly assigned to the genus, and redescribe all of them. We synonymize Binhister, previously used for a polyphyletic assemblage of species with varied relationships in the genus. We move four species into Baconia from other genera, and describe 85 species as new, bringing the total for the genus to 116 species. We divide these into 12 informal species groups, leaving 13 species unplaced to group. We present keys and diagnoses for all species, as well as habitus photos and illustrations of male genitalia for nearly all. The genus now contains the following species and species groups: Baconia loricata group [B. loricata Lewis, 1885, B. patula Lewis, 1885, B. gounellei (Marseul, 1887a, B. jubaris (Lewis, 1901, B. festiva (Lewis, 1891, B. foliosoma sp. n., B. sapphirina sp. n., B. furtiva sp. n., B. pernix sp. n., B. applanatis sp. n., B. disciformis sp. n., B. nebulosa sp. n., B. brunnea sp. n.], B. godmani group [B. godmani (Lewis, 1888, B. venusta (J. E. LeConte, 1845, B. riehli (Marseul, 1862, comb. n., B. scintillans sp. n., B. isthmia sp. n., B. rossi sp. n., B. navarretei sp. n., B. maculata sp. n., B. deliberata sp. n., B. excelsa sp. n., B. violacea (Marseul, 1853, B. varicolor (Marseul, 1887b, B. dives (Marseul, 1862, B. eximia (Lewis, 1888, B. splendida sp. n., B. jacinta sp. n., B. prasina sp. n., B. opulenta sp. n., B. illustris (Lewis, 1900, B. choaspites (Lewis, 1901, B. lewisi Mazur, 1984], B. salobrus group [B. salobrus (Marseul, 1887b, B. turgifrons sp. n., B. crassa sp. n., B. anthracina sp. n., B. emarginata sp. n., B. obsoleta sp. n.], B. ruficauda group [B. ruficauda sp. n., B. repens sp. n.], B. angusta group [B

  6. A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini).

    Science.gov (United States)

    Caterino, Michael S; Tishechkin, Alexey K

    2013-01-01

    Here we present a complete revision of the species of Baconia. Up until now there have been 27 species assigned to the genus (Mazur, 2011), in two subgenera (Binhister Cooman and Baconia s. str.), with species in the Neotropical, Nearctic, Palaearctic, and Oriental regions. We recognize all these species as valid and correctly assigned to the genus, and redescribe all of them. We synonymize Binhister, previously used for a polyphyletic assemblage of species with varied relationships in the genus. We move four species into Baconia from other genera, and describe 85 species as new, bringing the total for the genus to 116 species. We divide these into 12 informal species groups, leaving 13 species unplaced to group. We present keys and diagnoses for all species, as well as habitus photos and illustrations of male genitalia for nearly all. The genus now contains the following species and species groups: Baconia loricata group [Baconia loricata Lewis, 1885, B. patula Lewis, 1885, Baconia gounellei (Marseul, 1887a), Baconia jubaris (Lewis, 1901), Baconia festiva (Lewis, 1891), Baconia foliosoma sp. n., Baconia sapphirina sp. n., Baconia furtiva sp. n., Baconia pernix sp. n., Baconia applanatis sp. n., Baconia disciformis sp. n., Baconia nebulosa sp. n., Baconia brunnea sp. n.], Baconia godmani group [Baconia godmani (Lewis, 1888), Baconia venusta (J. E. LeConte, 1845), Baconia riehli (Marseul, 1862), comb. n., Baconia scintillans sp. n., Baconia isthmia sp. n., Baconia rossi sp. n., Baconia navarretei sp. n., Baconia maculata sp. n., Baconia deliberata sp. n., Baconia excelsa sp. n., Baconia violacea (Marseul, 1853), Baconia varicolor (Marseul, 1887b), Baconia dives (Marseul, 1862), Baconia eximia (Lewis, 1888), Baconia splendida sp. n., Baconia jacinta sp. n., Baconia prasina sp. n., Baconia opulenta sp. n., Baconia illustris (Lewis, 1900), Baconia choaspites (Lewis, 1901), Baconia lewisi Mazur, 1984], Baconia salobrus group [Baconia salobrus (Marseul, 1887b), Baconia

  7. Anion sensing with a Lewis acidic BODIPY-antimony(v) derivative.

    Science.gov (United States)

    Christianson, Anna M; Gabbaï, François P

    2017-02-21

    We describe the synthesis of a BODIPY dye substituted with a Lewis acidic antimony(v) moiety. This compound, which has been fully characterized, shows a high affinity for small anions including fluoride and cyanide, the complexation of which elicits a fluorescence turn-on response.

  8. Compensatory shifts in visual perception are associated with hallucinations in Lewy body disorders.

    Science.gov (United States)

    Bowman, Alan Robert; Bruce, Vicki; Colbourn, Christopher J; Collerton, Daniel

    2017-01-01

    Visual hallucinations are a common, distressing, and disabling symptom of Lewy body and other diseases. Current models suggest that interactions in internal cognitive processes generate hallucinations. However, these neglect external factors. Pareidolic illusions are an experimental analogue of hallucinations. They are easily induced in Lewy body disease, have similar content to spontaneous hallucinations, and respond to cholinesterase inhibitors in the same way. We used a primed pareidolia task with hallucinating participants with Lewy body disorders (n = 16), non-hallucinating participants with Lewy body disorders (n = 19), and healthy controls (n = 20). Participants were presented with visual "noise" that sometimes contained degraded visual objects and were required to indicate what they saw. Some perceptions were cued in advance by a visual prime. Results showed that hallucinating participants were impaired in discerning visual signals from noise, with a relaxed criterion threshold for perception compared to both other groups. After the presentation of a visual prime, the criterion was comparable to the other groups. The results suggest that participants with hallucinations compensate for perceptual deficits by relaxing perceptual criteria, at a cost of seeing things that are not there, and that visual cues regularize perception. This latter finding may provide a mechanism for understanding the interaction between environments and hallucinations.

  9. Dorothy L. Sayers and C. S. Lewis: Christian Postmodernism beyond Boundaries

    Science.gov (United States)

    Yuasa, Kyoko

    2012-01-01

    Modern critics do not consider science fiction and mystery novels to be "serious reading", but Dorothy L. Sayers and C. S. Lewis questioned the boundaries between "popular" and "serious" literature. Both Christian writers critically discuss the spiritual crisis of the modern world in each fiction genre. This paper…

  10. Lewis Nkosi: A Fragile Soul's Quest for Home | Gall | English in Africa

    African Journals Online (AJOL)

    Lewis Nkosi left South Africa in 1961 on a permanent exit visa on his way to study at Harvard as a Nieman Fellow. During his seventy-three years, he lived in England, America, Zambia, Poland, and Switzerland, and he transitioned from denying homesickness (because he had no home) to feeling it acutely (because he had ...

  11. Curcumin reduces trabecular and cortical bone in naive and Lewis lung carcinoma-bearing mice

    Science.gov (United States)

    The present study investigated the effects of dietary supplementation with curcumin on bone microstructural changes in female C57BL/6 mice in the presence or absence of Lewis lung carcinoma. Morphometric analysis showed that in tumor-bearing mice curcumin at 2% and 4% dietary levels (w/w) significa...

  12. Effect of induced hyperglycemia on metastatic spreading in Lewis lung carcinoma

    International Nuclear Information System (INIS)

    Shmakova, N.L.; Fomenkova, T.E.; Fadeeva, T.A.

    1991-01-01

    The effect of induced hyperglycemia on the intensity of metastatic dissemination of Lewis lung carcinoma was investigated in experiments on mice. Neither long-, nor short-term hyperglycemia, induced at different phases of dissemination, influenced the intensity of metastatic spreading, primary tumor growth, the time of appearance of metastases, and the average life duration of tumor-bearing animals

  13. Daniel Day-Lewis lihvis Oscari-rolli neli aastat / Triin Tael

    Index Scriptorium Estoniae

    Tael, Triin

    2008-01-01

    Paul Thomas Andersoni Upton Sinclairi "Õli" järgi lavastatud "Veri hakkab voolama" ("There Will Be Blood"), peaosas Daniel Day-Lewis : Ameerika Ühendriigid 2007. Näitleja võitis oma rolliga parima meespeaosatäitja Oscari. Tema tööst rolli(de)ga

  14. Lewis Acid-Base Properties of a Low Carbon Aluminium Killed Steel ...

    African Journals Online (AJOL)

    An important factor in achieving maximum adhesion of a particular coating system to the substrate lies in the proper preparation of the substrate prior to the application of paint. The Lewis acid-base properties of the outer metal surface play a determinant role in many of these applications, and the chemical reactions involved ...

  15. Providing Total Quality Fundamentals: 1995 Workshops for the NASA Lewis Research Center's Technical Services Directorate

    Science.gov (United States)

    Antczak, Paul; Jacinto,Gilda; Simek, Jimmy

    1997-01-01

    The National Aeronautics and Space Administration's (NASA) agency-wide movement to cultivate a quality workplace is the basis for Lewis Research Center to implement Total Quality Fundamentals (TQF) initiatives. The Lewis Technical Services Directorate (TSD) introduced the Total Quality Fundamentals (TQF) workshops to its work force as an opportunity to introduce the concepts and principles of TQF. These workshops also provided the participants with the opportunity to dialogue with fellow TSD employees and managers. This report describes, through the perspective of the Lewis TSD TQF Coaches, how the TQF work- shop process was accomplished in TSD. It describes the structure for addressing the need, implementation process, input the TSD Coaches provided, common themes and concerns raised, conclusions, and recommendations. The Coaches concluded that these types of workshops could be the key to open the communication channels that are necessary to help everyone at Lewis understand where they fit in the organization. TQF workshops can strengthen the participant's connection with the Mission, Vision of the Center, and Vision of the Agency. Reconunendations are given based on these conclusions that can help the TSD Quality Board develop attainable measures towards a quality workplace.

  16. Lewis-acid catalyzed depolymerization of Protobind lignin in supercritical water and ethanol

    NARCIS (Netherlands)

    Güvenatam, B.; Heeres, E.H.J.; Pidko, E.A.; Hensen, E.J.M.

    2014-01-01

    The use of metal acetates, metal chlorides and metal triflates as Lewis acid catalysts for the depolymerization of soda lignin under supercritical conditions was investigated. The reactions were carried out at 400°C in water and ethanol. Lignin conversion in supercritical water led to formation of

  17. Lewis-acid catalyzed depolymerization of Protobind lignin in supercritical water and ethanol

    NARCIS (Netherlands)

    Guvenatam, Burcu; Heeres, Erik H.J.; Pidko, Evgeny A.; Hensen, Ernie J. M.

    2016-01-01

    The use of metal acetates, metal chlorides and metal triflates as Lewis acid catalysts for the depolymerization of soda lignin under supercritical conditions was investigated. The reactions were carried out at 400 degrees C in water and ethanol. Lignin conversion in supercritical water led to

  18. The Brainstem Pathologies of Parkinson's Disease and Dementia with Lewy Bodies

    NARCIS (Netherlands)

    Seidel, Kay; Mahlke, Josefine; Siswanto, Sonny; Krueger, Reijko; Heinsen, Helmut; Auburger, Georg; Bouzrou, Mohamed; Grinberg, Lea T.; Wicht, Helmut; Korf, Horst-Werner; den Dunnen, Wilfred; Rueb, Udo

    Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are among the human synucleinopathies, which show alpha-synuclein immunoreactive neuronal and/or glial aggregations and progressive neuronal loss in selected brain regions (eg, substantia nigra, ventral tegmental area, pedunculopontine

  19. Navy John Lewis (TAO 205) Class Oiler Shipbuilding Program: Background and Issues for Congress

    Science.gov (United States)

    2016-08-18

    These wires are placed under tension to support fuel hoses for refueling operations or trolleys that move pallets of provisions, ammunition, or other...SECNAV Mabus Names First TAO(X) Next Generation Oiler After Rep. John Lewis,” USNI News, January 6, 2016. 6 Sam LaGrone, “Navy to Name Ship After Gay

  20. Lack of Neuronal IFN-β-IFNAR Causes Lewy Body- and Parkinson's Disease-like Dementia

    DEFF Research Database (Denmark)

    Ejlerskov, Patrick; Hultberg, Jeanette Göransdotter; Wang, JunYang

    2015-01-01

    -causing mutant proteins. Mice lacking Ifnb function exhibited motor and cognitive learning impairments with accompanying α-synuclein-containing Lewy bodies in the brain, as well as a reduction in dopaminergic neurons and defective dopamine signaling in the nigrostriatal region. Lack of IFN-β signaling caused...

  1. Life on the Fringe: The Early Writings of Lewis Nkosi and Nat Nakasa1

    African Journals Online (AJOL)

    One evening in the late 1950s, Lewis Nkosi and his friend Nat Nakasa were walking through downtown Johannesburg when, as both later recalled, they decided to stop into a whites-only restaurant called The Texan. They ordered their coffees at the bar, knowing that the American man behind the counter expected them to ...

  2. Solid State Technology Branch of NASA Lewis Research Center: Fifth Annual Digest

    International Nuclear Information System (INIS)

    1993-08-01

    The digest is a collection of papers written by the members of the Solid State Technology Branch of NASA Lewis Research Center from June 1992-June 1993. The papers cover a range of topics relating to superconductivity, monolithic microwave integrated circuits (MMIC's), coplanar waveguide, and material characterization. Individual papers are abstracted separately on the data base

  3. Paradise Lost and Found: Obedience, Disobedience, and Storytelling in C.S. Lewis and Philip Pullman.

    Science.gov (United States)

    Wood, Naomi

    2001-01-01

    Considers how in the fantasy series "The Chronicles of Narnia" and "His Dark Materials," by C.S. Lewis and Philip Pullman respectively, the authors use symbols and themes from "Paradise Lost." Notes that each author's narrative choice uses his view of cosmic order to persuade readers that obedience should be…

  4. David Lewis in the Lab: Experimental Results on the Emergence of Meaning

    NARCIS (Netherlands)

    Bruner, Justin; O'Connor, Cailin; Rubin, Hannah; Huttegger, S. (Simon)

    2014-01-01

    In this paper we use an experimental approach to investigate how linguistic conventions can emerge in a society without explicit agreement. As a starting point we consider the signaling game introduced by Lewis (Convention 1969). We find that in experimental settings, small groups can quickly

  5. α-Synuclein pathology in the cranial and spinal nerves in Lewy body disease.

    Science.gov (United States)

    Nakamura, Keiko; Mori, Fumiaki; Tanji, Kunikazu; Miki, Yasuo; Toyoshima, Yasuko; Kakita, Akiyoshi; Takahashi, Hitoshi; Yamada, Masahito; Wakabayashi, Koichi

    2016-06-01

    Accumulation of phosphorylated α-synuclein in neurons and glial cells is a histological hallmark of Lewy body disease (LBD) and multiple system atrophy (MSA). Recently, filamentous aggregations of phosphorylated α-synuclein have been reported in the cytoplasm of Schwann cells, but not in axons, in the peripheral nervous system in MSA, mainly in the cranial and spinal nerve roots. Here we conducted an immunohistochemical investigation of the cranial and spinal nerves and dorsal root ganglia of patients with LBD. Lewy axons were found in the oculomotor, trigeminal and glossopharyngeal-vagus nerves, but not in the hypoglossal nerve. The glossopharyngeal-vagus nerves were most frequently affected, with involvement in all of 20 subjects. In the spinal nerve roots, Lewy axons were found in all of the cases examined. Lewy axons in the anterior nerves were more frequent and numerous in the thoracic and sacral segments than in the cervical and lumbar segments. On the other hand, axonal lesions in the posterior spinal nerve roots appeared to increase along a cervical-to-sacral gradient. Although Schwann cell cytoplasmic inclusions were found in the spinal nerves, they were only minimal. In the dorsal root ganglia, axonal lesions were seldom evident. These findings indicate that α-synuclein pathology in the peripheral nerves is axonal-predominant in LBD, whereas it is restricted to glial cells in MSA. © 2015 Japanese Society of Neuropathology.

  6. Stress and Burden among Caregivers of Patients with Lewy Body Dementia

    Science.gov (United States)

    Leggett, Amanda N.; Zarit, Steven; Taylor, Angela; Galvin, James E.

    2011-01-01

    Purpose: Patients with Lewy body dementia (LBD) may present a unique set of symptoms and challenges to family caregivers compared with other types of dementia. Prominent difficulties include motor impairment, activities of daily living (ADLs) disability, recurrent behavioral and emotional problems (BEPs), and diagnostic difficulties. These…

  7. Random forest to differentiate dementia with Lewy bodies from Alzheimer's disease

    NARCIS (Netherlands)

    Dauwan, Meenakshi; van der Zande, Jessica J.; van Dellen, Edwin; Sommer, Iris E C; Scheltens, Philip; Lemstra, Afina W.; Stam, Cornelis J.

    2016-01-01

    Introduction The aim of this study was to build a random forest classifier to improve the diagnostic accuracy in differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) and to quantify the relevance of multimodal diagnostic measures, with a focus on electroencephalography

  8. Plasma turbulence

    International Nuclear Information System (INIS)

    Horton, W.

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates

  9. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1990-06-01

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  10. Plasma accelerators

    International Nuclear Information System (INIS)

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  11. Building new discrete supramolecular assemblies through the interaction of iso-tellurazole N-oxides with Lewis acids and bases.

    Science.gov (United States)

    Ho, Peter C; Jenkins, Hilary A; Britten, James F; Vargas-Baca, Ignacio

    2017-10-13

    The supramolecular macrocycles spontaneously assembled by iso-tellurazole N-oxides are stable towards Lewis bases as strong as N-heterocyclic carbenes (NHC) but readily react with Lewis acids such as BR 3 (R = Ph, F). The electron acceptor ability of the tellurium atom is greatly enhanced in the resulting O-bonded adducts, which consequently enables binding to a variety of Lewis bases that includes acetonitrile, 4-dimethylaminopyridine, 4,4'-bipyridine, triphenyl phosphine, a N-heterocyclic carbene and a second molecule of iso-tellurazole N-oxide.

  12. An order in Lewy body disorders: Retrograde degeneration in hyperbranching axons as a fundamental structural template accounting for focal/multifocal Lewy body disease.

    Science.gov (United States)

    Uchihara, Toshiki

    2017-04-01

    Initial clinical recognition of "paralysis agitans" by James Parkinson was expanded by Jean-Martin Charcot, who recognized additional clinical findings of his own, such as slowness (distinct from paralysis), rigidity (distinct from spasticity) and characteristic countenance. Charcot assembled these findings under the umbrella of "Parkinson disease (PD)". This purely clinical concept was so prescient and penetrating that subsequent neuropathological and biochemical evidences were ordered along this axis to establish the nigra-central trinity of PD (dopamine depletion, nigral lesion with Lewy bodies: LBs). Although dramatic efficacy of levodopa boosted an enthusiasm for this nigra-centralism, extranigral lesions were identified, especially after identification of alpha-synuclein (αS) as a major constituent of LBs. Frequent αS lesions in the lower brainstem with their presumed upward spread were coupled with the self-propagating property of αS molecule, as a molecular template, to constitute the prion-Braak hypothesis. This hybrid concept might expectedly explain clinical, structural and biochemical features of PD/dementia with Lewy bodies (DLB) as if they were stereotypic. In spite of this ordered explanation, recent studies have demonstrated unexpectedly that αS lesions in the human brain, as well as their corresponding clinical manifestations, are much more disordered. Even with such a chaos of LB disorders, affected neuronal groups are uniformly characterized by hyperbranching axons, which may facilitate distal-dominant degeneration and retrograde progression of LB-related degeneration along axons as a fundamental structural order to template LB disorders. This "structural template" hypothesis may explain why: (i) some selective groups are prone to develop Lewy pathology; (ii) their clinical manifestations (especially non-motor components) are vague and generalized without somatotopic accentuation; (iii) distal axons and terminals are preferentially affected

  13. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described for electron beam heating of a high-density plasma to drive a fast liner. An annular or solid relativistic electron beam is used to heat a plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the plasma then converges on a fast liner to explosively or ablatively drive the liner to implosion. (U.K.)

  14. Plasma Modes

    Science.gov (United States)

    Dubin, D. H. E.

    This chapter explores several aspects of the linear electrostatic normal modes of oscillation for a single-species non-neutral plasma in a Penning trap. Linearized fluid equations of motion are developed, assuming the plasma is cold but collisionless, which allow derivation of the cold plasma dielectric tensor and the electrostatic wave equation. Upper hybrid and magnetized plasma waves in an infinite uniform plasma are described. The effect of the plasma surface in a bounded plasma system is considered, and the properties of surface plasma waves are characterized. The normal modes of a cylindrical plasma column are discussed, and finally, modes of spheroidal plasmas, and finite temperature effects on the modes, are briefly described.

  15. ɑ-Synuclein strains and seeding in Parkinson's disease, incidental Lewy body disease, dementia with Lewy bodies and multiple system atrophy: similarities and differences.

    Science.gov (United States)

    Peelaerts, W; Bousset, L; Baekelandt, V; Melki, R

    2018-04-27

    Several age-related neurodegenerative disorders are characterized by the deposition of aberrantly folded endogenous proteins. These proteins have prion-like propagation and amplification properties but so far appear nontransmissible between individuals. Because of the features they share with the prion protein, PrP, the characteristics of pathogenic protein aggregates in several progressive brain disorders, including different types of Lewy body diseases (LBDs), such as Parkinson's disease (PD), multiple system atrophy (MSA) and dementia with Lewy bodies (DLB), have been actively investigated. Even though the pleomorphic nature of these syndromes might suggest different underlying causes, ɑ-synuclein (ɑSyn) appears to play an important role in this heterogeneous group of diseases (the synucleinopathies). An attractive hypothesis is that different types of ɑSyn protein assemblies have a unique and causative role in distinct synucleinopathies. We will discuss the recent research progress on ɑSyn assemblies involved in PD, MSA and DLB; their behavior as strains; current spreading hypotheses; their ability to seed centrally and peripherally; and their implication for disease pathogenesis.

  16. Brush Polymer of Donor-Accepter Dyads via Adduct Formation between Lewis Base Polymer Donor and All Carbon Lewis Acid Acceptor

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2017-09-01

    Full Text Available A synthetic method that taps into the facile Lewis base (LB→Lewis acid (LA adduct forming reaction between the semiconducting polymeric LB and all carbon LA C60 for the construction of covalently linked donor-acceptor dyads and brush polymer of dyads is reported. The polymeric LB is built on poly(3-hexylthiophene (P3HT macromers containing either an alkyl or vinyl imidazolium end group that can be readily converted into the N-heterocyclic carbene (NHC LB site, while the brush polymer architecture is conveniently constructed via radical polymerization of the macromer P3HT with the vinyl imidazolium chain end. Simply mixing of such donor polymeric LB with C60 rapidly creates linked P3HT-C60 dyads and brush polymer of dyads in which C60 is covalently linked to the NHC junction connecting the vinyl polymer main chain and the brush P3HT side chains. Thermal behaviors, electronic absorption and emission properties of the resulting P3HT-C60 dyads and brush polymer of dyads have been investigated. The results show that a change of the topology of the P3HT-C60 dyad from linear to brush architecture enhances the crystallinity and Tm of the P3HT domain and, along with other findings, they indicate that the brush polymer architecture of donor-acceptor domains provides a promising approach to improve performances of polymer-based solar cells.

  17. NASA Lewis Helps Company With New Single-Engine Business Turbojet

    Science.gov (United States)

    1998-01-01

    Century Aerospace Corporation, a small company in Albuquerque, New Mexico, is developing a six-seat aircraft powered by a single turbofan engine for general aviation. The company had completed a preliminary design of the jet but needed analyses and testing to proceed with detailed design and subsequent fabrication of a prototype aircraft. NASA Lewis Research Center used computational fluid dynamics (CFD) analyses to ferret out areas of excessive curvature in the inlet where separation might occur. A preliminary look at the results indicated very good inlet performance; and additional calculations, performed with vortex generators installed in the inlet, led to even better results. When it was initially determined that the airflow distortion pattern at the compressor face fell outside of the limits set by the engine manufacturer, the Lewis team studied possible solutions, selected the best, and provided recommendations. CFD results for the inlet system were so good that wind tunnel tests were unnecessary.

  18. Elk Monitoring Protocol for Lewis and Clark National Historical Park, Version 1.0

    Science.gov (United States)

    Jenkins, Kurt J.; Griffin, Paul C.; Boetsch, John R.; Cole, Carla

    2011-01-01

    Maintaining elk (Cervus elaphus roosevelti) herds that frequent Lewis and Clark National Historical Park (NHP) is central to the park’s purpose of preserving the historic, cultural, scenic, and natural resources. Elk were critical to sustaining the members of the Lewis and Clark expedition by providing food and clothing over the winter of 1805-1806. Today, elk viewing opportunities in the park and surrounding region generate broad appeal with the visiting public, which number over 250,000 per year at the Fort Clatsop visitor center. This protocol describes procedures for monitoring trends in the use of the Fort Clatsop area by Roosevelt elk. Specific objectives of elk monitoring in Lewis and Clark NHP are to measure the relative use and proportion of area used by elk during winter in the Fort Clatsop Unit of the park, and the rate at which elk are sighted from roads in and around the park. Relative use and the proportion of area used by elk are determined from elk fecal pellet surveys conducted every other year in the Fort Clatsop park unit. Pairs of observers visit a systematic array of permanent plots in the fall to clear them of elk fecal pellets, and return to the plots in late winter to count elk fecal pellets that have accumulated during winter. Half of the subplots are counted by two independent observers, which allows for the estimation of relative use and proportion of area occupied by elk with analyses of detection biases that account for unseen elk pellet groups. Standardized road surveys are conducted in and near the Fort Clatsop park unit three or four times monthly during alternate months. Data from road surveys are used to quantify the rate that park visitors would be expected to see elk, when driving the selected set of routes. The monitoring protocol is based on three field seasons of development and testing. The protocol narrative describes the background, rationale, sampling design, field methods, analytical methods, data management, reporting

  19. Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor

    Directory of Open Access Journals (Sweden)

    Rajesh Munirathinam

    2013-08-01

    Full Text Available Polystyrene sulfonate polymer brushes, grown on the interior of the microchannels in a microreactor, have been used for the anchoring of gallium as a Lewis acid catalyst. Initially, gallium-containing polymer brushes were grown on a flat silicon oxide surface and were characterized by FTIR, ellipsometry, and X-ray photoelectron spectroscopy (XPS. XPS revealed the presence of one gallium per 2–3 styrene sulfonate groups of the polymer brushes. The catalytic activity of the Lewis acid-functionalized brushes in a microreactor was demonstrated for the dehydration of oximes, using cinnamaldehyde oxime as a model substrate, and for the formation of oxazoles by ring closure of ortho-hydroxy oximes. The catalytic activity of the microreactor could be maintained by periodic reactivation by treatment with GaCl3.

  20. Applied high-speed imaging for the icing research program at NASA Lewis Research Center

    Science.gov (United States)

    Slater, Howard; Owens, Jay; Shin, Jaiwon

    1992-01-01

    The Icing Research Tunnel at NASA Lewis Research Center provides scientists a scaled, controlled environment to simulate natural icing events. The closed-loop, low speed, refrigerated wind tunnel offers the experimental capability to test for icing certification requirements, analytical model validation and calibration techniques, cloud physics instrumentation refinement, advanced ice protection systems, and rotorcraft icing methodology development. The test procedures for these objectives all require a high degree of visual documentation, both in real-time data acquisition and post-test image processing. Information is provided to scientific, technical, and industrial imaging specialists as well as to research personnel about the high-speed and conventional imaging systems will be on the recent ice protection technology program. Various imaging examples for some of the tests are presented. Additional imaging examples are available from the NASA Lewis Research Center's Photographic and Printing Branch.

  1. Autoinduced catalysis and inverse equilibrium isotope effect in the frustrated Lewis pair catalyzed hydrogenation of imines.

    Science.gov (United States)

    Tussing, Sebastian; Greb, Lutz; Tamke, Sergej; Schirmer, Birgitta; Muhle-Goll, Claudia; Luy, Burkhard; Paradies, Jan

    2015-05-26

    The frustrated Lewis pair (FLP)-catalyzed hydrogenation and deuteration of N-benzylidene-tert-butylamine (2) was kinetically investigated by using the three boranes B(C6F5)3 (1), B(2,4,6-F3-C6H2)3 (4), and B(2,6-F2-C6H3)3 (5) and the free activation energies for the H2 activation by FLP were determined. Reactions catalyzed by the weaker Lewis acids 4 and 5 displayed autoinductive catalysis arising from a higher free activation energy (2 kcal mol(-1)) for the H2 activation by the imine compared to the amine. Surprisingly, the imine reduction using D2 proceeded with higher rates. This phenomenon is unprecedented for FLP and resulted from a primary inverse equilibrium isotope effect. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. System Critical Design Audit (CDA). Books 1, 2 and 3; [Small Satellite Technology Initiative (SSTI Lewis Spacecraft Program)

    Science.gov (United States)

    1995-01-01

    Small Satellite Technology Initiative (SSTI) Lewis Spacecraft Program is evaluated. Spacecraft integration, test, launch, and spacecraft bus are discussed. Payloads and technology demonstrations are presented. Mission data management system and ground segment are also addressed.

  3. Intermolecular interactions of trifluorohalomethanes with Lewis bases in the gas phase: an ab initio study.

    Science.gov (United States)

    Wang, Yi-Siang; Yin, Chih-Chien; Chao, Sheng D

    2014-10-07

    We perform an ab initio computational study of molecular complexes with the general formula CF3X-B that involve one trifluorohalomethane CF3X (X = Cl or Br) and one of a series of Lewis bases B in the gas phase. The Lewis bases are so chosen that they provide a range of electron-donating abilities for comparison. Based on the characteristics of their electron pairs, we consider the Lewis bases with a single n-pair (NH3 and PH3), two n-pairs (H2O and H2S), two n-pairs with an unsaturated bond (H2CO and H2CS), and a single π-pair (C2H4) and two π-pairs (C2H2). The aim is to systematically investigate the influence of the electron pair characteristics and the central atom substitution effects on the geometries and energetics of the formed complexes. The counterpoise-corrected supermolecule MP2 and coupled-cluster single double with perturbative triple [CCSD(T)] levels of theory have been employed, together with a series of basis sets up to aug-cc-pVTZ. The angular and radial configurations, the binding energies, and the electrostatic potentials of the stable complexes have been compared and discussed as the Lewis base varies. For those complexes where halogen bonding plays a significant role, the calculated geometries and energetics are consistent with the σ-hole model. Upon formation of stable complexes, the C-X bond lengths shorten, while the C-X vibrational frequencies increase, thus rendering blueshifting halogen bonds. The central atom substitution usually enlarges the intermolecular bond distances while it reduces the net charge transfers, thus weakening the bond strengths. The analysis based on the σ-hole model is grossly reliable but requires suitable modifications incorporating the central atom substitution effects, in particular, when interaction components other than electrostatic contributions are involved.

  4. Sustainable Materials Replacement for Prevention of Corrosion at Fort Lewis, WA

    Science.gov (United States)

    2009-08-01

    documents a building reclamation project at Fort Lewis, WA, in which significant portions of the work were completed using market -available sustainable...contractors to submit previous technology performance or test documentation, which is generally published as products are introduced to the market . If...evaluate the performance of the E2C2 in its final configuration. Energy use will be analyzed using a Building Infor- mation Model ( BIM ) to simulate

  5. Humour in the Game of Kings: The Sideways Glancing Warder of the Lewis Chessmen

    OpenAIRE

    Hüsing, Annika

    2014-01-01

    The cultural turn of the twentieth century’s last quarter gradually led to a new approach to the classical objects of historical research. Historians nowadays are required to take on a 'cultural perspective' in the course of their studies. Using the example of a particular piece of the Lewis Chessmen this paper examines both the benefits and the limitations that come about with the cultural approach and cautions against a too rigid application.

  6. Fibre type composition of soleus and extensor digitorum longus muscles in normal female inbred Lewis rats

    Czech Academy of Sciences Publication Activity Database

    Soukup, Tomáš; Zachařová, Gisela; Smerdu, V.

    2002-01-01

    Roč. 104, č. 4 (2002), s. 399-405 ISSN 0065-1281 R&D Projects: GA ČR GA304/00/1653 Grant - others:CZ - SI Czech-Slovenian Intergovernmental S&T Co-operation(XC) - Institutional research plan: CEZ:AV0Z5011922 Keywords : inbred Lewis rats * skeletal muscles * soleus and EDL muscles Subject RIV: FH - Neurology Impact factor: 0.867, year: 2002

  7. Energy efficiency campaign for residential housing at the Fort Lewis army installation

    Energy Technology Data Exchange (ETDEWEB)

    AH McMakin; RE Lundgren; EL Malone

    2000-02-23

    In FY1999, Pacific Northwest National Laboratory conducted an energy efficiency campaign for residential housing at the Fort Lewis Army Installation near Tacoma, Washington. Preliminary weather-corrected calculations show energy savings of 10{percent} from FY98 for energy use in family housing. This exceeded the project's goal of 3{percent}. The work was funded by the U.S. DOEs Federal Energy Management Program (FEMP), Office of Energy Efficiency and Renewable Energy. The project adapted FEMP's national ``You Have the Power Campaign'' at the local level, tailoring it to the military culture. The applied research project was designed to demonstrate the feasibility of tailored, research-based strategies to promote energy conservation in military family housing. In contrast to many energy efficiency efforts, the campaign focused entirely on actions residents could take in their own homes, as opposed to technology or housing upgrades. Behavioral change was targeted because residents do not pay their own utility bills; thus other motivations must drive personal energy conservation. This campaign augments ongoing energy savings from housing upgrades carried out by Fort Lewis. The campaign ran from September 1998 through August 1999. The campaign strategy was developed based on findings from previous research and on input from residents and officials at Fort Lewis. Energy use, corrected to account for weather differences, was compared with the previous year's use. Survey responses from 377 of Fort Lewis residents of occupied housing showed that the campaign was moderately effective in promoting behavior change. Of those who were aware of the campaign, almost all said they were now doing one or more energy-efficient things that they had not done before. Most people were motivated by the desire to do the right thing and to set a good example for their children. They were less motivated by other factors.

  8. Vasoprotective effects of life span-extending peripubertal GH replacement in Lewis dwarf rats.

    Science.gov (United States)

    Ungvari, Zoltan; Gautam, Tripti; Koncz, Peter; Henthorn, Jim C; Pinto, John T; Ballabh, Praveen; Yan, Han; Mitschelen, Matthew; Farley, Julie; Sonntag, William E; Csiszar, Anna

    2010-11-01

    In humans, growth hormone deficiency (GHD) and low circulating levels of insulin-like growth factor 1 (IGF-1) significantly increase the risk for cerebrovascular disease. Genetic growth hormone (GH)/IGF-1 deficiency in Lewis dwarf rats significantly increases the incidence of late-life strokes, similar to the effects of GHD in elderly humans. Peripubertal treatment of Lewis dwarf rats with GH delays the occurrence of late-life stroke, which results in a significant extension of life span. The present study was designed to characterize the vascular effects of life span-extending peripubertal GH replacement in Lewis dwarf rats. Here, we report, based on measurements of dihydroethidium fluorescence, tissue isoprostane, GSH, and ascorbate content, that peripubertal GH/IGF-1 deficiency in Lewis dwarf rats increases vascular oxidative stress, which is prevented by GH replacement. Peripubertal GHD did not alter superoxide dismutase or catalase activities in the aorta nor the expression of Cu-Zn-SOD, Mn-SOD, and catalase in the cerebral arteries of dwarf rats. In contrast, cerebrovascular expression of glutathione peroxidase 1 was significantly decreased in dwarf vessels, and this effect was reversed by GH treatment. Peripubertal GHD significantly decreases expression of the Nrf2 target genes NQO1 and GCLC in the cerebral arteries, whereas it does not affect expression and activity of endothelial nitric oxide synthase and vascular expression of IGF-1, IGF-binding proteins, and inflammatory markers (tumor necrosis factor alpha, interluekin-6, interluekin-1β, inducible nitric oxide synthase, intercellular adhesion molecule 1, and monocyte chemotactic protein-1). In conclusion, peripubertal GH/IGF-1 deficiency confers pro-oxidative cellular effects, which likely promote an adverse functional and structural phenotype in the vasculature, and results in accelerated vascular impairments later in life.

  9. Divergent functional connectivity during attentional processing in Lewy body dementia and Alzheimer's disease

    OpenAIRE

    Kobeleva, Xenia; Firbank, Michael; Peraza, Luis; Gallagher, Peter; Thomas, Alan; Burn, David J.; O'Brien, John; Taylor, John-Paul

    2017-01-01

    Attention and executive dysfunction are features of Lewy body dementia (LBD) but their neuroanatomical basis is poorly understood. To investigate underlying dysfunctional attention-executive network (EXEC) interactions, we examined functional connectivity (FC) in 30 patients with LBD, 20 patients with Alzheimer's disease (AD), and 21 healthy controls during an event-related functional magnetic resonance imaging (fMRI) experiment. Participants performed a modified Attention Network Test (ANT),...

  10. Technology requirements to be addressed by the NASA Lewis Research Center Cryogenic Fluid Management Facility program

    Science.gov (United States)

    Aydelott, J. C.; Rudland, R. S.

    1985-01-01

    The NASA Lewis Research Center is responsible for the planning and execution of a scientific program which will provide advance in space cryogenic fluid management technology. A number of future space missions were identified that require or could benefit from this technology. These fluid management technology needs were prioritized and a shuttle attached reuseable test bed, the cryogenic fluid management facility (CFMF), is being designed to provide the experimental data necessary for the technology development effort.

  11. Effects of the immunomodulator, VGX-1027, in endotoxin-induced uveitis in Lewis rats

    DEFF Research Database (Denmark)

    Mangano, K; Sardesai, N Y; Quattrocchi, C

    2008-01-01

    VGX-1027 is a novel, low molecular weight, immunomodulatory compound that has shown efficacy against a variety of immuno-inflammatory disease models in animals including autoimmune diabetes in NOD mice, collagen-induced arthritis and chemically induced inflammatory colitis. Here, we have studied ...... the effects of VGX-1027 on the development of endotoxin-induced uveitis (EIU) in male Lewis rats, as a model of inflammatory ocular diseases in humans....

  12. Regionalization of the Modified Bartlett-Lewis Rectangular Pulse Stochastic Rainfall Model

    OpenAIRE

    Dongkyun Kim; Francisco Olivera; Huidae Cho; Scott A. Socolofsky

    2013-01-01

    Parameters of the Modified Bartlett-Lewis Rectangular Pulse (MBLRP) stochastic rainfall simulation model were regionalized across the contiguous United States. Three thousand four hundred forty-four National Climate Data Center (NCDC) rain gauges were used to obtain spatial and seasonal patterns of the model parameters. The MBLRP model was calibrated to minimize the discrepancy between the precipitation depth statistics between the observed and MBLRP-generated precipitation time series. These...

  13. Lewis base catalyzed enantioselective allylic hydroxylation of Morita-Baylis-Hillman carbonates with water

    KAUST Repository

    Zhu, Bo

    2011-08-19

    A Lewis base catalyzed allylic hydroxylation of Morita-Baylis-Hillman (MBH) carbonates has been developed. Various chiral MBH alcohols can be synthesized in high yields (up to 99%) and excellent enantioselectivities (up to 94% ee). This is the first report using water as a nucleophile in asymmetric organocatalysis. The nucleophilic role of water has been verified using 18O-labeling experiments. © 2011 American Chemical Society.

  14. Borax in the supraglacial moraine of the Lewis Cliff, Buckley Island quadrangle--first Antarctic occurrence

    Science.gov (United States)

    Fitzpatrick, J.J.; Muhs, D.R.

    1989-01-01

    During the 1987-1988 austral summer field season, membersof the south party of the antarctic search for meteorites south-ern team* working in the Lewis Cliff/Colbert Hills region dis-covered several areas of unusual mineralization within theLewis Cliff ice tongue and its associated moraine field (figure1). The Lewis Cliff ice tongue (84°15'S 161°25'E) is a meteorite-stranding surface of ablating blue ice, about 2.3 by 7.0 kilo-meters, bounded on the west by the Lewis Cliff, on the northand northeast by a large supraglacial moraine, and on the eastby the Colbert Hills. To the south it opens to the Walcott Névé.Because it is a meteorite-stranding surface, the major component of ice motion in the area is believed to be vertical(Whillans and Cassidy 1983). The presence of Thule-Baffinmoraines at the northern terminus of the blue ice tends tosupport the hypothesis that the area underlying the moraineis essentially stagnant and that ice arriving from the south ispiling up against it. Areas containing mineral deposits werefound within the moraine field to the north and east of theblue ice margin and also along the east margins of the blue iceitself. Subsequent X-ray diffraction analyses of these depositshave shown that they are composed predominantly of nah-colite (NaHCO3), trona [Na3(CO3)(HCO3) · 2H20], borax[Na2B405(OH)4 · 8H20], and a new hexagonal hydrous sulfatespecies. This paper reports the details of the borax occurrence,because it is the first known on the continent.

  15. Terrestrial ages of ordinary chondrites from the lewis cliff stranding area, East Antarctica

    Science.gov (United States)

    Welten, K. C.; Lindner, L.; Alderliesten, C.; van der Borg, K.

    1999-07-01

    We determined terrestrial ages of ordinary chondrites from the Lewis Cliff stranding area, East Antarctica, on the basis of the concentrations of cosmogenic 10Be (t1/2 = 1.51 Ma), 26Al (t1/2 = 0.705 Ma) and 36Cl (t1/2 = 0.301 Ma). After an initial 26Al -ray survey of 91 meteorites suggested that many have terrestrial ages larger than 0.1 Ma, we selected 62 meteorites for 10Be and 26Al measurements by accelerator mass spectrometry (AMS) and measured 36Cl in twelve of those. Low terrestrial ages (Ma) were found for about 60% of the meteorites, whereas all others have ages between 0.1 and 0.5 Ma, except for one exceptional age of >2 Ma (Welten et al., 1997). Our major conclusions are: (1) The Lewis Cliff H-chondrites show similar ages as those from the Allan Hills Ice-fields, but the L-chondrites are about a factor of two younger than those from Allan Hills, which indicates that Lewis Cliff is a younger stranding area. (2) The terrestrial age distributions at different parts of the Lewis Cliff stranding area generally agree with simple meteorite concentration models, although differences in weathering rate may also play a role. (3) We confirm that meteorites with natural thermoluminescence (TL) levels >80 krad are associated with low terrestrial ages (Benoit et al., 1992), but conclude that natural TL levels <80 krad can not be used to calculate the terrestrial age of a meteorite. Natural TL levels do seem useful to estimate relative terrestrial ages of large groups of meteorites and to determine differences in surface exposure age of paired meteorite fragments. (4) Of the 62 meteorites measured with AMS, 31 were assigned to eleven different pairing groups, mainly on the basis of their cosmogenic nuclide record. The meteorites are estimated to represent between 42 and 52 distinct falls.

  16. Lewis acid tuned facial stereodivergent HDA reactions using beta-substituted N-vinyloxazolidinones.

    Science.gov (United States)

    Gohier, Frédéric; Bouhadjera, Keltoum; Faye, Djibril; Gaulon, Catherine; Maisonneuve, Vincent; Dujardin, Gilles; Dhal, Robert

    2007-01-18

    The [4 + 2] acido-catalyzed heterocycloaddition between new beta-substituted N-vinyl-1,3-oxazolidin-2-ones (with R' = Me, Ar, CH2 Ar) and beta,gamma-unsaturated alpha-ketoesters (R = Ar) afforded heteroadducts with high levels of endo and facial selectivities. A complete reversal of facial differentiation was achieved by varying the Lewis acid, leading to the stereoselective formation of either endo-alpha or endo-beta adducts. [reaction: see text].

  17. Applied Analytical Combustion/emissions Research at the NASA Lewis Research Center - a Progress Report

    Science.gov (United States)

    Deur, J. M.; Kundu, K. P.; Nguyen, H. L.

    1992-01-01

    Emissions of pollutants from future commercial transports are a significant concern. As a result, the Lewis Research Center (LeRC) is investigating various low emission combustor technologies. As part of this effort, a combustor analysis code development program was pursued to guide the combustor design process, to identify concepts having the greatest promise, and to optimize them at the lowest cost in the minimum time.

  18. Applied analytical combustion/emissions research at the NASA Lewis Research Center

    Science.gov (United States)

    Deur, J. M.; Kundu, K. P.; Nguyen, H. L.

    1992-01-01

    Emissions of pollutants from future commercial transports are a significant concern. As a result, the Lewis Research Center (LeRC) is investigating various low emission combustor technologies. As part of this effort, a combustor analysis code development program was pursued to guide the combustor design process, to identify concepts having the greatest promise, and to optimize them at the lowest cost in the minimum time.

  19. Synthesis, characterization, and application of two Al(OR(F))3 Lewis superacids.

    Science.gov (United States)

    Kraft, Anne; Trapp, Nils; Himmel, Daniel; Böhrer, Hannes; Schlüter, Peter; Scherer, Harald; Krossing, Ingo

    2012-07-23

    We report herein the synthesis and full characterization of the donor-free Lewis superacids Al(OR(F))(3) with OR(F) = OC(CF(3))(3) (1) and OC(C(5)F(10))C(6)F(5) (2), the stabilization of 1 as adducts with the very weak Lewis bases PhF, 1,2-F(2)C(6)H(4), and SO(2), as well as the internal C-F activation pathway of 1 leading to Al(2)(F)(OR(F))(5) (4) and trimeric [FAl(OR(F))(2)](3) (5, OR(F) = OC(CF(3))(3)). Insights have been gained from NMR studies, single-crystal structure determinations, and DFT calculations. The usefulness of these Lewis acids for halide abstractions has been demonstrated by reactions with trityl chloride (NMR; crystal structures). The trityl salts allow the introduction of new, heteroleptic weakly coordinating [Cl-Al(OR(F))(3)](-) anions, for example, by hydride or alkyl abstraction reactions. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Surface functionalization of two-dimensional metal chalcogenides by Lewis acid-base chemistry

    Science.gov (United States)

    Lei, Sidong; Wang, Xifan; Li, Bo; Kang, Jiahao; He, Yongmin; George, Antony; Ge, Liehui; Gong, Yongji; Dong, Pei; Jin, Zehua; Brunetto, Gustavo; Chen, Weibing; Lin, Zuan-Tao; Baines, Robert; Galvão, Douglas S.; Lou, Jun; Barrera, Enrique; Banerjee, Kaustav; Vajtai, Robert; Ajayan, Pulickel

    2016-05-01

    Precise control of the electronic surface states of two-dimensional (2D) materials could improve their versatility and widen their applicability in electronics and sensing. To this end, chemical surface functionalization has been used to adjust the electronic properties of 2D materials. So far, however, chemical functionalization has relied on lattice defects and physisorption methods that inevitably modify the topological characteristics of the atomic layers. Here we make use of the lone pair electrons found in most of 2D metal chalcogenides and report a functionalization method via a Lewis acid-base reaction that does not alter the host structure. Atomic layers of n-type InSe react with Ti4+ to form planar p-type [Ti4+n(InSe)] coordination complexes. Using this strategy, we fabricate planar p-n junctions on 2D InSe with improved rectification and photovoltaic properties, without requiring heterostructure growth procedures or device fabrication processes. We also show that this functionalization approach works with other Lewis acids (such as B3+, Al3+ and Sn4+) and can be applied to other 2D materials (for example MoS2, MoSe2). Finally, we show that it is possible to use Lewis acid-base chemistry as a bridge to connect molecules to 2D atomic layers and fabricate a proof-of-principle dye-sensitized photosensing device.

  1. Visual cortex in dementia with Lewy bodies: magnetic resonance imaging study

    Science.gov (United States)

    Taylor, John-Paul; Firbank, Michael J.; He, Jiabao; Barnett, Nicola; Pearce, Sarah; Livingstone, Anthea; Vuong, Quoc; McKeith, Ian G.; O’Brien, John T.

    2012-01-01

    Background Visual hallucinations and visuoperceptual deficits are common in dementia with Lewy bodies, suggesting that cortical visual function may be abnormal. Aims To investigate: (1) cortical visual function using functional magnetic resonance imaging (fMRI); and (2) the nature and severity of perfusion deficits in visual areas using arterial spin labelling (ASL)-MRI. Method In total, 17 participants with dementia with Lewy bodies (DLB group) and 19 similarly aged controls were presented with simple visual stimuli (checkerboard, moving dots, and objects) during fMRI and subsequently underwent ASL-MRI (DLB group n = 15, control group n = 19). Results Functional activations were evident in visual areas in both the DLB and control groups in response to checkerboard and objects stimuli but reduced visual area V5/MT (middle temporal) activation occurred in the DLB group in response to motion stimuli. Posterior cortical perfusion deficits occurred in the DLB group, particularly in higher visual areas. Conclusions Higher visual areas, particularly occipito-parietal, appear abnormal in dementia with Lewy bodies, while there is a preservation of function in lower visual areas (V1 and V2/3). PMID:22500014

  2. Efficient Lewis Acid Ionic Liquid-Catalyzed Synthesis of the Key Intermediate of Coenzyme Q10 under Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Thomas Efferth

    2010-12-01

    Full Text Available An efficient synthesis of a valuable intermediate of coenzyme Q10 by microwave-assisted Lewis acidic ionic liquid (IL-catalyzed Friedel-Crafts alkylation is reported. The acidity of six [Etpy]BF4-based ionic liquids was characterized by means of the FT-IR technique using acetonitrile as a molecular probe. The catalytic activities of these ionic liquids were correlated with their Lewis acidity. With increasing Lewis acid strength of the ionic liquids, their catalytic activity in the Friedel-Crafts reaction increased, except for [Etpy]BF4-AlCl3. The effects of the reaction system, the molar fraction of Lewis acid in the Lewis acid ILs and heating techniques were also investigated. Among the six Lewis acid ionic liquids tested [Etpy]BF4-ZnCl2 showed the best catalytic activity, with a yield of 89% after a very short reaction time (150 seconds. This procedure has the advantages of higher efficiency, better reusability of ILs, energy conservation and eco-friendliness. The method has practical value for preparation of CoQ10 on an industrial scale.

  3. Case report of Lewy body disease mimicking Creutzfeldt-Jakob disease in a 44-year-old man.

    Science.gov (United States)

    Saint-Aubert, Laure; Pariente, Jérémie; Dumas, Herve; Payoux, Pierre; Brandel, Jean-Philippe; Puel, Michèle; Vital, Anne; Guedj, Eric; Lesage, Suzanne; Peoc'h, Katell; Brefel Courbon, Christine; Ory Magne, Fabienne

    2016-07-30

    Few patients are reported with dementia with Lewy bodies before fifty years-old, which may partly reflect the difficulty of accurate diagnosis in young population. We report the case of a 44-year-old male with pathologically confirmed sporadic dementia with Lewy bodies, who did not fulfil the revised clinical criteria for this disease. We document this atypical case with clinical and cognitive evaluation, imaging, biochemistry, genetics and pathology investigations. Creutzfeldt-Jakob disease was first suspected in this patient with no previous medical history, who developed acute and rapid cognitive impairment, L-dopa-non-responsive parkinsonism, and delusion. Positive 14-3-3 protein was initially detected in cerebrospinal fluid and until the late stages of the disease. Severe atrophy with no diffusion hypersignal was found on structural MRI as well as an extensive hypometabolism on (18)F-FDG-PET, in comparison to age-matched healthy volunteers. Genetic investigation found no alpha-synuclein gene mutation. The patient died within 5 years, and post-mortem examination found numerous Lewy bodies and Lewy neurites consistent with pure Lewy body disease. This comprehensively described case illustrates that dementia with Lewy bodies can occur in young patients with atypical clinical presentation. Biochemistry and neuroimaging investigations can sometimes be insufficient to allow accurate diagnostic. More specific markers to support such diagnosis are needed.

  4. Increase in Docetaxel-Resistance of Ovarian Carcinoma-Derived RMG-1 Cells with Enhanced Expression of Lewis Y Antigen

    Directory of Open Access Journals (Sweden)

    Bei Lin

    2011-10-01

    Full Text Available Epithelial carcinomas of the ovary exhibit the highest mortality rate among gynecologic malignancies. Studies found that the metabolism of glycolipids or carbohydrates is associated with acquirement of anticancer drug-resistance by cancer cells. This study was to characterize possible involvement of Lewis Y (LeY antigen in the drug-resistance of cancer cells. We transfected the α1,2-fucosyltransferase gene into human ovarian carcinoma-derived RMG-1 cells and established RMG-1-hFUT cells with enhanced expression of LeY. We determined the effects of docetaxel on the survival of cells by MTT assaying and observed the apoptosis of cells in the presence of docetaxel by flow cytometric analysis and by transmission electron microscopy. Plasma membranes and intracellular granules in RMG-1-hFUT cells were stained with anti-LeY antibody, the intensity of the staining was higher than that in control cells. The RMG-1-hFUT cells exhibited higher resistance to docetaxel than the control cells with regard to the docetaxel concentration and time course. After treatment with 10 μg/mL docetaxel for 72 h, the control cells, but not RMG-1-hFUT, contained abundant positively stained cell debris due to disintegration of the cytoskeleton. On transmission electron microscopy, although the control cells treated with docetaxel as above showed the following morphology, i.e., absence of villi, cells shrunken in size, pyknosis, agglutinated chromatin and cell buds containing nuclei in the process of apoptosis, the RMG-1-hFUT cells showed only agglutinated chromatin and vacuoles in the cytoplasm. In summary, cells with enhanced expression of LeY were shown to acquire docetaxel-resistance, indicating the possible involvement of glycoconjugates in the drug-resistance.

  5. Plasma centrifuges

    International Nuclear Information System (INIS)

    Karchevskij, A.I.; Potanin, E.P.

    2000-01-01

    The review of the most important studies on the isotope separation processes in the rotating plasma is presented. The device is described and the characteristics of operation of the pulse plasma centrifuges with weakly and strongly ionized plasma as well as the stationary plasma centrifuges with the medium weak ionization and devices, applying the stationary vacuum arc with the high ionization rate and the stationary beam-plasma discharge with complete ionization, are presented. The possible mechanisms of the isotope separation in plasma centrifuges are considered. The specific energy consumption for isotope separation in these devices is discussed [ru

  6. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  7. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  8. Freqüências relativas dos fenótipos eritrocitários ABO e Lewis na doença de Jorge Lobo Frequencies of ABO and Lewis blood groups in Jorge Lobo's disease

    Directory of Open Access Journals (Sweden)

    Eliane A. Silva

    2004-03-01

    Full Text Available A doença de Jorge Lobo é uma micose de evolução crônica, causada pelo Lacazia loboi. Os mecanismos envolvidos na suscetibilidade/resistência do hospedeiro frente ao agente não estão ainda elucidados, dentre eles encontra-se a constituição genética. Portanto, o objetivo deste trabalho é avaliar a distribuição dos grupos sangüíneos ABO e Lewis de pacientes com doença de Jorge Lobo em relação à população geral. Foram analisados 13 pacientes provenientes do estado do Acre, 60 indivíduos da região de Bauru (SP não acometidos pela doença em estudo (grupo controle Lewis e 2.673 doadores do Banco de Sangue da cidade de Rio Branco (AC como grupo controle ABO. As presenças dos antígenos eritrocitários foram determinadas pela reação de aglutinação em tubo através dos soros anti-AB, anti-A e anti-B para o fenótipo ABO e dos soros anti-Lewis a e Lewis b para fenotipagem Lewis. As freqüências fenotípicas Lewis e ABO nos pacientes e nos controles são, respectivamente: Le (a- b+ = 54,0% X 72,0%, Le (a+ b- = 15,0% X 6,0%, Le (a- b- = 31,0% X 22,0% ; A =15,4% X 33,6%, B = 30,8% X 10,8%, O = 53,8% X 52,9%, AB = 0 X 2,7%. Embora não tenhamos encontrado resultados estatisticamente significantes, nossos achados sugerem existir suscetibilidade à doença de Jorge Lobo em indivíduos com fenótipo B e com menor freqüência fenotípica Lewis b, conferindo assim um grau de importância epidemiológica como grupo de risco naquele meio ambiente.Jorge Lobo's disease is a mycosis with chronic evolution caused by the fungus Lacazia loboi. The mechanisms involved in host resistance and susceptibility to the agent, including aspects relating to the genetic background, are still not clear. The objective of the present study, therefore, is to evaluate the ABO and Lewis blood group distributions in Jorge Lobo's disease patients compared to the general population. Thirteen patients from Acre state, 60 healthy individuals (Lewis control group

  9. Lewis Acid Pairs for the Activation of Biomass-derived Oxygenates in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Roman, Yuriy [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2015-09-14

    The objective of this project is to understand the mechanistic aspects behind the cooperative activation of oxygenates by catalytic pairs in aqueous media. Specifically, we will investigate how the reactivity of a solid Lewis acid can be modulated by pairing the active site with other catalytic sites at the molecular level, with the ultimate goal of enhancing activation of targeted functional groups. Although unusual catalytic properties have been attributed to the cooperative effects promoted by such catalytic pairs, virtually no studies exist detailing the use heterogeneous water-tolerant Lewis pairs. A main goal of this work is to devise rational pathways for the synthesis of porous heterogeneous catalysts featuring isolated Lewis pairs that are active in the transformation of biomass-derived oxygenates in the presence of bulk water. Achieving this technical goal will require closely linking advanced synthesis techniques; detailed kinetic and mechanistic investigations; strict thermodynamic arguments; and comprehensive characterization studies of both materials and reaction intermediates. For the last performance period (2014-2015), two technical aims were pursued: 1) C-C coupling using Lewis acid and base pairs in Lewis acidic zeolites. Tin-, zirconium-, and hafnium containing zeolites (e.g., Sn-, Zr-, and Hf-Beta) are versatile solid Lewis acids that selectively activate carbonyl functional groups. In this aim, we demonstrate that these zeolites catalyze the cross-aldol condensation of aromatic aldehydes with acetone under mild reaction conditions with near quantitative yields. NMR studies with isotopically labeled molecules confirm that acid-base pairs in the Si-O-M framework ensemble promote soft enolization through α-proton abstraction. The Lewis acidic zeolites maintain activity in the presence of water and, unlike traditional base catalysts, in acidic solutions. 2) One-pot synthesis of MWW zeolite nanosheets for activation of bulky substrates. Through

  10. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described of providing electron beam heating of a high-density plasma to drive a fast liner to implode a structured microsphere. An annular relativistic electron beam is used to heat an annular plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the annular plasma then converges on a fast liner to explosively or ablatively drive the liner to convergence to implode the structured microsphere. (U.K.)

  11. Clinical and pathological study on early diagnosis of Parkinson's disease and dementia with Lewy bodies

    International Nuclear Information System (INIS)

    Orimo, Satoshi

    2008-01-01

    [ 123 I] Meta-iodobenzylguanidine (MIBG) myocardial scintigraphy has been used to evaluate postganglionic cardiac sympathetic innervation in heart diseases and some neurological disorders. To see clinical usefulness of MIBG myocardial scintigraphy to differentiate Parkinson's disease (PD) and dementia with Lewy bodies (DLB) from related movement disorders and Alzheimer disease (AD), we performed MIBG myocardial scintigraphy in patients with these disorders. Cardiac uptake of MIBG is specifically reduced in PD and DLB, and this imaging approach is a sensitive diagnostic tool that possibly differentiates PD and DLB from related movement disorders and AD. To see pathological basis of the reduced cardiac uptake of MIBG in Lewy body disease, we immunohistichemically examined cardiac tissues from patients with PD, DLB, related movement disorders and AD using antibodies against tyrosine hydroxylase (TH) and phosphorylated neurofilament (NF). Not only TH- but also NF-immunoreactive (ir) axons in the epicardial nerve fascicles were markedly decreased in Lewy body disease, namely cardiac sympathetic denervation, which accounts for the reduced cardiac uptake of MIBG in Lewy body disease. Patients with PD and DLB have Lewy bodies (LBs) in the nervous system, whereas patients with multiple system atrophy (MSA), progressive supranuclear palsy, corticobasal degeneration, parkin-associated PD and AD have no LBs in the nervous system. Even in patients with MSA, cardiac sympathetic denervation was associated with the presence of LBs. Therefore, cardiac sympathetic denervation is closely related to the presence of LBs in a wide range of neurodegenerative processes. Taken together, we conclude that the reduced cardiac uptake of MIBG is a potential biomarker for the presence of LBs. Because α-synuclein is one of the key molecules in the pathogenesis of PD, we further investigate how α-synuclein aggregates are involved in degeneration of the cardiac sympathetic nerve in PD. We

  12. Dusty plasmas

    International Nuclear Information System (INIS)

    Jones, M.E.; Winske, D.; Keinigs, R.; Lemons, D.

    1996-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project has been to develop a fundamental understanding of dusty plasmas at the Laboratory. While dusty plasmas are found in space in galactic clouds, planetary rings, and cometary tails, and as contaminants in plasma enhanced fabrication of microelectronics, many of their properties are only partially understood. Our work has involved both theoretical analysis and self-consistent plasma simulations to understand basic properties of dusty plasmas related to equilibrium, stability, and transport. Such an understanding can improve the control and elimination of plasma dust in industrial applications and may be important in the study of planetary rings and comet dust tails. We have applied our techniques to the study of charging, dynamics, and coagulation of contaminants in plasma processing reactors for industrial etching and deposition processes and to instabilities in planetary rings and other space plasma environments. The work performed in this project has application to plasma kinetics, transport, and other classical elementary processes in plasmas as well as to plasma waves, oscillations, and instabilities

  13. Plasma chromatography

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    This book examines the fundamental theory and various applications of ion mobility spectroscopy. Plasma chromatography developed from research on the diffusion and mobility of ions. Topics considered include instrument design and description (e.g., performance, spectral interpretation, sample handling, mass spectrometry), the role of ion mobility in plasma chromatography (e.g., kinetic theory of ion transport), atmospheric pressure ionization (e.g., rate equations), the characterization of isomers by plasma chromatography (e.g., molecular ion characteristics, polynuclear aromatics), plasma chromatography as a gas chromatographic detection method (e.g., qualitative analysis, continuous mobility monitoring, quantitative analysis), the analysis of toxic vapors by plasma chromatography (e.g., plasma chromatograph calibration, instrument control and data processing), the analysis of semiconductor devices and microelectronic packages by plasma chromatography/mass spectroscopy (e.g., analysis of organic surface contaminants, analysis of water in sealed electronic packages), and instrument design and automation (hardware, software)

  14. Fort Lewis natural gas and fuel oil energy baseline and efficiency resource assessment

    International Nuclear Information System (INIS)

    Brodrick, J.R.; Daellenbach, K.K.; Parker, G.B.; Richman, E.E.; Secrest, T.J.; Shankle, S.A.

    1993-02-01

    The mission of the US Department of Energy (DOE) Federal Energy Management Program (FEMP) is to lead the improvement of energy efficiency and fuel flexibility within the federal sector. Through the Pacific Northwest Laboratory (PNL), FEMP is developing a fuel-neutral approach for identifying, evaluating, and acquiring all cost-effective energy projects at federal installations; this procedure is entitled the Federal Energy Decision Screening (FEDS) system. Through a cooperative program between FEMP and the Army Forces Command (FORSCOM) for providing technical assistance to FORSCOM installations, PNL has been working with the Fort Lewis Army installation to develop the FEDS procedure. The natural gas and fuel oil assessment contained in this report was preceded with an assessment of electric energy usage that was used to implement a cofunded program between Fort Lewis and Tacoma Public Utilities to improve the efficiency of the Fort's electric-energy-using systems. This report extends the assessment procedure to the systems using natural gas and fuel oil to provide a baseline of consumption and an estimate of the energy-efficiency potential that exists for these two fuel types at Fort Lewis. The baseline is essential to segment the end uses that are targets for broad-based efficiency improvement programs. The estimated fossil-fuel efficiency resources are estimates of the available quantities of conservation for natural gas, fuel oils number-sign 2 and number-sign 6, and fuel-switching opportunities by level of cost-effectiveness. The intent of the baseline and efficiency resource estimates is to identify the major efficiency resource opportunities and not to identify all possible opportunities; however, areas of additional opportunity are noted to encourage further effort

  15. L-selectin-carbohydrate interactions: relevant modifications of the Lewis x trisaccharide.

    Science.gov (United States)

    Sanders, W J; Katsumoto, T R; Bertozzi, C R; Rosen, S D; Kiessling, L L

    1996-11-26

    Protein-carbohydrate interactions are known to mediate cell-cell recognition and adhesion events. Specifically, three carbohydrate binding proteins termed selectins (E-, P-, and L-selectin) have been shown to be essential for leukocyte rolling along the vascular endothelium, the first step in the recruitment of leukocytes from the blood into inflammatory sites or into secondary lymphoid organs. Although this phenomenon is well-established, little is known about the molecular-level interactions on which it depends. All three selectins recognize sulfated and sialylated derivatives of the Lewis x [Le(x):Gal beta 1-->4(Fuc alpha 1-->3)GlcNAc] and Lewis a [Le(a): Gal beta 1-->3(Fuc alpha 1-->4)GlcNAc] trisaccharide cores with affinities in the millimolar range, and it is believed that variants of these structures are the carbohydrate determinants of selectin recognition. Recently it was shown that the mucin GlyCAM-1, a secreted physiological ligand for L-selectin, is capped with sulfated derivatives of sialyl Lewis x [sLe(x): Sia alpha 2-->3Gal beta 1-->4(Fuc alpha 1-->3)GlcNAc] and that sulfation is required for the high-affinity interaction between GlyCAM-1 and L-selectin. To elucidate the important sites of sulfation on Le(x) with respect to L-selectin recognition, we have synthesized six sulfated Le(x) analogs and determined their abilities to block binding of a recombinant L-selectin-Ig chimera to immobilized GlyCAM-1. Our results suggest that 6-sulfo sLe(x) binds to L-selectin with higher affinity than does sLe(x) or 6'-sulfo sLe(x) and that sulfation of sLe(x) capping groups on GlyCAM-1 at the 6-position is important for L-selectin recognition.

  16. Lewis Acid-Base Chemistry of 7-Azaisoindigo-Based Organic Semiconductors.

    Science.gov (United States)

    Randell, Nicholas M; Fransishyn, Kyle M; Kelly, Timothy L

    2017-07-26

    Low-band-gap organic semiconductors are important in a variety of organic electronics applications, such as organic photovoltaic devices, photodetectors, and field effect transistors. Building on our previous work, which introduced 7-azaisoindigo as an electron-deficient building block for the synthesis of donor-acceptor organic semiconductors, we demonstrate how Lewis acids can be used to further tune the energies of the frontier molecular orbitals. Coordination of a Lewis acid to the pyridinic nitrogen of 7-azaisoindigo greatly diminishes the electron density in the azaisoindigo π-system, resulting in a substantial reduction in the lowest unoccupied molecular orbital (LUMO) energy. This results in a smaller highest occupied molecular orbital-LUMO gap and shifts the lowest-energy electronic transition well into the near-infrared region. Both H + and BF 3 are shown to coordinate to azaisoindigo and affect the energy of the S 0 → S 1 transition. A combination of time-dependent density functional theory and UV/vis and 1 H NMR spectroscopic titrations reveal that when two azaisoindigo groups are present and high concentrations of acid are used, both pyridinic nitrogens bind Lewis acids. Importantly, we demonstrate that this acid-base chemistry can be carried out at the solid-vapor interface by exposing thin films of aza-substituted organic semiconductors to vapor-phase BF 3 ·Et 2 O. This suggests the possibility of using the BF 3 -bound 7-azaisoindigo-based semiconductors as n-type materials in various organic electronic applications.

  17. The μ3 model of acids and bases: extending the Lewis theory to intermetallics.

    Science.gov (United States)

    Stacey, Timothy E; Fredrickson, Daniel C

    2012-04-02

    A central challenge in the design of new metallic materials is the elucidation of the chemical factors underlying the structures of intermetallic compounds. Analogies to molecular bonding phenomena, such as the Zintl concept, have proven very productive in approaching this goal. In this Article, we extend a foundational concept of molecular chemistry to intermetallics: the Lewis theory of acids and bases. The connection is developed through the method of moments, as applied to DFT-calibrated Hückel calculations. We begin by illustrating that the third and fourth moments (μ(3) and μ(4)) of the electronic density of states (DOS) distribution tune the properties of a pseudogap. μ(3) controls the balance of states above and below the DOS minimum, with μ(4) then determining the minimum's depth. In this way, μ(3) predicts an ideal occupancy for the DOS distribution. The μ(3)-ideal electron count is used to forge a link between the reactivity of transition metals toward intermetallic phase formation, and that of Lewis acids and bases toward adduct formation. This is accomplished through a moments-based definition of acidity which classifies systems that are electron-poor relative to the μ(3)-ideal as μ(3)-acidic, and those that are electron-rich as μ(3)-basic. The reaction of μ(3) acids and bases, whether in the formation of a Lewis acid/base adduct or an intermetallic phase, tends to neutralize the μ(3) acidity or basicity of the reactants. This μ(3)-neutralization is traced to the influence of electronegativity differences at heteroatomic contacts on the projected DOS curves of the atoms involved. The role of μ(3)-acid/base interactions in intermetallic phases is demonstrated through the examination of 23 binary phases forming between 3d metals, the stability range of the CsCl type, and structural trends within the Ti-Ni system.

  18. Did Immanuel Kant have dementia with Lewy bodies and REM behavior disorder?

    Science.gov (United States)

    Miranda, Marcelo; Slachevsky, Andrea; Garcia-Borreguero, Diego

    2010-06-01

    Immanuel Kant, one of the most brilliant minds of the XVIII century and of western philosophy, suffered from dementia in his late years. Based on the analysis of testimonies of his close friends, in this report we describe his neurological disorder which, after 8years of evolution, led to his death. His cognitive decline was strongly associated with a parasomnia compatible with a severe rapid eye movement (REM) behavior disorder (RBD) and dementia with Lewy bodies. Copyright 2010 Elsevier B.V. All rights reserved.

  19. Demystifying the constancy of the Ermakov-Lewis invariant for a time-dependent oscillator

    Science.gov (United States)

    Padmanabhan, T.

    2018-03-01

    It is well known that the time-dependent harmonic oscillator (TDHO) possesses a conserved quantity, usually called Ermakov-Lewis invariant. I provide a simple physical interpretation of this invariant as well as a whole family of related invariants. This interpretation does not seem to have been noticed in the literature before. The procedure also allows one to tackle some key conceptual issues which arise in the study of quantum fields in the external, time-dependent backgrounds like in the case of particle production in an expanding universe and Schwinger effect.

  20. Interphase transfer kinetics of uranium using the drop method, Lewis cell, and Kenics mixer

    International Nuclear Information System (INIS)

    Horner, D.E.; Mailen, J.C.; Thiel, S.W.; Scott, T.C.; Yates, R.G.

    1979-05-01

    The rate constants for the interphase transfer of uranium between 3.5 M HNO 3 and tributyl phosphate (TBP) - normal hydrocarbon diluent solutions have been measured using the single drop method, Lewis cell method, and a Kenics mixer - centrifugal separator. Rate constants obtained by all methods were the same within experimental error. The variables studied that affect the rate constants include the TBP concentration, the acidity and total neutral nitrate concentrations of the aqueous phase, and temperature. Results of these tests indicate that the rate controlling mechanism is chemical reaction at the interface

  1. Gothic elements in contemporary detective story : Matthew Gregory Lewis and Minette Walters compared

    Directory of Open Access Journals (Sweden)

    Vesna Marinko

    2009-12-01

    Full Text Available One of the most shocking Gothic novels was written by Matthew Gregory Lewis in 1796. His Gothic novel The Monk contains all the typical Gothic elements such as a ruined castle, aggressive villain, women in distress, the atmosphere of terror and horror and a lot more. This article analyses and compares to what extent the Gothic elements of the late 18th century survived in the contemporary detective story The Ice House (1993 written by Minette Walters and how these elements have changed.

  2. The study of fMRI in Alzheimer's disease, frontotemporal dementia and Lewy bodies dementia

    International Nuclear Information System (INIS)

    Zhang Bing; Xu Jun; Xu Yun; Zhu Bin

    2010-01-01

    Alzheimer's disease (AD), dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD) are the main type of neuro degenerative diseases, but the FTD and DLB are always confused with AD. Structural MRI, diffusion-weighted imaging and proton magnetic resonance spectroscopy have the potential to support the diagnosis of AD and the relative disease. Brain atrophy pattern, apparent diffusion coefficient and fractional anisotropy pattern, the distribution mode of N-acetylaspartate and myo-inositol in temporal lobe, hippocampus, parietal lobe, frontal lobe could help to differentiate AD from FTD, DLB and those patterns are in accordance with the pathological changes. (authors)

  3. Verba tene, res sequentur. Lewis Carroll’s play on words and linguistic-textual generation

    OpenAIRE

    Katajamäki, Sakari

    2016-01-01

    In the beginning of Lewis Carroll’s Through the Looking-Glass (1872), the chessman White King is writing a note in his memorandum book, but his pencil does not obey him. The poor King struggles with it but, despite his efforts, he is not able to write what he intends. The text that appears in his book is something entirely peculiar and contrary to his intention: “The White Knight is sliding down the poker. He balances badly.” This episode reflects the manner in which language is often represe...

  4. Recent advances in Ni-H2 technology at NASA Lewis Research Center

    Science.gov (United States)

    Gonzalezsanabria, O. D.; Britton, D. L.; Smithrick, J. J.; Reid, M. A.

    1986-01-01

    The NASA Lewis Research Center has concentrated its efforts on advancing the Ni-H2 system technology for low Earth orbit applications. Component technology as well as the design principles were studied in an effort to understand the system behavior and failure mechanisms in order to increase performance and extend cycle life. The design principles were previously addressed. The component development is discussed, in particular the separator and nickel electrode and how these efforts will advance the Ni-H2 system technology.

  5. General aviation internal combustion engine research programs at NASA-Lewis Research Center

    Science.gov (United States)

    Willis, E. A.

    1978-01-01

    An update is presented of non-turbine general aviation engine programs underway at the NASA-Lewis Research Center in Cleveland, Ohio. The program encompasses conventional, lightweight diesel and rotary engines. Its three major thrusts are: (a) reduced SFC's; (b) improved fuels tolerance; and (c) reducing emissions. Current and planned future programs in such areas as lean operation, improved fuel management, advanced cooling techniques and advanced engine concepts, are described. These are expected to lay the technology base, by the mid to late 1980's, for engines whose life cycle fuel costs are 30 to 50% lower than today's conventional engines.

  6. Lewis, S

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-01

    This paper briefly reviews the investigation between 1969 and 1975 into substitutes for chock support timber. The parameters for the design of the substitutes were very exacting, having been based on the original material and as the investigation progressed it was necessary to modify and make changes. Of the large variety of materials tested the discard was considerable; however suitable ductile structures were found, utilizing reinforced autoclaved aerated concrete. Successful laboratory testing was eventually confirmed by satisfactory trials in a number of underground situations.

  7. Quetiapine effective in treatment of inappropriate sexual behavior of lewy body disease with predominant frontal lobe signs.

    Science.gov (United States)

    Prakash, Ravi; Pathak, Amit; Munda, Sanjay; Bagati, Dhruv

    2009-01-01

    Dementia of Lewy body disease is the second most common degenerative cause of dementia after Alzheimer's disease, among all the dementias. The core features are a progressive dementia, fluctuations in cognitive functions, visual hallucinations, and spontaneous parkinsonism. Rapid eye movement sleep behavior disorder, severe neuroleptic sensitivity, and low dopamine transporter uptake in basal ganglia are other suggestive features. Behavioral abnormalities are commonly present in the form of aggressive behavior, irritability, and uninhibited behaviors. These are mostly seen in the advanced stages of dementia. However, inappropriate sexual behavior is uncommonly seen in such cases. Three types of inappropriate sexual behaviors commonly found in cases of dementia are sex talks, sexual acts, and implied sexual acts. Such inappropriate sexual behaviors have not been described adequately in dementia of Lewy body disease. We report inappropriate sexual behaviors in a case of dementia of Lewy body disease, which improved rapidly after treatment with quetiapine.

  8. Calibration and comparison of the NASA Lewis free-piston Stirling engine model predictions with RE-1000 test data

    Science.gov (United States)

    Geng, Steven M.

    1987-01-01

    A free-piston Stirling engine performance code is being upgraded and validated at the NASA Lewis Research Center under an interagency agreement between the Department of Energy's Oak Ridge National Laboratory and NASA Lewis. Many modifications were made to the free-piston code in an attempt to decrease the calibration effort. A procedure was developed that made the code calibration process more systematic. Engine-specific calibration parameters are often used to bring predictions and experimental data into better agreement. The code was calibrated to a matrix of six experimental data points. Predictions of the calibrated free-piston code are compared with RE-1000 free-piston Stirling engine sensitivity test data taken at NASA Lewis. Resonable agreement was obtained between the code predictions and the experimental data over a wide range of engine operating conditions.

  9. Self-Assembled Nanocomposite Organic Polymers with Aluminum and Scandium as Heterogeneous Water-Compatible Lewis Acid Catalysts.

    Science.gov (United States)

    Miyamura, Hiroyuki; Sonoyama, Arisa; Hayrapetyan, Davit; Kobayashi, Shū

    2015-09-01

    While water-compatible Lewis acids have great potential as accessible and environmentally benign catalysts for various organic transformations, efficient immobilization of such Lewis acids while keeping high activity and without leaching of metals even under aqueous conditions is a challenging task. Self-assembled nanocomposite catalysts of organic polymers, carbon black, aluminum reductants, and scandium salts as heterogeneous water-compatible Lewis acid catalysts are described. These catalysts could be successfully applied to various C-C bond-forming reactions without leaching of metals. Scanning transmission electron microscopy analyses revealed that the nanocomposite structure of Al and Sc was fabricated in these heterogeneous catalysts. It is noted that Al species, which are usually decomposed rapidly in the presence of water, are stabilized under aqueous conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Controlled synthesis of multi-morphology Te crystals by a convenient Lewis acid/base-assisted solvothermal method

    International Nuclear Information System (INIS)

    Wu Xiaoping; Yuan Lin; Zhou Shaomin; Lou Shiyun; Wang Yongqiang; Gao Tao; Liu YuBiao; Shi Xiaojing

    2012-01-01

    This paper reports on the controlled growth of multi-morphology Te crystals by a convenient Lewis acid/base-assisted solvothermal method for the first time. The morphological transformation from one-dimension (1D) nanostructures to 2D hierarchical flowerlike microarchitecture has been observed. The nanorods and nanowires with a well-defined crystallographical structure and the hierarchical flowers microarchitecture were obtained by changing the Lewis acids/bases. Lewis acids/bases were found to be crucial for the formation of the products by not only acting as the pH regulator but also as the shape controller, owing to their hydrolysis in the solvent to in situ form H + /OH − and hydrates. The results suggest that this should be an effective approach to the control the growth of t-Te crystals with interesting multiple morphologies, which are of interest for both theoretical investigations and practical applications.

  11. Familial diffuse Lewy body disease, eye movement abnormalities, and distribution of pathology.

    Science.gov (United States)

    Brett, Francesca M; Henson, Craig; Staunton, Hugh

    2002-03-01

    Familial diffuse Lewy body disease (DLBD) is rare and not yet associated with a defect in the synuclein gene. In the differential diagnosis of the parkinsonian syndromes, defects in vertical gaze tend to be identified with progressive supranuclear palsy. False-positive diagnosis of progressive supranuclear palsy can occur, and defects in vertical gaze have been reported in DLBD, although so far a pure vertical gaze palsy associated with pathological abnormalities in the substrate for vertical gaze has not been described. To report the clinical and pathological findings in 2 siblings with DLBD, and to relate the distribution of the pathological abnormalities in the brainstem to centers for vertical gaze. For several years, 2 Irish siblings experienced a progressive parkinsonism-dementia complex associated in one with a defect in vertical gaze and in both with visual hallucinations. In both patients, results of pathological examination revealed (1) Lewy bodies positive for ubiquitin and alpha-synuclein together with cell loss and gliosis in the substantia nigra, locus ceruleus, and neocortex; and (2) similar findings in the rostral interstitial nucleus of the medial longitudinal fasciculus, the posterior commissure, and the interstitial nucleus of Cajal (substrates for vertical gaze). Familial DLBD (not shown to be genetically as distinct from environmentally transmitted) has been shown to exist in an Irish family. Caution should be enjoined in the interpretation of defects in vertical gaze in the differential diagnosis of the parkinsonian syndromes.

  12. Serum expression of HA and LN in lewis rat models of autoimmune myocarditis

    International Nuclear Information System (INIS)

    Han Li'na; Li Tieling; Zhang Yajing; Yang Tingshu; Ding Yu; Guo Shuli; Zhao Xiaoning

    2011-01-01

    Objective: To study the clinical significance of dynamic changes of serum expressions of hyaluronic acid (HA) and laminin (LN) in Lewis rat models of experimental autoimmune myocarditis (EAM). Methods: Fifty Lewis rat models of experimental autoimmune myocarditis (EAM) were established with injection of recombinant cardiac C protein with complete freund adjuvant into two foot-pads plus intraperitoneal injection of pertussis toxin. At 1w, 2w, 4w, 6w and 8w, 10 models were sacrificed each time;cardiac tissues were examined with HE stain for myocardial inflammatory score and examined with picrosirius red stain for myocardial fibrosis score, also, serum HA and LN expressions were determined with RIA. These examinations were performed in 10 undisturbed animals as controls. Results: The myocardial inflammatory scores of the models at 1w were about the same as those in the controls, but the scores rapidly increased from 2w on to 4w then fell gradually. The myocardial fibrosis scores of the models at 1wk were also not much different from those in controls. The fibrosis scores increased rapidly at 4w and maintained at high level up to 8w. The changes of serum expressions of HA and LN roughly paralleled those of myocardial fibrosis scores i. e. rapidly increased at 4w up to 8w. Conclusion: Serum expressions of HA and LN could faithfully reflect the degree of myocardial fibrosis in rat models of EAM. HA and LN were useful markers of myocardial fibrois and were of prognostic importance. (authors)

  13. Lewis basicity, adhesion thermodynamic work and coordinating ability on aminated silicon surfaces

    International Nuclear Information System (INIS)

    Sánchez, M. Alejandra; Paniagua, Sergio A.; Borge, Ignacio; Viales, Christian; Montero, Mavis L.

    2014-01-01

    Highlights: • Silicon(1 0 0) surfaces with diamines followed by anchoring of copper complexes over the diamine layer, an approach that could be used for advanced functionalization of semiconducting surfaces. • Lewis basicity (using Fowkes–van Oss–Chaudhury–Good surface tension model) and adhesion thermodynamic work (using chemical force microscopy) were determined. • Higher basicity and thermodynamic work correlate with selective copper acetate monolayer grow. The cyclic voltammetry studies confirm the confined copper redox activity. - Abstract: Silicon(1 0 0) surfaces have been modified with three different amines (aniline, benzylamine and dodecylamine) and diamines (4-aminopyridine, 4-aminomethylpyridine, 1,12-dodecyldiamine). The surface energy was measured by contact angle technique. For Si-diamine surfaces, Lewis basicity (using Fowkes–van Oss–Chaudhury–Good surface tension model) and adhesion thermodynamic work (using chemical force microscopy) were determined. We related these data, the amine/diamine nature and their geometry on the surface (via DFT calculations) with the consequent ability to coordinate copper(II) acetate. Finally, copper(II) acetate monolayers behavior was studied by cyclic voltammetry

  14. Cholinergic and dopaminergic activities in senile dementia of Lewy body type.

    Science.gov (United States)

    Perry, E K; Marshall, E; Perry, R H; Irving, D; Smith, C J; Blessed, G; Fairbairn, A F

    1990-01-01

    Analyses of brain tissue in a recently identified group of elderly demented patients suggest a neurochemical basis for some of the clinical features. Senile dementia of the Lewy body type (SDLT) can be distinguished from classical Alzheimer disease (AD) clinically by its acute presentation with confusion frequently accompanied by visual hallucinations, and neuropathologically by the presence of Lewy bodies and senile plaques (but not generally neurofibrillary tangles) in the cerebral cortex. Reductions in the cortical cholinergic enzyme choline acetyltransferase were more pronounced in individuals with (80%) compared to those without (50%) hallucinations and correlated strongly with mental test scores in the group as a whole. In the caudate nucleus, dopamine levels were related to the number of neurons in the substantia nigra, there being a 40-60% loss of both in SDLT--probably accounting for mild extrapyramidal features in some of these cases--compared with an 80% loss in Parkinson disease and no change in AD. The cholinergic correlates of mental impairment in SDLT together with the relative absence of cortical neurofibrillary tangles and evidence for postsynaptic cholinergic receptor compensation raise the question of whether this type of dementia may be more amenable to cholinotherapy than classical AD.

  15. Diffusible gradients are out - an interview with Lewis Wolpert. Interviewed by Richardson, Michael K.

    Science.gov (United States)

    Wolpert, Lewis

    2009-01-01

    In 1969, Lewis Wolpert published a paper outlining his new concepts of "pattern formation" and "positional information". He had already published research on the mechanics of cell membranes in amoebae, and a series of classic studies of sea urchin gastrulation with Trygve Gustavson. Wolpert had presented his 1969 paper a year earlier at a Woods Hole conference, where it received a very hostile reception: "I wasnt asked back to America for many years!". But with Francis Crick lining up in support of diffusible morphogen gradients, positional information eventually became established as a guiding principle for research into biological pattern formation. It is now clear that pattern formation is much more complex than could possibly have been imagined in 1969. But Wolpert still believes in positional information, and regards intercalation during regeneration as its best supporting evidence. However, he and others doubt that diffusible morphogen gradients are a plausible mechanism: "Diffusible gradients are too messy", he says. Since his retirement, Lewis Wolpert has remained active as a theoretical biologist and continues to publish in leading journals. He has also campaigned for a greater public understanding of the stigma of depression. He was interviewed at home in London on July 26th, 2007 by Michael Richardson.

  16. Reflections on Centaur Upper Stage Integration by the NASA Lewis (Glenn) Research Center

    Science.gov (United States)

    Graham, Scott R.

    2015-01-01

    The NASA Glenn (then Lewis) Research Center (GRC) led several expendable launch vehicle (ELV) projects from 1963 to 1998, most notably the Centaur upper stage. These major, comprehensive projects included system management, system development, integration (both payload and stage), and launch operations. The integration role that GRC pioneered was truly unique and highly successful. Its philosophy, scope, and content were not just invaluable to the missions and vehicles it supported, but also had significant Agency-wide benefits. An overview of the NASA Lewis Research Center (now the NASA Glenn Research Center) philosophy on ELV integration is provided, focusing on Atlas/Centaur, Titan/Centaur, and Shuttle/Centaur vehicles and programs. The necessity of having a stable, highly technically competent in-house staff is discussed. Significant depth of technical penetration of contractor work is another critical component. Functioning as a cohesive team was more than a concept: GRC senior management, NASA Headquarters, contractors, payload users, and all staff worked together. The scope, content, and history of launch vehicle integration at GRC are broadly discussed. Payload integration is compared to stage development integration in terms of engineering and organization. Finally, the transition from buying launch vehicles to buying launch services is discussed, and thoughts on future possibilities of employing the successful GRC experience in integrating ELV systems like Centaur are explored.

  17. Alpha-synuclein oligomers - neurotoxic molecules in Parkinson’s disease and other Lewy body disorders

    Directory of Open Access Journals (Sweden)

    Martin Ingelsson

    2016-09-01

    Full Text Available Adverse intra- and extracellular effects of toxic α-synuclein are believed to be central to the pathogenesis in Parkinson’s disease and other disorders with Lewy body pathology in the nervous system. One of the physiological roles of α-synuclein relates to the regulation of neurotransmitter release at the presynapse, although it is still unclear whether this mechanism depends on the action of monomers or smaller oligomers. As for the pathogenicity, accumulating evidence suggest that prefibrillar species, rather than the deposits per se, are responsible for the toxicity in affected cells. In particular, larger oligomers or protofibrils of α-synuclein have been shown to impair protein degradation as well as the function of several organelles, such as the mitochondria and the endoplasmic reticulum. Accumulating evidence further suggest that oligomers/protofibrils may have a toxic effect on the synapse, which may lead to disrupted electrophysiological properties. In addition, recent data indicate that oligomeric α-synuclein species can spread between cells, either as free-floating proteins or via extracellular vesicles, and thereby act as seeds to propagate disease between interconnected brain regions. Taken together, several lines of evidence suggest that α-synuclein have neurotoxic properties and therefore should be an appropriate molecular target for therapeutic intervention in Parkinson’s disease and other disorders with Lewy pathology. In this context, immunotherapy with monoclonal antibodies against α-synuclein oligomers/protofibrils should be a particularly attractive treatment option.

  18. Recombinant human endostatin improves tumor vasculature and alleviates hypoxia in Lewis lung carcinoma

    International Nuclear Information System (INIS)

    Peng Fang; Wang Jin; Zou Yi; Bao Yong; Huang Wenlin; Chen Guangming; Luo Xianrong; Chen Ming

    2011-01-01

    Objective: To investigate whether recombinant human endostatin can create a time window of vascular normalization prior to vascular pruning to alleviate hypoxia in Lewis lung carcinoma in mice. Methods: Kinetic changes in morphology of tumor vasculature in response to recombinant human endostatin were detected under a confocal microscope with immunofluorescent staining in Lewis lung carcinomas in mice. The hypoxic cell fraction of different time was assessed with immunohistochemical staining . Effects on tumor growth were monitored as indicated in the growth curve of tumors . Results: Compared with the control group vascularity of the tumors was reduced over time by recombinant human endostatin treatment and significantly regressed for 9 days. During the treatment, pericyte coverage increased at day 3, increased markedly at day 5, and fell again at day 7. The vascular basement membrane was thin and closely associated with endothelial cells after recombinant human endostatin treatment, but appeared thickened, loosely associated with endothelial cells in control tumors. The decrease in hypoxic cell fraction at day 5 after treatment was also found. Tumor growth was not accelerated 5 days after recombinant human endostatin treatment. Conclusions: Recombinant human endostatin can normalize tumor vasculature within day 3 to 7, leading to improved tumor oxygenation. The results provide important experimental basis for combining recombinant human endostatin with radiation therapy in human tumors. (authors)

  19. Narrative Organization Deficit in Lewy Body Disorders Is Related to Alzheimer Pathology.

    Science.gov (United States)

    Grossman, Murray; Irwin, David J; Jester, Charles; Halpin, Amy; Ash, Sharon; Rascovsky, Katya; Weintraub, Daniel; McMillan, Corey T

    2017-01-01

    Background: Day-to-day interactions depend on conversational narrative, and we examine here the neurobiological basis for difficulty organizing narrative discourse in patients with Lewy body disorders (LBD). Method: Narrative organization was examined in 56 non-aphasic LBD patients, including a non-demented cohort ( n = 30) with Parkinson's disease (PD) or PD-Mild Cognitive Impairment PD-MCI,) and a cohort with mild dementia ( n = 26) including PD-dementia (PDD) and dementia with Lewy bodies (DLB), with similar age and education but differing in MMSE ( p organization of brief, familiar narratives (e.g., going fishing, wrapping a present). A subgroup of 24 patients had MRI assessment of regional gray matter (GM) atrophy and cerebrospinal fluid (CSF) levels of biomarkers for Alzheimer's disease (AD) pathology, including beta amyloid (Aβ), total-tau ( t -tau), and phosphorylated-tau ( p -tau). Results: Mildly demented LBD patients had a significant deficit judging narratives compared to non-demented patients, but this deficit was not correlated with MMSE. Regression analyses instead related narrative organization to regions of frontal GM atrophy, and CSF levels of Aβ and t -tau associated with presumed AD pathology in these frontal regions. Conclusion: These findings are consistent with the hypothesis that CSF markers of AD pathology associated with frontal regions play a role in difficulty organizing narratives in LBD.

  20. Plasma physics

    CERN Document Server

    Drummond, James E

    1961-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  1. Plasma generator

    International Nuclear Information System (INIS)

    Omichi, Takeo; Yamanaka, Toshiyuki.

    1976-01-01

    Object: To recycle a coolant in a sealed hollow portion formed interiorly of a plasma limiter itself to thereby to cause direct contact between the coolant and the plasma limiter and increase of contact area therebetween to cool the plasma limiter. Structure: The heat resulting from plasma generated during operation and applied to the body of the plasma limiter is transmitted to the coolant, which recycles through an inlet and outlet pipe, an inlet and outlet nozzle and a hollow portion to hold the plasma limiter at a level less than a predetermined temperature. On the other hand, the heater wire is, at the time of emergency operation, energized to heat the plasma limiter, but this heat is transmitted to the limiter body to increase the temperature thereof. However, the coolant recycling the hollow portion comes into direct contact with the limiter body, and since the plasma limiter surround the hollow portion, the heat amount transmitted from the limiter body to the coolant increases to sufficiently cool the plasma limiter. (Yoshihara, H.)

  2. Numerical Modeling of Climatic Change from the Terminus Record of Lewis Glacier, Mount Kenya.

    Science.gov (United States)

    Kruss, Phillip Donald

    Over the last 100 years, the glaciers and lakes of East Africa have undergone dramatic change in response to climatic forcing. However, the available conventional meterological series have not proven sufficient to explain these environmental events. The secular climatic change at Lewis Glacier, Mount Kenya (0(DEGREES)9'S, 37(DEGREES)19'E), is reconstructed from its terminus record documented since 1893. The short-time-step numerical model developed for this study consists of climate and ice dynamics segments. The climate segment directly computes the effect on the net balance of change in the four forcings: precipitation, albedo, cloudiness, and temperature. The flow segment calculates the dynamic glacier response to net balance variation. Climatic change occurs over a wide range of time scales. Each glacier responds in a unique fashion to this spectrum of climatic forcings. The response of the Lewis terminus extent to repeated sinusoidal fluctuation in the net balance is calculated. The net balance versus elevation profile is separately translated along the orthogonal balance and elevation axes. Net balance amplitudes of 0.1 to 0.5 m a('-1) of ice and 10 to 50 m elevation, respectively, and periods ranging from 20 to 1000 years are covered. Consideration of the Lewis response is perspective with similar results for Hintereisferner, Storglaciaren, and Berendon and South Cascade Glaciers identifies general characteristics of the time lag and amplitude of the terminus response. The magnitude and timing of the change in only one of the climatic forcings precipitation, albedo, cloudiness, or temperature necessary to produce the retreat of the Lewis terminus from its late 19th century maximum are computed. Equivalent changes for two scenarios of simultaneous variation, namely precipitation/albedo/cloudiness and temperature/albedo, are also estimated. These numerical results are interpreted in the light of long-term lake level, river flow, and instrumental information. A

  3. An exploratory study of proficient undergraduate Chemistry II students' application of Lewis's model

    Science.gov (United States)

    Lewis, Sumudu R.

    This exploratory study was based on the assumption that proficiency in chemistry must not be determined exclusively on students' declarative and procedural knowledge, but it should be also described as the ability to use variety of reasoning strategies that enrich and diversify procedural methods. The study furthermore assumed that the ability to describe the structure of a molecule using Lewis's model and use it to predict its geometry as well as some of its properties is indicative of proficiency in the essential concepts of covalent bonding and molecule structure. The study therefore inquired into the reasoning methods and procedural techniques of proficient undergraduate Chemistry II students when solving problems, which require them to use Lewis's model. The research design included an original survey, designed by the researcher for this study, and two types of interviews, with students and course instructors. The purpose of the survey was two-fold. First and foremost, the survey provided a base for the student interview selection, and second it served as the foundation for the inquiry into the strategies the student use when solving survey problems. Twenty two students were interviewed over the course of the study. The interview with six instructors allowed to identify expected prior knowledge and skills, which the students should have acquired upon completion of the Chemistry I course. The data, including videos, audios, and photographs of the artifacts produced by students during the interviews, were organized and analyzed manually and using QSR NVivo 10. The research found and described the differences between proficient and non-proficient students' reasoning and procedural strategies when using Lewis's model to describe the structure of a molecule. One of the findings clearly showed that the proficient students used a variety of cues to reason, whereas other students used one memorized cue, or an algorithm, which often led to incorrect representations in

  4. Lewis base catalyzed 1,3-dithiane addition to carbonyl and imino compounds using 2-trimethylsilyl-1,3-dithiane.

    Science.gov (United States)

    Michida, Makoto; Mukaiyama, Teruaki

    2008-09-01

    Lewis base-catalyzed 1,3-dithiane addition to electrophiles such as carbonyl compounds and N-substituted aldimines with 2-trimethylsilyl-1,3-dithiane (TMS-dithiane) is described. By the activation of the carbon-silicon bond in the presence of a Lewis base catalyst such as tetrabutylammonium phenoxide (PhONnBu(4)), a 1,3-dithiane addition reaction proceeded smoothly to afford the corresponding adducts in good to high yields under mild conditions. This synthesis is also applied to the reactions of ketones having alpha-protons, and of N-substituted aldimines.

  5. Tailoring the Synergistic Bronsted-Lewis acidic effects in Heteropolyacid catalysts: Applied in Esterification and Transesterification Reactions

    OpenAIRE

    Tao, Meilin; Xue, Lifang; Sun, Zhong; Wang, Shengtian; Wang, Xiaohong; Shi, Junyou

    2015-01-01

    In order to investigate the influences of Lewis metals on acidic properties and catalytic activities, a series of Keggin heteropolyacid (HPA) catalysts, HnPW11MO39 (M = TiIV, CuII, AlIII, SnIV, FeIII, CrIII, ZrIV and ZnII; for Ti and Zr, the number of oxygen is 40), were prepared and applied in the esterification and transesterification reactions. Only those cations with moderate Lewis acidity had a higher impact. Ti Substituted HPA, H5PW11TiO40, posse lower acid content compared with TixH3−4...

  6. FROM THE LEWIS AND CLARK EXPEDITION TO IBM, DELL, AND SOUTHWEST AIRLINES: TEACHING HISTORY AND LEADERSHIP TO BUSINESS STUDENTS

    Directory of Open Access Journals (Sweden)

    Jeffrey J. Matthews

    2006-01-01

    Full Text Available History is not a tomb of dead facts but a resource that can inform and improve everyday decision making. Experience as an analytical tool is invaluable for solving problems in changing and competitive environments. “From the Lewis and Clark Expedition,” which coincides with the National Lewis & Clark Bicentennial Commemoration (2003—2006, demonstrates how contemporary business concepts of visionary leadership, systematic planning, and organizational climate were instrumental to the success of Thomas Jefferson's “Corps of Discovery” and shows how a mastery of these concepts contributed to the successes of the pioneering US corporations IBM, Southwest Airlines, and Dell.

  7. Investigation of prototypal MOFs consisting of polyhedral cages with accessible Lewis-acid sites for quinoline synthesis.

    Science.gov (United States)

    Gao, Wen-Yang; Leng, Kunyue; Cash, Lindsay; Chrzanowski, Matthew; Stackhouse, Chavis A; Sun, Yinyong; Ma, Shengqian

    2015-03-21

    A series of prototypal metal-organic frameworks (MOFs) consisting of polyhedral cages with accessible Lewis-acid sites, have been systematically investigated for Friedländer annulation reaction, a straightforward approach to synthesizing quinoline and its derivatives. Amongst them MMCF-2 demonstrates significantly enhanced catalytic activity compared with the benchmark MOFs, HKUST-1 and MOF-505, as a result of a high-density of accessible Cu(II) Lewis acid sites and large window size in the cuboctahedral cage-based nanoreactor of MMCF-2.

  8. Bridge between fusion plasma and plasma processing

    International Nuclear Information System (INIS)

    Ohno, Noriyasu; Takamura, Shuichi

    2008-01-01

    In the present review, relationship between fusion plasma and processing plasma is discussed. From boundary-plasma studies in fusion devices new applications such as high-density plasma sources, erosion of graphite in a hydrogen plasma, formation of helium bubbles in high-melting-point metals and the use of toroidal plasmas for plasma processing are emerging. The authors would like to discuss a possibility of knowledge transfer from fusion plasmas to processing plasmas. (T. Ikehata)

  9. Plasma waves

    National Research Council Canada - National Science Library

    Swanson, D. G

    1989-01-01

    ... Swanson, D.G. (Donald Gary), D a t e - Plasma waves. Bibliography: p. Includes index. 1. Plasma waves. QC718.5.W3S43 1989 ISBN 0-12-678955-X I. Title. 530.4'4 88-34388 Printed in the United Sta...

  10. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1991-06-01

    The Magneto-Fluid Dynamics Division continues to study a broad range of problems originating in plasma physics. Its principal focus is fusion plasma physics, and most particularly topics of particular significance for the world magnetic fusion program. During the calendar year 1990 we explored a wide range of topics including RF-induced transport as a plasma control mechanism, edge plasma modelling, further statistical analysis of L and H mode tokamak plasmas, antenna design, simulation of the edge of a tokamak plasma and the L-H transition, interpretation of the CCT experimental results at UCLA, turbulent transport, studies in chaos, the validity of moment approximations to kinetic equations and improved neoclassical modelling. In more basic studies we examined the statistical mechanisms of Coulomb systems and applied plasma ballooning mode theory to conventional fluids in order to obtain novel fluid dynamics stability results. In space plasma physics we examined the problem of reconnection, the effect of Alfven waves in space environments, and correct formulation of boundary conditions of the Earth for waves in the ionosphere

  11. Plasma container

    International Nuclear Information System (INIS)

    Ebisawa, Katsuyuki.

    1985-01-01

    Purpose: To enable to easily detect that the thickness of material to be abraded is reduced to an allowable limit from the outerside of the plasma container even during usual operation in a plasma vessel for a thermonuclear device. Constitution: A labelled material is disposed to the inside or rear face of constituent members of a plasma container undergoing the irradiation of plasma particles. A limiter plate to be abraded in the plasma container is composed of an armour member and heat removing plate, in which the armour member is made of graphite and heat-removing plate is made of copper. If the armour member is continuously abraded under the effect of sputtering due to plasma particles, silicon nitride embedded so far in the graphite at last appears on the surface of the limiter plate to undergo the impact shocks of the plasma particles. Accordingly, abrasion of the limiter material can be detected by a detector comprising gas chromatography and it can easily be detected from the outside of the plasma content even during normal operation. (Horiuchi, T.)

  12. Cosmic plasma

    Energy Technology Data Exchange (ETDEWEB)

    Alfven, H [California Univ., San Diego, La Jolla (USA)

    1981-01-01

    The properties of space plasmas are analyzed, based on laboratory results and data obtained by in situ measurements in the magnetosphere (including the heliosphere). Attention is given to the question of how much knowledge can be gained by a systematic comparison of different regions of plasma, and plasmas are considered with linear dimensions varying from laboratory size up to the Hubble distance. The traditional magnetic field description of plasmas is supplemented by an electric current description and it is demonstrated that many problems are easier to understand with a dualistic approach. Using the general plasma properties obtained, the origin and evolution of the solar system is summarized and the evolution and present structure of the universe (cosmology) is discussed.

  13. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A relativistic electron beam generator or accelerator produces a high-voltage electron beam which is modulated to initiate electron bunching within the beam which is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10 17 to 10 20 electrons per cubic centimeter. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target. The high-temperature plasma can be used to heat a high Z material to generate radiation. Alternatively, a tunable radiation source is produced by using a moderate Z gas or a mixture of high Z and low Z gas as the target plasma. (author)

  14. Elk monitoring in Lewis and Clark National Historical Park: 2008-2012 synthesis report

    Science.gov (United States)

    Griffin, Paul C.; Jenkins, Kurt J.; Cole, Carla; Clatterbuck, Chris; Boetsch, John; Beirne, Katherine

    2014-01-01

    Maintaining elk (Cervus elaphus roosevelti) herds that frequent Lewis and Clark National Historical Park (NHP) is central to the park’s purpose of preserving the historic, cultural, scenic, and natural resources associated with the winter encampment of the Lewis and Clark expedition. Elk were critically important to the Lewis and Clark expedition in providing food and hides that sustained the expedition during the winter of 1805-06 and supplied them for their return east during 1806. Today, elk remain a key component of interpreting the Lewis and Clark story to over 200,000 park visitors each year at the Fort Clatsop visitor center. In 2008, the US Geological Survey (USGS) began collaborating with Lewis and Clark NHP and the NPS North Coast and Cascades Network to develop a protocol for monitoring long-term changes in the magnitude and spatial patterns of elk use within and adjacent to Lewis and Clark NHP (Griffin et al. 2011). Specific objectives of the monitoring program were to measure trends in (1) relative use of the Fort Clatsop unit by elk during winter; (2) the proportion of areas where elk sign is present in the Fort Clatsop unit in winter; and (3) the frequency of elk sightings from roads in and around the Fort Clatsop unit. This report synthesizes the results of the first four years of monitoring elk distribution and use in Lewis and Clark NHP from 2008-2012. We also present data from FY2012 (Appendix 1), in lieu of an annual report for that year. We used fecal pellet group surveys as the cornerstone for monitoring trends in both relative use of the Fort Clatsop Unit by elk and the proportion of areas where elk sign was present at the end of winter. We estimated pellet group density based on data collected from a network of fecal pellet plots distributed systematically throughout the unit. We developed a double observer sampling scheme that enabled us to estimate detection biases and improve the accuracy of pellet group density estimates. We computed

  15. Superconducting plasmas

    International Nuclear Information System (INIS)

    Ohnuma, Toshiro; Ohno, J.

    1994-01-01

    Superconducting (SC) plasmas are proposed and investigated. The SC plasmas are not yet familiar and have not yet been studied. However, the existence and the importance of SC plasmas are stressed in this report. The existence of SC plasmas are found as follows. There is a fundamental property of Meissner effect in superconductors, which shows a repulsive effect of magnetic fields. Even in that case, in a microscopic view, there is a region of magnetic penetration. The penetration length λ is well-known as London's penetration depth, which is expressed as δ = (m s /μ 0 n s q s 2 ) 1/2 where m s , n s , q s and μ o show the mass, the density, the charge of SC electron and the permeability in free space, respectively. Because this expression is very simple, no one had tried it into more simple and meaningful form. Recently, one of the authors (T.O.) has found that the length can be expressed into more simple and understandable fundamental form as λ = c/ω ps where c = (ε 0 μ 0 ) -1/2 and ω ps = (n s q s 2 /m s ε 0 ) 1/2 are the light velocity and the superconducting plasma frequency. From this simple expression, the penetration depth of the magnetic field to SC is found as a SC plasma skin depth, that is, the fundamental property of SC can be expressed by the SC plasmas. This discovery indicates an importance of the studies of superconducting plasmas. From these points, several properties (propagating modes et al) of SC plasmas, which consist of SC electrons, normal electrons and lattice ions, are investigated in this report. Observations of SC plasma frequency is also reported with a use of Terahertz electromagnet-optical waves

  16. Inhibitory effect of vitamin C in combination with vitamin K3 on tumor growth and metastasis of Lewis lung carcinoma xenografted in C57BL/6 mice.

    Science.gov (United States)

    Chen, Ming-Feng; Yang, Chih-Min; Su, Cheng-Ming; Liao, Jiunn-Wang; Hu, Miao-Lin

    2011-01-01

    Vitamin C in combination with vitamin K3 (vit CK3) has been shown to inhibit tumor growth and lung metastasis in vivo, but the mechanism of action is poorly understood. Herein, C57BL/6 mice were implanted (s.c.) with Lewis lung carcinoma (LLC) for 9 days before injection (i.p.) with low-dose (100 mg vit C/kg + 1 mg vit K3/kg), high-dose (1,000 mg vit C/kg + 10 mg vit K3/kg) vit CK3 twice a week for an additional 28 days. As expected, vit CK3 or cisplatin (6 mg/kg, as a positive control) significantly and dose-dependently inhibited tumor growth and lung metastasis in LLC-bearing mice. Vit CK3 restored the body weight of tumor-bearing mice to the level of tumor-free mice. Vit CK3 significantly decreased activities of plasma metalloproteinase (MMP)-2, -9, and urokinase plasminogen activator (uPA). In lung tissues, vit CK3 1) increased protein expression of tissue inhibitor of metalloproteinase-1 (TIMP-1), TIMP-2, nonmetastatic protein 23 homolog 1 and plasminogen activator inhibitor-1; 2) reduced protein expression of MMP-2 and MMP-9; and 3) inhibited the proliferating cell nuclear antigen (PCNA). These results demonstrate that vit CK3 inhibits primary tumor growth and exhibits antimetastastic potential in vivo through attenuated tumor invasion and proliferation.

  17. Carbonyl Activation by Borane Lewis Acid Complexation: Transition States of H2 Splitting at the Activated Carbonyl Carbon Atom in a Lewis Basic Solvent and the Proton-Transfer Dynamics of the Boroalkoxide Intermediate.

    Science.gov (United States)

    Heshmat, Mojgan; Privalov, Timofei

    2017-07-06

    By using transition-state (TS) calculations, we examined how Lewis acid (LA) complexation activates carbonyl compounds in the context of hydrogenation of carbonyl compounds by H 2 in Lewis basic (ethereal) solvents containing borane LAs of the type (C 6 F 5 ) 3 B. According to our calculations, LA complexation does not activate a ketone sufficiently enough for the direct addition of H 2 to the O=C unsaturated bond; but, calculations indicate a possibly facile heterolytic cleavage of H 2 at the activated and thus sufficiently Lewis acidic carbonyl carbon atom with the assistance of the Lewis basic solvent (i.e., 1,4-dioxane or THF). For the solvent-assisted H 2 splitting at the carbonyl carbon atom of (C 6 F 5 ) 3 B adducts with different ketones, a number of TSs are computed and the obtained results are related to insights from experiment. By using the Born-Oppenheimer molecular dynamics with the DFT for electronic structure calculations, the evolution of the (C 6 F 5 ) 3 B-alkoxide ionic intermediate and the proton transfer to the alkoxide oxygen atom were investigated. The results indicate a plausible hydrogenation mechanism with a LA, that is, (C 6 F 5 ) 3 B, as a catalyst, namely, 1) the step of H 2 cleavage that involves a Lewis basic solvent molecule plus the carbonyl carbon atom of thermodynamically stable and experimentally identifiable (C 6 F 5 ) 3 B-ketone adducts in which (C 6 F 5 ) 3 B is the "Lewis acid promoter", 2) the transfer of the solvent-bound proton to the oxygen atom of the (C 6 F 5 ) 3 B-alkoxide intermediate giving the (C 6 F 5 ) 3 B-alcohol adduct, and 3) the S N 2-style displacement of the alcohol by a ketone or a Lewis basic solvent molecule. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Efectos de inhibidores de colinesterasa en pacientes con enfermedad asociada a cuerpos de Lewy

    Directory of Open Access Journals (Sweden)

    Nilton Custodio

    2008-09-01

    Full Text Available Objetivos: Analizar los efectos de los inhibidores de colinesterasas (ICE donepezilo, rivastigmina y galantamina en el tratamiento de demencia con cuerpos de Lewy (DCL y demencia de la enfermedad de Parkinson (DEP. Diseño: Estudio tipo ensayo abierto. Lugar: Servicio de Neurología, Hospital Militar Central (HMC, y Unidad de Diagnóstico de Deterioro Cognitivo y Prevención de Demencia, Clínica Internacional. Participantes: Pacientes con demencia asociada a cuerpos de Lewy y demencia de la enfermedad de Parkinson. Intervenciones: Las mediciones de eficacia en 33 pacientes con diagnóstico de DCL y DEP se realizó con el Mini-Mental State Examination (MMSE, Alzheimer Disease Assessment Scale cognitive subscale (ADAS-cog, Alzheimer’s Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC, Alzheimer’s Disease Cooperative Study-Activities of Daily Living Inventory (ADCS-ADL, Neuro-Psychiatry Inventory (NPI, Prueba de dibujo de Reloj de Manos (PDR-M y la Unified Parkinson´s Disease Rating Scale-motor subscale (UPDRS-part III. Principales medidas de resultados: Síntomas cognitivos, funcionamiento global y actividades de vida diaria de los pacientes. Resultados: Diecisiete pacientes fueron tratados con rivastigmina, 9 con galantamina y 7 con donepezilo. Luego de 6 meses de tratamiento, los pacientes en tratamiento con rivastigmina mejoraron en 1,39 puntos en ADAS-cog respecto de su medición basal, mientras que los pacientes tratados con donepezilo y galantamina no mostraron cambios (cambios <0,2 puntos. Respecto al ADCS-ADL, los pacientes tratados con rivastigmina, donepezilo y galantamina demostraron disminución de 0,42, 0,58 y 0,75 puntos, respectivamente. En el MMSE, los pacientes tratados con rivastigmina y donepezilo no mostraron cambios y los pacientes tratados con galantamina tuvieron una disminución promedio de 1,19 puntos. No hubo diferencias significativas en la incidencia de síntomas parkinsonianos en los tres

  19. Plasma universe

    International Nuclear Information System (INIS)

    Alfven, H.

    1986-04-01

    Traditionally the views in our cosmic environment have been based on observations in the visual octave of the electromagnetic spectrum, during the last half-century supplemented by infrared and radio observations. Space research has opened the full spectrum. Of special importance are the X-ray-gamma-ray regions, in which a number of unexpected phenomena have been discovered. Radiations in these regions are likely to originate mainly from magnetised cosmic plasma. Such a medium may also emit synchrotron radiation which is observable in the radio region. If we try to base a model of the universe on the plasma phenomena mentioned we find that the plasma universe is drastically different from the traditional visual universe. Information about the plasma universe can also be obtained by extrapolation of laboratory experiments and magnetospheric in situ measurements of plasma. This approach is possible because it is likely that the basic properties of plasma are the same everywhere. In order to test the usefulness of the plasma universe model we apply it to cosmogony. Such an approach seems to be rather successful. For example, the complicated structure of the Saturnian C ring can be accounted for. It is possible to reconstruct certain phenomena 4-5 bilions years ago with an accuracy of better than 1 percent

  20. Differential impact of stress on hypothalamic–pituitary–adrenal axis: Gene expression changes in Lewis and Fisher rats

    Czech Academy of Sciences Publication Activity Database

    Ergang, Peter; Vodička, Martin; Soták, Matúš; Klusoňová, Petra; Behuliak, Michal; Řeháková, Lenka; Zach, P.; Pácha, Jiří

    2015-01-01

    Roč. 53, Mar 2015 (2015), s. 49-59 ISSN 0306-4530 R&D Projects: GA ČR(CZ) GAP303/10/0969 Institutional support: RVO:67985823 Keywords : 11beta-hydroxysteroid dehydrogenase type 1 * brain * neuropeptides * stress * Fisher rat * Lewis rat Subject RIV: ED - Physiology Impact factor: 4.704, year: 2015

  1. Comprehensive report of aeropropulsion, space propulsion, space power, and space science applications of the Lewis Research Center

    Science.gov (United States)

    1988-01-01

    The research activities of the Lewis Research Center for 1988 are summarized. The projects included are within basic and applied technical disciplines essential to aeropropulsion, space propulsion, space power, and space science/applications. These disciplines are materials science and technology, structural mechanics, life prediction, internal computational fluid mechanics, heat transfer, instruments and controls, and space electronics.

  2. Tumor Progression Is Associated with Increasing CD11b(+) Cells and CCL2 in Lewis Rat Sarcoma

    Czech Academy of Sciences Publication Activity Database

    Mishra, Rajbardhan; Kovalská, Jana; Janda, Jozef; Vannucci, Luca; Rajmon, R.; Horák, Vratislav

    2015-01-01

    Roč. 35, č. 2 (2015), s. 703-712 ISSN 0250-7005 R&D Projects: GA MŠk ED2.1.00/03.0124 Institutional support: RVO:67985904 ; RVO:61388971 Keywords : Lewis rat sarcoma * CD11b+cells * neutrophils Subject RIV: FD - Oncology ; Hematology Impact factor: 1.895, year: 2015

  3. The association of neuroleptic sensitivity in Lewy body disease with a false positive clinical diagnosis of Creutzfeldt-Jakob disease

    NARCIS (Netherlands)

    Lemstra, A. W.; Schoenmaker, N.; Rozemuller-Kwakkel, A. J. M.; van Gool, W. A.

    2006-01-01

    BACKGROUND: Dementia with Lewy bodies (DLB) and Creutzfeldt-Jakob disease (CJD) share clinical features like cognitive decline, motor disturbances en psychiatric symptoms. Overlapping symptoms may cause physicians to mistake DLB for CJD. METHODS: Clinical data of 12 patients with autopsy-confirmed

  4. Geminal phosphorus/aluminum-based frustrated Lewis pairs: C-H versus C≡C activation and CO2 fixation

    NARCIS (Netherlands)

    Appelt, C.; Westenberg, H.; Bertini, F.; Ehlers, A.W.; Slootweg, J.C.; Lammertsma, K.; Uhl, W.

    2011-01-01

    Catch it! Geminal phosphorus/aluminum-based frustrated Lewis pairs (FLPs) are easily obtained by hydroalumination of alkynylphosphines. These FLPs can activate terminal acetylenes by two competitive pathways, which were analyzed by DFT calculations, and they can bind carbon dioxide reversibly.

  5. An Alternative View of the Thirties: The Industrial Photographs of Lewis Wickes Hine and Margaret Bourke-White.

    Science.gov (United States)

    Smith, C. Zoe

    The photographs of Margaret Bourke-White and Lewis Wickes Hine are graphic accounts of the urban industrial United States during the Depression of the 1930s. Hine was a sociologist who initially used his camera to promote social reform and is best remembered for his photographs of immigrants at Ellis Island, New York, and of children laboring in…

  6. Experimental observation of pulsating instability under acoustic field in downward-propagating flames at large Lewis number

    KAUST Repository

    Yoon, Sung Hwan

    2017-10-12

    According to previous theory, pulsating propagation in a premixed flame only appears when the reduced Lewis number, β(Le-1), is larger than a critical value (Sivashinsky criterion: 4(1 +3) ≈ 11), where β represents the Zel\\'dovich number (for general premixed flames, β ≈ 10), which requires Lewis number Le > 2.1. However, few experimental observation have been reported because the critical reduced Lewis number for the onset of pulsating instability is beyond what can be reached in experiments. Furthermore, the coupling with the unavoidable hydrodynamic instability limits the observation of pure pulsating instabilities in flames. Here, we describe a novel method to observe the pulsating instability. We utilize a thermoacoustic field caused by interaction between heat release and acoustic pressure fluctuations of the downward-propagating premixed flames in a tube to enhance conductive heat loss at the tube wall and radiative heat loss at the open end of the tube due to extended flame residence time by diminished flame surface area, i.e., flat flame. The thermoacoustic field allowed pure observation of the pulsating motion since the primary acoustic force suppressed the intrinsic hydrodynamic instability resulting from thermal expansion. By employing this method, we have provided new experimental observations of the pulsating instability for premixed flames. The Lewis number (i.e., Le ≈ 1.86) was less than the critical value suggested previously.

  7. Streamlined Darwin simulation of nonneutral plasmas

    International Nuclear Information System (INIS)

    Hewett, D.W.; Boyd, J.K.

    1987-01-01

    Efficient, new algorithms that require less formal manipulation than previous implementations have been formulated for the numerical solution of the Darwin model. These new procedures reduce the effort required to achieve some of the advantages that the Darwin model offers. Because the Courant--Friedrichs--Lewy stability limit for radiation modes is eliminated, the Darwin model has the advantage of a substantially larger time-step. Further, without radiation modes, simulation results are less sensitive to enhanced particle fluctation noise. We discuss methods for calculating the magnetic field that avoid formal vector decomposition and offer a new procedure for finding the inductive electric field. This procedure avoids vector decomposition of plasma source terms and circumvents some source gradient issues that slow convergence. As a consequence, the numerical effort required for each of the field time-steps is reduced, and more importantly, the need to specify several nonintuitive boundary conditions is eliminated. copyright 1987 Academic Press, Inc

  8. Cationic two-dimensional inorganic networks of antimony oxide hydroxide for Lewis acid catalysis.

    Science.gov (United States)

    Yin, Jinlin; Fei, Honghan

    2018-03-28

    We have successfully synthesized a rare example of inorganic layered materials possessing a positive charge, which is well outside the isostructural set of layered double hydroxides. This layered architecture consists of two-dimensional corrugated [Sb 2 O 2 (OH)] + layers with linear α,ω-alkanedisulfonate anions residing in the interlamellar space. This cationic material displays a chemical robustness under highly acidic aqueous conditions (pH = 1). Combining the robust nature and the high density of Sb III sites on the exposed crystal facets, our cationic layered material is an efficient, recyclable catalyst for cyanosilylation of benzaldehyde derivatives with trimethylsilyl cyanide. In addition, the Lewis acidity of the Sb III sites also catalyzes the ketalization of carbonyl groups under "green" solvent-free conditions.

  9. Glucagon-Like Peptide-1 Analog, Liraglutide, Delays Onset of Experimental Autoimmune Encephalitis in Lewis Rats

    DEFF Research Database (Denmark)

    DellaValle, Brian; Brix, Gitte S; Brock, Birgitte

    2016-01-01

    (GLP-1) family, is also anti-diabetic and weight-reducing and is, moreover, directly neuroprotective and anti-inflammatory in a broad spectrum of experimental models of brain disease. In this study we investigate the potential for this FDA-approved drug, liraglutide, as a treatment for MS by utilizing...... the experimental model, experimental autoimmune encephalitis (EAE). Methods: EAE was induced in 30 female Lewis rats that subsequently received twice-daily liraglutide (200 μg/kg s.c.) or saline. Healthy controls were included (saline, n = 6, liraglutide, n = 7). Clinical score and weight were assessed daily...... treatment delayed disease onset (group clinical score significantly >0) by 2 days and markedly reduced disease severity (median clinical score 2 vs. 5; p = 0.0003). Fourteen of 15 (93%) of vehicle-treated rats reached the humane endpoint (clinical score ≥4) by day 11 compared to 5 of 15 (33%) of liraglutide...

  10. Electronics technician Bill Clark assembling a cannon plug with the help of Jim Lewis

    Science.gov (United States)

    1991-01-01

    There is always something needed for a NASA aircraft before a research flight can take place. This photo shows William J. Clark working on one of those 'somethings' while Jimmie C. Lewis watches ready to help. Working on a research project is a challenge, for there is no set pattern to follow. From the drawings to the final product there are many people who contribute to that final product -- the flight. The electronic technicians in the Instrumentation Laboratory at NASA Ames-Dryden Flight Research Facility are no exception. Bill Clark is busy creating a cannon plug to be used on the CV-990. He is soldering wires in the appropriate order so the plug will transmit electrical currents correctly when installed in the airplane. Jim stands by to give help and support on the project.

  11. Autonomous Navigation of the SSTI/Lewis Spacecraft Using the Global Positioning System (GPS)

    Science.gov (United States)

    Hart, R. C.; Long, A. C.; Lee, T.

    1997-01-01

    The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) is pursuing the application of Global Positioning System (GPS) technology to improve the accuracy and economy of spacecraft navigation. High-accuracy autonomous navigation algorithms are being flight qualified in conjunction with GSFC's GPS Attitude Determination Flyer (GADFLY) experiment on the Small Satellite Technology Initiative (SSTI) Lewis spacecraft, which is scheduled for launch in 1997. Preflight performance assessments indicate that these algorithms can provide a real-time total position accuracy of better than 10 meters (1 sigma) and velocity accuracy of better than 0.01 meter per second (1 sigma), with selective availability at typical levels. This accuracy is projected to improve to the 2-meter level if corrections to be provided by the GPS Wide Area Augmentation System (WAAS) are included.

  12. NASA Lewis Stirling SPRE testing and analysis with reduced number of cooler tubes

    International Nuclear Information System (INIS)

    Wong, W.A.; Cairelli, J.E.; Swec, D.M.; Doeberling, T.J.; Lakatos, T.F.; Madi, F.J.

    1994-01-01

    Free-piston Stirling power converters are a candidate for high capacity space power applications. The Space Power Research Engine (SPRE), a free-piston Stirling engine coupled with a linear alternator, is being tested at the NASA Lewis Research Center in support of the Civil Space Technology Initiative. The SPRE is used as a test bed for evaluating converter modifications which have the potential to improve converter performance and for validating computer code predictions. Reducing the number of cooler tubes on the SPRE has been identified as a modification with the potential to significantly improve power and efficiency. This paper describes experimental tests designed to investigate the effects of reducing the number of cooler tubes on converter power, efficiency and dynamics. Presented are test results from the converter operating with a reduced number of cooler tubes and comparisons between this data and both baseline test data and computer code predictions

  13. Cognitive and motor symptoms in dementia: focus on dementia with Lewy bodies.

    Science.gov (United States)

    Lingler, Jennifer Hagerty; Kaufer, Daniel I

    2002-09-01

    To describe the clinical syndrome called dementia with Lewy bodies (DLB) and highlight its common and unique characteristics with respect to diagnosis and management. Review of the scientific literature including psychiatric literature, reports of clinical trials, and clinical practice guidelines. DLB is a clinical and histopathologic disease, which is second only to Alzheimer's disease (AD) as a cause of dementia in older adults. The clinical syndrome of DLB includes cognitive and motor deterioration reminiscent of symptoms associated with AD and Parkinson's disease (PD) respectively. The late life intersection of cognitive and motor symptoms can present significant challenges in the primary care setting. Recognizing key features of common neurodegenerative disorders is essential to accurately diagnosing and appropriately treating the growing population of older adults who suffer from AD, PD, and DLB.

  14. Cholinesterase inhibitors in Alzheimer's disease and Lewy body spectrum disorders: the emerging pharmacogenetic story

    Directory of Open Access Journals (Sweden)

    Lam Benjamin

    2009-12-01

    Full Text Available Abstract This review provides an update on the current state of pharmacogenetic research in the treatment of Alzheimer's disease (AD and Lewy body disease (LBD as it pertains to the use of cholinesterase inhibitors (ChEI. AD and LBD are first reviewed from clinical and pathophysiological perspectives. This is followed by a discussion of ChEIs used in the symptomatic treatment of these conditions, focusing on their unique and overlapping pharmacokinetic and pharmacodynamic profiles, which can be used to identify candidate genes for pharmacogenetics studies. The literature published to date is then reviewed and limitations are discussed. This is followed by a discussion of potential endophenotypes which may help to refine future pharmacogenetic studies of response and adverse effects to ChEIs.

  15. Genetic Alzheimer Disease and Sporadic Dementia With Lewy Bodies: A Comorbidity Presenting as Primary Progressive Aphasia.

    Science.gov (United States)

    Picková, Tereza; Matěj, Radoslav; Bezdicek, Ondrej; Keller, Jiří; van der Zee, Julie; Van Broeckhoven, Christine; Cséfalvay, Zsolt; Rusina, Robert

    2017-03-01

    We report a 44-year-old woman, with a family history of early-onset dementia, presenting with primary progressive aphasia. This clinically variable syndrome has multiple underlying pathologies, and correlations between clinical manifestations and postmortem neuropathologic findings are controversial. Our patient suffered worsening language impairment with major word-finding difficulties but preserved comprehension. She also developed episodic memory impairment. Her condition progressed to dementia with behavioral changes. Magnetic resonance imaging showed early left perisylvian and bitemporal atrophy. The patient died shortly afterward from colon cancer. Neuropathologic examination revealed advanced early-onset Alzheimer and Lewy body disease, plus a clinically nonrelevant metastasis of her colon cancer in her left parietal lobe. Genetic examination revealed a p.Glu184Asp mutation in the presenilin1 gene. Our findings confirm the importance of a thorough appreciation for the clinical and neuropathologic correlations in patients with atypical neurodegenerative dementias.

  16. The NASA-Lewis/ERDA Solar Heating and Cooling Technology Program

    Science.gov (United States)

    Couch, J. P.; Bloomfield, H. S.

    1975-01-01

    The NASA Lewis Research Center plans to carry out a major role in the ERDA Solar Heating and Cooling Program. This role would be to create and test the enabling technology for future solar heating, cooling, and combined heating/cooling systems. The major objectives of the project are to achieve reduction in solar energy system costs, while maintaining adequate performance, reliability, life, and maintenance characteristics. The project approach is to move progressively through component, subsystem, and then system technology advancement phases in parallel with continuing manufacturing cost assessment studies. This approach will be accomplished principally by contract with industry to develop advanced components and subsystems. This advanced hardware will be tested to establish 'technology readiness' both under controlled laboratory conditions and under real sun conditions.

  17. New Model Exhaust System Supports Testing in NASA Lewis' 10- by 10-Foot Supersonic Wind Tunnel

    Science.gov (United States)

    Roeder, James W., Jr.

    1998-01-01

    In early 1996, the ability to run NASA Lewis Research Center's Abe Silverstein 10- by 10- Foot Supersonic Wind Tunnel (10x10) at subsonic test section speeds was reestablished. Taking advantage of this new speed range, a subsonic research test program was scheduled for the 10x10 in the fall of 1996. However, many subsonic aircraft test models require an exhaust source to simulate main engine flow, engine bleed flows, and other phenomena. This was also true of the proposed test model, but at the time the 10x10 did not have a model exhaust capability. So, through an in-house effort over a period of only 5 months, a new model exhaust system was designed, installed, checked out, and made ready in time to support the scheduled test program.

  18. Cognitive decline in patients with Alzheimer's disease, vascular dementia and senile dementia of Lewy body type.

    Science.gov (United States)

    Ballard, C; Patel, A; Oyebode, F; Wilcock, G

    1996-05-01

    One hundred and twenty-four patients with DSM-III-R dementia were assessed with a standardized battery which included the Geriatric Mental State Schedule, the History and Aetiology Schedule, the Secondary Dementia Schedule and the CAMCOG. Patients with Alzheimer's disease, vascular dementia and senile dementia of Lewy body type (SDLT) all had a similar degree of cognitive impairment at the time of the baseline interview. Patients with Alzheimer's disease and vascular dementia each experienced a mean decline of 27 points in patients with SDLT. Patients with SDLT had a significantly greater decline of verbal fluency than both the other groups. Women were significantly more impaired than men at the time of the baseline assessment but experienced a similar decline during the year of follow-up.

  19. Cortical serotonin-S2 receptor binding in Lewy body dementia, Alzheimer's and Parkinson's diseases.

    Science.gov (United States)

    Cheng, A V; Ferrier, I N; Morris, C M; Jabeen, S; Sahgal, A; McKeith, I G; Edwardson, J A; Perry, R H; Perry, E K

    1991-11-01

    The binding of the selective 5-HT2 antagonist [3H]ketanserin has been investigated in the temporal cortex of patients with Alzheimer's disease (SDAT), Parkinson's disease (PD), senile dementia of Lewy body type (SDLT) and neuropathologically normal subjects (control). 5-HT2 binding was reduced in SDAT, PD with dementia and SDLT. SDAT showed a 5-HT2 receptor deficit across most of the cortical layers. A significant decrease in 5-HT2 binding in the deep cortical layers was found in those SDLT cases without hallucinations. SDLT cases with hallucinations only showed a deficit in one upper layer. There was a significant difference in cortical layers III and V between SDLT without hallucinations and SDLT with hallucinations. The results confirm an abnormality of serotonin binding in various forms of dementia and suggest that preservation of 5-HT2 receptor in the temporal cortex may differentiate hallucinating from non-hallucinating cases of SDLT.

  20. Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers

    Directory of Open Access Journals (Sweden)

    Davide Bello

    2015-10-01

    Full Text Available A new method for the preparation of α-fluorovinyl thioethers is reported which involves the hydrofluorination of alkynyl sulfides with 3HF·Et3N, a process that requires Lewis acid activation using BF3·Et2O and TiF4. The method gives access to a range of α-fluorovinyl thioethers, some in high stereoselectivity with the Z-isomer predominating over the E-isomer. The α-fluorovinyl thioether motif has prospects as a steric and electronic mimetic of thioester enols and enolates, important intermediates in enzymatic C–C bond forming reactions. The method opens access to appropriate analogues for investigations in this direction.

  1. Hot Corrosion Test Facility at the NASA Lewis Special Projects Laboratory

    Science.gov (United States)

    Robinson, Raymond C.; Cuy, Michael D.

    1994-01-01

    The Hot Corrosion Test Facility (HCTF) at the NASA Lewis Special Projects Laboratory (SPL) is a high-velocity, pressurized burner rig currently used to evaluate the environmental durability of advanced ceramic materials such as SiC and Si3N4. The HCTF uses laboratory service air which is preheated, mixed with jet fuel, and ignited to simulate the conditions of a gas turbine engine. Air, fuel, and water systems are computer-controlled to maintain test conditions which include maximum air flows of 250 kg/hr (550 lbm/hr), pressures of 100-600 kPa (1-6 atm), and gas temperatures exceeding 1500 C (2732 F). The HCTF provides a relatively inexpensive, yet sophisticated means for researchers to study the high-temperature oxidation of advanced materials, and the injection of a salt solution provides the added capability of conducting hot corrosion studies.

  2. Automating the Analytical Laboratories Section, Lewis Research Center, National Aeronautics and Space Administration: a feasibility study

    International Nuclear Information System (INIS)

    Boyle, W.G.; Barton, G.W.

    1979-01-01

    We studied the feasibility of computerized automation of the Analytical Laboratories Section at NASA's Lewis Research Center. Since that laboratory's duties are not routine, we set our automation goals with that in mind. We selected four instruments as the most likely automation candidates: an atomic absorption spectrophotometer, an emission spectrometer, an x-ray fluorescence spectrometer, and an x-ray diffraction unit. Our study describes two options for computer automation: a time-shared central computer and a system with microcomputers for each instrument connected to a central computer. A third option, presented for future planning, expands the microcomputer version. We determine costs and benefits for each option. We conclude that the microcomputer version best fits the goals and duties of the laboratory and that such an automated system is needed to meet the laboratory's future requirements

  3. Asymmetric Synthesis of Hydrocarbazoles Catalyzed by an Octahedral Chiral-at-Rhodium Lewis Acid.

    Science.gov (United States)

    Huang, Yong; Song, Liangliang; Gong, Lei; Meggers, Eric

    2015-12-01

    A bis-cyclometalated chiral-at-metal rhodium complex catalyzes the Diels-Alder reaction between N-Boc-protected 3-vinylindoles (Boc = tert-butyloxycarbonyl) and β-carboxylic ester-substituted α,β-unsaturated 2-acyl imidazoles with good-to-excellent regioselectivity (up to 99:1) and excellent diastereoselectivity (>50:1 d.r.) as well as enantioselectivity (92-99% ee) under optimized conditions. The rhodium catalyst serves as a chiral Lewis acid to activate the 2-acyl imidazole dienophile by two-point binding and overrules the preferred regioselectivity of the uncatalyzed reaction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Gear noise, vibration, and diagnostic studies at NASA Lewis Research Center

    Science.gov (United States)

    Zakrajsek, J. J.; Oswald, F. B.; Townsend, D. P.; Coy, J. J.

    1990-01-01

    The NASA Lewis Research Center and the U.S. Army Aviation Systems Command are involved in a joint research program to advance the technology of rotorcraft transmissions. This program consists of analytical as well as experimental efforts to achieve the overall goals of reducing weight, noise, and vibration, while increasing life and reliability. Recent analytical activities are highlighted in the areas of gear noise, vibration, and diagnostics performed in-house and through NASA and U.S. Army sponsored grants and contracts. These activities include studies of gear tooth profiles to reduce transmission error and vibration as well as gear housing and rotordynamic modeling to reduce structural vibration and transmission and noise radiation, and basic research into current gear failure diagnostic methodologies. Results of these activities are presented along with an overview of near-term research plans in the gear noise, vibration, and diagnostics area.

  5. Dark science and techno-utopia: the conservative approach of C. S. Lewis

    Directory of Open Access Journals (Sweden)

    Mario Ramos Vera

    2017-08-01

    Full Text Available The rise of scientific, illustrated and progressive late nineteenth century utopias triggered proposals with alternative meanings. Some of those were articulated through a conservative thought as well as a christian, transcendent and otherworldly metanarrative. C. S. Lewis, for example, provided his answer to the techno-utopia in his essay The Abolition of Man as well as in the novel That Hideous Strength —conclusion of the Cosmic Trilogy (or Ransom Trilogy. We will introduce his challenge through three different arguments: (1 contrary to the project of personality conditioning , education is a link of continuity with the past and of respect for tradition; (2 in the light of the methodological atheism of these dystopias elicited the metaphysical and transcendent lewisian foundation of the imperfection of the human condition; (3 He will reply to the arrogance of social and political engineering by reducing power to a technical criterion of instrumental knowledge with the modest language of politics.

  6. Mineral compositions of plutonic rocks from the Lewis Hills massif, Bay of Islands ophiolite

    Science.gov (United States)

    Smith, Susan E.; Elthon, Don

    1988-01-01

    Mineral compositions of residual and cumulate rocks from the Lewis Hills massif of the Bay of Islands ophiolite complex are reported and interpreted in the context of magnetic processes involved in the geochemical evolution of spatially associated diabase dikes. The mineral compositions reflect greater degrees of partial melting than most abyssal peridotites do and appear to represent the most depleted end of abyssal peridotite compositions. Subsolidus equilibration between Cr-Al spinal and olivine generally has occurred at temperatures of 700 to 900 C. The spinel variations agree with the overall fractionation of basaltic magmas producing spinels with progressively lower Cr numbers. The compositions of clinopyroxenes suggest that the fractionation of two different magma series produced the various cumulate rocks.

  7. User manual for NASA Lewis 10 by 10 foot supersonic wind tunnel. Revised

    Science.gov (United States)

    Soeder, Ronald H.

    1995-01-01

    This manual describes the 10- by 10-Foot Supersonic Wind Tunnel at the NASA Lewis Research Center and provides information for users who wish to conduct experiments in this facility. Tunnel performance operating envelopes of altitude, dynamic pressure, Reynolds number, total pressure, and total temperature as a function of test section Mach number are presented. Operating envelopes are shown for both the aerodynamic (closed) cycle and the propulsion (open) cycle. The tunnel test section Mach number range is 2.0 to 3.5. General support systems, such as air systems, hydraulic system, hydrogen system, fuel system, and Schlieren system, are described. Instrumentation and data processing and acquisition systems are also described. Pretest meeting formats and schedules are outlined. Tunnel user responsibility and personnel safety are also discussed.

  8. Improved DNA electrophoresis in conditions favoring polyborates and lewis acid complexation.

    Directory of Open Access Journals (Sweden)

    Hari Singhal

    2010-06-01

    Full Text Available Spatial compression among the longer DNA fragments occurs during DNA electrophoresis in agarose and non-agarose gels when using certain ions in the conductive buffer, impairing the range of fragment sizes resolved well in a single gel. Substitutions using various polyhydroxyl anions supported the underlying phenomenon as the complexation of Lewis acids to DNA. We saw significant improvements using conditions (lithium borate 10 mM cations, pH 6.5 favoring the formation of borate polyanions and having lower conductance and Joule heating, delayed electrolyte exhaustion, faster electrophoretic run-speed, and sharper separation of DNA bands from 100 bp to 12 kb in a single run.

  9. Plasma physics

    International Nuclear Information System (INIS)

    1979-01-01

    This report contains the papers delivered at the AEB - Natal University summer school on plasma physics held in Durban during January 1979. The following topics were discussed: Tokamak devices; MHD stability; trapped particles in tori; Tokamak results and experiments; operating regime of the AEB Tokamak; Tokamak equilibrium; high beta Tokamak equilibria; ideal Tokamak stability; resistive MHD instabilities; Tokamak diagnostics; Tokamak control and data acquisition; feedback control of Tokamaks; heating and refuelling; neutral beam injection; radio frequency heating; nonlinear drift wave induced plasma transport; toroidal plasma boundary layers; microinstabilities and injected beams and quasilinear theory of the ion acoustic instability

  10. Plasma centrifuge

    International Nuclear Information System (INIS)

    Ikehata, Takashi; Mase, Hiroshi

    1998-01-01

    The plasma centrifuge is one of statistical isotope separation processes which uses the centrifugal force of a J x B driven rotating plasma in a magnetic field to give rise to the mass-dependent radial transport of isotopic ions. The system has been developed as an alternative to the gas centrifuge because a much higher rotational velocity and separation factor have been achieved. In this review, the physical aspects of the plasma centrifuge followed by the recent experimental achievements are described, especially in comparison with the gas centrifuge. (author)

  11. UPLC-MS method for quantification of pterostilbene and its application to comparative study of bioavailability and tissue distribution in normal and Lewis lung carcinoma bearing mice.

    Science.gov (United States)

    Deng, Li; Li, Yongzhi; Zhang, Xinshi; Chen, Bo; Deng, Yulin; Li, Yujuan

    2015-10-10

    A UPLC-MS method was developed for determination of pterostilbene (PTS) in plasma and tissues of mice. PTS was separated on Agilent Zorbax XDB-C18 column (50 × 2.1 mm, 1.8 μm) with gradient mobile phase at the flow rate of 0.2 ml/min. The detection was performed by negative ion electrospray ionization in multiple reaction monitoring mode. The linear calibration curve of PTS in mouse plasma and tissues ranged from 1.0 to 5000 and 0.50 to 500 ng/ml (r(2)>0.9979), respectively, with lowest limits of quantification (LLOQ) were between 0.5 and 2.0 ng/ml, respectively. The accuracy and precision of the assay were satisfactory. The validated method was applied to the study of bioavailability and tissue distribution of PTS in normal and Lewis lung carcinoma (LLC) bearing mice. The bioavailability of PTS (dose 14, 28 and 56 mg/kg) in normal mice were 11.9%, 13.9% and 26.4%, respectively; and the maximum level (82.1 ± 14.2 μg/g) was found in stomach (dose 28 mg/kg). The bioavailability, peak concentration (Cmax), time to peak concentration (Tmax) of PTS in LLC mice was increased compared with normal mice. The results indicated the UPLC-MS method is reliable and bioavailability and tissue distribution of PTS in normal and LLC mice were dramatically different. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Enhanced expressions of mRNA for neuropeptide Y and interleukin 1 beta in hypothalamic arcuate nuclei during adjuvant arthritis-induced anorexia in Lewis rats.

    Science.gov (United States)

    Stofkova, Andrea; Haluzik, Martin; Zelezna, Blanka; Kiss, Alexander; Skurlova, Martina; Lacinova, Zdenka; Jurcovicova, Jana

    2009-01-01

    Food intake is activated by hypothalamic orexigenic neuropeptide Y (NPY), which is mainly under the dual control of leptin and ghrelin. Rat adjuvant arthritis (AA), similarly as human rheumatoid arthritis, is associated with cachexia caused by yet unknown mechanisms. The aim of our study was to evaluate NPY expression in hypothalamic arcuate nuclei (nARC) under the conditions of AA-induced changes in leptin, ghrelin and adiponectin. Since IL-1beta is involved in the central induction of anorexia, we studied its expression in the nARC as well. AA was induced to Lewis rats using complete Freund's adjuvant. On days 12, 15 and 18 after complete Freund's adjuvant injection, the levels of leptin, adiponectin, ghrelin and IL-1beta were determined by RIA or ELISA. The mRNA expressions for NPY, leptin receptor (OB-R), ghrelin receptor (Ghsr) and IL-1beta were determined by TaqMan RT-PCR from isolated nARC. In AA rats, decreased appetite, body mass and epididymal fat stores positively correlated with reduced circulating and epididymal fat leptin and adiponectin. Ghrelin plasma levels were increased. In nARC, mRNA for OB-R, Ghsr and NPY were overexpressed in AA rats. AA rats showed overexpression of mRNA for IL-1beta in nARC while circulating, and spleen IL-1beta was unaltered. During AA, overexpression of orexigenic NPY mRNA in nARC along with enhanced plasma ghrelin and lowered leptin levels occur. Decreased food intake indicates a predominant effect of the anorexigenic pathway. Activated expression of IL-1beta in nARC suggests its role in keeping AA-induced anorexia in progress. The reduction in adiponectin may also contribute to AA-induced anorexia. Copyright 2009 S. Karger AG, Basel.

  13. Fischer 344 and Lewis Rat Strains as a Model of Genetic Vulnerability to Drug Addiction.

    Science.gov (United States)

    Cadoni, Cristina

    2016-01-01

    Today it is well acknowledged that both nature and nurture play important roles in the genesis of psychopathologies, including drug addiction. Increasing evidence suggests that genetic factors contribute for at least 40-60% of the variation in liability to drug dependence. Human genetic studies suggest that multiple genes of small effect, rather than single genes, contribute to the genesis of behavioral psychopathologies. Therefore, the use of inbred rat strains might provide a valuable tool to identify differences, linked to genotype, important in liability to addiction and related disorders. In this regard, Lewis and Fischer 344 inbred rats have been proposed as a model of genetic vulnerability to drug addiction, given their innate differences in sensitivity to the reinforcing and rewarding effects of drugs of abuse, as well their different responsiveness to stressful stimuli. This review will provide evidence in support of this model for the study of the genetic influence on addiction vulnerability, with particular emphasis on differences in mesolimbic dopamine (DA) transmission, rewarding and emotional function. It will be highlighted that Lewis and Fischer 344 rats differ not only in several indices of DA transmission and adaptive changes following repeated drug exposure, but also in hypothalamic-pituitary-adrenal (HPA) axis responsiveness, influencing not only the ability of the individual to cope with stressful events, but also interfering with rewarding and motivational processes, given the influence of corticosteroids on dopamine neuron functionality. Further differences between the two strains, as impulsivity or anxiousness, might contribute to their different proneness to addiction, and likely these features might be linked to their different DA neurotransmission plasticity. Although differences in other neurotransmitter systems might deserve further investigation, results from the reviewed studies might open new vistas in understanding aberrant

  14. Effects of fuel Lewis number on localised forced ignition of turbulent homogeneous mixtures: A numerical investigation

    Directory of Open Access Journals (Sweden)

    Dipal Patel

    2016-09-01

    Full Text Available The influences of fuel Lewis number LeF (ranging from 0.8 to 1.2 on localised forced ignition and early stages of combustion of stoichiometric and fuel-lean homogeneous mixtures have been analysed using simple chemistry three-dimensional compressible direct numerical simulations for different values of root-mean-square velocity fluctuation and the energy deposition characteristics (i.e. characteristic width and the duration of energy deposition by the ignitor. The localised forced ignition is modelled using a source term in the energy transport equation, which deposits energy in a Gaussian manner from the centre of the ignitor over a stipulated period of time. The fuel Lewis number LeF has been found to have significant influences on the extent of burning of stoichiometric and fuel-lean homogeneous mixtures. It has been shown that the width of ignition energy deposition and the duration over which the ignition energy is deposited have significant influences on the success of ignition and subsequent flame propagation. An increase in the width of ignition energy deposition and the duration of energy deposition for a given amount of ignition energy have been found to have detrimental effects on the ignition event, which may ultimately lead to misfire. For a given value of u' (LeF, the rate of heat transfer from the hot gas kernel increases with increasing LeF (u', which in turn leads to a reduction in the extent of overall burning for both stoichiometric and fuel-lean homogeneous mixtures but the detrimental effects of high values of u' on localised forced ignition are particularly prevalent for fuel-lean mixtures. Detailed physical explanations have been provided for the observed LeF,u' and energy deposition characteristics effects.

  15. The Organization and Anatomy of Narrative Comprehension and Expression in Lewy Body Spectrum Disorders

    Science.gov (United States)

    Ash, Sharon; Xie, Sharon; Gross, Rachel Goldmann; Dreyfuss, Michael; Boller, Ashley; Camp, Emily; Morgan, Brianna; O’Shea, Jessica; Grossman, Murray

    2012-01-01

    Objective Patients with Lewy body spectrum disorders (LBSD) such as Parkinson’s disease (PD), Parkinson’s disease with dementia (PDD), and dementia with Lewy bodies (DLB) exhibit deficits in both narrative comprehension and narrative expression. The present research examines the hypothesis that these impairments are due to a material-neutral deficit in organizational executive resources rather than to impairments of language per se. We predicted that comprehension and expression of narrative would be similarly affected and that deficits in both expression and comprehension of narrative would be related to the same anatomic distribution of prefrontal disease. Method We examined 29 LBSD patients and 26 healthy seniors on their comprehension and expression of narrative discourse. For comprehension, we measured accuracy and latency in judging events with high and low associativity from familiar scripts such as “going fishing.” The expression task involved maintaining the connectedness of events while narrating a story from a wordless picture book. Results LBSD patients were impaired on measures of narrative organization during both comprehension and expression relative to healthy seniors. Measures of organization during narrative expression and comprehension were significantly correlated with each other. These measures both correlated with executive measures but not with neuropsychological measures of lexical semantics or grammar. Voxel-based morphometry revealed overlapping regressions relating frontal atrophy to narrative comprehension, narrative expression, and measures of executive control. Conclusions Difficulty with narrative discourse in LBSD stems in part from a deficit of organization common to comprehension and expression. This deficit is related to prefrontal cortical atrophy in LBSD. PMID:22309984

  16. Transhiatal Chest Drainage After Hybrid Ivor Lewis Esophagectomy: Proof of Concept Study.

    Science.gov (United States)

    Asti, Emanuele; Sironi, Andrea; Bonitta, Gianluca; Bernardi, Daniele; Bonavina, Luigi

    2018-04-01

    Intercostal pleural drainage is standard practice after transthoracic esophagectomy but has some drawbacks. We hypothesized that a transhiatal pleural drain introduced through the subxyphoid port site incision at laparoscopy can be as effective as the intercostal drainage and may enhance patient recovery. A proof of concept study was designed to assess a new method of pleural drainage in patients undergoing hybrid Ivor Lewis esophagectomy (laparoscopy and right thoracotomy). The main study aims were safety and efficacy of transhiatal pleural drainage with a 15 Fr Blake tube connected to a portable vacuum system. Pre- and postoperative data, mean duration, and total and daily output of drainage were recorded in an electronic database. Postoperative complications were scored according to the Dindo-Clavien classification. Between June 2015 and December 2016, 50 of 63 consecutive patients met the criteria for inclusion in the study. No conversions from the portable vacuum system to underwater seal and suction occurred. There was no mortality. The overall morbidity rate was 40%. Two patients (4%) required reoperation for hemothorax and chylothorax, respectively. Percutaneous catheter drainage for residual pneumothorax was necessary in 2 patients (4%) on postoperative day 2. The mean duration of drainage was 7 days (interquartile range [IQR] = 2), and the total volume of drain output was 1580 mL (IQR = 880). No pleural effusion on chest X-ray was detected at the 3-month follow-up visit. Transhiatal pleural drainage is safe and effective after hybrid Ivor Lewis esophagectomy and could replace the intercostal drain in selected patients.

  17. Fischer 344 and Lewis rat strains as a model of genetic vulnerability to drug addiction

    Directory of Open Access Journals (Sweden)

    Cristina eCadoni

    2016-02-01

    Full Text Available Today it is well acknowledged that both nature and nurture play important roles in the genesis of psychopathologies, including drug addiction. Increasing evidence suggests that genetic factors contribute for at least 40-60 % of the variation in liability to drug dependence. Human genetic studies suggest that multiple genes of small effect, rather than single genes, contribute to the genesis of behavioral psychopathologies. Therefore the use of inbred rat strains might provide a valuable tool to identify differences, linked to genotype, important in liability to addiction and related disorders. In this regard, Lewis and Fischer 344 inbred rats have been proposed as a model of genetic vulnerability to drug addiction, given their innate differences in sensitivity to the reinforcing and rewarding effects of drugs of abuse, as well their different responsiveness to stressful stimuli. This review will provide evidence in support of this model for the study of the genetic influence on addiction vulnerability, with particular emphasis to differences in mesolimbic dopamine (DA transmission, rewarding and emotional function. It will be highlighted that Lewis and Fischer 344 rats differ not only in several indices of DA transmission and adaptive changes following repeated drug exposure, but also in hypothalamic-pituitary-adrenal (HPA axis responsiveness, influencing not only the ability of the individual to cope with stressful events, but also interfering with rewarding and motivational processes, given the influence of corticosteroids on dopamine neurons functionality.Further differences between the two strains, as impulsivity or anxiousness, might contribute to their different proneness to addiction, and likely these features might be linked to their different DA neurotransmission plasticity. Although differences in other neurotransmitter systems might deserve further investigations, results from the reviewed studies might open new vistas in

  18. The generalized lewis acid-base titration of palladium and niobium

    Science.gov (United States)

    Cima, M.; Brewer, L.

    1988-12-01

    The high thermodynamic stability of alloys composed of platinum group metals and group IVB and VB metals has been explained by an electronic interaction analogous to the Lewis acid-base concept for nontransition elements. The analogy is further demonstrated by the titration of palladium by addition of niobium. The activity of niobium in solid palladium was measured as a function of concentration by solid-state galvanic cells and study of the ternary oxide phase diagram. The galvanic cells were of the type Pt/NbO2,Nb2O4.8/YDTJNbOy,Nbpd/Pt where the solid electrolyte is yttria-doped thoria (YDT). Ternary phase diagrams for the Pd-Nb-0 and Rh-Nb-0 systems were obtained by characterizing samples equilibrated at 1000 °C. The phase relationships found in the ternary diagrams were also used to derive thermochemical data for the alloys. Thermochemical quantities for other acid-base stabilized alloys such as Nb-Rh, Ti-Pd, and Ti-Rh were also measured. The excess partial molar ΔGxs/R of niobium at infinite dilution was determined to be -31 kilo-Kelvin at 1000 °C, and the AG°JR of formation of a mole of NbPd3.55 is —21 kilo-Kelvin. These results and those for the other systems are used to assess the importance of valence electron configuration, nuclear charge, and crystal field effects in the context of generalized Lewis acid-base theory. It is concluded that both the nuclear charge of the atom and crystal field splitting of the valence orbitals significantly affect the basicity of the platinum group metals.

  19. A Comprehensive Approach to Management of Workplace and Environmental Noise at NASA Lewis Research Center

    Science.gov (United States)

    Cooper, Beth A.

    1995-01-01

    NASA Lewis Research Center is home to more than 100 experimental research testing facilities and laboratories, including large wind tunnels and engine test cells, which in combination create a varied and complex noise environment. Much of the equipment was manufactured prior to the enactment of legislation limiting product noise emissions or occupational noise exposure. Routine facility maintenance and associated construction also contributes to a noise exposure management responsibility which is equal in magnitude and scope to that of several small industrial companies. The Noise Program, centrally managed within the Office of Environmental Programs at LRC, maintains overall responsibility for hearing conservation, community noise control, and acoustical and noise control engineering. Centralized management of the LRC Noise Program facilitates the timely development and implementation of engineered noise control solutions for problems identified via either the Hearing Conservation of Community Noise Program. The key element of the Lewis Research Center Noise Program, Acoustical and Noise Control Engineering Services, is focused on developing solutions that permanently reduce employee and community noise exposure and maximize research productivity by reducing or eliminating administrative and operational controls and by improving the safety and comfort of the work environment. The Hearing Conservation Program provides noise exposure assessment, medical monitoring, and training for civil servant and contractor employees. The Community Noise Program aims to maintain the support of LRC's neighboring communities while enabling necessary research operations to accomplish their programmatic goals. Noise control engineering capability resides within the Noise Program. The noise control engineering, based on specific exposure limits, is a fundamental consideration throughout the design phase of new test facilities, labs, and office buildings. In summary, the Noise Program

  20. [Abdominothoracic esophageal resection according to Ivor Lewis with intrathoracic anastomosis : standardized totally minimally invasive technique].

    Science.gov (United States)

    Runkel, N; Walz, M; Ketelhut, M

    2015-05-01

    The clinical and scientific interest in minimally invasive techniques for esophagectomy (MIE) are increasing; however, the intrathoracic esophagogastric anastomosis remains a surgical challenge and lacks standardization. Surgeons either transpose the anastomosis to the cervical region or perform hybrid thoracotomy for stapler access. This article reports technical details and early experiences with a completely laparoscopic-thoracoscopic approach for Ivor Lewis esophagectomy without additional thoracotomy. The extent of radical dissection follows clinical guidelines. Laparoscopy is performed with the patient in a beach chair position and thoracoscopy in a left lateral decubitus position using single lung ventilation. The anvil of the circular stapler is placed transorally into the esophageal stump. The specimen and gastric conduit are exteriorized through a subcostal rectus muscle split incision. The stapler body is placed into the gastric conduit and both are advanced through the abdominal mini-incision transhiatally into the right thoracic cavity, where the anastomosis is constructed. Data were collected prospectively and analyzed retrospectively. A total of 23 non-selected consecutive patients (mean age 69 years, range 46-80 years) with adenocarcinoma (n = 19) or squamous cell carcinoma (n = 4) were surgically treated between June 2010 and July 2013. Neoadjuvant therapy was performed in 15 patients resulting in 10 partial and 4 complete remissions. There were no technical complications and no conversions. Mean operative time was 305 min (range 220-441 min). The median lymph node count was 16 (range 4-42). An R0 resection was achieved in 91 % of patients and 3 anastomotic leaks occurred which were successfully managed endoscopically. There were no postoperative deaths. The intrathoracic esophagogastric anastomosis during minimally invasive Ivor Lewis esophagectomy can be constructed in a standardized fashion without an additional thoracotomy

  1. Emergence of nitrosourea resistant sublines of Lewis lung tumour following MeCCNU treatment in vivo.

    Science.gov (United States)

    Stephens, T. C.; Adams, K.; Peacock, J. H.

    1986-01-01

    Several different drug retreatment protocols were employed to examine the emergence of resistance to MeCCNU in Lewis lung tumours. Previous studies suggested that although the majority of cells in untreated Lewis lung tumours were sensitive to MeCCNU, there was a very small proportion of resistant cells (approximately 0.001%) that limited "tumour cure' with that drug. If such cells were inherently drug resistant then it should be possible to derive highly resistant tumours by repeated drug treatment. In the first experiment tumours were treated with a single high dose of MeCCNU (35 or 40 mgkg-1) and on regrowth, transplanted into fresh mice and tested for drug sensitivity. Using both excision cell survival and growth delay endpoints, only approximately 25% of tumours were significantly resistant to the test dose, suggesting that many tumours resist the effects of the drug for reasons other than the presence of inherently drug resistant cells. One of the tumours (R4), that regrew after the initial treatment and appeared to be resistant to the test treatment, was retreated with a further 30 mgkg-1 MeCCNU and became more resistant. This line, designated R4/1, was cross-resistant to the other nitrosoureas, BCNU and CCNU, but not to cyclophosphamide, melphalan, cis-platinum or ionising radiation. The effect of treatment dose on the kinetics of MeCCNU resistance development was also studied in a retreatment regimen where the tumours were allowed to regrow and then transplanted into fresh hosts for the next treatment. Resistance developed more quickly at an intermediate dose of 15 mgkg-1 than at 7.5 mgkg-1 where the selective pressure was lower, or at 30 mgkg-1 where there was probably extinction of partially resistant cells. Resistance to MeCCNU developed even more quickly when tumours were retreated several times in the same host, although in a similar experiment with cyclophosphamide no resistance occurred. PMID:3954945

  2. Optimization of Fluosol-DA administration during a fractionated radiation protocol in the Lewis lung carcinoma

    International Nuclear Information System (INIS)

    Teicher, B.A.; McIntosh, N.L.

    1987-01-01

    The perfluorchemical emulsion, Fluosol-DA, in combination with breathing a 100% or 95% oxygen atmosphere, has been shown to enhance the response of several solid rodent tumors to single dose and fractionated radiation treatment. As an approach to determining the optimal dose schedule for Fluosol-DA during a course of fractionated radiation therapy, a total dose of 16 ml/kg of Fluosol-DA was administered either as two doses of 8 ml/kg on days 1 and 3 or as four doses of 4 ml/kg on days 1,2,3 and 4 of a four day protocol using the Lewis lung tumor model system. The Lewis lung tumor was grown s.c. in the flanks of C57BL/6J mice. Treatment was initiated when the tumors were 50-100 mm/sup 3/. Radiation was delivered as 4 daily fractions of 2.5, 4.0 or 5.0 Gray. Fluosol-DA was adminstered i.v. prior to irradiation. Each day carbogen breathing was maintained for 1 hr prior to and during each x-ray treatment. When Fluosol-DA was administered as two doses of 8 ml/kg, the dose modifying factor (DMF) observed was 1.7 +- 0.3. When Fluosol-DA was given as four doses of 4 ml/kg, the DMF was 1.5+-0.3 compared to x-ray treatment with carbogen breathing. It appears, therefore, administering Fluosol-DA at a therapeutic dose less frequently with carbogen breathing with every fraction may produce a better treatment outcome than giving more frequent lower doses

  3. Thoracoscopic management of volvulus of the gastric conduit following minimally invasive Ivor-Lewis esophagectomy.

    Science.gov (United States)

    Linson, Jeremy; Latzko, Michael; Ahmed, Bestoun; Awad, Ziad

    2016-07-01

    We present a case of emergent thoracoscopic management of volvulus of the gastric conduit following minimally invasive Ivor-Lewis esophagectomy. The patient is a 69-year-old Caucasian male with a history of adenocarcinoma of the lower third of the esophagus. Initial presentation was dysphagia with solid foods, which progressed in severity until he was unable to swallow anything. EUS demonstrated a partially obstructing mass at 33 cm; biopsy revealed poorly differentiated adenocarcinoma, stage T3N2Mx. PET scan did not reveal any metastatic disease. Preoperative management included neo-adjuvant chemoradiation therapy (5-FU and cisplatin) and early placement of a jejunal feeding tube. Intra-operative leak test was performed as a matter of routine following completion of the esophagogastric anastomosis. A nasogastric tube was placed intra-operatively and removed on POD2 according to our standard pathway. Postoperatively, the patient progressed without difficulty to POD4, when we routinely obtain an upper GI swallow study. This demonstrated a lack of transit of contrast through the distal neo-esophagus. Follow-up endoscopy revealed volvulus of the gastric conduit with obliteration of the lumen. We immediately took the patient to the OR for thoracoscopic detorsion, which we accomplished successfully by entering the existing trochar sites and using blunt dissection.␣Upon entering the thoracic cavity, the staple line that had been oriented anteriorly was now posterior. Attachments were gently teased away from the chest wall and the conduit was detorsed and anchored to the chest wall in the correct orientation with silk suture. Intra-operative endoscopy demonstrated a patent conduit. Postoperative upper GI fluoroscopy now showed good transit of contrast. The patient continued to improve and was eventually advanced to mechanical soft diet and discharged on postoperative day 9. Early intervention is indicated in cases of volvulus of the gastric conduit following Ivor-Lewis

  4. Cycloheptatrienyl zirconium sandwich complexes with lewis basic phospholyl ligands (phosphatrozircenes): synthesis, structure, bonding and coordination chemistry.

    Science.gov (United States)

    Glöckner, Andreas; Bannenberg, Thomas; Büschel, Susanne; Daniliuc, Constantin G; Jones, Peter G; Tamm, Matthias

    2011-05-23

    The transmetalation reaction between [(η(7) -C(7) H(7) )ZrCl(tmeda)] (1; tmeda=N,N,N',N'-tetramethylethylenediamine) and various phospholide anions leads to a new class of mixed sandwich complexes: [(η(7)-C(7)H(7))Zr(η(5)-C(4)PMe(4))] (2), [(η(7)-C(7)H(7))Zr(η(5)-C(4)PH(2)Me(2))] (3) and [(η(7)-C(7)H(7))Zr(η(5)-C(4)PPhHMe(2))] (4). The presence of Lewis basic phosphorus atoms and Lewis acidic zirconium atoms allows ambiphilic behaviour to be observed, and X-ray diffraction analysis reveals dimeric arrangements for 2 and 3 with long intermolecular Zr-P bonds, whereas 4 remains monomeric in the solid state. DFT calculations indicate that the metal-phosphorus interaction is weak, and accordingly, complexes 2-4 act as monodentate ligands upon reaction with [W(CO)(5)(thf)]. The resulting complexes [W(CO)(5)(L)] 5-7 (L=2-4) were studied by IR spectroscopy and compared with the [W(CO)(5) ] complex 9, containing the phosphane-functionalised trozircene [(η(7)-C(7)H(7))Zr(η(5)-C(5)H(4)PPh(2))] (8). They all show a close resemblance to simple phosphanes, such as PMe(3) , although molecular orbital analysis of 2 reveals that the free electron pair in the phosphatrozircenes is not the HOMO. Four equivalents of 2 can replace 1,4-cyclooctadiene (COD) in [Ni(cod)(2)] to form the homoleptic, distorted tetrahedral complex [Ni{2}(4)] (10). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Effects of non-unity Lewis number of gas-phase species in turbulent nonpremixed sooting flames

    KAUST Repository

    Attili, Antonio; Bisetti, Fabrizio; Mueller, Michael E.; Pitsch, Heinz

    2016-01-01

    Turbulence statistics from two three-dimensional direct numerical simulations of planar n-heptane/air turbulent jets are compared to assess the effect of the gas-phase species diffusion model on flame dynamics and soot formation. The Reynolds number based on the initial jet width and velocity is around 15, 000, corresponding to a Taylor scale Reynolds number in the range 100 ≤ Reλ ≤ 150. In one simulation, multicomponent transport based on a mixture-averaged approach is employed, while in the other the gas-phase species Lewis numbers are set equal to unity. The statistics of temperature and major species obtained with the mixture-averaged formulation are very similar to those in the unity Lewis number case. In both cases, the statistics of temperature are captured with remarkable accuracy by a laminar flamelet model with unity Lewis numbers. On the contrary, a flamelet with a mixture-averaged diffusion model, which corresponds to the model used in the multi-component diffusion three-dimensional DNS, produces significant differences with respect to the DNS results. The total mass of soot precursors decreases by 20-30% with the unity Lewis number approximation, and their distribution is more homogeneous in space and time. Due to the non-linearity of the soot growth rate with respect to the precursors' concentration, the soot mass yield decreases by a factor of two. Being strongly affected by coagulation, soot number density is not altered significantly if the unity Lewis number model is used rather than the mixture-averaged diffusion. The dominant role of turbulent transport over differential diffusion effects is expected to become more pronounced for higher Reynolds numbers. © 2016 The Combustion Institute.

  6. Effects of non-unity Lewis number of gas-phase species in turbulent nonpremixed sooting flames

    KAUST Repository

    Attili, Antonio

    2016-02-13

    Turbulence statistics from two three-dimensional direct numerical simulations of planar n-heptane/air turbulent jets are compared to assess the effect of the gas-phase species diffusion model on flame dynamics and soot formation. The Reynolds number based on the initial jet width and velocity is around 15, 000, corresponding to a Taylor scale Reynolds number in the range 100 ≤ Reλ ≤ 150. In one simulation, multicomponent transport based on a mixture-averaged approach is employed, while in the other the gas-phase species Lewis numbers are set equal to unity. The statistics of temperature and major species obtained with the mixture-averaged formulation are very similar to those in the unity Lewis number case. In both cases, the statistics of temperature are captured with remarkable accuracy by a laminar flamelet model with unity Lewis numbers. On the contrary, a flamelet with a mixture-averaged diffusion model, which corresponds to the model used in the multi-component diffusion three-dimensional DNS, produces significant differences with respect to the DNS results. The total mass of soot precursors decreases by 20-30% with the unity Lewis number approximation, and their distribution is more homogeneous in space and time. Due to the non-linearity of the soot growth rate with respect to the precursors\\' concentration, the soot mass yield decreases by a factor of two. Being strongly affected by coagulation, soot number density is not altered significantly if the unity Lewis number model is used rather than the mixture-averaged diffusion. The dominant role of turbulent transport over differential diffusion effects is expected to become more pronounced for higher Reynolds numbers. © 2016 The Combustion Institute.

  7. Catalytic Ozonation of Toluene Using Chilean Natural Zeolite: The Key Role of Brønsted and Lewis Acid Sites

    Directory of Open Access Journals (Sweden)

    Serguei Alejandro-Martín

    2018-05-01

    Full Text Available The influence of surface physical-chemical characteristics of Chilean natural zeolite on the catalytic ozonation of toluene is presented in this article. Surface characteristics of natural zeolite were modified by acid treatment with hydrochloric acid and ion-exchange with ammonium sulphate. Prior to catalytic ozonation assays, natural and chemically modified zeolite samples were thermally treated at 623 and 823 K in order to enhance Brønsted and Lewis acid sites formation, respectively. Natural and modified zeolite samples were characterised by N2 adsorption at 77 K, elemental analysis, X-ray fluorescence, and Fourier transform infrared (FTIR spectroscopy, using pyridine as a probe molecule. The highest values of the reaction rate of toluene oxidation were observed when NH4Z1 and 2NH4Z1 zeolite samples were used. Those samples registered the highest density values of Lewis acid sites compared to other samples used here. Results indicate that the presence of strong Lewis acid sites at the 2NH4Z1 zeolite surface causes an increase in the reaction rate of toluene oxidation, confirming the role of Lewis acid sites during the catalytic ozonation of toluene at room temperature. Lewis acid sites decompose gaseous ozone into atomic oxygen, which reacts with the adsorbed toluene at Brønsted acid sites. On the other hand, no significant contribution of Brønsted acid sites on the reaction rate was registered when NH4Z1 and 2NH4Z1 zeolite samples were used.

  8. Plasma Cleaning

    Science.gov (United States)

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  9. Laser Plasmas

    Indian Academy of Sciences (India)

    -focusing in a plasma ... Center for Energy Studies, Indian Institute of Technology, New Delhi 110 016, India; Tata Consultancy Services, Gurgaon, India; Ideal Institute of Technology, Ghaziabad, India; Center for Research in Cognitive, ...

  10. Plasma will…

    Czech Academy of Sciences Publication Activity Database

    Lunov, Oleg

    2016-01-01

    Roč. 174, č. 3 (2016), s. 486-487 ISSN 0007-0963 Institutional support: RVO:68378271 Keywords : plasma * ionized gas Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 4.706, year: 2016

  11. Plasma technology

    International Nuclear Information System (INIS)

    Drouet, M.G.

    1984-03-01

    IREQ was contracted by the Canadian Electrical Association to review plasma technology and assess the potential for application of this technology in Canada. A team of experts in the various aspects of this technology was assembled and each team member was asked to contribute to this report on the applications of plasma pertinent to his or her particular field of expertise. The following areas were examined in detail: iron, steel and strategic-metals production; surface treatment by spraying; welding and cutting; chemical processing; drying; and low-temperature treatment. A large market for the penetration of electricity has been identified. To build up confidence in the technology, support should be provided for selected R and D projects, plasma torch demonstrations at full power, and large-scale plasma process testing

  12. Plasma metallization

    International Nuclear Information System (INIS)

    Crowther, J.M.

    1997-09-01

    Many methods are currently used for the production of thin metal films. However, all of these have drawbacks associated with them, for example the need for UHV conditions, high temperatures, exotic metal precursors, or the inability to coat complex shaped objects. Reduction of supported metal salts by non-isothermal plasma treatment does not suffer from these drawbacks. In order to produce and analyse metal films before they become contaminated, a plasma chamber which could be attached directly to a UHV chamber with XPS capability was designed and built. This allowed plasma treatment of supported metal salts and surface analysis by XPS to be performed without exposure of the metal film to the atmosphere. Non-equilibrium plasma treatment of Nylon 66 supported gold(lll) chloride using hydrogen as the feed gas resulted in a 95% pure gold film, the remaining 5% of the film being carbon. If argon or helium were used as the feed gases during plasma treatment the resultant gold films were 100% pure. Some degree of surface contamination of the films due to plasma treatment was observed but was easily removed by argon ion cleaning. Hydrogen plasma reduction of glass supported silver(l) nitrate and palladium(ll) acetate films reveals that this metallization technique is applicable to a wide variety of metal salts and supports, and has also shown the ability of plasma reduction to retain the complex 'fern-like' structures seen for spin coated silver(l) nitrate layers. Some metal salts are susceptible to decomposition by X-rays. The reduction of Nylon 66 supported gold(lll) chloride films by soft X-rays to produce nanoscopic gold particles has been studied. The spontaneous reduction of these X-ray irradiated support gold(lll) chloride films on exposure to the atmosphere to produce gold rich metallic films has also been reported. (author)

  13. Plasma confinement

    CERN Document Server

    Hazeltine, R D

    2003-01-01

    Detailed and authoritative, this volume examines the essential physics underlying international research in magnetic confinement fusion. It offers readable, thorough accounts of the fundamental concepts behind methods of confining plasma at or near thermonuclear conditions. Designed for a one- or two-semester graduate-level course in plasma physics, it also represents a valuable reference for professional physicists in controlled fusion and related disciplines.

  14. Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Zaveryaev, V [Kurchatov Institute, Moscow (Russian Federation); others, and

    2012-09-15

    The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

  15. Stereocontrol during the radical polymerization of methyl methacrylates with combined Lewis acids:Aluminium trichloride(AlCl3) and iron dichloride tetrahydrate

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The radical polymerization of methyl methacrylate(MMA) was carried out in the presence of combined Lewis acids of the AlCl3-FeCl2 system.Compared with the polymerization produced in the presence of single Lewis acids,AlCl3 or FeCl2,the MMA polymerization in the presence of AlCl3-FeCl2 composite in CHCl3 or 1-butanol produced a polymer with a higher isotacticity and in toluene produced a polymer with a much higher isotacticity(mm=50%) .The molecular weight and polydispersity of PMMA in the presence of Lewis acids were similar with those in the absence of Lewis acids,although Lewis acids decelerate the polymerization of MMA.The effects of the Lewis acids were greater in a solvent with a lower polarity.A possible stereocontrol mechanism of the polymerization was proposed.The Lewis acid composite of AlCl3-FeCl2 readily formed a complex with growing species.These complexes possessed apparent bulkiness that changes the direction of monomer addition to the growing radical center.

  16. Stability of EBT of guiding-centre fluid theory

    International Nuclear Information System (INIS)

    Miller, R.L.

    1981-01-01

    The stability of the hot-electron annulus in the ELMO Bumpy Torus (EBT) is not yet completely understood despite considerable attention. Most stability studies have dealt with localized analysis of simplified models in which the actual magnetic configuration is replaced by a straight-line slab with a gravity to emulate the effects of curvature and gradients in the actual magnetic field. Here, a more realistic geometry, a 'bumpy' cylinder with a 2:1 magnetic mirror ratio, is considered and the response of the hot-electron rings to various non-local perturbations, specifying only the mode number in the ignorable co-ordinate, is examined. Guiding-centre theory (with psub(perpendicular) > psub(parallel)) is used and the second variation in the plasma energy (σW) using a finite-element representation to identify the least stable mode for the plasma is studied. All the equilibria that are examined are found to be unstable for all poloidal mode numbers m>=1, with growth rates increasing with increasing ring beta, plasma beta, and poloidal mode number. It is concluded that two-fluid and/or kinetic effects are required to explain the observed global stability of EBT-I. (author)

  17. Cold plasmas

    International Nuclear Information System (INIS)

    Franz, G.

    1990-01-01

    This textbook discusses the following topics: Phenomenological description of a direct current glow discharge; the plasma (temperature distribution and measurement, potential variation, electron energy distribution function, charge neutralization, wall potentials, plasma oscillations); Production of charge carriers (ions, electrons, ionization in the cathode zone, negative glowing zone, Faraday dark space, positive column, anode zone, hollow cathode discharges); RF-discharges (charge carrier production, RF-Shields, scattering mechanisms); Sputtering (ion-surface interaction, kinetics, sputtering yield and energy distribution, systems and conditions, film formation and stresses, contamination, bias techniques, multicomponent film deposition, cohesion, magnetrons, triode systems, plasma enhanced chemical vapor deposition); Dry etching (sputter etching, reactive etching, topography, process control, quantitative investigations); Etching mechanisms (etching of Si and SiO 2 with CF 4 , of III/V-compound-semiconductors, combination of isotrope and anisotrope etching methods, surface cleaning); ion beam systems (applications, etching); Dyclotron-resonance-systems (electron cyclotron resonance systems, whistler-sources and 'resonant inductive plasma etching'); Appendix (electron energy distribution functions, Bohm's transition zone, plasma oscillations, scattering cross sections and mean free path, metastable states, Child-Langmuir-Schottky equation, loss mechanisms, charge carrier distribution in the positive column, breakdown at high frequencies, motion in a magnetic field, skin depth of an electric field for a HF-discharge, whistler waves, dispersion relations for plane wave propagation). (orig.) With 138 figs

  18. Plasma heating

    International Nuclear Information System (INIS)

    Wilhelm, R.

    1989-01-01

    Successful plasma heating is essential in present fusion experiments, for the demonstration of DpT burn in future devices and finally for the fusion reactor itself. This paper discusses the common heating systems with respect to their present performance and their applicability to future fusion devices. The comparative discussion is oriented to the various function of heating, which are: - plasma heating to fusion-relevant parameters and to ignition in future machines, -non-inductive, steady-pstate current drive, - plasma profile control, -neutral gas breakdown and plasma build-up. In view of these different functions, the potential of neutral beam injection (NBI) and the various schemes of wave heating (ECRH, LH, ICRH and Alven wave heating) is analyzed in more detail. The analysis includes assessments of the present physical and technical state of these heating methods, and makes suggestions for future developments and about outstanding problems. Specific attention is given to the still critical problem of efficient current drive, especially with respect to further extrapolation towards an economically operating tokamak reactor. Remarks on issues such as reliability, maintenance and economy conclude this comparative overview on plasma heating systems. (author). 43 refs.; 13 figs.; 3 tabs

  19. Stereodivergent Mannich reaction of bis(trimethylsilyl)ketene acetals with N-tert-butanesulfinyl imines by Lewis acid or Lewis base activation, a one-pot protocol to obtain chiral β-amino acids.

    Science.gov (United States)

    Cantú-Reyes, Margarita; Alvarado-Beltrán, Isabel; Ballinas-Indilí, Ricardo; Álvarez-Toledano, Cecilio; Hernández-Rodríguez, Marcos

    2017-09-20

    We report a one-pot synthesis of chiral β 2,2,3 -amino acids by the Mannich addition of bistrimethylsilyl ketene acetals to N-tert-butanesulfinyl imines followed by the removal of the chiral auxiliary. The synthesis and isolation of pure β-amino acid hydrochlorides were conducted under mild conditions, without strong bases and this method is operationally simple. The stereoselective reaction was promoted by two different activation methods that lead to different stereoisomers: (1) Lewis Acid (LA) catalysis with boron trifluoride diethyl etherate and (2) Lewis Base (LB) catalysis with tetrabutylammonium difluorotriphenylsilicate. The reaction presented good diastereoselectivity with LB activation and moderate to good dr with LA catalysis. The exceptions in both protocols were imines with electron donating groups in the aromatic ring.

  20. PLASMA DEVICE

    Science.gov (United States)

    Gow, J.D.; Wilcox, J.M.

    1961-12-26

    A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)

  1. Predominance of AT1 Blockade Over Mas–Mediated Angiotensin-(1–7) Mechanisms in the Regulation of Blood Pressure and Renin–Angiotensin System in mRen2.Lewis Rats

    Science.gov (United States)

    2013-01-01

    BACKGROUND We investigated whether the antihypertensive actions of the angiotensin II (Ang II) receptor (AT1-R) blocker, olmesartan medoxomil, may in part be mediated by increased Ang-(1–7) in the absence of significant changes in plasma Ang II. METHODS mRen2.Lewis congenic hypertensive rats were administered either a vehicle (n = 14) or olmesartan (0.5mg/kg/day; n = 14) by osmotic minipumps. Two weeks later, rats from both groups were further randomized to receive either the mas receptor antagonist A-779 (0.5mg/kg/day; n = 7 per group) or its vehicle (n = 7 per group) for the next 4 weeks. Blood pressure was monitored by telemetry, and circulating and tissue components of the renin–angiotensin system (RAS) were measured at the completion of the experiments. RESULTS Antihypertensive effects of olmesartan were associated with an increase in plasma renin concentration, plasma Ang I, Ang II, and Ang-(1–7), whereas serum aldosterone levels and kidney Ang II content were reduced. Preserved Ang-(1–7) content in kidneys was associated with increases of ACE2 protein but not activity and no changes on serum and kidney ACE activity. There was no change in cardiac peptide levels after olmesartan treatment. The antihypertensive effects of olmesartan were not altered by concomitant administration of the Ang-(1–7) receptor antagonist except for a mild further increase in plasma renin concentration. CONCLUSIONS Our study highlights the independent regulation of RAS among plasma, heart, and kidney tissue in response to AT1-R blockade. Ang-(1–7) through the mas receptor does not mediate long-term effects of olmesartan besides counterbalancing renin release in response to AT1-R blockade. PMID:23459599

  2. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1989-08-01

    A cursory examination of the research activities of the Magneto-Fluid Dynamics Division for the calendar year 1988 shows the effects of the gradual transformation of the group. Although our principal activity, fusion plasma physics research, is unchanged, the work shows closer ties to problems relevant to present experiments than previously. Most notable is the concentrated effort on tokamak equilibrium and transport. We are exploring the implication of turbulence induced transport, resistive MHD effects, neoclassical transport, and possible interpretations of transport based on classical phenomena. In addition, one of our members has chosen to focus on problems of enhanced statistical methods for interpretation of experiments. All of this activity preceded the Tokamak Transport Initiative and reflects our active involvement and concern with the world-wide tokamak program. Since equilibrium and transport are by no means the only theoretical plasma physics problems affecting fusion devices we continue substantial efforts in wave propagation and heating, particle simulation of plasmas, stability theory, enhancement of numerical algorithms, and general plasma physics. We are attempting to develop effective numerical schemes for the Boltzmann equation, adaptive grid methods for MHD, and particle simulation of boundary and antenna effects. Many of these topics reflect our continuing concern to maintain a modest effort in the development of theoretical models and tools for problems of real significance to fusion, but not necessarily of immediate highest priority. We select problems which we expect to become extremely important in the future. Our space plasma physics activities, funded by agencies other than DOE, transfers knowledge learned in fusion plasma physics to another area and conversely stimulates work also relevant to fusion problems

  3. Electron plasma waves and plasma resonances

    International Nuclear Information System (INIS)

    Franklin, R N; Braithwaite, N St J

    2009-01-01

    In 1929 Tonks and Langmuir predicted of the existence of electron plasma waves in an infinite, uniform plasma. The more realistic laboratory environment of non-uniform and bounded plasmas frustrated early experiments. Meanwhile Landau predicted that electron plasma waves in a uniform collisionless plasma would appear to be damped. Subsequent experimental work verified this and revealed the curious phenomenon of plasma wave echoes. Electron plasma wave theory, extended to finite plasmas, has been confirmed by various experiments. Nonlinear phenomena, such as particle trapping, emerge at large amplitude. The use of electron plasma waves to determine electron density and electron temperature has not proved as convenient as other methods.

  4. ''Dusty plasmas''

    International Nuclear Information System (INIS)

    Tsytovich, V.N.; Bingham, R.; Angelis, U. de

    1989-09-01

    The field of ''dusty plasmas'' promises to be a very rewarding topic of research for the next decade or so, not only from the academic point of view where the emphasis is on developing the theory of the often complex collective and non-linear processes, but also from the point of view of applications in astrophysics, space physics, environmental and energy research. In this ''comment'' we should like to sketch the current development of this fast growing and potentially very important research area. We will discuss the new features of ''dusty'' plasmas in the most general terms and then briefly mention some successful applications and effects which have already been examined. (author)

  5. CSF tau and β-amyloid predict cerebral synucleinopathy in autopsied Lewy body disorders.

    Science.gov (United States)

    Irwin, David J; Xie, Sharon X; Coughlin, David; Nevler, Naomi; Akhtar, Rizwan S; McMillan, Corey T; Lee, Edward B; Wolk, David A; Weintraub, Daniel; Chen-Plotkin, Alice; Duda, John E; Spindler, Meredith; Siderowf, Andrew; Hurtig, Howard I; Shaw, Leslie M; Grossman, Murray; Trojanowski, John Q

    2018-03-20

    To test the association of antemortem CSF biomarkers with postmortem pathology in Lewy body disorders (LBD). Patients with autopsy-confirmed LBD (n = 24) and autopsy-confirmed Alzheimer disease (AD) (n = 23) and cognitively normal (n = 36) controls were studied. In LBD, neuropathologic criteria defined Lewy body α-synuclein (SYN) stages with medium/high AD copathology (SYN + AD = 10) and low/no AD copathology (SYN - AD = 14). Ordinal pathology scores for tau, β-amyloid (Aβ), and SYN pathology were averaged across 7 cortical regions to obtain a global cerebral score for each pathology. CSF total tau (t-tau), phosphorylated tau at threonine 181 , and Aβ 1-42 levels were compared between LBD and control groups and correlated with global cerebral pathology scores in LBD with linear regression. Diagnostic accuracy for postmortem categorization of LBD into SYN + AD vs SYN - AD or neocortical vs brainstem/limbic SYN stage was tested with receiver operating curves. SYN + AD had higher CSF t-tau (mean difference 27.0 ± 8.6 pg/mL) and lower Aβ 1-42 (mean difference -84.0 ± 22.9 g/mL) compared to SYN - AD ( p CSF t-tau ( R 2 = 0.15-0.16, p CSF Aβ 1-42 ( R 2 = 0.31, p CSF t-tau/Aβ 1-42 ratio ( R 2 = 0.27, p = 0.01). CSF t-tau/Aβ 1-42 ratio had 100% specificity and 90% sensitivity for SYN + AD, and CSF Aβ 1-42 had 77% specificity and 82% sensitivity for neocortical SYN stage. Higher antemortem CSF t-tau/Aβ 1-42 and lower Aβ 1-42 levels are predictive of increasing cerebral AD and SYN pathology. These biomarkers may identify patients with LBD vulnerable to cortical SYN pathology who may benefit from both SYN and AD-targeted disease-modifying therapies. © 2018 American Academy of Neurology.

  6. Depression associated with dementia with Lewy bodies (DLB) and the effect of somatotherapy.

    Science.gov (United States)

    Takahashi, Sho; Mizukami, Katsuyoshi; Yasuno, Fumihiko; Asada, Takashi

    2009-06-01

    Dementia with Lewy bodies (DLB) is a common type of dementia. It is difficult to make an initial diagnosis of DLB because of a variety of early symptoms, including psychosis-like and depressive states. In this study, we examined the characteristic depressive symptoms of the prestage of DLB and the efficacy and safety of somatotherapy for depression accompanying DLB. Subjects in the study were 167 consecutive clinical cases aged 50 years or more, hospitalized at Tsukuba University Hospital from December 2002 to September 2007. At the time of admission, patients were diagnosed with certain types of mood disorders according to the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition Text Revision. For each subject, a series of neuropsychological tests, along with a standard psychiatric and neurological assessment and biological examinations, were conducted. Using the data from these exams, we diagnosed probable and possible DLB according to the criteria for dementia with Lewy bodies established by McKeith et al. 1 We compared patients' depressive symptoms according to the Hamilton Depression Scale, and distinguished between patients with depression associated with DLB and those with other mood disorders. 2 We also examined the efficacy and safety of somatotherapy (electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS)) for patients with drug therapy-resistant depression associated with DLB. 1 The characteristic symptoms of patients with DLB were classified into two groups: psychotic and non-psychotic. The former consisted of patients with states such as delusion and agitation, and the latter included patients exhibiting psychomotor retardation, loss of insight and hypochondriasis. 2 Eight DLB patients with therapy-resistant depression underwent ECT. After ECT, significant improvement was observed, with no remarkable safety hazards. Six patients with drug therapy-resistant DLB underwent TMS. TMS appears to be an effective, safe

  7. Plasma physics and engineering

    CERN Document Server

    Fridman, Alexander

    2011-01-01

    Part I: Fundamentals of Plasma Physics and Plasma ChemistryPlasma in Nature, in the Laboratory, and in IndustryOccurrence of Plasma: Natural and Man MadeGas DischargesPlasma Applications, Plasmas in IndustryPlasma Applications for Environmental ControlPlasma Applications in Energy ConversionPlasma Application for Material ProcessingBreakthrough Plasma Applications in Modern TechnologyElementary Processes of Charged Species in PlasmaElementary Charged Particles in Plasma and Their Elastic and Inelastic CollisionsIonization ProcessesMechanisms of Electron Losses: The Electron-Ion RecombinationEl

  8. Simple annulus power balance in EBT-I

    International Nuclear Information System (INIS)

    Borowski, S.K.; Uckan, N.A.; Jaeger, E.F.; Kammash, T.

    1979-09-01

    An essential feature of the ELMO Bumpy Torus (EBT) concept is the presence of a relativistic electron annulus in each of the toroidal mirror sectors. These high beta annuli are formed and sustained by microwave heating and are of sufficient density and temperature that diamagnetic currents produce the necessary minimum in the magnetic field required for MHD stability of the toroidal core plasma. Because electron rings play an important role in confinement characteristics and performance of EBT, the trade-off between the quality of the confinement afforded by the rings and the power required to sustain the rings represents an important problem in a fusion reactor. Theoretical estimates of the microwave power required to sustain the annulus are found to be within a factor of 2 of the experimentally determined value. Scaling projections that are shown for both EBT-I and EBT-S enable one to examine the sensitivity of the annulus electron temperature as a function of core plasma density for various microwave power levels. The results are found to be sensitive to the details of the hot electron distribution function as well as geometric and scaling parameters. Improvements to the model are under way in order to increase its capability and accuracy in assessing the overall power balance

  9. Status of the theoretical study of microwave heating in EBT

    International Nuclear Information System (INIS)

    Batchelor, D.B.

    1978-09-01

    The basic strategy of the theoretical study of microwave heating in the ELMO Bumpy Torus (EBT) is outlined and the current status of the various aspects of the study is described. There are four broad areas which are being investigated: (1) heating and wave damping mechanisms, (2) the geometrical optics of microwave propagation in EBT, (3) reflection and mode conversion effects at regions such as cutoff and resonances where the geometrical optics approximation breaks down, and (4) nonlinear effects such as ponderamotive effects and parametric decay. Details are given of the geometrical optics code which has been developed to do ray tracing in arbitrary three dimensional (3-D) plasma equilibria. Examples are given for plasma parameters characteristic of EBT-I and EBT-II. Details are also given of the stochastic heating model currently in use with the 1-D transport code and of the linear wave damping model used in the ray tracing code. The most pressing problems of physics yet to be addressed and the directions for future work are indicated

  10. Fusion Energy Division annual progress report period ending December 31, 1983

    International Nuclear Information System (INIS)

    1984-09-01

    The Fusion Program carries out work in a number of areas: (1) experimental and theoretical research on two magnetic confinement concepts - the ELMO Bumpy Torus (EBT) and the tokamak, (2) theoretical and engineering studies on a third concept - the stellarator, (3) engineering and physics of present-generation fusion devices, (4) development and testing of diagnostic tools and techniques, (5) development and testing of materials for fusion devices, (6) development and testing of the essential technologies for heating and fueling fusion plasmas, (7) development and testing of the superconducting magnets that will be needed to confine these plasmas, (8) design of future devices, (9) assessment of the environmental impact of fusion energy, and (10) assembly and distribution to the fusion community of data bases on atomic physics and radiation effects. The interactions between these activities and their integration into a unified program are major factors in the success of the individual activities, and the ORNL Fusion Program strives to maintain a balance among these activities that will lead to continued growth

  11. Radio frequency heating of fusion plasms

    International Nuclear Information System (INIS)

    Swanson, D.G.

    1983-01-01

    The electron cyclotron range of frequencies has been used successfully for plasma heating perhaps longer than any other RF plasma heating scheme and is generally well understood. The problem has always been that the strong magnetic field required for fusion devices puts the electron cyclotron frequency so high that it is at or above the high power technology limit. The development of high power gyrotrons (> 200 kW) in recent years with steadily rising frequency limits, however, has brought about a renaissance of interest in ECRH as relativistic electron energies well in excess of those required for fusion have been obtained. The relativistic electron ring stabilization of the Elmo Bumpy Torus (EBT), which was achieved with ECRF, only at one point made the EBT the most promising new fusion concept of the last decade. The results also made clear that the physical understanding of the heating processes in this frequency range, so long neglected because of the technology limitation, are not fully understood so that more basic physics is necessary before ECRF can reach the potential that technology now seems to allow

  12. Electron-confinement studies on EBT-S using soft-x-ray techniques

    International Nuclear Information System (INIS)

    Hillis, D.L.; Haste, G.R.; Berry, L.A.

    1982-08-01

    Soft x-ray bremsstrahlung measurements have been performed on the ELMO Bumpy Torus (EBT-S) plasma to determine the electron temperature T/sub e/ and electron density n/sub e/ using a calibrated Si(Li) detector over a wide range of operating conditions. The purpose of this paper is to outline the necessary assumptions and essential x-ray techniques that are inherent in soft x-ray measurements in order to investigate the electron heating and confinement properties of EBT-S. In addition, by utilizing the electron density as determined by the soft x-ray measurements, the previous EBT-S confinement analyses have been extended. The steady-state plasma of EBT-S is heated by microwaves using a cw gyrotron that can operate up to power levels of 200 kW. From the soft x-ray measurements, both the electron temperature and density are found to increase at higher microwave power levels. For operation at microwave power levels of 200 kW, T/sub e/ approaches 1 keV while n/sub e/ approaches 1.2 x 10 12 cm -3 . In general, confinement properties are found to improve with increased microwave power. The data are compared with neoclassical transport scaling and the electron transport is found to be collisionless (nu/Ω < 1) as well as neoclassical

  13. Design for the National RF Test Facility at ORNL

    International Nuclear Information System (INIS)

    Gardner, W.L.; Hoffman, D.J.; Becraft, W.R.

    1983-01-01

    Conceptual and preliminary engineering design for the National RF Test Facility at Oak Ridge National Laboratory (ORNL) has been completed. The facility will comprise a single mirror configuration embodying two superconducting development coils from the ELMO Bumpy Torus Proof-of-Principle (EBT-P) program on either side of a cavity designed for full-scale antenna testing. The coils are capable of generating a 1.2-T field at the axial midpoint between the coils separated by 1.0 m. The vacuum vessel will be a stainless steel, water-cooled structure having an 85-cm-radius central cavity. The facility will have the use of a number of continuous wave (cw), radio-frequency (rf) sources at levels including 600 kW at 80 MHz and 100 kW at 28 GHz. Several plasma sources will provide a wide range of plasma environments, including densities as high as approx. 5 x 10 13 cm -3 and temperatures on the order of approx. 10 eV. Furthermore, a wide range of diagnostics will be available to the experimenter for accurate appraisal of rf testing

  14. Equilibrium: three-dimensional configurations

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    This chapter considers toroidal MHD configurations that are inherently three-dimensional. The motivation for investigation such complicated equilibria is that they possess the potential for providing toroidal confinement without the need of a net toroidal current. This leads to a number of advantages with respect to fusion power generation. First, the attractive feature of steady-state operation becomes more feasible since such configurations no longer require a toroidal current transformer. Second, with zero net current, one potentially dangerous class of MHD instabilities, the current-driven kink modes, is eliminated. Finally, three-dimensional configurations possess nondegenerate flux surfaces even in the absence of plasma pressure and plasma current. Although there is an enormous range of possible three-dimensional equilibria, the configurations of interest are accurately described as axisymmetric tori with superimposed helical fields; furthermore, they possess no net toroidal current. Instead, two different and less obvious restoring forces are developed: the helical sideband force and the toroidal dipole current force. Each is discussed in detail in Chapter 7. A detailed discussion of the parallel current constraint, including its physical significance, is given in section 7.2. A general analysis of helical sideband equilibria, along with a detailed description of the Elmo bumpy torus, is presented in sections 7.3 and 7.4. A general description of toroidal dipole-current equilibria, including a detailed discussion of stellarators, heliotrons, and torsatrons, is given in sections 7.5 and 7.6

  15. Fusion Energy Division annual progress report period ending December 31, 1983

    Energy Technology Data Exchange (ETDEWEB)

    1984-09-01

    The Fusion Program carries out work in a number of areas: (1) experimental and theoretical research on two magnetic confinement concepts - the ELMO Bumpy Torus (EBT) and the tokamak, (2) theoretical and engineering studies on a third concept - the stellarator, (3) engineering and physics of present-generation fusion devices, (4) development and testing of diagnostic tools and techniques, (5) development and testing of materials for fusion devices, (6) development and testing of the essential technologies for heating and fueling fusion plasmas, (7) development and testing of the superconducting magnets that will be needed to confine these plasmas, (8) design of future devices, (9) assessment of the environmental impact of fusion energy, and (10) assembly and distribution to the fusion community of data bases on atomic physics and radiation effects. The interactions between these activities and their integration into a unified program are major factors in the success of the individual activities, and the ORNL Fusion Program strives to maintain a balance among these activities that will lead to continued growth.

  16. Chiral relay: a novel strategy for the control and amplification of enantioselectivity in chiral Lewis acid promoted reactions.

    Science.gov (United States)

    Corminboeuf, Olivier; Quaranta, Laura; Renaud, Philippe; Liu, Mei; Jasperse, Craig P; Sibi, Mukund P

    2003-01-03

    Chiral Lewis acid catalysis has emerged as one of the premiere method to control stereochemistry. Much effort has gone into the design of superior ligands with increasing steric extension to shield distant reactive sites. We report here an alternative and complementary approach based on a "chiral relay". This strategy focuses on the improved design of achiral templates which may relay and amplify the stereochemistry from ligands. The essence of this strategy is that the chiral Lewis acid would effectively convert an achiral template into a chiral non-racemic template. This approach combines the advantages of enantioselective catalysis (substoichiometric amount of the chiral inducer) with the ones of chiral auxiliary control (efficient and predictable stereocontrol).

  17. Metal Fluorides, Metal Chlorides and Halogenated Metal Oxides as Lewis Acidic Heterogeneous Catalysts. Providing Some Context for Nanostructured Metal Fluorides.

    Science.gov (United States)

    Lennon, David; Winfield, John M

    2017-01-28

    Aspects of the chemistry of selected metal fluorides, which are pertinent to their real or potential use as Lewis acidic, heterogeneous catalysts, are reviewed. Particular attention is paid to β-aluminum trifluoride, aluminum chlorofluoride and aluminas γ and η, whose surfaces become partially fluorinated or chlorinated, through pre-treatment with halogenating reagents or during a catalytic reaction. In these cases, direct comparisons with nanostructured metal fluorides are possible. In the second part of the review, attention is directed to iron(III) and copper(II) metal chlorides, whose Lewis acidity and potential redox function have had important catalytic implications in large-scale chlorohydrocarbons chemistry. Recent work, which highlights the complexity of reactions that can occur in the presence of supported copper(II) chloride as an oxychlorination catalyst, is featured. Although direct comparisons with nanostructured fluorides are not currently possible, the work could be relevant to possible future catalytic developments in nanostructured materials.

  18. Dr. Lewis Kitchener Dahl, the Dahl Rats and the ‘Inconvenient truth’ abou the Genetics of Hypertension

    Science.gov (United States)

    Joe, Bina

    2014-01-01

    Synopsis Lewis K. Dahl is regarded as an iconic figure in the field of hypertension research. During the 1960s and 1970s he published several seminal articles in the field that shed light on the relationship between salt and hypertension. Further, the Dahl rat models of hypertension that he developed by a selective breeding strategy are among the most widely used models for hypertension research. To this day, genetic studies using this model are ongoing in our laboratory. While Dr. Dahl is known for his contributions to the field of hypertension, very little, if any, of his personal history is documented. This article details a short biography of Dr. Lewis Dahl, the history behind the development of the Dahl rats and presents an overview of the results obtained through the genetic analysis of the Dahl rat as an experimental model to study the inheritance of hypertension. PMID:25646295

  19. WATER TEMPERATURE and other data from LEWIS B. PULLER in the NE Pacific from 1992-05-07 to 1992-06-28 (NCEI Accession 9200230)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data in this accession were collected in NE Pacific (limit-180) from ship LEWIS B. PULLER between May 7, 1992 to June 28, 1992. The real time data of water...

  20. Plasma chromograninx

    DEFF Research Database (Denmark)

    Goetze, Jens P; Hilsted, Linda M; Rehfeld, Jens F

    2014-01-01

    Cardiovascular risk assessment remains difficult in elderly patients. We examined whether chromogranin A (CgA) measurement in plasma may be valuable in assessing risk of death in elderly patients with symptoms of heart failure in a primary care setting. A total of 470 patients (mean age 73 years...

  1. Burning plasmas

    International Nuclear Information System (INIS)

    Furth, H.P.; Goldston, R.J.; Zweben, S.J.

    1990-10-01

    The fraction of fusion-reaction energy that is released in energetic charged ions, such as the alpha particles of the D-T reaction, can be thermalized within the reacting plasma and used to maintain its temperature. This mechanism facilitates the achievement of very high energy-multiplication factors Q, but also raises a number of new issues of confinement physics. To ensure satisfactory reaction operation, three areas of energetic-ion interaction need to be addressed: single-ion transport in imperfectly symmetric magnetic fields or turbulent background plasmas; energetic-ion-driven (or stabilized) collective phenomena; and fusion-heat-driven collective phenomena. The first of these topics is already being explored in a number of tokamak experiments, and the second will begin to be addressed in the D-T-burning phase of TFTR and JET. Exploration of the third topic calls for high-Q operation, which is a goal of proposed next-generation plasma-burning projects. Planning for future experiments must take into consideration the full range of plasma-physics and engineering R ampersand D areas that need to be addressed on the way to a fusion power demonstration

  2. Prevalence and Clinical Implication of Microbleeds in Dementia with Lewy Bodies in Comparison with Microbleeds in Alzheimer's Disease

    OpenAIRE

    Toshiya Fukui; Yoshiyuki Oowan; Takahiro Yamazaki; Ryuta Kinno

    2013-01-01

    Background: Cerebral microbleeds (MBs) have been well investigated in Alzheimer's disease (AD), but not very extensively in non-AD dementias or in dementia with Lewy bodies (DLB). Aims: To elucidate the clinical significance of MBs in DLB. Methods: We compared the prevalence, locations and risk factors for MBs in 59 DLB and 81 AD patients. We visually counted MBs in each of the cortical and subjacent areas (frontal, temporal, parietal and occipital), the basal ganglia and the thalamus, and th...

  3. Contemporary Greedy Institutions: An Essay on Lewis Coser’s Concept in Times of the ‘Hive Mind’

    OpenAIRE

    de Campo, Marianne Egger

    2013-01-01

    Lewis Coser perennially discussed various forms and facets of ‘greedy institutions’ with their total grasp on the individual. Coser’s ‘greedy institutions’ demand undivided time and loyalty from the individual who will voluntarily devote him/herself for exclusive benefits only granted to loyal followers. Although the ancient authorities have vanished—princes with their court Jews, masters with their servants, or religious and political missionaries— one can argue that the idea of the greedy i...

  4. Polystyrene-supported pyridinium chloroaluminate ionic liquid as a new heterogeneous Lewis acid catalyst for selective synthesis of benzimidazoles

    Directory of Open Access Journals (Sweden)

    Parvanak Boroujeni Kaveh

    2013-01-01

    Full Text Available Polystyrene-supported pyridinium chloroaluminate ionic liquid was prepared from the reaction of Merrifield resin with pyridine followed by reaction with aluminium chloride. This catalyst was used as a new chemoselective Lewis acid catalyst for the exclusive synthesis of 2-substituted benzimidazoles from the reaction of aldehydes with o-phenylenediamines. The catalyst is stable (as a bench top catalyst and can be easily recovered and reused without appreciable change in its efficiency.

  5. Differentiating between visual hallucination-free dementia with Lewy bodies and corticobasal syndrome on the basis of neuropsychology and perfusion single-photon emission computed tomography

    OpenAIRE

    Misch, Michael R; Mitchell, Sara; Francis, Philip L; Sherborn, Kayla; Meradje, Katayoun; McNeely, Alicia A; Honjo, Kie; Zhao, Jiali; Scott, Christopher JM; Caldwell, Curtis B; Ehrlich, Lisa; Shammi, Prathiba; MacIntosh, Bradley J; Bilbao, Juan M; Lang, Anthony E

    2014-01-01

    Introduction Dementia with Lewy bodies (DLB) and Corticobasal Syndrome (CBS) are atypical parkinsonian disorders with fronto-subcortical and posterior cognitive dysfunction as common features. While visual hallucinations are a good predictor of Lewy body pathology and are rare in CBS, they are not exhibited in all cases of DLB. Given the clinical overlap between these disorders, neuropsychological and imaging markers may aid in distinguishing these entities. Methods Prospectively recruited ca...

  6. Temporal interactions in the Lewis lung tumour between cytotoxic drugs and acute or fractionated radiotherapy

    International Nuclear Information System (INIS)

    Stephens, T.C.; Adams, K.; Peacock, J.H.; Steel, G.G.

    1986-01-01

    Lewis lung tumours were treated in vivo with acute radiation (20 Gy) and 1-(2-chloroethyl)-3-(4-methyl cyclohexyl)-1-nitrosourea (MeCCNU, 10 mg . kg -1 ), cyclophosphamide (CY, 120 mg . kg -1 ) or cis-dichlorodiammine platinum (cis-Pt, 10 mg . kg -1 ) with time intervals ranging from simultaneous to 9 days in either sequence. Tumour response was measured by regrowth delay and combination responses were evaluated relative to calculated 'additivity envelopes'. With CY and cis-Pt, tumour volume response was approximately additive, whether the drugs were administered simultaneously, or up to 7 days before or after radiation. However, with simultaneous administration, MeCCNU and radiation were supra-additive in terms of volume response. In the fractionation studies, drugs were given either at the beginning or at the end of a regime of 5 daily 6 Gy doses. With CY and MeCCNU the drugs were more effective when given with the first radiation dose, but with cis-Pt either regime was equally effective. There was no evidence that repopulation could be exploited to improve therapeutic effect with any of the combination treatments used in this study. (Auth.)

  7. The life and achievements of Erwin-Félix Lewy-Bertaut (1913-2003)

    Science.gov (United States)

    Férey, Gérard; Hodeau, Jean-Louis

    2015-02-01

    Erwin-Félix Lewy-Bertaut was initially a lawyer. He left Germany for France when the Nazis rose to power, having been born into a German Jewish family. He became a French citizen in 1936 and embarked upon a scientific career, first in organic chemistry in Bordeaux. The troubles associated with World War II obliged him to move to Grenoble under the protection of Louis Néel. In addition to his creative activity in the new field of inorganic solid state chemistry, he rapidly became a crystallographer and a physicist of magnetism, noted for his impressive activity in both of these domains. He became a pioneer of neutron diffraction and was pivotal to the creation of the Institut Laue-Langevin. Owing to the impact of his work, he was involved in the key international organizations responsible for shaping crystallography and physics. A member of the French Academy of Sciences, Monsieur Bertaut received many international awards. He was a very kind man of culture.

  8. The role of radionuclide studies in the differential diagnosis of dementia with Lewy Body (DLB)

    International Nuclear Information System (INIS)

    Brockhuis, B.; Romanowicz, G.; Slawek, J.; Wieczorek, D.; Ussorowska, D.; Derejko, M.

    2006-01-01

    Dementia with Lewy Body (DLB) is considered to be the second most common (20%) neuropathological cause of degenerative dementia after Alzheimer's disease (AD). Typical clinical features of DLB include a progressive and fluctuating cognitive impairment and visual hallucinations along with Parkinsonian symptoms. Early diagnosis is important in DLB because of dangerous neuroleptic sensitivity which is associated with increased morbidity and mortality. Cholinergic deficit in DLB is more extensive when compared with AD. This might explain the beneficial effect of therapy with cholinesterase inhibitors, with improvement of cognitive and psychiatric functions. The functional neuroimaging with the use of SPECT and PET may contribute to the clinical diagnosis and understanding the possible pathogenesis of DLB. There are many similarities between DLB and AD with pronounced parietotemporal hypoperfusion whereas occipital hypoperfusion is more pronounced in DLB. Using tracers for presynaptic dopamine transporters such as I-123 β-CIT recent studies have found severely impaired dopaminergic function in DLB, similar to Parkinson Disease (PD) but not present in AD. Authors present a review of current literature on the role of SPECT and PET imaging in the diagnosis of DLB and three illustrated cases of probable DLB with rCBF SPECT scanning showing mostly parieto-occipital hypoperfusion. (author)

  9. Photothermal therapy of Lewis lung carcinoma in mice using gold nanoshells on carboxylated polystyrene spheres

    Science.gov (United States)

    Liu, Huiyu; Chen, Dong; Tang, Fangqiong; Du, Gangjun; Li, Linlin; Meng, Xianwei; Liang, Wei; Zhang, Yangde; Teng, Xu; Li, Yi

    2008-11-01

    A new approach towards the design of gold nanoshells on carboxylated polystyrene spheres (GNCPSs) is reported here. Gold nanoshells were self-assembled on the surface of carboxylated polystyrene spheres by a seed growth method. Chitosan (CHI) was used as a functional agent of carboxylated polystyrene spheres for attaching gold seeds. The surface plasmon resonance (SPR) peak of GNCPSs can be tuned, greatly redshifted, over a broad spectral range including the near-infrared (NIR) wavelength region, which provides maximal penetration of light through tissue. Irradiation of GNCPSs at their peak extinction coefficient results in the conversion of light to heat energy that produces a local rise in temperature. Our study revealed that the Lewis lung carcinoma (LLC) in mice treated with GNCPSs exposed to a low dose of NIR light (808 nm, 4 W cm-2) induced irreversible tissue damage. The tumor volumes of the treatment group by GNCPSs were significantly lower than those of control groups, with an average inhibition rate over 55% (P<0.005). This study proves that GNCPSs are promising in plasmonic photothermal tumor therapy.

  10. Magneto-reactance based detection of MnO nanoparticle-embedded Lewis lung carcinoma cells

    Science.gov (United States)

    Devkota, J.; Howell, M.; Mukherjee, P.; Srikanth, H.; Mohapatra, S.; Phan, M. H.

    2015-05-01

    We demonstrate the capacity of detecting magnetically weak manganese oxide (MnO) nanoparticles and the Lewis lung carcinoma (LLC) cancer cells that have taken up these nanoparticles using a novel biosensor based on the magneto-reactance (MX) effect of a soft ferromagnetic amorphous ribbon with a microhole-patterned surface. While the magnetic moment of the MnO nanoparticles is relatively small, and a magneto-impedance based sensor fails to detect them in solution (0.05 mg/ml manganese oxide lipid micellar nanoparticles) and inside cells at low concentrations (8.25 × 104 cells/ml), the detection of these nanoparticles and the LLC cells containing them is achieved with the MX-based sensor, which, respectively, reaches the detection sensitivity of ˜3.6% and 2.8% as compared to the blank cells. Since the MnO nanoparticles are a promising contrast agent for magnetic resonance imaging (MRI) of lung cells, the MX-based biosensing technique can be developed as a pre-detection method for MRI of lung cancer cells.

  11. Overview of the 1985 NASA Lewis Research Center SP-100 free-piston stirling engine activities

    International Nuclear Information System (INIS)

    Slaby, J.G.

    1985-01-01

    An overview of the 1985 (NASA) Lewis Research Center free-piston Stirling engine activities in support of the SP-100 Program is presented. The SP-100 program is being conducted in support of the Department of Advanced Research Projects Agency (DARPA) and the Department of Energy (DOE), and NASA. This effort is keyed on the design, fabrication, assembly, and testing of a 25 kW /SUB e/ Stirling space-power technology-feasibility demonstrator engine. Another facet of the SP-100 project covers the status of a 9000-hr goal endurance test conducted on a 2 kW /SUB e/ free-piston Stirling/ linear alternator system employing hydrostatic gas bearings. Dynamic balancing of the RE-1000 engine (a 1 kW /SUB e/ free-piston Stirling engine) using a passive dynamic absorber will be discussed along with the results of a parametric study showing the relationships of Stirling power converter specific weight and efficiency as functions of Stirling engine heater to cooler temperature ratio. Planned tests will be described covering a hydrodynamic gas bearing concept for potential SP-100 application

  12. Organoboron compounds as Lewis acid receptors of fluoride ions in polymeric membranes.

    Science.gov (United States)

    Jańczyk, Martyna; Adamczyk-Woźniak, Agnieszka; Sporzyński, Andrzej; Wróblewski, Wojciech

    2012-07-06

    Newly synthesized organoboron compounds - 4-octyloxyphenylboronic acid (OPBA) and pinacol ester of 2,4,6-trifluorophenylboronic acid (PE-PBA) - were applied as Lewis acid receptors of fluoride anions. Despite enhanced selectivity, the polymer membrane electrodes containing the lipophilic receptor OPBA exhibited non-Nernstian slopes of the responses toward fluoride ions in acidic conditions. Such behavior was explained by the lability of the B-O bond in the boronic acids, and the OH(-)/F(-) exchange at higher fluoride content in the sample solution. In consequence, the stoichiometry of the OPBA-fluoride complexes in the membrane could vary during the calibration, changing the equilibrium concentration of the primary anion in membrane and providing super-Nernstian responses. The proposed mechanism was supported by (19)F NMR studies, which indicated that the fluoride complexation proceeds more effectively in acidic solution leading mainly to PhBF(3)(-) species. Finally, the performances of the membranes based on the phenylboronic acid pinacol ester, with a more stable B-O bond, were tested. As it was expected, Nernstian fluoride responses were recorded for such membranes with worsened fluoride selectivity. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Memantine improves attention and episodic memory in Parkinson's disease dementia and dementia with Lewy bodies.

    Science.gov (United States)

    Wesnes, Keith A; Aarsland, Dag; Ballard, Clive; Londos, Elisabet

    2015-01-01

    In both dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), attentional dysfunction is a core clinical feature together with disrupted episodic memory. This study evaluated the cognitive effects of memantine in DLB and PDD using automated tests of attention and episodic memory. A randomised double-blind, placebo-controlled, 24-week three centre trial of memantine (20 mg/day) was conducted in which tests of attention (simple and choice reaction time) and word recognition (immediate and delayed) from the CDR System were administered prior to dosing and again at 12 and 24 weeks. Although other results from this study have been published, the data from the CDR System tests were not included and are presented here for the first time. Data were available for 51 patients (21 DLB and 30 PDD). In both populations, memantine produced statistically significant medium to large effect sized improvements to choice reaction time, immediate and delayed word recognition. These are the first substantial improvements on cognitive tests of attention and episodic recognition memory identified with memantine in either DLB or PDD. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Dysphagia in Lewy body dementia - a clinical observational study of swallowing function by videofluoroscopic examination.

    Science.gov (United States)

    Londos, Elisabet; Hanxsson, Oskar; Alm Hirsch, Ingrid; Janneskog, Anna; Bülow, Margareta; Palmqvist, Sebastian

    2013-10-07

    Dysphagia, which can result in aspiration pneumonia and death, is a well-known problem in patients with dementia and Parkinson's disease. There are few studies on dysphagia in patients with dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), especially studies objectively documenting the type of swallowing dysfunction. The aim of this study was therefore to investigate the prevalence, and define the actual swallowing dysfunction according to a videofluoroscopic swallowing examination (VFSE) in patients with DLB and PDD. Eighty-two consecutive patients with DLB or PDD in a clinical follow-up program were asked about symptoms of dysphagia. Those experiencing dysphagia were examined with VFSE. Prevalence and type of swallowing dysfunction was recorded. Twenty-six patients (32%) reported symptoms of dysphagia such as swallowing difficulties or coughing. Twenty-four (92%) of these had a documented swallowing dysfunction on VFSE. Eighty-eight percent suffered from pharyngeal dysfunction. Almost all DLB or PDD patients with subjective signs of dysphagia had pathologic results on VFSE, the majority of pharyngeal type. This type of dysphagia has not been reported in DLB before. The results have clinical implications and highlight the importance of asking for and examining swallowing function to prevent complications such as aspiration.

  15. Driving Competence in Mild Dementia with Lewy Bodies: In Search of Cognitive Predictors Using Driving Simulation

    Directory of Open Access Journals (Sweden)

    Stephanie Yamin

    2015-01-01

    Full Text Available Driving is a multifactorial behaviour drawing on multiple cognitive, sensory, and physical systems. Dementia is a progressive and degenerative neurological condition that impacts the cognitive processes necessary for safe driving. While a number of studies have examined driving among individuals with Alzheimer’s disease, less is known about the impact of Dementia with Lewy Bodies (DLB on driving safety. The present study compared simulated driving performance of 15 older drivers with mild DLB with that of 21 neurologically healthy control drivers. DLB drivers showed poorer performance on all indicators of simulated driving including an increased number of collisions in the simulator and poorer composite indicators of overall driving performance. A measure of global cognitive function (i.e., the Mini Mental State Exam was found to be related to the overall driving performance. In addition, measures of attention (i.e., Useful Field of View, UFOV and space processing (Visual Object and Space Perception, VOSP, Test correlated significantly with a rater’s assessment of driving performance.

  16. Time course of development of metastasis in irradiated Lewis lung carcinoma

    International Nuclear Information System (INIS)

    Ohizumi, Yukio; Maezawa, Hiroshi; Mori, Tomoyuki

    1988-01-01

    The influence of local irradiation on the development of metastases and primary tumor volume was studied in Lewis lung carcinoma growing intramuscularly in the hind leg of C57BL/6 mice. The time course of development of metastases was determined from the size of the lung colonies at autopsy by determining the growth rate of the colonies. Irradiation within five days after tumor cell injection inhibited the incidence of metastases in accordance with irradiation dose. For irradiation more than seven days after the injection, promotion of metastases was observed around the time of the experiment as a function of irradiation dose and tumor volume. After the irradiation phase, the development of metastases was inhibited in accordance with radiation dose. When delay in metastasis was defined as additional days needed to develop two or ten colonies compared with controls, the relationship between delay and dose was linear. At the regrowth phase of the primary tumor, the incidence of metastases from the irradiated tumor was reduced in comparison with that from unirradiated tumors of the same size. Inhibition of metastases was observed only at 5 Gy and showed slight dose-dependency. Mechanisms in the development of metastases as they related to these findings are also discussed. (autho)

  17. Pareidolias in REM Sleep Behavior Disorder: A Possible Predictive Marker of Lewy Body Diseases?

    Science.gov (United States)

    Sasai-Sakuma, Taeko; Nishio, Yoshiyuki; Yokoi, Kayoko; Mori, Etsuro; Inoue, Yuichi

    2017-02-01

    To investigate conditions and clinical significance of pareidolias in patients with idiopathic rapid eyemovent (REM) sleep behavior disorder (iRBD). This cross-sectional study examined 202 patients with iRBD (66.8 ± 8.0 yr, 58 female) and 46 healthy control subjects (64.7 ± 5.8 years, 14 females). They underwent the Pareidolia test, a newly developed instrument for evoking pareidolias, video polysomnography, olfactory tests, and Addenbrooke's cognitive examination-revised. Results show that 53.5% of iRBD patients exhibited one or more pareidolic responses: The rate was higher than control subjects showed (21.7%). The pictures evoking pareidolic responses were more numerous for iRBD patients than for control subjects (1.2 ± 1.8 vs. 0.4 ± 0.8, p Pareidolias in iRBD are useful as a predictive marker of future development of Lewy body diseases. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  18. Hallucinators find meaning in noises: pareidolic illusions in dementia with Lewy bodies.

    Science.gov (United States)

    Yokoi, Kayoko; Nishio, Yoshiyuki; Uchiyama, Makoto; Shimomura, Tatsuo; Iizuka, Osamu; Mori, Etsuro

    2014-04-01

    By definition, visual illusions and hallucinations differ in whether the perceived objects exist in reality. A recent study challenged this dichotomy, in which pareidolias, a type of complex visual illusion involving ambiguous forms being perceived as meaningful objects, are very common and phenomenologically similar to visual hallucinations in dementia with Lewy bodies (DLB). We hypothesise that a common psychological mechanism exists between pareidolias and visual hallucinations in DLB that confers meaning upon meaningless visual information. Furthermore, we believe that these two types of visual misperceptions have a common underlying neural mechanism, namely, cholinergic insufficiency. The current study investigated pareidolic illusions using meaningless visual noise stimuli (the noise pareidolia test) in 34 patients with DLB, 34 patients with Alzheimer׳s disease and 28 healthy controls. Fifteen patients with DLB were administered the noise pareidolia test twice, before and after donepezil treatment. Three major findings were discovered: (1) DLB patients saw meaningful illusory images (pareidolias) in meaningless visual stimuli, (2) the number of pareidolic responses correlated with the severity of visual hallucinations, and (3) cholinergic enhancement reduced both the number of pareidolias and the severity of visual hallucinations in patients with DLB. These findings suggest that a common underlying psychological and neural mechanism exists between pareidolias and visual hallucinations in DLB. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Cardiac 123I-metaiodobenzylguanidine imaging allows early identification of dementia with Lewy bodies during life

    International Nuclear Information System (INIS)

    Estorch, Montserrat; Camacho, Valle; Paredes, Pilar; Rivera, Elisabet; Rodriguez-Revuelto, Ato; Flotats, Albert; Carrio, Ignasi; Kulisevsky, Jaume

    2008-01-01

    Differential diagnosis between dementia with Lewy bodies (DLB) and other neurodegenerative diseases with cognitive impairment represents a clinical challenge. Due to the overlapping of symptoms, the clinical diagnosis can be modified during the prolonged follow-up of these diseases. The purpose of this study was to assess the ability of cardiac metaiodobenzylguanidine (MIBG) imaging for early identification of DLB. Since January 2003, all patients with neurodegenerative diseases with cognitive impairment at their first visit at the Memory Unit and clinical criteria of DLB were consecutively recruited and underwent a cardiac 123 I-MIBG study. The heart-to-mediastinum ratio (HMR) and the washout rate (WR) of cardiac MIBG uptake were obtained. Sixty-five patients were included. After a clinical follow-up of 4 years, the progress of the disease procured a definite diagnosis in 44 (68%) patients: 19 DLB, 12 Alzheimer disease (AD), and 13 other neurodegenerative diseases with cognitive impairment. HMR was significantly decreased in DLB with respect to the other neurodegenerative diseases. WR was only significantly different between DLB and AD. The HMR cut off point of 1.36 differentiated DLB from the other dementias with a sensitivity of 94% and a specificity of 96% with an accuracy of 95%. Cardiac MIBG imaging performed at the time of the first clinical diagnosis of DLB can help early clinical identification or exclusion of this disease. (orig.)

  20. Clinical Subtypes of Dementia with Lewy Bodies Based on the Initial Clinical Presentation.

    Science.gov (United States)

    Morenas-Rodríguez, Estrella; Sala, Isabel; Subirana, Andrea; Pascual-Goñi, Elba; Sánchez-Saudinós, MaBelén; Alcolea, Daniel; Illán-Gala, Ignacio; Carmona-Iragui, María; Ribosa-Nogué, Roser; Camacho, Valle; Blesa, Rafael; Fortea, Juan; Lleó, Alberto

    2018-06-04

    Dementia with Lewy bodies (DLB) is a heterogeneous disease in which clinical presentation, symptoms, and evolution widely varies between patients. To investigate the existence of clinical subtypes in DLB based on the initial clinical presentation. 81 patients with a clinical diagnosis of probable DLB were consecutively included. All patients underwent a neurological evaluation including a structured questionnaire about neuropsychiatric symptoms and sleep, an assessment of motor impairment (Unified Parkinson Disease Rating Scale subscale III), and a formal neuropsychological evaluation. Onset of core symptoms (hallucinations, parkinsonism, and fluctuations) and dementia were systematically reviewed from medical records. We applied a K-means clustering method based on the initial clinical presentation. Cluster analysis yielded three different groups. Patients in cluster I (cognitive-predominant, n = 46) presented more frequently with cognitive symptoms (95.7%, n = 44, p presented more frequently with psychotic symptoms (77.3%, n = 17), and had a shorter duration until the onset of hallucinations (p clinical DLB can be defined when considering the differential initial presentations. The proposed subtypes have distinct clinical profiles and progression patterns.

  1. Clinical Correlations With Lewy Body Pathology in LRRK2-Related Parkinson Disease

    Science.gov (United States)

    Kalia, Lorraine V.; Lang, Anthony E.; Hazrati, Lili-Naz; Fujioka, Shinsuke; Wszolek, Zbigniew K.; Dickson, Dennis W.; Ross, Owen A.; Van Deerlin, Vivianna M.; Trojanowski, John Q.; Hurtig, Howard I.; Alcalay, Roy N.; Marder, Karen S.; Clark, Lorraine N.; Gaig, Carles; Tolosa, Eduardo; Ruiz-Martínez, Javier; Marti-Masso, Jose F.; Ferrer, Isidre; de Munain, Adolfo López; Goldman, Samuel M.; Schüle, Birgitt; Langston, J. William; Aasly, Jan O.; Giordana, Maria T.; Bonifati, Vincenzo; Puschmann, Andreas; Canesi, Margherita; Pezzoli, Gianni; De Paula, Andre Maues; Hasegawa, Kazuko; Duyckaerts, Charles; Brice, Alexis; Stoessl, A. Jon; Marras, Connie

    2015-01-01

    IMPORTANCE Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of genetic Parkinson disease (PD) known to date. The clinical features of manifesting LRRK2 mutation carriers are generally indistinguishable from those of patients with sporadic PD. However, some PD cases associated with LRRK2 mutations lack Lewy bodies (LBs), a neuropathological hallmark of PD. We investigated whether the presence or absence of LBs correlates with different clinical features in LRRK2-related PD. OBSERVATIONS We describe genetic, clinical, and neuropathological findings of 37 cases of LRRK2-related PD including 33 published and 4 unpublished cases through October 2013. Among the different mutations, the LRRK2 p.G2019S mutation was most frequently associated with LB pathology. Nonmotor features of cognitive impairment/dementia, anxiety, and orthostatic hypotension were correlated with the presence of LBs. In contrast, a primarily motor phenotype was associated with a lack of LBs. CONCLUSIONS AND RELEVANCE To our knowledge, this is the first report of clinicopathological correlations in a series of LRRK2-related PD cases. Findings from this selected group of patients with PD demonstrated that parkinsonian motor features can occur in the absence of LBs. However, LB pathology in LRRK2-related PD may be a marker for a broader parkinsonian symptom complex including cognitive impairment. PMID:25401511

  2. Clinical and cognitive correlates of visual hallucinations in dementia with Lewy bodies.

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    Cagnin, Annachiara; Gnoato, Francesca; Jelcic, Nela; Favaretto, Silvia; Zarantonello, Giulia; Ermani, Mario; Dam, Mauro

    2013-05-01

    The presence of recurrent complex visual hallucinations (VHs) is a core feature of dementia with Lewy bodies (DLB). The aim of this study was to investigate which clinical and neuropsychological characteristics are associated with VHs and their predictive value over a 1 year follow-up. 81 DLB patients, 41 with (VH+) and 36 without (VH-) VHs, and 45 patients with Alzheimer's disease (AD), were enrolled. All participants underwent extensive neuropsychological testing. Visual-spatial and perceptual abilities were evaluated with the Visual and Object Space Perception (VOSP) battery. Fluctuations in attention, rapid eye movement sleep behaviour disorder (RBD) symptoms, extrapyramidal signs and behavioural disturbances were studied with dedicated clinical scales. The presence of VHs was associated with older age and later disease onset, but not with disease duration or with fluctuations, RBD or parkinsonism severity. Cognitive correlates of VHs were deficits in visual attention (digit cancellation: pspan forward: pVisual-perceptual and visual-spatial deficits were significantly worse in DLB than in AD patients (VOSP subtests scores 1, 6, 7 and 8) but were not different in DLB VH+ and VH-, except for subtest 6. Poor performance in the visual attention task was an independent predictor of VHs. Impairment of visual-spatial and perceptual abilities in DLB represents a disease related cognitive signature, independent of the presence of VHs, for which it may represent a predisposing condition. Visual attention, instead, is the main cognitive determinant for the genesis of VHs.

  3. The Prince Edward Island-Mayo Clinic connection: Malcolm B. Dockerty and Lewis B. Woolner.

    Science.gov (United States)

    Wright, James R

    2014-03-01

    Malcolm B. Dockerty and Lewis B. Woolner, 2 preeminent mid-20th-century surgical pathologists, spent their entire careers at the Mayo Clinic. Both were raised in poverty on potato farms only 49 miles apart in Canada's smallest province (Prince Edward Island); both were educated in 1-room schools and graduated as gold medalists from Prince Edward Island's only college and then from Maritime Canada's only medical school; both then trained at the Mayo Clinic. To explore the lives and accomplishments of these 2 important surgical pathologists. Standard historiographic methods were used to explore primary and secondary historical sources. Both became world-renowned general surgical pathologists, one developing subspecialty expertise in gynecologic pathology and the other in cytopathology, pulmonary pathology, and thyroid/parathyroid pathology. Both were prolific authors with h-indices higher than 40, and between them, they published more than 750 peer-reviewed papers and book chapters. As educators, they trained hundreds of pathology and surgery residents/fellows who disseminated their knowledge around the world. Both were fascinated by poetry from childhood and could quote the classics from memory. One wrote poetry throughout his entire life and even used it to teach pathology and serve as his memoir; the other strongly preferred the classics and in jest called his colleague "a (minor) poet." Both received postretirement honorary doctorates from their alma maters. Dockerty died in 1987; Woolner celebrates his 100th birthday on November 17, 2013. Every pathologist should know of these 2 pioneering surgical pathologists.

  4. Preclinical Polymodal Hallucinations for 13 Years before Dementia with Lewy Bodies

    Directory of Open Access Journals (Sweden)

    Carlo Abbate

    2014-01-01

    Full Text Available Objective. We describe a case of dementia with Lewy bodies (DLB that presented long-lasting preclinical complex polymodal hallucinations. Background. Few studies have deeply investigated the characteristics of hallucinations in DLB, especially in the preclinical phase. Moreover, the clinical phenotype of mild cognitive impairment-(MCI- DLB is poorly understood. Methods. The patient was followed for 4 years and a selective phenomenological and cognitive study was performed at the predementia stage. Results. The phenomenological study showed the presence of hypnagogic and hypnopompic hallucinations that allowed us to make a differential diagnosis between DLB and Charles Bonnet syndrome (CBS. The neuropsychological evaluation showed a multiple domain without amnesia MCI subtype with prefrontal dysexecutive, visuoperceptual, and visuospatial impairments and simultanagnosia, which has not previously been reported in MCI-DLB. Conclusions. This study extends the prognostic value of hallucinations for DLB to the preclinical phases. It supports and refines the MCI-DLB concept and identifies simultanagnosia as a possible early cognitive marker. Finally, it confirms an association between hallucinations and visuoperceptual impairments at an intermediate stage of the disease course and strongly supports the hypothesis that hallucinations in the earliest stages of DLB may reflect a narcolepsy-like REM-sleep disorder.

  5. Comparison with Parkinson's disease and Parkinsonism in dementia with lewy bodies

    International Nuclear Information System (INIS)

    Kang, Do Young; Park, Kyung Won; Kim, Jae Woo

    2002-01-01

    Dementia with lewy bodies (DLB) is recognized as a common cause of dementia in elderly people. It is characterized by Parkinsonism as well as fluctuation cognition and visual hallucination. It is not easy to differentiated DLB with Parkinsonism from Parkinson's disease (PD). We compared clinical features and I-123 IPT SPECT findings between two groups. Ten probable DLB patients and 15 PD patients were included. They were all matched for age (66.9±8.5) vs 65.8±8.5), education period (9.8±4.9 vs 9.1±4.5) and H and Y stage (2.9±0.8). Clinical features were scored. I-123 IPT SPECT were performed. The mean age of disease onset was seen more common in PD, but the severity of rigidity and bradykinesia was not significantly different. We found no significant difference of responsiveness to levodopa measured with decrement of UPDRS scores before and after treatment of levodopa. The mean disease duration reaching same H and Y stage was longer in PD than in DLB. The average K-MMSE score was significantly lower in DLB than in PD. The uptake ratio in the striatum in DLB was comparable to that in PD. In differentiating the two conditions the speed of disease progression and cognitive state were considered to be important. The level of dopamine transporter was not different between two diseases with same H and Y stage

  6. Differential Atrophy of Hippocampal Subfields: A Comparative Study of Dementia with Lewy Bodies and Alzheimer Disease.

    Science.gov (United States)

    Mak, Elijah; Su, Li; Williams, Guy B; Watson, Rosie; Firbank, Michael; Blamire, Andrew; O'Brien, John

    2016-02-01

    Dementia with Lewy bodies (DLB) is characterized by relative preservation of the medial temporal lobe compared with Alzheimer disease (AD). The differential involvement of the hippocampal subfields in both diseases has not been clearly established, however. We aim to investigate hippocampal subfield differences in vivo in a clinical cohort of DLB and AD subjects. 104 participants (35 DLBs, 36 ADs, and 35 healthy comparison [HC] subjects) underwent clinical assessment and 3T T1-weighted imaging. A Bayesian model implemented in Freesurfer was used to automatically segment the hippocampus and its subfields. We also examined associations between hippocampal subfields and tests of memory function. Both the AD and DLB groups demonstrated significant atrophy of the total hippocampus relative to HC but the DLB group was characterized by preservation of the cornu ammonis 1 (CA1), fimbria, and fissure. In contrast, all the hippocampal subfields except the fissure were significantly atrophied in AD compared with both DLB and HC groups. Among DLB subjects, CA1 was correlated with the Recent Memory score of the CAMCOG and Delayed Recall subscores of the HVLT. DLB is characterized by milder hippocampal atrophy that was accompanied by preservation of the CA1. The CA1 was also associated with memory function in DLB. Our findings highlight the promising role of hippocampal subfield volumetry, particularly that of the CA1, as a biomarker for the distinction between AD and DLB. Copyright © 2016 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  7. Functional Disconnectivity during Inter-Task Resting State in Dementia with Lewy Bodies.

    Science.gov (United States)

    Chabran, Eléna; Roquet, Daniel; Gounot, Daniel; Sourty, Marion; Armspach, Jean-Paul; Blanc, Frédéric

    2018-05-03

    Limited research has been done on the functional connectivity in visuoperceptual regions in dementia with Lewy bodies (DLB) patients. This study aimed to investigate the functional connectivity differences between a task condition and an inter-task resting state condition within a visuoperceptual paradigm, in DLB patients compared with Alzheimer disease (AD) patients and healthy elderly control subjects. Twenty-six DLB, 29 AD, and 22 healthy subjects underwent a detailed clinical and neuropsychological examination along with a functional MRI during the different conditions of a visuoperceptual paradigm. Functional images were analyzed using group-level spatial independent component analysis and seed-based connectivity analyses. While the DLB patients scored well and did not differ from the control and AD groups in terms of functional activity and connectivity during the task conditions, they showed decreased functional connectivity in visuoperceptual regions during the resting state condition, along with a temporal impairment of the default-mode network activity. Functional connectivity disturbances were also found within two attentional-executive networks and between these networks and visuoperceptual regions. We found a specific functional profile in the switching between task and resting state conditions in DLB patients. This result could help better characterize functional impairments in DLB and their contribution to several core symptoms of this pathology such as visual hallucinations and cognitive fluctuations. © 2018 S. Karger AG, Basel.

  8. Cholinergic nicotinic and muscarinic receptors in dementia of Alzheimer, Parkinson and Lewy body types.

    Science.gov (United States)

    Perry, E K; Smith, C J; Court, J A; Perry, R H

    1990-01-01

    Cholinergic nicotinic and muscarinic receptor binding were measured in post mortem human brain tissue, using low (nM) concentrations of (3H)-nicotine to detect predominately the high affinity nicotinic site and (3H)-N-methylscopolamine in the presence and absence of 3 x 10(-4) M carbachol to measure both the low and high affinity agonist subtypes of the muscarinic receptor group. Consistent with most previous reports, the nicotinic but not muscarinic binding was reduced in the different forms of dementia associated with cortical cholinergic deficits, including Alzheimer's and Parkinson's disease, senile dementia of Lewy body type (SDLT) and Down's syndrome (over 50 years). Analysis of (3H)-nicotine binding displaced by a range of carbachol concentrations (10(-9)-10(-3) M) indicated 2 binding sites for nicotine and that the high affinity rather than low affinity site was reduced in Alzheimer's disease. In all 3 cortical areas investigated (temporal, parietal and occipital) there were increases in the low affinity muscarinic site in Parkinson's disease and SDLT but not Alzheimer's disease or middle-aged Down's syndrome. This observation raised the question of whether the presence of neurofibrillary tangles (evident in the latter but not former 2 disorders) is incompatible with denervation-induced muscarinic supersensitivity in cholinoceptive neurons which include cortical pyramids generally affeted by tangle formation.

  9. The clinical diagnosis and misdiagnosis of senile dementia of Lewy body type (SDLT).

    Science.gov (United States)

    McKeith, I G; Fairbairn, A F; Perry, R H; Thompson, P

    1994-09-01

    Current clinical classifications do not contain specific diagnostic categories for patients with senile dementia of the Lewy body type (SDLT), recently proposed as the second commonest neuropathological cause of dementia in the elderly. This study determines how existing clinical diagnosis systems label SDLT patients and suggests how such patients may be identified. A range of clinical diagnostic criteria for dementia were applied to case notes of autopsy-confirmed SDLT (n = 20), dementia of Alzheimer type (DAT; n = 21) and multi-infarct dementia (MID; n = 9) patients who had received psychogeriatric assessment. The predictive validity of each set of clinical criteria was calculated against the external criterion of neuropathological diagnosis. Many SDLT patients erroneously met criteria for MID (35% with Hachinski scores > or = 7) or for DAT (15% by NINCDS 'probable AD', 35% by DSM-III-R DAT and 50% by NINCDS 'possible AD'). Up to 85% of SDLT cases could be correctly identified using recently published specific criteria. SDLT usually has a discernible clinical syndrome and existing clinical classifications may need revision to diagnose correctly such patients.

  10. Enforcing the Courant-Friedrichs-Lewy condition in explicitly conservative local time stepping schemes

    Science.gov (United States)

    Gnedin, Nickolay Y.; Semenov, Vadim A.; Kravtsov, Andrey V.

    2018-04-01

    An optimally efficient explicit numerical scheme for solving fluid dynamics equations, or any other parabolic or hyperbolic system of partial differential equations, should allow local regions to advance in time with their own, locally constrained time steps. However, such a scheme can result in violation of the Courant-Friedrichs-Lewy (CFL) condition, which is manifestly non-local. Although the violations can be considered to be "weak" in a certain sense and the corresponding numerical solution may be stable, such calculation does not guarantee the correct propagation speed for arbitrary waves. We use an experimental fluid dynamics code that allows cubic "patches" of grid cells to step with independent, locally constrained time steps to demonstrate how the CFL condition can be enforced by imposing a constraint on the time steps of neighboring patches. We perform several numerical tests that illustrate errors introduced in the numerical solutions by weak CFL condition violations and show how strict enforcement of the CFL condition eliminates these errors. In all our tests the strict enforcement of the CFL condition does not impose a significant performance penalty.

  11. Photothermal therapy of Lewis lung carcinoma in mice using gold nanoshells on carboxylated polystyrene spheres

    International Nuclear Information System (INIS)

    Liu Huiyu; Chen Dong; Tang Fangqiong; Li Linlin; Meng Xianwei; Li Yi; Du Gangjun; Liang Wei; Zhang Yangde; Teng Xu

    2008-01-01

    A new approach towards the design of gold nanoshells on carboxylated polystyrene spheres (GNCPSs) is reported here. Gold nanoshells were self-assembled on the surface of carboxylated polystyrene spheres by a seed growth method. Chitosan (CHI) was used as a functional agent of carboxylated polystyrene spheres for attaching gold seeds. The surface plasmon resonance (SPR) peak of GNCPSs can be tuned, greatly redshifted, over a broad spectral range including the near-infrared (NIR) wavelength region, which provides maximal penetration of light through tissue. Irradiation of GNCPSs at their peak extinction coefficient results in the conversion of light to heat energy that produces a local rise in temperature. Our study revealed that the Lewis lung carcinoma (LLC) in mice treated with GNCPSs exposed to a low dose of NIR light (808 nm, 4 W cm -2 ) induced irreversible tissue damage. The tumor volumes of the treatment group by GNCPSs were significantly lower than those of control groups, with an average inhibition rate over 55% (P<0.005). This study proves that GNCPSs are promising in plasmonic photothermal tumor therapy.

  12. Correlation between pathology and neuromelanin MR imaging in Parkinson's disease and dementia with Lewy bodies

    International Nuclear Information System (INIS)

    Kitao, Shinichiro; Fujii, Shinya; Miyoshi, Fuminori; Kaminou, Toshio; Ogawa, Toshihide; Matsusue, Eiji; Kato, Shinsuke; Ito, Hisao

    2013-01-01

    Direct correlation between neuropathological findings and postmortem neuromelanin MR imaging (NmMRI) was performed in the substantia nigra pars compacta (SNc) to clarify the pathological background of the signal changes in normal, Parkinson's disease (PD), and dementia with Lewy bodies (DLB) cases. NmMRI of 10 % formalin-fixed autopsied midbrains was performed in three cases (normal control, DLB, and PD) with a 3T imaging system, using a 3D gradient echo T1-weighted sequence with a magnetization transfer contrast pulse. Neuropathological examinations of the midbrains were performed, and the density of neuromelanin-positive neurons (number per square millimeter) was determined. The extent of iron deposition in the midbrain was also evaluated using ferritin immunohistochemistry. Furthermore, we directly correlated the contrast signal ratio in the SNc and the density of neuromelanin-containing neurons. Diffuse hyperintense areas in the SNc reflected well-preserved neuromelanin-containing neurons in the normal control case, whereas an iso-intense area in the SNc showed severe loss of neuromelanin-containing neurons in the DLB and PD cases. Increased signal intensity in the SNc was apparently not influenced by iron deposition. Furthermore, a significant positive correlation between signal intensity and the density of neuromelanin-containing neurons was seen in the SNc. Based on the direct correlation between postportem NmMRI and neuropathological findings, signal intensity in the SNc is closely related to the quantity of neuromelanin-containing neurons but is not influenced by iron deposition. (orig.)

  13. The life and achievements of Erwin-Félix Lewy-Bertaut (1913–2003)

    International Nuclear Information System (INIS)

    Férey, Gérard; Hodeau, Jean-Louis

    2015-01-01

    Erwin-Félix Lewy-Bertaut was initially a lawyer. He left Germany for France when the Nazis rose to power, having been born into a German Jewish family. He became a French citizen in 1936 and embarked upon a scientific career, first in organic chemistry in Bordeaux. The troubles associated with World War II obliged him to move to Grenoble under the protection of Louis Néel. In addition to his creative activity in the new field of inorganic solid state chemistry, he rapidly became a crystallographer and a physicist of magnetism, noted for his impressive activity in both of these domains. He became a pioneer of neutron diffraction and was pivotal to the creation of the Institut Laue-Langevin. Owing to the impact of his work, he was involved in the key international organizations responsible for shaping crystallography and physics. A member of the French Academy of Sciences, Monsieur Bertaut received many international awards. He was a very kind man of culture. (invited comment)

  14. Preclinical Polymodal Hallucinations for 13 Years before Dementia with Lewy Bodies

    Science.gov (United States)

    Abbate, Carlo; Trimarchi, Pietro Davide; Inglese, Silvia; Viti, Niccolò; Cantatore, Alessandra; De Agostini, Lisa; Pirri, Federico; Marino, Lorenza; Bagarolo, Renzo

    2014-01-01

    Objective. We describe a case of dementia with Lewy bodies (DLB) that presented long-lasting preclinical complex polymodal hallucinations. Background. Few studies have deeply investigated the characteristics of hallucinations in DLB, especially in the preclinical phase. Moreover, the clinical phenotype of mild cognitive impairment-(MCI-) DLB is poorly understood. Methods. The patient was followed for 4 years and a selective phenomenological and cognitive study was performed at the predementia stage. Results. The phenomenological study showed the presence of hypnagogic and hypnopompic hallucinations that allowed us to make a differential diagnosis between DLB and Charles Bonnet syndrome (CBS). The neuropsychological evaluation showed a multiple domain without amnesia MCI subtype with prefrontal dysexecutive, visuoperceptual, and visuospatial impairments and simultanagnosia, which has not previously been reported in MCI-DLB. Conclusions. This study extends the prognostic value of hallucinations for DLB to the preclinical phases. It supports and refines the MCI-DLB concept and identifies simultanagnosia as a possible early cognitive marker. Finally, it confirms an association between hallucinations and visuoperceptual impairments at an intermediate stage of the disease course and strongly supports the hypothesis that hallucinations in the earliest stages of DLB may reflect a narcolepsy-like REM-sleep disorder. PMID:24868122

  15. Distinct perfusion patterns in Alzheimer's disease, frontotemporal dementia and dementia with Lewy bodies

    International Nuclear Information System (INIS)

    Binnewijzend, Maja A.A.; Wattjes, Mike P.; Berckel, Bart N.M. van; Barkhof, Frederik; Kuijer, Joost P.A.; Flier, Wiesje M. van der; Benedictus, Marije R.; Moeller, Christiane M.; Pijnenburg, Yolande A.L.; Lemstra, Afina W.; Prins, Niels D.; Scheltens, Philip

    2014-01-01

    To compare pseudo-continuous arterial spin-labelled (PCASL) magnetic resonance imaging (MRI) measured quantitative cerebral blood flow (CBF) of patients with frontotemporal dementia (FTD), dementia with Lewy Bodies (DLB), Alzheimer's disease (AD) and controls, in a region of interest (ROI) and voxel-wise fashion. We analysed whole-brain 3D fast-spin-echo PCASL images of 20 FTD patients, 14 DLB patients, 48 AD patients and 50 controls from the Amsterdam Dementia Cohort. Regional CBF patterns were compared using analyses of variance for repeated measures. Permutation tests were used for voxel-wise comparisons. Analyses were performed using uncorrected and partial volume corrected (PVC) maps. All analyses were corrected for age and sex. There was an interaction between diagnosis and region (p < 0.001), implying differences in regional CBF changes between diagnostic groups. In AD patients, CBF was decreased in all supratentorial regions, most prominently so in the posterior regions. DLB patients showed lowest CBF values throughout the brain, but temporal CBF was preserved. Supratentorial PVC cortical CBF values were lowest in the frontal lobes in FTD patients, and in the temporal lobes in AD patients. Patients with AD, FTD and DLB display distinct patterns of quantitative regional CBF changes. 3D-PCASL may provide additional value in the workup of dementia patients. (orig.)

  16. Distinct perfusion patterns in Alzheimer's disease, frontotemporal dementia and dementia with Lewy bodies

    Energy Technology Data Exchange (ETDEWEB)

    Binnewijzend, Maja A.A.; Wattjes, Mike P.; Berckel, Bart N.M. van; Barkhof, Frederik [VU University Medical Center and Neuroscience Campus Amsterdam, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Kuijer, Joost P.A. [VU University Medical Center and Neuroscience Campus Amsterdam, Department of Physics and Medical Technology, Amsterdam (Netherlands); Flier, Wiesje M. van der [VU University Medical Center and Neuroscience Campus Amsterdam, Alzheimercenter and Department of Neurology, Amsterdam (Netherlands); VU University Medical Center and Neuroscience Campus Amsterdam, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands); Benedictus, Marije R.; Moeller, Christiane M.; Pijnenburg, Yolande A.L.; Lemstra, Afina W.; Prins, Niels D.; Scheltens, Philip [VU University Medical Center and Neuroscience Campus Amsterdam, Alzheimercenter and Department of Neurology, Amsterdam (Netherlands)

    2014-09-15

    To compare pseudo-continuous arterial spin-labelled (PCASL) magnetic resonance imaging (MRI) measured quantitative cerebral blood flow (CBF) of patients with frontotemporal dementia (FTD), dementia with Lewy Bodies (DLB), Alzheimer's disease (AD) and controls, in a region of interest (ROI) and voxel-wise fashion. We analysed whole-brain 3D fast-spin-echo PCASL images of 20 FTD patients, 14 DLB patients, 48 AD patients and 50 controls from the Amsterdam Dementia Cohort. Regional CBF patterns were compared using analyses of variance for repeated measures. Permutation tests were used for voxel-wise comparisons. Analyses were performed using uncorrected and partial volume corrected (PVC) maps. All analyses were corrected for age and sex. There was an interaction between diagnosis and region (p < 0.001), implying differences in regional CBF changes between diagnostic groups. In AD patients, CBF was decreased in all supratentorial regions, most prominently so in the posterior regions. DLB patients showed lowest CBF values throughout the brain, but temporal CBF was preserved. Supratentorial PVC cortical CBF values were lowest in the frontal lobes in FTD patients, and in the temporal lobes in AD patients. Patients with AD, FTD and DLB display distinct patterns of quantitative regional CBF changes. 3D-PCASL may provide additional value in the workup of dementia patients. (orig.)

  17. Comparison of FDG-PET and IMP-SPECT in patients with dementia with Lewy bodies

    International Nuclear Information System (INIS)

    Ishii, Kazunari; Hosaka, Kayo; Mori, Tetsuya; Mori, Etsuro

    2004-01-01

    To investigate regional differences in cerebral glucose metabolism and blood flow of dementia with Lewy bodies (DLB), we studied 7 subjects with DLB and 20 normal controls using F-18 fluorodeoxyglucose (FDG) and positron emission tomography (PET) and then examined the same 7 subjects and 20 other normal controls with I-123 iodoamphetamine (IMP) and single photon emission computed tomography (SPECT). The anatomically standardized images were produced with NEUROSTAT and the regional relative metabolic and perfusional values were calculated. The mean reduction ratios of FDG uptake in the DLB group relative to the mean normal controls in the parietal lobe and occipital lobe were 0.72 and 0.83, respectively, while the corresponding mean reduction ratios of IMP uptake were 0.81 and 0.88, respectively. In the DLB group, parietal FDG uptake was significantly lower than parietal IMP uptake (p<0.05), occipital FDG uptake was significantly lower than occipital IMP uptake (p<0.05), and parietal IMP uptake was significantly lower than occipital IMP uptake (p<0.01), but there was no difference between parietal and occipital FDG uptake. Our findings suggest that parietal metabolism and perfusion are severely affected in DLB patients, though the occipital metabolic and perfusional reduction is thought to be a feature of DLB. FDG-PET is thought to be superior to IMP-SPECT in detecting functional changes in the DLB brain. (author)

  18. Anion capture and sensing with cationic boranes: on the synergy of Coulombic effects and onium ion-centred Lewis acidity.

    Science.gov (United States)

    Zhao, Haiyan; Leamer, Lauren A; Gabbaï, François P

    2013-06-21

    Stimulated by the growing importance and recognized toxicity of anions such as fluoride, cyanide and azides, we have, in the past few years, developed a family of Lewis acidic triarylboranes that can be used for the complexation of these anions in organic and protic solvents, including water. A central aspect of our approach lies in the decoration of the boranes with peripheral ammonium, phosphonium, sulfonium stibonium or telluronium groups. The presence of these cationic groups provides a Coulombic drive for the capture of the anion, leading to boranes that can be used in aqueous solutions where anion hydration and/or protonation are usually competitive. The anion affinity of these boranes can be markedly enhanced by narrowing the separation between the anion binding site (i.e. the boron atom) and the onium ion. In such systems, the latent Lewis acidity of the onium ion also plays a role as manifested by the formation of B-X→E (E = P, S, Sb, or Te; X = F, CN or N3) chelate motifs that provide additional stability to the resulting complexes. These effects, which are maximum in stibonium and telluronium boranes, show that the Lewis acidity of heavy onium ions can be exploited for anion coordination and capture. The significance of these advances is illustrated by the development of applications in anion sensing, fluorination chemistry and (18)F radiolabeling for positron emission tomography.

  19. Controlled and Efficient Polymerization of Conjugated Polar Alkenes by Lewis Pairs Based on Sterically Hindered Aryloxide-Substituted Alkylaluminum

    Directory of Open Access Journals (Sweden)

    Xiaojun Wang

    2018-02-01

    Full Text Available Reported herein is the development of an effective strategy for controlled and efficient Lewis pair polymerization of conjugated polar alkenes, including methyl methacrylate (MMA, n-butyl methacrylate (nBuMA, and γ-methyl-α-methylene-γ-butyrolactone (γMMBL, by the utilization of sterically encumbered Al(BHT2Me (BHT: 2,6-di-tert-butyl-4-methylphenol as a Lewis acid that shuts down intramolecular backbiting termination. In combination with a selected N-heterocyclic carbene (NHC as a Lewis base, the polymerization of MMA exhibited activity up to 3000 h−1 TOF and an acceptable initiation efficiency of 60.6%, producing polymers with high molecular weight (Mn up to 130 kg/mol and extremely narrow dispersity (Đ = 1.06~1.13. This controlled polymerization with a living characteristic has been evidenced by chain-extension experiments and chain-end analysis, and enabled the synthesis of well-defined diblock copolymers.

  20. Construction of recombinant plasmid pIRESEgr-IFN γ and its expression in Lewis lung carcinoma induced by irradiation

    International Nuclear Information System (INIS)

    Yang Wei; Li Xiuyi; Gong Shouliang; Sun Ting; Gong Pingsheng

    2007-01-01

    Objective: To construct the recombinant plasmid pIRESEgr-IFN γ and detect its expression in Lewis lung carcinoma induced by irradiation in vitro. Methods: The recombinant plasmid pIRESEgr-IFN γ containing Egr-1 promoter and IFN γ gene was constructed with gene recombinant technique. The plasmid was transferred into Lewis lung carcinoma by liposome in vitro. The correlations of dose- and time-effects in the expression of IFN γ gene induced by X-ray were detected by ELISA. Results: The identification with enzymes proved that Egr-1 promoter and IFN γ gene were inserted into vector pIRESlneo correctly. After X-ray irradiation with different doses, the expression of IFN γ in the supernatant of Lewis lung carcinoma transfected by pIRESEgr-IFN γ was significantly higher than that in 0 Gy group (P<0.001). After 5 Gy X-ray irradiation, the expression of IFN γ was the highest, being 4.39 times as much as that in 0 Gy group. The expression of IFN γ in the supernatant increased after 5 Gy X-ray irradiation, being 6.27 times as much as that in 0 h group 36 h after irradiation. Conclusion: The recombinant plasmid pIRESEgr-IFN γ is constructed successfully, and it has the property of enhancing the expression of IFN γ gene induced by irradiation. (authors)