WorldWideScience

Sample records for activated reactive evaporation

  1. Photo- and Electrochromic Properties of Activated Reactive Evaporated MoO3 Thin Films Grown on Flexible Substrates

    Directory of Open Access Journals (Sweden)

    K. Hari Krishna

    2008-01-01

    Full Text Available The molybdenum trioxide (MoO3 thin films were grown onto ITO-coated flexible Kapton substrates using plasma assisted activated reactive evaporation technique. The film depositions were carried out at constant glow power and oxygen partial pressures of 8 W and 1×10−3 Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. The MoO3 thin films prepared at a substrate temperature of 523 K were found to be composed of uniformly distributed nanosized grains with an orthorhombic structure of α-MoO3. These nanocrystalline MoO3 thin films exhibited higher optical transmittance of about 80% in the visible region with an evaluated optical band gap of 3.29 eV. With the insertion of 12.5 mC/cm2, the films exhibited an optical modulation of 40% in the visible region with coloration efficiency of 22 cm2/C at the wavelength of 550 nm. The MoO3 films deposited at 523 K demonstrated better photochromic properties and showed highest color center concentration for the irradiation time of 30 minutes at 100 mW/cm2.

  2. Calculation of Reactive-evaporation Rates of Chromia

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, G.R.

    2008-04-01

    A methodology is developed to calculate Cr-evaporation rates from Cr2O3 with a flat planar geometry. Variables include temperature, total pressure, gas velocity, and gas composition. The methodology was applied to solid-oxide, fuel cell conditions for metallic interconnects and to advanced-steam turbines conditions. The high velocities and pressures of the advanced steam turbine led to evaporation predictions as high as 5.18 9 10-8 kg/m2/s of CrO2(OH)2(g) at 760 °C and 34.5 MPa. This is equivalent to 0.080 mm per year of solid Cr loss. Chromium evaporation is expected to be an important oxidation mechanism with the types of nickel-base alloys proposed for use above 650 °C in advanced-steam boilers and turbines. It is shown that laboratory experiments, with much lower steam velocities and usually much lower total pressure than found in advanced steam turbines, would best reproduce chromium-evaporation behavior with atmospheres that approach either O2 + H2O or air + H2O with 57% H2O.

  3. Evaporators

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard

    1996-01-01

    Type of evaporators. Regulation. Thermal dimensioning. Determination of pressure loss and heat transfer coefficients.......Type of evaporators. Regulation. Thermal dimensioning. Determination of pressure loss and heat transfer coefficients....

  4. Evaporative cooling of reactive polar molecules confined in a two-dimensional geometry

    CERN Document Server

    Zhu, Bihui; Rey, Ana M; Holland, Murray J

    2013-01-01

    Recent experimental developments in the loading of ultracold KRb molecules into quasi-two-dimensional traps, combined with the ability to tune the ratio between elastic and loss (inelastic/reactive) collisions through application of an external electric field, are opening the door to achieving efficient evaporative cooling of reactive polar molecules. In this paper, we use Monte Carlo simulations and semianalytic models to study theoretically the experimental parameter regimes in which evaporative cooling is feasible under current trapping conditions. We investigate the effect of the anisotropic character of dipole-dipole collisions and reduced dimensionality on evaporative cooling. We also present an analysis of the experimentally relevant anti-evaporation effects that are induced by chemical reactions that take place when more than one axial vibrational state is populated.

  5. Development of novel control system to grow ZnO thin films by reactive evaporation

    Directory of Open Access Journals (Sweden)

    Gerardo Gordillo

    2016-07-01

    Full Text Available This work describes a novel system implemented to grow ZnO thin films by plasma assisted reactive evaporation with adequate properties to be used in the fabrication of photovoltaic devices with different architectures. The innovative aspect includes both an improved design of the reactor used to activate the chemical reaction that leads to the formation of the ZnO compound as an electronic system developed using the virtual instrumentation concept. ZnO thin films with excellent opto-electrical properties were prepared in a reproducible way, controlling the deposition system through a virtual instrument (VI with facilities to control the amount of evaporated zinc involved in the process that gives rise to the formation of ZnO, by means of the incorporation of PID (proportional integral differential and PWM (pulse width modulation control algorithms. The effectiveness and reliability of the developed system was verified by obtaining with good reproducibility thin films of n+-ZnO and i-ZnO grown sequentially in situ with thicknesses and resistivities suitable for use as window layers in chalcopyrite based thin film solar cells.

  6. Electrical properties of silver selenide thin films prepared by reactive evaporation

    Indian Academy of Sciences (India)

    M C Santhosh Kumar; B Pradeep

    2002-10-01

    The electrical properties of silver selenide thin films prepared by reactive evaporation have been studied. Samples show a polymorphic phase transition at a temperature of 403 ± 2 K. Hall effect study shows that it has a mobility of 2000 cm2V–1s–1 and carrier concentration of 1018 cm–3 at room temperature. The carriers are of -type. X-ray diffraction study indicates that the as-prepared films are polycrystalline in nature. The lattice parameters were found to be = 4.353 Å, = 6.929 Å and = 7.805 Å.

  7. Production and characterization of thin film group IIIB, IVB and rare earth hydrides by reactive evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Provo, James L., E-mail: jlprovo@verizon.net [Consultant, J.L. Provo Consulting, Trinity, Florida 34655-7179 (United States)

    2015-07-15

    A recent short history of reactive evaporation by D. M. Mattox [History Corner—A Short History of Reactive Evaporation, SVC Bulletin (Society of Vacuum Coaters, Spring 2014), p. 50–51] describes various methods for producing oxides, nitrides, carbides, and some compounds, but hydrides were not mentioned. A study was performed in the mid-1970s at the General Electric Company Neutron Devices Department in Largo, FL, by the author to study preparation of thin film hydrides using reactive evaporation and to determine their unique characteristics and properties. Films were produced of scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), and the rare earth praseodymium (Pr), neodymium (Nd), gadolinium (Gd), dysprosium (Dy), and erbium (Er) hydrides by hot crucible filament and electron beam evaporation in atmospheres of deuterium and tritium gases. All-metal vacuum systems were used and those used with tritium were dedicated for this processing. Thin film test samples 1000 nm thick were prepared on 1.27 cm diameter molybdenum disk substrates for each occluder (i.e., an element that can react with hydrogen to form a hydride) material. Loading characteristics as determined by gas-to-metal atomic ratios, oxidation characteristics as determined by argon–sputter Auger analysis, film structure as determined by scanning electron microscope analysis, and film stress properties as determined by a double resonator technique were used to define properties of interest. Results showed hydrogen-to-metal atomic ratios varied from 1.5 to 2.0 with near maximum loading for all but Pr and Nd occluders which correlated with the oxidation levels observed, with all occluder oxidation levels being variable due to vacuum system internal processing conditions and the materials used. Surface oxide levels varied from ∼80 Å to over 1000 Å. For most films studied, results showed that a maximum loading ratio of near 2.0 and a minimum surface oxide level of ∼80 Å could be

  8. XPS analysis of the activation process in non-evaporable getter thin films

    CERN Document Server

    Lozano, M

    2000-01-01

    The surface activation process of sputter-coated non-evaporable getter (NEG) thin films based on Ti-Zr and Ti-Zr-V alloys has been studied in situ by means of X-ray photoelectron spectroscopy. After exposure of the NEG thin films to ambient air they become reactivated after a thermal treatment in an ultrahigh vacuum. In our case the films are heated up to ~250 degrees C for 2 h in a base pressure of ~10/sup -9/ Torr. (18 refs).

  9. Species profiles and normalized reactivity of volatile organic compounds from gasoline evaporation in China

    Science.gov (United States)

    Zhang, Yanli; Wang, Xinming; Zhang, Zhou; Lü, Sujun; Shao, Min; Lee, Frank S. C.; Yu, Jianzhen

    2013-11-01

    In China, fast increase in passenger cars and gasoline consumption with yet quite limited vapor recovery during gasoline distribution has procured growing concern about gasoline evaporation as an important emission source of volatile organic compounds (VOCs), particularly in megacities hard-hit by air quality problems. This study presents VOC species profiles related to major pathways of gasoline evaporative loss in China, including headspace displacement, refueling operations and spillage/leakage. Apart from liquid gasoline and headspace vapors, gasoline vapors emitted when refueling cars in service stations or tank trucks in oil marketing depots were also sampled in situ with vapor recovery units (VRUs) turning on/off. Alkanes, alkenes and aromatic hydrocarbons accounted for 55-66, 21-35 and 4-8% in refueling vapors, 59-72, 18-28 and 4-10% in headspace vapors and 33-51, 8-15 and 38-48% in liquid gasoline samples, respectively. During refueling with VRUs turning on, total VOCs in vapors were less than one fifth of that with VRUs turning off, and aromatic hydrocarbons had higher weight percentages of about 8% in contrast with that of about 4% during refueling with VRUs turning off. Refueling vapors, especially for that with VRUs turning off, showed a larger fraction of light hydrocarbons including C3-C5 light alkenes when compared to headspace vapors, probably due to splashing and disturbance during filling operation. In refueling or headspace vapors the ratios of i-pentane/benzene, i-pentane/toluene, and MTBE (methyl tert-butyl ether)/benzene ranged 8.7-57, 2.7-4.8, and 1.9-6.6, respectively; and they are distinctively much higher than those previously reported in vehicle exhausts. Calculated normalized reactivity or ozone formation potential of the gasoline vapors in China ranged 3.3-4.4 g O3 g-1 VOC, about twice that of gasoline headspace vapors reported in USA as a result of larger fractions of alkenes in China's gasoline vapors. The results suggested that

  10. Preparation of Indium Tin Oxide films deposited by reactive evaporation at different substrate-temperature and the properties

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Indium Tin Oxide films have been prepared at different substrate-temperature on glass substrates by reactive evaporation of In-Sn alloy with an oxygen pressure of 1.3 × 10-1 Pa and a deposition rate of 10-2 nm/s. The best ITO films obtained cm2v-1s-1. The influence of the substrate-temperature on the structural, optical and electrical properties of the obtained films has been investigated.

  11. Thermal decomposition routes of CrN hard coatings synthesized by reactive arc evaporation and magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, W.; Neidhardt, J. [Christian Doppler Laboratory for Advanced Hard Coatings, Department of Physical Metallurgy and Materials Testing, Franz-Josef Strasse 18, University of Leoben, 8700 Leoben (Austria); Willmann, H. [Materials Center Leoben, Franz-Josef Strasse 13, 8700 Leoben (Austria); Sartory, B. [Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck (Austria); Mayrhofer, P.H. [Department of Physical Metallurgy and Materials Testing, Franz-Josef Strasse 18, University of Leoben, 8700 Leoben (Austria)], E-mail: paul.mayrhofer@unileoben.ac.at; Mitterer, C. [Christian Doppler Laboratory for Advanced Hard Coatings, Department of Physical Metallurgy and Materials Testing, Franz-Josef Strasse 18, University of Leoben, 8700 Leoben (Austria); Department of Physical Metallurgy and Materials Testing, Franz-Josef Strasse 18, University of Leoben, 8700 Leoben (Austria)

    2008-11-28

    This study presents a comparison of the thermal decomposition of CrN hard coatings synthesized by reactive arc evaporation and magnetron sputtering. Structural changes in the coating material were determined by in-situ high-temperature X-ray diffraction and correlated to the results of simultaneous thermal analysis. Annealing temperatures up to 1440 deg. C in Ar and a variation in heating rates gave insights to the different decomposition kinetics for the material deposited by reactive arc evaporation and magnetron sputtering. Both single-phase CrN coatings start to decompose above 925 deg. C under release of nitrogen in two major reaction steps to pure Cr via the intermediate step of Cr{sub 2}N. While the kinetics for the first decomposition reaction from CrN to Cr{sub 2}N is different for both samples, the second step from Cr{sub 2}N into Cr is similar. This behavior can be understood considering the differences in structure, composition, and morphology of both as-deposited coatings and their evolution during thermal analysis.

  12. Strong pinning in very fast grown reactive co-evaporated GdBa2Cu3O7 coated conductors

    Directory of Open Access Journals (Sweden)

    J. L. MacManus-Driscoll

    2014-08-01

    Full Text Available We report on compositional tuning to create excellent field-performance of Jc in “self-doped,” GdBa2Cu3O7−y (GdBCO coated conductors grown by ultrafast reactive co-evaporation. In order to give excess liquid and Gd2O3, the overall compositions were all Ba-poor and Cu-rich compared to GdBCO. The precise composition was found to be critical to the current carrying performance. The most copper-rich composition had an optimum self-field Jc of 3.2 MA cm−2. A more Gd-rich composition had the best in-field performance because of the formation of low coherence, splayed Gd2O3 nanoparticles, giving Jc (77 K, 1 T of over 1 MA cm−2 and Jc (77 K, 5 T of over 0.1 MA cm−2.

  13. Plasma synthesis of titanium nitride, carbide and carbonitride nanoparticles by means of reactive anodic arc evaporation from solid titanium

    Energy Technology Data Exchange (ETDEWEB)

    Kiesler, D., E-mail: dennis.kiesler@uni-due.de; Bastuck, T.; Theissmann, R.; Kruis, F. E. [University of Duisburg-Essen, Institute of Technology for Nanostructures (NST) and Center for Nanointegration Duisburg-Essen (CENIDE) (Germany)

    2015-03-15

    Plasma methods using the direct evaporation of a transition metal are well suited for the cost-efficient production of ceramic nanoparticles. In this paper, we report on the development of a simple setup for the production of titanium-ceramics by reactive anodic arc evaporation and the characterization of the aerosol as well as the nanopowder. It is the first report on TiC{sub X}N{sub 1 − X} synthesis in a simple anodic arc plasma. By means of extensive variations of the gas composition, it is shown that the composition of the particles can be tuned from titanium nitride over a titanium carbonitride phase (TiC{sub X}N{sub 1 − X}) to titanium carbide as proven by XRD data. The composition of the plasma gas especially a very low concentration of hydrocarbons around 0.2 % of the total plasma gas is crucial to tune the composition and to avoid the formation of free carbon. Examination of the particles by HR-TEM shows that the material consists mostly of cubic single crystalline particles with mean sizes between 8 and 27 nm.

  14. Cardiovascular Reactivity, Stress, and Physical Activity

    Directory of Open Access Journals (Sweden)

    Chun-Jung eHuang

    2013-11-01

    Full Text Available Psychological stress has been proposed as a major contributor to the progression of cardiovascular disease (CVD. Acute mental stress can activate the sympathetic-adrenal-medullary (SAM axis, eliciting the release of catecholamines (NE and EPI resulting in the elevation of heart rate (HR and blood pressure (BP. Combined stress (psychological and physical can exacerbate these cardiovascular responses, which may partially contribute to the elevated risk of CVD and increased proportionate mortality risks experienced by some occupations (e.g., firefighting and law enforcement. Studies have supported the benefits of physical activity on physiological and psychological health, including the cardiovascular response to acute stress. Aerobically trained individuals exhibit lower sympathetic nervous system (e.g., HR reactivity and enhanced cardiovascular efficiency (e.g., lower vascular reactivity and decreased recovery time in response to physical and/or psychological stress. In addition, resistance training has been demonstrated to attenuate cardiovascular responses and improve mental health. This review will examine stress-induced cardiovascular reactivity and plausible explanations for how exercise training and physical fitness (aerobic and resistance exercise can attenuate cardiovascular responses to stress. This enhanced functionality may facilitate a reduction in the incidence of stroke and myocardial infarction. Finally, this review will also address the interaction of obesity and physical activity on cardiovascular reactivity and CVD.

  15. Evaporation Of Hanford Waste Treatment Plant Direct Feed Low Activity Waste Effluent Management Facility Core Simulant

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Mcclane, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate, LMOGC) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation, and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator, in the Effluent Management Facility (EMF), and then return it to the LAW melter. It is important to understand the composition of the effluents from the melter, and new evaporator so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of the LMOGC stream would eliminate recycling of problematic components, and would reduce the need for closely integrated operation of the LAW melter and the Pretreatment Facilities. Long-term implementation of this option after WTP start-up would decrease the LAW vitrification mission duration and quantity of glass waste, amongst the other operational complexities such a recycle stream presents. In order to accurately plan for the disposition path, it is key to experimentally determine the fate of contaminants. To do this, testing is needed to accurately account for the buffering chemistry of the components, determine the achievable evaporation end point, identify insoluble solids that form, and determine the distribution of key regulatory-impacting constituents.

  16. Measuring low radium activity concentration in water with RAD7 by means of evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Kappke, Jaqueline; Marussig, Camila G.T.; Paschuk, Sergei; Zambianchi Junior, Pedro; Correa, Janine N.; Perna, Allan Felipe Nunes; Martin, Aline, E-mail: jaquelinekappke@gmail.com, E-mail: mila_garciatb@hotmail.com, E-mail: spaschuk@gmail.com, E-mail: zambianchi@utfpr.edu.br, E-mail: janine_nicolosi@hotmail.com, E-mail: allan_perna@hotmail.com, E-mail: nocamartin@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2015-07-01

    Preliminary activity measurements of low radium concentration in mineral water by using RAD7 equipment showed high values of statistical errors. Therefore, the need to develop a new protocol for measuring and proofing the evaporation test for radium measurements in water is in place. This study evaluates the possibility of using RAD7 equipment to measure Ra-226 activity in equilibrium with Rn-222 present in water samples. The technique involves evaporation process so as to increase the Ra-226 concentration in the sample in a controlled manner and thus reduce statistical errors. Two samples were compared, 10 L sample of distilled water and a 7.75 L sample of known concentration (0.1 Bq/L). The evaporation was carried out starting with different initial volumes for both samples: 500 mL, 1000 mL, 2000 mL, 4000 mL and a 250 mL sample not subject to evaporation. All samples reached a final volume of approximately 250 mL. After evaporation, the samples were stored for 30 days until secular equilibrium was achieved between Ra-226 and Rn-222. The values obtained, by using RAD7 detector, for distilled water, as expected, are near zero averaging 0.021 ± 0.016 Bq/L. The average value found in the water of known concentration was 0.099 ± 0.011 Bq/L, also close to the expected 0.1 Bq/L. The conclusion is that the application of an evaporation process is efficient and the proposed methodology is a proven alternative to decrease the statistical errors. (author)

  17. Laboratory Evaporation Testing Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, Duane J.; Nash, Charles A.; McCabe, Daniel J.; Crawford, Charles L.; Wilmarth, William R.

    2014-01-27

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream, LAW Off-Gas Condensate, from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of canistered glass waste forms. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to be within acceptable concentration ranges in the LAW glass. Diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task examines the impact of potential future disposition of this stream in the Hanford tank farms, and investigates auxiliary evaporation to enable another disposition path. Unless an auxiliary evaporator is used, returning the stream to the tank farms would require evaporation in the 242-A evaporator. This stream is expected to be unusual because it will be very high in corrosive species that are volatile in the melter

  18. Evaporation Of Hanford Waste Treatment Plant Direct Feed Low Activity Waste Effluent Management Facility Core Simulant

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Mcclane, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate, LMOGC) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation, and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator, in the Effluent Management Facility (EMF), and then return it to the LAW melter. It is important to understand the composition of the effluents from the melter and new evaporator, so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of the LMOGC stream would eliminate recycling of problematic components, and would reduce the need for closely integrated operation of the LAW melter and the Pretreatment Facilities. Long-term implementation of this option after WTP start-up would decrease the LAW vitrification mission duration and quantity of glass waste, amongst the other operational complexities such a recycle stream presents. In order to accurately plan for the disposition path, it is key to experimentally determine the fate of contaminants. To do this, testing is needed to accurately account for the buffering chemistry of the components, determine the achievable evaporation end point, identify insoluble solids that form, and determine the distribution of key regulatory-impacting constituents. The LAW Melter Off-Gas Condensate stream will contain components that are volatile at melter temperatures, have limited solubility in the glass waste form, and represent a materials corrosion concern, such as halides and sulfate. Because this stream will recycle within WTP, these components will accumulate in the Melter Condensate

  19. Kinetics of Evaporation and Growth of Drops of Aqueous Solutions of Surface Active Substances at Negative Temperatures,

    Science.gov (United States)

    2014-09-26

    RD-Ri56 961 KINETICS OF EVAPORATION FIND GROWTH OF DROPS OF AQUEOUS i/i SOLUTIONS OF SURFA .(U) FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AlFB OH Y I...Jall IN ,I" FTD-ID(RS)T-0938-84 t FOREIGN TECHNOLOGY DIVISION Lfl -• KINETICS OF EVAPORATION AND GROWTH OF DROPS OF AQUEOUS SOLUTIONS OF SURFACE ACTIVE...TRANSLATION FTD-ID(RS)T-0938-84 25 June 1985 MICROFICHE NR: FTD-85-C-000451 KINETICS OF EVAPORATION AND GROWTH OF DROPS OF AQUEOUS SOLUTIONS OF SURFACE

  20. Autonomous Active and Reactive Power Distribution Strategy in Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan; Tang, Fen; Guerrero, Josep M.;

    2014-01-01

    This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...... in a distributed way. Real-time hardware-in-the-loop results are presented to verify the proposed control strategy.......This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...

  1. Stresses and Temperature Stability of Dense Wavelength Division Multiplexing Filters Prepared by Reactive Ion-Assisted E-Gun Evaporation

    Science.gov (United States)

    Wei, Chao-Tsang; Shieh, Han-Ping D.

    2005-10-01

    In this paper, we report the in situ measurement of the temperature stability of narrow-band-pass filters on different types of substrate, for dense wavelength division multiplexing (DWDM) filters in optical-fiber transmission systems. The DWDM filters were designed as all-dielectric Fabry-Perot filters and fabricated by reactive ion-assisted deposition. Ta2O5 and SiO2 were used as high- and low-refractive-index layers, respectively, for constructing the DWDM filters. The accuracy and stability of the coating process were evaluated for fabricating the DWDM filters for the temperature stability of the center wavelength. The center wavelength shift was determined to be greatly dependent on the coefficient of thermal expansion of the substrate on which the filter is deposited.

  2. Adaptive Compensation of Reactive Power With Shunt Active Power Filters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Hansen, Steffan;

    2008-01-01

    This paper describes an adaptive method for compensating the reactive power with an active power filter (APF), which is initially rated for mitigation of only the harmonic currents given by a nonlinear industrial load. It is proven that, if the harmonic currents do not load the APF at the rated...

  3. Spectroscopic ellipsometry study of xPbO-(1 - x)TiO{sub 2} thin films elaborated by mixed reactive thermal co-evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Boulouz, A; Koutti, L [Faculte des Sciences, LabSIV, Universite Ibn Zohr, 80000 Agadir (Morocco); Nacri, A En [LPMD, Universite Paul Verlaine-Metz, Technopole-Arago, 57010 Metz (France); Pascal-Delannoy, F; Sorli, B, E-mail: ennacir@univ-metz.f [Institut d' Electronique de Sud (IES) UMR CNRS 5214, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier, cedex 05 (France)

    2009-12-21

    In this paper, the refractive index, extinction coefficient and optical band gap of xPbO-(1 - x)TiO{sub 2} systems are determined by spectroscopic ellipsometry in the spectral range of wavelength 250-850 nm. All films are elaborated by mixed reactive thermal co-evaporation on a SiO{sub 2}/Si substrate. The Tauc-Lorentz model is used to extract the optical responses and characteristics of the layers. The best values of the fitted parameters are reported. The wavelength-by-wavelength numerical inversion, carried out without considering any fitting parameter, is also represented as another way to derive the optical constants of the layers. The refractive index and the extinction coefficient depend on the PbO content in xPbO-(1 - x)TiO{sub 2} systems. The obtained values of the optical band gap are found to change between 2.54 and 3.38 eV. It is demonstrated here that the xPbO-(1 - x)TiO{sub 2} systems with the studied compositions have an indirect optical band gap.

  4. Correlations between the Optical Properties and the Microstructure of TiO2 Thin Films Prepared by Reactive Electron-beam Evaporation

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-hua; XUE Yi-yu; ZHANG You-ling; CAO Hong

    2004-01-01

    High refractive index TiO2 thin films were deposited on BK7 glass by reactive electron - beam(REB) evaporation at pressure of 2 × 10- 2 Pa, deposition rate of 0.2nm/s and at various substrate temperaturesfrom 120℃ to 300℃ . The refractive index and the thickness of the films were measured by visible spectroscopic el-lipsometry (SE) and determined from transmission spectra. Optical properties and structure features were charac-terized by UV - VIS, SEM and XRD, respectively. The measurement and analysis on transmission spectra of allsamples shaw that with the substrate temperature increasing from 120℃ to 300℃ , the refractive indices of thinfilms increase from 1.7 to 2.1 and the films after heat treatment have higher refractive indices due to its crystalliz-ing. The XRD analysis results indicate that the structure of TiO2 thin films deposited on BK7 glass at substratetemperatures of 120℃ ,200℃ and 300℃ is amorphous, after post-annealing under air condition at 400℃ for 1hour, the amorphous structure is crystallized, the crystal phase is of 100% anatase with strong preferred orientation(004) and the grain size of crystalline is within 3.6-8.1 nm, which is consistent with results from SEM observation.

  5. Anticipating Human Activities Using Object Affordances for Reactive Robotic Response.

    Science.gov (United States)

    Koppula, Hema S; Saxena, Ashutosh

    2016-01-01

    An important aspect of human perception is anticipation, which we use extensively in our day-to-day activities when interacting with other humans as well as with our surroundings. Anticipating which activities will a human do next (and how) can enable an assistive robot to plan ahead for reactive responses. Furthermore, anticipation can even improve the detection accuracy of past activities. The challenge, however, is two-fold: We need to capture the rich context for modeling the activities and object affordances, and we need to anticipate the distribution over a large space of future human activities. In this work, we represent each possible future using an anticipatory temporal conditional random field (ATCRF) that models the rich spatial-temporal relations through object affordances. We then consider each ATCRF as a particle and represent the distribution over the potential futures using a set of particles. In extensive evaluation on CAD-120 human activity RGB-D dataset, we first show that anticipation improves the state-of-the-art detection results. We then show that for new subjects (not seen in the training set), we obtain an activity anticipation accuracy (defined as whether one of top three predictions actually happened) of 84.1, 74.4 and 62.2 percent for an anticipation time of 1, 3 and 10 seconds respectively. Finally, we also show a robot using our algorithm for performing a few reactive responses.

  6. Physical activity moderates stressor-induced rumination on cortisol reactivity

    Science.gov (United States)

    Puterman, Eli; O’Donovan, Aoife; Adler, Nancy E.; Tomiyama, A. Janet; Kemeny, Margaret; Wolkowitz, Owen M.; Epel, Elissa

    2011-01-01

    Objective Physically active individuals have lower rates of morbidity and mortality, and recent evidence indicates that physical activity may be particularly beneficial to those experiencing chronic stress. The tendency to ruminate increases and prolongs physiological stress responses, including hypothalamic-pituitary adrenal (HPA) axis responses as indexed by cortisol reactivity to stressful experiences. We examined the association between ruminating in response to a laboratory stressor task and HPA axis reactivity and recovery, and whether a physically active lifestyle moderates the associations between rumination and cortisol output trajectories. Methods Forty-six post-menopausal women underwent the Trier Social Stress Test while salivary cortisol was repeatedly measured. Twenty-five minutes after the end of the stressor, participants reported level of rumination in response to the stress. Results Findings indicate that physical activity moderated the initial rate (B = −.10, SE = .04, p < .05) and curvature (B = −.03, SE = .01, p = .06) of the relationship between rumination and log-transformed cortisol trajectory. Among sedentary participants, those who responded to the stressor with higher levels of rumination had a more rapid initial increase in cortisol (0.26 vs 0.21, p < .001), a later peak (56 vs. 39 minutes), and a delayed recovery (curvature −0.07 vs. −0.08, p < .001) compared to those with lower levels of rumination. In active participants, cortisol trajectories were equivalent, regardless of level of rumination. Conclusions In sum, individuals who maintain a physically active lifestyle may be protected against the effects of rumination on HPA axis reactivity to and recovery from acute stress. PMID:21873586

  7. The disk evaporation model for the spectral features of low-luminosity active galactic nuclei

    CERN Document Server

    Qiao, Erlin; Panessa, Francesca; Liu, J Y

    2013-01-01

    Observations show that the accretion flows in low-luminosity active galactic nuclei (LLAGNs) probably have a two-component structure with an inner ADAF and an outer truncated accretion disk. As shown by Taam et al. (2012), the truncation radius as a function of mass accretion rate is strongly affected by including the magnetic field within the framework of disk evaporation model, i.e., an increase of the magnetic field results in a smaller truncation radius of the accretion disk. In this work, we calculate the emergent spectrum of an inner ADAF + an outer truncated accretion disk around a supermassive black hole based on the prediction by Taam et al. (2012). It is found that an increase of the magnetic field from $\\beta=0.8$ to $\\beta=0.5$ (with magnetic pressure $p_{\\rm m}=B^2/{8\\pi}=(1-\\beta)p_{\\rm tot}$, $p_{\\rm tot}=p_{\\rm gas}+p_{\\rm m}$) results in an increase of $\\sim 8.7$ times of the luminosity from the truncated accretion disk. We found that the equipartition of gas pressure to magnetic pressure, i....

  8. Differentiating challenge reactivity from psychomotor activity in studies of children's psychophysiology: considerations for theory and measurement.

    Science.gov (United States)

    Bush, Nicole R; Alkon, Abbey; Obradović, Jelena; Stamperdahl, Juliet; Boyce, W Thomas

    2011-09-01

    Current methods of assessing children's physiological "stress reactivity" may be confounded by psychomotor activity, biasing estimates of the relation between reactivity and health. We examined the joint and independent contributions of psychomotor activity and challenge reactivity during a protocol for 5- and 6-year-old children (N = 338). Measures of parasympathetic reactivity (respiratory sinus arrhythmia [RSA]) and sympathetic reactivity (preejection period [PEP]) were calculated for social, cognitive, sensory, and emotional challenge tasks. Reactivity was calculated relative to both resting and a paired comparison task that accounted for psychomotor activity effects during each challenge. Results indicated that comparison tasks themselves elicited RSA and PEP responses, and reactivity adjusted for psychomotor activity was incongruent with reactivity calculated using rest. Findings demonstrate the importance of accounting for confounding psychomotor activity effects on physiological reactivity.

  9. Concentration and Separation of Active Proteins from Potato Industry Waste Based on Low-Temperature Evaporation and Ethanol Precipitation

    Science.gov (United States)

    Ahokas, Mikko; Järvinen, Juho; Toivanen, Juho; Tanskanen, Juha P.

    2017-01-01

    Purpose. Potato fruit juice, a residue of starch industry, contains up to 2.5% [w/w] of proteins that are potentially valuable raw-materials of food, cosmetic, and pharma industries. The recovery of protein from the potato fruit juice is limited by the lack of industrially feasible concentration and separation technologies. The present research thus aimed at development of such process for the separation of active protease inhibitors from potato fruit juice. Methods. Low temperature mechanical vapor recompression evaporation was applied for concentration of potato fruit juice followed by ethanol precipitation for recovery of active proteins. The effects of precipitation temperature and precipitative agents were investigated employing response surface modeling methodology. Results. Concentration of potato fruit juice by evaporation was successful without loss of trypsin inhibition activity. Precipitation using 6.5 M ethanol at low temperature (0–+4°C) was found suitable for the recovery of active protease inhibitors from the concentrate. Piloting at starch industry yielded 50% of total proteins, with a high quantity of active protease inhibitors and a minor inclusion of other proteins. Conclusion. Concentration by low-temperature evaporation, followed by ethanol precipitation of protease inhibitors at optimized temperature, is an attractive option for valorization of potato fruit juice. PMID:28299232

  10. Production of active lysozyme films by matrix assisted pulsed laser evaporation at 355 nm

    DEFF Research Database (Denmark)

    Purice, Andreea; Schou, Jørgen; Kingshott, P.;

    2007-01-01

    Thin lysozyme films have been produced in a dry environment by MAPLE (matrix assisted pulsed laser evaporation) from a water ice matrix irradiated by laser light at 355 nm above the absorption threshold of the protein. A significant part of the lysozyme molecules are transferred to the film without...

  11. Flavonoids: hemisynthesis, reactivity, characterization and free radical scavenging activity.

    Science.gov (United States)

    Es-Safi, Nour-Eddine; Ghidouche, Souhila; Ducrot, Paul Henri

    2007-09-26

    Phenolic compounds form one of the main classes of secondary metabolites. They display a large range of structures and they are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Phenolic compounds are also highly unstable compounds which undergo numerous enzymatic and chemical reactions during postharvest food storage and processing thus adding to the complexity of plant polyphenol composition. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structures, their reactivity and chemical properties in addition to the mechanisms generating them appears essential to predict and control food quality. The purpose of this work is an overview of our findings concerning the hemisynthesis, the reactivity and the enzymatic oxidation of some flavonoids and shed light on the mechanisms involved in some of these processes and the structures of the resulting products. The free radical scavenging activity of some of the synthesized compounds is also presented and a structure-activity relationship is discussed. The first part of this review concerns the synthesis and structural characterization of modified monomeric flavanols. The use of these compounds as precursor for the preparation of natural and modified dimeric procyanidin derivatives was then explored through different coupling reactions. The full characterization of the synthesized compounds was achieved by concerted use of NMR and ESI-MS techniques. The free radical scavenging activity of some of the synthesized compounds was investigated. The second part of this review concerns the enzymatic oxidation of several flavonols by Trametes versicolor laccase. Most of the major oxidation products have been

  12. Flavonoids: Hemisynthesis, Reactivity, Characterization and Free Radical Scavenging Activity

    Directory of Open Access Journals (Sweden)

    Paul Henri Ducrot

    2007-09-01

    Full Text Available Phenolic compounds form one of the main classes of secondary metabolites. They display a large range of structures and they are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Phenolic compounds are also highly unstable compounds which undergo numerous enzymatic and chemical reactions during postharvest food storage and processing thus adding to the complexity of plant polyphenol composition. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structures, their reactivity and chemical properties in addition to the mechanisms generating them appears essential to predict and control food quality. The purpose of this work is an overview of our findings concerning the hemisynthesis, the reactivity and the enzymatic oxidation of some flavonoids and shed light on the mechanisms involved in some of these processes and the structures of the resulting products. The free radical scavenging activity of some of the synthesized compounds is also presented and a structure-activity relationship is discussed. The first part of this review concerns the synthesis and structural characterization of modified monomeric flavanols. The use of these compounds as precursor for the preparation of natural and modified dimeric procyanidin derivatives was then explored through different coupling reactions. The full characterization of the synthesized compounds was achieved by concerted use of NMR and ESI-MS techniques. The free radical scavenging activity of some of the synthesized compounds was investigated. The second part of this review concerns the enzymatic oxidation of several flavonols by Trametes versicolor laccase. Most of the major oxidation

  13. On Variable Reverse Power Flow-Part I: Active-Reactive Optimal Power Flow with Reactive Power of Wind Stations

    Directory of Open Access Journals (Sweden)

    Aouss Gabash

    2016-02-01

    Full Text Available It has recently been shown that using battery storage systems (BSSs to provide reactive power provision in a medium-voltage (MV active distribution network (ADN with embedded wind stations (WSs can lead to a huge amount of reverse power to an upstream transmission network (TN. However, unity power factors (PFs of WSs were assumed in those studies to analyze the potential of BSSs. Therefore, in this paper (Part-I, we aim to further explore the pure reactive power potential of WSs (i.e., without BSSs by investigating the issue of variable reverse power flow under different limits on PFs in an electricity market model. The main contributions of this work are summarized as follows: (1 Introducing the reactive power capability of WSs in the optimization model of the active-reactive optimal power flow (A-R-OPF and highlighting the benefits/impacts under different limits on PFs. (2 Investigating the impacts of different agreements for variable reverse power flow on the operation of an ADN under different demand scenarios. (3 Derivation of the function of reactive energy losses in the grid with an equivalent-π circuit and comparing its value with active energy losses. (4 Balancing the energy curtailment of wind generation, active-reactive energy losses in the grid and active-reactive energy import-export by a meter-based method. In Part-II, the potential of the developed model is studied through analyzing an electricity market model and a 41-bus network with different locations of WSs.

  14. Variability in cold front activities modulating cool-season evaporation from a southern inland water in the USA

    Science.gov (United States)

    Liu, Heping; Blanken, Peter D.; Weidinger, Tamas; Nordbo, Annika; Vesala, Timo

    2011-04-01

    Understanding seasonal variations in the evaporation of inland waters (e.g., lakes and reservoirs) is important for water resource management as well as the prediction of the hydrological cycles in response to climate change. We analyzed eddy covariance-based evaporation measurements from the Ross Barnett Reservoir (32°26'N, 90°02'W which is always ice-free) in central Mississippi during the cool months (i.e., September-March) of 2007 and 2008, and found that the variability in cold front activities (i.e., passages of cold fronts and cold/dry air masses behind cold fronts) played an important role in modulating the exchange of sensible (H) and latent (λE) heat fluxes. Our analysis showed that 2007's warmer cool season had smaller mean H and λE than 2008's cooler cool season. This implies that the warmer cool season did not accelerate evaporation and heat exchange between the water surface and the atmosphere. Instead, more frequent cold fronts and longer periods of cold/dry air masses behind the cold fronts in 2008 resulted in overall larger H and λE as compared with 2007, this primarily taking the form of sporadic short-term rapid 'pulses' of H and λE losses from the water's surface. These results suggest that future climate-induced changes in frequency of cold fronts and the meteorological properties of the air masses behind cold fronts (e.g., wind speeds, temperature, and humidity), rather than other factors of climate change, would produce significant variations in the water surface's energy fluxes and subsequent evaporation rates.

  15. A Wolf Pack Algorithm for Active and Reactive Power Coordinated Optimization in Active Distribution Network

    Science.gov (United States)

    Zhuang, H. M.; Jiang, X. J.

    2016-08-01

    This paper presents an active and reactive power dynamic optimization model for active distribution network (ADN), whose control variables include the output of distributed generations (DGs), charge or discharge power of energy storage system (ESS) and reactive power from capacitor banks. To solve the high-dimension nonlinear optimization model, a new heuristic swarm intelligent method, namely wolf pack algorithm (WPA) with better global convergence and computational robustness, is adapted so that the network loss minimization can be achieved. In this paper, the IEEE33-bus system is used to show the effectiveness of WPA technique compared with other techniques. Numerical tests on the modified IEEE 33-bus system show that WPA for active and reactive multi-period optimization of ADN is exact and effective.

  16. Catalytic Role Of Palladium And Relative Reactivity Of Substituted Chlorines During Adsorption And Treatment Of PCBs On Reactive Activated Carbon

    Science.gov (United States)

    The adsorption-mediated dechlorination of polychlorinated biphenyls (PCBs) is a unique feature of reactive activated cabon (RAC). Here, we address the RAC system, containing a tunable amount of Fe as a primary electron donor coupled with Pd as an electrochemical catalyst to pote...

  17. Activation of chalcogens and chalcogenides at reactive uranium centers

    Energy Technology Data Exchange (ETDEWEB)

    Franke, Michael Sebastian

    2015-07-23

    The high reactivity of many trivalent uranium complexes was investigated in the Meyer group, however, these studies were not limited to small-molecule activation, but were extended to other relatively inert reagents like the heavier elemental chalcogens sulfur, selenium, and tellurium. The tripodal N-anchored chelate ({sup Ad,Me}ArO){sub 3}N{sup 3-} (trianion of tris(3-Adamantyl-2-hydroxy-5-methylbenzyl)amine) was found to be a very suitable candidate for this task and the respective uranium(III) complex [(({sup Ad,Me}ArO){sub 3}N)U{sup III}(DME)] is able to activate elemental sulfur and selenium to form the dinuclear, chalcogenido-bridged complexes [{(("A"d","M"eArO)_3N)U"I"V(DME)}{sub 2}(μ-E)] (E = S, Se). Starting from this previously accomplished work, research in this thesis aimed at furthering reactivity studies of trivalent [(({sup Ad,Me}ArO){sub 3}N)U{sup III}(DME)], but also its chalcogenido-bridged uranium(IV) products, and the spectroscopic characterization of all newly synthesized compounds. Furthermore, the development of the new phenol HOAr* (Ar* = 2,6-(CHPh{sub 2}){sub 2}-4-Me-C{sub 6}H{sub 2}, 2,6-bis(diphenylmethyl)-4-methylphenyl) and its establishment as a ligand to be used for uranium coordination chemistry was another goal of this thesis. The activation of CO{sub 2} by uranium(III) complex [(({sup Ad,Me}ArO){sub 3}N)U{sup III}(DME)] to yield the dinuclear, carbonate-bridged uranium(IV/IV) complex [{(("A"d","M"eArO)_3N)U"I"V(DME)}{sub 2}(μ-κ{sup 1}:κ{sup 2}-CO{sub 3})] and CO was reported in 2010 by Meyer and co-workers. These previous results led to the pursuit of the isolation of mixed chalcogenocarbonate complexes from the reaction of the bridging chalcogenidos [{(("A"d","M"eArO)_3N)U"I"V(DME)}{sub 2}(μ-E)] (E = S, Se) with either CO{sub 2} or its heterocumulene analogs COS or CS{sub 2}. The chalcogeno-carbonates [{(("A"d","M"eArO)_3N)U"I"V(DME)}{sub 2}(μ-κ{sup 1}:κ{sup 2}-CO{sub 2}E)] und [{(("A"d","M"eArO)_3N)U"I"V-(DME)}{sub 2}(

  18. Structure-activity relationship for the reactivators of acetylcholinesterase inhibited by nerve agent VX.

    Science.gov (United States)

    Kuca, Kamil; Musilek, Kamil; Jun, Daniel; Karasova, Jana; Soukup, Ondrej; Pejchal, Jaroslav; Hrabinova, Martina

    2013-08-01

    Nerve agents such as sarin, VX and tabun are organophosphorus compounds able to inhibit an enzyme acetylcholinesterase (AChE). AChE reactivators and anticholinergics are generally used as antidotes in the case of intoxication with these agents. None from the known AChE reactivators is able to reactivate AChE inhibited by all kinds of nerve agents. In this work, reactivation potency of seventeen structurally different AChE reactivators was tested in vitro and subsequently, relationship between their chemical structure and biological activity was outlined. VX was chosen as appropriate member of the nerve agent family.

  19. Evaporating firewalls

    Science.gov (United States)

    Van Raamsdonk, Mark

    2014-11-01

    In this note, we begin by presenting an argument suggesting that large AdS black holes dual to typical high-energy pure states of a single holographic CFT must have some structure at the horizon, i.e. a fuzzball/firewall, unless the procedure to probe physics behind the horizon is state-dependent. By weakly coupling the CFT to an auxiliary system, such a black hole can be made to evaporate. In a case where the auxiliary system is a second identical CFT, it is possible (for specific initial states) that the system evolves to precisely the thermofield double state as the original black hole evaporates. In this case, the dual geometry should include the "late-time" part of the eternal AdS black hole spacetime which includes smooth spacetime behind the horizon of the original black hole. Thus, if a firewall is present initially, it evaporates. This provides a specific realization of the recent ideas of Maldacena and Susskind that the existence of smooth spacetime behind the horizon of an evaporating black hole can be enabled by maximal entanglement with a Hawking radiation system (in our case the second CFT) rather than prevented by it. For initial states which are not finely-tuned to produce the thermofield double state, the question of whether a late-time infalling observer experiences a firewall translates to a question about the gravity dual of a typical high-energy state of a two-CFT system.

  20. Enhanced capacitive properties of commercial activated carbon by re-activation in molten carbonates

    Science.gov (United States)

    Lu, Beihu; Xiao, Zuoan; Zhu, Hua; Xiao, Wei; Wu, Wenlong; Wang, Dihua

    2015-12-01

    Simple, affordable and green methods to improve capacitive properties of commercial activated carbon (AC) are intriguing since ACs possess a predominant role in the commercial supercapacitor market. Herein, we report a green reactivation of commercial ACs by soaking ACs in molten Na2CO3-K2CO3 (equal in mass ratios) at 850 °C combining the merits of both physical and chemical activation strategies. The mechanism of molten carbonate treatment and structure-capacitive activity correlations of the ACs are rationalized. Characterizations show that the molten carbonate treatment increases the electrical conductivity of AC without compromising its porosity and wettability of electrolytes. Electrochemical tests show the treated AC exhibited higher specific capacitance, enhanced high-rate capability and excellent cycle performance, promising its practical application in supercapacitors. The present study confirms that the molten carbonate reactivation is a green and effective method to enhance capacitive properties of ACs.

  1. Droplet evaporation with complexity of evaporation modes

    Science.gov (United States)

    Hwang, In Gyu; Kim, Jin Young; Weon, Byung Mook

    2017-01-01

    Evaporation of a sessile droplet often exhibits a mixed evaporation mode, where the contact radius and the contact angle simultaneously vary with time. For sessile water droplets containing polymers with different initial polymer concentrations, we experimentally study their evaporation dynamics by measuring mass and volume changes. We show how diffusion-limited evaporation governs droplet evaporation, regardless of the complexity of evaporation behavior, and how the evaporation rate depends on the polymer concentration. Finally, we suggest a unified expression for a diffusion-limited evaporation rate for a sessile droplet with complexity in evaporation dynamics.

  2. A study of the evaporation of heterogeneous water droplets under active heating

    Science.gov (United States)

    Piskunov, Maxim; Legros, Jean Claude; Strizhak, Pavel

    2016-11-01

    Using high-speed video registration tools with a sample rate of 102-104 frames per second (fps), we studied the patterns in the evaporation of water droplets containing 1 and 2 mm individual metallic inclusions in a high-temperature gas environment. The materials of choice for the inclusions were steels (AISI 1080 carbon steel and AISI type 316L stainless steel) and pure nickel. We established the lifetimes τh of the liquid droplets under study with a controlled increase in the gas environment temperature up to 900 K. We also considered the physical aspects behind the τh distribution in the experiments conducted and specified the conditions for more effective cooling of metallic inclusions. Following the experimental research findings, a method was devised for effective reactor vessel cooling to avoid a meltdown at a nuclear power plant. The optimization of heat and mass transfer modes was performed within the framework of the strategic plan for the development of National Research Tomsk Polytechnic University as one of the world-leading universities.

  3. Interactive effects of social adversity and respiratory sinus arrhythmia activity on reactive and proactive aggression.

    Science.gov (United States)

    Zhang, Wei; Gao, Yu

    2015-10-01

    Abnormal parasympathetic nervous system (PNS)-related cardiac activity has been linked to aggression. However, little is known about how it interacts with psychosocial adversity in predisposing to reactive-proactive aggression. In the current study, 84 male and female college students self-reported reactive and proactive aggression, and were assessed for respiratory sinus arrhythmia (RSA), a measure of PNS-related cardiac activity, during rest and when they contemplated an emotion-evoking decision-making task. Regression analyses showed that (a) resting RSA was positively linked to reactive aggression in conditions of high social adversity, and (b) RSA reactivity was positively associated with reactive but negatively associated with proactive aggression, in conditions of low social adversity. Main effects were not found for psychophysiological functioning or psychosocial adversity, suggesting the importance of their interaction. Findings support a biosocial basis for aggression and add additional support for the distinctions between reactive and proactive aggression.

  4. Laser-induced evaporation, reactivity and deposition of ZrO 2, CeO 2, V 2O 5 and mixed Ce-V oxides

    Science.gov (United States)

    Flamini, C.; Ciccioli, A.; Traverso, P.; Gnecco, F.; Giardini Guidoni, A.; Mele, A.

    2000-12-01

    It has been found that pulsed laser ablation has good potentiality for the deposition of ZrO2, CeO2, V2O5 and mixed Ce-V oxides which are very important materials for their application in optics and electrochromic devices. Laser induced compositional changes of thin films in the ablation and deposition processes of these materials have been explored. The effect of the oxygen gas pressure on the thin film composition has been examined. The congruency of the process has been treated on the basis of a thermal mechanism of evaporation-decomposition of the compounds. An attempt to model the processes by means of a thermodynamic approach is reported.

  5. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Energy Technology Data Exchange (ETDEWEB)

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  6. DMPD: NF-kappaB activation by reactive oxygen species: fifteen years later. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16723122 NF-kappaB activation by reactive oxygen species: fifteen years later. Gloi...svg) (.html) (.csml) Show NF-kappaB activation by reactive oxygen species: fifteen years later. PubmedID 16723122 Title NF-kappaB act...ivation by reactive oxygen species: fifteen years later.

  7. Lowering the activation temperature of TiZrV non-evaporable getter films [for LHC

    CERN Document Server

    Prodromides, A E; Taborelli, M

    2001-01-01

    In order to reduce the activation temperature of the TiZrV alloy, thin films of various compositions were produced by three-cathode magnetron sputtering on stainless-steel substrates. For the characterisation of the activation behaviour the surface chemical composition has been monitored by Auger electron spectroscopy during specific in situ thermal cycles. The volume elemental composition of the film has been measured by energy dispersive X-ray spectroscopy and the morphology (crystal structure and size of the crystallites) has been investigated by X-ray diffraction. The criteria indicating the sample quality and its dependence on film structure and chemical composition are presented and discussed. (13 refs).

  8. Lowering the activation temperature of TiZrV non-evaporable getter films

    CERN Document Server

    Taborelli, M; Scheuerlein, C

    1999-01-01

    In order to reduce the activation temperature of the TiZrV alloy, thin films of various compositions were produced by three-cathode magnetron sputtering on stainless steel substrates. For the characterisation of the activation behaviour the surface chemical composition has been monitored by Auger Electron Spectroscopy (AES) during specific in situ thermal cycles. The volume elemental composition of the film has been measured by Energy Dispersive X-ray spectroscopy (EDX) and the morphology (crystal structure and size of the crystallites) has been investigated by X-ray diffraction (XRD). The criteria indicating the sample quality and its dependence on film structure and chemical composition are presented and discussed.

  9. The Activation of Non-evaporable Getters Monitored by AES, XPS, SSIMS and Secondary Electron Yield Measurements

    CERN Document Server

    Scheuerlein, C

    2002-01-01

    In this thesis the potential of the three classical surface analysis techniques Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectrometry (SSIMS) for the characterisation of non-evaporable getter (NEG) materials is assessed and artefacts are described. The various NEG samples have been analysed in the context of the development of NEG thin film coatings for use in accelerator ultra high vacuum (UHV) systems. The secondary electron yield (SEY), which is a functional surface property of great importance for the application of NEG to accelerators, has been measured. The maximum SEY of an air exposed TiZr and TiZrV coating can be reduced from above 2.0 to below 1.1 during a 2 h heat treatment at 250 and 200 °C, respectively. Saturating an activated TiZrV surface in UHV increases the maximum SEY by about 0.1. Thus, in UHV the SEY of an activated NEG coating does not exceed the threshold value of 1.35, above which multipacting is predicted to occur in th...

  10. Streamer Evaporation

    Science.gov (United States)

    Suess, Steven T.; Wang, A. H.; Wu, Shi T.; Nerney, S.

    1998-01-01

    Evaporation is the consequence of slow plasma heating near the tops of streamers where the plasma is only weakly contained by the magnetic field. The form it takes is the slow opening of field lines at the top of the streamer and transient formation of new solar wind. It was discovered in polytropic model calculations, where due to the absence of other energy loss mechanisms in magnetostatic streamers, its ultimate endpoint is the complete evaporation of the streamer. This takes, for plausible heating rates, weeks to months in these models. Of course streamers do not behave this way, for more than one reason. One is that there are losses due to thermal conduction to the base of the streamer and radiation from the transition region. Another is that streamer heating must have a characteristic time constant and depend on the ambient physical conditions. We use our global Magnetohydrodynamics (MHD) model with thermal conduction to examine a few examples of the effect of changing the heating scale height and of making ad hoc choices for how the heating depends on ambient conditions. At the same time, we apply and extend the analytic model of streamers, which showed that streamers will be unable to contain plasma for temperatures near the cusp greater than about 2xl0(exp 6) K. Slow solar wind is observed to come from streamers through transient releases. A scenario for this that is consistent with the above physical process is that heating increases the near-cusp temperature until field lines there are forced open. The subsequent evacuation of the flux tubes by the newly forming slow wind decreases the temperature and heating until the flux tubes are able to reclose. Then, over a longer time scale, heating begins to again refill the flux tubes with plasma and increase the temperature until the cycle repeats itself. The calculations we report here are first steps towards quantitative evaluation of this scenario.

  11. A method to determine photosynthetic activity from oxygen microsensor data in biofilms subjected to evaporation.

    Science.gov (United States)

    Li, Tong; Podola, Björn; de Beer, Dirk; Melkonian, Michael

    2015-10-01

    Phototrophic biofilms are widely distributed in nature and their ecological importance is well recognized. More recently, there has been a growing interest in using artificial phototrophic biofilms in innovative photobioreactors for production of microalgal biomass in biotechnological applications. To study physiological processes within these biofilms, microsensors have been applied in several studies. Here, the 'light-dark shift method' relies on measurement of photosynthetic activity in terms of light-induced oxygen production. However, when applied to non-submerged biofilms that can be found in numerous locations in nature, as well as in some types of photobioreactors, limitations of this approach are obvious due to rapid removal of gaseous species at the biofilm surface. Here, we introduce a mathematical correction to recover the distribution of the actual photosynthetic activity along the depth gradient in the biofilm, based on a numerical solution of the inversed diffusion equation of oxygen. This method considers changes in mass transport during the measurement period as can found on biofilms possessing a thin flow/mass transfer boundary layer (e. g., non-submerged biofilms). Using both simulated and real microsensor data, the proposed method was shown to be much more accurate than the classical method, which leads to underestimations of rates near the biofilm surface. All test profiles could be recovered with a high fit. According to our simulated microsensor measurements, a depth resolution of ≤20 μm is recommended near the surface. We conclude that our method strongly improves the quality of data acquired from light-dark measurements of photosynthetic activity in biofilms.

  12. Simultaneous Determination of Four Active Ingredients in Sargentodoxa cuneata by HPLC Coupled with Evaporative Light Scattering Detection

    OpenAIRE

    Di-Hua Li; Yuan-Shan Lv; Jun-Hong Liu; Lei Yang; Yan Wang; Shu-Kun Zhang; Yu-Zhen Zhuo

    2016-01-01

    A HPLC coupled with evaporative light scattering detection method had been developed for the simultaneous determination of 3,4-dihydroxyphenylethyl alcohol glycoside, salidroside, chlorogenic acid, and liriodendrin in the stem of Sargentodoxa cuneata. With a C18 column, the analysis was performed using acetonitrile and 0.2% formic acid aqueous solution as mobile phase in gradient program at a flow rate of 0.9 mL/min. The optimum drift tube temperature of evaporative light scattering detection...

  13. Structural ordering, morphology and optical properties of amorphous Al{sub x}In{sub 1−x}N thin films grown by plasma-assisted dual source reactive evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, M., E-mail: alizadeh_kozerash@yahoo.com [Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Ganesh, V. [Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mehdipour, H. [Plasma Nanoscience @ Complex Systems, The University of Sydney, New South Wales 2006 (Australia); Department of Physics, Sharif University of Technology, Tehran 11155-9161 (Iran, Islamic Republic of); Nazarudin, N.F.F.; Goh, B.T.; Shuhaimi, A. [Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Rahman, S.A., E-mail: saadah@um.edu.my [Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-05-25

    Highlights: • In-rich and Al-rich Al{sub x}In{sub 1−x}N films were grown by plasma-aided reactive evaporation. • The A{sub 1}(LO) phonon mode of the Al-rich films exhibits two-mode behavior. • The band gap of the films was tuned from 1.08 to 2.50 eV. • A bowing parameter of 4.3 eV was calculated for the grown Al{sub x}In{sub 1−x}N films. • The morphology was changed from clusters to uniformly shaped grains by decreasing x. - Abstract: Amorphous aluminum indium nitride (Al{sub x}In{sub 1−x}N) thin films were deposited on quartz substrates by plasma-assisted dual source reactive evaporation system. In-rich (x = 0.10 and 0.18) and Al-rich (x = 0.60 and 0.64) films were prepared by simply varying an AC voltage applied to indium wire. The X-ray-diffraction patterns revealed a small broad peak assigned to Al{sub 0.10}In{sub 0.90}N (0 0 2) plane, but no perceivable peaks assigned to crystalline Al{sub x}In{sub 1−x}N were observed for the films with x = 0.18, 0.60 and 0.64. The morphology of the film was changed from clusters of small grains to uniformly shaped particles with decrease of x. The band gap energy of the films increased from 1.08 eV to 2.50 eV as the Al composition varied from 0.1 to 0.64. Also, Raman results indicated that E{sub 2}(high) and A{sub 1}(LO) peaks of the Al{sub x}In{sub 1−x}N films are remarkably blue-shifted by increasing x and the A{sub 1}(LO) phonon mode of the Al-rich films exhibits two-mode behavior. A bowing parameter of 4.3 eV was obtained for AlInN films. The extrapolated value from bowing equation was 0.85 eV for band gap energy of InN.

  14. Interface description using computational methods and tribological characteristic of Ti N/Ti C films prepared by reactive pulse arc evaporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Devia N, D. M. [Universidad Nacional de Colombia, Sede Manizales, Campus La Nubia, Manizales, Caldas (Colombia); Gonzalez C, J. M.; Ruden M, A., E-mail: dmdevian@utp.edu.co [Universidad del Valle, Edificio 349, espacio 1003, Ciudad Universitaria Melendez, Cali (Colombia)

    2013-10-01

    The Ti N/Ti C bilayers have been deposited by Plasma Assisted Physical Vapor Deposition Technique - Reactive Pulsed Arc. The coatings were analyzed by X-ray photoelectron spectroscopy (XP S) and X-ray diffraction (XRD). From the signal treatment of the narrow XP S spectra and the XRD diffraction patterns, the formation of Ti N (titanium nitride), Ti C (titanium carbide) and Ti CN (titanium carbonitride) was confirmed, with fm-3m spatial group, corresponding to the Fcc phase of the synthesized compounds. The multilayer was simulated using Density Functional Theory (DFT) by the Unrestricted Hartree Fock method. Charge distributions and electron total density were obtained; finding bond formation at the interphase, electrical neutrality and system stability. Anomalies in the corners of the structures due to edge effect, simulation ideality and the no internal tension inclusion, intrinsic to the growing, are observed. The ball on disc tribometer was used to measure the friction and wear coefficient to verify the interface formation. (Author)

  15. Determination of laser-evaporated uranium dioxide by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Allred, R.

    1987-05-01

    Safety analyses of nuclear reactors require information about the loss of fuel which may occur at high temperatures. In this study, the surface of a uranium dioxide target was heated rapidly by a laser. The uranium surface was vaporized into a vacuum. The uranium bearing species condensed on a graphite disk placed in the pathway of the expanding uranium vapor. Scanning electron microscopy and X-ray analysis showed very little droplet ejection directly from the laser target surface. Neutron activation analysis was used to measure the amount of uranium deposited. The surface temperature was measured by a fast-response automatic optical pyrometer. The maximum surface temperature ranged from 2400 to 3700/sup 0/K. The Hertz-Langmuir formula, in conjunction with the measured surface temperature transient, was used to calculate the theoretical amount of uranium deposited. There was good agreement between theory and experiment above the melting point of 3120/sup 0/K. Below the melting point much more uranium was collected than was expected theoretically. This was attributed to oxidation of the surface. 29 refs., 16 figs., 7 tabs.

  16. Unified active and reactive power modulation of HVDC transmission systems

    Science.gov (United States)

    Grund, C. E.; Pohl, R. V.

    1981-11-01

    The power modulation of a high voltage direct current (HVDC) system for stabilization of an ac/dc network was investigated. It was found that simultaneous modulation of both dc current and voltage was more effective than just current modulation by itself, since the dc voltage modulation could be used to minimize the reactive power changes resulting from a change of the dc current. This helps stabilize the ac busbar voltages at the converters, which reduces undesirable load flow changes to voltage dependent ac loads, thus improving the effectiveness of the dc power modulation. This unified modulation control concept was evaluated by means of digital computer studies as well as a special purpose HVDC simulator. Several combined ac/dc power transmission systems were synthesized for testing of different modulation controller concepts. An optimum controller design incorporating a linear quadratic control algorithm with full state feedback was first studied. This provided a basis for comparison of suboptimal controller designs utilizing reduced state feedback and a Kalman filter state reconstruction technique.

  17. Developing mononuclear copper-active-oxygen complexes relevant to reactive intermediates of biological oxidation reactions.

    Science.gov (United States)

    Itoh, Shinobu

    2015-07-21

    Active-oxygen species generated on a copper complex play vital roles in several biological and chemical oxidation reactions. Recent attention has been focused on the reactive intermediates generated at the mononuclear copper active sites of copper monooxygenases such as dopamine β-monooxygenase (DβM), tyramine β-monooxygenase (TβM), peptidylglycine-α-hydroxylating monooxygenase (PHM), and polysaccharide monooxygenases (PMO). In a simple model system, reaction of O2 and a reduced copper(I) complex affords a mononuclear copper(II)-superoxide complex or a copper(III)-peroxide complex, and subsequent H(•) or e(-)/H(+) transfer, which gives a copper(II)-hydroperoxide complex. A more reactive species such as a copper(II)-oxyl radical type species could be generated via O-O bond cleavage of the peroxide complex. However, little had been explored about the chemical properties and reactivity of the mononuclear copper-active-oxygen complexes due to the lack of appropriate model compounds. Thus, a great deal of effort has recently been made to develop efficient ligands that can stabilize such reactive active-oxygen complexes in synthetic modeling studies. In this Account, I describe our recent achievements of the development of a mononuclear copper(II)-(end-on)superoxide complex using a simple tridentate ligand consisting of an eight-membered cyclic diamine with a pyridylethyl donor group. The superoxide complex exhibits a similar structure (four-coordinate tetrahedral geometry) and reactivity (aliphatic hydroxylation) to those of a proposed reactive intermediate of copper monooxygenases. Systematic studies based on the crystal structures of copper(I) and copper(II) complexes of the related tridentate supporting ligands have indicated that the rigid eight-membered cyclic diamine framework is crucial for controlling the geometry and the redox potential, which are prerequisites for the generation of such a unique mononuclear copper(II)-(end-on)superoxide complex

  18. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    OpenAIRE

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.; Jain, Praveen

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications.The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately estimate the active/reactive power values. The proposed control system enables the hybrid renewable energy generation system to be able to perform real-time grid interconnection services such as active v...

  19. Micro RNA-155 participates in re-activation of encephalitogenic T cells.

    Science.gov (United States)

    Jevtić, Bojan; Timotijević, Gordana; Stanisavljević, Suzana; Momčilović, Miljana; Mostarica Stojković, Marija; Miljković, Djordje

    2015-08-01

    MicroRNAs (miR) are small non-coding RNAs involved in the immune response regulation. miR-155 has been attributed a major pro-inflammatory role in the pathogenesis of multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE). Here, a role of miR-155 in re-activation of encephalitogenic CD4(+) T cells was investigated. Dark Agouti rats were immunized with myelin basic protein (MBP) emulsified in complete Freund's adjuvant. CD4(+) T cells were purified from draining lymph node cells (DLNC) obtained in the inductive phase and from spinal cord immune cells (SCIC) isolated at the peak of EAE. CD4(+) T cells obtained from SCIC (i.e., in vivo re-activated cells) had markedly higher expression of miR-155 in comparison to those purified from DLNC (not re-activated). Likewise, in vitro re-activation of DLNC with MBP led to increase in miR-155 expression. Further, DLNC and DLNC CD4(+) T cells were transfected with an inhibitor of miR-155 during in vitro re-activation. As a result, expression of important CD4(+) T cell effector cytokines IFN-γ and IL-17, but not of regulatory cytokines IL-10 and TGF-β, was reduced. These results imply that miR-155 supports re-activation of encephalitogenic CD4(+) T cells. Our results contribute to a view that miR-155 might be a valuable target in multiple sclerosis therapy.

  20. Horst Meyer and Quantum Evaporation

    Science.gov (United States)

    Balibar, S.

    2016-11-01

    With their 1963 article in Cryogenics Horst Meyer and his collaborators triggered intense research activity on the evaporation of superfluid helium. Discussing this subject with him in 1975 was enlightening. Fifty years later, the analogy between the photoelectric effect and the evaporation of superfluid helium in the low temperature limit is not yet clear, although remarkable progress has been made in its observation and its understanding. This special issue of the Journal of Low Temperature Physics is an opportunity to recall the history of quantum evaporation, and to express my gratitude to Horst Meyer. It describes quickly most of the experimental and theoretical works which have been published on quantum evaporation during the last 50 years, but it is not a comprehensive review of this fascinating subject.

  1. A New Monodisperse Reactive Resin with Active Groups on the Particle Surface

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A novel reactive resin as active support was synthesized by an improved method based on seed swelling and surface coating polymerization. The resin is monosized beads with inner nucleus of cross-linked polymer and surface layer of copolymer containing epoxy groups. The physico-chemical structures of beads were characterized.

  2. Active Epstein-Barr virus infection after allogeneic stem cell transplantation : re-infection or reactivation?

    NARCIS (Netherlands)

    Meijer, E; Spijkers, S; Moschatsis, S; Boland, GJ; Thijsen, SFT; van Loon, AM; Verdonck, LF

    2005-01-01

    Recipients of allogeneic stem cell transplants (SCT) often show active Epstein-Barr virus (EBV) infection, which may progress to EBV-associated lymphoproliferative disorders. It is not known whether these EBV infections are true reactivations of the endogenous EBV strain or re-infections with an exo

  3. Ensemble statistics of active and reactive sound intensity in reverberation rooms

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Molares, Alfonso Rodrıguez

    2011-01-01

    This paper examines fundamental statistical properties of the active and reactive sound intensity in reverberant enclosures driven with pure tones. The existing theory for sound intensity in a diffuse sound field, which is based on Waterhouse’s random wave model and therefore limited to the region...

  4. Chemical reactivity and biological activity of chalcones and other α,β-unsaturated carbonyl compounds.

    Science.gov (United States)

    Maydt, Daniela; De Spirt, Silke; Muschelknautz, Christian; Stahl, Wilhelm; Müller, Thomas J J

    2013-08-01

    Abstract 1. Chalcones are structural analogues of benzalacetophenone (BAP). Several derivatives have been identified in plants and anticarcinogenic and anti-inflammatory properties were attributed to the compounds, probably related to their direct antioxidant activity or stimulatory effects on the expression of endogenous defence enzymes like hemeoxygenase-1 (HO-1). HO-1 expression is triggered by the Nrf2-Keap1 signalling pathway, initiated by the addition of chalcones to thiol groups of Keap1 via Michael-type reaction. 2. The present study used a model system estimating the reactivity of different synthetic chalcones and other α,β-unsaturated carbonyl compounds with thiols and compared the chemical reactivity with the biological activity, measured by HO-1 expression in human dermal fibroblasts. 3. Chemical reactivity with the thiol group of N-acetylcysteine was determined with 5,5'-dithiobis-(2-nitrobenzoic acid) and followed chemical principles of structure-reactivity relationship. Most reactive were sulforaphane, dimethylfumarate, chalcone 3 ((2E)-1-phenyl-3-pyrimidin-2-ylprop-2-en-1-one) and chalcone 7 (1,3-diphenylprop-2-yn-1-one). This result demonstrates that α,β-unsaturated carbonyl derivatives react with thiols differently. All compounds were also biologically active; however, expression of HO-1 was not only related to the chemical reactivity but also to the lipophilicity of the molecules which likely affected transmembrane uptake. Most efficient inducers of HO-1 expression were BAP, 4-hydroxynonenal and chalcone 1 (4-[(1E)-3-oxo-3-phenylprop-1-en-1-yl]benzonitrile), chalcone 5 ((2E)-1-phenyl-3-[4-(trifluoromethyl)-phenyl]prop-2-en-1-one) and chalcone 7.

  5. Is autoimmune diabetes caused by aberrant immune activity or defective suppression of physiological self-reactivity?

    Science.gov (United States)

    Askenasy, Enosh M; Askenasy, Nadir

    2013-03-01

    Two competing hypotheses are proposed to cause autoimmunity: evasion of a sporadic self-reactive clone from immune surveillance and ineffective suppression of autoreactive clones that arise physiologically. We question the relevance of these hypotheses to the study of type 1 diabetes, where autoreactivity may accompany the cycles of physiological adjustment of β-cell mass to body weight and nutrition. Experimental evidence presents variable and conflicting data concerning the activities of both effector and regulatory T cells, arguing in favor and against: quantitative dominance and deficit, aberrant reactivity and expansion, sensitivity to negative regulation and apoptosis. The presence of autoantibodies in umbilical cord blood of healthy subjects and low incidence of the disease following early induction suggest that suppression of self-reactivity is the major determinant factor.

  6. Photocatalytic Activity of Reactively Sputtered Titania Coatings Deposited Using a Full Face Erosion Magnetron

    OpenAIRE

    Farahani, Nick; Kelly, Peter,; West, Glen; Hill, Claire; Vishnyakov, Vladimir

    2013-01-01

    Titanium dioxide (titania) is widely used as a photocatalyst for its moderate band gap, high photoactivity, recyclability, nontoxicity, low cost and its significant chemical stability. The anatase phase of titania is known to show the highest photocatalytic activity, however, the presence of this phase alone is not sufficient for sustained activity. In this study TiO2 coatings were deposited onto glass substrates by mid-frequency pulsed magnetron sputtering from metallic targets in reactive m...

  7. C-H bond activation by metal-superoxo species: what drives high reactivity?

    Science.gov (United States)

    Ansari, Azaj; Jayapal, Prabha; Rajaraman, Gopalan

    2015-01-01

    Metal-superoxo species are ubiquitous in metalloenzymes and bioinorganic chemistry and are known for their high reactivity and their ability to activate inert C-H bonds. The comparative oxidative abilities of M-O2(.-) species (M = Cr(III), Mn(III), Fe(III), and Cu(II)) towards C-H bond activation reaction are presented. These superoxo species generated by oxygen activation are found to be aggressive oxidants compared to their high-valent metal-oxo counterparts generated by O⋅⋅⋅O bond cleavage. Our calculations illustrate the superior oxidative abilities of Fe(III)- and Mn(III)-superoxo species compared to the others and suggest that the reactivity may be correlated to the magnetic exchange parameter.

  8. Combined Active and Reactive Power Control of Wind Farms based on Model Predictive Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Wang, Jianhui;

    2017-01-01

    This paper proposes a combined wind farm controller based on Model Predictive Control (MPC). Compared with the conventional decoupled active and reactive power control, the proposed control scheme considers the significant impact of active power on voltage variations due to the low X=R ratio...... of wind farm collector systems. The voltage control is improved. Besides, by coordination of active and reactive power, the Var capacity is optimized to prevent potential failures due to Var shortage, especially when the wind farm operates close to its full load. An analytical method is used to calculate...... the sensitivity coefficients to improve the computation efficiency and overcome the convergence problem. Two control modes are designed for both normal and emergency conditions. A wind farm with 20 wind turbines was used to verify the proposed combined control scheme....

  9. Determination of reactive oxygen generated from natural medicines and their antibacterial activity$

    Institute of Scientific and Technical Information of China (English)

    Noriko Tajima; Makiko Takasaki; Haruka Fukamachi; Takeshi Igarashi; Yoshijiro Nakajima; Hidetoshi Arakawa

    2016-01-01

    Extracts of 16 natural medicine powders (Galla chinensis, Malloti cortex, Cassiae semen, Sophorae radix, Myricae cortex, Crataegi fructus, Gambir, Mume fructus, Geranii herba, Phellodendri cortex, Coptidis rhizoma, Swertiae herba, and Cinnamomi cortex) were assayed for reactive oxygen concentrations using the per-oxyoxalate chemiluminescent detection system. High luminescence intensity was observed in Galla chinensis, Geranii herba, Malloti cortex, Myricae cortex, and Cinnamomi cortex. Additional experiments identified the reactive oxygen species as hydrogen peroxide. Galla chinensis generated 2.4 ? 10 ? 4 mol/L hydrogen peroxide from a 1 mg/mL solution. In bacterial growth tests, Galla chinensis extract had antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacteroides thetaiotaomicron, Campylobacter sputorum biovar sputorum, Streptococcus salivarius thermophilus, Lactobacillus casei, and Bifidobacterium longum infantis. This antibacterial activity was de-creased by the addition of catalase. It revealed that hydrogen peroxide which Galla chinensis produced participated in antibacterial activity.

  10. EFFECT OF REACTIVE MAGNESIUM OXIDE ON PROPERTIES OF ALKALI ACTIVATED SLAG GEOPOLYMER CEMENT PASTES

    Directory of Open Access Journals (Sweden)

    H. A. Abdel-Gawwad

    2015-03-01

    Full Text Available The effect of different proportions and different reactivities of MgO on the drying shrinkage and compressive strength of alkali activated slag pastes (AAS has been investigated. The slag was activated by 6 wt.% sodium hydroxide and liquid sodium silicate at ratio of 3:3 (wt.. The different reactivities of MgOs were produced from the calcination of hydromagnesite at different temperatures (550, 1000, 1250 C. The results showed that the reactivity of magnesium oxide decreases with increasing the calcination temperature. Also, the drying shrinkage of AAS was reduced by the replacement of slag with MgOs. The highly reactive MgO accelerated the hydration of AAS at early ages. The replacement of slag with 5% MgO550 increased one day compressive strength by ~26 % while MgO1250 had little effect. A significant increase in strength was observed after 7 days in case of replacement of slag with 5 % MgO1250. The MgO reacts with slag to form hydrotalcite likephases (Ht as detected by XRD, FTIR spectroscopy, TGA/DTG analysis and SEM.

  11. What Happens after Activation of Ascaridole? Reactive Compounds and Their Implications for Skin Sensitization.

    Science.gov (United States)

    Chittiboyina, Amar G; Avonto, Cristina; Khan, Ikhlas A

    2016-09-19

    To replace animal testing and improve the prediction of skin sensitization, significant attention has been directed to the use of alternative methods. The direct peptide reactivity assay (DPRA), the regulatory agencies' approved alternative in chemico method, has been applied for understanding the sensitization capacity of activated ascaridole. Ascaridole, the oxidative metabolite of α-terpinene, is considered to be one of the components responsible for the contact allergy associated with essential oils derived from Chenopodium and Melaleuca species. The recently developed high-throughput screening based on the dansyl cysteamine (HTS-DCYA) method was applied to understand the reported enhanced reactivity of activated ascaridole and possibly to identify the resulting elusive radical or other reactive species. For the first time, a substituted cyclohexenone was identified as a potential electrophilic intermediate resulting in higher depletion of nucleophilic DCYA, along with several nonreactive byproducts of ascaridole via a radical degradation mechanism. Formation of electrophilic species via radical degradation is one of the possible pathways should be considered for the peptide reactivity of in aged tea tree oil or oils rich in terpinenes along with commonly believed reactants, allylic-epoxides and allylic-peroxides.

  12. Evaluation of Antibacterial Activity and Reactive Species Generation of N-Benzenesulfonyl Derivatives of Heterocycles.

    Science.gov (United States)

    Martínez, Sol Romina; Miana, Gisele Emilse; Albesa, Inés; Mazzieri, María Rosa; Becerra, María Cecilia

    2016-01-01

    Two N-benzenesulfonyl (BS) derivatives of 1,2,3,4-tetrahydroquinoline (THQ) were designed, prepared, and screened for antibacterial activity. This approach was based on combining the two privileged structures, BS and THQ, which are known to be active. The objective of this study was to evaluate the antibacterial activity of BS-THQ and its analogue 4-NH2BS-THQ, and to investigate the roles of reactive oxygen species and reactive nitrogen species in their lethality. Both showed bactericidal activity against Staphylococcus aureus ATCC 29213 and methicillin-resistant S. aureus (MRSA) ATCC 43300, with transmission electron microscopy revealing a disturbed membrane architecture. Furthermore, an increase of reactive oxygen species (ROS) in strains treated with BS-THQ with respect to the control was detected when fluorescent microscopy and spectrophotometric techniques were used. The analogue 4-NH2BS-THQ demonstrated a broader spectrum of activity than BS-THQ, with a minimum inhibitory concentration of 100 µg/mL against reference strains of S. aureus, Escherichia coli and Pseudomonas aeruginosa. The assayed compounds represent promising structures for the development of new synthetic classes of antimicrobials.

  13. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    DEFF Research Database (Denmark)

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.;

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications. The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately...... estimate the active/reactive power values. The proposed control system enables the hybrid renewable energy generation system to be able to perform real-time grid interconnection services such as active voltage regulation, active power control, and fault ride-through.Simulation and experimental results...... demonstrate the superior performance of the proposed closed-loop control system....

  14. Evaporation and Climate Change

    NARCIS (Netherlands)

    Brandsma, T.

    1993-01-01

    In this article the influence of climate change on evaporation is discussed. The emphasis is on open water evaporation. Three methods for calculating evaporation are compared considering only changes in temperature and factors directly dependent on temperature. The Penman-method is used to investiga

  15. EVALUATING DEGREE OF ACTIVE POWER LOSSES REDUCTION IN THE ELECTRIC POWER LINES WITH REACTIVE POWER COMPENSATION

    Directory of Open Access Journals (Sweden)

    V. N. Radkevich

    2016-01-01

    Full Text Available The paper considers evaluation procedure for the degree of active power losses reduction in the power transmission lines under 1 kV and 6–10 kV of the systems of electric power supply of industrial enterprises with compensating installations mounted at the side of the customer. The capacitor installations conform to the applied voltage level and factor in dielectric losses in the capacitors. The voltage at the compensating device terminal changes from 0.95 to 1.05 of the capacitors nominal voltage. The study did not account for reactive power losses in the line, nor did it for its charge capacity, conditioned by relative shortness of the cable lines generally operating in the mains of industrial enterprises. For this reason, the quantities of reactive power being consumed and generated by the transmission line are negligible and do not significantly affect the reactive power flux. The researchers obtain functional relations that allow estimating the degree of power loss reduction in the transmission line factoring in its explicit initial data. They perform mathematical analysis of the obtained functional relations and study the function by means of derivatives. The function extremum points are found as well as the intervals of its increment and decrement. A graphical research of the obtained functional relation is performed. It is ascertained that reduction of the active power losses is contingent on the line and the capacitor-installation engineering factors, the electrical energy consumer reactive load value as well as the voltage applied to the capacitor installation. The functional relations presented in the article can be employed in scoping calculation necessary for decision making on the reactive power compensation in systems of the industrial facilities electric power supply. Their account will allow a more accurate estimate of technical and economic effect of the capacitor bank installation in the electrical mains under 1 kV and 6

  16. Pu isotopes and {sup 241}Am activities determination in the evaluation of radiochemical sequential analyzes methodology for evaporator concentrate samples using alpha spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Reis Junior, Aluisio S.; Temba, Eliane S.C.; Kastner, Geraldo F.; Monteiro, Roberto P.G., E-mail: reisas@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (SERTA/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico do Reator e Tecnicas Analiticas

    2015-07-01

    Alpha spectrometry analyzes were used for activity determinations of Pu and Am isotopes in evaporator concentrate samples from nuclear power plants. In this work it was used tracers for isotopes determination and quantification. The radiometric yields ranged from 60% to 100% and the Lower Limit of Detection was estimated as being 2.05 mBqKg{sup -1}. The relative standard deviations for replicate analysis were calculated for {sup 241}Am, 15.13% (sample J) and 9.38% (sample N), and for {sup 239+240}Pu, 8.16% (sample J) and 7.95% (sample N). (author)

  17. Simulation and reliability analysis of shunt active power filter based on instantaneous reactive power theory

    Institute of Scientific and Technical Information of China (English)

    CUI Yu-long; LIU Hong; WANG Jing-qin; SUN Shu-guang

    2007-01-01

    This paper first discusses the operating principle ofinstantaneous reactive power theory. Then, the theory is introduced into shunt active power filter and its control scheme is studied. Finally, Matlab/Simulink power system toolbox is used to simulate the system. In the simulation model, as the most common harmonic source, 3-phase thyfistor bridge rectifier circuit is constructed.The simulation results before and after the shunt active filter was switched to the system corresponding to different firing angles of the thyristors are presented and analyzed, which demonstrate the practicability and reliability of the proposed shunt active filter scheme.

  18. Active and Reactive Power Control of a Doubly Fed Induction Generator

    Directory of Open Access Journals (Sweden)

    Zerzouri Nora

    2014-10-01

    Full Text Available Wind turbine WT occupies gradually a large part in world energy market, Doubly fed induction generator DFIG is mostly used in WT, it allow highly flexible active and reactive power generation control. This paper presents dynamic modeling and simulation of a doubly fed induction generator based on grid-side and rotor-side converter control. The DFIG, grid-side converter, rotor-side converter, and its controllers are performed in MATLAB/Simulink software. Dynamic response in grid connected mode for variable speed wind operation is investigated. Simulation results on a 3 MW DFIG system are provided to demonstrate the effectiveness of the proposed control strategy during variations of active and reactive power, rotor speed, and converter dc link voltage.

  19. Serum Adenosine deaminase activity and C-reactive protein levels in unstable angina

    Directory of Open Access Journals (Sweden)

    Rani Surekha

    2003-01-01

    Full Text Available In unstable angina (USA patients, immunological responses contributing to inflammation play a vital role in plaque rupture and thrombosis causing stroke. In the present study an attempt is made to estimate the levels of adenosine deaminase activity, an immunoenzyme marker and C-reactive protein, a marker of inflammation in USA patients. 45 patients presenting USA and 50 age and sex matched healthy controls were included in the study. Serum ADA activity was measured spectrophotometrically at 630nm and serum C-reactive protein was detected using Avitex CRP kit, which is a rapid latex agglutination test. The Mean ADA levels were 41.15 ± 11.04 in patients and 20.71±5.63 in controls and 66.6% of patients and none of the controls were positive to CRP. The present study observed the importance of ADA as a serum marker in addition to CRP for assessing the immune response in USA patients.

  20. QSAR classification of metabolic activation of chemicals into covalently reactive species.

    Science.gov (United States)

    Liew, Chin Yee; Pan, Chuen; Tan, Andre; Ang, Ke Xin Magneline; Yap, Chun Wei

    2012-05-01

    Metabolic activation of chemicals into covalently reactive species might lead to toxicological consequences such as tissue necrosis, carcinogenicity, teratogenicity, or immune-mediated toxicities. Early prediction of this undesirable outcome can help in selecting candidates with increased chance of success, thus, reducing attrition at all stages of drug development. The ensemble modelling of mixed features was used for the development of a model to classify the metabolic activation of chemicals into covalently reactive species. The effects of the quality of base classifiers and performance measure for sorting were examined. An ensemble model of 13 naive Bayes classifiers was built from a diverse set of 1,479 compounds. The ensemble model was validated internally with five-fold cross validation and it has achieved sensitivity of 67.4% and specificity of 93.4% when tested on the training set. The final ensemble model was made available for public use.

  1. Simultaneous Determination of Four Active Ingredients in Sargentodoxa cuneata by HPLC Coupled with Evaporative Light Scattering Detection

    Directory of Open Access Journals (Sweden)

    Di-Hua Li

    2016-01-01

    Full Text Available A HPLC coupled with evaporative light scattering detection method had been developed for the simultaneous determination of 3,4-dihydroxyphenylethyl alcohol glycoside, salidroside, chlorogenic acid, and liriodendrin in the stem of Sargentodoxa cuneata. With a C18 column, the analysis was performed using acetonitrile and 0.2% formic acid aqueous solution as mobile phase in gradient program at a flow rate of 0.9 mL/min. The optimum drift tube temperature of evaporative light scattering detection was at 105°C with the air flow rate of 2.5 L/min. The calibration curves showed good linearity during the test ranges. This method was validated for limits of detection and quantification, precision, and reproducibility. The recoveries were within the range of 96.39%–104.64%. The relative standard deviations of intraday and interday precision were less than 2.90% and 3.30%, respectively. The developed method can be successfully used to quantify the four analytes in the stem of Sargentodoxa cuneata from various regions in China.

  2. Simultaneous Determination of Four Active Ingredients in Sargentodoxa cuneata by HPLC Coupled with Evaporative Light Scattering Detection.

    Science.gov (United States)

    Li, Di-Hua; Lv, Yuan-Shan; Liu, Jun-Hong; Yang, Lei; Wang, Yan; Zhang, Shu-Kun; Zhuo, Yu-Zhen

    2016-01-01

    A HPLC coupled with evaporative light scattering detection method had been developed for the simultaneous determination of 3,4-dihydroxyphenylethyl alcohol glycoside, salidroside, chlorogenic acid, and liriodendrin in the stem of Sargentodoxa cuneata. With a C18 column, the analysis was performed using acetonitrile and 0.2% formic acid aqueous solution as mobile phase in gradient program at a flow rate of 0.9 mL/min. The optimum drift tube temperature of evaporative light scattering detection was at 105°C with the air flow rate of 2.5 L/min. The calibration curves showed good linearity during the test ranges. This method was validated for limits of detection and quantification, precision, and reproducibility. The recoveries were within the range of 96.39%-104.64%. The relative standard deviations of intraday and interday precision were less than 2.90% and 3.30%, respectively. The developed method can be successfully used to quantify the four analytes in the stem of Sargentodoxa cuneata from various regions in China.

  3. The Removal of Composite Reactive Dye from Dyeing Unit Effluent Using Sewage Sludge Derived Activated Carbon

    OpenAIRE

    REDDY, Sajjala SREEDHAR

    2006-01-01

    Activated carbon was prepared from dried municipal sewage sludge and batch mode adsorption experiments were conducted to study its potential to remove composite reactive dye from dyeing unit effluent. Adsorption parameters for the Langmuir and Freundlich isotherms were determined and the effects of effluent pH, adsorbent dosage, contact time and initial dye concentration were studied. The toxicity characteristic leaching protocol (TCLP) was used to assess the acceptability of sewage ...

  4. The mystery of gold's chemical activity: local bonding, morphology and reactivity of atomic oxygen.

    Science.gov (United States)

    Baker, Thomas A; Liu, Xiaoying; Friend, Cynthia M

    2011-01-07

    Recently, gold has been intensely studied as a catalyst for key synthetic reactions. Gold is an attractive catalyst because, surprisingly, it is highly active and very selective for partial oxidation processes suggesting promise for energy-efficient "green" chemistry. The underlying origin of the high activity of Au is a controversial subject since metallic gold is commonly thought to be inert. Herein, we establish that one origin of the high activity for gold catalysis is the extremely reactive nature of atomic oxygen bound in 3-fold coordination sites on metallic gold. This is the predominant form of O at low concentrations on the surface, which is a strong indication that it is most relevant to catalytic conditions. Atomic oxygen bound to metallic Au in 3-fold sites has high activity for CO oxidation, oxidation of olefins, and oxidative transformations of alcohols and amines. Among the factors identified as important in Au-O interaction are the morphology of the surface, the local binding site of oxygen, and the degree of order of the oxygen overlayer. In this Perspective, we present an overview of both theory and experiments that identify the reactive forms of O and their associated charge density distributions and bond strengths. We also analyze and model the release of Au atoms induced by O binding to the surface. This rough surface also has the potential for O(2) dissociation, which is a critical step if Au is to be activated catalytically. We further show the strong parallels between product distributions and reactivity for O-covered Au at low pressure (ultrahigh vacuum) and for nanoporous Au catalysts operating at atmospheric pressure as evidence that atomic O is the active species under working catalytic conditions when metallic Au is present. We briefly discuss the possible contributions of oxidants that may contain intact O-O bonds and of the Au-metal oxide support interface in Au catalysis. Finally, the challenges and future directions for fully

  5. Coordinated Volt/Var Control in Distribution Systems with Distributed Generations Based on Joint Active and Reactive Powers Dispatch

    Directory of Open Access Journals (Sweden)

    Abouzar Samimi

    2016-01-01

    Full Text Available One of the most significant control schemes in optimal operation of distribution networks is Volt/Var control (VVC. Owing to the radial structure of distribution systems and distribution lines with a small X/R ratio, the active power scheduling affects the VVC issue. A Distribution System Operator (DSO procures its active and reactive power requirements from Distributed Generations (DGs along with the wholesale electricity market. This paper proposes a new operational scheduling method based on a joint day-ahead active/reactive power market at the distribution level. To this end, based on the capability curve, a generic reactive power cost model for DGs is developed. The joint active/reactive power dispatch model presented in this paper motivates DGs to actively participate not only in the energy markets, but also in the VVC scheme through a competitive market. The proposed method which will be performed in an offline manner aims to optimally determine (i the scheduled active and reactive power values of generation units; (ii reactive power values of switched capacitor banks; and (iii tap positions of transformers for the next day. The joint active/reactive power dispatch model for daily VVC is modeled in GAMS and solved with the DICOPT solver. Finally, the plausibility of the proposed scheduling framework is examined on a typical 22-bus distribution test network over a 24-h period.

  6. Involvement of reactive oxygen species and nitric oxide radicals in activation and proliferation of rat hepatic stellate cells

    NARCIS (Netherlands)

    Svegliati-Baroni, G; Saccomanno, S; van Goor, H; Jansen, P; Benedetti, A; Moshage, H

    2001-01-01

    Background/Aims: Reactive oxygen species (ROS) induce HSCs activation, proliferation and collagen gene expression in vitro. Nitric oxide (NO) represents a reactive molecule that reacts with ROS, yielding peroxynitrite. We thus verified the effect of NO on ROS-induced HSCs proliferation in vitro and

  7. Platelet activation, function, and reactivity in atherosclerotic carotid artery stenosis: a systematic review of the literature.

    LENUS (Irish Health Repository)

    Kinsella, J A

    2012-09-27

    An important proportion of transient ischemic attack or ischemic stroke is attributable to moderate or severe (50-99%) atherosclerotic carotid stenosis or occlusion. Platelet biomarkers have the potential to improve our understanding of the pathogenesis of vascular events in this patient population. A detailed systematic review was performed to collate all available data on ex vivo platelet activation and platelet function\\/reactivity in patients with carotid stenosis. Two hundred thirteen potentially relevant articles were initially identified; 26 manuscripts met criteria for inclusion in this systematic review. There was no consistent evidence of clinically informative data from urinary or soluble blood markers of platelet activation in patients with symptomatic moderate or severe carotid stenosis who might be considered suitable for carotid intervention. Data from flow cytometry studies revealed evidence of excessive platelet activation in patients in the early, sub-acute, or late phases after transient ischemic attack or stroke in association with moderate or severe carotid stenosis and in asymptomatic moderate or severe carotid stenosis compared with controls. Furthermore, pilot data suggest that platelet activation may be increased in recently symptomatic than in asymptomatic severe carotid stenosis. Excessive platelet activation and platelet hyperreactivity may play a role in the pathogenesis of first or subsequent transient ischemic attack or stroke in patients with moderate or severe carotid stenosis. Larger longitudinal studies assessing platelet activation status with flow cytometry and platelet function\\/reactivity in symptomatic vs. asymptomatic carotid stenosis are warranted to improve our understanding of the mechanisms responsible for transient ischemic attack or stroke.

  8. Reactive oxygen species activity in the interaction of rice with Erwinia chrysanthemi pv. zeae

    Institute of Scientific and Technical Information of China (English)

    Qiongguang LIU; Landi HE; Jingyi ZHANG; Yutao WANG; Zhenzhong WANG

    2008-01-01

    Activities of reactive oxygen species (ROS) were investigated in the interaction between rice and Erwinia chrysanthemi pv. zeae. Results showed that variety (128) had higher increases in activity compared to those in the susceptible variety (Texian 13) 24 hours after bacteria inoculation. The activities of superoxide dismutase (SOD) increased in 128 and Texian 13 twenty-four hours after inoculation and then decreased, but the SOD activity in 128 was found to be usually lower than that in Texian 13. The CAT activity in Texian 13 had two peaks at 24 h and 96 h after inoculation, while little change was seen in 128. In conclusion, ROS and its related enzymes could be correlated to rice resistance against E. chrysanthemi pv. zeae.

  9. Activation of the ventral and dorsal striatum during cue reactivity in Internet gaming disorder.

    Science.gov (United States)

    Liu, Lu; Yip, Sarah W; Zhang, Jin-Tao; Wang, Ling-Jiao; Shen, Zi-Jiao; Liu, Ben; Ma, Shan-Shan; Yao, Yuan-Wei; Fang, Xiao-Yi

    2017-05-01

    Studies conducted in drug addiction suggest a transition in processing of drug-related cues from the ventral to the dorsal component of the striatum. However, this process has not been studied in a behavioral addiction. Assessment of this process in a non-drug addiction can provide insight into the pathophysiology of both substance and behavioral addictions. Thirty-nine male Internet gaming disorder (IGD) subjects and 23 male matched healthy controls (HCs) participated in functional magnetic resonance imaging during performance of a cue-reactivity task involving alternating presentation of Internet gaming-related stimuli (game cues) and general Internet surfing-related stimuli (control cues). Cue-induced neural activations in the ventral and dorsal striatum (DS) were compared between IGD and HC participants. Associations between cue-reactivity within these regions and cue-induced craving and severity and duration of IGD were also explored. IGD participants exhibited higher cue-induced activations within both the ventral and DS when compared with HCs. Within the IGD group, activity within the left ventral striatum (VS) was correlated negatively with cue-induced craving; positive associations were found between activations within the DS (right putamen, pallidum and left caudate) and duration of IGD. Cue-induced activity within the left putamen was negatively associated with right VS volumes among IGD participants. Consistent with studies in substance addictions, our results suggest that a transition from ventral to dorsal striatal processing may occur among individuals with IGD, a condition without the impact of substance intake.

  10. Reactive oxygen species in signalling the transcriptional activation of WIPK expression in tobacco.

    Science.gov (United States)

    Xu, Juan; Yang, Kwang-Yeol; Yoo, Seung Jin; Liu, Yidong; Ren, Dongtao; Zhang, Shuqun

    2014-07-01

    Plant mitogen-activated protein kinases represented by tobacco WIPK (wounding-induced protein kinase) and its orthologs in other species are unique in their regulation at transcriptional level in response to stress and pathogen infection. We previously demonstrated that transcriptional activation of WIPK is essential for induced WIPK activity, and activation of salicylic acid-induced protein kinase (SIPK) by the constitutively active NtMEK2(DD) is sufficient to induce WIPK gene expression. Here, we report that the effect of SIPK on WIPK gene expression is mediated by reactive oxygen species (ROS). Using a combination of pharmacological and gain-of-function transgenic approaches, we studied the relationship among SIPK activation, WIPK gene activation in response to fungal cryptogein, light-dependent ROS generation in chloroplasts, and ROS generated via NADPH oxidase. In the conditional gain-of-function GVG-NtMEK2(DD) transgenic tobacco, induction of WIPK expression is dependent on the ROS generation in chloroplasts. Consistently, methyl viologen, an inducer of ROS generation in chloroplasts, highly activated WIPK expression. In addition to chloroplast-originated ROS, H(2)O(2) generated from the cell-surface NADPH oxidase could also activate WIPK gene expression, and inhibition of cryptogein-induced ROS generation also abolished WIPK gene activation. Our data demonstrate that WIPK gene activation is mediated by ROS, which provides a mechanism by which ROS influence cellular signalling processes in plant stress/defence response.

  11. Study of effect annealing temperature on the structure, morphology and photocatalytic activity of Si doped TiO{sub 2} thin films deposited by electron beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Lu Zhongdan [Key Lab of Soft Chemistry and Functional Materials of Ministry of Education, Nanjing University of Science and Technology, Xiaolingwei 200, Nanjing 210094 (China); Jiang Xiaohong, E-mail: jiangxh24@mail.njust.edu.cn [Key Lab of Soft Chemistry and Functional Materials of Ministry of Education, Nanjing University of Science and Technology, Xiaolingwei 200, Nanjing 210094 (China); Zhou Bing; Wu Xiaodong; Lu Lude [Key Lab of Soft Chemistry and Functional Materials of Ministry of Education, Nanjing University of Science and Technology, Xiaolingwei 200, Nanjing 210094 (China)

    2011-10-01

    Transparent Si-doped TiO{sub 2} thin films (Si-TiO{sub 2}) were deposited on quartz glasses using electron beam evaporation (EBE) and annealed at different temperature in an air atmosphere. The structure and morphology of these films were analyzed by X-ray diffraction (XRD), Raman microscopy (Raman), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Meanwhile the photocatalytic activity of the films has also been evaluated on the basis of the degradation degree of rhodamine B in aqueous solution. Our experimental results suggest that the annealing temperature impact a strong effect on the structure, morphology and photocatalytic activity of Si-TiO{sub 2} thin films. Furthermore the enhanced thermal stability of Si-TiO{sub 2} films enabled them to elevate the phase transformation temperature of TiO{sub 2} from anatase to rutile and enhanced the photocatalytic efficiency.

  12. Reactive oxygen species in the paraventricular nucleus of the hypothalamus alter sympathetic activity during metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    JOSIANE CAMPOS CRUZ

    2015-12-01

    Full Text Available The paraventricular nucleus of the hypothalamus (PVN contains heterogeneous populations of neurons involved in autonomic and neuroendocrine regulation. The PVN plays an important role in the sympathoexcitatory response to increasing circulating levels of angiotensin II (Ang-II, which activates AT1 receptors in the circumventricular organs (OCVs, mainly in the subfornical organ (SFO. Circulating Ang-II induces a de novo synthesis of Ang-II in SFO neurons projecting to pre-autonomic PVN neurons. Activation of AT1 receptors induces intracellular increases in reactive oxygen species (ROS, leading to increases in sympathetic nerve activity (SNA. Chronic sympathetic nerve activation promotes a series of metabolic disorders that characterizes the metabolic syndrome (MetS: dyslipidemia, hyperinsulinemia, glucose intolerance, hyperleptinemia and elevated plasma hormone levels, such as noradrenaline, glucocorticoids, leptin, insulin and Ang-II. This review will discuss the contribution of our laboratory and others regarding the sympathoexcitation caused by peripheral Ang-II-induced reactive oxygen species along the subfornical organ and paraventricular nucleus of the hypothalamus. We hypothesize that this mechanism could be involved in metabolic disorders underlying MetS.

  13. Adsorption of reactive brilliant red K-2BP on activated carbon developed from sewage sludge

    Institute of Scientific and Technical Information of China (English)

    Jiankun XIE; Qinyan YUE; Hui YU; Wenwen YUE; Renbo LI; Shengxiao ZHANG; Xiaona WANG

    2008-01-01

    Activated carbon was prepared from the sewage sludge of municipal wastewater treatment plant by chemical activation (activation reagent is ZnCl2) and was used for the adsorption of dye (reactive brilliant red K-2BP). The impact of adsorbent amount, adsorption time and pH value on adsorption effect, the adsorption kinetics, and the adsorption thermodynamics were dis-cussed according to batch adsorption tests. The results indicated that the activated carbon developed from sewage sludge (ACSS), which was mesoporous, possessed opened porous structures. The iodine number of the ACSS was heavy metals in the leachate didn't exceed the contents limit. The adsorption kinetics of reactive brilliant red K-2BP on the ACSS was accorded with the two-step kinetics rate equation and pseudo-second-order kinetics equation. Compared to the Freundlich isotherm equation, the Langmuir isotherm equation showed better applicability for the adsorption. The adsorption which was favorable was an endothermic (enthalpy △H > 0) and spontaneous (flee energy △G 0).

  14. Pomegranate-Derived Polyphenols Reduce Reactive Oxygen Species Production via SIRT3-Mediated SOD2 Activation

    Science.gov (United States)

    Zhao, Chong; Sakaguchi, Takenori; Fujita, Kosuke; Ito, Hideyuki; Nishida, Norihisa; Nagatomo, Akifumi; Tanaka-Azuma, Yukimasa

    2016-01-01

    Pomegranate-derived polyphenols are expected to prevent life-style related diseases. In this study, we evaluated the ability of 8 pomegranate-derived polyphenols, along with other polyphenols, to augment SIRT3, a mammalian SIR2 homolog localized in mitochondria. We established a system for screening foods/food ingredients that augment the SIRT3 promoter in Caco-2 cells and identified 3 SIRT3-augmenting pomegranate-derived polyphenols (eucalbanin B, pomegraniin A, and eucarpanin T1). Among them, pomegraniin A activated superoxide dismutase 2 (SOD2) through SIRT3-mediated deacetylation, thereby reducing intracellular reactive oxygen species. The other SIRT3-augmenting polyphenols tested also activated SOD2, suggesting antioxidant activity. Our findings clarify the underlying mechanisms involved in the antioxidant activity of pomegraniin A. PMID:27840668

  15. Force-activated reactivity switch in a bimolecular chemical reaction at the single molecule level

    Science.gov (United States)

    Szoszkiewicz, Robert; Garcia-Manyes, Sergi; Liang, Jian; Kuo, Tzu-Ling; Fernandez, Julio M.

    2010-03-01

    Mechanical force can deform the reacting molecules along a well-defined direction of the reaction coordinate. However, the effect of mechanical force on the free-energy surface that governs a chemical reaction is still largely unknown. The combination of protein engineering with single-molecule AFM force-clamp spectroscopy allows us to study the influence of mechanical force on the rate at which a protein disulfide bond is reduced by some reducing agents in a bimolecular substitution reaction (so-called SN2). We found that cleavage of a protein disulfide bond by hydroxide anions exhibits an abrupt reactivity ``switch'' at 500 pN, after which the accelerating effect of force on the rate of an SN2 chemical reaction greatly diminishes. We propose that an abrupt force-induced conformational change of the protein disulfide bond shifts its ground state, drastically changing its reactivity in SN2 chemical reactions. Our experiments directly demonstrate the action of a force-activated switch in the chemical reactivity of a single molecule. References: Sergi Garcia-Manyes, Jian Liang, Robert Szoszkiewicz, Tzu-Ling Kuo and Julio M. Fernandez, Nature Chemistry, 1, 236-242, 2009.

  16. The influence of pH, temperature and hydrolyzate concentration on the removal of volatile and nonvolatile compounds from sugarcane bagasse hemicellulosic hydrolyzate treated with activated charcoal before or after vacuum evaporation

    Directory of Open Access Journals (Sweden)

    R.C.L.B. Rodrigues

    2001-09-01

    Full Text Available This paper analyzes the influence of pH, temperature and degree of hydrolyzate concentration on the removal of volatile and nonvolatile compounds from sugarcane bagasse hemicellulosic hydrolyzate treated with activated charcoal before or after the vacuum evaporation process. Furfural and 5-Hydroxymethylfurfural were almost totally removed in all the experiments, irrespective of pH and temperature and whether the charcoal was added before or after the vacuum evaporation process. Adding activated charcoal before the vacuum evaporation process favored the removal of phenolic compounds for all values of pH. Acetic acid, on the contrary, was most effectively removed when the activated charcoal was added after the vacuum evaporation process at an acid pH (0.92 and at the highest degree of hydrolyzate concentration (f=4. However, addition of activated charcoal before or after vacuum evaporation at an acid pH (0.92 and at the highest degree of hydrolyzate concentration (f=4 favored the removal of both acetic acid and phenolic compounds.

  17. Active and reactive behaviour in human mobility: the influence of attraction points on pedestrians

    Science.gov (United States)

    Gutiérrez-Roig, M.; Sagarra, O.; Oltra, A.; Palmer, J. R. B.; Bartumeus, F.; Díaz-Guilera, A.; Perelló, J.

    2016-07-01

    Human mobility is becoming an accessible field of study, thanks to the progress and availability of tracking technologies as a common feature of smart phones. We describe an example of a scalable experiment exploiting these circumstances at a public, outdoor fair in Barcelona (Spain). Participants were tracked while wandering through an open space with activity stands attracting their attention. We develop a general modelling framework based on Langevin dynamics, which allows us to test the influence of two distinct types of ingredients on mobility: reactive or context-dependent factors, modelled by means of a force field generated by attraction points in a given spatial configuration and active or inherent factors, modelled from intrinsic movement patterns of the subjects. The additive and constructive framework model accounts for some observed features. Starting with the simplest model (purely random walkers) as a reference, we progressively introduce different ingredients such as persistence, memory and perceptual landscape, aiming to untangle active and reactive contributions and quantify their respective relevance. The proposed approach may help in anticipating the spatial distribution of citizens in alternative scenarios and in improving the design of public events based on a facts-based approach.

  18. Targeted activation of CREB in reactive astrocytes is neuroprotective in focal acute cortical injury.

    Science.gov (United States)

    Pardo, Luis; Schlüter, Agatha; Valor, Luis M; Barco, Angel; Giralt, Mercedes; Golbano, Arantxa; Hidalgo, Juan; Jia, Peilin; Zhao, Zhongming; Jové, Mariona; Portero-Otin, Manuel; Ruiz, Montserrat; Giménez-Llort, Lydia; Masgrau, Roser; Pujol, Aurora; Galea, Elena

    2016-05-01

    The clinical challenge in acute injury as in traumatic brain injury (TBI) is to halt the delayed neuronal loss that occurs hours and days after the insult. Here we report that the activation of CREB-dependent transcription in reactive astrocytes prevents secondary injury in cerebral cortex after experimental TBI. The study was performed in a novel bitransgenic mouse in which a constitutively active CREB, VP16-CREB, was targeted to astrocytes with the Tet-Off system. Using histochemistry, qPCR, and gene profiling we found less neuronal death and damage, reduced macrophage infiltration, preserved mitochondria, and rescued expression of genes related to mitochondrial metabolism in bitransgenic mice as compared to wild type littermates. Finally, with meta-analyses using publicly available databases we identified a core set of VP16-CREB candidate target genes that may account for the neuroprotective effect. Enhancing CREB activity in astrocytes thus emerges as a novel avenue in acute brain post-injury therapeutics.

  19. Effect of axial ligands on the molecular configurations, stability, reactivity, and photodynamic activities of silicon phthalocyanines.

    Science.gov (United States)

    Luan, Liqiang; Ding, Lanlan; Shi, Jiawei; Fang, Wenjuan; Ni, Yuxing; Liu, Wei

    2014-12-01

    To demonstrate the effect of axial ligands on the structure-activity relationship, a series of axially substituted silicon phthalocyanines (SiPcs) have been synthesized with changes to the axial ligands. The reactivity of the axial ligand upon shielding by the phthalocyanine ring current, along with their stability, photophysical, and photodynamic therapy (PDT) activities were compared and evaluated for the first time. As revealed by single-crystal XRD analysis, rotation of the axial -OMe ligands was observed in SiPc 3, which resulted in two molecular configurations coexisting synchronously in both the solid and solution states and causing a split of the phthalocyanine α protons in the (1)H NMR spectra that is significantly different from all SiPcs reported so far. The remarkable photostability, good singlet oxygen quantum yield, and efficient in vitro photodynamic activity synergistically show that compound 3 is one of the most promising photosensitizers for PDT.

  20. Structure-activity analysis of aging and reactivation of human butyrylcholinesterase inhibited by analogues of tabun.

    Science.gov (United States)

    Carletti, Eugénie; Aurbek, Nadine; Gillon, Emilie; Loiodice, Mélanie; Nicolet, Yvain; Fontecilla-Camps, Juan-Carlos; Masson, Patrick; Thiermann, Horst; Nachon, Florian; Worek, Franz

    2009-06-12

    hBChE [human BChE (butyrylcholinesterase)] naturally scavenges OPs (organophosphates). This bioscavenger is currently in Clinical Phase I for pretreatment of OP intoxication. Phosphylated ChEs (cholinesterases) can undergo a spontaneous time-dependent process called 'aging' during which the conjugate is dealkylated, leading to creation of an enzyme that cannot be reactivated. hBChE inhibited by phosphoramidates such as tabun displays a peculiar resistance to oxime-mediated reactivation. We investigated the basis of oxime resistance of phosphoramidyl-BChE conjugates by determining the kinetics of inhibition, reactivation (obidoxime {1,1'-(oxybis-methylene) bis[4-(hydroxyimino) methyl] pyridinium dichloride}, TMB-4 [1,3-trimethylene-bis(4-hydroxyiminomethylpyridinium) dibromide], HLö 7 {1-[[[4-(aminocarbonyl) pyridinio]methoxy]methyl]-2,4-bis-[(hydroxyimino)methyl] pyridinium dimethanesulfonate)}, HI-6 {1-[[[4-(aminocarbonyl) pyridinio] methoxy] methyl]-2-[(hydroxyimino)methyl]pyridinium dichloride monohydrate} and aging, and the crystal structures of hBChE inhibited by different N-monoalkyl and N,N-dialkyl tabun analogues. The refined structures of aged hBChE conjugates show that aging proceeds through O-dealkylation of the P(R) enantiomer of N,N-diethyl and N-propyl analogues, with subsequent formation of a salt bridge preventing reactivation, similarly to a previous observation made on tabun-ChE conjugates. Interestingly, the N-methyl analogue projects its amino group towards the choline-binding pocket, so that aging proceeds through deamination. This orientation results from a preference of hBChE's acyl-binding pocket for larger than 2-atoms linear substituents. The correlation between the inhibitory potency and the N-monoalkyl chain length is related to increasingly optimized interactions with the acyl-binding pocket as shown by the X-ray structures. These kinetics and X-ray data lead to a structure-activity relationship that highlights steric and electronic

  1. Reactive Landing of Gramicidin S and Ubiquitin Ions onto Activated Self-Assembled Monolayer Surfaces

    Science.gov (United States)

    Laskin, Julia; Hu, Qichi

    2017-03-01

    Using mass-selected ion deposition combined with in situ infrared reflection absorption spectroscopy (IRRAS), we examined the reactive landing of gramicidin S and ubiquitin ions onto activated self-assembled monolayer (SAM) surfaces terminated with N-hydroxysuccinimidyl ester (NHS-SAM) and acyl fluoride (COF-SAM) groups. Doubly protonated gramicidin S, [GS + 2H]2+, and two charge states of ubiquitin, [U + 5H]5+ and [U + 13H]13+, were used as model systems, allowing us to explore the effect of the number of free amino groups and the secondary structure on the efficiency of covalent bond formation between the projectile ion and the surface. For all projectile ions, ion deposition resulted in the depletion of IRRAS bands corresponding to the terminal groups on the SAM and the appearance of several new bands not associated with the deposited species. These new bands were assigned to the C=O stretching vibrations of COOH and COO- groups formed on the surface as a result of ion deposition. The presence of these bands was attributed to an alternative reactive landing pathway that competes with covalent bond formation. This pathway with similar yields for both gramicidin S and ubiquitin ions is analogous to the hydrolysis of the NHS ester bond in solution. The covalent bond formation efficiency increased linearly with the number of free amino groups and was found to be lower for the more compact conformation of ubiquitin compared with the fully unfolded conformation. This observation was attributed to the limited availability of amino groups on the surface of the folded conformation. Our results have provided new insights on the efficiency and mechanism of reactive landing of peptides and proteins onto activated SAMs.

  2. Measure Guideline: Evaporative Condensers

    Energy Technology Data Exchange (ETDEWEB)

    German, A [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Dakin, B. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2012-03-01

    This measure guideline on evaporative condensers provides information on properly designing, installing, and maintaining evaporative condenser systems as well as understanding the benefits, costs, and tradeoffs. This is a prescriptive approach that outlines selection criteria, design and installation procedures, and operation and maintenance best practices.

  3. Evaporation and weather

    NARCIS (Netherlands)

    Bruin, H.A.R. de; Feddes, R.A.; Holtslag, A.A.M.; Lablans, W.N.; Schuurmans, C.J.E.; Shuttleworth, W.J.

    1987-01-01

    Data on evaporation to be used in agriculture, hydrology, forestry, etc. are usually supplied by meteorologists. Meteorologists themselves also use evaporation data. Air mass properties determining weather are strongly dependent on the input of water vapour from the surface. So for weather predictio

  4. Evaporation, Boiling and Bubbles

    Science.gov (United States)

    Goodwin, Alan

    2012-01-01

    Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

  5. Voltage stability in low voltage microgrids in aspects of active and reactive power demand

    Directory of Open Access Journals (Sweden)

    Parol Mirosław

    2016-03-01

    Full Text Available Low voltage microgrids are autonomous subsystems, in which generation, storage and power and electrical energy consumption appear. In the paper the main attention has been paid to the voltage stability issue in low voltage microgrid for different variants of its operation. In the introduction a notion of microgrid has been presented, and also the issue of influence of active and reactive power balance on node voltage level has been described. Then description of voltage stability issue has been presented. The conditions of voltage stability and indicators used to determine voltage stability margin in the microgrid have been described. Description of the low voltage test microgrid, as well as research methodology along with definition of considered variants of its operation have been presented further. The results of exemplary calculations carried out for the daily changes in node load of the active and reactive power, i.e. the voltage and the voltage stability margin indexes in nodes have been presented. Furthermore, the changes of voltage stability margin indexes depending on the variant of the microgrid operation have been presented. Summary and formulation of conclusions related to the issue of voltage stability in microgrids have been included at the end of the paper.

  6. Continuous Wavelet and Hilbert-Huang Transforms Applied for Analysis of Active and Reactive Power Consumption

    Directory of Open Access Journals (Sweden)

    Avdakovic Samir

    2014-08-01

    Full Text Available Analysis of power consumption presents a very important issue for power distribution system operators. Some power system processes such as planning, demand forecasting, development, etc.., require a complete understanding of behaviour of power consumption for observed area, which requires appropriate techniques for analysis of available data. In this paper, two different time-frequency techniques are applied for analysis of hourly values of active and reactive power consumption from one real power distribution transformer substation in urban part of Sarajevo city. Using the continuous wavelet transform (CWT with wavelet power spectrum and global wavelet spectrum some properties of analysed time series are determined. Then, empirical mode decomposition (EMD and Hilbert-Huang Transform (HHT are applied for the analyses of the same time series and the results showed that both applied approaches can provide very useful information about the behaviour of power consumption for observed time interval and different period (frequency bands. Also it can be noticed that the results obtained by global wavelet spectrum and marginal Hilbert spectrum are very similar, thus confirming that both approaches could be used for identification of main properties of active and reactive power consumption time series.

  7. Adsorption of phenol and reactive dye from aqueous solution on activated carbons derived from solid wastes.

    Science.gov (United States)

    Nakagawa, Kyuya; Namba, Akio; Mukai, Shin R; Tamon, Hajime; Ariyadejwanich, Pisit; Tanthapanichakoon, Wiwut

    2004-04-01

    Activated carbons were produced from several solid wastes, namely, waste PET, waste tires, refuse derived fuel and wastes generated during lactic acid fermentation from garbage. Activated carbons having various pore size distributions were obtained by the conventional steam-activation method and via the pre-treatment method (i.e., mixture of raw materials with a metal salt, carbonization and acid treatment prior to steam-activation) that was proposed by the authors. The liquid-phase adsorption characteristics of organic compounds from aqueous solution on the activated carbons were determined to confirm the applicability of these carbons, where phenol and a reactive dye, Black5, were employed as representative adsorbates. The hydrophobic surface of the carbons prepared was also confirmed by water vapor adsorption. The characteristics of a typical commercial activated carbon were also measured and compared. It was found that the activated carbons with plentiful mesopores prepared from PET and waste tires had quite high adsorption capacity for large molecules. Therefore they are useful for wastewater treatment, especially, for removal of bulky adsorbates.

  8. Wolbachia Do Not Induce Reactive Oxygen Species-Dependent Immune Pathway Activation in Aedes albopictus

    Directory of Open Access Journals (Sweden)

    Jennifer C. Molloy

    2015-08-01

    Full Text Available Aedes albopictus is a major vector of dengue (DENV and chikungunya (CHIKV viruses, causing millions of infections annually. It naturally carries, at high frequency, the intracellular inherited bacterial endosymbiont Wolbachia strains wAlbA and wAlbB; transinfection with the higher-density Wolbachia strain wMel from Drosophila melanogaster led to transmission blocking of both arboviruses. The hypothesis that reactive oxygen species (ROS-induced immune activation plays a role in arbovirus inhibition in this species was examined. In contrast to previous observations in Ae. aegypti, elevation of ROS levels was not observed in either cell lines or mosquito lines carrying the wild-type Wolbachia or higher-density Drosophila Wolbachia strains. There was also no upregulation of genes controlling innate immune pathways or with antioxidant/ROS-producing functions. These data suggest that ROS-mediated immune activation is not an important component of the viral transmission-blocking phenotype in this species.

  9. In vitro antifilarial activity of Azadirachta indica aqueous extract through reactive oxygen species enhancement

    Institute of Scientific and Technical Information of China (English)

    Niladri Mukherjee; Prasanta Saini; Suprabhat Mukherjee; Priya Roy; Santi P. Sinha Babu

    2014-01-01

    Objective:To evaluate an aqueous preparation from the Azadirachta indica leaves (AEA) against Setaria cervi (S. cervi), a model filarial parasite. Methods:In vitro efficacy of AEA was evaluated against S. cervi through estimation of relative motility value, dye exclusion test and MTT assay. Visible morphological alterations were monitored using conventional microscopic techniques in microfilariae and haematoxylin-eosin stained sections of AEA-treated adults. Results:Enhancement of reactive oxygen species in S. cervi treated with AEA was established through alteration in the activity of glutathione S-transferase, superoxide dismutase, catalase, peroxidase and level of superoxide anion and reduced glutathione. Conclusions:In vitro filaricidal activity of AEA is possibly through disturbing redox homeostasis by down-regulating and altering the level of some key antioxidants and regulatory enzymes like reduced glutathione, glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase of S. cervi.

  10. Active and reactive behaviour in human mobility: the influence of attraction points on pedestrians

    CERN Document Server

    Gutiérrez-Roig, Mario; Oltra, Aitana; Bartumeus, Frederic; Diaz-Guilera, Albert; Perelló, Josep

    2015-01-01

    Human mobility is becoming an accessible field of study thanks to the progress and availability of tracking technologies as a common feature of smart phones. We describe an example of a scalable experiment exploiting these circumstances at a public, outdoor fair in Barcelona (Spain). Participants were tracked while wandering through an open space with activity stands attracting their attention. We develop a general modeling framework based on Langevin Dynamics, which allows us to test the influence of two distinct types of ingredients on mobility: reactive or context-dependent factors, modelled by means of a force field generated by attraction points in a given spatial configuration, and active or inherent factors, modelled from intrinsic movement patterns of the subjects. The additive and constructive framework model accounts for the observed features. Starting with the simplest model (purely random walkers) as a reference, we progressively introduce different ingredients such as persistence, memory, and per...

  11. Electron transport chain inhibitors induce microglia activation through enhancing mitochondrial reactive oxygen species production.

    Science.gov (United States)

    Ye, Junli; Jiang, Zhongxin; Chen, Xuehong; Liu, Mengyang; Li, Jing; Liu, Na

    2016-01-15

    Reactive oxygen species (ROS) are believed to be mediators of excessive microglial activation, yet the resources and mechanism are not fully understood. Here we stimulated murine microglial BV-2 cells and primary microglial cells with different inhibitors of electron transport chain (ETC), rotenone, thenoyltrifluoroacetone (TTFA), antimycin A, and NaN3 to induce mitochondrial ROS production and we observed the role of mitochondrial ROS in microglial activation. Our results showed that ETC inhibitors resulted in significant changes in cell viability, microglial morphology, cell cycle arrest and mitochondrial ROS production in a dose-dependent manner in both primary cultural microglia and BV-2 cell lines. Moreover, ETC inhibitors, especially rotenone and antimycin A stimulated secretion of interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 12 (IL-12) and tumor necrosis factor α (TNF-α) by microglia with marked activation of mitogen-activated proteinkinases (MAPKs) and nuclear factor κB (NF-κB), which could be blocked by specific inhibitors of MAPK and NF-κB and mitochondrial antioxidants, Mito-TEMPO. Taken together, our results demonstrated that inhibition of mitochondrial respiratory chain in microglia led to production of mitochondrial ROS and therefore may activate MAPK/NF-кB dependent inflammatory cytokines release in microglia, which indicated that mitochondrial-derived ROS were contributed to microglial activation.

  12. Arsenite activates NFκB through induction of C-reactive protein

    Energy Technology Data Exchange (ETDEWEB)

    Druwe, Ingrid L.; Sollome, James J.; Sanchez-Soria, Pablo; Hardwick, Rhiannon N.; Camenisch, Todd D.; Vaillancourt, Richard R., E-mail: vaillancourt@pharmacy.arizona.edu

    2012-06-15

    C-reactive protein (CRP) is an acute phase protein in humans. Elevated levels of CRP are produced in response to inflammatory cytokines and are associated with atherosclerosis, hypertension, cardiovascular disease and insulin resistance. Exposure to inorganic arsenic, a common environmental toxicant, also produces cardiovascular disorders, namely atherosclerosis and is associated with insulin-resistance. Inorganic arsenic has been shown to contribute to cardiac toxicities through production of reactive oxygen species (ROS) that result in the activation of NFκB. In this study we show that exposure of the hepatic cell line, HepG2, to environmentally relevant levels of arsenite (0.13 to 2 μM) results in elevated CRP expression and secretion. ROS analysis of the samples showed that a minimal amount of ROS are produced by HepG2 cells in response to these concentrations of arsenic. In addition, treatment of FvB mice with 100 ppb sodium arsenite in the drinking water for 6 months starting at weaning age resulted in dramatically higher levels of CRP in both the liver and inner medullary region of the kidney. Further, mouse Inner Medullary Collecting Duct cells (mIMCD-4), a mouse kidney cell line, were stimulated with 10 ng/ml CRP which resulted in activation of NFκB. Pretreatment with 10 nM Y27632, a known Rho-kinase inhibitor, prior to CRP exposure attenuated NFκB activation. These data suggest that arsenic causes the expression and secretion of CRP and that CRP activates NFκB through activation of the Rho-kinase pathway, thereby providing a novel pathway by which arsenic can contribute to metabolic syndrome and cardiovascular disease. -- Highlights: ► Exposure to arsenic can induce the expression and secretion of CRP. ► Mice treated with NaAsO{sub 2} showed higher levels of CRP in both the liver and kidney. ► mIMCD-3 were stimulated with CRP which resulted in activation of NFκB. ► CRP activates NFκB through activation of the Rho-kinase pathway. ► Data

  13. Evaporation in hydrology and meteorology

    OpenAIRE

    Brandsma, T.

    1990-01-01

    In this paper the role of evaporation in hydrology and meteorology is discussed, with the emphasis on hydrology. The basic theory of evaporation is given and methods to determine evaporation are presented. Some applications of evaporation studies in literature are given in order to illustrate the theory. Further, special conditions in evaporation are considered, followed by a fotmulation of the difficulties in determining evaporation, The last part of the paper gives a short discussion about ...

  14. Adaptive and Context-Aware Reconciliation of Reactive and Pro-active Behavior in Evolving Systems

    Science.gov (United States)

    Trajcevski, Goce; Scheuermann, Peter

    One distinct characteristics of the context-aware systems is their ability to react and adapt to the evolution of the environment, which is often a result of changes in the values of various (possibly correlated) attributes. Based on these changes, reactive systems typically take corrective actions, e.g., adjusting parameters in order to maintain the desired specifications of the system's state. Pro-active systems, on the other hand, may change the mode of interaction with the environment as well as the desired goals of the system. In this paper we describe our (ECA)2 paradigm for reactive behavior with proactive impact and we present our ongoing work and vision for a system that is capable of context-aware adaptation, while ensuring the maintenance of a set of desired behavioral policies. Our main focus is on developing a formalism that provides tools for expressing normal, as well as defeasible and/or exceptional specification. However, at the same time, we insist on a sound semantics and the capability of answering hypothetical "what-if" queries. Towards this end, we introduce the high-level language L_{ EAR} that can be used to describe the dynamics of the problem domain, specify triggers under the (ECA)2 paradigm, and reason about the consequences of the possible evolutions.

  15. Probabilistic Approach to Optimizing Active and Reactive Power Flow in Wind Farms Considering Wake Effects

    Directory of Open Access Journals (Sweden)

    Yong-Cheol Kang

    2013-10-01

    Full Text Available This paper presents a novel probabilistic optimization algorithm for simultaneous active and reactive power dispatch in power systems with significant wind power integration. Two types of load and wind-speed uncertainties have been assumed that follow normal and Weibull distributions, respectively. A PV bus model for wind turbines and the wake effect for correlated wind speed are used to achieve accurate AC power flow analysis. The power dispatch algorithm for a wind-power integrated system is modeled as a probabilistic optimal power flow (P-OPF problem, which is operated through fixed power factor control to supply reactive power. The proposed P-OPF framework also considers emission information, which clearly reflects the impact of the energy source on the environment. The P-OPF was tested on a modified IEEE 118-bus system with two wind farms. The results show that the proposed technique provides better system operation performance evaluation, which is helpful in making decisions about power system optimal dispatch under conditions of uncertainty.

  16. Amaranth peptides from simulated gastrointestinal digestion: antioxidant activity against reactive species.

    Science.gov (United States)

    Delgado, María C Orsini; Galleano, Mónica; Añón, María C; Tironi, Valeria A

    2015-03-01

    We evaluated the capacity of simulated gastrointestinal digests or alcalase hydrolysates of protein isolates from amaranth to scavenge diverse physiologically relevant reactive species. The more active hydrolysate was obtained with the former method. Moreover, a prior alcalase treatment of the isolate followed by the same simulated gastrointestinal digestion did not improve the antioxidant capacity in any of the assays performed and even produced a negative effect under some conditions. Gastrointestinal digestion produced a strong increment in the scavenging capacity against peroxyl radicals (ORAC assay), hydroxyl radicals (ESR-OH assay), and peroxynitrites; thus decreasing the IC50 values to approximately 20, 25, and 20%, respectively, of the levels attained with the nonhydrolyzed proteins. Metal chelation (HORAC assay) also enhanced respect to isolate levels, but to a lesser extent (decreasing IC50 values to only 50%). The nitric-oxide- and superoxide-scavenging capacities of the digests were not relevant with respect to the methodologies used. The gastrointestinal digests from amaranth proteins acted against reactive species by different mechanisms, thus indicating the protein isolate to be a potential polyfunctional antioxidant ingredient.

  17. Adsorption of the reactive azo dyes onto NH4Cl-induced activated carbon

    Directory of Open Access Journals (Sweden)

    Sakine Shekoohiyan

    2016-03-01

    Full Text Available Background: The efficacy of NH4Cl-induced activated carbon (NAC was examined in order to adsorb RR198, an azo reactive model dye, from an aqueous solution. Methods: The effects of pH (3 to 10, adsorbent dose (0.1 to 1.2 g/L, dye concentration and contact time on the adsorption efficiency were investigated. Results: The results showed that the removal of dye was highest at a solution pH of 7 and a powder dose of 1.1 g/L. The 85.9%, 72.6% and 65.4% removal of RR198 was obtained for a concentration of 25, 50 and 100 mg/L, respectively, at a relatively short contact time of 30 minutes, and at optimum pH and NAC concentrations of 1 g/L. The experimental data for kinetic analysis illustrated a best fit to the pseudo-second-order model. The study data on equilibrium were modeled using Langmuir, Freundlich and Dubinin–Radushkevich models; the Langmuir equation provided the best fit for the data. Conclusion: Therefore, the NAC appears to be an efficient and appropriate adsorbent for the removal of reactive azo dyes from waste streams.

  18. Quiescent and Active Tear Protein Profiles to Predict Vernal Keratoconjunctivitis Reactivation

    Directory of Open Access Journals (Sweden)

    Alessandra Micera

    2016-01-01

    Full Text Available Objective. Vernal keratoconjunctivitis (VKC is a chronic recurrent bilateral inflammation of the conjunctiva associated with atopy. Several inflammatory and tissue remodeling factors contribute to VKC disease. The aim is to provide a chip-based protein analysis in tears from patients suffering from quiescent or active VKC. Methods. This study cohort included 16 consecutive patients with VKC and 10 controls. Participants were subjected to clinical assessment of ocular surface and tear sampling. Total protein quantification, total protein sketch, and protein array (sixty protein candidates were evaluated. Results. An overall increased Fluorescent Intensity expression was observed in VKC arrays. Particularly, IL1β, IL15, IL21, Eotaxin2, TACE, MIP1α, MIP3α, NCAM1, ICAM2, βNGF, NT4, BDNF, βFGF, SCF, MMP1, and MMP2 were increased in quiescent VKC. Of those candidates, only IL1β, IL15, IL21, βNGF, SCF, MMP2, Eotaxin2, TACE, MIP1α, MIP3α, NCAM1, and ICAM2 were increased in both active and quiescent VKC. Finally, NT4, βFGF, and MMP1 were highly increased in active VKC. Conclusion. A distinct “protein tear-print” characterizes VKC activity, confirming some previously reported factors and highlighting some new candidates common to quiescent and active states. Those candidates expressed in quiescent VKC might be considered as predictive indicators of VKC reactivation and/or exacerbation out-of-season.

  19. Quiescent and Active Tear Protein Profiles to Predict Vernal Keratoconjunctivitis Reactivation

    Science.gov (United States)

    Micera, Alessandra; Di Zazzo, Antonio; Esposito, Graziana; Sgrulletta, Roberto; Calder, Virginia L.; Bonini, Stefano

    2016-01-01

    Objective. Vernal keratoconjunctivitis (VKC) is a chronic recurrent bilateral inflammation of the conjunctiva associated with atopy. Several inflammatory and tissue remodeling factors contribute to VKC disease. The aim is to provide a chip-based protein analysis in tears from patients suffering from quiescent or active VKC. Methods. This study cohort included 16 consecutive patients with VKC and 10 controls. Participants were subjected to clinical assessment of ocular surface and tear sampling. Total protein quantification, total protein sketch, and protein array (sixty protein candidates) were evaluated. Results. An overall increased Fluorescent Intensity expression was observed in VKC arrays. Particularly, IL1β, IL15, IL21, Eotaxin2, TACE, MIP1α, MIP3α, NCAM1, ICAM2, βNGF, NT4, BDNF, βFGF, SCF, MMP1, and MMP2 were increased in quiescent VKC. Of those candidates, only IL1β, IL15, IL21, βNGF, SCF, MMP2, Eotaxin2, TACE, MIP1α, MIP3α, NCAM1, and ICAM2 were increased in both active and quiescent VKC. Finally, NT4, βFGF, and MMP1 were highly increased in active VKC. Conclusion. A distinct “protein tear-print” characterizes VKC activity, confirming some previously reported factors and highlighting some new candidates common to quiescent and active states. Those candidates expressed in quiescent VKC might be considered as predictive indicators of VKC reactivation and/or exacerbation out-of-season. PMID:26989694

  20. Cross-Sectional and Prospective Associations between Physical Activity and C-Reactive Protein in Males.

    Directory of Open Access Journals (Sweden)

    Aírton J Rombaldi

    Full Text Available There is conflicting evidence about the association between physical activity and inflammatory markers. Few prospective studies are available, particularly from low and middle-income countries. This study was aimed at assessing the cross-sectional and prospective associations between physical activity and C-reactive protein (CRP levels in males belonging to the 1982 Pelotas (Brazil Birth Cohort Study.The sample comprised 2,213 males followed up at the ages of 18 and 23 years. We performed high sensitivity CRP assays; we used a cut-off of 3 mg/L in categorical analyses. We measured physical activity by self-report at ages 18 and 23 years. Body mass index and waist circumference were studies as possible mediators.CRP levels above the 3mg/L cut-off were found in 13.3% (95%CI: 11.7; 14.8 of the individuals. We found no evidence for an association between physical activity (leisure-time or all-domains and either continuous (geometrical mean or categorical CRP. We confirmed these null findings in (a prospective and cross-sectional analyses; (b trajectories analyses.There was no association between CRP levels and physical activity levels in early adulthood in a large birth cohort. Little variability in CRP at this early age is the likely explanation for these null findings.

  1. Nuclear factor-kappaB activation on the reactive oxygen species in acute necrotizing pancreatitic rats

    Institute of Scientific and Technical Information of China (English)

    Jin Long; Na Song; Xi-Ping Liu; Ke-Jian Guo; Ren-Xuan Guo

    2005-01-01

    AIM: To investigate the potential role of nuclear factor kappa-B (NF-κB) activation on the reactive oxygen species in rat acute necrotizing pancreatitis (ANP) and to assess the effect of pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB).METHODS: Rat ANP model was established by retrograde injection of 5% sodium taurocholate into biliopancreatic duct. Rats were randomly assigned to three groups (10rats each): Control group, ANP group and PDTC group. At the 6th h of the model, the changes of the serum amylase,nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD) and pancreatic morphological damage were observed. The expressions of inducible nitric oxide (iNOS) were observed by SP immunohistochemistry. And the expressions of NF-κB p65 subunit mRNA were observed by hybridization in situ.RESULTS: Serum amylase and NO level decreased significantly in ANP group as compared with PDTC administrated group [(7 170.40±1 308.63) U/L vs(4 074.10±1 719.78) U/L,P<0.05], [(76.95±9.04) μmol/L vs (65.18±9.02) μmol/L,P<0.05] respectively. MDA in both ANP and PDTC group rose significantly over that in control group [(9.88±1.52)nmol/L, (8.60±1.41) nmol/L, vs (6.04±1.78) nmol/L,P<0.05], while there was no significant difference between them. SOD levels in both ANP and PDTC group underwent a significant decrease as compared with that in control [(3 214.59±297.74) NU/mL, (3 260.62±229.44) NU/mL,vs (3 977.80±309.09) NU/mL, P<0.05], but there was no significant difference between them. Though they were still higher than those in Control group, pancreas destruction was slighter in PDTC group, iNOS expression and NF-κB p65 subunit mRNA expression were lower in PDTC group as compared with ANP group.CONCLUSION: We conclude that correlation among NF-κB activation, serum amylase, reactive oxygen species level and tissue damage suggests a key role of NF-κB in the pathogenesis of ANP. Inhibition of NF-κB activation may reverse the pancreatic damage

  2. CAPSULE REPORT: EVAPORATION PROCESS

    Science.gov (United States)

    Evaporation has been an established technology in the metal finishing industry for many years. In this process, wastewaters containing reusable materials, such as copper, nickel, or chromium compounds are heated, producing a water vapor that is continuously removed and condensed....

  3. Low temperature syntheses and reactivity of Cu2O2 active-site models.

    Science.gov (United States)

    Citek, Cooper; Herres-Pawlis, Sonja; Stack, T Daniel P

    2015-08-18

    Nature's facility with dioxygen outmatches modern chemistry in the oxidation and oxygenation of materials and substrates for biosynthesis and cellular metabolism. The Earth's most abundant naturally occurring oxidant is-frankly-poorly understood and controlled, and thus underused. Copper-based enzyme metallocofactors are ubiquitous to the efficient consumption of dioxygen by all domains of life. Over the last several decades, we have joined many research groups in the study of copper- and dioxygen-dependent enzymes through close investigation of synthetically derived, small-molecule active-site analogs. Simple copper-dioxygen clusters bearing structural and spectroscopic similarity to dioxygen-activating enzymes can be probed for their fundamental geometrical, electronic, and reactive properties using the tools available to inorganic and synthetic chemistry. Our exploration of the copper-dioxygen arena has sustained product evaluation of the key dynamics and reactivity of binuclear Cu2O2 compounds. Almost exclusively operating at low temperatures, from -78 °C to solution characterization even at -125 °C, we have identified numerous compounds supported by simple and easily accessed, low molecular weight ligands-chiefly families of bidentate diamine chelates. We have found that by stripping away complexity in comparison to extended protein tertiary structures or sophisticated, multinucleating architectures, we can experimentally manipulate activated compounds and open pathways of reactivity toward exogenous substrates that both inform on and extend fundamental mechanisms of oxygenase enzymes. Our recent successes have advanced understanding of the tyrosinase enzyme, and related hemocyanin and NspF, and the copper membrane monooxygenases, specifically particulate methane monooxygenase (pMMO) and ammonia monooxygenase (AMO). Tyrosinase, ubiquitously distributed throughout life, is fundamental to the copper-based oxidation of phenols and the production of chromophores

  4. Re-activation of bovine tuberculosis in a patient treated with infliximab

    DEFF Research Database (Denmark)

    Larsen, Mette Vang; Thomsen, V Ø; Sørensen, Inge Juul;

    2008-01-01

    Treatment with tumour necrosis factor-alpha inhibitors increases the risk of tuberculosis (TB). Screening for latent TB infection (LTBI) and prophylactic treatment has become mandatory. A 79-yr-old female with a history of severe erosive sero-positive rheumatoid arthritis was screened for LTBI....... QuantiFERON-TB (QFT) testing performed during screening and immunosuppressive treatment was indeterminate, whereas the QFT test performed at the time of ascites puncture was positive. The patient history revealed previous work at a dairy, with probable exposure to unpasteurised milk from M. bovis......-infected cattle. Re-activation of bovine tuberculosis is a risk in people with recent or previous exposure to unpasteurised dairy products. The QuantiFERON-TB test has the potential to detect Mycobacterium bovis infection. Indeterminate test results reflect either anergy, due to poor immunity, or technical...

  5. Re-activation of bovine tuberculosis in a patient treated with infliximab

    DEFF Research Database (Denmark)

    Larsen, Mette Vang; Thomsen, V Ø; Sørensen, Inge Juul

    2008-01-01

    Treatment with tumour necrosis factor-alpha inhibitors increases the risk of tuberculosis (TB). Screening for latent TB infection (LTBI) and prophylactic treatment has become mandatory. A 79-yr-old female with a history of severe erosive sero-positive rheumatoid arthritis was screened for LTBI......-infected cattle. Re-activation of bovine tuberculosis is a risk in people with recent or previous exposure to unpasteurised dairy products. The QuantiFERON-TB test has the potential to detect Mycobacterium bovis infection. Indeterminate test results reflect either anergy, due to poor immunity, or technical...... problems and should be cautiously interpreted and as a minimum be repeated. Studies are ongoing to determine the role of QuantiFERON-TB testing in the screening for latent tuberculosis infection....

  6. Peroxiredoxin-3 Is Involved in Bactericidal Activity through the Regulation of Mitochondrial Reactive Oxygen Species

    Science.gov (United States)

    Lee, Sena; Wi, Sae Mi; Min, Yoon

    2016-01-01

    Peroxiredoxin-3 (Prdx3) is a mitochondrial protein of the thioredoxin family of antioxidant peroxidases and is the principal peroxidase responsible for metabolizing mitochondrial hydrogen peroxide. Recent reports have shown that mitochondrial reactive oxygen species (mROS) contribute to macrophage-mediated bactericidal activity in response to Toll-like receptors. Herein, we investigated the functional effect of Prdx3 in bactericidal activity. The mitochondrial localization of Prdx3 in HEK293T cells was confirmed by cell fractionation and confocal microscopy analyses. To investigate the functional role of Prdx3 in bactericidal activity, Prdx3-knockdown (Prdx3KD) THP-1 cells were generated. The mROS levels in Prdx3KD THP-1 cells were significantly higher than those in control THP-1 cells. Moreover, the mROS levels were markedly increased in response to lipopolysaccharide. Notably, the Salmonella enterica serovar Typhimurium infection assay revealed that the Prdx3KD THP-1 cells were significantly resistant to S. Typhimurium infection, as compared with control THP-1 cells. Taken together, these results indicate that Prdx3 is functionally important in bactericidal activity through the regulation of mROS. PMID:28035213

  7. Copper compound induces autophagy and apoptosis of glioma cells by reactive oxygen species and jnk activation

    Directory of Open Access Journals (Sweden)

    Trejo-Solís Cristina

    2012-04-01

    Full Text Available Abstract Background Glioblastoma multiforme (GBM is the most aggressive of the primary brain tumors, with a grim prognosis despite intensive treatment. In the past decades, progress in research has not significantly increased overall survival rate. Methods The in vitro antineoplastic effect and mechanism of action of Casiopeina III-ia (Cas III-ia, a copper compound, on rat malignant glioma C6 cells was investigated. Results Cas III-ia significantly inhibited cell proliferation, inducing autophagy and apoptosis, which correlated with the formation of autophagic vacuoles, overexpression of LC3, Beclin 1, Atg 7, Bax and Bid proteins. A decrease was detected in the mitochondrial membrane potential and in the activity of caspase 3 and 8, together with the generation of intracellular reactive oxygen species (ROS and increased activity of c-jun NH2-terminal kinase (JNK. The presence of 3-methyladenine (as selective autophagy inhibitor increased the antineoplastic effect of Cas III-ia, while Z-VAD-FMK only showed partial protection from the antineoplastic effect induced by Cas III-ia, and ROS antioxidants (N-acetylcysteine decreased apoptosis, autophagy and JNK activity. Moreover, the JNK –specific inhibitor SP600125 prevented Cas III-ia-induced cell death. Conclusions Our data suggest that Cas III-ia induces cell death by autophagy and apoptosis, in part due to the activation of ROS –dependent JNK signaling. These findings support further studies of Cas III-ia as candidate for treatment of human malignant glioma.

  8. Measure Guideline: Evaporative Condensers

    Energy Technology Data Exchange (ETDEWEB)

    German, A.; Dakin, B.; Hoeschele, M.

    2012-03-01

    The purpose of this measure guideline on evaporative condensers is to provide information on a cost-effective solution for energy and demand savings in homes with cooling loads. This is a prescriptive approach that outlines selection criteria, design and installation procedures, and operation and maintenance best practices. This document has been prepared to provide a process for properly designing, installing, and maintaining evaporative condenser systems as well as understanding the benefits, costs, and tradeoffs.

  9. Desorption, partitioning, and dechlorination characteristics of PCBs in sediments in interaction with reactive activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyeok, E-mail: hchoi@uta.edu [Department of Civil Engineering, The University of Texas at Arlington, 416 Yates Street, Arlington, TX 76019-0308 (United States); Environmental and Earth Sciences Program, The University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019-0049 (United States); Lawal, Wasiu [Environmental and Earth Sciences Program, The University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019-0049 (United States); Al-Abed, Souhail R. [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 (United States)

    2015-04-28

    Highlights: • Problematic aged real PCBs-contaminated sediment (WHS) was examined. • Performance of reactive activated carbon (RAC) impregnated with Pd–ZVI was tested. • Fate and transport of PCBs bound to WHS in the presence of RAC was fully traced. • Direct mixing configuration was compared with compartment configuration. • Results reflected real world complexities associated with slow desorption of PCBs. - Abstract: Sediment (WHS) in Waukegan Harbor, Illinois, heavily contaminated and aged with polychlorinated biphenyls (PCBs), was treated with reactive activated carbon (RAC) impregnated with palladized iron nanoparticles. Lab test proceeded in a direct mixing configuration of RAC and WHS. A compartment configuration, where RAC was physically separated from WHS, was also designed to trace the sequential transport and fate of PCBs, including desorption, adsorption, dechlorination, and re-partitioning. PCBs, once desorbed from WHS, were immediately sequestrated to RAC and subject to dechlorination. Direct mixing of WHS with RAC was one-order of magnitude more effective for dechlorination than compartment configuration. Compared to their desorption-followed by-adsorption route, direct physical contact of RAC with PCBs bound to WHS exhibited negligible contribution to the availability of PCBs for dechlorination reaction. Addition of RAC even in compartment configuration facilitated PCBs desorption from WHS. However, slow desorption of PCBs limited overall performance, resulting in a five-order of magnitude lower dechlorination yield when compared with treatment of purely aqueous PCBs. The low dechlorination yield reflected real world complexities in treating 3.19% organic carbon-containing WHS aged with PCBs for 40 years. These observations were further supported when compared with results on clean Cesar Creek sediment spiked with 2-chlorinated biphenyls.

  10. Pattern evaporation process

    Directory of Open Access Journals (Sweden)

    Z. Żółkiewicz

    2007-04-01

    Full Text Available The paper discusses the process of thermal evaporation of a foundry pattern. At several research-development centres, studies have been carried out to examine the physico-chemical phenomena that take place in foundry mould filled with polystyrene pattern when it is poured with molten metal. In the technique of evaporative patterns, the process of mould filling with molten metal (the said mould holding inside a polystyrene pattern is interrelated with the process of thermal decomposition of this pattern. The transformation of an evaporative pattern (e.g. made from foamed polystyrene from the solid into liquid and then gaseous state occurs as a result of the thermal effect that the liquid metal exerts onto this pattern. Consequently, at the liquid metal-pattern-mould phase boundary some physico-chemical phenomena take place, which until now have not been fully explained. When the pattern is evaporating, some solid and gaseous products are evolved, e.g. CO, CO2, H2, N2, and hydrocarbons, e.g. styrene, toluene, ethane, methane, benzene [16, 23]. The process of polystyrene pattern evaporation in foundry mould under the effect of molten metal is of a very complex nature and depends on many different factors, still not fully investigated. The kinetics of pattern evaporation is also affected by the technological properties of foundry mould, e.g. permeability, thermophysical properties, parameters of the gating system, temperature of pouring, properties of pattern material, and the size of pattern-liquid metal contact surface.

  11. Embryonic turkey liver: activities of biotransformation enzymes and activation of DNA-reactive carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Perrone, Carmen E.; Duan, Jian Dong; Jeffrey, Alan M.; Williams, Gary M. [New York Medical College, Department of Pathology, Valhalla (United States); Ahr, Hans-Juergen; Schmidt, Ulrich [Bayer AG, Institute of Toxicology, Wuppertal (Germany); Enzmann, Harald H. [Federal Institute for Drugs and Medical Devices, Bonn (Germany)

    2004-10-01

    Avian embryos are a potential alternative model for chemical toxicity and carcinogenicity research. Because the toxic and carcinogenic effects of some chemicals depend on bioactivation, activities of biotransformation enzymes and formation of DNA adducts in embryonic turkey liver were examined. Biochemical analyses of 22-day in ovoturkey liver post-mitochondrial fractions revealed activities of the biotransformation enzymes 7-ethoxycoumarin de-ethylase (ECOD), 7-ethoxyresorufin de-ethylase (EROD), aldrin epoxidase (ALD), epoxide hydrolase (EH), glutathione S-transferase (GST), and UDP-glucuronyltransferase (GLUT). Following the administration of phenobarbital (24 mg/egg) on day 21, enzyme activities of ECOD, EROD, ALD, EH and GLUT, but not of GST, were increased by two-fold or higher levels by day 22. In contrast, acute administration of 3-methylcholanthrene (5 mg/egg) induced only ECOD and EROD activities. Bioactivation of structurally diverse pro-carcinogens was also examined using {sup 32}P-postlabeling for DNA adducts. In ovoexposure of turkey embryos on day 20 of gestation to 2-acetylaminofluorene (AAF), 4,4'-methylenebis(2-chloroaniline) (MOCA), benzo[a]pyrene (BaP), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) resulted in the formation of DNA adducts in livers collected by day 21. Some of the DNA adducts had {sup 32}P-postlabeling chromatographic migration patterns similar to DNA adducts found in livers from Fischer F344 rats exposed to the same pro-carcinogens. We conclude that 21-day embryonic turkey liver is capable of chemical biotransformation and activation of genotoxic carcinogens to form DNA adducts. Thus, turkey embryos could be utilized to investigate potential chemical toxicity and carcinogenicity. (orig.)

  12. Reactive oxygen species mediate TNFR1 increase after TRPV1 activation in mouse DRG neurons

    Directory of Open Access Journals (Sweden)

    Westlund Karin N

    2009-06-01

    Full Text Available Abstract Background Transient receptor potential vanilloid subtype 1 (TRPV1 is activated by low pH/protons and is well known to be involved in hyperalgesia during inflammation. Tumor necrosis factor α (TNF-α, a proinflammatory cytokine, is involved in nociceptive responses causing hyperalgesia through TNF receptor type 1 (TNFR1 activation. Reactive oxygen species (ROS production is also prominently increased in inflamed tissue. The present study investigated TNFR1 receptors in primary cultured mouse dorsal root ganglion (DRG neurons after TRPV1 activation and the involvement of ROS. C57BL/6 mice, both TRPV1 knockout and wild type, were used for immunofluorescent and live cell imaging. The L4 and L5 DRGs were dissected bilaterally and cultured overnight. TRPV1 was stimulated with capsaicin or its potent analog, resiniferatoxin. ROS production was measured with live cell imaging and TNFR1 was detected with immunofluorescence in DRG primary cultures. The TRPV1 knockout mice, TRPV1 antagonist, capsazepine, and ROS scavenger, N-tert-Butyl-α-phenylnitrone (PBN, were employed to explore the functional relationship among TRPV1, ROS and TNFR1 in these studies. Results The results demonstrate that TRPV1 activation increases TNFR1 receptors and ROS generation in primary cultures of mouse DRG neurons. Activated increases in TNFR1 receptors and ROS production are absent in TRPV1 deficient mice. The PBN blocks increases in TNFR1 and ROS production induced by capsaicin/resiniferatoxin. Conclusion TRPV1 activation increases TNFR1 in cultured mouse DRG neurons through a ROS signaling pathway, a novel sensitization mechanism in DRG neurons.

  13. New hybrid active power filter for harmonic current suppression and reactive power compensation

    Science.gov (United States)

    Biricik, Samet; Cemal Ozerdem, Ozgur; Redif, Soydan; Sezai Dincer, Mustafa

    2016-08-01

    In the case of undistorted and balanced grid voltages, low ratio shunt active power filters (APFs) can give unity power factors and achieve current harmonic cancellation. However, this is not possible when source voltages are distorted and unbalanced. In this study, the cost-effective hybrid active power filter (HAPF) topology for satisfying the requirements of harmonic current suppression and non-active power compensation for industry is presented. An effective strategy is developed to observe the effect of the placement of power capacitors and LC filters with the shunt APF. A new method for alleviating the negative effects of a nonideal grid voltage is proposed that uses a self-tuning filter algorithm with instantaneous reactive power theory. The real-time control of the studied system was achieved with a field-programmable gate array (FPGA) architecture, which was developed using the OPAL-RT system. The performance result of the proposed HAPF system is tested and presented under nonideal supply voltage conditions.

  14. Measurement based analysis of active and reactive power losses in a distribution network with wind farms and CHPs

    DEFF Research Database (Denmark)

    Lund, Torsten

    2007-01-01

    The paper presents an investigation of the active and reactive power losses in a distribution network with wind turbines and combined heat and power plants. The investigation is based on 15 min average power measurements and load flow calculations in the power system simulation tool Power......Factory®. Based on the measurements and simulations, a regressive model for calculation and allocation of active and reactive power losses has been derived. The influence of the covariance between load and production on the system losses is investigated separately....

  15. Anomalous behavior of visible light active TiO2 for the photocatalytic degradation of different Reactive dyes.

    Science.gov (United States)

    Kaur, Navneet; Shahi, Satwant Kaur; Singh, Vasundhara

    2015-11-01

    Nanocrystalline undoped, N-doped, N and metal codoped titania with different particle size, surface area, anatase phase content, crystallinity, band gap and zeta potential were synthesized by the sol-gel method. The photocatalytic activities of the synthesized TiO2 powders were compared by employing four different Reactive dyes. The order of photocatalytic activity observed for Reactive Red 198 dye (RR 198) was undoped = N,Cu codoped = N-doped > N,Fe codoped TiO2, Reactive Blue 4 dye (RB 4) was N,Cu codoped > N,Fe codoped > N-doped > undoped TiO2, Reactive Black 5 dye (RB 5) was N,Cu codoped* > undoped > N-doped > N,Fe codoped TiO2 and negligible degradation was observed for Reactive Orange 16 dye (RO 16). In this paper, the anomalous trend of the photocatalytic activity of various photocatalysts for the degradation of a particular class of dyes has been observed and accounted for based upon three parameters: mechanism of degradation, physicochemical properties of the catalyst and adsorption behavior based on the zeta potential. It was concluded that apart from these parameters, the substrate-specificity of the catalyst is also of equal importance in developing new catalysts for the photodegradation of dyes present in textile effluents.

  16. Evaporation in hydrology and meteorology

    NARCIS (Netherlands)

    Brandsma, T.

    1990-01-01

    In this paper the role of evaporation in hydrology and meteorology is discussed, with the emphasis on hydrology. The basic theory of evaporation is given and methods to determine evaporation are presented. Some applications of evaporation studies in literature are given in order to illustrate the th

  17. The moderating effect of physical activity on cardiovascular reactivity following single fat feedings.

    Science.gov (United States)

    Faulk, Kathryn E; Bartholomew, John B

    2012-01-01

    This experiment examined the effects of consuming a high-fat meal on cardiovascular reactivity and the ability of exercise to act as a moderator between dietary fat consumption and cardiovascular reactivity. Forty healthy, college-age students were randomly assigned to one of four experimental groups: (1) low-fat meal, no exercise; (2) low-fat meal, postprandial exercise; (3) high-fat meal, no exercise; and (4) high-fat meal, postprandial exercise. To induce stress, all participants performed a public speaking task, while heart rate and blood pressure reactivity were measured. Multilevel analyses revealed that consuming a high-fat meal led to heightened mean arterial pressure reactivity. Acute high-intensity exercise resulted in attenuated heart rate and mean arterial pressure reactivity. The results of this study offer insight into how diet and exercise may influence cardiovascular reactivity, which is a key determinant of cardiovascular disease.

  18. Reactive Oxygene Species and Thioredoxin Activity in Plants at Development of Hypergravity and Oxidative Stresses

    Science.gov (United States)

    Jadko, Sergiy

    Early increasing of reactive oxygen species (ROS) content, including H2O2, occurs in plant cells under various impacts and than these ROS can function as signaling molecules in starting of cell stress responses. At the same time thioredoxins (TR) are significant ROS and H2O2 sensors and transmitters to activation of various redox sensitive proteins, transcription factors and MAP kinases. This study was aimed to investigate early increasing of ROS and H2O2 contents and TR activity in the pea roots and in tissue culture under hypergravity and oxidative stresses. Pea roots of 3-5 days old seedlings and 12-14 days old tissue culture of Arabidopsis thaliana were studied. The pea seedlings were grown on wet filter paper and the tissue culture was grown on MS medium in dark conditions under 24oC. Hypergravity stress was induced by centrifugation at 10 and 15 g. Chemiluminescence (ChL) intensity for ROS concentration, H2O2 content and TR activity were determined. All experiments were repeated by 3-5 times. Early and reliable increasing of ChL intensity and H2O2 contents in the pea roots and in the tissue culture took place under hypergravity and oxidative stresses to 30, 60 and 90 min. At the same time TR activity increased on 11 and 19 percents only to 60 and 90 min. Thus under hypergravity and oxidative stresses in both investigated plants take place early increasing of ROS and H2O2 contents which as second messengers lead to increasing of TR activity with creating of ROS-TR stress signaling pathway.

  19. Reactive oxygen species-dependent RhoA activation mediates collagen synthesis in hyperoxic lung fibrosis.

    Science.gov (United States)

    Kondrikov, Dmitry; Caldwell, Ruth B; Dong, Zheng; Su, Yunchao

    2011-06-01

    Lung fibrosis is an ultimate consequence of pulmonary oxygen toxicity in human and animal models. Excessive production and deposition of extracellular matrix proteins, e.g., collagen-I, is the most important feature of pulmonary fibrosis in hyperoxia-induced lung injury. In this study, we investigated the roles of RhoA and reactive oxygen species (ROS) in collagen-I synthesis in hyperoxic lung fibroblasts and in a mouse model of oxygen toxicity. Exposure of human lung fibroblasts to hyperoxia resulted in RhoA activation and an increase in collagen-I synthesis and cell proliferation. Inhibition of RhoA by C3 transferase CT-04, dominant-negative RhoA mutant T19N, or RhoA siRNA prevented hyperoxia-induced collagen-I synthesis. The constitutively active RhoA mutant Q63L mimicked the effect of hyperoxia on collagen-I expression. Moreover, the Rho kinase inhibitor Y27632 inhibited collagen-I synthesis in hyperoxic lung fibroblasts and fibrosis in mouse lungs after oxygen toxicity. Furthermore, the ROS scavenger tiron attenuated hyperoxia-induced increases in RhoA activation and collagen-I synthesis in lung fibroblasts and mouse lungs after oxygen toxicity. More importantly, we found that hyperoxia induced separation of guanine nucleotide dissociation inhibitor (GDI) from RhoA in lung fibroblasts and mouse lungs. Further, tiron prevented the separation of GDI from RhoA in hyperoxic lung fibroblasts and mouse lungs with oxygen toxicity. Together, these results indicate that ROS-induced separation of GDI from RhoA leads to RhoA activation with oxygen toxicity. ROS-dependent RhoA activation is responsible for the increase in collagen-I synthesis in hyperoxic lung fibroblasts and mouse lungs.

  20. Reactive oxygen species scavenging activity of aminoderivatized chitosan with different degree of deacetylation.

    Science.gov (United States)

    Je, Jae-Young; Kim, Se-Kwon

    2006-09-01

    Chitosans with different degree of deacetylation were prepared from crab shell chitin in the presence of alkali. Aminoderivatized chitosan derivatives were prepared in addition of amino functional groups at a hydroxyl site in the chitosan backbone. Six kinds of aminoderivatized chitosan such as aminoethyl-chitosan (AEC90), dimethylaminoethyl-chitosan (DMAEC90), and diethylaminoethyl-chitosan (DEAEC90), which were prepared from 90% deacetylated chitosan, and AEC50, DMAEC50 and DEAEC50, which were prepared from 50% deacetylated chitosan, were prepared and their reactive oxygen species (ROS) scavenging activities were investigated against hydroxyl radical, superoxide anion radical and hydrogen peroxide. The electron spin resonance (ESR) spectrum revealed that AEC90 showed the highest scavenging effects against hydroxyl and superoxide anion radical, the effects were 91.67% and 65.34% at 0.25 and 5 mg/mL, respectively. For hydrogen peroxide scavenging effect, DEAEC90 exhibited the strongest activity. These results suggest that the scavenging effect depends on their degree of deacetylation and substituted group.

  1. Cytotoxic Effects of Re-Activated Lunar Dust Stimulant on Human Lung Cells

    Science.gov (United States)

    Upadhyaya, Krishna

    2009-01-01

    Lunar dust has been of significant concern due to various problems observed on the Apollo missions. Reports from astronauts have shown that the dust may have caused eye and nasal irritation as well as possible hay fever like symptoms. As NASA hopes to go to the Moon within the next few years, we hope to understand the possible toxic effects the dust might have. In these studies, we are looking at the effect of "re-activated" lunar dust stimulant on human bronchial cells. A simple grinding analog as a method of simulating micrometeorite crushing on the moon is used to "activate" the dust stimulant, i.e. capable of producing hydroxyl radicals. These radicals could then interact with human cells and may lead to a loss in membrane integrity and cell death. (Castranova, 1994) Cells are exposed to the dust for 6 and 24 hour intervals to assess cytotoxicity. Cytotoxicity is measured by looking at the production of inflammatory cytokines. Cells are exposed to ground and unground stimulant and compared to cytokine production from cells exposed to quartz which have a known toxicity. Here we look at the cytotoxicity of the lunar dust stimulant relative to quartz by measuring the production of inflammatory cytokines.

  2. Removal of reactive dyes from wastewater by adsorption on coir pith activated carbon.

    Science.gov (United States)

    Santhy, K; Selvapathy, P

    2006-07-01

    The removal efficiency of activated carbon prepared from coir pith towards three highly used reactive dyes in textile industry was investigated. Batch experiments showed that the adsorption of dyes increased with an increase in contact time and carbon dose. Maximum de-colorisation of all the dyes was observed at acidic pH. Adsorption of dyes was found to follow the Freundlich model. Kinetic studies indicated that the adsorption followed first order and the values of the Lagergren rate constants of the dyes were in the range of 1.77 x 10(-2)-2.69 x 10(-2)min(-1). The column experiments using granular form of the carbon (obtained by agglomeration with polyvinyl acetate) showed that adsorption efficiency increased with an increase in bed depth and decrease of flow rate. The bed depth service time (BDST) analysis carried out for the dyes indicated a linear relationship between bed depth and service time. The exhausted carbon could be completely regenerated and put to repeated use by elution with 1.0M NaOH. The coir pith activated carbon was not only effective in removal of colour but also significantly reduced COD levels of the textile wastewater.

  3. The criminal use of improvised and re-activated firearms in Great Britain and Northern Ireland.

    Science.gov (United States)

    Warlow, Thomas A

    2007-11-01

    Following the Hungerford Massacre the British Government imposed additional strict firearms legislation in 1988 that involved several classes of arms being placed into the prohibited category. By way of compensation a scheme was introduced to allow the unrestricted possession and transfer of the newly prohibited arms, other firearms and "prohibited weapons", if de-activated to a standard acceptable to the Secretary of State. Approved standards for firearm de-activation were drawn up in 1989. The inspection of the de-activated arms was devolved to the two Gun Barrel Proof Houses at London and Birmingham, as otherwise the task of inspecting the thousands of guns involved would have overloaded the firearms section at the Huntingdon Forensic Science Service Laboratory, who were already dealing with criminal firearms cases submitted by 41 of the 43 police forces throughout England and Wales, as well as providing technical assistance to the Home Office and Government Ministers. Members of the Gun Trade made representations to the Minister involved during the initial stages of setting up the official de-activation standards. This resulted in some measure of compromise in the range and nature of the de-activation requirements. Although it was clear that some individuals possessing the necessary skill and equipment might attempt to restore the odd weapon to a working condition, the scheme appeared to work reasonably well for the next few years. However, over the passage of time, criminal casework submissions to the Huntingdon Laboratory from industrial city areas along the M62 corridor of northern England revealed a steadily growing trend in the use of re-activated arms, which in a significant number of cases involved the use of fully automatic weapons. At first, the nature of the re-activation processes used to restore these arms was quite crude. However, with the passage of time a steady improvement in the machining and welding skills used by the some of the culprits

  4. An fMRI study of nicotine-deprived smokers' reactivity to smoking cues during novel/exciting activity.

    Directory of Open Access Journals (Sweden)

    Xiaomeng Xu

    Full Text Available Engaging in novel/exciting ("self-expanding" activities activates the mesolimbic dopamine pathway, a brain reward pathway also associated with the rewarding effects of nicotine. This suggests that self-expanding activities can potentially substitute for the reward from nicotine. We tested this model among nicotine-deprived smokers who, during fMRI scanning, played a series of two-player cooperative games with a relationship partner. Games were randomized in a 2 (self-expanding vs. not x 2 (cigarette cue present vs. absent design. Self-expansion conditions yielded significantly greater activation in a reward region (caudate than did non-self-expansion conditions. Moreover, when exposed to smoking cues during the self-expanding versus the non-self-expanding cooperative games, smokers showed less activation in a cigarette cue-reactivity region, a priori defined [temporo-parietal junction (TPJ] from a recent meta-analysis of cue-reactivity. In smoking cue conditions, increases in excitement associated with the self-expanding condition (versus the non-self-expanding condition were also negatively correlated with TPJ activation. These results support the idea that a self-expanding activity promoting reward activation attenuates cigarette cue-reactivity among nicotine-deprived smokers. Future research could focus on the parameters of self-expanding activities that produce this effect, as well as test the utility of self-expansion in clinical interventions for smoking cessation.

  5. Ferrocenes as potential chemotherapeutic drugs: synthesis, cytotoxic activity, reactive oxygen species production and micronucleus assay.

    Science.gov (United States)

    Pérez, Wanda I; Soto, Yarelys; Ortíz, Carmen; Matta, Jaime; Meléndez, Enrique

    2015-02-01

    Three new ferrocene complexes were synthesized with 4-(1H-pyrrol-1-yl)phenol group appended to one of the Cp ring. These are: 1,1'-4-(1H-pyrrol-1-yl)phenyl ferrocenedicarboxylate, ('Fc-(CO2-Ph-4-Py)2'), 1,4-(1H-pyrrol-1-yl)phenyl, 1'-carboxyl ferrocenecarboxylate ('Fc-(CO2-Ph-4-Py)CO2H') and 4-(1H-pyrrol-1-yl)phenyl ferroceneacetylate ('Fc-CH2CO2-Ph-4-Py'). The new species were characterized by standard analytical methods. Cyclic voltammetry experiments showed that Fc-CH2CO2-Ph-4-Py has redox potential very similar to the Fc/Fc(+) redox couple whereas Fc-(CO2-Ph-4-Py)2 and Fc-(CO2-Ph-4-Py)CO2H have redox potentials of over 400 mV higher than Fc/Fc(+) redox couple. The in vitro studies on Fc-(CO2-Ph-4-Py)2 and Fc-(CO2-Ph-4-Py)CO2H revealed that these two compounds have moderate anti-proliferative activity on MCF-7 breast cancer cell line. In contrast Fc-CH2CO2-Ph-4-Py which displayed low anti-proliferative activity. In the HT-29 colon cancer cell line, the new species showed low anti-proliferative activity. Cytokinesis-block micronucleus assay (CBMN) was performed on these ferrocenes and it was determined they induce micronucleus formation on binucleated cells and moderate genotoxic effects on the MCF-7 breast cancer cell line. There is a correlation between the IC50 values of the ferrocenes and the amount of micronucleus formation activity on binucleated cells and the reactive oxygen species (ROS) production on MCF-7 cell line.

  6. Early activation of STAT3 regulates reactive astrogliosis induced by diverse forms of neurotoxicity.

    Directory of Open Access Journals (Sweden)

    James P O'Callaghan

    Full Text Available Astrogliosis, a cellular response characterized by astrocytic hypertrophy and accumulation of GFAP, is a hallmark of all types of central nervous system (CNS injuries. Potential signaling mechanisms driving the conversion of astrocytes into "reactive" phenotypes differ with respect to the injury models employed and can be complicated by factors such as disruption of the blood-brain barrier (BBB. As denervation tools, neurotoxicants have the advantage of selective targeting of brain regions and cell types, often with sparing of the BBB. Previously, we found that neuroinflammation and activation of the JAK2-STAT3 pathway in astrocytes precedes up regulation of GFAP in the MPTP mouse model of dopaminergic neurotoxicity. Here we show that multiple mechanistically distinct mouse models of neurotoxicity (MPTP, AMP, METH, MDA, MDMA, KA, TMT engender the same neuroinflammatory and STAT3 activation responses in specific regions of the brain targeted by each neurotoxicant. The STAT3 effects seen for TMT in the mouse could be generalized to the rat, demonstrating cross-species validity for STAT3 activation. Pharmacological antagonists of the neurotoxic effects blocked neuroinflammatory responses, pSTAT3tyr705 and GFAP induction, indicating that damage to neuronal targets instigated astrogliosis. Selective deletion of STAT3 from astrocytes in STAT3 conditional knockout mice markedly attenuated MPTP-induced astrogliosis. Monitoring STAT3 translocation in GFAP-positive cells indicated that effects of MPTP, METH and KA on pSTAT3tyr705 were localized to astrocytes. These findings strongly implicate the STAT3 pathway in astrocytes as a broadly triggered signaling pathway for astrogliosis. We also observed, however, that the acute neuroinflammatory response to the known inflammogen, LPS, can activate STAT3 in CNS tissue without inducing classical signs of astrogliosis. Thus, acute phase neuroinflammatory responses and neurotoxicity-induced astrogliosis both

  7. Asian dust particles induce macrophage inflammatory responses via mitogen-activated protein kinase activation and reactive oxygen species production.

    Science.gov (United States)

    Higashisaka, Kazuma; Fujimura, Maho; Taira, Mayu; Yoshida, Tokuyuki; Tsunoda, Shin-ichi; Baba, Takashi; Yamaguchi, Nobuyasu; Nabeshi, Hiromi; Yoshikawa, Tomoaki; Nasu, Masao; Yoshioka, Yasuo; Tsutsumi, Yasuo

    2014-01-01

    Asian dust is a springtime meteorological phenomenon that originates in the deserts of China and Mongolia. The dust is carried by prevailing winds across East Asia where it causes serious health problems. Most of the information available on the impact of Asian dust on human health is based on epidemiological investigations, so from a biological standpoint little is known of its effects. To clarify the effects of Asian dust on human health, it is essential to assess inflammatory responses to the dust and to evaluate the involvement of these responses in the pathogenesis or aggravation of disease. Here, we investigated the induction of inflammatory responses by Asian dust particles in macrophages. Treatment with Asian dust particles induced greater production of inflammatory cytokines interleukin-6 and tumor necrosis factor- α (TNF- α ) compared with treatment with soil dust. Furthermore, a soil dust sample containing only particles ≤10  μ m in diameter provoked a greater inflammatory response than soil dust samples containing particles >10  μ m. In addition, Asian dust particles-induced TNF- α production was dependent on endocytosis, the production of reactive oxygen species, and the activation of nuclear factor- κ B and mitogen-activated protein kinases. Together, these results suggest that Asian dust particles induce inflammatory disease through the activation of macrophages.

  8. Asian Dust Particles Induce Macrophage Inflammatory Responses via Mitogen-Activated Protein Kinase Activation and Reactive Oxygen Species Production

    Directory of Open Access Journals (Sweden)

    Kazuma Higashisaka

    2014-01-01

    Full Text Available Asian dust is a springtime meteorological phenomenon that originates in the deserts of China and Mongolia. The dust is carried by prevailing winds across East Asia where it causes serious health problems. Most of the information available on the impact of Asian dust on human health is based on epidemiological investigations, so from a biological standpoint little is known of its effects. To clarify the effects of Asian dust on human health, it is essential to assess inflammatory responses to the dust and to evaluate the involvement of these responses in the pathogenesis or aggravation of disease. Here, we investigated the induction of inflammatory responses by Asian dust particles in macrophages. Treatment with Asian dust particles induced greater production of inflammatory cytokines interleukin-6 and tumor necrosis factor-α (TNF-α compared with treatment with soil dust. Furthermore, a soil dust sample containing only particles ≤10 μm in diameter provoked a greater inflammatory response than soil dust samples containing particles >10 μm. In addition, Asian dust particles-induced TNF-α production was dependent on endocytosis, the production of reactive oxygen species, and the activation of nuclear factor-κB and mitogen-activated protein kinases. Together, these results suggest that Asian dust particles induce inflammatory disease through the activation of macrophages.

  9. Activation of LVGCCs and CB1 Receptors Required for Destabilization of Reactivated Contextual Fear Memories

    Science.gov (United States)

    Suzuki, Akinobu; Mukawa, Takuya; Tsukagoshi, Akinori; Frankland, Paul W.; Kida, Satoshi

    2008-01-01

    Previous studies have shown that inhibiting protein synthesis shortly after reactivation impairs the subsequent expression of a previously consolidated fear memory. This has suggested that reactivation returns a memory to a labile state and that protein synthesis is required for the subsequent restabilization of memory. While the molecular…

  10. Modeling black hole evaporation

    CERN Document Server

    Fabbri, Alessandro

    2005-01-01

    The scope of this book is two-fold: the first part gives a fully detailed and pedagogical presentation of the Hawking effect and its physical implications, and the second discusses the backreaction problem, especially in connection with exactly solvable semiclassical models that describe analytically the black hole evaporation process. The book aims to establish a link between the general relativistic viewpoint on black hole evaporation and the new CFT-type approaches to the subject. The detailed discussion on backreaction effects is also extremely valuable.

  11. An easy method for the determination of active concentrations of cholinesterase reactivators in blood samples: Application to the efficacy assessment of non quaternary reactivators compared to HI-6 and pralidoxime in VX-poisoned mice.

    Science.gov (United States)

    Calas, André-Guilhem; Dias, José; Rousseau, Catherine; Arboléas, Mélanie; Touvrey-Loiodice, Mélanie; Mercey, Guillaume; Jean, Ludovic; Renard, Pierre-Yves; Nachon, Florian

    2016-03-10

    Organophosphorus nerve agents, like VX, are highly toxic due to their strong inhibition potency against acetylcholinesterase (AChE). AChE inhibited by VX can be reactivated using powerful nucleophilic molecules, most commonly oximes, which are one major component of the emergency treatment in case of nerve agent intoxication. We present here a comparative in vivo study on Swiss mice of four reactivators: HI-6, pralidoxime and two uncharged derivatives of 3-hydroxy-2-pyridinaldoxime that should more easily cross the blood-brain barrier and display a significant central nervous system activity. The reactivability kinetic profile of the oximes is established following intraperitoneal injection in healthy mice, using an original and fast enzymatic method based on the reactivation potential of oxime-containing plasma samples. HI-6 displays the highest reactivation potential whatever the conditions, followed by pralidoxime and the two non quaternary reactivators at the dose of 50 mg/kg bw. But these three last reactivators display equivalent reactivation potential at the same dose of 100 μmol/kg bw. Maximal reactivation potential closely correlates to surviving test results of VX intoxicated mice.

  12. Sustained Na+/H+ exchanger activation promotes gliotransmitter release from reactive hippocampal astrocytes following oxygen-glucose deprivation.

    Directory of Open Access Journals (Sweden)

    Pelin Cengiz

    Full Text Available Hypoxia ischemia (HI-related brain injury is the major cause of long-term morbidity in neonates. One characteristic hallmark of neonatal HI is the development of reactive astrogliosis in the hippocampus. However, the impact of reactive astrogliosis in hippocampal damage after neonatal HI is not fully understood. In the current study, we investigated the role of Na(+/H(+ exchanger isoform 1 (NHE1 protein in mouse reactive hippocampal astrocyte function in an in vitro ischemia model (oxygen/glucose deprivation and reoxygenation, OGD/REOX. 2 h OGD significantly increased NHE1 protein expression and NHE1-mediated H(+ efflux in hippocampal astrocytes. NHE1 activity remained stimulated during 1-5 h REOX and returned to the basal level at 24 h REOX. NHE1 activation in hippocampal astrocytes resulted in intracellular Na(+ and Ca(2+ overload. The latter was mediated by reversal of Na(+/Ca(2+ exchange. Hippocampal astrocytes also exhibited a robust release of gliotransmitters (glutamate and pro-inflammatory cytokines IL-6 and TNFα during 1-24 h REOX. Interestingly, inhibition of NHE1 activity with its potent inhibitor HOE 642 not only reduced Na(+ overload but also gliotransmitter release from hippocampal astrocytes. The noncompetitive excitatory amino acid transporter inhibitor TBOA showed a similar effect on blocking the glutamate release. Taken together, we concluded that NHE1 plays an essential role in maintaining H(+ homeostasis in hippocampal astrocytes. Over-stimulation of NHE1 activity following in vitro ischemia disrupts Na(+ and Ca(2+ homeostasis, which reduces Na(+-dependent glutamate uptake and promotes release of glutamate and cytokines from reactive astrocytes. Therefore, blocking sustained NHE1 activation in reactive astrocytes may provide neuroprotection following HI.

  13. Deposition of Visible Light Active Photocatalytic Bismuth Molybdate Thin Films by Reactive Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Marina Ratova

    2016-01-01

    Full Text Available Bismuth molybdate thin films were deposited by reactive magnetron co-sputtering from two metallic targets in an argon/oxygen atmosphere, reportedly for the first time. Energy dispersive X-ray spectroscopy (EDX analysis showed that the ratio of bismuth to molybdenum in the coatings can be effectively controlled by varying the power applied to each target. Deposited coatings were annealed in air at 673 K for 30 min. The crystalline structure was assessed by means of Raman spectroscopy and X-ray diffraction (XRD. Oxidation state information was obtained by X-ray photoelectron spectroscopy (XPS. Photodegradation of organic dyes methylene blue and rhodamine B was used for evaluation of the photocatalytic properties of the coatings under a visible light source. The photocatalytic properties of the deposited coatings were then compared to a sample of commercial titanium dioxide-based photocatalytic product. The repeatability of the dye degradation reactions and photocatalytic coating reusability are discussed. It was found that coatings with a Bi:Mo ratio of approximately 2:1 exhibited the highest photocatalytic activity of the coatings studied; its efficacy in dye photodegradation significantly outperformed a sample of commercial photocatalytic coating.

  14. Oxidative modification of rat liver 5'-nucleotidase: the mechanisms for protection and re-activation.

    Science.gov (United States)

    Kocic, G; Pavlovic, D; Jevtovic, T; Kocic, R; Bojic, A; Vlahovic, P; Djordjevic, V; Sokolovic, D; Djindjic, B

    2001-10-01

    The effect of oxidative stress catalysed by transition metals appears to have a critical relevance for the structure and function not only of membrane lipids but also of integral membrane proteins in a complex lipid-protein assembling, and membrane-dependent function. The integral membrane enzyme 5'-nucleotidase is susceptible to Fe((2+))-ion catalysed oxidative modification, and the extent of enzyme inhibition is in inverse relationship (r = -0.820) with lipid peroxidation (MDA) level. This work is also a comparative study about possible effectiveness of different Fe-ion chelators (deferoxamine, Na-citrate, Na-salicylate, ammonium oxalate and EDTA), antioxidants (GSH, GSH/GSH-Px system, Cu, Zn-SOD and mannitol) and metal cations (Mg(2+) and Mn(2+)) to protect or restore Fe(2+)-ion induced 5'-nucleotidase inhibition and to suppress Fe(2+)-ion enhanced lipid peroxidation. Among the examined chelators it was only deferoxamine and Na-citrate that exerted a fully protective and reactivating ability; among the antioxidants it was only GSH; among the metal cations it was only Mn(2+). The ability to protect or restore 5'-nucleotidase activity and to diminish chain-induced lipid peroxidation is explicable in terms of: metal-binding ability, capacity of taking iron away from a biological molecule, or ability of transferring the damage to itself. After a short incubation period, the iron associated with enzyme or lipid hydroperoxides could be in a labile coordinative linkage, still able to interact with possible ligands or metal cations.

  15. ADENOSINE DEAMINASE ACTIVITY AND SERUM C-REACTIVE PROTEIN AS PROGNOSTIC MARKERS OF CHAGAS DISEASE SEVERITY

    Directory of Open Access Journals (Sweden)

    Iván Darío BRAVO-TOBAR

    2015-10-01

    Full Text Available SUMMARY Chagas disease is a public health problem worldwide. The availability of diagnostic tools to predict the development of chronic Chagas cardiomyopathy is crucial to reduce morbidity and mortality. Here we analyze the prognostic value of adenosine deaminase serum activity (ADA and C-reactive protein serum levels (CRP in chagasic individuals. One hundred and ten individuals, 28 healthy and 82 chagasic patients were divided according to disease severity in phase I (n = 35, II (n = 29, and III (n = 18. A complete medical history, 12-lead electrocardiogram, chest X-ray, and M-mode echocardiogram were performed on each individual. Diagnosis of Chagas disease was confirmed by ELISA and MABA using recombinant antigens; ADA was determined spectrophotometrically and CRP by ELISA. The results have shown that CRP and ADA increased linearly in relation to disease phase, CRP being significantly higher in phase III and ADA at all phases. Also, CRP and ADA were positively correlated with echocardiographic parameters of cardiac remodeling and with electrocardiographic abnormalities, and negatively with ejection fraction. CRP and ADA were higher in patients with cardiothoracic index ≥ 50%, while ADA was higher in patients with ventricular repolarization disturbances. Finally, CRP was positively correlated with ADA. In conclusion, ADA and CRP are prognostic markers of cardiac dysfunction and remodeling in Chagas disease.

  16. Oscillatory brain activity related to control mechanisms during laboratory-induced reactive aggression

    Directory of Open Access Journals (Sweden)

    Ulrike M Krämer

    2009-11-01

    Full Text Available Aggressive behavior is a common reaction in humans after an interpersonal provocation, but little is known about the underlying brain mechanisms. The present study analyzed oscillatory brain activity while participants were involved in an aggressive interaction to examine the neural processes subserving the associated decision and evaluation processes. Participants were selected from a larger sample because of their high scores in trait aggressiveness. We used a competitive reaction time task that induces aggressive behavior through provocation. Each trial is separated in a decision phase, during which the punishment for the opponent is set, and an outcome phase, during which the actual punishment is applied or received. We observed provocation-related differences during the decision phase in the theta band which differed depending on participants’ aggressive behavior: High provocation was associated with an increased frontal theta response in participants refraining from retaliation, but with reduced theta power in those who got back to the opponent. Moreover, more aggressive decisions after being punished were associated with a decrease of frontal theta power. Non-aggressive and aggressive participants differed also in their outcome-related response: Being punished led to an increased frontal theta power compared to win trials in the latter only, pointing to differences in evaluation processes associated with their different behavioral reactions. The data thus support previous evidence for a role of prefrontal areas in the control of reactive aggression and extend behavioral studies on associations between aggression or violence and impaired prefrontal functions.

  17. DNA binding, anti-tumour activity and reactivity toward cell thiols of acridin-9-ylalkenoic derivatives

    Indian Academy of Sciences (India)

    O Salem; M Vilkova; J Plsikova; A Grolmusova; M Burikova; M Prokaiova; H Paulikova; J Imrich; M Kozurkova

    2015-05-01

    In this paper, we describe the synthesis, biochemical properties and biological activity of a series of new 9-substituted acridine derivatives with a reactive alkene moiety: 9-[(E)-2-phenylethenyl] acridine (1) and methyl (2E)-3-(acridin-9-yl)-prop-2-enoate (2). The interaction of derivatives 1 and 2 with calf thymus DNA was investigated using UV-Vis, fluorescence and circular dichroism spectroscopy. The binding constants K were estimated as being in the range of 1.9 to 7.1 × 105 M−1, and the percentage of hypochromism was found to be 40–57% (from spectral titration). UV-Vis, fluorescence, and CD measurements indicate that the compounds were effective DNA-intercalating agents. Electrophoretic separation proved that ligands 1 and 2 relaxed topoisomerase I at a concentration of 5 M. Ester 2 was shown to have a stronger cytostatic effect on leukemia cell line L1210 than alkene 1. The incubation of ligands 1 and 2 with the ovarian carcinoma cell line A2780 confirmed their extensive cytotoxic effects, an effect which was particularly pronounced in the case of ligand 2. Cytotoxicity tests against A2780 cells demonstrate that a conjugate of compound 2 with -cysteine (3) is less cytotoxic than compound 2, especially at concentrations greater than 10 M.

  18. ADENOSINE DEAMINASE ACTIVITY AND SERUM C-REACTIVE PROTEIN AS PROGNOSTIC MARKERS OF CHAGAS DISEASE SEVERITY

    Science.gov (United States)

    BRAVO-TOBAR, Iván Darío; NELLO-PÉREZ, Carlota; FERNÁNDEZ, Alí; MOGOLLÓN, Nora; PÉREZ, Mary Carmen; VERDE, Juan; CONCEPCIÓN, Juan Luis; RODRIGUEZ-BONFANTE, Claudina; BONFANTE-CABARCAS, Rafael

    2015-01-01

    SUMMARY Chagas disease is a public health problem worldwide. The availability of diagnostic tools to predict the development of chronic Chagas cardiomyopathy is crucial to reduce morbidity and mortality. Here we analyze the prognostic value of adenosine deaminase serum activity (ADA) and C-reactive protein serum levels (CRP) in chagasic individuals. One hundred and ten individuals, 28 healthy and 82 chagasic patients were divided according to disease severity in phase I (n = 35), II (n = 29), and III (n = 18). A complete medical history, 12-lead electrocardiogram, chest X-ray, and M-mode echocardiogram were performed on each individual. Diagnosis of Chagas disease was confirmed by ELISA and MABA using recombinant antigens; ADA was determined spectrophotometrically and CRP by ELISA. The results have shown that CRP and ADA increased linearly in relation to disease phase, CRP being significantly higher in phase III and ADA at all phases. Also, CRP and ADA were positively correlated with echocardiographic parameters of cardiac remodeling and with electrocardiographic abnormalities, and negatively with ejection fraction. CRP and ADA were higher in patients with cardiothoracic index ≥ 50%, while ADA was higher in patients with ventricular repolarization disturbances. Finally, CRP was positively correlated with ADA. In conclusion, ADA and CRP are prognostic markers of cardiac dysfunction and remodeling in Chagas disease. PMID:26603224

  19. Noninvasive bioluminescence imaging of the dynamics of sanguinarine induced apoptosis via activation of reactive oxygen species.

    Science.gov (United States)

    Wang, Yan; Zhang, Beilei; Liu, Wei; Dai, Yunpeng; Shi, Yaru; Zeng, Qi; Wang, Fu

    2016-04-19

    Most chemotherapeutic drugs exert their anti-tumor effects primarily by triggering a final pathway leading to apoptosis. Noninvasive imaging of apoptotic events in preclinical models would greatly facilitate the development of apoptosis-inducing compounds and evaluation of their therapeutic efficacy. Here we employed a cyclic firefly luciferase (cFluc) reporter to screen potential pro-apoptotic compounds from a number of natural agents. We demonstrated that sanguinarine (SANG) could induce apoptosis in a dose- and time-dependent manner in UM-SCC-22B head and neck cancer cells. Moreover, SANG-induced apoptosis was associated with the generation of reactive oxygen species (ROS) and activation of c-Jun-N-terminal kinase (JNK) and nuclear factor-kappaB (NF-κB) signal pathways. After intravenous administration with SANG in 22B-cFluc xenograft models, a dramatic increase of luminescence signal can be detected as early as 48 h post-treatment, as revealed by longitudinal bioluminescence imaging in vivo. Remarkable apoptotic cells reflected from ex vivo TUNEL staining confirmed the imaging results. Importantly, SANG treatment caused distinct tumor growth retardation in mice compared with the vehicle-treated group. Taken together, our results showed that SANG is a candidate anti-tumor drug and noninvasive imaging of apoptosis using cFluc reporter could provide a valuable tool for drug development and therapeutic efficacy evaluation.

  20. A new class of radiation-activating antitumor prodrugs releasing 5-fluorodeoxyuridine: synthesis, reactivity and biological activity

    Energy Technology Data Exchange (ETDEWEB)

    Sakakibara, S.; Zhou, L.; Mori, M.; Hatta, H.; Nishimoto, S. [Department of Energy and Hydrocarbon Chemistry, Kyoto Univ., Kyoto (Japan); Shibamoto, Y. [Kyoto Univ., Institute for Frontier Medical Science, Kyoto (Japan)

    2000-03-01

    A number of 3-substituted 5-fluorodeoxyuridine (5-FdUrd) derivatives (1-6) were synthesized to evaluate their radiation reactivity and biological activity as a new class of prodrugs that can be radiation-activated to release 5-FdUrd. The compounds 2-6 bearing substituents with a 2-oxo group underwent radiolytic reduction to release 5-FdUrd in considerably high yields under anoxic conditions, while the compound 1 without 2-oxo substituent was inactive in releasing 5-FdUrd. The cytotoxicities of 2-6 toward P388 T cells of mouse leukemia were less than 5-FdUrd, as indicated by an MTT assay. The apparent cytotoxicities were significantly enhanced by X-irradiation under hypoxic conditions. A conclusion was that 2-6 have no antitumor effect in contrast to 5-FdUrd, but can potentiate the effect of cancer radiotherapy by releasing a cell-killing component 5-FdUrd. (author)

  1. Passive evaporative cooling

    NARCIS (Netherlands)

    Tzoulis, A.

    2011-01-01

    This "designers' manual" is made during the TIDO-course AR0531 Smart & Bioclimatic Design. Passive techniques for cooling are a great way to cope with the energy problem of the present day. This manual introduces passive cooling by evaporation. These methods have been used for many years in traditi

  2. Evaporation/Hadronization Correspondence

    CERN Document Server

    Allahbakhshi, Davood

    2016-01-01

    A holographic duality is proposed between black hole evaporation in the bulk and hadronization (confinement) in dual field theory. Information paradox is discussed in this duality. We also propose that the recently introduced semi black brane solution is holographically dual to a mixed plasma of quarks, gluons and hadrons in global equilibrium.

  3. Evaporation into Couette Flow

    Science.gov (United States)

    2008-01-01

    v Yi Statistical analysis dependent variable Greek Symbols 13 Contact angle of sessile drop a Concentration thickness A Evaporated vapor penetration...31 5 FIGURES 1. Configuration of Three Sessile Drops ............................................. 10 2. Sketch of...Droplet Geometry ............................................................. 11 3. Shape Factor as a Function of Contact Angle

  4. Advanced Chemical Reduction of Reduced Graphene Oxide and Its Photocatalytic Activity in Degrading Reactive Black 5

    Directory of Open Access Journals (Sweden)

    Christelle Pau Ping Wong

    2015-10-01

    Full Text Available Textile industries consume large volumes of water for dye processing, leading to undesirable toxic dyes in water bodies. Dyestuffs are harmful to human health and aquatic life, and such illnesses as cholera, dysentery, hepatitis A, and hinder the photosynthetic activity of aquatic plants. To overcome this environmental problem, the advanced oxidation process is a promising technique to mineralize a wide range of dyes in water systems. In this work, reduced graphene oxide (rGO was prepared via an advanced chemical reduction route, and its photocatalytic activity was tested by photodegrading Reactive Black 5 (RB5 dye in aqueous solution. rGO was synthesized by dispersing the graphite oxide into the water to form a graphene oxide (GO solution followed by the addition of hydrazine. Graphite oxide was prepared using a modified Hummers’ method by using potassium permanganate and concentrated sulphuric acid. The resulted rGO nanoparticles were characterized using ultraviolet-visible spectrophotometry (UV-Vis, X-ray powder diffraction (XRD, Raman, and Scanning Electron Microscopy (SEM to further investigate their chemical properties. A characteristic peak of rGO-48 h (275 cm−1 was observed in the UV spectrum. Further, the appearance of a broad peak (002, centred at 2θ = 24.1°, in XRD showing that graphene oxide was reduced to rGO. Based on our results, it was found that the resulted rGO-48 h nanoparticles achieved 49% photodecolorization of RB5 under UV irradiation at pH 3 in 60 min. This was attributed to the high and efficient electron transport behaviors of rGO between aromatic regions of rGO and RB5 molecules.

  5. Reactive magnetron sputtering deposition of bismuth tungstate onto titania nanoparticles for enhancing visible light photocatalytic activity

    Science.gov (United States)

    Ratova, Marina; Kelly, Peter J.; West, Glen T.; Tosheva, Lubomira; Edge, Michele

    2017-01-01

    Titanium dioxide - bismuth tungstate composite materials were prepared by pulsed DC reactive magnetron sputtering of bismuth and tungsten metallic targets in argon/oxygen atmosphere onto anatase and rutile titania nanoparticles. The use of an oscillating bowl placed beneath the two magnetrons arranged in a co-planar closed field configuration enabled the deposition of bismuth tungstate onto loose powders, rather than a solid substrate. The atomic ratio of the bismuth/tungsten coatings was controlled by varying the power applied to each target. The effect of the bismuth tungstate coatings on the phase, optical and photocatalytic properties of titania was investigated by X-ray diffraction, energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET) surface area measurements, transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy and an acetone degradation test. The latter involved measurements of the rate of CO2 evolution under visible light irradiation of the photocatalysts, which indicated that the deposition of bismuth tungstate resulted in a significant enhancement of visible light activity, for both anatase and rutile titania particles. The best results were achieved for coatings with a bismuth to tungsten atomic ratio of 2:1. In addition, the mechanism by which the photocatalytic activity of the TiO2 nanoparticles was enhanced by compounding it with bismuth tungstate was studied by microwave cavity perturbation. The results of these tests confirmed that such enhancement of the photocatalytic properties is due to more efficient photogenerated charge carrier separation, as well as to the contribution of the intrinsic photocatalytic properties of Bi2WO6.

  6. Production and characterization of activated carbon prepared from safflower seed cake biochar and its ability to absorb reactive dyestuff

    Energy Technology Data Exchange (ETDEWEB)

    Angın, Dilek, E-mail: angin@sakarya.edu.tr [Department of Food Engineering, Faculty of Engineering, Sakarya University, Sakarya (Turkey); Köse, T. Ennil, E-mail: ennilb@ogu.edu.tr [Department of Chemical Engineering, Faculty of Engineering and Architecture, Eskisehir Osmangazi University, 26480 Meselik-Eskisehir (Turkey); Selengil, Uğur, E-mail: uselen@ogu.edu.tr [Department of Chemical Engineering, Faculty of Engineering and Architecture, Eskisehir Osmangazi University, 26480 Meselik-Eskisehir (Turkey)

    2013-09-01

    The use of activated carbon obtained from biochar for the removal of reactive dyestuff from aqueous solutions at various contact times, pHs and temperatures was investigated. The biochar was chemically modified with potassium hydroxide. The surface area and micropore volume of activated carbon was 1277 m{sup 2}/g and 0.4952 cm{sup 3}/g, respectively. The surface characterization of both biochar and activated carbon was undertaken using by Fourier transform infrared spectroscopy and scanning electron microscopy. The experimental data indicated that the adsorption isotherms are well described by the Dubinin–Radushkevich (DR) isotherm equation. The adsorption kinetics of reactive dyestuff obeys the pseudo second-order kinetic model. The thermodynamic parameters such as ΔG{sup o}, ΔH{sup o} and ΔS{sup o} were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 1.12 kJ/mol. According to these results, prepared activated carbon could be used as a low-cost adsorbent to compare with the commercial activated carbon for the removal reactive dyestuff from waste water.

  7. Antibacterial activity of reactive quaternary ammonium compounds in solution and in nonleachable coatings

    NARCIS (Netherlands)

    Gozzelino, G.; Romero Tobar, D.E.; Chaitiemwong, N.; Hazeleger, W.C.; Beumer, R.R.

    2011-01-01

    Antibacterial polymers suitable for coating applications without leaching of the biocidal component have been obtained by UV copolymerization of acrylic resins with acrylic monomers containing quaternary ammonium moieties. Suitable reactive biocides, based on quaternary ammonium monomers (QAMs), end

  8. Voltage/Pitch Control for Maximization and Regulation of Active/Reactive Powers in Wind Turbines with Uncertainties

    CERN Document Server

    Guo, Yi; Jiang, John N; Tang, Choon Yik; Ramakumar, Rama G

    2010-01-01

    This paper addresses the problem of controlling a variable-speed wind turbine with a Doubly Fed Induction Generator (DFIG), modeled as an electromechanically-coupled nonlinear system with rotor voltages and blade pitch angle as its inputs, active and reactive powers as its outputs, and most of the aerodynamic and mechanical parameters as its uncertainties. Using a blend of linear and nonlinear control strategies (including feedback linearization, pole placement, uncertainty estimation, and gradient-based potential function minimization) as well as time-scale separation in the dynamics, we develop a controller that is capable of maximizing the active power in the Maximum Power Tracking (MPT) mode, regulating the active power in the Power Regulation (PR) mode, seamlessly switching between the two modes, and simultaneously adjusting the reactive power to achieve a desired power factor. The controller consists of four cascaded components, uses realistic feedback signals, and operates without knowledge of the C_p-...

  9. Prevention of a systematic underestimation of antioxidant activity in competition assays. The impact of unspecific reactions of the reactive species.

    Science.gov (United States)

    Beljaars, Christiaan P; Balk, Jiska M; Bast, Aalt; Haenen, Guido R M M

    2010-02-12

    In antioxidant competition assays, an antioxidant (A) and a detector compound (D) compete for a reactive species (R). In the evaluation of these assays, it is tacitly assumed that all of R is captured by either D or A. Due to the - by definition - high reactivity of R, unspecific reactions of R are likely to occur and neglecting these reactions will result in a systematic underestimation of antioxidant activity. It was shown that in the standard hydroxyl radical scavenging assay this was indeed the case; the inaccurate mathematical evaluation resulted in an underestimation of antioxidant activity of 25% in this competition assay. The systematic underestimation of antioxidant activity can be prevented by using an adjusted Stern-Volmer equation that takes into account that only part of R is captured by D or A.

  10. Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    Sindhu M R

    2014-12-01

    Full Text Available Variable speed drives are mostly preferred in industries, while considering energy saving, smooth control, flexible operation and fast response. On the other hand, this equipment generates dynamic harmonic distortions in source currents and draws variable reactive power demand depending on variation in load condition. These distortions propagate throughout the system and affect all the loads connected to the point of common coupling. Hence a dynamic harmonic and reactive compensator is necessary to enhance power quality to meet current and voltage distortion limits at point of common coupling as per IEEE standard. The most common choice for adjustable speed drives in industries is three phase voltage source inverter based induction motor drives which uses PWM technique for voltage, frequency and current control. This paper presents harmonic analysis of an induction motor drive in an industrial plant and development of adaptive dynamic harmonic and reactive compensator to improve power quality. A digital controller which is programmed with adaptive Artificial Neural Network (ANN based control algorithm is used for controlling shunt active filter. The simulation and experimental results show that the adaptive shunt active filter provides effective harmonic and reactive compensation in the system under steady state and dynamic load conditions.

  11. Evaluation of novel reactive MgO activated slag binder for the immobilisation of lead and zinc.

    Science.gov (United States)

    Jin, Fei; Al-Tabbaa, Abir

    2014-12-01

    Although Portland cement is the most widely used binder in the stabilisation/solidification (S/S) processes, slag-based binders have gained significant attention recently due to their economic and environmental merits. In the present study, a novel binder, reactive MgO activated slag, is compared with hydrated lime activated slag in the immobilisation of lead and zinc. A series of lead or zinc-doped pastes and mortars were prepared with metal to binder ratio from 0.25% to 1%. The hydration products and microstructure were studied by X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. The major hydration products were calcium silicate hydrate and hydrotalcite-like phases. The unconfined compressive strength was measured up to 160 d. Findings show that lead had a slight influence on the strength of MgO-slag paste while zinc reduced the strength significantly as its concentration increased. Leachate results using the TCLP tests revealed that the immobilisation degree was dependent on the pH and reactive MgO activated slag showed an increased pH buffering capacity, and thus improved the immobilisation efficiency compared to lime activated slag. It was proposed that zinc was mainly immobilised within the structure of the hydrotalcite-like phases or in the form of calcium zincate, while lead was primarily precipitated as the hydroxide. It is concluded, therefore, that reactive MgO activated slag can serve as clinker-free alternative binder in the S/S process.

  12. Toward Effective HIV Vaccination INDUCTION OF BINARY EPITOPE REACTIVE ANTIBODIES WITH BROAD HIV NEUTRALIZING ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, Yasuhiro; Planque, Stephanie; Mitsuda, Yukie; Nitti, Giovanni; Taguchi, Hiroaki; Jin, Lei; Symersky, Jindrich; Boivin, Stephane; Sienczyk, Marcin; Salas, Maria; Hanson, Carl V.; Paul, Sudhir; (Texas-MED); (Viral Rickettsial)

    2009-11-23

    We describe murine monoclonal antibodies (mAbs) raised by immunization with an electrophilic gp120 analog (E-gp120) expressing the rare ability to neutralize genetically heterologous human immunodeficiency virus (HIV) strains. Unlike gp120, E-gp120 formed covalent oligomers. The reactivity of gp120 and E-gp120 with mAbs to reference neutralizing epitopes was markedly different, indicating their divergent structures. Epitope mapping with synthetic peptides and electrophilic peptide analogs indicated binary recognition of two distinct gp120 regions by anti-E-gp120 mAbs, the 421-433 and 288-306 peptide regions. Univalent Fab and single chain Fv fragments expressed the ability to recognize both peptides. X-ray crystallography of an anti-E-gp120 Fab fragment revealed two neighboring cavities, the typical antigen-binding cavity formed by the complementarity determining regions (CDRs) and another cavity dominated by antibody heavy chain variable (VH) domain framework (FR) residues. Substitution of the FR cavity VH Lys-19 residue by an Ala residue resulted in attenuated binding of the 421-433 region peptide probe. The CDRs and VH FR replacement/silent mutation ratios exceeded the ratio for a random mutation process, suggesting adaptive development of both putative binding sites. All mAbs studied were derived from VH1 family genes, suggesting biased recruitment of the V gene germ line repertoire by E-gp120. The conserved 421-433 region of gp120 is essential for HIV binding to host CD4 receptors. This region is recognized weakly by the FR of antibodies produced without exposure to HIV, but it usually fails to induce adaptive synthesis of neutralizing antibodies. We present models accounting for improved CD4-binding site recognition and broad HIV neutralizing activity of the mAbs, long sought goals in HIV vaccine development.

  13. Cost of reactive nitrogen release from human activities to the environment in the United States

    Science.gov (United States)

    Sobota, Daniel J.; Compton, Jana E.; McCrackin, Michelle L.; Singh, Shweta

    2015-02-01

    Leakage of reactive nitrogen (N) from human activities to the environment can cause human health and ecological problems. Often these harmful effects are not reflected in the costs of food, fuel, and fiber that derive from N use. Spatial analyses of damage costs attributable to source at management-relevant scales could inform decisions in areas where anthropogenic N leakage causes harm. We used recently compiled data describing N inputs in the conterminous United States (US) to assess potential damage costs associated with anthropogenic N. We estimated fates of N leaked to the environment (air/deposition, surface freshwater, groundwater, and coastal zones) in the early 2000s by multiplying watershed-level N inputs (8-digit US Geologic Survey Hydrologic Unit Codes; HUC8s) with published coefficients describing nutrient uptake efficiency, leaching losses, and gaseous emissions. We scaled these N leakage estimates with mitigation, remediation, direct damage, and substitution costs associated with human health, agriculture, ecosystems, and climate (per kg of N) to calculate annual damage cost (US dollars in 2008 or as reported) of anthropogenic N per HUC8. Estimates of N leakage by HUC8 ranged from effects of atmospheric N pollution were important across HUC8s. However, significant data gaps remain in our ability to fully assess N damages, such as damage costs from harmful algal blooms and drinking water contamination. Nationally, potential health and environmental damages of anthropogenic N in the early 2000s totaled 210 billion yr-1 USD (range: 81-441 billion yr-1). While a number of gaps and uncertainties remain in these estimates, overall this work represents a starting point to inform decisions and engage stakeholders on the costs of N pollution.

  14. Loss of receptor on tuberculin-reactive T-cells marks active pulmonary tuberculosis.

    Directory of Open Access Journals (Sweden)

    Mathias Streitz

    Full Text Available BACKGROUND: Tuberculin-specific T-cell responses have low diagnostic specificity in BCG vaccinated populations. While subunit-antigen (e.g. ESAT-6, CFP-10 based tests are useful for diagnosing latent tuberculosis infection, there is no reliable immunological test for active pulmonary tuberculosis. Notably, all existing immunological tuberculosis-tests are based on T-cell response size, whereas the diagnostic potential of T-cell response quality has never been explored. This includes surface marker expression and functionality of mycobacterial antigen specific T-cells. METHODOLOGY/PRINCIPAL FINDINGS: Flow-cytometry was used to examine over-night antigen-stimulated T-cells from tuberculosis patients and controls. Tuberculin and/or the relatively M. tuberculosis specific ESAT-6 protein were used as stimulants. A set of classic surface markers of T-cell naïve/memory differentiation was selected and IFN-gamma production was used to identify T-cells recognizing these antigens. The percentage of tuberculin-specific T-helper-cells lacking the surface receptor CD27, a state associated with advanced differentiation, varied considerably between individuals (from less than 5% to more than 95%. Healthy BCG vaccinated individuals had significantly fewer CD27-negative tuberculin-reactive CD4 T-cells than patients with smear and/or culture positive pulmonary tuberculosis, discriminating these groups with high sensitivity and specificity, whereas individuals with latent tuberculosis infection exhibited levels in between. CONCLUSIONS/SIGNIFICANCE: Smear and/or culture positive pulmonary tuberculosis can be diagnosed by a rapid and reliable immunological test based on the distribution of CD27 expression on peripheral blood tuberculin specific T-cells. This test works very well even in a BCG vaccinated population. It is simple and will be of great utility in situations where sputum specimens are difficult to obtain or sputum-smear is negative. It will also help

  15. Aging Enhances the Production of Reactive Oxygen Species and Bactericidal Activity in Peritoneal Macrophages by Upregulating Classical Activation Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Smallwood, Heather S.; López-Ferrer, Daniel; Squier, Thomas C.

    2011-10-07

    . Collectively, these results indicate that macrophages isolated from old mice are in a preactivated state that enhances their sensitivities to LPS exposure. The hyper-responsive activation of macrophages in aged animals may act to minimize infection by general bacterial threats that arise due to age-dependent declines in adaptive immunity. Finally, however, this hypersensitivity and the associated increase in the level of formation of reactive oxygen species are likely to contribute to observed age-dependent increases in the level of oxidative damage that underlie many diseases of the elderly.

  16. PARTICLE DEPOSITION ON SUPERHYDROPHOBIC SURFACES BY SESSILE DROPLET EVAPORATION

    OpenAIRE

    Dicuangco, Mercy G.

    2014-01-01

    Prediction and active control of the spatial distribution of particulate deposits obtained from sessile droplet evaporation is essential in ink-jet printing, nanostructure assembly, biotechnology, and other applications that require localized deposits. In recent years, sessile droplet evaporation on bio-inspired superhydrophobic surfaces has become an attractive method for depositing materials on a site-specific, localized region, but is less explored compared to evaporative deposition on hyd...

  17. Climate analysis of evaporation ducts in the South China Sea

    OpenAIRE

    McKeon, Brian D.

    2013-01-01

    Approved for public release; distribution is unlimited. Evaporation ducts have important implications for U.S. Naval activities involving electromagnetic propagation. The presence of an evaporation duct can affect naval operations involving communications, surveillance, electronic warfare, and detection of low-flying missiles, surface ships, or submarine periscopes. We conducted a climate scale analysis of evaporation duct heights (EDH) in the northern South China Sea (SCS), including how ...

  18. Monitoring exposure of northern cardinals, Cardinalis cardinalis, to cholinesterase-inhibiting pesticides: enzyme activity, reactivations, and indicators of environmental stress.

    Science.gov (United States)

    Maul, Jonathan D; Farris, Jerry L

    2005-07-01

    Northern cardinals (Cardinalis cardinalis) frequently use agricultural field edges in northeast Arkansas, USA, and may be at risk of exposure to cholinesterase (ChE)-inhibiting pesticides. We monitored northern cardinal exposure to ChE-inhibiting pesticides by comparing plasma total ChE (TChE) activity to reference-derived benchmarks and TChE reactivations. Total ChE and acetylcholinesterase (AChE) were measured for 128 plasma samples from 104 northern cardinals from nine study sites. Of birds sampled from sites treated with ChE-inhibiting pesticides, 4.3% of the samples had TChE activities below the diagnostic threshold (2 standard deviations [SD] below the reference mean) and 8.7% of the samples had TChE reactivations. No difference was found in TChE (p = 0.553) and AChE (p = 0.288) activity between treated and reference sites; however, activity varied among treated sites (p = 0.003). These data do not suggest uniform exposure to individuals, but rather exposure was variable and likely influenced by mitigating factors at individual and site scales. Furthermore, monitoring of TChE reactivation appeared to be a more sensitive indicator of exposure than the diagnostic threshold. Fluctuating asymmetry (FA) was greater at agricultural sites than reference sites (p = 0.016), supporting the hypothesis that FA may be useful for assessing a combination of habitat- and contaminant-related environmental stress.

  19. Retinol increases catalase activity and protein content by a reactive species-dependent mechanism in Sertoli cells.

    Science.gov (United States)

    Gelain, Daniel Pens; de Bittencourt Pasquali, Matheus Augusto; Zanotto-Filho, Alfeu; de Souza, Luiz Fernando; de Oliveira, Ramatis Birnfeld; Klamt, Fábio; Moreira, José Cláudio Fonseca

    2008-07-10

    Vitamin A (retinol) is widely used as an antioxidant in therapeutic interventions and dietary supplementations. However, the redox properties of retinoids have been the subject of intense debate in the last few years, as recent works observed deleterious effects caused by retinol supplementation in clinical trials. In the present work, we show that retinol treatment (7 microM, 24 h) led to catalase (EC 1.11.1.6; CAT) activation in cultured Sertoli cells by increasing its protein content in a reactive species-dependent manner. Retinol treatment also increased cell lipoperoxidation, assessed by determination of thiobarbituric acid-reactive substances (TBARS), and intracellular reactive species production, determined by the real-time dihydrochlorofluorescein (DCFH-DA) assay. However, no alterations on CAT mRNA expression (assessed by RT-PCR) were observed, indicating an effect independent of CAT gene-transcription regulation. Importantly, all the effects induced by retinol were inhibited by the antioxidant Trolox, a hydrophilic analogue of alpha-tocopherol. These results show for the first time that retinol increases CAT activity by a redox-dependent modulation of its protein content in a cell culture model. CAT activity or expression are widely used as indexes of oxidative stress in biological systems; since no changes in CAT mRNA expression were detected in these conditions, the use of CAT gene-transcription activation when assessing oxidative stress should be re-evaluated.

  20. Quantum Soliton Evaporation

    CERN Document Server

    Villari, Leone Di Mauro; Biancalana, Fabio; Conti, Claudio

    2016-01-01

    We have very little experience of the quantum dynamics of the ubiquitous nonlinear waves. Observed phenomena in high energy physics are perturbations to linear waves, and classical nonlinear waves, like solitons, are barely affected by quantum effects. We know that solitons, immutable in classical physics, exhibit collapse and revivals according to quantum mechanics. However this effect is very weak and has never been observed experimentally. By predicting black hole evaporation Hawking first introduced a distinctly quantum effect in nonlinear gravitational physics.Here we show the existence of a general and universal quantum process whereby a soliton emits quantum radiation with a specific frequency content, and a temperature given by the number of quanta, the soliton Schwarzschild radius, and the amount of nonlinearity, in a precise and surprisingly simple way. This result may ultimately lead to the first experimental evidence of genuine quantum black hole evaporation. In addition, our results show that bla...

  1. Ru(0) and Ru(II) nitrosyl pincer complexes: structure, reactivity, and catalytic activity.

    Science.gov (United States)

    Fogler, Eran; Iron, Mark A; Zhang, Jing; Ben-David, Yehoshoa; Diskin-Posner, Yael; Leitus, Gregory; Shimon, Linda J W; Milstein, David

    2013-10-07

    Despite considerable interest in ruthenium carbonyl pincer complexes and their substantial catalytic activity, there has been relatively little study of the isoelectronic ruthenium nitrosyl complexes. Here we describe the synthesis and reactivity of several complexes of this type as well as the catalytic activity of complex 6. Reaction of the PNP ligand (PNP = 2,6-bis((t)Bu2PCH2)pyridine) with RuCl3(NO)(PPh3)2 yielded the Ru(II) complex 3. Chloride displacement by BAr(F-) (BAr(F-) = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) gave the crystallographicaly characterized, linear NO Ru(II) complex 4, which upon treatment with NaBEt3H yielded the Ru(0) complexes 5. The crystallographically characterized Ru(0) square planar complex 5·BF4 bears a linear NO ligand located trans to the pyridilic nitrogen. Further treatment of 5·BF4 with excess LiOH gave the crystallographicaly characterized Ru(0) square planar, linear NO complex 6. Complex 6 catalyzes the dehydrogenative coupling of alcohols to esters, reaching full conversion under air or under argon. Reaction of the PNN ligand (PNN = 2-((t)Bu2PCH2)-6-(Et2NCH2)pyridine) with RuCl3(NO)(H2O)2 in ethanol gave an equilibrium mixture of isomers 7a and 7b. Further treatment of 7a + 7b with 2 equivalent of sodium isopropoxide gave the crystallographicaly characterized, bent-nitrosyl, square pyramidal Ru(II) complex 8. Complex 8 was also synthesized by reaction of PNN with RuCl3(NO)(H2O)2 and Et3N in ethanol. Reaction of the "long arm" PN(2)N ligand (PN(2)N = 2-((t)Bu2PCH2-)-6-(Et2NCH2CH2)pyridine) with RuCl3(NO)(H2O)2 in ethanol gave complex 9, which upon treatment with 2 equiv of sodium isopropoxide gave complex 10. Complex 10 was also synthesized directly by reaction of PN(2)N with RuCl3(NO)(H2O)2 and a base in ethanol. A noteworthy aspect of these nitrosyl complexes is their preference for the Ru(0) oxidization state over Ru(II). This preference is observed with both aromatized and dearomatized pincer ligands, in

  2. Water Membrane Evaporator

    Science.gov (United States)

    Ungar, Eugene K.; Almlie, Jay C.

    2010-01-01

    A water membrane evaporator (WME) has been conceived and tested as an alternative to the contamination-sensitive and corrosion-prone evaporators currently used for dissipating heat from space vehicles. The WME consists mainly of the following components: An outer stainless-steel screen that provides structural support for the components mentioned next; Inside and in contact with the stainless-steel screen, a hydrophobic membrane that is permeable to water vapor; Inside and in contact with the hydrophobic membrane, a hydrophilic membrane that transports the liquid feedwater to the inner surface of the hydrophobic membrane; Inside and in contact with the hydrophilic membrane, an annular array of tubes through which flows the spacecraft coolant carrying the heat to be dissipated; and An inner exclusion tube that limits the volume of feedwater in the WME. In operation, a pressurized feedwater reservoir is connected to the volume between the exclusion tube and the coolant tubes. Feedwater fills the volume, saturates the hydrophilic membrane, and is retained by the hydrophobic membrane. The outside of the WME is exposed to space vacuum. Heat from the spacecraft coolant is conducted through the tube walls and the water-saturated hydrophilic membrane to the liquid/vapor interface at the hydrophobic membrane, causing water to evaporate to space. Makeup water flows into the hydrophilic membrane through gaps between the coolant tubes.

  3. Adsorption of dissolved Reactive red dye from aqueous phase onto activated carbon prepared from agricultural waste.

    Science.gov (United States)

    Senthilkumaar, S; Kalaamani, P; Porkodi, K; Varadarajan, P R; Subburaam, C V

    2006-09-01

    The adsorption of Reactive red dye (RR) onto Coconut tree flower carbon (CFC) and Jute fibre carbon (JFC) from aqueous solution was investigated. Adsorption studies were carried out at different initial dye concentrations, initial solution pH and adsorbent doses. The kinetic studies were also conducted; the adsorption of Reactive red onto CFC and JFC followed pseudosecond-order rate equation. The effective diffusion coefficient was evaluated to establish the film diffusion mechanism. Quantitative removal of Reactive red dye was achieved at strongly acidic conditions for both the carbons studied. The adsorption isotherm data were fitted well to Langmuir isotherm and the adsorption capacity were found to be 181.9 and 200 mg/g for CFC and JFC, respectively. The overall rate of dye adsorption appeared to be controlled by chemisorption, in this case in accordance with poor desorption studies.

  4. Independent Control of Active and Reactive Powers of a DFIG Based Wind Energy Conversion System by Vector Control

    Directory of Open Access Journals (Sweden)

    Ibrahim Ahmad A

    2015-03-01

    Full Text Available The paper deals with a design and implementation of a doubly fed induction generator (DFIG wind energy conversion system (WECS connected to the power grid. A back-to-back AC/DC/AC converter is incorporated between the stator and the rotor windings of a DFIG, in order to obtain variable speed operation. The DFIG can be controlled from sub-synchronous speed to super synchronous speed operation. The main objective of the paper is to control the flow of the Active and Reactive powers produced by the DFIG based wind energy conversion system. A vector control strategy with stator flux orientation is applied to both the grid side converter and the rotor side converter for the independent control of Active and reactive powers produced by the DFIG based wind energy conversion system. The system along with its control circuit were simulated in a Matlab/simulink and the results are presented and discussed.

  5. Structure-activity approach in the reactivation of tabun-phosphorylated human acetylcholinesterase with bispyridinium para-aldoximes.

    Science.gov (United States)

    Kovarik, Zrinka; Calić, Maja; Sinko, Goran; Bosak, Anita

    2007-06-01

    We investigated interactions of bispyridinium para-aldoximes N,N'-(propano)bis(4-hydroxyiminomethyl) pyridinium bromide (TMB-4), N,N'-(ethano)bis(4-hydroxyiminomethyl)pyridinium methanosulphonate (DMB-4), and N,N'-(methano)bis(4-hydroxyiminomethyl)pyridinium chloride (MMB-4) with human erythrocyte acetylcholinesterase phosphorylated by tabun. We analysed aldoxime conformations to determine the flexibility of aldoxime as an important feature for binding to the acetylcholinesterase active site. Tabun-inhibited human erythrocyte acetylcholinesterase was completely reactivated only by the most flexible bispyridinium aldoxime - TMB-4 with a propylene chain between two rings. Shorter linkers than propylene (methylene or ethylene) as in MMB-4 and DMB-4 did not allow appropriate orientation in the active site, and MMB-4 and DMB-4 were not efficient reactivators of tabun-phosphorylated acetylcholinesterase. Since aldoximes are also reversible inhibitors of native acetylcholinesterase, we determined dissociation constants and their protective index against acetylcholinesterase inactivation by tabun.

  6. Long-lasting increase of corticosterone after fear memory reactivation: anxiolytic effects and network activity modulation in the ventral hippocampus.

    Science.gov (United States)

    Albrecht, Anne; Çalışkan, Gürsel; Oitzl, Melly S; Heinemann, Uwe; Stork, Oliver

    2013-02-01

    Pathological fear and anxiety can be studied, in rodents, with fear conditioning and exposure to reminder cues. These paradigms are thought to critically involve the ventral hippocampus, which also serves as key site of glucocorticoid action in the brain. Here, we demonstrate a long-lasting reduction of kainate-induced gamma oscillations in slice preparations of the ventral hippocampal area CA3, 30 days after a single fear conditioning training. Reduction of gamma power was sensitive to corticosterone application and associated with a decrease in glucocorticoid and mineralocorticoid receptor mRNA expression across strata of the ventral hippocampal CA3. A fear reactivation session 24 h after the initial conditioning normalized receptor expression levels and attenuated the corticosterone-mediated recovery of gamma oscillations. It moreover increased both baseline and stimulus-induced corticosterone plasma levels and evoked a generalization of fear memory to the background context. Reduced ventral hippocampal gamma oscillation in both fear reactivated and non-reactivated mice were associated with a decrease of anxiety-like behavior in an elevated plus maze. Taking advantage of the circadian fluctuation in corticosterone, we demonstrated the association of high endogenous basal corticosterone plasma concentrations during morning hours with reduced anxiety-like behavior in fear reactivated mice. The anxiolytic effect of the hormone was verified with local applications to the ventral hippocampus. Our data suggest that corticosterone acting on ventral hippocampal network activity has anxiolytic-like effects following fear exposure, highlighting its potential therapeutic value for anxiety disorders.

  7. Assessment of conformational, spectral, antimicrobial activity, chemical reactivity and NLO application of Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone)

    Science.gov (United States)

    Rawat, Poonam; Singh, R. N.

    2015-04-01

    An orange colored pyrrole dihydrazone: Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone) (PDBO) has been synthesized by reaction of oxalic acid dihydrazide with 2,5 diformyl-1H-pyrrole and has been characterized by spectroscopic analysis (1H, 13C NMR, UV-visible, FT-IR and DART Mass). The properties of the compound has been evaluated using B3LYP functional and 6-31G(d,p)/6-311+G(d,p) basis set. The symmetric (3319, 3320 cm-1) and asymmetric (3389, 3382 cm-1) stretching wave number confirm free NH2 groups in PDBO. NBO analysis shows, inter/intra molecular interactions within the molecule. Topological parameters have been analyzed by QTAIM theory and provide the existence of intramolecular hydrogen bonding (N-H⋯O). The local reactivity descriptors analyses determine the reactive sites within molecule. The calculated first hyperpolarizability value (β0 = 23.83 × 10-30 esu) of pyrrole dihydrazone shows its suitability for non-linear optical (NLO) response. The preliminary bioassay suggested that the PDBO exhibits relatively good antibacterial and fungicidal activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, Aspergillus niger. The local reactivity descriptors - Fukui functions (fk+, fk-), local softnesses (sk+, sk-) and electrophilicity indices (ωk+, ωk-) analyses have been used to determine the reactive sites within molecule.

  8. Determination of reactive oxygen species from ZnO micro-nano structures with shape-dependent photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    He, Weiwei; Zhao, Hongxiao; Jia, Huimin [Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, Xuchang University, Henan 461000 (China); Yin, Jun-Jie [Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD 20740 (United States); Zheng, Zhi, E-mail: zhengzhi99999@gmail.com [Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, Xuchang University, Henan 461000 (China)

    2014-05-01

    Graphical abstract: ZnO micro/nano structures with shape dependent photocatalytic activity were prepared by hydrothermal reaction. The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were identified precisely by electron spin resonance spectroscopy. The type of reactive oxygen species was determined by band gap structure of ZnO. - Highlights: • ZnO micro/nano structures with different morphologies were prepared by solvothermal reaction. • Multi-pod like ZnO structures exhibited superior photocatalytic activity. • The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were characterized precisely by electron spin resonance spectroscopy. • The type of reactive oxygen species was determined by band gap structure of ZnO. - Abstract: ZnO micro/nano structures with different morphologies have been prepared by the changing solvents used during their synthesis by solvothermal reaction. Three typical shapes of ZnO structures including hexagonal, bell bottom like and multi-pod formed and were characterized by scanning electron microscopy and X-ray diffraction. Multi pod like ZnO structures exhibited the highest photocatalytic activity toward degradation of methyl orange. Using electron spin resonance spectroscopy coupled with spin trapping techniques, we demonstrate an effective way to identify precisely the generation of hydroxyl radicals, superoxide and singlet oxygen from the irradiated ZnO multi pod structures. The type of reactive oxygen species formed was predictable from the band gap structure of ZnO. These results indicate that the shape of micro-nano structures significantly affects the photocatalytic activity of ZnO, and demonstrate the value of electron spin resonance spectroscopy for characterizing the type of reactive oxygen species formed during photoexcitation of semiconductors.

  9. Influence of constriction, wall tension, smooth muscle activation and cellular deformation on rat resistance artery vasodilator reactivity.

    Science.gov (United States)

    Colton, Ilsley; Mandalà, Maurizio; Morton, Jude; Davidge, Sandra T; Osol, George

    2012-01-01

    This study investigated how vasoconstriction (tone), wall tension, smooth muscle activation, and vascular wall deformation influence resistance artery vasodilator reactivity. Resistance arteries, from two different regional circulations (splanchnic, uterine) and from pregnant and non-pregnant rats, were cannulated and pressurized, or mounted on a wire myograph under isometric conditions prior to being exposed to both endothelium-dependent (acetylcholine, ACh) and -independent (sodium nitroprusside, SNP) vasodilator agonists. A consistent pattern of reduced vasodilator sensitivity was noted as a function of extent of preconstriction for both agonists noted in pressurized arteries. A similar pattern regarding activation was noted in wire-mounted arteries in response to SNP but not ACh. Wall tension proved to be a major determinant of vascular smooth muscle vasodilator reactivity and its normalization reversed this pattern, as more constricted vessels were more sensitive to ACh relaxation without any change in SNP sensitivity, suggesting that endothelial deformation secondary to vasoconstriction augments its vasodilator output. To our knowledge, this is the first study to dissect out the complex interplay between biophysical forces impinging on VSM (pressure, wall tension), the ambient level of tone (vasoconstriction, smooth muscle cell activation), and consequences of cellular (particularly endothelial) deformation secondary to constriction in determining resistance artery vasodilatory reactivity.

  10. Passive Reactive Berm (PRBerm) to Provide Low Maintenance Lead Containment at Active Small Arms Firing Ranges

    Science.gov (United States)

    2011-10-01

    ppm Parts per million PRBerm Passive Reactive Berm PVC Polyvinyl Chloride QA Quality assurance QC Quality control RO Reverse Osmosis Water RO...1228. Manninen, S., and N. Tanskanen. 1993. Transfer of lead from shotgun pellets to humus and three plant species in a Finnish shooting range

  11. Measuring Physical Activity with Pedometers in Older Adults with Intellectual Disability : Reactivity and Number of Days

    NARCIS (Netherlands)

    Hilgenkamp, Thessa; Van Wijck, Ruud; Evenhuis, Heleen

    2012-01-01

    The minimum number of days of pedometer monitoring needed to estimate valid average weekly step counts and reactivity was investigated for older adults with intellectual disability. Participants (N = 268) with borderline to severe intellectual disability ages 50 years and older were instructed to we

  12. Measuring Physical Activity with Pedometers in Older Adults with Intellectual Disability: Reactivity and Number of Days

    Science.gov (United States)

    Hilgenkamp, Thessa; Van Wijck, Ruud; Evenhuis, Heleen

    2012-01-01

    The minimum number of days of pedometer monitoring needed to estimate valid average weekly step counts and reactivity was investigated for older adults with intellectual disability. Participants (N = 268) with borderline to severe intellectual disability ages 50 years and older were instructed to wear a pedometer for 14 days. The outcome measure…

  13. What happens after the activation of ascaridole? Reactive compounds and their implications for skin sensitization

    Science.gov (United States)

    To replace animal testing and to improve the prediction of skin sensitization, significant attention has been directed to the use of alternative methods. Along with induction of Nrf2 target gene and upregulation of CD86 and C54 markers, the direct peptide reactivity assay (DPRA), the regulatory agen...

  14. Adsorption-desorption characteristics of phenol and reactive dyes from aqueous solution on mesoporous activated carbon prepared from waste tires.

    Science.gov (United States)

    Tanthapanichakoon, W; Ariyadejwanich, P; Japthong, P; Nakagawa, K; Mukai, S R; Tamon, H

    2005-04-01

    Liquid-phase adsorption-desorption characteristics and ethanol regeneration efficiency of an activated carbon prepared from waste tires and a commercial activated carbon were investigated. Water vapor adsorption experiments reveal that both activated carbons showed hydrophobic surface characteristics. Adsorption experiments reveal that the prepared activated carbon possessed comparable phenol adsorption capacity as the commercial one but clearly larger adsorption capacity of two reactive dyes, Black 5 and Red 31. It was ascertained that the prepared activated carbon exhibited less irreversible adsorption of phenol and the two dyes than its commercial counterpart. Moreover, ethanol regeneration efficiency of the prepared AC saturated with either dye was higher than that of the commercial AC. Because of its superior liquid-phase adsorption-desorption characteristics as well as higher ethanol regeneration efficiency, the prepared activated carbon is more suitable for wastewater treatment, especially for adsorbing similarly bulky adsorbates.

  15. Experimental Antithrombotic Effect of Garlic Varieties Measured by a Global In Vitro Test of Platelet Reactivity and Spontaneous Thrombolytic Activity

    Directory of Open Access Journals (Sweden)

    Yoshinobu Ijiri

    2016-06-01

    Full Text Available Prevention of arterial thrombotic diseases has high priority over treatment in developed countries. Unsuitable life style such as inappropriate quality and quantity of daily diet is known to increase the risk for acute thrombotic events, while a regular diet with proven antithrombotic effects might be beneficial in preventing the disease. The present study was undertaken as a part of a series of research in screening vegetables, fruits and medicinal herbs for antithrombotic activity by animal models of thrombosis. In the present study the effects of fifteen garlic varieties (accessions on platelet reactivity and spontaneous (endogenous thrombolytic activity were measured ex vivo from saline-diluted rat blood by the Global Thrombosis Test (GTT. All accessions showed antithrombotic activity but the activity varied between accessions. The heat stable antithrombotic activity was dominantly due to inhibition of platelet reactivity to high shear stress while the spontaneous thrombolytic activity was not affected. These findings suggest that daily intake of garlic as part of an antithrombotic diet may be beneficial for the prevention of arterial thrombotic disorders.

  16. Polyenylpyrrole derivatives inhibit NLRP3 inflammasome activation and inflammatory mediator expression by reducing reactive oxygen species production and mitogen-activated protein kinase activation.

    Directory of Open Access Journals (Sweden)

    Kuo-Feng Hua

    Full Text Available Two polyenylpyrroles from a soil ascomycete Gymnoascus reessii were previously identified as hit compounds in screening for cytotoxicity against lung cancer cells. These compounds and various analogs, which have been previously synthesized and tested for anti-lung cancer cell activity, were tested for anti-inflammatory activity. After preliminary screening for cytotoxicity for RAW 264.7 murine macrophage cells, the non-toxic compounds were tested for anti-inflammatory activity using lipopolysaccharide (LPS-activated RAW 264.7 cells. Compounds 1h, 1i, and 1n reduced LPS-induced nitric oxide (NO production, with respective ED50 values of 15 ± 2, 16 ± 2, and 17 ± 2 µM. They also reduced expression of inducible NO synthase and interleukin-6 (IL-6 without affecting cyclooxygenase-2 expression. Compound 1h also reduced secretion of IL-6 and tumor necrosis factor-α by LPS-activated J774A.1 murine macrophage cells, primary mice peritoneal macrophages, and JAWSII murine bone marrow-derived dendritic cells and reduced NLRP3 inflammasome-mediated interleukin-1β (IL-1β secretion by LPS + adenosine triphosphate-activated J774A.1 and JAWSII cells. The underlying mechanisms for the anti-inflammatory activity of compound 1h were found to be a decrease in LPS-induced reactive oxygen species (ROS production, mitogen-activated protein kinase phosphorylation, and NF-κB activation and a decrease in ATP-induced ROS production and PKC-α phosphorylation. These results provide promising insights into the anti-inflammatory activity of these conjugated polyenes and a molecular rationale for future therapeutic intervention in inflammation-related diseases. They also show how compound 1h regulates inflammation and suggest it may be a new source for the development of anti-inflammatory agents to ameliorate inflammation- and NLRP3 inflammasome-related diseases.

  17. Alkali-aggregate reactivity of typical siliceious glass and carbonate rocks in alkali-activated fly ash based geopolymers

    Science.gov (United States)

    Lu, Duyou; Liu, Yongdao; Zheng, Yanzeng; Xu, Zhongzi; Shen, Xiaodong

    2013-08-01

    For exploring the behaviour of alkali-aggregate reactivity (AAR) in alkali-activated geopolymeric materials and assessing the procedures for testing AAR in geopolymers, the expansion behaviour of fly ash based geopolymer mortars with pure silica glass and typical carbonate rocks were studied respectively by curing at various conditions, i.e. 23°C and 38°C with relative humidity over 95%, immersed in 1M NaOH solution at 80°C. Results show that, at various curing conditions, neither harmful ASR nor harmful ACR was observed in geopolymers with the criteria specified for OPC system. However, with the change of curing conditions, the geopolymer binder and reactive aggregates may experience different reaction processes leading to quite different dimensional changes, especially with additional alkalis and elevated temperatures. It suggests that high temperature with additional alkali for accelerating AAR in traditional OPC system may not appropriate for assessing the alkali-aggregate reactivity behaviour in geopolymers designed for normal conditions. On the other hand, it is hopeful to control the dimensional change of geopolymer mortar or concrete by selecting the type of aggregates and the appropriate curing conditions, thus changing the harmful AAR in OPC into beneficial AAR in geopolymers and other alkali-activated cementitious systems.

  18. A Data-Driven Stochastic Reactive Power Optimization Considering Uncertainties in Active Distribution Networks and Decomposition Method

    DEFF Research Database (Denmark)

    Ding, Tao; Yang, Qingrun; Yang, Yongheng

    2017-01-01

    To address the uncertain output of distributed generators (DGs) for reactive power optimization in active distribution networks, the stochastic programming model is widely used. The model is employed to find an optimal control strategy with minimum expected network loss while satisfying all......, in this paper, a data-driven modeling approach is introduced to assume that the probability distribution from the historical data is uncertain within a confidence set. Furthermore, a data-driven stochastic programming model is formulated as a two-stage problem, where the first-stage variables find the optimal...... control for discrete reactive power compensation equipment under the worst probability distribution of the second stage recourse. The second-stage variables are adjusted to uncertain probability distribution. In particular, this two-stage problem has a special structure so that the second-stage problem...

  19. Kepler Planets: A Tale of Evaporation

    Science.gov (United States)

    Owen, James E.; Wu, Yanqin

    2013-10-01

    Inspired by the Kepler mission's planet discoveries, we consider the thermal contraction of planets close to their parent star, under the influence of evaporation. The mass-loss rates are based on hydrodynamic models of evaporation that include both X-ray and EUV irradiation. We find that only low mass planets with hydrogen envelopes are significantly affected by evaporation, with evaporation being able to remove massive hydrogen envelopes inward of ~0.1 AU for Neptune-mass objects, while evaporation is negligible for Jupiter-mass objects. Moreover, most of the evaporation occurs in the first 100 Myr of stars' lives when they are more chromospherically active. We construct a theoretical population of planets with varying core masses, envelope masses, orbital separations, and stellar spectral types, and compare this population with the sizes and densities measured for low-mass planets, both in the Kepler mission and from radial velocity surveys. This exercise leads us to conclude that evaporation is the driving force of evolution for close-in Kepler planets. In fact, some 50% of the Kepler planet candidates may have been significantly eroded. Evaporation explains two striking correlations observed in these objects: a lack of large radius/low density planets close to the stars and a possible bimodal distribution in planet sizes with a deficit of planets around 2 R ⊕. Planets that have experienced high X-ray exposures are generally smaller than this size, and those with lower X-ray exposures are typically larger. A bimodal planet size distribution is naturally predicted by the evaporation model, where, depending on their X-ray exposure, close-in planets can either hold on to hydrogen envelopes ~0.5%-1% in mass or be stripped entirely. To quantitatively reproduce the observed features, we argue that not only do low-mass Kepler planets need to be made of rocky cores surrounded with hydrogen envelopes, but few of them should have initial masses above 20 M ⊕ and the

  20. Titanium dioxide induces apoptotic cell death through reactive oxygen species-mediated Fas upregulation and Bax activation

    Directory of Open Access Journals (Sweden)

    Yoon TH

    2012-03-01

    Full Text Available Ki-Chun Yoo1, Chang-Hwan Yoon1, Dongwook Kwon2, Kyung-Hwan Hyun1, Soo Jung Woo1, Rae-Kwon Kim1, Eun-Jung Lim1, Yongjoon Suh1, Min-Jung Kim1, Tae Hyun Yoon2, Su-Jae Lee11Laboratory of Molecular Biochemistry, 2Laboratory of Nanoscale Characterization and Environmental Chemistry, Department of Chemistry, Hanyang University, Seoul, Republic of KoreaBackground: Titanium dioxide (TiO2 has been widely used in many areas, including biomedicine, cosmetics, and environmental engineering. Recently, it has become evident that some TiO2 particles have a considerable cytotoxic effect in normal human cells. However, the molecular basis for the cytotoxicity of TiO2 has yet to be defined.Methods and results: In this study, we demonstrated that combined treatment with TiO2 nanoparticles sized less than 100 nm and ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-dependent upregulation of Fas and conformational activation of Bax in normal human cells. Treatment with P25 TiO2 nanoparticles with a hydrodynamic size distribution centered around 70 nm (TiO2P25–70 together with ultraviolet A irradiation-induced caspase-dependent apoptotic cell death, accompanied by transcriptional upregulation of the death receptor, Fas, and conformational activation of Bax. In line with these results, knockdown of either Fas or Bax with specific siRNA significantly inhibited TiO2-induced apoptotic cell death. Moreover, inhibition of reactive oxygen species with an antioxidant, N-acetyl-L-cysteine, clearly suppressed upregulation of Fas, conformational activation of Bax, and subsequent apoptotic cell death in response to combination treatment using TiO2P25–70 and ultraviolet A irradiation.Conclusion: These results indicate that sub-100 nm sized TiO2 treatment under ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-mediated upregulation of the death receptor, Fas, and activation of the preapoptotic protein

  1. Evaporating metal nanocrystal arrays

    Science.gov (United States)

    Zhang, Xue; Joy, James C.; Zhao, Chenwei; Kim, Jin Ho; Fernandes, Gustavo; Xu, J. M.; Valles, James M., Jr.

    2017-03-01

    Anodic aluminum oxide (AAO) substrates with a self-ordered triangular array of nanopores provide the means to fabricate multiple forms of nano materials, such as nanowires and nanoparticles. This study focuses on nanostructures that emerge in thin films of metals thermally evaporated onto the surface of AAO. Previous work showed that films of different evaporated metals assume dramatically different structures, e.g. an ordered triangular array of nearly monodisperse nanoparticles forms for lead (Pb) while a polycrystalline nanohoneycomb structure forms for silver (Ag). Here, we present investigations of the effects of substrate temperature and deposition angle that reveal the processes controlling the nano particle array formation. Our findings indicate that arrays form provided the grain nucleation density exceeds the pore density and the atomic mobility is high enough to promote grain coalescence. They introduce a method for producing films with anisotropic grain array structure. The results provide insight into the influence of substrate nano-morphology on thin film growth energetics and kinetics that can be harnessed for creating films with other novel nano-structures.

  2. Evaporation of inclined water droplets

    Science.gov (United States)

    Kim, Jin Young; Hwang, In Gyu; Weon, Byung Mook

    2017-02-01

    When a drop is placed on a flat substrate tilted at an inclined angle, it can be deformed by gravity and its initial contact angle divides into front and rear contact angles by inclination. Here we study on evaporation dynamics of a pure water droplet on a flat solid substrate by controlling substrate inclination and measuring mass and volume changes of an evaporating droplet with time. We find that complete evaporation time of an inclined droplet becomes longer as gravitational influence by inclination becomes stronger. The gravity itself does not change the evaporation dynamics directly, whereas the gravity-induced droplet deformation increases the difference between front and rear angles, which quickens the onset of depinning and consequently reduces the contact radius. This result makes the evaporation rate of an inclined droplet to be slow. This finding would be important to improve understanding on evaporation dynamics of inclined droplets.

  3. Evaporation of inclined water droplets

    Science.gov (United States)

    Kim, Jin Young; Hwang, In Gyu; Weon, Byung Mook

    2017-01-01

    When a drop is placed on a flat substrate tilted at an inclined angle, it can be deformed by gravity and its initial contact angle divides into front and rear contact angles by inclination. Here we study on evaporation dynamics of a pure water droplet on a flat solid substrate by controlling substrate inclination and measuring mass and volume changes of an evaporating droplet with time. We find that complete evaporation time of an inclined droplet becomes longer as gravitational influence by inclination becomes stronger. The gravity itself does not change the evaporation dynamics directly, whereas the gravity-induced droplet deformation increases the difference between front and rear angles, which quickens the onset of depinning and consequently reduces the contact radius. This result makes the evaporation rate of an inclined droplet to be slow. This finding would be important to improve understanding on evaporation dynamics of inclined droplets. PMID:28205642

  4. Transient Control of Synchronous Machine Active and Reactive Power in Micro-grid Power Systems

    Science.gov (United States)

    Weber, Luke G.

    There are two main topics associated with this dissertation. The first is to investigate phase-to-neutral fault current magnitude occurring in generators with multiple zero-sequence current sources. The second is to design, model, and tune a linear control system for operating a micro-grid in the event of a separation from the electric power system. In the former case, detailed generator, AC8B excitation system, and four-wire electric power system models are constructed. Where available, manufacturers data is used to validate the generator and exciter models. A gain-delay with frequency droop control is used to model an internal combustion engine and governor. The four wire system is connected through a transformer impedance to an infinite bus. Phase-to-neutral faults are imposed on the system, and fault magnitudes analyzed against three-phase faults to gauge their severity. In the latter case, a balanced three-phase system is assumed. The model structure from the former case - but using data for a different generator - is incorporated with a model for an energy storage device and a net load model to form a micro-grid. The primary control model for the energy storage device has a high level of detail, as does the energy storage device plant model in describing the LC filter and transformer. A gain-delay battery and inverter model is used at the front end. The net load model is intended to be the difference between renewable energy sources and load within a micro-grid system that has separated from the grid. Given the variability of both renewable generation and load, frequency and voltage stability are not guaranteed. This work is an attempt to model components of a proposed micro-grid system at the University of Wisconsin Milwaukee, and design, model, and tune a linear control system for operation in the event of a separation from the electric power system. The control module is responsible for management of frequency and active power, and voltage and reactive

  5. Modulation of Active Site Electronic Structure by the Protein Matrix to Control [NiFe] Hydrogenase Reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Dayle MA; Raugei, Simone; Squier, Thomas C.

    2014-09-30

    Control of the reactivity of the nickel center of the [NiFe] hydrogenase and other metalloproteins commonly involves outer coordination sphere ligands that act to modify the geometry and physical properties of the active site metal centers. We carried out a combined set of classical molecular dynamics and quantum/classical mechanics calculations to provide quantitative estimates of how dynamic fluctuations of the active site within the protein matrix modulate the electronic structure at the catalytic center. Specifically we focused on the dynamics of the inner and outer coordination spheres of the cysteinate-bound Ni–Fe cluster in the catalytically active Ni-C state. There are correlated movements of the cysteinate ligands and the surrounding hydrogen-bonding network, which modulate the electron affinity at the active site and the proton affinity of a terminal cysteinate. On the basis of these findings, we hypothesize a coupling between protein dynamics and electron and proton transfer reactions critical to dihydrogen production.

  6. Reactive Oxygen and Nitrogen Species in Defense/Stress Responses Activated by Chitosan in Sycamore Cultured Cells

    Directory of Open Access Journals (Sweden)

    Massimo Malerba

    2015-01-01

    Full Text Available Chitosan (CHT is a non-toxic and inexpensive compound obtained by deacetylation of chitin, the main component of the exoskeleton of arthropods as well as of the cell walls of many fungi. In agriculture CHT is used to control numerous diseases on various horticultural commodities but, although different mechanisms have been proposed, the exact mode of action of CHT is still unknown. In sycamore (Acer pseudoplatanus L. cultured cells, CHT induces a set of defense/stress responses that includes production of H2O2 and nitric oxide (NO. We investigated the possible signaling role of these reactive molecules in some CHT-induced responses by means of inhibitors of production and/or scavengers. The results show that both reactive nitrogen and oxygen species are not only a mere symptom of stress conditions but are involved in the responses induced by CHT in sycamore cells. In particular, NO appears to be involved in a cell death form induced by CHT that shows apoptotic features like DNA fragmentation, increase in caspase-3-like activity and release of cytochrome c from the mitochondrion. On the contrary, reactive oxygen species (ROS appear involved in a cell death form induced by CHT that does not show these apoptotic features but presents increase in lipid peroxidation.

  7. Reactive oxygen and nitrogen species in defense/stress responses activated by chitosan in sycamore cultured cells.

    Science.gov (United States)

    Malerba, Massimo; Cerana, Raffaella

    2015-01-29

    Chitosan (CHT) is a non-toxic and inexpensive compound obtained by deacetylation of chitin, the main component of the exoskeleton of arthropods as well as of the cell walls of many fungi. In agriculture CHT is used to control numerous diseases on various horticultural commodities but, although different mechanisms have been proposed, the exact mode of action of CHT is still unknown. In sycamore (Acer pseudoplatanus L.) cultured cells, CHT induces a set of defense/stress responses that includes production of H2O2 and nitric oxide (NO). We investigated the possible signaling role of these reactive molecules in some CHT-induced responses by means of inhibitors of production and/or scavengers. The results show that both reactive nitrogen and oxygen species are not only a mere symptom of stress conditions but are involved in the responses induced by CHT in sycamore cells. In particular, NO appears to be involved in a cell death form induced by CHT that shows apoptotic features like DNA fragmentation, increase in caspase-3-like activity and release of cytochrome c from the mitochondrion. On the contrary, reactive oxygen species (ROS) appear involved in a cell death form induced by CHT that does not show these apoptotic features but presents increase in lipid peroxidation.

  8. Relative reactivity of ribosyl 2'-OH vs. 3'-OH in concentrated aqueous solutions of phosphoimidazolide activated nucleotides

    Science.gov (United States)

    Kanavarioti, A.; Lee, L. F.; Gangopadhyay, S.

    1999-01-01

    Phosphoimidazolide activated ribomononucleotides (*pN, see structure) are useful substrates for the non-enzymatic synthesis of oligonucleotides. In the presence of metal ions, aqueous solutions of *pN yield primarily the two internucleotide-linked (pN2' pN and pN3' pN) and the pyrophosphate-linked (N5' ppN) dimers. Small amounts of cyclic dimers and higher oligomers are also produced. In this study the relative reactivity of 2'-OH vs. 3'-OH was determined from the ratio of the yields of pN2' pN vs. pN3' pN. Experiments were performed at 23 degrees C in the range 7.2 dimers, and a higher pN2' pN: pN3' pN ratio. Trends in the data, observed with all three leaving groups, suggest an increase in pN2' pN: pN3' pN ratio with decreasing substrate concentration (up to 5.47 with 0.051 M ImpG). The observations are in accord with earlier studies reporting a relative reactivity 2'-5': 3'-5' = 6 to 9 obtained with Im as the leaving group, in dilute nucleotide solutions and under conditions that disfavor stacking. It is speculated that the concentration induced change in the relative reactivity is the result of self-association via base-stacking that enhances selectively the proximity of the 3'-OH of one molecule to the reactive P-N bond of an other molecule. The implication of these conclusions for oligomerization/ligation reactions is discussed.

  9. Sleep- and wake-dependent changes in neuronal activity and reactivity demonstrated in fly neurons using in vivo calcium imaging.

    Science.gov (United States)

    Bushey, Daniel; Tononi, Giulio; Cirelli, Chiara

    2015-04-14

    Sleep in Drosophila shares many features with mammalian sleep, but it remains unknown whether spontaneous and evoked activity of individual neurons change with the sleep/wake cycle in flies as they do in mammals. Here we used calcium imaging to assess how the Kenyon cells in the fly mushroom bodies change their activity and reactivity to stimuli during sleep, wake, and after short or long sleep deprivation. As before, sleep was defined as a period of immobility of >5 min associated with a reduced behavioral response to a stimulus. We found that calcium levels in Kenyon cells decline when flies fall asleep and increase when they wake up. Moreover, calcium transients in response to two different stimuli are larger in awake flies than in sleeping flies. The activity of Kenyon cells is also affected by sleep/wake history: in awake flies, more cells are spontaneously active and responding to stimuli if the last several hours (5-8 h) before imaging were spent awake rather than asleep. By contrast, long wake (≥29 h) reduces both baseline and evoked neural activity and decreases the ability of neurons to respond consistently to the same repeated stimulus. The latter finding may underlie some of the negative effects of sleep deprivation on cognitive performance and is consistent with the occurrence of local sleep during wake as described in behaving rats. Thus, calcium imaging uncovers new similarities between fly and mammalian sleep: fly neurons are more active and reactive in wake than in sleep, and their activity tracks sleep/wake history.

  10. Reactivity of mononuclear alkylperoxo copper(II) complex. O-O bond cleavage and C-H bond activation.

    Science.gov (United States)

    Kunishita, Atsushi; Ishimaru, Hirohito; Nakashima, Satoru; Ogura, Takashi; Itoh, Shinobu

    2008-04-02

    A detailed reactivity study has been carried out for the first time on a new mononuclear alkylperoxo copper(II) complex, which is generated by the reaction of copper(II) complex supported by the bis(pyridylmethyl)amine tridentate ligand containing a phenyl group at the 6-position of the pyridine donor groups and cumene hydroperoxide (CmOOH) in CH3CN. The cumylperoxo copper(II) complex thus obtained has been found to undergo homolytic cleavage of the O-O bond and induce C-H bond activation of exogenous substrates, providing important insights into the catalytic mechanism of copper monooxygenases.

  11. Calpain and reactive oxygen species targets Bax for mitochondrial permeabilisation and caspase activation in zerumbone induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Praveen K Sobhan

    Full Text Available Fluorescent protein based signaling probes are emerging as valuable tools to study cell signaling because of their ability to provide spatio- temporal information in non invasive live cell mode. Previously, multiple fluorescent protein probes were employed to characterize key events of apoptosis in diverse experimental systems. We have employed a live cell image based approach to visualize the key events of apoptosis signaling induced by zerumbone, the active principle from ginger Zingiber zerumbet, in cancer cells that enabled us to analyze prominent apoptotic changes in a hierarchical manner with temporal resolution. Our studies substantiate that mitochondrial permeabilisation and cytochrome c dependent caspase activation dominate in zerumbone induced cell death. Bax activation, the essential and early event of cell death, is independently activated by reactive oxygen species as well as calpains. Zerumbone failed to induce apoptosis or mitochondrial permeabilisation in Bax knockout cells and over-expression of Bax enhanced cell death induced by zerumbone confirming the essential role of Bax for mitochondrial permeabilsation. Simultaneous inhibition of reactive oxygen species and calpain is required for preventing Bax activation and cell death. However, apoptosis induced by zerumbone was prevented in Bcl 2 and Bcl-XL over-expressing cells, whereas more protection was afforded by Bcl 2 specifically targeted to endoplasmic reticulum. Even though zerumbone treatment down-regulated survival proteins such as XIAP, Survivin and Akt, it failed to affect the pro-apoptotic proteins such as PUMA and BIM. Multiple normal diploid cell lines were employed to address cytotoxic activity of zerumbone and, in general, mammary epithelial cells, endothelial progenitor cells and smooth muscle cells were relatively resistant to zerumbone induced cell death with lesser ROS accumulation than cancer cells.

  12. Characteristic Research on Evaporated Explosive Film

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The evaporation source of evaporated explosive was designed and improved based on the inherent specialties of explosive. The compatibility of explosives and addition agent with evaporation vessels was analyzed. The influence of substrate temperature on explosive was analyzed, the control method of substrate temperature was suggested. The influences of evaporation rate on formation of explosive film and mixed explosive film were confirmed. Optimum evaporation rate for evaporation explosive and the better method for evaporating mixed explosive were presented. The necessary characteristics of the evaporated explosive film were obtained by the research of the differences between the evaporated explosive and other materials.

  13. Hyperosmotic stress-dependent NFkappaB activation is regulated by reactive oxygen species and IGF-1 in cultured cardiomyocytes.

    Science.gov (United States)

    Eisner, Verónica; Criollo, Alfredo; Quiroga, Clara; Olea-Azar, Claudio; Santibañez, Juan Francisco; Troncoso, Rodrigo; Chiong, Mario; Díaz-Araya, Guillermo; Foncea, Rocío; Lavandero, Sergio

    2006-08-07

    We have recently shown that hyperosmotic stress activates p65/RelB NFkappaB in cultured cardiomyocytes with dichotomic actions on caspase activation and cell death. It remains unexplored how NFkappaB is regulated in cultured rat cardiomyocytes exposed to hyperosmotic stress. We study here: (a) if hyperosmotic stress triggers reactive oxygen species (ROS) generation and in turn whether they regulate NFkappaB and (b) if insulin-like growth factor-1 (IGF-1) modulates ROS production and NFkappaB activation in hyperosmotically-stressed cardiomyocytes. The results showed that hyperosmotic stress generated ROS in cultured cardiac myocytes, in particular the hydroxyl and superoxide species, which were inhibited by N-acetylcysteine (NAC). Hyperosmotic stress-induced NFkappaB activation as determined by IkappaBalpha degradation and NFkappaB DNA binding. NFkappaB activation and procaspase-3 and -9 fragmentation were prevented by NAC and IGF-1. However, this growth factor did not decrease ROS generation induced by hyperosmotic stress, suggesting that its actions over NFkappaB and caspase activation may be due to modulation of events downstream of ROS generation. We conclude that hyperosmotic stress induces ROS, which in turn activates NFkappaB and caspases. IGF-1 prevents NFkappaB activation by a ROS-independent mechanism.

  14. Surface-induced evaporative cooling

    Institute of Scientific and Technical Information of China (English)

    Ke Min; Yan Bo; Cheng Feng; Wang Yu-Zhu

    2009-01-01

    The effects of surface-induced evaporative cooling on an atom chip are investigated. The evolutions of temperature, number and phase-space density of the atom cloud are measured when the atom cloud is brought close to the surface. Rapid decrease of the temperature and number of the atoms is found when the atom-surface distance is < 100 μm. A gain of about a factor of five on the phase-space density is obtained. It is found that the efficiency of the surface-induced evaporative cooling depends on the atom-surface distance and the shape of the evaporative trap. When the atoms are moved very close to the surface, severe heating is observed, which dominates when the holding time is > 8 ms. It is important that the surface-induced evaporative cooling offers novel possibilities for the realization of a continuous condensation, where a spatially varying evaporative cooling is required.

  15. Catalytic Activity of Porous Phosphate Heterostructures-Fe towards Reactive Black 5 Degradation

    Directory of Open Access Journals (Sweden)

    Marco S. Lucas

    2013-01-01

    Full Text Available Fenton’s reaction is often used to decompose stable substances in wastewater. In this study, experiments based on the effect of porous phosphate heterostructures as catalyst sorbent of Fe2+ synthesised by different procedures were planned. The examined PPH-Fe/H2O2 as oxidant in a heterogeneous process under mild conditions at pH 5 was found to be very efficient for discoloration of a simulated wastewater containing 50 mg L−1 of a commercial azo dye (Reactive Black 5 reaching 95% of decolourization. Under the described conditions total visual decolourization was achieved after 360 min. This study can provide a simple, effective, and economic system ideal for the treatment of toxic and nonbiodegradable azo dyes.

  16. Determining Chemical Reactivity Driving Biological Activity from SMILES Transformations: The Bonding Mechanism of Anti-HIV Pyrimidines

    Directory of Open Access Journals (Sweden)

    Mihai V. Putz

    2013-07-01

    Full Text Available Assessing the molecular mechanism of a chemical-biological interaction and bonding stands as the ultimate goal of any modern quantitative structure-activity relationship (QSAR study. To this end the present work employs the main chemical reactivity structural descriptors (electronegativity, chemical hardness, chemical power, electrophilicity to unfold the variational QSAR though their min-max correspondence principles as applied to the Simplified Molecular Input Line Entry System (SMILES transformation of selected uracil derivatives with anti-HIV potential with the aim of establishing the main stages whereby the given compounds may inhibit HIV infection. The bonding can be completely described by explicitly considering by means of basic indices and chemical reactivity principles two forms of SMILES structures of the pyrimidines, the Longest SMILES Molecular Chain (LoSMoC and the Branching SMILES (BraS, respectively, as the effective forms involved in the anti-HIV activity mechanism and according to the present work, also necessary intermediates in molecular pathways targeting/docking biological sites of interest.

  17. Proteasome inhibition mediates p53 reactivation and anti-cancer activity of 6-gingerol in cervical cancer cells.

    Science.gov (United States)

    Rastogi, Namrata; Duggal, Shivali; Singh, Shailendra Kumar; Porwal, Konica; Srivastava, Vikas Kumar; Maurya, Rakesh; Bhatt, M L B; Mishra, Durga Prasad

    2015-12-22

    Human papilloma virus (HPV) expressing E6 and E7 oncoproteins, is known to inactivate the tumor suppressor p53 through proteasomal degradation in cervical cancers. Therefore, use of small molecules for inhibition of proteasome function and induction of p53 reactivation is a promising strategy for induction of apoptosis in cervical cancer cells. The polyphenolic alkanone, 6-Gingerol (6G), present in the pungent extracts of ginger (Zingiber officinale Roscoe) has shown potent anti-tumorigenic and pro-apoptotic activities against a variety of cancers. In this study we explored the molecular mechanism of action of 6G in human cervical cancer cells in vitro and in vivo. 6G potently inhibited proliferation of the HPV positive cervical cancer cells. 6G was found to: (i) inhibit the chymotrypsin activity of proteasomes, (ii) induce reactivation of p53, (iii) increase levels of p21, (iv) induce DNA damage and G2/M cell cycle arrest, (v) alter expression levels of p53-associated apoptotic markers like, cleaved caspase-3 and PARP, and (vi) potentiate the cytotoxicity of cisplatin. 6G treatment induced significant reduction of tumor volume, tumor weight, proteasome inhibition and p53 accumulation in HeLa xenograft tumor cells in vivo. The 6G treatment was devoid of toxic effects as it did not affect body weights, hematological and osteogenic parameters. Taken together, our data underscores the therapeutic and chemosensitizing effects of 6G in the management and treatment of cervical cancer.

  18. Active and reactive power control of the doubly fed induction generator based on wind energy conversion system

    Directory of Open Access Journals (Sweden)

    Ghulam Sarwar Kaloi

    2016-11-01

    Full Text Available This paper presents a dynamic modeling and control of doubly fed induction-generator (DFIG based on the wind turbine systems. Active and reactive power control of the DFIG are based on the feedback technique by using the suitable voltage vectors on the rotor side. The rotor flux has no impact on the changes of the stator active and reactive power. The proposed controller is based on the feedback technique in order to reduce the oscillation of the generator. The control approach is estimated through the simulation result of the feedback controller assembled with DFIG wind turbines. It is applied by the feedback control based techniques in order to control the power flowing of DFIG and the power grid. Hence, an improved feedback control technique is adopted to get a better power flow transfer and to improve the dynamic system and transient stability. In stable condition, the improved performance of the controller, the proposed method is verified for the effectiveness of the control method is done in stable conditions.

  19. Jack bean urease: the effect of active-site binding inhibitors on the reactivity of enzyme thiol groups.

    Science.gov (United States)

    Krajewska, Barbara; Zaborska, Wiesława

    2007-10-01

    In view of the complexity of the role of the active site flap cysteine in the urease catalysis, in this work we studied how the presence of typical active-site binding inhibitors of urease, phenylphosphorodiamidate (PPD), acetohydroxamic acid (AHA), boric acid and fluoride, affects the reactivity of enzyme thiol groups, the active site flap thiol in particular. For that the inhibitor-urease complexes were prepared with excess inhibitors and had their thiol groups titrated with DTNB. The effects observed were analyzed in terms of the structures of the inhibitor-urease complexes reported in the literature. We found that the effectiveness in preventing the active site cysteine from the modification by disulfides, varied among the inhibitors studied, even though they all bind to the active site. The variations were accounted for by different extents of geometrical distortion in the active site that the inhibitors introduced upon binding, leaving the flap either open in AHA-, boric acid- and fluoride-inhibited urease, like in the native enzyme or closed in PPD-inhibited urease. Among the inhibitors, only PPD was found to be able to thoroughly protect the flap cysteines from the further reaction with disulfides, this apparently resulting from the closed conformation of the flap. Accordingly, in practical terms PPD may be regarded as the most suitable inhibitor for active-site protection experiments in inhibition studies of urease.

  20. Can systemically generated reactive oxygen species help to monitor disease activity in generalized vitiligo? A pilot study

    Directory of Open Access Journals (Sweden)

    Richeek Pradhan

    2014-01-01

    Full Text Available Background: Generalized vitiligo is a disease with unpredictable bursts of activity, goal of treatment during the active phase being to stabilize the lesions. This emphasizes the need for a prospective marker for monitoring disease activity to help decide the duration of therapy. Aims and Objectives: In the present study, we examined whether reactive oxygen species (ROS generated in erythrocytes can be translated into a marker of activity in vitiligo. Materials and Methods: Level of intracellular ROS was measured flow cytometrically in erythrocytes from venous blood of 21 patients with generalized vitiligo and 21 healthy volunteers using the probe dichlorodihydrofluorescein diacetate. Results: The levels of ROS differed significantly between patients and healthy controls, as well as between active versus stable disease groups. In the active disease group, ROS levels were significantly lower in those being treated with systemic steroids than those that were not. ROS levels poorly correlated with disease duration or body surface area involved. Conclusion: A long-term study based on these findings can be conducted to further validate the potential role of ROS in monitoring disease activity vitiligo.

  1. Synthesis of SiC/Ag/Cellulose Nanocomposite and Its Antibacterial Activity by Reactive Oxygen Species Generation

    Directory of Open Access Journals (Sweden)

    Andrzej Borkowski

    2016-09-01

    Full Text Available We describe the synthesis of nanocomposites, based on nanofibers of silicon carbide, silver nanoparticles, and cellulose. Silver nanoparticle synthesis was achieved with chemical reduction using hydrazine by adding two different surfactants to obtain a nanocomposite with silver nanoparticles of different diameters. Determination of antibacterial activity was based on respiration tests. Enzymatic analysis indicates oxidative stress, and viability testing was conducted using an epifluorescence microscope. Strong bactericidal activity of nanocomposites was found against bacteria Escherichia coli and Bacillus cereus, which were used in the study as typical Gram-negative and Gram-positive bacteria, respectively. It is assumed that reactive oxygen species generation was responsible for the observed antibacterial effect of the investigated materials. Due to the properties of silicon carbide nanofiber, the obtained nanocomposite may have potential use in technology related to water and air purification. Cellulose addition prevented silver nanoparticle release and probably enhanced bacterial adsorption onto aggregates of the nanocomposite material.

  2. Reactive oxygen species-related activities of nano-iron metal and nano-iron oxides

    Directory of Open Access Journals (Sweden)

    Haohao Wu

    2014-03-01

    Full Text Available Nano-iron metal and nano-iron oxides are among the most widely used engineered and naturally occurring nanostructures, and the increasing incidence of biological exposure to these nanostructures has raised concerns about their biotoxicity. Reactive oxygen species (ROS-induced oxidative stress is one of the most accepted toxic mechanisms and, in the past decades, considerable efforts have been made to investigate the ROS-related activities of iron nanostructures. In this review, we summarize activities of nano-iron metal and nano-iron oxides in ROS-related redox processes, addressing in detail the known homogeneous and heterogeneous redox mechanisms involved in these processes, intrinsic ROS-related properties of iron nanostructures (chemical composition, particle size, and crystalline phase, and ROS-related bio-microenvironmental factors, including physiological pH and buffers, biogenic reducing agents, and other organic substances.

  3. Controls on open water evaporation

    Directory of Open Access Journals (Sweden)

    R. J. Granger

    2010-05-01

    Full Text Available The paper presents the initial results of a field study of boundary layer behaviour and open water evaporation carried out on two small- to medium-sized lakes in Western and Northern Canada. Meteorological and boundary layer measurements were made over the water surfaces and over the upwind land surface, allowing for an examination of the effect of lake-land contrasts of temperature on the wind speed over the open water and on the evaporation rates. Lake evaporation was measured directly using eddy covariance equipment.

    The study showed that, for time periods shorter than daily, the open water evaporation bears no relationship to the net radiation. The wind speed is the most significant factor governing the evaporation rates, followed by the land-water temperature contrast and the land-water vapour pressure contrast. The effect of the stability on the wind field is demonstrated; stability over the water and adjacent land surfaces are, for the most part, out of phase. The derived relationships will be used to develop a model for estimating the hourly evaporation rates from open water.

    Examination of the seasonal trends shows that the open water period can be separated into two distinct evaporative regimes: the warming period in the Spring, when the land temperature is greater than the water temperature, the turbulent fluxes over water are suppressed; and the cooling period, when the water temperature is greater than the air temperature, and the turbulent fluxes over water are enhanced.

  4. Reactive Air Aluminization

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.

    2011-10-28

    Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.

  5. Thermodynamic Modeling of Savannah River Evaporators

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.F.

    2001-08-02

    A thermodynamic model based on the code SOLGASMIX is developed to calculate phase equilibrium in evaporators and related tank wastes at the Savannah River Site (SRS). This model uses the Pitzer method to calculate activity coefficients, and many of the required Pitzer parameters have been determined in the course of this work. Principal chemical species in standard SRS simulant solutions are included, and the temperature range for most parameters has been extended above 100 C. The SOLGASMIX model and calculations using the code Geochemists Workbench are compared to actual solubility data including silicate, aluminate, and aluminosilicate solutions. In addition, SOLGASMIX model calculations are also compared to transient solubility data involving SRS simulant solutions. These comparisons indicate that the SOLGASMIX predictions closely match reliable data over the range of temperature and solution composition expected in the SRS evaporator and related tanks. Predictions using the Geochemists Workbench may be unreliable, due primarily to the use of an inaccurate activity coefficient model.

  6. Intermolecular C-H activation with an Ir-METAMORPhos piano-stool complex--multiple reaction steps at a reactive ligand.

    Science.gov (United States)

    Oldenhof, S; Lutz, M; van der Vlugt, J I; Reek, J N H

    2015-10-21

    Substrate activation by means of a reactive ligand is a topic of much interest. Herein we describe a stoichiometric anti-Markovnikov C-N bond formation involving ligand reactivity in multiple steps along the reaction coordinate, including ligand assisted substrate (de)protonation and C-N bond formation, as illustrated by a combined experimental, spectroscopic and computational study. This affords a highly unusual four-membered iridacycle bearing an exo-cyclic C=C double bond.

  7. Post-Transition State Dynamics in Gas Phase Reactivity: Importance of Bifurcations and Rotational Activation.

    Science.gov (United States)

    Martín-Sómer, Ana; Yáñez, Manuel; Hase, William L; Gaigeot, Marie-Pierre; Spezia, Riccardo

    2016-03-01

    Beyond the established use of thermodynamic vs kinetic control to explain chemical reaction selectivity, the concept of bifurcations on a potential energy surface (PES) is proving to be of pivotal importance with regard to selectivity. In this article, we studied by means of post-transition state (TS) direct dynamics simulations the effect that vibrational and rotational excitation at the TS may have on selectivity on a bifurcating PES. With this aim, we studied the post-TS unimolecular reactivity of the [Ca(formamide)](2+) ion, for which Coulomb explosion and neutral loss reactions compete. The PES exhibits different kinds of nonintrinsic reaction coordinate (IRC) dynamics, among them PES bifurcations, which direct the trajectories to multiple reaction paths after passing the TS. Direct dynamics simulations were used to distinguish between the bifurcation non-IRC dynamics and non-IRC dynamics arising from atomistic motions directing the trajectories away from the IRC. Overall, we corroborated the idea that kinetic selectivity often does not reduce to a simple choice between paths with different barrier heights and instead dynamical behavior after passing the TS may be crucial. Importantly, rotational excitation may play a pivotal role on the reaction selectivity favoring nonthermodynamic products.

  8. The Role of Reactive Oxygen Species (ROS in the Biological Activities of Metallic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ahmed Abdal Dayem

    2017-01-01

    Full Text Available Nanoparticles (NPs possess unique physical and chemical properties that make them appropriate for various applications. The structural alteration of metallic NPs leads to different biological functions, specifically resulting in different potentials for the generation of reactive oxygen species (ROS. The amount of ROS produced by metallic NPs correlates with particle size, shape, surface area, and chemistry. ROS possess multiple functions in cellular biology, with ROS generation a key factor in metallic NP-induced toxicity, as well as modulation of cellular signaling involved in cell death, proliferation, and differentiation. In this review, we briefly explained NP classes and their biomedical applications and describe the sources and roles of ROS in NP-related biological functions in vitro and in vivo. Furthermore, we also described the roles of metal NP-induced ROS generation in stem cell biology. Although the roles of ROS in metallic NP-related biological functions requires further investigation, modulation and characterization of metallic NP-induced ROS production are promising in the application of metallic NPs in the areas of regenerative medicine and medical devices.

  9. Pyrylium Salts as Reactive Matrices for MALDI-MS Imaging of Biologically Active Primary Amines

    Science.gov (United States)

    Shariatgorji, Mohammadreza; Nilsson, Anna; Källback, Patrik; Karlsson, Oskar; Zhang, Xiaoqun; Svenningsson, Per; Andren, Per E.

    2015-06-01

    Many neuroactive substances, including endogenous biomolecules, environmental compounds, and pharmaceuticals possess primary amine functional groups. Among these are catecholamine neurotransmitters (e.g., dopamine), many substituted phenethylamines (e.g., amphetamine), as well as amino acids and neuropeptides. In most cases, mass spectrometric (ESI and MALDI) analyses of trace amounts of such compounds are challenging because of their poor ionization properties. We present a method for chemical derivatization of primary amines by reaction with pyrylium salts that facilitates their detection by MALDI-MS and enables the imaging of primary amines in brain tissue sections. A screen of pyrylium salts revealed that the 2,4-diphenyl-pyranylium ion efficiently derivatizes primary amines and can be used as a reactive MALDI-MS matrix that induces both derivatization and desorption. MALDI-MS imaging with such matrix was used to map the localization of dopamine and amphetamine in brain tissue sections and to quantitatively map the distribution of the neurotoxin β- N-methylamino-L-alanine.

  10. Adaptive Control with SSNN of UPFC System for the Compensation of Active and Reactive Power

    Directory of Open Access Journals (Sweden)

    A. Bouanane

    2013-06-01

    Full Text Available The focus of this study is the effectiveness of the controller’s Unified Power Flow Controller UPFC with the choice of a control strategy. This Unified Power Flow Controller (UPFC is used to control the power flow in the transmission systems by controlling the impedance, voltage magnitude and phase angle. This controller offers advantages in terms of static and dynamic operation of the power system. It also brings in new challenges in power electronics and power system design. To evaluate the performance and robustness of the system, we proposed a hybrid control combining the concept of identification neural networks with conventional regulators and with the changes in characteristics of the transmission line in order to improve the stability of the electrical power network. With its unique capability to control simultaneously real and reactive power flows on a transmission line as well as to regulate voltage at the bus where it is connected, this device creates a tremendous quality impact on power system stability. The result which has been obtained from using MATLAB and SIMULINK software showed a good agreement with the simulation result.

  11. Interfacial Instabilities in Evaporating Drops

    Science.gov (United States)

    Moffat, Ross; Sefiane, Khellil; Matar, Omar

    2007-11-01

    We study the effect of substrate thermal properties on the evaporation of sessile drops of various liquids. An infra-red imaging technique was used to record the interfacial temperature. This technique illustrates the non-uniformity in interfacial temperature distribution that characterises the evaporation process. Our results also demonstrate that the evaporation of methanol droplets is accompanied by the formation of wave-trains in the interfacial temperature field; similar patterns, however, were not observed in the case of water droplets. More complex patterns are observed for FC-72 refrigerant drops. The effect of substrate thermal conductivity on the structure of the complex pattern formation is also elucidated.

  12. Multileg Heat-Pipe Evaporator

    Science.gov (United States)

    Alario, J. P.; Haslett, R. A.

    1986-01-01

    Parallel pipes provide high heat flow from small heat exchanger. Six parallel heat pipes extract heat from overlying heat exchanger, forming evaporator. Vapor channel in pipe contains wick that extends into screen tube in liquid channel. Rods in each channel hold wick and screen tube in place. Evaporator compact rather than extended and more compatible with existing heat-exchanger geometries. Prototype six-pipe evaporator only 0.3 m wide and 0.71 m long. With ammonia as working fluid, transports heat to finned condenser at rate of 1,200 W.

  13. Determination of reactive oxygen generated from natural medicines and their antibacterial activity

    Directory of Open Access Journals (Sweden)

    Noriko Tajima

    2016-08-01

    Galla chinensis generated 2.4×10−4 mol/L hydrogen peroxide from a 1 mg/mL solution. In bacterial growth tests, Galla chinensis extract had antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacteroides thetaiotaomicron, Campylobacter sputorum biovar sputorum, Streptococcus salivarius thermophilus, Lactobacillus casei, and Bifidobacterium longum infantis. This antibacterial activity was decreased by the addition of catalase. It revealed that hydrogen peroxide which Galla chinensis produced participated in antibacterial activity.

  14. In vitro reactivity to implant metals demonstrates a person-dependent association with both T-cell and B-cell activation.

    Science.gov (United States)

    Hallab, Nadim James; Caicedo, Marco; Epstein, Rachel; McAllister, Kyron; Jacobs, Joshua J

    2010-02-01

    Hypersensitivity to metallic implants remains relatively unpredictable and poorly understood. We initially hypothesized that metal-induced lymphocyte proliferation responses to soluble metal challenge (ions) are mediated exclusively by early T-cell activation (not B-cells), typical of a delayed-type-hypersensitivity response. We tested this by comparing proliferation (6 days) of primary lymphocytes with early T-cell and B-cell activation (48 h) in three groups of subjects likely to demonstrate elevated metal reactivity: group 1 (n = 12) history of metal sensitivity with no implant; group 2a (n = 6) well performing metal-on-metal THRs, and group 2b (n = 20) subjects with poorly performing metal-on-polymer total joint arthroplasties (TJA). Group 1 showed 100% (12/12) metal reactivity (stimulation index > 2) to Ni. Groups 2a and 2b were 83% (5/6) and 75% (15/22) metal reactive (to Co, Cr, or Ni), respectively. Of the n = 32 metal-reactive subjects to Co, Cr, or Ni (SI > 2), n = 22/32 demonstrated >2-fold elevations in % of T-cell or B-cell activation (CD25+, CD69+) to metal challenge when compared with untreated control. 18/22 metal-activated subjects demonstrated an exclusively T-cell or B-cell activation response to metal challenge, where 6/18 demonstrated exclusively B-cell activation and 12/18 demonstrated a T-cell only response, as measured by surface activation markers CD25+ and CD69+. However, there was no direct correlation (R(2) metal reactivity than did subject-dependent results of flow-cytometry analysis of T-cell or B-cell activation. The high incidence of lymphocyte reactivity and activation indicate that more complex than initially hypothesized immune responses may contribute to the etiology of debris-induced osteolysis in metal-sensitive individuals.

  15. Spectroscopic evidence for an engineered, catalytically active Trp radical that creates the unique reactivity of lignin peroxidase.

    Science.gov (United States)

    Smith, Andrew T; Doyle, Wendy A; Dorlet, Pierre; Ivancich, Anabella

    2009-09-22

    The surface oxidation site (Trp-171) in lignin peroxidase (LiP) required for the reaction with veratryl alcohol a high-redox-potential (1.4 V) substrate, was engineered into Coprinus cinereus peroxidase (CiP) by introducing a Trp residue into a heme peroxidase that has similar protein fold but lacks this activity. To create the catalytic activity toward veratryl alcohol in CiP, it was necessary to reproduce the Trp site and its negatively charged microenvironment by means of a triple mutation. The resulting D179W+R258E+R272D variant was characterized by multifrequency EPR spectroscopy. The spectra unequivocally showed that a new Trp radical [g values of g(x) = 2.0035(5), g(y) = 2.0027(5), and g(z) = 2.0022(1)] was formed after the [Fe(IV)=O Por(*+)] intermediate, as a result of intramolecular electron transfer between Trp-179 and the porphyrin. Also, the EPR characterization crucially showed that [Fe(IV)=O Trp-179(*)] was the reactive intermediate with veratryl alcohol. Accordingly, our work shows that it is necessary to take into account the physicochemical properties of the radical, fine-tuned by the microenvironment, as well as those of the preceding [Fe(IV)=O Por(*+)] intermediate to engineer a catalytically competent Trp site for a given substrate. Manipulation of the microenvironment of the Trp-171 site in LiP allowed the detection by EPR spectroscopy of the Trp-171(*), for which direct evidence has been missing so far. Our work also highlights the role of Trp residues as tunable redox-active cofactors for enzyme catalysis in the context of peroxidases with a unique reactivity toward recalcitrant substrates that require oxidation potentials not realized at the heme site.

  16. Low-level laser therapy activates NF-kB via generation of reactive oxygen species in mouse embryonic fibroblasts.

    Directory of Open Access Journals (Sweden)

    Aaron C-H Chen

    Full Text Available BACKGROUND: Despite over forty years of investigation on low-level light therapy (LLLT, the fundamental mechanisms underlying photobiomodulation at a cellular level remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we isolated murine embryonic fibroblasts (MEF from transgenic NF-kB luciferase reporter mice and studied their response to 810 nm laser radiation. Significant activation of NF-kB was observed at fluences higher than 0.003 J/cm(2 and was confirmed by Western blot analysis. NF-kB was activated earlier (1 hour by LLLT compared to conventional lipopolysaccharide treatment. We also observed that LLLT induced intracellular reactive oxygen species (ROS production similar to mitochondrial inhibitors, such as antimycin A, rotenone and paraquat. Furthermore, we observed similar NF-kB activation with these mitochondrial inhibitors. These results, together with inhibition of laser induced NF-kB activation by antioxidants, suggests that ROS play an important role in the laser induced NF-kB signaling pathways. However, LLLT, unlike mitochondrial inhibitors, induced increased cellular ATP levels, which indicates that LLLT also upregulates mitochondrial respiration. CONCLUSION: We conclude that LLLT not only enhances mitochondrial respiration, but also activates the redox-sensitive NFkB signaling via generation of ROS. Expression of anti-apoptosis and pro-survival genes responsive to NFkB could explain many clinical effects of LLLT.

  17. Influence of reactive oxygen species on the enzyme stability and activity in the presence of ionic liquids.

    Directory of Open Access Journals (Sweden)

    Pankaj Attri

    Full Text Available In this paper, we have examined the effect of ammonium and imidazolium based ionic liquids (ILs on the stability and activity of proteolytic enzyme α-chymotrypsin (CT in the presence of cold atmospheric pressure plasma jet (APPJ. The present work aims to illustrate the state of art implementing the combined action of ILs and APPJ on the enzyme stability and activity. Our circular dichroism (CD, fluorescence and enzyme activity results of CT have revealed that buffer and all studied ILs {triethylammonium hydrogen sulphate (TEAS from ammonium family and 1-butyl-3-methyl imidazolium chloride ([Bmim][Cl], 1-methylimidazolium chloride ([Mim][Cl] from imidazolium family} are notable to act as protective agents against the deleterious action of the APPJ, except triethylammonium dihydrogen phosphate (TEAP ammonium IL. However, TEAP attenuates strongly the deleterious action of reactive oxygen species (ROS created by APPJ on native structure of CT. Further, TEAP is able to retain the enzymatic activity after APPJ exposure which is absent in all the other systems.This study provides the first combined effect of APPJ and ILs on biomolecules that may generate many theoretical and experimental opportunities. Through this methodology, we can utilise both enzyme and plasma simultaneously without affecting the enzyme structure and activity on the material surface; which can prove to be applicable in various fields.

  18. Enhanced Multisensory Integration and Motor Reactivation after Active Motor Learning of Audiovisual Associations

    Science.gov (United States)

    Butler, Andrew J.; James, Thomas W.; James, Karin Harman

    2011-01-01

    Everyday experience affords us many opportunities to learn about objects through multiple senses using physical interaction. Previous work has shown that active motor learning of unisensory items enhances memory and leads to the involvement of motor systems during subsequent perception. However, the impact of active motor learning on subsequent…

  19. Nucleolar re-activation is delayed in mouse embryos cloned from two different cell lines

    DEFF Research Database (Denmark)

    Svarcova, Olga; Dinnyes, A.; Polgar, Z.

    2009-01-01

    displayed early NPBs transformation. In conclusion, despite normal onset of EGA in cloned embryos, activation of functional nucleoli was one cell cycle delayed in NT embryos. NT-MEF embryos displayed normal targeting but delayed activation of nucleolar proteins. Contrary, in NT-HM1 embryos, both......Aim of this study was to evaluate and compare embryonic genome activation (EGA) in mouse embryos of different origin using nucleolus as a marker. Early and late 2-cell and late 4-cell stage embryos, prepared by in vitro fertilization (IVF), parthenogenetic activation (PG), and nuclear transfer...... ofmouse embryonic fibroblast (MEF) and mouse HM1 emryonic stem cells (HM1), were processed for autoradiography following 3H-uridine incubation (transcriptional activity), transmission electron microscopy (ultrastructure) and immunofluorescence (nucleolar proteins; upstream binding factor, UBF...

  20. Refractory material crucibles evaluation for U evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Damiao, A.J.; Vasconcelos, G.; Silveira, C.A.B.; Rodrigues, N.A.S. [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados

    1996-12-31

    In studies that involve small amounts of U vapor generation, such as spectroscopy or thin films, most of the E-gun power is delivered to the cooling system. Normally crucibles are used as container and thermal insulator. Since liquid U is extremely reactive at evaporation temperatures, the crucibles are seriously attacked, decreasing the insulation efficiency and adding contaminants to the U vapor. There is no complete solution for the problem, however, with a careful choice of materials, one can design crucibles with extended lifetime and reduced contamination. This work reports some preliminary results we have obtained in the assessing of crucible materials and design, such as, graphite, Si C, vitreous carbon and Al{sub 2} O{sub 3}. (author) 1 refs., 3 figs.,2 tabs.

  1. Evaporative cooling: effective latent heat of evaporation in relation to evaporation distance from the skin.

    Science.gov (United States)

    Havenith, George; Bröde, Peter; den Hartog, Emiel; Kuklane, Kalev; Holmer, Ingvar; Rossi, Rene M; Richards, Mark; Farnworth, Brian; Wang, Xiaoxin

    2013-03-15

    Calculation of evaporative heat loss is essential to heat balance calculations. Despite recognition that the value for latent heat of evaporation, used in these calculations, may not always reflect the real cooling benefit to the body, only limited quantitative data on this is available, which has found little use in recent literature. In this experiment a thermal manikin, (MTNW, Seattle, WA) was used to determine the effective cooling power of moisture evaporation. The manikin measures both heat loss and mass loss independently, allowing a direct calculation of an effective latent heat of evaporation (λeff). The location of the evaporation was varied: from the skin or from the underwear or from the outerwear. Outerwear of different permeabilities was used, and different numbers of layers were used. Tests took place in 20°C, 0.5 m/s at different humidities and were performed both dry and with a wet layer, allowing the breakdown of heat loss in dry and evaporative components. For evaporation from the skin, λeff is close to the theoretical value (2,430 J/g) but starts to drop when more clothing is worn, e.g., by 11% for underwear and permeable coverall. When evaporation is from the underwear, λeff reduction is 28% wearing a permeable outer. When evaporation is from the outermost layer only, the reduction exceeds 62% (no base layer), increasing toward 80% with more layers between skin and wet outerwear. In semi- and impermeable outerwear, the added effect of condensation in the clothing opposes this effect. A general formula for the calculation of λeff was developed.

  2. Evaporation from open microchannel grooves.

    Science.gov (United States)

    Kachel, Sibylle; Zhou, Ying; Scharfer, Philip; Vrančić, Christian; Petrich, Wolfgang; Schabel, Wilhelm

    2014-02-21

    The evaporation of water from open u-shaped microchannel grooves was investigated with particular emphasis on the roles of channel width and air flow conditions. Given the small dimensions of the microchannels, all measurements were conducted in a range where convection and diffusion are of equal importance and known correlations for the calculation of mass transfer coefficients cannot be applied. The evaporation rates were measured using a new optical method and a gravimetric method. Both measurement methods yielded mass transfer coefficients that are in agreement with each other. The observed relation between mass transfer coefficient, air velocity and channel width vastly differs from the predictions obtained from macroscopic structures. With respect to diagnostic devices we conclude that analyte concentration in an open microchannel groove strongly increases even within short times due to the evaporation process and we show that wider channels are more favourable in terms of minimizing the relative evaporation rate.

  3. Pinch analysis of evaporation systems

    Directory of Open Access Journals (Sweden)

    Westphalen D.L.

    2000-01-01

    Full Text Available Evaporation systems are separation processes widely used in chemical industries. Some guidelines can be found in the literature for the process integration of multiple effect evaporators. In the published methodologies some aspects are neglected as boiling point rise, effect of pressure on latent heat of water, sensible heat of liquid streams, heat of mixing, effects configuration and inclusion of accessories. In this work, a new graphical representation for the integration of multiple effect evaporators was developed, using rigorous physical properties. From this representation, an algorithm for optimization of bleed streams was conceived using the concepts of Pinch Analysis. As a case study, a crystal glucose plant was optimized using this new methodology. The optimization of bleed streams showed as result a steam consumption 16% smaller than a similar previous study. From energy and capital costs, it is shown that the integrated evaporator exhibits a total cost 14% smaller than the non-integrated configuration.

  4. Wnt signaling activates Shh signaling in early postnatal intervertebral discs, and re-activates Shh signaling in old discs in the mouse.

    Science.gov (United States)

    Winkler, Tamara; Mahoney, Eric J; Sinner, Debora; Wylie, Christopher C; Dahia, Chitra Lekha

    2014-01-01

    Intervertebral discs (IVDs) are strong fibrocartilaginous joints that connect adjacent vertebrae of the spine. As discs age they become prone to failure, with neurological consequences that are often severe. Surgical repair of discs treats the result of the disease, which affects as many as one in seven people, rather than its cause. An ideal solution would be to repair degenerating discs using the mechanisms of their normal differentiation. However, these mechanisms are poorly understood. Using the mouse as a model, we previously showed that Shh signaling produced by nucleus pulposus cells activates the expression of differentiation markers, and cell proliferation, in the postnatal IVD. In the present study, we show that canonical Wnt signaling is required for the expression of Shh signaling targets in the IVD. We also show that Shh and canonical Wnt signaling pathways are down-regulated in adult IVDs. Furthermore, this down-regulation is reversible, since re-activation of the Wnt or Shh pathways in older discs can re-activate molecular markers of the IVD that are lost with age. These data suggest that biological treatments targeting Wnt and Shh signaling pathways may be feasible as a therapeutic for degenerative disc disease.

  5. Droplets Evaporation on Heated Wall

    Directory of Open Access Journals (Sweden)

    Misyura S. Y.

    2015-01-01

    Full Text Available Various modes of evaporation in a wide range of droplet sizes and wall temperatures have been investigated in the present work. For any initial drop size there are three typical boiling regime: 1 the nucleate boiling; 2 the transitional regime; 3 the film boiling. The width of the transition region of boiling crisis increases with increasing the initial volume V0. Evaporation of large droplets at high superheat depends on the initial droplet shape.

  6. Metal-loaded polystyrene-based activated carbons as DBT removal media via reactive adsorption

    OpenAIRE

    2006-01-01

    [EN] To improve the desulfurization capability of activated carbons, new metal-loaded carbon-based sorbents containing sodium, cobalt, copper, and silver highly dispersed within the carbon matrix were prepared and tested at room temperature for dibenzothiophene (DBT) adsorption. The content of metals can be controlled by selective washing. The new adsorbents showed good adsorption capacities and selectivity towards DBT. The metals incorporated to the surface act not only as active sites for s...

  7. Protective effects of kaempferol against reactive oxygen species-induced hemolysis and its antiproliferative activity on human cancer cells.

    Science.gov (United States)

    Liao, Wenzhen; Chen, Luying; Ma, Xiang; Jiao, Rui; Li, Xiaofeng; Wang, Yong

    2016-05-23

    The protective effects of kaempferol against reactive oxygen species (ROS)-induced hemolysis and its antiproliferative activity on human cancer cells were evaluated in this study. Kaempferol exhibited strong cellular antioxidant ability (CAA) with a CAA value of 59.80 ± 0.379 μM of quercetin (QE)/100 μM (EC50 = 7.74 ± 0.049 μM). Pretreatment with kaempferol significantly attenuated the ROS-induced hemolysis of human erythrocyte (87.4% hemolysis suppressed at 100 μg/mL) and reduced the accumulation of toxic lipid peroxidation product malondialdehyde (MDA). The anti-hemolytic activity of kaempferol was mainly through scavenging excessive ROS and preserving the intrinsic antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GPx) activities in normal levels. Additionally, kaempferol showed significant antiproliferative activity on a panel of human cancer cell lines including human breast carcinoma (MCF-7) cells, human stomach carcinoma (SGC-7901) cells, human cervical carcinoma (Hela) cells and human lung carcinoma (A549) cells. Kaemperol induced apoptosis of MCF-7 cells accompanied with nuclear condensation and mitochondria dysfunction.

  8. Performance of iron filings and activated sludge as media for permeable reactive barriers to treat zinc contaminated groundwater

    Directory of Open Access Journals (Sweden)

    Chayapat Hassapak

    2015-02-01

    Full Text Available Zinc is one of the important contaminants in groundwater. Removal of zinc by iron filings, activated sludge and lateritic soil was studied with batch test. The lowest optimum pH for removal of zinc by iron filings, activated sludge and lateritic soil was 6. From isotherm studies iron filings and activated sludge were chosen as media for permeable reactive barrier (PRB. The PRB of 0.5-m thick was simulated in the unconfined aquifer with the distance of 21.5 m downgradient of the zinc contaminated site having constant concentration of 100 mg/l. The groundwater flow in the site was induced by the hydraulic gradient of 0.02. Simulation results indicated that the concentration of zinc of treated groundwater was less than 5 mg/l, which met Thai Groundwater Quality Standard for Drinking Purposes. The continuous PRBs using iron filings and activated sludge could treat zinc for 2,170 and 2,248 days, respectively

  9. Xanthohumol induces apoptosis in human malignant glioblastoma cells by increasing reactive oxygen species and activating MAPK pathways.

    Science.gov (United States)

    Festa, Michela; Capasso, Anna; D'Acunto, Cosimo W; Masullo, Milena; Rossi, Adriano G; Pizza, Cosimo; Piacente, Sonia

    2011-12-27

    The effect of the biologically active prenylated chalcone and potential anticancer agent xanthohumol (1) has been investigated on apoptosis of the T98G human malignant glioblastoma cell line. Compound 1 decreased the viability of T98G cells by induction of apoptosis in a time- and concentration-dependent manner. Apoptosis induced by 1 was associated with activation of caspase-3, caspase-9, and PARP cleavage and was mediated by the mitochondrial pathway, as exemplified by mitochondrial depolarization, cytochrome c release, and downregulation of the antiapoptotic Bcl-2 protein. Xanthohumol induced intracellular reactive oxygen species (ROS), an effect that was reduced by pretreatment with the antioxidant N-acetyl-L-cysteine (NAC). Intracellular ROS production appeared essential for the activation of the mitochondrial pathway and induction of apoptosis after exposure to 1. Oxidative stress due to treatment with 1 was associated with MAPK activation, as determined by ERK1/2 and p38 phosphorylation. Phosphorylation of ERK1/2 and p38 was attenuated using NAC to inhibit ROS production. After treatment with 1, ROS provided a specific environment that resulted in MAPK-induced cell death, with this effect reduced by the ERK1/2 specific inhibitor PD98059 and partially inhibited by the p38 inhibitor SB203580. These findings suggest that xanthohumol (1) is a potential chemotherapeutic agent for the treatment of glioblastoma multiforme.

  10. Personality effects on cardiovascular reactivity: need for closure moderates the impact of task difficulty on engagement-related myocardial beta-adrenergic activity.

    Science.gov (United States)

    Richter, Michael; Baeriswyl, Eric; Roets, Arne

    2012-05-01

    An experiment assessed the joint effect of dispositional need for closure (NFC) and task difficulty on engagement-related myocardial beta-adrenergic activity. Participants who scored either low or high on the NFC scale performed an ambiguous categorization task with either low or high difficulty. Confirming the theory-derived predictions, task difficulty effects on pre-ejection period (PEP) reactivity were moderated by NFC. If difficulty was low, PEP reactivity was low and independent of the participants' NFC level. If difficulty was high, participants with high NFC showed increased PEP reactivity compared to participants with low NFC. These results extend previous research on Wright's model of engagement-related cardiovascular reactivity and suggest that the model may provide a useful framework for assessing the impact of personality on cardiovascular response.

  11. Efficient transformation of DDT by peroxymonosulfate activated with cobalt in aqueous systems: Kinetics, products, and reactive species identification.

    Science.gov (United States)

    Qin, Wenxiu; Fang, Guodong; Wang, Yujun; Wu, Tongliang; Zhu, Changyin; Zhou, Dongmei

    2016-04-01

    Recently, sulfate radical ( [Formula: see text] ) based-advanced oxidation technologies (AOTs) have been attracted great attention in the remediation of contaminated soil and groundwater. In the present study, Co(2+) ions activated peroxymonosulfate (PMS) system was used to degrade 1, 1, 1-trichloro-2, 2'bis(p-chlorophenyl) ethane (DDT) in aqueous solutions. It was found that DDT was efficiently degraded in the PMS/Co(II) solutions within several hours, and the degradation efficiency of DDT was dependent on the concentrations of PMS and Co(II), and the optimum molar ratio of PMS and Co(II) was 50:1. The degradation kinetics of DDT were well described with pseudo-first-order equations over a range of temperature (10-40 °C), and the activation energy that was calculated with Arrhenius equation was 72.3 ± 2.6 kJ/mol. Electron paramagnetic resonance (EPR) and GC-MS techniques were applied to identify the intermediates and reactive species for DDT degradation. The results indicated that [Formula: see text] and OH were the main reactive species accounting for DDT degradation. Dichlorobenzophenone, 4-chlorobenzoic acid and benzylalcohol were the dominant intermediates for DDT degradation, and the likely degradation pathway of DDT was proposed on the basis of these identified products. Increasing pH inhibited the formation of [Formula: see text] and OH, and thus decreased the catalytic degradation of DDT. Cl(-) ion was found to significantly inhibit, while [Formula: see text] and dissolved oxygen had limited effects on DDT degradation.

  12. Graphitic-C(3)N(4)-hybridized TiO(2) nanosheets with reactive {001} facets to enhance the UV- and visible-light photocatalytic activity.

    Science.gov (United States)

    Gu, Liuan; Wang, Jingyu; Zou, Zhijuan; Han, Xijiang

    2014-03-15

    AnataseTiO(2)nanosheets with dominant {001} facets were hybridized with graphitic carbon nitride (g-C(3)N(4)) using a facile solvent evaporation method. On top of the superior photocatalytic performance of highly reactive {001} facets, the hybridization with g-C(3)N(4) is confirmed to further improve the reactivity through degrading a series of organic molecules under both UV- and visible-light irradiation. It is proposed that an effective charge separation between g-C(3)N(4) and TiO2 exists in the photocatalytic process, i.e., the transferring of photogenerated holes from the valence band (VB) of TiO(2) to the highest occupied molecular orbital (HOMO) of g-C(3)N(4), and the injecting of electrons from the lowest unoccupied molecular orbital (LUMO) of g-C(3)N(4) to the conduction band (CB) of TiO(2). Due to this synergistic effect, the enhancement of UV- and visible-light photoactivity over the hybrid is achieved. Furthermore, it has been revealed that holes were the main factor for the improved photoactivity under UV-light, while the OH radicals gained the predominance for degrading organic molecules under visible-light. Overall, this work would be significant for fabricating efficient UV-/visible-photocatalysts and providing deeper insight into the enhanced mechanisms of π-conjugated molecules hybridized semiconductors.

  13. Selective estrogen receptor modulator BC-1 activates antioxidant signaling pathway in vitro via formation of reactive metabolites

    Institute of Scientific and Technical Information of China (English)

    Bo-lan YU; Zi-xin MAI; Xu-xiang LIU; Zhao-feng HUANG

    2013-01-01

    Aim:Benzothiophene compounds are selective estrogen receptor modulators (SERMs),which are recently found to activate antioxidant signaling.In this study the molecular mechanisms of antioxidant signaling activation by benzothiophene compound BC-1 were investigated.Methods:HepG2 cells were stably transfected with antioxidant response element (ARE)-Iuciferase reporter (HepG2-ARE cells).The expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in HepG2-ARE cells was suppressed using siRNA.The metabolites of BC-1 in rat liver microsome incubation were analyzed using LC-UV and LC-MS.Results:Addition of BC-1 (5 μmol/L) in HepG2-ARE cells resulted in a 17-fold increase of ARE-luciferase activity.Pretreatment with the estrogen receptor agonist E2 (5 μmol/L) or antagonist ICl 182,780 (5 μmol/L) did not affect BC-1-induced ARE-luciferase activity.However,transfection of the cells with anti-Nrf2 siRNA suppressed this effect by 79%.Addition of BC-1 in rat microsome incubation resulted in formation of di-quinone methides and o-quinones,followed by formation of GSH conjugates.BC-1 analogues with hydrogen (BC-2) or fluorine (BC-3) at the 4' position did not form the di-quinone methides.Both BC-2 and BC-3 showed comparable estrogenic activity with BC-1,but did not induce ARE-luciferase activity in HepG2-ARE cells.Conclusion:Benzothiophene compound BC-1 activates ARE signaling via reactive metabolite formation that is independent of estrogen receptors.

  14. Serum Albumin and C-Reactive Protein/Albumin Ratio Are Useful Biomarkers of Crohn's Disease Activity.

    Science.gov (United States)

    Qin, Guangming; Tu, Jiangfeng; Liu, Lingang; Luo, Laisheng; Wu, Jiaqi; Tao, Lisha; Zhang, Chenjing; Geng, Xiaoge; Chen, Xiaojun; Ai, Xinbo; Shen, Bo; Pan, Wensheng

    2016-11-16

    BACKGROUND Serum albumin (ALB) may be low during acute inflammation, but it is also affected by nutritional status. Therefore, we hypothesized that ALB and the C-reactive protein/ALB ratio (CRP/ALB) may be associated with disease activity in patients with Crohn's disease (CD). MATERIAL AND METHODS Altogether, 100 patients with CD and 100 age- and sex-matched healthy volunteers were retrospectively enrolled in the current study. The patients with CD were subdivided into patients with active disease (Crohn's Disease Activity Index >150) and those in remission. ALB levels, CRP levels, and lipid profiles were measured. RESULTS ALB and CRP levels and the CRP/ALB ratio were the most useful for differentiating between active and nonactive CD. ALB levels (r=-0.50, Pratio (r=0.42, Panalysis indicated that the area under the curve (AUC) representing ALB (0.79) was higher than the AUC representing CRP (0.73) or CRP/ALB ratio (0.75; P>0.05). The AUCs corresponding to ALB level, CRP level, and CRP/ALB ratio were more prominent in males versus females (Pratio (0.69) had sensitivities of 67.7%, 72.6%, and 59.7%, and specificities of 73.7%, 78.9%, and 81.6%, respectively, for CD activity. CONCLUSIONS In the present retrospective study, we found that ALB level and CRP/ALB ratio were useful biomarkers for identifying CD activity, especially in males. These results suggest that, in addition to inflammation, assessment of patient nutritional status could also aid in identifying CD activity.

  15. Non evaporable getter (NEG) technology: A powerful tool for UHV-XHV systems

    Science.gov (United States)

    Maccallini, Enrico; Siviero, Fabrizio; Bonucci, Antonio; Conte, Andrea; Srivastava, Peeyush; Paolo, Manini

    2012-06-01

    Ultra and Extreme High Vacuum (UHV and XHV respectively) levels are needed in several vacuum-related applications for wide pressure and time range. The Non Evaporable Getter (NEG) technology is one of the most important examples to get XHV/UHV condition in the vacuum systems. In fact the high reactivity of the getter materials towards active gases in a wide temperature range (from room temperature to several hundreds of °C) allows removing very efficiently active gases such as H2, H2O, CO2, CO, N2, and so on. When declining, the pumping speed of NEG can be easily restored, by reactivating the getter material with a thermal process ("reactivation"). In this framework, SAES Getters S.p.A. has a long expertise in producing NEG pumps (and more in general NEG technology) which can provide vacuum conditions from the low to the ultra high level. An overall overview of NEG pump technology will be given in this paper considering 1) the involved mechanisms for gas adsorption into the NEG material, 2) operational conditions of NEG pumps and 3) example of applications which demonstrate the benefits of NEG pumps use in XHV/UHV systems. Future perspectives for NEG pumps in UHV/XHV applications will be also given.

  16. DWPF Recycle Evaporator Simulant Tests

    Energy Technology Data Exchange (ETDEWEB)

    Stone, M

    2005-04-05

    Testing was performed to determine the feasibility and processing characteristics of an evaporation process to reduce the volume of the recycle stream from the Defense Waste Processing Facility (DWPF). The concentrated recycle would be returned to DWPF while the overhead condensate would be transferred to the Effluent Treatment Plant. Various blends of evaporator feed were tested using simulants developed from characterization of actual recycle streams from DWPF and input from DWPF-Engineering. The simulated feed was evaporated in laboratory scale apparatus to target a 30X volume reduction. Condensate and concentrate samples from each run were analyzed and the process characteristics (foaming, scaling, etc) were visually monitored during each run. The following conclusions were made from the testing: Concentration of the ''typical'' recycle stream in DWPF by 30X was feasible. The addition of DWTT recycle streams to the typical recycle stream raises the solids content of the evaporator feed considerably and lowers the amount of concentration that can be achieved. Foaming was noted during all evaporation tests and must be addressed prior to operation of the full-scale evaporator. Tests were conducted that identified Dow Corning 2210 as an antifoam candidate that warrants further evaluation. The condensate has the potential to exceed the ETP WAC for mercury, silicon, and TOC. Controlling the amount of equipment decontamination recycle in the evaporator blend would help meet the TOC limits. The evaporator condensate will be saturated with mercury and elemental mercury will collect in the evaporator condensate collection vessel. No scaling on heating surfaces was noted during the tests, but splatter onto the walls of the evaporation vessels led to a buildup of solids. These solids were difficult to remove with 2M nitric acid. Precipitation of solids was not noted during the testing. Some of the aluminum present in the recycle streams was converted

  17. Cardiovascular Reactivity: its Association with Physical Activity, and Some Hemodynamic and Anthropometric Variables

    Directory of Open Access Journals (Sweden)

    Milagros Lisset León Regal

    2016-09-01

    Full Text Available Background: several studies show the influence of physical activity as a protective factor of the cardiovascular system. New evidence forcorroborating this are needed to ensure the prevention of cardiovascular disease. Objective: to determine the relationship between cardiovascular hyperactivity, physical activity and some homodynamic and anthropometric variables in normotensive individuals. Methods: a descriptive correlational cross-sectional study was conducted. The universe of the study consisted of the population between 15 and 74 of the municipality of Cienfuegos in 2010, the sample was 644. The variables were considered: sex, skin colour, age, height, weight, index of body mass, abdominal waist, blood pressures: systolic, diastolic, average and differential (basal and sustained weight test and physical activity. Pearson Chi- square test was calculated and t was applied for comparison of average independent samples with a significance level of p = 0,05. Prevalence ratios were determined with a confidence interval of 95 %. Results: the prevalence of cardiovascular hyperactivity was higher in the group of 65-74 years and males. Cardiovascular hyperactives showed values of the average hemodynamic variables studied cardiovascular over normoreactive. There is an association between physical activity and better cardiovascular response in normal weight individuals. Conclusions: there is an association between increased blood pressure and obesity in cardiovascular hyperactivity. Physical activity is associated with cardiovascular normoreactivity in normal weight.

  18. Evaporation kinetics of DIDP plasticizer from PVC

    Science.gov (United States)

    Djouani, Fatma; Mkacher, Inès; Colin, Xavier; Brument, Yves; Cristiano-Tassi, Antonella

    2014-05-01

    The physical loss of diisodecyl phthalate (DIDP) plasticizer from PVC films of about 50 μm thickness has been investigated between 95 and 160°C in air by FTIR spectrophotometry and gravimetry. Complementary OIT measurements have been performed to follow the stabilizer depletion and to confirm that the dehydrochlorination of PVC remains negligible for all exposure durations under study. As expected for thin PVC films, the overall loss kinetics obeys a first order law, indicating that it is controlled by DIDP evaporation. The corresponding coefficient of DIDP evaporation obeys an Arrhenius law with an activation energy of about 96 kJ mol-1. These results are in good agreement with those previously reported in the literature for other types of phthalate plasticizers of PVC.

  19. Regulatory functions of hapten-reactive helper and suppressor T lymphocytes. I. Detection and characterization of hapten-reactive suppressor T-cell activity in mice immunized with hapten-isologous protein conjugate

    Science.gov (United States)

    Yamamoto, H; Hamaoka, T; Yoshizawa, M; Kuroki, M; Kitagawa, M

    1977-01-01

    Helper and suppressor T-cell activities were detected simultaneously in the spleen cells of mice immunized with para-azobenzoate (PAB)-mouse gammaglobulin (MGG). Dinitrophenyl (DNP)-specific B cells were raised by immunization with DNP-keyhole limpet hemocyanin (KLH) and used as the indicator B-cell population. The helper and suppressor T-cell activities were determined after adoptively transferring spleen cells from PAB-MGG- primed donors and DNP-KLH-primed donors into X-irradiated recipients. Stimulation of these recipients with DNP-MGG-PAB detected helper T-cell activity, which was measured in terms of increased anti-DNP antibody responses of DNP-KLH-primed cells over these responses in the presence of unprimed cells. On the other hand, when DNP-KLH-primed cells were stimulated with DNP-KLH-PAB in the presence of PAB-MGG-primed cells, anti-DNP antibody responses were substantially lower than in unprimed normal cells. This suppressor cell population was (a) hapten-reactive, (b) present in B-cell-depleted spleen cells, (c) Thy-1 positive, (d) detectable earlier than the helper T-cell activities after priming (e) more radiosensitive than helper cells, and (f) found in the spleen but not the lymph nodes in contrast to helper T cells. These data indicate that these suppressor T cells are distinct from the helper T cells. PAB-reactive T cells clearly suppressed the antibody response by inhibiting KLH-reactive helper T-cell functions. The hapten-reactive T-lymphocyte system described here should be useful for analyzing and manipulating the immune response and for studying regulatory interactions of helper and suppressor T cells in the induction of antibody responses. PMID:68994

  20. Thermal Effects of the Substrate on Water Droplet Evaporation

    Science.gov (United States)

    Sobac, Benjamin; Brutin, David

    2012-11-01

    Since a few decades, the evaporation of a drop deposited onto a substrate has been subject to numerous research activities due to the increase of the range of applications underpinned by this phenomenon. However, this process today is always a challenging problem in soft matter physics due to the complexity of present couplings: fluid dynamic, physical chemistry of the substrate, heat and mass transfer. The originality of the presented experiment is to decouple the effects of wetting properties and thermal properties of the substrate. Thus, whereas we previously presented the role of wetting properties on evaporation by changing the surface energy and the roughness while maintaining the thermal properties constant thanks to nanoscale coatings on the substrate surface (B. Sobac and D. Brutin, Langmuir 27, 14999 (2011)), we investigate here the influence of the thermal properties of the substrate while keeping the wetting properties the same (B. Sobac and D. Brutin, Phys. Rev. E, underpress). We experimentally investigate the behavior of a pinned droplet evaporating into air. The influences of the substrate temperature and substrate thermal properties on the evaporation process are studied in both hydrophilic and hydrophobic conditions. Experimental data are compared to the quasi-steady diffusion-driven evaporation model assuming the isothermia of the drop at the substrate temperature. This comparison permits to highlights several thermal mechanisms linked to evaporation and their respective contributions in regard of pure mass diffusion mechanism. The range of validity of the classical evaporation model is also discussed.

  1. Nipping cue reactivity in the bud: baclofen prevents limbic activation elicited by subliminal drug cues.

    Science.gov (United States)

    Young, Kimberly A; Franklin, Teresa R; Roberts, David C S; Jagannathan, Kanchana; Suh, Jesse J; Wetherill, Reagan R; Wang, Ze; Kampman, Kyle M; O'Brien, Charles P; Childress, Anna Rose

    2014-04-02

    Relapse is a widely recognized and difficult to treat feature of the addictions. Substantial evidence implicates cue-triggered activation of the mesolimbic dopamine system as an important contributing factor. Even drug cues presented outside of conscious awareness (i.e., subliminally) produce robust activation within this circuitry, indicating the sensitivity and vulnerability of the brain to potentially problematic reward signals. Because pharmacological agents that prevent these early cue-induced responses could play an important role in relapse prevention, we examined whether baclofen-a GABAB receptor agonist that reduces mesolimbic dopamine release and conditioned drug responses in laboratory animals-could inhibit mesolimbic activation elicited by subliminal cocaine cues in cocaine-dependent individuals. Twenty cocaine-dependent participants were randomized to receive baclofen (60 mg/d; 20 mg t.i.d.) or placebo. Event-related BOLD fMRI and a backward-masking paradigm were used to examine the effects of baclofen on subliminal cocaine (vs neutral) cues. Sexual and aversive cues were included to examine specificity. We observed that baclofen-treated participants displayed significantly less activation in response to subliminal cocaine (vs neutral) cues, but not sexual or aversive (vs neutral) cues, than placebo-treated participants in a large interconnected bilateral cluster spanning the ventral striatum, ventral pallidum, amygdala, midbrain, and orbitofrontal cortex (voxel threshold p baclofen may inhibit the earliest type of drug cue-induced motivational processing-that which occurs outside of awareness-before it evolves into a less manageable state.

  2. Autonomic nervous activation triggered during induction of reactive hyperemia exerts a greater influence on the measured reactive hyperemia index by peripheral arterial tonometry than on flow-mediated vasodilatation of the brachial artery in patients with hypertension.

    Science.gov (United States)

    Tomiyama, Hirofumi; Yoshida, Masanobu; Higashi, Yukihito; Takase, Bonpei; Furumoto, Tomoo; Kario, Kazuomi; Ohya, Yusuke; Yamashina, Akira

    2014-10-01

    Flow-mediated vasodilatation of the brachial artery (FMD) and reactive hyperemia index (RHI) measured by peripheral arterial tonometry are known to be weakly associated with one another, but the mechanisms underlying this weak association remain to be clarified. We examined whether the autonomic nervous activation induced by the 5 min forearm clamping used to induce reactive hyperemia might exert any influence on the FMD and RHI in subjects with hypertension. In 115 subjects with hypertension (age 61±1 years), the FMD and RHI were measured simultaneously, and the heart rate variability (HRV) parameters (low-frequency component (LF), high-frequency component (HF), and the ratio (LF/HF) between the two) were calculated from the electrocardiographic recordings obtained before and after the start of forearm clamping. A multivariate linear regression analysis with adjustments for confounding variables demonstrated that the RHI, but not the FMD, was significantly associated with the percent change of the LF/HF associated with forearm clamping (beta=-0.204, P=0.043). In conclusion, autonomic nervous system activation, especially sympathetic activation, induced by 5-min forearm clamping utilized to provoke reactive hyperemia may significantly affect the RHI rather than FMD in subjects with hypertension.

  3. Neogene and active shortening offshore the reactivated Levant margin in Lebanon: results of the SHALIMAR cruise

    Science.gov (United States)

    Briais, A.; Singh, S. C.; Tapponnier, P.; Elias, A.; Sursock, A.; Jomaa, R.; Carton, H.; Daeron, M.; King, G.; Jacques, E.

    2004-12-01

    . The particularly large negative anomalies in the north likely reflect flexure of the lithosphere due to subduction under Cyprus and underthrusting beneath Lebanon. The SHALIMAR data suggest that local compression induced by the bend in the Dead Sea Transform reactivated faults of the Mesozoic Levant margin into lateral ramps and thrusts whose evolution may lead to subduction. It is possible that the shorter distance between the transform and margin in central Lebanon (35 km) than in Syria (65 km) is one measure of continental shortening. That the oceanic lithosphere is strong may explain why the Carmel and Roum faults did not extend into the Levant basin.

  4. Molecular hydrogen inhibits lipopolysaccharide-triggered NLRP3 inflammasome activation in macrophages by targeting the mitochondrial reactive oxygen species.

    Science.gov (United States)

    Ren, Jian-Dong; Wu, Xiao-Bo; Jiang, Rui; Hao, Da-Peng; Liu, Yi

    2016-01-01

    The NLRP3 inflammasome, an intracellular multi-protein complex controlling the maturation of cytokine interleukin-1β, plays an important role in lipopolysaccharide (LPS)-induced inflammatory cascades. Recently, the production of mitochondrial reactive oxygen species (mtROS) in macrophages stimulated with LPS has been suggested to act as a trigger during the process of NLRP3 inflammasome activation that can be blocked by some mitochondria-targeted antioxidants. Known as a ROS scavenger, molecular hydrogen (H2) has been shown to possess therapeutic benefit on LPS-induced inflammatory damage in many animal experiments. Due to the unique molecular structure, H2 can easily target the mitochondria, suggesting that H2 is a potential antagonist of mtROS-dependent NLRP3 inflammasome activation. Here we have showed that, in mouse macrophages, H2 exhibited substantial inhibitory activity against LPS-initiated NLRP3 inflammasome activation by scavenging mtROS. Moreover, the elimination of mtROS by H2 resultantly inhibited mtROS-mediated NLRP3 deubiquitination, a non-transcriptional priming signal of NLRP3 in response to the stimulation of LPS. Additionally, the removal of mtROS by H2 reduced the generation of oxidized mitochondrial DNA and consequently decreased its binding to NLRP3, thereby inhibiting the NLRP3 inflammasome activation. Our findings have, for the first time, revealed the novel mechanism underlying the inhibitory effect of molecular hydrogen on LPS-caused NLRP3 inflammasome activation, highlighting the promising application of this new antioxidant in the treatment of LPS-associated inflammatory pathological damage.

  5. Preliminary Evidence for Impaired Brain Activity of Neural Reward Processing in Children and Adolescents with Reactive Attachment Disorder.

    Science.gov (United States)

    Tomoda, Akemi

    2016-01-01

    Childhood maltreatment, which markedly increases risks for psychopathology, is associated with structural and functional brain differences. Especially, exposure to parental verbal abuse (PVA) or interparental violence during childhood is associated with negative outcomes such as depression, posttraumatic stress disorder (PTSD), and reduced cognitive abilities. Other forms of childhood maltreatment have been associated with brain structure or developmental alteration. Our earlier studies elucidated potential discernible effects of PVA and witnessing domestic violence during childhood on brain morphology, including gray matter volume or cortical thickness. Brain regions that process and convey the adverse sensory input of the abuse might be modified specifically by such experiences, particularly in subjects exposed to a single type of maltreatment. Exposure to multiple types of maltreatment is more commonly associated with morphological alterations in the corticolimbic regions. These findings fit with preclinical studies showing that sensory cortices are highly plastic structures. Using tasks with high and low monetary rewards while subjects underwent functional MRI, we also examined whether neural activity during reward processing was altered, or not, in children and adolescents with reactive attachment disorder (RAD). Significantly reduced activity in the caudate and nucleus accumbens was observed during a high monetary reward condition in the RAD group compared to the typically developed group. The striatal neural reward activity in the RAD group was also markedly decreased. The present results suggest that dopaminergic dysfunction occurred in the striatum in children and adolescents with RAD, potentially leading to a future risk of psychiatric disorders such as dependence.

  6. Novel activated alumina-supported iron oxide-composite as a heterogeneous catalyst for photooxidative degradation of reactive black 5

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, C.L. [Department of Chemical Engineering, National Cheng Kung University, Tainan City 701, Taiwan (China); Huang, Y.H. [Department of Chemical Engineering, National Cheng Kung University, Tainan City 701, Taiwan (China); Chen, C.Y. [Department of Chemical Engineering, National Cheng Kung University, Tainan City 701, Taiwan (China)]. E-mail: ccy7@ccmail.ncku.edu.tw

    2006-02-28

    A novel activated alumina-supported iron oxide-composite (denoted as FeAA-500) was prepared by so-called fluidized-bed reactor (FBR) crystallization. X-ray powder diffraction (XRD), N{sub 2} adsorption/desorption, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to characterize the FeAA-500. The photo-catalytic activity of the FeAA-500 was evaluated in the photooxidative degradation of 0.1 mM azo-dye reactive black 5 (RB5) in the presence of H{sub 2}O{sub 2} and UVA light ({lambda} = 365 nm) in a solution with a pH of 2.5. Complete decolorization of the model pollutant RB5 was achieved; the total organic carbon (TOC) removal ratio was 95%, and a trace amount of leached ferric ion was detected following 75 min of reaction when 2.0 g/L FeAA-500 was used as a catalyst. FeAA-500 has high photo-catalytic activity; it is therefore a promising heterogeneous photocatalysis of the degradation of organic compounds.

  7. Reactive astrocytes promote the metastatic growth of breast cancer stem-like cells by activating Notch signalling in brain.

    Science.gov (United States)

    Xing, Fei; Kobayashi, Aya; Okuda, Hiroshi; Watabe, Misako; Pai, Sudha K; Pandey, Puspa R; Hirota, Shigeru; Wilber, Andrew; Mo, Yin-Yuan; Moore, Brian E; Liu, Wen; Fukuda, Koji; Iiizumi, Megumi; Sharma, Sambad; Liu, Yin; Wu, Kerui; Peralta, Elizabeth; Watabe, Kounosuke

    2013-03-01

    Brain metastasis of breast cancer profoundly affects the cognitive and sensory functions as well as morbidity of patients, and the 1 year survival rate among these patients remains less than 20%. However, the pathological mechanism of brain metastasis is as yet poorly understood. In this report, we found that metastatic breast tumour cells in the brain highly expressed IL-1β which then 'activated' surrounding astrocytes. This activation significantly augmented the expression of JAG1 in the astrocytes, and the direct interaction of the reactivated astrocytes and cancer stem-like cells (CSCs) significantly stimulated Notch signalling in CSCs. We also found that the activated Notch signalling in CSCs up-regulated HES5 followed by promoting self-renewal of CSCs. Furthermore, we have shown that the blood-brain barrier permeable Notch inhibitor, Compound E, can significantly suppress the brain metastasis in vivo. These results represent a novel paradigm for the understanding of how metastatic breast CSCs re-establish their niche for their self-renewal in a totally different microenvironment, which opens a new avenue to identify a novel and specific target for the brain metastatic disease.

  8. Glibenclamide decreases ATP-induced intracellular calcium transient elevation via inhibiting reactive oxygen species and mitochondrial activity in macrophages.

    Directory of Open Access Journals (Sweden)

    Duo-ling Li

    Full Text Available Increasing evidence has revealed that glibenclamide has a wide range of anti-inflammatory effects. However, it is unclear whether glibenclamide can affect the resting and adenosine triphosphate (ATP-induced intracellular calcium ([Ca(2+]i handling in Raw 264.7 macrophages. In the present study, [Ca(2+]i transient, reactive oxygen species (ROS and mitochondrial activity were measured by the high-speed TILLvisION digital imaging system using the indicators of Fura 2-am, DCFDA and rhodamine-123, respectively. We found that glibenclamide, pinacidil and other unselective K(+ channel blockers had no effect on the resting [Ca(2+]i of Raw 264.7 cells. Extracellular ATP (100 µM induced [Ca(2+]i transient elevation independent of extracellular Ca(2+. The transient elevation was inhibited by an ROS scavenger (tiron and mitochondria inhibitor (rotenone. Glibenclamide and 5-hydroxydecanoate (5-HD also decreased ATP-induced [Ca(2+]i transient elevation, but pinacidil and other unselective K(+ channel blockers had no effect. Glibenclamide also decreased the peak of [Ca(2+]i transient induced by extracellular thapsigargin (Tg, 1 µM. Furthermore, glibenclamide decreased intracellular ROS and mitochondrial activity. When pretreated with tiron and rotenone, glibenclamide could not decrease ATP, and Tg induced maximal [Ca(2+]i transient further. We conclude that glibenclamide may inhibit ATP-induced [Ca(2+]i transient elevation by blocking mitochondria KATP channels, resulting in decreased ROS generation and mitochondrial activity in Raw 264.7 macrophages.

  9. Loss of Receptor on Tuberculin-Reactive T-Cells Marks Active Pulmonary Tuberculosis

    OpenAIRE

    2007-01-01

    BACKGROUND: Tuberculin-specific T-cell responses have low diagnostic specificity in BCG vaccinated populations. While subunit-antigen (e.g. ESAT-6, CFP-10) based tests are useful for diagnosing latent tuberculosis infection, there is no reliable immunological test for active pulmonary tuberculosis. Notably, all existing immunological tuberculosis-tests are based on T-cell response size, whereas the diagnostic potential of T-cell response quality has never been explored. This includes surface ...

  10. Body composition, physical activity and C-reactive protein in children : the PLAY study / Berna Harmse

    OpenAIRE

    Harmse, Berna

    2006-01-01

    Obesity is currently the most common and costly nutritional problem in developed countries and ten percent of the world's school-aged children are estimated to be overweight to some extent. Low-grade systemic inflammation is increasingly emerging as a significant component of the metabolic syndrome. Youth in lower income families are particularly vulnerable because of poor diet and limited opportunities for physical activity. In developing countries obesity among youth is ri...

  11. Temperature-dependent regioselectivity of nucleophilic aromatic photosubstitution. Evidence that activation energy controls reactivity.

    Science.gov (United States)

    Wubbels, Gene G; Tamura, Ryo; Gannon, Emmett J

    2013-05-17

    Irradiation (λ > 330 nm) of 2-chloro-4-nitroanisole (1) at 25 °C in aqueous NaOH forms three substitution photoproducts: 2-methoxy-5-nitrophenol (2), 2-chloro-4-nitrophenol (3), and 3-chloro-4-methoxyphenol (4), in chemical yields of 69.2%, 14.3%, and 16.5%. The activation energies for the elementary steps from the triplet state at 25 °C were determined to be 1.8, 2.4, and 2.7 kcal/mol, respectively. The chemical yields of each of the three products were determined for exhaustive irradiations at 0, 35, and 70 °C. The variation with temperature of the experimental yields is reproduced almost exactly by the yields calculated with the Arrhenius equation. This indicates that activation energy is the fundamental property related to regioselectivity in nucleophilic aromatic photosubstitution of the S(N)2 Ar* type. The many methods proposed for predicting regioselectivity in reactions of this type have had limited success and have not been related to activation energy.

  12. Thermal mineralization behavior of PFOA, PFHxA, and PFOS during reactivation of granular activated carbon (GAC) in nitrogen atmosphere.

    Science.gov (United States)

    Watanabe, Nobuhisa; Takata, Mitsuyasu; Takemine, Shusuke; Yamamoto, Katsuya

    2015-09-11

    Waste disposal site is one of the important sinks of chemicals. A significant amount of perfluoroalkyl and polyfluoroalkyl substances (PFASs) such as perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexanoic acid (PFHxA) have been brought into it. Because of their aqueous solubility, PFASs are released to landfill effluent waters, from which PFASs are efficiently collected by adsorption technique using granular activated carbon (GAC). The exhausted GAC is reactivated by heating processes. The mineralization of PFASs during the reactivation process was studied. Being thermally treated in N2 atmosphere, the recovery rate of mineralized fluorine and PFC homologues including short-chained perfluorocarboxylic acids was determined. If the reagent form of PFOA, PFHxA, and PFOS were treated at 700 °C, the recovery of mineralized fluorine was less than 30, 46, and 72 %, respectively. The rate increased to 51, 74, and 70 %, if PFASs were adsorbed onto GAC in advance; moreover, addition of excess sodium hydroxide (NaOH) improved the recovery to 74, 91, and 90 %. Residual PFAS homologue was less than 1 % of the original amount. Steamed condition did not affect destruction. The significant role of GAC was to suppress volatile release of PFASs from thermal ambient, whereas NaOH enhanced destruction and retained mineralized fluorine on the GAC surface. Comparing the recovery of mineralized fluorine, the degradability of PFOS was considered to be higher than PFOA and PFHxA. Whole mass balance missing 9~26 % of initial amount suggested formation of some volatile organofluoro compounds beyond analytical coverage.

  13. Effect of reaction environments on the reactivity of PCB (2-chlorobiphenyl) over activated carbon impregnated with palladized iron

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyeok [Department of Civil Engineering, University of Texas at Arlington, 416 Yates Drive, Arlington, TX 76019-0308 (United States); Al-Abed, Souhail R., E-mail: al-abed.souhail@epa.gov [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States)

    2010-07-15

    Reactive activated carbon (RAC) impregnated with palladized iron nanoparticles has been developed to treat polychlorinated biphenyls (PCBs). In this study, we evaluated the effects of various reaction environments on the adsorption-mediated dechlorination of 2-chlorobiphenyl (2-ClBP) in the RAC system. The results were discussed in close connection to the implementation issue of the RAC system for the remediation of contaminated sites with PCBs. Adsorption event of 2-ClBP onto RAC limited the overall performance under condition with a 2-ClBP/RAC mass ratio of less than 1.0 x 10{sup -4} above which dechlorination of 2-ClBP adsorbed to RAC was the reaction rate-determining step. Acidic and basic conditions were harmful to 2-ClBP adsorption and iron stability while neutral pH showed the highest adsorption-promoted dechlorination of 2-ClBP and negligible metal leaching. Coexisting natural organic matter (NOM) slightly inhibited 2-ClBP adsorption onto RAC due to the partial partitioning of 2-ClBP into NOM in the liquid phase while the 2-ClBP absorbed into NOM, which also tended to adsorb onto RAC, was less available for the dechlorination reaction. Common anions slowed down 2-ClBP adsorption but adsorbed 2-ClBP was almost simultaneously dechlorinated. Some exceptions included strong inhibitory effect of carbonate species on 2-ClBP adsorption and severe detrimental effect of sulfite on 2-ClBP dechlorination. Results on treatment of 2-ClBP spiked to actual sediment supernatants implied site-specific reactivity of RAC.

  14. Negative Regulation of Leptin-induced Reactive Oxygen Species (ROS) Formation by Cannabinoid CB1 Receptor Activation in Hypothalamic Neurons.

    Science.gov (United States)

    Palomba, Letizia; Silvestri, Cristoforo; Imperatore, Roberta; Morello, Giovanna; Piscitelli, Fabiana; Martella, Andrea; Cristino, Luigia; Di Marzo, Vincenzo

    2015-05-29

    The adipocyte-derived, anorectic hormone leptin was recently shown to owe part of its regulatory effects on appetite-regulating hypothalamic neuropeptides to the elevation of reactive oxygen species (ROS) levels in arcuate nucleus (ARC) neurons. Leptin is also known to exert a negative regulation on hypothalamic endocannabinoid levels and hence on cannabinoid CB1 receptor activity. Here we investigated the possibility of a negative regulation by CB1 receptors of leptin-mediated ROS formation in the ARC. Through pharmacological and molecular biology experiments we report data showing that leptin-induced ROS accumulation is 1) blunted by arachidonyl-2'-chloroethylamide (ACEA) in a CB1-dependent manner in both the mouse hypothalamic cell line mHypoE-N41 and ARC neuron primary cultures, 2) likewise blocked by a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, troglitazone, in a manner inhibited by T0070907, a PPAR-γ antagonist that also inhibited the ACEA effect on leptin, 3) blunted under conditions of increased endocannabinoid tone due to either pharmacological or genetic inhibition of endocannabinoid degradation in mHypoE-N41 and primary ARC neuronal cultures from MAGL(-/-) mice, respectively, and 4) associated with reduction of both PPAR-γ and catalase activity, which are reversed by both ACEA and troglitazone. We conclude that CB1 activation reverses leptin-induced ROS formation and hence possibly some of the ROS-mediated effects of the hormone by preventing PPAR-γ inhibition by leptin, with subsequent increase of catalase activity. This mechanism might underlie in part CB1 orexigenic actions under physiopathological conditions accompanied by elevated hypothalamic endocannabinoid levels.

  15. Thyroid gland in vitro activity and reactivity to TRH in newborn lambs.

    Science.gov (United States)

    Wronska, D

    2015-10-01

    The aim of the study was to determine the thyroid gland tissue concentration and activity on T4 and T3 in vitro release to the medium without (control) or with TRH (10 μg/ml) for 90 min of incubation in lambs just after birth and after the first 6h of postnatal life. The results obtained show that T4 concentration in the blood plasma in newborn lambs as well after 6h of life is higher than in thyroid gland tissue. In the case of T3 the concentration in blood plasma of lambs just after birth is lower than after 6h of postnatal life. Inversely, the higher level of that hormone concentration in blood plasma just after birth is higher than in the thyroid gland tissue. The results clearly indicate the inhibitory TRH effect on in vitro T4 especially, and in lesser degree T3 release from the thyroid gland tissue of lambs just after birth. Stimulation of the TRH thyroid gland tissue from lambs after 6h of life caused an increase in T4 release, especially after 60 min of the experiment. Similarly, a significant increase of T3 release was found only after 60 min of incubation. The transient promoting TRH effect on the amount of iodothyronine release from the thyroid gland in older lambs is probably connected with this gland's function not occurring before the designated time of postnatal adaptation. The described in vitro experiment visibly shows that changing thyroid gland activity in newborn lambs is not only conditioned by the entire HPT activity, but by the immanent thyroid gland attributes as well.

  16. Reactivity of CO2 Activated on Transition Metals and Sulfur Ligands.

    Science.gov (United States)

    Kobayashi, Katsuaki; Tanaka, Koji

    2015-06-01

    Dicationic dicarbonyl [Ru(bpy)2(CO)2](2+) (bpy = 2,2'- bipyridyl) exists as equilibrium mixtures with [Ru(bpy)2(CO)(COOH)](+) and [Ru(bpy)2(CO)(CO2)](0) depending on the pH in H2O. Those three complexes work as the precursors to CO, HCOOH production, and CO2 carrier, respectively, in electro- and photochemical CO2 reduction in aqueous solutions. However, [Ru(bpy)2(CO)2](2+) loses the catalytic activity toward CO2 reduction under aprotic conditions because [Ru(bpy)2(CO)2](2+) is not regenerated from [Ru(bpy)2(CO)(CO2)](0) in the absence of proton sources. Analogous monocarbonylruthenium complexes such as [Ru(tpy)(bpy)(CO)](2+) and [Ru(bpy)2(qu)(CO)](2+) catalyze CO2 reduction in the absence and presence of proton sources. Both complexes are reproduced through oxide transfer from the corresponding Ru-CO2 to CO2 in CO2 reduction and produce the same amount of CO and CO3(2-) in the absence of proton donors. The reduction of CO2 catalyzed by polypyridylrhenium complexes in the presence of proton sources takes place via essentially the similar mechanism as that in the case of ruthenium complexes. On the other hand, CO evolution in CO2 reduction under aprotic conditions is ascribed to the dissociation of CO from a dimeric Re-C(O)OC(O)O-Re scaffold. Visible-light irradiation to a catalytic system composed of [Ru(bpy)2(CO)2](2+)/[Ru(bpy)3](2+)/Me2NH2(+)/Me2NH as the catalyst, photosensitizer, proton donor, and nucleophile in addition to the electron donor, respectively, in CO2-saturated CH3CN selectively produces N,N-dimethylformamide without concomitant CO and HCOOH formation. Structurally robust μ3-S of reduced metal-sulfur clusters provides a suitable site for reductive activation of CO2 with retention of the framework. Indeed, CO2 activated on μ3-S of [Fe6Mo2S8(SEt)3](5-) is fixed at the carbonyl carbon of thioesters trapped on a neighboring iron of the cluster, and α-keto acids are produced catalytically. Furthermore, two-electron reduction of [(CpMen)3M3S3](2+) (n

  17. Reactive Oxygen Species Scavenging Activity of Flavone Glycosides from Melilotus neapolitana

    Directory of Open Access Journals (Sweden)

    Pietro Monaco

    2007-02-01

    Full Text Available One new and six known flavone glycosides were isolated from the MeOH extract of Melilotus neapolitana Ten. The new compound, identified as 7-O-β-D-gluco-pyranosyloxy-4',5-dihydroxy-3-[O-α-L-rhamnopyranosyl-(1→6-3-O-β-D-glucopyrano-syloxy]flavone (1 by 1D and 2D NMR techniques and mass spectra, was isolated along with kaempferol-3-O-rutinoside (2, kaempferol-3-O-glucoside (3, rutin (4, quercetin-3-O-glucoside (5, isorhamnetin-3-O-rutinoside (6, and isorhamnetin-3-O-glucoside (7. The antioxidant and radical scavenging activities of these compounds and the whole crude methanol extract were evaluated. The organic extract can inhibit MDA marker’s synthesis by 57%. All the metabolites displayed good reducing power, with the kaempferol (2,3 and isorhamnetin derivatives (6,7 being less active than the corresponding quercetin derivatives 4,5.

  18. Correlation for Sessile Drop Evaporation

    Science.gov (United States)

    Kelly-Zion, Peter; Pursell, Christopher; Wassom, Gregory; Mandelkorn, Brenton; Nkinthorn, Chris

    2016-11-01

    To better understand how the evaporation of sessile drops and small puddles is controlled by the vapor phase transport mechanisms of mass diffusion and buoyancy-induced convection, the evaporation rates of eight liquids evaporating under a broad range of ambient conditions were correlated with physical and geometrical properties. Examination of the correlation provides valuable insight into how the roles of diffusive and convective transport change with physical and geometrical parameters. The correlation predicts measured evaporation rates to within a root-mean-square error of 7.3%. The correlation is composed of two terms, a term which provides the rate of evaporation under diffusion-only conditions, and a term which provides the influence of convection. This second term suggests the manner in which the processes of diffusion and convection are coupled. Both processes are dependent on the distribution of the vapor, through the molar concentration gradient for diffusion and through the mass density gradient for convection. The term representing the influence of convection is approximately inversely proportional to the square root of diffusivity, indicating the tendency of diffusive transport to reduce convection by making the vapor distribution more uniform. Financial support was provided by the ACS Petroleum Research Fund.

  19. New avenues for ligand-mediated processes--expanding metal reactivity by the use of redox-active catechol, o-aminophenol and o-phenylenediamine ligands.

    Science.gov (United States)

    Broere, Daniël L J; Plessius, Raoul; van der Vlugt, Jarl Ivar

    2015-10-01

    Redox-active ligands have evolved from being considered spectroscopic curiosities - creating ambiguity about formal oxidation states in metal complexes - to versatile and useful tools to expand on the reactivity of (transition) metals or to even go beyond what is generally perceived possible. This review focusses on metal complexes containing either catechol, o-aminophenol or o-phenylenediamine type ligands. These ligands have opened up a new area of chemistry for metals across the periodic table. The portfolio of ligand-based reactivity invoked by these redox-active entities will be discussed. This ranges from facilitating oxidative additions upon d(0) metals or cross coupling reactions with cobalt(iii) without metal oxidation state changes - by functioning as an electron reservoir - to intramolecular ligand-to-substrate single-electron transfer to create a reactive substrate-centered radical on a Pd(ii) platform. Although the current state-of-art research primarily consists of stoichiometric and exploratory reactions, several notable reports of catalysis facilitated by the redox-activity of the ligand will also be discussed. In conclusion, redox-active ligands containing catechol, o-aminophenol or o-phenylenediamine moieties show great potential to be exploited as reversible electron reservoirs, donating or accepting electrons to activate substrates and metal centers and to enable new reactivity with both early and late transition as well as main group metals.

  20. Structural models of vanadate-dependent haloperoxidases, their reactivity, immobilization on polymer support and catalytic activities

    Indian Academy of Sciences (India)

    Mannar R Maurya

    2011-03-01

    The design of structural and functional models of enzymes vanadate-dependent haloperoxidases (VHPO) and the isolation and/or generation of species having {VO(H2O)}, {VO2}, {VO(OH)} and {VO(O2)} cores, proposed as intermediate(s) during catalytic action, in solution have been studied. Catalytic potential of these complexes have been tested for oxo-transfer as well as oxidative bromination and sulfide oxidation reactions. Some of the oxidovanadium(IV) and dioxidovanadium(V) complexes have been immobilized on polymer support in order to improve their recycle ability during catalytic activities and turn over number. The formulations of the polymer-anchored complexes are based on the respective neat complexes and conclusions drawn from the various characterization studies. These catalysts have successfully been used for all catalytic reactions mentioned above. These catalysts are stable and recyclable.

  1. Thermodynamic performance testing of the orbiter flash evaporator system

    Science.gov (United States)

    Jaax, J. R.; Melgares, M. A.; Frahm, J. P.

    1980-01-01

    System level testing of the space shuttle orbiter's development flash evaporator system (FES) was performed in a thermal vacuum chamber capable of simulating ambient ascent, orbital, and entry temperature and pressure profiles. The test article included the evaporator assembly, high load and topping exhaust duct and nozzle assemblies, and feedwater supply assembly. Steady state and transient heat load, water pressure/temperature and ambient pressure/temperature profiles were imposed by especially designed supporting test hardware. Testing in 1978 verified evaporator and duct heater thermal design, determined FES performance boundaries, and assessed topping evaporator plume characteristics. Testing in 1979 combined the FES with the other systems in the orbiter active thermal control subsystem (ATCS). The FES met or exceeded all nominal and contingency performance requirements during operation with the integrated ATCS. During both tests stability problems were encountered during steady state operations which resulted in subsequent design changes to the water spray nozzle and valve plate assemblies.

  2. Reactive standard deontic logic

    OpenAIRE

    Gabbay, Dov M.; Straßer, Christian

    2015-01-01

    We introduce a reactive variant of SDL (standard deontic logic): SDLR1 (reactive standard deontic logic). Given a Kripkean view on the semantics of SDL in terms of directed graphs where arrows -> represent the accessibility relation between worlds, reactive models add two elements: arrows -> are labelled as 'active' or 'inactive', and double arrows a dagger connect arrows, e.g. (x(1) -> x(2)) a dagger (x(3) -> x(4)). The idea is that passing through x(1) -> x(2) activates a switch represented...

  3. Nanostructured AgBr loaded TiO2: An efficient sunlight active photocatalyst for degradation of Reactive Red 120

    Directory of Open Access Journals (Sweden)

    Sreedhar Bojja

    2011-07-01

    Full Text Available Abstract The AgBr loaded TiO2 catalyst was prepared by a feasible approach with AgBr and tetraisopropyl orthotitanate and characterized by BET surface area measurement, diffuse reflectance spectra (DRS, scanning electron microscope (SEM, energy dispersive spectra (EDS, X-ray diffraction (XRD, transmission electron microscope (TEM and atomic force microscope (AFM analysis. The results of characterization reveal that AgBr loaded TiO2 has a nanostructure. Formation of the nanostructure in AgBr loaded TiO2 results in substantial shifting of the absorption edge of TiO2 to red and enhancement of visible light absorption. Electrochemical impedance spectroscopy measurements reveal that AgBr loaded TiO2 has a higher photoconductivity than prepared TiO2 due to higher separation efficiency of electron-hole pairs. Cyclic voltammetric studies reveal enhanced conductivity in AgBr loaded TiO2, which causes an increase in its photocatalytic activity. AgBr loaded TiO2 exhibited a higher photocatalytic activity than TiO2-P25 and prepared TiO2 in the photodegradation of Reactive Red 120 (RR 120.

  4. Effective SERS-active substrates composed of hierarchical micro/nanostructured arrays based on reactive ion etching and colloidal masks

    Science.gov (United States)

    Zhang, Honghua; Liu, Dilong; Hang, Lifeng; Li, Xinyang; Liu, Guangqiang; Cai, Weiping; Li, Yue

    2016-09-01

    A facile route has been proposed for the fabrication of morphology-controlled periodic SiO2 hierarchical micro/nanostructured arrays by reactive ion etching (RIE) using monolayer colloidal crystals as masks. By effectively controlling the experimental conditions of RIE, the morphology of a periodic SiO2 hierarchical micro/nanostructured array could be tuned from a dome-shaped one to a circular truncated cone, and finally to a circular cone. After coating a silver thin layer, these periodic micro/nanostructured arrays were used as surface-enhanced Raman scattering (SERS)-active substrates and demonstrated obvious SERS signals of 4-Aminothiophenol (4-ATP). In addition, the circular cone arrays displayed better SERS enhancement than those of the dome-shaped and circular truncated cone arrays due to the rougher surface caused by physical bombardment. After optimization of the circular cone arrays with different periodicities, an array with the periodicity of 350 nm exhibits much stronger SERS enhancement and possesses a low detection limit of 10-10 M 4-ATP. This offers a practical platform to conveniently prepare SERS-active substrates.

  5. Cadmium Activates Reactive Oxygen Species-dependent AKT/mTOR and Mitochondrial Apoptotic Pathways in Neuronal Cells

    Institute of Scientific and Technical Information of China (English)

    YUAN Yan; BIAN Jian Chun; LIU Zong Ping; WANG Yi; HU Fei Fei; JIANG Chen Yang; ZHANG Ya Jing; YANG Jin Long; ZHAO Shi Wen; GU Jian Hong; LIU Xue Zhong

    2016-01-01

    ObjectiveTo examine the role of Cd-induced reactive oxygen species (ROS) generation in the apoptosis of neuronal cells. MethodsNeuronal cells (primary rat cerebral cortical neurons and PC12cells) were incubated with or without Cd post-pretreatment with rapamycin (Rap) or N-acetyl-L-cysteine (NAC). Cell viability was determined by MTT assay, apoptosis was examined using flow cytometry and fluorescence microscopy, and the activation of phosphoinositide 3'-kinase/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and mitochondrial apoptotic pathways were measured by western blotting or immunofluorescence assays. ResultsCd-induced activation of Akt/mTOR signaling, including Akt, mTOR,p70 S6 kinase (p70 S6K), and eukaryotic initiation factor 4E binding protein 1(4E-BP1). Rap, an mTOR inhibitor and NAC, a ROS scavenger, blocked Cd-induced activation of Akt/mTOR signaling and apoptosis of neuronal cells. Furthermore, NAC blocked the decrease of B-cell lymphoma 2/Bcl-2 associated X protein (Bcl-2/Bax) ratio, release of cytochrome c, cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP), and nuclear translocation of apoptosis-inducing factor(AIF)and endonuclease G (Endo G). ConclusionCd-induced ROS generation activates Akt/mTOR and mitochondrial pathways, leading to apoptosis ofneuronal cells. Our findings suggest that mTOR inhibitors or antioxidants have potential for preventing Cd-induced neurodegenerative diseases.

  6. Hydrodynamics of evaporating sessile drops

    CERN Document Server

    Barash, L Yu

    2010-01-01

    Several dynamical stages of the Marangoni convection of an evaporating sessile drop are obtained. We jointly take into account the hydrodynamics of an evaporating sessile drop, effects of the thermal conduction in the drop and the diffusion of vapor in air. The stages are characterized by different number of vortices in the drop and the spatial location of vortices. During the early stage the array of vortices arises near a surface of the drop and induces a non-monotonic spatial distribution of the temperature over the drop surface. The number of near-surface vortices in the drop is controlled by the Marangoni cell size, which is calculated similar to that given by Pearson for flat fluid layers. The number of vortices quickly decreases with time, resulting in three bulk vortices in the intermediate stage. The vortex structure finally evolves into the single convection vortex in the drop, existing during about 1/2 of the evaporation time.

  7. Characterization of TiO2 Loaded on Activated Carbon Fibers and Its Photocatalytic Reactivity

    Institute of Scientific and Technical Information of China (English)

    JIA,Bing-Yu; DUAN,Li-Yan; MA,Chuan-Li; WANG,Chun-Ming

    2007-01-01

    In this paper,TiO2 loaded on activated carbon fibers(ACF)was prepared by a coating treatment,followed by calcination at different temperatures in air atmosphere.The photocatalyst developed was characterized by SEM,XRD,XPS and UV-Vis adsorption spectroscopy.It was observed from SEM images that TiO2 loaded on ACF was in the form of small clusters with nanometer size.As confirmed by XRD and XPS determinations,the crystalline pattern of immobilized TiO2 was still anatase-form after calcination,and the micrographic structure and surface properties of ACF have not been damaged by the deposition process and calcination at different temperatures.Photocatalytic degradation of methylene blue(MB)in aqueous solution was investigated using TiO2/ACF as photocatalyst.The comparison of photolysis,absorption and photocatalysis was carried out.The results indicated that the photocatalysis process of combined photocatalyst showed much higher degradation rate than that of photolysis and absorption processes.In addition,the possibility of cyclic usage of the photocatalyst was also confirmed.

  8. Large-activation-energy analysis of gaseous reactive flow in pipes

    Science.gov (United States)

    Moreno-Boza, Daniel; Iglesias, Immaculada; Sanchez, Antonio L.

    2016-11-01

    Frank-Kamenetskii's analysis of thermal explosions is applied, using also a single-reaction model with an Arrhenius rate having a large activation energy, to describe the evolution of an initially cold gaseous mixture flowing along a circular pipe with constant wall temperature for moderately large values of the relevant Reynolds number. The analysis shows two modes of combustion. There is a flameless slowly reacting mode for low wall temperatures or small pipe radii, when the temperature rise resulting from the heat released by the reaction is kept small by the heat-conduction losses to the wall, so as not to change significantly the order of magnitude of the reaction rate. In the other mode, the slow reaction rates occur only in an initial ignition stage, which ends abruptly when very large reaction rates cause a temperature runaway, or thermal explosion, at a well-defined ignition distance. The analysis determines the slow streamwise evolution for the flameless mode of combustion as well as the ignition distance for the explosive mode.

  9. Isothermal evaporation of ethanol in a dynamic gas atmosphere.

    Science.gov (United States)

    Milev, Adriyan S; Wilson, Michael A; Kannangara, G S Kamali; Feng, Hai; Newman, Phillip A

    2012-01-12

    Optimization of evaporation and pyrolysis conditions for ethanol are important in carbon nanotube (CNT) synthesis. The activation enthalpy (ΔH(‡)), the activation entropy (ΔS(‡)), and the free energy barrier (ΔG(‡)) to evaporation have been determined by measuring the molar coefficient of evaporation, k(evap), at nine different temperatures (30-70 °C) and four gas flow rates (25-200 mL/min) using nitrogen and argon as carrier gases. At 70 °C in argon, the effect of the gas flow rate on k(evap) and ΔG(‡) is small. However, this is not true at temperatures as low as 30 °C, where the increase of the gas flow rate from 25 to 200 mL/min results in a nearly 6 times increase of k(evap) and decrease of ΔG(‡) by ~5 kJ/mol. Therefore, at 30 °C, the effect of the gas flow rate on the ethanol evaporation rate is attributed to interactions of ethanol with argon molecules. This is supported by simultaneous infrared spectroscopic analysis of the evolved vapors, which demonstrates the presence of different amounts of linear and cyclic hydrogen bonded ethanol aggregates. While the amount of these aggregates at 30 °C depends upon the gas flow rate, no such dependence was observed during evaporation at 70 °C. When the evaporation was carried out in nitrogen, ΔG(‡) was almost independent of the evaporation temperature (30-70 °C) and the gas flow rate (25-200 mL/min). Thus the evaporation of ethanol in a dynamic gas atmosphere at different temperatures may go via different mechanisms depending on the nature of the carrier gas.

  10. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    Energy Technology Data Exchange (ETDEWEB)

    Simões, Maylla Ronacher, E-mail: yllars@hotmail.com [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Aguado, Andrea [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Zhenyukh, Olha; Briones, Ana María [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Alonso, María Jesús [Dept. of Biochemistry, Physiology and Molecular Genetics, Universidad Rey Juan Carlos, Alcorcón (Spain); Vassallo, Dalton Valentim [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Health Science Center of Vitória-EMESCAM, Vitória, ES CEP 29045-402 (Brazil); Salaices, Mercedes, E-mail: mercedes.salaices@uam.es [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain)

    2015-03-01

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  11. New avenues for ligand-mediated processes: expanding metal reactivity by the use of redox-active catechol, o-aminophenol and o-phenylenediamine ligands

    NARCIS (Netherlands)

    D.L.J. Broere; R. Plessius; J.I. van der Vlugt

    2015-01-01

    Redox-active ligands have evolved from being considered spectroscopic curiosities - creating ambiguity about formal oxidation states in metal complexes - to versatile and useful tools to expand on the reactivity of (transition) metals or to even go beyond what is generally perceived possible. This r

  12. Biological variation and reference intervals for circulating osteopontin, osteoprotegerin, total soluble receptor activator of nuclear factor kappa B ligand and high-sensitivity C-reactive protein

    DEFF Research Database (Denmark)

    Sennels, H P; Jacobsen, Søren; Jensen, T

    2007-01-01

    Objective. Monitoring inflammatory diseases and osteoclastogenesis with osteopontin (OPN), osteoprotegerin (OPG), total soluble receptor activator of nuclear factor kappa B ligand (total sRANKL) and high-sensitivity C-reactive protein (hsCRP) has recently attracted increased interest. The purpose...

  13. Activation by malaria antigens renders mononuclear cells susceptible to HIV infection and re-activates replication of endogenous HIV in cells from HIV-infected adults.

    Science.gov (United States)

    Froebel, K; Howard, W; Schafer, J R; Howie, F; Whitworth, J; Kaleebu, P; Brown, A L; Riley, E

    2004-05-01

    We have tested the hypothesis that activation of T cells by exposure to malaria antigens facilitates both de novo HIV infection and viral reactivation and replication. PBMC from malaria-naive HIV-uninfected European donors could be productively infected with HIV following in vitro stimulation with a lysate of Plasmodium falciparum schizonts and PBMC from malaria-naive and malaria-exposed (semi-immune) HIV-positive adults were induced to produce higher levels of virus after stimulation with the same malaria extract. These findings suggest that effective malaria control measures might con-tribute to reducing the spread of HIV and extending the life span of HIV-infected individuals living in malaria endemic areas.

  14. Modeling evaporation from spent nuclear fuel storage pools: A diffusion approach

    Science.gov (United States)

    Hugo, Bruce Robert

    Accurate prediction of evaporative losses from light water reactor nuclear power plant (NPP) spent fuel storage pools (SFPs) is important for activities ranging from sizing of water makeup systems during NPP design to predicting the time available to supply emergency makeup water following severe accidents. Existing correlations for predicting evaporation from water surfaces are only optimized for conditions typical of swimming pools. This new approach modeling evaporation as a diffusion process has yielded an evaporation rate model that provided a better fit of published high temperature evaporation data and measurements from two SFPs than other published evaporation correlations. Insights from treating evaporation as a diffusion process include correcting for the effects of air flow and solutes on evaporation rate. An accurate modeling of the effects of air flow on evaporation rate is required to explain the observed temperature data from the Fukushima Daiichi Unit 4 SFP during the 2011 loss of cooling event; the diffusion model of evaporation provides a significantly better fit to this data than existing evaporation models.

  15. Multiwalled carbon nanotube/TiO2 nanocomposite as a highly active photocatalyst for photodegradation of Reactive Black 5 dye

    Institute of Scientific and Technical Information of China (English)

    Sharifah Bee Abd Hamid; Tong Ling Tan; Chin Wei Lai; Emy Marlina Samsudin

    2014-01-01

    A nanocomposite UV‐visible light‐responsive multiwalled carbon nanotube (MWCNT)/titanium dioxide (TiO2) nanophotocatalyst was successfully synthesized by a modified sol‐gel method using titanium isopropoxide and functionalized MWCNTs as the starting precursors. The photocatalytic activity of the TiO2 and the nanohybrid material was investigated through the photodegradation of Reactive Black 5 dye under ultraviolet light irradiation. X‐ray diffraction analysis indicated that anatase phase was obtained for both the pure TiO2 and the MWCNT/TiO2 composite, while Raman spectroscopy confirmed the presence of MWCNTs in the composite. Field emission scanning elec‐tron microscopy revealed that TiO2 nanoparticles with an individual diameter of about 10–20 nm were coated on the surface of the MWCNTs. The specific surface areas of the samples were found to be 80 and 181 m2/g for the pure TiO2 and MWCNT/TiO2, respectively. As a result, MWCNT/TiO2 showed better photocatalytic performance than pure TiO2 because the high surface area of MWCNTs enabled them to function as good electron acceptors for the retardation of electron‐hole pair recombination.

  16. Emodin-Induced Generation of Reactive Oxygen Species Inhibits RhoA Activation to Sensitize Gastric Carcinoma Cells to Anoikis

    Directory of Open Access Journals (Sweden)

    Jun Cai

    2008-01-01

    Full Text Available RhoA is a critical signaling molecule regulating a variety of cellular processes, such as cytoskeletal organization, adhesion, and apoptosis. It is recently considered responsive to reactive oxygen species (ROS. Nevertheless, how RhoA regulates anoikis, a detachment-initiated apoptosis, and how this regulation is affected by ROS are not clear. The present study investigated the role of RhoA in apoptosis/anoikis in gastric cancer cells and the changes of RhoA and anoikis under oxidative stress. Immunohistochemistry showed that RhoA expression was upregulated in the primary gastric carcinoma compared with normal gastric mucosa. Overactivation of RhoA by transfection with the V14RhoA mutant prevented gastric cancer line SGC-7901 cells from arsenic-induced apoptosis and conferred anoikis resistance through, at least in part, promoting formations of F-actin fibers and focal adhesion. Oxidative stress caused by emodin, an ROS producer, in combination with arsenic trioxide (ATO led to RhoA inactivation that triggered structural disruption of focal adhesion complex and eventually resulted in anoikis, and these effects could be partially reversed by antioxidant N-acetylcysteine (NAC. In conclusion, activation of RhoA is required for the maintenance of anoikis resistance phenotype of gastric cancer cells, and oxidative stress might be a therapeutic strategy for the inhibition of RhoA in cancer cells.

  17. Treatment of Reactive Black 5 by combined electrocoagulation-granular activated carbon adsorption-microwave regeneration process

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Shih-Hsien, E-mail: shchang@csmu.edu.tw [Department of Public Health, Chung-Shan Medical University, 110 Chen-Kuo N. Road, Taichung 402, Taiwan (China); Wang, Kai-Sung; Liang, Hsiu-Hao; Chen, Hsueh-Yu; Li, Heng-Ching; Peng, Tzu-Huan [Department of Public Health, Chung-Shan Medical University, 110 Chen-Kuo N. Road, Taichung 402, Taiwan (China); Su, Yu-Chun; Chang, Chih-Yuan [Institute of Environmental Engineering, National Chiao-Tung University, Hsinchu, 300, Taiwan (China)

    2010-03-15

    Treatment of an azo dye, Reactive Black 5 (RB5) by combined electrocoagulation-activated carbon adsorption-microwave regeneration process was evaluated. The toxicity was also monitored by the Vibrio fischeri light inhibition test. GAC of 100 g L{sup -1} sorbed 82% of RB5 (100 mg L{sup -1}) within 4 h. RB5-loaded GAC was not effectively regenerated by microwave irradiation (800 W, 30 s). Electrocoagulation showed high decolorization of RB5 within 8 min at pH{sub 0} of 7, current density of 277 A m{sup -2}, and NaCl of 1 g L{sup -1}. However, 61% COD residue remained after treatment and toxicity was high (100% light inhibition). GAC of 20 g L{sup -1} effectively removed COD and toxicity of electrocoagulation-treated solution within 4 h. Microwave irradiation effectively regenerated intermediate-loaded GAC within 30 s at power of 800 W, GAC/water ratio of 20 g L{sup -1}, and pH of 7.8. The adsorption capacity of GAC for COD removal from the electrocoagulation-treated solution did not significantly decrease at the first 7 cycles of adsorption/regeneration. The adsorption capacity of GAC for removal of both A{sub 265} (benzene-related groups) and toxicity slightly decreased after the 6th cycle.

  18. Treatment of Reactive Black 5 by combined electrocoagulation-granular activated carbon adsorption-microwave regeneration process.

    Science.gov (United States)

    Chang, Shih-Hsien; Wang, Kai-Sung; Liang, Hsiu-Hao; Chen, Hsueh-Yu; Li, Heng-Ching; Peng, Tzu-Huan; Su, Yu-Chun; Chang, Chih-Yuan

    2010-03-15

    Treatment of an azo dye, Reactive Black 5 (RB5) by combined electrocoagulation-activated carbon adsorption-microwave regeneration process was evaluated. The toxicity was also monitored by the Vibrio fischeri light inhibition test. GAC of 100 g L(-1) sorbed 82% of RB5 (100 mg L(-1)) within 4h. RB5-loaded GAC was not effectively regenerated by microwave irradiation (800 W, 30s). Electrocoagulation showed high decolorization of RB5 within 8 min at pH(0) of 7, current density of 277 A m(-2), and NaCl of 1 g L(-1). However, 61% COD residue remained after treatment and toxicity was high (100% light inhibition). GAC of 20 g L(-1) effectively removed COD and toxicity of electrocoagulation-treated solution within 4h. Microwave irradiation effectively regenerated intermediate-loaded GAC within 30s at power of 800 W, GAC/water ratio of 20 g L(-1), and pH of 7.8. The adsorption capacity of GAC for COD removal from the electrocoagulation-treated solution did not significantly decrease at the first 7 cycles of adsorption/regeneration. The adsorption capacity of GAC for removal of both A(265) (benzene-related groups) and toxicity slightly decreased after the 6th cycle.

  19. Elevated salivary C-reactive protein levels are associated with active and passive smoking in healthy youth: A pilot study

    Directory of Open Access Journals (Sweden)

    Azar Rima

    2011-12-01

    Full Text Available Abstract Background We examined salivary C-reactive protein (CRP levels in the context of tobacco smoke exposure (TSE in healthy youth. We hypothesized that there would be a dose-response relationship between TSE status and salivary CRP levels. Methods This work is a pilot study (N = 45 for a larger investigation in which we aim to validate salivary CRP against serum CRP, the gold standard measurement of low-grade inflammation. Participants were healthy youth with no self-reported periodontal disease, no objectively measured obesity/adiposity, and no clinical depression, based on the Beck Depression Inventory (BDI-II. We assessed tobacco smoking and confirmed smoking status (non-smoking, passive smoking, and active smoking with salivary cotinine measurement. We measured salivary CRP by the ELISA method. We controlled for several potential confounders. Results We found evidence for the existence of a dose-response relationship between the TSE status and salivary CRP levels. Conclusions Our preliminary findings indicate that salivary CRP seems to have a similar relation to TSE as its widely used serum (systemic inflammatory biomarker counterpart.

  20. Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier

    Science.gov (United States)

    Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

    2015-10-01

    This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR + PRB showed the lowest leaching value for each HM in the S2 and S3 regions.

  1. Norepinephrine causes epigenetic repression of PKCε gene in rodent hearts by activating Nox1-dependent reactive oxygen species production.

    Science.gov (United States)

    Xiong, Fuxia; Xiao, Daliao; Zhang, Lubo

    2012-07-01

    Heart disease is the leading cause of death in the United States. Recent studies demonstrate that fetal programming of PKCε gene repression results in ischemia-sensitive phenotype in the heart. The present study tests the hypothesis that increased norepinephrine causes epigenetic repression of PKCε gene in the heart via Nox1-dependent reactive oxygen species (ROS) production. Prolonged norepinephrine treatment increased ROS production in fetal rat hearts and embryonic ventricular myocyte H9c2 cells via a selective increase in Nox1 expression. Norepinephrine-induced ROS resulted in an increase in PKCε promoter methylation at Egr-1 and Sp-1 binding sites, leading to PKCε gene repression. N-acetylcysteine, diphenyleneiodonium, and apocynin blocked norepinephrine-induced ROS production and the promoter methylation, and also restored PKCε mRNA and protein to control levels in vivo in fetal hearts and in vitro in embryonic myocyte cells. Accordingly, norepinephrine-induced ROS production, promoter methylation, and PKCε gene repression were completely abrogated by knockdown of Nox1 in cardiomyocytes. These findings provide evidence of a novel interaction between elevated norepinephrine and epigenetic repression of PKCε gene in the heart mediated by Nox1-dependent oxidative stress and suggest new insights of molecular mechanisms linking the heightened sympathetic activity to aberrant cardioprotection and increased ischemic vulnerability in the heart.

  2. Evaporative Condensers in Comfortable Air Conditioning System

    Institute of Scientific and Technical Information of China (English)

    YIN Ying-de; ZHU Dong-sheng; DU Gui-mei; LI Yuan-xi; SUN He-jing; LIU Qing-ming

    2009-01-01

    The operating theory of an evaporative condenser was expatiated.The difference between an e-vaporative condensing refrigeration system and a general refrigeration system was analyzed.Compared with the air-cooled and the water-cooled,the virtues of energy-conservation and water-conservation of evaporative con-densers were analyzed.Some questions existing in the application of evaporative condensers were pointed out,the corresponding solving methods were analyzed accordingly,and the development trend of evaporative con-densing technique in mechanical refrigeration system field and the applied foreground of evaporative condensers in comfortable air conditioning were prospected.

  3. Evaporating Drops of Alkane Mixtures

    CERN Document Server

    Gu'ena, G; Poulard, C; Cazabat, Anne-Marie; Gu\\'{e}na, Geoffroy; Poulard, Christophe

    2005-01-01

    Alkane mixtures are model systems where the influence of surface tension gradients during the spreading and the evaporation of wetting drops can be easily studied. The surface tension gradients are mainly induced by concentration gradients, mass diffusion being a stabilising process. Depending on the relative concentration of the mixture, a rich pattern of behaviours is obtained.

  4. Evaporation in relation to hydrology

    NARCIS (Netherlands)

    Wartena, L.; Keijman, J.Q.; Bruijn, H.A.R. de; Bakel, P.J.T. van; Stricker, J.N.M.; Velds, C.A.

    1981-01-01

    In meteorology some topics enjoy particular interest from other disciplines. The interest of hydrologists for the evaporation of water is a case in point, understandably and rightly so. In fact, over the last few decades, hydrology has clearly done more than using meteorological knowledge thus offer

  5. Evaporating Drops of Alkane Mixtures

    OpenAIRE

    Guéna, Geoffroy; Poulard, Christophe; Cazabat, Anne-Marie

    2005-01-01

    22 pages 9 figures; Alkane mixtures are model systems where the influence of surface tension gradients during the spreading and the evaporation of wetting drops can be easily studied. The surface tension gradients are mainly induced by concentration gradients, mass diffusion being a stabilising process. Depending on the relative concentration of the mixture, a rich pattern of behaviours is obtained.

  6. The sustainability of LNG evaporation

    NARCIS (Netherlands)

    Stougie, L.; Van der Kooi, H.J.

    2011-01-01

    Numerous LNG (Liquefied Natural Gas) import terminals are under construction to fulfil the growing demand for energy carriers. After storage in tanks, the LNG needs to be heated and evaporated, also called ‘regasified’, to the natural gas needed in households and industry. Several options exist for

  7. Apogossypolone targets mitochondria and light enhances its anticancer activity by stimulating generation of singlet oxygen and reactive oxygen species

    Institute of Scientific and Technical Information of China (English)

    Zhe-Yu Hu; Jing Wang; Gang Cheng; Xiao-Feng Zhu; Peng Huang; Dajun Yang; Yi-Xin Zeng

    2011-01-01

    Apogossypolone (ApoG2), a novel derivative of gossypol, has been shown to be a potent inhibitor of antiapoptotic Bcl-2 family proteins and to have antitumor activity in multiple types of cancer cells. Recent reports suggest that gossypol stimulates the generation of cellular reactive oxygen species (ROS) in leukemia and colorectal carcinoma cells; however, gossypol-mediated cell death in leukemia cells was reported to be ROS-independent. This study was conducted to clarify the effect of ApoG2-induced ROS on mitochondria and cell viability, and to further evaluate its utility as a treatment for nasopharyngeal carcinoma (NPC). We tested the photocytotoxicity of ApoG2 to the pooriy differentiated NPC cell line CNE-2 using the ROS-generating TL/10 illumination system. The rapid ApoG2-induced cell death was partially reversed by the antioxidant N-acetyI-L-cysteine (NAC), but the ApoG2-induced reduction of mitochondrial membrane potential (MMP) was not reversed by NAC. In the presence of TL/10 illumination, APOG2 generated massive amounts of singlet oxygen and was more effective in inhibiting cell growth than in the absence of illumination. We also determined the influence of light on the anti-proliferative activity of ApoG2 using a CNE-2-xenograft mouse model. ApoG2 under TL/10 illumination healed tumor wounds and suppressed tumor growth more effectively than ApoG2 treatment alone. These results indicate that the ApoG2-induced CNE-2 cell death is partly ROS-dependent. ApoG2 may be used with photodynamic therapy (PDT) to treat NPC.

  8. Effect of reproductive status on hypothalamic-pituitary-adrenal (HPA) activity and reactivity in male California mice (Peromyscus californicus).

    Science.gov (United States)

    Harris, Breanna N; Saltzman, Wendy

    2013-03-15

    Previous studies indicate that reproductive condition can alter stress response and glucocorticoid release. Although the functional significance of hypothalamic-pituitary-adrenal (HPA) axis modulation by breeding condition is not fully understood, one possible explanation is the behavior hypothesis, which states that an animal's need to express parental behavior may be driving modulation of the HPA axis. This possibility is consistent with findings of blunted activity and reactivity of the HPA axis in lactating female mammals; however, effects of reproductive status on HPA function have not been well characterized in male mammals that express parental behavior. Therefore, we tested this hypothesis in the monogamous and biparental California mouse. Several aspects of HPA activity were compared in males from three reproductive conditions: virgin males (housed with another male), non-breeding males (housed with a tubally ligated female), and first-time fathers (housed with a female and their first litter of pups). In light of the behavior hypothesis we predicted that new fathers would differ from virgin and non-breeding males in several aspects of HPA function and corticosterone (CORT) output: decreased amplitude of the diurnal rhythm in CORT, a blunted CORT increase following predator-odor stress, increased sensitivity to glucocorticoid negative feedback, and/or a blunted CORT response to pharmacological stimulation. In addition, we predicted that first-time fathers would be more resistant to CORT-induced suppression of testosterone secretion, as testosterone is important for paternal behavior in this species. We found that virgin males, non-breeding males and first-time fathers did not display any CORT differences in diurnal rhythm, response to a predator-odor stressor, or response to pharmacological suppression or stimulation. Additionally, there were no differences in circulating testosterone concentrations. Adrenal mass was, however, significantly lower in new

  9. Reactivity and antiproliferative activity of ferrocenyl-tamoxifen adducts with cyclodextrins against hormone-independent breast-cancer cell lines.

    Science.gov (United States)

    Buriez, Olivier; Heldt, Jan Martin; Labbé, Eric; Vessières, Anne; Jaouen, Gerard; Amatore, Christian

    2008-01-01

    Hydroxyferrocifen compounds are a new and promising class of ferrocifen-type breast-cancer drug candidates. They possess both endocrine-modulating properties and cytotoxic activity, which come from the tamoxifen skeleton and the presence of a ferrocene moiety, respectively. However, they suffer from reduced solubility in water, which presents a problem for their eventual therapeutic use. Herein, we examined the interactions of hydroxyferrocifen compounds with cyclodextrins (CDs) to evaluate whether or not their electron-transfer oxidation pathways were affected by their inclusion. It has been demonstrated that these inclusion complexes are soluble in pure water, which shows that CDs can be used to deliver these biologically active molecules. Therefore, a series of these compounds has been investigated by cyclic voltametry in various media in the presence of CDs (beta-CD and Me-beta-CD). In methanol, the hydroxyferrocifen compounds exhibited a weak interaction with the CD cavity. These interactions became stronger as the amount of added water increased. The complexation effect between the hydroxyferrocifen compounds and beta-CD was found to be stronger if the CD was partially methylated, which is probably due to hydrophobic effects between the cyclopentadienyl ring and/or the aromatic rings and the methoxy groups. Moreover, it appears that the structure of the hydroxyferrocifen compounds affects both their solubility and their complexation dynamics. Investigations in the presence of pyridine show that the base kinetically favors the dissociation of the ferrocifen-CD complex during the electron transfer step, but does not affect the follow-up reactivity of the electrogenerated ferrocenium cation, which leads eventually to the corresponding quinone methide, as reported in the absence of CD. Accordingly, the cytotoxicity of these beta-CD-encapsulated organometallic complexes in hormone-independent breast-cancer cells (MDA-MB231) were confirmed to be similar to those

  10. Reactive oxygen species regulate urokinase plasminogen activator expression and cell invasion via mitogen-activated protein kinase pathways after treatment with hepatocyte growth factor in stomach cancer cells

    Directory of Open Access Journals (Sweden)

    Kim Jae-Ryong

    2009-06-01

    Full Text Available Abstract Background Reactive oxygen species (ROS are closely associated with the intracellular signal cascade, thus strongly implicating involvement in tumor progression. However, the mechanism by which ROS are generated and how ROS target downstream molecules to trigger tumor metastasis is unclear. In this study, we investigated the underlying signal pathways in ROS-induced urokinase plasminogen activator (uPA expression in the human gastric cancer cells, NUGC-3 and MKN-28. Methods and Results Intracellular ROS, as determined using the fluorescent probe, 2'-7' dichlorofluorescein diacetate, decreased after treatment with hepatocyte growth factor (HGF. We confirmed that Rac-1 regulated ROS production after activation of the AKT pathway with HGF. Exogenously added H2O2 promoted the expression of HGF, but not in a dose-dependent manner and also showed negative expression of HGF after co-treatment with H2O2 and HGF. Treatment with NAC, an intracellular free radical scavenger, decreased the enhancement of uPA production and tumor invasion in both cells. We clarified the downstream pathways regulated by ROS after treatment with H2O2, which showed negative control between FRK and p38 kinase activities for uPA regulation. Conclusion HGF regulates Rac-1-induced ROS production through the Akt pathway and ROS regulates uPA production and invasion via MAP kinase, which provides novel insight into the mechanisms underlying the progression of gastric cancer.

  11. Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

    OpenAIRE

    Sindhu M R; Aneesh P; Manjula G Nair; T N P Nambiar

    2014-01-01

    Variable speed drives are mostly preferred in industries, while considering energy saving, smooth control, flexible operation and fast response. On the other hand, this equipment generates dynamic harmonic distortions in source currents and draws variable reactive power demand depending on variation in load condition. These distortions propagate throughout the system and affect all the loads connected to the point of common coupling. Hence a dynamic harmonic and reactive compensator is necess...

  12. Aberrant Activation of Heat Shock Protein 60/65 Reactive T Cells in Patients with Behcet’s Disease

    Directory of Open Access Journals (Sweden)

    Jun Shimizu

    2012-01-01

    Full Text Available Behcet’s disease (BD is a multisystemic inflammatory disease and is characterized by recurrent attacks on eyes, brain, skin, and gut. There is evidence that skewed T-cell responses contributed to its pathophysiology in patients with BD. We found that heat shock proteins (HSPs reactive T cells were prevalent in patients with BD. Here, we summarize current findings on HSP reactive T cells and their contribution to the pathogenesis in patients with BD.

  13. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  14. The surface temperature of free evaporating drops

    Science.gov (United States)

    Borodulin, V. Y.; Letushko, V. N.; Nizovtsev, M. I.; Sterlyagov, A. N.

    2016-10-01

    Complex experimental and theoretical investigation of heat and mass transfer processes was performed at evaporation of free liquid drops. For theoretical calculation the emission-diffusion model was proposed. This allowed taking into account the characteristics of evaporation of small droplets, for which heat and mass transfer processes are not described in the conventional diffusion model. The calculation results of evaporation of droplets of different sizes were compared using two models: the conventional diffusion and emission-diffusion models. To verify the proposed physical model, the evaporation of droplets suspended on a polypropylene fiber was experimentally investigated. The form of droplets in the evaporation process was determined using microphotographing. The temperature was measured on the surfaces of evaporating drops using infrared thermography. The experimental results have showed good agreement with the numerical data for the time of evaporation and the temperature of evaporating drops.

  15. A Modular Cascaded Multilevel Inverter Based Shunt Hybrid Active Power Filter for Selective Harmonic and Reactive Power Compensation Under Distorted/Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    T. Demirdelen

    2016-10-01

    Full Text Available In recent years, shunt hybrid active power filters are being increasingly considered as a viable alternative to both passive filters and active power filters for compensating harmonics. In literature, their applications are restricted to balanced systems and low voltage applications and therefore not for industrial applications. This paper investigates the performance of a modular cascaded multilevel inverter based Shunt Hybrid Active Power Filter (SHAPF for reactive power compensation and selective harmonics elimination under distorted/unbalanced grid voltage conditions in medium voltage levels. In the proposed control method, reactive power compensation is achieved successfully with a perceptible amount and the performance results of harmonic compensation are satisfactory. Theoretical analysis and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for a proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

  16. Value of Computerized Tomography Enterography in Predicting Crohn’s Disease Activity: Correlation with Crohn’s Disease Activity Index and C-Reactive Protein

    Science.gov (United States)

    Park, Eun Kyung; Han, Na Yeon; Park, Beom Jin; Sung, Deuk Jae; Cho, Sung Beom; Jeen, Yoon Tae; Keum, Bora; Kim, Min Ju

    2016-01-01

    Background The accurate evaluation of Crohn’s disease activity is important for the treatment of the disease and for monitoring the response. Computerized tomography (CT) enterography is a useful imaging modality that reflects enteric inflammation, as well as extramural complications. Objectives The aim of this study was to evaluate the correlation between CT enterographic (CTE) findings of active Crohn’s disease and the Crohn’s disease activity index (CDAI) and C-reactive protein (CRP). Patients and Methods Fifty CT enterographies of 39 patients with Crohn’s disease in the small bowel were used in our study. The CDAI was assessed through clinical and laboratory variables. Multiple CT parameters, including mural hyperenhancement, mural thickness, mural stratification, comb sign, and mesenteric fat attenuation, were evaluated with a four-point scale. The presence or absence of enhanced lymph nodes, fibrofatty proliferation, sinus or fistula, abscess, and stricture were also assessed. Two gastrointestinal radiologists independently reviewed all CT images, and inter-observer agreement was examined. Correlations between CT findings, CRP, and CDAI were assessed using Spearman’s rank correlation and logistic regression analysis. To assess the predictive accuracy of the model, a receiver-operating characteristic curve analysis for the sum of CT enterographic scores was used. Results Mural hyperenhancement, mural thickness, comb sign, mesenteric fat density, and fibrofatty proliferation were significantly correlated with CDAI and CRP (P < 0.05). The binary logistic regression model demonstrated that mesenteric fat density, mural stratification, and the presence of enhanced lymph nodes (P < 0.05) had an influence on CDAI severity. The area under the receiver operating characteristic curve (AUROC) of the CTE index for predicting disease activity was 0.85. Using a cut-off value of 8, the sensitivity and negative predictive values were 95% and 94%, respectively

  17. Oral Administration of the Japanese Traditional Medicine Keishibukuryogan-ka-yokuinin Decreases Reactive Oxygen Metabolites in Rat Plasma: Identification of Chemical Constituents Contributing to Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Yosuke Matsubara

    2017-02-01

    Full Text Available Insufficient detoxification and/or overproduction of reactive oxygen species (ROS induce cellular and tissue damage, and generated reactive oxygen metabolites become exacerbating factors of dermatitis. Keishibukuryogan-ka-yokuinin (KBGY is a traditional Japanese medicine prescribed to treat dermatitis such as acne vulgaris. Our aim was to verify the antioxidant properties of KBGY, and identify its active constituents by blood pharmacokinetic techniques. Chemical constituents were quantified in extracts of KBGY, crude components, and the plasma of rats treated with a single oral administration of KBGY. Twenty-three KBGY compounds were detected in plasma, including gallic acid, prunasin, paeoniflorin, and azelaic acid, which have been reported to be effective for inflammation. KBGY decreased level of the diacron-reactive oxygen metabolites (d-ROMs in plasma. ROS-scavenging and lipid hydroperoxide (LPO generation assays revealed that gallic acid, 3-O-methylgallic acid, (+-catechin, and lariciresinol possess strong antioxidant activities. Gallic acid was active at a similar concentration to the maximum plasma concentration, therefore, our findings indicate that gallic acid is an important active constituent contributing to the antioxidant effects of KBGY. KBGY and its active constituents may improve redox imbalances induced by oxidative stress as an optional treatment for skin diseases.

  18. 2F Evaporator CP class instrumentation uncertainties evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, E.

    1994-01-28

    There are two instrumentation systems in the 2F Evaporator facilities (bldg. 242-16F) that are classified as the Critical Protection (CP). They are the Evaporator Pot Temperature instrumentations and Steam Condensate Gamma Monitor. The pot instrumentation consists of two interrelated circuits sharing the same temperature sensor and transducer. They are the high alarm and interlock circuit and the recorder circuit. The gamma monitor instrumentation consists of four interrelated circuits sharing the same scintillation detector. They are the gamma alarm and interlock circuit, failure alarm and interlock circuit, condensate cesium activity recorder circuit, and condensate americium activity recorder circuit. The resulting uncertainties for the instrument circuits are tabulated. (GHH)

  19. Reactive Arthritis

    Directory of Open Access Journals (Sweden)

    Eren Erken

    2013-06-01

    Full Text Available Reactive arthritis is an acute, sterile, non-suppurative and inflammatory arthropaty which has occured as a result of an infectious processes, mostly after gastrointestinal and genitourinary tract infections. Reiter syndrome is a frequent type of reactive arthritis. Both reactive arthritis and Reiter syndrome belong to the group of seronegative spondyloarthropathies, associated with HLA-B27 positivity and characterized by ongoing inflammation after an infectious episode. The classical triad of Reiter syndrome is defined as arthritis, conjuctivitis and urethritis and is seen only in one third of patients with Reiter syndrome. Recently, seronegative asymmetric arthritis and typical extraarticular involvement are thought to be adequate for the diagnosis. However, there is no established criteria for the diagnosis of reactive arthritis and the number of randomized and controlled studies about the therapy is not enough. [Archives Medical Review Journal 2013; 22(3.000: 283-299

  20. Tyrosinase and catechol oxidase activity of copper(I) complexes supported by imidazole-based ligands: structure-reactivity correlations.

    Science.gov (United States)

    Wendt, Franziska; Näther, Christian; Tuczek, Felix

    2016-09-01

    Four new imidazole-based ligands, 4-((1H-imidazol-4-yl)methyl)-2-phenyl-4,5-dihydrooxyzole (L OL 1), 4-((1H-imidazol-4-yl)methyl)-2-(tert-butyl)-4,5-dihydrooxyzole (L OL 2), 4-((1H-imidazol-4-yl)methyl)-2-methyl-4,5-dihydrooxyzole (L OL 3), and N-(2,2-dimethylpropylidene)-2-(1-trityl-1H-imidazol-4-yl-)ethyl amine (L imz 1), have been synthesized. The corresponding copper(I) complexes [Cu(I)(L OL 1)(CH3CN)]PF6 (CuL OL 1), [Cu(I)(L OL 2)(CH3CN)]PF6 (CuL OL 2), [Cu(I)(L OL 3)(CH3CN)]PF6 (CuL OL 3), [Cu(I)(L imz 1)(CH3CN)2]PF6 (CuL imz 1) as well as the Cu(I) complex derived from the known ligand bis(1-methylimidazol-2-yl)methane (BIMZ), [Cu(I)(BIMZ)(CH3CN)]PF6 (CuBIMZ), are screened as catalysts for the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC-H2) to 3,5-di-tert-butylquinone (3,5-DTBQ). The primary reaction product of these oxidations is 3,5-di-tert-butylsemiquinone (3,5-DTBSQ) which slowly converts to 3,5-DTBQ. Saturation kinetic studies reveal a trend of catalytic activity in the order CuL OL 3 ≈ CuL OL 1 > CuBIMZ > CuL OL 2 > CuL imz 1. Additionally, the catalytic activity of the copper(I) complexes towards the oxygenation of monophenols is investigated. As substrates 2,4-di-tert-butylphenol (2,4-DTBP-H), 3-tert-butylphenol (3-TBP-H), 4-methoxyphenol (4-MeOP-H), N-acetyl-L-tyrosine ethyl ester monohydrate (NATEE) and 8-hydroxyquinoline are employed. The oxygenation products are identified and characterized with the help of UV/Vis and NMR spectroscopy, mass spectrometry, and fluorescence measurements. Whereas the copper complexes with ligands containing combinations of imidazole and imine functions or two imidazole units (CuL imz 1 and CuBIMZ) are found to exhibit catalytic tyrosinase activity, the systems with ligands containing oxazoline just mediate a stoichiometric conversion. Correlations between the structures of the complexes and their reactivities are discussed.

  1. DeoxyArbutin and its derivatives inhibit tyrosinase activity and melanin synthesis without inducing reactive oxygen species or apoptosis.

    Science.gov (United States)

    Chawla, Smita; Kvalnes, Kalla; deLong, Mitchell A; Wickett, Randall; Manga, Prashiela; Boissy, Raymond E

    2012-10-01

    Safety is a major concern in developing commercial skin-lightening agents. Here, we report the modulating effects of deoxyArbutin (dA) and its second-generation derivatives - deoxyFuran (dF), 2-fluorodeoxyArbutin (fdA), and thiodeoxyArbutin (tdA) - on tyrosinase, and consequently, on melanization. Results demonstrate that dA and its derivatives inhibit tyrosine hydroxylase and dopa oxidase activity of tyrosinase. The inhibition is dose-dependent, thereby inhibiting melanin synthesis in intact melanocytes, when used at concentrations that retain 95% viability of the treated cells in culture. Herein we demonstrate that dA, and its second-generation derivatives dF, fdA, and tdA, exhibit dose-dependent reductions in melanocyte cell number, primarily due to inhibition of proliferation rather than initiation of apoptosis as exemplified by hydroquinone (HQ), ie, cytostatic as opposed to cytotoxic. Human and murine melanocytes with functional mutations in either tyrosinase or tyrosinase-related protein 1 (Tyrp1) are less sensitive to the cytostatic effects of dA and its derivatives. Minimal amounts of reactive oxygen species (ROS) were generated upon treatment with dA and its derivatives, in contrast to a dramatic amount of ROS induced by HQ. This increase in ROS subsequently induced the expression of the endogenous antioxidant catalase in treated melanocytes. Treatment with exogenous antioxidants provided protection for melanocytes treated with HQ, but not dA and its derivatives, suggesting that HQ exerts more oxidative stress. These studies demonstrate that dA and its derivatives are relatively safe tyrosinase inhibitors for skin lightening or for ameliorating hyperpigmented lesions.

  2. 21 CFR 131.130 - Evaporated milk.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Evaporated milk. 131.130 Section 131.130 Food and... CONSUMPTION MILK AND CREAM Requirements for Specific Standardized Milk and Cream § 131.130 Evaporated milk. (a) Description. Evaporated milk is the liquid food obtained by partial removal of water only from milk....

  3. Modelling refrigerant distribution in microchannel evaporators

    DEFF Research Database (Denmark)

    Brix, Wiebke; Kærn, Martin Ryhl; Elmegaard, Brian

    2009-01-01

    The effects of refrigerant maldistribution in parallel evaporator channels on the heat exchanger performance are investigated numerically. For this purpose a 1D steady state model of refrigerant R134a evaporating in a microchannel tube is built and validated against other evaporator models. A study...

  4. Thermogravimetric analysis of fuel film evaporation

    Institute of Scientific and Technical Information of China (English)

    HU Zongjie; LI Liguang; YU Shui

    2006-01-01

    Thermogravimetric analysis (TGA) was compared with the petrochemical distillation measurement method to better understand the characteristics of fuel film evaporation at different wall tem- peratures. The film evaporation characteristics of 90# gasoline, 93# gasoline and 0# diesel with different initial thicknesses were investigated at different environmental fluxes and heating rates. The influences of heating rate, film thickness and environmental flux on fuel film evaporation for these fuels were found. The results showed that the environmental conditions in TGA were similar to those for fuel films in the internal combustion engines, so data from TGA were suitable for the analysis of fuel film evaporation. TGA could simulate the key influencing factors for fuel film evaporation and could investigate the basic quantificational effect of heating rate and film thickness. To get a rapid and sufficient fuel film evaporation, sufficiently high wall temperature is necessary. Evaporation time decreases at a high heating rate and thin film thickness, and intense gas flow is important to promoting fuel film evaporation. Data from TGA at a heating rate of 100℃/min are fit to analyze the diesel film evaporation during cold-start and warming-up. Due to the tense molecular interactions, the evaporation sequence could not be strictly divided according to the boiling points of each component for multicomponent dissolved mixture during the quick evaporation process, and the heavier components could vaporize before reaching their boiling points. The 0# diesel film would fully evaporate when the wall temperature is beyond 250℃.

  5. Evaluation of antioxidant activity, colour and some nutritional characteristics of pomegranate (Punica granatum L.) juice and its sour concentrate processed by conventional evaporation.

    Science.gov (United States)

    Orak, H Hülya

    2009-01-01

    In this study the antioxidant activity, colour and some nutritional characteristics of pomegranate juice (PJ) and its traditional sour concentrate (CPJ), produced in Denizli, Turkey, were analysed. The total anthocyanin content of PJ was found to be 492.9 mg/l but it was not determined in CPJ. The total phenolics were also found to be 3,246 and 9,870 microg/ml in PJ and CPJ, respectively. The antioxidant activity (percentage of inhibition of on peroxidation in linoleic acid system) of CPJ was determined to be higher (85.91%) than that of PJ (79.06%). During the concentration process, the reducing sugars, glucose and fructose level of CPJ showed an increase to 46.46%, 23.89%, and 22.53%, respectively. In CPJ the amounts of sodium, iron, zinc, copper and lead were found lower than those of PJ. On the other hand, potassium and magnesium mineral contents increased during concentration. Among the various elements, cadmium, mercury, manganese, cobalt and boron were also analysed for determination of metallic contamination, but they were not found in PJ juice and CPJ. 5-Hydroxymethyl furfural was determined to be at a significant level in CPJ as a result of the heat process.

  6. Water Evaporation in Swimming Baths

    DEFF Research Database (Denmark)

    Hyldgård, Carl-Erik

    This paper is publishing measuring results from models and full-scale baths of the evaporation in swimming baths, both public baths and retraining baths. Moreover, the heat balance of the basin water is measured. In addition the full-scale measurements have given many experiences which are repres......This paper is publishing measuring results from models and full-scale baths of the evaporation in swimming baths, both public baths and retraining baths. Moreover, the heat balance of the basin water is measured. In addition the full-scale measurements have given many experiences which...... are represented in instructions for carrying out and running swimming baths. If you follow the instructions you can achieve less investments, less heat consumption and a better comfort to the bathers....

  7. Experimental results on evaporation waves

    Science.gov (United States)

    Grana Otero, Jose; Parra Fabian, Ignacio

    2010-11-01

    A liquid contained in a vertical glass tube is suddenly depressurized from a high initial pressure down to one for which the stable state is vapour, so vaporization sets off at the free surface. For large enough evaporation rates, the planar vapour-liquid interface is Darrieus-Landau unstable [1], leading to the interface surface rippling close to the instability threshold. Further increasing the initial to final pressure ratio brings about evaporation waves [2,3], in which a highly corrugated front propagates downwards into the liquid. A new experimental method is presented as well as some experimental results obtained by tracking the evolution of the front with a high speed camera. In addition, a number of new phenomena related to the dynamics of bubbles growth at the walls has been uncovered. In particular, a new mode of propagation of the evaporation front is found. In this mode the front originates from below the interface, so the propagation is upwards against gravity with a curved but smooth front.[4pt] [1] F. J. Higuera, Phys. Fluids, V. 30, 679 (1987).[0pt] [2] J.E.Shepherd and B.Sturtevant, J.Fluid Mech., V.121,379 (1982).[0pt] [3] P.Reinke and G.Yadigaroglu, Int.J.Multiph. Flow, V.27,1487 (2001).

  8. Improvements of evaporation drag model

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Yan; XU Ji-Jun

    2004-01-01

    A special visible experiment facility has been designed and built, and an observable experiment is performed by pouring one or several high-temperature particles into a water pool in the facility. The experiment result has verified Yang's evaporation drag model, which holds that the non-symmetric profile of the local evaporation rate and the local density of vapor would bring about a resultant force on the hot particle so as to resist its motion. However, in Yang's evaporation drag model, radiation heat transfer is taken as the only way to transfer heat from hot particle to the vapor-liquid interface, and all of the radiation energy is deposited on the vapor-liquid interface and contributed to the vaporization rate and mass balance of the vapor film. In improved model heat conduction and heat convection are taken into account. This paper presents calculations of the improved model, putting emphasis on the effect of hot particle's temperature on the radiation absorption behavior of water.

  9. Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho; Jung, Young Do, E-mail: ydjung@chonnam.ac.kr

    2012-03-01

    Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promoter activity. The intracellular hydrogen peroxide (H{sub 2}O{sub 2}) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H{sub 2}O{sub 2} increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial cells

  10. Modeling evaporation processes in a saline soil from saturation to oven dry conditions

    Directory of Open Access Journals (Sweden)

    M. Gran

    2011-01-01

    Full Text Available Thermal, suction and osmotic gradients interact during evaporation from a salty soil. Vapor fluxes become the main water flow mechanism under very dry conditions. A coupled nonisothermal multiphase flow and a reactive transport model of a salty sand soil was developed to study such an intricate system. The model was calibrated with data from an evaporation experiment (volumetric water content, temperature and concentration. The retention curve and relative permeability functions were modified to simulate oven dry conditions. Experimental observations were satisfactorily reproduced, which suggests that the model can be used to assess the underlying processes. Results show that evaporation is controlled by heat, and limited by salinity and liquid and vapor fluxes. Below evaporation front vapor flows downwards controlled by temperature gradient and thus generates a dilution. Vapor diffusion and dilution are strongly influenced by heat boundary conditions. Gas diffusion plays a major role in the magnitude of vapor fluxes.

  11. Heat and mass transfer analogies for evaporation models at high evaporation rate

    OpenAIRE

    Trontin, P.; Villedieu, P.

    2014-01-01

    International audience; In the framework of anti and deicing applications, heated liquid films can appear above the ice thickness, or directly above the wall. Then, evaporation plays a major role in the Messinger balance and evaporated mass has to be predicted accurately. Unfortunately, it appears that existing models under-estimate evaporation at high temperature. In this study, different evaporation models at high evaporation rates are studied. The different hypothesis on which these models...

  12. Evaluation of structure-reactivity descriptors and biological activity spectra of 4-(6-methoxy-2-naphthyl)-2-butanone using spectroscopic techniques

    Science.gov (United States)

    Agrawal, Megha; Deval, Vipin; Gupta, Archana; Sangala, Bagvanth Reddy; Prabhu, S. S.

    2016-10-01

    The structure and several spectroscopic features along with reactivity parameters of the compound 4-(6-methoxy-2-naphthyl)-2-butanone (Nabumetone) have been studied using experimental techniques and tools derived from quantum chemical calculations. Structure optimization is followed by force field calculations based on density functional theory (DFT) at the B3LYP/6-311++G(d,p) level of theory. The vibrational spectra have been interpreted with the aid of normal coordinate analysis. UV-visible spectrum and the effect of solvent have been discussed. The electronic properties such as HOMO and LUMO energies have been determined by TD-DFT approach. In order to understand various aspects of pharmacological sciences several new chemical reactivity descriptors - chemical potential, global hardness and electrophilicity have been evaluated. Local reactivity descriptors - Fukui functions and local softnesses have also been calculated to find out the reactive sites within molecule. Aqueous solubility and lipophilicity have been calculated which are crucial for estimating transport properties of organic molecules in drug development. Estimation of biological effects, toxic/side effects has been made on the basis of prediction of activity spectra for substances (PASS) prediction results and their analysis by Pharma Expert software. Using the THz-TDS technique, the frequency-dependent absorptions of NBM have been measured in the frequency range up to 3 THz.

  13. Activation-strain analysis reveals unexpected origin of fast reactivity in heteroaromatic azadiene inverse-electron-demand diels-alder cycloadditions.

    Science.gov (United States)

    Talbot, Austin; Devarajan, Deepa; Gustafson, Samantha J; Fernández, Israel; Bickelhaupt, F Matthias; Ess, Daniel H

    2015-01-02

    Heteroaromatic azadienes, especially 1,2,4,5-tetrazines, are extremely reactive partners with alkenes in inverse-electron-demand Diels-Alder reactions. Azadiene cycloaddition reactions are used to construct heterocycles in synthesis and are popular as bioorthogonal reactions. The origin of fast azadiene cycloaddition reactivity is classically attributed to the inverse frontier molecular orbital (FMO) interaction between the azadiene LUMO and alkene HOMO. Here, we use a combination of ab initio, density functional theory, and activation-strain model calculations to analyze physical interactions in heteroaromatic azadiene-alkene cycloaddition transition states. We find that FMO interactions do not control reactivity because, while the inverse FMO interaction becomes more stabilizing, there is a decrease in the forward FMO interaction that is offsetting. Rather, fast cycloadditions are due to a decrease in closed-shell Pauli repulsion between cycloaddition partners. The kinetic-thermodynamic relationship found for these inverse-electron-demand cycloadditions is also due to the trend in closed-shell repulsion in the cycloadducts. Cycloaddition regioselectivity, however, is the result of differences in occupied-unoccupied orbital interactions due to orbital overlap. These results provide a new predictive model and correct physical basis for heteroaromatic azadiene reactivity and regioselectivity with alkene dieneophiles.

  14. Reactivation of Kaposi's sarcoma-associated herpesvirus from latency requires MEK/ERK, JNK and p38 multiple mitogen-activated protein kinase pathways.

    Science.gov (United States)

    Xie, Jianping; Ajibade, Adetola Olalekan; Ye, Fengchun; Kuhne, Kurt; Gao, Shou-Jiang

    2008-02-05

    Lytic replication of Kaposi's sarcoma-associated herpesvirus (KSHV) promotes the progression of Kaposi's sarcoma (KS), a dominant malignancy in patients with AIDS. While 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced KSHV reactivation from latency is mediated by the protein kinase C delta and MEK/ERK mitogen-activated protein kinase (MAPK) pathways, we have recently shown that the MEK/ERK, JNK and p38 MAPK pathways modulate KSHV lytic replication during productive primary infection of human umbilical vein endothelial cells [Pan, H., Xie, J., Ye, F., Gao, S.J., 2006. Modulation of Kaposi's sarcoma-associated herpesvirus infection and replication by MEK/ERK, JNK, and p38 multiple mitogen-activated protein kinase pathways during primary infection. J. Virol. 80 (11), 5371-5382]. Here, we report that, besides the MEK/ERK pathway, the JNK and p38 MAPK pathways also mediate TPA-induced KSHV reactivation from latency. The MEK/ERK, JNK and p38 MAPK pathways were constitutively activated in latent KSHV-infected BCBL-1 cells. TPA treatment enhanced the levels of activated ERK and p38 but not those of activated JNK. Inhibitors of all three MAPK pathways reduced TPA-induced production of KSHV infectious virions in BCBL-1 cells in a dose-dependent fashion. The inhibitors blocked KSHV lytic replication at the early stage(s) of reactivation, and reduced the expression of viral lytic genes including RTA, a key immediate-early transactivator of viral lytic replication. Activation of MAPK pathways was necessary and sufficient for activating the promoter of RTA. Furthermore, we showed that the activation of RTA promoter by MAPK pathways was mediated by their downstream target AP-1. Together, these findings suggest that MAPK pathways might have general roles in regulating the life cycle of KSHV by mediating both viral infection and switch from viral latency to lytic replication.

  15. Heat and mass transfer with evaporation cooling of a porous plate

    Science.gov (United States)

    Makarova, S. N.; Shibaev, A. A.

    2016-10-01

    In this paper the results of experimental and theoretical investigation of heat and mass transfer with adiabatic evaporation of bicomponent water/ethanol fluid to an air flow are presented. An innovative test section for the wind tunnel with an active thermal stabilization system, maintaining the cuvette temperature equal to the evaporation surface temperature, is used to provide the evaporation adiabatic conditions. The wall temperature obtained experimentally shows the presence of expressed quasi-stationary evaporation area, qualitatively similar to sublimation curves of volatile organometallic compounds. A theoretical model based on the similarity of heat and mass transfer processes for each of the evaporating solution component is suggested. This model allows to determine evaporation surface temperature (sublimation temperature) accounting for radiation effect.

  16. Chicken Fetal Liver DNA Damage and Adduct Formation by Activation-Dependent DNA-Reactive Carcinogens and Related Compounds of Several Structural Classes

    OpenAIRE

    2014-01-01

    The chicken egg genotoxicity assay (CEGA), which utilizes the liver of an intact and aseptic embryo-fetal test organism, was evaluated using four activation-dependent DNA-reactive carcinogens and four structurally related less potent carcinogens or non-carcinogens. In the assay, three daily doses of test substances were administered to eggs containing 9–11-day-old fetuses and the fetal livers were assessed for two endpoints, DNA breaks using the alkaline single cell gel electrophoresis (comet...

  17. Preoperative plasma plasminogen activator inhibitor type-1 and serum C-reactive protein levels in patients with colorectal cancer. The RANX05 Colorectal Cancer Study Group

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Christensen, Ib Jarle; Sørensen, Steen

    2000-01-01

    BACKGROUND: Preoperative plasma plasminogen activator inhibitor-1 (PAI-1) is a prognostic variable in patients with colorectal cancer. It has been suggested, however, that plasma PAI-1 is a nonspecific prognostic parameter similar to the acute-phase reactant C-reactive protein (CRP). In the present...... statistical analysis including Dukes classification, gender, age, tumor location, perioperative blood transfusion, PAI-1 and CRP, plasma PAI-1 was a dependent prognostic variable, while serum CRP (P

  18. Thermodynamic Modeling of the SRS Evaporators: Part II. The 3H System

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.M.

    2001-10-02

    Accumulations of two solid phases have formed scale deposits in the Savannah River Site 2H Evaporator system since late 1996. The aluminosilicate scale deposits caused the evaporator pot to become inoperable in October 1999. Accumulations of the diuranate phase have caused criticality concerns in the SRS 2H Evaporator. In order to ensure that similar deposits are not and will not form in the SRS 3H Evaporator, thermodynamically derived activity diagrams specific to the feeds processed from Tanks 30 and 32 are evaluated in this report.

  19. A New Robust Decoupled Control of the Stator Active and Reactive Currents for Grid-Connected Doubly-Fed Induction Generators

    Directory of Open Access Journals (Sweden)

    Ahmad Bashar Ataji

    2016-03-01

    Full Text Available This paper addresses the grid-connected variable speed doubly-fed induction generator, and proposes a new decoupled control to replace the conventional decoupled active and reactive powers (P-Q control. The proposed decoupled control is based on decoupling the stator active and reactive currents, in contrast with the conventional decoupled P-Q control, which is based on decoupling the stator active and reactive powers by forcing the stator d- or q-voltage to zero. The proposed decoupled control has all the advantages of the conventional decoupled P-Q control such as constant switching frequency and robustness against slip angle inaccuracy, and it has some additional advantages: The proposed control requires less machine parameters; for the controller design, it requires the stator-to-rotor turns ratio only; for the online calculation, it does not requires any machine parameter. The proposed decoupled control is more flexible and robust since the control is independent of the grid voltage orientation. It is robust against variation in the grid voltage amplitude. Several experiments are carried out using a 1.1 kW doubly-fed induction generator (DFIG, and the results support the proposed decoupled control and demonstrate some of its advantages.

  20. Real-Time Control of Active and Reactive Power for Doubly Fed Induction Generator (DFIG-Based Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Aman Abdulla Tanvir

    2015-09-01

    Full Text Available This paper presents the modeling, rapid control prototyping, and hardware-in-the-loop testing for real-time simulation and control of a grid-connected doubly fed induction generator (DFIG in a laboratory-size wind turbine emulator for wind energy conversation systems. The generator is modeled using the direct-quadrature rotating reference frame circuit along with the aligned stator flux, and the field-oriented control approach is applied for independent control of the active and reactive power and the DC-link voltage at the grid side. The control of the active, reactive power and the DC-link voltage are performed using a back-to-back converter at sub- and super-synchronous as well as at variable speeds. The control strategy is experimentally validated on an emulated wind turbine driven by the Opal-RT real-time simulator (OP5600 for simultaneous control of the DC-link voltage, active and reactive power.

  1. Enhanced photocatalytic activity of hexagonal flake-like Bi2S3 / ZnS composites with a large percentage of reactive facets

    Science.gov (United States)

    Xiong, Dan-Ni; Huang, Gui-Fang; Zhou, Bing-Xin; Chang, Shengli; Wang, Fei; Huang, Wei-Qing

    2016-08-01

    Selectively exposing surfaces with high reactivity is an effective strategy to enhance the photocatalytic activity of semiconductor photocatalysts. We report the facile synthesis of hexagonal flake-like Bi2S3/ZnS composites with a large percentage of reactive exposed {2 2 1} facets by tuning only the molar ratios of Bi to Zn. The samples exhibit enhanced optical absorption and red shift of absorption edge. The Bi2S3/ZnS composites with hexagon morphology display superior photocatalytic degradation of methylene blue (MB), faster than that with pure Bi2S3 and pure ZnS by a factor of 7.1 and 3.6, respectively. The enhanced photocatalytic activity can be attributed to the highly reactive {2 2 1} exposed facets and the more efficient separation of photogenerated electron-hole pairs is due to the interface of the hetero-junction. Furthermore, a tentative mechanism for photodegradation of MB over Bi2S3/ZnS composites has been proposed involving the photogenerated holes and ṡOH radicals as the main active species, which is confirmed by using different scavengers. The novel constructed Bi2S3/ZnS composite is expected to be an attractive candidate as a photocatalyst for environmental purification and energy conversion.

  2. Biochemical passive reactors for treatment of acid mine drainage: Effect of hydraulic retention time on changes in efficiency, composition of reactive mixture, and microbial activity.

    Science.gov (United States)

    Vasquez, Yaneth; Escobar, Maria C; Neculita, Carmen M; Arbeli, Ziv; Roldan, Fabio

    2016-06-01

    Biochemical passive treatment represents a promising option for the remediation of acid mine drainage. This study determined the effect of three hydraulic retention times (1, 2, and 4 days) on changes in system efficiency, reactive mixture, and microbial activity in bioreactors under upward flow conditions. Bioreactors were sacrificed in the weeks 8, 17 and 36, and the reactive mixture was sampled at the bottom, middle, and top layers. Physicochemical analyses were performed on reactive mixture post-treatment and correlated with sulfate-reducing bacteria and cellulolytic and dehydrogenase activity. All hydraulic retention times were efficient at increasing pH and alkalinity and removing sulfate (>60%) and metals (85-99% for Fe(2+) and 70-100% for Zn(2+)), except for Mn(2+). The longest hydraulic retention time (4 days) increased residual sulfides, deteriorated the quality of treated effluent and negatively impacted sulfate-reducing bacteria. Shortest hydraulic retention time (1 day) washed out biomass and increased input of dissolved oxygen in the reactors, leading to higher redox potential and decreasing metal removal efficiency. Concentrations of iron, zinc and metal sulfides were high in the bottom layer, especially with 2 day of hydraulic retention time. Sulfate-reducing bacteria, cellulolytic and dehydrogenase activity were higher in the middle layer at 4 days of hydraulic retention time. Hydraulic retention time had a strong influence on overall performance of passive reactors.

  3. Effect of superhydrophobic surface morphology on evaporative deposition patterns

    Science.gov (United States)

    Dicuangco, Mercy; Dash, Susmita; Weibel, Justin A.; Garimella, Suresh V.

    2014-05-01

    Prediction and active control of the spatial distribution of particulate deposits obtained from sessile droplet evaporation are vital in printing, nanostructure assembly, biotechnology, and other applications that require localized deposits. This Letter presents surface wettability-based localization of evaporation-driven particulate deposition and the effect of superhydrophobic surface morphology on the distribution of deposits. Sessile water droplets containing suspended latex particles are evaporated on non-wetting textured surfaces with varying microstructure geometry at ambient conditions. The droplets are visualized throughout the evaporation process to track the temporal evolution of contact radius and apparent contact angle. The resulting particle deposits on the substrates are quantitatively characterized. The experimental results show that superhydrophobic surfaces suppress contact-line deposition during droplet evaporation, thereby providing an effective means of localizing the deposition of suspended particles. A correlation between deposit size and surface morphology, explained in terms of the interface pressure balance at the transition between wetting states, reveals an optimum surface morphology for minimizing the deposit coverage area.

  4. An assessment of the antagonistic activity of reactive blue 2 at P1- and P2-purinoceptors: supporting evidence for purinergic innervation of the rabbit portal vein.

    Science.gov (United States)

    Reilly, W M; Saville, V L; Burnstock, G

    1987-08-04

    A comparison of the effect of the putative adenosine 5'-triphosphate (ATP) antagonist, reactive blue 2, was made on the inhibitory responses to exogenous purines and non-adrenergic, non-cholinergic nerve stimulation in the rabbit portal vein, a preparation possessing both P1- and P2Y-purinoceptors, and on the excitatory responses to alpha, beta-methylene ATP in the rat portal vein where P2X-purinoceptors are present. In the ergotamine-contracted rabbit portal vein, ATP, adenosine and isoprenaline induced concentration-dependent relaxations. Reactive blue 2 (10-50 microM) produced a 2-9-fold shift to the right of the concentration-response curve to ATP, while the responses to adenosine and isoprenaline were not significantly altered. The inhibition of ATP assessed in the concentration-response curves appeared to be non-competitive. Electrical field stimulation of the ergotamine-contracted rabbit portal vein produced frequency-dependent relaxations that were abolished following incubation with tetrodotoxin (1 microM) and were inhibited by reactive blue 2 (30-50 microM), in a concentration-dependent manner. The rat portal vein contracted in response to the application of exogenous noradrenaline and alpha, beta-methylene ATP. Responses to both alpha, beta-methylene ATP (a P2X-purinoceptor agonist) and noradrenaline were not significantly inhibited by concentrations of reactive blue 2 that produced inhibition of the P2Y-mediated responses of the rabbit portal vein. In conclusion, it is suggested that reactive blue 2 is a non-competitive P2Y-purinoceptor antagonist, although the drug has a narrow range of activity and non-specific side effects become apparent at high concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Promoting Conceptual Change in First Year Students' Understanding of Evaporation

    Science.gov (United States)

    Costu, Bayram; Ayas, Alipasa; Niaz, Mansoor

    2010-01-01

    We constructed the PDEODE (Predict-Discuss-Explain-Observe-Discuss-Explain) teaching strategy, a variant of the classical POE (Predict-Observe-Explain) activity, to promote conceptual change, and investigated its effectiveness on student understanding of the evaporation concept. The sample consisted of 52 first year students in a primary science…

  6. Putting the "vap" into evaporation

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available In the spirit of the Special Issue of HESS to which it contributes, this paper documents the origin and development of the science of natural evaporation from land surfaces over the last 30–35 years, since the symposium A View from the Watershed was held to commemorate the opening of the new Institute of Hydrology (IH building in 1973. Important subsequent technical progress includes the ability to measure routinely the diurnal cycle of near-surface meteorological variables using automatic weather stations, and of surface energy and momentum exchanges using automated implementations of the Bowen Ratio/Energy Budget technique and the Eddy Correlation technique, along with the capability to estimate the "fetch" for which these measurements apply. These improvements have been complemented by new methods to measure the separate components of evaporation, including: the interception process using randomly relocated below-canopy gauges, transpiration fluxes from individual leaves/shoots using porometers and from plants/plant components using stem-flow gauges and soil evaporation using micro-lysimeters and soil moisture depletion methods. In recent years progress has been made in making theory-based area-average estimates of evaporation using scintillometers, and model-based area-average estimates by assembling many streams of relevant data into Land Data Assimilation Systems. Theoretical progress has been made in extending near-surface turbulence theory to accommodate the effect of the "excess" boundary layer resistance to leaf-to-air transfer of energy and mass fluxes relative to that for momentum, and to allow for observed shortcoming in stability factors in the transition layer immediately above vegetation. Controversy regarding the relative merits of multi-layer model and "big leaf" representations of whole-canopy exchanges has been resolved in favour of the latter approach. Important gaps in the theory of canopy-atmosphere interactions have

  7. Study of the interactions bacteria - phenanthrene - activated carbon for the preparation of a permeable reactive barrier; Etude des interactions bacteries - phenanthrene - charbon en vue de l'elaboration d'une barriere permeable reactive

    Energy Technology Data Exchange (ETDEWEB)

    Leglize, P.

    2004-12-01

    Permeable Reactive Barrier (PRB) is a new way for the remediation of contaminated groundwater, but up to now Polycyclic Aromatic Hydrocarbons (PAHs) were rarely considered. We investigated PAH - bacteria - materials interactions in order to validate the feasibility of PRB for PAH contamination. PHE Adsorption/desorption kinetics onto different materials, activated carbons (CA), pozzolana (Pz) and pozzolana coated with heavy fuel (PzF), were investigated. PHE biodegradation were performed on batch using PAH degrading bacteria and the PRB materials. CA was a good media for PRB process: Phenanthrene sorption capacity is 100 to 10000 fold higher than PzF and Pz. Phenanthrene mineralization with CA was higher than without material. Bacterial properties affected PHE biodegradation. Bio-film production improved PHE biodegradation by PAH degrading bacteria. Column studies showed that inoculation of the column improved its efficiency: adsorbed PHE degradation and increased retardation of PHE. (author)

  8. Initial evidence for the link between activities and health: Associations between a balance of activities, functioning and serum levels of cytokines and C-reactive protein.

    Science.gov (United States)

    Dür, Mona; Steiner, Günter; Stoffer, Michaela Alexandra; Fialka-Moser, Veronika; Kautzky-Willer, Alexandra; Dejaco, Clemens; Ekmekcioglu, Cem; Prodinger, Birgit; Binder, Alexa; Smolen, Josef; Stamm, Tanja Alexandra

    2016-03-01

    Growing evidence shows interrelations of psychological factors, neurological and immunological processes. Therefore, constructs like a balance of activities, the so called "occupational balance", could also have biological correlates. The aim of this study was to investigate potential associations between occupational balance, functioning, cytokines and C-reactive protein (CRP) in patients suffering from a chronic inflammatory disease like rheumatoid arthritis (RA) and healthy people. Moreover, we wanted to explore potential differences in gender and employment status. A descriptive study in patients with RA and healthy people was conducted using the Occupational Balance-Questionnaire (OB-Quest) and the Short-Form 36 Health Survey (SF-36). Serum levels of cytokines, such as interleukin 6 (IL-6) and 8 (IL-8), interferon alpha (INFα), tumour necrosis factor alpha (TNFα), rheumatoid factor (RF) and of CRP were measured. Descriptive statistics, as well as Mann-Whitney U tests and Spearmen's rank correlation coefficients (rs) were calculated. One-hundred-thirty-two patients with RA and 76 healthy people participated. Occupational balance was associated with functioning, cytokines and CRP. The strongest associations were identified in the unemployed healthy-people sample with cytokines and CRP being within the normal range. For example, the OB-Quest item challenging activities was associated with IL-8 (rs=-0.63, p=0.04) and the SF-36 sub-scale bodily pain was associated with IFNα (rs=-0.69, p=0.02). The items rest and sleep (rs=-0.71, p=0.01) and variety of different activities (rs=-0.74, psocial functioning. Employed and unemployed people differed in their age and CRP levels. Additionally, gender differences were found in two OB-Quest items in that fewer women were able to adapt their activities to changing living conditions and fewer men were overstressed. In conclusion, we found preliminary biological evidence for the link between occupation and health in that the

  9. The Role of Sulfhydryl Reactivity of Small Molecules for the Activation of the KEAP1/NRF2 Pathway and the Heat Shock Response

    Directory of Open Access Journals (Sweden)

    Albena T. Dinkova-Kostova

    2012-01-01

    Full Text Available The KEAP1/NRF2 pathway and the heat shock response are two essential cytoprotective mechanisms that allow adaptation and survival under conditions of oxidative, electrophilic, and thermal stress by regulating the expression of elaborate networks of genes with versatile protective functions. The two pathways are independently regulated by the transcription factor nuclear factor-erythroid 2 p45-related factor 2 (NRF2 and heat shock factor 1 (HSF1, respectively. The activity of these transcriptional master regulators increases during conditions of stress and also upon encounter of small molecules (inducers, both naturally occurring as well as synthetically produced. Inducers have a common chemical property: the ability to react with sulfhydryl groups. The protein targets of such sulfhydryl-reactive compounds are equipped with highly reactive cysteine residues, which serve as sensors for inducers. The initial cysteine-sensed signal is further relayed to affect the expression of large networks of genes, which in turn can ultimately influence complex cell fate decisions such as life and death. The paper summarizes the multiple lines of experimental evidence demonstrating that the reactivity with sulfhydryl groups is a major determinant of the mechanism of action of small molecule dual activators of the KEAP1/NRF2 pathway and the heat shock response.

  10. Validity and Agreement between the 28-Joint Disease Activity Score Based on C-Reactive Protein and Erythrocyte Sedimentation Rate in Patients with Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Nielung, Louise; Christensen, Robin; Danneskiold-Samsøe, Bente;

    2015-01-01

    Objective. To validate the agreement between the 28-joint disease activity score based on erythrocyte sedimentation rate (DAS28-ESR) and the 28-joint disease activity score based on C-reactive protein (DAS28-CRP) in a group of Danish patients with rheumatoid arthritis (RA). Methods. Data from 109...... Danish RA patients initiating biologic treatment were analysed at baseline and following one year of treatment. Participants were retrospectively enrolled from a previous cohort study and were considered eligible for this project if CRP and ESR were measured at baseline and at the follow-up visit...

  11. Circulating levels of osteopontin, osteoprotegerin, total soluble receptor activator of nuclear factor-kappa B ligand, and high-sensitivity C-reactive protein in patients with active rheumatoid arthritis randomized to etanercept alone or in combination with methotrexate

    DEFF Research Database (Denmark)

    Sennels, H.; Sørensen, Steen; Østergaard, Mikkel;

    2008-01-01

    OBJECTIVE: To determine whether circulating levels of osteopontin (OPN), osteoprotegerin (OPG), total soluble receptor activator of nuclear factor-kappa B ligand (total sRANKL), and high-sensitivity C-reactive protein (hsCRP) change in patients with rheumatoid arthritis (RA) during...

  12. Preparation and properties of evaporated CdTe films

    Science.gov (United States)

    Bube, R. H.; Fahrenbruch, A. L.; Chien, K. F.

    1987-07-01

    Previous work on evaporated CdTe films for photovoltaics showed no clear path to successful p-type doping of CdTe during deposition. Post-deposition annealing of the films in various ambients thus was examined as a means of doping. Anneals were done in Te, Cd, P, and As vapors and in vacuum, air and Ar, all of which showed large effects on series resistance and diode parameters. With As, series resistance values of In/p-CdTe/graphite structures decreased markedly. This decrease was due to a decrease in grain boundary and/or back contact barrier height, and thus was due to large increases in mobility; the carrier density was not altered substantially. Although the series-resistance decreases were substantial, the diode characteristics became worse. The decreases were not observed when CdS/CdTe cells were fabricated on Te vapor-annealed films. Preparation of ZnO films by reactive evaporation yielded promising results. Deposition of p-ZnTe films by hot-wall vapor evaporation, using conventional techniques, yielded acceptable specimens.

  13. A multi-objective optimization of the active and reactive resource scheduling at a distribution level in a smart grid context

    DEFF Research Database (Denmark)

    Sousa, Tiago; Morais, Hugo; Vale, Zita

    2015-01-01

    at a distribution level, due to the high number of resources connected in distribution levels. This paper proposes a new multi-objective methodology to deal with the optimal resource scheduling considering the distributed generation, electric vehicles and capacitor banks for the joint active and reactive power...... the best compromise solution. The proposed methodology has been tested in the 33-bus distribution network. The case study shows the results of three different scenarios for the economic, technical, and multi-objective perspectives, and the results demonstrated the importance of incorporating the reactive...... scheduling in the distribution network using the multi-objective perspective to obtain the best compromise solution for the economic and technical perspectives....

  14. Reactive Coevaporation Synthesis and Characterization of SrTiO3 Thin Films

    Science.gov (United States)

    Yamaguchi, Hiromu; Matsubara, Shogo; Miyasaka, Yoichi

    1991-09-01

    SrTiO3 thin films were prepared by the reactive coevaporation method, where the Ti and Sr metals were evaporated in oxygen ambient with an E-gun and K-cell, respectively. A uniform depth profile in composition was achieved by altering the Ti evaporation rate according to the Sr evaporation rate change. A typical dielectric constant of 170 was measured on films of 75 nm in thickness. The in-situ annealing in oxygen plasma reduced the leakage current.

  15. Particle deposition on superhydrophobic surfaces by sessile droplet evaporation

    Science.gov (United States)

    Dicuangco, Mercy Grace

    Prediction and active control of the spatial distribution of particulate deposits obtained from sessile droplet evaporation is essential in ink-jet printing, nanostructure assembly, biotechnology, and other applications that require localized deposits. In recent years, sessile droplet evaporation on bio-inspired superhydrophobic surfaces has become an attractive method for depositing materials on a site-specific, localized region, but is less explored compared to evaporative deposition on hydrophilic surfaces. It is therefore of interest to understand particle deposition during droplet evaporation on superhydrophobic surfaces to enable accurate prediction and tunable control of localized deposits on such surfaces. The purpose of the present work is to explore the morphology of particles deposited on superhydrophobic surfaces by the evaporation of sessile water droplets containing suspended latex spheres. Droplet evaporation experiments are performed on non-wetting, textured surfaces with varying geometric parameters. The temporal evolution of the droplet contact radius and contact angle throughout the evaporation process are tracked by visualizing the transient droplet shape and wetting behavior. The droplets are observed to exhibit a combination of the following modes of evaporation: the constant contact radius mode, the constant contact angle mode, and the mixed mode in which the contact angle and the contact radius change simultaneously. After complete dry-out, the remaining particulate deposits are qualitatively and quantitatively characterized to describe their spatial distribution. In the first part of the study, the test surfaces are maintained at different temperatures. Experiments are conducted at ambient conditions and at elevated substrate temperatures of approximately 40°C, 50°C, and 60°C. The results show that droplet evaporation on superhydrophobic surfaces, driven by either mass diffusion at ambient conditions or by substrate heating, suppresses

  16. The effects of phorbol ester activation and reactive oxygen species scavengers on the macrophage-mediated foreign body reaction to polyurethanes.

    Science.gov (United States)

    McBane, Joanne E; Matheson, Loren A; Santerre, J Paul; Labow, Rosalind S

    2009-12-15

    Phorbol myristate acetate, a protein kinase C activator, inhibited monocyte-derived macrophage (MDM)-mediated degradation of aliphatic (HDI) polycarbonate-based polyurethanes but not degradation of the aromatic polycarbonate-based polyurethane (MDI). The objectives of this study were to determine if reactive oxygen species are involved in the phorbol myristate acetate effect on esterase activity and MDM-mediated polycarbonate-based polyurethane degradation and to find a good marker of material-initiated activation of MDM. The phorbol myristate acetate-dependent effects of the material chemistry on cell activation and degradation were evaluated by adding reactive oxygen species scavengers, catalase plus superoxide dismutase to MDM and assaying possible markers of MDM activation: esterase activity, acid phosphatase activity, and high molecular weight group box 1 protein (HMGB1). All treatments reduced the esterase activity in MDM on HDI but not in MDM on MDI. Acid phosphatase was inhibited in MDM to varying degrees on all surfaces by phorbol myristate acetate or catalase plus superoxide dismutase either alone or together. Secretion of HMGB1 from MDM on HDI431 was higher than MDI; however only secretion from MDM on HDI was inhibited by phorbol myristate acetate. In MDM on HDI, catalase plus superoxide dismutase reduced intracellular HMGB1 levels +/- phorbol myristate acetate; whereas, catalase, superoxide dismutase plus phorbol myristate acetate increased intracellular HMGB1 in MDM on MDI, suggesting that esterase and HMGB1 are more specific markers of activation than acid phosphatase. Manipulation of signaling pathways may provide insight surrounding the mechanism of activation for oxidative and/or hydrolytic degradative pathways in the MDM response to material surface chemistry.

  17. New models for droplet heating and evaporation

    KAUST Repository

    Sazhin, Sergei S.

    2013-02-01

    A brief summary of new models for droplet heating and evaporation, developed mainly at the Sir Harry Ricardo Laboratory of the University of Brighton during 2011-2012, is presented. These are hydrodynamic models for mono-component droplet heating and evaporation, taking into account the effects of the moving boundary due to evaporation, hydrodynamic models of multi-component droplet heating and evaporation, taking and not taking into account the effects of the moving boundary, new kinetic models of mono-component droplet heating and evaporation, and a model for mono-component droplet evaporation, based on molecular dynamics simulation. The results, predicted by the new models are compared with experimental data and the prehctions of the previously developed models where possible. © 2013 Asian Network for Scientific Information.

  18. Expressions for the evaporation of sessile liquid droplets incorporating the evaporative cooling effect.

    Science.gov (United States)

    Wang, Yilin; Ma, Liran; Xu, Xuefeng; Luo, Jianbin

    2016-12-15

    The evaporation along the surface of pinned, sessile droplets is investigated numerically by using the combined field approach. In the present model, the evaporative cooling at the droplet surface which leads to a reduction in the evaporation is taken into account. Simple, yet accurate analytical expressions for the local evaporation flux and for the total evaporation rate of sessile droplets are obtained. The theoretical analyses indicate that the reduction in the evaporation becomes more pronounced as the evaporative cooling number Ec increases. The results also reveal that the variation of total evaporation rate with contact angle will change its trend as the intensity of the evaporative cooling changes. For small values of Ec, the total evaporation rate increases with the contact angle, the same as predicted by Deegan et al. and by Hu and Larson in their isothermal models in which the evaporative cooling is neglected. Contrarily, when the evaporative cooling effect is strong enough, the total evaporation rate will decrease as the contact angle increases. The present theory is corroborated experimentally, and found in good agreement with the expressions proposed by Hu and Larson in the limiting isothermal case.

  19. Sessile Drop Evaporation and Leidenfrost Phenomenon

    OpenAIRE

    A. K. Mozumder; M. R. Ullah; Hossain, A.; Islam, M A

    2010-01-01

    Problem statement: Quenching and cooling are important process in manufacturing industry for controlling the mechanical properties of materials, where evaporation is a vital mode of heat transfer. Approach: This study experimentally investigated the evaporation of sessile drop for four different heated surfaces of Aluminum, Brass, Copper and Mild steel with a combination of four different liquids as Methanol, Ethanol, Water and NaCl solution. The time of evaporation for the droplet on the hot...

  20. Molecular Effects on Evaporation and Condensation

    OpenAIRE

    Meland, Roar

    2002-01-01

    In this thesis the evaporation from and condensation on a plane liquid surface have been studied by analysis and molecular dynamics simulations. The effect of the condensation coefficient on the inverted temperature gradient for a two-surface evaporation-condensation geometry is investigated by the moment method. The influence of the molecular exchange phenomenon on the gas-kinetic treatment of evaporation and condensation is shown to be neglible under certain assumptions. Methods to simulate...

  1. Mdm2 ligase dead mutants did not act in a dominant negative manner to re-activate p53, but promoted tumor cell growth.

    Science.gov (United States)

    Swaroop, Manju; Sun, Yi

    2003-01-01

    Mdm2 (murine double minute 2) is an oncogene, first identified in BALB/c 3T3 cells. Over-expression and gene amplification of Mdm2 were found in a variety of human cancers. Recently, Mdm2 was found to be an E3 ubiquitin ligase that promotes degradation of p53, which contributes significantly to its oncogenic activity. In this study, we test a hypothesis that Mdm2 ligase dead mutants, which retained p53 binding activity but lost degradation activity, would act in a dominant negative manner to re-activate p53, especially upon stressed conditions. Five Mdm2 constructs expressing wild-type and E3 ligase-dead Mdm2 proteins were generated in a Tet-Off system and transfected into MCF-7 breast cancer cells (p53+/+ with Mdm2 overexpression) as well as MCF10A immortalized breast cells (p53+/+ without Mdm2 overexpression) as a normal control. We found that expression of Mdm2 mutants were tightly regulated by doxycycline. Withdrawal of doxycycline in culture medium triggered overexpression of Mdm2 mutants. However, expression of ligase dead mutants in MCF7 and MCF10A cells did not reactivate p53 as shown by a luciferase-reporter transcription assay and Western blot of p53 and its downstream target p21 under either unstressed condition or after exposure to DNA damaging agents. Biologically, over-expression of Mdm2 mutants had no effect on p53-induced apoptosis following DNA damage. Interestingly, over-expression of Mdm2 mutants promoted growth of MCF7 tumor cells probably via a p53-independent mechanism. Over-expression of Mdm2 mutants, however, had no effect on the growth of normal MCF10A cells and did not cause their transformation. Thus, ligase dead mutants of Mdm2 did not act in a dominant negative manner to reactivate p53 and they are not oncogenes in MCF10A cells.

  2. Role of evaporation in gravitational collapse

    CERN Document Server

    Baccetti, Valentina; Terno, Daniel R

    2016-01-01

    We study collapse of evaporating thin dust shells using two families of metrics to describe the {exterior geometry: the outgoing Vaidya metric and the retarded Schwarzschild metric. Both allow incorporation of Page's evaporation law (the latter in terms of the time at infinity), resulting in a modified equation} of motion for the shell. In these scenarios we find in each case that the collapse is accelerated due to evaporation, but the Schwarzschild radius is not crossed. Instead the shell is always at a certain sub-Planckian distance from this would-be horizon that depends only on the mass and evaporation rate.

  3. Evaporating Black Holes and Long Range Scaling

    CERN Document Server

    Salehi, H

    2003-01-01

    For an effective treatment of the evaporation process of a large black hole the problem concerning the role played by the fluctuations of the (vacuum) stress tensor close to the horizon is addressed. We present arguments which establish a principal relationship between the outward fluctuations of the stress tensor close to the horizon and quantities describing the onset of the evaporation process. This suggest that the evaporation process may be described by a fluctuation-dissipation theorem relating the noise of the horizon to the black hole evaporation rate.

  4. Out-of-tank evaporator demonstration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lucero, A.J.; Jennings, H.L.; VanEssen, D.C. [and others

    1998-02-01

    The project reported here was conducted to demonstrate a skid-mounted, subatmospheric evaporator to concentrate liquid low-level waste (LLLW) stored in underground tanks at Oak Ridge National Laboratory (ORNL). This waste is similar to wastes stored at Hanford and Savannah River. A single-stage subatmospheric evaporator rated to produce 90 gallons of distillate per hour was procured from Delta Thermal, Inc., of Pensacola, Florida, and installed in an existing building. During the 8-day demonstration, 22,000 gal of LLLW was concentrated by 25% with the evaporator system. Decontamination factors achieved averaged 5 x 10{sup 6} (i.e., the distillate contained five million times less Cesium 137 than the feed). Evaporator performance substantially exceeded design requirements and expectations based on bench-scale surrogate test data. Out-of tank evaporator demonstration operations successfully addressed the feasibility of hands-on maintenance. Demonstration activities indicate that: (1) skid-mounted, mobile equipment is a viable alternative for the treatment of ORNL LLLW, and (2) hands-on maintenance and decontamination for movement to another site is achievable. Cost analysis show that 10% of the demonstration costs will be immediately recovered by elimination of solidification and disposal costs. The entire cost of the demonstration can be recovered by processing the inventory of Melton Valley Storage Tank waste and/or sluice water prior to solidifications. An additional savings of approximately $200,000 per year can be obtained by processing newly generated waste through the system. The results indicate that this type of evaporator system should be considered for application across the DOE complex. 25 refs., 11 figs., 2 tabs.

  5. Reactive Systems

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand

    A reactive system comprises networks of computing components, achieving their goals through interaction among themselves and their environment. Thus even relatively small systems may exhibit unexpectedly complex behaviours. As moreover reactive systems are often used in safety critical systems......, the need for mathematically based formal methodology is increasingly important. There are many books that look at particular methodologies for such systems. This book offers a more balanced introduction for graduate students and describes the various approaches, their strengths and weaknesses, and when...... they are best used. Milner's CCS and its operational semantics are introduced, together with the notions of behavioural equivalences based on bisimulation techniques and with recursive extensions of Hennessy-Milner logic. In the second part of the book, the presented theories are extended to take timing issues...

  6. Notopterygium forbesii boiss extract and its active constituents increase reactive species and heme oxygenase-1 in human fetal hepatocytes: mechanisms of action.

    Science.gov (United States)

    Tang, Soon Yew; Wang, Huansong; Zhang, Wenxia; Halliwell, Barry

    2008-12-01

    Notopterygium forbesii Boiss (NF) has been used as a traditional Chinese medicine for the treatment of common cold and rheumatism. However, there has been limited research on the biological properties of NF, and the mechanisms of action remain unknown. Here, we aimed to study the mechanism of NF-induced heme oxygenase-1 (HO-1) in human fetal hepatocytes (HFHs) and to identify the constituents responsible. Exposure of HFHs to NF causes oxidative stress with the accumulation of reactive species, which in turn leads to the phosphorylation of p38 MAPK and nuclear accumulation of Nrf2 transcription factor, and eventually increased levels of HO-1 mRNA and protein. The increases in reactive species and HO-1 protein are inhibited by agonists of glucocorticoid receptors (GR), such as RU28362, prednisolone, and dexamethasone, as well as by N-acetyl-L-cysteine and SB203580 (a p38 inhibitor), suggesting a role of GR in NF-induced increases in reactive species and HO-1. Assay-guided fractionation of NF led to three active compounds, phenethyl ferulate, bergaptol, and isoimperatorin, that were found to increase oxidative stress and HO-1 protein levels in HFHs. The induction of HO-1 protein in response to moderate oxidative stress may explain some of the beneficial pharmacological effects of NF.

  7. Evaporative instabilities in climbing films

    Science.gov (United States)

    Hosoi, A. E.; Bush, John W. M.

    2001-09-01

    We consider flow in a thin film generated by partially submerging an inclined rigid plate in a reservoir of ethanol or methanol water solution and wetting its surface. Evaporation leads to concentration and surface tension gradients that drive flow up the plate. An experimental study indicates that the climbing film is subject to two distinct instabilities. The first is a convective instability characterized by flattened convection rolls aligned in the direction of flow and accompanied by free-surface deformations; in the meniscus region, this instability gives rise to pronounced ridge structures aligned with the mean flow. The second instability, evident when the plate is nearly vertical, takes the form of transverse surface waves propagating up the plate.

  8. Evaporative Instability in Binary Mixtures

    Science.gov (United States)

    Narayanan, Ranga; Uguz, Erdem

    2012-11-01

    In this talk we depict the physics of evaporative convection for binary systems in the presence of surface tension gradient effects. Two results are of importance. The first is that a binary system, in the absence of gravity, can generate an instability only when heated from the vapor side. This is to be contrasted with the case of a single component where instability can occur only when heated from the liquid side. The second result is that a binary system, in the presence of gravity, will generate an instability when heated from either the vapor or the liquid side provided the heating is strong enough. In addition to these results we show the conditions at which interfacial patterns can occur. Support from NSF OISE 0968313, Partner Univ. Fund and a Chateaubriand Fellowship is acknowledged.

  9. Nanofluid Drop Evaporation: Experiment, Theory, and Modeling

    Science.gov (United States)

    Gerken, William James

    Nanofluids, stable colloidal suspensions of nanoparticles in a base fluid, have potential applications in the heat transfer, combustion and propulsion, manufacturing, and medical fields. Experiments were conducted to determine the evaporation rate of room temperature, millimeter-sized pendant drops of ethanol laden with varying amounts (0-3% by weight) of 40-60 nm aluminum nanoparticles (nAl). Time-resolved high-resolution drop images were collected for the determination of early-time evaporation rate (D2/D 02 > 0.75), shown to exhibit D-square law behavior, and surface tension. Results show an asymptotic decrease in pendant drop evaporation rate with increasing nAl loading. The evaporation rate decreases by approximately 15% at around 1% to 3% nAl loading relative to the evaporation rate of pure ethanol. Surface tension was observed to be unaffected by nAl loading up to 3% by weight. A model was developed to describe the evaporation of the nanofluid pendant drops based on D-square law analysis for the gas domain and a description of the reduction in liquid fraction available for evaporation due to nanoparticle agglomerate packing near the evaporating drop surface. Model predictions are in relatively good agreement with experiment, within a few percent of measured nanofluid pendant drop evaporation rate. The evaporation of pinned nanofluid sessile drops was also considered via modeling. It was found that the same mechanism for nanofluid evaporation rate reduction used to explain pendant drops could be used for sessile drops. That mechanism is a reduction in evaporation rate due to a reduction in available ethanol for evaporation at the drop surface caused by the packing of nanoparticle agglomerates near the drop surface. Comparisons of the present modeling predictions with sessile drop evaporation rate measurements reported for nAl/ethanol nanofluids by Sefiane and Bennacer [11] are in fairly good agreement. Portions of this abstract previously appeared as: W. J

  10. Intrinsic Evaporative Cooling by Hygroscopic Earth Materials

    Directory of Open Access Journals (Sweden)

    Alexandra R. Rempel

    2016-08-01

    Full Text Available The phase change of water from liquid to vapor is one of the most energy-intensive physical processes in nature, giving it immense potential for cooling. Diverse evaporative cooling strategies have resulted worldwide, including roof ponds and sprinklers, courtyard fountains, wind catchers with qanats, irrigated green roofs, and fan-assisted evaporative coolers. These methods all require water in bulk liquid form. The evaporation of moisture that has been sorbed from the atmosphere by hygroscopic materials is equally energy-intensive, however, yet has not been examined for its cooling potential. In arid and semi-arid climates, hygroscopic earth buildings occur widely and are known to maintain comfortable indoor temperatures, but evaporation of moisture from their walls and roofs has been regarded as unimportant since water scarcity limits irrigation and rainfall; instead, their cool interiors are attributed to well-established mass effects in delaying the transmission of sensible gains. Here, we investigate the cooling accomplished by daily cycles of moisture sorption and evaporation which, requiring only ambient humidity, we designate as “intrinsic” evaporative cooling. Connecting recent soil science to heat and moisture transport studies in building materials, we use soils, adobe, cob, unfired earth bricks, rammed earth, and limestone to reveal the effects of numerous parameters (temperature and relative humidity, material orientation, thickness, moisture retention properties, vapor diffusion resistance, and liquid transport properties on the magnitude of intrinsic evaporative cooling and the stabilization of indoor relative humidity. We further synthesize these effects into concrete design guidance. Together, these results show that earth buildings in diverse climates have significant potential to cool themselves evaporatively through sorption of moisture from humid night air and evaporation during the following day’s heat. This finding

  11. Electrochemically reduced water exerts superior reactive oxygen species scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water

    Science.gov (United States)

    Hamasaki, Takeki; Harada, Gakuro; Nakamichi, Noboru; Kabayama, Shigeru; Teruya, Kiichiro; Fugetsu, Bunshi; Gong, Wei; Sakata, Ichiro; Shirahata, Sanetaka

    2017-01-01

    Electrochemically reduced water (ERW) is produced near a cathode during electrolysis and exhibits an alkaline pH, contains richly dissolved hydrogen, and contains a small amount of platinum nanoparticles. ERW has reactive oxygen species (ROS)-scavenging activity and recent studies demonstrated that hydrogen-dissolved water exhibits ROS-scavenging activity. Thus, the antioxidative capacity of ERW is postulated to be dependent on the presence of hydrogen levels; however, there is no report verifying the role of dissolved hydrogen in ERW. In this report, we clarify whether the responsive factor for antioxidative activity in ERW is dissolved hydrogen. The intracellular ROS scavenging activity of ERW and hydrogen-dissolved water was tested by both fluorescent stain method and immuno spin trapping assay. We confirm that ERW possessed electrolysis intensity-dependent intracellular ROS-scavenging activity, and ERW exerts significantly superior ROS-scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water. ERW retained its ROS-scavenging activity after removal of dissolved hydrogen, but lost its activity when autoclaved. An oxygen radical absorbance capacity assay, the 2,2-diphenyl-1-picrylhydrazyl assay and chemiluminescence assay could not detect radical-scavenging activity in both ERW and hydrogen-dissolved water. These results indicate that ERW contains electrolysis-dependent hydrogen and an additional antioxidative factor predicted to be platinum nanoparticles. PMID:28182635

  12. Representational Issues in Students Learning about Evaporation

    Science.gov (United States)

    Tytler, Russell; Prain, Vaughan; Peterson, Suzanne

    2007-01-01

    This study draws on recent research on the central role of representation in learning. While there has been considerable research on students' understanding of evaporation, the representational issues entailed in this understanding have not been investigated in depth. The study explored students' engagement with evaporation phenomena through…

  13. Evaporation experiments and modelling for glass melts

    NARCIS (Netherlands)

    Limpt, J.A.C. van; Beerkens, R.G.C.

    2007-01-01

    A laboratory test facility has been developed to measure evaporation rates of different volatile components from commercial and model glass compositions. In the set-up the furnace atmosphere, temperature level, gas velocity and batch composition are controlled. Evaporation rates have been measured f

  14. Advanced evaporator technology progress report FY 1992

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlain, D.; Hutter, J.C.; Leonard, R.A. [and others

    1995-01-01

    This report summarizes the work that was completed in FY 1992 on the program {open_quotes}Technology Development for Concentrating Process Streams.{close_quotes} The purpose of this program is to evaluate and develop evaporator technology for concentrating radioactive waste and product streams such as those generated by the TRUEX process. Concentrating these streams and minimizing the volume of waste generated can significantly reduce disposal costs; however, equipment to concentrate the streams and recycle the decontaminated condensates must be installed. LICON, Inc., is developing an evaporator that shows a great deal of potential for this application. In this report, concepts that need to be incorporated into the design of an evaporator operated in a radioactive environment are discussed. These concepts include criticality safety, remote operation and maintenance, and materials of construction. Both solubility and vapor-liquid equilibrium data are needed to design an effective process for concentrating process streams. Therefore, literature surveys were completed and are summarized in this report. A model that is being developed to predict vapor phase compositions is described. A laboratory-scale evaporator was purchased and installed to study the evaporation process and to collect additional data. This unit is described in detail. Two new LICON evaporators are being designed for installation at Argonne-East in FY 1993 to process low-level radioactive waste generated throughout the laboratory. They will also provide operating data from a full-sized evaporator processing radioactive solutions. Details on these evaporators are included in this report.

  15. The characterisation of non-evaporable getters by Auger electron spectroscopy Analytical potential and artefacts

    CERN Document Server

    Scheuerlein, C; Taborelli, M

    2002-01-01

    The surfaces of getter materials are particularly difficult to analyse because of their high chemical reactivity. The results obtained can be strongly influenced by the experimental set-up and procedures. In this paper the experimental influence on the Auger electron spectroscopy results is discussed, based on the measurements of more than 100 different non-evaporable getter (NEG) materials. There are four typical changes in the Auger electron spectra when a NEG becomes activated. The oxygen peak intensity decreases, the shape of the metal peaks changes, the carbon peak shape changes shape and intensity and a chlorine peak occurs. All these changes are affected by instrumental artefacts. The Zr-MNV peak shape changes occurring during the reduction of ZrO2 are well suited to determine the onset of NEG activation, while the slope with which the O-KLL peak intensity decreases in a certain temperature range is a better criterion for the determination of the temperature at which activation is complete. The O-KLL i...

  16. What Is Reactive Arthritis?

    Science.gov (United States)

    ... Arthritis PDF Version Size: 69 KB November 2014 What is Reactive Arthritis? Fast Facts: An Easy-to- ... Information About Reactive Arthritis and Other Related Conditions What Causes Reactive Arthritis? Sometimes, reactive arthritis is set ...

  17. Evaporative cooling: water for thermal comfort

    Directory of Open Access Journals (Sweden)

    José Rui Camargo

    2008-08-01

    Full Text Available Evaporative cooling is an environmentally friendly air conditioning system that operates using induced processes of heat and mass transfer, where water and air are the working fluids. It consists, specifically, in water evaporation, induced by the passage of an air flow, thus decreasing the air temperature. This paper presents three methods that can be used as reference for efficient use of evaporative cooling systems, applying it to several Brazilian cities, characterized by different climates. Initially it presents the basic operation principles of direct and indirect evaporative cooling and defines the effectiveness of the systems. Afterwards, it presents three methods that allows to determinate where the systems are more efficient. It concludes that evaporative cooling systems have a very large potential to propitiate thermal comfort and can still be used as an alternative to conventional systems in regions where the design wet bulb temperature is under 24ºC.

  18. Water evaporation in silica colloidal deposits.

    Science.gov (United States)

    Peixinho, Jorge; Lefèvre, Grégory; Coudert, François-Xavier; Hurisse, Olivier

    2013-10-15

    The results of an experimental study on the evaporation and boiling of water confined in the pores of deposits made of mono-dispersed silica colloidal micro-spheres are reported. The deposits are studied using scanning electron microscopy, adsorption of nitrogen, and adsorption of water through attenuated total reflection-infrared spectroscopy. The evaporation is characterized using differential scanning calorimetry and thermal gravimetric analysis. Optical microscopy is used to observe the patterns on the deposits after evaporation. When heating at a constant rate and above boiling temperature, the release of water out of the deposits is a two step process. The first step is due to the evaporation and boiling of the surrounding and bulk water and the second is due to the desorption of water from the pores. Additional experiments on the evaporation of water from membranes having cylindrical pores and of heptane from silica deposits suggest that the second step is due to the morphology of the deposits.

  19. Controlling water evaporation through self-assembly.

    Science.gov (United States)

    Roger, Kevin; Liebi, Marianne; Heimdal, Jimmy; Pham, Quoc Dat; Sparr, Emma

    2016-09-13

    Water evaporation concerns all land-living organisms, as ambient air is dryer than their corresponding equilibrium humidity. Contrarily to plants, mammals are covered with a skin that not only hinders evaporation but also maintains its rate at a nearly constant value, independently of air humidity. Here, we show that simple amphiphiles/water systems reproduce this behavior, which suggests a common underlying mechanism originating from responding self-assembly structures. The composition and structure gradients arising from the evaporation process were characterized using optical microscopy, infrared microscopy, and small-angle X-ray scattering. We observed a thin and dry outer phase that responds to changes in air humidity by increasing its thickness as the air becomes dryer, which decreases its permeability to water, thus counterbalancing the increase in the evaporation driving force. This thin and dry outer phase therefore shields the systems from humidity variations. Such a feedback loop achieves a homeostatic regulation of water evaporation.

  20. Multi-leg heat pipe evaporator

    Science.gov (United States)

    Alario, J. P.; Haslett, R. A.

    1986-04-01

    A multileg heat pipe evaporator facilitates the use and application of a monogroove heat pipe by providing an evaporation section which is compact in area and structurally more compatible with certain heat exchangers or heat input apparatus. The evaporation section of a monogroove heat pipe is formed by a series of parallel legs having a liquid and a vapor channel and a communicating capillary slot therebetween. The liquid and vapor channels and interconnecting capillary slots of the evaporating section are connected to the condensing section of the heat pipe by a manifold connecting liquid and vapor channels of the parallel evaporation section legs with the corresponding liquid and vapor channels of the condensing section.

  1. Multi-leg heat pipe evaporator

    Science.gov (United States)

    Alario, J. P.; Haslett, R. A. (Inventor)

    1986-01-01

    A multileg heat pipe evaporator facilitates the use and application of a monogroove heat pipe by providing an evaporation section which is compact in area and structurally more compatible with certain heat exchangers or heat input apparatus. The evaporation section of a monogroove heat pipe is formed by a series of parallel legs having a liquid and a vapor channel and a communicating capillary slot therebetween. The liquid and vapor channels and interconnecting capillary slots of the evaporating section are connected to the condensing section of the heat pipe by a manifold connecting liquid and vapor channels of the parallel evaporation section legs with the corresponding liquid and vapor channels of the condensing section.

  2. Activation of the KCa3.1 channel contributes to traumatic scratch injury-induced reactive astrogliosis through the JNK/c-Jun signaling pathway.

    Science.gov (United States)

    Yi, Mengni; Dou, Fangfang; Lu, Qin; Yu, Zhihua; Chen, Hongzhuan

    2016-06-15

    Reactive astrogliosis is widely considered to contribute to pathogenic responses to stress and brain injury and to diseases as diverse as ischemia and neurodegeneration. We previously found that expression of the intermediate-conductance calcium-activated potassium channel (KCa3.1) involved in TGF-β-activated astrogliosis. In the present study, we investigated whether migration of cortical astrocytes following mechanical scratch injury involves the KCa3.1 channel, which contributes to Ca(2+)-mediated migration in other cells. We found that scratch injury increased the expression of KCa3.1 protein in reactive astrocytes. Application of the KCa3.1 blocker TRAM-34 decreased glial fibrillary acidic protein (GFAP) expression and slowed migration in a concentration-dependent manner. Application of the Ca(2+) chelators, EGTA and BAPTA-AM, also slowed the migration of astrocytes. Blockade or genetic deletion of KCa3.1 both slowed and dramatically reduced the scratch injuries induced the sharp rise in astrocytes Ca(2+) concentrations. The scratch injury-induced phosphorylation of JNK and c-Jun proteins was also attenuated both by blockade of KCa3.1 with TRAM-34 and in KCa3.1(-/-) astrocytes. Using KCa3.1 knockout mice, we further confirmed that deletion of KCa3.1 reduced expression of GFAP in an in vivo stab wound model. Taken together, our findings highlight a novel role for KCa3.1 in phenotypic modulation of reactive astrocytes and in astrocyte mobilization in response to mechanical stress, providing a potential target for therapeutic intervention in brain injuries.

  3. Evaporation of sessile droplets on smooth and structured substrates

    Science.gov (United States)

    Colinet, Pierre; Flandroy, Marie; Dehaeck, Sam; Rednikov, Alexey; Sobac, Benjamin; Tsoumpas, Yannis

    2015-11-01

    Evaporation of sessile droplets remains a topic of active research nowadays, not only due to its widespread occurrence both in nature and technology, but also because it raises a number of interesting fundamental questions. Among these, the influence of the substrate topography is far from being understood. In this presentation, we focus on the difference between droplet evaporation dynamics on a smooth substrate and on substrates with controlled geometrical heterogeneities (square or hexagonal arrays of cylindrical pillars). While the wetting dynamics of droplets on such structured substrates has already been studied (in particular it is known that the droplet shape typically tends to adopt the symmetry of the pattern it lies upon), the influence the structure has on the evaporation dynamics (including the influence of pinning) has not yet received much attention. From interferometric measurements of droplet shapes, we highlight in particular that the evaporation from structured substrates is generally faster than on smooth substrates, and that the scaling exponents characterizing the evolution of radius versus time are also different. Pinning is also shown to be favored above a certain surface fraction of pillars, both for hexagonal and square arrays. Financial support of FRS-FNRS, ESA-BELSPO PRODEX, ULB, and BELSPO IAP 7/38 is gratefully acknowledged.

  4. Two-State Reactivity in Low-Valent Iron-Mediated C-H Activation and the Implications for Other First-Row Transition Metals.

    Science.gov (United States)

    Sun, Yihua; Tang, Hao; Chen, Kejuan; Hu, Lianrui; Yao, Jiannian; Shaik, Sason; Chen, Hui

    2016-03-23

    C-H bond activation/functionalization promoted by low-valent iron complexes has recently emerged as a promising approach for the utilization of earth-abundant first-row transition metals to carry out this difficult transformation. Herein we use extensive density functional theory and high-level ab initio coupled cluster calculations to shed light on the mechanism of these intriguing reactions. Our key mechanistic discovery for C-H arylation reactions reveals a two-state reactivity (TSR) scenario in which the low-spin Fe(II) singlet state, which is initially an excited state, crosses over the high-spin ground state and promotes C-H bond cleavage. Subsequently, aryl transmetalation occurs, followed by oxidation of Fe(II) to Fe(III) in a single-electron transfer (SET) step in which dichloroalkane serves as an oxidant, thus promoting the final C-C coupling and finalizing the C-H functionalization. Regeneration of the Fe(II) catalyst for the next round of C-H activation involves SET oxidation of the Fe(I) species generated after the C-C bond coupling. The ligand sphere of iron is found to play a crucial role in the TSR mechanism by stabilization of the reactive low-spin state that mediates the C-H activation. This is the first time that the successful TSR concept conceived for high-valent iron chemistry is shown to successfully rationalize the reactivity for a reaction promoted by low-valent iron complexes. A comparative study involving other divalent middle and late first-row transition metals implicates iron as the optimum metal in this TSR mechanism for C-H activation. It is predicted that stabilization of low-spin Mn(II) using an appropriate ligand sphere should produce another promising candidate for efficient C-H bond activation. This new TSR scenario therefore emerges as a new strategy for using low-valent first-row transition metals for C-H activation reactions.

  5. A Simulation Stud on Effect of Surface Film—Forming Material on Water Evaporation

    Institute of Scientific and Technical Information of China (English)

    ZHUANGSHUNYAO; YINBIN; 等

    2001-01-01

    A greenhouse experiment was conducted to investigate the effect of surface film-forming material(SFFM),a mixture of 16-18-octadecanols by emulsification,on water evaporation,Air-dired soil with distilled water was incubated firstly for 7days to reestablish soil biological activity and then for another 7 days atfer treated with SFFM at rates of 0,1,2,4,6,8 and 8 g m-2,respectively,Everyday during the 7-day incubation after addition of SFFM,water losses due to evaporation were measured by an electronic balance.The rate of water evaporation with the addition of SFFM was reduced significantly compared with the control treatment and the effectiveness of SFFM on water evaporation reduced with time.According to the equation expressions of the effect of SFFM on water evaporation ,the half-life of effectiveness of SFFM on water evaporation was introduced and calculated to analyze quantitative relationship between the effectiveness of SFFM on water evaporation and the addition rate of SFFM.The calculaed half-life increased with the addition rate of SFFM and the confidence of the calculated values of the half-life was high,suggesting that the half-life of effectiveness of SFFM on water evaporation could be described quantitaively and may be helpful for ameliorating application method of SFFM and screening surface-film forming materials in order to improve nitrogen fetilizer use efficiency in floodey rice fields.

  6. ANTIMICROBIAL ACTIVITY OF COPOLYMERS OF 2,4-DICHLOROPHENYL ACRYLATE WITH STYRENE:SYNTHESIS,CHARACTERIZATION AND REACTIVITY RATIOS

    Institute of Scientific and Technical Information of China (English)

    Hetal J. Patel; Mitesh G. Patel; Kirit H. Patel; Arabinda K. Ray; Rajni M. Patel

    2009-01-01

    Some copolymers of 2,4-dichlorophenyl acrylate (2,4-DCPA) with styrene (St) of different feed compositions were prepared by free radical polymerization technique using 2,2'-azobisisobutyronitrile (AIBN) as an initiator,and the copolymers were characterized by IR spectroscopy.The copolymer composition obtained by UV-spectra led to determination of reactivity ratio by employing Fineman-Ross (F-R) and Kelen-Tudos (K-T) methods.Average molecular weight,as well as intrinsic viscosity,was obtained by vapor pressure osmometry (VPO) and Ubbleholde viscometer.Thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) of copolymers were carried out under nitrogen atmosphere.Antimicrobial effects of the homo and copolymers were also investigated against various microorganisms such as bacteria,fungi and yeasts.

  7. Soluble and particulate Co-Cr-Mo alloy implant metals activate the inflammasome danger signaling pathway in human macrophages: a novel mechanism for implant debris reactivity.

    Science.gov (United States)

    Caicedo, Marco S; Desai, Ronak; McAllister, Kyron; Reddy, Anand; Jacobs, Joshua J; Hallab, Nadim J

    2009-07-01

    Immune reactivity to soluble and particulate implant debris remains the primary cause of aseptic inflammation and implant loosening. However, the intracellular mechanisms that trigger immune cells to sense and respond to exogenous nonbiological agents such as metal particles or metal ions released from orthopedic implants remain unknown. Recent studies in immunology have outlined the importance of the intracellular inflammasome complex of proteins in sensing danger/stress signals triggered by nonbiological agents in the cytosol of macrophages. We hypothesized that metal implant debris can activate the inflammasome pathway in macrophages that causes caspase-1-induced cleavage of intracellular pro-IL-1beta into its mature form, resulting in IL-1beta secretion and induction of a broader proinflammatory response. We tested this hypothesis by examining whether soluble cobalt, chromium, molybdenum, and nickel ions and Co-Cr-Mo alloy particles induce inflammasome- mediated macrophage reactivity. Our results demonstrate that these agents stimulate IL-1beta secretion in human macrophages that is inflammasome mediated (i.e., NADPH-, caspase-1-, Nalp3-, and ASC-dependent). Thus, metal ion- and particle-induced activation of the inflammasome in human macrophages provides evidence of a novel pathway of implant debris-induced inflammation, where contact with implant debris is sensed and transduced by macrophages into a proinflammatory response.

  8. Covalent modification of mutant rat P2X2 receptors with a thiol-reactive fluorophore allows channel activation by zinc or acidic pH without ATP.

    Directory of Open Access Journals (Sweden)

    Shlomo S Dellal

    Full Text Available Rat P2X2 receptors open at an undetectably low rate in the absence of ATP. Furthermore, two allosteric modulators, zinc and acidic pH, cannot by themselves open these channels. We describe here the properties of a mutant receptor, K69C, before and after treatment with the thiol-reactive fluorophore Alexa Fluor 546 C(5-maleimide (AM546. Xenopus oocytes expressing unmodified K69C were not activated under basal conditions nor by 1,000 µM ATP. AM546 treatment caused a small increase in the inward holding current which persisted on washout and control experiments demonstrated this current was due to ATP independent opening of the channels. Following AM546 treatment, zinc (100 µM or acidic external solution (pH 6.5 elicited inward currents when applied without any exogenous ATP. In the double mutant K69C/H319K, zinc elicited much larger inward currents, while acidic pH generated outward currents. Suramin, which is an antagonist of wild type receptors, behaved as an agonist at AM546-treated K69C receptors. Several other cysteine-reactive fluorophores tested on K69C did not cause these changes. These modified receptors show promise as a tool for studying the mechanisms of P2X receptor activation.

  9. Low-dose radiation activates Nrf1/2 through reactive species and the Ca(2+)/ERK1/2 signaling pathway in human skin fibroblast cells.

    Science.gov (United States)

    Lee, Eun Kyeong; Kim, Jin-Ah; Park, Seong Joon; Kim, Jeung Ki; Heo, Kyu; Yang, Kwang Mo; Son, Tae Gen

    2013-05-01

    In the current study, we explored the effect of LDR on the activation of Nrfs transcription factor involved in cellular redox events. Experiments were carried out utilizing 0.05 and 0.5 Gy X-ray irradiated normal human skin fibroblast HS27 cells. The results showed LDR induced Nrf1 and Nrf2 activation and expression of antioxidant genes HO-1, Mn-SOD, and NQO1. In particular, 0.05 Gy-irradiation increased only Nrf1 activation, but 0.5 Gy induced both Nrf1 and Nrf2 activation. LDR-mediated Nrf1/2 activation was accompanied by reactive species (RS) generation and Ca(2+) flux. This effect was abolished in the presence of N-acetyl-cysteine and BAPTA- AM. Furthermore, Nrf1/2 activation by LDR was suppressed by PD98059, an inhibitor of ERK1/2. In conclusion, LDR induces Nrf1 and Nrf2 activation and expression of Nrf-regulated antioxidant defense genes through RS and Ca(2+)/ERK1/2 pathways, suggesting new insights into the molecular mechanism underlying the beneficial role of LDR in HS27 cells.

  10. Post-mortem MRI-guided sampling of multiple sclerosis brain lesions: increased yield of active demyelinating and (p)reactive lesions.

    Science.gov (United States)

    De Groot, C J; Bergers, E; Kamphorst, W; Ravid, R; Polman, C H; Barkhof, F; van der Valk, P

    2001-08-01

    Macroscopic sampling of multiple sclerosis lesions in the brain tends to find chronic lesions. For a better understanding of the dynamics of the multiple sclerosis disease process, research into new and developing lesions is of great interest. As MRI in vivo effectively demonstrates lesions in multiple sclerosis patients, we have applied it to unfixed post-mortem brain slices to identify abnormalities, in order to obtain a higher yield of active lesions. The Netherlands Brain Bank organized the rapid autopsy of 29 multiple sclerosis patients. The brain was cut in 1 cm coronal slices. One or two slices were subjected to T(1)- and T(2)-weighted MRI, and then cut at the plane of the MRI scan into 5 mm thick opposing sections. Areas of interest were identified based on the MRI findings and excised. One half was fixed in 10% formalin and paraffin-embedded, and the corresponding area in the adjacent half was snap-frozen in liquid nitrogen. In total, 136 out of 174 brain tissue samples could be matched with the abnormalities seen on T(2)-weighted MRIs. The stage of lesional development was determined (immuno) histochemically. For 54 MRI-detectable samples, it was recorded whether they were macroscopically detectable, i.e. visible and/or palpable. Histopathological analysis revealed that 48% of the hyperintense areas seen on T(2)-weighted images represented active lesions, including lesions localized in the normal appearing white matter, without apparent loss of myelin but nevertheless showing a variable degree of oedema, small clusters of microglial cells with enhanced major histocompatibility complex class II antigen, CD45 and CD68 antigen expression and a variable number of perivascular lymphocytes around small blood vessels [designated as (p)reactive lesions]. From the macroscopically not-visible/not-palpable MRI-detected abnormalities, 58% were (p)reactive lesions and 21% contained active demyelinating lesions. In contrast, visible and/or palpable brain tissue samples

  11. Synthesis of monooxime-monocarbamoyl bispyridinium compounds bearing (E)-but-2-ene linker and evaluation of their reactivation activity against tabun- and paraoxon-inhibited acetylcholinesterase.

    Science.gov (United States)

    Musilek, Kamil; Holas, Ondrej; Kuca, Kamil; Jun, Daniel; Dohnal, Vlastimil; Opletalova, Veronika; Dolezal, Martin

    2008-02-01

    Six AChE monooxime-monocarbamoyl reactivators with an (E)-but-2-ene linker were synthesized using modification of currently known synthetic pathways. Their potency to reactivate AChE inhibited by the nerve agent tabun and insecticide paraoxon was tested in vitro. The reactivation efficacies of pralidoxime, HI-6, obidoxime, K048, K075 and the newly prepared reactivators were compared. According to the results obtained, one reactivator seems to be promising against tabun-inhibited AChE and two reactivators against paraoxon-inhibited AChE. The best results were obtained for bisquaternary substances with at least one oxime group in position four.

  12. Catastrophic Evaporation of Rocky Planets

    CERN Document Server

    Perez-Becker, Daniel

    2013-01-01

    Short-period exoplanets can have dayside surface temperatures surpassing 2000 K, hot enough to vaporize rock and drive a thermal wind. Small enough planets evaporate completely. We construct a radiative-hydrodynamic model of atmospheric escape from strongly irradiated, low-mass rocky planets, accounting for dust-gas energy exchange in the wind. Rocky planets with masses 2000 K are found to disintegrate entirely in 0.1 M_Earth/Gyr --- our model yields a present-day planet mass of < 0.02 M_Earth or less than about twice the mass of the Moon. Mass loss rates depend so strongly on planet mass that bodies can reside on close-in orbits for Gyrs with initial masses comparable to or less than that of Mercury, before entering a final short-lived phase of catastrophic mass loss (which KIC 12557548b has entered). Because this catastrophic stage lasts only up to a few percent of the planet's life, we estimate that for every object like KIC 12557548b, there should be 10--100 close-in quiescent progenitors with sub-da...

  13. Tuning the reactivity of an actor ligand for tandem CO2 and C-H activations: from spectator metals to metal-free.

    Science.gov (United States)

    Annibale, Vincent T; Dalessandro, Daniel A; Song, Datong

    2013-10-30

    The 4,5-diazafluorenide ligand (L(-)) serves as an actor ligand in the formal insertion of CO2 into a C-H bond remote from the metal center. With the Ru(II) complex of L(-) as the starting point, Rh(III), Rh(I), and Cu(I) were used as spectator metal centers to tune the reactivity of the actor ligand toward CO2. In the case of Rh(III)-diazafluorenide a room temperature reversible activation of CO2 was observed, similar to the isoelectronic Ru(II) analogue. In the case of Rh(I)- and Cu(I)-diazafluorenide CO2 is trapped by the formation of dinuclear carboxylate complexes and diazafluorene (LH). The spectator metal center could even be replaced entirely with an organic group allowing for the first metal-free reversible tandem CO2 and C-H activation.

  14. Heterogeneous fenton-like degradation of an azo dye reactive brilliant orange by the combination of activated carbon-FeOOH catalyst and H 2O2

    DEFF Research Database (Denmark)

    Wu, Jinhua; Lin, Guanghui; Li, Ping;

    2013-01-01

    The decoloration of an azo dye reactive brilliant orange (X-GN) by a heterogeneous Fenton system using activated carbon-FeOOH catalyst (AC-FeOOH) and H2O2 was studied. Under typical conditions (pH 7.0, H2O2 10 mmol/L, AC-FeOOH 1.0g/L and 30°C), 98% decoloration rate of X-GN was achieved in 240 mm...... that the decoloration of X-GN followed a pseudo-first order reaction and the activation energy was 17.2 kJ/mol. Iron leaching from AC-FeOOH occurred during the reaction, but the decoloration efficiency of X-GN was still higher than 80% after four runs. The AC-FeOOH has a good stability and can be reused. Besides...

  15. Peripheral physiological reactivity and brain activity in specific phobias - Reactividad fisiológica periférica y actividad cerebral en las fobias específicas

    Directory of Open Access Journals (Sweden)

    José María Martínez Selva

    2009-12-01

    Full Text Available Specific phobias are exaggerated and irrational fears caused by specific stimuli. These anxiety disorders can appear together with physiological reactions and fight or flight responses. At a peripheral level the phobic response is featured by an increase in somatic and autonomic reactivity as shown by different physiological indices (heart rate, electrodermal activity and a potentiation of defensive reflexes, such as the cardiac defense response and the blink reflex. At a central level it has been described a network of brain structures that are involved both in the processing of the phobic stimulus and in the reaction that it provokes. This brain network is composed by the amygdala, the orbitofrontal and cingulate cortices and the anterior insula. An increase in the activity of these brain regions occurs during the phobic reaction that can be associated with the somatic and autonomic changes, the subjective experience of intense fear and the avoidance behavior elicited by the phobic stimulus.

  16. Ebselen protects against behavioral and biochemical toxicities induced by 3-nitropropionic acid in rats: correlations between motor coordination, reactive species levels, and succinate dehydrogenase activity.

    Science.gov (United States)

    Wilhelm, Ethel A; Bortolatto, Cristiani F; Jesse, Cristiano R; Luchese, Cristiane

    2014-12-01

    The protective effect of ebselen was investigated against 3-nitropropionic acid (3-NP)-induced behavioral and biochemical toxicities in rats. Ebselen (10 or 25 mg/kg, intragastrically) was administered to rats 30 min before 3-NP (20 mg/kg, intraperitoneally) once a day for a period of 4 days. Locomotor activity, motor coordination, and body weight gain were determined. The striatal content of reactive oxygen species (ROS), reduced glutathione (GSH), ascorbic acid (AA), and protein carbonyl as well as catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) activities was determined 24 h after the last dose of 3-NP. Na(+)/ K(+)-ATPase, succinate dehydrogenase (SDH), and δ-aminolevulinic dehydratase (δ-ALA-D) activities were also determined. The results demonstrated that ebselen at a dose of 25 mg/kg, but not at 10 mg/kg, protected against (1) a decrease in locomotor activity, motor coordination impairment, and body weight loss; (2) striatal oxidative damage, which was characterized by an increase in ROS levels, protein carbonyl content, and GR activity, an inhibition of CAT and GPx activities, and a decrease in GSH levels; and (3) an inhibition of SDH and Na(+)/K(+)-ATPase activities, induced by 3-NP. GST activity and AA levels were not modified by ebselen or 3-NP. Ebselen was not effective against the inhibition of δ-ALA-D activity induced by 3-NP. The results revealed a significant correlation between SDH activity and ROS levels, and SDH activity and latency to fall (rotarod test). The present study highlighted the protective effect of ebselen against 3-NP-induced toxicity in rats.

  17. 242-A evaporator safety analysis report

    Energy Technology Data Exchange (ETDEWEB)

    CAMPBELL, T.A.

    1999-05-17

    This report provides a revised safety analysis for the upgraded 242-A Evaporator (the Evaporator). This safety analysis report (SAR) supports the operation of the Evaporator following life extension upgrades and other facility and operations upgrades (e.g., Project B-534) that were undertaken to enhance the capabilities of the Evaporator. The Evaporator has been classified as a moderate-hazard facility (Johnson 1990). The information contained in this SAR is based on information provided by 242-A Evaporator Operations, Westinghouse Hanford Company, site maintenance and operations contractor from June 1987 to October 1996, and the existing operating contractor, Waste Management Hanford (WMH) policies. Where appropriate, a discussion address the US Department of Energy (DOE) Orders applicable to a topic is provided. Operation of the facility will be compared to the operating contractor procedures using appropriate audits and appraisals. The following subsections provide introductory and background information, including a general description of the Evaporator facility and process, a description of the scope of this SAR revision,a nd a description of the basic changes made to the original SAR.

  18. Evaporation of nanofluid droplet on heated surface

    Directory of Open Access Journals (Sweden)

    Yeung Chan Kim

    2015-04-01

    Full Text Available In this study, an experiment on the evaporation of nanofluid sessile droplet on a heated surface was conducted. A nanofluid of 0.5% volumetric concentration mixed with 80-nm-sized CuO powder and pure water were used for experiment. Droplet was applied to the heated surface, and images of the evaporation process were obtained. The recorded images were analyzed to find the volume, diameter, and contact angle of the droplet. In addition, the evaporative heat transfer coefficient was calculated from experimental result. The results of this study are summarized as follows: the base diameter of the droplet was maintained stably during the evaporation. The measured temperature of the droplet was increased rapidly for a very short time, then maintained constantly. The nanofluid droplet was evaporated faster than the pure water droplet under the experimental conditions of the same initial volume and temperature, and the average evaporative heat transfer coefficient of the nanofluid droplet was higher than that of pure water. We can consider the effects of the initial contact angle and thermal conductivity of nanofluid as the reason for this experimental result. However, the effect of surface roughness on the evaporative heat transfer of nanofluid droplet appeared unclear.

  19. Mesoporous magnetic activated carbon: Effect of preparation route on texture and surface properties and on effect for Reactive Black 5 adsorption.

    Science.gov (United States)

    Giannakoudakis, Dimitrios; Saroyan, Hayarpi; Lazaridis, Nikolaos; Deliyanni, Eleni

    2016-04-01

    Mesoporous magnetic activated carbon: Effect of preparation route on texture and surface properties and on effect for Reactive Black 5 adsorption. Dimitrios Giannakoudakis1, Hayarpi Saroyan2, Nikolaos Lazaridis2, Eleni Deliyanni2 1 City College of New York, Chemistry Department, 160 Convent Avenue, New York, United States 2 Laboratory of General and oInorganic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece In this study, the effect of preparation route of a mesoporous magnetic activated carbon on Reactive Black 5 (RB5) adsorption was investigated. The synthesis of the magnetic activated carbon was achieved both with (i) impregnation method (Bmi), and (ii) co-precipitation with two precipitation agents: NaOH (Bm) and NH4OH (Bma). After synthesis, the full characterization with various techniques (SEM, FTIR, XRD, DTA, DTG, VSM) was achieved in order to testify the effect of the preparation route on its textural and surface properties. It was shown that after the precipitation method the prepared carbon presented a collapsed texture and small magnetic properties. Effects of initial solution pH, effect of temperature, adsorption isotherms and kinetics were investigated in order to conclude about the aforementioned effect of the preparation method on dye adsorption performance of the magnetic carbons. The adsorption evaluation of the magnetic activated carbon presented higher adsorption capacity of Bmi carbon (350 mg/g) and lower of Bm (150 mg/g). Equilibrium experiments are also performed studying the effect of contact time (pseudo-first and -second order equations) and temperature (isotherms at 25, 45 and 65 °C fitted to Langmuir and Freundlich model). A full thermodynamic evaluation was carried out, calculating the parameters of enthalpy, free energy and entropy (ΔHο, ΔGο and ΔSο). The characterization with various techniques revealed the possible interactions/forces of dye-composite system.

  20. Evolution of broadly cross-reactive HIV-1-neutralizing activity: therapy-associated decline, positive association with detectable viremia, and partial restoration of B-cell subpopulations.

    Science.gov (United States)

    Ferreira, Carolina B; Merino-Mansilla, Alberto; Llano, Anuska; Pérez, Ignacio; Crespo, Isabel; Llinas, Laia; Garcia, Felipe; Gatell, Jose M; Yuste, Eloisa; Sanchez-Merino, Victor

    2013-11-01

    Little is known about the stability of HIV-1 cross-neutralizing responses. Taking into account the fact that neutralization breadth has been positively associated with plasma viral load, there is no explanation for the presence of broadly neutralizing responses in a group of patients on treatment with undetectable viremia. In addition, the B-cell profile responsible for broadly cross-neutralizing responses is unknown. Here we studied the evolution of neutralizing responses and the B-cell subpopulation distribution in a group of patients with broadly cross-reactive HIV-1-neutralizing activity. We studied neutralization breadth evolution in a group of six previously identified broadly cross-neutralizing patients and six control patients during a 6-year period with a previously described minipanel of recombinant viruses from five different subtypes. B-cell subpopulation distribution during the study was also determined by multiparametric flow cytometry. Broadly cross-neutralizing activity was transient in four broad cross-neutralizers and stable, up to 4.6 years, in the other two. In four out of five broad cross-neutralizers who initiated treatment, a neutralization breadth loss occurred after viremia had been suppressed for as much as 20 months. B-cell subpopulation analyses revealed a significant increase in the frequency of naive B cells in broadly cross-reactive samples, compared with samples with less neutralization breadth (increased from 44% to 62%). We also observed a significant decrease in tissue-like and activated memory B cells (decreased from 19% to 12% and from 17% to 9%, respectively). Our data suggest that HIV-1 broadly cross-neutralizing activity is variable over time and associated with detectable viremia and partial B-cell restoration.

  1. Towards a rational definition of potential evaporation

    Directory of Open Access Journals (Sweden)

    J.-P. Lhommel

    1997-01-01

    Full Text Available The concept of potential evaporation is defined on the basis of the following criteria: (i it must establish an upper limit to the evaporation process in a given environment (the term 'environment' including meteorological and surface conditions, and (ii this upper limit must be readily calculated from measured input data. It is shown that this upper limit is perfectly defined and is given by the Penman equation, applied with the corresponding meteorological data (incoming radiation and air characteristics measured at a reference height and the appropriate surface characteristics (albedo, roughness length, soil heat flux. Since each surface has its own potential evaporation, a function of its own surface characteristics, it is useful to define a reference potential evaporation as a short green grass completely shading the ground. Although the potential evaporation from a given surface is readily calculated from the Penman equation, its physical significance or interpretation is not so straightforward, because it represents only an idealized situation, not a real one. Potential evaporation is the evaporation from this surface, when saturated and extensive enough to obviate any effect of local advection, under the same meteorological conditions. Due to the feedback effects of evaporation on air characteristics, it does not represent the 'real' evaporation (i.e. the evaporation which could be physically observed in the real world from such an extensive saturated surface in these given meteorological conditions (if this saturated surface were substituted for an unsaturated one previously existing. From a rigorous standpoint, this calculated potential evaporation is not physically observable. Nevertheless, an approximate representation can be given by the evaporation from a limited saturated area, the dimension of which depends on the height of measurement of the air characteristics used as input in the Penman equation. If they are taken at a height

  2. On the evaporation of ammonium sulfate solution

    Energy Technology Data Exchange (ETDEWEB)

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-07-16

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

  3. Light geodesics near an evaporating black hole

    Energy Technology Data Exchange (ETDEWEB)

    Guerreiro, Thiago, E-mail: thiago.barbosa@unige.ch; Monteiro, Fernando, E-mail: fernando.monteiro@unige.ch

    2015-10-16

    Quantum effects imply that an infalling observer cannot cross the event horizon of an evaporating black hole, even in her proper time. The Penrose diagram of an evaporating black hole is different from the one usually reported in the literature. We show that before the observer can cross the horizon the black hole disappears. Possible observational consequences are discussed. - Highlights: • We calculate the in-falling light geodesics in an evaporating black hole. • For our calculation we use a non-static metric called Vaydia metric. • We show that in-falling light cannot cross the event horizon. • In this case there is no information paradox.

  4. Particle detection by evaporation from superfluid helium

    Energy Technology Data Exchange (ETDEWEB)

    Bandler, S.R.; Lanou, R.E.; Maris, H.J.; More, T.; Porter, F.S.; Seidel, G.M.; Torii, R.H. (Department of Physics, Brown University, Providence, Rhode Island 02912 (United States))

    1992-04-20

    We report the first experiments in which 5-MeV alpha particles are detected via evaporation from a bath of superfluid helium. The {alpha} excites phonons and rotons in the liquid helium, and these excitations are sufficiently energetic to evaporate helium atoms when they reach the free surface of the liquid. The approximate overall efficiency of this process has been determined, and we compare this with expectations. We have also been able to detect evaporation induced by a flux of {gamma}'s from a {sup 137}Cs source.

  5. Upgrading existing evaporators to reduce energy consumption

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    This manual is intended to assist the evaporator engineer who will be performing the technical and economic analyses to determine the most suitable evaporator upgrading technique for his particular plant. Information is included on potentials for upgrading evaporators; correctable operating factors; heat recovery and other improvements in energy use with minor capital investments; upgrading through major capital investments; guidelines for formulating an upgrading program; and new technologies encompassing advanced designs, use of solar and low-grade heat sources, and heat transfer enhancement. A 36 item bibliography is included. (LCL)

  6. Modified Transition State Theory for Evaporation and Condensation

    Institute of Scientific and Technical Information of China (English)

    王遵敬; 陈民; 过增元

    2002-01-01

    A modification of the transition state theory for evaporation and condensation is presented by analysing the kinetic characteristics of liquid-vapour interphase transport. In the modified transition state theory, the moving orientation of molecules is introduced into the calculation of the free volume of the activated complex. The condensation coefficients of argon at different temperatures are calculated with the modified transition state theory. The results agree well with those from molecular dynamics simulations.

  7. MuRF1 activity is present in cardiac mitochondria and regulates reactive oxygen species production in vivo

    DEFF Research Database (Denmark)

    Mattox, Taylor A; Young, Martin E; Rubel, Carrie E;

    2014-01-01

    be cardioprotective in ischemia reperfusion injury, in addition to its inhibition of apoptosis via proteasome-mediate degradation of c-Jun. The lack of mitochondrial function phenotype identified in MuRF1-/- hearts may be due to the overlapping interactions of MuRF1 and MuRF2 with energy regulating proteins found...... mitochondrial function to date. In the present study, we measured cardiac mitochondrial function from isolated permeabilized muscle fibers in previously phenotyped MuRF1 transgenic and MuRF1-/- mouse models to determine the role of MuRF1 in intermediate energy metabolism and ROS production. We identified...... a significant decrease in reactive oxygen species production in cardiac muscle fibers from MuRF1 transgenic mice with increased α-MHC driven MuRF1 expression. Increased MuRF1 expression in ex vivo and in vitro experiments revealed no alterations in the respiratory chain complex I and II function. Working...

  8. Gender and the active smoking and high-sensitivity C-reactive protein relation in late adolescence.

    Science.gov (United States)

    Le-Ha, Chi; Beilin, Lawrence J; Burrows, Sally; Oddy, Wendy H; Hands, Beth; Mori, Trevor A

    2014-04-01

    C-reactive protein (CRP), smoking, and oral contraceptive (OC) use are associated with CVD risk in adults. This study examines the effect of smoking on high-sensitivity CRP (hs-CRP) levels, and the interactive effects of sex and OC use on this relationship in an adolescent cohort. A total of 1,050 adolescents (mean age 17 ± 0.25 years) from the Western Australian Pregnancy Cohort (Raine) Study had anthropometric, lifestyle, and metabolic measures recorded. The association between smoking status and log-transformed hs-CRP was analyzed using multivariable Tobit linear regression models, with adjustment for adiposity, lifestyle, and early-life confounders. A three-level variable (girls not using OCs, girls using OCs, and boys) was employed to assess the interactive effects of sex, OC use, and smoking. Smoking associated with higher hs-CRP levels in girls not using OCs (b = 0.571; P = 0.001), but not in girls using OCs (b = -0.117; P = 0.598) or in boys (b = 0.183; P = 0.2). OC use in nonsmoking girls was the strongest factor associated with higher hs-CRP levels (b = 1.189; P smoking on hs-CRP levels in girls not using OCs compared with boys. The findings may explain why CVD risk conferred by smoking is higher in women than in men.

  9. Microbial decolorization of reactive black-5 in a two-stage anaerobic-aerobic reactor using acclimatized activated textile sludge.

    Science.gov (United States)

    Mohanty, Sagarika; Dafale, Nishant; Rao, Nageswara Neti

    2006-10-01

    A two-stage anaerobic-aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent was used to degrade reactive black 5 dye (RB-5). The anaerobic step was studied in more detail by varying the dye concentration from 100 to 3000 mg l(-1). The results showed that major decolorization was achieved during the anaerobic process. The time required for decolorization by > 90% increased as the concentration of the dye increased. It was also found that maintaining dissolved oxygen (DO) concentration below 0.5 mg l(-1 )and addition of a co-substrate viz., glucose, facilitates anaerobic decolorization reaction remarkably. An attempt was made to identify the metabolites formed in anaerobic process by using high performance liquid chromatography (HPLC) and UV-VIS spectrophotometry. A plate assay was performed for the detection of dominant decolorizing bacteria. Only a few bacterial colonies with high clearing zones (decolorization zones) were found. The results showed that under anaerobic condition RB-5 molecules were reduced and aromatic amines were generated. The aromatic amine metabolite was partly removed in subsequent aerobic bio-treatment. It was possible to achieve more than 90% decolorization and approximately 46% reduction in amine metabolite concentration through two-stage anaerobic-aerobic treatment after a reaction period of 2 days.

  10. Possible Involvement of Nitric Oxide and Reactive Oxygen Species in Glucose Deprivation-Induced Activation of Transcription Factor Rst2

    OpenAIRE

    Toshiaki Kato; Xin Zhou; Yan Ma

    2013-01-01

    Glucose is one of the most important sources of cellular nutrition and glucose deprivation induces various cellular responses. In Schizosaccharomyces pombe, zinc finger protein Rst2 is activated upon glucose deprivation, and regulates gene expression via the STREP (stress response element of Schizosaccharomyces pombe) motif. However, the activation mechanism of Rst2 is not fully understood. We monitored Rst2 transcriptional activity in living cells using a Renilla luciferase reporter system. ...

  11. Active power filter for the reduction of the harmonic distortion and fundamental reactive power with improved dynamic response

    Energy Technology Data Exchange (ETDEWEB)

    Voncina, D.; Nastran, J.; Cajhen, R.; Nedeljkovic, D. [Ljubljana Univ. (Slovenia). Faculty of Electrical Engineering and Computer Science

    1995-12-31

    The parallel active power filter for nonlinear loads is described. First the method for extracting the fundamental active component from the load current, based on the combined analogue and digital signal processing is presented in detail. The load current is filtered by a precision analogue circuit. The phase and the amplitude of the load current fundamental component is passed to the microcontroller to calculate its active component. The implemented control principle provides fast response of the actual filter current. The results, obtained from the experimental circuit, illustrate the active filter`s performance in steady state and during load transients. 14 refs, 10 figs

  12. Anti-apoptotic mechanism of Bacoside rich extract against reactive nitrogen species induced activation of iNOS/Bax/caspase 3 mediated apoptosis in L132 cell line.

    Science.gov (United States)

    Anand, T; Pandareesh, M D; Bhat, Pratiksha V; Venkataramana, M

    2014-10-01

    Nitric oxide is a highly reactive free radical gas that reacts with a wide range of bio-molecules to produce reactive nitrogen species and exerts nitrative stress. Bacopa monniera is a traditional folk and ayurvedic medicine known to alleviate a variety of disorders. Aim of the present study is to evaluate the protective propensity of Bacopa monniera extract (BME) through its oxido-nitrosative and anti-apoptotic mechanism to attenuate sodium nitroprusside (SNP)-induced apoptosis in a human embryonic lung epithelial cell line (L132). Our results elucidate that pre-treatment of L132 cells with BME ameliorates the mitochondrial and plasma membrane damage induced by SNP as evidenced by MTT and LDH leakage assays. BME pre-treatment inhibited NO generation by down-regulating inducible nitric oxide synthase expression. BME exhibited potent antioxidant activity by up-regulating the antioxidant enzymes. SNP-induced damage to cellular, nuclear and mitochondrial integrity was also restored by BME, which was confirmed by ROS estimation, comet assay and mitochondrial membrane potential assays respectively. BME pre-treatment efficiently attenuated the SNP-induced apoptotic biomarkers such as Bax, cytochrome-c and caspase-3, which orchestrate the proteolytic damage of the cell. By considering all these findings, we report that BME protects L132 cells against SNP-induced toxicity via its free radical scavenging and anti-apoptotic mechanism.

  13. Thermal ethane activation by bare [V₂O₅]⁺ and [Nb₂O₅]⁺ cluster cations: on the origin of their different reactivities.

    Science.gov (United States)

    Wu, Xiao-Nan; Tang, Shi-Ya; Zhao, Hai-Tao; Weiske, Thomas; Schlangen, Maria; Schwarz, Helmut

    2014-05-26

    The gas-phase reactivity of [V2O5](+) and [Nb2O5](+) towards ethane has been investigated by means of mass spectrometry and density functional theory (DFT) calculations. The two metal oxides give rise to the formation of quite different reaction products; for example, the direct room-temperature conversions C2H6→C2H5OH or C2H6→CH3CHO are brought about solely by [V2O5](+). In distinct contrast, for the couple [Nb2O5](+)/C2H6, one observes only single and double hydrogen-atom abstraction from the hydrocarbon. DFT calculations reveal that different modes of attack in the initial phase of C-H bond activation together with quite different bond-dissociation energies of the M-O bonds cause the rather varying reactivities of [V2O5](+) and [Nb2O5](+) towards ethane. The gas-phase generation of acetaldehyde from ethane by bare [V2O5](+) may provide mechanistic insight in the related vanadium-catalyzed large-scale process.

  14. Generation and reactivity of putative support systems, Ce-Al neutral binary oxide nanoclusters: CO oxidation and C–H bond activation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhe-Chen; Yin, Shi; Bernstein, Elliot R., E-mail: erb@lamar.colostate.edu [Department of Chemistry and NSF ERC for Extreme Ultraviolet Science and Technology, Colorado State University, Fort Collins, Colorado 80523 (United States)

    2013-11-21

    Both ceria (CeO{sub 2}) and alumina (Al{sub 2}O{sub 3}) are very important catalyst support materials. Neutral binary oxide nanoclusters (NBONCs), Ce{sub x}Al{sub y}O{sub z}, are generated and detected in the gas phase and their reactivity with carbon monoxide (CO) and butane (C{sub 4}H{sub 10}) is studied. The very active species CeAlO{sub 4}{sup •} can react with CO and butane via O atom transfer (OAT) and H atom transfer (HAT), respectively. Other Ce{sub x}Al{sub y}O{sub z} NBONCs do not show reactivities toward CO and C{sub 4}H{sub 10}. The structures, as well as the reactivities, of Ce{sub x}Al{sub y}O{sub z} NBONCs are studied theoretically employing density functional theory (DFT) calculations. The ground state CeAlO{sub 4}{sup •} NBONC possesses a kite-shaped structure with an O{sub t}CeO{sub b}O{sub b}AlO{sub t} configuration (O{sub t}, terminal oxygen; O{sub b}, bridging oxygen). An unpaired electron is localized on the O{sub t} atom of the AlO{sub t} moiety rather than the CeO{sub t} moiety: this O{sub t} centered radical moiety plays a very important role for the reactivity of the CeAlO{sub 4}{sup •} NBONC. The reactivities of Ce{sub 2}O{sub 4}, CeAlO{sub 4}{sup •}, and Al{sub 2}O{sub 4} toward CO are compared, emphasizing the importance of a spin-localized terminal oxygen for these reactions. Intramolecular charge distributions do not appear to play a role in the reactivities of these neutral clusters, but could be important for charged isoelectronic BONCs. DFT studies show that the reaction of CeAlO{sub 4}{sup •} with C{sub 4}H{sub 10} to form the CeAlO{sub 4}H•C{sub 4}H{sub 9}{sup •} encounter complex is barrierless. While HAT processes have been previously characterized for cationic and anionic oxide clusters, the reported study is the first observation of a HAT process supported by a ground state neutral oxide cluster. Mechanisms for catalytic oxidation of CO over surfaces of Al{sub x}O{sub y}/M{sub m}O{sub n} or M{sub m}O{sub n

  15. Sunlight-Triggered Nanoparticle Synergy: Teamwork of Reactive Oxygen Species and Nitric Oxide Released from Mesoporous Organosilica with Advanced Antibacterial Activity.

    Science.gov (United States)

    Gehring, Julia; Trepka, Bastian; Klinkenberg, Nele; Bronner, Hannah; Schleheck, David; Polarz, Sebastian

    2016-03-09

    Colonization of surfaces by microorganisms is an urging problem. In combination with the increasing antibiotic resistance of pathogenic bacteria, severe infections are reported more frequently in medical settings. Therefore, there is a large demand to explore innovative surface coatings that provide intrinsic and highly effective antibacterial activity. Materials containing silver nanoparticles have been developed in the past for this purpose, but this solution has come into criticism due to various disadvantages like notable toxicity against higher organisms, the high price, and low abundance of silver. Here, we introduce a new, sunlight-mediated organosilica nanoparticle (NP) system based on silver-free antibacterial activity. The simultaneous release of nitric oxide (NO) in combination with singlet oxygen and superoxide radicals (O2(•-)) as reactive oxygen species (ROS) leads to the emergence of highly reactive peroxynitrite molecules with significantly enhanced biocidal activity. This special cooperative effect can only be realized, if the ROS-producing moieties and the functional entities releasing NO are spatially separated from each other. In one type of particle, Rose Bengal as an efficient singlet oxygen ((1)O2) producer was covalently bound to SH functionalities applying thiol-ene click chemistry. "Charging" the second type of particles with NO was realized by quantitatively transferring the thiol groups into S-nitrosothiol functionalities. We probed the oxidation power of ROS-NP alone and in combination with NO-NP using sunlight as a trigger. The high antibacterial efficiency of dual-action nanoparticles was demonstrated using disinfection assays with the pathogenic bacterium Pseudomonas aeruginosa.

  16. Reactive oxygen species scavenging activities in a chemiluminescence model and neuroprotection in rat pheochromocytoma cells by astaxanthin, beta-carotene, and canthaxanthin.

    Science.gov (United States)

    Chang, Chi-Sen; Chang, Chia-Lin; Lai, Guia-Hung

    2013-08-01

    The objective of this study was to determine chemiluminescence (CL) antioxidant activities and neuroprotective effects of astaxanthin, beta-carotene (β-carotene), and canthaxanthin on undifferentiated rat pheochromocytoma (PC12) cells. We performed three CL antioxidant assays, and the three carotenoids showed varying degrees of antioxidant activity, with astaxanthin exhibiting the highest antioxidant activity than the other two samples. Results of a pyrogallol-luminol assay revealed β-carotene to have higher antioxidant activity than canthaxanthin, whereas cupric sulfate-Phen-Vc-hydrogen peroxide (H₂O₂) assay showed canthaxanthin to have higher antioxidant activity than β-carotene. Luminol-H₂O₂ assay showed the antioxidant activity series as canthaxanthin > β-carotene at 62.5-1000 μg/mL and β-carotene > canthaxanthin at 1000-4000 μg/mL. Astaxanthin exhibited partial neuroprotective activity against H₂O₂ and the strongest neuroprotective activity against amyloid beta-peptide(25-35) [(Aβ)(25-35)]-induced undifferentiated PC12 cell deaths at 0.5-5.0 μM. Canthaxanthin showed partial neuroprotective activity in Aβ(25-35)-induced undifferentiated PC12 cell deaths at 1.0-5.0 μM. Astaxanthin protected undifferentiated PC12 cells from the damaging effects of H₂O₂ and Aβ(25-35) by the following ways: (1) scavenging superoxide anion radicals, hydroxyl radicals, and H₂O₂; (2) securing cell viability; (3) suppressing the production of reactive oxygen species; and (4) eliminating calcium ion influx. Our results conclusively show that astaxanthin has the merit as a potential neuron protectant.

  17. Divergent Trends of Anti-JCPyV Serum Reactivity and Neutralizing Activity in Multiple Sclerosis (MS Patients during Treatment with Natalizumab

    Directory of Open Access Journals (Sweden)

    Roberta Antonia Diotti

    2016-05-01

    Full Text Available The association between natalizumab and progressive multifocal leukoencephalopathy (PML is established, but a reliable clinical risk stratification flow-chart is lacking. New risk factors are needed, such as the possible role of the anti-JC polyomavirus (JCPyV neutralizing antibody. In this pilot study, we analyzed this parameter during natalizumab treatment. Sequential sera of 38 multiple sclerosis patients during their first year of natalizumab treatment were collected, and grouped according to the number of infusions. For 11 patients, samples were also available after 24 infusions (T24, when progressive multifocal leukoencephalopathy (PML risk is higher. The reactivity against VP1, the main JCPyV surface protein, and the anti-JCPyV neutralizing activity were evaluated. During the first year, a lack of correlation between anti-JCPyV antibody response and its neutralizing activity was observed: a significant decrease in anti-JCPyV antibody response was observed (p = 0.0039, not paralleled by a similar trend in the total anti-JCPyV neutralizing activity (p = 0.2239. This lack of correlation was even more evident at T24 when, notwithstanding a significant increase in the anti-JCPyV response (p = 0.0097, a further decrease of the neutralizing activity was observed (p = 0.0062. This is the first study evidencing, prospectively, the lack of correlation between the anti-JCPyV antibody response and its neutralizing activity during natalizumab treatment.

  18. Divergent Trends of Anti-JCPyV Serum Reactivity and Neutralizing Activity in Multiple Sclerosis (MS) Patients during Treatment with Natalizumab

    Science.gov (United States)

    Diotti, Roberta Antonia; Capra, Ruggero; Moiola, Lucia; Caputo, Valeria; De Rossi, Nicola; Sangalli, Francesca; Martinelli, Vittorio; Burioni, Roberto; Clementi, Massimo; Mancini, Nicasio

    2016-01-01

    The association between natalizumab and progressive multifocal leukoencephalopathy (PML) is established, but a reliable clinical risk stratification flow-chart is lacking. New risk factors are needed, such as the possible role of the anti-JC polyomavirus (JCPyV) neutralizing antibody. In this pilot study, we analyzed this parameter during natalizumab treatment. Sequential sera of 38 multiple sclerosis patients during their first year of natalizumab treatment were collected, and grouped according to the number of infusions. For 11 patients, samples were also available after 24 infusions (T24), when progressive multifocal leukoencephalopathy (PML) risk is higher. The reactivity against VP1, the main JCPyV surface protein, and the anti-JCPyV neutralizing activity were evaluated. During the first year, a lack of correlation between anti-JCPyV antibody response and its neutralizing activity was observed: a significant decrease in anti-JCPyV antibody response was observed (p = 0.0039), not paralleled by a similar trend in the total anti-JCPyV neutralizing activity (p = 0.2239). This lack of correlation was even more evident at T24 when, notwithstanding a significant increase in the anti-JCPyV response (p = 0.0097), a further decrease of the neutralizing activity was observed (p = 0.0062). This is the first study evidencing, prospectively, the lack of correlation between the anti-JCPyV antibody response and its neutralizing activity during natalizumab treatment. PMID:27164128

  19. Upregulation of NAD(P)H oxidase 1 in hypoxia activates hypoxia-inducible factor 1 via increase in reactive oxygen species.

    Science.gov (United States)

    Goyal, Parag; Weissmann, Norbert; Grimminger, Friedrich; Hegel, Cornelia; Bader, Lucius; Rose, Frank; Fink, Ludger; Ghofrani, Hossein A; Schermuly, Ralph T; Schmidt, Harald H H W; Seeger, Werner; Hänze, Jörg

    2004-05-15

    Hypoxia sensing and related signaling events, including activation of hypoxia-inducible factor 1 (HIF-1), represent key features in cell physiology and lung function. Using cultured A549 cells, we investigated the role of NAD(P)H oxidase 1 (Nox1), suggested to be a subunit of a low-output NAD(P)H oxidase complex, in hypoxia signaling. Nox1 expression was detected on both the mRNA and protein levels. Upregulation of Nox1 mRNA and protein occurred during hypoxia, accompanied by enhanced reactive oxygen species (ROS) generation. A549 cells, which were transfected with a Nox1 expression vector, revealed an increase in ROS generation accompanied by activation of HIF-1-dependent target gene expression (heme oxygenase 1 mRNA, hypoxia-responsive-element reporter gene activity). In A549 cells stably overexpressing Nox1, accumulation of HIF-1alpha in normoxia and an additional increase in hypoxia were noted. Interference with ROS metabolism by the flavoprotein inhibitor diphenylene iodonium (DPI) and catalase inhibited HIF-1 induction. This suggests that H2O2 links Nox1 and HIF-1 activation. We conclude that hypoxic upregulation of Nox1 and subsequently augmented ROS generation may activate HIF-1-dependent pathways.

  20. Increased mitochondrial emission of reactive oxygen species and calpain activation are required for doxorubicin-induced cardiac and skeletal muscle myopathy.

    Science.gov (United States)

    Min, Kisuk; Kwon, Oh-Sung; Smuder, Ashley J; Wiggs, Michael P; Sollanek, Kurt J; Christou, Demetra D; Yoo, Jeung-Ki; Hwang, Moon-Hyon; Szeto, Hazel H; Kavazis, Andreas N; Powers, Scott K

    2015-04-15

    Although doxorubicin (DOX) is a highly effective anti-tumour agent used to treat a variety of cancers, DOX administration is associated with significant side effects, including myopathy of both cardiac and skeletal muscles. The mechanisms responsible for DOX-mediated myopathy remain a topic of debate. We tested the hypothesis that both increased mitochondrial reactive oxygen species (ROS) emission and activation of the cysteine protease calpain are required for DOX-induced myopathy in rat cardiac and skeletal muscle. Cause and effect was determined by administering a novel mitochondrial-targeted anti-oxidant to prevent DOX-induced increases in mitochondrial ROS emission, whereas a highly-selective pharmacological inhibitor was exploited to inhibit calpain activity. Our findings reveal that mitochondria are a major site of DOX-mediated ROS production in both cardiac and skeletal muscle fibres and the prevention of DOX-induced increases in mitochondrial ROS emission protects against fibre atrophy and contractile dysfunction in both cardiac and skeletal muscles. Furthermore, our results indicate that DOX-induced increases in mitochondrial ROS emission are required to activate calpain in heart and skeletal muscles and, importantly, calpain activation is a major contributor to DOX-induced myopathy. Taken together, these findings show that increased mitochondrial ROS production and calpain activation are significant contributors to the development of DOX-induced myopathy in both cardiac and skeletal muscle fibres.

  1. Experiences With The Reactive Low Voltage Ion Plating In Optical Thin Film Production

    Science.gov (United States)

    Guertler, Karlheinz; Jeschkowski, Ulrich; Conrath, E.

    1989-02-01

    The transmission of interference filters consisting of Ta205, Ti02, Zr02 and Si02 layers were measured at temperatures between 25°C and 185°C. Some characteristic differences between filters produced by reactive evaporation and reactive ion plating are demonstrated and discussed.

  2. Lattice-Boltzmann simulations of droplet evaporation

    KAUST Repository

    Ledesma-Aguilar, Rodrigo

    2014-09-04

    © the Partner Organisations 2014. We study the utility and validity of lattice-Boltzmann (LB) simulations to explore droplet evaporation driven by a concentration gradient. Using a binary-fluid lattice-Boltzmann algorithm based on Cahn-Hilliard dynamics, we study the evaporation of planar films and 3D sessile droplets from smooth solid surfaces. Our results show that LB simulations accurately reproduce the classical regime of quasi-static dynamics. Beyond this limit, we show that the algorithm can be used to explore regimes where the evaporative and diffusive timescales are not widely separated, and to include the effect of boundaries of prescribed driving concentration. We illustrate the method by considering the evaporation of a droplet from a solid surface that is chemically patterned with hydrophilic and hydrophobic stripes. This journal is

  3. Spacesuit Evaporator-Absorber-Radiator (SEAR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project builds from the work of the first year of effort that successfully integrated the Spacesuit  Water Membrane Evaporator (SWME), developed by the...

  4. Hawking evaporation and space-time structure

    Energy Technology Data Exchange (ETDEWEB)

    Balbinot, R.; Bergamini, R. (Consiglio Nazionale delle Ricerche, Bologna (Italy). Lab. di Radioastronomia); Giorgini, B. (Bologna Univ. (Italy). Ist. di Fisica)

    1982-08-11

    The Vaidya radiating metric is used to model an evaporating black-hole space-time. It is shown that, thus, a wormhole is produced in analogy with the Einstein-Rosen bridge. Its physical consequences are discussed.

  5. Denton E-beam Evaporator #1

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Name: E-Beam Evap 1This is a dual e-beam/thermal evaporator for the deposition of metal and dielectric thin films. Materials available are: Ag, Al,...

  6. Denton E-beam Evaporator #2

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Name: E-Beam Evap 2This is an electron gun evaporator for the deposition of metals and dielectrics thin films. Materials available are: Ag, Al, Au,...

  7. Blackhole evaporation model without information loss

    CERN Document Server

    Villegas, Kristian Hauser A

    2016-01-01

    A simple model of a blackhole evaporation without information loss is given. In this model, the blackhole is \\textit{not} in a specific mass eigenstate as it evaporates but rather, is in a superposition of various mass eigenstates and is entangled with the radiation. For astrophysical blackhole, the mass distribution is sharply peak about its average value with a vanishingly small standard deviation, which is consistent with our intuition of a classical object. It is then shown that as the blackhole evaporates, the evolution of the closed blackhole-radiation system is unitary. This is done by showing that the full density matrix satisfies Tr$\\rho^2=1$ at all times. Finally, it is shown that the entanglement entropy, after an initial increase, decreases and approaches zero. These show that this model of blackhole evaporation has no infromation loss.

  8. Denton E-beam Evaporator #2

    Data.gov (United States)

    Federal Laboratory Consortium — Description: CORAL Name: E-Beam Evap 2 This is an electron gun evaporator for the deposition of metals and dielectrics thin films. Materials available are: Ag, Al,...

  9. Effects of nanoparticles on nanofluid droplet evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ruey-Hung [Univ. of Central Florida, Orlando, FL (United States). Dept. of Mechanical, Materials and Aerospace Engineering; Phuoc, Tran X. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Martello, Donald [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2010-09-01

    Laponite, Fe2O3 and Ag nanoparticles were added to deionized water to study their effect of evaporation rates. The results show that these nanofluid droplets evaporate at different rates (as indicated by the evaporation rate constant K in the well known D2-law) from the base fluid. Different particles lead to different values of K. As the particle concentration increases due to evaporation. K values of various Ag and Fe2O3 nanofluids go through a transition from one value to another, further demonstrating the effect of increasing nanoparticle concentration. The implication for the heat of vaporization (hfg) is discussed.

  10. Denton E-beam Evaporator #1

    Data.gov (United States)

    Federal Laboratory Consortium — Description: CORAL Name: E-Beam Evap 1 This is a dual e-beam/thermal evaporator for the deposition of metal and dielectric thin films. Materials available are: Ag,...

  11. MuRF1 activity is present in cardiac mitochondria and regulates reactive oxygen species production in vivo.

    Science.gov (United States)

    Mattox, Taylor A; Young, Martin E; Rubel, Carrie E; Spaniel, Carolyn; Rodríguez, Jessica E; Grevengoed, Trisha J; Gautel, Mathias; Xu, Zhelong; Anderson, Ethan J; Willis, Monte S

    2014-06-01

    MuRF1 is a previously reported ubiquitin-ligase found in striated muscle that targets troponin I and myosin heavy chain for degradation. While MuRF1 has been reported to interact with mitochondrial substrates in yeast two-hybrid studies, no studies have identified MuRF1's role in regulating mitochondrial function to date. In the present study, we measured cardiac mitochondrial function from isolated permeabilized muscle fibers in previously phenotyped MuRF1 transgenic and MuRF1-/- mouse models to determine the role of MuRF1 in intermediate energy metabolism and ROS production. We identified a significant decrease in reactive oxygen species production in cardiac muscle fibers from MuRF1 transgenic mice with increased α-MHC driven MuRF1 expression. Increased MuRF1 expression in ex vivo and in vitro experiments revealed no alterations in the respiratory chain complex I and II function. Working perfusion experiments on MuRF1 transgenic hearts demonstrated significant changes in glucose oxidation. However, total oxygen consumption was decreased [corrected]. This data provides evidence for MuRF1 as a novel regulator of cardiac ROS, offering another mechanism by which increased MuRF1 expression may be cardioprotective in ischemia reperfusion injury, in addition to its inhibition of apoptosis via proteasome-mediate degradation of c-Jun. The lack of mitochondrial function phenotype identified in MuRF1-/- hearts may be due to the overlapping interactions of MuRF1 and MuRF2 with energy regulating proteins found by yeast two-hybrid studies reported here, implying a duplicity in MuRF1 and MuRF2's regulation of mitochondrial function.

  12. Modeling evaporation processes in a saline soil from saturation to oven dry conditions

    Directory of Open Access Journals (Sweden)

    M. Gran

    2011-07-01

    Full Text Available Thermal, suction and osmotic gradients interact during evaporation from a salty soil. Vapor fluxes become the main water flow mechanism under very dry conditions. A coupled nonisothermal multiphase flow and reactive transport model was developed to study mass and energy transfer mechanisms during an evaporation experiment from a sand column. Very dry and hot conditions, including the formation of a salt crust, necessitate the modification of the retention curve to represent oven dry conditions. Experimental observations (volumetric water content, temperature and concentration profiles were satisfactorily reproduced using mostly independently measured parameters, which suggests that the model can be used to assess the underlying processes. Results show that evaporation concentrates at a very narrow front and is controlled by heat flow, and limited by salinity and liquid and vapor fluxes. The front divides the soil into a dry and saline portion above and a moist and diluted portion below. Vapor diffusses not only upwards but also downwards from the evaporation front, as dictated by temperature gradients. Condensation of this downward flux causes dilution, so that salt concentration is minimum and lower than the initial one, just beneath the evaporation front. While this result is consistent with observations, it required adopting a vapor diffusion enhancement factor of 8.

  13. Modeling Evaporation of Drops of Different Kerosenes

    Science.gov (United States)

    Bellan, Josette; Harstad, Kenneth

    2007-01-01

    A mathematical model describes the evaporation of drops of a hydrocarbon liquid composed of as many as hundreds of chemical species. The model is intended especially for application to any of several types of kerosenes commonly used as fuels. The concept of continuous thermodynamics, according to which the chemical composition of the evaporating multicomponent liquid is described by use of a probability distribution function (PDF). However, the present model is more generally applicable than is its immediate predecessor.

  14. Sucrose synthase activity and carbohydrates content in relation to phosphorylation status of Vicia faba root meristems during reactivation from sugar depletion.

    Science.gov (United States)

    Polit, Justyna Teresa; Ciereszko, Iwona

    2012-11-01

    Carbohydrate starvation of Vicia faba root meristems leads to readjustment of carbohydrate metabolism and blocks the cell cycle in two principal control points (PCP1/2). The cell cycle reactivation is possible after sucrose provision, although with a delay of about 12h. During this period, the cells are sensitive to 6-dimethylaminopurine (6-DMAP) and okadaic acid (OA), inhibitors of protein kinases and phosphatases, respectively. The aim of the present study was to investigate whether those inhibitors are involved in inhibition of cell cycle revival through interference with the activities of two sucrose-cleaving enzymes: sucrose synthase (SuSy; EC 2.4.1.13) and invertase (INV; EC 3.2.1.26). In sugar-starved cells, the in situ activity of both enzymes decreased significantly. Following supplementation of root meristems with sugar, INV remained inactive, but SuSy activity increased. Despite the lack of INV activity, glucose was present in meristem cells, but its content was low in cells treated with OA. In the latter case, the size of plastids was reduced, they had less starch, and Golgi structures were affected. In sugar-starved cells, SuSy activity was induced more by exogenous sucrose than by glucose. The sucrose-induced activity was strongly inhibited by OA (less by 6-DMAP) at early stages of regeneration, but not at the stages preceding DNA replication or mitotic activities. The results indicate that prolongation of regeneration and a marked decrease in the number of cells resuming proliferation (observed in previous studies) and resulting from the action of inhibitors, are correlated with the process of SuSy activation at the beginning of regeneration from sugar starvation.

  15. Evaporation mitigation by floating modular devices

    Science.gov (United States)

    Hassan, M. M.; Peirson, W. L.

    2016-05-01

    Prolonged periods of drought and consequent evaporation from open water bodies in arid parts of Australia continue to be a threat to water availability for agricultural production. Over many parts of Australia, the annual average evaporation exceeds the annual precipitation by more than 5 times. Given its significance, it is surprising that no evaporation mitigation technique has gained widespread adoption to date. High capital and maintenance costs of manufactured products are a significant barrier to implementation. The use of directly recycled clean plastic containers as floating modular devices to mitigate evaporation has been investigated for the first time. A six-month trial at an arid zone site in Australia of this potential cost effective solution has been undertaken. The experiment was performed using clean conventional drinking water bottles as floating modules on the open water surface of 240-L tanks with three varying degrees of covering (nil, 34% and 68%). A systematic reduction in evaporation is demonstrated during the whole study period that is approximately linearly proportional to the covered surface. These results provide a potential foundation for robust evaporation mitigation with the prospect of implementing a cost-optimal design.

  16. Sheet Membrane Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Bue, Grant; Trevino, Luis; Zapata, Felipe; Dillion, Paul; Castillo, Juan; Vonau, Walter; Wilkes, Robert; Vogel, Matthew; Frodge, Curtis

    2013-01-01

    A document describes a sheet membrane spacesuit water membrane evaporator (SWME), which allows for the use of one common water tank that can supply cooling water to the astronaut and to the evaporator. Test data showed that heat rejection performance dropped only 6 percent after being subjected to highly contaminated water. It also exhibited robustness with respect to freezing and Martian atmospheric simulation testing. Water was allowed to freeze in the water channels during testing that simulated a water loop failure and vapor backpressure valve failure. Upon closing the backpressure valve and energizing the pump, the ice eventually thawed and water began to flow with no apparent damage to the sheet membrane. The membrane evaporator also serves to de-gas the water loop from entrained gases, thereby eliminating the need for special degassing equipment such as is needed by the current spacesuit system. As water flows through the three annular water channels, water evaporates with the vapor flowing across the hydrophobic, porous sheet membrane to the vacuum side of the membrane. The rate at which water evaporates, and therefore, the rate at which the flowing water is cooled, is a function of the difference between the water saturation pressure on the water side of the membrane, and the pressure on the vacuum side of the membrane. The primary theory is that the hydrophobic sheet membrane retains water, but permits vapor pass-through when the vapor side pressure is less than the water saturation pressure. This results in evaporative cooling of the remaining water.

  17. Accelerated evaporation of water on graphene oxide.

    Science.gov (United States)

    Wan, Rongzheng; Shi, Guosheng

    2017-03-15

    Using molecular dynamics simulations, we show that the evaporation of nanoscale volumes of water on patterned graphene oxide is faster than that on homogeneous graphene oxide. The evaporation rate of water is insensitive to variation in the oxidation degree of the oxidized regions, so long as the water film is only distributed on the oxidized regions. The evaporation rate drops when the water film spreads onto the unoxidized regions. Further analysis showed that varying the oxidation degree observably changed the interaction between the outmost water molecules and the solid surface, but the total interaction for the outmost water molecules only changed a very limited amount due to the correspondingly regulated water-water interaction when the water film is only distributed on the oxidized regions. When the oxidation degree is too low and some unoxidized regions are also covered by the water film, the thickness of the water film decreases, which extends the lifetime of the hydrogen bonds for the outmost water molecules and lowers the evaporation rate of the water. The insensitivity of water evaporation to the oxidation degree indicates that we only need to control the scale of the unoxidized and oxidized regions for graphene oxide to regulate the evaporation of nanoscale volumes of water.

  18. Water repellency diminishes peatland evaporation after wildfire

    Science.gov (United States)

    Kettridge, Nick; Lukenbach, Max; Hokanson, Kelly; Devito, Kevin; Hopkinson, Chris; Petrone, Rich; Mendoza, Carl; Waddington, Mike

    2016-04-01

    Peatlands are a critically important global carbon reserve. There is increasing concern that such ecosystems are vulnerable to projected increases in wildfire severity under a changing climate. Severe fires may exceed peatland ecological resilience resulting in the long term degradation of this carbon store. Evaporation provides the primary mechanisms of water loss from such environments and can regulate the ecological stress in the initial years after wildfire. We examine variations in evaporation within burned peatlands after wildfire through small scale chamber and large scale remote sensing measurements. We show that near-surface water repellency limits peatland evaporation in these initial years post fire. Water repellent peat produced by the fire restricts the supply of water to the surface, reducing evaporation and providing a strong negative feedback to disturbance. This previously unidentified feedback operates at the landscape scale. High surface temperatures that result from large reductions in evaporation within water repellent peat are observed across the 60,000 ha burn scar three months after the wildfire. This promotes high water table positions at a landscape scale which limit the rate of peat decomposition and supports the post fire ecohydrological recovery of the peatlands. However, severe burns are shown to exceed this negative feedback response. Deep burns at the peatland margins remove the hydrophobic layer, increasing post fire evaporation and leaving the peatland vulnerable to drying and associated ecological shifts.

  19. Droplet evaporation on a soluble substrate

    Science.gov (United States)

    Mailleur, Alexandra; Pirat, Christophe; Colombani, Jean; CNES Collaboration

    2015-11-01

    Stains left by evaporated droplets are ubiquitous in everyday life as well as in industrial processes. Whatever the composition of the evaporating liquid (colloidal suspensions, biological fluids...), the stains are mostly constituted by a deposit at the periphery of the dried drop, similar to a coffee stain (Deegan, 1997). All these studies have been carried with non-reacting solids. In this presentation, we focus on the behavior of a pure-water droplet evaporating on a soluble substrate which is more complex, since three phenomena are strongly interacting: the dissolution of the substrate, the diffusion/convection of the dissolved species into the drop and the evaporation of the liquid. NaCl and KCl single crystals have been chosen for this experimental study as they are fast-dissolving solids. We have observed that the dissolution induces a pinning of the triple line from the beginning of the evaporation, leading to a decrease of the contact angle in time. At the end of the evaporation, a peripheral deposit is always formed, proof of an outward flow inside the drop (coffee-ring effect). The authors would like to thank the CNES for the financial support.

  20. AMPK is Involved in Mediation of Erythropoietin Influence on Metabolic Activity and Reactive Oxygen Species Production in White Adipocytes

    OpenAIRE

    Wang, Li; Di, Lijun; Noguchi, Constance Tom

    2014-01-01

    Erythropoietin, discovered for its indispensable role during erythropoiesis, has been used in the therapy for selected red blood cell disorders in erythropoietin-deficient patients. The biological activities of erythropoietin have been found to extend to non-erythroid tissues due to the expression of erythropoietin receptor. We previously demonstrated that erythropoietin promotes metabolic activity and white adipocytes browning to increase mitochondrial function and energy expenditure via per...

  1. Density Functional Studies of the Reaction of Ytterbium Monocation with Fluoromethane: C-F Bond Activation and Electron-Transfer Reactivity

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane,which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare lanthanide cations,have been investigated for the first time by using density functional theory.A direct fluorine abstraction mechanism was revealed,and the related thermochemistry data were determined.The electron-transfer reactivity of the reaction was analyzed using the two-state model,and a strongly avoided crossing behavior on the transition state region was shown.The present results support the reaction mechanism inferred from early experimental data and the related thermochemistry data can provide a guide for further experimental researches.

  2. Tissue-type plasminogen activator and C-reactive protein in acute coronary heart disease. A nested case-control study

    DEFF Research Database (Denmark)

    Gram, J; Bladbjerg, E-M; Møller, L

    2000-01-01

    OBJECTIVES: To study the importance of inflammation and fibrinolysis for evolution of ischaemic heart disease in a cohort of initially healthy subjects. DESIGN: Nested case-control study. Follow-up periods 7-15 years. SUBJECTS: Included in the study were 133 cases with coronary heart disease...... and 258 controls. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Subjects with ischaemic heart disease identified in 1991 by the Danish National Hospital Register. Protein concentration of C-reactive protein (CRP) and tissue-type plasminogen activator (t-PA) were measured with ELISA methods in stored serum...... samples. RESULTS: CRP and t-PA concentrations were both significantly higher in cases than in controls (P difference between cases and controls for CRP and t-PA was present in both men (CRP: P = 0.022; t-PA: P = 0.001) and women (CRP: P = 0.013; t-PA: P = 0...

  3. Soluble urokinase plasminogen activator receptor is in contrast to high-sensitive C-reactive-protein associated with coronary artery calcifications in healthy middle-aged subjects

    DEFF Research Database (Denmark)

    Sørensen, Mette Hjortdal; Gerke, Oke; Eugen-Olsen, Jesper;

    2014-01-01

    OBJECTIVE: The main objective of this study was to investigate the association between two markers of low-grade inflammation; soluble urokinase plasminogen activator receptor (suPAR) and high-sensitive C-reactive protein (hs-CRP); and coronary artery calcification (CAC) score detected by cardiac...... computed tomography (CT) scan. DESIGN: A cross sectional study of 1126 randomly sampled middle-aged men and women. METHODS: CAC score was measured by a non-contrast cardiac CT scan and total 10-year cardiovascular mortality risk was estimated using the Systematic Coronary Risk Evaluation (SCORE). Plasma...... samples were analysed for suPAR and hs-CRP. The association of suPAR and hs-CRP to CAC was evaluated by logistic regression analyses adjusting for categorised SCORE. The additive effect of suPAR to SCORE was evaluated by comparing area under curve (AUC) and net reclassification improvement (NRI). RESULTS...

  4. EVAPORATION FORM OF ICE CRYSTALS IN SUBSATURATED AIR AND THEIR EVAPORATION MECHANISM

    OpenAIRE

    ゴンダ, タケヒコ; セイ, タダノリ; Takehiko, Gonda; Tadanori, Sei

    1987-01-01

    The evaporation form and the evaporation mechanism of dendritic ice crystals grown in air of 1.0×(10)^5 Pa and at water saturation and polyhedral ice crystals grown in air of 4.0×10 Pa and at relatively low supersaturation are studied. In the case of dendritic ice crystals, the evaporation preferentially occurs in the convex parts of the crystal surfaces and in minute secondary branches. On the other hand, in the case of polyhedral ice crystals, the evaporation preferentially occurs in the pa...

  5. Effects of the local structure dependence of evaporation fields on field evaporation behavior

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Lan; Marquis, Emmanuelle A., E-mail: emarq@umich.edu [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Withrow, Travis; Restrepo, Oscar D.; Windl, Wolfgang [Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2015-12-14

    Accurate three dimensional reconstructions of atomic positions and full quantification of the information contained in atom probe microscopy data rely on understanding the physical processes taking place during field evaporation of atoms from needle-shaped specimens. However, the modeling framework for atom probe microscopy has only limited quantitative justification. Building on the continuum field models previously developed, we introduce a more physical approach with the selection of evaporation events based on density functional theory calculations. This model reproduces key features observed experimentally in terms of sequence of evaporation, evaporation maps, and depth resolution, and provides insights into the physical limit for spatial resolution.

  6. Identification of differential anti-neoplastic activity of copper bis(thiosemicarbazones) that is mediated by intracellular reactive oxygen species generation and lysosomal membrane permeabilization.

    Science.gov (United States)

    Stefani, Christian; Al-Eisawi, Zaynab; Jansson, Patric J; Kalinowski, Danuta S; Richardson, Des R

    2015-11-01

    Bis(thiosemicarbazones) and their copper (Cu) complexes possess unique anti-neoplastic properties. However, their mechanism of action remains unclear. We examined the structure-activity relationships of twelve bis(thiosemicarbazones) to elucidate factors regarding their anti-cancer efficacy. Importantly, the alkyl substitutions at the diimine position of the ligand backbone resulted in two distinct groups, namely, unsubstituted/monosubstituted and disubstituted bis(thiosemicarbazones). This alkyl substitution pattern governed their: (1) Cu(II/I) redox potentials; (2) ability to induce cellular (64)Cu release; (3) lipophilicity; and (4) anti-proliferative activity. The potent anti-cancer Cu complex of the unsubstituted bis(thiosemicarbazone) analog, glyoxal bis(4-methyl-3-thiosemicarbazone) (GTSM), generated intracellular reactive oxygen species (ROS), which was attenuated by Cu sequestration by a non-toxic Cu chelator, tetrathiomolybdate, and the anti-oxidant, N-acetyl-l-cysteine. Fluorescence microscopy suggested that the anti-cancer activity of Cu(GTSM) was due, in part, to lysosomal membrane permeabilization (LMP). For the first time, this investigation highlights the role of ROS and LMP in the anti-cancer activity of bis(thiosemicarbazones).

  7. Artemisinin induces A549 cell apoptosis dominantly via a reactive oxygen species-mediated amplification activation loop among caspase-9, -8 and -3.

    Science.gov (United States)

    Gao, Weijie; Xiao, Fenglian; Wang, Xiaoping; Chen, Tongsheng

    2013-10-01

    This report is designed to explore the roles of caspase-8, -9 and -3 in artemisinin (ARTE)-induced apoptosis in non-small cell lung cancer cells (A549 cells). ARTE induced reactive oxygen species (ROS)-mediated apoptosis in dose- and time-dependent fashion. Although ARTE treatment did not induce Bid cleavage and significant loss of mitochondrial membrane potential, it induced release of Smac and AIF but not cytochrome c from mitochondria, and silencing of Bak but not Bax significantly prevented ARTE-induced cytotoxicity. Moreover, ARTE treatment induced ROS-dependent activation of caspase-9, -8 and -3. Of the utmost importance, silencing or inhibiting any one of caspase-8, -9 and -3 almost completely prevented ARTE-induced activation of all the three caspases and remarkably abrogated the cytotoxicity of ARTE, suggesting that ARTE triggered an amplification activation loop among caspase-9, -8 and -3. Collectively, our data demonstrate that ARTE induces a ROS-mediated amplification activation loop among caspase-9, -8 and -3 to dominantly mediate the apoptosis of A549 cells.

  8. Impact of Trans-Resveratrol-Sulfates and -Glucuronides on Endothelial Nitric Oxide Synthase Activity, Nitric Oxide Release and Intracellular Reactive Oxygen Species

    Directory of Open Access Journals (Sweden)

    Angela Ladurner

    2014-10-01

    Full Text Available Resveratrol (3,5,4'-trihydroxy-trans-stilbene is a polyphenolic natural product mainly present in grape skin, berries and peanuts. In the vasculature resveratrol is thought to boost endothelial function by increasing endothelial nitric oxide synthase (eNOS expression, by enhancing eNOS activity, and by reduction of reactive oxygen species (ROS levels. Recent studies show that dietary resveratrol is metabolized in the liver and intestine into resveratrol-sulfate and -glucuronide derivatives questioning the relevance of multiple reported mechanistic in vitro data on resveratrol. In this study, we compare side by side different physiologically relevant resveratrol metabolites (resveratrol sulfates- and -glucuronides and their parent compound in their influence on eNOS enzyme activity, endothelial NO release, and intracellular ROS levels. In contrast to resveratrol, none of the tested resveratrol metabolites elevated eNOS enzyme activity and endothelial NO release or affected intracellular ROS levels, leaving the possibility that not tested metabolites are active and able to explain in vivo findings.

  9. Induction of apoptosis by casticin in cervical cancer cells: reactive oxygen species-dependent sustained activation of Jun N-terminal kinase

    Institute of Scientific and Technical Information of China (English)

    Fanxiang Zeng; Li Tian; Fei Liu; Jianguo Cao; Meifang Quan; Xifeng Sheng

    2012-01-01

    Casticin,a polymethoxyflavone from Fructus viticis used as an anti-inflammatory agent in Chinese traditional medicine,has been reported to have anti-cancer activity.The purpose of this study was to examine the apoptotic activity of casticin on human cervical cancer cells and its molecular mechanism.We revealed a novel mechanism by which casticin-induced apoptosis occurs and showed for the first time that the apoptosis induced by casticin is mediated through generation of reactive oxygen species (ROS) and sustained activation of c-Jun N-terminal kinase (JNK) in HeLa cells.Casticin markedly increased the levels of intracellular ROS and induced the expression of phosphorylated JNK and cJun protein.Pre-treatment with N-acetylcvsteine and SP600125 effectively attenuated induction of apoptosis by casticin in HeLa cells.Moreover,casticin induced ROS production and apoptotic cell death in other cervical cancer cell lines,such as CasKi and SiHa.Importantly,casticin did not cause generation of ROS or induction of apoptosis in normal human peripheral blood mononuclear cells and embryonic kidney epithelium 293 cells.These results suggest that ROS generation and sustained JNK activation by casticin play a role in casticin-induced apoptosis and raise the possibility that treatment with casticin might be promising as a new therapy against human cervical cancer.

  10. Reactive Sulfur Species-Mediated Activation of the Keap1-Nrf2 Pathway by 1,2-Naphthoquinone through Sulfenic Acids Formation under Oxidative Stress.

    Science.gov (United States)

    Shinkai, Yasuhiro; Abiko, Yumi; Ida, Tomoaki; Miura, Takashi; Kakehashi, Hidenao; Ishii, Isao; Nishida, Motohiro; Sawa, Tomohiro; Akaike, Takaaki; Kumagai, Yoshito

    2015-05-18

    Sulfhydration by a hydrogen sulfide anion and electrophile thiolation by reactive sulfur species (RSS) such as persulfides/polysulfides (e.g., R-S-SH/R-S-Sn-H(R)) are unique reactions in electrophilic signaling. Using 1,2-dihydroxynaphthalene-4-thioacetate (1,2-NQH2-SAc) as a precursor to 1,2-dihydroxynaphthalene-4-thiol (1,2-NQH2-SH) and a generator of reactive oxygen species (ROS), we demonstrate that protein thiols can be modified by a reactive sulfenic acid to form disulfide adducts that undergo rapid cleavage in the presence of glutathione (GSH). As expected, 1,2-NQH2-SAc is rapidly hydrolyzed and partially oxidized to yield 1,2-NQ-SH, resulting in a redox cycling reaction that produces ROS through a chemical disproportionation reaction. The sulfenic acid forms of 1,2-NQ-SH and 1,2-NQH2-SH were detected by derivatization experiments with dimedone. 1,2-NQH2-SOH modified Keap1 at Cys171 to produce a Keap1-S-S-1,2-NQH2 adduct. Subsequent exposure of A431 cells to 1,2-NQ or 1,2-NQH2-SAc caused an extensive chemical modification of cellular proteins in both cases. Protein adduction by 1,2-NQ through a thio ether (C-S-C) bond slowly declined through a GSH-dependent S-transarylation reaction, whereas that originating from 1,2-NQH2-SAc through a disulfide (C-S-S-C) bond was rapidly restored to the free protein thiol in the cells. Under these conditions, 1,2-NQH2-SAc activated Nrf2 and upregulated its target genes, which were enhanced by pretreatment with buthionine sulfoximine (BSO), to deplete cellular GSH. Pretreatment of catalase conjugated with poly(ethylene glycol) suppressed Nrf2 activation by 1,2-NQH2-SAc. These results suggest that RSS-mediated reversible electrophilic signaling takes place through sulfenic acids formation under oxidative stress.

  11. Preparation of Candesartan and Atorvastatin Nanoparticles by Solvent Evaporation

    Directory of Open Access Journals (Sweden)

    Josef Jampilek

    2012-11-01

    Full Text Available The solubility, absorption and distribution of a drug are involved in the basic aspects of oral bioavailability Solubility is an essential characteristic and influences the efficiency of the drug. Over the last ten years, the number of poorly soluble drugs has steadily increased. One of the progressive ways for increasing oral bioavaibility is the technique of nanoparticle preparation, which allows many drugs to thus reach the intended site of action. Candesartan cilexetil and atorvastatin, belonging to class II of the biopharmaceutical classification system, were chosen as model active pharmaceutical ingredients in this study. Forty samples were prepared either by antisolvent precipitation/solvent evaporation method or by the emulsion/solvent evaporation technique with various commonly used surface-active excipients as nanoparticle stabilizers. All samples were analyzed by means of dynamic light scattering. The particle size of the determined 36 nanoparticle samples was to 574 nm, whereas 32 samples contained nanoparticles of less than 200 nm. Relationships between solvents and excipients used and their amount are discussed. Based on the results the investigated solvent evaporation methods can be used as an effective and an affordable technique for the preparation of nanoparticles.

  12. Wolbachia induces reactive oxygen species (ROS)-dependent activation of the Toll pathway to control dengue virus in the mosquito Aedes aegypti.

    Science.gov (United States)

    Pan, Xiaoling; Zhou, Guoli; Wu, Jiahong; Bian, Guowu; Lu, Peng; Raikhel, Alexander S; Xi, Zhiyong

    2012-01-03

    Wolbachia are maternally transmitted symbiotic bacteria that can spread within insect populations because of their unique ability to manipulate host reproduction. When introduced to nonnative mosquito hosts, Wolbachia induce resistance to a number of human pathogens, including dengue virus (DENV), Plasmodium, and filarial nematodes, but the molecular mechanism involved is unclear. In this study, we have deciphered how Wolbachia infection affects the Aedes aegypti host in inducing resistance to DENV. The microarray assay indicates that transcripts of genes with functions related to immunity and reduction-oxidation (redox) reactions are up-regulated in Ae. aegypti infected with Wolbachia. Infection with this bacterium leads to induction of oxidative stress and an increased level of reactive oxygen species in its mosquito host. Reactive oxygen species elevation is linked to the activation of the Toll pathway, which is essential in mediating the expression of antioxidants to counterbalance oxidative stress. This immune pathway also is responsible for activation of antimicrobial peptides-defensins and cecropins. We provide evidence that these antimicrobial peptides are involved in inhibition of DENV proliferation in Wolbachia-infected mosquitoes. Utilization of transgenic Ae. aegypti and the RNAi depletion approach has been instrumental in proving the role of defensins and cecropins in the resistance of Wolbachia-infected Ae. aegypti to DENV. These results indicate that a symbiotic bacterium can manipulate the host defense system to facilitate its own persistent infection, resulting in a compromise of the mosquito's ability to host human pathogens. Our discoveries will aid in the development of control strategies for mosquito-transmitted diseases.

  13. TLR2/MyD88/NF-κB pathway, reactive oxygen species, potassium efflux activates NLRP3/ASC inflammasome during respiratory syncytial virus infection.

    Directory of Open Access Journals (Sweden)

    Jesus Segovia

    Full Text Available Human respiratory syncytial virus (RSV constitute highly pathogenic virus that cause severe respiratory diseases in newborn, children, elderly and immuno-compromised individuals. Airway inflammation is a critical regulator of disease outcome in RSV infected hosts. Although "controlled" inflammation is required for virus clearance, aberrant and exaggerated inflammation during RSV infection results in development of inflammatory diseases like pneumonia and bronchiolitis. Interleukin-1β (IL-1β plays an important role in inflammation by orchestrating the pro-inflammatory response. IL-1β is synthesized as an immature pro-IL-1β form. It is cleaved by activated caspase-1 to yield mature IL-1β that is secreted extracellularly. Activation of caspase-1 is mediated by a multi-protein complex known as the inflammasome. Although RSV infection results in IL-1β release, the mechanism is unknown. Here in, we have characterized the mechanism of IL-1β secretion following RSV infection. Our study revealed that NLRP3/ASC inflammasome activation is crucial for IL-1β production during RSV infection. Further studies illustrated that prior to inflammasome formation; the "first signal" constitutes activation of toll-like receptor-2 (TLR2/MyD88/NF-κB pathway. TLR2/MyD88/NF-κB signaling is required for pro-IL-1β and NLRP3 gene expression during RSV infection. Following expression of these genes, two "second signals" are essential for triggering inflammasome activation. Intracellular reactive oxygen species (ROS and potassium (K(+ efflux due to stimulation of ATP-sensitive ion channel promote inflammasome activation following RSV infection. Thus, our studies have underscored the requirement of TLR2/MyD88/NF-κB pathway (first signal and ROS/potassium efflux (second signal for NLRP3/ASC inflammasome formation, leading to caspase-1 activation and subsequent IL-1β release during RSV infection.

  14. Irradiation with UV-C inhibits TNF-α-dependent activation of the NF-κB pathway in a mechanism potentially mediated by reactive oxygen species.

    Science.gov (United States)

    Szoltysek, Katarzyna; Walaszczyk, Anna; Janus, Patryk; Kimmel, Marek; Widlak, Piotr

    2017-01-01

    Pathways depending on the NF-κB transcription factor are essential components of cellular response to stress. Plethora of stimuli modulating NF-κB includes inflammatory signals, ultraviolet radiation (UV) and reactive oxygen species (ROS), yet interference between different factors affecting NF-κB remains relatively understudied. Here, we aim to characterize the influence of UV radiation on TNF-α-induced activity of the NF-κB pathway. We document inhibition of TNF-α-induced activation of NF-κB and subsequent suppression of NF-κB-regulated genes in cells exposed to UV-C several hours before TNF-α stimulation. Accumulation of ROS and subsequent activation of NRF2, p53, AP-1 and NF-κB-dependent pathways, with downstream activation of antioxidant mechanisms (e.g., SOD2 and HMOX1 expression), is observed in the UV-treated cells. Moreover, NF-κB inhibition is not observed if generation of UV-induced ROS is suppressed by chemical antioxidants. It is noteworthy that stimulation with TNF-α also generates a wave of ROS, which is suppressed in cells pre-treated by UV. We postulate that irradiation with UV-C activates antioxidant mechanisms, which in turn affect ROS-mediated activation of NF-κB by TNF-α. Considering a potential cross talk between p53 and NF-κB, we additionally compare observed effects in p53-proficient and p53-deficient cells and find the UV-mediated suppression of TNF-α-activated NF-κB in both types of cells.

  15. Particle Swarm Optimization Based Reactive Power Optimization

    CERN Document Server

    Sujin, P R; Linda, M Mary

    2010-01-01

    Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...

  16. Performance investigation of advanced adsorption desalination cycle with condenser-evaporator heat recovery scheme

    KAUST Repository

    Thu, Kyaw

    2013-01-01

    Energy or heat recovery schemes are keys for the performance improvement of any heat-activated cycles such as the absorption and adsorption cycles. We present two innovative heat recovery schemes between the condensing and evaporating units of an adsorption desalination (AD) cycle. By recovering the latent heat of condenser and dumping it into the evaporative process of the evaporator, it elevates the evaporating temperature and hence the adsorption pressure seen by the adsorbent. From isotherms, this has an effect of increasing the vapour uptake. In the proposed configurations, one approach is simply to have a run-about water circuit between the condenser and the evaporator and a pump is used to achieve the water circulation. This run-around circuit is a practical method for retrofitting purposes. The second method is targeted towards a new AD cycle where an encapsulated condenser-evaporator unit is employed. The heat transfer between the condensing and evaporative vapour is almost immediate and the processes occur in a fully integrated vessel, thereby minimizing the heat transfer resistances of heat exchangers. © 2013 Desalination Publications.

  17. Mastl is required for timely activation of APC/C in meiosis I and Cdk1 reactivation in meiosis II.

    Science.gov (United States)

    Adhikari, Deepak; Diril, M Kasim; Busayavalasa, Kiran; Risal, Sanjiv; Nakagawa, Shoma; Lindkvist, Rebecca; Shen, Yan; Coppola, Vincenzo; Tessarollo, Lino; Kudo, Nobuaki R; Kaldis, Philipp; Liu, Kui

    2014-09-29

    In mitosis, the Greatwall kinase (called microtubule-associated serine/threonine kinase like [Mastl] in mammals) is essential for prometaphase entry or progression by suppressing protein phosphatase 2A (PP2A) activity. PP2A suppression in turn leads to high levels of Cdk1 substrate phosphorylation. We have used a mouse model with an oocyte-specific deletion of Mastl to show that Mastl-null oocytes resume meiosis I and reach metaphase I normally but that the onset and completion of anaphase I are delayed. Moreover, after the completion of meiosis I, Mastl-null oocytes failed to enter meiosis II (MII) because they reassembled a nuclear structure containing decondensed chromatin. Our results show that Mastl is required for the timely activation of anaphase-promoting complex/cyclosome to allow meiosis I exit and for the rapid rise of Cdk1 activity that is needed for the entry into MII in mouse oocytes.

  18. Simultaneous spreading and evaporation: recent developments.

    Science.gov (United States)

    Semenov, Sergey; Trybala, Anna; Rubio, Ramon G; Kovalchuk, Nina; Starov, Victor; Velarde, Manuel G

    2014-04-01

    The recent progress in theoretical and experimental studies of simultaneous spreading and evaporation of liquid droplets on solid substrates is discussed for pure liquids including nanodroplets, nanosuspensions of inorganic particles (nanofluids) and surfactant solutions. Evaporation of both complete wetting and partial wetting liquids into a nonsaturated vapour atmosphere are considered. However, the main attention is paid to the case of partial wetting when the hysteresis of static contact angle takes place. In the case of complete wetting the spreading/evaporation process proceeds in two stages. A theory was suggested for this case and a good agreement with available experimental data was achieved. In the case of partial wetting the spreading/evaporation of a sessile droplet of pure liquid goes through four subsequent stages: (i) the initial stage, spreading, is relatively short (1-2 min) and therefore evaporation can be neglected during this stage; during the initial stage the contact angle reaches the value of advancing contact angle and the radius of the droplet base reaches its maximum value, (ii) the first stage of evaporation is characterised by the constant value of the radius of the droplet base; the value of the contact angle during the first stage decreases from static advancing to static receding contact angle; (iii) during the second stage of evaporation the contact angle remains constant and equal to its receding value, while the radius of the droplet base decreases; and (iv) at the third stage of evaporation both the contact angle and the radius of the droplet base decrease until the drop completely disappears. It has been shown theoretically and confirmed experimentally that during the first and second stages of evaporation the volume of droplet to power 2/3 decreases linearly with time. The universal dependence of the contact angle during the first stage and of the radius of the droplet base during the second stage on the reduced time has been

  19. Ruthenium-modified zinc oxide, a highly active vis-photocatalyst: the nature and reactivity of photoactive centres.

    Science.gov (United States)

    Bloh, Jonathan Z; Dillert, Ralf; Bahnemann, Detlef W

    2014-03-28

    We recently reported a highly active photocatalyst, ruthenium-modified zinc oxide, which was found to be able to utilise the red part of the visible light spectrum for photocatalytic reactions [Bloh et al., Environ. Sci. Pollut. Res., 2012, 19, 3688-3695]. However, the origin and mechanism of the observed activity as well as the nature of the photoactive centres are still unknown. Herein, we expand on that by reporting a series of experiments specifically designed to unravel the mechanism of the visible light induced photocatalytic reactions. The absolute potentials of the valence and the conduction band edge are identified by the combined use of electrochemical impedance and UV-vis diffuse reflectance spectroscopy. The conduction band electron and the valence band hole activity are assessed through a novel approach tracing their signature oxidative species, i.e., hydrogen peroxide and hydroxyl radicals, respectively. Oxygen reduction currents are measured at different potentials to investigate the role of molecular oxygen as an electron scavenger as well as the underlying reduction pathways. Additionally, the photocatalytic activity of the samples is verified using another (ISO standard) degradation test, the gas-phase oxidation of nitric oxide. The experimental results reveal that the employed synthetic route yields a unique mixture of ruthenium(VI)-doped zinc oxide and ruthenium(VI) oxide particles with both forms of the ruthenium playing their own independent role in the enhancement of the photocatalytic activity. The ruthenium ions acting as dopants enable a better charge separation as well as the absorption of red light resulting in the direct promotion of electrons from the Ru(VI)-species to the conduction band. Both, the conduction band electrons and the thus formed Ru(VII) subsequently participate in the degradation of the pollutant molecules. The ruthenium dioxide particles, on the other hand, act as catalysts increasing the efficiency of the reaction by

  20. Reactive oxygen species and mitogen-activated protein kinase induce apoptotic death of SH-SY5Y cells in response to fipronil.

    Science.gov (United States)

    Ki, Yeo-Woon; Lee, Jeong Eun; Park, Jae Hyeon; Shin, In Chul; Koh, Hyun Chul

    2012-05-20

    There are multiple lines of evidence showing that environmental toxicants including pesticides may contribute to neuronal cell death. Fipronil (FPN) is a phenylpyrazole insecticide that acts on insect GABA receptors. Although the action of FPN is restricted to insect neuronal or muscular transmitter systems, a few studies have assessed the effects of this neurotoxicant on neuronal cell death distinct from an insect. To determine the mechanisms underlying FPN-induced neuronal cell death, we evaluated the ability of this chemical to induce oxidative stress and studied the involvement of mitogen activated protein kinases (MAPKs) in FPN-induced apoptosis stress in human neuroblastoma SH-SY5Y (SH-SY5Y) cells. Exposure of SH-SY5Y cells to FPN led to the production of reactive oxygen species (ROS) and apoptotic cell death via activation of caspase-9 and caspase-3. Interestingly, the antioxidant, N-acetyl-cysteine (NAC) attenuated apoptotic cell death and ROS production induced by FPN. These results indicated that oxidative stress plays a central role in FPN-induced cytotoxicity. Mitochondrial complex I activity was also inhibited by FPN treatment. These finding indicate that FPN triggers intrinsic apoptosis via the mitochondrial signaling pathway that is initiated by the generation of ROS. Furthermore, FPN treatment induced phosphorylation of MAPK members. Activation of these protein kinases by FPN was involved in the onset of apoptosis as inhibitors specific to these kinases protect against FPN-induced cell death as well as ROS generation. Our data indicate that FPN-induced apoptosis is mediated primarily by the generation of ROS and activation of MAPK members followed by activation of the intrinsic apoptotic pathway.

  1. Integrin alpha1beta1 controls reactive oxygen species synthesis by negatively regulating epidermal growth factor receptor-mediated Rac activation.

    Science.gov (United States)

    Chen, Xiwu; Abair, Tristin D; Ibanez, Maria R; Su, Yan; Frey, Mark R; Dise, Rebecca S; Polk, D Brent; Singh, Amar B; Harris, Raymond C; Zent, Roy; Pozzi, Ambra

    2007-05-01

    Integrins control many cell functions, including generation of reactive oxygen species (ROS) and regulation of collagen synthesis. Mesangial cells, found in the glomerulus of the kidney, are able to produce large amounts of ROS via the NADPH oxidase. We previously demonstrated that integrin alpha1-null mice develop worse fibrosis than wild-type mice following glomerular injury and this is due, in part, to excessive ROS production by alpha1-null mesangial cells. In the present studies, we describe the mechanism whereby integrin alpha1-null mesangial cells produce excessive ROS. Integrin alpha1-null mesangial cells have constitutively increased basal levels of activated Rac1, which result in its increased translocation to the cell membrane, excessive ROS production, and consequent collagen IV deposition. Basal Rac1 activation is a direct consequence of ligand-independent increased epidermal growth factor receptor (EGFR) phosphorylation in alpha1-null mesangial cells. Thus, our study demonstrates that integrin alpha1beta1-EGFR cross talk is a key step in negatively regulating Rac1 activation, ROS production, and excessive collagen synthesis, which is a hallmark of diseases characterized by irreversible fibrosis.

  2. Heat shock protein 27 regulates oxidative stress-induced apoptosis in cardiomyocytes:mechanisms via reactive oxygen species generation and Akt activation

    Institute of Scientific and Technical Information of China (English)

    LIU Li; ZHANG Xiao-jin; JIANG Su-rong; DING Zheng-nian; DING Guo-xian; HUANG Jun; CHENG Yun-lin

    2007-01-01

    Background Increased reactive oxygen species(ROS)formation,which in turn promotes cardiomyocytes apoptosis,is associated with the pathogenesis and progression of various cardiac diseases such as ischemia and heart failure.Recent studies have shown that over expression of heat shock protein 27(Hsp27)confers resistance to cardiac ischemia/reperfusion injury.However,not much is known about the regulation of myocyte survival by Hsp27.Methods The rat cardiac cell line H9c2,with a stable overexpression of Hsp27,was established,with empty vector transfected H9c2 cells as controls.Following the cells challenged by Hydrogen Peroxide(H2O2),lactate dehydrogenase (LDH)release,apoptosis,intracellular ROS,cell morphology,mitochondrial transmembrane potential and the activation of serine/threonine kinase Akt were determined.Results Along with marked suppression of H2O2-induced injury by Hsp27 overexpression in H9c2 cells,ROS generation and the loss of mitochondrial membrane potential were also significantly depressed.Furthermore,augmented Akt activation was observed in Hsp27 overexpressed H9c2 cells following H2O2 exposure.Conclusions Hsp27 inhibits oxidative stress-induced H9c2 damage and inhibition of ROS generation and the augmentation of Akt activation may be involved in the protective signaling.

  3. Rapid Diminution in the Level and Activity of DNA-Dependent Protein Kinase in Cancer Cells by a Reactive Nitro-Benzoxadiazole Compound

    Directory of Open Access Journals (Sweden)

    Viviane A. O. Silva

    2016-05-01

    Full Text Available The expression and activity of DNA-dependent protein kinase (DNA-PK is related to DNA repair status in the response of cells to exogenous and endogenous factors. Recent studies indicate that Epidermal Growth Factor Receptor (EGFR is involved in modulating DNA-PK. It has been shown that a compound 4-nitro-7-[(1-oxidopyridin-2-ylsulfanyl]-2,1,3-benzoxadiazole (NSC, bearing a nitro-benzoxadiazole (NBD scaffold, enhances tyrosine phosphorylation of EGFR and triggers downstream signaling pathways. Here, we studied the behavior of DNA-PK and other DNA repair proteins in prostate cancer cells exposed to compound NSC. We showed that both the expression and activity of DNA-PKcs (catalytic subunit of DNA-PK rapidly decreased upon exposure of cells to the compound. The decline in DNA-PKcs was associated with enhanced protein ubiquitination, indicating the activation of cellular proteasome. However, pretreatment of cells with thioglycerol abolished the action of compound NSC and restored the level of DNA-PKcs. Moreover, the decreased level of DNA-PKcs was associated with the production of intracellular hydrogen peroxide by stable dimeric forms of Cu/Zn SOD1 induced by NSC. Our findings indicate that reactive oxygen species and electrophilic intermediates, generated and accumulated during the redox transformation of NBD compounds, are primarily responsible for the rapid modulation of DNA-PKcs functions in cancer cells.

  4. Antiproliferative activity of Alisol B in MDA-MB-231 cells is mediated by apoptosis, dysregulation of mitochondrial functions, cell cycle arrest and generation of reactive oxygen species.

    Science.gov (United States)

    Zhang, Aifeng; Sheng, Yuqing; Zou, Mingchang

    2017-03-01

    Previous studies have demonstrated that Alisol B has inhibitory activity in cancer cells. However, the exact mechanism through which inhibition is achieved is still poorly understood. In the present study, the authors examined the effects of Alisol B in human breast cancer cells. Alisol B showed significant anticancer activity in MDA-MB-231 cells. The results demonstrated that the cytotoxicity induced by Alisol B was mediated by induction of apoptosis, decrease in mitochondrial membrane potential, cell cycle arrest, activation of caspases and accumulation of ROS (reactive oxygen species) level. Interestingly, pretreatment of cells with the general caspase inhibitor z-VAD-FMK significantly prevented Alisol B-induced apoptosis. Furthermore, western blot analysis revealed the upregulation of p-p38 and downregulation of p-AKT, p-p65 and p-mTOR. Taken together, the above results suggest that Alisol B suppresses the growth of MDA-MB-231 cells mainly through induction of apoptosis; this outcome may represent the major mechanism of Alisol B-mediated apoptosis.

  5. Antioxidant Activity/Capacity Measurement. 3. Reactive Oxygen and Nitrogen Species (ROS/RNS) Scavenging Assays, Oxidative Stress Biomarkers, and Chromatographic/Chemometric Assays.

    Science.gov (United States)

    Apak, Reşat; Özyürek, Mustafa; Güçlü, Kubilay; Çapanoğlu, Esra

    2016-02-10

    There are many studies in which the antioxidant potential of different foods have been analyzed. However, there are still conflicting results and lack of information as a result of unstandardized assay techniques and differences between the principles of the methods applied. The measurement of antioxidant activity, especially in the case of mixtures, multifunctional or complex multiphase systems, cannot be evaluated satisfactorily using a simple antioxidant test due to the many variables influencing the results. In the literature, there are many antioxidant assays that are used to measure the total antioxidant activity/capacity of food materials. In this review, reactive oxygen and nitrogen species (ROS/RNS) scavenging assays are evaluated with respect to their mechanism, advantages, disadvantages, and potential use in food systems. On the other hand, in vivo antioxidant activity (AOA) assays including oxidative stress biomarkers and cellular-based assays are covered within the scope of this review. Finally, chromatographic and chemometric assays are reviewed, focusing on their benefits especially with respect to their time saving, cost-effective, and sensitive nature.

  6. Visible-light active thin-film WO3 photocatalyst with controlled high-rate deposition by low-damage reactive-gas-flow sputtering

    Directory of Open Access Journals (Sweden)

    Nobuto Oka

    2015-10-01

    Full Text Available A process based on reactive gas flow sputtering (GFS for depositing visible-light active photocatalytic WO3 films at high deposition rates and with high film quality was successfully demonstrated. The deposition rate for this process was over 10 times higher than that achieved by the conventional sputtering process and the process was highly stable. Furthermore, Pt nanoparticle-loaded WO3 films deposited by the GFS process exhibited much higher photocatalytic activity than those deposited by conventional sputtering, where the photocatalytic activity was evaluated by the extent of decomposition of CH3CHO under visible light irradiation. The decomposition time for 60 ppm of CH3CHO was 7.5 times more rapid on the films deposited by the GFS process than on the films deposited by the conventional process. During GFS deposition, there are no high-energy particles bombarding the growing film surface, whereas the bombardment of the surface with high-energy particles is a key feature of conventional sputtering. Hence, the WO3 films deposited by GFS should be of higher quality, with fewer structural defects, which would lead to a decrease in the number of centers for electron-hole recombination and to the efficient use of photogenerated holes for the decomposition of CH3CHO.

  7. NLRP3 inflammasome activation by mitochondrial reactive oxygen species plays a key role in long-term cognitive impairment induced by paraquat exposure.

    Science.gov (United States)

    Chen, Liuji; Na, Ren; Boldt, Erin; Ran, Qitao

    2015-09-01

    Exposure to environmental toxins such as pesticides is implicated in increasing Alzheimer's disease risk. In this study, we investigated the long-term effects of paraquat exposure on cognition of Alzheimer's disease animal model APP/PS1 mice and wild-type (WT) mice. Our results showed that APP/PS1 mice had exacerbated cognition impairment and elevated Aβ levels at 5 months after paraquat exposure, and that WT mice had cognition impairment at 5 and 16 months after paraquat exposure. In addition, increased mitochondrial oxidative stress and augmented brain inflammation were observed in both paraquat-exposed APP/PS1 mice and WT mice. Interestingly, activation of NLRP3 inflammasome, which triggers inflammation in response to mitochondrial stress, was enhanced in paraquat-exposed mice. Moreover, transgenic mice overexpressing Prdx3, a key enzyme in detoxifying mitochondrial H2O2, had suppressed NLRP3 inflammasome activation, reduced brain inflammation, and attenuated cognition impairment after paraquat exposure. Together, our results indicate that NLRP3 inflammasome activation induced by mitochondrial reactive oxygen species plays a key role in mediating paraquat-induced long-term cognition decline by elevating brain inflammation.

  8. Role of focal adhesion tyrosine kinases in GPVI-dependent platelet activation and reactive oxygen species formation.

    Directory of Open Access Journals (Sweden)

    Naadiya Carrim

    Full Text Available We have previously shown the presence of a TRAF4/p47phox/Hic5/Pyk2 complex associated with the platelet collagen receptor, GPVI, consistent with a potential role of this complex in GPVI-dependent ROS formation. In other cell systems, NOX-dependent ROS formation is facilitated by Pyk2, which along with its closely related homologue FAK are known to be activated and phosphorylated downstream of ligand binding to GPVI.To evaluate the relative roles of Pyk2 and FAK in GPVI-dependent ROS formation and to determine their location within the GPVI signaling pathway.Human and mouse washed platelets (from WT or Pyk2 KO mice were pre-treated with pharmacological inhibitors targeting FAK or Pyk2 (PF-228 and Tyrphostin A9, respectively and stimulated with the GPVI-specific agonist, CRP. FAK, but not Pyk2, was found to be essential for GPVI-dependent ROS production and aggregation. Subsequent human platelet studies with PF-228 confirmed FAK is essential for GPVI-mediated phosphatidylserine exposure, α-granule secretion (P-selectin (CD62P surface expression and integrin αIIbβ3 activation. To determine the precise location of FAK within the GPVI pathway, we analyzed the effect of PF-228 inhibition in CRP-stimulated platelets in conjunction with immunoprecipitation and pulldown analysis to show that FAK is downstream of Lyn, Spleen tyrosine kinase (Syk, PI3-K and Bruton's tyrosine kinase (Btk and upstream of Rac1, PLCγ2, Ca2+ release, PKC, Hic-5, NOX1 and αIIbβ3 activation.Overall, these data suggest a novel role for FAK in GPVI-dependent ROS formation and platelet activation and elucidate a proximal signaling role for FAK within the GPVI pathway.

  9. Evaporation-triggered microdroplet nucleation and the four life phases of an evaporating Ouzo droplet

    NARCIS (Netherlands)

    Tan, Huanshu; Diddens, Christian; Lv, Pengyu; Kuerten, J.G.M.; Zhang, Xuehua; Lohse, Detlef

    2016-01-01

    Evaporating liquid droplets are omnipresent in nature and technology, such as in inkjet printing, coating, deposition of materials, medical diagnostics, agriculture, the food industry, cosmetics, or spills of liquids. Whereas the evaporation of pure liquids, liquids with dispersed particles, or even

  10. Marangoni Convection and Deviations from Maxwells' Evaporation Model

    Science.gov (United States)

    Segre, P. N.; Snell, E. H.; Adamek, D. H.

    2003-01-01

    We investigate the convective dynamics of evaporating pools of volatile liquids using an ultra-sensitive thermal imaging camera. During evaporation, there are significant convective flows inside the liquid due to Marangoni forces. We find that Marangoni convection during evaporation can dramatically affect the evaporation rates of volatile liquids. A simple heat balance model connects the convective velocities and temperature gradients to the evaporation rates.

  11. Surface tension of evaporating nanofluid droplets

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ruey-Hung [Univ. of Central Florida, Orlando, FL (United States); Phuoc, Tran X. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Martello, Donald [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2011-05-01

    Measurements of nanofluid surface tension were made using the pendant droplet method. Three different types of nanoparticles were used - laponite, silver and Fe2O3 - with de-ionized water (DW) as the base fluid. The reported results focus on the following categories; (1) because some nanoparticles require surfactants to form stable colloids, the individual effects of the surfactant and the particles were investigated; (2) due to evaporation of the pendant droplet, the particle concentration increases, affecting the apparent surface tension; (3) because of the evaporation process, a hysteresis was found where the evaporating droplet can only achieve lower values of surface tension than that of nanofluids at the same prepared concentrations: and (4) the Stefan equation relating the apparent surface tension and heat of evaporation was found to be inapplicable for nanofluids investigated. Comparisons with findings for sessile droplets are also discussed, pointing to additional effects of nanoparticles other than the non-equilibrium evaporation process.

  12. Fucoidan inhibits proliferation of the SKM-1 acute myeloid leukaemia cell line via the activation of apoptotic pathways and production of reactive oxygen species.

    Science.gov (United States)

    Wei, Chunmei; Xiao, Qing; Kuang, Xingyi; Zhang, Tao; Yang, Zesong; Wang, Li

    2015-11-01

    Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid disorders characterized by peripheral blood cytopenias and a high risk of progression to acute myeloid leukaemia (AML). Fucoidan, a complex sulphated polysaccharide isolated from the cell wall of brown seaweeds, has recently attracted attention for its multiple biological activities and its potential as a novel candidate for cancer therapy. In the present study, the anti‑cancer activity of fucoidan was investigated in the MDS/AML cell line SKM‑1. Fucoidan inhibited proliferation, induced apoptosis and caused G1-phase arrest of the cell cycle in SKM‑1 cells as determined by a cell counting kit 8 assay and flow cytometry. Furthermore, reverse transcription quantitative polymerase chain reaction and western blot analyses indicated that treatment with fucoidan (100 µg/ml for 48 h) activated Fas and caspase‑8 in SKM‑1 cells, which are critical for the extrinsic apoptotic pathway; furthermore, caspase‑9 was activated via decreases in phosphoinositide-3 kinase/Akt signaling as indicated by reduced levels of phosphorylated Akt, suggesting the involvement of the intrinsic apoptotic pathway. In addition, fucoidan treatment of SKM‑1 cells resulted in the generation of reactive oxygen species (ROS) as determined by staining with dichloro-dihydro-fluorescein diacetate. These results suggested that the mechanisms of the anti‑cancer effects of fucoidan in SKM‑1 are closely associated with cell cycle arrest and apoptotic cell death, which partly attributed to the activation of apoptotic pathways and accumulation of intracellular ROS. Our results demonstrated that Fucoidan inhibits proliferation and induces the apoptosis of SKM‑1 cells, which provides substantial therapeutic potential for MDS treatment.

  13. Reactive Oxygen Species (ROS)-Activated ATM-Dependent Phosphorylation of Cytoplasmic Substrates Identified by Large-Scale Phosphoproteomics Screen.

    Science.gov (United States)

    Kozlov, Sergei V; Waardenberg, Ashley J; Engholm-Keller, Kasper; Arthur, Jonathan W; Graham, Mark E; Lavin, Martin

    2016-03-01

    Ataxia-telangiectasia, mutated (ATM) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signaling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle checkpoints, initiating DNA repair, and regulating gene expression. ATM kinase can be activated by a variety of stimuli, including oxidative stress. Here, we confirmed activation of cytoplasmic ATM by autophosphorylation at multiple sites. Then we employed a global quantitative phosphoproteomics approach to identify cytoplasmic proteins altered in their phosphorylation state in control and ataxia-telangiectasia (A-T) cells in response to oxidative damage. We demonstrated that ATM was activated by oxidative damage in the cytoplasm as well as in the nucleus and identified a total of 9,833 phosphorylation sites, including 6,686 high-confidence sites mapping to 2,536 unique proteins. A total of 62 differentially phosphorylated peptides were identified; of these, 43 were phosphorylated in control but not in A-T cells, and 19 varied in their level of phosphorylation. Motif enrichment analysis of phosphopeptides revealed that consensus ATM serine glutamine sites were overrepresented. When considering phosphorylation events, only observed in control cells (not observed in A-T cells), with predicted ATM sites phosphoSerine/phosphoThreonine glutamine, we narrowed this list to 11 candidate ATM-dependent cytoplasmic proteins. Two of these 11 were previously described as ATM substrates (HMGA1 and UIMCI/RAP80), another five were identified in a whole cell extract phosphoproteomic screens, and the remaining four proteins had not been identified previously in DNA damage response screens. We validated the phosphorylation of three of these proteins (oxidative stress responsive 1 (OSR1), HDGF, and ccdc82) as ATM dependent after H2O2 exposure, and another protein (S100A11) demonstrated ATM

  14. Solute concentration-dependent contact angle hysteresis and evaporation stains.

    Science.gov (United States)

    Li, Yueh-Feng; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2014-07-08

    The presence of nonvolatile solutes in a liquid drop on a solid surface can affect the wetting properties. Depending on the surface-activity of the solutes, the extent of contact angle hysteresis (CAH) can vary with their concentration and the pattern of the evaporation stain is altered accordingly. In this work, four types of concentration-dependent CAH and evaporation stains are identified for a water drop containing polymeric additives on polycarbonate. For polymers without surface-activity such as dextran, advancing and receding contact angles (θa and θr) are independent of solute concentrations, and a concentrated stain is observed in the vicinity of the drop center after complete evaporation. For polymers with weak surface-activity such as poly(ethylene glycol) (PEG), both θa and θr are decreased by solute addition, and the stain pattern varies with increasing PEG concentration, including a concentrated stain and a mountain-like island. For polymers with intermediate surface-activity such as sodium polystyrenesulfonate (NaPSS), θa descends slightly, but θr decreases significantly after the addition of a substantial amount of NaPSS, and a ring-like stain pattern is observed. Moreover, the size of the ring stain can be controlled by NaPSS concentration. For polymers with strong surface-activity such as poly(vinylpyrrolidone) (PVP), θa remains essentially a constant, but θr is significantly lowered after the addition of a small amount of PVP, and the typical ring-like stain is seen.

  15. Mini-Membrane Evaporator for Contingency Spacesuit Cooling

    Science.gov (United States)

    Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Petty, Brian; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

    2015-01-01

    The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only approximately 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini-ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

  16. Enhancing radiolytic stability upon concentration of tritium-labeled pharmaceuticals utilizing centrifugal evaporation.

    Science.gov (United States)

    Marques, Rosemary; Helmy, Roy; Waterhouse, David

    2015-05-30

    Tritium radiopharmaceuticals are often used in drug development because of their desirable specific activity. The inherent instability of these radioactive tracers often leads to a requirement to purify prior to use. Purification methodologies such as preparative chromatography and solid/liquid extractions often utilize water as a solvent, which is not suitable for long-term storage and necessitates removal. Rotary evaporation has traditionally been utilized for the removal of this unwanted solvent, however, this method has been shown to lead to decomposition of the tritium species in some cases. Centrifugal evaporation is a milder concentration method which has been demonstrated to effectively remove solvents. In this study, we show that centrifugal evaporation leads to effective concentration of tritium samples without the decomposition typically observed by rotary evaporation.

  17. Design and development of a split-evaporator heat-pump system

    Energy Technology Data Exchange (ETDEWEB)

    Somerville, M.H.; Penoncello, S.G.

    1981-12-01

    The designs and experimental results of three types of multiple source heat pumps are presented. The three designs are the parallel evaporator, the series evaporator, and the parallel evaporator with active subcooling, with the parallel evaporator with the active subcooling showing the most promise for solving the problem of defrosting of air evaporators. Three design procedures for multiple source heat pumps were developed. One of these is a hand calculational procedure, the others are computer based. The models are based upon the refrigerant flow rate, rather than the refrigeration effect of the evaporator. The technical results of a detailed analytical and experimental model of the heat transfer rates on a flat plate ice maker are presented. It is shown, both analytically and experimentally, that the temperature of the air surrounding the flat plate ice maker can play a dominant role in the rate of ice formation. A detailed weather analysis for forty cities located throughout the nation was completed. These data were processed to allow easy computation of thermal storage requirements for full, partial, or minimum ACES systems, or upon other design requirements, such as off-peak air conditioning. The results of an innovative ice storage system that is thermally coupled to the earth are described. This system has the potential for meeting both the off-peak air conditioning needs and the thermal storage requirements for the heating cycle. An economic and energy comparison of multiple source heat pumps with ACES, and air-to-air heat pump systems is presented.

  18. Synthesis, chemical reactivity and fungicidal activity of pyrido[1,2-b][1,2,4]triazine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Magdy A.; Abdel-Rahman, Reda M.; Abdel-Halim, Ali M.; Ibrahim, Salah S.; Allimony, Hassan A. [Ain Shams University, Roxy, Cairo (Egypt). Faculty of Education. Dept. of Chemistry], e-mail: magdy_ahmed1977@yahoo.com

    2009-07-01

    The synthesis of some new pyrido[1,2-b][1,2,4]triazines (2-12) was achieved by cyclocondensation of 4-aryl-1,6-diamino-2-oxo-1,2-dihydropyridine-3,5-dicarbonitriles (1a,b) with {alpha},{beta}-bifunctional compounds. Pyrido[1,2:2'3']triazino[5'6'-f]triazines (13-14) were also prepared. The behavior of 1a,b toward interactions with indole-2,3-dione and its N-acetyl analogue have been studied under different reaction conditions. The structures of the new products have been deduced from elemental analysis and spectral data (UV, IR, {sup 1}H NMR, {sup 13}C NMR and mass spectra). The new synthesized compounds were screened for their antifungal activities. (author)

  19. Wood dusts induce the production of reactive oxygen species and caspase-3 activity in human bronchial epithelial cells.

    Science.gov (United States)

    Pylkkänen, Lea; Stockmann-Juvala, Helene; Alenius, Harri; Husgafvel-Pursiainen, Kirsti; Savolainen, Kai

    2009-08-21

    Wood dusts are associated with several respiratory symptoms, e.g. impaired lung function and asthma, in exposed workers. However, despite the evidence from epidemiological studies, the underlying mechanisms are not well understood. In the present study, we investigated different wood dusts for their capacity to induce cytotoxicity and production of radical oxygen species (ROS) as well as activation of the apoptotic caspase-3 enzyme in human bronchial epithelial cells (BEAS-2B). Dusts from three different tree species widely used in wood industry were studied; birch and oak represented hardwood species, and pine a common softwood species. All the experiments were carried out in three different concentrations (10, 50, and 500 microg/ml) and the analysis was performed after 0.5, 2, 6, and 24h exposure. All wood dusts studied were cytotoxic to human bronchial epithelial cells in a dose-dependent manner after 2 and 6h treatment. Exposure to pine, birch, or oak dust had a significant stimulating effect on the production of ROS. Also an induction in caspase-3 protease activity, one of the central components of the apoptotic cascade, was seen in BEAS-2B cells after 2 and 6h exposure to each of the wood dusts studied. In summary, we demonstrate that dusts from pine, birch and oak are cytotoxic, able to increase the production of ROS and the apoptotic response in human broncho-epithelial cells in vitro. Thus, our current data suggest oxidative stress by ROS as an important mechanism likely to function in wood dust related pulmonary toxicity although details of the cellular targets and cell-particle interactions remain to be solved. It is though tempting to speculate that redox-regulated transcription factors such as NFkappaB or AP-1 may play a role in this wood dust-evoked process leading to apparently induced apoptosis of target cells.

  20. Runaway evaporation for optically dressed atoms

    CERN Document Server

    Wilkowski, David

    2010-01-01

    Forced evaporative cooling in a far-off-resonance optical dipole trap is proved to be an efficient method to produce fermionic- or bosonic-degenerated gases. However in most of the experiences, the reduction of the potential height occurs with a diminution of the collision elastic rate. Taking advantage of a long-living excited state, like in two-electron atoms, I propose a new scheme, based on an optical knife, where the forced evaporation can be driven independently of the trap confinement. In this context, the runaway regime might be achieved leading to a substantial improvement of the cooling efficiency. The comparison with the different methods for forced evaporation is discussed in the presence or not of three-body recombination losses.

  1. Self-assembled monolayers of Aβ peptides on Au electrodes: an artificial platform for probing the reactivity of redox active metals and cofactors relevant to Alzheimer's disease.

    Science.gov (United States)

    Pramanik, Debajyoti; Sengupta, Kushal; Mukherjee, Soumya; Dey, Somdatta Ghosh; Dey, Abhishek

    2012-07-25

    The water-soluble hydrophilic part of human Aβ peptide has been extended to include a C-terminal cysteine residue. Utilizing the thiol functionality of this cysteine residue, self-assembled monolayers (SAM) of these peptides are formed on Au electrodes. Atomic force microscopy imaging confirms formation of small Aβ aggregates on the surface of the electrode. These aggregates bind redox active metals like Cu and cofactors like heme, both of which are proposed to generate toxic partially reduced oxygen species (PROS) and play a vital role in Alzheimer's disease. The spectroscopic and electrochemical properties of these Cu and heme bound Aβ SAM are similar to those reported for the soluble Cu and heme bound Aβ peptide. Experiments performed on these Aβ-SAM electrodes clearly demonstrate that (1) heme bound Aβ is kinetically more competent in reducing O(2) than Cu bound Aβ, (2) under physiological conditions the reduced Cu site produces twice as much PROS (measured in situ) than the reduced heme site, and (3) chelators like clioquinol remove Cu from these aggregates, while drugs like methylene blue inhibit O(2) reactivity of the heme cofactor. This artificial construct provides a very easy platform for investigating potential drugs affecting aggregation of human Aβ peptides and PROS generation by its complexes with redox active metals and cofactors.

  2. Matrine induction of reactive oxygen species activates p38 leading to caspase-dependent cell apoptosis in non-small cell lung cancer cells.

    Science.gov (United States)

    Tan, Caihong; Qian, Xiaoqiang; Jia, Rongdi; Wu, Min; Liang, Zhongqin

    2013-11-01

    Non-small cell lung carcinoma (NSCLC) is one of the most refractory cancers in the clinic; it is insensitive to chemotherapy and is usually excised. However, screening natural compounds from herbs is also considered a possible method for its therapy. In the present study, we investigated whether matrine, a natural compound isolated from Sophora flavescens Ait. and exerting an inhibitory effect on lung cancer cells, also indicates inhibition on NSCLC cells and elucidated its molecular mechanism. Firstly, it is confirmed that matrine induces apoptosis of human NSCLC cells with anti-apoptotic factors inhibited and dependent on caspase activity. In addition, we found that matrine increases the phosphorylation of p38 but not its total protein, and inhibition of the p38 pathway with SB202190 partially prevents matrine-induced apoptosis. Furthermore, matrine generates reactive oxygen species (ROS) in a dose- and time-dependent manner, which is reversed by pretreatment with N-acetyl-L-cysteine (NAC). Additionally, inhibition of cell proliferation and increase of phosphorylation of p38 was also partially reversed by NAC. Collectively, matrine activates p38 pathway leading to a caspase-dependent apoptosis by inducing generation of ROS in NSCLC cells and may be a potential chemical for NSCLC.

  3. Reactivating aberrantly hypermethylated p15 gene in leukemic T cells by a phenylhexyl isothiocyanate mediated inter-active mechanism on DNA and chromatin

    Directory of Open Access Journals (Sweden)

    Jiang Shaohong

    2010-11-01

    Full Text Available Abstract Background We have previously demonstrated that phenylhexyl isothiocyanate (PHI, a synthetic isothiocyanate, inhibits histone deacetylases and remodels chromatins to induce growth arrest in HL-60 myeloid leukemia cells in a concentration-dependent manner. Methods To investigate the effect of PHI, a novel histone deacetylases inhibitor (HDACi, on demethylation and activation of transcription of p15 in acute lymphoid leukemia cell line Molt-4, and to further decipher the potential mechanism of demethylation, DNA sequencing and modified methylation specific PCR (MSP were used to screen p15-M and p15-U mRNA after Molt-4 cells were treated with PHI, 5-Aza and TSA. DNA methyltransferase 1 (DNMT1, 3A (DNMT3A, 3B (DNMT3B and p15 mRNA were measured by RT-PCR. P15 protein, acetylated histone H3 and histone H4 were detected by Western Blot. Results The gene p15 in Molt-4 cells was hypermethylated and inactive. Hypermethylation of gene p15 was attenuated and p15 gene was activated de novo after 5 days exposure to PHI in a concentration-dependent manner. DNMT1 and DNMT3B were inhibited by PHI (P Conclusion PHI could induce both DNA demethylation and acetylated H3 and H4 accumulation in Molt-4 cells. Hypermethylation of gene p15 was reversed and p15 transcription could be reactivated de novo by PHI.

  4. Activation of biologically relevant levels of reactive oxygen species by Au/g-C3N4 hybrid nanozyme for bacteria killing and wound disinfection.

    Science.gov (United States)

    Wang, Zhenzhen; Dong, Kai; Liu, Zhen; Zhang, Yan; Chen, Zhaowei; Sun, Hanjun; Ren, Jinsong; Qu, Xiaogang

    2017-01-01

    As common reactive oxygen species, H2O2 is widely used for bacterial inactivation and wound disinfection. However, the concentrations used are always higher than physiological levels, which frequently result in potential toxicity to healthy tissue and even delay wound healing. Here we report highly efficient nanozyme hybrids that are capable of activating biologically relevant concentrations of H2O2 for defending bacterial infections. The integration of AuNPs with ultrathin graphitic carbon nitride (g-C3N4) provides excellent peroxidase-activity, which can catalyze the decomposition of H2O2 to OH radicals much more efficiently, allowing the use of bio-safety levels of H2O2 for the first time. Furthermore, our system not only exhibits striking bactericidal performance against both DR Gram-negative and DR Gram-positive bacteria, but also shows high efficiency in breaking down the existing DR-biofilms and prevented formation of new biofilms in vitro. More importantly, in vivo experiments indicate that our system could significantly prevent bacterial infections and accelerate the healing rate of wounds.

  5. Advanced glycation end products induce human corneal epithelial cells apoptosis through generation of reactive oxygen species and activation of JNK and p38 MAPK pathways.

    Directory of Open Access Journals (Sweden)

    Long Shi

    Full Text Available Advanced Glycation End Products (AGEs has been implicated in the progression of diabetic keratopathy. However, details regarding their function are not well understood. In the present study, we investigated the effects of intracellular reactive oxygen species (ROS and JNK, p38 MAPK on AGE-modified bovine serum albumin (BSA induced Human telomerase-immortalized corneal epithelial cells (HUCLs apoptosis. We found that AGE-BSA induced HUCLs apoptosis and increased Bax protein expression, decreased Bcl-2 protein expression. AGE-BSA also induced the expression of receptor for advanced glycation end product (RAGE. AGE-BSA-RAGE interaction induced intracellular ROS generation through activated NADPH oxidase and increased the phosphorylation of p47phox. AGE-BSA induced HUCLs apoptosis was inhibited by pretreatment with NADPH oxidase inhibitors, ROS quencher N-acetylcysteine (NAC or neutralizing anti-RAGE antibodies. We also found that AGE-BSA induced JNK and p38 MAPK phosphorylation. JNK and p38 MAPK inhibitor effectively blocked AGE-BSA-induced HUCLs apoptosis. In addition, NAC completely blocked phosphorylation of JNK and p38 MAPK induced by AGE-BSA. Our results indicate that AGE-BSA induced HUCLs apoptosis through generation of intracellular ROS and activation of JNK and p38 MAPK pathways.

  6. Synergistic anticandidal activity of pure polyphenol curcumin I in combination with azoles and polyenes generates reactive oxygen species leading to apoptosis.

    Science.gov (United States)

    Sharma, Monika; Manoharlal, Raman; Negi, Arvind Singh; Prasad, Rajendra

    2010-08-01

    We have shown previously that pure polyphenol curcumin I (CUR-I) shows antifungal activity against Candida species. By employing the chequerboard method, filter disc and time-kill assays, in the present study we demonstrate that CUR-I at non-antifungal concentration interacts synergistically with azoles and polyenes. For this, pure polyphenol CUR-I was tested for synergy with five azole and two polyene drugs - fluconazole (FLC), miconazole, ketoconazole (KTC), itraconazole (ITR), voriconazole (VRC), nystatin (NYS) and amphotericin B (AMB) - against 21 clinical isolates of Candida albicans with reduced antifungal sensitivity, as well as a drug-sensitive laboratory strain. Notably, there was a 10-35-fold drop in the MIC(80) values of the drugs when CUR-I was used in combination with azoles and polyenes, with fractional inhibitory concentration index (FICI) values ranging between 0.09 and 0.5. Interestingly, the synergistic effect of CUR-I with FLC and AMB was associated with the accumulation of reactive oxygen species, which could be reversed by the addition of an antioxidant such as ascorbic acid. Furthermore, the combination of CUR-I and FLC/AMB triggered apoptosis that could also be reversed by ascorbic acid. We provide the first evidence that pure CUR-I in combination with azoles and polyenes represents a novel therapeutic strategy to improve the activity of common antifungals.

  7. Biosynthesis of titanium dioxide nanoparticles using Bacillus amyloliquefaciens culture and enhancement of its photocatalytic activity for the degradation of a sulfonated textile dye Reactive Red 31.

    Science.gov (United States)

    Khan, Razia; Fulekar, M H

    2016-08-01

    The present study aims at exploiting Bacillus amyloliquefaciens for the biosynthesis of titanium dioxide nanoparticles and also investigates role of bacterial enzymes in the biosynthesis of titanium dioxide nanoparticles. Bacterial synthesized as well as metal doped titanium dioxide nanoparticles were characterized by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDAX). Amylase activity (43.37IU) in culture supernatant evinced a potential involvement of extracellular enzyme in TiO2 nanoparticle biosynthesis. Crystallite size of bio-synthesized nanoparticles was found to be in the range of 15.23-87.6nm. FTIR spectroscopy and native-PAGE (Polyacrylamide Gel Electrophoresis) clearly indicated involvement of alpha amylase in biosynthesis of TiO2 nanoparticles and in their stabilization. TEM micrographs of the synthesized titanium dioxide nanoparticles revealed the formation of spherical nanoparticles with a size range of 22.11-97.28nm. Photocatalytic degradation of Reactive Red 31 (RR31) dye was carried out using bio-synthesized TiO2 nanoparticles under UV radiation. Photocatalytic activity of synthesized nanoparticles was enhanced by Ag, La, Zn and Pt doping. Platinum doped TiO2 showed highest potential (90.98%) in RR31 degradation as compared to undoped (75.83%).

  8. Depletion of hepatoma-derived growth factor-related protein-3 induces apoptotic sensitization of radioresistant A549 cells via reactive oxygen species-dependent p53 activation

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hong Shik; Hong, Eun-Hee [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Su-Jae [Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Baek, Jeong-Hwa [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Lee, Chang-Woo [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Yim, Ji-Hye; Um, Hong-Duck [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Hwang, Sang-Gu, E-mail: sgh63@kcch.re.kr [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

    2013-09-27

    Highlights: •HRP-3 is a radiation- and anticancer drug-responsive protein in A549 cells. •Depletion of HRP-3 induces apoptosis of radio- and chemoresistant A549 cells. •Depletion of HRP-3 promotes ROS generation via inhibition of the Nrf2/HO-1 pathway. •Depletion of HRP-3 enhances ROS-dependent p53 activation and PUMA expression. -- Abstract: Biomarkers based on functional signaling have the potential to provide greater insight into the pathogenesis of cancer and may offer additional targets for anticancer therapeutics. Here, we identified hepatoma-derived growth factor-related protein-3 (HRP-3) as a radioresistance-related gene and characterized the molecular mechanism by which its encoded protein regulates the radio- and chemoresistant phenotype of lung cancer-derived A549 cells. Knockdown of HRP-3 promoted apoptosis of A549 cells and potentiated the apoptosis-inducing action of radio- and chemotherapy. This increase in apoptosis was associated with a substantial generation of reactive oxygen species (ROS) that was attributable to inhibition of the Nrf2/HO-1 antioxidant pathway and resulted in enhanced ROS-dependent p53 activation and p53-dependent expression of PUMA (p53 upregulated modulator of apoptosis). Therefore, the HRP-3/Nrf2/HO-1/ROS/p53/PUMA cascade is an essential feature of the A549 cell phenotype and a potential radiotherapy target, extending the range of targets in multimodal therapies against lung cancer.

  9. Physicochemical modeling of reactive violet 5 dye adsorption on home-made cocoa shell and commercial activated carbons using the statistical physics theory

    Science.gov (United States)

    Sellaoui, Lotfi; Lima, Éder Cláudio; Dotto, Guilherme Luiz; Dias, Silvio L. P.; Ben Lamine, Abdelmottaleb

    Two equilibrium models based on statistical physics, i.e., monolayer model with single energy and multilayer model with saturation, were developed and employed to access the steric and energetic aspects in the adsorption of reactive violet 5 dye (RV-5) on cocoa shell activated carbon (AC) and commercial activated carbon (CAC), at different temperatures (from 298 to 323 K). The results showed that the multilayer model with saturation was able to represent the adsorption system. This model assumes that the adsorption occurs by a formation of certain number of layers. The n values ranged from 1.10 to 2.98, indicating that the adsorbate molecules interacted in an inclined position on the adsorbent surface and aggregate in solution. The study of the total number of the formed layers (1 + L2) showed that the steric hindrance is the dominant factor. The description of the adsorbate-adsorbent interactions by calculation of the adsorption energy indicated that the process occurred by physisorption in nature, since the values were lower than 40 kJ mol-1.

  10. Macrophages generate reactive oxygen species in response to minimally oxidized LDL: TLR4- and Syk-dependent activation of Nox2

    Science.gov (United States)

    Bae, Yun Soo; Lee, Jee Hyun; Choi, Soo Ho; Kim, Sunah; Almazan, Felicidad; Witztum, Joseph L.; Miller, Yury I.

    2009-01-01

    Oxidative modification of low-density lipoprotein (LDL) plays a causative role in the development of atherosclerosis. In this study, we demonstrate that minimally oxidized LDL (mmLDL) stimulates intracellular reactive oxygen species (ROS) generation in macrophages through NADPH oxidase 2 (gp91phox/Nox2), which in turn induces production of RANTES and migration of smooth muscle cells. Peritoneal macrophages from gp91phox/Nox2−/− mice or J774 macrophages in which Nox2 was knocked down by siRNA failed to generate ROS in response to mmLDL. Because mmLDL-induced cytoskeletal changes were dependent on TLR4, we analyzed ROS generation in peritoneal macrophages from wild type, TLR4−/−, or MyD88−/− mice and found that mmLDL-mediated ROS was generated in a TLR4-dependent, but MyD88-independent manner. Furthermore, we found that ROS generation required the recruitment and activation of spleen tyrosine kinase (Syk) and that mmLDL also induced PLCγ1 phosphorylation and PKC membrane translocation. Importantly, the PLCγ1 phosphorylation was reduced in J774 cells expressing Syk-specific shRNA. Nox2 modulated mmLDL activation of macrophages by regulating the expression of proinflammatory cytokines IL-1β, IL-6 and RANTES. We showed that purified RANTES was able to stimulate migration of mouse aortic smooth muscle cells (MASMC) and addition of neutralizing antibody against RANTES abolished the migration of MASMC stimulated by mmLDL-stimulated macrophages. These results suggest that mmLDL induces generation of ROS through sequential activation of TLR4, Syk, PLCγ1, PKC, and gp91phox/Nox2 and thereby stimulates expression of proinflammatory cytokines. These data help explain mechanisms by which endogenous ligands, such as mmLDL, can induce TLR4-dependent, proatherogenic activation of macrophages. PMID:19096031

  11. Fatty acids modulate Toll-like receptor 4 activation through regulation of receptor dimerization and recruitment into lipid rafts in a reactive oxygen species-dependent manner.

    Science.gov (United States)

    Wong, Scott W; Kwon, Myung-Ja; Choi, Augustine M K; Kim, Hong-Pyo; Nakahira, Kiichi; Hwang, Daniel H

    2009-10-02

    The saturated fatty acids acylated on Lipid A of lipopolysaccharide (LPS) or bacterial lipoproteins play critical roles in ligand recognition and receptor activation for Toll-like Receptor 4 (TLR4) and TLR2. The results from our previous studies demonstrated that saturated and polyunsaturated fatty acids reciprocally modulate the activation of TLR4. However, the underlying mechanism has not been understood. Here, we report for the first time that the saturated fatty acid lauric acid induced dimerization and recruitment of TLR4 into lipid rafts, however, dimerization was not observed in non-lipid raft fractions. Similarly, LPS and lauric acid enhanced the association of TLR4 with MD-2 and downstream adaptor molecules, TRIF and MyD88, into lipid rafts leading to the activation of downstream signaling pathways and target gene expression. However, docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, inhibited LPS- or lauric acid-induced dimerization and recruitment of TLR4 into lipid raft fractions. Together, these results demonstrate that lauric acid and DHA reciprocally modulate TLR4 activation by regulation of the dimerization and recruitment of TLR4 into lipid rafts. In addition, we showed that TLR4 recruitment to lipid rafts and dimerization were coupled events mediated at least in part by NADPH oxidase-dependent reactive oxygen species generation. These results provide a new insight in understanding the mechanism by which fatty acids differentially modulate TLR4-mediated signaling pathway and consequent inflammatory responses which are implicated in the development and progression of many chronic diseases.

  12. Evaporative Cooling of Antiprotons to Cryogenic Temperatures

    CERN Document Server

    Andresen, G B; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A; Hydomako, R; Jonsell, S; Kurchaninov, L; Lambo, R; Madsen, N; Menary, S; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Silveira, D M; So, C; Storey, J W; Thompson, R I; van der Werf, D P; Wilding, D; Wurtele, J S; Yamazaki, Y

    2010-01-01

    We report the application of evaporative cooling to clouds of trapped antiprotons, resulting in plasmas with measured temperature as low as 9~K. We have modeled the evaporation process for charged particles using appropriate rate equations. Good agreement between experiment and theory is observed, permitting prediction of cooling efficiency in future experiments. The technique opens up new possibilities for cooling of trapped ions and is of particular interest in antiproton physics, where a precise CPT test on trapped antihydrogen is a long-standing goal.

  13. Do black holes really evaporate thermally

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, F.J.

    1980-09-22

    The Raychaudhuri equation is used to analyze the effect of the Hawking radiation back reaction upon a black-hole event horizon. It is found that if the effective stress-energy tensor of the Hawking radiation has negative energy density as expected, then an evaporating black hole initially a solar mass in size must disappear in less than a second. This implies that either the evaporation process, if it occurs at all, must be quite different from what is commonly supposed, or else black-hole event horizons: and hence black holes: do not exist.

  14. Do black holes really evaporate thermally

    Science.gov (United States)

    Tipler, F. J.

    1980-09-01

    The Raychaudhuri equation is used to analyze the effect of the Hawking radiation back reaction upon a black-hole event horizon. It is found that if the effective stress-energy tensor of the Hawking radiation has negative energy density as expected, then an evaporating black hole initially a solar mass in size must disappear in less than a second. This implies that either the evaporation process, if it occurs at all, must be quite different from what is commonly supposed, or else black-hole event horizons - and hence black holes - do not exist.

  15. Black hole evaporation in conformal gravity

    CERN Document Server

    Bambi, Cosimo; Porey, Shiladitya; Rachwal, Leslaw

    2016-01-01

    We study the formation and the evaporation of a spherically symmetric black hole in conformal gravity. From the collapse of a spherically symmetric thin shell of radiation, we find a singularity-free non-rotating black hole. This black hole has the same Hawking temperature as a Schwarzschild black hole with the same mass, and it completely evaporates either in a finite or in an infinite time, depending on the ensemble. We consider the analysis both in the canonical and in the micro-canonical statistical ensembles. Last, we discuss the corresponding Penrose diagram of this physical process.

  16. Direct Evaporative Precooling Model and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Ally, Moonis Raza [ORNL; Rice, C Keith [ORNL; Craddick, William G [ORNL

    2011-01-01

    Evaporative condenser pre-cooling expands the availability of energy saving, cost-effective technology options (market engagement) and serves to expedite the range of options in upcoming codes and equipment standards (impacting regulation). Commercially available evaporative pre-coolers provide a low cost retrofit for existing packaged rooftop units, commercial unitary split systems, and air cooled chillers. We map the impact of energy savings and peak energy reduction in the 3 building types (medium office, secondary school, and supermarket) in 16 locations for three building types with four pad effectivenesses and show the effect for HVAC systems using either refrigerants R22 or R410A

  17. Rhododenol and raspberry ketone impair the normal proliferation of melanocytes through reactive oxygen species-dependent activation of GADD45.

    Science.gov (United States)

    Kim, Minjeong; Baek, Heung Soo; Lee, Miri; Park, Hyeonji; Shin, Song Seok; Choi, Dal Woong; Lim, Kyung-Min

    2016-04-01

    Rhododenol or rhododendrol (RD, 4-(4-hydroxyphenyl)-2-butanol) occurs naturally in many plants along with raspberry ketone (RK, 4-(4-hydroxyphenyl)-2-butanone), a ketone derivative, which include Nikko maple tree (Acer nikoense) and white birch (Betula platyphylla). De-pigmenting activity of RD was discovered and it was used as a brightening ingredient for the skin whitening cosmetics. Recently, cosmetics containing RD were withdrawn from the market because a number of consumers developed leukoderma, inflammation and erythema on their face, neck and hands. Here, we explored the mechanism underlying the toxicity of RD and RK against melanocytes using B16F10 murine melanoma cells and human primary epidermal melanocytes. Treatment with RD or RK resulted in the decreased cell viability in a dose-dependent manner which appeared from cell growth arrest. Consistently, ROS generation was significantly increased by RD or RK as determined by DCF-enhanced fluorescence. An antioxidant enzyme, glutathione peroxidase was depleted as well. In line with ROS generation, oxidative damages and the arrest of normal cell proliferation, GADD genes (Growth Arrest and DNA Damage) that include GADD45 and GADD153, were significantly up-regulated. Prevention of ROS generation with an anti-oxidant, N-acetylcysteine (NAC) significantly rescued RD and RK-suppressed melanocyte proliferation. Consistently, up-regulation of GADD45 and GADD153 was significantly attenuated by NAC, suggesting that increased ROS and the resultant growth arrest of melanocytes may contribute to RD and RK-induced leukoderma.

  18. Reactivity-activity relationships of oral anti-diabetic vanadium complexes in gastrointestinal media: an X-ray absorption spectroscopic study.

    Science.gov (United States)

    Levina, Aviva; McLeod, Andrew I; Kremer, Lauren E; Aitken, Jade B; Glover, Christopher J; Johannessen, Bernt; Lay, Peter A

    2014-10-01

    The reactions of oral V(V/IV) anti-diabetic drugs within the gastrointestinal environment (particularly in the presence of food) are a crucial factor that affects their biological activities, but to date these have been poorly understood. In order to build up reactivity-activity relationships, the first detailed study of the reactivities of typical V-based anti-diabetics, Na3V(V)O4 (A), [V(IV)O(OH2)5](SO4) (B), [V(IV)O(ma)2] (C, ma = maltolato(-)) and (NH4)[V(V)(O)2(dipic)] (D, dipic = pyridine-2,5-dicarboxylato(2-)) with simulated gastrointestinal (GI) media in the presence or absence of food components has been performed by the use of XANES (X-ray absorption near edge structure) spectroscopy. Changes in speciation under conditions that simulate interactions in the GI tract have been discerned using correlations of XANES parameters that were based on a library of model V(V), V(IV), and V(III) complexes for preliminary assessment of the oxidation states and coordination numbers. More detailed speciation analyses were performed using multiple linear regression fits of XANES from the model complexes to XANES obtained from the reaction products from interactions with the GI media. Compounds B and D were relatively stable in the gastric environment (pH ∼ 2) in the absence of food, while C was mostly dissociated, and A was converted to [V10O28](6-). Sequential gastric and intestinal digestion in the absence of food converted A, B and D to poorly absorbed tetrahedral vanadates, while C formed five- or six-coordinate V(V) species where the maltolato ligands were likely to be partially retained. XANES obtained from gastric digestion of A-D in the presence of typical food components converged to that of a mixture of V(IV)-aqua, V(IV)-amino acid and V(III)-aqua complexes. Subsequent intestinal digestion led predominantly to V(IV) complexes that were assigned as citrato or complexes with 2-hydroxyacidato donor groups from other organic compounds, including certain

  19. Evaporation enhancement in soils: a critical review

    Science.gov (United States)

    Rutten, Martine; van de Giesen, Nick

    2015-04-01

    Temperature gradients in the top layer of the soil are, especially during the daytime, steeper than would be expected if thermal conduction was the primary heat transfer mechanism. Evaporation seems to have significant influence on the soil heat budget. Only part of the surface soil heat flux is conducted downwards, increasing the soil temperatures, and part is used for evaporation, acting as a sink to the soil heat budget. For moist soils, the evaporation is limited by the transport of water molecules to the surface. The classical view is that water vapor is transported from the evaporation front to the surface by diffusion. Diffusion is mixing due to the random movement of molecules resulting in flattening concentration gradients. In soil, the diffusive vapor flux and the resulting latent heat flux are generally small. We found that transport enhancement is necessary in order to sustain vapor fluxes that are large enough to sustain latent heat fluxes, as well as being large enough to explain the observed temperature gradients. Enhancement of vapor diffusion is a known phenomenon, subject to debate on the explanations of underlying mechanism. In an extensive literature review on vapor enhancement in soils, the plausibility of various mechanisms was assessed. We reviewed mechanisms based on (combinations of) diffusive, viscous, buoyant, capillary and external pressure forces including: thermodiffusion, dispersion, Stefan's flow, Knudsen diffusion, liquid island effect, hydraulic lift, free convection, double diffusive convection and forced convection. The analysis of the order of magnitude of the mechanisms based on first principles clearly distinguished between plausible and implausible mechanisms. Thermodiffusion, Stefan's flow, Knudsen effects, liquid islands do not significantly contribute to enhanced evaporation. Double diffusive convection seemed unlikely due to lack of experimental evidence, but could not be completely excluded from the list of potential

  20. High plasma C-reactive protein (CRP) is related to low paraoxonase-I (PON-I) activity independently of high leptin and low adiponectin in type 2 diabetes mellitus

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; de Vries, Rindert; Sluiter, Wim J.; Voorbij, Hieronymus A. M.

    2009-01-01

    In type 2 diabetes mellitus, circulating C-reactive protein (CRP) is increased, whereas the high density lipoprotein (HDL)-associated, anti-oxidative and anti-inflammatory enzyme, paraoxonase-I, is decreased. Both high CRP and low paraoxonase-I activity may predict cardiovascular disease. It is unkn