Increasing the High Voltage Capabilities and Exploring Parameter Space of an Inertial Electrostatic Confinement Fusion Neutron Source for the Detection of Chemical Explosives

NASA Astrophysics Data System (ADS)

Michalak, Matthew K.

The objectives of the work presented here include understanding key operating principles and providing precise data sets that can be used to test inertial electrostatic confinement (IEC) fusion theory and optimize IEC device operation. The underlying physical behavior was separated from superficial trends observed in an IEC device at the University of Wisconsin-Madison (UW). The effects of changing voltage (30-170 kV) and current (30-100 mA) were thoroughly explored, pressure effects (0.15-1.25 mTorr) were mapped, and the effect of impurities in the system was quantified. The most challenging part of this work was designing a high voltage feedthrough that could reliably operate at higher voltages for far longer times than previously attained. A system to detect conventional explosives using fusion neutrons was also designed, constructed, and tested. Precise data sets were created by taking into account and minimizing the effects of short and long term trends in the experiment. Detailed meter current scans were taken that showed a linear relationship of the neutron production rate with current. Cathode voltage scans were slightly greater than linear in the neutron rate from 30 to 170 kV, but the rate increase diminished to near linear as 170 kV was approached. A new high voltage feedthrough was designed that surpassed the performance of past UW IEC lab feedthroughs and shows promise for long duration operation at still higher voltages. Limitations of other equipment in the IEC lab prevented testing the feedthrough to voltages above 175 kV. A more robust construction of the feedthrough and reducing the consequences of a feedthrough failure were also important design criteria that were met. A detector array was made to detect explosives via the 10.8 MeV neutron capture prompt gamma from nitrogen. Signals from four separate detectors were combined to make the individual detectors act similar to one large detector. The detector signals were both summed and combined to compare the performance of the two methods. An overwhelming background radiation signal and insufficient time resolution were two factors that led to the combined signal not performing as well as the summed signal.

Simulation of proton-boron nuclear burning in the potential well of virtual cathode at nanosecond vacuum discharge

NASA Astrophysics Data System (ADS)

Kurilenkov, Yu K.; Tarakanov, V. P.; Gus'kov, S. Yu

2016-11-01

The neutron-free reaction of proton-boron nuclear burning accompanied with the yield of three alpha particles (p + 11B → α + 8Be* → 3α) is of great fundamental and applied interest. However, the implementation of the synthesis of p +11B requires such extreme plasma parameters that are difficult to achieve at well-known schemes of controlled thermonuclear fusion. Earlier, the yield of DD neutrons in a compact nanosecond vacuum discharge (NVD) of low energy with deuterated Pd anode have been observed. Further detailed particle-in-cell simulation by the electrodynamic code have recognized that this experiment represents the realization of rather old scheme of inertial electrostatic confinement (IEC). This IEC scheme is one of the few where the energies of ions needed for p + 11B reaction are quite possible. The purpose of this work on simulation of proton-boron reaction is studying the features of possible p + 11B burning at the IEC scheme based on NVD, thus, to look forward and planning the real experiment.

The fusion of advanced fuels to produce medical isotopes using inertial electrostatic confinement

NASA Astrophysics Data System (ADS)

Cipiti, Benjamin B.

Experiments are described that used an Inertial Electrostatic Confinement (IEC) fusion device to create radioisotopes for medical diagnostics. The IEC concept utilizes spherically concentric electrodes to accelerate fusion ions to high energies, allowing the use of the D-D and advanced D-3He fusion reactions. The D-3He reaction produces a high-energy 14.7 MeV proton, and this proton is energetic enough to be used to create radioisotopes. This dissertation focuses first on where specifically the fusion reactions are occurring in the IEC device. It was found that at 2 mtorr operating pressures, 70% of the D-D reactions occur throughout the entire volume of the vacuum chamber. About 22% of the reactions occur in a small core in the center of the device, and the other 8% are due to embedded D-D reactions in the cathode of the device. On the other hand, for D-3He, 95% of the reactions are due to embedded reactions, and the other 5% come from a small core in the center of the device. Beam-target D-3He fusion was used to create medical isotopes in two different systems. The designs focused on creating short-lived species capable of use in Positron Emission Tomography. The first isotope created was 94mTc, a positron emitter with a 52-minute half-life. Approximately 1.5 nCi of 94mTc were created using the 94Mo(p,n) 94mTc reaction. The second isotope created was 13N, a positron emitter with a ten-minute half-life. Approximately 1.0 nCi of 13N was created using the 16O(p,alpha)13N reaction. The final part of the research investigated the effects of deuterium and helium implantation in the tungsten-rhenium cathode of the IEC device. The effect of the implantation on the surface morphology of pure tungsten was also determined using scanning electron microscopy. Deuterium did not appear to affect the surface of tungsten after high temperature (>800 C) implantation. Helium created a porous surface structure at the same temperatures starting at about 4 x 1016 ions/cm2. The pores increased in size and decreased in density with increasing temperature and fluence.

IEC-Based Neutron Generator for Security Inspection System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Linchun; Miley, George H.

2002-07-01

Large nuclear reactors are widely employed for electricity power generation, but small nuclear radiation sources can also be used for a variety of industrial/government applications. In this paper we will discuss the use of a small neutron source based on Inertial Electrostatic Confinement (IEC) of accelerated deuterium ions. There is an urgent need of highly effective detection systems for explosives, especially in airports. While current airport inspection systems are strongly based on X-ray technique, neutron activation including Thermal Neutron Analysis (TNA) and Fast Neutron Analysis (FNA) is powerful in detecting certain types of explosives in luggage and in cargoes. Basicmore » elements present in the explosives can be measured through the (n, n'?) reaction initiated by fast neutrons. Combined with a time-of-flight technique, a complete imaging of key elements, hence of the explosive materials, is obtained. Among the various neutron source generators, the IEC is an ideal candidate to meet the neutron activation analysis requirements. Compared with other accelerators and radioisotopes such as {sup 252}Cf, the IEC is simpler, can be switched on or off, and can reliably produce neutrons with minimum maintenance. Theoretical and experimental studies of a spherical IEC have been conducted at the University of Illinois. In a spherical IEC device, 2.54-MeV neutrons of {approx}10{sup 8} n/s via DD reactions over recent years or 14-MeV neutrons of {approx}2x10{sup 10} n/s via DT reactions can be obtained using an ion gun injection technique. The possibility of the cylindrical IEC in pulsed operation mode combining with pulsed FNA method would also be discussed. In this paper we examine the possibility of using an alternative cylindrical IEC configuration. Such a device was studied earlier at the University of Illinois and it provides a very convenient geometry for security inspection. However, to calculate the neutron yield precisely with this configuration, an understanding of the potential wall trapping and acceleration of ions is needed. The theory engaged is an extension of original analytic study by R.L. Hirsh on the potential well structure in a spherical IEC device, i.e. roughly a 'line' source of neutrons from a cylindrical IEC is a 'point' source from the spherical geometry. Thus our present study focuses on the cylindrical IEC for its convenient application in an FNA detecting system. The conceptual design and physics of ion trapping and re-circulation in a cylindrical IEC intended for neutron-based inspection system will be presented. (authors)« less

NRF Based Nondestructive Inspection System for SNM by Using Laser-Compton-Backscattering Gamma-Rays

NASA Astrophysics Data System (ADS)

Ohgaki, H.; Omer, M.; Negm, H.; Daito, I.; Zen, H.; Kii, T.; Masuda, K.; Hori, T.; Hajima, R.; Hayakawa, T.; Shizuma, T.; Kando, M.

2015-10-01

A non-destructive inspection system for special nuclear materials (SNMs) hidden in a sea cargo has been developed. The system consists of a fast screening system using neutron generated by inertial electrostatic confinement (IEC) device and an isotope identification system using nuclear resonance fluorescence (NRF) measurements with laser Compton backscattering (LCS) gamma-rays has been developed. The neutron flux of 108 n/sec has been achieved by the IEC in static mode. We have developed a modified neutron reactor noise analysis method to detect fission neutron in a short time. The LCS gamma-rays has been generated by using a small racetrack microtoron accelerator and an intense sub-nano second laser colliding head-on to the electron beam. The gamma-ray flux has been achieved more than 105 photons/s. The NRF gamma-rays will be measured using LaBr3(Ce) scintillation detector array whose performance has been measured by NRF experiment of U-235 in HIGS facility. The whole inspection system has been designed to satisfy a demand from the sea port.

Electron Density and Two-Channel Neutron Emission Measurements in Steady-State Spherical Inertial-Electrostatically Confined Plasmas, with Review of the 1-D Kinetic Model

NASA Technical Reports Server (NTRS)

Dobson, Chris C.; Hrbud, Ivana

2004-01-01

Electron density measurements have been made in steady-state plasmas in a spherical inertial electrostatic confinement (IEC) discharge using microwave interferometry. Plasma cores interior to two cathodes, having diameters of 15 and 23 cm, respectively, were probed over a transverse range of 10 cm with a spatial resolution of about 1.4 cm for buffer gas pressures from 0.2 to 6 Pa in argon and deuterium. The transverse profiles are generally flat, in some cases with eccentric symmetric minima, and give mean densities of from approx. = 0.4 to 7x 10(exp 10)/cu cm, the density generally increasing with the neutral gas pressure. Numerical solutions of the 1-D Poisson equation for EC plasmas are reviewed and energy distribution functions are identified which give flat transverse profiles. These functions are used with the plasma approximation to obtain solutions which also give densities consistent with the measurements, and a double potential well solution is obtained which has minima qualitatively similar to those observed. Explicit consideration is given to the compatibility of the solutions interior and exterior to the cathode, and to grid transparency. Deuterium fusion neutron emission rates were also measured and found to be isotropic, to within the measurement error, over two simultaneous directions. Anisotropy was observed in residual emissions during operation with non-fusing hydrogen-1. The deuterium rates are consistent with predictions from the model.

The Use of an Electron Microchannel as a Self-Extracting and Focusing Plasma Cathode Electron Gun

NASA Astrophysics Data System (ADS)

Cornish, S.; Khachan, J.

2016-02-01

A new and simple type of electron gun is presented. Unlike conventional electron guns, which require a heated filament or extractor, accelerator and focusing electrodes, this gun uses the collimated electron microchannels of an inertial electrostatic confinement (IEC) discharge to achieve the same outcome. A cylindrical cathode is placed coaxially within a cylindrical anode to create the discharge. Collimated beams of electrons and fast neutrals emerge along the axis of the cylindrical cathode. This geometry isolates one of the microchannels that emerge in a negatively biased IEC grid. The internal operating pressure range of the gun is 35-190 mTorr. A small aperture separates the gun from the main vacuum chamber in order to achieve a pressure differential. The chamber was operated at pressures of 4-12 mTorr. The measured current produced by the gun was 0.1-3 mA (0.2-14 mA corrected measurement) for discharge currents of 1-45 mA and discharge voltages of 0.5-12 kV. The collimated electron beam emerges from the aperture into the vacuum chamber. The performance of the gun is unaffected by the pressure differential between the vacuum chamber and the gun. This allows the aperture to be removed and the chamber pressure to be equal to the gun pressure if required.

Giant magnetoresistance in perpendicularly magnetized synthetic antiferromagnetic coupling with Ir spacer

NASA Astrophysics Data System (ADS)

Fukushima, A.; Taniguchi, T.; Sugihara, A.; Yakushiji, K.; Kubota, H.; Yuasa, S.

2018-05-01

Perpendicularly magnetized magnetic tunnel junction (p-MTJ) is a key element for developing high-density spin-transfer torque switching magnetoresistive random access memory. Recently, a large exchange coupling (IEC) in the synthetic antiferromagnetic reference layer with Ir interlayer was observed in p-MTJs. The evaluation of the IEC is, however, difficult due to the electrostatic breakdown of MTJs. This study demonstrates the evaluation of the IEC with Ir interlayer in giant magnetoresistive (GMR) nanopillar. We fabricated three kinds of perpendicularly magnetized GMR elements; bottom-free structures with Cu or Ir spacer, and top-free structure with Ir spacer. The magnetoresistance (RH) loops of all samples show sharp changes of the magnetoresistance at the magnetic fields over ±10 kOe, indicating the existence of the large IECs. In particular, a sharp change of the magnetoresistance at the field over ±20 kOe was found for the element with Cu of 2 nm thickness.

Nuclear fusion of advanced fuels using converging focused ion beams

NASA Astrophysics Data System (ADS)

Egle, Brian James

The Six Ion Gun Fusion Experiment (SIGFE) was designed and built to investigate a possible avenue to increase the reaction rate efficiency of the D-D and D-3He nuclear fusion reactions in Inertial Electrostatic Confinement (IEC) devices to the levels required for several non-electric applications of nuclear fusion. The SIGFE is based on the seminal IEC experiment published by Hirsch in 1967, and is the first experiment to recreate the results and unique features of the Hirsch device. The SIGFE used six identical ion beams to focus and converge deuterium and helium-3 ions into a sphere of less than 2 mm at nearly mono-energetic ion energies up to 150 keV. With improved ion optics and diagnostics, the SIGFE concluded that within the investigated parameter space, the region where the ion beams converged accounted for less than 0.2% of the total D-D fusion reactions. The maximum D-D fusion rates were observed when the ion beams were intentionally defocused to strike the inside surface of the cathode lenses. In this defocused state, the total D-D fusion rate increased when the chamber pressure was decreased. The maximum D-D fusion rate was 4.3 x 107 neutrons per second at a cathode voltage of -130 kV, a total cathode current of 10 mA, and a chamber pressure of 27 mPa. The D and 3He ion beams were produced in six self-contained ion gun modules. The modules were each capable of at least 4 mA of ion current while maintaining a main chamber pressure as low as 13 mPa. The theoretically calculated extractable ion current agreed with the experiment within a factor of 2. A concept was also developed and evaluated for the production of radioisotopes from the 14.7 MeV D-3He fusion protons produced in an IEC device. Monte Carlo simulations of this concept determined that a D-3He fusion rate on the order of 1011 s-1 would be required for an IEC device to produce 1 mCi of the 11C radioisotope.

Embedding beyond electrostatics-The role of wave function confinement.

PubMed

Nåbo, Lina J; Olsen, Jógvan Magnus Haugaard; Holmgaard List, Nanna; Solanko, Lukasz M; Wüstner, Daniel; Kongsted, Jacob

2016-09-14

We study excited states of cholesterol in solution and show that, in this specific case, solute wave-function confinement is the main effect of the solvent. This is rationalized on the basis of the polarizable density embedding scheme, which in addition to polarizable embedding includes non-electrostatic repulsion that effectively confines the solute wave function to its cavity. We illustrate how the inclusion of non-electrostatic repulsion results in a successful identification of the intense π → π(∗) transition, which was not possible using an embedding method that only includes electrostatics. This underlines the importance of non-electrostatic repulsion in quantum-mechanical embedding-based methods.

Modeling of protein-anion exchange resin interaction for the human growth hormone charge variants.

PubMed

Lapelosa, Mauro; Patapoff, Thomas W; Zarraga, Isidro E

2015-12-01

Modeling ion exchange chromatography (IEC) behavior has generated significant interest because of the wide use of IEC as an analytical technique as well as a preparative protein purification process; indeed there is a need for better understanding of what drives the unique behavior of protein charge variants. We hypothesize that a complex protein molecule, which contains both hydrophobic and charged moieties, would interact strongly with an in silico designed resin through charged electrostatic patches on the surface of the protein. In the present work, variants of recombinant human growth hormone that mimic naturally-occurring deamidation products were produced and characterized in silico. The study included these four variants: rhGH, N149D, N152D, and N149D/N152D. Poisson-Boltzmann calculations were used to determine surface electrostatic potential. Metropolis Monte Carlo simulations were carried out with the resulting variants to simulate IEC systems, examining the free energy of the interaction of the protein with an in silico anion exchange column represented by polylysine polypeptide. The results show that the charge variants have different average binding energies and the free energy of interaction can be used to predict the retention time for the different variants. Copyright © 2015 Elsevier B.V. All rights reserved.

Alternative approaches to plasma confinement

NASA Technical Reports Server (NTRS)

Roth, J. R.

1978-01-01

The paper discusses 20 plasma confinement schemes each representing an alternative to the tokamak fusion reactor. Attention is given to: (1) tokamak-like devices (TORMAC, Topolotron, and the Extrap concept), (2) stellarator-like devices (Torsatron and twisted-coil stellarators), (3) mirror machines (Astron and reversed-field devices, the 2XII B experiment, laser-heated solenoids, the LITE experiment, the Kaktus-Surmac concept), (4) bumpy tori (hot electron bumpy torus, toroidal minimum-B configurations), (5) electrostatically assisted confinement (electrostatically stuffed cusps and mirrors, electrostatically assisted toroidal confinement), (6) the Migma concept, and (7) wall-confined plasmas. The plasma parameters of the devices are presented and the advantages and disadvantages of each are listed.

Magnetic and electrostatic confinement of plasma with tuning of electrostatic field

DOEpatents

Rostoker, Norman [Irvine, CA; Binderbauer, Michl [Irvine, CA; Qerushi, Artan [Irvine, CA; Tahsiri, Hooshang [Irvine, CA

2008-10-21

A system and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Magnetic and electrostatic confinement of plasma with tuning of electrostatic field

DOEpatents

Rostoker, Norman; Binderbauer, Michl; Qerushi, Artan; Tahsiri, Hooshang

2006-10-10

A system and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Magnetic and electrostatic confinement of plasma with tuning of electrostatic field

DOEpatents

Rostoker, Norman; Binderbauer, Michl; Qerushi, Artan; Tahsiri, Hooshang

2006-03-21

A system and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Electrostatically confined nanoparticle interactions and dynamics.

PubMed

Eichmann, Shannon L; Anekal, Samartha G; Bevan, Michael A

2008-02-05

We report integrated evanescent wave and video microscopy measurements of three-dimensional trajectories of 50, 100, and 250 nm gold nanoparticles electrostatically confined between parallel planar glass surfaces separated by 350 and 600 nm silica colloid spacers. Equilibrium analyses of single and ensemble particle height distributions normal to the confining walls produce net electrostatic potentials in excellent agreement with theoretical predictions. Dynamic analyses indicate lateral particle diffusion coefficients approximately 30-50% smaller than expected from predictions including the effects of the equilibrium particle distribution within the gap and multibody hydrodynamic interactions with the confining walls. Consistent analyses of equilibrium and dynamic information in each measurement do not indicate any roles for particle heating or hydrodynamic slip at the particle or wall surfaces, which would both increase diffusivities. Instead, lower than expected diffusivities are speculated to arise from electroviscous effects enhanced by the relative extent (kappaa approximately 1-3) and overlap (kappah approximately 2-4) of electrostatic double layers on the particle and wall surfaces. These results demonstrate direct, quantitative measurements and a consistent interpretation of metal nanoparticle electrostatic interactions and dynamics in a confined geometry, which provides a basis for future similar measurements involving other colloidal forces and specific biomolecular interactions.

Graphene quantum blisters: A tunable system to confine charge carriers

NASA Astrophysics Data System (ADS)

Abdullah, H. M.; Van der Donck, M.; Bahlouli, H.; Peeters, F. M.; Van Duppen, B.

2018-05-01

Due to Klein tunneling, electrostatic confinement of electrons in graphene is not possible. This hinders the use of graphene for quantum dot applications. Only through quasi-bound states with finite lifetime has one achieved to confine charge carriers. Here, we propose that bilayer graphene with a local region of decoupled graphene layers is able to generate bound states under the application of an electrostatic gate. The discrete energy levels in such a quantum blister correspond to localized electron and hole states in the top and bottom layers. We find that this layer localization and the energy spectrum itself are tunable by a global electrostatic gate and that the latter also coincides with the electronic modes in a graphene disk. Curiously, states with energy close to the continuum exist primarily in the classically forbidden region outside the domain defining the blister. The results are robust against variations in size and shape of the blister which shows that it is a versatile system to achieve tunable electrostatic confinement in graphene.

Apparatus for magnetic and electrostatic confinement of plasma

DOEpatents

Rostoker, Norman; Binderbauer, Michl

2013-06-11

An apparatus and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions ions are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Apparatus for magnetic and electrostatic confinement of plasma

DOEpatents

Rostoker, Norman; Binderbauer, Michl

2016-07-05

An apparatus and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions ions are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Apparatus for magnetic and electrostatic confinement of plasma

DOEpatents

Rostoker, Norman; Binderbauer, Michl

2006-10-31

An apparatus and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Apparatus for magnetic and electrostatic confinement of plasma

DOEpatents

Rostoker, Norman; Binderbauer, Michl

2006-04-11

An apparatus and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Apparatus for magnetic and electrostatic confinement of plasma

DOEpatents

Rostoker, Norman [Irvine, CA; Binderbauer, Michl [Irvine, CA

2009-08-04

An apparatus and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions ions are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Anomalous Ground State of the Electrons in Nano-confined Water

DTIC Science & Technology

2016-06-13

confined water system, Nafion, is so different from that of bulk water that the weakly electrostatically interacting molecule model of water is clearly...assume that water is made up molecules weakly interacting(on the scale of the zero point bond energy~.2eV) electrostatically with its neighbors2-3. In an...not possible for a collection of molecules interacting weakly electrostatically . These changes in the spatial distribution of valence electrons in

Perspectives on Lunar Helium-3

NASA Astrophysics Data System (ADS)

Schmitt, Harrison H.

1999-01-01

Global demand for energy will likely increase by a factor of six or eight by the mid-point of the 21st Century due to a combination of population increase, new energy intensive technologies, and aspirations for improved standards of living in the less-developed world (1). Lunar helium-3 (3He), with a resource base in the Tranquillitatis titanium-rich lunar maria (2,3) of at least 10,000 tonnes (4), represents one potential energy source to meet this rapidly escalating demand. The energy equivalent value of 3He delivered to operating fusion power plants on Earth would be about 3 billion per tonne relative to today's coal which supplies most of the approximately 90 billion domestic electrical power market (5). These numbers illustrate the magnitude of the business opportunity. The results from the Lunar Prospector neutron spectrometer (6) suggests that 3He also may be concentrated at the lunar poles along with solar wind hydrogen (7). Mining, extraction, processing, and transportation of helium to Earth requires new innovations in engineering but no known new engineering concepts (1). By-products of lunar 3He extraction, largely hydrogen, oxygen, and water, have large potential markets in space and ultimately will add to the economic attractiveness of this business opportunity (5). Inertial electrostatic confinement (IEC) fusion technology appears to be the most attractive and least capital intensive approach to terrestrial fusion power plants (8). Heavy lift launch costs comprise the largest cost uncertainty facing initial business planning, however, many factors, particularly long term production contracts, promise to lower these costs into the range of 1-2000 per kilogram versus about 70,000 per kilogram fully burdened for the Apollo Saturn V rocket (1). A private enterprise approach to developing lunar 3He and terrestrial IEC fusion power would be the most expeditious means of realizing this unique opportunity (9). In spite of the large, long-term potential return on investment, access to capital markets for a lunar 3He and terrestrial fusion power business will require a near-term return on investment, based on early applications of IEC fusion technology (10).

Formation of a field reversed configuration for magnetic and electrostatic confinement of plasma

DOEpatents

Rostoker, Norman; Binderbauer, Michl

2003-12-16

A system and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Formation of a field reversed configuration for magnetic and electrostatic confinement of plasma

DOEpatents

Rostoker, Norman; Binderbauer, Michl; Qerushi, Artan; Tahsiri, Hooshang

2007-02-20

A system and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Formation of a field reversed configuration for magnetic and electrostatic confinement of plasma

DOEpatents

Rostoker, Norman; Binderbauer, Michl; Qerushi, Artan; Tahsiri, Hooshang

2006-02-07

A system and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

Electrostatically confined quantum rings in bilayer graphene.

PubMed

Zarenia, M; Pereira, J M; Peeters, F M; Farias, G A

2009-12-01

We propose a new system where electron and hole states are electrostatically confined into a quantum ring in bilayer graphene. These structures can be created by tuning the gap of the graphene bilayer using nanostructured gates or by position-dependent doping. The energy levels have a magnetic field (B(0)) dependence that is strikingly distinct from that of usual semiconductor quantum rings. In particular, the eigenvalues are not invariant under a B(0) --> -B(0) transformation and, for a fixed total angular momentum index m, their field dependence is not parabolic, but displays two minima separated by a saddle point. The spectra also display several anticrossings, which arise due to the overlap of gate-confined and magnetically confined states.

Footwear and flooring: charge generation in combination with a person as influenced by environmental moisture

NASA Astrophysics Data System (ADS)

Swenson, D. E.

2015-10-01

It is well known that a person walking on a floor will liberate electrostatic charge. The amount of charge that can be accumulated on a person by walking is dependent on many factors that are also well understood. Among these factors is the electrical resistance between a person and ground. The electrical resistance of footwear, other clothing, a person's skin resistance and the contact resistance between footwear and the floor impact the total resistance of the system. As important as measuring resistance may be as an evaluation method, it does not take into account triboelectric generation of charge. The recent revisions of ANSI/ESD S20.20[1] from the ESD Association and IEC61340-5-1[2] from IEC TC101 - Electrostatics, both include a dynamic walking test since experience in recent years has shown that resistance alone does not predict how a footwear and flooring system will actually perform. The USA group ASHRAE1, commissioned a study to evaluate electrostatic charge generation inside data centres as influenced by environmental moisture (relative and absolute humidity)[3][4]. The reason for this study is that past data centre operating guidelines have called for a very narrow range of temperature and humidity control, largely because of the anecdotal evidence that moderate to high RH impacts static electricity generation and accumulation. This results in a massive consumption of electricity to maintain a narrow window of temperature and environmental moisture. Broadening or eliminating humidity controls could result in a major saving of electricity and money.

Unfolding of a model protein on ion exchange and mixed mode chromatography surfaces.

PubMed

Gospodarek, Adrian M; Hiser, Diana E; O'Connell, John P; Fernandez, Erik J

2014-08-15

Recent studies with proteins indicate that conformational changes and aggregation can occur during ion exchange chromatography (IEC). Such behavior is not usually expected, but could lead to decreased yield and product degradation from both IEC and multi mode chromatography (MMC) that has ligands of both hydrophobic and charged functionalities. In this study, we used hydrogen exchange mass spectrometry to investigate unfolding of the model protein BSA on IEC and MMC surfaces under different solution conditions at 25°C. Increased solvent exposure, indicating greater unfolding relative to that in solution, was found for protein adsorbed on cationic IEC and MMC surfaces in the pH range of 3.0 to 4.5, where BSA has decreased stability in solution. There was no effect of anionic surfaces at pH values in the range from 6.0 to 9.0. Differences of solvent exposure of whole molecules when adsorbed and in solution suggest that adsorbed BSA unfolds at lower pH values and may show aggregation, depending upon pH and the surface type. Measurements on digested peptides showed that classifications of stability can be made for various regions; these are generally retained as pH is changed. When salt was added to MMC systems, where electrostatic interactions would be minimized, less solvent exposure was seen, implying that it is the cationic moieties, rather than the hydrophobic ligands, which cause greater surface unfolding at low salt concentrations. These results suggest that proteins of lower stability may exhibit unfolding and aggregation during IEC and MMC separations, as they can with hydrophobic interaction chromatography. Copyright © 2014 Elsevier B.V. All rights reserved.

An electrostatically and a magnetically confined electron gun lens system

NASA Technical Reports Server (NTRS)

Bernius, Mark T.; Man, Kin F.; Chutjian, Ara

1988-01-01

Focal properties, electron trajectory calculations, and geometries are given for two electron 'gun' lens systems that have a variety of applications in, for example, electron-neutral and electron-ion scattering experiments. One nine-lens system utilizes only electrostatic confinement and is capable of focusing electrons onto a fixed target with extremely small divergence angles, over a range of final energies 1-790 eV. The second gun lens system is a simpler three-lens system suitable for use in a uniform, solenoidal magnetic field. While the focusing properties of such a magnetically confined lens systenm are simpler to deal with, the system does illustrate features of electron extraction and Brillouin flow that have not been suitably emphasized in the literature.

Structure of flexible and semiflexible polyelectrolyte chains in confined spaces of slit micro/nanochannels.

PubMed

Jeon, Jonggu; Chun, Myung-Suk

2007-04-21

Understanding the behavior of a polyelectrolyte in confined spaces has direct relevance in design and manipulation of microfluidic devices, as well as transport in living organisms. In this paper, a coarse-grained model of anionic semiflexible polyelectrolyte is applied, and its structure and dynamics are fully examined with Brownian dynamics (BD) simulations both in bulk solution and under confinement between two negatively charged parallel plates. The modeling is based on the nonlinear bead-spring discretization of a continuous chain with additional long-range electrostatic, Lennard-Jones, and hydrodynamic interactions between pairs of beads. The authors also consider the steric and electrostatic interactions between the bead and the confining wall. Relevant model parameters are determined from experimental rheology data on the anionic polysaccharide xanthan reported previously. For comparison, both flexible and semiflexible models are developed accompanying zero and finite intrinsic persistence lengths, respectively. The conformational changes of the polyelectrolyte chain induced by confinements and their dependence on the screening effect of the electrolyte solution are faithfully characterized with BD simulations. Depending on the intrinsic rigidity and the medium ionic strength, the polyelectrolyte can be classified as flexible, semiflexible, or rigid. Confined flexible and semiflexible chains exhibit a nonmonotonic variation in size, as measured by the radius of gyration and end-to-end distance, with changing slit width. For the semiflexible chain, this is coupled to the variations in long-range bond vector correlation. The rigid chain, realized at low ionic strength, does not have minima in size but exhibits a sigmoidal transition. The size of confined semiflexible and rigid polyelectrolytes can be well described by the wormlike chain model once the electrostatic effects are taken into account by the persistence length measured at long length scale.

Simulation study of charged nanoparticles confined in a rectangular tube with discrete wall charges.

PubMed

Yuet, Pak K

2006-03-28

The development of novel nanomaterials has been a subject of intense interest in recent years. An interesting structure among these materials is the so-called "pea pods" (i.e., nanoparticles confined in nanotubes). To facilitate the development and commercialization of these materials, it is important that we have an in-depth understanding of their behavior. The study of confined charged particles is particularly challenging because of the long-ranged nature of electrostatic interaction, and both interparticle and particle-confinement interactions are likely to play a role in determining the system behavior. The primary objective of this study is to develop a better understanding of the behavior of charged nanoparticles in a charged tubular confinement using Monte Carlo simulation, with particular focus on the effect of electrostatic interactions on the structure of the particles. Simulation results have shown that (i) the structuring of confined particles is associated with the asymmetry of the long-ranged interaction and (ii) factors such as confinement geometry and particle charge and size asymmetry can be manipulated to produce different particle structures. The present study represents the first step in an attempt to gain further insight into the behavior of confined nanosystems, with the ultimate objective of exploiting these characteristics, particularly the interactions between the confined particles and their external environment, in developing novel nanomaterials.

Active Neutron-Based Interrogation System with D-D Neutron Source for Detection of Special Nuclear Materials

NASA Astrophysics Data System (ADS)

Takahashi, Y.; Misawa, T.; Yagi, T.; Pyeon, C. H.; Kimura, M.; Masuda, K.; Ohgaki, H.

2015-10-01

The detection of special nuclear materials (SNM) is an important issue for nuclear security. The interrogation systems used in a sea port and an airport are developed in the world. The active neutron-based interrogation system is the one of the candidates. We are developing the active neutron-based interrogation system with a D-D fusion neutron source for the nuclear security application. The D-D neutron source is a compact discharge-type fusion neutron source called IEC (Inertial-Electrostatic Confinement fusion) device which provides 2.45 MeV neutrons. The nuclear materials emit the highenergy neutrons by fission reaction. High-energy neutrons with energies over 2.45 MeV amount to 30% of all the fission neutrons. By using the D-D neutron source, the detection of SNMs is considered to be possible with the attention of fast neutrons if there is over 2.45 MeV. Ideally, neutrons at En>2.45 MeV do not exist if there is no nuclear materials. The detection of fission neutrons over 2.45 MeV are hopeful prospect for the detection of SNM with a high S/N ratio. In the future, the experiments combined with nuclear materials and a D-D neutron source will be conducted. Furthermore, the interrogation system will be numerically investigated by using nuclear materials, a D-D neutron source, and a steel container.

Alternative approaches to plasma confinement

NASA Technical Reports Server (NTRS)

Roth, J. R.

1977-01-01

The potential applications of fusion reactors, the desirable properties of reactors intended for various applications, and the limitations of the Tokamak concept are discussed. The principles and characteristics of 20 distinct alternative confinement concepts are described, each of which may be an alternative to the Tokamak. The devices are classed as Tokamak-like, stellarator-like, mirror machines, bumpy tori, electrostatically assisted, migma concept, and wall-confined plasma.

"EGM" (Electrostatics of Granular Matter): A Space Station Experiment to Examine Natural Particulate Systems

NASA Astrophysics Data System (ADS)

Marshall, J.; Sauke, T.; Buehler, M.; Farrell, W.; Green, R.; Birchenough, A.

1999-09-01

A granular-materials experiment is being developed for a 2002 launch for Space Station deployment. The experiment is funded by NASA HQ and managed through NASA Lewis Research Center. The experiment will examine electrostatic aggregation of coarse granular materials with the goals of (a) obtaining proof for an electrostatic dipole model of grain interactions, and (b) obtaining knowledge about the way aggregation affects the behavior of natural particulate masses: (1) in unconfined dispersions (clouds such as nebulae, aeolian dust palls, volcanic plumes), (2) in semi-confined, self-loaded masses as in fluidized flows (pyroclastic surges, avalanches) and compacted regolith, or (3) in semi-confined non-loaded masses as in dust layers adhering to solar cells or space suits on Mars. The experiment addresses both planetary/astrophysical issues as well as practical concerns for human exploration of Mars or other solar system bodies. Additional information is contained in the original.

Observation of Oscillatory Radial Electric Field Relaxation in a Helical Plasma.

PubMed

Alonso, J A; Sánchez, E; Calvo, I; Velasco, J L; McCarthy, K J; Chmyga, A; Eliseev, L G; Estrada, T; Kleiber, R; Krupnik, L I; Melnikov, A V; Monreal, P; Parra, F I; Perfilov, S; Zhezhera, A I

2017-05-05

Measurements of the relaxation of a zonal electrostatic potential perturbation in a nonaxisymmetric magnetically confined plasma are presented. A sudden perturbation of the plasma equilibrium is induced by the injection of a cryogenic hydrogen pellet in the TJ-II stellarator, which is observed to be followed by a damped oscillation in the electrostatic potential. The waveform of the relaxation is consistent with theoretical calculations of zonal potential relaxation in a nonaxisymmetric magnetic geometry. The turbulent transport properties of a magnetic confinement configuration are expected to depend on the features of the collisionless damping of zonal flows, of which the present Letter is the first direct observation.

Gate-defined Quantum Confinement in Suspended Bilayer Graphene

NASA Astrophysics Data System (ADS)

Allen, Monica

2013-03-01

Quantum confined devices in carbon-based materials offer unique possibilities for applications ranging from quantum computation to sensing. In particular, nanostructured carbon is a promising candidate for spin-based quantum computation due to the ability to suppress hyperfine coupling to nuclear spins, a dominant source of spin decoherence. Yet graphene lacks an intrinsic bandgap, which poses a serious challenge for the creation of such devices. We present a novel approach to quantum confinement utilizing tunnel barriers defined by local electric fields that break sublattice symmetry in suspended bilayer graphene. This technique electrostatically confines charges via band structure control, thereby eliminating the edge and substrate disorder that hinders on-chip etched nanostructures to date. We report clean single electron tunneling through gate-defined quantum dots in two regimes: at zero magnetic field using the energy gap induced by a perpendicular electric field and at finite magnetic fields using Landau level confinement. The observed Coulomb blockade periodicity agrees with electrostatic simulations based on local top-gate geometry, a direct demonstration of local control over the band structure of graphene. This technology integrates quantum confinement with pristine device quality and access to vibrational modes, enabling wide applications from electromechanical sensors to quantum bits. More broadly, the ability to externally tailor the graphene bandgap over nanometer scales opens a new unexplored avenue for creating quantum devices.

Preparation of translationally cold neutral molecules.

PubMed

Di Domenicantonio, Giulia; Bertsche, Benjamin; Osterwalder, Andreas

2011-01-01

Efforts at EPFL to obtain translationally cold neutral molecules are described. Active deceleration of polar molecules is performed by confining the molecules in moving three-dimensional electrostatic traps, and by appropriately choosing the velocity of those traps. Alternatively, cold molecules can be obtained by velocity filtering. Here, the velocity of the molecules is not changed, but instead the cold molecules are extracted from a thermal sample by using the competition between the electrostatic force and the centrifugal force inside a bent electrostatic guide for polar molecules.

Fluctuation reduction and enhanced confinement in the MST reversed-field pinch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapman, Brett Edward

1997-10-01

Plasmas with a factor of ≥3 improvement in energy confinement have been achieved in the MST reversed-field pinch (RFP). These plasmas occur spontaneously, following sawtooth crashes, subject to constraints on, eg, toroidal magnetic field reversal and wall conditioning. Possible contributors to the improved confinement include a reduction of core-resonant, global magnetic fluctuations and a reduction of electrostatic fluctuations over the entire plasma edge. One feature of these plasmas is a region of strong ExB flow shear in the edge. Never before observed in conjunction with enhanced confinement in the RFP, such shear is common in enhanced confinement discharges in tokamaks and stellarators. Another feature of these plasmas is a new type of discrete dynamo event. Like sawtooth crashes, a common form of discrete dynamo, these events correspond to bursts of edge parallel current. The reduction of electrostatic fluctuations in these plasmas occurs within and beyond the region of strong ExB flow shear, similar to what is observed in tokamaks and stellarators. However, the reductions in the MST include fluctuations whose correlation lengths are larger than the width of the shear region. The reduction of the global magnetic fluctuations is most likely due to flattening of the μ=μ 0more » $$\\vec{J}$$∙$$\\vec{B}$$/B 2 profile. Flattening can occur, eg, due to the new type of discrete dynamo event and reduced edge resistivity. Enhanced confinement plasmas are also achieved in the MST when auxiliary current is applied to flatten the μ profile and reduce magnetic fluctuations. Unexpectedly, these plasmas also exhibit a region (broader than in the case above) of strong ExB flow shear in the edge, an edge-wide reduction of electrostatic fluctuations, and the new type of discrete dynamo event. Auxiliary current drive has historically been viewed as the principal route to fusion reactor viability for the RFP.« less

Simulations of Coulomb systems with slab geometry using an efficient 3D Ewald summation method

NASA Astrophysics Data System (ADS)

dos Santos, Alexandre P.; Girotto, Matheus; Levin, Yan

2016-04-01

We present a new approach to efficiently simulate electrolytes confined between infinite charged walls using a 3d Ewald summation method. The optimal performance is achieved by separating the electrostatic potential produced by the charged walls from the electrostatic potential of electrolyte. The electric field produced by the 3d periodic images of the walls is constant inside the simulation cell, with the field produced by the transverse images of the charged plates canceling out. The non-neutral confined electrolyte in an external potential can be simulated using 3d Ewald summation with a suitable renormalization of the electrostatic energy, to remove a divergence, and a correction that accounts for the conditional convergence of the resulting lattice sum. The new algorithm is at least an order of magnitude more rapid than the usual simulation methods for the slab geometry and can be further sped up by adopting a particle-particle particle-mesh approach.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gruenwald, J., E-mail: johannes.gruenwald@inp-greifswald.de; Fröhlich, M.

A model of the behavior of transit time instabilities in an electrostatic confinement fusion reactor is presented in this letter. It is demonstrated that different modes are excited within the spherical cathode of a Farnsworth fusor. Each of these modes is dependent on the fusion products as well as the acceleration voltage applied between the two electrodes and they couple to a resulting oscillation showing non-linear beat phenomena. This type of instability is similar to the transit time instability of electrons between two resonant surfaces but the presence of ions and the occurring fusion reactions alter the physics of thismore » instability considerably. The physics of this plasma instability is examined in detail for typical physical parameter ranges of electrostatic confinement fusion devices.« less

Spherical ion oscillations in a positive polarity gridded inertial-electrostatic confinement device

NASA Astrophysics Data System (ADS)

Bandara, R.; Khachan, J.

2013-07-01

A pulsed, positive polarity gridded inertial electrostatic confinement device has been investigated experimentally, using a differential emissive probe and potential traces as primary diagnostics. Large amplitude oscillations in the plasma current and plasma potential were observed within a microsecond of the discharge onset, which are indicative of coherent ion oscillations about a temporarily confined excess of recirculating electron space charge. The magnitude of the depth of the potential well in the established virtual cathode was determined using a differential emissive Langmuir probe, which correlated well to the potential well inferred from the ion oscillation frequency for both hydrogen and argon experiments. It was found that the timescale for ion oscillation dispersion is strongly dependent on the neutral gas density, and weakly dependent on the peak anode voltage. The cessation of the oscillations was found to be due to charge exchange processes converting ions to high velocity neutrals, causing the abrupt de-coherence of the oscillations through an avalanche dispersion in phase space.

Bimetallic Microswimmers Speed Up in Confining Channels.

PubMed

Liu, Chang; Zhou, Chao; Wang, Wei; Zhang, H P

2016-11-04

Synthetic microswimmers are envisioned to be useful in numerous applications, many of which occur in tightly confined spaces. It is therefore important to understand how confinement influences swimmer dynamics. Here we study the motility of bimetallic microswimmers in linear and curved channels. Our experiments show swimmer velocities increase, up to 5 times, with the degree of confinement, and the relative velocity increase depends weakly on the fuel concentration and ionic strength in solution. Experimental results are reproduced in a numerical model which attributes the swimmer velocity increase to electrostatic and electrohydrodynamic boundary effects. Our work not only helps to elucidate the confinement effect of phoretic swimmers, but also suggests that spatial confinement may be used as an effective control method for them.

Integral Transport Analysis Results for Ions Flowing Through Neutral Gas

NASA Astrophysics Data System (ADS)

Emmert, Gilbert; Santarius, John

2017-10-01

Results of a computational model for the flow of energetic ions and neutrals through a background neutral gas will be presented. The method models reactions as creating a new source of ions or neutrals if the energy or charge state of the resulting particle is changed. For a given source boundary condition, the creation and annihilation of the various species is formulated as a 1-D Volterra integral equation that can quickly be solved numerically by finite differences. The present work focuses on multiple-pass, 1-D ion flow through neutral gas and a nearly transparent, concentric anode and cathode pair in spherical, cylindrical, or linear geometry. This has been implemented as a computer code for atomic (3He, 3He +, 3He + +) and molecular (D, D2, D-, D +, D2 +, D3 +) ion and neutral species, and applied to modeling inertial-electrostatic connement (IEC) devices. The code yields detailed energy spectra of the various ions and energetic neutral species. Calculations for several University of Wisconsin IEC and ion implantation devices will be presented. Research supported by US Dept. of Homeland Security Grant 2015-DN-077-ARI095, Dept. of Energy Grant DE-FG02-04ER54745, and the Grainger Foundation.

Transport induced by large scale convective structures in a dipole-confined plasma.

PubMed

Grierson, B A; Mauel, M E; Worstell, M W; Klassen, M

2010-11-12

Convective structures characterized by E×B motion are observed in a dipole-confined plasma. Particle transport rates are calculated from density dynamics obtained from multipoint measurements and the reconstructed electrostatic potential. The calculated transport rates determined from the large-scale dynamics and local probe measurements agree in magnitude, show intermittency, and indicate that the particle transport is dominated by large-scale convective structures.

Communication: Nanoscale electrostatic theory of epistructural fields at the protein-water interface

NASA Astrophysics Data System (ADS)

Fernández, Ariel

2012-12-01

Nanoscale solvent confinement at the protein-water interface promotes dipole orientations that are not aligned with the internal electrostatic field of a protein, yielding what we term epistructural polarization. To quantify this effect, an equation is derived from first principles relating epistructural polarization with the magnitude of local distortions in water coordination causative of interfacial tension. The equation defines a nanoscale electrostatic model of water and enables an estimation of protein denaturation free energies and the inference of hot spots for protein associations. The theoretical results are validated vis-à-vis calorimetric data, revealing the destabilizing effect of epistructural polarization and its molecular origin.

Communication: Nanoscale electrostatic theory of epistructural fields at the protein-water interface.

PubMed

Fernández, Ariel

2012-12-21

Nanoscale solvent confinement at the protein-water interface promotes dipole orientations that are not aligned with the internal electrostatic field of a protein, yielding what we term epistructural polarization. To quantify this effect, an equation is derived from first principles relating epistructural polarization with the magnitude of local distortions in water coordination causative of interfacial tension. The equation defines a nanoscale electrostatic model of water and enables an estimation of protein denaturation free energies and the inference of hot spots for protein associations. The theoretical results are validated vis-à-vis calorimetric data, revealing the destabilizing effect of epistructural polarization and its molecular origin.

Preparation of a novel dual-function strong cation exchange/hydrophobic interaction chromatography stationary phase for protein separation.

PubMed

Zhao, Kailou; Yang, Li; Wang, Xuejiao; Bai, Quan; Yang, Fan; Wang, Fei

2012-08-30

We have explored a novel dual-function stationary phase which combines both strong cation exchange (SCX) and hydrophobic interaction chromatography (HIC) characteristics. The novel dual-function stationary phase is based on porous and spherical silica gel functionalized with ligand containing sulfonic and benzyl groups capable of electrostatic and hydrophobic interaction functionalities, which displays HIC character in a high salt concentration, and IEC character in a low salt concentration in mobile phase employed. As a result, it can be employed to separate proteins with SCX and HIC modes, respectively. The resolution and selectivity of the dual-function stationary phase were evaluated under both HIC and SCX modes with standard proteins and can be comparable to that of conventional IEC and HIC columns. More than 96% of mass and bioactivity recoveries of proteins can be achieved in both HIC and SCX modes, respectively. The results indicated that the novel dual-function column could replace two individual SCX and HIC columns for protein separation. Mixed retention mechanism of proteins on this dual-function column based on stoichiometric displacement theory (SDT) in LC was investigated to find the optimal balance of the magnitude of electrostatic and hydrophobic interactions between protein and the ligand on the silica surface in order to obtain high resolution and selectivity for protein separation. In addition, the effects of the hydrophobicity of the ligand of the dual-function packings and pH of the mobile phase used on protein separation were also investigated in detail. The results show that the ligand with suitable hydrophobicity to match the electrostatic interaction is very important to prepare the dual-function stationary phase, and a better resolution and selectivity can be obtained at pH 6.5 in SCX mode. Therefore, the dual-function column can replace two individual SCX and HIC columns for protein separation and be used to set up two-dimensional liquid chromatography with a single column (2DLC-1C), which can also be employed to separate three kinds of active proteins completely, such as lysozyme, ovotransferrin and ovalbumin from egg white. The result is very important not only to the development of new 2DLC technology with a single column for proteomics, but also to recombinant protein drug production for saving column expense and simplifying the process in biotechnology. Copyright © 2012 Elsevier B.V. All rights reserved.

Observations of velocity shear driven plasma turbulence

NASA Technical Reports Server (NTRS)

Kintner, P. M., Jr.

1976-01-01

Electrostatic and magnetic turbulence observations from HAWKEYE-1 during the low altitude portion of its elliptical orbit over the Southern Hemisphere are presented. The magnetic turbulence is confined near the auroral zone and is similar to that seen at higher altitudes by HEOS-2 in the polar cusp. The electrostatic turbulence is composed of a background component with a power spectral index of 1.89 + or - .26 and an intense component with a power spectral index of 2.80 + or - .34. The intense electrostatic turbulence and the magnetic turbulence correlate with velocity shears in the convective plasma flow. Since velocity shear instabilities are most unstable to wave vectors perpendicular to the magnetic field, the shear correlated turbulence is anticipated to be two dimensional in character and to have a power spectral index of 3 which agrees with that observed in the intense electrostatic turbulence.

Magnetic field design for a Penning ion source for a 200 keV electrostatic accelerator

NASA Astrophysics Data System (ADS)

Fathi, A.; Feghhi, S. A. H.; Sadati, S. M.; Ebrahimibasabi, E.

2017-04-01

In this study, the structure of magnetic field for a Penning ion source has been designed and constructed with the use of permanent magnets. The ion source has been designed and constructed for a 200 keV electrostatic accelerator. With using CST Studio Suite, the magnetic field profile inside the ion source was simulated and an appropriate magnetic system was designed to improve particle confinement. Designed system consists of two ring magnets with 9 mm distance from each other around the anode. The ion source was constructed and the cylindrical magnet and designed magnetic system were tested on the ion source. The results showed that the ignition voltage for ion source with the designed magnetic system is almost 300 V lower than the ion source with the cylindrical magnet. Better particle confinement causes lower voltage discharge to occur.

Angular trapping of anisometric nano-objects in a fluid.

PubMed

Celebrano, Michele; Rosman, Christina; Sönnichsen, Carsten; Krishnan, Madhavi

2012-11-14

We demonstrate the ability to trap, levitate, and orient single anisometric nanoscale objects with high angular precision in a fluid. An electrostatic fluidic trap confines a spherical object at a spatial location defined by the minimum of the electrostatic system free energy. For an anisometric object and a potential well lacking angular symmetry, the system free energy can further strongly depend on the object's orientation in the trap. Engineering the morphology of the trap thus enables precise spatial and angular confinement of a single levitating nano-object, and the process can be massively parallelized. Since the physics of the trap depends strongly on the surface charge of the object, the method is insensitive to the object's dielectric function. Furthermore, levitation of the assembled objects renders them amenable to individual manipulation using externally applied optical, electrical, or hydrodynamic fields, raising prospects for reconfigurable chip-based nano-object assemblies.

Dynamics of electrostatic fluctuations in the edge plasma in the U-3M torsatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olshansky, V. V.; Stepanov, K. N.; Tarasov, M. I.

2010-10-15

Results are presented from experimental and theoretical investigations of oscillatory and wave phenomena observed in the edge region in the U-3M torsatron during plasma creation and heating by an RF discharge in the ICR frequency range, accompanied by a transition to improved confinement. The main results are reported of diagnostic measurements of the spectral composition of oscillations, as well as of how the phase and amplitude relationships depend on time and on the RF power during its injection into the plasma. The measurements were carried out with electrostatic probes positioned at the edge of the plasma confinement region. The experimentalmore » results are interpreted using the kinetic theory of the electron-ion parametric instability of a plasma in the ion cyclotron frequency range and are compared with the results of numerical simulations.« less

Electric Field Controlled Spin Interference in a System with Rashba Spin-Orbit Coupling

DTIC Science & Technology

2016-08-29

conducting semi-circular channels. The strength of the confinement energy on the quantum dots is tuned by gate potentials that allow “ leakage ” of electrons...interesting applications. A detectable SO effect requires a strong electric field (as well as a semiconductor host for the electrons that satisfies a...quantum dots (which may be considered identical) are confined by an electrostatically created potential that can be tuned to allow “ leakage ” of

Electromagnetic and electrostatic emissions at the cusp-magnetosphere interface during substorms

NASA Technical Reports Server (NTRS)

Curtis, S. A.; Fairfield, D. H.; Wu, C. S.

1979-01-01

Strongly peaked electrostatic emissions near 10.0 kHz and electromagnetic emissions near 0.56 kHz have been observed by the VLF wave detector on board Imp 6 on crossings from the earth's magnetosphere into the polar cusp during the occurrence of large magnetospheric substorms. The electrostatic emissions were observed to be closely confined to the cusp-magnetosphere interface. The electromagnetic emissions were of somewhat broader spatial extent and were seen on higher-latitude field lines within the cusp. Using these plasma wave observations and additional information provided by plasma, magnetometer and particle measurements made simultaneously on Imp 6, theories are constructed to explain each of the two classes of emission. The electromagnetic waves are modeled as whistlers, and the electrostatic waves as electron-cyclotron harmonics. The resulting growth rates predict power spectra similar to those observed for both emission classes. The electrostatic waves may play a significant role via enhanced diffusion in the relaxation of the sharp substorm time cusp-magnetosphere boundary to a more diffuse quiet time boundary.

Simulations of Coulomb systems confined by polarizable surfaces using periodic Green functions.

PubMed

Dos Santos, Alexandre P; Girotto, Matheus; Levin, Yan

2017-11-14

We present an efficient approach for simulating Coulomb systems confined by planar polarizable surfaces. The method is based on the solution of the Poisson equation using periodic Green functions. It is shown that the electrostatic energy arising from the surface polarization can be decoupled from the energy due to the direct Coulomb interaction between the ions. This allows us to combine an efficient Ewald summation method, or any other fast method for summing over the replicas, with the polarization contribution calculated using Green function techniques. We apply the method to calculate density profiles of ions confined between the charged dielectric and metal surfaces.

CERT Resilience Management Model (RMM) v1.1: Code of Practice Crosswalk Commercial Version 1.1

DTIC Science & Technology

2011-10-01

ISO /IEC 24762:2008 (E) 6 2.8 ISO /IEC 27002 :2005 (E) 6 2.9 ISO /IEC 27005:2008 (E) 6 2.10 ISO /IEC 31000:2009 (E) 6 2.11...webstore.ansi.org/. 2.8 ISO /IEC 27002 :2005 (E) ISO /IEC 27002 , “Code of practice for information security management” [ ISO /IEC 2005b], broaches the full...scope of security management, at points touching upon both IT management and disaster recovery. ISO /IEC 27002 is part of a growing “27000

Particle trapping in 3-D using a single fiber probe with an annular light distribution.

PubMed

Taylor, R; Hnatovsky, C

2003-10-20

A single optical fiber probe has been used to trap a solid 2 ìm diameter glass bead in 3-D in water. Optical confinement in 2-D was produced by the annular light distribution emerging from a selectively chemically etched, tapered, hollow tipped metalized fiber probe. Confinement of the bead in 3-D was achieved by balancing an electrostatic force of attraction towards the tip and the optical scattering force pushing the particle away from the tip.

A Superconducting Magnet UCN Trap for Precise Neutron Lifetime Measurements.

PubMed

Picker, R; Altarev, I; Bröcker, J; Gutsmiedl, E; Hartmann, J; Müller, A; Paul, S; Schott, W; Trinks, U; Zimmer, O

2005-01-01

Finite-element methods along with Monte Carlo simulations were used to design a magnetic storage device for ultracold neutrons (UCN) to measure their lifetime. A setup was determined which should make it possible to confine UCN with negligible losses and detect the protons emerging from β-decay with high efficiency: stacked superconducting solenoids create the magnetic storage field, an electrostatic extraction field inside the storage volume assures high proton collection efficiency. Alongside with the optimization of the magnetic and electrostatic design, the properties of the trap were investigated through extensive Monte Carlo simulation.

Magnetic confinement system using charged ammonia targets

DOEpatents

Porter, Gary D.; Bogdanoff, Anatoly

1979-01-01

A system for guiding charged laser targets to a predetermined focal spot of a laser along generally arbitrary, and especially horizontal, directions which comprises a series of electrostatic sensors which provide inputs to a computer for real time calculation of position, velocity, and direction of the target along an initial injection trajectory, and a set of electrostatic deflection means, energized according to a calculated output of said computer, to change the target trajectory to intercept the focal spot of the laser which is triggered so as to illuminate the target of the focal spot.

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

NASA Technical Reports Server (NTRS)

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.

Steady state and transient simulation of anion exchange membrane fuel cells

NASA Astrophysics Data System (ADS)

Dekel, Dario R.; Rasin, Igal G.; Page, Miles; Brandon, Simon

2018-01-01

We present a new model for anion exchange membrane fuel cells. Validation against experimental polarization curve data is obtained for current densities ranging from zero to above 2 A cm-2. Experimental transient data is also successfully reproduced. The model is very flexible and can be used to explore the system's sensitivity to a wide range of material properties, cell design specifications, and operating parameters. We demonstrate the impact of gas inlet relative humidity (RH), operating current density, ionomer loading and ionomer ion exchange capacity (IEC) values on cell performance. In agreement with the literature, high air RH levels are shown to improve cell performance. At high current densities (>1 A cm-2) this effect is observed to be especially significant. Simulated hydration number distributions across the cell reveal the related critical dependence of cathode hydration on air RH and current density values. When exploring catalyst layer design, optimal intermediate ionomer loading values are demonstrated. The benefits of asymmetric (cathode versus anode) electrode design are revealed, showing enhanced performance using higher cathode IEC levels. Finally, electrochemical reaction profiles across the electrodes uncover inhomogeneous catalyst utilization. Specifically, at high current densities the cathodic reaction is confined to a narrow region near the membrane.

Phase Separation from Electron Confinement at Oxide Interfaces

NASA Astrophysics Data System (ADS)

Scopigno, N.; Bucheli, D.; Caprara, S.; Biscaras, J.; Bergeal, N.; Lesueur, J.; Grilli, M.

2016-01-01

Oxide heterostructures are of great interest for both fundamental and applicative reasons. In particular, the two-dimensional electron gas at the LaAlO3/SrTiO3 or LaTiO3/SrTiO3 interfaces displays many different properties and functionalities. However, there are clear experimental indications that the interface electronic state is strongly inhomogeneous and therefore it is crucial to investigate possible intrinsic mechanisms underlying this inhomogeneity. Here, the electrostatic potential confining the electron gas at the interface is calculated self-consistently, finding that such confinement may induce phase separation, to avoid a thermodynamically unstable state with a negative compressibility. This provides a robust mechanism for the inhomogeneous character of these interfaces.

Improved Confinement by Edge Multi-pulse Turbulent Heating on HT-6M Tokamak

NASA Astrophysics Data System (ADS)

Mao, Jian-shan; Luo, Jia-rong; Li, Jian-gang; Pan, Yuan; Wang, Mao-quan; Liu, Bao-hua; Wan, Yuan-xi; Li, Qiang; Wu, Xin-chao; Liang, Yun-feng; Xu, Yu-hong; Yu, Chang-xuan

1997-10-01

In the recent experiment on HT-6M tokamak, an improved ohmic confinement phase has been observed after application of the edge multi-pulse turbulent heating, and variance of plasma current ΔIp/Ip is about 14-20%. The improved edge plasma confinement phase is characterized by (a) increased average electron density bar Ne and electron temperature Te; (b) reduced Hα radiation from the edge; (c) steeper density and temperature profiles at the edge; (d) a more negative radial electric field over a region of ~ 5 mm deep inside the limiter; (e) a deeper electrostatic potential well at the edge; (f) reduced magnetic fluctuations at the edge.

Lattice model of ionic liquid confined by metal electrodes

NASA Astrophysics Data System (ADS)

Girotto, Matheus; Malossi, Rodrigo M.; dos Santos, Alexandre P.; Levin, Yan

2018-05-01

We study, using Monte Carlo simulations, the density profiles and differential capacitance of ionic liquids confined by metal electrodes. To compute the electrostatic energy, we use the recently developed approach based on periodic Green's functions. The method also allows us to easily calculate the induced charge on the electrodes permitting an efficient implementation of simulations in a constant electrostatic potential ensemble. To speed up the simulations further, we model the ionic liquid as a lattice Coulomb gas and precalculate the interaction potential between the ions. We show that the lattice model captures the transition between camel-shaped and bell-shaped capacitance curves—the latter characteristic of ionic liquids (strong coupling limit) and the former of electrolytes (weak coupling). We observe the appearance of a second peak in the differential capacitance at ≈0.5 V for 2:1 ionic liquids, as the packing fraction is increased. Finally, we show that ionic size asymmetry decreases substantially the capacitance maximum, when all other parameters are kept fixed.

Control of ion gyroscale fluctuations via electrostatic biasing and sheared E×B flow in the C-2 field reversed configuration

NASA Astrophysics Data System (ADS)

Schmitz, L.; Ruskov, E.; Deng, B. H.; Binderbauer, M.; Tajima, T.; Gota, H.; Tuszewski, M.

2016-03-01

Control of radial particle and thermal transport is instrumental for achieving and sustaining well-confined high-β plasma in a Field-Reversed Configuration (FRC). Radial profiles of low frequency ion gyro-scale density fluctuations (0.5≤kρs≤40), consistent with drift- or drift-interchange modes, have been measured in the scrape-off layer (SOL) and core of the C-2 Field-Reversed Configuration (FRC), together with the toroidal E×B velocity. It is shown here that axial electrostatic SOL biasing controls and reduces gyro-scale density fluctuations, resulting in very low FRC core fluctuation levels. When the radial E×B flow shearing rate decreases below the turbulence decorrelation rate, fluctuation levels increase substantially, concomitantly with onset of the n=2 instability and rapid loss of diamagnetism. Low turbulence levels, improved energy/particle confinement and substantially increased FRC life times are achieved when E×B shear near the separatrix is maintained via axial SOL biasing using an annular washer gun.

Coulomb Oscillations in a Gate-Controlled Few-Layer Graphene Quantum Dot.

PubMed

Song, Yipu; Xiong, Haonan; Jiang, Wentao; Zhang, Hongyi; Xue, Xiao; Ma, Cheng; Ma, Yulin; Sun, Luyan; Wang, Haiyan; Duan, Luming

2016-10-12

Graphene quantum dots could be an ideal host for spin qubits and thus have been extensively investigated based on graphene nanoribbons and etched nanostructures; however, edge and substrate-induced disorders severely limit device functionality. Here, we report the confinement of quantum dots in few-layer graphene with tunable barriers, defined by local strain and electrostatic gating. Transport measurements unambiguously reveal that confinement barriers are formed by inducing a band gap via the electrostatic gating together with local strain induced constriction. Numerical simulations according to the local top-gate geometry confirm the band gap opening by a perpendicular electric field. We investigate the magnetic field dependence of the energy-level spectra in these graphene quantum dots. Experimental results reveal a complex evolution of Coulomb oscillations with the magnetic field, featuring kinks at level crossings. The simulation of energy spectrum shows that the kink features and the magnetic field dependence are consistent with experimental observations, implying the hybridized nature of energy-level spectrum of these graphene quantum dots.

Energy gain calculations in Penning fusion systems using a bounce-averaged Fokker-Planck model

NASA Astrophysics Data System (ADS)

Chacón, L.; Miley, G. H.; Barnes, D. C.; Knoll, D. A.

2000-11-01

In spherical Penning fusion devices, a spherical cloud of electrons, confined in a Penning-like trap, creates the ion-confining electrostatic well. Fusion energy gains for these systems have been calculated in optimistic conditions (i.e., spherically uniform electrostatic well, no collisional ion-electron interactions, single ion species) using a bounce-averaged Fokker-Planck (BAFP) model. Results show that steady-state distributions in which the Maxwellian ion population is dominant correspond to lowest ion recirculation powers (and hence highest fusion energy gains). It is also shown that realistic parabolic-like wells result in better energy gains than square wells, particularly at large well depths (>100 kV). Operating regimes with fusion power to ion input power ratios (Q-value) >100 have been identified. The effect of electron losses on the Q-value has been addressed heuristically using a semianalytic model, indicating that large Q-values are still possible provided that electron particle losses are kept small and well depths are large.

A new quasi-thermal trap model for solar flare hard X-ray bursts - An electrostatic trap model

NASA Technical Reports Server (NTRS)

Spicer, D. S.; Emslie, A. G.

1988-01-01

A new quasi-thermal trap model of solar flare hard X-ray bursts is presented. The new model utilizes the trapping ability of a magnetic mirror and a magnetic field-aligned electrostatic potential produced by differences in anisotropies of the electron and ion distribution function. It is demonstrated that this potential can, together with the magnetic mirror itself, effectively confine electrons in a trap, thereby enhancing their bremsstrahlung yield per electron. This analysis makes even more untenable models involving precipitation of the bremsstrahlung-producing electrons onto a cold target.

CMMI(Registered) for Development, Version 1.3

DTIC Science & Technology

2010-11-01

ISO /IEC 15288:2008 Systems and Software Engineering – System Life Cycle Processes [ ISO 2008b] ISO /IEC 27001 :2005 Information technology – Security...IEC 2005 International Organization for Standardization and International Electrotechnical Commission. ISO /IEC 27001 Information Technology...International Electrotechnical Commission ( ISO /IEC) body of standards. CMMs focus on improving processes in an organization. They contain the

Optically controlled resonant tunneling in a double-barrier diode

NASA Astrophysics Data System (ADS)

Kan, S. C.; Wu, S.; Sanders, S.; Griffel, G.; Yariv, A.

1991-03-01

The resonant tunneling effect is optically enhanced in a GaAs/GaAlAs double-barrier structure that has partial lateral current confinement. The peak current increases and the valley current decreases simultaneously when the device surface is illuminated, due to the increased conductivity of the top layer of the structure. The effect of the lateral current confinement on the current-voltage characteristic of a double-barrier resonant tunneling structure was also studied. With increased lateral current confinement, the peak and valley current decrease at a different rate such that the current peak-to-valley ratio increases up to three times. The experimental results are explained by solving the electrostatic potential distribution in the structure using a simple three-layer model.

Edge Plasma behavior during Improved Confinement by Lower Hybrid Wave Heating in HT-6M Tokamak

NASA Astrophysics Data System (ADS)

Li, Jian-gang; Bao, Yi; Luo, Jia-rong; Wan, Bao-nian; Liu, Yue-xiu; Gong, Xian-zu; Chen, Jun-ling; Liang, Yun-feng

2002-10-01

Lower hybrid heating (LHH) has been successfully carried out in the HT-6M tokamak. The H-mode has been obtained with a power threshold of 50 kW under a boronized wall condition. Both energy and particle confinements have been improved along with a dropped edge plasma density and an increase electron temperature during the LHH phase. A negative Er well plays a key role of triggering and sustaining the good confinement. Both electrostatic fluctuation of the plasma potential and the density fluctuations dropped to an ultra-low level. The observation of an enhanced Er shear before the reduction in turbulence level is consistent with an increased Er shear as the cause of turbulence suppression.

A Structured Approach for Reviewing Architecture Documentation

DTIC Science & Technology

2009-12-01

as those found in ISO 12207 [ ISO /IEC 12207 :2008] (for software engineering), ISO 15288 [ ISO /IEC 15288:2008] (for systems engineering), the Rational...Open Distributed Processing - Reference Model: Foundations ( ISO /IEC 10746-2). 1996. [ ISO /IEC 12207 :2008] International Organization for...Standardization & International Electrotechnical Commission. Sys- tems and software engineering – Software life cycle processes ( ISO /IEC 12207 ). 2008. [ ISO

An electrostatic autoresonant ion trap mass spectrometer.

PubMed

Ermakov, A V; Hinch, B J

2010-01-01

A new method for ion extraction from an anharmonic electrostatic trap is introduced. Anharmonicity is a common feature of electrostatic traps which can be used for small scale spatial confinement of ions, and this feature is also necessary for autoresonant ion extraction. With the aid of ion trajectory simulations, novel autoresonant trap mass spectrometers (ART-MSs) have been designed based on these very simple principles. A mass resolution approximately 60 is demonstrated for the prototypes discussed here. We report also on the pressure dependencies, and the (mV) rf field strength dependencies of the ART-MS sensitivity. Importantly the new MS designs do not require heavy magnets, tight manufacturing tolerances, introduction of buffer gases, high power rf sources, nor complicated electronics. The designs described here are very inexpensive to implement relative to other instruments, and can be easily miniaturized. Possible applications are discussed.

Electrostatic and hydrodynamics effects in a sedimented magnetorheological suspension.

PubMed

Domínguez-García, P; Pastor, J M; Melle, Sonia; Rubio, Miguel A

2009-08-01

We present experimental results on the equilibrium microstructure of a sedimented magnetorheological suspension, namely, an aqueous suspension of micron-sized superparamagnetic particles. We develop a study of the electrical interactions on the suspension by processing video-microscopy images of the sedimented particles. We calculate the pair distribution function, g(r), which yields the electrostatic pair potential u(r), showing an anomalous attractive interaction for distances on the order of twice the particle diameter, with characteristic parameters whose values show a dependence with the two-dimensional concentration of particles. The repulsive body of the potential is adjusted to a DLVO expression in order to calculate the Debye screening length and the effective surface charge density. Influence of confinement and variations on the Boltzmann sedimentation profile because of the electrostatic interactions appear to be essential for the interpretation of experimental results.

Gate-defined quantum confinement in suspended bilayer graphene

NASA Astrophysics Data System (ADS)

Allen, M. T.; Martin, J.; Yacoby, A.

2012-07-01

Quantum-confined devices that manipulate single electrons in graphene are emerging as attractive candidates for nanoelectronics applications. Previous experiments have employed etched graphene nanostructures, but edge and substrate disorder severely limit device functionality. Here we present a technique that builds quantum-confined structures in suspended bilayer graphene with tunnel barriers defined by external electric fields that open a bandgap, thereby eliminating both edge and substrate disorder. We report clean quantum dot formation in two regimes: at zero magnetic field B using the energy gap induced by a perpendicular electric field and at B>0 using the quantum Hall ν=0 gap for confinement. Coulomb blockade oscillations exhibit periodicity consistent with electrostatic simulations based on local top-gate geometry, a direct demonstration of local control over the band structure of graphene. This technology integrates single electron transport with high device quality and access to vibrational modes, enabling broad applications from electromechanical sensors to quantum bits.

Suppressed ion-scale turbulence in a hot high-β plasma

NASA Astrophysics Data System (ADS)

Schmitz, L.; Fulton, D. P.; Ruskov, E.; Lau, C.; Deng, B. H.; Tajima, T.; Binderbauer, M. W.; Holod, I.; Lin, Z.; Gota, H.; Tuszewski, M.; Dettrick, S. A.; Steinhauer, L. C.

2016-12-01

An economic magnetic fusion reactor favours a high ratio of plasma kinetic pressure to magnetic pressure in a well-confined, hot plasma with low thermal losses across the confining magnetic field. Field-reversed configuration (FRC) plasmas are potentially attractive as a reactor concept, achieving high plasma pressure in a simple axisymmetric geometry. Here, we show that FRC plasmas have unique, beneficial microstability properties that differ from typical regimes in toroidal confinement devices. Ion-scale fluctuations are found to be absent or strongly suppressed in the plasma core, mainly due to the large FRC ion orbits, resulting in near-classical thermal ion confinement. In the surrounding boundary layer plasma, ion- and electron-scale turbulence is observed once a critical pressure gradient is exceeded. The critical gradient increases in the presence of sheared plasma flow induced via electrostatic biasing, opening the prospect of active boundary and transport control in view of reactor requirements.

Physical investigation of a quad confinement plasma source

NASA Astrophysics Data System (ADS)

Knoll, Aaron; Lucca Fabris, Andrea; Young, Christopher; Cappelli, Mark

2016-10-01

Quad magnetic confinement plasma sources are novel magnetized DC discharges suitable for applications in a broad range of fields, particularly space propulsion, plasma etching and deposition. These sources contain a square discharge channel with magnetic cusps at the four lateral walls, enhancing plasma confinement and electron residence time inside the device. The magnetic field topology is manipulated using four independent electromagnets on each edge of the channel, tuning the properties of the generated plasma. We characterize the plasma ejected from the quad confinement sources using a combination of traditional electrostatic probes and non-intrusive laser-based diagnostics. Measurements show a strong ion acceleration layer located 8 cm downstream of the exit plane, beyond the extent of the magnetic field. The ion velocity field is investigated with different magnetic configurations, demonstrating how ion trajectories may be manipulated. C.Y. acknowledges support from the DOE NSSA Stewardship Science Graduate Fellowship under contract DE-FC52-08NA28752.

Suppressed ion-scale turbulence in a hot high-β plasma

PubMed Central

Schmitz, L.; Fulton, D. P.; Ruskov, E.; Lau, C.; Deng, B. H.; Tajima, T.; Binderbauer, M. W.; Holod, I.; Lin, Z.; Gota, H.; Tuszewski, M.; Dettrick, S. A.; Steinhauer, L. C.

2016-01-01

An economic magnetic fusion reactor favours a high ratio of plasma kinetic pressure to magnetic pressure in a well-confined, hot plasma with low thermal losses across the confining magnetic field. Field-reversed configuration (FRC) plasmas are potentially attractive as a reactor concept, achieving high plasma pressure in a simple axisymmetric geometry. Here, we show that FRC plasmas have unique, beneficial microstability properties that differ from typical regimes in toroidal confinement devices. Ion-scale fluctuations are found to be absent or strongly suppressed in the plasma core, mainly due to the large FRC ion orbits, resulting in near-classical thermal ion confinement. In the surrounding boundary layer plasma, ion- and electron-scale turbulence is observed once a critical pressure gradient is exceeded. The critical gradient increases in the presence of sheared plasma flow induced via electrostatic biasing, opening the prospect of active boundary and transport control in view of reactor requirements. PMID:28000675

Generation and confinement of microwave gas-plasma in photonic dielectric microstructure.

PubMed

Debord, B; Jamier, R; Gérôme, F; Leroy, O; Boisse-Laporte, C; Leprince, P; Alves, L L; Benabid, F

2013-10-21

We report on a self-guided microwave surface-wave induced generation of ~60 μm diameter and 6 cm-long column of argon-plasma confined in the core of a hollow-core photonic crystal fiber. At gas pressure of 1 mbar, the micro-confined plasma exhibits a stable transverse profile with a maximum gas-temperature as high as 1300 ± 200 K, and a wall-temperature as low as 500 K, and an electron density level of 10¹⁴ cm⁻³. The fiber guided fluorescence emission presents strong Ar⁺ spectral lines in the visible and near UV. Theory shows that the observed combination of relatively low wall-temperature and high ionisation rate in this strongly confined configuration is due to an unprecedentedly wide electrostatic space-charge field and the subsequent ion acceleration dominance in the plasma-to-gas power transfer.

Analyzing Cases of Resilience Success and Failure - A Research Study

DTIC Science & Technology

2012-12-01

controls [NIST 2012, NIST 2008] ISO 27002 and ISO 27004 Guidelines for initiating, implementing, maintaining, and improving information security...Commission ( ISO /IEC). Information technology—Security techniques—Code of practice for information security management ( ISO /IEC 27002 :2005). ISO /IEC, 2005...security management system and controls or groups of controls [ ISO /IEC 2005, ISO /IEC 2009] CIS Security Metrics Outcome and practice metrics measuring

Regulation of Intestinal Epithelial Cells Properties and Functions by Amino Acids.

PubMed

Kong, Shanshan; Zhang, Yanhui H; Zhang, Weiqiang

2018-01-01

Intestinal epithelial cells (IECs) line the surface of intestinal epithelium, where they play important roles in the digestion of food, absorption of nutrients, and protection of the human body from microbial infections, and others. Dysfunction of IECs can cause diseases. The development, maintenance, and functions of IECs are strongly influenced by external nutrition, such as amino acids. Amino acids play important roles in regulating the properties and functions of IECs. In this article, we briefly reviewed the current understanding of the roles of amino acids in the regulation of IECs' properties and functions in physiological state, including in IECs homeostasis (differentiation, proliferation, and renewal), in intestinal epithelial barrier structure and functions, and in immune responses. We also summarized some important findings on the effects of amino acids supplementation (e.g., glutamine and arginine) in restoring IECs' and intestine functions in some diseased states. These findings will further our understanding of the important roles of amino acids in the homeostasis of IECs and could potentially help identify novel targets and reagents for the therapeutic interventions of diseases associated with dysfunctional IECs.

A Model for Joint Software Reviews

DTIC Science & Technology

1998-10-01

CEPMAN 1, 1996; Gabb, 1997], and with the growing popularity of outsourcing, they are becoming more important in the commercial sector [ ISO /IEC 12207 ...technical and management reviews [MIL-STD-498, 1996; ISO /IEC 12207 , 1995]. Management reviews occur after technical reviews, and are focused on the cost...characteristics, Standard (No. ISO /IEC 9126-1). [ ISO /IEC 12207 , 1995] Information Technology Software Life Cycle Processes, Standard (No. ISO /IEC 12207

Effects of electrostatic screening on the conformation of single DNA molecules confined in a nanochannel

NASA Astrophysics Data System (ADS)

Zhang, Ce; Zhang, Fang; van Kan, Jeroen A.; van der Maarel, Johan R. C.

2008-06-01

Single T4-DNA molecules were confined in rectangular-shaped channels with a depth of 300 nm and a width in the range of 150-300 nm casted in a poly(dimethylsiloxane) nanofluidic chip. The extensions of the DNA molecules were measured with fluorescence microscopy as a function of the ionic strength and composition of the buffer as well as the DNA intercalation level by the YOYO-1 dye. The data were interpreted with the scaling theory for a wormlike polymer in good solvent, including the effects of confinement, charge, and self-avoidance. It was found that the elongation of the DNA molecules with decreasing ionic strength can be interpreted in terms of an increase of the persistence length. Self-avoidance effects on the extension are moderate, due to the small correlation length imposed by the channel cross-sectional diameter. Intercalation of the dye results in an increase of the DNA contour length and a partial neutralization of the DNA charge, but besides effects of electrostatic origin it has no significant effect on the bare bending rigidity. In the presence of divalent cations, the DNA molecules were observed to contract, but they do not collapse into a condensed structure. It is proposed that this contraction results from a divalent counterion mediated attractive force between the segments of the DNA molecule.

Role of Reynolds Stress-Induced Poloidal Flow in Triggering the Transition to Improved Ohmic Confinement on the HT-6M Tokamak

NASA Astrophysics Data System (ADS)

Xu, Y. H.; Yu, C. X.; Luo, J. R.; Mao, J. S.; Liu, B. H.; Li, J. G.; Wan, B. N.; Wan, Y. X.

2000-04-01

Time and space resolved measurements of electrostatic Reynolds stress, radial electric field Er, and plasma rotations have been performed across the transition to improved Ohmic confinement in the Hefei Tokamak-6M (HT-6M). The first experimental evidence of the correlation between the enhanced Reynolds stress gradient and the poloidal flow acceleration in the edge plasma is presented. The results indicate that the turbulence-induced Reynolds stress might be the dominant mechanism to create the sheared poloidal flow and Er, which may further trigger the transition.

Role of reynolds stress-induced poloidal flow in triggering the transition to improved ohmic confinement on the HT-6M tokamak

PubMed

Xu; Yu; Luo; Mao; Liu; Li; Wan; Wan

2000-04-24

Time and space resolved measurements of electrostatic Reynolds stress, radial electric field E(r), and plasma rotations have been performed across the transition to improved Ohmic confinement in the Hefei Tokamak-6M (HT-6M). The first experimental evidence of the correlation between the enhanced Reynolds stress gradient and the poloidal flow acceleration in the edge plasma is presented. The results indicate that the turbulence-induced Reynolds stress might be the dominant mechanism to create the sheared poloidal flow and E(r), which may further trigger the transition.

The effect of power-law body forces on a thermally driven flow between concentric rotating spheres

NASA Technical Reports Server (NTRS)

Macaraeg, M. G.

1986-01-01

A numerical study is conducted to determine the effect of power-law body forces on a thermally-driven axisymmetric flow field confined between concentric co-rotating spheres. This study is motivated by Spacelab geophysical fluid-flow experiments, which use an electrostatic force on a dielectric fluid to simulate gravity; this force exhibits a (1/r)sup 5 distribution. Meridional velocity is found to increase when the electrostatic body force is imposed, relative to when the body force is uniform. Correlation among flow fields with uniform, inverse-square, and inverse-quintic force fields is obtained using a modified Grashof number.

The effect of power law body forces on a thermally-driven flow between concentric rotating spheres

NASA Technical Reports Server (NTRS)

Macaraeg, M. G.

1985-01-01

A numerical study is conducted to determine the effect of power-law body forces on a thermally-driven axisymmetric flow field confined between concentric co-rotating spheres. This study is motivated by Spacelab geophysical fluid-flow experiments, which use an electrostatic force on a dielectric fluid to simulate gravity; this force exhibits a (1/r)sup 5 distribution. Meridional velocity is found to increase when the electrostatic body force is imposed, relative to when the body force is uniform. Correlation among flow fields with uniform, inverse-square, and inverse-quintic force fields is obtained using a modified Grashof number.

Satellite auxiliary-propulsion selection techniques. Addendum: A survey of auxiliary electric propulsion systems

NASA Technical Reports Server (NTRS)

Holcomb, L. B.

1971-01-01

A review of electric thrusters for satellite auxiliary propulsion was conducted at JPL during the past year. Comparisons of the various thrusters for attitude propulsion and east-west and north-south stationkeeping were made based upon performance, mass, power, and demonstrated life. Reliability and cost are also discussed. The method of electrical acceleration of propellant served to divide the thruster systems into two groups: electrostatic and electromagnetic. Ion and colloid thrusters fall within the electrostatically accelerated group while MPD and pulsed plasma thrusters comprise the electromagnetically accelerated group. The survey was confined to research in the United States with accent on flight and flight prototype systems.

The CMMI Product Suite and International Standards

DTIC Science & Technology

2006-07-01

standards: “2.3 Reference Documents 2.3.1 Applicable ISO /IEC documents, including ISO /IEC 12207 and ISO /IEC 15504.” “3.1 Development User Requirements...related international standards such as ISO 9001:2000, 12207 , 15288 © 2006 by Carnegie Mellon University Page 12 Key Supplements Needed...the Measurement Framework in ISO /IEC 15504; and • the Process Reference Model included in ISO /IEC 12207 . A possible approach has been developed for

Inertial Electrostatic Confinement Fusion: The Laser Elevator Solar System Survey for Propellants Abstract

NASA Technical Reports Server (NTRS)

Pryor, Wayne

1999-01-01

Dr. Wayne Pryor worked on three projects this summer. These were: 1) Inertial Electrostatic Confinement; 2) The Laser Elevator; and 3) Solar System Survey for Propellants Abstract. We Assisted Jon Nadler from Richland Community College in assembling and operating a table-top nuclear fusion reactor. We successfully demonstrated neutron production in a deuterium plasma. Pryor also obtained basic spectroscopic information on the atomic and molecular emissions in the plasma. The second project consisted of the completion of a paper on a novel propulsion concept (due to Tom Meyer of Colorado, the first author): a laser sail that bounces light back to the laser source. Recycling the photons from source to sail perhaps 100-1000 times dramatically improves the energy efficiency of this system, which may become very important for high-velocity missions in the future. Lastly, we compiled a very basic inventory of solar system propellant resources, their locations, and their accessibility. This initial inventory concentrates on sunlight availability, water availability, and the difficulty (delta-velocity requirement and radiation environment) in getting there.

Harmonization of the Practice of Independent Ethics Committees in Italy: Project E-Submission

PubMed Central

De Feo, Gianfranco; Chiabrando, Giacomo; Cannovo, Nunzia; Galluccio, Antonio; Tomino, Carlo

2012-01-01

Aim The high variability of “centre-specific” documentation required by Independent Ethics Committee (IEC) plays a role in the time required for activation of participating centres of multicentre clinical trials. This study (a) provides a picture of the different activities, structural requirements and resources dedicated to the operation of the local IEC in Italy; (b) defines a detailed list of “centre-specific” documents considered as essential by the IEC for issuing its opinion and (c) suggests a “single document” to reduce the variability of the “centre-specific” documents required by the IEC. Methodology Two surveys were conducted through the portal of National Monitoring Centre of Clinical Trials (https://oss-sper-clin.agenziafarmaco.it/). The first survey focused on the local IEC resources and on the “centre-specific” documentation that local IEC required from the Sponsor and local Principal Investigator (PI). The second focused on “single document” required in the form of statements from the Sponsor and the PI. Answers were discussed and extended during regular scheduled teleconferences and plenary meeting. Principal Findings From 22/07/2009 to 15/12/2009, and from 19/04/2010 to 14/05/2010, 131 and 125 IECs responded to the first and the second surveys, respectively. 67% and 51% of IECs consider the structural requirements and the staff dedicated to the activity of the IECs as sufficient, respectively. Most of the IECs consider the “centre-specific” documentation as necessary for issuing the opinion, and a high percentage of IECs consider the proposed documentation as acceptable in substitution to any other “centre-specific” documentation already in use. Conclusions The harmonization of IECs practice in Italy is the first step to facilitate multicentre clinical trials. Similar efforts should be directed to reduce the total number of IECs and to standardize clinical trials approval procedures, focusing on administrative procedures as well. PMID:23145015

14 CFR 36.6 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-01-01

... No. 179, entitled “Precision Sound Level Meters,” dated 1973. (ii) IEC Publication No. 225, entitled... 1966. (iii) IEC Publication No. 651, entitled “Sound Level Meters,” first edition, dated 1979. (iv) IEC... edition, dated 1976. (v) IEC Publication No. 804, entitled “Integrating-averaging Sound Level Meters...

The American Association for Laboratory Accreditation

DTIC Science & Technology

2011-03-28

ISO / IEC 17025 ...Information Technology A2LA DoD ELAP Program n All labs are assessed to ISO / IEC 17025 :2005 as the base standard. n In addition, the requirements of 2003...n Inspection Body Accreditation ( ISO / IEC 17020) n Proficiency Testing Providers ( ISO / IEC 17043) n Reference Materials Producers ( ISO Guide

Naval Open Architecture Contract Guidebook for Program Managers

DTIC Science & Technology

2010-06-30

a whole, transform inputs into outputs. [IEEE/EIA Std. 12207 /1997] “APP233/ ISO 10303” – APP233 an “Application Protocol” for Systems Engineering...Language Metadata Interchange (XMI) and AP233/ ISO 10303). The contractor shall identify the proposed standards and formats to be used. The contractor...ANSI ISO /IEC 9075-1, ISO /IEC 9075-2, ISO /IEC 9075-3, ISO /IEC 9075-4, ISO /IEC 9075-5) 2. HTML for presentation layer (e.g., XML 1.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voytchev, Miroslav; Ambrosi, P.; Behrens, R.

This paper presents IEC/SC 45B Radiation protection instrumentation and its standards for individual monitoring of ionising radiation: IEC 61526 Ed. 3 for active personal dosemeters and IEC 62387-1 for passive integrating dosimetry systems. The transposition of these standards as CENELEC (European) standards is also discussed together with the collaboration between IEC/SC 45B and ISO/TC 85/SC 2.

Intestinal epithelial cells as producers but not targets of chronic TNF suffice to cause murine Crohn-like pathology

PubMed Central

Roulis, Manolis; Armaka, Maria; Manoloukos, Menelaos; Apostolaki, Maria; Kollias, George

2011-01-01

TNF plays a crucial role in the pathogenesis of Crohn disease. Dysregulated TNF production in mice that bear the genetic deletion of the TNF AU-rich regulatory elements (ARE) (TnfΔARE/+ mice) results in TNF receptor I (TNFRI)-dependent spontaneous Crohn-like pathology. Current concepts consider intestinal epithelial cell (IEC) responses to TNF to be critical for intestinal pathology, but the potential contribution of IEC-derived TNF in disease pathogenesis has not been addressed. In this study we examined whether IEC are sufficient as cellular targets or sources of TNF in the development of intestinal pathology. Using IEC-specific reactivation of a hypomorphic TnfΔAREneo allele in mice, we show that selective chronic overproduction of TNF by IEC suffices to cause full development of Crohn-like pathology. Epithelial TNF overexpression leads to early activation of the underlying intestinal myofibroblast, a cell type previously identified as a sufficient target of TNF for disease development in the TnfΔARE model. By contrast, restricted TNFRI expression on IEC although sufficient to confer IEC apoptosis after acute exogenous TNF administration, fails to induce pathology following chronic specific targeting of IEC by endogenous TNF in TnfΔARE/+ mice. Our results argue against IEC being early and sufficient responders to chronic TNF-mediated pathogenic signals and suggest that proinflammatory aberrations leading to chronic TNF production by IEC may initiate pathology in Crohn disease. PMID:21402942

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugi, Yutaka; Takahashi, Kyoko, E-mail: ktaka@brs.nihon-u.ac.jp; Nakano, Kou

Highlights: {yields} Transcriptional activation of the Tollitip gene is higher in IECs than in monocytes. {yields} Nt -194/-186 region acts as a cis-element and is recognized by Elf-1. {yields} Elf-1 suppresses Tollip gene transcription in monocytes but not in IECs. {yields} O-GlcNAc modification is necessary for nuclear translocation of Elf-1. {yields} O-GlcNAcylation-dependent nuclear translocation of Elf-1 is impaired in IECs. -- Abstract: Intestinal epithelial cells (IECs) must be tolerant of the large number of commensal bacteria inhabiting the intestinal tract to avoid excessive inflammatory reactions. Toll-interacting protein (Tollip), a negative regulator of Toll-like receptor signaling, is known to be expressedmore » at high levels in IECs, and to thereby contribute to the hyporesponsiveness of IECs to commensals. In this study, we analyzed the underlying mechanisms for elevated transcription of the Tollip gene in IECs using a human IEC line, Caco-2, and a human monocyte line, THP-1, as a control. Elf-1 was identified as a transcription factor that negatively regulates Tollip gene expression. The transcription factor Elf-1 was localized in the nucleus by O-linked N-acetylglucosamine (O-GlcNAc) modification, whereas the unmodified form was detected only in the cytoplasm. Comparison of Caco-2 and THP-1 cells revealed that O-GlcNAc modification of Elf-1 was significantly lower in IECs than in monocytes. Collectively, the results indicate that insufficient O-GlcNAc modification prevents Elf-1-mediated transcriptional repression and thereby upregulates Tollip gene expression in IECs.« less

Effect of confining wall potential on charged collimated dust beam in low-pressure plasma

NASA Astrophysics Data System (ADS)

Kausik, S. S.; Kakati, B.; Saikia, B. K.

2013-05-01

The effect of confining wall potential on charged collimated dust beam in low-pressure plasma has been studied in a dusty plasma experimental setup by applying electrostatic field to each channel of a multicusp magnetic cage. Argon plasma is produced by hot cathode discharge method at a pressure of 5×10-4 millibars and is confined by a full line cusped magnetic field confinement system. Silver dust grains are produced by gas-evaporation technique and move upward in the form of a collimated dust beam due to differential pressure maintained between the dust and plasma chambers. The charged grains in the beam after coming out from the plasma column enter into the diagnostic chamber and are deflected by a dc field applied across a pair of deflector plates at different confining potentials. Both from the amount of deflection and the floating potential, the number of charges collected by the dust grains is calculated. Furthermore, the collimated dust beam strikes the Faraday cup, which is placed above the deflector plates, and the current (˜pA) so produced is measured by an electrometer at different confining potentials. The experimental results demonstrate the significant effect of confining wall potential on charging of dust grains.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Repins, Ingrid; Jordan, Dirk; Bosco, Nick

The proposed new IEC standard will address the test temperature requirements in IEC 61215 (module design), IEC 61730 (module safety), IEC 62790 (junction box safety) and IEC 62852 (connectors), and will provide guidelines to modify temperature limits in four existing standards to better describe module performance in hotter climates. This workshop includes four presentations: Special Testing for Modules Deployed in Hot Use Environments - Are We Doing This in a Low-Cost Way?, Experimental Evidence, Why the highest temperatures are the most stressful to PV modules during thermal cycling, and Safety Aspects for Modules Deployed in Hot Use Environments.

H-Mode Behavior Induced by Modulated Toroidal Current on HT-7 and HT-6M Tokamak

NASA Astrophysics Data System (ADS)

Mao, J. S.; Luo, J. R.; Xu, Y. H.; Zhao, J. Y.; Zhang, X. M.; Li, J. G.; Zhang, X. M.; Gao, X.; Li, Y. D.; Jie, Y. X.; Wu, Z. W.; Hu, L. Q.; Liu, S. X.; Zhang, X. D.; Bao, Y.; Yang, K.; Wang, G. X.; Chen, L.; Shi, Y. J.; Qin, P. J.; Gu, X. M.; Cui, N. Z.; Fan, H. Y.; Chen, Y. F.; Xia, C. Y.; Ruan, H. L.; Tong, X. D.; Phillips, P. E.

2001-10-01

An improved Ohmic confinement phase (similar to H-mode) has been observed during Modulating Toroidal Current on the Hefei Tokamak-6M (HT-6M) and Hefei super-conducting Tokamak-7 (HT-7). This improved plasma confinement phase is characterized by: (a) an increase in ne and T_e(0); (b) reduced H_α radiation from the edge; (c) steeper density and temperature profiles at the edge; (d) a more negative radial electric field inside the limiter; (e) a deeper electrostatic potential well at the edge; (f) reduced magnetic fluctuations at the edge; (g) MHD suppressing; (h) and by an increase in global energy confinement time, τ _e, by 27%-45%. The well-like structure of the radial electric field E_r, appears at an L-H like transition.

Electro-osmotic flow of semidilute polyelectrolyte solutions.

PubMed

Uematsu, Yuki; Araki, Takeaki

2013-09-07

We investigate electro-osmosis in aqueous solutions of polyelectrolytes using mean-field equations. A solution of positively charged polyelectrolytes is confined between two negatively charged planar surfaces, and an electric field is applied parallel to the surfaces. When electrostatic attraction between the polymer and the surface is strong, the polymers adhere to the surface, forming a highly viscous adsorption layer that greatly suppresses the electro-osmosis. Conversely, electro-osmosis is enhanced by depleting the polymers from the surfaces. We also found that the electro-osmotic flow is invertible when the electrostatic potential decays to its bulk value with the opposite sign. These behaviors are well explained by a simple mathematical form of the electro-osmotic coefficient.

Magnetic radiation shielding - An idea whose time has returned?

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

1991-01-01

One solution to the problem of shielding crew from particulate radiation in space is to use active electromagnetic shielding. Practical types of shield include the magnetic shield, in which a strong magnetic field diverts charged particles from the crew region, and the magnetic/electrostatic plasma shield, in which an electrostatic field shields the crew from positively charged particles, while a magnetic field confines electrons from the space plasma to provide charge neutrality. Advances in technology include high-strength composite materials, high-temperature superconductors, numerical computational solutions to particle transport in electromagnetic fields, and a technology base for construction and operation of large superconducting magnets. These advances make electromagnetic shielding a practical alternative for near-term future missions.

Protective effect of aged garlic extract (AGE) on the apoptosis of intestinal epithelial cells caused by methotrexate.

PubMed

Li, Tiesong; Ito, Kousei; Sumi, Shin-Ichiro; Fuwa, Toru; Horie, Toshiharu

2009-04-01

Methotrexate (MTX) causes intestinal damage, resulting in diarrhea. The side effects often disturb the cancer chemotherapy. We previously reported that AGE protected the small intestine of rats from the MTX-induced damage. In the present paper, the mechanism of the protection of AGE against the MTX-induced damage of small intestine was investigated, using IEC-6 cells originating from rat jejunum crypt. The viability and apoptosis of IEC-6 cells were examined in the presence of MTX and/or AGE. The viability of IEC-6 cells exposed to MTX was decreased by the increase of MTX concentration. The MTX-induced loss of viable IEC-6 cells was almost completely prevented by the presence of more than 0.1% AGE. In IEC-6 cells exposed to MTX, the cromatin condensation, DNA fragmentation, caspase-3 activation and cytochrome c release were observed. These were preserved to the control levels by the presence of AGE. MTX markedly decreased intracellular GSH in IEC-6 cells, but the presence of AGE in IEC-6 cells with MTX preserved intracellular GSH to the control level. IEC-6 cells in G2/M stage markedly decreased 72 h after the MTX treatment, which was preserved to the control level by the presence of AGE. These results indicated that AGE protected IEC-6 cells from the MTX-induced damage. The MTX-induced apoptosis of IEC-6 cells was shown to be depressed by AGE. AGE may be useful for the cancer chemotherapy with MTX, since AGE reduces the MTX-induced intestinal damage.

Antigen presentation by small intestinal epithelial cells uniquely enhances IFN-γ secretion from CD4{sup +} intestinal intraepithelial lymphocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatano, Ryo; Yamada, Kiyoshi; Iwamoto, Taku

2013-06-14

Highlights: •Small intestinal epithelial cells (sIECs). •sIECs are able to induce antigen specific proliferation of CD4{sup +} IELs. •sIECs induce markedly enhanced IFN-γ secretion by CD4{sup +} IELs. •Induction of enhanced IFN-γ secretion by sIECs is uniquely observed in CD4{sup +} IELs. -- Abstract: Small intestinal epithelial cells (sIECs) express major histocompatibility complex class II molecules even in a normal condition, and are known to function as antigen presenting cells (APCs) at least in vitro. These findings raised the possibility that sIECs play an important role in inducing immune responses against luminal antigens, especially those of intestinal intraepithelial lymphocytes (IELs)more » and lamina propria lymphocytes (LPLs). We herein showed that antigenic stimulation with sIECs induced markedly greater secretion of interferon-gamma (IFN-γ) by CD4{sup +} IELs, but not interleukin (IL)-4, IL-10 and IL-17 although the proliferative response was prominently lower than that with T cell-depleted splenic APCs. In contrast, no enhanced IFN-γ secretion by CD4{sup +} LPLs and primed splenic CD4{sup +} T cells was observed when stimulated with sIECs. Taken together, these results suggest that sIECs uniquely activate CD4{sup +} IELs and induce remarkable IFN-γ secretion upon antigenic stimulation in vivo.« less

IEC 61850: Technology Standards and Cyber-Security Threats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Youssef, Tarek A; El Hariri, mohamed; Bugay, Nicole

Substations constitute a fundamental part in providing reliable electricity to consumers. For a substation to maintain electricity reliability and its own real-time operability, communication between its components is inevitable. Before the emergence of IEC 61850, inter-substation communication was established via expensive copper wires with limited capabilities. IEC 61850 is the standard set by the International Electrotechnical Commission (IEC) Technical Committee Number 57 Working Group 10 and IEEE for Ethernet (IEEE 802.3)-based communication in electrical substations. Like many power grid systems standards, IEC 61850 was set without extensive consideration for critical security measures. This paper discusses IEC 61850 technology standards andmore » applications thoroughly and points out major security vulnerabilities it introduces in the context of current cyber-physical smart grid systems.« less

Adsorption of virus-like particles on ion exchange surface: Conformational changes at different pH detected by dual polarization interferometry.

PubMed

Yang, Yanli; Mengran Yu; Zhang, Songping; Ma, Guanghui; Su, Zhiguo

2015-08-21

Disassembling of virus-like particles (VLPs) like hepatitis B virus surface antigen (HB-VLPs) during chromatographic process has been identified as a major cause of loss of antigen activity. In this study, dual polarization interferometry (DPI) measurement, together with chromatography experiments, were performed to study the adsorption and conformational change of HB-VLPs on ion exchange surface at three different pHs. Changes in pH values of buffer solution showed only minimal effect on the HB-VLPs assembly and antigen activity, while significantly different degree of HB-VLPs disassembling was observed after ion exchange chromatography (IEC) at different pHs, indicating the conformational change of HB-VLPs caused mainly by its interactions with the adsorbent surface. By creating an ion exchange surface on chip surface, the conformational changes of HB-VLPs during adsorption to the surface were monitored in real time by DPI for the first time. As pH increased from 7.0 to 9.0, strong electrostatic interactions between oppositely charged HB-VLPs and the ion exchange surface make the HB-VLPs spread thinly or even adsorbed in disassembled formation on the surface as revealed by significant decrease in thickness of the adsorbed layer measured by DPI. Such findings were consistent with the results of IEC experiments operated at different pHs, that more disassembled HB-VLPs were detected in the eluted proteins at pH 9.0. At low pH like pH 5.0, however, possible bi-layer adsorption was involved as evidenced by an adsorbed layer thickness higher than average diameter of the HB-VLPs. The "lateral" protein-protein interactions might be unfavorable and would make additional contribution to the disassembling of HB-VLPs besides the primary mechanism related to the protein-surface interactions; therefore, the lowest antigen activity was observed after IEC at pH 5.0. Such real-time information on conformational change of VLPs is helpful for better understanding the real mechanism for the disassembling of VLPs on the solid-liquid interface. Copyright © 2015 Elsevier B.V. All rights reserved.

46 CFR 110.10-1 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Explosive Gas Atmospheres—Part 15: Type of Protection “n”, Second Edition (2001) (“IEC 60079-15”), 111.105-1..., Part 202: System Design-Protection (1996) (“IEC 92-202”), 111.12-7; 111.50-3; 111.53-1; 111.54-1; (18..., First Edition (1975) (“IEC 92-503”), 111.30-5; (28) IEC 60529 Degrees of Protection Provided by...

46 CFR 110.10-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Explosive Gas Atmospheres—Part 15: Type of Protection “n”, Second Edition (2001) (“IEC 60079-15”), 111.105-1..., Part 202: System Design-Protection (1996) (“IEC 92-202”), 111.12-7; 111.50-3; 111.53-1; 111.54-1; (18..., First Edition (1975) (“IEC 92-503”), 111.30-5; (28) IEC 60529 Degrees of Protection Provided by...

Chaotic transport and damping from θ-ruffled separatrices.

PubMed

Kabantsev, A A; Dubin, Daniel H E; Driscoll, C F; Tsidulko, Yu A

2010-11-12

Variations in magnetic or electrostatic confinement fields give rise to trapping separatrices, and neoclassical transport theory analyzes effects from collision-induced separatrix crossings. Experiments on pure electron plasmas now quantitatively characterize a broad range of transport and wave damping effects due to "chaotic" separatrix crossings, which occur due to equilibrium plasma rotation across θ-ruffled separatrices, and due to wave-induced separatrix fluctuations.

CMMI (Trademark) for Development, Version 1.2

DTIC Science & Technology

2006-08-01

IEC TR 12207 Information Technology—Software Life Cycle Processes, 1995. http://www.jtc1-sc7.org. ISO 1998 International Organization for...We also consult other standards as needed, including the following: • ISO 9000 [ ISO 1987] • ISO /IEC 12207 [ ISO 1995] • ISO /IEC 15504 [ ISO 2006... ISO /IEC) body of standards. CMMs focus on improving processes in an organization. They contain the essential elements of effective processes for one

Common Criteria Evaluation and Validation Scheme for Information Technology Security: Guidance to Validators of IT Security Evaluations

DTIC Science & Technology

2002-02-01

NVLAP procedures are compatible with, among others, the most recent official publications of ISO / IEC 17025 (formally ISO / IEC Guide 25), ISO Guides 2, 30... IEC Guide 17025 and the relevant requirements of ISO 9002-1994. NVLAP Handbook 150-20 contains information that is specific to Common Criteria...Evaluation Technical Report EAP Evaluation Acceptance Package IEC International Electrotechnical Commission ISO International

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wohlgemuth, J.

Description and history of the IEC 61215 qualification test, what it accomplishes, and what it does not accomplish that would be useful to the community. The commercial success of PV is based on long term reliability of the PV modules. Today's modules are typically qualified/certified to: (1) IEC 61215 for Crystalline Silicon Modules; (2) IEC 61646 for Thin Film Modules; and (3) IEC 62108 for CPV Modules. These qualification tests do an excellent job of identifying design, materials and process flaws that could lead to premature field failures. This talk will provide a summary of how IEC 61215 was developed,more » how well it works and what its limitations are.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujimoto, Cy H.; Kim, Soowhan; Stains, Ronald

Sulfonated Diels Alder poly(phenylene) (SDAPP) was examined for vanadium redox flow battery (VRFB) use. The ion exchange capacity (IEC) was varied from 1.4, 1.6 and 2.0 meq/g in order to tune the proton conductivity and vanadium permeability. Coulombic efficiencies between 92 to 99% were observed, depending on IEC (lower IEC, higher coulombic efficiencies). In all cases the SDAPP displayed comparable energy efficiencies (88 - 90%) to Nafion 117 (88%) at 50mA/cm2. Membrane durability also was dependent on IEC; SDAPP with the highest IEC lasted slightly over 50 cycles while SDAPP with the lowest IEC lasted over 400 cycles and testingmore » was discontinued only due to time constraints. Accelerated vanadium lifetime studies were initialed with SDAPP, by soaking films in a 0.1 M V5+ and 5.0 M total SO4-2 solution. The rate of degradation was also proportional with IEC; the 2 meq/g sample dissolved within 376 hours, the 1.6 meq/g sample dissolved after 860 hours, while the 1.4 meq/g sample broke apart after 1527 hours.« less

Optical properties of voltage sensitive hemicyanine dyes of variable hydrophobicity confined within surfactant micelles

NASA Astrophysics Data System (ADS)

Naeem, Kashif; Naseem, Bushra; Shah, S. S.; Shah, Syed W. H.

2017-11-01

The optical properties of amphiphilic hemicyanine dyes with variable hydrophobicity, confined within anionic micelles of sodium dodecylbenzenesulfonate (NaDDBS) have been studied by UV-visible absorption spectroscopy. The confinement constant, K conf has been determined for each entrapped dye. The ion-pair formation between dye and surfactant causes a decline in electronic transition energy (ΔE T) when dye alkyl chains are smaller due to stabilization of both the ground and excited state. ΔE T values gradually increase with increase in dye hydrophobicity that hampers the electrostatic interaction with dialkylammonium moiety and consequently excited state stabilization is compromised. The average number of dye molecules trapped in a single micelle was also determined. The negative values of Gibbs free energy indicate that the dye entrapment within micelles is energetically favored. These findings have significance for developing functional materials with peculiar luminescent properties, especially for more effective probing of complex biological systems.

Long-Range Interactions Restrict Water Transport in Pyrophyllite Interlayers

DOE PAGES

Zarzycki, Piotr; Gilbert, Benjamin

2016-04-27

Water diffusion within smectite clay interlayers is reduced by confinement and hence is highly determined by the interlayer spacings that are adopted during swelling. However, a molecular understanding of the short-and long-range forces governing interlayer water structure and dynamics is lacking. Using molecular dynamics simulations of water intercalated between pyrophyllite (smectite prototype) layers we provide a detailed picture of the variation of interlayered water mobility accompanying smectite expansion. Subtle changes in hydrogen bond network structure cause significant changes in water mobility that is greater for stable hydration states and reduced for intermediate separations. By studying pyrophyllite with and without externalmore » water we reveal that long-range electrostatic forces apply a restraining effect upon interlayer water mobility. Our findings are relevant for broad range of confining nanostructures with walls thin enough to permit long-range interactions that could affect the mobility of confined solvent molecules and solute species.« less

Long-Range Interactions Restrict Water Transport in Pyrophyllite Interlayers

PubMed Central

Zarzycki, Piotr; Gilbert, Benjamin

2016-01-01

Water diffusion within smectite clay interlayers is reduced by confinement and hence is highly determined by the interlayer spacings that are adopted during swelling. However, a molecular understanding of the short- and long-range forces governing interlayer water structure and dynamics is lacking. Using molecular dynamics simulations of water intercalated between pyrophyllite (smectite prototype) layers we provide a detailed picture of the variation of interlayered water mobility accompanying smectite expansion. Subtle changes in hydrogen bond network structure cause significant changes in water mobility that is greater for stable hydration states and reduced for intermediate separations. By studying pyrophyllite with and without external water we reveal that long-range electrostatic forces apply a restraining effect upon interlayer water mobility. Our findings are relevant for broad range of confining nanostructures with walls thin enough to permit long-range interactions that could affect the mobility of confined solvent molecules and solute species. PMID:27118164

High-Energy Electron Confinement in a Magnetic Cusp Configuration

NASA Astrophysics Data System (ADS)

Park, Jaeyoung; Krall, Nicholas A.; Sieck, Paul E.; Offermann, Dustin T.; Skillicorn, Michael; Sanchez, Andrew; Davis, Kevin; Alderson, Eric; Lapenta, Giovanni

2015-04-01

We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when β (plasma pressure/magnetic field pressure) is of order unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high β a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. While not able to confirm the details of Grad's work, the current experiment does validate, for the first time, the conjecture that confinement is substantially improved at high β . This represents critical progress toward an understanding of the plasma dynamics in a high-β cusp system. We hope that these results will stimulate a renewed interest in the cusp configuration as a fusion confinement candidate. In addition, the enhanced high-energy electron confinement resolves a key impediment to progress of the Polywell fusion concept, which combines a high-β cusp configuration with electrostatic fusion for a compact, power-producing nuclear fusion reactor.

Fast visible imaging of turbulent plasma in TORPEX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iraji, D.; Diallo, A.; Fasoli, A.

2008-10-15

Fast framing cameras constitute an important recent diagnostic development aimed at monitoring light emission from magnetically confined plasmas, and are now commonly used to study turbulence in plasmas. In the TORPEX toroidal device [A. Fasoli et al., Phys. Plasmas 13, 055902 (2006)], low frequency electrostatic fluctuations associated with drift-interchange waves are routinely measured by means of extensive sets of Langmuir probes. A Photron Ultima APX-RS fast framing camera has recently been acquired to complement Langmuir probe measurements, which allows comparing statistical and spectral properties of visible light and electrostatic fluctuations. A direct imaging system has been developed, which allows viewingmore » the light, emitted from microwave-produced plasmas tangentially and perpendicularly to the toroidal direction. The comparison of the probability density function, power spectral density, and autoconditional average of the camera data to those obtained using a multiple head electrostatic probe covering the plasma cross section shows reasonable agreement in the case of perpendicular view and in the plasma region where interchange modes dominate.« less

Electrostatically self-assembled polyoxometalates on molecular-dye-functionalized diamond.

PubMed

Zhong, Yu Lin; Ng, Wibowo; Yang, Jia-Xiang; Loh, Kian Ping

2009-12-30

We have successfully immobilized phosphotungstic acid (PTA), a polyoxometalate, on the surface of boron-doped diamond (BDD) surface through electrostatic self-assembly of PTA on pyridinium dye-functionalized-BDD. The inorganic/organic bilayer structure on BDD is found to exhibit fast surface-confined reversible electron transfer. The molecular dye-grafted BDD can undergo controllable electrical stripping and regeneration of PTA which can be useful for electronics or sensing applications. Furthermore, we have demonstrated the use of PTA as a molecular switch in which the direction of photocurrent from diamond to methyl viologen is reversed by the surface bound PTA. Robust photocurrent converter based on such molecular system-diamond platform can operate in corrosive medium which is not tolerated by indium tin oxide electrodes.

Electrostatic ion cyclotron velocity shear instability

NASA Technical Reports Server (NTRS)

Lemons, D. S.; Winske, D.; Gary, S. P.

1992-01-01

A local electrostatic dispersion equation is derived for a shear flow perpendicular to an ambient magnetic field, which includes all kinetic effects and involves only one important parameter. The dispersion equation is cast in the form of Gordeyev integrals and is solved numerically. Numerical solutions indicate that an ion cyclotron instability is excited. The instability occurs roughly at multiples of the ion cyclotron frequency (modified by the shear), with the growth rate or the individual harmonics overlapping in the wavenumber. At large values of the shear parameter, the instability is confined to long wavelengths, but at smaller shear, a second distinct branch at shorter wavelengths also appears. The properties of the instability obtained are compared with those obtained in the nonlocal limit by Ganguli et al. (1985, 1988).

Measuring forces and dynamics for optically levitated 20μm PS particles in air using electrostatic modulation

NASA Astrophysics Data System (ADS)

Park, Haesung; LeBrun, Thomas W.

2015-08-01

We demonstrate the simultaneous measurement of optical trap stiffness and quadrant-cell photodetector (QPD) calibration of optically trapped polystyrene particle in air. The analysis is based on the transient response of particles, confined to an optical trap, subject to a pulsed electrostatic field generated by parallel indium tin oxide (ITO) coated substrates. The resonant natural frequency and damping were directly estimated by fitting the analytical solution of the transient response of an underdamped harmonic oscillator to the measured particle displacement from its equilibrium position. Because, the particle size was estimated independently with video microscopy, this approach allowed us to measure the optical force without ignoring the effects of inertia and temperature changes from absorption.

Gate-Defined Quantum Confinement in InSe-based van der Waals Heterostructures.

PubMed

Hamer, Matthew J; Tóvári, Endre; Zhu, Mengjian; Thompson, Michael Dermot; Mayorov, Alexander S; Prance, Jonathan; Lee, Yongjin; Haley, Richard; Kudrynskyi, Zakhar R; Patanè, Amalia; Terry, Daniel; Kovalyuk, Zakhar D; Ensslin, Klaus; Kretinin, Andrey V; Geim, Andre K; Gorbachev, Roman Vladislavovich

2018-05-15

Indium selenide, a post-transition metal chalcogenide, is a novel two-dimensional (2D) semiconductor with interesting electronic properties. Its tunable band gap and high electron mobility have already attracted considerable research interest. Here we demonstrate strong quantum confinement and manipulation of single electrons in devices made from few-layer crystals of InSe using electrostatic gating. We report on gate-controlled quantum dots in the Coulomb blockade regime as well as one-dimensional quantization in point contacts, revealing multiple plateaus. The work represents an important milestone in the development of quality devices based on 2D materials and makes InSe a prime candidate for relevant electronic and optoelectronic applications.

Coulomb double helical structure

NASA Astrophysics Data System (ADS)

Kamimura, Tetsuo; Ishihara, Osamu

2012-01-01

Structures of Coulomb clusters formed by dust particles in a plasma are studied by numerical simulation. Our study reveals the presence of various types of self-organized structures of a cluster confined in a prolate spheroidal electrostatic potential. The stable configurations depend on a prolateness parameter for the confining potential as well as on the number of dust particles in a cluster. One-dimensional string, two-dimensional zigzag structure and three-dimensional double helical structure are found as a result of the transition controlled by the prolateness parameter. The formation of stable double helical structures resulted from the transition associated with the instability of angular perturbations on double strings. Analytical perturbation study supports the findings of numerical simulations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Q. L., E-mail: maqinli@gmail.com, E-mail: mizukami@wpi-aimr.tohoku.ac.jp; Miyazaki, T.; Mizukami, S., E-mail: maqinli@gmail.com, E-mail: mizukami@wpi-aimr.tohoku.ac.jp

The laser-induced spin dynamics of FeCo in perpendicularly magnetized L1{sub 0}-MnGa/FeCo bilayers with ferromagnetic and antiferromagnetic interfacial exchange coupling (IEC) are examined using the time-resolved magneto-optical Kerr effect. We found a precessional phase reversal of the FeCo layer as the IEC changes from ferromagnetic to antiferromagnetic. Moreover, a precession-suspension window was observed when the magnetic field was applied in a certain direction for the bilayer with ferromagnetic IEC. Our observations reveal that the spin dynamics modulation is strongly dependent on the IEC type within the Landau-Lifshitz-Gilbert depiction. The IEC dependence of the precessional phase and amplitude suggests the interesting methodmore » for magnetization dynamics modulation.« less

IEC planning: eight state-of-the-art principles.

PubMed

Middleton, J

1983-12-01

Considerable experience and research has been accumulated in the last 20 years on the ways in which information/education/communication (IEC) programs can be effectively designed, implemented, and evaluated. Possibly more effort has focused on population and family planning IEC than on any other sectoral program of development communication. Several principles have emerged which, taken together, define the state of the art in the field. These principles provide a framework of experience which can guide the development of comprehensive IEC programs. They include: policy and resource assessment; audience analysis; strategy design; message research and pretesting; participation and feedback; management; evaluation; and collaboration. The nature of the national policy base for population and family planning programs will determine the goals and approaches of the IEC program. Strong policies of limitation on popultion growth lead to equally strong and pervasive IEC efforts designed to directly affect contraceptive behavior. Assessment of existing policy is an essential aspect of the design of an effective IEC program. Policies establish the rationale and boundaries for action. Population and family planning programs are concerned with some of the most intimate human behavior. Consequently, structured and sensitive audience analysis has become an integral part of the design of IEC programs. The design of communication strategy requires clearly stated objectives. Principles of human learning are used to structure information appropriately. Message research and pretesting have become integral components of the strategy design process. Small scale research on specific objectives is necessary to establish the basis for message design. Audience participation and feedback in remaining phases of program development and implementation are important. The management of an IEC program requires a specific combination of planning, flexibility, and creativity. Evaluation of program effects--identification of the degree of change toward stated objectives -- is critical to long term assessment of the underlying strategy and the identification both of needed corrections and new directions for the future. Collaboration with and involvement of stakeholders in the design and implementation of a national IEC program significantly raises the probability that support will be forthcoming. Taken together these 8 principles can become the basic building blocks of an effective population/family planning IEC program.

[Approval of ISO/IEC 17025 and quality control of laboratory testing].

PubMed

Yamamoto, Shigeki; Asakura, Hiroshi; Machii, Kenji; Igimi, Shizunobu

2010-01-01

First section of Division of Biomedical Food Research, National Institute of Health Sciences (NIHS) was approved by ISO/IEC 17025 as a laboratory having an appropriate laboratory testing technique. NIHS is the first national laboratory approved by ISO/IEC 17025. NIHS has also been accepted the appropriate technique and facility for the BSL3 level pathogens by ISO/IEC 17025. NIHS is necessary to take an external audit almost every year. This approval is renewed every 4 years.

Software Assurance in Acquisition: Mitigating Risks to the Enterprise. A Reference Guide for Security-Enhanced Software Acquisition and Outsourcing

DTIC Science & Technology

2009-02-01

management, available at <http://www.iso.org/ iso /en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=39612&ICS1=35&ICS2=40 &ICS3=>. ISO /IEC 27001 . Information...Management of the Systems Engineering Process. [ ISO /IEC 27001 ] ISO /IEC 27001 :2005. Information technology -- Security techniques -- Information security...software life cycles [ ISO /IEC 15026]. Software assurance is a key element of national security and homeland security. It is critical because dramatic

Surface nucleation and independent growth of Ce(OH)4 within confinement space on modified carbon black surface to prepare nano-CeO2 without agglomeration

NASA Astrophysics Data System (ADS)

Zhang, Xinyue; Xia, Chunhui; Li, Kaitao; Lin, Yanjun

2018-06-01

Highly dispersed negative carboxyl groups can be formed on carbon black (CB) surface modified with strong nitric acid. Therefore positive cations can be uniformly absorbed by carboxyl groups and precipitated within a confinement space on modified CB surface to prepare highly dispersed nanomaterials. In this paper, the formation and dispersion status of surface negative carboxyl groups, adsorption status of Ce3+, surface confinement nucleation, crystallization and calcination process were studied by EDS, SEM, and laser particle size analysis. The results show that the carboxyl groups formed on modified CB surface are highly dispersed, and Ce3+ cations can be uniformly anchored by carboxyl groups. Therefore, highly dispersed Ce3+ can react with OH- within a confinement surface region to form positive nano-Ce(OH)4 nuclei which also can be adsorbed by electrostatic attraction. After independent growth of Ce(OH)4 without agglomeration, highly dispersed CeO2 nanoparticles without agglomeration can be prepared together with the help of effectively isolates by CO2 released in the combustion of CB.

Surface nucleation and independent growth of Ce(OH)4 within confinement space on modified carbon black surface to prepare nano-CeO2 without agglomeration

NASA Astrophysics Data System (ADS)

Zhang, Xinyue; Xia, Chunhui; Li, Kaitao; Lin, Yanjun

2018-04-01

Highly dispersed negative carboxyl groups can be formed on carbon black (CB) surface modified with strong nitric acid. Therefore positive cations can be uniformly absorbed by carboxyl groups and precipitated within a confinement space on modified CB surface to prepare highly dispersed nanomaterials. In this paper, the formation and dispersion status of surface negative carboxyl groups, adsorption status of Ce3+, surface confinement nucleation, crystallization and calcination process were studied by EDS, SEM, and laser particle size analysis. The results show that the carboxyl groups formed on modified CB surface are highly dispersed, and Ce3+ cations can be uniformly anchored by carboxyl groups. Therefore, highly dispersed Ce3+ can react with OH- within a confinement surface region to form positive nano-Ce(OH)4 nuclei which also can be adsorbed by electrostatic attraction. After independent growth of Ce(OH)4 without agglomeration, highly dispersed CeO2 nanoparticles without agglomeration can be prepared together with the help of effectively isolates by CO2 released in the combustion of CB.

Genomic dissection of conserved transcriptional regulation in intestinal epithelial cells

PubMed Central

Camp, J. Gray; Weiser, Matthew; Cocchiaro, Jordan L.; Kingsley, David M.; Furey, Terrence S.; Sheikh, Shehzad Z.; Rawls, John F.

2017-01-01

The intestinal epithelium serves critical physiologic functions that are shared among all vertebrates. However, it is unknown how the transcriptional regulatory mechanisms underlying these functions have changed over the course of vertebrate evolution. We generated genome-wide mRNA and accessible chromatin data from adult intestinal epithelial cells (IECs) in zebrafish, stickleback, mouse, and human species to determine if conserved IEC functions are achieved through common transcriptional regulation. We found evidence for substantial common regulation and conservation of gene expression regionally along the length of the intestine from fish to mammals and identified a core set of genes comprising a vertebrate IEC signature. We also identified transcriptional start sites and other putative regulatory regions that are differentially accessible in IECs in all 4 species. Although these sites rarely showed sequence conservation from fish to mammals, surprisingly, they drove highly conserved IEC expression in a zebrafish reporter assay. Common putative transcription factor binding sites (TFBS) found at these sites in multiple species indicate that sequence conservation alone is insufficient to identify much of the functionally conserved IEC regulatory information. Among the rare, highly sequence-conserved, IEC-specific regulatory regions, we discovered an ancient enhancer upstream from her6/HES1 that is active in a distinct population of Notch-positive cells in the intestinal epithelium. Together, these results show how combining accessible chromatin and mRNA datasets with TFBS prediction and in vivo reporter assays can reveal tissue-specific regulatory information conserved across 420 million years of vertebrate evolution. We define an IEC transcriptional regulatory network that is shared between fish and mammals and establish an experimental platform for studying how evolutionarily distilled regulatory information commonly controls IEC development and physiology. PMID:28850571

Epithelial cell-intrinsic Notch signaling plays an essential role in the maintenance of gut immune homeostasis.

PubMed

Obata, Yuuki; Takahashi, Daisuke; Ebisawa, Masashi; Kakiguchi, Kisa; Yonemura, Shigenobu; Jinnohara, Toshi; Kanaya, Takashi; Fujimura, Yumiko; Ohmae, Masumi; Hase, Koji; Ohno, Hiroshi

2012-03-01

Intestinal epithelial cells (IECs) have important functions as the first line of defense against diverse microorganisms on the luminal surface. Impaired integrity of IEC has been implicated in increasing the risk for inflammatory disorders in the gut. Notch signaling plays a critical role in the maintenance of epithelial integrity by regulating the balance of secretory and absorptive cell lineages, and also by facilitating epithelial cell proliferation. We show in this article that mice harboring IEC-specific deletion of Rbpj (RBP-J(ΔIEC)), a transcription factor that mediates signaling through Notch receptors, spontaneously develop chronic colitis characterized by the accumulation of Th17 cells in colonic lamina propria. Intestinal bacteria are responsible for the development of colitis, because their depletion with antibiotics prevented the development of colitis in RBP-J(ΔIEC) mice. Furthermore, bacterial translocation was evident in the colonic mucosa of RBP-J(ΔIEC) mice before the onset of colitis, suggesting attenuated epithelial barrier functions in these mice. Indeed, RBP-J(ΔIEC) mice displayed increase in intestinal permeability after rectal administration of FITC-dextran. In addition to the defect in physical barrier, loss of Notch signaling led to arrest of epithelial cell turnover caused by downregulation of Hes1, a transcriptional repressor of p27(Kip1) and p57(Kip2). Thus, epithelial cell-intrinsic Notch signaling ensures integrity and homeostasis of IEC, and this mechanism is required for containment of intestinal inflammation.

33 CFR 154.106 - Incorporation by reference: Where can I get a copy of the publications incorporated by reference...

Code of Federal Regulations, 2011 CFR

2011-07-01

...://www.iec.ch/: (1) IEC 309-1—Plugs, Socket-Outlets and Couplers for Industrial Purposes: Part 1, General Requirements, 1979, IBR approved for § 154.812. (2) IEC 309-2—Plugs, Socket-Outlets and Couplers for Industrial...

33 CFR 154.106 - Incorporation by reference: Where can I get a copy of the publications incorporated by reference...

Code of Federal Regulations, 2012 CFR

2012-07-01

...://www.iec.ch/: (1) IEC 309-1—Plugs, Socket-Outlets and Couplers for Industrial Purposes: Part 1, General Requirements, 1979, IBR approved for § 154.812. (2) IEC 309-2—Plugs, Socket-Outlets and Couplers for Industrial...

Aged garlic extract protects against methotrexate-induced apoptotic cell injury of IEC-6 cells.

PubMed

Horie, Toshiharu; Li, Tiesong; Ito, Kousei; Sumi, Shin-ichiro; Fuwa, Toru

2006-03-01

Gastrointestinal toxicity is one of the most serious side effects of methotrexate (MTX) treatment. The side effects often disrupt the cancer chemotherapy. We previously reported that aged garlic extract (AGE) protects the small intestine of rats from MTX-induced damage. In this study, the protection of AGE against MTX-induced damage of IEC-6 cells originating from the rat jejunum crypt was investigated. MTX decreased the viability of IEC-6 cells, but this effect was prevented by AGE (0.5%). The MTX-induced apoptosis of IEC-6 cells was depressed by AGE. These results indicated that AGE protects IEC-6 cells from the MTX-induced damage. AGE may be useful in cancer chemotherapy with MTX because it reduces MTX-induced intestinal damage.

Streptococcal Adhesin P (SadP) contributes to Streptococcus suis adhesion to the human intestinal epithelium.

PubMed

Ferrando, Maria Laura; Willemse, Niels; Zaccaria, Edoardo; Pannekoek, Yvonne; van der Ende, Arie; Schultsz, Constance

2017-01-01

Streptococcus suis is a zoonotic pathogen, causing meningitis and septicemia. We previously demonstrated that the gastrointestinal tract (GIT) is an entry site for zoonotic S. suis infection. Here we studied the contribution of Streptococcal adhesin Protein (SadP) to host-pathogen interaction at GIT level. SadP expression in presence of Intestinal Epithelial Cells (IEC) was compared with expression of other virulence factors by measuring transcript levels using quantitative Real Time PCR (qRT-PCR). SadP variants were identified by phylogenetic analysis of complete DNA sequences. The interaction of SadP knockout and complementation mutants with IEC was tested in vitro. Expression of sadP was significantly increased in presence of IEC. Sequence analysis of 116 invasive strains revealed five SadP sequence variants, correlating with genotype. SadP1, present in zoonotic isolates of clonal complex 1, contributed to binding to both human and porcine IEC and translocation across human IEC. Antibodies against the globotriaosylceramide Gb3/CD77 receptor significantly inhibited adhesion to human IEC. SadP is involved in the host-pathogen interaction in the GIT. Differences between SadP variants may determine different affinities to the Gb3/CD77 host-receptor, contributing to variation in adhesion capacity to host IEC and thus to S. suis zoonotic potential.

Comparative efficacy of two poeciliid fish in indoor cement tanks against chikungunya vector Aedes aegypti in villages in Karnataka, India.

PubMed

Ghosh, Susanta K; Chakaravarthy, Preethi; Panch, Sandhya R; Krishnappa, Pushpalatha; Tiwari, Satyanarayan; Ojha, Vijay P; Manjushree, R; Dash, Aditya P

2011-07-28

In 2006, severe outbreaks of Aedes aegypti-transmitted chikungunya occurred in villages in Karnataka, South India. We evaluated the effectiveness of combined information, education and communication (IEC) campaigns using two potential poeciliid larvivorous fish guppy (Poecilia reticulata) and mosquitofish (Gambusia affinis), in indoor cement tanks for Aedes larval control. Trials were conducted in two villages (Domatmari and Srinivaspura) in Tumkur District from March to May 2006 for Poecilia and one village (Balmanda) in Kolar District from July to October 2006 for Gambusia. A survey on knowledge, attitude and practice (KAP) on chikungunya was initially conducted and IEC campaigns were performed before and after fish release in Domatmari (IEC alone, followed by IEC + Poecilia) and Balmanda (IEC + Gambusia). In Srinivaspura, IEC was not conducted. Larval surveys were conducted at the baseline followed by one-week and one-month post-intervention periods. The impact of fish on Aedes larvae and disease was assessed based on baseline and post-intervention observations. Only 18% of respondents knew of the role of mosquitoes in fever outbreaks, while almost all (n = 50 each) gained new knowledge from the IEC campaigns. In Domatmari, IEC alone was not effective (OR 0.54; p = 0.067). Indoor cement tanks were the most preferred Ae. aegypti breeding habitat (86.9%), and had a significant impact on Aedes breeding (Breteau Index) in all villages in the one-week period (p < 0.001). In the one-month period, the impact was most sustained in Domatmari (OR 1.58, p < 0.001) then Srinivaspura (OR 0.45, p = 0.063) and Balmanda (OR 0.51, p = 0.067). After fish introductions, chikungunya cases were reduced by 99.87% in Domatmari, 65.48% in Srinivaspura and 68.51% in Balmanda. Poecilia exhibited greater survival rates than Gambusia (86.04 vs.16.03%) in cement tanks. Neither IEC nor Poecilia alone was effective against Aedes (p > 0.05). We conclude that Poecilia + IEC is an effective intervention strategy. The operational cost was 0.50 (US$ 0.011, 1 US$= 47) per capita per application. Proper water storage practices, focused IEC with Poecilia introductions and vector sanitation involving the local administration and community, is suggested as the best strategy for Aedes control.

Electrostatics at the oil–water interface, stability, and order in emulsions and colloids

PubMed Central

Leunissen, Mirjam E.; van Blaaderen, Alfons; Hollingsworth, Andrew D.; Sullivan, Matthew T.; Chaikin, Paul M.

2007-01-01

Oil–water mixtures are ubiquitous in nature and are particularly important in biology and industry. Usually additives are used to prevent the liquid droplets from coalescing. Here, we show that stabilization can also be obtained from electrostatics, because of the well known remarkable properties of water. Preferential ion uptake leads to a tunable droplet charge and surprisingly stable, additive-free, water-in-oil emulsions that can crystallize. For particle-stabilized (“Pickering”) emulsions we find that even extremely hydrophobic, nonwetting particles can be strongly bound to (like-charged) oil–water interfaces because of image charge effects. These basic insights are important for emulsion production, encapsulation, and (self-)assembly, as we demonstrate by fabricating a diversity of structures in bulk, on surfaces, and in confined geometries. PMID:17307876

Gate-Tunable Electron Transport Phenomena in Al-Ge⟨111⟩-Al Nanowire Heterostructures.

PubMed

Brunbauer, Florian M; Bertagnolli, Emmerich; Lugstein, Alois

2015-11-11

Electrostatically tunable negative differential resistance (NDR) is demonstrated in monolithic metal-semiconductor-metal (Al-Ge-Al) nanowire (NW) heterostructures integrated in back-gated field-effect transistors (FETs). Unambiguous signatures of NDR even at room temperature are attributed to intervalley electron transfer. At yet higher electric fields, impact ionization leads to an exponential increase of the current in the ⟨111⟩ oriented Ge NW segments. Modulation of the transfer rates, manifested as a large tunability of the peak-to-valley ratio (PVR) and the onset of impact ionization is achieved by the combined influences of electrostatic gating, geometric confinement, and heterojunction shape on hot electron transfer and by electron-electron scattering rates that can be altered by varying the charge carrier concentration in the NW FETs.

A comparison of the pro-angiogenic potential of human induced pluripotent stem cell derived endothelial cells and induced endothelial cells in a murine model of peripheral arterial disease.

PubMed

Clayton, Zoe E; Yuen, Gloria S C; Sadeghipour, Sara; Hywood, Jack D; Wong, Jack W T; Huang, Ngan F; Ng, Martin K C; Cooke, John P; Patel, Sanjay

2017-05-01

Endothelial cells derived from human induced pluripotent stem cells (iPSC-ECs) promote angiogenesis, and more recently induced endothelial cells (iECs) have been generated via fibroblast trans-differentiation. These cell types have potential as treatments for peripheral arterial disease (PAD). However, it is unknown whether different reprogramming methods produce cells that are equivalent in terms of their pro-angiogenic capabilities. We aimed to directly compare iPSC-ECs and iECs in an animal model of PAD, in order to identify which cell type, if any, displays superior therapeutic potential. IPSC-ECs and iECs were generated from human fibroblasts, and transduced with a reporter construct encoding GFP and firefly luciferase for bioluminescence imaging (BLI). Endothelial phenotype was confirmed using in vitro assays. NOD-SCID mice underwent hindlimb ischaemia surgery and received an intramuscular injection of either 1×10 6 iPSC-ECs, 1×10 6 iECs or control vehicle only. Perfusion recovery was measured by laser Doppler. Hindlimb muscle samples were taken for histological analyses. Perfusion recovery was enhanced in iPSC-EC treated mice on day 14 (Control vs. iPSC-EC; 0.35±0.04 vs. 0.54±0.08, p<0.05) and in iEC treated mice on days 7 (Control vs. iEC; 0.23±0.02 vs. 0.44±0.06, p<0.05), 10 (0.31±0.04 vs. 0.64±0.07, p<0.001) and 14 (0.35±0.04 vs. 0.68±0.07, p<0.001) post-treatment. IEC-treated mice also had greater capillary density in the ischaemic gastrocnemius muscle (Control vs. iEC; 125±10 vs. 179±11 capillaries/image; p<0.05). BLI detected iPSC-EC and iEC presence in vivo for two weeks post-treatment. IPSC-ECs and iECs exhibit similar, but not identical, endothelial functionality and both cell types enhance perfusion recovery after hindlimb ischaemia. Copyright © 2017 Elsevier B.V. All rights reserved.

Predicting the impact of diet and enzymopathies on human small intestinal epithelial cells

PubMed Central

Sahoo, Swagatika; Thiele, Ines

2013-01-01

Small intestinal epithelial cells (sIECs) have a significant share in whole body metabolism as they perform enzymatic digestion and absorption of nutrients. Furthermore, the diet plays a key role in a number of complex diseases including obesity and diabetes. The impact of diet and altered genetic backgrounds on human metabolism may be studied by using computational modeling. A metabolic reconstruction of human sIECs was manually assembled using the literature. The resulting sIEC model was subjected to two different diets to obtain condition-specific metabolic models. Fifty defined metabolic tasks evaluated the functionalities of these models, along with the respective secretion profiles, which distinguished between impacts of different dietary regimes. Under the average American diet, the sIEC model resulted in higher secretion flux for metabolites implicated in metabolic syndrome. In addition, enzymopathies were analyzed in the context of the sIEC metabolism. Computed results were compared with reported gastrointestinal (GI) pathologies and biochemical defects as well as with biomarker patterns used in their diagnosis. Based on our simulations, we propose that (i) sIEC metabolism is perturbed by numerous enzymopathies, which can be used to study cellular adaptive mechanisms specific for such disorders, and in the identification of novel co-morbidities, (ii) porphyrias are associated with both heme synthesis and degradation and (iii) disturbed intestinal gamma-aminobutyric acid synthesis may be linked to neurological manifestations of various enzymopathies. Taken together, the sIEC model represents a comprehensive, biochemically accurate platform for studying the function of sIEC and their role in whole body metabolism. PMID:23492669

Electric fence standards comport with human data and AC limits.

PubMed

Kroll, Mark W; Perkins, Peter E; Panescu, Dorin

2015-08-01

The ubiquitous electric fence is essential to modern agriculture and has saved lives by reducing the number of livestock automobile collisions. Modern safety standards such as IEC 60335-2-76 and UL 69 have played a role in this positive result. However, these standards are essentially based on energy and power (RMS current), which have limited direct relationship to cardiac effects. We compared these standards to bioelectrically more relevant units of charge and average current in view of recent work on VF (ventricular fibrillation) induction and to existing IEC AC current limits. There are 3 limits for normal (low) pulsing rate: IEC energy limit, IEC current limit, and UL current limit. We then calculated the delivered charge allowed for each pulse duration for these limits and then compared them to a charge-based safety model derived from published human ventricular-fibrillation induction data. Both the IEC and UL also allow for rapid pulsing for up to 3 minutes. We calculated maximum outputs for various pulse durations assuming pulsing at 10, 20, and 30 pulses per second. These were then compared to standard utility power safety (AC) limits via the conversion factor of 7.4 to convert average current to RMS current for VF risk. The outputs of TASER electrical weapons (typically < 100 μC and ~100 μs duration) were also compared. The IEC and UL electric fence energizer normal rate standards are conservative in comparison with actual human laboratory experiments. The IEC and UL electric fence energizer rapid-pulsing standards are consistent with accepted IEC AC current limits for commercially used pulse durations.

Development of a Hand Held Thromboelastograph

DTIC Science & Technology

2014-01-01

on a prototype model, and there was no indication of damage and was found to comply with IEC 61010 -1. Currently, loss of calibration has not been...Standards. Task 4 - PCM Certification Testing Subtask 4a: IEC 60601-1 Subtask 4b: IEC 60601-1-2 Subtask 4c: ISO 10993 Subtask 4d: ISTA 2A

Development of a Hand Held Thromboelastograph

DTIC Science & Technology

2013-01-01

prototype model, and there was no indication of damage and was found to comply to IEC 61010 -1. Currently, loss of calibration has not been evaluated...Task 4 - PCM Certification Testing Subtask 4a: IEC 60601-1 Subtask 4b: IEC 60601-1-2 Subtask 4c: ISO 10993 Subtask 4d: ISTA 2A These tasks

15 CFR 995.3 - Availability of other publications.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Hydrographic Data, edition 2.0, dated October 2003, describes the validation checks to be used on ENC data... the 1974 SOLAS Convention. IEC Publication 61174, dated August 1998, can be purchased from the IEC Web site: http://www.iec.ch. (2) IHO Special Publication S57—The IHO Transfer Standard for Hydrographic...

15 CFR 995.3 - Availability of other publications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Hydrographic Data, edition 2.0, dated October 2003, describes the validation checks to be used on ENC data... the 1974 SOLAS Convention. IEC Publication 61174, dated August 1998, can be purchased from the IEC Web site: http://www.iec.ch. (2) IHO Special Publication S57—The IHO Transfer Standard for Hydrographic...

Kernel Method Based Human Model for Enhancing Interactive Evolutionary Optimization

PubMed Central

Zhao, Qiangfu; Liu, Yong

2015-01-01

A fitness landscape presents the relationship between individual and its reproductive success in evolutionary computation (EC). However, discrete and approximate landscape in an original search space may not support enough and accurate information for EC search, especially in interactive EC (IEC). The fitness landscape of human subjective evaluation in IEC is very difficult and impossible to model, even with a hypothesis of what its definition might be. In this paper, we propose a method to establish a human model in projected high dimensional search space by kernel classification for enhancing IEC search. Because bivalent logic is a simplest perceptual paradigm, the human model is established by considering this paradigm principle. In feature space, we design a linear classifier as a human model to obtain user preference knowledge, which cannot be supported linearly in original discrete search space. The human model is established by this method for predicting potential perceptual knowledge of human. With the human model, we design an evolution control method to enhance IEC search. From experimental evaluation results with a pseudo-IEC user, our proposed model and method can enhance IEC search significantly. PMID:25879050

A multiscale model for charge inversion in electric double layers

NASA Astrophysics Data System (ADS)

Mashayak, S. Y.; Aluru, N. R.

2018-06-01

Charge inversion is a widely observed phenomenon. It is a result of the rich statistical mechanics of the molecular interactions between ions, solvent, and charged surfaces near electric double layers (EDLs). Electrostatic correlations between ions and hydration interactions between ions and water molecules play a dominant role in determining the distribution of ions in EDLs. Due to highly polar nature of water, near a surface, an inhomogeneous and anisotropic arrangement of water molecules gives rise to pronounced variations in the electrostatic and hydration energies of ions. Classical continuum theories fail to accurately describe electrostatic correlations and molecular effects of water in EDLs. In this work, we present an empirical potential based quasi-continuum theory (EQT) to accurately predict the molecular-level properties of aqueous electrolytes. In EQT, we employ rigorous statistical mechanics tools to incorporate interatomic interactions, long-range electrostatics, correlations, and orientation polarization effects at a continuum-level. Explicit consideration of atomic interactions of water molecules is both theoretically and numerically challenging. We develop a systematic coarse-graining approach to coarse-grain interactions of water molecules and electrolyte ions from a high-resolution atomistic scale to the continuum scale. To demonstrate the ability of EQT to incorporate the water orientation polarization, ion hydration, and electrostatic correlations effects, we simulate confined KCl aqueous electrolyte and show that EQT can accurately predict the distribution of ions in a thin EDL and also predict the complex phenomenon of charge inversion.

Experimenting Design and Implementation of an Educational Services Management System Based on ISO/IEC 20000 Standard

NASA Astrophysics Data System (ADS)

Lezcano, Jean-Marc; Adachihara, Hatsuo; Prunier, Marc

European higher education organizations are encouraged to implement quality management practices. Existing quality standards and frameworks do not capitalize an important set of best practices addressing educational services delivery. The ISO/IEC 20000 standard, elaborated from IT service management issues, is widening its field of application and may represent an interesting alternative. A specific approach is needed to apprehend the particular nature of educational services, consider the systemic cooperating roles of educational system and learning system, and define ISO/IEC 20000 vocabulary and concepts adapted to the domain. ISO/IEC 20000 may provide an answer to European Standard Guideline compliance and improve educational services management. The current experimentation is expected to cast light on the complexity, practicality and effectiveness of the use of ISO/IEC 20000 in a first field of "non IT" services.

SIGIRR, a negative regulator of TLR/IL-1R signalling promotes Microbiota dependent resistance to colonization by enteric bacterial pathogens.

PubMed

Sham, Ho Pan; Yu, Emily Yi Shan; Gulen, Muhammet F; Bhinder, Ganive; Stahl, Martin; Chan, Justin M; Brewster, Lara; Morampudi, Vijay; Gibson, Deanna L; Hughes, Michael R; McNagny, Kelly M; Li, Xiaoxia; Vallance, Bruce A

2013-01-01

Enteric bacterial pathogens such as enterohemorrhagic E. coli (EHEC) and Salmonella Typhimurium target the intestinal epithelial cells (IEC) lining the mammalian gastrointestinal tract. Despite expressing innate Toll-like receptors (TLRs), IEC are innately hypo-responsive to most bacterial products. This is thought to prevent maladaptive inflammatory responses against commensal bacteria, but it also limits antimicrobial responses by IEC to invading bacterial pathogens, potentially increasing host susceptibility to infection. One reason for the innate hypo-responsiveness of IEC is their expression of Single Ig IL-1 Related Receptor (SIGIRR), a negative regulator of interleukin (IL)-1 and TLR signaling. To address whether SIGIRR expression and the innate hypo-responsiveness of IEC impacts on enteric host defense, Sigirr deficient (-/-) mice were infected with the EHEC related pathogen Citrobacter rodentium. Sigirr -/- mice responded with accelerated IEC proliferation and strong pro-inflammatory and antimicrobial responses but surprisingly, Sigirr -/- mice proved dramatically more susceptible to infection than wildtype mice. Through haematopoietic transplantation studies, it was determined that SIGIRR expression by non-haematopoietic cells (putative IEC) regulated these responses. Moreover, the exaggerated responses were found to be primarily dependent on IL-1R signaling. Whilst exploring the basis for their susceptibility, Sigirr -/- mice were found to be unusually susceptible to intestinal Salmonella Typhimurium colonization, developing enterocolitis without the typical requirement for antibiotic based removal of competing commensal microbes. Strikingly, the exaggerated antimicrobial responses seen in Sigirr -/- mice were found to cause a rapid and dramatic loss of commensal microbes from the infected intestine. This depletion appears to reduce the ability of the microbiota to compete for space and nutrients (colonization resistance) with the invading pathogens, leaving the intestine highly susceptible to pathogen colonization. Thus, SIGIRR expression by IEC reflects a strategy that sacrifices maximal innate responsiveness by IEC in order to promote commensal microbe based colonization resistance against bacterial pathogens.

DOD ELAP Lab Uncertainties

DTIC Science & Technology

2012-03-01

ISO / IEC   17025  Inspection Bodies – ISO / IEC  17020  RMPs – ISO  Guide 34 (Reference...certify to :  ISO  9001 (QMS),  ISO  14001 (EMS),   TS 16949 (US Automotive)  etc. 2 3 DoD QSM 4.2 standard   ISO / IEC   17025 :2005  Each has uncertainty...IPV6, NLLAP, NEFAP  TRAINING Programs  Certification Bodies – ISO / IEC  17021  Accreditation for  Management System 

Influence of strain relaxation in axial [Formula: see text] nanowire heterostructures on their electronic properties.

PubMed

Marquardt, Oliver; Krause, Thilo; Kaganer, Vladimir; Martín-Sánchez, Javier; Hanke, Michael; Brandt, Oliver

2017-05-26

We present a systematic theoretical study of the influence of elastic strain relaxation on the built-in electrostatic potentials and the electronic properties of axial [Formula: see text] nanowire (NW) heterostructures. Our simulations reveal that for a sufficiently large ratio between the thickness of the [Formula: see text] disk and the diameter of the NW, the elastic relaxation leads to a significant reduction of the built-in electrostatic potential in comparison to a planar system of similar layer thickness and In content. In this case, the ground state transition energies approach constant values with increasing thickness of the disk and only depend on the In content, a behavior usually associated to that of a quantum well free of built-in electrostatic potentials. We show that the structures under consideration are by no means field-free, and the built-in potentials continue to play an important role even for ultrathin NWs. In particular, strain and the resulting polarization potentials induce complex confinement features of electrons and holes, which depend on the In content, shape, and dimensions of the heterostructure.

A simple derivation for amplitude and time period of charged particles in an electrostatic bathtub potential

NASA Astrophysics Data System (ADS)

Prathap Reddy, K.

2016-11-01

An ‘electrostatic bathtub potential’ is defined and analytical expressions for the time period and amplitude of charged particles in this potential are obtained and compared with simulations. These kinds of potentials are encountered in linear electrostatic ion traps, where the potential along the axis appears like a bathtub. Ion traps are used in basic physics research and mass spectrometry to store ions; these stored ions make oscillatory motion within the confined volume of the trap. Usually these traps are designed and studied using ion optical software, but in this work the bathtub potential is reproduced by making two simple modifications to the harmonic oscillator potential. The addition of a linear ‘k 1|x|’ potential makes the simple harmonic potential curve steeper with a sharper turn at the origin, while the introduction of a finite-length zero potential region at the centre reproduces the flat region of the bathtub curve. This whole exercise of modelling a practical experimental situation in terms of a well-known simple physics problem may generate interest among readers.

Aeroelastic flutter energy harvesters self-polarized by triboelectric effects

NASA Astrophysics Data System (ADS)

Perez, M.; Boisseau, S.; Geisler, M.; Gasnier, P.; Willemin, J.; Despesse, G.; Reboud, J. L.

2018-01-01

This paper presents the performances of several electrostatic flutter energy harvesters tested in a wind tunnel between 0 and 20 m s-1. The main idea is to use the flutter capability of thin flexible films confined between lateral walls to induce simultaneously the capacitance variations and the electrostatic polarization required by the triboelectric/electrostatic conversion. This technology provides thin and flexible devices and solve the electret’s stability issue (Perez et al 2015 Smart Mater. Struct., Perez et al 2015 New Circuits and Systems). Our prototypes (<16 cm2) have a quick startup (from 3 m s-1) and an electrical power-flux density from 0.35 μW cm-2@3 m s-1 (light breeze) to 35 μW cm-2@20 m s-1 (fresh gale). A Maximum Power Point circuit has been developed to efficiently use the power provided by the energy harvesters. The energy harvester combined with its power management circuit has finally been used to supply an 868 MHz wireless sensor node with temperature and acceleration measurements, validating the complete energy harvesting chain.

IGF-IEc expression is increased in secondary compared to primary foci in neuroendocrine neoplasms.

PubMed

Alexandraki, Krystallenia I; Philippou, Anastassios; Boutzios, Georgios; Theohari, Irini; Koutsilieris, Michael; Delladetsima, Ioanna Kassiani; Kaltsas, Gregory A

2017-10-03

Different Insulin-like growth factor-I (IGF-I) mRNA transcripts are produced by alternative splicing and particularly the IGF-IEc isoform has been implicated in the development and/or progression of various types of cancer. In the present study, we examined the potential role of IGF-IEc expression as a new immunohistochemical marker of aggressiveness in neuroendocrine neoplasms (NENs). We utilized immunohistochemical analysis in tissue specimens of 47 patients with NENs, to evaluate the expression of IGF-IEc (%) and Ki-67 proliferation index (%). Specimens from patients with tumors of different tissue origin, of either primary or metastatic lesions and of different grade were examined. Cytoplasmic IGF-IEc staining was found in 23 specimens of NENs or NECs: 10 pancreatic, 4 small bowel, 3 gastric, 1 lung, 1 uterine and 4 poorly differentiated of unknown primary origin. Ki-67 and IGF-IEc expression was positively correlated in all the samples studied (r=0.31, p=0.03). IGF-1Ec expression was more prevalent in specimens originating from metastatic foci with high Ki-67 compared to primary sites with low Ki-67 expression (p=0.036). These findings suggest a possible role of IGF-IEc in NEN tumorigenesis and progression to metastases that could be used as an additional new marker of a more aggressive behavior and a potential drugable target.

CMMI(Registered) for Services, Version 1.3

DTIC Science & Technology

2010-11-01

ISO 2008b] ISO /IEC 27001 :2005 Information technology – Security techniques – Information Security Management Systems – Requirements [ ISO /IEC 2005...Commission. ISO /IEC 27001 Information Technology – Security Techniques – Information Security Management Systems – Requirements, 2005. http...CMM or International Organization for Standardization ( ISO ) 9001, you will immediately recognize many similarities in their structure and content

CMMI(Registered) for Acquisition, Version 1.3. CMMI-ACQ, V1.3

DTIC Science & Technology

2010-11-01

and Software Engineering – System Life Cycle Processes [ ISO 2008b] ISO /IEC 27001 :2005 Information technology – Security techniques – Information...International Organization for Standardization and International Electrotechnical Commission. ISO /IEC 27001 Information Technology – Security Techniques...International Organization for Standardization/International Electrotechnical Commission ( ISO /IEC) body of standards. CMMs focus on improving processes

Systems Security Engineering

DTIC Science & Technology

2010-08-22

Commission (IEC). “Information technology — Security techniques — Code of practice for information security management ( ISO /IEC 27002 ...Information technology — Security techniques — Information security management systems —Requirements ( ISO /IEC 27002 ),”, “Information technology — Security...was a draft ISO standard on Systems and software engineering, Systems and software assurance [18]. Created by systems engineers for systems

Escherichia coli isolated from a Crohn's disease patient adheres, invades, and induces inflammatory responses in polarized intestinal epithelial cells.

PubMed

Eaves-Pyles, Tonyia; Allen, Christopher A; Taormina, Joanna; Swidsinski, Alexander; Tutt, Christopher B; Jezek, G Eric; Islas-Islas, Martha; Torres, Alfredo G

2008-07-01

Inflammatory diseases of the intestinal tract are a major health concern both in the United States and around the world. Evidence now suggests that a new category of Escherichia coli, designated Adherent Invasive E. coli (AIEC) is highly prevalent in Crohn's Disease (CD) patients. AIEC strains have been shown to colonize and adhere to intestinal epithelial cells (IEC). However, the role AIEC strains play in the induction of an inflammatory response is not known. Therefore, we examined several E. coli strains (designated LF82, O83:H1, 6604 and 6655) that were isolated from CD patients for their ability to induce inflammation in two IEC, Caco-2BBe and T-84 cells. Results showed that each strain had varying abilities to adhere to and invade IEC as well as induced cytokine secretion from polarized IEC. However, E. coli O83:H1 displayed the best characteristics of AIEC strains as compared to the prototype AIEC strain LF82, inducing cytokine secretion from IEC and promoting immune cell migration through IEC. Upon further analysis, E. coli O83:H1 did not harbor virulence genes present in known pathogenic intestinal organisms. Further characterization of E. coli O83:H1 virulence determinants showed that a non-flagellated O83:H1 strain significantly decreased the organism's ability to adhere to and invade both IEC and elicit IEC cytokine secretion compared to the wild type and complemented strains. These findings demonstrate that E. coli O83:H1 possesses the characteristics of the AIEC LF82 strain that may contribute to the low-grade, chronic inflammation observed in Crohn's disease.

Optimization of Immobilization of Nanodiamonds on Graphene

NASA Astrophysics Data System (ADS)

Pille, A.; Lange, S.; Utt, K.; Eltermann, M.

2015-04-01

We report using simple dip-coating method to cover the surface of graphene with nanodiamonds for future optical detection of defects on graphene. Most important part of the immobilization process is the pre-functionalization of both, nanodiamond and graphene surfaces to obtain the selectiveness of the method. This work focuses on an example of using electrostatic attraction to confine nanodiamonds to graphene. Raman spectroscopy, microluminescence imaging and scanning electron microscopy were applied to characterize obtained samples.

Software And Systems Engineering Risk Management

DTIC Science & Technology

2010-04-01

RSKM 2004 COSO Enterprise RSKM Framework 2006 ISO/IEC 16085 Risk Management Process 2008 ISO/IEC 12207 Software Lifecycle Processes 2009 ISO/IEC...1 Software And Systems Engineering Risk Management John Walz VP Technical and Conferences Activities, IEEE Computer Society Vice-Chair Planning...Software & Systems Engineering Standards Committee, IEEE Computer Society US TAG to ISO TMB Risk Management Working Group Systems and Software

A Strategy for Improved System Assurance

DTIC Science & Technology

2007-06-20

Quality (Measurements Life Cycle Safety, Security & Others) ISO /IEC 12207 * Software Life Cycle Processes ISO 9001 Quality Management System...14598 Software Product Evaluation Related ISO /IEC 90003 Guidelines for the Application of ISO 9001:2000 to Computer Software IEEE 12207 Industry...Implementation of International Standard ISO /IEC 12207 IEEE 1220 Standard for Application and Management of the System Engineering Process Use in

Systems Security Engineering

DTIC Science & Technology

2010-08-22

practice for information security management ( ISO /IEC 27002 ),” “Information technology — Security techniques — Information security management...systems —Requirements ( ISO /IEC 27002 ),”, “Information technology — Security techniques — Information security risk management ( ISO /IEC 27005).” from...associated practice aids. Perhaps the most germane discovery from this effort was a draft ISO standard on Systems and software engineering, Systems and

Self-consistent electrostatic potential due to trapped plasma in the magnetosphere

NASA Technical Reports Server (NTRS)

Miller, Ronald H.; Khazanov, George V.

1993-01-01

A steady state solution for the self-consistent electrostatic potential due to a plasma confined in a magnetic flux tube is considered. A steady state distribution function is constructed for the trapped particles from the constants of the motion, in the absence of waves and collisions. Using Liouville's theorem, the particle density along the geomagnetic field is determined and found to depend on the local magnetic field, self-consistent electric potential, and the equatorial plasma distribution function. A hot anisotropic magnetospheric plasma in steady state is modeled by a bi-Maxwellian at the equator. The self-consistent electric potential along the magnetic field is calculated assuming quasineutrality, and the potential drop is found to be approximately equal to the average kinetic energy of the equatorially trapped plasma. The potential is compared with that obtained by Alfven and Faelthammar (1963).

A method for high purity intestinal epithelial cell culture from adult human and murine tissues for the investigation of innate immune function.

PubMed

Graves, Christina L; Harden, Scott W; LaPato, Melissa; Nelson, Michael; Amador, Byron; Sorenson, Heather; Frazier, Charles J; Wallet, Shannon M

2014-12-01

Intestinal epithelial cells (IECs) serve as an important physiologic barrier between environmental antigens and the host intestinal immune system. Thus, IECs serve as a first line of defense and may act as sentinel cells during inflammatory insults. Despite recent renewed interest in IEC contributions to host immune function, the study of primary IEC has been hindered by lack of a robust culture technique, particularly for small intestinal and adult tissues. Here, a novel adaptation for culture of primary IEC is described for human duodenal organ donor tissue as well as duodenum and colon of adult mice. These epithelial cell cultures display characteristic phenotypes and are of high purity. In addition, the innate immune function of human primary IEC, specifically with regard to Toll-like receptor (TLR) expression and microbial ligand responsiveness, is contrasted with a commonly used intestinal epithelial cell line (HT-29). Specifically, TLR expression at the mRNA level and production of cytokine (IFNγ and TNFα) in response to TLR agonist stimulation is assessed. Differential expression of TLRs as well as innate immune responses to ligand stimulation is observed in human-derived cultures compared to that of HT-29. Thus, use of this adapted method to culture primary epithelial cells from adult human donors and from adult mice will allow for more appropriate studies of IECs as innate immune effectors. Published by Elsevier B.V.

Increased IGF-IEc expression and mechano-growth factor production in intestinal muscle of fibrostenotic Crohn's disease and smooth muscle hypertrophy

PubMed Central

Li, Chao; Vu, Kent; Hazelgrove, Krystina

2015-01-01

The igf1 gene is alternatively spliced as IGF-IEa and IGF-IEc variants in humans. In fibrostenotic Crohn's disease, the fibrogenic cytokine TGF-β1 induces IGF-IEa expression and IGF-I production in intestinal smooth muscle and results in muscle hyperplasia and collagen I production that contribute to stricture formation. Mechano-growth factor (MGF) derived from IGF-IEc induces skeletal and cardiac muscle hypertrophy following stress. We hypothesized that increased IGF-IEc expression and MGF production mediated smooth muscle hypertrophy also characteristic of fibrostenotic Crohn's disease. IGF-IEc transcripts and MGF protein were increased in muscle cells isolated from fibrostenotic intestine under regulation by endogenous TGF-β1. Erk5 and MEF2C were phosphorylated in vivo in fibrostenotic muscle; both were phosphorylated and colocalized to nucleus in response to synthetic MGF in vitro. Smooth muscle-specific protein expression of α-smooth muscle actin, γ-smooth muscle actin, and smoothelin was increased in affected intestine. Erk5 inhibition or MEF2C siRNA blocked smooth muscle-specific gene expression and hypertrophy induced by synthetic MGF. Conditioned media of cultured fibrostenotic muscle induced muscle hypertrophy that was inhibited by immunoneutralization of endogenous MGF or pro-IGF-IEc. The results indicate that TGF-β1-dependent IGF-IEc expression and MGF production in patients with fibrostenotic Crohn's disease regulates smooth muscle cell hypertrophy a critical factor that contributes to intestinal stricture formation. PMID:26428636

Increased IGF-IEc expression and mechano-growth factor production in intestinal muscle of fibrostenotic Crohn's disease and smooth muscle hypertrophy.

PubMed

Li, Chao; Vu, Kent; Hazelgrove, Krystina; Kuemmerle, John F

2015-12-01

The igf1 gene is alternatively spliced as IGF-IEa and IGF-IEc variants in humans. In fibrostenotic Crohn's disease, the fibrogenic cytokine TGF-β1 induces IGF-IEa expression and IGF-I production in intestinal smooth muscle and results in muscle hyperplasia and collagen I production that contribute to stricture formation. Mechano-growth factor (MGF) derived from IGF-IEc induces skeletal and cardiac muscle hypertrophy following stress. We hypothesized that increased IGF-IEc expression and MGF production mediated smooth muscle hypertrophy also characteristic of fibrostenotic Crohn's disease. IGF-IEc transcripts and MGF protein were increased in muscle cells isolated from fibrostenotic intestine under regulation by endogenous TGF-β1. Erk5 and MEF2C were phosphorylated in vivo in fibrostenotic muscle; both were phosphorylated and colocalized to nucleus in response to synthetic MGF in vitro. Smooth muscle-specific protein expression of α-smooth muscle actin, γ-smooth muscle actin, and smoothelin was increased in affected intestine. Erk5 inhibition or MEF2C siRNA blocked smooth muscle-specific gene expression and hypertrophy induced by synthetic MGF. Conditioned media of cultured fibrostenotic muscle induced muscle hypertrophy that was inhibited by immunoneutralization of endogenous MGF or pro-IGF-IEc. The results indicate that TGF-β1-dependent IGF-IEc expression and MGF production in patients with fibrostenotic Crohn's disease regulates smooth muscle cell hypertrophy a critical factor that contributes to intestinal stricture formation. Copyright © 2015 the American Physiological Society.

Magnetic field extraction of trap-based electron beams using a high-permeability grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurst, N. C.; Danielson, J. R.; Surko, C. M., E-mail: csurko@physics.ucsd.edu

2015-07-15

A method to form high quality electrostatically guided lepton beams is explored. Test electron beams are extracted from tailored plasmas confined in a Penning-Malmberg trap. The particles are then extracted from the confining axial magnetic field by passing them through a high magnetic permeability grid with radial tines (a so-called “magnetic spider”). An Einzel lens is used to focus and analyze the beam properties. Numerical simulations are used to model non-adiabatic effects due to the spider, and the predictions are compared with the experimental results. Improvements in beam quality are discussed relative to the use of a hole in amore » high permeability shield (i.e., in lieu of the spider), and areas for further improvement are described.« less

Quantum Hall signatures of dipolar Mahan excitons

NASA Astrophysics Data System (ADS)

Schinner, G. J.; Repp, J.; Kowalik-Seidl, K.; Schubert, E.; Stallhofer, M. P.; Rai, A. K.; Reuter, D.; Wieck, A. D.; Govorov, A. O.; Holleitner, A. W.; Kotthaus, J. P.

2013-01-01

We explore the photoluminescence of spatially indirect, dipolar Mahan excitons in a gated double quantum well diode containing a mesoscopic electrostatic trap for neutral dipolar excitons at low temperatures down to 250 mK and in quantizing magnetic fields. Mahan excitons in the surrounding of the trap, consisting of individual holes interacting with a degenerate two-dimensional electron system confined in one of the quantum wells, exhibit strong quantum Hall signatures at integer filling factors and related anomalies around filling factor ν=(2)/(3),(3)/(5), and (1)/(2), reflecting the formation of composite fermions. Interactions across the trap perimeter are found to influence the energy of the confined neutral dipolar excitons by the presence of the quantum Hall effects in the two-dimensional electron system surrounding the trap.

Gate-tunable electron interaction in high-κ dielectric films

DOE PAGES

Kondovych, Svitlana; Luk’yanchuk, Igor; Baturina, Tatyana I.; ...

2017-02-20

The two-dimensional (2D) logarithmic character of Coulomb interaction between charges and the resulting logarithmic confinement is a remarkable inherent property of high dielectric constant (high-k) thin films with far reaching implications. Most and foremost, this is the charge Berezinskii-Kosterlitz-Thouless transition with the notable manifestation, low-temperature superinsulating topological phase. Here we show that the range of the confinement can be tuned by the external gate electrode and unravel a variety of electrostatic interactions in high-k films. Lastly, our findings open a unique laboratory for the in-depth study of topological phase transitions and a plethora of related phenomena, ranging from criticality ofmore » quantum metal- and superconductor-insulator transitions to the effects of charge-trapping and Coulomb scalability in memory nanodevices.« less

Materials and Manufacturing Research and Development Capability Assessment of the Southwest Ohio Region

DTIC Science & Technology

2011-09-01

ISO / IEC 17025 :2005, NADCAP Acuren...River Road Brackenridge, PA 250 (724) 224-1000 $4.8B 11,000 ISO -9001, AS- 9100, NADCAP, ISO / IEC 17025 ATI – Allegheny Ludlum (Houston, PA) 501...Western Ave Houston, PA 233 (724) 745-2000 $4.8B 11,000 ISO -9001, AS- 9100, NADCAP, ISO / IEC 17025 ATI – Allegheny Ludlum (Louisville, OH)

Incident Management Capability Metrics Version 0.1

DTIC Science & Technology

2007-04-01

guidance for proactively securing and hardening their infrastructure, for example6: • ISO 17799 ( ISO /IEC 17799:2005) [ ISO 2005a] • ISO 27001 ( ISO /IEC... 27001 :2005) [ ISO 2005b] • Control Objectives for Information and related Technology (COBIT) [ITGI 2006...security management systems – Requirements ( ISO /IEC 27001 :2005).http://www.iso.org/ iso /en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=421 03 (2005

Electrostatic interactions between ions near Thomas-Fermi substrates and the surface energy of ionic crystal at imperfect metals

PubMed Central

Kaiser, V.; Comtet, J.; Niguès, A.; Siria, A.; Coasne, B.; Bocquet, L.

2017-01-01

The electrostatic interaction between two charged particles is strongly modified in the vicinity of a metal. This situation is usually accounted for by the celebrated image charges approach, which was further extended to account for the electronic screening properties of the metal at the level of the Thomas-Fermi description. In this paper we build upon the approach by [Kornyshev et al. Zh. Eksp. Teor. Fiz., 78(3):1008–1019, 1980] and successive works to calculate the 1-body and 2-body electrostatic energy of ions near a metal in terms of the Thomas-Fermi screening length. We propose workable approximations suitable for molecular simulations of ionic systems close to metallic walls. Furthermore, we use this framework to calculate analytically the electrostatic contribution to the surface energy of a one dimensional crystal at a metallic wall and its dependence on the Thomas-Fermi screening length. These calculations provide a simple interpretation for the surface energy in terms of image charges, which allow for an estimate of interfacial properties in more complex situations of a disordered ionic liquid close to a metal surface. A counterintuitive outcome is that electronic screening, as characterized by a molecular Thomas-Fermi length ℓTF, profoundly affects the wetting of ionic systems close to a metal, in line with the recent experimental observation of capillary freezing of ionic liquids in metallic confinement. PMID:28436506

Breakdown of the Debye polarization ansatz at protein-water interfaces

NASA Astrophysics Data System (ADS)

Fernández Stigliano, Ariel

2013-06-01

The topographical and physico-chemical complexity of protein-water interfaces scales down to the sub-nanoscale range. At this level of confinement, we demonstrate that the dielectric structure of interfacial water entails a breakdown of the Debye ansatz that postulates the alignment of polarization with the protein electrostatic field. The tendencies to promote anomalous polarization are determined for each residue type and a particular kind of structural defect is shown to provide the predominant causal context.

Electrons in one dimension

PubMed Central

Berggren, K.-F.; Pepper, M.

2010-01-01

In this article, we present a summary of the current status of the study of the transport of electrons confined to one dimension in very low disorder GaAs–AlGaAs heterostructures. By means of suitably located gates and application of a voltage to ‘electrostatically squeeze’ the electronic wave functions, it is possible to produce a controllable size quantization and a transition from two-dimensional transport. If the length of the electron channel is sufficiently short, then transport is ballistic and the quantized subbands each have a conductance equal to the fundamental quantum value 2e2/h, where the factor of 2 arises from the spin degeneracy. This mode of conduction is discussed, and it is shown that a number of many-body effects can be observed. These effects are discussed as in the spin-incoherent regime, which is entered when the separation of the electrons is increased and the exchange energy is less than kT. Finally, results are presented in the regime where the confinement potential is decreased and the electron configuration relaxes to minimize the electron–electron repulsion to move towards a two-dimensional array. It is shown that the ground state is no longer a line determined by the size quantization alone, but becomes two distinct rows arising from minimization of the electrostatic energy and is the precursor of a two-dimensional Wigner lattice. PMID:20123751

Simultaneous measurements of ion and electron currents using a novel compact electrostatic end-loss-current detector

NASA Astrophysics Data System (ADS)

Hirata, M.; Miyake, Y.; Cho, T.; Kohagura, J.; Numakura, T.; Shimizu, K.; Ito, M.; Kiminami, S.; Morimoto, N.; Hirai, K.; Yamagishi, T.; Miyata, Y.; Nakashima, Y.; Miyoshi, S.; Ogura, K.; Kondoh, T.; Kariya, T.

2006-10-01

For the purpose of end-loss-ion and -electron analyses in open-field plasmas, a compact-sized electrostatic end-loss-current detector is proposed on the basis of a self-collection principle for suppressing the effects of secondary-electron emission from a metal collector. For employing this specific method, it is worth noting that no further additional magnetic systems except the ambient open-ended magnetic fields are required in the detector operation. This characteristic property provides a compactness of the total detection system and availability for its use in plasma confinement devices without disturbing plasma-confining magnetic fields. The detector consists of a set of parallel metal plates with respect to lines of ambient magnetic forces of a plasma device for analyzing incident ion currents along with a grid for shielding the collector against strays due to the metal-plate biasing. The characterization experiments are carried out by the use of a test-ion-beam line along with an additional use of a Helmholtz coil system for the formation of open magnetic fields similar to those in the GAMMA 10 end region. The applications of the developed end-loss-current detector in the GAMMA 10 plasma experiments are demonstrated under the conditions with simultaneous incidence of energetic electrons produced by electron-cyclotron heatings for end-loss-plugging potential formation.

Continuum Edge Gyrokinetic Theory and Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, X Q; Xiong, Z; Dorr, M R

The following results are presented from the development and application of TEMPEST, a fully nonlinear (full-f) five dimensional (3d2v) gyrokinetic continuum edge-plasma code. (1) As a test of the interaction of collisions and parallel streaming, TEMPEST is compared with published analytic and numerical results for endloss of particles confined by combined electrostatic and magnetic wells. Good agreement is found over a wide range of collisionality, confining potential, and mirror ratio; and the required velocity space resolution is modest. (2) In a large-aspect-ratio circular geometry, excellent agreement is found for a neoclassical equilibrium with parallel ion flow in the banana regimemore » with zero temperature gradient and radial electric field. (3) The four-dimensional (2d2v) version of the code produces the first self-consistent simulation results of collisionless damping of geodesic acoustic modes and zonal flow (Rosenbluth-Hinton residual) with Boltzmann electrons using a full-f code. The electric field is also found to agree with the standard neoclassical expression for steep density and ion temperature gradients in the banana regime. In divertor geometry, it is found that the endloss of particles and energy induces parallel flow stronger than the core neoclassical predictions in the SOL. (5) Our 5D gyrokinetic formulation yields a set of nonlinear electrostatic gyrokinetic equations that are for both neoclassical and turbulence simulations.« less

Alizarin Red S-Confined Layer-By-Layer Films as Redox-Active Coatings on Electrodes for the Voltammetric Determination of L-Dopa

PubMed Central

Takahashi, Shigehiro; Suzuki, Iwao; Sugawara, Tatsuro; Seno, Masaru; Minaki, Daichi; Anzai, Jun-Ichi

2017-01-01

The preparation of redox-active coatings is a key step in fabricating electrochemical biosensors. To this goal, a variety of coating materials have been used in combination with redox-active compounds. In this study, alizarin red S (ARS) was confined in layer-by-layer (LbL) films composed of poly(ethyleneimine) (PEI) and carboxymethylcellulose (CMC) to study the redox properties. A gold (Au) disc electrode coated with PEI/CMC LbL film was immersed in an ARS solution to uptake ARS into the film. ARS was successfully confined in the LbL film through electrostatic interactions. The cyclic voltammogram (CV) of ARS-confined PEI/CMC film-coated electrodes thus prepared exhibited redox waves in the potential range from −0.5 to −0.7 V originating from 9,10-anthraquinone moiety in ARS, demonstrating that ARS preserves its redox activity in the LbL film. An additional oxidation peak appeared around −0.4 V in the CV recorded in the solution containing phenylboronic acid (PBA), due to the formation of a boronate ester of ARS (ARS-PBA) in the film. The oxidation peak current at −0.4 V decreased upon addition of 3,4-dihydroxyphenylalanine (L-dopa) to the solution. Thus, the results suggest a potential use of the ARS-confined PEI/CMC films for constructing voltammetric sensors for L-dopa. PMID:28772942

ELMO Bumpy Square proposal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dory, R.A.; Uckan, N.A.; Ard, W.B.

The ELMO Bumpy Square (EBS) concept consists of four straight magnetic mirror arrays linked by four high-field corner coils. Extensive calculations show that this configuration offers major improvements over the ELMO Bumpy Torus (EBT) in particle confinement, heating, transport, ring production, and stability. The components of the EBT device at Oak Ridge National Laboratory can be reconfigured into a square arrangement having straight sides composed of EBT coils, with new microwave cavities and high-field corners designed and built for this application. The elimination of neoclassical convection, identified as the dominant mechanism for the limited confinement in EBT, will give themore » EBS device substantially improved confinement and the flexibility to explore the concepts that produce this improvement. The primary goals of the EBS program are twofold: first, to improve the physics of confinement in toroidal systems by developing the concepts of plasma stabilization using the effects of energetic electrons and confinement optimization using magnetic field shaping and electrostatic potential control to limit particle drift, and second, to develop bumpy toroid devices as attractive candidates for fusion reactors. This report presents a brief review of the physics analyses that support the EBS concept, discussions of the design and expected performance of the EBS device, a description of the EBS experimental program, and a review of the reactor potential of bumpy toroid configurations. Detailed information is presented in the appendices.« less

Core Logistics Capability Policy Applied to USAF Combat Aircraft Avionics Software: A Systems Engineering Analysis

DTIC Science & Technology

2010-06-01

cannot make a distinction between software maintenance and development” (Sharma, 2004). ISO /IEC 12207 Software Lifecycle Processes offers a guide to...synopsis of ISO /IEC 12207 , Raghu Singh of the Federal Aviation Administration states “Whenever a software product needs modifications, the development...Corporation. Singh, R. (1998). International Standard ISO /IEC 12207 Software Life Cycle Processes. Washington: Federal Aviation Administration. The Joint

Review of the National Information Assurance Partnership (NIAP)

DTIC Science & Technology

2006-01-01

accreditation is to ensure that laboratories meet the re- quirements of ISO / IEC 17025 :2005, General Requirement for the Competence of Cali- bration and...isoguide2. [ISO1999] ISO / IEC 17025 , General Requirements for the Competence of Testing and Calibration Laboratories, 1999, http://www.iso.ch/ iso ...Protection Profiles and Secu- rity Targets, 2003. [ISO2005] ISO / IEC 17025 , General Requirements for the Competence of Testing and Calibration Laboratories

Timing of developmental reduction in epithelial glutathione redox potential is associated with increased epithelial proliferation in the immature murine intestine.

PubMed

Reid, Graham K; Berardinelli, Andrew J; Ray, Laurie; Jackson, Arena R; Neish, Andrew S; Hansen, Jason M; Denning, Patricia W

2017-08-01

BackgroundThe intracellular redox potential of the glutathione (GSH)/glutathione disulfide (GSSG) couple regulates cellular processes. In vitro studies indicate that a reduced GSH/GSSG redox potential favors proliferation, whereas a more oxidized redox potential favors differentiation. Intestinal growth depends upon an appropriate balance between the two. However, how the ontogeny of intestinal epithelial cellular (IEC) GSH/GSSG redox regulates these processes in the developing intestine has not been fully characterized in vivo.MethodsOntogeny of intestinal GSH redox potential and growth were measured in neonatal mice.ResultsWe show that IEC GSH/GSSG redox potential becomes increasingly reduced (primarily driven by increased GSH concentration) over the first 3 weeks of life. Increased intracellular GSH has been shown to drive proliferation through increased poly-ADP-ribose polymerase (PARP) activity. We show that increasing IEC poly-ADP-ribose chains can be measured over the first 3 weeks of life, indicating an increase in IEC PARP activity. These changes are accompanied by increased intestinal growth and IEC proliferation as assessed by villus height/crypt depth, intestinal length, and Ki67 staining.ConclusionUnderstanding how IEC GSH/GSSG redox potential is developmentally regulated may provide insight into how premature human intestinal redox states can be manipulated to optimize intestinal growth and adaptation.

Porcine aminopeptidase N mediated polarized infection by porcine epidemic diarrhea virus in target cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cong, Yingying; Li, Xiaoxue; Bai, Yunyun

Infection of polarized intestinal epithelial cells by porcine epidemic diarrhea virus (PEDV) was characterized. Indirect immunofluorescence assay, real-time PCR, and transmission electron microscopy confirmed PEDV can be successfully propagated in immortalized swine small intestine epithelial cells (IECs). Infection involved porcine aminpeptidase N (pAPN), a reported cellular receptor for PEDV, transient expression of pAPN and siRNA targeted pAPN increased and decreased the infectivity of PEDV in IECs, respectively. Subsequently, polarized entry into and release from both Vero E6 and IECs was analyzed. PEDV entry into polarized cells and pAPN grown on membrane inserts occurs via apical membrane. The progeny virus releasedmore » into the medium was also quantified which demonstrated that PEDV is preferentially released from the apical membrane. Collectively, our data demonstrate that pAPN, the cellular receptor for PEDV, mediates polarized PEDV infection. These results imply the possibility that PEDV infection may proceed by lateral spread of virus in intestinal epithelial cells. - Highlights: • PEDV infection of polarized intestinal epithelial cells (IECs) was characterized. • Porcine aminpeptidase N (pAPN) facilitated PEDV infection in IECs. • PEDV entry into and release from polarized cell via its apical membrane. • PEDV infection may proceed by lateral spread of virus in IECs.« less

BCL-2 Modifying Factor (BMF) Is a Central Regulator of Anoikis in Human Intestinal Epithelial Cells*

PubMed Central

Hausmann, Martin; Leucht, Katharina; Ploner, Christian; Kiessling, Stephan; Villunger, Andreas; Becker, Helen; Hofmann, Claudia; Falk, Werner; Krebs, Michaela; Kellermeier, Silvia; Fried, Michael; Schölmerich, Jürgen; Obermeier, Florian; Rogler, Gerhard

2011-01-01

BCL-2 modifying factor (BMF) is a sentinel considered to register damage at the cytoskeleton and to convey a death signal to B-cell lymphoma 2. B-cell lymphoma 2 is neutralized by BMF and thereby facilitates cytochrome C release from mitochondria. We investigated the role of BMF for intestinal epithelial cell (IEC) homeostasis. Acute colitis was induced in Bmf-deficient mice (Bmf−/−) with dextran sulfate sodium. Colonic crypt length in Bmf−/− mice was significantly increased as compared with WT mice. Dextran sulfate sodium induced less signs of colitis in Bmf−/− mice, as weight loss was reduced compared with the WT. Primary human IEC exhibited increased BMF in the extrusion zone. Quantitative PCR showed a significant up-regulation of BMF expression after initiation of anoikis in primary human IEC. BMF was found on mitochondria during anoikis, as demonstrated by Western blot analysis. RNAi mediated knockdown of BMF reduced the number of apoptotic cells and led to reduced caspase 3 activity. A significant increase in phospho-AKT was determined after RNAi treatment. BMF knockdown supports survival of IEC. BMF is induced in human IEC by the loss of cell attachment and is likely to play an important role in the regulation of IEC survival. PMID:21673109

Absorption and emission spectroscopy of individual semiconductor nanostructures

NASA Astrophysics Data System (ADS)

McDonald, Matthew P.

The advent of controllable synthetic methods for the production of semiconductor nanostructures has led to their use in a host of applications, including light-emitting diodes, field effect transistors, sensors, and even television displays. This is, in part, due to the size, shape, and morphologically dependent optical and electrical properties that make this class of materials extremely customizable; wire-, rod- and sphere-shaped nanocrystals are readily synthesized through common wet chemical methods. Most notably, confining the physical dimension of the nanostructure to a size below its Bohr radius (aB) results in quantum confinement effects that increase its optical energy gap. Not only the size, but the shape of a particle can be exploited to tailor its optical and electrical properties. For example, confined CdSe quantum dots (QDs) and nanowires (NWs) of equivalent diameter possess significantly different optical gaps. This phenomenon has been ascribed to electrostatic contributions arising from dielectric screening effects that are more pronounced in an elongated (wire-like) morphology. Semiconducting nanostructures have thus received significant attention over the past two decades. However, surprisingly little work has been done to elucidate their basic photophysics on a single particle basis. What has been done has generally been accomplished through emission-based measurements, and thus does not fully capture the full breadth of these intriguing systems. What is therefore needed then are absorption-based studies that probe the size and shape dependent evolution of nanostructure photophysics. This thesis summarizes the single particle absorption spectroscopy that we have carried out to fill this knowledge gap. Specifically, the diameter-dependent progression of one-dimensional (1D) excitonic states in CdSe NWs has been revealed. This is followed by a study that focuses on the polarization selection rules of 1D excitons within single CdSe NWs. Finally, shape effects are explored by probing the absorption spectra of CdSe nanowires and nanorods of varying length. All experimental studies are complemented by theoretical predictions from an effective mass model that takes electrostatic interactions into account. Thus, this thesis seeks to show the delicate interplay between quantum confinement and dielectric screening effects in single CdSe nanostructures.

TU-G-213-00: The International Electrotechnical Commission (IEC): What Is It and Why Should Medical Physicists Care?

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The International Electrotechnical Commission (IEC) writes standards that manufacturers of electrical equipment must comply with. Medical electrical equipment, such as medical imaging, radiation therapy, and radiation dosimetry devices, fall under Technical Committee 62. Of particular interest to medical physicists are the standards developed within Subcommittees (SC) 62B, which addresses diagnostic radiological imaging equipment, and 62C, which addresses equipment for radiation therapy, nuclear medicine and dosimetry. For example, a Working Group of SC 62B is responsible for safety and quality assurance standards for CT scanners and a Working Group of SC 62C is responsible for standards that set requirements for dosimetricmore » safety and accuracy of linacs and proton accelerators. IEC standards thus have an impact on every aspect of a medical physicist’s job, including equipment testing, shielding design, room layout, and workflow. Consequently, it is imperative that US medical physicists know about existing standards, as well as have input on those under development or undergoing revision. The structure of the IEC and current standards development work will be described in detail. The presentation will explain how US medical physicists can learn about IEC standards and contribute to their development. Learning Objectives: Learn about the structure of the IEC and the influence that IEC standards have on the design of equipment for radiology and radiation therapy. Learn about the mechanisms by which the US participates in the development and revision of standards. Understand the specific requirements of several standards having direct relevance to diagnostic and radiation therapy physicists.« less

TU-G-213-01: IEC and US Committee Activities and Organizational Structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ibbott, G.

2015-06-15

The International Electrotechnical Commission (IEC) writes standards that manufacturers of electrical equipment must comply with. Medical electrical equipment, such as medical imaging, radiation therapy, and radiation dosimetry devices, fall under Technical Committee 62. Of particular interest to medical physicists are the standards developed within Subcommittees (SC) 62B, which addresses diagnostic radiological imaging equipment, and 62C, which addresses equipment for radiation therapy, nuclear medicine and dosimetry. For example, a Working Group of SC 62B is responsible for safety and quality assurance standards for CT scanners and a Working Group of SC 62C is responsible for standards that set requirements for dosimetricmore » safety and accuracy of linacs and proton accelerators. IEC standards thus have an impact on every aspect of a medical physicist’s job, including equipment testing, shielding design, room layout, and workflow. Consequently, it is imperative that US medical physicists know about existing standards, as well as have input on those under development or undergoing revision. The structure of the IEC and current standards development work will be described in detail. The presentation will explain how US medical physicists can learn about IEC standards and contribute to their development. Learning Objectives: Learn about the structure of the IEC and the influence that IEC standards have on the design of equipment for radiology and radiation therapy. Learn about the mechanisms by which the US participates in the development and revision of standards. Understand the specific requirements of several standards having direct relevance to diagnostic and radiation therapy physicists.« less

TU-G-213-03: IEC Subcommittee 62C (Equipment for Radiotherapy, Nuclear Medicine and Radiation Dosimetry): Recent and Active Projects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Culberson, W.

The International Electrotechnical Commission (IEC) writes standards that manufacturers of electrical equipment must comply with. Medical electrical equipment, such as medical imaging, radiation therapy, and radiation dosimetry devices, fall under Technical Committee 62. Of particular interest to medical physicists are the standards developed within Subcommittees (SC) 62B, which addresses diagnostic radiological imaging equipment, and 62C, which addresses equipment for radiation therapy, nuclear medicine and dosimetry. For example, a Working Group of SC 62B is responsible for safety and quality assurance standards for CT scanners and a Working Group of SC 62C is responsible for standards that set requirements for dosimetricmore » safety and accuracy of linacs and proton accelerators. IEC standards thus have an impact on every aspect of a medical physicist’s job, including equipment testing, shielding design, room layout, and workflow. Consequently, it is imperative that US medical physicists know about existing standards, as well as have input on those under development or undergoing revision. The structure of the IEC and current standards development work will be described in detail. The presentation will explain how US medical physicists can learn about IEC standards and contribute to their development. Learning Objectives: Learn about the structure of the IEC and the influence that IEC standards have on the design of equipment for radiology and radiation therapy. Learn about the mechanisms by which the US participates in the development and revision of standards. Understand the specific requirements of several standards having direct relevance to diagnostic and radiation therapy physicists.« less

Effects of information, education, and communication campaign on a community-based health insurance scheme in Burkina Faso

PubMed Central

Cofie, Patience; De Allegri, Manuela; Kouyaté, Bocar; Sauerborn, Rainer

2013-01-01

Objective The study analysed the effect of Information, Education, and Communication (IEC) campaign activities on the adoption of a community-based health insurance (CHI) scheme in Nouna, Burkina Faso. It also identified the factors that enhanced or limited the campaign's effectiveness. Design Complementary data collection approaches were used. A survey was conducted with 250 randomly selected household heads, followed by in-depth interviews with 22 purposively selected community leaders, group discussions with the project management team, and field observations. Bivariate analysis and multivariate logistic regression models were used to assess the association between household exposure to campaign and acquisition of knowledge as well as household exposure to campaign and enrolment. Results The IEC campaign had a positive effect on households’ knowledge about the CHI and to a lesser extent on household enrolment in the scheme. The effectiveness of the IEC strategy was mainly influenced by: (1) frequent and consistent IEC messages from multiple media channels (mass and interpersonal channels), including the radio, a mobile information van, and CHI team, and (2) community heads’ participation in the CHI scheme promotion. Education was the only significantly influential socio-demographic determinant of knowledge and enrolment among household heads. The relatively low effects of the IEC campaign on CHI enrolment are indicative of other important IEC mediating factors, which should be taken into account in future CHI campaign evaluation. Conclusion The study concludes that an IEC campaign is crucial to improving the understanding of the CHI scheme concept, which is an enabler to enrolment, and should be integrated into scheme designs and evaluations. PMID:24314344

Effects of information, education, and communication campaign on a community-based health insurance scheme in Burkina Faso.

PubMed

Cofie, Patience; De Allegri, Manuela; Kouyaté, Bocar; Sauerborn, Rainer

2013-12-06

The study analysed the effect of Information, Education, and Communication (IEC) campaign activities on the adoption of a community-based health insurance (CHI) scheme in Nouna, Burkina Faso. It also identified the factors that enhanced or limited the campaign's effectiveness. Complementary data collection approaches were used. A survey was conducted with 250 randomly selected household heads, followed by in-depth interviews with 22 purposively selected community leaders, group discussions with the project management team, and field observations. Bivariate analysis and multivariate logistic regression models were used to assess the association between household exposure to campaign and acquisition of knowledge as well as household exposure to campaign and enrolment. The IEC campaign had a positive effect on households' knowledge about the CHI and to a lesser extent on household enrolment in the scheme. The effectiveness of the IEC strategy was mainly influenced by: (1) frequent and consistent IEC messages from multiple media channels (mass and interpersonal channels), including the radio, a mobile information van, and CHI team, and (2) community heads' participation in the CHI scheme promotion. Education was the only significantly influential socio-demographic determinant of knowledge and enrolment among household heads. The relatively low effects of the IEC campaign on CHI enrolment are indicative of other important IEC mediating factors, which should be taken into account in future CHI campaign evaluation. The study concludes that an IEC campaign is crucial to improving the understanding of the CHI scheme concept, which is an enabler to enrolment, and should be integrated into scheme designs and evaluations.

Immunoregulatory actions of epithelial cell PPAR gamma at the colonic mucosa of mice with experimental inflammatory bowel disease.

PubMed

Mohapatra, Saroj K; Guri, Amir J; Climent, Montse; Vives, Cristina; Carbo, Adria; Horne, William T; Hontecillas, Raquel; Bassaganya-Riera, Josep

2010-04-20

Peroxisome proliferator-activated receptors are nuclear receptors highly expressed in intestinal epithelial cells (IEC) and immune cells within the gut mucosa and are implicated in modulating inflammation and immune responses. The objective of this study was to investigate the effect of targeted deletion of PPAR gamma in IEC on progression of experimental inflammatory bowel disease (IBD). In the first phase, PPAR gamma flfl; Villin Cre- (VC-) and PPAR gamma flfl; Villin Cre+ (VC+) mice in a mixed FVB/C57BL/6 background were challenged with 2.5% dextran sodium sulfate (DSS) in drinking water for 0, 2, or 7 days. VC+ mice express a transgenic recombinase under the control of the Villin-Cre promoter that causes an IEC-specific deletion of PPAR gamma. In the second phase, we generated VC- and VC+ mice in a C57BL/6 background that were challenged with 2.5% DSS. Mice were scored on disease severity both clinically and histopathologically. Flow cytometry was used to phenotypically characterize lymphocyte and macrophage populations in blood, spleen and mesenteric lymph nodes. Global gene expression analysis was profiled using Affymetrix microarrays. The IEC-specific deficiency of PPAR gamma in mice with a mixed background worsened colonic inflammatory lesions, but had no effect on disease activity (DAI) or weight loss. In contrast, the IEC-specific PPAR gamma null mice in C57BL/6 background exhibited more severe inflammatory lesions, DAI and weight loss in comparison to their littermates expressing PPAR gamma in IEC. Global gene expression profiling revealed significantly down-regulated expression of lysosomal pathway genes and flow cytometry results demonstrated suppressed production of IL-10 by CD4+ T cells in mesenteric lymph nodes (MLN) of IEC-specific PPAR gamma null mice. Our results demonstrate that adequate expression of PPAR gamma in IEC is required for the regulation of mucosal immune responses and prevention of experimental IBD, possibly by modulation of lysosomal and antigen presentation pathways.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voytchev, M; Radev, R; Chiaro, P

The International Electrotechnical Commission (IEC) is the leading and oldest global organization with over 100 years history of developing and publishing international standards for all electrical, electronic and related technologies, including radiation detection instrumentation. Subcommittee 45B 'Radiation Protection Instrumentation' of the IEC has recently started the development of two standards on radiation-generating devices. IEC 62463 'Radiation protection instrumentation--X-ray Systems for the Screening of Persons for Security and the Carrying of Illicit Items' is applicable to X-ray systems designed for screening people to detect if they are carrying objects such as weapons, explosives, chemical and biological agents and other concealed itemsmore » that could be used for criminal purposes, e.g. terrorist use, drug smuggling, etc. IEC 62523 'Radiation protection instrumentation--Cargo/Vehicle radiographic inspection systems' applies to cargo/vehicle imaging inspection systems using accelerator produced X-ray or gamma radiation to obtain images of the screened objects (e.g. cargo containers, transport and passenger vehicles and railroad cars). The objective of both standards is to specify standard requirements and general characteristics and test procedures, as well as, radiation, electrical, environmental, mechanical, and safety requirements and to provide examples of acceptable methods to test these requirements. In particular the standards address the design requirements as they relate to the radiation protection of the people being screened, people who are in the vicinity of the equipment and the operators. The standard IEC 62463 does not deal with the performance requirements for the quality of the object detection. Compliance with the standards requirements will provide the manufacturers with internationally acceptable specifications and the device users with assurance of the rigorous quality and accuracy of the measurements in relation to the radiological safety of the equipment. The main characteristics of IEC 62463 and IEC 62523 standards are presented and as well as the IEC methodology of standard development and approval.« less

Expression of Ifnlr1 on Intestinal Epithelial Cells Is Critical to the Antiviral Effects of Interferon Lambda against Norovirus and Reovirus.

PubMed

Baldridge, Megan T; Lee, Sanghyun; Brown, Judy J; McAllister, Nicole; Urbanek, Kelly; Dermody, Terence S; Nice, Timothy J; Virgin, Herbert W

2017-04-01

Lambda interferon (IFN-λ) has potent antiviral effects against multiple enteric viral pathogens, including norovirus and rotavirus, in both preventing and curing infection. Because the intestine includes a diverse array of cell types, however, the cell(s) upon which IFN-λ acts to exert its antiviral effects is unclear. Here, we sought to identify IFN-λ-responsive cells by generation of mice with lineage-specific deletion of the receptor for IFN-λ, Ifnlr1 We found that expression of IFNLR1 on intestinal epithelial cells (IECs) in the small intestine and colon is required for enteric IFN-λ antiviral activity. IEC Ifnlr1 expression also determines the efficacy of IFN-λ in resolving persistent murine norovirus (MNoV) infection and regulates fecal shedding and viral titers in tissue. Thus, the expression of Ifnlr1 by IECs is necessary for the response to both endogenous and exogenous IFN-λ. We further demonstrate that IEC Ifnlr1 expression is required for the sterilizing innate immune effects of IFN-λ by extending these findings in Rag1 -deficient mice. Finally, we assessed whether our findings pertained to multiple viral pathogens by infecting mice specifically lacking IEC Ifnlr1 expression with reovirus. These mice phenocopied Ifnlr1 -null animals, exhibiting increased intestinal tissue titers and enhanced reovirus fecal shedding. Thus, IECs are the critical cell type responding to IFN-λ to control multiple enteric viruses. This is the first genetic evidence that supports an essential role for IECs in IFN-λ-mediated control of enteric viral infection, and these findings provide insight into the mechanism of IFN-λ-mediated antiviral activity. IMPORTANCE Human noroviruses (HNoVs) are the leading cause of epidemic gastroenteritis worldwide. Type III interferons (IFN-λ) control enteric viral infections in the gut and have been shown to cure mouse norovirus, a small-animal model for HNoVs. Using a genetic approach with conditional knockout mice, we identified IECs as the dominant IFN-λ-responsive cells in control of enteric virus infection in vivo Upon murine norovirus or reovirus infection, Ifnlr1 depletion in IECs largely recapitulated the phenotype seen in Ifnlr1 -/- mice of higher intestinal tissue viral titers and increased viral shedding in the stool. Moreover, IFN-λ-mediated sterilizing immunity against murine norovirus requires the capacity of IECs to respond to IFN-λ. These findings clarify the mechanism of action of this cytokine and emphasize the therapeutic potential of IFN-λ for treating mucosal viral infections. Copyright © 2017 American Society for Microbiology.

Morphological and Functional Characterization of IL-12Rβ2 Chain on Intestinal Epithelial Cells: Implications for Local and Systemic Immunoregulation.

PubMed

Regoli, Mari; Man, Angela; Gicheva, Nadhezda; Dumont, Antonio; Ivory, Kamal; Pacini, Alessandra; Morucci, Gabriele; Branca, Jacopo J V; Lucattelli, Monica; Santosuosso, Ugo; Narbad, Arjan; Gulisano, Massimo; Bertelli, Eugenio; Nicoletti, Claudio

2018-01-01

Interaction between intestinal epithelial cells (IECs) and the underlying immune systems is critical for maintaining intestinal immune homeostasis and mounting appropriate immune responses. We have previously showed that the T helper type 1 (T H 1) cytokine IL-12 plays a key role in the delicate immunological balance in the gut and the lack of appropriate levels of IL-12 had important consequences for health and disease, particularly with regard to food allergy. Here, we sought to understand the role of IL-12 in the regulation of lymphoepithelial cross talk and how this interaction affects immune responses locally and systemically. Using a combination of microscopy and flow cytometry techniques we observed that freshly isolated IECs expressed an incomplete, yet functional IL-12 receptor (IL-12R) formed solely by the IL-12Rβ2 chain that albeit the lack of the complementary IL-12β1 chain responded to ex vivo challenge with IL-12. Furthermore, the expression of IL-12Rβ2 on IECs is strategically located at the interface between epithelial and immune cells of the lamina propria and using in vitro coculture models and primary intestinal organoids we showed that immune-derived signals were required for the expression of IL-12Rβ2 on IECs. The biological relevance of the IEC-associated IL-12Rβ2 was assessed in vivo in a mouse model of food allergy characterized by allergy-associated diminished intestinal levels of IL-12 and in chimeric mice that lack the IL-12Rβ2 chain on IECs. These experimental models enabled us to show that the antiallergic properties of orally delivered recombinant Lactococcus lactis secreting bioactive IL-12 (rLc-IL12) were reduced in mice lacking the IL-12β2 chain on IECs. Finally, we observed that the oral delivery of IL-12 was accompanied by the downregulation of the production of the IEC-derived proallergic cytokine thymic stromal lymphopoietin (TSLP). However, further analysis of intestinal levels of TSLP in IL-12Rβ2 -/- mice suggested that this event was not directly linked to the IEC-associated IL-12Rβ2 chain. We interpreted these data as showing that IEC-associated IL12Rβ2 is a component of the cytokine network operating at the interface between the intestinal epithelium and immune system that plays a role in immune regulation.

Expression of Ifnlr1 on Intestinal Epithelial Cells Is Critical to the Antiviral Effects of Interferon Lambda against Norovirus and Reovirus

PubMed Central

Baldridge, Megan T.; Lee, Sanghyun; Brown, Judy J.; McAllister, Nicole; Urbanek, Kelly; Dermody, Terence S.

2017-01-01

ABSTRACT Lambda interferon (IFN-λ) has potent antiviral effects against multiple enteric viral pathogens, including norovirus and rotavirus, in both preventing and curing infection. Because the intestine includes a diverse array of cell types, however, the cell(s) upon which IFN-λ acts to exert its antiviral effects is unclear. Here, we sought to identify IFN-λ-responsive cells by generation of mice with lineage-specific deletion of the receptor for IFN-λ, Ifnlr1. We found that expression of IFNLR1 on intestinal epithelial cells (IECs) in the small intestine and colon is required for enteric IFN-λ antiviral activity. IEC Ifnlr1 expression also determines the efficacy of IFN-λ in resolving persistent murine norovirus (MNoV) infection and regulates fecal shedding and viral titers in tissue. Thus, the expression of Ifnlr1 by IECs is necessary for the response to both endogenous and exogenous IFN-λ. We further demonstrate that IEC Ifnlr1 expression is required for the sterilizing innate immune effects of IFN-λ by extending these findings in Rag1-deficient mice. Finally, we assessed whether our findings pertained to multiple viral pathogens by infecting mice specifically lacking IEC Ifnlr1 expression with reovirus. These mice phenocopied Ifnlr1-null animals, exhibiting increased intestinal tissue titers and enhanced reovirus fecal shedding. Thus, IECs are the critical cell type responding to IFN-λ to control multiple enteric viruses. This is the first genetic evidence that supports an essential role for IECs in IFN-λ-mediated control of enteric viral infection, and these findings provide insight into the mechanism of IFN-λ-mediated antiviral activity. IMPORTANCE Human noroviruses (HNoVs) are the leading cause of epidemic gastroenteritis worldwide. Type III interferons (IFN-λ) control enteric viral infections in the gut and have been shown to cure mouse norovirus, a small-animal model for HNoVs. Using a genetic approach with conditional knockout mice, we identified IECs as the dominant IFN-λ-responsive cells in control of enteric virus infection in vivo. Upon murine norovirus or reovirus infection, Ifnlr1 depletion in IECs largely recapitulated the phenotype seen in Ifnlr1−/− mice of higher intestinal tissue viral titers and increased viral shedding in the stool. Moreover, IFN-λ-mediated sterilizing immunity against murine norovirus requires the capacity of IECs to respond to IFN-λ. These findings clarify the mechanism of action of this cytokine and emphasize the therapeutic potential of IFN-λ for treating mucosal viral infections. PMID:28077655

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sherwood, Larry

The Small Wind Certification Council (SWCC) created a successful accredited certification program for small and medium wind turbines using the funding from this grant. SWCC certifies small turbines (200 square meters of swept area or less) to the American Wind Energy Association (AWEA) Small Wind Turbine Performance and Safety Standard (AWEA Standard 9.1 – 2009). SWCC also certifies medium wind turbines to the International Electrical Commission (IEC) Power Performance Standard (IEC 61400-12-1) and Acoustic Performance Standard (IEC 61400-11).

Crosstalk: The Journal of Defense Software Engineering. Volume 22, Number 3

DTIC Science & Technology

2009-04-01

international standard for information security management systems like ISO /IEC 27001 :2005 [1] existed. Since that time, the organization has developed control...of ISO /IEC 27001 and the desire to make decisions based on business value and risk has prompted Ford’s IT Security and Controls organi- zation to begin...their conventional application security operation.u References 1. ISO /IEC 27001 :2005. “Information Technology – Security Techniques – Information

Effect of salt entropy on protein solubility and Hofmeister series

NASA Astrophysics Data System (ADS)

Dahal, Yuba; Schmit, Jeremy

We present a theory of salt effects on protein solubility that accounts for salting-in, salting-out, and the Hofmeister series. We represent protein charge by the first order multipole expansion to include attractive and repulsive electrostatic interactions in the model. Our model also includes non-electrostatic protein-ion interactions, and ion-solvent interactions via an effective solvated ion radius. We find that the finite size of the ions has significant effects on the translational entropy of the salt, which accounts for the changes in the protein solubility. At low salt the dominant effect comes from the entropic cost of confining ions within the aggregate. At high concentrations the salt drives a depletion attraction that favors aggregation. Our theory explains the reversal in the Hofmeister series observed in lysozyme cloud point measurements and semi-quantitatively describes the solubility of lysozyme and chymosin crystals.

New dynamic silicon photonic components enabled by MEMS technology

NASA Astrophysics Data System (ADS)

Errando-Herranz, Carlos; Edinger, Pierre; Colangelo, Marco; Björk, Joel; Ahmed, Samy; Stemme, Göran; Niklaus, Frank; Gylfason, Kristinn B.

2018-02-01

Silicon photonics is the study and application of integrated optical systems which use silicon as an optical medium, usually by confining light in optical waveguides etched into the surface of silicon-on-insulator (SOI) wafers. The term microelectromechanical systems (MEMS) refers to the technology of mechanics on the microscale actuated by electrostatic actuators. Due to the low power requirements of electrostatic actuation, MEMS components are very power efficient, making them well suited for dense integration and mobile operation. MEMS components are conventionally also implemented in silicon, and MEMS sensors such as accelerometers, gyros, and microphones are now standard in every smartphone. By combining these two successful technologies, new active photonic components with extremely low power consumption can be made. We discuss our recent experimental work on tunable filters, tunable fiber-to-chip couplers, and dynamic waveguide dispersion tuning, enabled by the marriage of silicon MEMS and silicon photonics.

Influence of strain relaxation in axial {{In}}_{x}{{Ga}}_{1-x}{\\rm{N}}/{GaN} nanowire heterostructures on their electronic properties

NASA Astrophysics Data System (ADS)

Marquardt, Oliver; Krause, Thilo; Kaganer, Vladimir; Martín-Sánchez, Javier; Hanke, Michael; Brandt, Oliver

2017-05-01

We present a systematic theoretical study of the influence of elastic strain relaxation on the built-in electrostatic potentials and the electronic properties of axial {{In}}x{{Ga}}1-x{{N}}/{GaN} nanowire (NW) heterostructures. Our simulations reveal that for a sufficiently large ratio between the thickness of the {{In}}x{{Ga}}1-x{{N}} disk and the diameter of the NW, the elastic relaxation leads to a significant reduction of the built-in electrostatic potential in comparison to a planar system of similar layer thickness and In content. In this case, the ground state transition energies approach constant values with increasing thickness of the disk and only depend on the In content, a behavior usually associated to that of a quantum well free of built-in electrostatic potentials. We show that the structures under consideration are by no means field-free, and the built-in potentials continue to play an important role even for ultrathin NWs. In particular, strain and the resulting polarization potentials induce complex confinement features of electrons and holes, which depend on the In content, shape, and dimensions of the heterostructure.

Ion association at discretely-charged dielectric interfaces: Giant charge inversion

NASA Astrophysics Data System (ADS)

Wang, Zhi-Yong; Wu, Jianzhong

2017-07-01

Giant charge reversal has been identified for the first time by Monte Carlo simulation for a discretely charged surface in contact with a trivalent electrolyte solution. It takes place regardless of the surface charge density under study and the monovalent salt. In stark contrast to earlier predictions based on the 2-dimensional Wigner crystal model to describe strong correlation of counterions at the macroion surface, we find that giant charge reversal reflects an intricate interplay of ionic volume effects, electrostatic correlations, surface charge heterogeneity, and the dielectric response of the confined fluids. While the novel phenomenon is yet to be confirmed with experiment, the simulation results appear in excellent agreement with a wide range of existing observations in the subregime of charge inversion. Our findings may have far-reaching implications to understanding complex electrochemical phenomena entailing ionic fluids under dielectric confinements.

Nonlocal spin-confinement of electrons in graphene with proximity exchange interaction

NASA Astrophysics Data System (ADS)

Ang, Yee Sin; Liang, Shi-Jun; Ooi, Kelvin J. A.; Zhang, Chao; Ma, Zhongshui; Ang, Lay Kee

In graphene-magnetic-insulator hybrid structure such as graphene-Europium-oxide (EuO-G), proximity induced exchange interaction opens up a spin-dependent bandgap and spin splitting in the Dirac band. We study the bound state formation in a hetero-interface composed of EuO-G. We theoretically predict a remarkable nonlocal spin-confinement effect in EuO-G and show that spin-polarized quasi-1D electron interface state can be generated in a magnetic-field-free channel. Quasiparticle transport mediated by the interface state can be efficiently controlled by the channel width and electrostatic gating. Our results suggest a pathway to further reduce the dimensionality of graphene quasiparticles from 2D to 1D, thus offering an exciting graphene-based platform for the search of exotic 1D physics and spintronic applications.

A Pearson Effective Potential for Monte Carlo Simulation of Quantum Confinement Effects in nMOSFETs

NASA Astrophysics Data System (ADS)

Jaud, Marie-Anne; Barraud, Sylvain; Saint-Martin, Jérôme; Bournel, Arnaud; Dollfus, Philippe; Jaouen, Hervé

2008-12-01

A Pearson Effective Potential model for including quantization effects in the simulation of nanoscale nMOSFETs has been developed. This model, based on a realistic description of the function representing the non zero-size of the electron wave packet, has been used in a Monte-Carlo simulator for bulk, single gate SOI and double-gate SOI devices. In the case of SOI capacitors, the electron density has been computed for a large range of effective field (between 0.1 MV/cm and 1 MV/cm) and for various silicon film thicknesses (between 5 nm and 20 nm). A good agreement with the Schroedinger-Poisson results is obtained both on the total inversion charge and on the electron density profiles. The ability of an Effective Potential approach to accurately reproduce electrostatic quantum confinement effects is clearly demonstrated.

Single nanowire extinction spectroscopy.

PubMed

Giblin, Jay; Vietmeyer, Felix; McDonald, Matthew P; Kuno, Masaru

2011-08-10

Here we show the first direct extinction spectra of single one-dimensional (1D) semiconductor nanostructures obtained at room temperature utilizing a spatial modulation approach. (1) For these materials, ensemble averaging in conventional extinction spectroscopy has limited our understanding of the interplay between carrier confinement and their electrostatic interactions. (2-4) By probing individual CdSe nanowires (NWs), we have identified and assigned size-dependent exciton transitions occurring across the visible. In turn, we have revealed the existence of room temperature 1D excitons in the narrowest NWs.

[Primary culture of cat intestinal epithelial cell and construction of its cDNA library].

PubMed

Ye, L; Gui-Hua, Z; Kun, Y; Hong-Fa, W; Ting, X; Gong-Zhen, L; Wei-Xia, Z; Yong, C

2017-04-12

Objective To establish the primary cat intestinal epithelial cells (IECs) culture methods and construct the cDNA library for the following yeast two-hybrid experiment, so as to screen the virulence interaction factors among the final host. Methods The primary cat IECs were cultured by the tissue cultivation and combined digestion with collagenase XI and dispase I separately. Then the cat IECs cultured was identified with the morphological observation and cyto-keratin detection, by using goat anti-cyto-keratin monoclonal antibodies. The mRNA of cat IECs was isolated and used as the template to synthesize the first strand cDNA by SMART™ technology, and then the double-strand cDNAs were acquired by LD-PCR, which were subsequently cloned into the plasmid PGADT7-Rec to construct yeast two-hybrid cDNA library in the yeast strain Y187 by homologous recombination. Matchmaker™ Insert Check PCR was used to detect the size distribution of cDNA fragments after the capacity calculation of the cDNA library. Results The comparison of the two cultivation methods indicated that the combined digestion of collagenase XI and dispase I was more effective than the tissue cultivation. The cat IECs system of continuous culture was established and the cat IECs with high purity were harvested for constructing the yeast two-hybrid cDNA library. The library contained 1.1×10 6 independent clones. The titer was 2.8×10 9 cfu/ml. The size of inserted fragments was among 0.5-2.0 kb. Conclusion The yeast two-hybrid cDNA library of cat IECs meets the requirements of further screen research, and this study lays the foundation of screening the Toxoplasma gondii virulence interaction factors among the cDNA libraries of its final hosts.

Actinic keratosis-related signs predictive of squamous cell carcinoma in renal transplant recipients: a nested case-control study.

PubMed

Jiyad, Z; O'Rourke, P; Soyer, H P; Green, A C

2017-04-01

Squamous cell carcinoma (SCC) and intraepidermal carcinoma (IEC) commonly arise in actinically damaged skin. To identify clinical features of actinic change that correlate with an increased risk of SCC or IEC in the short-to-medium term as guidance for prioritizing field treatment. In a nested case-control study, cases were renal transplant recipients who developed an incident SCC or IEC within 18 months following baseline examination and photography. Controls without SCC or IEC were matched to cases on age, sex and duration of immunosuppression. Predefined skin sites on the head, neck and upper limbs were examined using baseline photographs to assess objectively the following features of actinic damage: presence of actinic keratosis (AK) patch (defined as AK > 1 cm 2 ), number of AK patches, number of AKs and area affected by AK. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using McNemar's test to identify differences in SCC/IEC risk combined and SCC risk alone between case and control skin sites. Thirty-nine cases were matched to 39 controls. Significant associations with the presence of an AK patch, number of AK patches, number of AKs and area affected by AKs were identified. The presence of an AK patch conferred an 18-fold increased risk of SCC (OR 18·00, 95% CI 2·84-750) and more than a sixfold increased risk of SCC/IEC combined (OR 6·60, 95% CI 2·56-21·66). AK patches are predictive of SCC/IEC development within 18 months. This can be used to guide site selection for field treatment in patients with widespread actinic damage. © 2016 British Association of Dermatologists.

Interactions between peripheral blood CD8 T lymphocytes and intestinal epithelial cells (iEC).

PubMed

Arosa, F A; Irwin, C; Mayer, L; de Sousa, M; Posnett, D N

1998-05-01

Intestinal intraepithelial lymphocytes (iIEL) are primarily CD8 cells and most of them have a CD28- phenotype, the phenotype of effector cytotoxic T cells. We asked whether the predominance of CD8+CD28- T cells in the gut may result from peripheral blood T cells preferentially migrating to the iIEL compartment and adhering to iEC. Compared with CD4 cells, adhesion of resting CD8+ T cells to iEC cell lines was significantly higher. Adhesion could be blocked with a MoAb to gp180, a molecule expressed on iEC which is known to interact with CD8/lck. No significant difference in the level of adhesion was observed between CD8+CD28+ and CD8+CD28- T cells. Thus CD8 cells may preferentially migrate to the iIEL compartment, but loss of CD28 expression could occur in situ after migration. Consistent with this hypothesis, the CD8+CD28- cells became enriched after co-culturing T cells with iEC cell lines and primary iEC. Induction of the CD8+CD28- phenotype in cord blood and adult T cells was observed in co-cultures with iEC and also with mitogens and superantigens. In the latter case, CD28 down-modulation was seen specifically in the Vbeta subset targeted by the superantigen, indicating that loss of CD28 expression is a direct result of T cell receptor (TCR)-mediated stimulation. The combined results suggest that CD8+CD28- T cells are antigen experienced T cells, and that they may have a survival advantage in the presence of gut epithelial cells in vitro. This may contribute to the predominance of CD8+CD28- T cells in the iIEL compartment.

New focus on advocacy in South Asia. Advocacy for reproductive health: South Asia.

PubMed

Kapoor, I

1996-01-01

Initiatives like Vision 2000, the International Conference on Population and Development in Cairo, and the Fourth World Conference on Women in Beijing have focused attention on the activities of regional family planning associations (FPAs) in South Asia. These activities include male acceptance of the responsibility for family life, youth involvement in program design and implementation, the promotion of gender equality, and increased public awareness about the value of the female child. The Beijing conference also directed attention to the problem of not allocating resources to problems recognized by governments. In the South Asia region funding levels have been falling, which impacts the maintenance of current programs. The South Asia Regional Bureau began to coordinate an information, education, and communication (IEC) and Advocacy Working Group in the region with the participation of IEC officers from all regional FPAs. The group will be planning IEC and advocacy activities based on the regional FPAs' goals and aspirations. The IEC and advocacy activities will be examined to identify existing skills and experiences of group participants. The group will also try to identify the activities of each FPA. The information gathered will point out the similarities in IEC and advocacy activities serving as a common ground for the region. Problems of IEC and advocacy comprise their subordinate structure and the failure to evaluate to show the impact of the activities. Better planning and organization and more holistic evaluation of program components should be achieved. The group will be self-directed responding to the IEC and advocacy needs, while also developing the professional and personal capacity of FPA staff to meet these needs.

ANSI-ASQ National Accreditation Board /ACLASS

DTIC Science & Technology

2011-03-28

unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18  Laboratories – ISO / IEC 17025  Inspection...Bodies – ISO / IEC 17020  RMPs – ISO Guide 34 (Reference Materials)  PT Providers – ISO 17043  Product Certifiers – ISO Guide 65  Government...Programs: DoD ELAP, EPA Energy Star, CPSC Toy Safety, NRC, NIST IPV6, NLLAP, NEFAP  TRAINING Programs  Certification Bodies – ISO / IEC 17021

Trypsin-sensitive modulation of intestinal epithelial MD-2 as mechanism of lipopolysaccharide tolerance.

PubMed

Cario, Elke; Golenbock, Douglas T; Visintin, Alberto; Rünzi, Michael; Gerken, Guido; Podolsky, Daniel K

2006-04-01

Intestinal epithelial cells (IEC) are constantly exposed to both high concentrations of the bacterial ligand LPS and the serine protease trypsin. MD-2, which contains multiple trypsin cleavage sites, is an essential accessory glycoprotein required for LPS recognition and signaling through TLR4. The aim of this study was to characterize the expression and subcellular distribution of intestinal epithelial MD-2 and to delineate potential functional interactions with trypsin and then alteration in inflammatory bowel disease (IBD). Although MD-2 protein expression was minimal in primary IEC of normal colonic or ileal mucosa, expression was significantly increased in IEC from patients with active IBD colitis, but not in ileal areas from patients with severe Crohn's disease. Endogenous MD-2 was predominantly retained in the calnexin-calreticulin cycle of the endoplasmic reticulum; only a small fraction was exported to the Golgi. MD-2 expression correlated inversely with trypsin activity. Biochemical evidence and in vitro experiments demonstrated that trypsin exposure resulted in extensive proteolysis of endogenous and soluble MD-2 protein, but not of TLR4 in IEC, and was associated with desensitization of IEC to LPS. In conclusion, the present study suggests that endoplasmic reticulum-associated MD-2 expression in IBD may be altered by ileal protease in inflammation, leading to impaired LPS recognition and hyporesponsiveness through MD-2 proteolysis in IEC, thus implying a physiologic mechanism that helps maintain LPS tolerance in the intestine.

Assessment of Information Security Management System based on ISO/IEC 27001:2013 On Subdirectorate of Data Center and Data Recovery Center in Ministry of Internal Affairs

NASA Astrophysics Data System (ADS)

Kurnianto, Ari; Isnanto, Rizal; Widodo, Aris Puji

2018-02-01

Information security is a problem effected business process of an organization, so it needs special concern. Information security assessment which is good and has international standard is done using Information Security Management System (ISMS) ISO/IEC 27001:2013. In this research, the high level assessment has been done using ISO/IEC 27001:2013 to observe the strength of information secuity in Ministry of Internal Affairs. The research explains about the assessment of information security management which is built using PHP. The input data use primary and secondary data which passed observation. The process gets maturity using the assessment of ISO/IEC 27001:2013. GAP Analysis observes the condition now a days and then to get recommendation and road map. The result of this research gets all of the information security process which has not been already good enough in Ministry of Internal Affairs, gives recommendation and road map to improve part of all information system being running. It indicates that ISO/IEC 27001:2013 is good used to rate maturity of information security management. As the next analyzation, this research use Clause and Annex in ISO/IEC 27001:2013 which is suitable with condition of Data Center and Data Recovery Center, so it gets optimum result and solving problem of the weakness information security.

Overview of NASA MSFC IEC Federated Engineering Collaboration Capability

NASA Technical Reports Server (NTRS)

Moushon, Brian; McDuffee, Patrick

2005-01-01

The MSFC IEC federated engineering framework is currently developing a single collaborative engineering framework across independent NASA centers. The federated approach allows NASA centers the ability to maintain diversity and uniqueness, while providing interoperability. These systems are integrated together in a federated framework without compromising individual center capabilities. MSFC IEC's Federation Framework will have a direct affect on how engineering data is managed across the Agency. The approach is directly attributed in response to the Columbia Accident Investigation Board (CAB) finding F7.4-11 which states the Space Shuttle Program has a wealth of data sucked away in multiple databases without a convenient way to integrate and use the data for management, engineering, or safety decisions. IEC s federated capability is further supported by OneNASA recommendation 6 that identifies the need to enhance cross-Agency collaboration by putting in place common engineering and collaborative tools and databases, processes, and knowledge-sharing structures. MSFC's IEC Federated Framework is loosely connected to other engineering applications that can provide users with the integration needed to achieve an Agency view of the entire product definition and development process, while allowing work to be distributed across NASA Centers and contractors. The IEC DDMS federation framework eliminates the need to develop a single, enterprise-wide data model, where the goal of having a common data model shared between NASA centers and contractors is very difficult to achieve.

Partial discharge measurements on 110kV current transformers. Setting the control value. Case study

NASA Astrophysics Data System (ADS)

Dan, C.; Morar, R.

2017-05-01

The case study presents a series of partial discharge measurements, reflecting the state of insulation of 110kV CURRENT TRANSFORMERS located in Sibiu county substations. Measurements were performed based on electrical method, using MPD600: an acquisition and analysis toolkit for detecting, recording, and analyzing partial discharges. MPD600 consists of one acquisition unit, an optical interface and a computer with dedicated software. The system allows measurements of partial discharge on site, even in presence of strong electromagnetic interferences because it provides synchronous acquisition from all measurement points. Therefore, measurements, with the ability to be calibrated, do render: - a value subject to interpretation according to IEC 61869-1:2007 + IEC 61869-2:2012 + IEC 61869-3:2011 + IEC 61869-5:2011 and IEC 60270: 2000; - the possibility to determine the quantitative limit of PD (a certain control value) to which the equipment can be operated safely and repaired with minimal costs (relative to the high costs implied by eliminating the consequences of a failure) identified empirically (process in which the instrument transformer subjected to the tests was completely destroyed).

Immunoregulatory Actions of Epithelial Cell PPAR γ at the Colonic Mucosa of Mice with Experimental Inflammatory Bowel Disease

PubMed Central

Mohapatra, Saroj K.; Guri, Amir J.; Climent, Montse; Vives, Cristina; Carbo, Adria; Horne, William T.; Hontecillas, Raquel; Bassaganya-Riera, Josep

2010-01-01

Background Peroxisome proliferator-activated receptors are nuclear receptors highly expressed in intestinal epithelial cells (IEC) and immune cells within the gut mucosa and are implicated in modulating inflammation and immune responses. The objective of this study was to investigate the effect of targeted deletion of PPAR γ in IEC on progression of experimental inflammatory bowel disease (IBD). Methodology/Principal Findings In the first phase, PPAR γ flfl; Villin Cre- (VC-) and PPAR γ flfl; Villin Cre+ (VC+) mice in a mixed FVB/C57BL/6 background were challenged with 2.5% dextran sodium sulfate (DSS) in drinking water for 0, 2, or 7 days. VC+ mice express a transgenic recombinase under the control of the Villin-Cre promoter that causes an IEC-specific deletion of PPAR γ. In the second phase, we generated VC- and VC+ mice in a C57BL/6 background that were challenged with 2.5% DSS. Mice were scored on disease severity both clinically and histopathologically. Flow cytometry was used to phenotypically characterize lymphocyte and macrophage populations in blood, spleen and mesenteric lymph nodes. Global gene expression analysis was profiled using Affymetrix microarrays. The IEC-specific deficiency of PPAR γ in mice with a mixed background worsened colonic inflammatory lesions, but had no effect on disease activity (DAI) or weight loss. In contrast, the IEC-specific PPAR γ null mice in C57BL/6 background exhibited more severe inflammatory lesions, DAI and weight loss in comparison to their littermates expressing PPAR γ in IEC. Global gene expression profiling revealed significantly down-regulated expression of lysosomal pathway genes and flow cytometry results demonstrated suppressed production of IL-10 by CD4+ T cells in mesenteric lymph nodes (MLN) of IEC-specific PPAR γ null mice. Conclusions/Significance Our results demonstrate that adequate expression of PPAR γ in IEC is required for the regulation of mucosal immune responses and prevention of experimental IBD, possibly by modulation of lysosomal and antigen presentation pathways. PMID:20422041

Electrostatic interactions between ions near Thomas-Fermi substrates and the surface energy of ionic crystals at imperfect metals.

PubMed

Kaiser, V; Comtet, J; Niguès, A; Siria, A; Coasne, B; Bocquet, L

2017-07-01

The electrostatic interaction between two charged particles is strongly modified in the vicinity of a metal. This situation is usually accounted for by the celebrated image charges approach, which was further extended to account for the electronic screening properties of the metal at the level of the Thomas-Fermi description. In this paper we build upon a previous approach [M. A. Vorotyntsev and A. A. Kornyshev, Zh. Eksp. Teor. Fiz., 1980, 78(3), 1008-1019] and successive works to calculate the 1-body and 2-body electrostatic energy of ions near a metal in terms of the Thomas-Fermi screening length. We propose workable approximations suitable for molecular simulations of ionic systems close to metallic walls. Furthermore, we use this framework to calculate analytically the electrostatic contribution to the surface energy of a one dimensional crystal at a metallic wall and its dependence on the Thomas-Fermi screening length. These calculations provide a simple interpretation for the surface energy in terms of image charges, which allows for an estimation of the interfacial properties in more complex situations of a disordered ionic liquid close to a metal surface. The counter-intuitive outcome is that electronic screening, as characterized by a molecular Thomas-Fermi length l TF , profoundly affects the wetting of ionic systems close to a metal, in line with the recent experimental observation of capillary freezing of ionic liquids in metallic confinement.

Nondestructive Inspection System for Special Nuclear Material Using Inertial Electrostatic Confinement Fusion Neutrons and Laser Compton Scattering Gamma-Rays

NASA Astrophysics Data System (ADS)

Ohgaki, H.; Daito, I.; Zen, H.; Kii, T.; Masuda, K.; Misawa, T.; Hajima, R.; Hayakawa, T.; Shizuma, T.; Kando, M.; Fujimoto, S.

2017-07-01

A Neutron/Gamma-ray combined inspection system for hidden special nuclear materials (SNMs) in cargo containers has been developed under a program of Japan Science and Technology Agency in Japan. This inspection system consists of an active neutron-detection system for fast screening and a laser Compton backscattering gamma-ray source in coupling with nuclear resonance fluorescence (NRF) method for precise inspection. The inertial electrostatic confinement fusion device has been adopted as a neutron source and two neutron-detection methods, delayed neutron noise analysis method and high-energy neutron-detection method, have been developed to realize the fast screening system. The prototype system has been constructed and tested in the Reactor Research Institute, Kyoto University. For the generation of the laser Compton backscattering gamma-ray beam, a race track microtron accelerator has been used to reduce the size of the system. For the NRF measurement, an array of LaBr3(Ce) scintillation detectors has been adopted to realize a low-cost detection system. The prototype of the gamma-ray system has been demonstrated in the Kansai Photon Science Institute, National Institutes for Quantum and Radiological Science and Technology. By using numerical simulations based on the data taken from these prototype systems and the inspection-flow, the system designed by this program can detect 1 kg of highly enriched 235U (HEU) hidden in an empty 20-ft container within several minutes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clements, Samuel L.; Edgar, Thomas W.; Manz, David O.

The purpose of this workshop was to identify and discuss concerns with the use and adoption of IEC 62351 security standard for IEC 61850 compliant control system products. The industry participants discussed performance, interoperability, adoption, challenges, business cases, and future issues.

A model-driven approach to information security compliance

NASA Astrophysics Data System (ADS)

Correia, Anacleto; Gonçalves, António; Teodoro, M. Filomena

2017-06-01

The availability, integrity and confidentiality of information are fundamental to the long-term survival of any organization. Information security is a complex issue that must be holistically approached, combining assets that support corporate systems, in an extended network of business partners, vendors, customers and other stakeholders. This paper addresses the conception and implementation of information security systems, conform the ISO/IEC 27000 set of standards, using the model-driven approach. The process begins with the conception of a domain level model (computation independent model) based on information security vocabulary present in the ISO/IEC 27001 standard. Based on this model, after embedding in the model mandatory rules for attaining ISO/IEC 27001 conformance, a platform independent model is derived. Finally, a platform specific model serves the base for testing the compliance of information security systems with the ISO/IEC 27000 set of standards.

Ion-Exchange Chromatography: Basic Principles and Application.

PubMed

Cummins, Philip M; Rochfort, Keith D; O'Connor, Brendan F

2017-01-01

Ion-Exchange Chromatography (IEC) allows for the separation of ionizable molecules on the basis of differences in charge properties. Its large sample-handling capacity, broad applicability (particularly to proteins and enzymes), moderate cost, powerful resolving ability, and ease of scale-up and automation have led to it becoming one of the most versatile and widely used of all liquid chromatography (LC) techniques. In this chapter, we review the basic principles of IEC, as well as the broader criteria for selecting IEC conditions. By way of further illustration, we outline basic laboratory protocols to partially purify a soluble serine peptidase from bovine whole brain tissue, covering crude tissue extract preparation through to partial purification of the target enzyme using anion-exchange chromatography. Protocols for assaying total protein and enzyme activity in both pre- and post-IEC fractions are also described.

Evaluation of the measurement uncertainty when measuring the resistance of solid isolating materials to tracking

NASA Astrophysics Data System (ADS)

Stare, E.; Beges, G.; Drnovsek, J.

2006-07-01

This paper presents the results of research into the measurement of the resistance of solid isolating materials to tracking. Two types of tracking were investigated: the proof tracking index (PTI) and the comparative tracking index (CTI). Evaluation of the measurement uncertainty in a case study was performed using a test method in accordance with the IEC 60112 standard. In the scope of the tests performed here, this particular test method was used to ensure the safety of electrical appliances. According to the EN ISO/IEC 17025 standard (EN ISO/IEC 17025), in the process of conformity assessment, the evaluation of the measurement uncertainty of the test method should be carried out. In the present article, possible influential parameters that are in accordance with the third and fourth editions of the standard IEC 60112 are discussed. The differences, ambiguities or lack of guidance referring to both editions of the standard are described in the article 'Ambiguities in technical standards—case study IEC 60112—measuring the resistance of solid isolating materials to tracking' (submitted for publication). Several hundred measurements were taken in the present experiments in order to form the basis for the results and conclusions presented. A specific problem of the test (according to the IEC 60112 standard) is the great variety of influential physical parameters (mechanical, electrical, chemical, etc) that can affect the results. At the end of the present article therefore, there is a histogram containing information on the contributions to the measurement uncertainty.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Supanich, M.

The International Electrotechnical Commission (IEC) writes standards that manufacturers of electrical equipment must comply with. Medical electrical equipment, such as medical imaging, radiation therapy, and radiation dosimetry devices, fall under Technical Committee 62. Of particular interest to medical physicists are the standards developed within Subcommittees (SC) 62B, which addresses diagnostic radiological imaging equipment, and 62C, which addresses equipment for radiation therapy, nuclear medicine and dosimetry. For example, a Working Group of SC 62B is responsible for safety and quality assurance standards for CT scanners and a Working Group of SC 62C is responsible for standards that set requirements for dosimetricmore » safety and accuracy of linacs and proton accelerators. IEC standards thus have an impact on every aspect of a medical physicist’s job, including equipment testing, shielding design, room layout, and workflow. Consequently, it is imperative that US medical physicists know about existing standards, as well as have input on those under development or undergoing revision. The structure of the IEC and current standards development work will be described in detail. The presentation will explain how US medical physicists can learn about IEC standards and contribute to their development. Learning Objectives: Learn about the structure of the IEC and the influence that IEC standards have on the design of equipment for radiology and radiation therapy. Learn about the mechanisms by which the US participates in the development and revision of standards. Understand the specific requirements of several standards having direct relevance to diagnostic and radiation therapy physicists.« less

Nivalenol induces oxidative stress and increases deoxynivalenol pro-oxidant effect in intestinal epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Del Regno, Marisanta; Adesso, Simona; Popolo, Ada

Mycotoxins are secondary fungal metabolites often found as contaminants in almost all agricultural commodities worldwide, and the consumption of food or feed contaminated by mycotoxins represents a major risk for human and animal health. Reactive oxygen species are normal products of cellular metabolism. However, disproportionate generation of reactive oxygen species poses a serious problem to bodily homeostasis and causes oxidative tissue damage. In this study we analyzed the effect of two trichothecenes mycotoxins: nivalenol and deoxynivalenol, alone and in combination, on oxidative stress in the non-tumorigenic intestinal epithelial cell line IEC-6. Our results indicate the pro-oxidant nivalenol effect in IEC-6,more » the stronger pro-oxidant effect of nivalenol when compared to deoxynivalenol and, interestingly, that nivalenol increases deoxynivalenol pro-oxidative effects. Mechanistic studies indicate that the observed effects were mediated by NADPH oxidase, calcium homeostasis alteration, NF-kB and Nrf2 pathways activation and by iNOS and nitrotyrosine formation. The toxicological interaction by nivalenol and deoxynivalenol reported in this study in IEC-6, points out the importance of the toxic effect of these mycotoxins, mostly in combination, further highlighting the risk assessment process of these toxins that are of growing concern. - Highlights: • Nivalenol induces oxidative stress in intestinal epithelial cells (IECs). • Nivalenol increases deoxynivalenol pro-oxidant effects in IECs. • Nivalenol and deoxynivalenol trigger antioxidant response IECs. • These results indicate the importance of mycotoxins co-contamination.« less

Static and Dynamic Properties of DNA Confined in Nanochannels

NASA Astrophysics Data System (ADS)

Gupta, Damini

Next-generation sequencing (NGS) techniques have considerably reduced the cost of high-throughput DNA sequencing. However, it is challenging to detect large-scale genomic variations by NGS due to short read lengths. Genome mapping can easily detect large-scale structural variations because it operates on extremely large intact molecules of DNA with adequate resolution. One of the promising methods of genome mapping is based on confining large DNA molecules inside a nanochannel whose cross-sectional dimensions are approximately 50 nm. Even though this genome mapping technology has been commercialized, the current understanding of the polymer physics of DNA in nanochannel confinement is based on theories and lacks much needed experimental support. The results of this dissertation are aimed at providing a detailed experimental understanding of equilibrium properties of nanochannel-confined DNA molecules. The results are divided into three parts. In first part, we evaluate the role of channel shape on thermodynamic properties of channel confined DNA molecules using a combination of fluorescence microscopy and simulations. Specifically, we show that high aspect ratio of rectangular channels significantly alters the chain statistics as compared to an equivalent square channel with same cross-sectional area. In the second part, we present experimental evidence that weak excluded volume effects arise in DNA nanochannel confinement, which form the physical basis for the extended de Gennes regime. We also show how confinement spectroscopy and simulations can be combined to reduce molecular weight dispersity effects arising from shearing, photo-cleavage, and nonuniform staining of DNA. Finally, the third part of the thesis concerns the dynamic properties of nanochannel confined DNA. We directly measure the center-of-mass diffusivity of single DNA molecules in confinement and show that that it is necessary to modify the classical results of de Gennes to account for local chain stiffness of DNA in order to explain the experimental results. In the end, we believe that our findings from the experimental test of the phase diagram for channel-confined DNA, with careful control over molecular weight dispersity, channel geometry, and electrostatic interactions, will provide a firm foundation for the emerging genome mapping technology.

Immunomodulatory properties of fermented soy and dairy milks prepared with lactic acid bacteria.

PubMed

Wagar, L E; Champagne, C P; Buckley, N D; Raymond, Y; Green-Johnson, J M

2009-10-01

Fermented soy and dairy milk preparations provide a means for delivering lactic acid bacteria and their fermentation products into the diet. Our aims were to test immunomodulatory bioactivity of fermented soy beverage (SB) and dairy milk blend (MB) preparations on human intestinal epithelial cells (IEC) and to determine the impact of freezing medium on culture survival prior to bioactivity analyses. Fermented SB and MB were prepared using pure or mixed cultures of Streptococcus thermophilus ST5, Bifidobacterium longum R0175, and Lactobacillus helveticus R0052. Immunomodulatory bioactivity was assessed by testing selected SB and MB ferments on tumor necrosis factor alpha (TNFalpha)-treated IEC and measuring effects on Interleukin-8 (IL-8) production. Impact of timing of ferment administration relative to this pro-inflammatory challenge was investigated. The most pronounced reductions in IEC IL-8 production were observed when IEC were treated with either SB or MB ferment preparations prior to TNFalpha challenge. These results indicate that freezing-stable MB and SB ferments prepared with selected strains can modulate IEC IL-8 production in vitro, and suggest that yogurt-like fermented soy formulations could provide a functional food alternative to milk-based fermented products.

Continuing oversight through site monitoring: experiences of an institutional ethics committee in an Indian tertiary-care hospital.

PubMed

Shetty, Yashashri C; Marathe, Padmaja; Kamat, Sandhya; Thatte, Urmila

2012-01-01

WHO-TDR and the Indian Council of Medical Research recommend site visits by institutional ethics committees (IECs) for continued oversight, to ensure the ethical conduct of research. Our IEC conducted seven site visits in 2008-2009 using a standardised format to monitor adherence to protocol and the informed consent process. The study identified issues related to informed consent (6/7), deviation from protocol (5/7), reporting of study progress to the IEC (3/7), recruiting additional participants without IEC approval (2/7), reporting of serious adverse events (1/7), investigator's lack of awareness of protocol and the informed consent document (2/7) and other findings. Investigators were informed about the findings and were asked to submit an explanation. The IEC issued warnings about not repeating such lapses in the future (5/7), restricted enrollment of new participants (2/7), recommended continued good clinical practice training to the study team (4/7), advised the recruitment of additional study coordinators (2/7), and requested the submission of adverse event reports (2/7) or sponsors' audit reports (2/7). Our study showed that the ethical conduct of studies can be ensured by conducting routine site monitoring.

Islam and Environmental Consciousness: A New Scale Development.

PubMed

Emari, Hossein; Vazifehdoust, Hossein; Nikoomaram, Hashem

2017-04-01

This research proposed a new construct, Islamic environmental consciousness (IEC), and developed a measurement scale to support this construct. Churchill's (J Mark Res 16(1):64-73, 1979) paradigm, adapted by Negra and Mzoughi (Internet Res 22(4):426-442, 2012), was utilized. A total of 32 items were generated based on the verses of the Qur'an from nine interviews with teachers in an Islamic seminary. This set of items was reduced to 19 after dropping redundant or non-representative items. In a pilot study, factor analysis of the 19-item scale yielded a two-factor structure scale of seven items with a reliability ranging from 0.7 to 0.8. The Islamic environmental consciousness scale (IECS) was statistically confirmed and validated in a subsequent investigation. The proposed measurement scale warrants further exploratory study. Future research should assess the IECS's validity across different Muslim countries, locales, and various Islamic schools of thought and practice. IEC is proposed as a new construct that focuses primarily on the Qur'an and seeks to achieve acceptance by both Sunni and Shia denominations. In this study, both cognitive attitudes and behavioral aspects were considered in the design of the IECS.

Supramolecular 1-D polymerization of DNA origami through a dynamic process at the 2-dimensionally confined air-water interface.

PubMed

Yonamine, Yusuke; Cervantes-Salguero, Keitel; Minami, Kosuke; Kawamata, Ibuki; Nakanishi, Waka; Hill, Jonathan P; Murata, Satoshi; Ariga, Katsuhiko

2016-05-14

In this study, a Langmuir-Blodgett (LB) system has been utilized for the regulation of polymerization of a DNA origami structure at the air-water interface as a two-dimensionally confined medium, which enables dynamic condensation of DNA origami units through variation of the film area at the macroscopic level (ca. 10-100 cm(2)). DNA origami sheets were conjugated with a cationic lipid (dioctadecyldimethylammonium bromide, 2C18N(+)) by electrostatic interaction and the corresponding LB-film was prepared. By applying dynamic pressure variation through compression-expansion processes, the lipid-modified DNA origami sheets underwent anisotropic polymerization forming a one-dimensionally assembled belt-shaped structure of a high aspect ratio although the thickness of the polymerized DNA origami was maintained at the unimolecular level. This approach opens up a new field of mechanical induction of the self-assembly of DNA origami structures.

Harmonic field in knotted space

NASA Astrophysics Data System (ADS)

Duan, Xiuqing; Yao, Zhenwei

2018-04-01

Knotted fields enrich a variety of physical phenomena, ranging from fluid flows, electromagnetic fields, to textures of ordered media. Maxwell's electrostatic equations, whose vacuum solution is mathematically known as a harmonic field, provide an ideal setting to explore the role of domain topology in determining physical fields in confined space. In this work, we show the uniqueness of a harmonic field in knotted tubes, and reduce the construction of a harmonic field to a Neumann boundary value problem. By analyzing the harmonic field in typical knotted tubes, we identify the torsion driven transition from bipolar to vortex patterns. We also analogously extend our discussion to the organization of liquid crystal textures in knotted tubes. These results further our understanding about the general role of topology in shaping a physical field in confined space, and may find applications in the control of physical fields by manipulation of surface topology.

33 CFR 154.106 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 20, Switzerland. (1) IEC 60309-1 Plugs, Socket-Outlets and Couplers for Industrial Purposes—Part 1: General Requirements, Edition 4.2 2012-06, IBR approved for § 154.2102(b). (2) IEC 60309-2 Plugs, Socket...

Compact, Lightweight, Smart Battery Charger

DTIC Science & Technology

2005-10-26

with MIL-l- 45208A, ANSI/NCSL Z540-1-1994 and ISO / IEC 17025 :1999. I... lii i ... ...... , .00 0z .E 0 cc z0 E -𔃺’ 200-076 Temperature Honeywell...Institute of Standards and Technology, and in accordance with MIL-I- 45208A, ANSI/NCSL Z540-1-1994 and ISO / IEC 17025 :1999. Recorder 200-202 Temperature JO...1994 and ISO / IEC 17025 :1999. Recorder 200-214 Temperature Watlow F4 7/17/2003 7/18/2005 -200 to +80~0°C Controller 500-061 Thermal Cincinnati VTS-3.3

Characterization of the IEC 61000-4-6 Electromagnetic Clamp for Conducted-Immunity Testing

NASA Astrophysics Data System (ADS)

Grassi, F.; Pignari, S. A.; Spadacini, G.; Toscani, N.; Pelissou, P.

2016-05-01

A multiconductor transmission line model (MTL) is used to investigate the operation of the IEC 61000-4-6 electromagnetic (EM) clamp in a conducted-immunity test setup for aerospace applications. Aspects of interest include the performance of such a coupling device at very high frequencies (up to 1 GHz), and for extreme values of the common-mode impedance of equipment (short circuits, open circuits). The MTL model is finally exploited to predict the frequency response of coupling and decoupling factors defined in the IEC 61000-4-6 standard.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zohar, S.; Choi, Y.; Love, D. M.

We use X-ray Excited Luminescence Microscopy to investigate the elemental and layer resolved magnetic reversal in an interlayer exchange coupled (IEC) epitaxial Fe/Cr wedge/Co heterostructure. The transition from strongly coupled parallel Co-Fe reversal for Cr thickness t(Cr) < 0.34 nm to weakly coupled layer independent reversal for t(Cr) > 1.5 nm is punctuated at 0.34 < t(Cr) < 1.5 nm by a combination of IEC guided domain wall motion and stationary zig zag domain walls. Domain walls nucleated at switching field minima are guided by IEC spatial gradients and collapse at switching field maxima.

Highlights of session presentations. TSS / CST population IEC meeting.

PubMed

1995-01-01

The great deal of documentation which was prepared for the recent TSS/CST Population IEC (information, education, and communication) meeting from research, field experiments, and action projects will be useful to TSS/CST advisors and individual countries undertaking IEC and population education work. This article summarizes the 12 sessions held during the open forum. To illustrate some of the latest trends in population and health communication, the "enter-educate" approach and use of the interactive computer software called SCOPE (Strategic Communication Planning and Evaluation) were discussed. Next, ways in which to apply research effectively in IEC and population education were considered. Examples were provided of 1) a workshop methodology used to help a multidisciplinary group design a problem-solving communication strategy in Malaysia and Dominica; 2) the counseling training evaluation technique based on the GATHER (greet, ask, tell, help, explain, and return for follow-up) model; and 3) four types of evaluation of population education in schools. The third session was concerned with the program approach used in IEC and population education. Session 4 dealt with the implication of UNFPA support to family planning (FP) IEC. Counseling skills training and interpersonal communication were next on the agenda, followed by a consideration of how knowledge and policies are applied in the area of youth. The seventh session concentrated on ways to involve men in FP and reproductive health and included a discussion of a case study on the attitude and behavior of men with regard to FP which had IEC implications. The next session described the need to reconceptualize population education and what such a reconceptualization would entail. Session 9 was devoted to a consideration of gender issues and the education of girls. The tenth session covered the use of participatory approaches and community involvement in population communication programs. Innovative methodologies for school-based population education were described next, and the last session was concerned with new information technologies such as navigating the Internet and using new software for establishing databases.

Interactions between peripheral blood CD8 T lymphocytes and intestinal epithelial cells (iEC)

PubMed Central

Arosa, F A; Irwin, C; Mayer, L; De Sousa, M; Posnett, D N

1998-01-01

Intestinal intraepithelial lymphocytes (iIEL) are primarily CD8 cells and most of them have a CD28− phenotype, the phenotype of effector cytotoxic T cells. We asked whether the predominance of CD8+ CD28− T cells in the gut may result from peripheral blood T cells preferentially migrating to the iIEL compartment and adhering to iEC. Compared with CD4 cells, adhesion of resting CD8+ T cells to iEC cell lines was significantly higher. Adhesion could be blocked with a MoAb to gp180, a molecule expressed on iEC which is known to interact with CD8/lck. No significant difference in the level of adhesion was observed between CD8+ CD28+ and CD8+ CD28− T cells. Thus CD8 cells may preferentially migrate to the iIEL compartment, but loss of CD28 expression could occur in situ after migration. Consistent with this hypothesis, the CD8+ CD28− cells became enriched after co-culturing T cells with iEC cell lines and primary iEC. Induction of the CD8+ CD28− phenotype in cord blood and adult T cells was observed in co-cultures with iEC and also with mitogens and superantigens. In the latter case, CD28 down-modulation was seen specifically in the Vβ subset targeted by the superantigen, indicating that loss of CD28 expression is a direct result of T cell receptor (TCR)-mediated stimulation. The combined results suggest that CD8+ CD28− T cells are antigen experienced T cells, and that they may have a survival advantage in the presence of gut epithelial cells in vitro. This may contribute to the predominance of CD8+ CD28− T cells in the iIEL compartment. PMID:9649184

Overview of NASA MSFC IEC Multi-CAD Collaboration Capability

NASA Technical Reports Server (NTRS)

Moushon, Brian; McDuffee, Patrick

2005-01-01

This viewgraph presentation provides an overview of a Design and Data Management System (DDMS) for Computer Aided Design (CAD) collaboration in order to support the Integrated Engineering Capability (IEC) at Marshall Space Flight Center (MSFC).

15 CFR 287.2 - Definitions. 1

Code of Federal Regulations, 2011 CFR

2011-01-01

... International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC), Guide 2 (1996). In certain industrial sectors, it is recognized that organizations other than ISO or IEC may...; supplier's declaration of conformity; certification; and quality and environmental management system...

Primary culture of cat intestinal epithelial cells in vitro and the cDNA library construction.

PubMed

Zhao, Gui Hua; Liu, Ye; Cheng, Yun Tang; Zhao, Qing Song; Qiu, Xiao; Xu, Chao; Xiao, Ting; Zhu, Song; Liu, Gong Zhen; Yin, Kun

2018-06-26

Felids are the only definitive hosts of Toxoplasma gondii. To lay a foundation for screening the T. gondii-felids interaction factors, we have developed a reproducible primary culture method for cat intestinal epithelial cells (IECs). The primary IECs were isolated from a new born cat's small intestine jejunum region without food ingress, and respectively in vitro cultured by tissue cultivation and combined digestion method with collagenase XI and dispase I, then purified by trypsinization. After identification, the ds cDNA of cat IECs was synthesized for constructing pGADT7 homogenization three-frame plasmid, and transformed into the yeast Y187 for generating the cDNA library. Our results indicated that cultivation of primary cat IECs relays on combined digestion to form polarized and confluent monolayers within 3 days with typical features of normal epithelial cells. The purified cells cultured by digestion method were identified to be nature intestinal epithelial cells using immunohistochemical analysis and were able to maintain viability for at least 15 passages. The homogenizable ds cDNA, which is synthesized from the total RNA extracted from our cultured IECs, distributed among 0.5-2.0 kb, and generated satisfying three-frame cDNA library with the capacity of 1.2 × 106 and the titer of 5.2 × 107 pfu/mL. Our results established an optimal method for the culturing and passage of cat IECs model in vitro, and laid a cDNA library foundation for the subsequent interaction factors screening by yeast two-hybrid.

Strong radial electric field shear and reduced fluctuations in a reversed-field pinch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapman, B.E.; Chiang, C.S.; Prager, S.C.

1997-05-01

A strongly sheared radial electric field is observed in enhanced confinement discharges in the MST reversed-field pinch. The strong shear develops in a narrow region in the plasma edge. Electrostatic fluctuations are reduced over the entire plasma edge with an extra reduction in the shear region. Magnetic fluctuations, resonant in the plasma core but global in extent, are also reduced. The reduction of fluctuations in the shear region is presumably due to the strong shear, but the causes of the reductions outside this region have not been established.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miley, G.H.

Remarks made in the author{close_quote}s acceptance lecture for the 1995 Edward Teller Medal are presented and expanded. Topics covered include research on nuclear-pumped lasers, the first direct e-beam-pumped laser, direct energy conversion and advanced fuel fusion, plus recent work on inertial electrostatic confinement. {open_quote}{open_quote}Patience{close_quote}{close_quote} and {open_quote}{open_quote}optimism{close_quote}{close_quote} are viewed as essential elements needed by scientists following the {open_quote}{open_quote}zig-zag{close_quote}{close_quote} path to fusion energy production. {copyright} {ital 1996 American Institute of Physics.}

The influence of bio-conjugation on photoluminescence of CdSe/ZnS quantum dots

NASA Astrophysics Data System (ADS)

Torchynska, Tetyana V.; Vorobiev, Yuri V.; Makhniy, Victor P.; Horley, Paul P.

2014-11-01

We report a considerable blue shift in the luminescence spectra of CdSe/ZnS quantum dots conjugated to anti-interleukin-10 antibodies. This phenomenon can be explained theoretically by accounting for bio-conjugation as a process causing electrostatic interaction between a quantum dot and an antibody, which reduces effective volume of the dot core. To solve the Schrödinger equation for an exciton confined in the quantum dot, we use mirror boundary conditions that were successfully tested for different geometries of quantum wells.

46 CFR 39.10-5 - Incorporation by reference-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., 1 rue de Varembé, Geneva, Switzerland IEC 309-1—Plugs, Socket-Outlets and Couplers for Industrial Purposes: Part 1, General Requirements, 1979 39.20-9 IEC 309-2—Plugs, Socket-Outlets and Couplers for...

46 CFR 39.10-5 - Incorporation by reference-TB/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., 1 rue de Varembé, Geneva, Switzerland IEC 309-1—Plugs, Socket-Outlets and Couplers for Industrial Purposes: Part 1, General Requirements, 1979 39.20-9 IEC 309-2—Plugs, Socket-Outlets and Couplers for...

46 CFR 39.10-5 - Incorporation by reference-TB/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., 1 rue de Varembé, Geneva, Switzerland IEC 309-1—Plugs, Socket-Outlets and Couplers for Industrial Purposes: Part 1, General Requirements, 1979 39.20-9 IEC 309-2—Plugs, Socket-Outlets and Couplers for...

49 CFR Appendix C to Part 236 - Safety Assurance Criteria and Processes

Code of Federal Regulations, 2011 CFR

2011-10-01

.../Programmable/Electronic Safety (E/E/P/ES) Related Systems, Parts 1-7 as follows: (A) IEC 61508-1 (1998-12) Part.... (B) IEC 61508-2 (2000-05) Part 2: Requirements for electrical/electronic/programmable electronic...

49 CFR Appendix C to Part 236 - Safety Assurance Criteria and Processes

Code of Federal Regulations, 2012 CFR

2012-10-01

.../Programmable/Electronic Safety (E/E/P/ES) Related Systems, Parts 1-7 as follows: (A) IEC 61508-1 (1998-12) Part.... (B) IEC 61508-2 (2000-05) Part 2: Requirements for electrical/electronic/programmable electronic...

49 CFR Appendix C to Part 236 - Safety Assurance Criteria and Processes

Code of Federal Regulations, 2014 CFR

2014-10-01

.../Programmable/Electronic Safety (E/E/P/ES) Related Systems, Parts 1-7 as follows: (A) IEC 61508-1 (1998-12) Part.... (B) IEC 61508-2 (2000-05) Part 2: Requirements for electrical/electronic/programmable electronic...

49 CFR Appendix C to Part 236 - Safety Assurance Criteria and Processes

Code of Federal Regulations, 2013 CFR

2013-10-01

.../Programmable/Electronic Safety (E/E/P/ES) Related Systems, Parts 1-7 as follows: (A) IEC 61508-1 (1998-12) Part.... (B) IEC 61508-2 (2000-05) Part 2: Requirements for electrical/electronic/programmable electronic...

DNA Methylation and Transcription Patterns in Intestinal Epithelial Cells From Pediatric Patients With Inflammatory Bowel Diseases Differentiate Disease Subtypes and Associate With Outcome.

PubMed

Howell, Kate Joanne; Kraiczy, Judith; Nayak, Komal M; Gasparetto, Marco; Ross, Alexander; Lee, Claire; Mak, Tim N; Koo, Bon-Kyoung; Kumar, Nitin; Lawley, Trevor; Sinha, Anupam; Rosenstiel, Philip; Heuschkel, Robert; Stegle, Oliver; Zilbauer, Matthias

2018-02-01

We analyzed DNA methylation patterns and transcriptomes of primary intestinal epithelial cells (IEC) of children newly diagnosed with inflammatory bowel diseases (IBD) to learn more about pathogenesis. We obtained mucosal biopsies (N = 236) collected from terminal ileum and ascending and sigmoid colons of children (median age 13 years) newly diagnosed with IBD (43 with Crohn's disease [CD], 23 with ulcerative colitis [UC]), and 30 children without IBD (controls). Patients were recruited and managed at a hospital in the United Kingdom from 2013 through 2016. We also obtained biopsies collected at later stages from a subset of patients. IECs were purified and analyzed for genome-wide DNA methylation patterns and gene expression profiles. Adjacent microbiota were isolated from biopsies and analyzed by 16S gene sequencing. We generated intestinal organoid cultures from a subset of samples and genome-wide DNA methylation analysis was performed. We found gut segment-specific differences in DNA methylation and transcription profiles of IECs from children with IBD vs controls; some were independent of mucosal inflammation. Changes in gut microbiota between IBD and control groups were not as large and were difficult to assess because of large amounts of intra-individual variation. Only IECs from patients with CD had changes in DNA methylation and transcription patterns in terminal ileum epithelium, compared with controls. Colon epithelium from patients with CD and from patients with ulcerative colitis had distinct changes in DNA methylation and transcription patterns, compared with controls. In IECs from patients with IBD, changes in DNA methylation, compared with controls, were stable over time and were partially retained in ex-vivo organoid cultures. Statistical analyses of epithelial cell profiles allowed us to distinguish children with CD or UC from controls; profiles correlated with disease outcome parameters, such as the requirement for treatment with biologic agents. We identified specific changes in DNA methylation and transcriptome patterns in IECs from pediatric patients with IBD compared with controls. These data indicate that IECs undergo changes during IBD development and could be involved in pathogenesis. Further analyses of primary IECs from patients with IBD could improve our understanding of the large variations in disease progression and outcomes. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Ionic structure in liquids confined by dielectric interfaces

NASA Astrophysics Data System (ADS)

Jing, Yufei; Jadhao, Vikram; Zwanikken, Jos W.; Olvera de la Cruz, Monica

2015-11-01

The behavior of ions in liquids confined between macromolecules determines the outcome of many nanoscale assembly processes in synthetic and biological materials such as colloidal dispersions, emulsions, hydrogels, DNA, cell membranes, and proteins. Theoretically, the macromolecule-liquid boundary is often modeled as a dielectric interface and an important quantity of interest is the ionic structure in a liquid confined between two such interfaces. The knowledge gleaned from the study of ionic structure in such models can be useful in several industrial applications, such as in the design of double-layer supercapacitors for energy storage and in the extraction of metal ions from wastewater. In this article, we compute the ionic structure in a model system of electrolyte confined by two planar dielectric interfaces using molecular dynamics simulations and liquid state theory. We explore the effects of high electrolyte concentrations, multivalent ions, dielectric contrasts, and external electric field on the ionic distributions. We observe the presence of non-monotonic ionic density profiles leading to a layered structure in the fluid which is attributed to the competition between electrostatic and steric (entropic) interactions. We find that thermal forces that arise from symmetry breaking at the interfaces can have a profound effect on the ionic structure and can oftentimes overwhelm the influence of the dielectric discontinuity. The combined effect of ionic correlations and inhomogeneous dielectric permittivity significantly changes the character of the effective interaction between the two interfaces.

Electronic confining effects in Sierpiński triangle fractals

NASA Astrophysics Data System (ADS)

Wang, Hao; Zhang, Xue; Jiang, Zhuoling; Wang, Yongfeng; Hou, Shimin

2018-03-01

Electron confinement in fractal Sierpiński triangles (STs) on Ag(111) is investigated using scanning tunneling spectroscopy and theoretically simulated by employing an improved two-dimensional (2D) multiple scattering theory in which the energy-dependent phase shifts are explicitly calculated from the electrostatic potentials of the molecular building block of STs. Well-defined bound surface states are observed in three kinds of triangular cavities with their sides changing at a scale factor of 2. The decrease in length of the cavities results in an upshift of the resonances that deviates from an expected inverse quadratic dependence on the cavity length due to the less efficient confinement of smaller triangular cavities. Differential conductance maps at some specific biases present a series of alternative bright and dark rounded triangles preserving the symmetry of the boundary. Our improved 2D multiple scattering model reproduces the characteristics of the standing wave patterns and all features in the differential conductance spectra measured in experiments, illustrating that the elastic loss boundary scattering dominates the resonance broadening in these ST quantum corrals. Moreover, the self-similar structure of STs, that a larger central cavity is surrounded by three smaller ones with a half side length, gives rise to interactions of surface states confined in neighboring cavities, which are helpful for the suppression of the linewidth in differential conductance spectra.

Effect of basic physical parameters to control plasma meniscus and beam halo formation in negative ion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyamoto, K.; Okuda, S.; Nishioka, S.

2013-09-14

Our previous study shows that the curvature of the plasma meniscus causes the beam halo in the negative ion sources: the negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. In this article, the detail physics of the plasma meniscus and beam halo formation is investigated with two-dimensional particle-in-cell simulation. It is shown that the basic physical parameters such as the H{sup −} extraction voltage and the effective electron confinement time significantly affect the formation of the plasma meniscus and the resultant beammore » halo since the penetration of electric field for negative ion extraction depends on these physical parameters. Especially, the electron confinement time depends on the characteristic time of electron escape along the magnetic field as well as the characteristic time of electron diffusion across the magnetic field. The plasma meniscus penetrates deeply into the source plasma region when the effective electron confinement time is short. In this case, the curvature of the plasma meniscus becomes large, and consequently the fraction of the beam halo increases.« less

Electron-phonon interactions in semiconductor nanostructures

NASA Astrophysics Data System (ADS)

Yu, Segi

In this dissertation, electron-phonon interactions are studied theoretically in semiconductor nanoscale heterostructures. Interactions of electrons with interface optical phonons dominate over other electron-phonon interactions in narrow width heterostructures. Hence, a transfer matrix method is used to establish a formalism for determining the dispersion relations and electrostatic potentials of the interface phonons for multiple-interface heterostructure within the macroscopic dielectric continuum model. This method facilitates systematic calculations for complex structures where the conventional method is difficult to implement. Several specific cases are treated to illustrate advantages of the formalism. Electrophonon resonance (EPR) is studied in cylindrical quantum wires using the confined/interface optical phonons representation and bulk phonon representation. It has been found that interface phonon contribution to EPR is small compared with confined phonon. Different selection rules for bulk phonons and confined phonons result in different EPR behaviors as the radius of cylindrical wire changes. Experiment is suggested to test which phonon representation is appropriate for EPR. The effects of phonon confinement on elect ron-acoustic-phonon scattering is studied in cylindrical and rectangular quantum wires. In the macroscopic elastic continuum model, the confined-phonon dispersion relations are obtained for several crystallographic directions with free-surface and clamped-surface boundary conditions in cylindrical wires. The scattering rates due to the deformation potential are obtained for these confined phonons and are compared with those of bulk-like phonons. The results show that the inclusion of acoustic phonon confinement may be crucial for calculating accurate low-energy electron scattering rates. Furthermore, it has been found that there is a scaling rule governing the directional dependence of the scattering rates. The Hamiltonian describing the deformation-potential of confined acoustic phonons is derived by quantizing the appropriate, experimentally verified approximate compressional acoustic-phonon modes in a free-standing rectangular quantum wire. The scattering rate is obtained for GaAs quantum wires with a range of cross-sectional dimensions. The results demonstrate that a proper treatment of confined acoustic phonons may be essential to correctly model electron scattering rates at low energies in nanoscale structures.

Building Assured Systems Framework

DTIC Science & Technology

2010-09-01

of standards such as ISO 27001 as frameworks [NASCIO 2009]. In this context, a framework is a standard intended to assist in auditing and compliance...Information Security ISO /IEC 27004 Information technology – Security techniques - Information security management measurement ISO /IEC 15939, System and

Implementation of the OECD principles of good laboratory practice in test facilities complying with a quality system accredited to the ISO/IEC 17025 standard.

PubMed

Feller, Etty

2008-01-01

Laboratories with a quality system accredited to the ISO/IEC 17025 standard have a definite advantage, compared to non-accredited laboratories, when preparing their facilities for the implementation of the principles of good laboratory practice (GLP) of the Organisation for Economic Co-operation and Development (OECD). Accredited laboratories have an established quality system covering the administrative and technical issues specified in the standard. The similarities and differences between the ISO/IEC 17025 standard and the OECD principles of GLP are compared and discussed.

Ultrasensitive photodetectors exploiting electrostatic trapping and percolation transport

DOE PAGES

Zhang, Yingjie; Hellebusch, Daniel J.; Bronstein, Noah D.; ...

2016-06-21

The sensitivity of semiconductor photodetectors is limited by photocarrier recombination during the carrier transport process. We developed a new photoactive material that reduces recombination by physically separating hole and electron charge carriers. This material has a specific detectivity (the ability to detect small signals) of 5 × 10 17 Jones, the highest reported in visible and infrared detectors at room temperature, and 4-5 orders of magnitude higher than that of commercial single-crystal silicon detectors. The material was fabricated by sintering chloride-capped CdTe nanocrystals into polycrystalline films, where Cl selectively segregates into grain boundaries acting as n-type dopants. Photogenerated electrons concentratemore » in and percolate along the grain boundaries - a network of energy valleys, while holes are confined in the grain interiors. This electrostatic field-assisted carrier separation and percolation mechanism enables an unprecedented photoconductive gain of 10 10 e - per photon, and allows for effective control of the device response speed by active carrier quenching.« less

High frequency plasma generator for ion thrusters

NASA Technical Reports Server (NTRS)

Goede, H.; Divergilio, W. F.; Fosnight, V. V.; Komatsu, G.

1984-01-01

The results of a program to experimentally develop two new types of plasma generators for 30 cm electrostatic argon ion thrusters are presented. The two plasma generating methods selected for this study were by radio frequency induction (RFI), operating at an input power frequency of 1 MHz, and by electron cyclotron heating (ECH) at an operating frequency of 5.0 GHz. Both of these generators utilize multiline cusp permanent magnet configurations for plasma confinement and beam profile optimization. The program goals were to develop a plasma generator possessing the characteristics of high electrical efficiency (low eV/ion) and simplicity of operation while maintaining the reliability and durability of the conventional hollow cathode plasma sources. The RFI plasma generator has achieved minimum discharge losses of 120 eV/ion while the ECH generator has obtained 145 eV/ion, assuming a 90% ion optical transparency of the electrostatic acceleration system. Details of experimental tests with a variety of magnet configurations are presented.

Ultrasensitive photodetectors exploiting electrostatic trapping and percolation transport

PubMed Central

Zhang, Yingjie; Hellebusch, Daniel J.; Bronstein, Noah D.; Ko, Changhyun; Ogletree, D. Frank; Salmeron, Miquel; Alivisatos, A. Paul

2016-01-01

The sensitivity of semiconductor photodetectors is limited by photocarrier recombination during the carrier transport process. We developed a new photoactive material that reduces recombination by physically separating hole and electron charge carriers. This material has a specific detectivity (the ability to detect small signals) of 5 × 1017 Jones, the highest reported in visible and infrared detectors at room temperature, and 4–5 orders of magnitude higher than that of commercial single-crystal silicon detectors. The material was fabricated by sintering chloride-capped CdTe nanocrystals into polycrystalline films, where Cl selectively segregates into grain boundaries acting as n-type dopants. Photogenerated electrons concentrate in and percolate along the grain boundaries—a network of energy valleys, while holes are confined in the grain interiors. This electrostatic field-assisted carrier separation and percolation mechanism enables an unprecedented photoconductive gain of 1010 e− per photon, and allows for effective control of the device response speed by active carrier quenching. PMID:27323904

Semiconducting double-dot exchange-only qubit dynamics in the presence of magnetic and charge noises

NASA Astrophysics Data System (ADS)

Ferraro, E.; Fanciulli, M.; De Michielis, M.

2018-06-01

The effects of magnetic and charge noises on the dynamical evolution of the double-dot exchange-only qubit (DEOQ) is theoretically investigated. The DEOQ consisting of three electrons arranged in an electrostatically defined double quantum dot deserves special interest in quantum computation applications. Its advantages are in terms of fabrication, control and manipulation in view of implementation of fast single and two-qubit operations through only electrical tuning. The presence of the environmental noise due to nuclear spins and charge traps, in addition to fluctuations in the applied magnetic field and charge fluctuations on the electrostatic gates adopted to confine the electrons, is taken into account including random magnetic field and random coupling terms in the Hamiltonian. The behavior of the return probability as a function of time for initial conditions of interest is presented. Moreover, through an envelope-fitting procedure on the return probabilities, coherence times are extracted when model parameters take values achievable experimentally in semiconducting devices.

Controlled Growth of Gigantic Swirls in a Laboratory Magnetosphere

NASA Astrophysics Data System (ADS)

Worstell, M. W.; Mauel, M. E.; Roberts, T. M.

2012-10-01

Space and laboratory plasma confined by a strong magnetic field have remarkable properties. Low frequency mixing of the plasma occurs through the interchange of long plasma-filled tubes aligned with the magnetic field. The plasma dynamics becomes two-dimensional because these tubes can only move radially or circulate around the poles of the magnetic dipole. Studies of turbulent interchange dynamics made using the Collisionless Terella Experiment (CTX) show that turbulence appears as chaotic time-varying modes with broad global mode structures that interact nonlinearly and form an inverse cascade.footnotetextB.A. Grierson, M.W. Worstell, M.E. Mauel, Phys. Plasmas 16 055902 (2009) When we drive vortex mixing through the application of electrostatic bias to multiple probes, we break the rotational symmetry of the plasma and small vortex tubes are seen to drive larger ``gigantic'' swirls. Statistical analysis of the time-evolving spectra and measurement of the bicoherence of the turbulence show an increase of three wave coupling during non-axisymmetric electrostatic drive of the probe array.

Ionic Structure at Dielectric Interfaces

NASA Astrophysics Data System (ADS)

Jing, Yufei

The behavior of ions in liquids confined between macromolecules determines the outcome of many nanoscale assembly processes in synthetic and biological materials such as colloidal dispersions, emulsions, hydrogels, DNA, cell membranes, and proteins. Theoretically, the macromolecule-liquid boundary is often modeled as a dielectric interface and an important quantity of interest is the ionic structure in a liquid confined between two such interfaces. The knowledge gleaned from the study of ionic structure in such models can be useful in several industrial applications, such as biosensors, lithium-ion batteries double-layer supercapacitors for energy storage and seawater desalination. Electrostatics plays a critical role in the development of such functional materials. Many of the functions of these materials, result from charge and composition heterogeneities. There are great challenges in solving electrostatics problems in heterogeneous media with arbitrary shapes because electrostatic interactions remains unknown but depend on the particular density of charge distributions. Charged molecules in heterogeneous media affect the media's dielectric response and hence the interaction between the charges is unknown since it depends on the media and on the geometrical properties of the interfaces. To determine the properties of heterogeneous systems including crucial effects neglected in classical mean field models such as the hard core of the ions, the dielectric mismatch and interfaces with arbitrary shapes. The effect of hard core interactions accounts properly for short range interactions and the effect of local dielectric heterogeneities in the presence of ions and/or charged molecules for long-range interactions are both analyzed via an energy variational principle that enables to update charges and the medium's response in the same simulation time step. In particular, we compute the ionic structure in a model system of electrolyte confined by two planar dielectric interfaces using molecular dynamics(MD) simulations and compared it with liquid state theory result. We explore the effects of high electrolyte concentrations, multivalent ions, and dielectric contrasts on the ionic distributions. We observe the presence of non-monotonous ionic density profiles leading to structure deformation in the fluid which is attributed to the competition between electrostatic and steric (entropic) interactions. We find that thermal forces that arise from symmetry breaking at the interfaces can have a profound effect on the ionic structure and can oftentimes overwhelm the influence of dielectric discontinuity. The combined effect of ionic correlations and inhomogeneous dielectric permittivity significantly changes the character of effective interaction between two interfaces. We show that, in concentrated electrolytes with confinement, it is imperative to take into account the finite-size of the ions as well as proper description of electrostatic interactions in heterogeneous media, which is not fully fulfilled by Poisson-Boltzmann based approaches. The effect of electric field at interface between two immiscible electrolyte solutions is studied as well. The classical Poisson-Boltzmann theory has been widely used to describe the corresponding ionic distribution, even though it neglects the polarization and ion correlations typical of these charged systems. Using Monte Carlo simulations, we provide an enhanced description of an oil-water interface in the presence of an electric field without needing any adjustable parameter, including realistic ionic sizes, ion correlations, and image charges. Our data agree with experimental measurements of excess surface tension for a wide range of electrolyte concentrations of LiCl and TBATPB (tetrabutylammonium-tetraphenylborate), contrasting with the result of the classical non-linear Poisson-Boltzmann theory. More importantly, we show that the size-asymmetry between small Li+ and large Cl- ions can significantly increase the electric field near the liquid interface, or can even reverse it locally, at high salt concentrations in the aqueous phase. These observations suggest a novel trapping/release mechanism of charged nanoparticles at oil-water interfaces in the vicinity of the point of zero charge. In addition, we study the effects of size asymmetry and charge asymmetry on ion distribution at a dielectric interface using coarse-grained MD based on an energy variational principle. The goal is to explore charge amplification with exact consideration of surface polarization. We find that both size asymmetry and charge asymmetry lead to charge separation at the interfaces. In addition, charge separation is enhanced by interface polarization. We are currently extending the research to charged interfaces that has broad applications such as batteries and supercapacitors for energy storage.

ANAB, Certification and Scope of Accreditation (ISO/IEC 17025:2005) for the National Vehicle and Fuel Emissions Laboratory

EPA Pesticide Factsheets

This document certifies that the EPA National Vehicle and Fuel Emissions Laboratory has been assessed by the ANSI-ASQ National Accredation Board and accredited in meeting ISO-IEC 17025:2005 quality standards.

Effect of patchouli alcohol on the regulation of heat shock-induced oxidative stress in IEC-6 cells.

PubMed

Liu, Xiaoxi; Jiang, Linshu; Liu, Fenghua; Chen, Yuping; Xu, Lei; Li, Deyin; Ma, Yunfei; Li, Huanrong; Xu, Jianqin

2016-08-01

Purpose Patchouli alcohol (PA) is used to treat gastrointestinal dysfunction. The purpose of this study was to ascertain the function of PA in the regulated process of oxidative stress in rat intestinal epithelial cells (IEC-6). Materials and methods Oxidative stress was stimulated by exposing IEC-6 cells to heat shock (42 °C for 3 h). IEC-6 cells in treatment groups were pretreated with various concentrations of PA (10, 40, and 80 ng/mL) for 3 h before heat shock. Results Heat shock caused damage to the morphology of IEC-6 cells, and increased reactive oxygen species (ROS) level and malondialdehyde (MDA) content. Moreover, mRNA and protein expression by target genes related to oxidative stress in heat shock were also altered. Specifically, the mRNA expression by HSP70, HSP90, GSH-px, NRF2 nd HO-1were all increased, and Nrf2 and Keap1 protein expression were increased after heat shock. However, pretreatment with PA weakened the level of damage to the cellular morphology, and decreased the MDA content caused by heat shock, indicating PA had cytoprotective activities. Pretreatment with PA at high dose significantly increased generation of intracellular ROS. Compared with the heat shock group alone, PA pretreatment significantly decreased the mRNA expression by HSP70, HSP90, SOD, CAT, GSH-px, KEAP1 and HO-1. Furthermore, the high dose of PA significantly increased Nrf2 protein expression, while both the intermediate and high dose of PA significantly increased HO-1 protein expression. Conclusion Heat-shock-induced oxidative stress in IEC-6 cells, and PA could alleviate the Nrf2-Keap1 cellular oxidative stress responses.

Effective IEC approaches for Asia. IEC evaluation workshop.

PubMed

1996-02-01

The UNFPA-supported project on development and distribution of information, education, and communication (IEC) materials in support of improving women's health and status was evaluated at a workshop held in Tokyo in December 13-15, 1995. The 1992-95 cycle of the project was analyzed by experts from Bangladesh, China, India, Indonesia, Malaysia, Nepal, the Philippines, and Vietnam plus three experts from the UNFPA/Country Support Team. The workshop also made it possible for the experts to identify needs as well as effective utilization of existing IEC materials. It was suggested that a nongovernmental organization be established for the distribution and effective use of these materials. The workshop mostly reviewed the print and audiovisual materials. Videos were also evaluated. The materials were found useful for the targeted region. Among other subregional issues it was noted that youth needs were inadequately addressed as they related to sexually transmitted diseases (STDs), unwanted pregnancy, risk of maternal mortality and morbidity, low birth weight, and premature birth. Although the women of the region comprise one-third of the world's population, 70% of the global annual maternal mortality of 500,000 occurs in the subregion. IEC materials should also target adolescents and their support groups. Other needs were also outlined: the expansion of educational opportunities for women, the promotion of employment, the involvement of men, and the training of personnel. The strategies used in the cycle helped strengthen self-reliance through information and experience sharing. The focus on women should be continued with more attention paid to adolescents and young adults, including males. Women's health issues should be expanded to include menopause, reproductive tract infections, STDs, HIV/AIDS prevention, and legal rights including abortion. The production of IEC materials should be identified through research and analysis of existing materials, focus group discussions, or field visits.

Unveiling the Mode of Interaction of Berberine Alkaloid in Different Supramolecular Confined Environments: Interplay of Surface Charge between Nano-Confined Charged Layer and DNA.

PubMed

Kundu, Niloy; Roy, Arpita; Banik, Debasis; Sarkar, Nilmoni

2016-02-18

In this Article, we demonstrate a detailed characterization of binding interaction of berberine chloride (BBCl) with calf-thymus DNA (CT-DNA) in buffer solution as well as in two differently charged reverse micelles (RMs). The photophyscial properties of this alkaloid have been modulated within these microheterogeneous bioassemblies. The mode of binding of this alkaloid with DNA is of debate to date. However, fluorescence spectroscopic measurements, circular dichroism (CD) measurement, and temperature-dependent study unambiguously establish that BBCl partially intercalates into the DNA base pairs. The nonplanarity imposed by partial saturation in their structure causes the nonclassical types of intercalation into DNA. Besides the intercalation, electrostatic interactions also play a significant role in the binding between BBCl and DNA. DNA structure turns into a condensed form after encapsulation into RMs, which is followed by the CD spectra and microscopy study. The probe location and dynamics in the nanopool of the RMs depended on the electrostatic interaction between the charged surfactants and cationic berberine. The structural alteration of CT-DNA from B form to condensed form and the interplay of surface charge between RMs and DNA determine the interaction between the alkaloid and DNA in RMs. Time-resolved study and fluorescence anisotropy measurements successfully provide the binding interaction of BBCl in the nanopool of the RMs in the absence and in the presence of DNA. This study motivates us to judge further the potential applicability of this alkaloid in other biological systems or other biomimicking organized assemblies.

10 CFR 431.15 - Materials incorporated by reference.

Code of Federal Regulations, 2013 CFR

2013-01-01

... INDUSTRIAL EQUIPMENT Electric Motors Test Procedures, Materials Incorporated and Methods of Determining... of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, Sixth.... (1) IEC 60034-1 Edition 12.0 2010-02, (“IEC 60034-1”), Rotating Electrical Machines, Part 1: Rating...

Composite regulation of ERK activity dynamics underlying tumour-specific traits in the intestine.

PubMed

Muta, Yu; Fujita, Yoshihisa; Sumiyama, Kenta; Sakurai, Atsuro; Taketo, M Mark; Chiba, Tsutomu; Seno, Hiroshi; Aoki, Kazuhiro; Matsuda, Michiyuki; Imajo, Masamichi

2018-06-05

Acting downstream of many growth factors, extracellular signal-regulated kinase (ERK) plays a pivotal role in regulating cell proliferation and tumorigenesis, where its spatiotemporal dynamics, as well as its strength, determine cellular responses. Here, we uncover the ERK activity dynamics in intestinal epithelial cells (IECs) and their association with tumour characteristics. Intravital imaging identifies two distinct modes of ERK activity, sustained and pulse-like activity, in IECs. The sustained and pulse-like activities depend on ErbB2 and EGFR, respectively. Notably, activation of Wnt signalling, the earliest event in intestinal tumorigenesis, augments EGFR signalling and increases the frequency of ERK activity pulses through controlling the expression of EGFR and its regulators, rendering IECs sensitive to EGFR inhibition. Furthermore, the increased pulse frequency is correlated with increased cell proliferation. Thus, ERK activity dynamics are defined by composite inputs from EGFR and ErbB2 signalling in IECs and their alterations might underlie tumour-specific sensitivity to pharmacological EGFR inhibition.

Developing IEC prototypes for adolescents. IEC workshop.

PubMed

1997-01-01

Participants of the IEC Workshop for the Production of OHP Material on Reproductive Health for Adolescents and Young Adults held November 25-30 in Japan developed innovative, visually appealing overhead projector (OHP) transparencies to serve as prototype information, education, and communication (IEC) materials for the Asian Region. The materials cover a wide range of topics from early marriage to unwanted pregnancy. This paper briefly describes the prototypes. One group focused upon early marriage, an issue of considerable importance to the health and welfare of young women in countries such as Bhutan, India, and Nepal. Participants from China, Laos, Malaysia, and Thailand focused upon the issue of gender equality, while a third group developed OHP material to teach a range of issues related to young people's sexual and reproductive health. Finally, the fourth group, drawn from Indonesia, the Philippines, and Vietnam, focused upon the topic of menstruation with a prototype targeted to boys and girls aged 9-14 years. Boys were included to foster their understanding of menstruation as a natural phenomenon.

Five key players shape institution's ethical character.

PubMed

Craig, R P; Middleton, C J; O'Connell, L J

1986-05-01

Various individuals or groups play important roles in achieving moral insight and direction in a health care facility. The administration, medical and nursing staffs, the professional theologian, and the bishop all contribute unique perspectives to the complex process of developing an institution's ethical character. An institutional ethics committee's (IEC's) effectiveness depends largely on the administrator's ability to support educational programming in ethics for the entire staff, coordinate ethical reflection throughout the organization, and shape ethically informed policy based on an IEC's practical experience. The medical staff brings its scientific background and practical experience to ethical issues under a committee's consideration, and nurses offer valuable insights based on their close contact with patients and family. The theologian provides resources and background on Catholic tradition as well as information on current theological developments. The IEC also should maintain a relationship with the local bishop whose duty is to articulate the Church's positions in health care ethics. Forthright dialogue among all parties is central to the IEC's task.

Induction of dsRNA-activated protein kinase links mitochondrial unfolded protein response to the pathogenesis of intestinal inflammation.

PubMed

Rath, Eva; Berger, Emanuel; Messlik, Anja; Nunes, Tiago; Liu, Bo; Kim, Sandy C; Hoogenraad, Nick; Sans, Miquel; Sartor, R Balfour; Haller, Dirk

2012-09-01

Inflammatory bowel diseases (IBDs) feature multiple cellular stress responses, including endoplasmic reticulum (ER) unfolded protein responses (UPRs). UPRs represent autoregulatory pathways that adjust organelle capacity to cellular demand. A similar mechanism, mitochondrial UPR (mtUPR), has been described for mitochondria. ER UPR in intestinal epithelial cells (IECs) contributes to the development of intestinal inflammation, and since mitochondrial alterations and dysfunction are implicated in the pathogenesis of IBDs, the authors characterised mtUPR in the context of intestinal inflammation. Truncated ornithine transcarbamylase was used to selectively induce mtUPR in a murine IEC line. Dextran sodium sulphate (DSS) was administered to PKR (double-stranded-RNA-activated protein kinase) knockout mice to induce IEC stress in vivo and to test for their susceptibility to DSS-induced colitis. Expression levels of the mitochondrial chaperone chaperonin 60 (CPN60) and PKR were quantified in IECs from patients with IBDs and from murine models of colitis using immunohistochemistry and Western blot analysis. Selective mtUPR induction by truncated ornithine transcarbamylase transfection triggered the phosphorylation of eukaryotic translation initiation factor (eIF) 2α and cJun through the recruitment of PKR. Using pharmacological inhibitors and small inhibitory RNA, the authors identified mtUPR-induced eIF2α phosphorylation and transcription factor activation (cJun/AP1) as being dependent on the activities of the mitochondrial protease ClpP and the cytoplasmic kinase PKR. Pkr(-/-) mice failed to induce CPN60 in IECs upon DSS treatment at early time points and subsequently showed an almost complete resistance to DSS-induced colitis. Under inflammatory conditions, primary IECs from patients with IBDs and two murine models of colitis exhibited a strong induction of the mtUPR marker protein CPN60 associated with enhanced expression of PKR. PKR integrates mtUPR into the disease-relevant ER UPR via eIF2α phosphorylation and AP1 activation. Induction of mtUPR and PKR was observed in IECs from murine models and patients with IBDs. The authors' results indicate that PKR might link mitochondrial stress to intestinal inflammation.

Influence of the membrane ion exchange capacity on the catalyst layer of proton exchange membrane fuel cell

NASA Astrophysics Data System (ADS)

Navessin, Titichai

2005-07-01

This work investigated the effect of ion exchange capacity (IEC) of polymer electrolyte membranes (PEM) on the PEM fuel cell cathode catalyst layer. A series of radiation grafted ethylene tetrafluoroethylene-g-polystyrene sulfonic acid (ETFE-g-PSSA) membranes was used to provide a systematic variation of IEC. A method to fabricate gas diffusion electrodes (GDEs) was adapted and custom-made GDEs with known compositions were prepared. Oxygen electrochemistry, mass transport properties, water absorption behaviour and proton conductivity were studied in relation to the IEC. Electrochemical characterization including cyclic voltammetry, electrochemical impedance spectroscopy and linear sweep voltammetry were employed. The agglomerate model for cathodes was adapted and used to extract mass transport parameters from experimental results. Prior to investigation in fuel cell systems, studies were performed in a half-fuel cell, which simplified complicating parameters associated with fuel cell operation. It was found that membranes with higher IEC resulted in a higher active surface area of electrode. In contrast, they exhibited lower oxygen reduction performance. The extracted effective diffusion coefficient of oxygen and O2 solubility in the catalyst layer was used to estimate the extent of flooding, which revealed that ˜67--70% of void space was filled with water. The membrane's IEC regulates the extent of flooding of the cathode, which in turn affects its electrochemical characteristics. The investigation under operating fuel cell conditions revealed an increase in fuel cell performance with increasing IEC---a contradicting trend to that found for the half-fuel cell. This is explained by the interplay of electroosmotic flux and hydraulic counterflux in the membrane which affects water management in the membrane electrode assembly (MEA). The influence was most significant in the cathode catalyst layer, where it affects mass transport and electrochemical characteristics. It was found that the higher IEC facilitated better water management in MEAs. Comparing results obtained with half fuel cell and fuel cell systems revealed insights into the state of hydration and effective use of Pt in the catalyst layer. The two types of measurements provide a convenient approach to study the interplay of different mechanisms of water flux in the membrane.

Modelling of plug and play interface for energy router based on IEC61850

NASA Astrophysics Data System (ADS)

Shi, Y. F.; Yang, F.; Gan, L.; He, H. L.

2017-11-01

Under the background of the “Internet Plus”, as the energy internet infrastructure equipment, energy router will be widely developed. The IEC61850 standard is the only universal standard in the field of power system automation which realizes the standardization of engineering operation of intelligent substation. To eliminate the lack of International unified standard for communication of energy router, this paper proposes to apply IEC61850 to plug and play interface and establishes the plug and play interface information model and information transfer services. This paper provides a research approach for the establishment of energy router communication standards, and promotes the development of energy router.

33 CFR 154.106 - Incorporation by reference: Where can I get a copy of the publications incorporated by reference...

Code of Federal Regulations, 2013 CFR

2013-07-01

...) IEC 309-1—Plugs, Socket-Outlets and Couplers for Industrial Purposes: Part 1, General Requirements, 1979, IBR approved for § 154.812. (2) IEC 309-2—Plugs, Socket-Outlets and Couplers for Industrial...

Accreditation - ISO/IEC 17025

NASA Astrophysics Data System (ADS)

Kaus, Rüdiger

This chapter gives the background on the accreditation of testing and calibration laboratories according to ISO/IEC 17025 and sets out the requirements of this international standard. ISO 15189 describes similar requirements especially tailored for medical laboratories. Because of these similarities ISO 15189 is not separately mentioned throughout this lecture.

21 CFR 26.60 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Vocabulary of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC)” (ISO/IEC Guide 2) (1996 edition), which is incorporated by reference in accordance with 5 U...://www.iso.ch or may be examined at the Food and Drug Administration's Medical Library, 5600 Fishers Lane...

Magnolol pretreatment attenuates heat stress-induced IEC-6 cell injury.

PubMed

Mei, Chen; He, Sha-Sha; Yin, Peng; Xu, Lei; Shi, Ya-Ran; Yu, Xiao-Hong; Lyu, An; Liu, Feng-Hua; Jiang, Lin-Shu

2016-06-01

Heat stress (HS) is an important environmental stressor that adversely influences livestock during the summer. The aim of this study was to investigate whether magnolol protects against HS-induced intestinal epithelial cell injury. An intestinal epithelial cell line (IEC-6) was subjected to HS at 42 °C, with and without magnolol pretreatment. Cell injury was detected by monitoring lactate dehydrogenase (LDH) release. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay was used to assess cell proliferation and viability, including identifying effective concentrations of magnolol. Flow cytometry confirmed G1-phase cell-cycle arrest and its alleviation by magnolol. Active DNA synthesis was measured by incorporation of nucleic acid 5-ethynyl-2'-deoxyuridine (EdU). G1-phase cell-cycle-related gene expression was assessed by real-time reverse transcription polymerase chain reaction (RT-PCR) and levels of G1-phase-related proteins by Western blotting. HS induced IEC-6 cell injury and decreased cell viability, as demonstrated by data from LDH and MTS assays, respectively. Based on a number of criteria, IEC-6 cells subjected to HS were arrested in the G1 phase of the cell cycle. Magnolol pretreatment decreased HS-induced cell injury through relief of this cell-cycle arrest. Magnolol pretreatment attenuates HS-induced injury in IEC-6 cells. Magnolol is potentially promising as a protective strategy for HS in livestock.

Characteristic Changes in Cell Surface Glycosylation Accompany Intestinal Epithelial Cell (IEC) Differentiation: High Mannose Structures Dominate the Cell Surface Glycome of Undifferentiated Enterocytes*

PubMed Central

Park, Dayoung; Brune, Kristin A.; Mitra, Anupam; Marusina, Alina I.; Maverakis, Emanual; Lebrilla, Carlito B.

2015-01-01

Changes in cell surface glycosylation occur during the development and differentiation of cells and have been widely correlated with the progression of several diseases. Because of their structural diversity and sensitivity to intra- and extracellular conditions, glycans are an indispensable tool for analyzing cellular transformations. Glycans present on the surface of intestinal epithelial cells (IEC) mediate interactions with billions of native microorganisms, which continuously populate the mammalian gut. A distinct feature of IECs is that they differentiate as they migrate upwards from the crypt base to the villus tip. In this study, nano-LC/ESI QTOF MS profiling was used to characterize the changes in glycosylation that correspond to Caco-2 cell differentiation. As Caco-2 cells differentiate to form a brush border membrane, a decrease in high mannose type glycans and a concurrent increase in fucosylated and sialylated complex/hybrid type glycans were observed. At day 21, when cells appear to be completely differentiated, remodeling of the cell surface glycome ceases. Differential expression of glycans during IEC maturation appears to play a key functional role in regulating the membrane-associated hydrolases and contributes to the mucosal surface innate defense mechanisms. Developing methodologies to rapidly identify changes in IEC surface glycans may lead to a rapid screening approach for a variety of disease states affecting the GI tract. PMID:26355101

Effects of helium ion implantation on the surface morphology of tungsten at high temperature for the first wall armor and divertor plates of fusion reactors

NASA Astrophysics Data System (ADS)

Zenobia, Samuel J.

Three devices at the University of Wisconsin-Madison Inertial Electrostatic Confinement (UW IEC) laboratory were used to implant W and W alloys with helium ions at high temperatures. These devices were HOMER, HELIOS, and the Materials Irradiation Experiment (MITE-E). The research presented in this thesis will focus on the experiments carried out utilizing the MITE-E. Early UW work in HOMER and HELIOS on silicon carbide, carbon velvet, W-coated carbon velvet, fine-grain W, nano-grain W, W needles, and single- and polycrystalline W showed that these materials were not resistant to He+ implantation above ˜800 °C. Unalloyed W developed a "coral-like" surface morphology after He+ implantation, but appeared to be the most robust material investigated. The MITE-E used an ion gun technology to implant tungsten with 30 keV He+. Tungsten specimens were implanted at 900 °C to total average fluences of 6x1016 -- 6x1018 He +/cm2. Other specimens were implanted to a total average fluence of 5x1018 He+/cm2 at temperatures between 500 and 900 °C. Micrographs of the implanted W specimens revealed the development of three distinct surface morphologies. These morphologies are classified as "blistering", "pitting", and "orientated ridges". Preferential sputtering of the W by the energetic He+ appears to be responsible for pitting and orientated ridges which developed at high fluences (1019 He+/cm2) in the MITE-E. While the orientated ridges were the dominant morphology on the W surface above 700 °C, the pitting was prevalent below 700 °C. The blister morphology was observed at all of the examined temperatures at fluences ≥5x1017 He+/cm2 but disappeared above fluences of 1019 He+/cm 2. The "coral-like" surface morphology on W inherent to He + implantation experiments in HOMER and HELIOS developed from a combination of sources: multiangular ion incidence, ion energy spread (softening), and electron field emission from nano-scale surface features induced by He + implantation. The HOMER and HELIOS devices were found to be better suited for simulation of magnetic fusion environments with off-normal particle incidences, and the MITE-E was found to be more suited for simulating the normal particle incidence of inertial fusion environments.

Supporting Refugee Students in School Education in Greater Western Sydney

ERIC Educational Resources Information Center

Ferfolja, Tania; Vickers, Margaret

2010-01-01

Rarely do refugee students entering Australian schools possess the multiple forms of social, linguistic and cultural capital that are taken for granted in mainstream classrooms. While refugees of high-school age are assisted initially through Intensive English Centres (IECs), the transition from IECs to mainstream classrooms presents substantial…

Improve Your Students' Writing with a Class Magazine.

ERIC Educational Resources Information Center

Stuart, Moira K.

This paper describes two different English programs for international students at the American Language Institute in San Diego, California. One is English for Academic Purposes (EAP), and the other is Intensive English for Communication (IEC). The paper focuses on one teacher's experiences teaching IEC writing after 2 years of teaching EAP…

Multitude of core-localized shear Alfvén waves in a high-temperature fusion plasma.

PubMed

Nazikian, R; Berk, H L; Budny, R V; Burrell, K H; Doyle, E J; Fonck, R J; Gorelenkov, N N; Holcomb, C; Kramer, G J; Jayakumar, R J; La Haye, R J; McKee, G R; Makowski, M A; Peebles, W A; Rhodes, T L; Solomon, W M; Strait, E J; Vanzeeland, M A; Zeng, L

2006-03-17

Evidence is presented for a multitude of discrete frequency Alfvén waves in the core of magnetically confined high-temperature fusion plasmas. Multiple diagnostic instruments confirm wave excitation over a wide spatial range from the device size at the longest wavelengths down to the thermal ion Larmor radius. At the shortest scales, the poloidal wavelengths are comparable to the scale length of electrostatic drift wave turbulence. Theoretical analysis confirms a dominant interaction of the modes with particles in the thermal ion distribution traveling well below the Alfvén velocity.

A nonlinear MEMS electrostatic kinetic energy harvester for human-powered biomedical devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Y.; Cottone, F.; Marty, F.

This article proposes a silicon-based electrostatic kinetic energy harvester with an ultra-wide operating frequency bandwidth from 1 Hz to 160 Hz. This large bandwidth is obtained, thanks to a miniature tungsten ball impacting with a movable proof mass of silicon. The motion of the silicon proof mass is confined by nonlinear elastic stoppers on the fixed part standing against two protrusions of the proof mass. The electrostatic transducer is made of interdigited-combs with a gap-closing variable capacitance that includes vertical electrets obtained by corona discharge. Below 10 Hz, the e-KEH offers 30.6 nJ per mechanical oscillation at 2 g{sub rms}, which makes it suitable formore » powering biomedical devices from human motion. Above 10 Hz and up to 162 Hz, the harvested power is more than 0.5 μW with a maximum of 4.5 μW at 160 Hz. The highest power of 6.6 μW is obtained without the ball at 432 Hz, in accordance with a power density of 142 μW/cm{sup 3}. We also demonstrate the charging of a 47-μF capacitor to 3.5 V used to power a battery-less wireless temperature sensor node.« less

From dots to doughnuts: Two-dimensionally confined deposition of polyelectrolytes on block copolymer templates

DOE PAGES

Oded, Meirav; Kelly, Stephen T.; Gilles, Mary K.; ...

2016-07-05

The combination of block copolymer templating with electrostatic self-assembly provides a simple and robust method for creating nano-patterned polyelectrolyte multilayers over large areas. The deposition of the first polyelectrolyte layer provides important insights on the initial stages of multilayer buildup. Here, we focus on two-dimensionally confined “dots” patterns afforded by block copolymer films featuring hexagonally-packed cylinders that are oriented normal to the substrate. Rendering the cylinder caps positively charged enables the selective deposition of negatively charged polyelectrolytes on them under salt-free conditions. The initially formed polyelectrolyte nanostructures adopt a toroidal (“doughnut”) shape, which results from retraction of dangling polyelectrolyte segmentsmore » into the “dots” upon drying. With increasing exposure time to the polyelectrolyte solution, the final shape of the deposited polyelectrolyte transitions from a doughnut to a hemisphere. In conclusion, these insights would enable the creation of patterned polyelectrolyte multilayers with increased control over adsorption selectivity of the additional incoming polyelectrolytes.« less

From dots to doughnuts: Two-dimensionally confined deposition of polyelectrolytes on block copolymer templates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oded, Meirav; Kelly, Stephen T.; Gilles, Mary K.

The combination of block copolymer templating with electrostatic self-assembly provides a simple and robust method for creating nano-patterned polyelectrolyte multilayers over large areas. The deposition of the first polyelectrolyte layer provides important insights on the initial stages of multilayer buildup. Here, we focus on two-dimensionally confined “dots” patterns afforded by block copolymer films featuring hexagonally-packed cylinders that are oriented normal to the substrate. Rendering the cylinder caps positively charged enables the selective deposition of negatively charged polyelectrolytes on them under salt-free conditions. The initially formed polyelectrolyte nanostructures adopt a toroidal (“doughnut”) shape, which results from retraction of dangling polyelectrolyte segmentsmore » into the “dots” upon drying. With increasing exposure time to the polyelectrolyte solution, the final shape of the deposited polyelectrolyte transitions from a doughnut to a hemisphere. In conclusion, these insights would enable the creation of patterned polyelectrolyte multilayers with increased control over adsorption selectivity of the additional incoming polyelectrolytes.« less

Ion association at discretely-charged dielectric interfaces: Giant charge inversion [Dielectric response controlled ion association at physically heterogeneous surfaces: Giant charge reversal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhi -Yong; Wu, Jianzhong

2017-07-11

Giant charge reversal has been identified for the first time by Monte Carlo simulation for a discretely charged surface in contact with a trivalent electrolyte solution. It takes place regardless of the surface charge density under study and the monovalent salt. In stark contrast to earlier predictions based on the 2-dimensional Wigner crystal model to describe strong correlation of counterions at the macroion surface, we find that giant charge reversal reflects an intricate interplay of ionic volume effects, electrostatic correlations, surface charge heterogeneity, and the dielectric response of the confined fluids. While the novel phenomenon is yet to be confirmedmore » with experiment, the simulation results appear in excellent agreement with a wide range of existing observations in the subregime of charge inversion. Lastly, our findings may have far-reaching implications to understanding complex electrochemical phenomena entailing ionic fluids under dielectric confinements.« less

Engineering of frustration in colloidal artificial ice (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ortiz-Ambriz, Antonio; Tierno, Pietro

2016-09-01

Artificial spin-ice systems have been used to date as microscopic models of frustration induced by lattice topology, as they allow for the direct visualization of spin arrangements and textures. However, the engineering of frustrated ice states in which individual spins can be manipulated in situ and the real-time observation of their collective dynamics remain both challenging tasks. Recently, an analogue system has been proposed theoretically, where an optical landscape confined colloidal particles that interacted electrostatically. Here we realize experimentally another version of a colloidal artificial ice system using interacting magnetically polarizable particles confined to lattices of bistable gravitational traps. We show quantitatively that ice-selection rules emerge in this frustrated soft matter system by tuning the strength of the pair-interactions between the microscopic units. By using optical tweezers, we can control particle positioning and dipolar coupling, we introduce monopole-like defects and strings and use loops with defined chirality as an elementary unit to store binary information.

Mapping the Coulomb Environment in Interference-Quenched Ballistic Nanowires.

PubMed

Gutstein, D; Lynall, D; Nair, S V; Savelyev, I; Blumin, M; Ercolani, D; Ruda, H E

2018-01-10

The conductance of semiconductor nanowires is strongly dependent on their electrostatic history because of the overwhelming influence of charged surface and interface states on electron confinement and scattering. We show that InAs nanowire field-effect transistor devices can be conditioned to suppress resonances that obscure quantized conduction thereby revealing as many as six sub-bands in the conductance spectra as the Fermi-level is swept across the sub-band energies. The energy level spectra extracted from conductance, coupled with detailed modeling shows the significance of the interface state charge distribution revealing the Coulomb landscape of the nanowire device. Inclusion of self-consistent Coulomb potentials, the measured geometrical shape of the nanowire, the gate geometry and nonparabolicity of the conduction band provide a quantitative and accurate description of the confinement potential and resulting energy level structure. Surfaces of the nanowire terminated by HfO 2 are shown to have their interface donor density reduced by a factor of 30 signifying the passivating role played by HfO 2 .

High temperature surface effects of He + implantation in ICF fusion first wall materials

NASA Astrophysics Data System (ADS)

Zenobia, Samuel J.; Radel, R. F.; Cipiti, B. B.; Kulcinski, Gerald L.

2009-06-01

The first wall armor of the inertial confinement fusion reactor chambers must withstand high temperatures and significant radiation damage from target debris and neutrons. The resilience of multiple materials to one component of the target debris has been investigated using energetic (20-40 keV) helium ions generated in the inertial electrostatic confinement device at the University of Wisconsin. The materials studied include: single-crystalline, and polycrystalline tungsten, tungsten-coated tantalum-carbide 'foams', tungsten-rhenium alloy, silicon carbide, carbon-carbon velvet, and tungsten-coated carbon-carbon velvet. Steady-state irradiation temperatures ranged from 750 to 1250 °C with helium fluences between 5 × 10 17 and 1 × 10 20 He +/cm 2. The crystalline, rhenium alloyed, carbide foam, and powder metallurgical tungsten specimens each experienced extensive pore formation after He + irradiation. Flaking and pore formation occurred on silicon carbide samples. Individual fibers of carbon-carbon velvet specimens sustained erosion and corrugation, in addition to the roughening and rupturing of tungsten coatings after helium ion implantation.

Collisional tests and an extension of the TEMPEST continuum gyrokinetic code

NASA Astrophysics Data System (ADS)

Cohen, R. H.; Dorr, M.; Hittinger, J.; Kerbel, G.; Nevins, W. M.; Rognlien, T.; Xiong, Z.; Xu, X. Q.

2006-04-01

An important requirement of a kinetic code for edge plasmas is the ability to accurately treat the effect of colllisions over a broad range of collisionalities. To test the interaction of collisions and parallel streaming, TEMPEST has been compared with published analytic and numerical (Monte Carlo, bounce-averaged Fokker-Planck) results for endloss of particles confined by combined electrostatic and magnetic wells. Good agreement is found over a wide range of collisionality, confining potential and mirror ratio, and the required velocity space resolution is modest. We also describe progress toward extension of (4-dimensional) TEMPEST into a ``kinetic edge transport code'' (a kinetic counterpart of UEDGE). The extension includes averaging of the gyrokinetic equations over fast timescales and approximating the averaged quadratic terms by diffusion terms which respect the boundaries of inaccessable regions in phase space. F. Najmabadi, R.W. Conn and R.H. Cohen, Nucl. Fusion 24, 75 (1984); T.D. Rognlien and T.A. Cutler, Nucl. Fusion 20, 1003 (1980).

Experimental investigations and guidelines for PCB design for a fuel injection ECU to meet automotive environmental, EMI/EMC and ESD standards

NASA Astrophysics Data System (ADS)

Kalyankar-Narwade, Supriya; Kumar, C. Ramesh; Patil, Sanjay A.

2017-11-01

Engine Management ECU plays a vital role in controlling different important features related to the engine performance. ECU is an embedded system which includes hardware and firmware platform for control logics. However, it is necessary to verify its smooth performance by its functionality testing in the Electromagnetic environment for approval. If these requirements are not known at earlier stages, then ECU may not fulfil functional requirements during required automotive electronic test standards. Hence, focusing on EMS ECU, this paper highlights hardware, layout and software guidelines for solving problems related with Electromagnetic Interference (EMI) to comply ISO 7637, CISPR 25 standard, Electromagnetic Compatibility (EMC) to comply ISO 11452-4,5 standard, Electrostatic Discharge (ESD) to comply ISO 10605 standard and Environmental Testing to comply standards as per IEC standards. This paper specifies initially the importance, need and guidelines for reducing the EMI effect on PCB i.e. making ECU more electromagnetically compatible as per automotive standards. The guidelines are useful for the designers to avoid pitfalls at the later stage. After mentioned modifications in the paper, ECU successfully passed the requirements for all standard tests.

Electromagnetic Compatibility of Transcutaneous Energy Transmission Systemfor Totally Implantable Artificial Heart

NASA Astrophysics Data System (ADS)

Shiba, Kenji; Koshiji, Kohji

Transcutaneous Energy Transmission (TET) is one way of providing the energy needed to power a totally implantable artificial heart (TIAH). In the present study, an externally coupled TET system was implanted in a prototype human phantom to evaluate emission and immunity. In the emission evaluation, measurements were conducted based on CISPR Pub.11 and VDE 0871 standards, while immunity tests were based on the standards of the IEC 61000-4 series. The magnetic field of the radiated emission was measured using a loop antenna. At 0.1[MHz], we found the greatest magnetic field of 47.8 [dBμA/m], somewhat less than CISPR’s upper limit of 54 [dBμA/m]. For the conducted emission, by installing a noise filter and ferrite beads in the input section of the DC-power supply, conducted emission could be kept within the allowable limits of CISPR Pub.11 and VDE 0871. Finally, the immunity tests against radiated and conducted emission, electrostatic discharge and voltage fluctuation proved that the prototype could withstand the maximum level of disturbance. These results confirmed that the TET system implanted in a human phantom could, through modification, meet the emission and immunity standards.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hakjoon; Bac, Seul-Ki; Lee, Sangyeop

We report direct experimental determination of next-nearest-neighbor (NNN) interlayer exchange coupling (IEC) in antiferromagnetically coupled GaMnAs/GaAs:Be multilayers. Magnetoresistance in such multilayers shows step-like transitions as a function of applied magnetic field that corresponds to abrupt changes of spin configuration. By adjusting the field range, one obtains minor hysteresis loops that allow one to determine spin configurations occurring in the multilayer, which in turn can be used to obtain the ratio of NNN IEC to NN IEC. By using this method on a series of GaMnAs/GaAs:Be with different numbers of GaMnAs layers, we obtain this ratio to be 0.23, in goodmore » agreement with theoretical predictions.« less

"Data Acquisition Systems"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unterweger, Michael; Costrell, Louis deceased

2009-07-07

This project involved support for Lou Costrell and myself in the development of IEEE and IEC standards for nuclear counting and data acquisition systems. Over the years, as a result of this support, Lou and I were able to attend standards meetings of IEEE and IEC, which led directly to the publication of many standards for NIM systems, FastBus and CAMAC. We also chaired several writing committees as well as ANSI N42 (Nuclear instrumentation), IEEE NIM (NIM standard), IEEE NID (NPSS nuclear instruments and detector) and IEC TC45 WG9 (Nuclear instrumentation). Through this support we were able to assure thatmore » the interests of the US and DOE were expressed and implemented in the various standards.« less

Duration Test Report for the Entegrity EW50 Wind Turbine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, J.; Huskey, A.; Jager, D.

2012-12-01

This report summarizes the results of a duration test that NREL conducted on the Entegrity EW50 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.

Using Adult Education Principles for HIV/AIDS Awareness Intervention Strategies in Botswana

ERIC Educational Resources Information Center

Preece, Julia; Ntseane, Gabo

2004-01-01

This paper reports on a mainly qualitative study into company strategies for HIV/AIDS information, education and communication (IEC) strategies in the Botswana workplace. The authors argue that HIV/AIDS awareness and prevention strategies in Botswana need a new approach. The research proposal hypothesized that IEC strategies need to take account…

Polyphenols from evening primrose ( Oenothera paradoxa ) defatted seeds induce apoptosis in human colon cancer Caco-2 cells.

PubMed

Gorlach, Sylwia; Wagner, Waldemar; Podsedek, Anna; Sosnowska, Dorota; Dastych, Jarosław; Koziołkiewicz, Maria

2011-07-13

Polyphenols extracted from evening primrose seeds (industrial waste product) were studied as apoptosis inducers in human colorectal adenocarcinoma Caco-2 and HT-29 cell lines and in rat normal intestinal IEC-6 cells. The extract dose-dependently inhibited the growth of Caco-2, HT-29, and IEC-6 cells. However, nuclear DNA fragmentation characteristic of apoptosis was observed only in Caco-2. After 72 h of incubation with the extract at 150 μM gallic acid equivalents (44.1 μg extract/mL), Caco-2 cell numbers decreased to 19% of control and 48.8% of the cells were identified by flow cytometry as apoptotic. Under the same conditions only 8% of HT-29 cells and 12.6% of IEC-6 cells exhibited hypodiploid DNA content. The effects of the extract and its fractions on phosphatidylserine exposure and cell membrane integrity were assessed by high content screening image cytometry. The fractions strongly and dose-dependently reduced Caco-2 cell numbers, whereas HT-29 and IEC-6 cells were affected to lesser extents.

Experimental and analytical investigation of a modified ring cusp NSTAR engine

NASA Technical Reports Server (NTRS)

Sengupta, Anita

2005-01-01

A series of experimental measurements on a modified laboratory NSTAR engine were used to validate a zero dimensional analytical discharge performance model of a ring cusp ion thruster. The model predicts the discharge performance of a ring cusp NSTAR thruster as a function the magnetic field configuration, thruster geometry, and throttle level. Analytical formalisms for electron and ion confinement are used to predict the ionization efficiency for a given thruster design. Explicit determination of discharge loss and volume averaged plasma parameters are also obtained. The model was used to predict the performance of the nominal and modified three and four ring cusp 30-cm ion thruster configurations operating at the full power (2.3 kW) NSTAR throttle level. Experimental measurements of the modified engine configuration discharge loss compare well with the predicted value for propellant utilizations from 80 to 95%. The theory, as validated by experiment, indicates that increasing the magnetic strength of the minimum closed reduces maxwellian electron diffusion and electrostatically confines the ion population and subsequent loss to the anode wall. The theory also indicates that increasing the cusp strength and minimizing the cusp area improves primary electron confinement increasing the probability of an ionization collision prior to loss at the cusp.

Magnolol pretreatment attenuates heat stress-induced IEC-6 cell injury*

PubMed Central

Mei, Chen; He, Sha-sha; Yin, Peng; Xu, Lei; Shi, Ya-ran; Yu, Xiao-hong; Lyu, An; Liu, Feng-hua; Jiang, Lin-shu

2016-01-01

Objective: Heat stress (HS) is an important environmental stressor that adversely influences livestock during the summer. The aim of this study was to investigate whether magnolol protects against HS-induced intestinal epithelial cell injury. Materials and methods: An intestinal epithelial cell line (IEC-6) was subjected to HS at 42 °C, with and without magnolol pretreatment. Cell injury was detected by monitoring lactate dehydrogenase (LDH) release. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay was used to assess cell proliferation and viability, including identifying effective concentrations of magnolol. Flow cytometry confirmed G1-phase cell-cycle arrest and its alleviation by magnolol. Active DNA synthesis was measured by incorporation of nucleic acid 5-ethynyl-2'-deoxyuridine (EdU). G1-phase cell-cycle-related gene expression was assessed by real-time reverse transcription polymerase chain reaction (RT-PCR) and levels of G1-phase-related proteins by Western blotting. Results: HS induced IEC-6 cell injury and decreased cell viability, as demonstrated by data from LDH and MTS assays, respectively. Based on a number of criteria, IEC-6 cells subjected to HS were arrested in the G1 phase of the cell cycle. Magnolol pretreatment decreased HS-induced cell injury through relief of this cell-cycle arrest. Conclusions: Magnolol pretreatment attenuates HS-induced injury in IEC-6 cells. Magnolol is potentially promising as a protective strategy for HS in livestock. PMID:27256675

New mechanistic explanation for the localization of ulcers in the rat duodenum: role of iron and selective uptake of cysteamine.

PubMed

Khomenko, Tetyana; Kolodney, Joanna; Pinto, John T; McLaren, Gordon D; Deng, Xiaoming; Chen, Longchuan; Tolstanova, Ganna; Paunovic, Brankica; Krasnikov, Boris F; Hoa, Neil; Cooper, Arthur J L; Szabo, Sandor

2012-09-01

Cysteamine, a coenzyme A metabolite, induces duodenal ulcers in rodents. Our recent studies showed that ulcer formation was aggravated by iron overload and diminished in iron deficiency. We hypothesized that cysteamine is selectively taken up in the duodenal mucosa, where iron absorption primarily occurs, and is transported by a carrier-mediated process. Here we report that cysteamine administration in rats leads to cysteamine accumulation in the proximal duodenum, where the highest concentration of iron in the gastrointestinal tract is found. In vitro, iron loading of intestinal epithelial cells (IEC-6) accelerated reactive oxygen species (ROS) production and increased [(14)C]cysteamine uptake. [(14)C]Cysteamine uptake by isolated gastrointestinal mucosal cells and by IEC-6 was pH-dependent and inhibited by unlabeled cysteamine. The uptake of [(14)C]cysteamine by IEC-6 was Na(+)-independent, saturable, inhibited by structural analogs, H(2)-histamine receptor antagonists, and organic cation transporter (OCT) inhibitors. OCT1 mRNA was markedly expressed in the rat duodenum and in IEC-6, and transfection of IEC-6 with OCT1 siRNA decreased OCT1 mRNA expression and inhibited [(14)C]cysteamine uptake. Cysteamine-induced duodenal ulcers were decreased in OCT1/2 knockout mice. These studies provide new insights into the mechanism of cysteamine absorption and demonstrate that intracellular iron plays a critical role in cysteamine uptake and in experimental duodenal ulcerogenesis. Copyright © 2012 Elsevier Inc. All rights reserved.

Processing of whey modulates proliferative and immune functions in intestinal epithelial cells.

PubMed

Nguyen, Duc Ninh; Sangild, Per T; Li, Yanqi; Bering, Stine B; Chatterton, Dereck E W

2016-02-01

Whey protein concentrate (WPC) is often subjected to heat treatment during industrial processing, resulting in protein denaturation and loss of protein bioactivity. We hypothesized that WPC samples subjected to different degrees of thermal processing are associated with different levels of bioactive proteins and effects on proliferation and immune response in intestinal epithelial cells (IEC). The results showed that low-heat-treated WPC had elevated levels of lactoferrin and transforming growth factor-β2 compared with that of standard WPC. The level of aggregates depended on the source of whey, with the lowest level being found in WPC derived from acid whey. Following acid activation, WPC from acid whey enhanced IEC proliferation compared with WPC from sweet whey or nonactivated WPC. Low-heat-treated WPC from acid whey induced greater secretion of IL-8 in IEC than either standard WPC from acid whey or low-heat-treated WPC from sweet whey. Following acid activation (to activate growth factors), low-heat-treated WPC from sweet whey induced higher IL-8 levels in IEC compared with standard WPC from sweet whey. In conclusion, higher levels of bioactive proteins in low-heat-treated WPC, especially from acid whey, may enhance proliferation and cytokine responses of IEC. These considerations could be important to maintain optimal bioactivity of infant formulas, including their maturational and immunological effects on the developing intestine. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Characteristic Changes in Cell Surface Glycosylation Accompany Intestinal Epithelial Cell (IEC) Differentiation: High Mannose Structures Dominate the Cell Surface Glycome of Undifferentiated Enterocytes.

PubMed

Park, Dayoung; Brune, Kristin A; Mitra, Anupam; Marusina, Alina I; Maverakis, Emanual; Lebrilla, Carlito B

2015-11-01

Changes in cell surface glycosylation occur during the development and differentiation of cells and have been widely correlated with the progression of several diseases. Because of their structural diversity and sensitivity to intra- and extracellular conditions, glycans are an indispensable tool for analyzing cellular transformations. Glycans present on the surface of intestinal epithelial cells (IEC) mediate interactions with billions of native microorganisms, which continuously populate the mammalian gut. A distinct feature of IECs is that they differentiate as they migrate upwards from the crypt base to the villus tip. In this study, nano-LC/ESI QTOF MS profiling was used to characterize the changes in glycosylation that correspond to Caco-2 cell differentiation. As Caco-2 cells differentiate to form a brush border membrane, a decrease in high mannose type glycans and a concurrent increase in fucosylated and sialylated complex/hybrid type glycans were observed. At day 21, when cells appear to be completely differentiated, remodeling of the cell surface glycome ceases. Differential expression of glycans during IEC maturation appears to play a key functional role in regulating the membrane-associated hydrolases and contributes to the mucosal surface innate defense mechanisms. Developing methodologies to rapidly identify changes in IEC surface glycans may lead to a rapid screening approach for a variety of disease states affecting the GI tract. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Candida parapsilosis Protects Premature Intestinal Epithelial Cells from Invasion and Damage by Candida albicans

PubMed Central

Gonia, Sara; Archambault, Linda; Shevik, Margaret; Altendahl, Marie; Fellows, Emily; Bliss, Joseph M.; Wheeler, Robert T.; Gale, Cheryl A.

2017-01-01

Candida is a leading cause of late-onset sepsis in premature infants and is thought to invade the host via immature or damaged epithelial barriers. We previously showed that the hyphal form of Candida albicans invades and causes damage to premature intestinal epithelial cells (pIECs), whereas the non-hyphal Candida parapsilosis, also a fungal pathogen of neonates, has less invasion and damage abilities. In this study, we investigated the potential for C. parapsilosis to modulate pathogenic interactions of C. albicans with the premature intestine. While a mixed infection with two fungal pathogens may be expected to result in additive or synergistic damage to pIECs, we instead found that C. parapsilosis was able to protect pIECs from invasion and damage by C. albicans. C. albicans-induced pIEC damage was reduced to a similar extent by multiple different C. parapsilosis strains, but strains differed in their ability to inhibit C. albicans invasion of pIECs, with the inhibitory activity correlating with their adhesiveness for C. albicans and epithelial cells. C. parapsilosis cell-free culture fractions were also able to significantly reduce C. albicans adhesion and damage to pIECs. Furthermore, coadministration of C. parapsilosis cell-free fractions with C. albicans was associated with decreased infection and mortality in zebrafish. These results indicate that C. parapsilosis is able to reduce invasion, damage, and virulence functions of C. albicans. Additionally, the results with cellular and cell-free fractions of yeast cultures suggest that inhibition of pathogenic interactions between C. albicans and host cells by C. parapsilosis occurs via secreted molecules as well as by physical contact with the C. parapsilosis cell surface. We propose that non-invasive commensals can be used to inhibit virulence features of pathogens and deserve further study as a non-pharmacological strategy to protect the fragile epithelial barriers of premature infants. PMID:28382297

IL-17A alone weakly affects the transcriptome of intestinal epithelial cells but strongly modulates the TNF-α-induced expression of inflammatory mediators and inflammatory bowel disease susceptibility genes.

PubMed

Friedrich, Matthias; Diegelmann, Julia; Beigel, Florian; Brand, Stephan

2014-09-01

In contrast to anti-TNF-α antibodies, anti-IL-17A antibodies lacked clinical efficacy in a trial with patients suffering from Crohn's disease. We therefore analyzed how IL-17A modulates the inflammatory response elicited by TNF-α in intestinal epithelial cells (IEC). Target mRNA levels in IEC and colonic biopsies were assessed by RNA microarray and quantitative real-time PCR. Signaling pathways were analyzed using receptor neutralization and pharmacological inhibitors. Target protein levels were determined by immunoblotting. Microarray analysis demonstrated that IL-17A alone is a weak inducer of gene expression in IEC (29 regulated transcripts), but significantly affected the TNF-α-induced expression of 547 genes, with strong amplification of proinflammatory chemokines and cytokines (>200-fold increase of CCL20, CXCL1, and CXCL8). Interestingly, IL-17A differentially modulated the TNF-α-induced expression of several inflammatory bowel disease susceptibility genes in IEC (increase of JAK2 mRNA, decrease of FUT2, ICAM1, and LTB mRNA). Negative regulation of ICAM-1 by IL-17A was verified on protein level. The significance of these findings is emphasized by inflamed lesions of patients with inflammatory bowel disease demonstrating significant correlations (P < 0.01, Rho, 0.57-0.85) for JAK2, ICAM1, and LTB mRNA with IL17A and TNF mRNA. Our study demonstrates the modulation of inflammatory bowel disease susceptibility gene mRNA in IEC as a novel important property of IL-17A. Given the weak impact of sole IL-17A stimulation on IEC target gene expression, our study provides an important explanation for the lack of clinical efficacy of sole IL-17A neutralization, but suggests a beneficial effect of combined IL-17A/TNF-α that is currently in clinical development.

Arginine Consumption by the Intestinal Parasite Giardia intestinalis Reduces Proliferation of Intestinal Epithelial Cells

PubMed Central

Stadelmann, Britta; Merino, María C.; Persson, Lo; Svärd, Staffan G.

2012-01-01

In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the host´s production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consumes arginine as main energy source and secretes an arginine-consuming enzyme, arginine deiminase (ADI). Reduced intestinal epithelial cell (IEC) proliferation is a common theme during bacterial and viral intestinal infections, but it has never been connected to arginine-consumption. Our specific question was thereby, whether the arginine-consumption by Giardia leads to reduced IEC proliferation, in addition to NO reduction. In vitro cultivation of human IEC lines in arginine-free or arginine/citrulline-complemented medium, as well as in interaction with different G. intestinalis isolates, were used to study effects on host cell replication by MTT assay. IEC proliferation was further analyzed by DNA content analysis, polyamine measurements and expressional analysis of cell cycle regulatory genes. IEC proliferation was reduced upon arginine-withdrawal and also in an arginine-dependent manner upon interaction with G. intestinalis or addition of Giardia ADI. We show that arginine-withdrawal by intestinal pathogens leads to a halt in the cell cycle in IECs through reduced polyamine levels and upregulated cell cycle inhibitory genes. This is of importance with regards to intestinal tissue homeostasis that is affected through reduced cell proliferation. Thus, the slower epithelial cell turnover helps the pathogen to maintain a more stable niche for colonization. This study also shows why supplementation therapy of diarrhea patients with arginine/citrulline is helpful and that citrulline especially should gain further attention in future treatment strategies. PMID:23028934

Interleukin 31 mediates MAP kinase and STAT1/3 activation in intestinal epithelial cells and its expression is upregulated in inflammatory bowel disease

PubMed Central

Dambacher, Julia; Beigel, Florian; Seiderer, Julia; Haller, Dirk; Göke, Burkhard; Auernhammer, Christoph J; Brand, Stephan

2007-01-01

Background/aim Interleukin 31 (IL31), primarily expressed in activated lymphocytes, signals through a heterodimeric receptor complex consisting of the IL31 receptor alpha (IL31Rα) and the oncostatin M receptor (OSMR). The aim of this study was to analyse IL31 receptor expression, signal transduction, and specific biological functions of this cytokine system in intestinal inflammation. Methods Expression studies were performed by RT‐PCR, quantitative PCR, western blotting, and immunohistochemistry. Signal transduction was analysed by western blotting. Cell proliferation was measured by MTS assays, cell migration by restitution assays. Results Colorectal cancer derived intestinal epithelial cell (IEC) lines express both IL31 receptor subunits, while their expression in unstimulated primary murine IEC was low. LPS and the proinflammatory cytokines TNF‐α, IL1β, IFN‐γ, and sodium butyrate stimulation increased IL31, IL31Rα, and OSMR mRNA expression, while IL31 itself enhanced IL8 expression in IEC. IL31 mediates ERK‐1/2, Akt, STAT1, and STAT3 activation in IEC resulting in enhanced IEC migration. However, at low cell density, IL31 had significant antiproliferative capacities (p<0.005). IL31 mRNA expression was not increased in the TNFΔARE mouse model of ileitis but in inflamed colonic lesions compared to non‐inflamed tissue in patients with Crohn's disease (CD; average 2.4‐fold increase) and in patients with ulcerative colitis (UC; average 2.6‐fold increase) and correlated with the IL‐8 expression in these lesions (r = 0.564 for CD; r = 0.650 for UC; total number of biopsies analysed: n = 88). Conclusion IEC express the functional IL31 receptor complex. IL31 modulates cell proliferation and migration suggesting a role in the regulation of intestinal barrier function particularly in intestinal inflammation. PMID:17449633

Characterization of the Giardia intestinalis secretome during interaction with human intestinal epithelial cells: The impact on host cells

PubMed Central

Ma’ayeh, Showgy Y.; Liu, Jingyi; Peirasmaki, Dimitra; Hörnaeus, Katarina; Bergström Lind, Sara; Grabherr, Manfred; Bergquist, Jonas

2017-01-01

Background Giardia intestinalis is a non-invasive protozoan parasite that causes giardiasis in humans, the most common form of parasite-induced diarrhea. Disease mechanisms are not completely defined and very few virulence factors are known. Methodology To identify putative virulence factors and elucidate mechanistic pathways leading to disease, we have used proteomics to identify the major excretory-secretory products (ESPs) when Giardia trophozoites of WB and GS isolates (assemblages A and B, respectively) interact with intestinal epithelial cells (IECs) in vitro. Findings The main parts of the IEC and parasite secretomes are constitutively released proteins, the majority of which are associated with metabolism but several proteins are released in response to their interaction (87 and 41 WB and GS proteins, respectively, 76 and 45 human proteins in response to the respective isolates). In parasitized IECs, the secretome profile indicated effects on the cell actin cytoskeleton and the induction of immune responses whereas that of Giardia showed anti-oxidation, proteolysis (protease-associated) and induction of encystation responses. The Giardia secretome also contained immunodominant and glycosylated proteins as well as new candidate virulence factors and assemblage-specific differences were identified. A minor part of Giardia ESPs had signal peptides (29% for both isolates) and extracellular vesicles were detected in the ESPs fractions, suggesting alternative secretory pathways. Microscopic analyses showed ESPs binding to IECs and partial internalization. Parasite ESPs reduced ERK1/2 and P38 phosphorylation and NF-κB nuclear translocation. Giardia ESPs altered gene expression in IECs, with a transcriptional profile indicating recruitment of immune cells via chemokines, disturbances in glucose homeostasis, cholesterol and lipid metabolism, cell cycle and induction of apoptosis. Conclusions This is the first study identifying Giardia ESPs and evaluating their effects on IECs. It highlights the importance of host and parasite ESPs during interactions and reveals the intricate cellular responses that can explain disease mechanisms and attenuated inflammatory responses during giardiasis. PMID:29228011

Cost-effectiveness analysis of malaria rapid diagnostic test incentive schemes for informal private healthcare providers in Myanmar.

PubMed

Chen, Ingrid T; Aung, Tin; Thant, Hnin Nwe Nwe; Sudhinaraset, May; Kahn, James G

2015-02-05

The emergence of artemisinin-resistant Plasmodium falciparum parasites in Southeast Asia threatens global malaria control efforts. One strategy to counter this problem is a subsidy of malaria rapid diagnostic tests (RDTs) and artemisinin-based combination therapy (ACT) within the informal private sector, where the majority of malaria care in Myanmar is provided. A study in Myanmar evaluated the effectiveness of financial incentives vs information, education and counselling (IEC) in driving the proper use of subsidized malaria RDTs among informal private providers. This cost-effectiveness analysis compares intervention options. A decision tree was constructed in a spreadsheet to estimate the incremental cost-effectiveness ratios (ICERs) among four strategies: no intervention, simple subsidy, subsidy with financial incentives, and subsidy with IEC. Model inputs included programmatic costs (in dollars), malaria epidemiology and observed study outcomes. Data sources included expenditure records, study data and scientific literature. Model outcomes included the proportion of properly and improperly treated individuals with and without P. falciparum malaria, and associated disability-adjusted life years (DALYs). Results are reported as ICERs in US dollars per DALY averted. One-way sensitivity analysis assessed how outcomes depend on uncertainty in inputs. ICERs from the least to most expensive intervention are: $1,169/DALY averted for simple subsidy vs no intervention, $185/DALY averted for subsidy with financial incentives vs simple subsidy, and $200/DALY averted for a subsidy with IEC vs subsidy with financial incentives. Due to decreasing ICERs, each strategy was also compared to no intervention. The subsidy with IEC was the most favourable, costing $639/DALY averted compared with no intervention. One-way sensitivity analysis shows that ICERs are most affected by programme costs, RDT uptake, treatment-seeking behaviour, and the prevalence and virulence of non-malarial fevers. In conclusion, private provider subsidies with IEC or a combination of IEC and financial incentives may be a good investment for malaria control.

Deep learning and the electronic structure problem

NASA Astrophysics Data System (ADS)

Mills, Kyle; Spanner, Michael; Tamblyn, Isaac

In the past decade, the fields of artificial intelligence and computer vision have progressed remarkably. Supported by the enthusiasm of large tech companies, as well as significant hardware advances and the utilization of graphical processing units to accelerate computations, deep neural networks (DNN) are gaining momentum as a robust choice for many diverse machine learning applications. We have demonstrated the ability of a DNN to solve a quantum mechanical eigenvalue equation directly, without the need to compute a wavefunction, and without knowledge of the underlying physics. We have trained a convolutional neural network to predict the total energy of an electron in a confining, 2-dimensional electrostatic potential. We numerically solved the one-electron Schrödinger equation for millions of electrostatic potentials, and used this as training data for our neural network. Four classes of potentials were assessed: the canonical cases of the harmonic oscillator and infinite well, and two types of randomly generated potentials for which no analytic solution is known. We compare the performance of the neural network and consider how these results could lead to future advances in electronic structure theory.

Effects of protein conformational flexibilities and electrostatic interactions on the low-frequency vibrational spectrum of hydration water.

PubMed

Pal, Somedatta; Bandyopadhyay, Sanjoy

2013-05-16

The conformational flexibility of a protein and its ability to form hydrogen bonds with water are expected to influence the microscopic properties of water layer hydrating the protein. Detailed molecular dynamics simulations with an aqueous solution of the globular protein barstar have been carried out to explore such influence on the low-frequency vibrational spectrum of the hydration water molecules. The calculations reveal that enhanced degree of confinement at the protein surface on freezing its local motions leads to increasingly restricted oscillatory motions of the hydration water molecules as evident from larger blue shifts of the corresponding band. Interestingly, conformational fluctuations of the protein and electrostatic component of its interaction with the solvent have been found to affect the transverse and longitudinal oscillations of hydration water molecules in a nonuniform manner. It is further noticed that the distributions of the low-frequency modes for the water molecules hydrogen bonded to the residues of different segments of the protein are heterogeneously altered. The effect is more around the frozen protein matrix and agrees well with slower protein-water hydrogen bond relaxations.

Collision Models for Particle Orbit Code on SSX

NASA Astrophysics Data System (ADS)

Fisher, M. W.; Dandurand, D.; Gray, T.; Brown, M. R.; Lukin, V. S.

2011-10-01

Coulomb collision models are being developed and incorporated into the Hamiltonian particle pushing code (PPC) for applications to the Swarthmore Spheromak eXperiment (SSX). A Monte Carlo model based on that of Takizuka and Abe [JCP 25, 205 (1977)] performs binary collisions between test particles and thermal plasma field particles randomly drawn from a stationary Maxwellian distribution. A field-based electrostatic fluctuation model scatters particles from a spatially uniform random distribution of positive and negative spherical potentials generated throughout the plasma volume. The number, radii, and amplitude of these potentials are chosen to mimic the correct particle diffusion statistics without the use of random particle draws or collision frequencies. An electromagnetic fluctuating field model will be presented, if available. These numerical collision models will be benchmarked against known analytical solutions, including beam diffusion rates and Spitzer resistivity, as well as each other. The resulting collisional particle orbit models will be used to simulate particle collection with electrostatic probes in the SSX wind tunnel, as well as particle confinement in typical SSX fields. This work has been supported by US DOE, NSF and ONR.

The standards process: X3 information processing systems

NASA Technical Reports Server (NTRS)

Emard, Jean-Paul

1993-01-01

The topics are presented in viewgraph form and include the following: International Organization for Standards (ISO); International Electrotechnical Committee (IEC); ISO/IEC Joint Technical Committee 1 (JTC-1); U.S. interface to JTC-1; ANSI; national organizations; U.S. standards development processes; national and international standards developing organizations; regional organizations; and X3 information processing systems.

How IECs Fit into the Counseling Puzzle

ERIC Educational Resources Information Center

Brown, Andy

2017-01-01

Independent educational consultants (IECs) are rapidly becoming a regular part of the college search and admission process as students search for the right fit. Although the cost of going to college has risen sharply in recent years, the cost of hiring a consultant hasn't gone up nearly so quickly. Families are beginning to see consulting as…

46 CFR 111.01-9 - Degrees of protection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (both incorporated by reference; see 46 CFR 110.10-1) IP 22 degree of protection as appropriate for the... control enclosures must be manufactured to at least NEMA 250 Type 2 or IEC 60529 IP 22 degree of... protection must be manufactured to at least NEMA 250 Type 1 with dripshield or IEC 60529 IP 11 as specified...

46 CFR 111.01-9 - Degrees of protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (both incorporated by reference; see 46 CFR 110.10-1) IP 22 degree of protection as appropriate for the... control enclosures must be manufactured to at least NEMA 250 Type 2 or IEC 60529 IP 22 degree of... protection must be manufactured to at least NEMA 250 Type 1 with dripshield or IEC 60529 IP 11 as specified...

76 FR 58345 - Energy Conservation Program: Test Procedures for Residential Dishwashers, Dehumidifiers, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-20

...Where appropriate, the U.S. Department of Energy (DOE) has proposed to amend its test procedures for residential dishwashers, dehumidifiers, and conventional cooking products (which includes cooktops, ovens, and ranges) to include provisions for measuring standby mode and off mode energy consumption, as required by the Energy Independence and Security Act of 2007 (EISA 2007). These test procedure amendments would incorporate by reference certain provisions of the International Electrotechnical Commission (IEC) Standard 62301, ``Household electrical appliances--Measurement of standby power.'' Since publication of DOE's initial proposal in December 2010, the IEC has replaced the First Edition of this standard with the current Second Edition. This supplemental notice of proposed rulemaking proposes to incorporate the latest edition of IEC Standard 62301.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santos, Rick; van Dam, Jeroen

The objective of the test was to obtain a baseline characterization of the mechanical loads of the DOE 1.5 wind turbine located at NREL. The test was conducted in accordance with the International Electrotechnical Commission (IEC) Technical Specification, IEC 61400-13 Wind Turbine Generator Systems – Part 13: Measurement of mechanical loads; First Edition 2001-06 [1]. The National Wind Technology Center (NWTC) at NREL conducted this test in accordance with its quality system procedures so that the final test report meets the full requirements of its accreditation by the American Association for Laboratory Accreditation (A2LA). NREL’s quality system requires that allmore » applicable requirements specified by A2LA and International Standards Organization/IEC 17025 be met or to note any exceptions in the test report.« less

Justice in jeopardy: a qualitative study of institutional ethics committees in New Delhi.

PubMed

Kandhari, Rohini

2013-01-01

Protecting the safety and welfare of clinical trial subjects is the primary responsibility of the multidisciplinary ethics committee. In India, ethics committees have come under increasing criticism for functioning as "secret societies unaccountable to the public" (1). Yet, little effort has been made to undertake qualitative research on the ethics review bodies. This article describes the essential findings of a study that aimed at providing an insight into the structure and functioning of institutional ethics committees (IECs) in selected hospitals in Delhi. Importantly, the study also attempted to investigate the challenges faced by IEC members that pose barriers to IEC performance and thus jeopardise a just and effective system of protection for the human trial subject.

Tailoring ISO/IEC 27001 for SMEs: A Guide to Implement an Information Security Management System in Small Settings

NASA Astrophysics Data System (ADS)

Valdevit, Thierry; Mayer, Nicolas; Barafort, Béatrix

While Information Security Management Systems (ISMS) are being adopted by the biggest IT companies, it remains quite difficult for smaller entities to implement and maintain all the requirements of ISO/IEC 27001. In order to increase information security in Luxembourg, the Public Research Centre Henri Tudor has been charged by the Luxembourg Ministry of Economy and Foreign Trade to find solutions to facilitate ISMS deployment for SMEs. After an initial experiment aiming at assisting a SME in getting the first national ISO/IEC 27001 certification for a private company, an implementation guide for deploying an ISMS, validated by local experts and experimented in SMEs, has been released and is presented in this paper.

Optimized anion exchange membranes for vanadium redox flow batteries.

PubMed

Chen, Dongyang; Hickner, Michael A; Agar, Ertan; Kumbur, E Caglan

2013-08-14

In order to understand the properties of low vanadium permeability anion exchange membranes for vanadium redox flow batteries (VRFBs), quaternary ammonium functionalized Radel (QA-Radel) membranes with three ion exchange capacities (IECs) from 1.7 to 2.4 mequiv g(-1) were synthesized and 55-60 μm thick membrane samples were evaluated for their transport properties and in-cell battery performance. The ionic conductivity and vanadium permeability of the membranes were investigated and correlated to the battery performance through measurements of Coulombic efficiency, voltage efficiency and energy efficiency in single cell tests, and capacity fade during cycling. Increasing the IEC of the QA-Radel membranes increased both the ionic conductivity and VO(2+) permeability. The 1.7 mequiv g(-1) IEC QA-Radel had the highest Coulombic efficiency and best cycling capacity maintenance in the VRFB, while the cell's voltage efficiency was limited by the membrane's low ionic conductivity. Increasing the IEC resulted in higher voltage efficiency for the 2.0 and 2.4 mequiv g(-1) samples, but the cells with these membranes displayed reduced Coulombic efficiency and faster capacity fade. The QA-Radel with an IEC of 2.0 mequiv g(-1) had the best balance of ionic conductivity and VO(2+) permeability, achieving a maximum power density of 218 mW cm(-2) which was higher than the maximum power density of a VRFB assembled with a Nafion N212 membrane in our system. While anion exchange membranes are under study for a variety of VRFB applications, this work demonstrates that the material parameters must be optimized to obtain the maximum cell performance.

Six-year activity on approval of compassionate use of medicines by the Ethics Committee of the University Hospital of Bologna (Italy): time to update rules and recommendations.

PubMed

Montanaro, Nicola; Melis, Mauro; Proni, Stefania; Chiabrando, Giacomo; Motola, Domenico

2017-04-01

Compassionate use of forthcoming drugs has become an increasing pathway through which patients can take advantage of promising medicines. We aimed to analyse the main features of the requests of compassionate use submitted to the Independent Ethics Committee (IEC) of the University Hospital of Bologna in the period 2010-2015. The present analysis concerns the requests of compassionate use received by the IEC in the period 2010-2015. For each requested drug, we paired the date of the first request to our IEC with the date(s) of (a) submission to EMA, (b) CHMP positive opinion, and (c) European marketing authorization (if issued). In the period 2010-2015, our IEC received compassionate use requests for 610 patients. Most of the requests concerned patients suffering from solid or haematological cancers not responsive to first or second line of treatment. Sixty-five couples of medicine/clinical condition (corresponding to 56 individual medicines) were submitted to our IEC, and 62 of them regarded products following the centralised procedure at the EMA. Twenty-one out of the latter (34%) had already obtained CHMP positive opinion. Our results indicate that compassionate use of forthcoming medicines represents a not negligible portion of the therapies utilized in hospital care. The observed large resort to medicines still on trial may suggest that doctors are more aware with the potential benefits of the new drugs. However, this trend may also indicate an increasing marketing activity of the pharmaceutical industry, addressing to get the clinicians used to the upcoming medicines.

Activities of the task group 8 on thin film PV module reliability (Conference Presentation)

NASA Astrophysics Data System (ADS)

Dhere, Neelkanth G.

2016-09-01

Photovoltaic (PV) modules and systems are being used increasingly to provide renewable energy to schools, residences, small businesses and utilities. At this time, the home owners and small businesses have considerable difficulty in detecting module and/or system degradation and especially enforcing warranty. It needs to be noted that IEC 61215-1 (test req.), -2 (test proc.) and -1-1 (c-Si) are forecasted to be circulated end of Feb 2016 and only editorial changes would be possible. 61215 series does include thin film technologies and would be replacing 61646. Moreover, IEC 61215-1, section 7.2 power output and electric circuitry does contain significant changes to acceptance criteria regarding rated label values, particularly rated power. Even though it is believed that consensus could be achieved within IEC TC82 WG2, some of the smaller players that do not participate actively in IEC TC82 - may not be surprised and must be informed. The other tech specific parts 61215-1-2 (CdTe), -1-3 (a-Si, µc-Si) and -1-4 (CIS, CIGS) are out for comments. The IEC closing date was January 29, 2016. The additions alternative damp heat (DH) test proposed Solar Frontier is being reviewed. In the past, only 600 V systems were permitted in the grid-connected residential and commercial systems in the US. The US commercial systems can now use higher voltage (1,000-1500V) in order to reduce BOS component costs. It is believed that there would not be any problems. The Task Group 8 is collecting data on higher voltage systems.

Teaching and Evaluating Instructor Effectiveness Using the Instructor Effectiveness Questionnaire and the Instructor Effectiveness Check Sheet Combination

ERIC Educational Resources Information Center

Phipps, Maurice L.; Hayashi, Aya; Lewandowski, April; Padgett, Allison H.

2005-01-01

This article describes the use of two linked instruments, the Instructor Effectiveness Check Sheet (IEC) and Instructor Effectiveness Questionnaire (IEQ). The use of an evaluation instrument during a course can enable improvements to be made--even with experienced instructors. Detail can be taken from the IEC and IEQ to find obvious and not so…

78 FR 47712 - Food and Drug Administration Modernization Act of 1997: Modifications to the List of Recognized...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-06

... Application of risk management for IT networks IEC 80001-1 Edition 1.0 2010- incorporating medical devices--Part 1: Roles, 10 responsibilities and activities. 13-39 Application of risk management for IT networks... activities. 13-40 Application of risk management for IT networks IEC/TR 80001-2-1 Edition 1.0 incorporating...

Comparison of the identification and ease of use of two alarm sound sets by critical and acute care nurses with little or no music training: a laboratory study.

PubMed

Atyeo, J; Sanderson, P M

2015-07-01

The melodic alarm sound set for medical electrical equipment that was recommended in the International Electrotechnical Commission's IEC 60601-1-8 standard has proven difficult for clinicians to learn and remember, especially clinicians with little prior formal music training. An alarm sound set proposed by Patterson and Edworthy in 1986 might improve performance for such participants. In this study, 31 critical and acute care nurses with less than one year of formal music training identified alarm sounds while they calculated drug dosages. Sixteen nurses used the IEC and 15 used the Patterson-Edworthy alarm sound set. The mean (SD) percentage of alarms correctly identified by nurses was 51.3 (25.6)% for the IEC alarm set and 72.1 (18.8)% for the Patterson-Edworthy alarms (p = 0.016). Nurses using the Patterson-Edworthy alarm sound set reported that it was easier to distinguish between alarm sounds than did nurses using the IEC alarm sound set (p = 0.015). Principles used to construct the Patterson-Edworthy alarm sounds should be adopted for future alarm sound sets. © 2015 The Association of Anaesthetists of Great Britain and Ireland.

Protective effects of essential oil of Citrus limon against aspirin-induced toxicity in IEC-6 cells.

PubMed

Bouzenna, Hafsia; Hfaiedh, Najla; Giroux-Metges, Marie-Agnès; Elfeki, Abdelfattah; Talarmin, Hélène

2017-05-01

Aspirin, one of the widely used nonsteroidal anti-inflammatory drugs, is the most highly consumed pharmaceutical product in the world. However, it has several side effects in cells. This study was designed to investigate the antioxidative activity and cytoprotective effects of essential oil of Citrus limon (EOC) extracted from leaves against aspirin-induced damages in the rat small intestine epithelial cells (IEC-6). Biochemical indicators were used to assess cytotoxicity and oxidative damages caused by aspirin treatment on IEC-6. Our results showed that the chemical characterization of EOC identified 25 compounds representing 98.19% of the total oil. The major compounds from this oil were z-citral (53.21%), neryl acetate (13.06%), geranyl acetate (10.33%), and limonene (4.23%). Aspirin induced a decrease in cell viability as well as an increase in superoxide dismutase (SOD) and catalase (CAT) activities. Contrariwise, the co-exposure of cells to aspirin and EOC alleviated every above syndrome by an increase in cell survival and decrease in SOD and CAT activities. In conclusion, the essential oil of C. limon has a potent cytoprotective effect against aspirin-induced toxicity in IEC-6 cells.

Development of ion-exchange collectors for monitoring atmospheric deposition of inorganic pollutants in Alaska parklands

USGS Publications Warehouse

Brumbaugh, William G.; Arms, Jesse W.; Linder, Greg L.; Melton, Vanessa D.

2016-09-19

Between 2010 and 2014, the U.S. Geological Survey completed a series of laboratory and field experiments designed to develop methodology to support the National Park Service’s long-term atmospheric pollutant monitoring efforts in parklands of Arctic Alaska. The goals of this research were to develop passive sampling methods that could be used for long-term monitoring of inorganic pollutants in remote areas of arctic parklands and characterize relations between wet and dry deposition of atmospheric pollutants to that of concentrations accumulated by mosses, specifically the stair-step, splendid feather moss, Hylocomium splendens. Mosses and lichens have been used by National Park Service managers as atmospheric pollutant biomonitors since about 1990; however, additional research is needed to better characterize the dynamics of moss bioaccumulation for various classes of atmospheric pollutants. To meet these research goals, the U.S. Geological Survey investigated the use of passive ionexchange collectors (IECs) that were adapted from the design of Fenn and others (2004). Using a modified IEC configuration, mulitple experiments were completed that included the following: (a) preliminary laboratory and development testing of IECs, (b) pilot-scale validation field studies during 2012 with IECs at sites with instrumental monitoring stations, and (c) deployment of IECs in 2014 at sites in Alaska having known or suspected regional sources of atmospheric pollutants where samples of Hylocomium splendens moss also could be collected for comparison. The targeted substances primarily included ammonium, nitrate, and sulfate ions, and certain toxicologically important trace metals, including cadmium, cobalt, copper, nickel, lead, and zinc.Deposition of atmospheric pollutants is comparatively low throughout most of Alaska; consequently, modifications of the original IEC design were needed. The most notable modification was conversion from a single-stage mixed-bed column to a two-stage arrangement. With the modified IEC design, ammonium, nitrate, and sulfate ions were determined with a precision of between 5 and 10 percent relative standard deviation for the low loads that happen in remote areas of Alaska. Results from 2012 field studies demonstrated that the targeted ions were stable and fully retained on the IEC during field deployment and could be fully recovered by extraction in the laboratory. Importantly, measurements of annual loads determined by combining snowpack and IEC sampling at sites near National Atmospheric Deposition Program monitoring stations was comparable to results obtained by the National Atmospheric Deposition Program.Field studies completed in 2014 included snowpack and IEC samples to measure depositional loads; the results were compared to concentrations of similar substances in co-located moss samples. Analyses of constituents in snow and IECs included ammonium, nitrate, and sulfate ions; and a suite of trace metals. Constituent measurements in Hylocomium splendens moss included total nitrogen, phosphorous, and sulfur, and trace metals. To recover ammonium ions and metal ions from the upper cation-exchange column, a two-step extraction procedure was developed from laboratory spiking experiments. The 2014 studies determined that concentrations of certain metals, nitrogen, and sulfur in tissues of Hylocomium splendens moss reflected differences in presumptive deposition from local atmospheric sources. Moss tissues collected from two sites farthest from urban locales had the lowest levels of total nitrogen and sulfur, whereas tissues collected from three of the urban sites had the greatest concentrations of many of the trace metals. Moss tissue concentrations of three trace metals (cobalt, chromium, and nickel) were strongly (positively) Spearman’s rank correlated (p<0.05) with annual depositional loads of those metals. In addition, moss sulfur concentrations were positively rank correlated with annual depositional loads of sulfate (p<0.07). Exploratory models indicated linear uptake of the three metals by Hylocomium splendens moss and nonlinear uptake of sulfur from sulfate.Our results provided useful preliminary models for several of the targeted substances; however, our ability to characterize relations between concentrations in moss and loadings for many of the metals was precluded by several factors. The few test sites, small concentration gradients, and generally low concentrations hampered model developments. In addition, the weather was unusually warm throughout Alaska during the winter of 2013–14, which caused intermittent melting of the snowpack at some of the test sites; consequently, our measurements of overwinter loads based on snowpack samples (obtained in late March) probably underestimated the actual loads. Regardless of these potential limitations, these studies have established a foundation to support further studies that can improve our understanding of how mosses accumulate inorganic substances and ultimately how mosses might be used as biomonitors of atmospheric pollutants; moreover, the successful development and validation of the IECs during this research documents how the methodology can be used for future monitoring efforts in remote regions of Alaska and elsewhere.

Numerical simulations of gas mixing effect in electron cyclotron resonance ion sources

NASA Astrophysics Data System (ADS)

Mironov, V.; Bogomolov, S.; Bondarchenko, A.; Efremov, A.; Loginov, V.

2017-01-01

The particle-in-cell Monte Carlo collisions code nam-ecris is used to simulate the electron cyclotron resonance ion source (ECRIS) plasma sustained in a mixture of Kr with O2 , N2 , Ar, Ne, and He. The model assumes that ions are electrostatically confined in the ECR zone by a dip in the plasma potential. A gain in the extracted krypton ion currents is seen for the highest charge states; the gain is maximized when oxygen is used as a mixing gas. The special feature of oxygen is that most of the singly charged oxygen ions are produced after the dissociative ionization of oxygen molecules with a large kinetic energy release of around 5 eV per ion. The increased loss rate of energetic lowly charged ions of the mixing element requires a building up of the retarding potential barrier close to the ECR surface to equilibrate electron and ion losses out of the plasma. In the mixed plasmas, the barrier value is large (˜1 V ) compared to pure Kr plasma (˜0.01 V ), with longer confinement times of krypton ions and with much higher ion temperatures. The temperature of the krypton ions is increased because of extra heating by the energetic oxygen ions and a longer time of ion confinement. In calculations, a drop of the highly charged ion currents of lighter elements is observed when adding small fluxes of krypton into the source. This drop is caused by the accumulation of the krypton ions inside plasma, which decreases the electron and ion confinement times.

A Low-cost, Lightweight, and Miniaturized Time-of-flight Mass Spectrometer (TOFMS)

NASA Technical Reports Server (NTRS)

Srivastava, S. K.

1993-01-01

Time-of-flight mass spectrometers (TOFMS) are commonly used for mass analysis and for the measurement of energy distributions of charged particles. For achieving high mass and energy resolution these instruments generally comprise long flight tubes, often as long as a few meters. This necessitates high voltages and a very clean environment. These requirements make them bulky and heavy. We have developed an instrument and calibration techniques that are based on the design principles of TOFMS. However, instead of one long flight tube it consists of a series of cylindrical electrostatic lenses that confine ions under study along the axis of the flight tube.

An effect of nuclear electric quadrupole moments in thermonuclear fusion plasmas

NASA Technical Reports Server (NTRS)

De, B. R.; Srnka, L. J.

1978-01-01

Consideration of the nuclear electric quadrupole terms in the expression for the fusion Coulomb barrier suggests that this electrostatic barrier may be substantially modified from that calculated under the usual plasma assumption that the nuclei are electric monopoles. This effect is a result of the nonspherical potential shape and the spatial quantization of the nuclear spins of the fully stripped ions in the presence of a magnetic field. For monopole-quadrupole fuel cycles like p-B-11, the fusion cross-section may be substantially increased at low energies if the protons are injected at a small angle relative to the confining magnetic field.

Identification of Essential Sensitive Regions of the Aerolysin Nanopore for Single Oligonucleotide Analysis.

PubMed

Wang, Ya-Qian; Li, Meng-Yin; Qiu, Hu; Cao, Chan; Wang, Ming-Bo; Wu, Xue-Yuan; Huang, Jin; Ying, Yi-Lun; Long, Yi-Tao

2018-06-11

The aerolysin nanopore channel is one of the confined spaces for single molecule analysis which displays high spatial and temporal resolution for the discrimination of single nucleotides, identification of DNA base modification, and analyzing the structural transition of DNAs. However, to overcome the challenge of achieving the ultimate goal of the widespread real analytical application, it is urgent to probe the sensing regions of the aerolysin to further improve the sensitivity. In this paper, we explore the sensing regions of the aerolysin nanopore by a series of well-designed mutant nanopore experiments combined with molecular dynamics simulations-based electrostatic analysis. The positively charged lumen-exposed Lys-238, identified as one of the key sensing sites due to the presence of a deep valley in the electrostatic potentials, was replaced by different charged and sized amino acids. The results show that the translocation time of oligonucleotides through the nanopore can be readily modulated by the choice of the target amino acid at the 238 site. In particular, a 7-fold slower translocation at a voltage bias of +120 mV is observed with respect to the wild-type aerolysin, which provides a high resolution for methylated cytosine discrimination. We further determine that both the electrostatic properties and geometrical structure of the aerolysin nanopore are crucial to its sensing ability. These insights open ways for rationally designing the sensing mechanism of the aerolysin nanopore, thus providing a novel paradigm for nanopore sensing.

Iron translocation into and out of Listeria innocua Dps and size distribution of the protein-enclosed nanomineral are modulated by the electrostatic gradient at the 3-fold "ferritin-like" pores.

PubMed

Bellapadrona, Giuliano; Stefanini, Simonetta; Zamparelli, Carlotta; Theil, Elizabeth C; Chiancone, Emilia

2009-07-10

Elucidating pore function at the 3-fold channels of 12-subunit, microbial Dps proteins is important in understanding their role in the management of iron/hydrogen peroxide. The Dps pores are called "ferritin-like" because of the structural resemblance to the 3-fold channels of 24-subunit ferritins used for iron entry and exit to and from the protein cage. In ferritins, negatively charged residues lining the pores generate a negative electrostatic gradient that guides iron ions toward the ferroxidase centers for catalysis with oxidant and destined for the mineralization cavity. To establish whether the set of three aspartate residues that line the pores in Listeria innocua Dps act in a similar fashion, D121N, D126N, D130N, and D121N/D126N/D130N proteins were produced; kinetics of iron uptake/release and the size distribution of the iron mineral in the protein cavity were compared. The results, discussed in the framework of crystal growth in a confined space, indicate that iron uses the hydrophilic 3-fold pores to traverse the protein shell. For the first time, the strength of the electrostatic potential is observed to modulate kinetic cooperativity in the iron uptake/release processes and accordingly the size distribution of the microcrystalline iron minerals in the Dps protein population.

10 CFR Appendix A to Subpart B of... - Policy Statement for Electric Motors Covered Under the Energy Policy and Conservation Act

Code of Federal Regulations, 2011 CFR

2011-01-01

... with NEMA Design A or B characteristics, or equivalent designs such as IEC Design N (IEC); and (8... design for use at variable speeds. However, NEMA Design A or B motors that are single speed, meet all... single-speed induction motor, built in a two-digit frame number series in accordance with NEMA Standards...

10 CFR Appendix A to Subpart B of... - Policy Statement for Electric Motors Covered Under the Energy Policy and Conservation Act

Code of Federal Regulations, 2012 CFR

2012-01-01

... with NEMA Design A or B characteristics, or equivalent designs such as IEC Design N (IEC); and (8... design for use at variable speeds. However, NEMA Design A or B motors that are single speed, meet all... single-speed induction motor, built in a two-digit frame number series in accordance with NEMA Standards...

Air Force Space Command. Space and Missile Systems Center Standard. Configuration Management

DTIC Science & Technology

2008-06-13

Aerospace Corporation report number TOR-2006( 8583 )-1. 3. Beneficial comments (recommendations, additions, deletions) and any pertinent data that...Engineering Drawing Practices IEEE STD 610.12 Glossary of Software Engineering Terminology, September 28,1990 ISO /IEC 12207 Software Life...item, regardless of media, formally designated and fixed at a specific time during the configuration item’s life cycle. (Source: ISO /IEC 12207

The Quality Adaptation Model: Adaptation and Adoption of the Quality Standard ISO/IEC 19796-1 for Learning, Education, and Training

ERIC Educational Resources Information Center

Pawlowski, Jan M.

2007-01-01

In 2005, the new quality standard for learning, education, and training, ISO/IEC 19796-1, was published. Its purpose is to help educational organizations to develop quality systems and to improve the quality of their processes, products, and services. In this article, the standard is presented and compared to existing approaches, showing the…

Type I and Type III Interferons Display Different Dependency on Mitogen-Activated Protein Kinases to Mount an Antiviral State in the Human Gut.

PubMed

Pervolaraki, Kalliopi; Stanifer, Megan L; Münchau, Stephanie; Renn, Lynnsey A; Albrecht, Dorothee; Kurzhals, Stefan; Senís, Elena; Grimm, Dirk; Schröder-Braunstein, Jutta; Rabin, Ronald L; Boulant, Steeve

2017-01-01

Intestinal epithelial cells (IECs) are constantly exposed to commensal flora and pathogen challenges. How IECs regulate their innate immune response to maintain gut homeostasis remains unclear. Interferons (IFNs) are cytokines produced during infections. While type I IFN receptors are ubiquitously expressed, type III IFN receptors are expressed only on epithelial cells. This epithelium specificity strongly suggests exclusive functions at epithelial surfaces, but the relative roles of type I and III IFNs in the establishment of an antiviral innate immune response in human IECs are not clearly defined. Here, we used mini-gut organoids to define the functions of types I and III IFNs to protect the human gut against viral infection. We show that primary non-transformed human IECs, upon viral challenge, upregulate the expression of both type I and type III IFNs at the transcriptional level but only secrete type III IFN in the supernatant. However, human IECs respond to both type I and type III IFNs by producing IFN-stimulated genes that in turn induce an antiviral state. Using genetic ablation of either type I or type III IFN receptors, we show that either IFN can independently restrict virus infection in human IECs. Importantly, we report, for the first time, differences in the mechanisms by which each IFN establishes the antiviral state. Contrary to type I IFN, the antiviral activity induced by type III IFN is strongly dependent on the mitogen-activated protein kinases signaling pathway, suggesting a pathway used by type III IFNs that non-redundantly contributes to the antiviral state. In conclusion, we demonstrate that human intestinal epithelial cells specifically regulate their innate immune response favoring type III IFN-mediated signaling, which allows for efficient protection against pathogens without producing excessive inflammation. Our results strongly suggest that type III IFN constitutes the frontline of antiviral response in the human gut. We propose that mucosal surfaces, particularly the gastrointestinal tract, have evolved to favor type III IFN-mediated response to pathogen infections as it allows for spatial segregation of signaling and moderate production of inflammatory signals which we propose are key to maintain gut homeostasis.

Long-term impact of community-based information, education and communication activities on food hygiene and food safety behaviors in Vietnam: a longitudinal study.

PubMed

Takanashi, Kumiko; Quyen, Dao To; Le Hoa, Nguyen Thi; Khan, Nguyen Cong; Yasuoka, Junko; Jimba, Masamine

2013-01-01

Ingestion of contaminated water or food is a major contributor to childhood diarrhea in developing countries. In Vietnam, the use of community-based information, education and communication (IEC) activities could be a sustainable strategy to improve food hygiene and food safety behaviors. This study thus examined the long-term impact of community-based IEC activities on food hygiene and food safety behaviors. In this longitudinal study, we interviewed caregivers of children aged between six months and four years in suburban Hanoi. Baseline data were collected in January 2006 (n = 125). After conducting IEC interventions, we collected a 1(st) set of evaluation data in January 2007 (n = 132). To examine the long-term impact of the interventions, we then collected a 2(nd) set of evaluation data in January 2008 (n = 185). Changes in childhood diarrhea prevalence, IEC coverage, and food hygiene and food safety behaviors were assessed over a two-year period using bivariate and logistic regression analyses. Effective IEC channels were determined through multiple linear regression analysis. Childhood diarrhea was significantly reduced from 21.6% at baseline to 7.6% at the 1(st) post-intervention evaluation (P = 0.002), and to 5.9% at the 2(nd) evaluation. Among 17 food hygiene and food safety behaviors measured, a total of 11 behaviors were improved or maintained by the 2(nd) evaluation. Handwashing after toilet use was significantly improved at both evaluation points. Overall, 3 food safety behaviors and 7 food hygiene behaviors were found to have significantly improved at the 1(st) and at the 2(nd) evaluations, respectively. Flip chart communication administered by community groups was identified to be the most effective IEC channel for effecting behavior change (P = 0.018). Flip chart communication administered by community groups is effective for improving multiple food hygiene and food safety behaviors in sustainable ways, and should be included in water and health promotion programs.

NIMROD Simulations of Spheromak Formation, Magnetic Reconnection and Energy Confinement in SSPX

NASA Astrophysics Data System (ADS)

Hooper, E. B.; Sovinec, C. R.

2005-10-01

The SSPX spheromak is formed and driven by a coaxial electrostatic gun that injects current and magnetic flux. Magnetic fluctuations are associated with the conversion of toroidal to poloidal magnetic flux during formation. After formation, fluctuations that break axisymmetry degrade magnetic surfaces, and are anti-correlated with the core temperature and energy confinement time. We report NIMROD simulations extending earlier work^1 supporting the SSPX experiment through predictions of performance and providing insight. The simulations are in fairly good agreement with features observed in SSPX and underscore the importance of current profile control in mitigating magnetic fluctuation amplitudes and improving confinement. The simulations yield insight into magnetic reconnection and the relationship of fluctuations to field line stochasticity. We have added external circuit equations for the new 32 module capacitor bank in SSPX that will add flexibility in shaping the injector current pulses and substantially increase the injected currents and the magnetic energy. New NIMROD simulations of SSPX lead to higher temperature plasmas than in previous simulations. *Work supported by U.S. DOE, under Contr. No. W-7405-ENG-48 at U. Cal. LLNL and under grant FG02-01ER54661 at U. Wisc Madison. ^1C. R. Sovinec, B. I. Cohen, et al., Phys. Rev. Lett. 94, 035003 (2005); B. I. Cohen, E. B. Hooper, et al., Phys. Plasmas 12, 056106 (2005).

Luminal-Applied Flagellin Is Internalized by Polarized Intestinal Epithelial Cells and Elicits Immune Responses via the TLR5 Dependent Mechanism

PubMed Central

Eaves-Pyles, Tonyia; Bu, Heng-Fu; Tan, Xiao-di; Cong, Yingzi; Patel, Jignesh; Davey, Robert A.; Strasser, Jane E.

2011-01-01

Bacteria release flagellin that elicits innate responses via Toll-like receptor 5 (TLR5). Here, we investigated the fate of apically administrated full length flagellin from virulent and avirulent bacteria, along with truncated recombinant flagellin proteins in intestinal epithelial cells and cellular responses. Flagellin was internalized by intestinal epithelial cell (IEC) monolayers of IEC-18. Additionally, apically applied flagellin was internalized by polarized human Caco-2BBe and T-84 cells in a TLR5 dependent mechanism. More, flagellin exposure did not affect the integrity of intestinal monolayers. With immunofluorescent staining, internalized flagellin was detected in both early endosomes as well as lysosomes. We found that apical exposure of polarized Caco-2BBe and T-84 to flagellin from purified Salmonella, Escherichia coli O83:H1 (isolate from Crohn’s lesion) or avirulent E. coli K12 induced comparable levels of basolateral IL-8 secretion. A recombinant protein representing the conserved amino (N) and carboxyl (C) domains (D) of the flagellin protein (ND1/2ECHCD2/1) induced IL-8 secretion from IEC similar to levels elicited by full-length flagellins. However, a recombinant flagellin protein containing only the D3 hypervariable region elicited no IL-8 secretion in both cell lines compared to un-stimulated controls. Silencing or blocking TLR5 in Caco-2BBe cells resulted in a lack of flagellin internalization and decreased IL-8 secretion. Furthermore, apical exposure to flagellin stimulated transepithelial migration of neutrophils and dendritic cells. The novel findings in this study show that luminal-applied flagellin is internalized by normal IEC via TLR5 and co-localizes to endosomal and lysosomal compartments where it is likely degraded as flagellin was not detected on the basolateral side of IEC cultures. PMID:21949773

Hes1 promotes the IL-22-mediated antimicrobial response by enhancing STAT3-dependent transcription in human intestinal epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murano, Tatsuro; Okamoto, Ryuichi, E-mail: rokamoto.gast@tmd.ac.jp; Department of Advanced GI Therapeutics, Graduate School, Tokyo Medical and Dental University, Tokyo

Highlights: •Hes1 enhances IL-22-STAT3 signaling in human intestinal epithelial cells. •Hes1 enhances REG family gene induction by IL-22-STAT3 signaling. •Protein level of Hes1 restricts the response to IL-22. •Present regulation of a cytokine signal represents a new mode of Hes1 function. -- Abstract: Notch signaling plays an essential role in the proliferation and differentiation of intestinal epithelial cells (IECs). We have previously shown that Notch signaling is up-regulated in the inflamed mucosa of ulcerative colitis (UC) and thereby plays an indispensable role in tissue regeneration. Here we show that in addition to Notch signaling, STAT3 signaling is highly activated inmore » the inflamed mucosa of UC. Forced expression of the Notch target gene Hes1 dramatically enhanced the IL-22-mediated STAT3-dependent transcription in human IECs. This enhancement of STAT3-dependent transcription was achieved by the extended phosphorylation of STAT3 by Hes1. Microarray analysis revealed that Hes1-mediated enhancement of IL-22-STAT3 signaling significantly increased the induction of genes encoding antimicrobial peptides, such as REG1A, REG3A and REG3G, in human IECs. Conversely, the reduction of Hes1 protein levels with a γ-secretase inhibitor significantly down-regulated the induction of those genes in IECs, resulting in a markedly poor response to IL-22. Our present findings identify a new role for the molecular function of Hes1 in which the protein can interact with cytokine signals and regulate the immune response of IECs.« less

Curcumin improves intestinal barrier function: modulation of intracellular signaling, and organization of tight junctions.

PubMed

Wang, Jing; Ghosh, Siddhartha S; Ghosh, Shobha

2017-04-01

Association between circulating lipopolysaccharide (LPS) and metabolic diseases (such as type 2 diabetes and atherosclerosis) has shifted the focus from high-fat high-cholesterol containing Western-type diet (WD)-induced changes in gut microbiota per se to release of gut bacteria-derived products (e.g., LPS) into circulation due to intestinal barrier dysfunction as the possible mechanism for the chronic inflammatory state underlying the development of these diseases. We demonstrated earlier that oral supplementation with curcumin attenuates WD-induced development of type 2 diabetes and atherosclerosis. Poor bioavailability of curcumin has precluded the establishment of a causal relationship between oral supplementation and it is in vivo effects. We hypothesized that curcumin attenuates WD-induced chronic inflammation and associated metabolic diseases by modulating the function of intestinal epithelial cells (IECs) and the intestinal barrier function. The objective of the present study was to delineate the underlying mechanisms. The human IEC lines Caco-2 and HT-29 were used for these studies and modulation of direct as well as indirect effects of LPS on intracellular signaling as well as tight junctions were examined. Pretreatment with curcumin significantly attenuated LPS-induced secretion of master cytokine IL-1β from IECs and macrophages. Furthermore, curcumin also reduced IL-1β-induced activation of p38 MAPK in IECs and subsequent increase in expression of myosin light chain kinase involved in the phosphorylation of tight junction proteins and ensuing disruption of their normal arrangement. The major site of action of curcumin is, therefore, likely the IECs and the intestinal barrier, and by reducing intestinal barrier dysfunction, curcumin modulates chronic inflammatory diseases despite poor bioavailability. Copyright © 2017 the American Physiological Society.

Anomalous fluxes in the plateau regime for a weakly turbulent, magnetically confined plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balescu, R.

1990-09-01

The anomalous particle and heat fluxes, together with the parallel electric current, are determined for a confined plasma in the plateau regime in the presence of weak electrostatic drift-wave turbulence. Proper account is taken of nonstationarity and of the finite ion Larmor radius (FLR). The quasineutrality of the drift-wave fluctuations imposes a consistency condition, by which the evaluation of the anomalous fluxes is closely related to the drift-wave dispersion equation. On the other hand, these fluxes are related to the thermodynamic forces via the poloidal fluxes. For the weak turbulence approximation considered here, a unified formulation of the anomalous transportmore » problem has been obtained, including all aspects of neoclassical theory. The complete set of transport coefficients is calculated and various relations between them are exhibited. It clearly appears, for instance, that the anomalous ion heat flux is a pure FLR effect that vanishes as the Larmor radius goes to zero. The Onsager symmetry is broken for anomalous transport. The Appendix is devoted to a general discussion of the concept of heat flux in turbulent plasmas.« less

3D Localized Trions in Monolayer WSe2 in a Charge Tunable van der Waals Heterostructure.

PubMed

Chakraborty, Chitraleema; Qiu, Liangyu; Konthasinghe, Kumarasiri; Mukherjee, Arunabh; Dhara, Sajal; Vamivakas, Nick

2018-05-09

Monolayer transition metal dichalcogenides (TMDCs) have recently emerged as a host material for localized optically active quantum emitters that generate single photons. (1-5) Here, we investigate fully localized excitons and trions from such TMDC quantum emitters embedded in a van der Waals heterostructure. We use direct electrostatic doping through the vertical heterostructure device assembly to generate quantum confined trions. Distinct spectral jumps as a function of applied voltage bias, and excitation power-dependent charging, demonstrate the observation of the two different excitonic complexes. We also observe a reduction of the intervalley electron-hole exchange interaction in the confined trion due to the addition of an extra electron, which is manifested by a decrease in its fine structure splitting. We further confirm this decrease of exchange interaction for the case of the charged states by a comparative study of the circular polarization resolved photoluminescence from individual excitonic states. The valley polarization selection rules inherited by the localized trions will provide a pathway toward realizing a localized spin-valley-photon interface.

NIMROD resistive magnetohydrodynamic simulations of spheromak physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hooper, E. B.; Cohen, B. I.; McLean, H. S.

The physics of spheromak plasmas is addressed by time-dependent, three-dimensional, resistive magnetohydrodynamic simulations with the NIMROD code [C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004)]. Included in some detail are the formation of a spheromak driven electrostatically by a coaxial plasma gun with a flux-conserver geometry and power systems that accurately model the sustained spheromak physics experiment [R. D. Wood et al., Nucl. Fusion 45, 1582 (2005)]. The controlled decay of the spheromak plasma over several milliseconds is also modeled as the programmable current and voltage relax, resulting in simulations of entire experimental pulses. Reconnection phenomena andmore » the effects of current profile evolution on the growth of symmetry-breaking toroidal modes are diagnosed; these in turn affect the quality of magnetic surfaces and the energy confinement. The sensitivity of the simulation results addresses variations in both physical and numerical parameters, including spatial resolution. There are significant points of agreement between the simulations and the observed experimental behavior, e.g., in the evolution of the magnetics and the sensitivity of the energy confinement to the presence of symmetry-breaking magnetic fluctuations.« less

NIMROD Resistive Magnetohydrodynamic Simulations of Spheromak Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hooper, E B; Cohen, B I; McLean, H S

The physics of spheromak plasmas is addressed by time-dependent, three-dimensional, resistive magneto-hydrodynamic simulations with the NIMROD code. Included in some detail are the formation of a spheromak driven electrostatically by a coaxial plasma gun with a flux-conserver geometry and power systems that accurately model the Sustained Spheromak Physics Experiment (SSPX) (R. D. Wood, et al., Nucl. Fusion 45, 1582 (2005)). The controlled decay of the spheromak plasma over several milliseconds is also modeled as the programmable current and voltage relax, resulting in simulations of entire experimental pulses. Reconnection phenomena and the effects of current profile evolution on the growth ofmore » symmetry-breaking toroidal modes are diagnosed; these in turn affect the quality of magnetic surfaces and the energy confinement. The sensitivity of the simulation results address variations in both physical and numerical parameters, including spatial resolution. There are significant points of agreement between the simulations and the observed experimental behavior, e.g., in the evolution of the magnetics and the sensitivity of the energy confinement to the presence of symmetry-breaking magnetic fluctuations.« less

Ion-exchange chromatography purification of extracellular vesicles.

PubMed

Kosanović, Maja; Milutinović, Bojana; Goč, Sanja; Mitić, Ninoslav; Janković, Miroslava

2017-08-01

Despite numerous studies, isolating pure preparations of extracellular vesicles (EVs) has proven challenging. Here, we compared ion-exchange chromatography (IEC) to the widely used sucrose density gradient (SDG) centrifugation method for the purification of EVs. EVs in bulk were isolated from pooled normal human amniotic fluid (AF) by differential centrifugation followed by IEC or sucrose density gradient separation. The purity of the isolated EVs was evaluated by electrophoresis and lectin blotting/immuno blotting to monitor the distribution of total proteins, different EVs markers, and selected N-glycans. Our data showed efficient separation of negatively charged EVs from other differently charged molecules, while comparative profiling of EVs using SDG centrifugation confirmed anion-exchange chromatography is advantageous for EV purification. Finally, although this IEC-based method was validated using AF, the approach should be readily applicable to isolation of EVs from other sources as well.

Effect of information education and communication (IEC) programme on knowledge of pregnant mothers regarding prevention and management of warning signs during pregnancy.

PubMed

Takoo, Sarla; Chhugani, Manju; Sharma, Veena

2013-01-01

The present study was conducted to evaluate the effectiveness of an Information, Education and Communication (IEC) programme on knowledge of pregnant mothers regarding prevention and management of warning signs during pregnancy in a selected health care setting at New Delhi. An evaluative research approach with one group pre-test and post-test design was adopted for the present study. A structured interview schedule was prepared. Purposive non-probability sampling technique was employed to interview 30 pregnant mothers who attended antenatal clinic. Data gathered was analysed and interpreted using both descriptive and inferential statistics. The study revealed that there was maximum knowledge deficit regarding warning signs of pregnancy. IEC programme was effective in enhancing the knowledge of pregnant mothers on prevention and management of warning signs during pregnancy.

Risk Management Considerations for Interoperable Acquisition

DTIC Science & Technology

2006-08-01

Electronics Engineers (IEEE) to harmonize the standards for software (IEEE 12207 ) and system (IEEE 15288) life-cycle processes. A goal of this harmonization...management ( ISO /IEC 16085) is being generalized to apply to the systems level. The revised, generalized standard will add require- ments and guidance for the...risk management. The documents include the following: • ISO /IEC Guide 73: Risk Management—Vocabulary—Guidelines for use in stan- dards [ ISO 02

A Recommended Framework for the Network-Centric Acquisition Process

DTIC Science & Technology

2009-09-01

ISO /IEC 12207 , Systems and Software Engineering-Software Life-Cycle Processes  ANSI/EIA 632, Processes for Engineering a System. There are...engineering [46]. Some of the process models presented in the DAG are:  ISO /IEC 15288, Systems and Software Engineering-System Life-Cycle Processes...e.g., ISO , IA, Security, etc.). Vetting developers helps ensure that they are using industry best industry practices and maximize the IA compliance

Reliability Prediction Approaches For Domestic Intelligent Electric Energy Meter Based on IEC62380

NASA Astrophysics Data System (ADS)

Li, Ning; Tong, Guanghua; Yang, Jincheng; Sun, Guodong; Han, Dongjun; Wang, Guixian

2018-01-01

The reliability of intelligent electric energy meter is a crucial issue considering its large calve application and safety of national intelligent grid. This paper developed a procedure of reliability prediction for domestic intelligent electric energy meter according to IEC62380, especially to identify the determination of model parameters combining domestic working conditions. A case study was provided to show the effectiveness and validation.

Multinational Experiment 7. Outcome 3 - Cyber Domain, Objective 3.2: Information Sharing Framework

DTIC Science & Technology

2013-01-22

Assessments internally and across the community of interest, using an agreed methodology, such as ISO /IEC 27000 series. This should cover: (1) Policies...so that identities can be revealed if there are grounds to do so. (See ISO /IEC 29191 – Partially anonymous, partially unlinkable authentication...available from national ISO bodies). Generation and Maintenance of Cyber Situational Awareness 69. Cyber SA depends on all participating organisations

14th EuCheMS International Conference on Chemistry and the Environment ICCE 2013: IEC-WTC, Barcelona, Spain, 25-28 June 2013.

PubMed

Luis, Santiago V; Jover, Eric

2014-10-01

The 14th European Association of Chemical and Molecular Sciences (EuCheMS) International Conference on Chemistry and the Environment (ICCE 2013) took place on 25-28 June 2013 at the IEC and the WTC in Barcelona, Spain. The ICCE is a well-established biannual conference organized by the Division of Chemistry and the EuCheMS.

Hypoxia inducible factor-1α-induced interleukin-33 expression in intestinal epithelia contributes to mucosal homeostasis in inflammatory bowel disease.

PubMed

Sun, M; He, C; Wu, W; Zhou, G; Liu, F; Cong, Y; Liu, Z

2017-03-01

Intestinal epithelial cells (IECs), an important barrier to gut microbiota, are subject to low oxygen tension, particularly during intestinal inflammation. Hypoxia inducible factor-1α (HIF-1α) is expressed highly in the inflamed mucosa of inflammatory bowel disease (IBD) and functions as a key regulator in maintenance of intestinal homeostasis. However, how IEC-derived HIF-1α regulates intestinal immune responses in IBD is still not understood completely. We report here that the expression of HIF-1α and IL-33 was increased significantly in the inflamed mucosa of IBD patients as well as mice with colitis induced by dextran sulphate sodium (DSS). The levels of interleukin (IL)-33 were correlated positively with that of HIF-1α. A HIF-1α-interacting element was identified in the promoter region of IL-33, indicating that HIF-1α activity regulates IL-33 expression. Furthermore, tumour necrosis factor (TNF) facilitated the HIF-1α-dependent IL-33 expression in IEC. Our data thus demonstrate that HIF-1α-dependent IL-33 in IEC functions as a regulatory cytokine in inflamed mucosa of IBD, thereby regulating the intestinal inflammation and maintaining mucosal homeostasis. © 2016 British Society for Immunology.

Priorities for Standards and Measurements to Accelerate Innovations in Nano-Electrotechnologies: Analysis of the NIST-Energetics-IEC TC 113 Survey+,*

PubMed Central

Bennett, Herbert S.; Andres, Howard; Pellegrino, Joan; Kwok, Winnie; Fabricius, Norbert; Chapin, J. Thomas

2009-01-01

In 2008, the National Institute of Standards and Technology and Energetics Incorporated collaborated with the International Electrotechnical Commission Technical Committee 113 (IEC TC 113) on nano-electrotechnologies to survey members of the international nanotechnologies community about priorities for standards and measurements to accelerate innovations in nano-electrotechnologies. In this paper, we analyze the 459 survey responses from 45 countries as one means to begin building a consensus on a framework leading to nano-electrotechnologies standards development by standards organizations and national measurement institutes. The distributions of priority rankings from all 459 respondents are such that there are perceived distinctions with statistical confidence between the relative international priorities for the several items ranked in each of the following five Survey category types: 1) Nano-electrotechnology Properties, 2) Nano-electrotechnology Taxonomy: Products, 3) Nano-electrotechnology Taxonomy: Cross-Cutting Technologies, 4) IEC General Discipline Areas, and 5) Stages of the Linear Economic Model. The global consensus prioritizations for ranked items in the above five category types suggest that the IEC TC 113 should focus initially on standards and measurements for electronic and electrical properties of sensors and fabrication tools that support performance assessments of nano-technology enabled sub-assemblies used in energy, medical, and computer products. PMID:27504216

The intestinal complement system in inflammatory bowel disease: Shaping intestinal barrier function.

PubMed

Sina, Christian; Kemper, Claudia; Derer, Stefanie

2018-06-01

The complement system is part of innate sensor and effector systems such as the Toll-like receptors (TLRs). It recognizes and quickly systemically and/or locally respond to microbial-associated molecular patterns (MAMPs) with a tailored defense reaction. MAMP recognition by intestinal epithelial cells (IECs) and appropriate immune responses are of major importance for the maintenance of intestinal barrier function. Enterocytes highly express various complement components that are suggested to be pivotal for proper IEC function. Appropriate activation of the intestinal complement system seems to play an important role in the resolution of chronic intestinal inflammation, while over-activation and/or dysregulation may worsen intestinal inflammation. Mice deficient for single complement components suffer from enhanced intestinal inflammation mimicking the phenotype of patients with chronic inflammatory bowel disease (IBD) such as Crohn's disease (CD) or ulcerative colitis (UC). However, the mechanisms leading to complement expression in IECs seem to differ markedly between UC and CD patients. Hence, how IECs, intestinal bacteria and epithelial cell expressed complement components interact in the course of IBD still remains to be mostly elucidated to define potential unique patterns contributing to the distinct subtypes of intestinal inflammation observed in CD and UC. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ion-exchange chromatography: basic principles and application to the partial purification of soluble mammalian prolyl oligopeptidase.

PubMed

Cummins, Philip M; Dowling, Oonagh; O'Connor, Brendan F

2011-01-01

Ion-exchange chromatography (IEC) allows for the separation of ionizable molecules on the basis of differences in charge properties. Its large sample-handling capacity, broad applicability (particularly to proteins and enzymes), moderate cost, powerful resolving ability, and ease of scale-up and automation have led to it becoming one of the most versatile and widely used of all liquid chromatography (LC) techniques. In this chapter, we review the basic principles of IEC, as well as the broader criteria for selecting IEC conditions. By way of further illustration, we outline protocols necessary to partially purify a serine peptidase from bovine whole brain cytosolic fraction, covering crude tissue extract preparation through to partial purification of the target enzyme using anion-exchange chromatography. Protocols for assaying total protein and enzyme activity in both pre- and post-IEC fractions are also described. The target serine peptidase, prolyl oligopeptidase (POP, EC3.4.21.26), is an 80-kDa enzyme with endopeptidase activity towards peptide substrates of ≤30 amino acids. POP is a ubiquitous post-proline cleaving enzyme with particularly high expression levels in the mammalian brain, where it participates in the metabolism of neuroactive peptides and peptide-like hormones (e.g. thyroliberin, gonadotropin-releasing hormone).

Ultrathin CsPbX3 Nanowire Arrays with Strong Emission Anisotropy.

PubMed

Gao, Yan; Zhao, Liyun; Shang, Qiuyu; Zhong, Yangguang; Liu, Zhen; Chen, Jie; Zhang, Zhepeng; Shi, Jia; Du, Wenna; Zhang, Yanfeng; Chen, Shulin; Gao, Peng; Liu, Xinfeng; Wang, Xina; Zhang, Qing

2018-06-19

1D nanowires of all-inorganic lead halide perovskites represent a good architecture for the development of polarization-sensitive optoelectronic devices due to their high absorption efficient, emission yield, and dielectric constants. However, among as-fabricated perovskite nanowires with the lateral dimensions of hundreds nanometers so far, the optical anisotropy is hindered and rarely explored owing to the invalidating of electrostatic dielectric mismatch in the physical dimensions. Here, well-aligned CsPbBr 3 and CsPbCl 3 nanowires with thickness T down to 15 and 7 nm, respectively, are synthesized using a vapor phase van der Waals epitaxial method. Strong emission anisotropy with polarization ratio up to ≈0.78 is demonstrated in the nanowires with T < 40 nm due to the electrostatic dielectric confinement. With the increasing of thickness, the polarization ratio remarkably reduces monotonously to ≈0.17 until T ≈140 nm; and further oscillates in a small amplitude owing to the wave characteristic of light. These findings not only represent a demonstration of perovskite-based polarization-sensitive light sources, but also advance fundamental understanding of their polarization properties of perovskite nanowires. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectrally resolved single-molecule electrometry

NASA Astrophysics Data System (ADS)

Ruggeri, F.; Krishnan, M.

2018-03-01

Escape-time electrometry is a recently developed experimental technique that offers the ability to measure the effective electrical charge of a single biomolecule in solution with sub-elementary charge precision. The approach relies on measuring the average escape-time of a single charged macromolecule or molecular species transiently confined in an electrostatic fluidic trap. Comparing the experiments with the predictions of a mean-field model of molecular electrostatics, we have found that the measured effective charge even reports on molecular conformation, e.g., folded or disordered state, and non-uniform charge distribution in disordered proteins or polyelectrolytes. Here we demonstrate the ability to use the spectral dimension to distinguish minute differences in electrical charge between individual molecules or molecular species in a single simultaneous measurement, under identical experimental conditions. Using one spectral channel for referenced measurement, this kind of photophysical distinguishability essentially eliminates the need for accurate knowledge of key experimental parameters, otherwise obtained through intensive characterization of the experimental setup. As examples, we demonstrate the ability to detect small differences (˜5%) in the length of double-stranded DNA fragments as well as single amino acid exchange in an intrinsically disordered protein, prothymosin α.

Electrostatic and magnetic instabilities in the transition layer of a collisionless weakly relativistic pair shock

NASA Astrophysics Data System (ADS)

Dieckmann, M. E.; Bret, A.

2018-01-01

Energetic electromagnetic emissions by astrophysical jets like those that are launched during the collapse of a massive star and trigger gamma-ray bursts are partially attributed to relativistic internal shocks. The shocks are mediated in the collisionless plasma of such jets by the filamentation instability of counterstreaming particle beams. The filamentation instability grows fastest only if the beams move at a relativistic relative speed. We model here with a particle-in-cell simulation, the collision of two cold pair clouds at the speed c/2 (c: speed of light). We demonstrate that the two-stream instability outgrows the filamentation instability for this speed and is thus responsible for the shock formation. The incomplete thermalization of the upstream plasma by its quasi-electrostatic waves allows other instabilities to grow. A shock transition layer forms, in which a filamentation instability modulates the plasma far upstream of the shock. The inflowing upstream plasma is progressively heated by a two-stream instability closer to the shock and compressed to the expected downstream density by the Weibel instability. The strong magnetic field due to the latter is confined to a layer 10 electron skin depths wide.

8-Anilino-1-naphthalenesulfonate/Layered Double Hydroxide Ultrathin Films: Small Anion Assembly and Its Potential Application as a Fluorescent Biosensor.

PubMed

Zhang, Ping; Li, Ling; Zhao, Yun; Tian, Zeyun; Qin, Yumei; Lu, Jun

2016-09-06

The fluorescent dye 8-anilino-1-naphthalenesulfonate (ANS) is a widely used fluorescent probe molecule for biochemistry analysis. This paper reported the fabrication of ANS/layered double hydroxide nanosheets (ANS/LDH)n ultrathin films (UTFs) via the layer-by-layer small anion assembly technique based on electrostatic interaction and two possible weak interactions: hydrogen-bond and induced electrostatic interactions between ANS and positive-charged LDH nanosheets. The obtained UTFs show a long-range-ordered periodic layered stacking structure and weak fluorescence in dry air or water, but it split into three narrow strong peaks in a weak polarity environment induced by the two-dimensional (2D) confinement effect of the LDH laminate; the fluorescence intensity increases with decreasing the solvent polarity, concomitant with the blue shift of the emission peaks, which show good sensoring reversibility. Meanwhile, the UTFs exhibit selective fluorescence enhancement to the bovine serum albumin (BSA)-like protein biomolecules, and the rate of fluorescence enhancement with the protein concentration is significantly different with the different protein aggregate states. The (ANS/LDH)n UTF has the potential to be a novel type of biological flourescence sensor material.

A statistical study of gyro-averaging effects in a reduced model of drift-wave transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fonseca, Julio; Del-Castillo-Negrete, Diego B.; Sokolov, Igor M.

2016-08-25

Here, a statistical study of finite Larmor radius (FLR) effects on transport driven by electrostatic driftwaves is presented. The study is based on a reduced discrete Hamiltonian dynamical system known as the gyro-averaged standard map (GSM). In this system, FLR effects are incorporated through the gyro-averaging of a simplified weak-turbulence model of electrostatic fluctuations. Formally, the GSM is a modified version of the standard map in which the perturbation amplitude, K 0, becomes K 0J 0(more » $$\\hat{p}$$), where J 0 is the zeroth-order Bessel function and $$\\hat{p}$$ s the Larmor radius. Assuming a Maxwellian probability density function (pdf) for $$\\hat{p}$$ , we compute analytically and numerically the pdf and the cumulative distribution function of the effective drift-wave perturba- tion amplitude K 0J 0($$\\hat{p}$$). Using these results, we compute the probability of loss of confinement (i.e., global chaos), P c provides an upper bound for the escape rate, and that P t rovides a good estimate of the particle trapping rate. Lastly. the analytical results are compared with direct numerical Monte-Carlo simulations of particle transport.« less

Generalization of the van der Pauw relationship derived from electrostatics

NASA Astrophysics Data System (ADS)

Weiss, Jonathan D.

2011-08-01

In an earlier paper, this author, along with two others Weiss et al. (2008) [1], demonstrated that the original van der Pauw relationship could be derived from three-dimensional electrostatics, as opposed to van der Pauw's use of conformal mapping. The earlier derivation was done for a conducting material of rectangular cross section with contacts placed at the corners. Presented here is a generalization of the previous work involving a square sample and a square array of electrodes that are not confined to the corners, since this measurement configuration could be a more convenient one. As in the previous work, the effects of non-zero sample thickness and contact size have been investigated. Buehler and Thurber derived a similar relationship using an infinite series of current images on a large and thin conducting sheet to satisfy the conditions at the boundary of the sample. The results presented here agree with theirs numerically, but analytic agreement could not be shown using any of the perused mathematical literature. By simply equating the two solutions, it appears that, as a byproduct of this work, a new mathematical relationship has been uncovered. Finally, the application of this methodology to the Hall Effect is discussed.

Investigations of Particle Transport in the Texas Helimak

NASA Astrophysics Data System (ADS)

Taylor, E. I.; Rowan, W. L.; Gentle, K. W.; Huang, H.; Williams, C. B.

2016-10-01

The correlation between electrostatic turbulence and particle flux is investigated in a simple magnetic torus, the Helimak. The Helimak is an experimental realization of a sheared cylindrical slab that generates and heats a plasma with microwaves at 2.45 GHz and confines it in a helical magnetic field. Although it is MHD stable, the plasma is always in a nonlinearly saturated state of microturbulence. The causes of this turbulence are diverse and it is thought that it is either due to drift wave instabilities or interchange instabilites. The local particle flux is estimated over most of the plasma cross section by measuring the particle source using filtered cameras. Plasma flow along the field lines is physically similar to SOL flows in tokamaks. It is significant and can be measured directly as well as inferred from asymmetries in the electron density. The cross field transport due to electrostatic turbulence is measured as the cross correlation of radial electric field fluctuations with electron density fluctuations with the data acquired using Langmuir probes. This material is based upon work supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award Number DE-FG02-04ER54766.

Electrochemical Glucose Sensors—Developments Using Electrostatic Assembly and Carbon Nanotubes for Biosensor Construction

PubMed Central

Harper, Alice; Anderson, Mark R.

2010-01-01

In 1962, Clark and Lyons proposed incorporating the enzyme glucose oxidase in the construction of an electrochemical sensor for glucose in blood plasma. In their application, Clark and Lyons describe an electrode in which a membrane permeable to glucose traps a small volume of solution containing the enzyme adjacent to a pH electrode, and the presence of glucose is detected by the change in the electrode potential that occurs when glucose reacts with the enzyme in this volume of solution. Although described nearly 50 years ago, this seminal development provides the general structure for constructing electrochemical glucose sensors that is still used today. Despite the maturity of the field, new developments that explore solutions to the fundamental limitations of electrochemical glucose sensors continue to emerge. Here we discuss two developments of the last 15 years; confining the enzyme and a redox mediator to a very thin molecular films at electrode surfaces by electrostatic assembly, and the use of electrodes modified by carbon nanotubes (CNTs) to leverage the electrocatalytic effect of the CNTs to reduce the oxidation overpotential of the electrode reaction or for the direct electron transport to the enzyme. PMID:22163652

Electrochemical glucose sensors--developments using electrostatic assembly and carbon nanotubes for biosensor construction.

PubMed

Harper, Alice; Anderson, Mark R

2010-01-01

In 1962, Clark and Lyons proposed incorporating the enzyme glucose oxidase in the construction of an electrochemical sensor for glucose in blood plasma. In their application, Clark and Lyons describe an electrode in which a membrane permeable to glucose traps a small volume of solution containing the enzyme adjacent to a pH electrode, and the presence of glucose is detected by the change in the electrode potential that occurs when glucose reacts with the enzyme in this volume of solution. Although described nearly 50 years ago, this seminal development provides the general structure for constructing electrochemical glucose sensors that is still used today. Despite the maturity of the field, new developments that explore solutions to the fundamental limitations of electrochemical glucose sensors continue to emerge. Here we discuss two developments of the last 15 years; confining the enzyme and a redox mediator to a very thin molecular films at electrode surfaces by electrostatic assembly, and the use of electrodes modified by carbon nanotubes (CNTs) to leverage the electrocatalytic effect of the CNTs to reduce the oxidation overpotential of the electrode reaction or for the direct electron transport to the enzyme.

Confined-space synthesis of nanostructured anatase, directed by genetically engineered living organisms for lithium-ion batteries.

PubMed

Ping, Hang; Xie, Hao; Xiang, Mingyu; Su, Bao-Lian; Wang, Yucheng; Zhang, Jinyong; Zhang, Fan; Fu, Zhengyi

2016-10-01

Biomineral formation processes in nature are temporally and spatially regulated under the functions of biomolecules in a confined space. It is potentially very productive to rationally design a mineralized system by taking into account confined space as well as biomolecules. The laboratory technique of "bacterial cell surface display" is an ideal platform to host catalytically active proteins in a three-dimensionally confined space. In the present study, aiming to regulate the synthesis of nanostructured TiO 2 anatase, repeating segments of silaffin were displayed on Escherichia coli surfaces through genetic manipulation. The displayed protein electrostatically interacted with a titanium source and catalyzed the hydrolysis of titanium dioxide precursors through hydrogen bonding interactions on the cell surface. In the subsequent calcination process, the genetically modified cells not only served as a framework for producing rod-shaped TiO 2 assembled by nanoparticles, but also provided a carbon source in situ . The size of nanoparticles was controlled by changing the number of tandem repeats of the protein segment. The as prepared TiO 2 anatase exhibited unique characteristics including nanosized anatase crystals, mesoporous structure and carbon coating. When tested as the anode electrode of a lithium-ion battery, it showed excellent lithium storage performance. The carbon coated anatase anode shows a higher specific capacity of 207 mA h g -1 after 200 cycles at a current rate of 1C and an ultra-long cycling lifetime of 5000 cycles with an outstanding retention capacity of 149 mA h g -1 at a higher rate of 10C. This bioprocess-inspired approach may help broaden the scope and impact of nanosized biominerals.

Aggregation and disaggregation dynamics of sedimented and charged superparamagnetic micro-particles in water suspension.

PubMed

Domínguez-García, P; Pastor, J M; Rubio, M A

2011-04-01

This article presents results on the aggregation and disaggregation kinetics on a 1 μm diameter charged superparamagnetic particles dispersed in water under a constant uniaxial magnetic field in experiments with salt (KCl) added to the suspension in order to observe the behaviour of the system when the electrical properties of the particles have been screened. These particles have an electric charge and are confined between two separated 100 μm thick quartz windows, and sediment near the charged bottom wall. The electrostatic interactions that take place in this experimental setup may affect the micro-structure and colloidal stability of the suspension and thus, the dynamics of aggregation and disaggregation.

Two-dimensional superconducting phase in LaTiO3/SrTiO3 heterostructures induced by high-mobility carrier doping.

PubMed

Biscaras, J; Bergeal, N; Hurand, S; Grossetête, C; Rastogi, A; Budhani, R C; LeBoeuf, D; Proust, C; Lesueur, J

2012-06-15

In this Letter, we show that a superconducting two-dimensional electron gas is formed at the LaTiO3/SrTiO3 interface whose transition temperature can be modulated by a back-gate voltage. The gas consists of two types of carriers: a majority of low-mobility carriers always present, and a few high-mobility ones that can be injected by electrostatic doping. The calculation of the electron spatial distribution in the confinement potential shows that the high-mobility electrons responsible for superconductivity set at the edge of the gas whose extension can be tuned by the field effect.

Dynamic nuclear polarization at high Landau levels in a quantum point contact

NASA Astrophysics Data System (ADS)

Fauzi, M. H.; Noorhidayati, A.; Sahdan, M. F.; Sato, K.; Nagase, K.; Hirayama, Y.

2018-05-01

We demonstrate a way to polarize and detect nuclear spin in a gate-defined quantum point contact operating at high Landau levels. Resistively detected nuclear magnetic resonance (RDNMR) can be achieved up to the fifth Landau level and at a magnetic field lower than 1 T. We are able to retain the RDNMR signals in a condition where the spin degeneracy of the first one-dimensional (1D) subband is still preserved. Furthermore, the effects of orbital motion on the first 1D subband can be made smaller than those due to electrostatic confinement. This developed RDNMR technique is a promising means to study electronic states in a quantum point contact near zero magnetic field.

Sequence-Dependent Persistence Length of Long DNA

NASA Astrophysics Data System (ADS)

Chuang, Hui-Min; Reifenberger, Jeffrey G.; Cao, Han; Dorfman, Kevin D.

2017-12-01

Using a high-throughput genome-mapping approach, we obtained circa 50 million measurements of the extension of internal human DNA segments in a 41 nm ×41 nm nanochannel. The underlying DNA sequences, obtained by mapping to the reference human genome, are 2.5-393 kilobase pairs long and contain percent GC contents between 32.5% and 60%. Using Odijk's theory for a channel-confined wormlike chain, these data reveal that the DNA persistence length increases by almost 20% as the percent GC content increases. The increased persistence length is rationalized by a model, containing no adjustable parameters, that treats the DNA as a statistical terpolymer with a sequence-dependent intrinsic persistence length and a sequence-independent electrostatic persistence length.

Fast Low-to-High Confinement Mode Bifurcation Dynamics in a Tokamak Edge Plasma Gyrokinetic Simulation.

PubMed

Chang, C S; Ku, S; Tynan, G R; Hager, R; Churchill, R M; Cziegler, I; Greenwald, M; Hubbard, A E; Hughes, J W

2017-04-28

Transport barrier formation and its relation to sheared flows in fluids and plasmas are of fundamental interest in various natural and laboratory observations and of critical importance in achieving an economical energy production in a magnetic fusion device. Here we report the first observation of an edge transport barrier formation event in an electrostatic gyrokinetic simulation carried out in a realistic diverted tokamak edge geometry under strong forcing by a high rate of heat deposition. The results show that turbulent Reynolds-stress-driven sheared E×B flows act in concert with neoclassical orbit loss to quench turbulent transport and form a transport barrier just inside the last closed magnetic flux surface.

Molecular Theory for Electrokinetic Transport in pH-Regulated Nanochannels.

PubMed

Kong, Xian; Jiang, Jian; Lu, Diannan; Liu, Zheng; Wu, Jianzhong

2014-09-04

Ion transport through nanochannels depends on various external driving forces as well as the structural and hydrodynamic inhomogeneity of the confined fluid inside of the pore. Conventional models of electrokinetic transport neglect the discrete nature of ionic species and electrostatic correlations important at the boundary and often lead to inconsistent predictions of the surface potential and the surface charge density. Here, we demonstrate that the electrokinetic phenomena can be successfully described by the classical density functional theory in conjunction with the Navier-Stokes equation for the fluid flow. The new theoretical procedure predicts ion conductivity in various pH-regulated nanochannels under different driving forces, in excellent agreement with experimental data.

A fast low-to-high confinement mode bifurcation dynamics in the boundary-plasma gyrokinetic code XGC1

NASA Astrophysics Data System (ADS)

Ku, S.; Chang, C. S.; Hager, R.; Churchill, R. M.; Tynan, G. R.; Cziegler, I.; Greenwald, M.; Hughes, J.; Parker, S. E.; Adams, M. F.; D'Azevedo, E.; Worley, P.

2018-05-01

A fast edge turbulence suppression event has been simulated in the electrostatic version of the gyrokinetic particle-in-cell code XGC1 in a realistic diverted tokamak edge geometry under neutral particle recycling. The results show that the sequence of turbulent Reynolds stress followed by neoclassical ion orbit-loss driven together conspire to form the sustaining radial electric field shear and to quench turbulent transport just inside the last closed magnetic flux surface. The main suppression action is located in a thin radial layer around ψN≃0.96 -0.98 , where ψN is the normalized poloidal flux, with the time scale ˜0.1 ms.

Dusty plasma in the region of the lunar terminator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popel, S. I., E-mail: popel@iki.rssi.ru; Zelenyi, L. M.; Atamaniuk, B.

2016-05-15

Dusty plasma in the region of the lunar terminator is considered. It is shown that, in this region, a structure resembling a plasma sheath forms near the lunar surface. This sheath creates a potential barrier, due to which electrons over the illuminated part of the Moon are confined by electrostatic forces. The width of the sheath-like structure is on the order of the ion Debye length. In this structure, significant (about several hundred V/m) electric fields arise, which lift charged micron-size dust grains to heights of several tens of centimeters. The suggested effect may be used to explain the glowmore » observed by the Surveyor spacecraft over the lunar terminator.« less

5.5-7.5 MeV Proton Generation by a Moderate-Intensity Ultrashort-Pulse Laser Interaction with H2O Nanowire Targets

NASA Astrophysics Data System (ADS)

Zigler, A.; Palchan, T.; Bruner, N.; Schleifer, E.; Eisenmann, S.; Botton, M.; Henis, Z.; Pikuz, S. A.; Faenov, A. Y., Jr.; Gordon, D.; Sprangle, P.

2011-04-01

We report on the first generation of 5.5-7.5 MeV protons by a moderate-intensity short-pulse laser (˜5×1017W/cm2, 40 fsec) interacting with frozen H2O nanometer-size structure droplets (snow nanowires) deposited on a sapphire substrate. In this setup, the laser intensity is locally enhanced by the snow nanowire, leading to high spatial gradients. Accordingly, the nanoplasma is subject to enhanced ponderomotive potential, and confined charge separation is obtained. Electrostatic fields of extremely high intensities are produced over the short scale length, and protons are accelerated to MeV-level energies.

Antiswarming: Structure and dynamics of repulsive chemically active particles

NASA Astrophysics Data System (ADS)

Yan, Wen; Brady, John F.

2017-12-01

Chemically active Brownian particles with surface catalytic reactions may repel each other due to diffusiophoretic interactions in the reaction and product concentration fields. The system behavior can be described by a "chemical" coupling parameter Γc that compares the strength of diffusiophoretic repulsion to Brownian motion, and by a mapping to the classical electrostatic one component plasma (OCP) system. When confined to a constant-volume domain, body-centered cubic (bcc) crystals spontaneously form from random initial configurations when the repulsion is strong enough to overcome Brownian motion. Face-centered cubic (fcc) crystals may also be stable. The "melting point" of the "liquid-to-crystal transition" occurs at Γc≈140 for both bcc and fcc lattices.

Reduction of Noise from the J-52 and F-404 Jet Engines During Static Testing Using the Noise Attenuation Device (NAD)

DTIC Science & Technology

2009-06-01

Filters, Order 3, Type 0-C, Optional Range B.2.2 Sound Level Meter Calibration • ISO / IEC 17025 :2005 General requirements for the competence of...noise levels − NCSL -National Conference of Standards Laboratories − ISO - International Standards Organization − IEC - The International...testing and calibration laboratories • ISO 10012:2003 Measurement management systems -- Requirements for measurement processes and measuring

Intelligent Hybrid Vehicle Power Control. Part 2. Online Intelligent Energy Management

DTIC Science & Technology

2012-06-30

IEC_HEV for vehicle energy optimization. IEC_HEV, the Figure 1. Power Split HEV configuration into VSC 5 online energy control is a component...in the Vehicle System Controller ( VSC ). The VSC for this configuration must manage the powertrain control in order to maintain a proper level of...charge in the battery. However, since two power sources are available to propel the vehicle, the VSC in this configuration has the additional

CrossTalk: The Journal of Defense Software Engineering. Volume 20, Number 3, March 2007

DTIC Science & Technology

2007-03-01

Capability Maturity Model ® Integration (CMMI®). CMU Software Engineering Institute <www.sei.cmu.edu/cmmi>. 5. ISO /IEC 27001 :2005. Information Security...international standards bodies – International Organization for Standardi- zation ( ISO ) and International Electro- technical Commission (IEC) – are working on a...number of projects that affect soft- ware security: • The ISO Technical Management Board (TMB) performs strategic planning and coordination for ISO

Measuring Operational Resilience Using the CERT(Registered) Resilience Management Model

DTIC Science & Technology

2010-09-01

such as ISO 27002 [ ISO 2005]) and then measure the implementation and performance of practices contained in the standard. This checklist-based ap...Security techniques – Code of practice for information security management. ISO /IEC 27002 :2005, June 2005. Also known as ISO /IEC 17799:2005. [ ISO 2007...Table 23: ISO 15939 Process Activities and Tasks 54 Table 24: CERT-RMM Measurement and Analysis Process Area Goals and Practices 55 CMU/SEI

Making the Business Case for Software Assurance

DTIC Science & Technology

2009-04-01

and Capability dEtermination-SPICE, ISO /IEC 15504, 1998. [ ISO 2007] International Organization for Standardization. " ISO /IEC 27001 & 27002 ...Implementing the Process Areas 6.2.7 Differences Between the CMMI and Software CMM Process Areas 6.3 The CMMI Appraisal Process 6.4 Adapting ISO 15504 to...Secure Software Assurance 6.4.1 Assessment and the Secure Life Cycle 6.4.2 ISO 15504 Capability Levels 6.5 Adapting the ISOIIEC 21287 Standard Approach to

Software Assurance Curriculum Project Volume 3: Master of Software Assurance Course Syllabi

DTIC Science & Technology

2011-07-01

and International Electrotechnical Commission ( ISO /IEC). ISO /IEC 27002 :2005 Information Technology – Security Techniques – Code of Practice for...Compliance and Policy (CP) practice • [ ISO 2008] ISO 27002 Section 15 Research and identify (or develop) an example of policy language that...Microsoft SDL • [Merkow 2010] Chapters 5, 6, 8 • [ ISO 2008] ISO 27002 Sections 12.1-12.5 Identify practices to mitigate selected risks for sample

Impulse Current Waveform Compliance with IEC 60060-1

NASA Astrophysics Data System (ADS)

Sato, Shuji; Harada, Tatsuya; Yokoyama, Taizou; Sakaguchi, Sumiko; Ebana, Takao; Saito, Tatsunori

After numerous simulations, authors could unsuccessfully design an impulse current calibrator, whose output's time parameters (front time, T1 and time to half the peak, T2 ) are quite close to ideals defined in IEC 60060-1. The investigation for the failed trial was commenced. Using normalized damped oscillating waveform e-tsin(ωt), a relationship of the ratio T2/T1 and undershoot value are studied for all possible value for . With this relationship, it is derived that 1) one cannot generate an ideal wave form unless one has to accept a certain margin for the two parameters, 2) even with the allowable margin, one can generate a wave form only in a case a value for T1 is smaller and T2 is larger than standard values. In the paper, possible time parameter combination, which fulfils IEC 60060-1 requirements, is illustrated for a calibrator design.

Two-dimensional modelling of internal arc effects in an enclosed MV cell provided with a protection porous filter

NASA Astrophysics Data System (ADS)

Rochette, D.; Clain, S.; André, P.; Bussière, W.; Gentils, F.

2007-05-01

Medium voltage (MV) cells have to respect standards (for example IEC ones (IEC TC 17C 2003 IEC 62271-200 High Voltage Switchgear and Controlgear—Part 200 1st edn)) that define security levels against internal arc faults such as an accidental electrical arc occurring in the apparatus. New protection filters based on porous materials are developed to provide better energy absorption properties and a higher protection level for people. To study the filter behaviour during a major electrical accident, a two-dimensional model is proposed. The main point is the use of a dedicated numerical scheme for a non-conservative hyperbolic problem. We present a numerical simulation of the process during the first 0.2 s when the safety valve bursts and we compare the numerical results with tests carried out in a high power test laboratory on real electrical apparatus.

Sophisticated Calculation of the 1oo4-architecture for Safety-related Systems Conforming to IEC61508

NASA Astrophysics Data System (ADS)

Hayek, A.; Bokhaiti, M. Al; Schwarz, M. H.; Boercsoek, J.

2012-05-01

With the publication and enforcement of the standard IEC 61508 of safety related systems, recent system architectures have been presented and evaluated. Among a number of techniques and measures to the evaluation of safety integrity level (SIL) for safety-related systems, several measures such as reliability block diagrams and Markov models are used to analyze the probability of failure on demand (PFD) and mean time to failure (MTTF) which conform to IEC 61508. The current paper deals with the quantitative analysis of the novel 1oo4-architecture (one out of four) presented in recent work. Therefore sophisticated calculations for the required parameters are introduced. The provided 1oo4-architecture represents an advanced safety architecture based on on-chip redundancy, which is 3-failure safe. This means that at least one of the four channels have to work correctly in order to trigger the safety function.

Cytoprotective effects of essential oil of Pinus halepensis L. against aspirin-induced toxicity in IEC-6 cells.

PubMed

Bouzenna, Hafsia; Hfaiedh, Najla; Bouaziz, Mouhamed; Giroux-Metges, Marie-Agnès; Elfeki, Abdelfattah; Talarmin, Hélène

2017-12-01

Essential oils from Pinus species have been reported to have various therapeutic properties. This study was undertaken to identify the chemical composition and cytoprotective effects of the essential oil of Pinus halepensis L. against aspirin-induced damage in cells in vitro. The cytoprotection of the oil against toxicity of aspirin on the small intestine epithelial cells IEC-6 was tested. The obtained results have shown that 35 different compounds were identified. Aspirin induced a decrease in cell viability, and exhibited significant damage to their morphology and an increase in superoxide dismutase (SOD) and catalase (CAT) activities. However, the co-treatment of aspirin with the essential oil of Pinus induced a significant increase in cell viability and a decrease in SOD and CAT activities. Overall, these finding suggest that the essential oil of Pinus halepensis L. has potent cytoprotective effect against aspirin-induced toxicity in IEC-6 cells.

Time-dependent Electron Acceleration in Pulsar Wind Termination Shocks: Application to the 2011 April Crab Nebula Gamma-Ray Flare

NASA Astrophysics Data System (ADS)

Kroon, John J.; Becker, Peter A.; Finke, Justin D.

2018-01-01

The γ-ray flares from the Crab Nebula observed by AGILE and Fermi-LAT between 2007 and 2013 reached GeV photon energies and lasted several days. The strongest emission, observed during the 2011 April “superflare”, exceeded the quiescent level by more than an order of magnitude. These observations challenge the standard models for particle acceleration in pulsar wind nebulae, because the radiating electrons have energies exceeding the classical radiation-reaction limit for synchrotron emission. Particle-in-cell simulations have suggested that the classical synchrotron limit can be exceeded if the electrons also experience electrostatic acceleration due to shock-driven magnetic reconnection. In this paper, we revisit the problem using an analytic approach based on solving a fully time-dependent electron transport equation describing the electrostatic acceleration, synchrotron losses, and escape experienced by electrons in a magnetically confined plasma “blob” as it encounters and passes through the pulsar wind termination shock. We show that our model can reproduce the γ-ray spectra observed during the rising and decaying phases of each of the two sub-flare components of the 2011 April superflare. We integrate the spectrum for photon energies ≥slant 100 MeV to obtain the light curve for the event, which also agrees with the observations. We find that strong electrostatic acceleration occurs on both sides of the termination shock, driven by magnetic reconnection. We also find that the dominant mode of particle escape changes from diffusive escape to advective escape as the blob passes through the shock.

Comparison of methods for acceptance and constancy testing in dental cone-beam computed tomography.

PubMed

Steiding, C; Kolditz, D; Kalender, W

2015-04-01

The aim of this work was to implement, validate, and compare two procedures for routine image quality (IQ) assurance in dental cone-beam computed tomography (CBCT): 1. the German standard DIN 6868 - 161 introduced in 2013 and 2. the established standard IEC 61,223 - 3-5 for clinical CT x-ray equipment referenced as "DIN" and "IEC" below. The approximated in-plane modulation transfer function (MTF), the contrast-to-noise indicator (CNI), and the uniformity indicator (UI*) were determined in accordance with DIN. Image noise, the uniformity index (UI), the contrast-to-noise ratio (CNR), and the 3 D MTF were measured according to IEC 61,223 - 3-5 using a previously proposed quality assurance (QA) framework. For this, a modular phantom was used. All experiments were performed on a clinical dental CBCT unit. The severity of image artefacts was measured at different z-positions. A dedicated computer program was implemented to allow for automated QA procedure. The position and orientation of the phantoms were detected automatically in all of the measurements providing a reproducible placement of the evaluation regions and volumes. 50 % and 10 % in-plane MTF values of the approximated and the exact MTF calculation procedure were in agreement to within 5 %. With increasing axial distance from the isocentre, UI* and CNI dropped by 30 % and 19 %, respectively. Conventional IQ parameters showed higher sensitivity to image artefacts; i. e., UI and CNR were reduced by about 197 % and 37 %. The implemented automated QA routines are compatible with both the DIN and the IEC approach and offer reliable and quantitative tracking of imaging performance in dental CBCT for clinical practice. However, there is no equivalence between the DIN and the IEC metrics. In addition, direct measurements of physical IQ parameters such as image contrast and noise, uniformity, and axial resolution are not supported by the new concept according to DIN. The new DIN 6868 - 161 is not equivalent to the established IEC 61 223 - 3-5. Noise, uniformity, and contrast are well-suited to assess image artefacts. The implemented automated quality assurance program fits clinical routine. © Georg Thieme Verlag KG Stuttgart · New York.

Effectiveness of publications in family planning program.

PubMed

Noor Laily Abu Bakar; Tan, B A; Tey, N P; Yusuf, Y

1983-12-01

The aim of the present study is to evaluate the degree of exposure to to Information, Education, and Communication (I.E.C.) publications such as pamphlets and booklets on contraceptive methods among those who have attended the dialog sessions; and to investigate the effects of such exposure on contraceptive use as well as the ppropensity to talk about family planning. The survey, conducted by the National Family Planning Board and assisted by the Sciences University of Malaysia in 1978/79, covers 6 states. A total of 1190 respondents were selected from those who attended dialog sessions during that period. Of the total sample, 723 respondents (60.8%) were contacted and interviewed. The I.E.C. publications evaluated in this survey include booklets on methods of contraception; pamphlets on the pill, IUD, condom, rhythm method, tubal ligation, vasectomy; booklets on responsible parenthood, flip charts and posters. 61% of the respondents have been exposed to at least 1 form of the I.E.C. materials. About 17 to 18% of currently married respondents have been exposed to pamphlets on tubal ligation, rhythm methods, IUD and condom; 22% have been exposed to pamphlets on the pill and 43% to booklets on contraceptive methods. In gerneral, those who have been exposed to pamphlets on a particular method were more likely to use that method. Among those who have been exposed to pamphlets on the pill 26.4% were using the pill compared to 16.2% who have not been exposed. The proportion of condom users were 3 times more after exposure to pamphlets on the condom: 16% vs. 4.7%. About 50% of currently married respondents were using a contraceptive method at the time of the survey. Of those who have not been exposed to I.E.C. materials, only 34.4% were using a method, compared to 53-60% of those who had been exposed. Exposure to I.E.C. materials and its interaction with ethnicity act as the most important factor in accounting for the differntials in contraceptive use, both in the bivariate context and multivariate context. For all 3 ethnic groups studied -- Malays, Chinese, Indians--those who have been exposed to I.E.C. publications appear to be more vocal about family planning than those who have not. Tables and charts illustrate detailed results of the study.

ASSIP Study of Real-Time Safety-Critical Embedded Software-Intensive System Engineering Practices

DTIC Science & Technology

2008-02-01

and assessment 2. product engineering processes 3. tooling processes 6 | CMU/SEI-2008-SR-001 Slide 1 Process Standards IEC/ ISO 12207 Software...and technical effort to align with 12207 IEC/ ISO 15026 System & Software Integrity Levels Generic Safety SAE ARP 4754 Certification Considerations...Process Frameworks in revision – ISO 9001, ISO 9004 – ISO 15288/ ISO 12207 harmonization – RTCA DO-178B, MOD Standard UK 00-56/3, … • Methods & Tools

Status of the Body of Knowledge and Curriculum to Advance Systems Engineering (BKCASE (trademark)) Project

DTIC Science & Technology

2011-10-01

Systems engineer- ing knowledge has also been documented through the standards bodies, most notably : • ISO /IEC/IEEE 15288, Systems Engineer- ing...System Life Cycle Processes, 2008 (see [10]). • ANSI/EIA 632, Processes for Engineering a System, (1998) • IEEE 1220, ISO /IEC 26702 Application...tion • United States Defense Acquisition Guidebook, Chapter 4, June 27, 2011 • IEEE/EIA 12207 , Software Life Cycle Processes, 2008 • United

Test Methods for Telemetry Systems and Subsystems. Volume 1. Test Methods for Vehicle Telemetry Systems

DTIC Science & Technology

2006-06-01

IEC Web Site - http://www.iec.org/ National Instruments Web Site - http://www.ni.com/ ASA ( Acoustical Society of America) - http://asa.aip.org/ Flow...1994 (R2004), Acoustical Terminology. ANSI S1.10-1966 (R2001), USA Standard Method for Calibration of Microphones. ANSI S1.15-1997, USA Standard...R2001), American National Standard Specification for Acoustical Calibrators. ANSI S1.9-1996 (R2001), American National Standard Instruments for

Breast milk-derived exosomes promote intestinal epithelial cell growth.

PubMed

Hock, Alison; Miyake, Hiromu; Li, Bo; Lee, Carol; Ermini, Leonardo; Koike, Yuhki; Chen, Yong; Määttänen, Pekka; Zani, Augusto; Pierro, Agostino

2017-05-01

Breast milk administration prevents necrotizing enterocolitis (NEC). However, the mechanism remains unclear. Exosomes are cell-derived vesicles highly present in human milk and regulate intercellular signaling, inflammation, and immune response. We hypothesized that milk-derived exosomes beneficially affect intestinal epithelial cells. Rat milk was collected, and exosomes were isolated using ExoQuick reagent and visualized by Nanoparticle Tracking Analysis. Protein was extracted from encapsulating exosomes, and concentration was measured. 2×10 4 intestinal epithelial cells (IEC-18) were treated for five hours with 0.5-μg/μl exosomes, an equal volume of exosome-free milk, or control solution (PBS). IEC-18 viability was measured using a colorimetric assay (MTT), and gene expression was analyzed by qRT-PCR. Data were compared using one-way ANOVA with Bonferroni post-test. Rat milk was collected, and exosome isolation was confirmed. Compared to control, treatment with exosomes significantly increased IEC viability, proliferation, and stem cell activity (all p<0.05). However, administration of exosome-free milk had less significant effects. Rat milk-derived exosomes promote IEC viability, enhance proliferation, and stimulate intestinal stem cell activity. These findings provide insight into the mechanism of action of breast milk in the intestines. Exosome administration is a promising prevention method for infants at risk of developing NEC when breastfeeding is not tolerated. Copyright © 2017 Elsevier Inc. All rights reserved.

Primary human polarized small intestinal epithelial barriers respond differently to a hazardous and an innocuous protein.

PubMed

Eaton, A D; Zimmermann, C; Delaney, B; Hurley, B P

2017-08-01

An experimental platform employing human derived intestinal epithelial cell (IEC) line monolayers grown on permeable Transwell ® filters was previously investigated to differentiate between hazardous and innocuous proteins. This approach was effective at distinguishing these types of proteins and perturbation of monolayer integrity, particularly transepithelial electrical resistance (TEER), was the most sensitive indicator. In the current report, in vitro indicators of monolayer integrity, cytotoxicity, and inflammation were evaluated using primary (non-transformed) human polarized small intestinal epithelial barriers cultured on Transwell ® filters to compare effects of a hazardous protein (Clostridium difficile Toxin A [ToxA]) and an innocuous protein (bovine serum albumin [BSA]). ToxA exerted a reproducible decrease on barrier integrity at doses comparable to those producing effects observed from cell line-derived IEC monolayers, with TEER being the most sensitive indicator. In contrast, BSA, tested at concentrations substantially higher than ToxA, did not cause changes in any of the tested variables. These results demonstrate a similarity in response to certain proteins between cell line-derived polarized IEC models and a primary human polarized small intestinal epithelial barrier model, thereby reinforcing the potential usefulness of cell line-derived polarized IECs as a valid experimental platform to differentiate between hazardous and non-hazardous proteins. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Distinct Phospholipase C-β Isozymes Mediate Lysophosphatidic Acid Receptor 1 Effects on Intestinal Epithelial Homeostasis and Wound Closure

PubMed Central

Lee, Sei-Jung; Leoni, Giovanna; Neumann, Philipp-Alexander; Chun, Jerold; Nusrat, Asma

2013-01-01

Maintenance of the epithelial barrier in the intestinal tract is necessary to protect the host from the hostile luminal environment. Phospholipase C-β (PLC-β) has been implicated to control myriad signaling cascades. However, the biological effects of selective PLC-β isozymes are poorly understood. We describe novel findings that lysophosphatidic acid (LPA) regulates PLC-β1 and PLC-β2 via two distinct pathways to enhance intestinal epithelial cell (IEC) proliferation and migration that facilitate wound closure and recovery of the intestinal epithelial barrier. LPA acting on the LPA1 receptor promotes IEC migration by facilitating the interaction of Gαq with PLC-β2. LPA-induced cell proliferation is PLC-β1 dependent and involves translocation of Gαq to the nucleus, where it interacts with PLC-β1 to induce cell cycle progression. An in vivo study using LPA1-deficient mice (Lpar1−/−) shows a decreased number of proliferating IECs and migration along the crypt-luminal axis. Additionally, LPA enhances migration and proliferation of IECs in an LPA1-dependent manner, and Lpar1−/− mice display defective mucosal wound repair that requires cell proliferation and migration. These findings delineate novel LPA1-dependent lipid signaling that facilitates mucosal wound repair via spatial targeting of distinct PLC-βs within the cell. PMID:23478264

Probiotic bacteria cell walls stimulate the activity of the intestinal epithelial cells and macrophage functionality.

PubMed

Lemme-Dumit, J M; Polti, M A; Perdigón, G; Galdeano, C Maldonado

2018-01-29

The effect of oral administration of probiotic bacteria cell walls (PBCWs) in the stimulation of the immune system in healthy BALB/c mice was evaluated. We focused our investigation mainly on intestinal epithelial cells (IECs) which are essential for coordinating an adequate mucosal immune response and on the functionality of macrophages. The probiotic bacteria and their cell walls were able to stimulate the IECs exhibiting an important activation and cytokine releases. Supplementation with PBCWs promoted macrophage activation from peritoneum and spleen, indicating that the PBCWs oral administration was able to improve the functionality of the macrophages. In addition, the PBCWs increased immunoglobulin A (IgA)-producing cells in the gut lamina propria in a similar way to probiotic bacteria, but this supplementation did not have an effect on the population of goblet cells in the small intestine epithelium. These results indicate that the probiotic bacteria and their cell walls have an important immunoregulatory effect on the IECs without altering the homeostatic environment but with an increase in IgA+ producing cells and in the innate immune cells, mainly those distant from the gut such as spleen and peritoneum. These findings about the capacity of the cell walls from probiotic bacteria to stimulate key cells, such as IECs and macrophages, and to improve the functioning of the immune system, suggest that those structures could be applied as a new oral adjuvant.

Phase separation and ion conductivity in the bulk and at the surface of anion exchange membranes with different ion exchange capacities at different humidities

NASA Astrophysics Data System (ADS)

Kimura, Taro; Akiyama, Ryo; Miyatake, Kenji; Inukai, Junji

2018-01-01

For higher performances of anion exchange membrane (AEM) fuel cells, understanding the phase-separated structures inside AEMs is essential, as well as those at the catalyst layer/membrane interfaces. The AEMs based on quaternized aromatic semi-block copolymers with different ion exchange capacities (IECs) were systematically investigated. With IECs of 1.23 and 1.95 mequiv g-1, the water uptakes at room temperature were 37% and 98%, and the anion conductivities 23.6 and 71.4 mS cm-1, respectively. The increases were not proportional to the IEC. Images obtained by transmission electron microscopy in vacuum were similar with both IEC values, but the development of a clear phase separation in humidified nitrogen was observed in the profiles only with 1.95 mequiv g-1obtained by small-angle X-ray scattering. At the temperature of 40 °C and the relative humidity (RH) of 30%, the average currents observed at the tip apex by current-sensing atomic force microscopy were <0.5 and 10 pA with 1.23 and 1.95 mequiv g-1, respectively, and those at 70% RH were 10 and 15 pA, respectively. The humidity gave a larger influence on the bulk structure with 1.95 mequiv g-1, whereas a larger influence on the surface conductivity with 1.23 mequiv g-1.

Spirulina platensis Improves Mitochondrial Function Impaired by Elevated Oxidative Stress in Adipose-Derived Mesenchymal Stromal Cells (ASCs) and Intestinal Epithelial Cells (IECs), and Enhances Insulin Sensitivity in Equine Metabolic Syndrome (EMS) Horses.

PubMed

Nawrocka, Daria; Kornicka, Katarzyna; Śmieszek, Agnieszka; Marycz, Krzysztof

2017-08-03

Equine Metabolic Syndrome (EMS) is a steadily growing life-threatening endocrine disorder linked to insulin resistance, oxidative stress, and systemic inflammation. Inflammatory microenvironment of adipose tissue constitutes the direct tissue milieu for various cell populations, including adipose-derived mesenchymal stromal cells (ASCs), widely considered as a potential therapeutic cell source in the course of the treatment of metabolic disorders. Moreover, elevated oxidative stress induces inflammation in intestinal epithelial cells (IECs)-the first-line cells exposed to dietary compounds. In the conducted research, we showed that in vitro application of Spirulina platensis contributes to the restoration of ASCs' and IECs' morphology and function through the reduction of cellular oxidative stress and inflammation. Enhanced viability, suppressed senescence, and improved proliferation of ASCs and IECs isolated from metabolic syndrome-affected individuals were evident following exposition to Spirulina. A protective effect of the investigated extract against mitochondrial dysfunction and degeneration was also observed. Moreover, our data demonstrate that Spirulina extract effectively suppressed LPS-induced inflammatory responses in macrophages. In vivo studies showed that horses fed with a diet based on Spirulina platensis supplementation lost weight and their insulin sensitivity improved. Thus, our results indicate the engagement of Spirulina platensis nourishing as an interesting alternative approach for supporting the conventional treatment of equine metabolic syndrome.

Incorporation of in vitro digestive enzymes in an intestinal epithelial cell line model for protein hazard identification.

PubMed

Markell, Lauren K; Wezalis, Stephanie M; Roper, Jason M; Zimmermann, Cindi; Delaney, Bryan

2017-10-01

Relatively few proteins in nature produce adverse effects following oral exposure. Of those that do, effects are often observed in the gut, particularly on intestinal epithelial cells (IEC). Previous studies reported that addition of protein toxins to IEC lines disrupted monolayer integrity but innocuous dietary proteins did not. Studies presented here investigated the effects of innocuous (bovine serum albumin, β-lactoglobulin, RuBisCO, fibronectin) or hazardous (phytohaemagglutinin-E, concanavalin A, wheat germ agglutinin, melittin) proteins that either were untreated or exposed to digestive enzymes prior to addition to Caco-2 human IEC line monolayers. At high concentrations intact fibronectin caused an increase in monolayer permeability but other innocuous proteins did not whether exposed to digestive enzymes or not. In contrast, all untreated hazardous proteins and those that were resistant to digestion (ex. wheat germ agglutinin) disrupted monolayer integrity. However, proteins sensitive to degradation by digestive enzymes (ex. melittin) did not adversely affect monolayers when exposed to these enzymes prior to addition to IEC line monolayers. These results indicate that in vitro exposure of proteins to digestive enzymes can assist in differentiating between innocuous and hazardous proteins as another component to consider in the overall weight of evidence approach in protein hazard assessment. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Population communication services: a global perspective.

PubMed

Piotrow, P T; Coleman, P L; Rimon, J G

1987-06-01

Communication support for health and family planning programs is receiving renewed attention. The johns Hopkins University (JHU) Population Communication Services (PCS) project was established in 1982 to respond to the increasing need for communication expertise, to provide a responsive source for advice, and to develop implement the new directions that are necessary to make family planning communication programs more effective. The project extends a range of services to government programs, private family planning associations, and to media that want to improve the content or coverage of family planning communication, JHU/PCS emphasizes the close links between good communication and good management and the need for managers at all levels, from the Minister of Health to the supervisor of grass-roots field workers, to understand the components of a communication program for the 1980s. Principles underlying the project's work include: communication as process rather than product, the audience as participant, linking mass media and interpersonal communication, coordination with and among agencies, training that is specific and relevant, IEC as institution building, use of the private sector, an attempt to recover some of the costs of IEC work, and ongoing evaluation of program activities. IEC activities can be strengthened considerably b a knowledgeable commitment at the top of the decision-making process; constant feedback from intended audiences; and interactions among service delivery personnel, influential community members, and the media. In turn, strong IEC activities can substantially strengthen existing family planning programs.

A Central Role for Heme Oxygenase-1 in the Control of Intestinal Epithelial Chemokine Expression.

PubMed

Onyiah, Joseph C; Schaefer, Rachel E M; Colgan, Sean P

2018-05-23

In mucosal inflammatory disorders, the protective influence of heme oxygenase-1 (HO-1) and its metabolic byproducts, carbon monoxide (CO) and biliverdin, is a topic of significant interest. Mechanisms under investigation include the regulation of macrophage function and mucosal cytokine expression. While there is an increasing recognition of the importance of epithelial-derived factors in the maintenance of intestinal mucosal homeostasis, the contribution of intestinal epithelial cell (IEC) HO-1 on inflammatory responses has not previously been investigated. We examined the influence of modulating HO-1 expression on the inflammatory response of human IECs. Engineered deficiency of HO-1 in Caco-2 and T84 IECs led to increased proinflammatory chemokine expression in response to pathogenic bacteria and inflammatory cytokine stimulation. Crosstalk with activated leukocytes also led to increased chemokine expression in HO-1-deficient cells in an IL-1β dependent manner. Treatment of Caco-2 cells with a pharmacological inducer of HO-1 led to the inhibition of chemokine expression. Mechanistic studies suggest that HO-1 and HO-1-related transcription factors, but not HO-1 metabolic products, are partly responsible for the influence of HO-1 on chemokine expression. In conclusion, our data identify HO-1 as a central regulator of IEC chemokine expression that may contribute to homeo-stasis in the intestinal mucosa. © 2018 S. Karger AG, Basel.

Peru: population and policy.

PubMed

Sobrevilla, L A

1987-06-01

Peru's 1985 Population Policy Law states as its second objective that individuals and couples should be well informed and provided with the education and health services that will assist them in making responsible decisions about the number and spacing of their children. Thus, the law establishes a firm basis for IEC programs. With regard to population education, the purpose of the law is to create awareness through all educational channels of the reciprocal influence of population dynamics and socioeconomic development and to promote positive attitudes toward small family size. The law promotes the use of the communications media to educate and inform about population issues. The National Population Council, which coordinates and supervises the IEC activities of public sector agencies, has issued publications and audiovisual materials, conducted meetings with government officials and opinion leaders, and promoted awareness of population policy as a key part of development planning. In 1984, the Council organized the First National Seminar on Communication and Population to review activities, set the basis for intersectoral coordination, unify criteria, and review population policy concepts and language. The Ministry of Health carries out IEC activities as part of its family planning services program. In addition, the Ministry of Education has organized a national population education program that aims to revise school curricula to include a greater emphasis on population dynamics and family life education. The activities of a number of private institutions complement the IEC work public sector organizations.

Dynamics, Surface Electrostatics and Phase Properties of Nanoscale Curved Lipid Bilayers

NASA Astrophysics Data System (ADS)

Koolivand, Amir

Surface electrostatic potential of a lipid bilayer governs many vital functions of living cells. Several classes of proteins are known of exhibiting strong binding preferences to curved lipid bilayer surfaces. In this project we employed electron paramagnetic resonance (EPR) of a recently introduced phospholipid (IMTSL-PTE) bearing a pH-sensitive nitroxide covalently attached to the lipid head group to measure the surface electrostatics of the lipid membrane and nanopore-confined lipid bilayers as a function of the bilayer curvature. The pKa of the ionizable group of this lipid-based spin probe is reporting on the bilayer surface electrostatics potential by changes in the EPR spectra. Specifically, both rotational dynamics and magnetic parameters of the nitroxide are affected by the probe protonation. Effect of curvature on the surface electrostatic potential and dynamics of lipid bilayer was studied for POPG and DMPG unilamellar vesicles (ULVs). It was found that the magnitude of the negative surface electrostatic potential increased upon decrease in the vesicle diameter for the bilayers in the fluid phase; however, no significant changes were observed for DMPG ULVs in a gel phase. We speculate that biologically relevant fluid bilayer phase allows for a larger variability in the lipid packing density in the lipid polar head group region than a more ordered gel phase and it is likely that the lipid flip-flop is responsible for pH equilibration of IMTSL-PTE. The kinetic EPR study of nitroxide reduction showed that the rate of flip-flop is in the order of 10-5 s-1. The flip-flop rate constant increases when vesicle size deceases. Oxygen permeability measured by X-ban EPR decreases in higher curved vesicles---an observation that is consistent with a tighter packing in smaller vesicles. Partitioning of a small nitroxide molecule TEMPO into ULVs was measured by X-band (9 GHz) and W-band (95 GHz) EPR spectroscopy. The partitioning coefficient of this probe in the lipid phase of the bilayer was higher in smaller vesicles likely due to a larger number of defects in smaller vesicles allowing more water soluble molecules partitioning into lipid bilayers. However, the rotational correlation time for TEMPO slows down in smaller vesicles indicating an increase in the lipid packing. Pulsed EPR techniques, HYSCORE and ESEEM spectroscopy, were used to detect local water concentration and distinguish the hydrogen bonded water to the nitroxide from the bulk one. HYSCORE was then employed to investigate the effect of bilayer curvature on the water penetration into lipid bilayer and it was found that the higher curved lipids allow more water to penetrate into lipid bilayer as a result of more defects in the highly curved lipid vesicles. Nanopore-confined lipid bilayers formed inside ordered nanochannels of anodic aluminum oxide (AAO) have found many practical applications, serving as thermodynamically stable biophysical models of cellular membranes of concave curvature and allowing for stabilization of membrane proteins in functional conformations. It was found that surface potential of POPG lipids inside the AAO pores are higher than that of vesicles---the effect that is attributed to highly ordered and packed lipids inside the AAO nanopores. At pH=7.0 the AAO zeta potential was found to be -29+/-0.64 mV. Cytochrome C and poly glutamic acid as positively and negatively charged macromolecules in physiological pH (7.4) were used to prepare multilayer protein nanotubes and cytochrome c interaction with AAO was studied by CD and UV-Vis spectroscopy. Lipid nanotube arrays containing a transmembrane WALP peptide were also formed and these macroscopically aligned lipid nanotubes were studied by CD spectroscopy. The lipid phase transition of DMPC and binding of melittin, an antibacterial peptide model, were observed from a frequency change for the QCM quartz-AAO-Lipid as a promising "biosensor".

N-Doped Dual Carbon-Confined 3D Architecture rGO/Fe3O4/AC Nanocomposite for High-Performance Lithium-Ion Batteries.

PubMed

Ding, Ranran; Zhang, Jie; Qi, Jie; Li, Zhenhua; Wang, Chengyang; Chen, Mingming

2018-04-25

To address the issues of low electrical conductivity, sluggish lithiation kinetics and dramatic volume variation in Fe 3 O 4 anodes of lithium ion battery, herein, a double carbon-confined three-dimensional (3D) nanocomposite architecture was synthesized by an electrostatically assisted self-assembly strategy. In the constructed architecture, the ultrafine Fe 3 O 4 subunits (∼10 nm) self-organize to form nanospheres (NSs) that are fully coated by amorphous carbon (AC), formatting core-shell structural Fe 3 O 4 /AC NSs. By further encapsulation by reduced graphene oxide (rGO) layers, a constructed 3D architecture was built as dual carbon-confined rGO/Fe 3 O 4 /AC. Such structure restrains the adverse reaction of the electrolyte, improves the electronic conductivity and buffers the mechanical stress of the entire electrode, thus performing excellent long-term cycling stability (99.4% capacity retention after 465 cycles relevant to the second cycle at 5 A g -1 ). Kinetic analysis reveals that a dual lithium storage mechanism including a diffusion reaction mechanism and a surface capacitive behavior mechanism coexists in the composites. Consequently, the resulting rGO/Fe 3 O 4 /AC nanocomposite delivers a high reversible capacity (835.8 mA h g -1 for 300 cycles at 1 A g -1 ), as well as remarkable rate capability (436.7 mA h g -1 at 10 A g -1 ).

A collimator-converter system for IEC propulsion

NASA Astrophysics Data System (ADS)

Momota, Hiromu; Miley, George H.

2002-01-01

The collimator-converter system extracts fusion power from D-3He fueled IEC devices and provides electricity needed to operate ionic thrusters and other-power components. The whole system is linear and consists of a series of collimator units at the center, magnetic expander units at both sides of the fusion units, followed by direct energy converters at both ends. This system is enclosed in a vacuum chamber with a magnetic channel provided by magnetic solenoids out of respective chambers. The fusion unit consists of an IEC fusion core, a pair of coils anti-parallel to the solenoid coils, and a stabilization coil that stabilizes the position of coil pair coils. The IEC fusion core is installed at the center of the pair coils. After the magnetic expander, velocities of fusion particles from D-3He fueled IEC units are directed to the magnetic channel, which guides energetic fusion particles as well as leaking unburned fuel components to a high-efficiency traveling wave direct energy converter (TWDEC). Leaking unburned fuel components are separated with a magnetic separator at the entrance of a direct energy converter and pumped out for further refueling. A TWDEC is made of an array of metallic meshed grids, each of which is connected to every terminal with an external transmission circuit. The transmission line couples to the direct energy converter. Substations for electricity, a cryogenic plant, and various power control systems are outside of the vacuum chamber. The length of the cylindrical system is essentially determined by the proton energy of 14.8 MeV and the radius should be large so as to reduce power flow density. The present system provides 250 MWf fusion power and converting it to 150 MWc electricity. Its size is 150 m(length)×6.6 m(diameter) in size and 185 tons in weight. .

Human iPSC-derived myocardium-on-chip with capillary-like flow for personalized medicine.

PubMed

Ellis, Bradley W; Acun, Aylin; Can, U Isik; Zorlutuna, Pinar

2017-03-01

The heart wall tissue, or the myocardium, is one of the main targets in cardiovascular disease prevention and treatment. Animal models have not been sufficient in mimicking the human myocardium as evident by the very low clinical translation rates of cardiovascular drugs. Additionally, current in vitro models of the human myocardium possess several shortcomings such as lack of physiologically relevant co-culture of myocardial cells, lack of a 3D biomimetic environment, and the use of non-human cells. In this study, we address these shortcomings through the design and manufacture of a myocardium-on-chip (MOC) using 3D cell-laden hydrogel constructs and human induced pluripotent stem cell (hiPSC) derived myocardial cells. The MOC utilizes 3D spatially controlled co-culture of hiPSC derived cardiomyocytes (iCMs) and hiPSC derived endothelial cells (iECs) integrated among iCMs as well as in capillary-like side channels, to better mimic the microvasculature seen in native myocardium. We first fully characterized iCMs using immunostaining, genetic, and electrochemical analysis and iECs through immunostaining and alignment analysis to ensure their functionality, and then seeded these cells sequentially into the MOC device. We showed that iECs could be cultured within the microfluidic device without losing their phenotypic lineage commitment, and align with the flow upon physiological level shear stresses. We were able to incorporate iCMs within the device in a spatially controlled manner with the help of photocrosslinkable polymers. The iCMs were shown to be viable and functional within the device up to 7 days, and were integrated with the iECs. The iCMs and iECs in this study were derived from the same hiPSC cell line, essentially mimicking the myocardium of an individual human patient. Such devices are essential for personalized medicine studies where the individual drug response of patients with different genetic backgrounds can be tested in a physiologically relevant manner.

Human iPSC-derived myocardium-on-chip with capillary-like flow for personalized medicine

PubMed Central

Ellis, Bradley W.; Acun, Aylin; Can, U. Isik; Zorlutuna, Pinar

2017-01-01

The heart wall tissue, or the myocardium, is one of the main targets in cardiovascular disease prevention and treatment. Animal models have not been sufficient in mimicking the human myocardium as evident by the very low clinical translation rates of cardiovascular drugs. Additionally, current in vitro models of the human myocardium possess several shortcomings such as lack of physiologically relevant co-culture of myocardial cells, lack of a 3D biomimetic environment, and the use of non-human cells. In this study, we address these shortcomings through the design and manufacture of a myocardium-on-chip (MOC) using 3D cell-laden hydrogel constructs and human induced pluripotent stem cell (hiPSC) derived myocardial cells. The MOC utilizes 3D spatially controlled co-culture of hiPSC derived cardiomyocytes (iCMs) and hiPSC derived endothelial cells (iECs) integrated among iCMs as well as in capillary-like side channels, to better mimic the microvasculature seen in native myocardium. We first fully characterized iCMs using immunostaining, genetic, and electrochemical analysis and iECs through immunostaining and alignment analysis to ensure their functionality, and then seeded these cells sequentially into the MOC device. We showed that iECs could be cultured within the microfluidic device without losing their phenotypic lineage commitment, and align with the flow upon physiological level shear stresses. We were able to incorporate iCMs within the device in a spatially controlled manner with the help of photocrosslinkable polymers. The iCMs were shown to be viable and functional within the device up to 7 days, and were integrated with the iECs. The iCMs and iECs in this study were derived from the same hiPSC cell line, essentially mimicking the myocardium of an individual human patient. Such devices are essential for personalized medicine studies where the individual drug response of patients with different genetic backgrounds can be tested in a physiologically relevant manner. PMID:28396709

Cyclin-dependent kinases regulate apoptosis of intestinal epithelial cells

PubMed Central

Bhattacharya, Sujoy; Ray, Ramesh M.; Johnson, Leonard R.

2014-01-01

Homeostasis of the gastrointestinal epithelium is dependent upon a balance between cell proliferation and apoptosis. Cyclin-dependent kinases (Cdks) are well known for their role in cell proliferation. Previous studies from our group have shown that polyamine-depletion of intestinal epithelial cells (IEC-6) decreases cyclin-dependent kinase 2 (Cdk2) activity, increases p53 and p21Cip1 protein levels, induces G1 arrest, and protects cells from camptothecin (CPT)-induced apoptosis. Although emerging evidence suggests that members of the Cdk family are involved in the regulation of apoptosis, their roles directing apoptosis of IEC-6 cells are not known. In this study, we report that inhibition of Cdk1, 2, and 9 (with the broad range Cdk inhibitor, AZD5438) in proliferating IEC-6 cells triggered DNA damage, activated p53 signaling, inhibited proliferation, and induced apoptosis. By contrast, inhibition of Cdk2 (with NU6140) increased p53 protein and activity, inhibited proliferation, but had no effect on apoptosis. Notably, AZD5438 sensitized, whereas, NU6140 rescued proliferating IEC-6 cells from CPT-induced apoptosis. However, in colon carcinoma (Caco2) cells with mutant p53, treatment with either AZD5438 or NU6140 blocked proliferation, albeit more robustly with AZD5438. Both Cdk inhibitors induced apoptosis in Caco2 cells in a p53-independent manner. In serum starved quiescent IEC-6 cells, both AZD5438 and NU6140 decreased TNF- /CPT-induced activation of p53 and, consequently, rescued cells from apoptosis, indicating that sustained Cdk activity is required for apoptosis of quiescent cells. Furthermore, AZD5438 partially reversed the protective effect of polyamine depletion whereas NU6140 had no effect. Together, these results demonstrate that Cdks possess opposing roles in the control of apoptosis in quiescent and proliferating cells. In addition, Cdk inhibitors uncouple proliferation from apoptosis in a p53-dependent manner. PMID:24242917

Video: useful tool for delivering family planning messages.

PubMed

Sumarsono, S K

1985-10-01

In 1969, the Government of Indonesia declared that the population explosion was a national problem. The National Family Planning Program was consequently launched to encourage adoption of the ideal of a small, happy and prosperous family norm. Micro-approach messages are composed of the following: physiology of menstruation; reproductive process; healthy pregnancy; rational family planning; rational application of contraceptives; infant and child care; nutrition improvement; increase in breastfeeding; increase in family income; education in family life; family health; and deferred marriage age. Macro-approach messages include: the population problem and its impact on socioeconomic aspects; efforts to cope with the population problem; and improvement of women's lot. In utilizing the media and communication channels, the program encourages the implementation of units and working units of IEC to produce IEC materials; utilizes all possible existing media and IEC channels; maintains the consistent linkage between the activity of mass media and the IEC activities in the field; and encourages the private sector to participate in the production of IEC media and materials. A media production center was set up and carries out the following activities: producing video cassettes for tv broadcasts of family planning drama, family planning news, and tv spots; producing duplicates of the video cassettes for distribution to provinces in support of the video network; producing teaching materials for family planning workers; and transfering family planning films into video cassettes. A video network was developed and includes video monitors in family planning service points such as hospitals, family planning clinics and public places like bus stations. In 1985, the program will be expanded by 50 mobile information units equipped with video monitors. Video has potentials to increase the productivity and effectiveness of the family planning program. The video production process is cheaper and simpler than film production. Video will be very helpful as a communication aid in group meetings. It can also be used as a teaching aid for training.

Yielding impressive results. The Egyptian experience in family planning communication campaign has been an exemplary model for many developing countries.

PubMed

Wafai, M

1994-09-01

In Egypt the current use of family planning methods nearly doubled from 1980 to 1992. The toughest obstacles to the promotion of family planning are the deeply rooted pronatalism, the high rate of illiteracy, and low use of print media. The early efforts of the 1960s through the 1970s helped raise people's awareness of the problem, but traditional attitudes to family planning persisted. The Information, Education and Communication (IEC) Center established in 1979 in the State Information Service (SIS) of the Ministry of Information spearheaded the IEC efforts for family planning throughout the country. The Egyptian Contraceptives Prevalence Survey conducted in 1984 showed that the current use of family planning methods had increased 6.1% from the 1980 level, and that 56% of married women wished to stop having children, but were afraid of side effects of contraceptive use. The SIS/IEC Center launched a creative mass media campaign using TV spots and dramas. It also pioneered community-based public communication activities on population and family planning by organizing population communication forums. The local communication work is implemented by each of the 60 regional offices of SIS. Other government agencies, such as Health Insurance Organization, also launched IEC campaigns promoting their own services. Non-governmental organizations (NGOs) such as the Family of the Future and the Clinical Service Improvement Project also engaged in social marketing of contraceptives. The use of family planning methods mounted between 1980 and 1992 from 24% to nearly 48%, and the method of choice shifted from the pill to the IUD. The country's crude birth rate declined steadily from 40 per 1000 population in 1985 down to 29/1000 in 1992. The six major factors for success included an innovative communication program, religious support, political commitment, an improved service delivery system, involvement of NGOs, and the economic influence. The Egyptian experience in family planning IEC has been an exemplary model for many developing countries.

K+ Channel Inhibition Differentially Regulates Migration of Intestinal Epithelial Cells in Inflamed vs. Non-Inflamed Conditions in a PI3K/Akt-Mediated Manner

PubMed Central

Zundler, Sebastian; Caioni, Massimiliano; Müller, Martina; Strauch, Ulrike; Kunst, Claudia; Woelfel, Gisela

2016-01-01

Background Potassium channels have been shown to determine wound healing in different tissues, but their role in intestinal epithelial restitution–the rapid closure of superficial wounds by intestinal epithelial cells (IEC)–remains unclear. Methods In this study, the regulation of IEC migration by potassium channel modulation was explored with and without additional epidermal growth factor (EGF) under baseline and interferon-γ (IFN-γ)-pretreated conditions in scratch assays and Boyden chamber assays using the intestinal epithelial cell lines IEC-18 and HT-29. To identify possibly involved subcellular pathways, Western Blot (WB)-analysis of ERK and Akt phosphorylation was conducted and PI3K and ERK inhibitors were used in scratch assays. Furthermore, mRNA-levels of the potassium channel KCNN4 were determined in IEC from patients suffering from inflammatory bowel diseases (IBD). Results Inhibition of Ca2+-dependent potassium channels significantly increased intestinal epithelial restitution, which could not be further promoted by additional EGF. In contrast, inhibition of KCNN4 after pretreatment with IFN-γ led to decreased or unaffected migration. This effect was abolished by EGF. Changes in Akt, but not in ERK phosphorylation strongly correlated with these findings and PI3K but not ERK inhibition abrogated the effect of KCNN4 inhibition. Levels of KCNN4 mRNA were higher in samples from IBD patients compared with controls. Conclusions Taken together, we demonstrate that inhibition of KCNN4 differentially regulates IEC migration in IFN-γ-pretreated vs. non pretreated conditions. Moreover, our data propose that the PI3K signaling cascade is responsible for this differential regulation. Therefore, we present a cellular model that contributes new aspects to epithelial barrier dysfunction in chronic intestinal inflammation, resulting in propagation of inflammation and symptoms like ulcers or diarrhea. PMID:26824610

Exposure to Heavy Ion Radiation Induces Persistent Oxidative Stress in Mouse Intestine

PubMed Central

Datta, Kamal; Suman, Shubhankar; Kallakury, Bhaskar V. S.; Fornace, Albert J.

2012-01-01

Ionizing radiation-induced oxidative stress is attributed to generation of reactive oxygen species (ROS) due to radiolysis of water molecules and is short lived. Persistent oxidative stress has also been observed after radiation exposure and is implicated in the late effects of radiation. The goal of this study was to determine if long-term oxidative stress in freshly isolated mouse intestinal epithelial cells (IEC) is dependent on radiation quality at a dose relevant to fractionated radiotherapy. Mice (C57BL/6J; 6 to 8 weeks; female) were irradiated with 2 Gy of γ-rays, a low-linear energy transfer (LET) radiation, and intestinal tissues and IEC were collected 1 year after radiation exposure. Intracellular ROS, mitochondrial function, and antioxidant activity in IEC were studied by flow cytometry and biochemical assays. Oxidative DNA damage, cell death, and mitogenic activity in IEC were assessed by immunohistochemistry. Effects of γ radiation were compared to 56Fe radiation (iso-toxic dose: 1.6 Gy; energy: 1000 MeV/nucleon; LET: 148 keV/µm), we used as representative of high-LET radiation, since it's one of the important sources of high Z and high energy (HZE) radiation in cosmic rays. Radiation quality affected the level of persistent oxidative stress with higher elevation of intracellular ROS and mitochondrial superoxide in high-LET 56Fe radiation compared to unirradiated controls and γ radiation. NADPH oxidase activity, mitochondrial membrane damage, and loss of mitochondrial membrane potential were greater in 56Fe-irradiated mice. Compared to γ radiation oxidative DNA damage was higher, cell death ratio was unchanged, and mitotic activity was increased after 56Fe radiation. Taken together our results indicate that long-term functional dysregulation of mitochondria and increased NADPH oxidase activity are major contributing factors towards heavy ion radiation-induced persistent oxidative stress in IEC with potential for neoplastic transformation. PMID:22936983

Specialty Engineering Supplement to IEEE-15288.1

DTIC Science & Technology

2015-05-15

receiver required to work in a dense EMI environment. (15) Any RF receiver with a burnout level of less than 30 dBm (1 mW). b. A summary of all...Context 2.1 ISO-IEC-IEEE-15288: 2015, Systems and Software Engineering — System life cycle processes ISO-IEC-IEEE 15288 is the DOD-adopted standard for...to ISO-15288 for application of systems engineering on defense programs that was developed by a joint services working group under the auspices of the

ISO/IEC 17025 laboratory accreditation of NRC Acoustical Standards Program

NASA Astrophysics Data System (ADS)

Wong, George S. K.; Wu, Lixue; Hanes, Peter; Ohm, Won-Suk

2004-05-01

Experience gained during the external accreditation of the Acoustical Standards Program at the Institute for National Measurement Standards of the National Research Council is discussed. Some highlights include the preparation of documents for calibration procedures, control documents with attention to reducing future paper work and the need to maintain documentation or paper trails to satisfy the external assessors. General recommendations will be given for laboratories that are contemplating an external audit in accordance to the requirements of ISO/IEC 17025.

Assessing the Alignment of Information Security with Strategic Business, and Strategic Information System Planning: A Department of Defense Perspective

DTIC Science & Technology

2010-06-01

Wolfgang. "Appraisal of the effectivness and efficiency of an Information Security Management System based on ISO 27001 ." International Conference on...of corporate information resources (Doherty and 29 Fulford, 2006) ( ISO /IEC 17799, 2005). Both public and private sectors of business have...Science Ltd, 2002. Iacovou, Charalambos L. "The IPACS project: when IT hits the fan." Journal of Information Technology, 1999: 267-275. ISO /IEC 17799

Design and development of electric vehicle charging station equipped with RFID

NASA Astrophysics Data System (ADS)

Panatarani, C.; Murtaddo, D.; Maulana, D. W.; Irawan, S.; Joni, I. M.

2016-02-01

This paper reports the development of electric charging station from distributed renewable for electric vehicle (EV). This designed refer to the input voltage standard of IEC 61851, plugs features of IEC 62196 and standard communication of ISO 15118. The developed electric charging station used microcontroller ATMEGA8535 and RFID as controller and identifier of the EV users, respectively. The charging station successfully developed as desired features for electric vehicle from renewable energy resources grid with solar panel, wind power and batteries storage.

Proposal and evaluation of subordinate standard solar irradiance spectra for applications in solar energy systems

DOE PAGES

Jessen, Wilko; Wilbert, Stefan; Gueymard, Christian A.; ...

2018-04-10

Reference solar irradiance spectra are needed to specify key parameters of solar technologies such as photovoltaic cell efficiency, in a comparable way. The IEC 60904-3 and ASTM G173 standards present such spectra for Direct Normal Irradiance (DNI) and Global Tilted Irradiance (GTI) on a 37 degrees tilted sun-facing surface for one set of clear-sky conditions with an air mass of 1.5 and low aerosol content. The IEC/G173 standard spectra are the widely accepted references for these purposes. Hence, the authors support the future replacement of the outdated ISO 9845 spectra with the IEC spectra within the ongoing update of thismore » ISO standard. The use of a single reference spectrum per component of irradiance is important for clarity when comparing and rating solar devices such as PV cells. However, at some locations the average spectra can differ strongly from those defined in the IEC/G173 standards due to widely different atmospheric conditions and collector tilt angles. Therefore, additional subordinate standard spectra for other atmospheric conditions and tilt angles are of interest for a rough comparison of product performance under representative field conditions, in addition to using the main standard spectrum for product certification under standard test conditions. This simplifies the product selection for solar power systems when a fully-detailed performance analysis is not feasible (e.g. small installations). Also, the effort for a detailed yield analyses can be reduced by decreasing the number of initial product options. After appropriate testing, this contribution suggests a number of additional spectra related to eight sets of atmospheric conditions and tilt angles that are currently considered within ASTM and ISO working groups. The additional spectra, called subordinate standard spectra, are motivated by significant spectral mismatches compared to the IEC/G173 spectra (up to 6.5%, for PV at 37 degrees tilt and 10-15% for CPV). These mismatches correspond to potential accuracy improvements for a quick estimation of the average efficiency by applying the appropriate subordinate standard spectrum instead of the IEC/G173 spectra. The applicability of these spectra for PV performance analyses is confirmed at five test sites, for which subordinate spectra could be intuitively selected based on the average atmospheric aerosol optical depth (AOD) and precipitable water vapor at those locations. The development of subordinate standard spectra for DNI and concentrating solar power (CSP) and concentrating PV (CPV) is also considered. However, it is found that many more sets of atmospheric conditions would be required to allow the intuitive selection of DNI spectra for the five test sites, due in particular to the stronger effect of AOD on DNI compared to GTI. The matrix of subordinate GTI spectra described in this paper are recommended to appear as an option in the annex of future standards, in addition to the obligatory use of the main spectrum from the ASTM G173 and IEC 60904 standards.« less

Proposal and evaluation of subordinate standard solar irradiance spectra for applications in solar energy systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jessen, Wilko; Wilbert, Stefan; Gueymard, Christian A.

Reference solar irradiance spectra are needed to specify key parameters of solar technologies such as photovoltaic cell efficiency, in a comparable way. The IEC 60904-3 and ASTM G173 standards present such spectra for Direct Normal Irradiance (DNI) and Global Tilted Irradiance (GTI) on a 37 degrees tilted sun-facing surface for one set of clear-sky conditions with an air mass of 1.5 and low aerosol content. The IEC/G173 standard spectra are the widely accepted references for these purposes. Hence, the authors support the future replacement of the outdated ISO 9845 spectra with the IEC spectra within the ongoing update of thismore » ISO standard. The use of a single reference spectrum per component of irradiance is important for clarity when comparing and rating solar devices such as PV cells. However, at some locations the average spectra can differ strongly from those defined in the IEC/G173 standards due to widely different atmospheric conditions and collector tilt angles. Therefore, additional subordinate standard spectra for other atmospheric conditions and tilt angles are of interest for a rough comparison of product performance under representative field conditions, in addition to using the main standard spectrum for product certification under standard test conditions. This simplifies the product selection for solar power systems when a fully-detailed performance analysis is not feasible (e.g. small installations). Also, the effort for a detailed yield analyses can be reduced by decreasing the number of initial product options. After appropriate testing, this contribution suggests a number of additional spectra related to eight sets of atmospheric conditions and tilt angles that are currently considered within ASTM and ISO working groups. The additional spectra, called subordinate standard spectra, are motivated by significant spectral mismatches compared to the IEC/G173 spectra (up to 6.5%, for PV at 37 degrees tilt and 10-15% for CPV). These mismatches correspond to potential accuracy improvements for a quick estimation of the average efficiency by applying the appropriate subordinate standard spectrum instead of the IEC/G173 spectra. The applicability of these spectra for PV performance analyses is confirmed at five test sites, for which subordinate spectra could be intuitively selected based on the average atmospheric aerosol optical depth (AOD) and precipitable water vapor at those locations. The development of subordinate standard spectra for DNI and concentrating solar power (CSP) and concentrating PV (CPV) is also considered. However, it is found that many more sets of atmospheric conditions would be required to allow the intuitive selection of DNI spectra for the five test sites, due in particular to the stronger effect of AOD on DNI compared to GTI. The matrix of subordinate GTI spectra described in this paper are recommended to appear as an option in the annex of future standards, in addition to the obligatory use of the main spectrum from the ASTM G173 and IEC 60904 standards.« less

Electrostatically confined trilayer graphene quantum dots

NASA Astrophysics Data System (ADS)

Mirzakhani, M.; Zarenia, M.; Vasilopoulos, P.; Peeters, F. M.

2017-04-01

Electrically gating of trilayer graphene (TLG) opens a band gap offering the possibility to electrically engineer TLG quantum dots. We study the energy levels of such quantum dots and investigate their dependence on a perpendicular magnetic field B and different types of stacking of the graphene layers. The dots are modeled as circular and confined by a truncated parabolic potential which can be realized by nanostructured gates or position-dependent doping. The energy spectra exhibit the intervalley symmetry EKe(m ) =-EK'h(m ) for the electron (e ) and hole (h ) states, where m is the angular momentum quantum number and K and K ' label the two valleys. The electron and hole spectra for B =0 are twofold degenerate due to the intervalley symmetry EK(m ) =EK'[-(m +1 ) ] . For both ABC [α =1.5 (1.2) for large (small) R ] and ABA (α =1 ) stackings, the lowest-energy levels show approximately a R-α dependence on the dot radius R in contrast with the 1 /R3 one for ABC-stacked dots with infinite-mass boundary. As functions of the field B , the oscillator strengths for dipole-allowed transitions differ drastically for the two types of stackings.

Edge gyrokinetic theory and continuum simulations

NASA Astrophysics Data System (ADS)

Xu, X. Q.; Xiong, Z.; Dorr, M. R.; Hittinger, J. A.; Bodi, K.; Candy, J.; Cohen, B. I.; Cohen, R. H.; Colella, P.; Kerbel, G. D.; Krasheninnikov, S.; Nevins, W. M.; Qin, H.; Rognlien, T. D.; Snyder, P. B.; Umansky, M. V.

2007-08-01

The following results are presented from the development and application of TEMPEST, a fully nonlinear (full-f) five-dimensional (3d2v) gyrokinetic continuum edge-plasma code. (1) As a test of the interaction of collisions and parallel streaming, TEMPEST is compared with published analytic and numerical results for endloss of particles confined by combined electrostatic and magnetic wells. Good agreement is found over a wide range of collisionality, confining potential and mirror ratio, and the required velocity space resolution is modest. (2) In a large-aspect-ratio circular geometry, excellent agreement is found for a neoclassical equilibrium with parallel ion flow in the banana regime with zero temperature gradient and radial electric field. (3) The four-dimensional (2d2v) version of the code produces the first self-consistent simulation results of collisionless damping of geodesic acoustic modes and zonal flow (Rosenbluth-Hinton residual) with Boltzmann electrons using a full-f code. The electric field is also found to agree with the standard neoclassical expression for steep density and ion temperature gradients in the plateau regime. In divertor geometry, it is found that the endloss of particles and energy induces parallel flow stronger than the core neoclassical predictions in the SOL.

Toward Intelligent Synthetic Neural Circuits: Directing and Accelerating Neuron Cell Growth by Self-Rolled-Up Silicon Nitride Microtube Array

PubMed Central

2015-01-01

In neural interface platforms, cultures are often carried out on a flat, open, rigid, and opaque substrate, posing challenges to reflecting the native microenvironment of the brain and precise engagement with neurons. Here we present a neuron cell culturing platform that consists of arrays of ordered microtubes (2.7–4.4 μm in diameter), formed by strain-induced self-rolled-up nanomembrane (s-RUM) technology using ultrathin (<40 nm) silicon nitride (SiNx) film on transparent substrates. These microtubes demonstrated robust physical confinement and unprecedented guidance effect toward outgrowth of primary cortical neurons, with a coaxially confined configuration resembling that of myelin sheaths. The dynamic neural growth inside the microtube, evaluated with continuous live-cell imaging, showed a marked increase (20×) of the growth rate inside the microtube compared to regions outside the microtubes. We attribute the dramatic accelerating effect and precise guiding of the microtube array to three-dimensional (3D) adhesion and electrostatic interaction with the SiNx microtubes, respectively. This work has clear implications toward building intelligent synthetic neural circuits by arranging the size, site, and patterns of the microtube array, for potential treatment of neurological disorders. PMID:25329686

Hydrophobic Characteristics of Composite Insulators in Simulated Inland Arid Desert Environment

NASA Astrophysics Data System (ADS)

Khan, Yasin; Al-Arainy, Abdulrehman Ali; Malik, Nazar Hussain; Qureshi, Muhammad Iqbal

2010-06-01

Presently along with traditional insulators i.e. glass and porcelain, etc., the polymeric insulators are also used world widely. These polymeric insulators are very sensitive to various environmental parameters e.g. UV radiations, heat, etc. The UV radiation level in the central region of Saudi Arabia is high as compared to the recommended IEC-61109 standard for the accelerated aging of the composite insulators. In this study, thermoplastic elastomer (TPE) and Ethylene Propylene Diene Monomer (EPDM) insulators were subjected to accelerated aging stress as per IEC standard as well as modified IEC standard simulating the inland arid desert's atmospheric conditions. The hydrophobic characteristics were studied by measuring the contact angle along the insulator surface before and after the accelerated aging of the samples. It was found that TPE loses its hydrophobic properties more as compared to EPDM insulator. This loss was proportional to the intensity of UV irradiation. The rate of recovery is also low for both the tested materials as compared to Silicone Rubber insulators.

Chromatographic study of highly methoxylated lime pectins deesterified by different pectin methyl-esterases.

PubMed

Ralet, M C; Bonnin, E; Thibault, J F

2001-03-25

The inter-molecular distribution of free carboxyl groups of two highly methoxylated pectins enzymatically deesterified by plant and fungus pectin methyl-esterases were investigated by size-exclusion (SEC) and ion-exchange chromatography (IEC). "Homogeneous" populations with respect to molar mass or charge density were thereby obtained and their chemical composition and physico-chemical properties (transport parameter for monovalent cations and calcium, calcium activity coefficient) were studied. Chemical analysis showed that the composition varies from one SEC fraction to another, the highest molar mass fraction being richer in rhamnose and galactose and exhibiting a slightly higher degree of methylation. Separation of pectins by IEC revealed a quite homogeneous charge density distribution for F58 contrary to P60 which exhibited a large distribution of methoxyl groups. The free carboxyl groups distributions and calcium binding behaviours of SEC and IEC fractions were shown to differ widely for highly methoxylated pectins deesterified by plant and fungus pectin methyl-esterases.

Transformer fault diagnosis using continuous sparse autoencoder.

PubMed

Wang, Lukun; Zhao, Xiaoying; Pei, Jiangnan; Tang, Gongyou

2016-01-01

This paper proposes a novel continuous sparse autoencoder (CSAE) which can be used in unsupervised feature learning. The CSAE adds Gaussian stochastic unit into activation function to extract features of nonlinear data. In this paper, CSAE is applied to solve the problem of transformer fault recognition. Firstly, based on dissolved gas analysis method, IEC three ratios are calculated by the concentrations of dissolved gases. Then IEC three ratios data is normalized to reduce data singularity and improve training speed. Secondly, deep belief network is established by two layers of CSAE and one layer of back propagation (BP) network. Thirdly, CSAE is adopted to unsupervised training and getting features. Then BP network is used for supervised training and getting transformer fault. Finally, the experimental data from IEC TC 10 dataset aims to illustrate the effectiveness of the presented approach. Comparative experiments clearly show that CSAE can extract features from the original data, and achieve a superior correct differentiation rate on transformer fault diagnosis.

HYDROPHOBIC CHARACTERISTICS OF COMPOSITE INSULATORS IN SIMULATED INLAND ARID DESERT ENVIRONMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Yasin; Al-Arainy, Abdulrehman Ali; Malik, Nazar Hussain

2010-06-15

Presently along with traditional insulators i.e. glass and porcelain, etc., the polymeric insulators are also used world widely. These polymeric insulators are very sensitive to various environmental parameters e.g. UV radiations, heat, etc. The UV radiation level in the central region of Saudi Arabia is high as compared to the recommended IEC-61109 standard for the accelerated aging of the composite insulators. In this study, thermoplastic elastomer (TPE) and Ethylene Propylene Diene Monomer (EPDM) insulators were subjected to accelerated aging stress as per IEC standard as well as modified IEC standard simulating the inland arid desert's atmospheric conditions. The hydrophobic characteristicsmore » were studied by measuring the contact angle along the insulator surface before and after the accelerated aging of the samples. It was found that TPE loses its hydrophobic properties more as compared to EPDM insulator. This loss was proportional to the intensity of UV irradiation. The rate of recovery is also low for both the tested materials as compared to Silicone Rubber insulators.« less

Fast low-to-high confinement mode bifurcation dynamics in a tokamak edge plasma gyrokinetic simulation

DOE PAGES

Chang, C. S.; Ku, S.; Tynan, G. R.; ...

2017-04-25

Transport barrier formation and its relation to sheared flows in fluids and plasmas are of fundamental interest in various natural and laboratory observations and of critical importance in achieving an economical energy production in a magnetic fusion device. Here we report the first observation of an edge transport barrier formation event in an electrostatic gyrokinetic simulation carried out in a realistic diverted tokamak edge geometry under strong forcing by a high rate of heat deposition. Here, the results show that turbulent Reynolds-stress-driven sheared E x B flows act in concert with neoclassical orbit loss to quench turbulent transport and formmore » a transport barrier just inside the last closed magnetic flux surface.« less

5.5-7.5 MeV Proton Generation by a Moderate-Intensity Ultrashort-Pulse Laser Interaction with H{sub 2}O Nanowire Targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zigler, A.; Palchan, T.; Bruner, N.

We report on the first generation of 5.5-7.5 MeV protons by a moderate-intensity short-pulse laser ({approx}5x10{sup 17} W/cm{sup 2}, 40 fsec) interacting with frozen H{sub 2}O nanometer-size structure droplets (snow nanowires) deposited on a sapphire substrate. In this setup, the laser intensity is locally enhanced by the snow nanowire, leading to high spatial gradients. Accordingly, the nanoplasma is subject to enhanced ponderomotive potential, and confined charge separation is obtained. Electrostatic fields of extremely high intensities are produced over the short scale length, and protons are accelerated to MeV-level energies.

A fast low-to-high confinement mode bifurcation dynamics in the boundary-plasma gyrokinetic code XGC1

DOE PAGES

Ku, S.; Chang, C. S.; Hager, R.; ...

2018-04-18

Here, a fast edge turbulence suppression event has been simulated in the electrostatic version of the gyrokinetic particle-in-cell code XGC1 in a realistic diverted tokamak edge geometry under neutral particle recycling. The results show that the sequence of turbulent Reynolds stress followed by neoclassical ion orbit-loss driven together conspire to form the sustaining radial electric field shear and to quench turbulent transport just inside the last closed magnetic flux surface. As a result, the main suppression action is located in a thin radial layer around ψ N≃0.96–0.98, where ψ N is the normalized poloidal flux, with the time scale ~0.1more » ms.« less

Parametric decay instability near the upper hybrid resonance in magnetically confined fusion plasmas

NASA Astrophysics Data System (ADS)

Hansen, S. K.; Nielsen, S. K.; Salewski, M.; Stejner, M.; Stober, J.; the ASDEX Upgrade Team

2017-10-01

In this paper we investigate parametric decay of an electromagnetic pump wave into two electrostatic daughter waves, particularly an X-mode pump wave decaying into a warm upper hybrid wave (a limit of an electron Bernstein wave) and a warm lower hybrid wave. We describe the general theory of the above parametric decay instability (PDI), unifying earlier treatments, and show that it may occur in underdense and weakly overdense plasmas. The PDI theory is used to explain anomalous sidebands observed in collective Thomson scattering (CTS) spectra at the ASDEX Upgrade tokamak. The theory may also account for similar observations during CTS experiments in stellarators, as well as in some 1st harmonic electron cyclotron resonance and O-X-B heating experiments.

Hole injection and electron overflow improvement in InGaN/GaN light-emitting diodes by a tapered AlGaN electron blocking layer.

PubMed

Lin, Bing-Chen; Chen, Kuo-Ju; Wang, Chao-Hsun; Chiu, Ching-Hsueh; Lan, Yu-Pin; Lin, Chien-Chung; Lee, Po-Tsung; Shih, Min-Hsiung; Kuo, Yen-Kuang; Kuo, Hao-Chung

2014-01-13

A tapered AlGaN electron blocking layer with step-graded aluminum composition is analyzed in nitride-based blue light-emitting diode (LED) numerically and experimentally. The energy band diagrams, electrostatic fields, carrier concentration, electron current density profiles, and hole transmitting probability are investigated. The simulation results demonstrated that such tapered structure can effectively enhance the hole injection efficiency as well as the electron confinement. Consequently, the LED with a tapered EBL grown by metal-organic chemical vapor deposition exhibits reduced efficiency droop behavior of 29% as compared with 44% for original LED, which reflects the improvement in hole injection and electron overflow in our design.

Inter-conversion of Work and Heat With Plasma Electric Fields

NASA Astrophysics Data System (ADS)

Avinash, K.

2010-11-01

Thermodynamics of a model system where a group of cold charged particles locally confined in a volume VP within a warm plasma of temperature T and fixed volume V (VP<

Targeting AIDS through information, education, and communications programs: implications for Africa and the Caribbean.

PubMed

Ward, W B

1989-01-01

IEC campaigns targeted at acquired immunodeficiency syndrome (AIDS) must seek to achieve the maximum impact within a contest of extremely limited resources. This implies a careful assessment of population groups and behaviors that carry the highest risk. Rather than expending large sums of money on mass media campaigns, the approach should be to target IEC activities at the social networks of those most at risk. This may include, for example, prostitutes, homosexual men, hotel and tourist employees, students, and military personnel. Once epidemiologic studies have identified the at-risk population, volunteers form these groups should be recruited and trained to reach their peers through the networks available to them. This education component of IEC work takes priority. The second step involves information diffusion to health providers who are likely to come into contact with human immunodeficiency virus (HIV)-infected individuals, especially those who have access to pregnant women and mothers. Some of these providers are not aware of the risks involved in the reuse of immunization needles. The third step--communication with the general public--is aimed at making the population aware of the factors that place people at risk of HIV infection. Radio seems to be the media capable of reaching the greatest numbers, although traditional means of communication should not be neglected. The IEC effort should consider options at the community, institutional, and individual levels and address those factors that enable, reinforce, and predispose appropriate health behaviors.

Three dimensional liquid chromatography coupling ion exchange chromatography/hydrophobic interaction chromatography/reverse phase chromatography for effective protein separation in top-down proteomics.

PubMed

Valeja, Santosh G; Xiu, Lichen; Gregorich, Zachery R; Guner, Huseyin; Jin, Song; Ge, Ying

2015-01-01

To address the complexity of the proteome in mass spectrometry (MS)-based top-down proteomics, multidimensional liquid chromatography (MDLC) strategies that can effectively separate proteins with high resolution and automation are highly desirable. Although various MDLC methods that can effectively separate peptides from protein digests exist, very few MDLC strategies, primarily consisting of 2DLC, are available for intact protein separation, which is insufficient to address the complexity of the proteome. We recently demonstrated that hydrophobic interaction chromatography (HIC) utilizing a MS-compatible salt can provide high resolution separation of intact proteins for top-down proteomics. Herein, we have developed a novel 3DLC strategy by coupling HIC with ion exchange chromatography (IEC) and reverse phase chromatography (RPC) for intact protein separation. We demonstrated that a 3D (IEC-HIC-RPC) approach greatly outperformed the conventional 2D IEC-RPC approach. For the same IEC fraction (out of 35 fractions) from a crude HEK 293 cell lysate, a total of 640 proteins were identified in the 3D approach (corresponding to 201 nonredundant proteins) as compared to 47 in the 2D approach, whereas simply prolonging the gradients in RPC in the 2D approach only led to minimal improvement in protein separation and identifications. Therefore, this novel 3DLC method has great potential for effective separation of intact proteins to achieve deep proteome coverage in top-down proteomics.

Considerations of the Effects of Naphthalene Moieties on the Design of Proton-Conductive Poly(arylene ether ketone) Membranes for Direct Methanol Fuel Cells.

PubMed

Wang, Baolong; Hong, Lihua; Li, Yunfeng; Zhao, Liang; Wei, Yuxue; Zhao, Chengji; Na, Hui

2016-09-14

Novel sulfonated poly(arylene ether ketones) (SDN-PAEK-x), consisting of dual naphthalene and flexible sulfoalkyl groups, were prepared via polycondensation, demethylation, and sulfobutylation grafting reaction. Among them, SDN-PAEK-1.94 membrane with the highest ion exchange capacity (IEC = 2.46 mequiv·g(-1)) exhibited the highest proton conductivity, which was 0.147 S· cm(-1) at 25 °C and 0.271 S·cm(-1) at 80 °C, respectively. The introduction of dual naphthalene moieties is expected to achieve much enhanced properties compared to those of sulfonated poly(arylene ether ketones) (SNPAEK-x), consisting of single naphthalene and flexible sulfoalkyl groups. Compared with SNPAEK-1.60 with a similar IEC, SDN-PAEK-1.74 membrane showed higher proton conductivity, higher IEC normalized conductivity, and higher effective proton mobility, although it had lower analytical acid concentration. The SDN-PAEK-x membranes with IECs higher than 1.96 mequiv·g(-1) also exhibited higher proton conductivity than that of recast Nafion membrane. Furthermore, SDN-PAEK-1.94 displayed a better single cell performance with a maximum power density of 60 mW·cm(-2) at 80 °C. Considering its high proton conductivity, excellent single cell performance, good mechanical stabilities, low membrane swelling, and methanol permeability, SDN-PAEK-x membranes are promising candidates as alternative polymer electrolyte membranes to Nafion for direct methanol fuel cell applications.

A new 3D finite element model of the IEC 60318-1 artificial ear: II. Experimental and numerical validation

NASA Astrophysics Data System (ADS)

Bravo, Agustín; Barham, Richard; Ruiz, Mariano; López, Juan Manuel; De Arcas, Guillermo; Alonso, Jesus

2012-12-01

In part I, the feasibility of using three-dimensional (3D) finite elements (FEs) to model the acoustic behaviour of the IEC 60318-1 artificial ear was studied and the numerical approach compared with classical lumped elements modelling. It was shown that by using a more complex acoustic model that took account of thermo-viscous effects, geometric shapes and dimensions, it was possible to develop a realistic model. This model then had clear advantages in comparison with the models based on equivalent circuits using lumped parameters. In fact results from FE modelling produce a better understanding about the physical phenomena produced inside ear simulator couplers, facilitating spatial and temporal visualization of the sound fields produced. The objective of this study (part II) is to extend the investigation by validating the numerical calculations against measurements on an ear simulator conforming to IEC 60318-1. For this purpose, an appropriate commercially available device is taken and a complete 3D FE model developed for it. The numerical model is based on key dimensional data obtained with a non-destructive x-ray inspection technique. Measurements of the acoustic transfer impedance have been carried out on the same device at a national measurement institute using the method embodied in IEC 60318-1. Having accounted for the actual device dimensions, the thermo-viscous effects inside narrow slots and holes and environmental conditions, the results of the numerical modelling were found to be in good agreement with the measured values.

Intraparenchymal epidermoid cyst: proper surgical management may lead to satisfactory outcome.

PubMed

Zheng, Jian; Wang, Chun; Liu, Fengqiang

2018-03-12

Intraparenchymal epidermoid cysts (IECs) are rare lesions, thus the preoperative diagnosis and proper surgical management are still a challenge. We searched the database at our institution and performed a search of English literature in PubMed and Google Scholar. Keywords used were as follows: "intraparenchymal"; "intracerebral"; "intraaxial"; "epidermoid cyst"; "brainstem"; "cholesteatoma"; "pearly tumor". Only cases that were true intraparenchymally located and contained adequate clinical information were included. Six cases of IECs were recorded at our institution. Total removal was achieved in all the six patients with good outcomes. 29 cases meeting the above criteria were found in the literature. Including ours, a total of 35 patients were analyzed. Females were more frequently affected (F/M ratio, 1.9:1). Most of them were located in the brainstem (42.9%) and temporal lobe (22.9%). While in children, all were located in the brainstem. 45.2% showed subtle peripheral enhancement on Magnetic Resonance Imaging (MRI), and all appeared hyperintense on Diffusion Weighted Imaging (DWI). In the subgroup of cerebral lobes and cerebellums, total resection was achieved in 89.5%, and they all showed good outcomes. While in the subgroup of brainstem, 46.7% (seven cases) underwent total resection and 50% (three cases) of them died postoperatively. MRI with DWI is helpful in the preoperative diagnosis. Total resection should be achieved for the IECs located in cerebral lobes and cerebellums, while subtotal resection is a wise and safe strategy for the IECs located in the brainstem.

INCOSE Systems Engineering Handbook v3.2: Improving the Process for SE Practitioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

R. Douglas Hamelin; David D. Walden; Michael E. Krueger

2010-07-01

The INCOSE Systems Engineering Handbook is the official INCOSE reference document for understanding systems engineering (SE) methods and conducting SE activities. Over the years, the Handbook has evolved to accommodate advances in the SE discipline and now serves as the basis for the Certified Systems Engineering Professional (CSEP) exam. Due to its evolution, the Handbook had become somewhat disjointed in its treatment and presentation of SE topics and was not aligned with the latest version of International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) 15288:2008, Systems and Software Engineering. As a result, numerous inconsistencies were identified that could confuse practitionersmore » and directly impact the probability of success in passing the CSEP exam. Further, INCOSE leadership had previously submitted v3.1 of the Handbook to ISO/IEC for consideration as a Technical Report, but was told that the Handbook would have to be updated to conform with the terminology and structure of new ISO/IEC15288:2008, Systems and software engineering, prior to being considered. The revised INCOSE Systems Engineering Handbook v3.2 aligns with the structure and principles of ISO/IEC 15288:2008 and presents the generic SE life-cycle process steps in their entirety, without duplication or redundancy, in a single location within the text. As such, the revised Handbook v3.2 serves as a comprehensive instructional and reference manual for effectively understanding SE processes and conducting SE and better serves certification candidates preparing for the CSEP exam.« less

Escherichia coli STb toxin induces apoptosis in intestinal epithelial cell lines.

PubMed

Syed, H Claudia; Dubreuil, J Daniel

2012-09-01

A previous study conducted in our laboratory demonstrated that cells having internalized Escherichia coli STb toxin display apoptotic-like morphology. We therefore investigated if STb could induce programmed cell death in both a human and an animal intestinal epithelial cell lines. HRT-18 (Human Colon Tumor) and IEC-18 (Rat Ileum Epithelial Cells) cell lines were used. As STb is frequently tested in a rat model, the IEC-18 cell line was most relevant to our work. The cell lines were treated with various amounts of purified STb (nanomole range) for a period of 24 h after which cells were harvested and examined for apoptotic characteristics. Caspase-9, the initiator of mitochondrion-mediated apoptosis, and caspase-3, an effector of caspase-9, were both activated following STb intoxication of HRT-18 and IEC-18 cells whereas caspase-8, the initiator caspase of the extrinsic pathway, was not activated. For both cell lines, agarose gel electrophoresis of the cell DNA content reveals laddering of DNA, resulting from DNA fragmentation, a characteristic of apoptosis. Hoechst 33342-stained DNA of STb-treated cell lines, observed using fluorescence microscopy, revealed condensation and fragmentation of the nuclei. Apoptotic indexes calculated from fragmented nuclei of Hoechst 33342-stained DNA for HRT-18 and IEC-18 cells showed an STb dose-dependent response. Overall, these data indicate that STb toxin induces a mitochondrion-mediated caspase-dependent apoptotic pathway. Copyright © 2012 Elsevier Ltd. All rights reserved.

Molecular interactions and residues involved in force generation in the T4 viral DNA packaging motor.

PubMed

Migliori, Amy D; Smith, Douglas E; Arya, Gaurav

2014-12-12

Many viruses utilize molecular motors to package their genomes into preformed capsids. A striking feature of these motors is their ability to generate large forces to drive DNA translocation against entropic, electrostatic, and bending forces resisting DNA confinement. A model based on recently resolved structures of the bacteriophage T4 motor protein gp17 suggests that this motor generates large forces by undergoing a conformational change from an extended to a compact state. This transition is proposed to be driven by electrostatic interactions between complementarily charged residues across the interface between the N- and C-terminal domains of gp17. Here we use atomistic molecular dynamics simulations to investigate in detail the molecular interactions and residues involved in such a compaction transition of gp17. We find that although electrostatic interactions between charged residues contribute significantly to the overall free energy change of compaction, interactions mediated by the uncharged residues are equally if not more important. We identify five charged residues and six uncharged residues at the interface that play a dominant role in the compaction transition and also reveal salt bridging, van der Waals, and solvent hydrogen-bonding interactions mediated by these residues in stabilizing the compact form of gp17. The formation of a salt bridge between Glu309 and Arg494 is found to be particularly crucial, consistent with experiments showing complete abrogation in packaging upon Glu309Lys mutation. The computed contributions of several other residues are also found to correlate well with single-molecule measurements of impairments in DNA translocation activity caused by site-directed mutations. Copyright © 2014 Elsevier Ltd. All rights reserved.

DIFFUSED SOLUTE-SOLVENT INTERFACE WITH POISSON-BOLTZMANN ELECTROSTATICS: FREE-ENERGY VARIATION AND SHARP-INTERFACE LIMIT.

PubMed

Li, B O; Liu, Yuan

A phase-field free-energy functional for the solvation of charged molecules (e.g., proteins) in aqueous solvent (i.e., water or salted water) is constructed. The functional consists of the solute volumetric and solute-solvent interfacial energies, the solute-solvent van der Waals interaction energy, and the continuum electrostatic free energy described by the Poisson-Boltzmann theory. All these are expressed in terms of phase fields that, for low free-energy conformations, are close to one value in the solute phase and another in the solvent phase. A key property of the model is that the phase-field interpolation of dielectric coefficient has the vanishing derivative at both solute and solvent phases. The first variation of such an effective free-energy functional is derived. Matched asymptotic analysis is carried out for the resulting relaxation dynamics of the diffused solute-solvent interface. It is shown that the sharp-interface limit is exactly the variational implicit-solvent model that has successfully captured capillary evaporation in hydrophobic confinement and corresponding multiple equilibrium states of underlying biomolecular systems as found in experiment and molecular dynamics simulations. Our phase-field approach and analysis can be used to possibly couple the description of interfacial fluctuations for efficient numerical computations of biomolecular interactions.

Phase-field approach to implicit solvation of biomolecules with Coulomb-field approximation

NASA Astrophysics Data System (ADS)

Zhao, Yanxiang; Kwan, Yuen-Yick; Che, Jianwei; Li, Bo; McCammon, J. Andrew

2013-07-01

A phase-field variational implicit-solvent approach is developed for the solvation of charged molecules. The starting point of such an approach is the representation of a solute-solvent interface by a phase field that takes one value in the solute region and another in the solvent region, with a smooth transition from one to the other on a small transition layer. The minimization of an effective free-energy functional of all possible phase fields determines the equilibrium conformations and free energies of an underlying molecular system. All the surface energy, the solute-solvent van der Waals interaction, and the electrostatic interaction are coupled together self-consistently through a phase field. The surface energy results from the minimization of a double-well potential and the gradient of a field. The electrostatic interaction is described by the Coulomb-field approximation. Accurate and efficient methods are designed and implemented to numerically relax an underlying charged molecular system. Applications to single ions, a two-plate system, and a two-domain protein reveal that the new theory and methods can capture capillary evaporation in hydrophobic confinement and corresponding multiple equilibrium states as found in molecular dynamics simulations. Comparisons of the phase-field and the original sharp-interface variational approaches are discussed.

Minutes. Accredited Standards Committee on Acoustics, S1. U.S. Tag for ISO/TC43 Acoustics and IEC/TC29 Electroacoustics, Held in Denver, Colorado on 7 October 1993

DTIC Science & Technology

1993-10-07

Oroanizational matters and reports on working grouos . including regorts on letter ballots and international matters (continued) e) S1/WG5 - Band Filter Sets...Band Analog and Digital Filters "* ANSI S1.20-1988 Procedures for Calibration of Underwater Electroacoustics Transducers "* ANSI S;1.42-1986 Design ...New International Standards Available a IEC 118-2 - Amendment 1 - 1993 Hearing aids. Part 2: Hearina aids with automatic gain control circuits 9

National Environmental Field Activities Program

DTIC Science & Technology

2011-03-31

holder community. –It is one of a kind! –Written for any type of field sampling  and testing  • Builds of the foundation of  ISO / IEC   17025 ! Why TNI...Why chose the TNI standard and not others – ISO  9000 – ISO / IEC  17020 – ISO  14000 – ASTM, USGS, EPA, Etc. – XXXXXX, XXX or XXXX REDUCE DATA VARIABILITY

Software validation applied to spreadsheets used in laboratories working under ISO/IEC 17025

NASA Astrophysics Data System (ADS)

Banegas, J. M.; Orué, M. W.

2016-07-01

Several documents deal with software validation. Nevertheless, more are too complex to be applied to validate spreadsheets - surely the most used software in laboratories working under ISO/IEC 17025. The method proposed in this work is intended to be directly applied to validate spreadsheets. It includes a systematic way to document requirements, operational aspects regarding to validation, and a simple method to keep records of validation results and modifications history. This method is actually being used in an accredited calibration laboratory, showing to be practical and efficient.

Preservation of Thermal Control Specular Gold Baffle Surface on the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) Electronics Compartment (IEC)

NASA Technical Reports Server (NTRS)

MonteedeGarcia, Kristina; Patel, Jignasha; Perry, Radford, III

2010-01-01

Extremely tight thermal control property degradation allowances on the vapor-deposited, gold-coated IEC baffle surface, made necessary by the cryogenic JWST Observatory operations, dictate tight contamination requirements on adjacent surfaces. Theoretical degradation in emittance with contaminant thickness was calculated. Maximum allowable source outgassing rates were calculated using worst case view factors from source to baffle surface. Tight requirements pushed the team to change the design of the adjacent surfaces to minimize the outgassing sources

Preservation of thermal control specular gold baffle surface on the James Webb Space Telescope (JWST) integrated science instrument module (ISIM) electronics compartment (IEC)

NASA Astrophysics Data System (ADS)

Montt de Garcia, Kristina; Patel, Jignasha; Perry, Radford, III

2010-08-01

Extremely tight thermal control property degradation allowances on the vapor-deposited, gold-coated IEC baffle surface, made necessary by the cryogenic JWST Observatory operations, dictate tight contamination requirements on adjacent surfaces. Theoretical degradation in emittance with contaminant thickness was calculated. Maximum allowable source outgassing rates were calculated using worst case view factors from source to baffle surface. Tight requirements pushed the team to change the design of the adjacent surfaces to minimize the outgassing sources.

Minireview: Mechano-Growth Factor: A Putative Product of IGF-I Gene Expression Involved in Tissue Repair and Regeneration

DTIC Science & Technology

2010-03-01

Ec in humans) has been the topic of several research studies, particularly in skeletal muscle. It has been proposed that age-related sarcopenia results...performed in elderly men (74 yr old), increases in IGF-IEc mRNA were seen after 5 and 12 wk GH administration or resistance training compared with the...increased after mechanical stress is not entirely clear. In elderly men, IGF-IEc (MGF) mRNA is increased after long-term exer- cise and GH administration but

An Optical Trap for Relativistic Plasma

NASA Astrophysics Data System (ADS)

Zhang, Ping

2002-11-01

Optical traps have achieved remarkable success recently in confining ultra-cold matter.Traps capable of confining ultra-hot matter, or plasma, have also been built for applications such as basic plasma research and thermonuclear fusion. For instance, low-density plasmas with temperature less than 1 keV have been confined with static magnetic fields in Malmberg-Penning traps. Low-density 10-50 keV plasmas are confined in magnetic mirrors and tokamaks. High density plasmas have been trapped in optical traps with kinetic energies up to 10 keV [J. L. Chaloupka and D. D. Meyerhofer, Phys. Rev. Lett. 83, 4538 (1999)]. We present the results of experiment, theory and numerical simulation on an optical trap capable of confining relativistic plasma. A stationary interference grating with submicron spacing is created when two high-power (terawatt) laser pulses of equal wavelength (1-micron) are focused from orthogonal directions to the same point in space and time in high density underdense plasma. Light pressure gradients bunch electrons into sheets located at the minima of the interference pattern. The density of the bunched electrons is found to be up to ten times the background density, which is orders-of-magnitude above that previously reported for other optical traps or plasma waves. The amplitudes and frequencies of multiple satellites in the scattered spectrum also indicate the presence of a highly nonlinear ion wave and an electron temperature about 100 keV. Energy transfer from the stronger beam to the weaker beam is also observed. Potential applications include a test-bed for detailed studies of relativistic nonlinear scattering, a positron source and an electrostatic wiggler. This research is also relevant to fast igniter fusion or ion acceleration experiments, in which laser pulses with intensities comparable to those used in the experiment may also potentially beat [Y. Sentoku, et al., Appl. Phys. B 74, 207215 (2002)]. The details of a specific application, the injection of electrons into laser-driven plasma waves, will also be presented. With crossed beams, the energy of a laser-accelerated electron beam is increased and its emittance is decreased compared with a single beam, potentially paving the way towards an all-optical monoenergetic electron injector.

MO-D-218-01: Overview of Methodology and Standards (QIBA, IEC, AIUM and AAPM).

PubMed

Carson, P

2012-06-01

Ultrasound system standards and professional guidelines can facilitate efficient provision of medical physics services and growth of ultrasound imaging if the documents are well designed and are utilized. We too often develop our own phantoms and procedures and never converge to obtain a critical mass of data on system performance and value of such services. Standards can also produce unnecessary costs and limit innovation if not carefully developed, reviewed, and changed as needed. There are quite a few new initiatives that, if followed vigorously, could improve medical ultrasound and medical physicists' contributions thereto. This talk is to explain many of the existing standards and recommendations for ultrasound system quality control, performance evaluation, and safety, as well as current and suggested efforts in these areas. The primary standards body for medical ultrasound systems is now the International Electrotechnical Commission (IEC). Uniformity across the world is helpful to all if the documents are reasonably current. There still is a role for traditional bodies such as the AAPM with its valuable report series and the American Inst. of Ultras. in Med. (AIUM) with its own standards and reports and its joint work with the Medical Imaging Technology Alliance (MITA). All three, with strong involvement of FDA scientists and with some efforts from the Acoustical Society of America have historically provided the main standards affecting medical physicists. Now that the lengthy IEC process is moving more smoothly, our national bodies still can provide new developments and drafts that can be offered as needed for international standardization. The ACR in particular can provide meaningful incentives through ultrasound service accreditation. Without any regulatory or strong consumer push, reports and standards on ultrasound system performance have received only modest use in the USA. A consistent consumer or accreditation push might be justified now. A series of three standards on performance evaluation is well on its way to covering pulse echo ultrasound well, with IEC 61319-1 on spatial measurements, IEC 61319-2 on depth of penetration and local dynamic range and one draft and one Technical Specification 62558 on small void imaging. A new effort has just been initiated to help drive more and better use of quantitative ultrasound imaging in human and surrogate studies and in clinical use. A shear wave speed ultrasound technical committee will carry out this effort in the Quantitative Imaging Biomarkers Alliance (QIBA) that is managed by the RSNA. 1. Understand the coverage of the two current and third planned IEC medical ultrasound performance evaluation standards that could form a basis for stable performance evaluation tests. 2. Understand the coverage of the Current AIUM and ACR QC documents and the drafting and support efforts in the IEC. 3. Understand the need for and partial availability of simplified software and instructions to improve and facilitate performance of these tests? 4. Understand how standards development can lead to improved understanding and performance of medical ultrasound imaging as is anticipated for the new QIBA effort. © 2012 American Association of Physicists in Medicine.

Limoniastrum guyonianum prevents H2O2-induced oxidative damage in IEC-6 cells by enhancing enzyamtic defense, reducing glutathione depletion and JNK phosphorylation.

PubMed

Bettaib, Jamila; Talarmin, Hélène; Kalai, Feten Zar; Giroux-Metges, Marie-Agnès; Ksouri, Riadh

2017-11-01

Limoniastrum guyonianum is used in several regions of North Africa as a folk medicine. The objective of this study was to determine the in vitro antioxidant activities of L. guyonianum roots and their cytoprotective action on H 2 O 2 -challenged rat small intestine epithelial cells (IEC-6 cells). To assess the cytoprotective effect of L. guyonianum extract (LGE), IEC-6 cells were pre-incubated with different LGE concentrations. Then, IEC-6 cultures were exposed to 40μM H 2 O 2 during 4h. Modulation of endogenous antioxidant system including SOD, CAT, MDA, GSH and the expression of possibly involved MAPKs was evaluated. Main results reported that L. guyonianum was rich in polyphenols and exhibited an important antioxidant activity as revealed by different tests (DPPH Assay, IC 50 =1.6μg/mL; ABTS + test, IC 50 =27μg/mL; Fe-reducing power, EC 50 =44μg/mL). HPLC analysis showed that quercetin, catechin, and isorhamnetin-3-O-rutinoside were major phenolics. The exposure of IEC-6 cells to 40μM H 2 O 2 during 4h resulted in oxidative stress manifested by (i) over 70% cell mortality, (ii) over-activity of CAT (246%), (iii) decrease in GSH level (10.4nmol/mg), (iv) excess in MDA content (18.4nmol/mg), and (v) a trigger of JNK phosphorylation. Pretreatment with LGE, especially at 0.25μg/mL, restored cell viability to 100%, and normal cell morphology in H 2 O 2 -chalenged cells. In addition, this extract maintained a high CAT activity, enhanced SOD capacity (120%) and increased GSH level (45.5nmol/mg). Furthermore, reducing cell death seems to be due to dephosphorylated JNK MAPK exerted by L. guyonianum bioactive compounds. In all, L. guyonianum components provided a cross-talk between regulatory pathways, implying their role as cytoprotector against oxidative stress. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The Emergence and Spread of Multiple Livestock-Associated Clonal Complex 398 Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus Strains among Animals and Humans in the Republic of Ireland, 2010–2014

PubMed Central

Brennan, Gráinne I.; Abbott, Yvonne; Burns, Aisling; Leonard, Finola; McManus, Brenda A.; O’Connell, Brian; Coleman, David C.; Shore, Anna C.

2016-01-01

Clonal complex (CC) 398 methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) are associated with carriage and infection among animals and humans but only a single case of CC398 MRSA has been reported in the Republic of Ireland (ROI). The present study investigated the molecular epidemiology of CC398 MRSA (n = 22) and MSSA (n = 10) from animals and humans in the ROI from 2010–2014. Isolates underwent antimicrobial susceptibility testing, spa typing, DNA microarray profiling and PCR for CC398-associated resistance genes. All MRSA underwent SCCmec IV or V subtyping. Four distinct CC398-MRSA incidents were identified from (i) a man in a nursing home (spa type t011-SCCmec IVa, immune evasion complex (IEC) negative), (ii) a horse and veterinarian who had recently travelled to Belgium (t011-IVa, IEC positive), (iii) pigs (n = 9) and farm workers (n = 9) on two farms, one which had been restocked with German gilts and the other which was a finisher farm (t034-VT, IEC negative, 3/9 pigs; t011- VT, IEC negative, 6/9 pigs & 9/9 farm workers), and (iv) a child who had worked on a pig farm in the UK (t034-VT, IEC negative). Isolates also carried different combinations of multiple resistance genes including erm(A), erm(B), tet(K), tet(M) & tet(L), fexA, spc, dfrG, dfrK aacA-aphD and aadD further highlighting the presence of multiple CC398-MRSA strains. CC398 MSSA were recovered from pigs (n = 8) and humans (n = 2). CC398 MSSA transmission was identified among pigs but zoonotic transmission was not detected with animal and human isolates exhibiting clade-specific traits. This study highlights the importation and zoonotic spread of CC398 MRSA in the ROI and the spread of CC398 MSSA among pigs. Increased surveillance is warranted to prevent further CC398 MRSA importation and spread in a country that was considered CC398 MRSA free. PMID:26886749

Amendments to the Center for Devices and Radiological Health federal performance standard for laser products.

PubMed

Dennis, J E

1997-12-01

Federal law requires that all laser products that are imported into or introduced into commerce in the United States comply with the performance standard published in the Code of Federal Regulations (CRF), Title 21, Parts 1040.10 and 1040.11, administered by the Center for Devices and Radiological Health (CDRH), US Food and Drug Administration. Although it contains somewhat different requirements for hazard classification, engineering controls and labeling, the ANSI Z136.1 standard defers to the CDRH standard. The CDRH standard became effective in August, 1976 and was amended, in 1978 and also in 1985. In the early 1990s, US experts met to formulate an approach to bring the requirements of the CDRH standard and those of the International Electrotechnical Commission (IEC) standard, IEC 825, into closer agreement in order to lower barriers to international trade and to remove any excessive compliance burdens on manufacturers. In 1993, the CDRH published, formally in the Federal Register and informally, a Notice of Intent to amend the CDRH standard. Responses to those notices have now been analyzed and informal draft amendments were distributed in 1996. This draft is now being prepared for formal issuance as a Notice of Proposed Rulemaking. Meanwhile, the IEC standard was amended in 1993 and republished as IEC 825-1; these amendments created considerable controversy since they resulted in over classification of the hazard of many products, especially light emitting diodes (LEDs) that have a large divergence and increased source dimensions. Additional amendments are now being developed to correct this problem. The CDRH has carefully monitored developments in the IEC and actively participated in its proceedings as a guide in developing its own proposal. This paper describes the major changes that are being proposed for the CDRH standard and presents some rationale for the major changes. The more significant changes include expansion of applicability to include LEDs, reduced emission durations for classification, revised measurement for hazard classification, reduced performance requirements for lower power visible radiation products, and revised requirements for medical products.

Electrical safety of conducted electrical weapons relative to requirements of relevant electrical standards.

PubMed

Panescu, Dorin; Nerheim, Max; Kroll, Mark

2013-01-01

TASER(®) conducted electrical weapons (CEW) deliver electrical pulses that can inhibit a person's neuromuscular control or temporarily incapacitate. TASER X26, X26P, and X2 are among CEW models most frequently deployed by law enforcement agencies. The X2 CEW uses two cartridge bays while the X26 and X26P CEWs have only one. The TASER X26P CEW electronic output circuit design is equivalent to that of any one of the two TASER X2 outputs. The goal of this paper was to analyze the nominal electrical outputs of TASER X26, X26P, and X2 CEWs in reference to provisions of several international standards that specify safety requirements for electrical medical devices and electrical fences. Although these standards do not specifically mention CEWs, they are the closest electrical safety standards and hence give very relevant guidance. The outputs of two TASER X26 and two TASER X2 CEWs were measured and confirmed against manufacturer and other published specifications. The TASER X26, X26P, and X2 CEWs electrical output parameters were reviewed against relevant safety requirements of UL 69, IEC 60335-2-76 Ed 2.1, IEC 60479-1, IEC 60479-2, AS/NZS 60479.1, AS/NZS 60479.2 and IEC 60601-1. Prior reports on similar topics were reviewed as well. Our measurements and analyses confirmed that the nominal electrical outputs of TASER X26, X26P and X2 CEWs lie within safety bounds specified by relevant requirements of the above standards.

New conducted electrical weapons: Electrical safety relative to relevant standards.

PubMed

Panescu, Dorin; Nerheim, Max; Kroll, Mark W; Brave, Michael A

2017-07-01

We have previously published about TASER ® conducted electrical weapons (CEW) compliance with international standards. CEWs deliver electrical pulses that can inhibit a person's neuromuscular control or temporarily incapacitate. An eXperimental Rotating-Field (XRF) waveform CEW and the X2 CEW are new 2-shot electrical weapon models designed to target a precise amount of delivered charge per pulse. They both can deploy 1 or 2 dart pairs, delivered by 2 separate cartridges. Additionally, the XRF controls delivery of incapacitating pulses over 4 field vectors, in a rotating sequence. As in our previous study, we were motivated by the need to understand the cardiac safety profile of these new CEWs. The goal of this paper is to analyze the nominal electrical outputs of TASER XRF and X2 CEWs in reference to provisions of all relevant international standards that specify safety requirements for electrical medical devices and electrical fences. Although these standards do not specifically mention CEWs, they are the closest electrical safety standards and hence give very relevant guidance. The outputs of several TASER XRF and X2 CEWs were measured under normal operating conditions. The measurements were compared against manufacturer specifications. CEWs electrical output parameters were reviewed against relevant safety requirements of UL 69, IEC 60335-2-76 Ed 2.1, IEC 60479-1, IEC 60479-2, AS/NZS 60479.1, AS/NZS 60479.2, IEC 60601-1 and BS EN 60601-1. Our study confirmed that the nominal electrical outputs of TASER XRF and X2 CEWs lie within safety bounds specified by relevant standards.

“I didn’t know that…” patient perceptions of print information, education, and communication related to HIV/AIDS treatment

PubMed Central

STONE, COSBY A.; SIRIL, HELLEN; NAMPANDA, EMERENSIANA; GARCIA, MARIA E.; TITO, JUSTINA; NAMBIAR, DEVAKI; CHALAMILLA, GUERINO; KAAYA, SYLVIA F.

2017-01-01

Improving health literacy is a necessary intervention for people with chronic health conditions to ensure adherence with long or life therapies and increase participation in self-care. While adherence is a multifactorial process, increasing health literacy among HIV-infected patients at all stages of living with HIV has been shown to improve treatment outcomes. In the era of rapid scale up of HIV care and treatment, little has been done to evaluate the utility of IEC materials for increasing patient health literacy and how patients perceive such materials. Four patient-oriented print IEC brochures in Swahili were designed to be read at the clinic waiting areas and also carried home by patients to supplement the knowledge received from routine counselling during clinic visits. Brochures detail antiretroviral therapy and address common myths, side effects, types and management of opportunistic infections, and prevention of mother to child transmission of HIV. We conducted focus group discussions with HIV-infected patients to explore patient perceptions of IEC materials in the urban congested HIV care setting of Dar es Salaam, Tanzania. Groups of participants were recruited from eight public PEPFAR-supported HIV care and treatment centres in the city (N=50). In this paper we present the results of those focus group discussions and introduce the print IEC materials as a pilot intervention in a Swahili-speaking setting where a need for additional health literacy exists. Further evaluation of these materials will follow as the data becomes available. PMID:25566605

The Recognizability and Localizability of Auditory Alarms: Setting Global Medical Device Standards.

PubMed

Edworthy, Judy; Reid, Scott; McDougall, Siné; Edworthy, Jonathan; Hall, Stephanie; Bennett, Danielle; Khan, James; Pye, Ellen

2017-11-01

Objective Four sets of eight audible alarms matching the functions specified in IEC 60601-1-8 were designed using known principles from auditory cognition with the intention that they would be more recognizable and localizable than those currently specified in the standard. Background The audible alarms associated with IEC 60601-1-8, a global medical device standard, are known to be difficult to learn and retain, and there have been many calls to update them. There are known principles of design and cognition that might form the basis of more readily recognizable alarms. There is also scope for improvement in the localizability of the existing alarms. Method Four alternative sets of alarms matched to the functions specified in IEC 60601-1-8 were tested for recognizability and localizability and compared with the alarms currently specified in the standard. Results With a single exception, all prototype sets of alarms outperformed the current IEC set on both recognizability and localizability. Within the prototype sets, auditory icons were the most easily recognized, but the other sets, using word rhythms and simple acoustic metaphors, were also more easily recognized than the current alarms. With the exception of one set, all prototype sets were also easier to localize. Conclusion Known auditory cognition and perception principles were successfully applied to an existing audible alarm problem. Application This work constitutes the first (benchmarking) phase of replacing the alarms currently specified in the standard. The design principles used for each set demonstrate the relative ease with which different alarm types can be recognized and localized.

Tissue-nonspecific alkaline phosphatase is activated in enterocytes by oxidative stress via changes in glycosylation.

PubMed

López-Posadas, Rocío; González, Raquel; Ballester, Isabel; Martínez-Moya, Patricia; Romero-Calvo, Isabel; Suárez, María Dolores; Zarzuelo, Antonio; Martínez-Augustin, Olga; Sánchez de Medina, Fermín

2011-02-01

Intestinal inflammation produces an induction of alkaline phosphatase (AP) activity that is attributable in part to augmented expression, accompanied by a change in isoform, in epithelial cells. This study focuses on induction of AP in intestinal epithelial cells in vitro. Treatment with the oxidants H2O2, monochloramine, or tButOOH increases AP activity in vitro in Caco-2, HT29, and IEC18 cells. We selected IEC18 cells for further testing. Basal AP activity in IEC18 cells is of the tissue-nonspecific (bone-liver-kidney) type, as indicated by Northern and Western blot analysis. Oxidative stress augments AP activity and the sensitivity of the enzyme to levamisole, homoarginine, and heat in IEC18 cells. Increased immunoreactivity to tissue-nonspecific AP antibodies suggests an isoform shift from liver to either kidney or bone type. This effect occurs without changes at the mRNA level and is sensitive to tunicamycin, an inhibitor of N-glycosylation, and neuraminidase digestion. Saponin and deoxycholate produce similar effects to oxidants. Butyrate but not proinflammatory cytokines or LPS can induce a similar effect but without toxicity. The AP increase is not prevented by modulators of the MAPK, NF-κB, calcium, and cyclic adenosine monophosphate (cAMP) pathways, and is actually enhanced by actinomycin D via higher cell stress. Oxidative stress causes a distinct increase in enterocyte AP activity together with cell toxicity via changes in the glycosylation of the enzyme that correspond to a shift in isotype within the tissue-nonspecific paradigm. We speculate that this may have physiological implication for gut defense.

Characteristics of low-latitude TEC during solar cycles 23 and 24 using global ionospheric maps (GIMs) over Indian sector

NASA Astrophysics Data System (ADS)

Dashora, N.; Suresh, Sunanda

2015-06-01

The characteristics of quiet time equatorial and low-latitude total electron content over the Indian sector using global ionospheric map (GIM) data (1998-2014) are obtained filtering out the solar flare and storm effects. The results are examined and interpreted in the context of large number of previous studies. The newly found features from this study are as follows. Marked difference in nature of equinoctial asymmetry is noted between solar cycles 23 and 24. Long absence of winter anomaly both during low and high solar activity (HSA) in LL (low-latitude) regions is found. Climatology of the diurnal cycle is provided in four categories using new criteria for demarcation of solar activity levels. Highest correlation (~77%) between GIM ionospheric electron content (IEC) and PI (solar EUV proxy index) is noted over equator in contrast to previous studies. The minimum positive contribution of PI in variation of IEC requires minimum of 2 years of data, and if more than 7-8 years of data are used, it saturates. Root-mean-square width of PI can be used to define the HSA. Strong QBO (quasi-biennial oscillations) in IEC is noted in tune with the one in PI over both LL locations but QBO remains surprisingly subdued over equator. The semiannual oscillations in GIM-IEC are found to be stronger at all locations during high solar activity and weaker between 2005 and 2011, whereas the annual oscillations are found to be substantially stronger only during HSA-23 and weakest over southern LL location throughout 17 years.

Galectin-9 Produced by Intestinal Epithelial Cells Enhances Aldehyde Dehydrogenase Activity in Dendritic Cells in a PI3K- and p38-Dependent Manner.

PubMed

de Kivit, Sander; Kostadinova, Atanaska I; Kerperien, JoAnn; Ayechu Muruzabal, Veronica; Morgan, Mary E; Knippels, Leon M J; Kraneveld, Aletta D; Garssen, Johan; Willemsen, Linette E M

2017-01-01

Intestinal epithelial cells (IEC) drive regulatory T cell (Treg) responses by promoting the differentiation of aldehyde dehydrogenase (ALDH)-expressing CD103+ dendritic cells (DC). Apical stimulation of TLR9 by CpG DNA on IEC supports galectin-9 expression by IEC, which is promoted by short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (GF). While galectin-9 can induce the maturation of monocyte-derived DC (moDC), the contribution of galectin-9 on the induction of ALDH activity in DC is not known. To this end, DC were stimulated with galectin-9, and ALDH activity and the expression of CD103 were assessed. ALDH activity was increased by moDC exposed to galectin-9, while the expression of CD103 remained unaltered. Galectin-9 secreted by IEC apically exposed to CpG DNA and GF enhanced ALDH activity, but not CD103 expression by moDC, which was abrogated upon galectin-9 neutralization. Similar observations were found in murine GM-CSF-cultured bone marrow-derived DC (BMDC). Using Flt3L-cultured BMDC and ex vivo murine splenic DC, it was observed that galectin-9 only enhanced ALDH activity in the presence of GM-CSF in CD103- cells. The induction of ALDH activity in BMDC was dependent on p38 and PI3K signaling. These data indicate a novel role for galectin-9 in modulating innate immunity by inducing ALDH activity in DC. © 2017 S. Karger AG, Basel.

Barrier-protective function of intestinal epithelial Toll-like receptor 2.

PubMed

Cario, E

2008-11-01

The intestinal epithelial cell (IEC) barrier plays an important role in maintaining mucosal immune homeostasis. Dysregulated IEC barrier function appears to trigger and perpetuate inflammation in inflammatory bowel diseases (IBD). Novel risk variants in the Toll-like receptor 2 (TLR2) gene have previously been associated with a more severe disease phenotype in a subgroup of IBD patients. Recent studies have provided important insights of the commensal and host defense mechanisms to maintain functional barrier integrity of the intestinal epithelium through TLR2. Deficient TLR2 signaling may imbalance commensal-dependent intestinal epithelial barrier defense, facilitating mucosal injury and leading to increased susceptibility of colitis. Treatment with a synthetic TLR2 ligand significantly suppresses mucosal inflammation by efficiently protecting tight junction-associated integrity of the intestinal epithelium in vivo. These beneficial effects may be supplemented by TLR2-induced anti-inflammatory immune responses (such as interleukin-10 production) in lamina propria mononuclear cells. Thus, cell-specific TLR2 targeting may offer a novel therapeutic approach to human IBD therapy by protecting IEC barrier function.

ISO-IEC MPEG-2 software video codec

NASA Astrophysics Data System (ADS)

Eckart, Stefan; Fogg, Chad E.

1995-04-01

Part 5 of the International Standard ISO/IEC 13818 `Generic Coding of Moving Pictures and Associated Audio' (MPEG-2) is a Technical Report, a sample software implementation of the procedures in parts 1, 2 and 3 of the standard (systems, video, and audio). This paper focuses on the video software, which gives an example of a fully compliant implementation of the standard and of a good video quality encoder, and serves as a tool for compliance testing. The implementation and some of the development aspects of the codec are described. The encoder is based on Test Model 5 (TM5), one of the best, published, non-proprietary coding models, which was used during MPEG-2 collaborative stage to evaluate proposed algorithms and to verify the syntax. The most important part of the Test Model is controlling the quantization parameter based on the image content and bit rate constraints under both signal-to-noise and psycho-optical aspects. The decoder has been successfully tested for compliance with the MPEG-2 standard, using the ISO/IEC MPEG verification and compliance bitstream test suites as stimuli.

Advanced Plasma Propulsion for Human Missions to Jupiter

NASA Technical Reports Server (NTRS)

Donahue, Benjamin B.; Pearson, J. Boise

1999-01-01

This paper will briefly identify a promising fusion plasma power source, which when coupled with a promising electric thruster technology would provide for an efficient interplanetary transfer craft suitable to a 4 year round trip mission to the Jovian system. An advanced, nearly radiation free Inertial Electrostatic Confinement scheme for containing fusion plasma was judged as offering potential for delivering the performance and operational benefits needed for such high energy human expedition missions, without requiring heavy superconducting magnets for containment of the fusion plasma. Once the Jovian transfer stage has matched the heliocentric velocity of Jupiter, the energy requirements for excursions to its outer satellites (Callisto, Ganymede and Europa) by smaller excursion craft are not prohibitive. The overall propulsion, power and thruster system is briefly described and a preliminary vehicle mass statement is presented.

77 FR 28805 - Energy Conservation Program: Test Procedures for Microwave Ovens

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-16

...On November 23, 2011, the U.S. Department of Energy (DOE) issued a supplemental notice of proposed rulemaking (SNOPR) to amend the test procedures for microwave ovens. That SNOPR proposed amendments to the DOE test procedure to incorporate provisions from the International Electrotechnical Commission (IEC) Standard 62301, ``Household electrical appliances--Measurement of standby power,'' Edition 2.0 2011-01 (IEC Standard 62301 (Second Edition)). Today's SNOPR proposes additional provisions for measuring the standby mode and off mode energy use of products that combine a microwave oven with other appliance functionality, as well as minor technical clarifications.

Procedural considerations for CPV outdoor power ratings per IEC 62670

NASA Astrophysics Data System (ADS)

Muller, Matthew; Kurtz, Sarah; Rodriguez, Jose

2013-09-01

The IEC Working Group 7 (WG7) is in the process of developing a draft procedure for an outdoor concentrating photovoltaic (CPV) module power rating at Concentrator Standard Operating Conditions (CSOC). WG7 recently achieved some consensus that using component reference cells to monitor/limit spectral variation is the preferred path for the outdoor power rating. To build on this consensus, the community must quantify these spectral limits and select a procedure for calculating and reporting a power rating. This work focuses on statistically comparing several procedures the community is considering in context with monitoring/limiting spectral variation.

A comparative study between evaluation methods for quality control procedures for determining the accuracy of PET/CT registration

NASA Astrophysics Data System (ADS)

Cha, Min Kyoung; Ko, Hyun Soo; Jung, Woo Young; Ryu, Jae Kwang; Choe, Bo-Young

2015-08-01

The Accuracy of registration between positron emission tomography (PET) and computed tomography (CT) images is one of the important factors for reliable diagnosis in PET/CT examinations. Although quality control (QC) for checking alignment of PET and CT images should be performed periodically, the procedures have not been fully established. The aim of this study is to determine optimal quality control (QC) procedures that can be performed at the user level to ensure the accuracy of PET/CT registration. Two phantoms were used to carry out this study: the American college of Radiology (ACR)-approved PET phantom and National Electrical Manufacturers Association (NEMA) International Electrotechnical Commission (IEC) body phantom, containing fillable spheres. All PET/CT images were acquired on a Biograph TruePoint 40 PET/CT scanner using routine protocols. To measure registration error, the spatial coordinates of the estimated centers of the target slice (spheres) was calculated independently for the PET and the CT images in two ways. We compared the images from the ACR-approved PET phantom to that from the NEMA IEC body phantom. Also, we measured the total time required from phantom preparation to image analysis. The first analysis method showed a total difference of 0.636 ± 0.11 mm for the largest hot sphere and 0.198 ± 0.09 mm for the largest cold sphere in the case of the ACR-approved PET phantom. In the NEMA IEC body phantom, the total difference was 3.720 ± 0.97 mm for the largest hot sphere and 4.800 ± 0.85 mm for the largest cold sphere. The second analysis method showed that the differences in the x location at the line profile of the lesion on PET and CT were (1.33, 1.33) mm for a bone lesion, (-1.26, -1.33) mm for an air lesion and (-1.67, -1.60) mm for a hot sphere lesion for the ACR-approved PET phantom. For the NEMA IEC body phantom, the differences in the x location at the line profile of the lesion on PET and CT were (-1.33, 4.00) mm for the air lesion and (1.33, -1.29) mm for a hot sphere lesion. These registration errors from this study were reasonable compared to the errors reported in previous studies. Meanwhile, the total time required from phantom preparation was 67.72 ± 4.50 min for the ACR-approved PET phantom and 96.78 ± 8.50 min for the NEMA IEC body phantom. When the registration errors and the lead times are considered, the method using the ACR-approved PET phantom was more practical and useful than the method using the NEMA IEC body phantom.

Confined compression and torsion experiments on a pHEMA gel in various bath concentrations.

PubMed

Roos, Reinder W; Petterson, Rob; Huyghe, Jacques M

2013-06-01

The constitutive behaviour of cartilaginous tissue is the result of complex interaction between electrical, chemical and mechanical forces. Electrostatic interactions between fixed charges and mobile ions are usually accounted for by means of Donnan osmotic pressure. Recent experimental data show, however, that the shear modulus of articular cartilage depends on ionic concentration even if the strain is kept constant. Poisson-Boltzmann simulations suggest that this dependence is intrinsic to the double-layer around the proteoglycan chains. In order to verify this premise, this study measures whether--at a given strain--this ionic concentration-dependent shear modulus is present in a polymerized hydroxy-ethyl-methacrylate gel or not. A combined 1D confined compression and torque experiment is performed on a thin cylindrical hydrogel sample, which is brought in equilibrium with, respectively, 1, 0.1 and 0.03 M NaCl. The sample was placed in a chamber that consists of a stainless steel ring placed on a sintered glass filter, and on top a sintered glass piston. Stepwise ionic loading was cascaded by stepwise 1D compression, measuring the total stress after equilibration of the sample. In addition, a torque experiment was interweaved by applying a harmonic angular displacement and measuring the torque, revealing the relation between aggregate shear modulus and salt concentration at a given strain.

Fan-out Estimation in Spin-based Quantum Computer Scale-up.

PubMed

Nguyen, Thien; Hill, Charles D; Hollenberg, Lloyd C L; James, Matthew R

2017-10-17

Solid-state spin-based qubits offer good prospects for scaling based on their long coherence times and nexus to large-scale electronic scale-up technologies. However, high-threshold quantum error correction requires a two-dimensional qubit array operating in parallel, posing significant challenges in fabrication and control. While architectures incorporating distributed quantum control meet this challenge head-on, most designs rely on individual control and readout of all qubits with high gate densities. We analysed the fan-out routing overhead of a dedicated control line architecture, basing the analysis on a generalised solid-state spin qubit platform parameterised to encompass Coulomb confined (e.g. donor based spin qubits) or electrostatically confined (e.g. quantum dot based spin qubits) implementations. The spatial scalability under this model is estimated using standard electronic routing methods and present-day fabrication constraints. Based on reasonable assumptions for qubit control and readout we estimate 10 2 -10 5 physical qubits, depending on the quantum interconnect implementation, can be integrated and fanned-out independently. Assuming relatively long control-free interconnects the scalability can be extended. Ultimately, the universal quantum computation may necessitate a much higher number of integrated qubits, indicating that higher dimensional electronics fabrication and/or multiplexed distributed control and readout schemes may be the preferredstrategy for large-scale implementation.

Oxidation and reduction under cover: Chemistry at the confined space between ultra-thin nanoporous silicates and Ru(0001)

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. Anibal Boscoboinik; Zhong, Jian -Qiang; Kestell, John

2016-03-23

The oxidation and reduction of Ru(0001) surfaces at the confined space between two-dimensional nanoporous silica frameworks and Ru(0001) have been investigated using synchrotron-based ambient pressure X-ray photoelectron spectroscopy (AP-XPS). The porous nature of the frameworks and the weak interaction between the silica and the ruthenium substrate allow oxygen and hydrogen molecules to go through the nanopores and react with the metal at the interface between the silica framework and the metal surface. In this work, three types of two-dimensional silica frameworks have been used to study their influence in the oxidation and reduction of the ruthenium surface at elevated pressuresmore » and temperatures. These frameworks are bilayer silica (0.5 nm thick), bilayer aluminosilicate (0.5 nm thick), and zeolite MFI nanosheets (3 nm thick). It is found that the silica frameworks stay essentially intact under these conditions, but they strongly affect the oxidation of ruthenium, with the 0.5 nm thick aluminosilicate bilayer completely inhibiting the oxidation. Furthermore, the latter is believed to be related to the lower chemisorbed oxygen content arising from electrostatic interactions between the negatively charged aluminosilicate framework and the Ru(0001) substrate.« less

L-H transitions driven by ion heating in scrape-off layer turbulence (SOLT) model simulations

NASA Astrophysics Data System (ADS)

Russell, D. A.; D'Ippolito, D. A.; Myra, J. R.

2015-11-01

The original SOLT model now includes the evolution of ion pressure consistent with drift-ordering. It is a two-dimensional, electrostatic reduced model wherein closure relations, obtained by integrating the equations along the B-field, model parallel physics that includes sheath-mediated current and heat flux in the scrape-off-layer and electron drift waves inside the separatrix. Low (L) and high (H) confinement regimes are observed in SOLT simulations, depending on the strength of an ion pressure (i.e., ion heating) source localized inside the separatrix: With increasing heating, particle and energy confinement times at first decrease in the L-mode then rise in the H-mode. The L-H transition is marked by distinct changes in sheared-flow profiles. The addition of ion pressure dynamics enables modeling the self-consistent interaction between the ion diamagnetic drift and the radial electric field (mean and zonal flows). The roles of these sheared flows in mediating the L-H transition are explored. A new diagnostic, based on the density correlation function, is applied to study blob velocities in different regimes. Work supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences, under Award Number DE-FG02-97ER54392.

Quantum point contacts for electrons on H-Si(111) surfaces using a Ga focused-ion beam for direct-write implant lithography

NASA Astrophysics Data System (ADS)

Robertson, Luke D.; Kane, B. E.

Quantum point contacts (QPCs) realized in materials with anisotropic electron mass, such as Si, may exhibit valley filter phenomena leading to extreme sensitivity to single donor occupancy, and thus are of interest to measurement schemes for donor-based quantum information processing. To this end, we have developed ambipolar devices on a H-Si(111):Si(100)/SiO2 flip-chip assembly which utilize in-plane, degenerately doped n+ (P) and p+ (B) contacts to probe transport in a 2D electron system (2DES). In addition to providing electrostatic isolation of carriers, these p-type contacts can be used as lateral depletion gates to modulate the 2DES conductance, and if extended to the nanoscale can lead to 1D confinement and quantized conductance of the 2DES. In this talk, I will describe our efforts to use a Ga focused-ion beam for direct-write implant lithography to pattern QPCs and Ga nanowires on H-Si(111) surfaces. I will present low temperature (4.2K) conductance data collected on 30nm Ga nanowires to demonstrate their effectiveness as lateral depletion gates, and discuss on going measurements to confine and modulate the conductance of the 2DES using Ga QPCs.

Anomalous neutron yield in indirect-drive inertial-confinement-fusion due to the formation of collisionless shocks in the corona

NASA Astrophysics Data System (ADS)

Zhang, Wen-Shuai; Cai, Hong-Bo; Shan, Lian-Qiang; Zhang, Hua-Sen; Gu, Yu-Qiu; Zhu, Shao-Ping

2017-06-01

Observations of anomalous neutron yield in the indirect-drive inertial confinement fusion implosion experiments conducted at SG-III prototype and SG-II upgrade laser facilities are interpreted. The anomalous mechanism results in a neutron yield which is 100-times higher than that predicted by 1D radiation-hydrodynamic simulations. 2D radiation-hydrodynamic simulations show that the supersonic, radially directed gold (Au) plasma jets arising from the laser-hohlraum interactions can collide with the carbon-deuterium (CD) corona plasma of the compressed pellet. It is found that in the interaction front of the high-Z jet with the low-Z corona, with low density  ˜{{10}20}~\\text{c}{{\\text{m}}-3} and high temperature  ˜keV, kinetic effects become important. Particle-in-cell simulations indicate that an electrostatic shock wave can be driven when the high-temperature Au jet expands into the low-temperature CD corona. Deuterium ions with an amount of  ˜1015 can be accelerated to  ˜25 keV by the collisionless shock wave, thus causing efficient neutron productions though the beam-target method by stopping these energetic ions in the corona. The evaluated neutron yield is consistent with the experiments conducted at SG laser facilities.

In Inflamed Intestinal Tissues and Epithelial Cells, Interleukin 22 Signaling Increases Expression of H19 Long Noncoding RNA, Which Promotes Mucosal Regeneration.

PubMed

Geng, Hua; Bu, Heng-Fu; Liu, Fangyi; Wu, Longtao; Pfeifer, Karl; Chou, Pauline M; Wang, Xiao; Sun, Jiaren; Lu, Lu; Pandey, Ashutosh; Bartolomei, Marisa S; De Plaen, Isabelle G; Wang, Peng; Yu, Jindan; Qian, Jiaming; Tan, Xiao-Di

2018-04-03

Inflammation affects regeneration of the intestinal epithelia; long non-coding RNAs (lncRNAs) regulate cell functions, such as proliferation, differentiation, and migration. We investigated the mechanisms by which the lncRNA H19, imprinted maternally expressed transcript (H19) regulates regeneration of intestinal epithelium using cell cultures and mouse models of inflammation. We performed RNA-sequencing transcriptome analyses of intestinal tissues from mice with lipopolysaccharide (LPS)-induced sepsis to identify lncRNAs associated with inflammation; findings were confirmed by quantitative real-time polymerase chain reaction and in situ hybridization analyses of intestinal tissues from mice with sepsis or dextran sulfate sodium (DSS)-induced mucosal wound healing and patients with ulcerative colitis compared to healthy individuals (controls). We screened cytokines for their ability to induce expression of H19 in HT-29 cells and intestinal epithelial cells (IECs), and confirmed findings in crypt epithelial organoids derived from mouse small intestine. IECs were incubated with different signal transduction inhibitors and effects on H19 lncRNA levels were measured. We assessed intestinal epithelial proliferation or regeneration in H19 ΔEx1/+ mice given LPS or DSS vs wild-type littermates (control mice). H19 was overexpressed in IECs using lentiviral vectors and cell proliferation was measured. We performed RNA antisense purification, RNA immunoprecipitation, and luciferase reporter assays to study functions of H19 in IECs. In RNA-sequencing transcriptome analysis of lncRNA expression in intestinal tissues from mice, we found levels of H19 only changed significantly with LPS exposure. Levels of H19 lncRNA increased in intestinal tissues of patients with ulcerative colitis, mice with LPS-induced sepsis, or mice with DSS-induced colitis, compared with controls. Increased H19 lncRNA localized to epithelial cells in the intestine, regardless of Lgr5 messenger RNA expression. Exposure of IECs to interleukin (IL) 22 increased levels of H19 lncRNA with time and dose, which required STAT3 and protein kinase A activity. IL22 induced expression of H19 in mouse intestinal epithelial organoids within 6 hours. Exposure to IL22 increased growth of intestinal epithelial organoids derived from control mice, but not H19 ΔEx1/+ mice. Overexpression of H19 in HT-29 cells increased their proliferation. Intestinal mucosa healed more slowly after withdrawal of DSS from H19 ΔEx1/+ mice vs control mice. Crypt epithelial cells from H19 ΔEx1/+ mice proliferated more slowly than those from control mice after exposure to LPS. H19 lncRNA bound to p53 and microRNAs that inhibit cell proliferation, including microRNA 34a and let-7; H19 lncRNA binding blocked their function, leading to increased expression of genes that promote regeneration of the epithelium. The level of lncRNA H19 is increased in inflamed intestinal tissues from mice and patients. The inflammatory cytokine IL22 induces expression of H19 in IECs, which is required for intestinal epithelial proliferation and mucosal healing. H19 lncRNA appears to inhibit p53 protein and microRNA 34a and let-7 to promote proliferation of IECs and epithelial regeneration. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Interfering with interferon-γ signalling in intestinal epithelial cells: selective inhibition of apoptosis-maintained secretion of anti-inflammatory interleukin-18 binding protein

PubMed Central

Schuhmann, D; Godoy, P; Weiß, C; Gerloff, A; Singer, M V; Dooley, S; Böcker, U

2011-01-01

The intestinal epithelial barrier represents an important component in the pathogenesis of inflammatory bowel diseases. Interferon (IFN)-γ, a T helper type 1 (Th1) cytokine, regulated by the interleukin (IL)-18/IL-18 binding protein (bp) system, modulates the integrity of this barrier. The aim of this work was to study functionally the consequences of IFN-γ on intestinal epithelial cells (IEC) and to interfere selectively with identified adverse IFN-γ effects. IEC lines were stimulated with IFN-γ. IL-18 and IL-18bp were assessed by enzyme-linked immunosorbent assay. Staining of phosphatidylserine, DNA laddering, lactate dehydrogenase (LDH) release, cleavage of poly-adenosine diphosphate-ribose-polymerase (PARP) and activation of caspase-3 were analysed to determine cell death. Inhibitors of tyrosine kinase, caspase-3 or p38 mitogen-activated kinase ((MAP) activity were used. Cytokines were measured in supernatants of colonic biopsies of healthy controls and inflammatory bowel disease (IBD) patients. In IEC lines, IFN-γ up-regulated IL-18bp selectively. Ex vivo, IFN-γ was present in supernatants from cultured biopsies and up-regulated with inflammation. Contrary to previous reports, IFN-γ alone induced apoptosis in IEC lines, as demonstrated by phosphatidylserin staining, DNA cleavage and LDH release. Further, activation of caspase-3, PARP cleavage and expression of pro-apoptotic Bad were induced. Partial inhibition of caspase-3 and of p38 but not JAK tyrosine kinase, preserved up-regulation of IL-18bp expression. Selective inhibition of IFN-γ mediated apoptosis, while preserving its beneficial consequences on the ratio of IL-18/IL-18bp, could contribute to the integrity of the mucosal barrier in intestinal inflammation. PMID:21078084

Investigation of JAKs/STAT‐3 in lipopolysaccharide‐induced intestinal epithelial cells

PubMed Central

Fu, L.; Wei, L.‐W.; Zhao, M.‐D.; Zhu, J.‐L.; Chen, S.‐Y.; Jia, X.‐B.

2016-01-01

Summary Janus‐activated kinase (JAKs)‐signal transducer and activator of transcription 3 (STAT‐3) signalling play critical roles in immunoregulation and immunopathology, which involve inflammatory responses and enteritis. JAK phosphorylates STAT‐3 in response to stimulation by cytokines or growth factors, and then activates or represses the gene expression. STAT‐3 is activated persistently in cancer cells and contributes to the malignant progression of various types of cancer and inflammation. To elucidate the different roles of JAKs in the activation of STAT‐3, the lipopolysaccharide‐induced primary intestinal epithelial cell (IEC) acute inflammatory model was established. Small interference RNAs (siRNAs) were then employed to attenuate the expression levels of JAKs. Real‐time quantitative reverse transcription–polymerase chain reaction (PCR) (qRT–PCR) revealed that JAK mRNA levels were reduced efficiently by JAK‐specific siRNAs. Under the IEC inflammatory model transfected with si‐JAK, which equates to effective silencing, qRT–PCR and Western blot assays, suggested that knockdowns of JAK attenuated the JAK‐induced down‐regulation of STAT‐3 at the mRNA or protein levels. In particular, JAK1 played a key role, which was consistent with the RNA‐Seq results. Subsequently, the expression levels of proinflammatory cytokines interleukin (IL)‐1β and tumour necrosis factor (TNF)‐α were down‐regulated in the IEC inflammatory model transfected with si‐JAK1. JAK1 appears as a direct activator for STAT‐3, whereas treatments targeting JAK1 repressed STAT‐3 sufficiently pathways in the IEC inflammatory model. Therefore, the control of JAK1 using siRNAs has the potential to be an effective strategy against enteritis. PMID:27357529

Grape seed extract protects IEC-6 cells from chemotherapy-induced cytotoxicity and improves parameters of small intestinal mucositis in rats with experimentally-induced mucositis.

PubMed

Cheah, Ker Y; Howarth, Gordon S; Yazbeck, Roger; Wright, Tessa H; Whitford, Eleanor J; Payne, Caroline; Butler, Ross N; Bastian, Susan E P

2009-02-01

Mucositis is a common side-effect of high-dose chemotherapy regimens. Grape seed extract (GSE) represents a rich source of proanthocyanidins with the potential to decrease oxidative damage and inflammation within the gastrointestinal tract. We evaluated GSE for its capacity to decrease the severity of chemotherapy-induced mucositis in vitro and in vivo. In vitro: GSE was administered to IEC-6 intestinal epithelial cells prior to damage induced by 5-Fluorouracil (5-FU). Cell viability was determined by neutral red assay. In vivo: Female Dark Agouti rats (130-180 g) were gavaged with 1 ml GSE (400 mg/kg) daily (day 3-11) and received 5-FU (150 mg/kg) by intraperitoneal (i.p.) injection on day nine to induce mucositis. Rats were sacrificed at day 12 and intestinal tissues collected for myeloperoxidase and sucrase activity assays and histological analyses. Statistical analysis was performed by one-way ANOVA. GSE prevented the decrease in IEC-6 cell viability induced by 5-FU (p < 0.01). Compared with 5-FU controls, GSE significantly reduced myeloperoxidase activity by 86% and 27% in the proximal jejunum (p < 0.001) and distal ileum (p < 0.05) respectively; decreased qualitative histological scores of damage (p < 0.05) in the proximal jejunum; increased villus height in the proximal jejunum (17%; p < 0.05) and distal ileum (50%; p < 0.01), and attenuated the 5-FU-induced reduction of mucosal thickness by 16% in the jejunum (p < 0.05) and 45% in the ileum (p < 0.01). GSE partially protected IEC-6 cells from 5-FU-induced cytotoxicity and ameliorated intestinal damage induced by 5-FU in rats. GSE may represent a promising prophylactic adjunct to conventional chemotherapy for preventing intestinal mucositis.

What's in a name? Atopic dermatitis or atopic eczema, but not eczema alone.

PubMed

Silverberg, J I; Thyssen, J P; Paller, A S; Drucker, A M; Wollenberg, A; Lee, K H; Kabashima, K; Todd, G; Schmid-Grendelmeier, P; Bieber, T

2017-12-01

The ideal nomenclature of atopic dermatitis (AD) / atopic eczema (AE) has long been contested. However, it is becoming increasingly clear that the disparate nomenclature of this disease may have important deleterious ramifications for clinical care and research. An electronic questionnaire regarding the preferred nomenclature for AD was sent to councilors of the International Eczema Council (IEC) (n=77), an international group of clinicians and researchers with expertise in AD/AE. The survey consisted of 2 questions for consensus regarding the preference for an atopic prefix, and preference for the term AD or AE, and an exploratory question about the acceptability of the terms AD, AE or eczema. Consensus was defined a priori as at least 90% agreement for each question with a response rate of at least 90%. Seventy-one of 77 (92.2%) IEC councilors and associates responded to the survey, with all respondents completing the entire survey. Consensus was reached for question 1, with 69 of 71 respondents (97.2%) preferring the atopic prefix. However, consensus was not reached for question 2, with 40 respondents (58.0%) preferring the term AD and 30 (43,5%) preferring AE. Sixty-three respondents (88.7%) and 55 (77.5%) felt that the terms AD and AE were acceptable, whereas only 11 (15.5%) felt that eczema was acceptable. The IEC noted that the term eczema is imprecise, and its use is confusing. The consensus of the IEC was to recommend use of the prefix "atopic" (i.e., AD or AE) in all publications, presentations and discussions about the disorder. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Toll-like receptor 2 enhances ZO-1-associated intestinal epithelial barrier integrity via protein kinase C.

PubMed

Cario, Elke; Gerken, Guido; Podolsky, Daniel K

2004-07-01

Protein kinase C (PKC) has been implicated in regulation of intestinal epithelial integrity in response to lumenal bacteria. Intestinal epithelial cells (IECs) constitutively express Toll-like receptor (TLR)2, which contains multiple potential PKC binding sites. The aim of this study was to determine whether TLR2 may activate PKC in response to specific ligands, thus potentially modulating barrier function in IECs. TLR2 agonist (synthetic bacterial lipopeptide Pam(3)CysSK4, peptidoglycan)-induced activation of PKC-related signaling cascades were assessed by immunoprecipitation, Western blotting, immunofluorescence, and kinase assays-combined with functional transfection studies in the human model IEC lines HT-29 and Caco-2. Transepithelial electrical resistance characterized intestinal epithelial barrier function. Stimulation with TLR2 ligands led to activation (phosphorylation, enzymatic activity, translocation) of specific PKC isoforms (PKCalpha and PKCdelta). Phosphorylation of PKC by TLR2 ligands was blocked specifically by transfection with a TLR2 deletion mutant. Ligand-induced activation of TLR2 greatly enhanced transepithelial resistance in IECs, which was prevented by pretreatment with PKC-selective antagonists. This effect correlated with apical tightening and sealing of tight junction (TJ)-associated ZO-1, which was mediated via PKC in response to TLR2 ligands, whereas morphologic changes of occludin, claudin-1, or actin cytoskeleton were not evident. Downstream the endogenous PKC substrate myristoylated alanine-rich C kinase substrate (MARCKS), but not transcriptional factor activator protein-1 (AP-1), was activated significantly on stimulation. The present study provides evidence that PKC is an essential component of the TLR2 signaling pathway with the physiologic consequence of directly enhancing intestinal epithelial integrity through translocation of ZO-1 on activation.

Lactobacillus rhamnosus CNCMI-4317 Modulates Fiaf/Angptl4 in Intestinal Epithelial Cells and Circulating Level in Mice

PubMed Central

Jacouton, Elsa; Mach, Núria; Cadiou, Julie; Lapaque, Nicolas; Clément, Karine; Doré, Joël; van Hylckama Vlieg, Johan E. T.; Smokvina, Tamara; Blottière, Hervé M

2015-01-01

Background and Objectives Identification of new targets for metabolic diseases treatment or prevention is required. In this context, FIAF/ANGPTL4 appears as a crucial regulator of energy homeostasis. Lactobacilli are often considered to display beneficial effect for their hosts, acting on different regulatory pathways. The aim of the present work was to study the effect of several lactobacilli strains on Fiaf gene expression in human intestinal epithelial cells (IECs) and on mice tissues to decipher the underlying mechanisms. Subjects and Methods Nineteen lactobacilli strains have been tested on HT–29 human intestinal epithelial cells for their ability to regulate Fiaf gene expression by RT-qPCR. In order to determine regulated pathways, we analysed the whole genome transcriptome of IECs. We then validated in vivo bacterial effects using C57BL/6 mono-colonized mice fed with normal chow. Results We identified one strain (Lactobacillus rhamnosus CNCMI–4317) that modulated Fiaf expression in IECs. This regulation relied potentially on bacterial surface-exposed molecules and seemed to be PPAR-γ independent but PPAR-α dependent. Transcriptome functional analysis revealed that multiple pathways including cellular function and maintenance, lymphoid tissue structure and development, as well as lipid metabolism were regulated by this strain. The regulation of immune system and lipid and carbohydrate metabolism was also confirmed by overrepresentation of Gene Ontology terms analysis. In vivo, circulating FIAF protein was increased by the strain but this phenomenon was not correlated with modulation Fiaf expression in tissues (except a trend in distal small intestine). Conclusion We showed that Lactobacillus rhamnosus CNCMI–4317 induced Fiaf expression in human IECs, and increased circulating FIAF protein level in mice. Moreover, this effect was accompanied by transcriptome modulation of several pathways including immune response and metabolism in vitro. PMID:26439630

β-Galactomannan and Saccharomyces cerevisiae var. boulardii modulate the immune response against Salmonella enterica serovar Typhimurium in porcine intestinal epithelial and dendritic cells.

PubMed

Badia, Roger; Brufau, M Teresa; Guerrero-Zamora, Ana Maria; Lizardo, Rosil; Dobrescu, Irina; Martin-Venegas, Raquel; Ferrer, Ruth; Salmon, Henri; Martínez, Paz; Brufau, Joaquim

2012-03-01

Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that causes inflammation, necrosis, and diarrhea in pigs, as well as being an important source of food-borne diseases in humans. Probiotics and prebiotics are promising alternatives to antibiotics to control and prevent intestinal infections. The present work investigated a recently developed β-galactomannan (βGM) prebiotic compared to the proven probiotic Saccharomyces cerevisiae var. boulardii on porcine ileum intestinal epithelial cells (IECs) of the IPI-2I line and monocyte-derived dendritic cells (DCs) cocultured in vitro with Salmonella. We observed that both S. cerevisiae var. boulardii and βGM inhibited the association of Salmonella with IECs in vitro. Our data indicated that βGM has a higher ability than S. cerevisiae var. boulardii to inhibit Salmonella-induced proinflammatory mRNA (cytokines tumor necrosis factor alpha [TNF-α], interleukin-1α [IL-1α], IL-6, and granulocyte-macrophage colony-stimulating factor [GM-CSF] and chemokines CCL2, CCL20, and CXCL8) and at protein levels (IL-6 and CXCL8). Additionally, βGM and S. cerevisiae var. boulardii induced some effects on DCs that were not observed on IECs: βGM and S. cerevisiae var. boulardii showed slight upregulation of mRNA for TNF-α, GM-CSF, and CCR7 receptor on porcine monocyte-derived dendritic cells (DCs). Indeed, the addition of βGM or S. cerevisiae var. boulardii on DCs cocultured with Salmonella showed higher gene expression (mRNA) for TNF-α, GM-CSF, and CXCL8 compared to that of the control with Salmonella. In conclusion, the addition of βGM inhibits Salmonella-induced proinflammatory profiles in IECs but may promote DC activation, although associated molecular mechanisms remain to be elucidated.

β-Galactomannan and Saccharomyces cerevisiae var. boulardii Modulate the Immune Response against Salmonella enterica Serovar Typhimurium in Porcine Intestinal Epithelial and Dendritic Cells

PubMed Central

Brufau, M. Teresa; Guerrero-Zamora, Ana Maria; Lizardo, Rosil; Dobrescu, Irina; Martin-Venegas, Raquel; Ferrer, Ruth; Salmon, Henri; Martínez, Paz

2012-01-01

Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that causes inflammation, necrosis, and diarrhea in pigs, as well as being an important source of food-borne diseases in humans. Probiotics and prebiotics are promising alternatives to antibiotics to control and prevent intestinal infections. The present work investigated a recently developed β-galactomannan (βGM) prebiotic compared to the proven probiotic Saccharomyces cerevisiae var. boulardii on porcine ileum intestinal epithelial cells (IECs) of the IPI-2I line and monocyte-derived dendritic cells (DCs) cocultured in vitro with Salmonella. We observed that both S. cerevisiae var. boulardii and βGM inhibited the association of Salmonella with IECs in vitro. Our data indicated that βGM has a higher ability than S. cerevisiae var. boulardii to inhibit Salmonella-induced proinflammatory mRNA (cytokines tumor necrosis factor alpha [TNF-α], interleukin-1α [IL-1α], IL-6, and granulocyte-macrophage colony-stimulating factor [GM-CSF] and chemokines CCL2, CCL20, and CXCL8) and at protein levels (IL-6 and CXCL8). Additionally, βGM and S. cerevisiae var. boulardii induced some effects on DCs that were not observed on IECs: βGM and S. cerevisiae var. boulardii showed slight upregulation of mRNA for TNF-α, GM-CSF, and CCR7 receptor on porcine monocyte-derived dendritic cells (DCs). Indeed, the addition of βGM or S. cerevisiae var. boulardii on DCs cocultured with Salmonella showed higher gene expression (mRNA) for TNF-α, GM-CSF, and CXCL8 compared to that of the control with Salmonella. In conclusion, the addition of βGM inhibits Salmonella-induced proinflammatory profiles in IECs but may promote DC activation, although associated molecular mechanisms remain to be elucidated. PMID:22301691

Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Eun Sang; Lee, Hae-June; Lee, Yoon-Jin

Highlights: • UPR activation precedes caspase activation in irradiated IEC-6 cells. • Chemical ER stress inducers radiosensitize IEC-6 cells. • siRNAs that targeted ER stress responses ameliorate IR-induced cell death. • Chemical chaperons prevent cell death in irradiated IEC-6 cells. - Abstract: Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by whichmore » ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.« less